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Simple Summary: Neuroendocrine neoplasms are a heterogeneous group of malignant tumors that originate from the diffuse endocrine system. They generally have a slow course and somatostatin receptor-targeted based management is the first line of treatment. However, high-grade tumors and neuroendocrine carcinomas have a poor prognosis and somatostatin receptor-targeted therapy is not effective. The membrane receptor CXCR4 has been studied in several neoplasms and it is known to be overexpressed in aggressive tumors and associated with a worse prognosis. However, there is a lack of evidence of its use in neuroendocrine neoplasms. For that reason, this review describes the significance of CXCR4 and its possible clinical applications in the diagnostic and therapeutic management of neuroendocrine neoplasms. There are several well-described molecular mechanisms that influence cell growth and are related to the development of cancer. Chemokines constitute a fundamental element that is not only involved in local growth but also affects angiogenesis, tumor spread, and metastatic disease. Among them, the C-X-C motif chemokine ligand 12 (CXCL12) and its specific receptor the chemokine C-X-C motif receptor 4 (CXCR4) have been widely studied. The overexpression in cell membranes of CXCR4 has been shown to be associated with the development of different kinds of histological malignancies, such as adenocarcinomas, epidermoid carcinomas, mesenchymal tumors, or neuroendocrine neoplasms (NENs). The molecular synapsis between CXCL12 and CXCR4 leads to the interaction of G proteins and the activation of different intracellular signaling pathways in both gastroenteropancreatic (GEP) and bronchopulmonary (BP) NENs, conferring greater capacity for locoregional aggressiveness, the epithelial–mesenchymal transition (EMT), and the appearance of metastases. Therefore, it has been hypothesized as to how to design tools that target this receptor. The aim of this review is to focus on current knowledge of the relationship between CXCR4 and NENs, with a special emphasis on diagnostic and therapeutic molecular targets. [ABSTRACT FROM AUTHOR]

Simple Summary: Circulating tumor cells are cancer cells that detach from the primary tumor and enter the bloodstream. These cancer cells in the blood stream eventually result in secondary tumor growth referred to as metastasis. Research on circulating tumor cells is crucial because they can provide valuable insights into cancer progression and treatment response that enhances the patient outcomes. Findings from circulating-tumor-cell-based research can also shed light on cancer metastasis, drug resistance, and tumor evolution, ultimately benefiting the research community by advancing our understanding of cancer biology and guiding the development of innovative treatments. In this review, we have attempted to consolidate the milestones in CTC-based research and their utility in understanding the biology of cancer from origin to progression. Circulating tumor cells (CTCs) are cancer cells that slough off from the tumor and circulate in the peripheral blood and lymphatic system as micro metastases that eventually results in macro metastases. Through a simple blood draw, sensitive CTC detection from clinical samples has proven to be a useful tool for determining the prognosis of cancer. Recent technological developments now make it possible to detect CTCs reliably and repeatedly from a simple and straightforward blood test. Multicenter trials to assess the clinical value of CTCs have demonstrated the prognostic value of these cancer cells. Studies on CTCs have filled huge knowledge gap in understanding the process of metastasis since their identification in the late 19th century. However, these rare cancer cells have not been regularly used to tailor precision medicine and or identify novel druggable targets. In this review, we have attempted to summarize the milestones of CTC-based research from the time of identification to molecular characterization. Additionally, the need for a paradigm shift in dissecting these seeds of metastasis and the possible future avenues to improve CTC-based discoveries are also discussed. [ABSTRACT FROM AUTHOR]

Background: Bladder cancer is very common worldwide. PIGT is a subunit of the glycosylphosphatidylinositol transamidase which involves in tumorigenesis and invasiveness. m6A modification of mRNA has been linked to cell proliferation, tumor progression and other biological events. However, how PIGT is regulated and what is the function of PIGT in bladder cancer remains to be elucidated. Methods: PIGT was silenced or overexpressed to study its role in regulating bladder cancer. Cell proliferation and invasion were examined with the Cell Counting Kit-8, colony formation and Transwell assay, respectively. Cellular oxygen consumption rates or extracellular acidification rates were detected by a XF24 Analyzer. Quantitative RT-PCR and immunoblots were performed to detect mRNA and protein levels. Results: PIGT was overexpressed in bladder cancer. Silencing PIGT inhibited cell proliferation, oxidative phosphorylation, and glycolysis. Overexpressing PIGT promoted cell proliferation, oxidative phosphorylation, glycolysis in vitro and tumor metastasis in vivo by activating glucose transporter 1 (GLUT1). PIGT also promoted GLUT1 glycosylation and membrane trafficking. Wilms' tumor 1-associated protein (WTAP) mediated PIGT m6A modification, and m6A reader, insulin-like growth factor 2 mRNA-binding protein (IGF2BP2), binds to the methylated PIGT to promote the stability of PIGT, leading to up-regulation of PIGT. Conclusion: WTAP mediates PIGT m6A modification to increase the stability of PIGT via the IGF2BP2, which enhances cell proliferation, glycolysis, and metastasis in bladder cancer by modulating GLUT1 glycosylation and membrane trafficking. [ABSTRACT FROM AUTHOR]

The Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1), also known as CD66a, is a member of the immunoglobulin superfamily. CEACAM1 was shown to be a prognostic marker in patients suffering from cancer. In this review, we summarize pre-clinical and clinical evidence linking CEACAM1 to tumorigenicity and cancer progression. Furthermore, we discuss potential CEACAM1-based mechanisms that may affect cancer biology. [ABSTRACT FROM AUTHOR]

Simple Summary: Colorectal cancer (CRC) is one of the most common malignancies worldwide, causing thousands to die each year. Its complex molecular nature leads to significant heterogeneity and variable responses to therapy. ABC proteins, which for many years were regarded as the pillar of the resistance to chemotherapy because they export anticancer drugs from cancer cells, have recently been identified as interesting molecular markers associated with many other physiological functions. We previously reported that during the phenotypic transition, CRC differentially regulates the expression of two transporters, ABCC4 and ABCG2. In cells with a mesenchymal and invasive phenotype, ABCC4 is upregulated, and ABCG2 is downregulated. We have therefore decided to explore this phenomenon by analysing samples from CRC patients with high expression of either ABCC4 or ABCG2 to determine their potential use as markers of therapeutic outcome. Background: Our previous findings proved that ABCC4 and ABCG2 proteins present much more complex roles in colorectal cancer (CRC) than typically cancer-associated functions as drug exporters. Our objective was to evaluate their predictive/diagnostic potential. Methods: CRC patients' transcriptomic data from the Gene Expression Omnibus database (GSE18105, GSE21510 and GSE41568) were discriminated into two subpopulations presenting either high expression levels of ABCC4 (ABCC4 High) or ABCG2 (ABCG2 High). Subpopulations were analysed using various bioinformatical tools and platforms (KEEG, Gene Ontology, FunRich v3.1.3, TIMER2.0 and STRING 12.0). Results: The analysed subpopulations present different gene expression patterns. The protein–protein interaction network of subpopulation-specific genes revealed the top hub proteins in ABCC4 High: RPS27A, SRSF1, DDX3X, BPTF, RBBP7, POLR1B, HNRNPA2B1, PSMD14, NOP58 and EIF2S3 and in ABCG2 High: MAPK3, HIST2H2BE, LMNA, HIST1H2BD, HIST1H2BK, HIST1H2AC, FYN, TLR4, FLNA and HIST1H2AJ. Additionally, our multi-omics analysis proved that the ABCC4 expression correlates with substantially increased tumour-associated macrophage infiltration and sensitivity to FOLFOX treatment. Conclusions: ABCC4 and ABCG2 may be used to distinguish CRC subpopulations that present different molecular and physiological functions. The ABCC4 High subpopulation demonstrates significant EMT reprogramming, RNA metabolism and high response to DNA damage stimuli. The ABCG2 High subpopulation may resist the anti-EGFR therapy, presenting higher proteolytical activity. [ABSTRACT FROM AUTHOR]

Simple Summary: In recent years, several therapeutic advances have been made in clear cell renal cell carcinoma (ccRCC) resulting in novel treatment regimens of increased effectiveness. These advances are largely due to breakthroughs in technologies, particularly in transcriptomics, such as single-cell RNA sequencing (scRNA-seq). Using this technology, we have gained a deeper understanding of the biology of ccRCC and revealed various cell populations and their interactions in disease progression. While localized ccRCC patients have shown promising responses to treatment, however, patients with advanced or metastatic disease remain a therapeutic challenge. To address this gap, recent studies have utilized scRNA-seq to investigate both primary and metastatic ccRCC in search of promising therapeutic targets. This review aims to summarize the current state of knowledge in the field, highlight available treatment options and underscore the critical steps needed to improve survival rates, especially for metastatic ccRCC patients. Over the past two decades, significant progress has been made in the treatment of clear cell renal cell carcinoma (ccRCC), with a shift towards adopting new treatment approaches ranging from monotherapy to triple-combination therapy. This progress has been spearheaded by fundamental technological advancements that have allowed a deeper understanding of the various biological components of this cancer. In particular, the rapid commercialization of transcriptomics technologies, such as single-cell RNA-sequencing (scRNA-seq) methodologies, has played a crucial role in accelerating this understanding. Through precise measurements facilitated by these technologies, the research community has successfully identified and characterized diverse tumor, immune, and stromal cell populations, uncovering their interactions and pathways involved in disease progression. In localized ccRCC, patients have shown impressive response rates to treatment. However, despite the emerging findings and new knowledge provided in the field, there are still patients that do not respond to treatment, especially in advanced disease stages. One of the key challenges lies in the limited study of ccRCC metastases compared to localized cases. This knowledge gap may contribute to the relatively low survival rates and response rates observed in patients with metastatic ccRCC. To bridge this gap, we here delve into recent research utilizing scRNA-seq technologies in both primary and metastatic ccRCC. The goal of this review is to shed light on the current state of knowledge in the field, present existing treatment options, and emphasize the crucial steps needed to improve survival rates, particularly in cases of metastatic ccRCC. [ABSTRACT FROM AUTHOR]

Simple Summary: Angiotensin-Converting Enzyme 2 (ACE2), Transmembrane Serine Protease 2 (TMPRSS2), and Furin are highly expressed in the normal thyroid gland. The putative role played by these molecules in thyroid tumours has not been thoroughly explored to date. Our study shows that the downregulation of ACE2 mRNA and overexpression of Furin mRNA may play a role in thyroid neoplastic transformation. ACE2 mRNA expression was lower in thyroid neoplasms, as for Furin an increased expression in neoplastic lesions was observed. Furin revealed a high discriminative power between normal adjacent and neoplastic thyroid tissue. Its high expression was significantly correlated with poor prognostic features for thyroid neoplasia. Angiotensin-Converting Enzyme 2 (ACE2), Transmembrane Serine Protease 2 (TMPRSS2), and Furin were known to be key players in the SARS-CoV-2 infection, and the thyroid gland was revealed to be one of the relevant targets of the virus. Regardless of the viral infection, the expression of these molecules in the thyroid gland and their putative role in the neoplastic transformation of the thyrocytes has not been thoroughly explored. In this work, we aimed to characterize the mRNA and protein expression pattern of ACE2, TMPRSS2, and Furin in a series of patients with thyroid lesions. Our main results revealed a significantly decreased expression of ACE2 mRNA in the thyroid neoplasms in comparison to normal adjacent tissue. Furin mRNA was significantly increased in thyroid neoplasms when compared to normal adjacent tissue. In addition, a higher Furin mRNA level in thyroid carcinomas was associated with the presence of lymph node metastasis. Furin mRNA expression revealed a high discriminatory power between adjacent tissue and neoplasms. Protein expression of these molecules did not correlate with mRNA expression. Our study shows the mRNA downregulation of ACE2 and overexpression of Furin in thyroid neoplasms. Further studies are required to clarify if Furin expression can be a potential diagnostic indicator in thyroid neoplasia. [ABSTRACT FROM AUTHOR]

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Cancer is a major cause of mortality in humans; often, rather than the primary tumor, it is the presence of metastases that are the cause of death. Extracellular vesicles (EVs) are small structures released by both normal and cancer cells; regarding the latter, they have been demonstrated to modulate almost all cancer-related processes, such as invasion, angiogenesis induction, drug resistance, and immune evasion. In the last years, it has become clear how EVs are widely involved in metastatic dissemination as well as in pre-metastatic niche (PMN) formation. Indeed, in order to achieve a successful metastatic process, i.e., penetration by cancer cells into distant tissues, the shaping of a favorable environment into those distant tissue, i.e., PMN formation, is mandatory. This process consists of an alteration that takes place in a distant organ and paves the way for the engraftment and growth of circulating tumor cells derived from the tumor primary site. This review focuses on the role of EVs in pre-metastatic niche formation and metastatic dissemination, also reporting the last studies suggesting the EVs role as biomarkers of metastatic diseases, possibly in a liquid biopsy approach. [ABSTRACT FROM AUTHOR]

The introduction of targeted therapy (TT) and immuno-oncology (IO) agents have revolutionized the treatment of metastatic renal cell carcinoma (mRCC). However, despite the significant improvements in survival and clinical response yielded by these agents, a significant percentage of patients still experience progressive disease. Evidence now suggests that microorganisms living in the gut (i.e., the gut microbiome) could be used as a biomarker for response and may also have utility in increasing response to these treatments. In this review, we present an overview of the role of the gut microbiome in cancer and its potential implications in the treatment of mRCC. [ABSTRACT FROM AUTHOR]

Sparc/osteonectin, cwcv, and kazal-like domains proteoglycan 1 (SPOCK1) has been reported to play an oncogenic role in certain cancer types; however, the role of SPOCK1 in the progression of clear cell renal cell carcinoma (ccRCC) remains elusive. Here, higher SPOCK1 transcript and protein levels were observed in ccRCC tissues compared to normal tissues and correlated with advanced clinical stages, larger tumor sizes, and lymph node and distal metastases. Knockdown and overexpression of SPOCK1 in ccRCC cells led to decreased and increased cell clonogenic and migratory/invasive abilities in vitro as well as lower and higher tumor growth and invasion in vivo, respectively. Mechanistically, the gene set enrichment analysis (GSEA) database was used to identify the gene set of epithelial-to-mesenchymal transition (EMT) pathways enriched in ccRCC samples with high SPOCK1 expression. Further mechanistic investigations revealed that SPOCK1 triggered the Snail/Slug–matrix metalloproteinase (MMP)-2 axis to promote EMT and cell motility. Clinical ccRCC samples revealed SPOCK1 to be an independent prognostic factor for overall survival (OS), and positive correlations of SPOCK1 with MMP-2 and mesenchymal-related gene expression levels were found. We observed that patients with SPOCK1high/MMP2high tumors had the shortest OS times compared to others. In conclusion, our findings reveal that SPOCK1 can serve as a useful biomarker for predicting ccRCC progression and prognosis, and as a promising target for treating ccRCC. [ABSTRACT FROM AUTHOR]

The spread of tumor cells throughout the body by traveling through the bloodstream is a critical step in metastasis, which continues to be the main cause of cancer-related death. The detection and analysis of circulating tumor cells (CTCs) is important for understanding the biology of metastasis and the development of antimetastatic therapy. However, the isolation of CTCs is challenging due to their high heterogeneity and low representation in the bloodstream. Different isolation methods have been suggested, but most of them lead to CTC damage. However, viable CTCs are an effective source for developing preclinical models to perform drug screening and model the metastatic cascade. In this review, we summarize the available literature on methods for isolating viable CTCs based on different properties of cells. Particular attention is paid to the importance of in vitro and in vivo models obtained from CTCs. Finally, we emphasize the current limitations in CTC isolation and suggest potential solutions to overcome them. [ABSTRACT FROM AUTHOR]

Background: Most prostate cancer patients die from metastasis and lack accurate efficacious biomarkers to monitor the disease behavior, optimize treatment and assess prognosis. Herein, we aimed to identify meaningful lncRNA biomarkers associated with prostate cancer metastatic progression. Methods: By repurposing microarray probes, 11,624 lncRNAs in prostate cancer were obtained from Gene Expression Omnibus database (GSE46691, N = 545; GSE29079, N = 235; GSE94767, N = 130). Weighted gene co-expression network analysis was applied to determine the co-expression lncRNA network pertinent to metastasis. Hub lncRNAs were screened. RNA-seq and clinical data from the Cancer Genome Atlas prostate cancer (TCGA-PRAD) cohort (N = 531) were analyzed. Transwell assay and bioinformatic analysis were performed for mechanism research. Results: The high expression levels of nine hub lncRNAs (FTX, AC005261.1, NORAD, LINC01578, AC004542.2, ZFAS1, EBLN3P, THUMPD3-AS1, GAS5) were significantly associated with Gleason score and increased probability of metastatic progression. Among these lncRNAs, ZFAS1 had the consistent trends of expression in all of the analysis from different cohorts, and the Kaplan-Meier survival analyses showed higher expression of ZFAS1 was associated with shorter relapse free survival. In-vitro studies confirmed that downregulation of ZFAS1 decreased prostate cancer cell migration. Conclusion: We offered some new insights into discovering lncRNA markers correlated with metastatic progression of prostate cancer using the WGCNA. Some may serve as potential prognostic biomarkers and therapeutic targets for advanced metastatic prostate cancer. [ABSTRACT FROM AUTHOR]

Long Intergenic Non-Protein Coding RNA 1133 (LINC01133) is a long non-coding RNA (lncRNA) which interacts with miR-106a-3p, miR-576-5p, miR-495-3p, miR-205, miR-199a-5p, miR-4784, miR-30a-5p, miR-199a, miR-30b-5p, miR-216a -5p and miR-422a, thus increasing expression of mRNA targets of these miRNAs. LINC01133 can affect cancer metastasis through regulation of epithelial-mesenchymal transition program. Dysregulation of this lncRNA has been repeatedly detected in the process of tumorigenesis. In this review, we summarize the results of various studies that reported dysregulation of LINC01133 in different samples and described the role of this lncRNA as a marker for these disorders. [ABSTRACT FROM AUTHOR]

Simple Summary: Immune checkpoint inhibitors (ICIs), such as programmed cell death protein 1 (PD-1) blockade, have proven to be the most effective agents for the management of many cancer types. Although ICIs are the current standard of care for treating metastatic clear cell renal cell carcinoma (ccRCC), 40–60% of patients still have intrinsic resistance to ICIs across multiple clinical trials. Therefore, identifying optimal biomarkers that can predict either responders or non-responders to ICIs has been of tremendous importance. Here, we generated targeted sequencing and whole transcriptomic sequencing of 60 patients with metastatic ccRCC treated with ICIs. Moreover, transcriptomic analysis was integrated to identify molecular subtypes using a total of 177 tumor samples by merging our data and published data derived from the CheckMate 025 trial. Our results show that these molecular subtypes are associated with specific genomic alterations, distinct molecular pathways, and differential clinical outcomes in patients with metastatic ccRCC treated with ICIs. Clear cell renal cell carcinoma (ccRCC) has been reported to be highly immune to and infiltrated by T cells and has angiogenesis features, but the effect of given features on clinical outcomes followed by immune checkpoint inhibitors (ICIs) in ccRCC has not been fully characterized. Currently, loss of function mutation in PBRM1, a PBAF-complex gene frequently mutated in ccRCC, is associated with clinical benefit from ICIs, and is considered as a predictive biomarker for response to anti-PD-1 therapy. However, functional mechanisms of PBRM1 mutation regarding immunotherapy responsiveness are still poorly understood. Here, we performed targeted sequencing (n = 60) and whole transcriptomic sequencing (WTS) (n = 61) of patients with metastatic ccRCC treated by ICIs. By integrating WTS data from the CheckMate 025 trial, we obtained WTS data of 177 tumors and finally identified three molecular subtypes that are characterized by distinct molecular phenotypes and frequency of PBRM1 mutations. Patient clustered subtypes 1 and 3 demonstrated worse responses and survival after ICIs treatment, with a low proportion of PBRM1 mutation and angiogenesis-poor, but were immune-rich and cell-cycle enriched. Notably, patients clustered in the subtype 2 showed a better response and survival after ICIs treatment, with enrichment of PBRM1 mutation and metabolic programs and a low exhausted immune phenotype. Further analysis of the subtype 2 population demonstrated that GATM (glycine amidinotransferase), as a novel gene associated with PBRM1 mutation, plays a pivotal role in ccRCC by using a cell culture model, revealing tumor, suppressive-like features in reducing proliferation and migration. In summary, we identified that metastatic ccRCC treated by ICIs have distinct genomic and transcriptomic features that may account for their responsiveness to ICIs. We also revealed that the novel gene GATM can be a potential tumor suppressor and/or can be associated with therapeutic efficacy in metastatic ccRCC treated by ICIs. [ABSTRACT FROM AUTHOR]

Introduction: The advent of immune checkpoint inhibitors (ICIs) such as nivolumab has enabled outcomes for metastatic renal cell carcinoma (mRCC) to be improved. However, only around 25% of patients respond to these therapies without being able to formally identify them. Data on relevant predictive markers are still lacking. The obesity paradox has been shown as a relevant prognostic marker in mRCC with better outcomes for obese patients. Nevertheless, the impact of weight variation and the presence of sarcopenia during ICI treatment is not known for now. Methods: In a retrospective study, weight and its variations were collected at first day of ICI and at 6 weeks of treatment. Scanographic imagery was used to define the skeletal muscle index (SMI) as a reflect of sarcopenia. The impact of these parameters as predictive and prognostic factors for mRCC with nivolumab was evaluated. Results: A higher body mass index (BMI) at baseline was significantly associated with response at the first scan (p = 0.036). Longer overall survival (OS) was observed for patients with a weight gain compared to the group with weight loss (p = 0.00028). Median OS for sarcopenic patients was 17.2 months and 31.6 months for the non-sarcopenic group of patients, but there was no statistical difference. Conclusion: This trial showed that a higher BMI and weight gain during nivolumab treatment were good predictive markers for outcomes in mRCC with nivolumab. Sarcopenia and variations in SMI could thus be of interest, but further studies are required. [ABSTRACT FROM AUTHOR]

Background: Immune checkpoint inhibitors (ICIs) represent the standard of care as first- or second-line treatment in patients with renal cell carcinoma (RCC). Proton pump inhibitors (PPIs) are among the most prescribed drugs worldwide and are known to affect gut microbiota, which is gaining interest in its association with outcomes for patients on ICIs. Objective: The aim of this study was to evaluate the impact of PPIs on outcomes in RCC patients receiving immunotherapy. Patients and Methods: We retrospectively collected data from patients with metastatic RCC who received the combination of ipilimumab and nivolumab for first-line treatment (Cohort 1) or single-agent nivolumab for second-line or third-line treatment (Cohort 2) from five international centers with expertise in the treatment of RCC. Data about clinicopathological characteristics, PPI use, and outcome on ICIs were collected. Endpoints of the study were objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). Results: Two hundred and eighteen patients (71% male, median age 61 years) were included in the analysis, 62 in Cohort 1 (including 25 patients receiving PPIs) and 156 in Cohort 2 (including 88 patients receiving PPIs), and were followed up for a median of 42 months. In Cohort 1, no difference was observed in ORR (48% vs 57%; p = 0.203), PFS (12.2 vs 8.5 months; p = 0.928), or OS (not reached [NR] vs 27.3 months; p = 0.84). In Cohort 2, no difference was observed in ORR (32% vs 28%; p = 0.538), PFS (6.7 vs 9.0 months; p = 0.799), or OS (16.0 vs 26.0 months; p = 0.324). Conclusions: In patients with RCC, concomitant PPI use did not seem to affect survival outcomes on ICIs, either as combination therapy or monotherapy. [ABSTRACT FROM AUTHOR]

Introduction: Tivozanib is a potent and selective tyrosine kinase inhibitor of vascular endothelial growth factor receptor 1 (VEGFR-1), VEGFR-2, and VEGFR-3, recently approved in Europe for the first-line treatment of metastatic renal cell carcinoma (mRCC). Methods: Retrospective analysis of safety and activity of tivozanib administered at 1.34 mg daily (3 weeks on, 1 week off) within a compassionate-use program to patients with mRCC with no prior systemic treatment in Italy. Results: From August 2018 to April 2019, 64 patients have started tivozanib in 9 oncology units. The median age was 67.5 years (range 40–85), 62.5% males. According to International Metastatic Renal Cell Carcinoma Database Consortium criteria, 27.1% of patients were good prognosis, 57.6% intermediate, and 15.3% poor. Primary tumor had been removed in 71.9% of patients. Histology was clear cell 89%, papillary 4.7%, and unclassified 6.3%. The response rate was 34.4%, stable disease 40.6%, and progression 15.6%. Grade 3–4 toxicities were 7.8% hypertension, 4.7% anemia, 3.1% mucositis, 3.1% asthenia, 1.6% diarrhea, 1.6% anorexia, 1.6% worsening of renal function, and 3.1% cardiac events. Dose reduction to 0.89 mg was applied to 17.2% of patients, and the discontinuation rate due to toxicity was 5.8%. Median progression-free survival was 12.4 months, with 68.7% of patients alive at 12 months. The developing of hypertension predicted increased progression-free survival at multivariate analysis (HR, 0.128; 95% CI, 0.03–0.59; p = 0.008). Conclusions: Tivozanib showed good activity and favorable safety profile in a real-world cohort of unselected patients with mRCC. Predictive biomarkers of response to antiangiogenic therapy are urgently needed in order to identify RCC patients who could still receive a monotherapy with VEGFR inhibitors in the first line. [ABSTRACT FROM AUTHOR]

Purpose: Obesity associated fat infiltration of organ systems is accompanied by organ dysfunction and poor cancer outcomes. Obese women demonstrate variable degrees of fat infiltration of axillary lymph nodes (LNs), and they are at increased risk for node-positive breast cancer. However, the relationship between enlarged axillary nodes and axillary metastases has not been investigated. The purpose of this study is to evaluate the association between axillary metastases and fat-enlarged axillary nodes visualized on mammograms and breast MRI in obese women with a diagnosis of invasive breast cancer. Methods: This retrospective case–control study included 431 patients with histologically confirmed invasive breast cancer. The primary analysis of this study included 306 patients with pre-treatment and pre-operative breast MRI and body mass index (BMI) > 30 (201 node-positive cases and 105 randomly selected node-negative controls) diagnosed with invasive breast cancer between April 1, 2011, and March 1, 2020. The largest visible LN was measured in the axilla contralateral to the known breast cancer on breast MRI. Multivariate logistic regression models were used to assess the association between node-positive status and LN size adjusting for age, BMI, tumor size, tumor grade, tumor subtype, and lymphovascular invasion. Results: A strong likelihood of node-positive breast cancer was observed among obese women with fat-expanded lymph nodes (adjusted OR for the 4th vs. 1st quartile for contralateral LN size on MRI: 9.70; 95% CI 4.26, 23.50; p < 0.001). The receiver operating characteristic curve for size of fat-enlarged nodes in the contralateral axilla identified on breast MRI had an area under the curve of 0.72 for predicting axillary metastasis, and this increased to 0.77 when combined with patient and tumor characteristics. Conclusion: Fat expansion of axillary lymph nodes was associated with a high likelihood of axillary metastases in obese women with invasive breast cancer independent of BMI and tumor characteristics. [ABSTRACT FROM AUTHOR]

Introduction: Clear cell renal cell carcinoma (ccRCC) is the most lethal type of malignancy of the urinary tract system as it is resistant to chemotherapy and radiation and has a survival rate of less than 5% in cases of metastasis. Inflammation plays an essential role in the metastasis of ccRCC. Cyclooxygenase-2 (COX-2) is an inflammatory protein that affects the processes of carcinogenesis, invasion, migration, metastasis, and angiogenesis. COX-2 can modulate programmed death ligand-1 (PD-L1) expression and play a role in immune evasion, meaning that tumor cells are able to escape the body's immune response and more easily metastasize. Purpose: This study aims to determine the role of COX-2 and PD-L1 in the occurrence of ccRCC metastases. Materials and Methods: This study is an observational analytical study, which employed a cross-sectional approach to examine the paraffin block samples of 40 ccRCC cases from Dr. Hasan Sadikin Hospital Bandung, Indonesia, between 2014 and 2021. Immunoexpression was measured using immunohistochemical staining for COX-2 in tumor cells and for PD-L1 in immune cells. PD-L1 calculation was measured using Qupath 0.2.3. digital software. Metastatic data were obtained using radiological imaging and pathological examinations. Meanwhile, the data were analyzed using the chi-square test for COX-2 and Fischer's exact test for PD-L1. Results: The research results revealed a significant association between COX-2 and the occurrence of metastases in ccRCC (p=0.001) with a prevalence odds ratio of 10.28. Positive PD-L1 immunoexpression of the immune cells (≥ 1%) was found in 14% (3/21) of the metastatic group and 5% (1/19) of the non-metastatic group (p=0.607). There was no association between COX-2 and PD-L1 immunoexpression (p=0.278). Conclusion: This study shows that metastases in ccRCC patients are ten times as likely to be associated with high COX-2 immunoexpression than low COX-2 immunoexpression. COX-2 plays a role in the process of ccRCC metastasis without PD-L1 involvement. [ABSTRACT FROM AUTHOR]

Mesothelioma (MESO) is an infrequent tumor derived from mesothelial cells of pleura, peritoneum, pericardium, and tunica vaginalis testis. Despite advancement in technologies and better understanding of tumor progression mechanism, the prognosis of MESO remains poor. The role of alternative splicing events (ASEs) in the oncogenesis, tumor metastasis and drug resistance has been widely discussed in multiple cancers. But the prognosis and potential therapeutic value of ASEs in MESO were not clearly studied by now. We constructed a prognostic model using RNA sequencing data and matched ASE data of MESO patients obtained from the TCGA and TCGASpliceSeq database. A total of 3,993 ASEs were identified associated with overall survival using Cox regression analysis. Eight of them were finally figured out to institute the model by lasso regression analysis. The risk score of the model can predict the prognosis independently. Among the identified 390 splicing factors (SF), HSPA1A and DDX3Y was significantly associated with 43 OS‐SEs. Among these OS‐SEs, SNX5‐58744‐AT (p = 0.048) and SNX5‐58745‐AT (p = 0.048) were significantly associated with bone metastasis. Co‐expression analysis of signal pathways and SNX5‐58744‐AT, SNX5‐58745‐AT was also depicted using GSVA. Finally, we proposed that splicing factor (SF) HSPA1A could regulate SNX5‐58744‐AT (R = −0.414) and SNX5‐58745‐AT (R = 0.414) through the pathway "Class I MHC mediated antigen processing and presentation" (R = 0.400). In this way, tumorigenesis and bone metastasis of MESO were controlled. [ABSTRACT FROM AUTHOR]

Background: Alternative splicing (AS) plays critical roles in generating protein diversity and complexity. Dysregulation of AS underlies the initiation and progression of tumors. Machine learning approaches have emerged as efficient tools to identify promising biomarkers. It is meaningful to explore pivotal AS events (ASEs) to deepen understanding and improve prognostic assessments of lung adenocarcinoma (LUAD) via machine learning algorithms.Method: RNA sequencing data and AS data were extracted from The Cancer Genome Atlas (TCGA) database and TCGA SpliceSeq database. Using several machine learning methods, we identified 24 pairs of LUAD-related ASEs implicated in splicing switches and a random forest-based classifiers for identifying lymph node metastasis (LNM) consisting of 12 ASEs. Furthermore, we identified key prognosis-related ASEs and established a 16-ASE-based prognostic model to predict overall survival for LUAD patients using Cox regression model, random survival forest analysis, and forward selection model. Bioinformatics analyses were also applied to identify underlying mechanisms and associated upstream splicing factors (SFs).Results: Each pair of ASEs was spliced from the same parent gene, and exhibited perfect inverse intrapair correlation (correlation coefficient = - 1). The 12-ASE-based classifier showed robust ability to evaluate LNM status of LUAD patients with the area under the receiver operating characteristic (ROC) curve (AUC) more than 0.7 in fivefold cross-validation. The prognostic model performed well at 1, 3, 5, and 10 years in both the training cohort and internal test cohort. Univariate and multivariate Cox regression indicated the prognostic model could be used as an independent prognostic factor for patients with LUAD. Further analysis revealed correlations between the prognostic model and American Joint Committee on Cancer stage, T stage, N stage, and living status. The splicing network constructed of survival-related SFs and ASEs depicts regulatory relationships between them.Conclusion: In summary, our study provides insight into LUAD researches and managements based on these AS biomarkers. [ABSTRACT FROM AUTHOR]

Background: Tumor progression and distant metastasis are the main causes of deaths in colorectal cancer (CRC) patients, and the molecular mechanisms in CRC metastasis have not been completely discovered. Methods: We identified differentially expressed genes (DEGs) and lncRNAs (DELs) of CRC from The Cancer Genome Atlas (TCGA) database. Then we conducted the weighted gene co-expression network analysis (WGCNA) to investigate co-expression modules related with CRC metastasis. Gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, DEG-DEL co-expression network and survival analyses of significant modules were also conducted. Finally, the expressions of selected biomarkers were validated in cell lines by quantitative real-time PCR (qRT-PCR). Results: 2032 DEGs and 487 DELs were involved the construction of WGCNA network, and greenyellow, turquoise and brown module were identified to have more significant correlation with CRC metastasis. GO and KEGG pathway analysis of these three modules have proven that the functions of DEGs were closely involved in many important processes in cancer pathogenesis. Through the DEG-DEL co-expression network, 12 DEGs and 2 DELs were considered as hub nodes. Besides, survival analysis showed that 30 DEGs were associated with the overall survival of CRC. Then 10 candidate biomarkers were chosen for validation and the expression of CA2, CHP2, SULT1B1, MOGAT2 and C1orf115 were significantly decreased in CRC cell lines when compared to normal human colonic epithelial cells, which were consistent with the results of differential expression analysis. Especially, low expression of SULT1B1, MOGAT2 and C1orf115 were closely correlated with poorer survival of CRC. Conclusion: This study identified 5 genes as new biomarkers affecting the metastasis of CRC. Besides, SULT1B1, MOGAT2 and C1orf115 might be implicated in the prognosis of CRC patients. [ABSTRACT FROM AUTHOR]

The analysis of circulating tumor cells (CTCs) is an outstanding tool to provide insights into the biology of metastatic cancers, to monitor disease progression and with potential for use in liquid biopsy-based personalized cancer treatment. These goals are ambitious, yet recent studies are already allowing a sharper understanding of the strengths, challenges, and opportunities provided by liquid biopsy approaches. For instance, through single-cell-resolution genomics and transcriptomics, it is becoming increasingly clear that CTCs are heterogeneous at multiple levels and that only a fraction of them is capable of initiating metastasis. It also appears that CTCs adopt multiple ways to enhance their metastatic potential, including homotypic clustering and heterotypic interactions with immune and stromal cells. On the clinical side, both CTC enumeration and molecular analysis may provide new means to monitor cancer progression and to take individualized treatment decisions, but their use for early cancer detection appears to be challenging compared to that of other tumor derivatives such as circulating tumor DNA. In this review, we summarize current data on CTC biology and CTC-based clinical applications that are likely to impact our understanding of the metastatic process and to influence the clinical management of patients with metastatic cancer, including new prospects that may favor the implementation of precision medicine. [ABSTRACT FROM AUTHOR]

Purpose: Pancreatic ductal adenocarcinoma (PDAC), the most common malignancy of the pancreas, is the fourth most common cause of cancer-related death in the USA. Local progression, early tumor dissemination and low efficacy of current treatments are the major reasons for its high mortality rate. The ERBB family is over-expressed in PDAC and plays essential roles in its tumorigenesis; however, single-targeted ERBB inhibitors have shown limited activity in this disease. Here, we examined the anti-tumor activity of dacomitinib, a pan-ERBB receptor inhibitor, on PDAC cells. Methods: Anti-proliferative effects of dacomitinib were determined using a cell proliferation assay and crystal violet staining. Annexin V/PI staining, radiation therapy and cell migration and invasion assays were carried out to examine the effects of dacomitinib on apoptosis, radio-sensitivity and cell motility, respectively. Quantitative reverse transcription-PCR (qRT-PCR) and Western blot analyses were applied to elucidate the molecular mechanisms underlying the anti-tumor activity of dacomitinib. Results: We found that dacomitinib diminished PDAC cell proliferation via inhibition of FOXM1 and its targets Aurora kinase B and cyclin B1. Moreover, we found that dacomitinib induced apoptosis and potentiated radio-sensitivity via inhibition of the anti-apoptotic proteins survivin and MCL1. Treatment with dacomitinib attenuated cell migration and invasion through inhibition of the epithelial-to-mesenchymal transition (EMT) markers ZEB1, Snail and N-cadherin. In contrast, we found that the anti-tumor activity of single-targeted ERBB agents including cetuximab (anti-EGFR mAb), trastuzumab (anti-HER2 mAb), H3.105.5 (anti-HER3 mAb) and erlotinib (EGFR small molecule inhibitor) were marginal. Conclusions: Our findings indicate that dacomitinib-mediated blockade of the ERBB receptors yields advantages over single-targeted ERBB inhibition and provide a rationale for further investigation of the therapeutic potential of dacomitinib in the treatment of ERBB-driven PDAC. [ABSTRACT FROM AUTHOR]

Cancer is a complex disease that starts with mutations of key genes in one cell or a small group of cells at a primary site in the body. If these cancer cells continue to grow successfully and, at some later stage, invade the surrounding tissue and acquire a vascular network, they can spread to distant secondary sites in the body. This process, known as metastatic spread, is responsible for around 90% of deaths from cancer and is one of the so-called hallmarks of cancer. To shed light on the metastatic process, we present a mathematical modelling framework that captures for the first time the interconnected processes of invasion and metastatic spread of individual cancer cells in a spatially explicit manner—a multigrid, hybrid, individual-based approach. This framework accounts for the spatiotemporal evolution of mesenchymal- and epithelial-like cancer cells, membrane-type-1 matrix metalloproteinase (MT1-MMP) and the diffusible matrix metalloproteinase-2 (MMP-2), and for their interactions with the extracellular matrix. Using computational simulations, we demonstrate that our model captures all the key steps of the invasion-metastasis cascade, i.e. invasion by both heterogeneous cancer cell clusters and by single mesenchymal-like cancer cells; intravasation of these clusters and single cells both via active mechanisms mediated by matrix-degrading enzymes (MDEs) and via passive shedding; circulation of cancer cell clusters and single cancer cells in the vasculature with the associated risk of cell death and disaggregation of clusters; extravasation of clusters and single cells; and metastatic growth at distant secondary sites in the body. By faithfully reproducing experimental results, our simulations support the evidence-based hypothesis that the membrane-bound MT1-MMP is the main driver of invasive spread rather than diffusible MDEs such as MMP-2. [ABSTRACT FROM AUTHOR]

Clear cell renal cell carcinoma (ccRCC) is the third most common urological cancer, and it has the highest mortality rate. The increasing drug resistance of metastatic ccRCC has resulted in the search for new biomarkers. Epigenetic regulatory mechanisms, such as genome-wide DNA methylation and inhibition of protein translation by interaction of microRNA (miRNA) with its target messenger RNA (mRNA), are deeply involved in the pathogenesis of human cancers, including ccRCC, and may be used in its diagnosis and prognosis. Here, we review oncogenic and oncosuppressive miRNAs, their putative target genes, and the crucial pathways they are involved in. The contradictory behavior of a number of miRNAs, such as suppressive and anti-metastatic miRNAs with oncogenic potential (for example, miR-99a, miR-106a, miR-125b, miR-144, miR-203, miR-378), is examined. miRNAs that contribute mostly to important pathways and processes in ccRCC, for instance, PI3K/AKT/mTOR, Wnt-β, histone modification, and chromatin remodeling, are discussed in detail. We also separately consider their participation in crucial oncogenic processes, such as hypoxia and angiogenesis, metastasis, and epithelial-mesenchymal transition (EMT). The review also considers the interactions of long non-coding RNAs (lncRNAs) and miRNAs of significance in ccRCC. Recent advances in the understanding of the role of hypermethylated miRNA genes in ccRCC and their usefulness as biomarkers are reviewed based on our own data and those available in the literature. Finally, new data and perspectives concerning the clinical applications of miRNAs in the diagnosis, prognosis, and treatment of ccRCC are discussed. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the expression level of cytochrome P450 4B1 (CYP4B1) protein and its clinical significance in specimens from patients with urothelial carcinomas (UC) including upper tract urothelial carcinoma (UTUC, n = 340) and urinary bladder urothelial carcinoma (UBUC, n = 295). Data mining on public domains identified five potential candidate transcripts which were downregulated in advanced UBUCs, indicating that it might implicate in UC progression. Immunohistochemistry was performed to analyze the CYP4B1 protein levels on 635 tissues from UC patients retrospectively. Immunoexpression of CYP4B1 was further estimated using the H‐score method. Correlations between CYP4B1 H‐score and important clinicopathological factors, as well as the significance of CYP4B1 expression level for disease‐specific and metastasis‐free survivals were evaluated. In UTUCs and UBUCs, 118 (34.7%) and 92 (31.2%) patients, respectively, were identified to be of CYP4B1 downregulation. The CYP4B1 expression level was found to be associated with several clinicopathological factors and patient survivals. Downregulation of CYP4B1 protein was correlated to advanced primary tumor (p < 0.001), nodal metastasis (p < 0.001), high histological grade (p = 0.001), vascular invasion (p < 0.001), perineural invasion (p = 0.017) and mitotic rate (p = 0.036) in UTUCs and/or UBUCs. Low CYP4B1 protein level independently predicted inferior disease‐specific (p = 0.009; p < 0.001) and metastasis‐free (p = 0.035; p < 0.001) survivals in UTUC and UBUC patients. Our findings showed that downregulation of CYP4B1 protein level is an independent unfavorable prognosticator. Loss of the CYP4B1 gene expression may play an important role in UC progression. [ABSTRACT FROM AUTHOR]

Introduction. It has been suggested that the metastatic potential of neoplastic cells can be predicted on the basis of their biological features, including expression of proteins involved in the epithelial to mesenchymal transition (EMT). Therefore, the purpose of this work was to (1) evaluate the expression of EMT markers: ZEB2, vimentin, N-cadherin, TWIST, PTEN, survivin, E-cadherin, Ki-67 and GLUT-1, (2) assess mutation status of two genes: PIK3CA and KRAS, and (3) investigate the potential relationships between the studied biomarkers and clinicopathological factors in clear-cell renal cell carcinoma (ccRCC). Material and methods. Tumor tissue samples (embedded in paraffin blocks) from 159 patients undergoing radical nephrectomy were analyzed. Proteins expression was evaluated immunohistochemically. DNA mutations were analyzed on DNA isolated from tumor tissue and amplified by real-time PCR detection using suitable fluorescent labeled TaqMan assays. Results. One hundred and seven men and 52 women of mean age of 63.1years were enrolled. Fifty four cancers at pTNM stage I-II and 98 at pTNM III-IV stage were diagnosed. There were 30 Fuhrman grade G1, 61 Fuhrman G2, 49 Fuhrman G3 and 19 Fuhrman G4 tumors. A negative correlation between ZEB2 (p = 0.047, r = -0.172) or E-cadherin expression (p = 0.027, r = -0.191) and TNM was observed. Positive association between grade and Ki-67 (p < 0.001), survivin (p < 0.001), vimentin (p < 0.001) immunoreactivity and negative association between TWIST expression (p = 0.029) or PTEN expression (p = 0.013) were found. Ki-67 expression was positively correlated with survivin (p < 0.001, r = 0.617), vimentin (p = 0.001, r = 0.251) and N-cadherin (p = 0,009, r = 0.207) immunoreactivity which can suggest tumor aggressiveness. TWIST was negatively correlated with E-cadherin (p < 0.001, r = -0.284), vimentin (p < 0.001, r = -0.297) and N-cadherin (p < 0.002, r = -0.241). ZEB2 was not associated with ccRCC grade but was negatively correlated with E-cadherin (p = 0.055, r= -0.153) and PTEN (p = 0.006). GLUT-1 expression was inversely linked to E-cadherin expression (p = 0.022, r= -0.182). Mutations in PIK3CA and KRAS genes were not found in any of the studied ccRCC tumors. Conclusions. Low-grade tumors showed higher expression of ZEB2 and TWIST proteins than high-grade tumors, which can suggest that EMT in ccRCC begins at early stages of tumor development and, therefore, evaluation of these proteins, together with other biomarkers, may be useful for assessment of the tumor metastatic potential. [ABSTRACT FROM AUTHOR]

Novel therapies are required for the treatment of metastatic renal cell carcinoma (RCC), which is associated with inoperable disease and patient death. Histone deacetylases (HDACs) are epigenetic modifiers and potential drug targets. Additional information on molecular pathways that are altered by histone deacetylase inhibitors (HDACi) in RCC cells is warranted. It should equally be delineated further which individual members of the 18 mammalian HDACs determine the survival and tumor-associated gene expression programs of such cells. Most importantly, an ongoing dispute whether HDACi promote or suppress metastasis-associated epithelial-to-mesenchymal transition (EMT) has to be resolved before HDACi are considered further as clinically relevant drugs. Here we show how HDACi affect murine and primary human RCC cells. We find that these agents induce morphological alterations resembling the metastasis-associated EMT. However, individual and proteomics-based analyses of epithelial and mesenchymal marker proteins and of EMT-associated transcription factors (EMT-TFs) reveal that HDACi do not trigger EMT. Pathway deconvolution analysis identifies reduced proliferation and apoptosis induction as key effects of HDACi. Furthermore, these drugs lead to a reduction of the cell adhesion molecule E-cadherin and of the platelet-derived growth factor receptor-β (PDGFRβ), which is a key driver of RCC metastasis formation. Accordingly, HDACi reduce the pulmonary spread of syngeneic transplanted renal carcinoma cells in mice. Specific genetic elimination of the histone deacetylases HDAC1/HDAC2 reflects the effects of pharmacological HDAC inhibition regarding growth suppression, apoptosis, and the downregulation of E-cadherin and PDGFRβ. Thus, these epigenetic modifiers are non-redundant gatekeepers of cell fate and precise pharmacological targets. [ABSTRACT FROM AUTHOR]

Bufalin is a monomer compound extract from Chansu, which is a traditional Chinese medicine obtained from the skin and parotid venom glands of toads, such as Bufo bufo gargarizans Cantor and Bufo melanostictus Schneider. Chansu had been used in traditional Chinese medicine for >1,000 years due to its cardiac, anti-inflammatory and anticancer properties. Previous studies identified bufalin as the main anticancer compound of Chansu, and recent evidence has corroborated its anticancer properties. Bufalin inhibits cancer cell proliferation, induces cell cycle arrest, induces cancer cell apoptosis, inhibits neovascularization, induces cell differentiation, inhibits cancer metastasis and invasion, and enhances chemotherapeutic drug sensitivity. However, the function and mechanism of bufalin in metastatic cancer cells have not yet been expounded. The aim of the present review was to discuss the recent progress and prospects of bufalin in the prevention of cancer metastasis, particularly in inhibiting epithelial-to-mesenchymal transition. [ABSTRACT FROM AUTHOR]

The enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) gene has been recognized to be a proto‑oncogene and to be linked to human malignancies. However, the additional functions of EZH2 in renal cell carcinoma (RCC) are not completely understood. In the present study, a possible role of EZH2 in RCC was identified. EZH2 was demonstrated to promote the cell proliferation and invasion potential of 769‑P cells, and inhibition of EZH2 was demonstrated to prevent these two processes in 786‑O cells. Mechanically, EZH2 was demonstrated to increase the phosphorylation of signal transducer and activator of transcription 3 (STAT3) and upregulate 72 kDa type IV collagenase (MMP‑2) expression. When cells were treated with small interfering RNA targeting STAT3 or Stattic, a specific inhibitor of STAT3, the invasive ability of the cells was decreased and downregulation of MMP‑2 was observed. Based on these results, in the present study it was hypothesized that EZH2 may serve a critical role in the progression of RCC. Its ability to facilitate invasion makes EZH2 a promising target for the management of advanced RCC. [ABSTRACT FROM AUTHOR]

Purpose: Pancreatic cancer (PC) is an aggressive type of cancer that exhibits a rapid progression. Previously LOX-1, which is a type II trans-membrane glycoprotein that is expressed in endothelial cells, has been found to be involved in the development of several types of cancer. As yet, however, the expression of LOX-1 and its functional consequences in PC have not been documented. The present study was aimed at investigating the prognostic relevance of LOX-1 expression in PC patients and at resolving its role in PC metastasis. Methods: LOX-1 expression was assessed by immunohistochemistry on a tissue microarray containing samples from 98 PC patients. Kaplan-Meier analyses were performed to compare survival curves, whereas Cox regression analyses were performed to explore the independent prognostic value of LOX-1 expression on the overall survival (OS) of PC patients. Harrel's concordance index was applied to calculate the predictive accuracy of established models. In addition, in vitro scratch wound healing and Transwell assays were used to assess the effect of LOX-1 expression silencing and over-expression on PC cell migration and invasion, whereas Cell Counting Kit-8 (CCK8) and Flow Cytometry (FCM) assays were used to assess its effects on PC cell proliferation and apoptosis. Results: We found that LOX-1 is highly expressed in the PC tumor tissues tested and is related to the occurrence of lymph node metastases, higher TNM stages and a poor OS. We also found that LOX-1 expression may serve as an independent prognostic factor for the OS of PC patients. Our in vitro assays revealed that LOX-1 expression may promote the migration and invasion of PC cells through epithelial-mesenchymal transition (EMT). No effect on PC cell proliferation was noted. Conclusions: From our data we conclude that a high LOX-1 expression in PC tissues is indicative for the occurrence of lymph node metastases, high TNM stages and a poor prognosis. LOX-1 may serve as an independent prognostic biomarker. Our in vitro assays additionally revealed that LOX-1 may enhance the migration and invasion of PC cells through EMT. LOX-1 may also serve as a novel therapeutic target. [ABSTRACT FROM AUTHOR]

Previous studies have indicated that high expression of lactate dehydrogenase A (LDHA) exists in many human cancers. Recently, several reports showed that silencing or inhibition of LDHA could suppress metastasis of human cancer including renal cell carcinoma (RCC). However, the mechanism remains unknown. The role of LDHA in RCC migration and invasion was investigated using immunohistochemistry, western blotting, Transwell and scratch assays, and in vivo experiment. The influence of LDHA on the Warburg effect was also investigated by LDHA activity and lactate production assay. LDHA was overexpressed in RCC tissues and predicted a worse survival following renal resection. Correlation analysis demonstrated that LDHA was negatively correlated with E-cadherin and positively with N-cadherin. Experimentally, both in vivo and in vitro experiments found downregulation of LDHA suppressed RCC cells migration and invasion by inhibiting EMT. In addition, results indicated LDHA could promote the Warburg effect. Further research presented that the LDHA inhibitor, oxamate, suppressed tumor metastasis by inhibiting LDHA activity and EMT. These results demonstrated that LDHA mediates tumor metastasis by promoting EMT in RCC, suggesting that LDHA could be a promising therapeutic target for RCC therapy. [ABSTRACT FROM AUTHOR]

Clear cell renal cell carcinoma (CCRCC) is a heterogeneous and complex disease that frequently develops distant metastases. Fibroblast activation protein (FAP) is a serine peptidase the expression of which in cancer-associated fibroblasts has been associated with higher risk of metastases and poor survival. The objective of this study was to evaluate the role of FAP in metastatic CCRCC (mCCRCC). A series of 59 mCCRCC retrospectively collected was included in the study. Metastases developed either synchronous (n = 14) or metachronous to renal disease (n = 45). Tumor specimens were obtained from both primary lesion (n = 59) and metastases (n = 54) and FAP expression was immunohistochemically analyzed. FAP expression in fibroblasts from primary tumors correlated with FAP expression in the corresponding metastatic lesions. Also, primary and metastatic FAP expression was correlated with large tumor diameter (>7cm), high grade (G3/4), high stage (pT3/4), tumor necrosis and sarcomatoid transformation. The expression of FAP in primary tumors and in their metastases was associated both with synchronous metastases and also with metastases to the lymph nodes. FAP expression in the primary tumor was correlated with worse 10-year overall survival. Immunohistochemical detection of FAP in the stromal tumor fibroblasts could be a biomarker of early lymph node metastatic status and therefore could account for the poor prognosis of FAP positive CCRCC. [ABSTRACT FROM AUTHOR]

The outcome of patients with prostate cancer (PCa) is mainly dependent on the presence or absence of distant metastases. Although several advances have been made in understanding the biological basis of this tumor, the mechanisms underlying PCa metastatic spread are not fully clear. The lack of a clear origin for PCa metastasis may be partially due to the evidence of PCa heterogeneity between primary tumor and metastases and among different metastatic sites. Cross-metastatic seeding and the de novo monoclonal seeding of daughter metastases have been proposed as crucial events during metastasis. This process requires the contribution of tumor environment, which modulates cancer cell homing and growth, and involves several components including cancer stem cells (CSCs), tumor secreted microvesicles, circulating tumor cells (CTCs), and immune cells. In this review, we have focused on the recent findings on the origin of prostate metastasis, showing the contribution of tumor microenvironment to this evolutionary process. [ABSTRACT FROM AUTHOR]

Cancer stem cells (CSCs) are responsible for cancer progression, metastasis, and recurrence. To date, the specific markers of CSCs remain undiscovered. The aim of this study was to identify novel biomarkers of gastric CSCs for clinical diagnosis using proteomics technology. CSC-like SP cells, OCUM-12/SP cells, OCUM-2MD3/SP cells, and their parent OCUM-12 cells and OCUM-2MD3 cells were used in this study. Protein lysates from each cell line were analyzed using QSTAR Elite Liquid Chromatography with Tandem Mass Spectrometry, coupled with isobaric tags for relative and absolute quantitation technology. Candidate proteins detected by proteomics technology were validated by immunohistochemical analysis of 300 gastric cancers. Based on the results of LC-MS/MS, eight proteins, including RBBP6, GLG1, VPS13A, DCTPP1, HSPA9, HSPA4, ALDOA, and KRT18, were up-regulated in both OCUM-12/SP cells and OCUM-2MD3/SP cells when compared to their corresponding parent cells. RT-PCR analysis indicated that the expression level of RBBP6, HSPA4, DCTPP1, HSPA9, VPS13A, ALDOA, GLG1, and CK18 was high in OCUM-12/SP and OCUM-2MD3/SP, in compared with the control of parent OCUM-12 and OCUM-2MD3. These proteins were significantly associated with advanced invasion depth, lymph node metastasis, distant metastasis, or advanced clinical stage. RBBP6, DCTPP1, HSPA4, and ALDOA expression in particular were significantly associated with a poor prognosis in the 300 gastric cancer patients. RBBP6 was determined to be an independent prognostic factor. The motility-stimulating ability of OCUM-12/SP cells and OCUM-2MD3/SP cells was inhibited by RBBP6 siRNA. These findings might suggest that the eight proteins, RBBP6, GLG1, VPS13A, DCTPP1, HSPA9, HSPA4, ALDOA, and KRT18, utilizing comparative proteomics analysis, were perceived to be potential CSC markers of gastric cancer. Of the eight candidate proteins, RBBP6 was suggested to be a promising prognostic biomarker and a therapeutic target for gastric cancer. [ABSTRACT FROM AUTHOR]

RRP1B (ribosomal RNA processing 1 homolog B) was first identified as a metastasis susceptibility gene in breast cancer through its ability to modulate gene expression in a manner that can be used to accurately predict prognosis in breast cancer. However, the mechanism(s) by which RRP1B modulates gene expression is currently unclear. Many RRP1B binding candidates are involved in alternative splicing, a mechanism of gene expression regulation that is increasingly recognized to be involved in cancer progression and metastasis. One such target is SRSF1 (serine/arginine-rich splicing factor 1) (SF2/ASF, splicing factor 2/alternative splicing factor), an essential splicing regulator that also functions as an oncoprotein. Earlier studies demonstrated that splicing and transcription occur concurrently and are coupled processes. Given that RRP1B regulates transcriptional activity, we hypothesized that RRP1B also regulates the expression of alternative mRNA isoforms through its interaction with SRSF1. Interaction between RRP1B and SRSF1 was verified by coimmunoprecipitation and coimmunofluorescence. Treatment of cells with transcriptional inhibitors significantly increased this interaction, demonstrating that the association of these two proteins is transcriptionally regulated. To assess the role of RRP1B in the regulation of alternative isoform expression, RNA-sequencing data were generated from control and Rrp1b-knockdown cells. Knockdown of Rrp1b induced a significant change in isoform expression in over 600 genes compared with control cell lines. This was verified by quantitative reverse-transcription PCR using isoform-specific primers. Pathway enrichment analyses identified cell cycle and checkpoint regulation to be those most affected by Rrp1b knockdown. These data suggest that RRP1B suppresses metastatic progression by altering the transcriptome through its interaction with splicing regulators such as SRSF1. [ABSTRACT FROM AUTHOR]

Simple Summary: Circulating tumor cells dissociate from the primary tumor, enter the bloodstream and travel to distant sites where they seed metastases. To endow these tumor cells with the features necessary for this journey, they must undergo dramatic shape changes, acquire migratory potential, alter their metabolism, and quickly adapt to insults in each new environment. To permit such phenotypic changes in multiple directions, they often acquire a more primitive state reminiscent of stem cells in the embryo. These changes are coupled with altered capacities and qualities to remove DNA lesions such as those induced by a metabolic shift or an immune cell attack. Defects in DNA repair cause mutations, leading to hereditary breast cancer and accelerating progression. Enhanced DNA repair causes resistance to chemotherapeutic treatment. Therefore, it is of utmost interest to understand the choreography of these functions in circulating tumor cells at the molecular level, because they represent targets to fight chemoresistant metastases. Circulating tumor cells (CTCs) traverse vessels to travel from the primary tumor to distant organs where they adhere, transmigrate, and seed metastases. To cope with these challenges, CTCs have reached maximal flexibility to change their differentiation status, morphology, migratory capacity, and their responses to genotoxic stress caused by metabolic changes, hormones, the inflammatory environment, or cytostatic treatment. A significant percentage of breast cancer cells are defective in homologous recombination repair and other mechanisms that protect the integrity of the replication fork. To prevent cell death caused by broken forks, alternative, mutagenic repair, and bypass pathways are engaged but these increase genomic instability. CTCs, arising from such breast tumors, are endowed with an even larger toolbox of escape mechanisms that can be switched on and off at different stages during their journey according to the stress stimulus. Accumulating evidence suggests that DNA damage responses, DNA repair, and replication are integral parts of a regulatory network orchestrating the plasticity of stemness features and transitions between epithelial and mesenchymal states in CTCs. This review summarizes the published information on these regulatory circuits of relevance for the design of biomarkers reflecting CTC functions in real-time to monitor therapeutic responses and detect evolving chemoresistance mechanisms. [ABSTRACT FROM AUTHOR]

Renal cell carcinoma (RCC) is an increasingly common malignancy that can progress to metastatic renal cell carcinoma (mRCC) in approximately one-third of RCC patients. The 5-year survival rate for mRCC is abysmally low, and, at the present time, there are sparingly few if any effective treatments. Current surgical and pharmacological treatments can have a long-lasting impact on renal function, as well. Thus, there is a compelling unmet need to discover novel biomarkers and surveillance methods to improve patient outcomes with more targeted therapies earlier in the course of the disease. Circulating biomarkers, such as circulating tumor DNA, noncoding RNA, proteins, extracellular vesicles, or cancer cells themselves potentially represent a minimally invasive tool to fill this gap and accelerate both diagnosis and treatment. Here, we discuss the clinical relevance of different circulating biomarkers in metastatic renal cell carcinoma by clarifying their potential role as novel biomarkers of response or resistance to treatments but also by guiding clinicians in novel therapeutic approaches. [ABSTRACT FROM AUTHOR]

Simple Summary: Despite recent advances, some patients with pancreatic cancer are refractory to treatment and the disease rapidly progresses, resulting in early death. The potential prognostic value of circulating tumor cells (CTCs) has been demonstrated in other cancer types, but the clinical validity in pancreatic cancer remains elusive. Here, we show that CTC clusters, which show mesenchymal characteristics and platelet marker expression, are highly correlated with poor prognosis in patients with unresectable pancreatic cancer. Circulating tumor cells (CTCs) are known to be heterogeneous and clustered with tumor-associated cells, such as macrophages, neutrophils, fibroblasts, and platelets. However, their molecular profile and clinical significance remain largely unknown. Thus, we aimed to perform a comprehensive gene expression analysis of single CTCs and CTC clusters in patients with pancreatic cancer and to identify their potential clinical relevance to provide personalized medicine. Epitope-independent, rapid (>3 mL of whole blood/min) isolation of single CTCs and CTC clusters was achieved from a prospective cohort of 16 patients with unresectable pancreatic cancer using a centrifugal microfluidic device. Forty-eight mRNA expressions of individual CTCs and CTC clusters were analyzed to identify pancreatic CTC phenotype. CTC clusters had a larger proportion of mesenchymal expression than single CTCs (p = 0.0004). The presence of CTC clusters positively correlated with poor prognosis (progression-free survival, p = 0.0159; overall survival, p = 0.0186). Furthermore, we found that most CTCs in these patients (90.7%) were cloaked with platelets and found the presence of a positive correlation between the increase in CTC clusters and rapid disease progression during follow-ups. Efficient CTC cluster isolation and analysis techniques will enhance the understanding of complex tumor metastasis processes and can facilitate personalized disease management. [ABSTRACT FROM AUTHOR]

Simple Summary: Even today, pancreatic cancer still has a dismal prognosis. It is characterized by a lack of early symptoms and thus late diagnosis as well as early metastasis. The majority of patients suffer from pancreatic ductal adenocarcinoma (PDAC). PDACs communicate extensively with cellular components of their microenvironment, but also with distant metastatic niches to facilitate tumor progression and dissemination. This crosstalk is substantially enabled by small extracellular vesicles (sEVs, exosomes) with a size of 30–150 nm that are released from the tumor cells. sEVs carry bioactive cargos that reprogram target cells to promote tumor growth, migration, metastasis, immune evasion, or chemotherapy resistance. Interestingly, sEVs also carry novel diagnostic, prognostic and potentially also predictive biomarkers. Moreover, engineered sEVs may be utilized as therapeutic agents, improving treatment options. The role of sEVs for PDAC development, progression, diagnosis, prognosis, and treatment is the focus of this review. Even with all recent advances in cancer therapy, pancreatic cancer still has a dismal 5-year survival rate of less than 7%. The most prevalent tumor subtype is pancreatic ductal adenocarcinoma (PDAC). PDACs display an extensive crosstalk with their tumor microenvironment (TME), e.g., pancreatic stellate cells, but also immune cells to regulate tumor growth, immune evasion, and metastasis. In addition to crosstalk in the local TME, PDACs were shown to induce the formation of pre-metastatic niches in different organs. Recent advances have attributed many of these interactions to intercellular communication by small extracellular vesicles (sEVs, exosomes). These nanovesicles are derived of endo-lysosomal structures (multivesicular bodies) with a size range of 30–150 nm. sEVs carry various bioactive cargos, such as proteins, lipids, DNA, mRNA, or miRNAs and act in an autocrine or paracrine fashion to educate recipient cells. In addition to tumor formation, progression, and metastasis, sEVs were described as potent biomarker platforms for diagnosis and prognosis of PDAC. Advances in sEV engineering have further indicated that sEVs might once be used as effective drug carriers. Thus, extensive sEV-based communication and applications as platform for biomarker analysis or vehicles for treatment suggest a major impact of sEVs in future PDAC research. [ABSTRACT FROM AUTHOR]

Simple Summary: Urothelial bladder cancer (BC) is one of the most fatal cancers, with a dismal five-year survival rate of 5% in patients with metastatic disease. Clinically relevant benefits of immunotherapy in advanced or metastatic bladder cancer have led to Food and Drug Administration (FDA) approval of immune checkpoint inhibitors (ICIs) as second- or first-line therapy in patients unresponsive to or ineligible for standard treatment. The advantage of ICIs is being investigated in various stages of BC, either as monotherapy or in combination with other drugs. In this review we discuss the role of ICIs in BC, highlighting their current clinical application and outlining future therapeutic perspectives. Bladder cancer (BC) is the most common malignancy of the genitourinary tract, with high morbidity and mortality rates. Until recently, the treatment of locally advanced or metastatic urothelial BC was based on the use of chemotherapy alone. Since 2016, five immune checkpoint inhibitors (ICIs) have been approved by the Food and Drug Administration (FDA) in different settings, i.e., first-line, maintenance and second-line treatment, while several trials are still ongoing in the perioperative context. Lately, pembrolizumab, a programmed death-1 (PD-1) inhibitor, has been approved for Bacillus Calmette–Guérin (BCG)-unresponsive high-risk non-muscle invasive bladder cancer (NMIBC), using immunotherapy at an early stage of the disease. This review investigates the current state and future perspectives of immunotherapy in BC, focusing on the rationale and results of combining immunotherapy with other therapeutic strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: Pancreatic cancer is one of the hardest-to-treat cancers. This is mainly due to its heterogeneity, where subsets of cancer cells possess distinct properties and abilities that determine if and how they metastasize or respond to therapy. DNA barcoding technologies have emerged as a powerful tool to study this heterogeneity, as they allow labeling of individual tumor cells within a cancer cell pool and follow their cellular states and fates during metastasis or upon therapy. The aim of this review was to provide an overview of the various levels of tumor heterogeneity in pancreatic cancer, the obstacles these levels of heterogeneity can cause for effective personalized treatment strategies, and how different barcoding approaches can be applied to study these important questions. Tumor heterogeneity is a hallmark of many solid tumors, including pancreatic ductal adenocarcinoma (PDAC), and an inherent consequence of the clonal evolution of cancers. As such, it is considered the underlying concept of many characteristics of the disease, including the ability to metastasize, adapt to different microenvironments, and to develop therapy resistance. Undoubtedly, the high mortality of PDAC can be attributed to a high extent to these properties. Despite its apparent importance, studying tumor heterogeneity has been a challenging task, mainly due to its complexity and lack of appropriate methods. However, in recent years molecular DNA barcoding has emerged as a sophisticated tool that allows mapping of individual cells or subpopulations in a cell pool to study heterogeneity and thus devise new personalized treatment strategies. In this review, we provide an overview of genetic and non-genetic inter- and intra-tumor heterogeneity and its impact on (personalized) treatment strategies in PDAC and address how DNA barcoding technologies work and can be applied to study this clinically highly relevant question. [ABSTRACT FROM AUTHOR]

Chemokines are chemotactic cytokines that promote cancer growth, metastasis, and regulate resistance to chemotherapy. Stromal cell-derived factor 1 (SDF1) also known as C-X-C motif chemokine 12 (CXCL12), a prognostic factor, is an extracellular homeostatic chemokine that is the natural ligand for chemokine receptors C-X-C chemokine receptor type 4 (CXCR4), also known as fusin or cluster of differentiation 184 (CD184) and chemokine receptor type 7 (CXCR7). CXCR4 is the most widely expressed rhodopsin-like G protein coupled chemokine receptor (GPCR). The CXCL12–CXCR4 axis is involved in tumor growth, invasion, angiogenesis, and metastasis in colorectal cancer (CRC). CXCR7, recently termed as atypical chemokine receptor 3 (ACKR3), is amongst the G protein coupled cell surface receptor family that is also commonly expressed in a large variety of cancer cells. CXCR7, like CXCR4, regulates immunity, angiogenesis, stem cell trafficking, cell growth and organ-specific metastases. CXCR4 and CXCR7 are expressed individually or together, depending on the tumor type. When expressed together, CXCR4 and CXCR7 can form homo- or hetero-dimers. Homo- and hetero-dimerization of CXCL12 and its receptors CXCR4 and CXCR7 alter their signaling activity. Only few drugs have been approved for clinical use targeting CXCL12-CXCR4/CXCR7 axis. Several CXCR4 inhibitors are in clinical trials for solid tumor treatment with limited success whereas CXCR7-specific inhibitors are still in preclinical studies for CRC. This review focuses on current knowledge of chemokine CXCL12 and its receptors CXCR4 and CXCR7, with emphasis on targeting the CXCL12–CXCR4/CXCR7 axis as a treatment strategy for CRC. [ABSTRACT FROM AUTHOR]

Simple Summary: The oligometastatic prostate cancer state is defined as the presence of a number of lesions ≤ 5 and has been significantly correlated with better survival if compared to a number of metastases > 5. In particular, patients in an oligometastatic setting could benefit from a metastates directed therapy, which could control the disease delaying the start of systemic therapies. For this reason, the selection of true-oligometastatic patients who could benefit from such approach is particularly important in this setting. The aim of the present narrative review is to report the current state of the art on the liquid biopsy-derived analytes and their reliability as biomarkers in the clinics for the identification of true-oligometastatic patients. This kind of molecular profiling could refine current developments in the era of precision oncology allowing patients' stratification and leading to more refined therapeutic strategies. In recent years, a growing interest has been directed towards oligometastatic prostate cancer (OMPC), as patients with three to five metastatic lesions have shown a significantly better survival as compared with those harboring a higher number of lesions. The efficacy of local ablative treatments directed on metastatic lesions (metastases-directed treatments) was extensively investigated, with the aim of preventing further disease progression and delaying the start of systemic androgen deprivation therapies. Definitive diagnosis of prostate cancer is traditionally based on histopathological analysis. Nevertheless, a bioptic sample—static in nature—inevitably fails to reflect the dynamics of the tumor and its biological response due to the dynamic selective pressure of cancer therapies, which can profoundly influence spatio-temporal heterogeneity. Furthermore, even with new imaging technologies allowing an increasingly early detection, the diagnosis of oligometastasis is currently based exclusively on radiological investigations. Given these premises, the development of minimally-invasive liquid biopsies was recently promoted and implemented as predictive biomarkers both for clinical decision-making at pre-treatment (baseline assessment) and for monitoring treatment response during the clinical course of the disease. Through liquid biopsy, different biomarkers, commonly extracted from blood, urine or saliva, can be characterized and implemented in clinical routine to select targeted therapies and assess treatment response. Moreover, this approach has the potential to act as a tissue substitute and to accelerate the identification of novel and consistent predictive analytes cost-efficiently. However, the utility of tumor profiling is currently limited in OMPC due to the lack of clinically validated predictive biomarkers. In this scenario, different ongoing trials, such as the RADIOSA trial, might provide additional insights into the biology of the oligometastatic state and on the identification of novel biomarkers for the outlining of true oligometastatic patients, paving the way towards a wider ideal approach of personalized medicine. The aim of the present narrative review is to report the current state of the art on the solidity of liquid biopsy-related analytes such as CTCs, cfDNA, miRNA and epi-miRNA, and to provide a benchmark for their further clinical implementation. Arguably, this kind of molecular profiling could refine current developments in the era of precision oncology and lead to more refined therapeutic strategies in this subset of oligometastatic patients. [ABSTRACT FROM AUTHOR]

Recent findings suggest that tumor microenvironment (TME) plays an important regulatory role in the occurrence, proliferation, and metastasis of tumors. Different from normal tissue, the condition around tumor significantly altered, including immune infiltration, compact extracellular matrix, new vasculatures, abundant enzyme, acidic pH value, and hypoxia. Increasingly, researchers focused on targeting TME to prevent tumor development and metastasis. With the development of nanotechnology and the deep research on the tumor environment, stimulation-responsive intelligent nanostructures designed based on TME have attracted much attention in the anti-tumor drug delivery system. TME-targeted nano therapeutics can regulate the distribution of drugs in the body, specifically increase the concentration of drugs in the tumor site, so as to enhance the efficacy and reduce adverse reactions, can utilize particular conditions of TME to improve the effect of tumor therapy. This paper summarizes the major components and characteristics of TME, discusses the principles and strategies of relevant nano-architectures targeting TME for the treatment and diagnosis systematically. [ABSTRACT FROM AUTHOR]

Simple Summary: Triple-negative breast cancer (TNBC) represents a heterogeneous group of breast cancers that lack estrogen receptor (ER), progesterone receptor (PR), and human epidermal factor 2 (HER2) amplifications. This triple negativity represents a challenge in choosing the right treatment, as without the aforementioned biomarkers there are no efficient therapeutic targets. Nevertheless, some triple-negative breast cancers express androgen receptor (AR), which could be used as a novel therapeutic target in such subgroup of breast cancers. In our review, we aimed to identify clinical features and proposed potential therapeutic approaches of this specific subgroup—AR-positive triple-negative breast cancer. Our findings contributed to a better understanding of the current problematics regarding AR-positive TNBC. This review summarizes the recent findings of a vast array of studies conducted on androgen receptor-positive triple-negative breast cancer (AR-positive TNBC) to provide a better understanding of this specific breast cancer subgroup. AR expression is correlated with higher age, lower histological grade, lower proliferation index Ki-67, spiculated masses, and calcifications on mammography. Studies investigating the correlation between AR expression and lymph node metastasis are highly discordant. In addition, results regarding prognosis are highly contradictory. AR antagonists are a promising novel therapeutic approach in AR-positive TNBC. However, AR signaling pathways should be more investigated in order to understand the influence of AR expression on TNBC more thoroughly. [ABSTRACT FROM AUTHOR]

Simple Summary: Circulating tumour cells (CTCs) are cancer cells shed into the bloodstream from tumours and their analysis can provide important insights into cancer detection and monitoring, with the potential to direct personalised therapies for the patient. These CTCs are rare in the blood, which makes their detection and enrichment challenging and to date, only one technology (the CellSearch) has gained FDA approval for determining the prognosis of patients with advanced breast, prostate and colorectal cancers. Here, we review the wide range of enrichment technologies available to isolate CTCs from other blood components and highlight the important characteristics that new technologies should possess for routine clinical use. Circulating tumour cells (CTCs) are the precursor cells for the formation of metastatic disease. With a simple blood draw, liquid biopsies enable the non-invasive sampling of CTCs from the blood, which have the potential to provide important insights into cancer detection and monitoring. Since gaining FDA approval in 2004, the CellSearch system has been used to determine the prognosis of patients with metastatic breast, prostate and colorectal cancers. This utilises the cell surface marker Epithelial Cell Adhesion Molecule (EpCAM), to enrich CTCs, and many other technologies have adopted this approach. More recently, the role of mesenchymal-like CTCs in metastasis formation has come to light. It has been suggested that these cells are more aggressive metastatic precursors than their epithelial counterparts; however, mesenchymal CTCs remain undetected by EpCAM-based enrichment methods. This has prompted the development of a variety of 'label free' enrichment technologies, which exploit the unique physical properties of CTCs (such as size and deformability) compared to other blood components. Here, we review a wide range of both immunocapture and label free CTC enrichment technologies, summarising the most significant advantages and disadvantages of each. We also highlight the important characteristics that technologies should possess for routine clinical use, since future developments could have important clinical implications, with the potential to direct personalised therapies for patients with cancer. [ABSTRACT FROM AUTHOR]