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Abstract Despite progress in breast cancer treatment, a significant portion of patients still relapse because of drug resistance. The involvement of microRNAs in cancer progression and chemotherapy response is well established. Therefore, this study aimed to elucidate the dysregulation of the microRNA-449 family (specifically, microRNA-449a, microRNA-449b-5p, and microRNA-449c-5p) and its impact on resistance to doxorubicin, a commonly used chemotherapeutic drug for the treatment of triple-negative breast cancer. We found that the microRNA-449 family is downregulated in triple-negative breast cancer and demonstrated its potential as a diagnostic biomarker. Besides, our findings indicate that the downregulation of the microRNA-449 family is mediated by the microRNAs-449/SIRT1-HDAC1 negative feedback loop. Moreover, it was found that the microRNA-449 family dysregulates the fatty acid metabolism by targeting ACSL4, which is a potential prognostic biomarker that mediates doxorubicin response through regulation of the drug extrusion pump ABCG2. Altogether, our results suggest that the microRNA-449 family might be a potential therapeutic target for the treatment of triple-negative breast cancer since it is implicated in doxorubicin response through ACSL4/ABCG2 axis regulation. Ultimately, our results also highlight the value of microRNAs-449 and ACSL4 as diagnostic and prognostic biomarkers in triple-negative breast cancer. Proposed model of miRNAs-449 downregulation in TNBC and doxorubicin response. MiRNAs-449 are downregulated in TNBC through a negative feedback loop with SIRT1 and HDAC1. Moreover, ACSL4 increases ABCG2 expression, thus diminishing the intracellular doxorubicin concentration and promoting doxorubicin resistance. MiRNAs-449 overexpression downregulates the ACSL4/ABCG2 axis and sensitizes doxorubicin-resistant cells to doxorubicin. Created with BioRender. TNBC: triple-negative breast cancer; DOX: doxorubicin; SIRT1: Sirtuin 1; HDAC1: Histone deacetylase 1; ACSL4: Acyl-CoA Synthetase Long-Chain Family Member 4; ABCG2: ATP-binding cassette superfamily G member 2.

Abstract Background The variability in responses to neoadjuvant treatment with anti-HER2 antibodies prompts to personalized clinical management and the development of innovative treatment strategies. Tumor-infiltrating Natural Killer (TI-NK) cells can predict the efficacy of HER2-targeted antibodies independently from clinicopathological factors in primary HER2-positive breast cancer patients. Understanding the mechanism/s underlying this association would contribute to optimizing patient stratification and provide the rationale for combinatorial approaches with immunotherapy. Methods We sought to uncover processes enriched in NK cell-infiltrated tumors as compared to NK cell-desert tumors by microarray analysis. Findings were validated in clinical trial-derived transcriptomic data. In vitro and in vivo preclinical models were used for mechanistic studies. Findings were analysed in clinical samples (tumor and serum) from breast cancer patients. Results NK cell-infiltrated tumors were enriched in CCL5/IFNG-CXCL9/10 transcripts. In multivariate logistic regression analysis, IFNG levels underlie the association between TI-NK cells and pathological complete response to neoadjuvant treatment with trastuzumab. Mechanistically, the production of IFN-ɣ by CD16+ NK cells triggered the secretion of CXCL9/10 from cancer cells. This effect was associated to tumor growth control and the conversion of CD16 into CD16-CD103+ NK cells in humanized in vivo models. In human breast tumors, the CD16 and CD103 markers identified lineage-related NK cell subpopulations capable of producing CCL5 and IFN-ɣ, which correlated with tissue-resident CD8+ T cells. Finally, an early increase in serum CCL5/CXCL9 levels identified patients with NK cell-rich tumors showing good responses to anti-HER2 antibody-based neoadjuvant treatment. Conclusions This study identifies specialized NK cell subsets as the source of IFN-ɣ influencing the clinical efficacy of anti-HER2 antibodies. It also reveals the potential of serum CCL5/CXCL9 as biomarkers for identifying patients with NK cell-rich tumors and favorable responses to anti-HER2 antibody-based neoadjuvant treatment.

Introduction: RET inhibitors with impressive overall response rates are now available for patients with NSCLC, yet the identification of RET fusions remains a difficult challenge. Most guidelines encourage the upfront use of next-generation sequencing (NGS), or alternatively, fluorescence in situ hybridization (FISH) or reverse transcriptase-polymerase chain reaction (RT-PCR) when NGS is not possible or available. Taken together, the suboptimal performance of single-analyte assays to detect RET fusions, although consistent with the notion of encouraging universal NGS, is currently widening some of the clinical practice gaps in the implementation of predictive biomarkers in patients with advanced NSCLC. Methods: This situation prompted us to evaluate several RET assays in a large multicenter cohort of RET fusion–positive NSCLC (n = 38) to obtain real-world data. In addition to RNA-based NGS (the criterion standard method), all positive specimens underwent break-apart RET FISH with two different assays and were also tested by an RT-PCR assay. Results: The most common RET partners were KIF5B (78.9%), followed by CCDC6 (15.8%). The two RET NGS-positive but FISH-negative samples contained a KIF5B(15)-RET(12) fusion. The three RET fusions not identified with RT-PCR were AKAP13(35)-RET(12), KIF5B(24)-RET(9) and KIF5B(24)-RET(11). All three false-negative RT-PCR cases were FISH-positive, exhibited a typical break-apart pattern, and contained a very high number of positive tumor cells with both FISH assays. Signet ring cells, psammoma bodies, and pleomorphic features were frequently observed (in 34.2%, 39.5%, and 39.5% of tumors, respectively). Conclusions: In-depth knowledge of the advantages and disadvantages of the different RET testing methodologies could help clinical and molecular tumor boards implement and maintain sensible algorithms for the rapid and effective detection of RET fusions in patients with NSCLC. The likelihood of RET false-negative results with both FISH and RT-PCR reinforces the need for upfront NGS in patients with NSCLC.

Abstract Objective This study aimed to describe the performance of a next‐generation sequencing (NGS) panel for the detection of precise genomic alterations in cancer in Spanish clinical practice. The impact of tumor characteristics was evaluated on informative NGS and actionable mutation rates. Materials and Methods A cross‐sectional study was conducted at the Fundación Jiménez Díaz University Hospital (May 2021–March 2022) where molecular diagnostic of 537 Formalin‐Fixed Paraffin‐Embedded (FFPE) tissue samples of diverse solid tumors (lung, colorectal, melanoma, gastrointestinal stromal, among others) was performed using AVENIO Tumor Tissue Targeted Kit. A descriptive analysis of the features of all samples was carried out. Multivariable logistic analysis was conducted to assess the impact of sample characteristics on NGS performance defined by informative results rate (for all tumors and for lung tumors), and on actionable mutations rate (for lung tumors only). Results AVENIO performance rate was 75.2% in all tumor samples and 75.3% in lung cancer samples, and the multivariable analysis showed that surgical specimens are most likely to provide informative results than diagnostic biopsies. Regarding the mutational findings, 727 pathogenic, likely pathogenic, or variant of unknown significance mutations were found in all tumor samples. Single nucleotide variant was the most common genomic alteration, both for all tumor samples (85.3% and 81.9% for all solid tumors and lung samples, respectively). In lung tumors, multivariable analysis showed that it is more likely to find actionable mutations from non‐smokers and patients with adenocarcinoma, large cell, or undifferentiated histologies. Conclusion This is the largest cohort‐level study in Spain to profile the analyses of biopsy samples of different tumors using NGS in routine clinical practice. Our findings showed that the use of NGS routinely provides good rates of informative results and can improve tumor characterization and identify a greater number of actionable mutations.

The combination of trastuzumab and pertuzumab as first-line therapy in patients with HER2-positive breast cancer has shown significant clinical benefits compared to trastuzumab alone. However, despite initial therapeutic success, most patients eventually progress, and tumors develop acquired resistance and invariably relapse. Therefore, there is an urgent need to improve our understanding of the mechanisms governing resistance in order to develop targeted therapeutic strategies with improved efficacy. We generated four novel HER2-positive cell lines via prolonged exposure to trastuzumab and pertuzumab and determined their resistance rates. Long-term resistance was confirmed by a significant increase in the colony-forming capacity of the derived cells. We authenticated the molecular identity of the new lines via both immunohistochemistry for the clinical phenotype and molecular profiling of point mutations. HER2 overexpression was confirmed in all resistant cell lines, and acquisition of resistance to trastuzumab and pertuzumab did not translate into differences in ER, PR, and HER2 receptor expression. In contrast, changes in the expression and activity of other HER family members, particularly HER4, were observed. In the same vein, analyses of the receptor and effector kinase status of different cellular pathways revealed that the MAPK pathway may be involved in the acquisition of resistance to trastuzumab and pertuzumab. Finally, proteomic analysis confirmed a significant change in the abundance patterns of more than 600 proteins with implications in key biological processes, such as ribosome formation, mitochondrial activity, and metabolism, which could be relevant mechanisms in the generation of resistance in HER2-positive breast cancer. We concluded that these resistant BCCLs may be a valuable tool to better understand the mechanisms of acquisition of resistance to trastuzumab and pertuzumab-based anti-HER2 therapy.

Abstract Background Detection of the ROS1 rearrangement is mandatory in patients with advanced or metastatic non-small cell lung cancer (NSCLC) to allow targeted therapy with specific inhibitors. However, in Spanish clinical practice ROS1 determination is not yet fully widespread. The aim of this study is to determine the clinical and economic impact of sequentially testing ROS1 in addition to EGFR and ALK in Spain. Methods A joint model (decision-tree and Markov model) was developed to determine the cost-effectiveness of testing ROS1 strategy versus a no-ROS1 testing strategy in Spain. Distribution of ROS1 techniques, rates of testing, positivity, and invalidity of biomarkers included in the analysis (EGFR, ALK, ROS1 and PD-L1) were based on expert opinion and Lungpath real-world database. Treatment allocation depending on the molecular testing results was defined by expert opinion. For each treatment, a 3-states Markov model was developed, where progression-free survival (PFS) and overall survival (OS) curves were parameterized using exponential extrapolations to model transition of patients among health states. Only medical direct costs were included (€ 2021). A lifetime horizon was considered and a discount rate of 3% was applied for both costs and effects. Both deterministic and probabilistic sensitivity analyses were performed to address uncertainty. Results A target population of 8755 patients with advanced NSCLC (non-squamous or never smokers squamous) entered the model. Over a lifetime horizon, the ROS1 testing scenario produced additional 157.5 life years and 121.3 quality-adjusted life years (QALYs) compared with no-ROS1 testing scenario. Total direct costs were increased up to € 2,244,737 for ROS1 testing scenario. The incremental cost-utility ratio (ICUR) was 18,514 €/QALY. Robustness of the base-case results were confirmed by the sensitivity analysis. Conclusions Our study shows that ROS1 testing in addition to EGFR and ALK is a cost-effective strategy compared to no-ROS1 testing, and it generates more than 120 QALYs in Spain over a lifetime horizon. Despite the low prevalence of ROS1 rearrangements in NSCLC patients, the clinical and economic consequences of ROS1 testing should encourage centers to test all advanced or metastatic NSCLC (non-squamous and never-smoker squamous) patients.

Introduction: In recent years, target therapies to specific molecular alterations in advanced non–small cell lung cancer (NSCLC) have been identified and have shown superior efficacy compared to non-targeted treatments. Anaplastic lymphoma kinase (ALK) is one of the therapeutic targets; nevertheless, ALK diagnosis is not performed in all NSCLC patients in Spain. The objective of this study is to estimate in monetary terms the benefit for the Spanish society of ALK diagnosis in advanced NSCLC patients. Methods: A cost-benefit analysis of ALK diagnosis vs. non-diagnosis in advanced NSCLC patients was carried out from the Spanish social perspective, with a time horizon of 5 years. Costs, benefits and the cost-benefit ratio weremeasured. The analysis has considered the overall survival in advanced NSCLC patients treated with the ALKtyrosine kinase inhibitor (TKI) alectinib. The natural history of NSCLC was simulated using a Markov model. A 3% discount rate was applied to both costs and benefits. The result was tested using a deterministic sensitivity analysis. Results: The cost of ALK diagnosis vs. non-diagnosis in the base case would be €10.19 million, generating benefits of €11.71 million. The cost-benefit ratio would be €1.15. In the sensitivity analysis, the cost-benefit ratio could range from €0.89 to €2.10. Conclusions: The results justify the universal application of ALK diagnosis in advanced NSCLC, which generates a benefit for Spanish society that outweighs its costs and allows optimal treatment with targeted therapies for these patients.

Abstract Analysis of the genomic landscape of prostate cancer has identified different molecular subgroups with relevance for novel or existing targeted therapies. The recent approvals of the poly(ADP‐ribose) polymerase (PARP) inhibitors olaparib and rucaparib in the metastatic castration‐resistant prostate cancer (mCRPC) setting signal the need to embed molecular diagnostics in the clinical pathway of patients with mCRPC to identify those who can benefit from targeted therapies. Best practice guidelines in overall biospecimen collection and processing for molecular analysis are widely available for several tumour types. However, there is no standard protocol for molecular diagnostic testing in prostate cancer. Here, we provide a series of recommendations on specimen handling, sample pre‐analytics, laboratory workflow, and testing pathways to maximise the success rates for clinical genomic analysis in prostate cancer. Early involvement of a multidisciplinary team of pathologists, urologists, oncologists, radiologists, nurses, molecular scientists, and laboratory staff is key to enable optimal workflow for specimen selection and preservation at the time of diagnosis so that samples are available for molecular analysis when required. Given the improved outcome of patients with mCRPC and homologous recombination repair gene alterations who have been treated with PARP inhibitors, there is an urgent need to incorporate high‐quality genomic testing in the routine clinical pathway of these patients.

Abstract Identification of the different elements intervening at the tumor microenvironment seems key to explain clinical evolution in several tumor types. In this study, a set of immune biomarkers (myeloid derived suppressor cells, regulatory T cells, and OX40 + and PD-1 + T lymphocytes counts) in peripheral blood of patients diagnosed with advanced breast cancer were analyzed along of first line antineoplastic therapy. Subsequently, a comparison between groups with clinical benefit versus progression of disease and with a healthy women cohort was executed. Results reflected that patients showed higher basal levels of myeloid derived suppressor cells (35.43, IR = 180.73 vs 17.53, IR = 16.96 cells/μl; p = 0.001) and regulatory T cells (32.05, IR = 29.84 vs 22.61, IR = 13.57 cells/μl; p = 0.001) in comparison with healthy women. Furthermore, an increase in the number of activated T lymphocytes (expressing OX40), a decrease of immune inhibitory cells (MDSCs and Tregs) and inhibited T lymphocytes (expressing PD-1) were observed along the treatment in patients with clinical benefit (p ≤ 0.001). The opposite trend was observed in the case of disease progression. These findings suggest that some critical immune elements can be easily detected and measured in peripheral blood, which open a new opportunity for translational research, as they seem to be correlated with clinical evolution, at least in ABC.

Abstract Background Currently biomarkers play an essential role in diagnosis, treatment, and management of cancer. In non-small cell lung cancer (NSCLC) determination of biomarkers such as ALK, EGFR, ROS1 or PD-L1 is mandatory for an adequate treatment decision. The aim of this study is to determine the clinical and economic impact of current anaplastic lymphoma kinase testing scenario in Spain. Methods A joint model, composed by decision-tree and Markov models, was developed to estimate the long-term health outcomes and costs of NSCLC patients, by comparing the current testing scenario for ALK in Spain vs a hypothetical no-testing. The current distribution of testing strategies for ALK determination and their sensitivity and specificity data were obtained from the literature. Treatment allocation based on the molecular testing result were defined by a panel of Spanish experts. To assess long-term effects of each treatment, 3-states Markov models were developed, where progression-free survival and overall survival curves were extrapolated using exponential models. Medical direct costs (expressed in €, 2019) were included. A lifetime horizon was used and a discount rate of 3% was applied for both costs and health effects. Several sensitivity analyses, both deterministic and probabilistic, were performed in order test the robustness of the analysis. Results We estimated a target population of 7628 NSCLC patients, including those with non-squamous histology and those with squamous carcinomas who were never smokers. Over the lifetime horizon, the current ALK testing scenario produced additional 5060 and 3906 life-years and quality-adjusted life-years (QALY), respectively, compared with the no-testing scenario. Total direct costs were increased up to € 51,319,053 for testing scenario. The incremental cost-effectiveness ratio was 10,142 €/QALY. The sensitivity analyses carried out confirmed the robustness of the base-case results, being the treatment allocation and the test accuracy (sensitivity and specificity data) the key drivers of the model. Conclusions ALK testing in advanced NSCLC patients, non-squamous and never-smoker squamous, provides more than 3000 QALYs in Spain over a lifetime horizon. Comparing this gain in health outcomes with the incremental costs, the resulting incremental cost-effectiveness ratio reinforces that testing non-squamous and never-smoker squamous NSCLC is a cost-effective strategy in Spain.

MicroRNA (miR)-19b is deregulated in colorectal cancer (CRC) and locally advanced rectal cancer (LARC), predicting worse outcome and disease progression in CRC patients, and acting as a promising prognostic marker of patient recurrence and pathological response to 5-fluorouracil (5-FU)-based neoadjuvant chemoradiotherapy in LARC. Moreover, there is a strong inverse correlation between miR-19b and PPP2R5E in LARC, and both predict the response to neoadjuvant therapy in LARC patients. However, the functional role of the miR-19b/PPP2R5E axis in CRC cells remains to be experimentally evaluated. Here, we confirm with luciferase assays that miR-19b is a direct negative regulator of PPP2R5E in CRC, which is concordant with the observed decreased PP2A activity levels after miR-19b overexpression. Furthermore, PPP2R5E downregulation plays a key role mediating miR-19b-induced oncogenic effects, increasing cell viability, colonosphere formation ability, and the migration of CRC cells. Lastly, we also confirm the role of miR-19b mediating 5-FU sensitivity of CRC cells through negative PPP2R5E regulation. Altogether, our findings demonstrate the functional relevance of the miR-19b/PPP2R5E signaling pathway in disease progression, and its potential therapeutic value determining the 5-FU response of CRC cells.

Trastuzumab treatment has significantly improved the prognosis of HER2-positive breast cancer patients. Despite this, resistance to therapy still remains the main clinical challenge. In order to evaluate the implication of microRNAs in the trastuzumab response, we performed a microRNA array in parental and acquired trastuzumab-resistant HER2-positive breast cancer cell lines. Our results identified miR-146a-5p as the main dysregulated microRNA. Interestingly, high miR-146a-5p expression in primary tumor tissue significantly correlated with shorter disease-free survival in HER2-positive breast cancer patients. The gain- and loss-of-function of miR-146a-5p modulated the response to trastuzumab. Furthermore, the overexpression of miR-146a-5p increased migration and angiogenesis, and promoted cell cycle progression by reducing CDKN1A expression. Exosomes from trastuzumab-resistant cells showed a high level of miR-146a-5p expression compared with the parental cells. In addition, the co-culture with resistant cells’ exosomes was able to decrease in sensitivity and increase the migration capacities in trastuzumab-sensitive cells, as well as angiogenesis in HUVEC-2 cells. Collectively, these data support the role of miR-146a-5p in resistance to trastuzumab, and demonstrate that it can be transferred by exosomes conferring resistance properties to other cells.

Due to the lack of specific targets, cytotoxic chemotherapy still represents the common standard treatment for triple-negative breast patients. Despite the harmful effect of chemotherapy on tumor cells, there is evidence that treatment could modulate the tumor microenvironment in a way favoring the propagation of the tumor. In addition, the lymphangiogenesis process and its factors could be involved in this counter-therapeutic event. In our study, we have evaluated the expression of the main lymphangiogenic receptor VEGFR3 in two triple-negative breast cancer in vitro models, resistant or not to doxorubicin treatment. The expression of the receptor, at mRNA and protein levels, was higher in doxorubicin-resistant cells than in parental cells. In addition, we confirmed the upregulation of VEGFR3 levels after a short treatment with doxorubicin. Furthermore, VEGFR3 silencing reduced cell proliferation and migration capacities in both cell lines. Interestingly, high VEGFR3 expression was significantly positively correlated with worse survival in patients treated with chemotherapy. Furthermore, we have found that patients with high expression of VEGFR3 present shorter relapse-free survival than patients with low levels of the receptor. In conclusion, elevated VEGFR3 levels correlate with poor survival in patients and with reduced doxorubicin treatment efficacy in vitro. Our results suggest that the levels of this receptor could be a potential marker of meager doxorubicin response. Consequently, our results suggest that the combination of chemotherapy and VEGFR3 blockage could be a potentially useful therapeutic strategy for the treatment of triple-negative breast cancer.

Human epidermal growth factor receptor 2–positive (HER2-positive) breast cancer accounts for 15 to 25% of breast cancer cases. Although therapies based on the use of monoclonal anti-HER2 antibodies present clinical benefit for a subtype of patients with HER2-positive breast cancer, more than 50% of them are unresponsive to targeted therapies or they eventually relapse. In recent years, reactivation of the adaptive immune system in patients with solid tumors has emerged as a therapeutic option with great potential for clinical benefit. Since the approval of the first treatment directed against HER2 as a therapeutic target, the range of clinical options has expanded greatly, and, in this sense, cellular immunotherapy with T cells relies on the cytotoxicity generated by these cells, which ultimately leads to antitumor activity. Lymphocytic infiltration of tumors encompasses a heterogeneous population of immune cells within the tumor microenvironment that exhibits distinct patterns of immune activation and exhaustion. The prevalence and prognostic value of tumor-infiltrating lymphocyte (TIL) counts are associated with a favorable prognosis in HER2-positive breast cancers. This review discusses emerging findings that contribute to a better understanding of the role of immune infiltrates in HER2-positive breast cancer. In addition, it summarizes the most recent results in HER2-positive breast cancer immunotherapy and anticipates which therapeutic strategies could be applied in the immediate future.

Treatment for the HER2+ breast cancer subtype is still unsatisfactory, despite breakthroughs in research. The discovery of various new molecular mechanisms of transcription factors may help to make treatment regimens more effective. The transcription factor SALL4 has been related to aggressiveness and resistance therapy in cancer. Its molecular mechanisms and involvement in various signaling pathways are unknown in the HER2+ breast cancer subtype. In this study, we have evaluated the implication of SALL4 in the HER2+ subtype through its expression in patients’ samples and gain and loss of function in HER2+ cell lines. We found higher SALL4 expression in breast cancer tissues compared to healthy tissue. Interestingly, high SALL4 expression was associated with disease relapse and poor patient survival. In HER2+ cell lines, transient overexpression of SALL4 modulates PI3K/AKT signaling through regulating PTEN expression and BCL2, which increases cell survival and proliferation while reducing the efficacy of trastuzumab. SALL4 has also been observed to regulate the epithelial–mesenchymal transition and stemness features. SALL4 overexpression significantly reduced the epithelial markers E-cadherin, while it increased the mesenchymal markers β-catenin, vimentin and fibronectin. Furthermore, it has been also observed an increased expression of MYC, an essential transcription factor for regulating epithelial-mesenchymal transition and/or cancer stem cells. Our study demonstrates, for the first time, the importance of SALL4 in the HER2+ subtype and partial regulation of trastuzumab sensitivity. It provides a viable molecular mechanism-driven therapeutic strategy for an important subset of HER2-overexpressing patients whose malignancies are mediated by SALL4 expression.

The standard clinical management of locally advanced rectal cancer (LARC) patients includes neoadjuvant 5-fluorouracil (5-FU)-based chemoradiotherapy (CRT) followed by mesorectal excision. MicroRNA (miR)-19b expression levels in LARC biopsies obtained from initial colonoscopy have recently been identified as independent predictors of both patient outcome and pathological response to preoperative CRT in this disease. Moreover, it has been discovered that this miR increases its expression in 5-FU resistant colon cancer cells after 5-FU exposure. Despite the fact that these observations suggest a functional role of miR-19b modulating 5-FU response of LARC cells, this issue still remains to be clarified. Here, we show that downregulation of miR-19b enhances the antitumor effects of 5-FU treatment. Moreover, ectopic miR-19b modulation was able to restore sensitivity to 5-FU treatment using an acquired resistant model to this compound. Notably, we also evaluated the potential clinical impact of miR-19b as a predictive marker of disease progression after tumor surgery resection in LARC patients, observing that miR-19b overexpression significantly anticipates patient recurrence in our cohort (p = 0.002). Altogether, our findings demonstrate the functional role of miR-19b in the progressively decreasing sensitivity to 5-FU treatment and its potential usefulness as a therapeutic target to overcome 5-FU resistance, as well as its clinical impact as predictor of tumor progression and relapse.

Gynecological cancer accounts for an elevated incidence worldwide requiring responsiveness regarding its care. The comprehensive genomic approach agrees with the classification of certain tumor types. We evaluated 49 patients with gynecological tumors undergoing high-throughput sequencing to explore whether identifying alterations in cancer-associated genes could characterize concrete histological subtypes. We performed immune examination and analyzed subsequent clinical impact. We found 220 genomic aberrations mostly distributed as single nucleotide variants (SNV, 77%). Only 3% were classified as variants of strong clinical significance in BRCA1 and BRCA2 of ovarian high-grade serous (HGSC) and uterine endometrioid carcinoma. TP53 and BRCA1 occurred in 72% and 28% of HGSC. Cervical squamous cell carcinoma was entirely HPV-associated and mutations occurred in PIK3CA (60%), as well as in uterine serous carcinoma (80%). Alterations were seen in PTEN (71%) and PIK3CA (60%) of uterine endometrioid carcinoma. Elevated programmed death-ligand 1 (PD-L1) was associated with high TILs. Either PD-L1 augmented in deficient mis-matched repair (MMR) proteins or POLE mutated cases when compared to a proficient MMR state. An 18% received genotype-guided therapy and a 4% immunotherapy. The description of tumor subtypes is plausible through high-throughput sequencing by recognizing clinically relevant alterations. Additional concomitant assessment of immune biomarkers identifies candidates for immunotherapy.

Type 2 diabetes mellitus (T2DM) has been associated with an increased risk of cancer, including colon cancer (CC). However, we recently reported no influence of T2DM on CC prognosis, suggesting that any effect might be at the early stages of tumor development. We hypothesized that T2DM may create an environment in the healthy tissue, which acts as a carcinogenesis driver in agreement with the field of cancerization concept. Here, we focused on early carcinogenesis by analyzing paired tumor and normal colonic mucosa samples from the same patients. The proteome of CC and paired mucosa was quantitatively analyzed in 28 individuals (12 diabetics and 16 nondiabetics) by mass spectrometry with isobaric labeling. Out of 3076 identified proteins, 425 were differentially expressed at the tumor in diabetics compared with nondiabetics. In the adjacent mucosa, 143 proteins were differentially expressed in diabetics and nondiabetics. An enrichment analysis of this signature pointed to mitochondria, ribosome, and translation. Only six proteins were upregulated by diabetes both in tumor and mucosa, of which five were mitochondrial proteins. Differential expression in diabetic versus nondiabetic mucosa was confirmed for MRPL53, MRPL18, and TIMM8B. Higher levels of MRPL18, TIMM8B, and EIF1A were also found in normal colon epithelial cells exposed to high‐glucose conditions. We conclude that T2DM is associated with specific molecular changes in the normal mucosa of CC patients, consistent with field of cancerization in a diabetic environment. The mitochondrial protein signature identifies a potential therapeutic target that could underlie the higher risk of CC in diabetics.

The potential involvement of type 2 diabetes mellitus (T2DM) as a risk factor for colon cancer (CC) has been previously reported. While several clinical studies show a higher incidence of CC and a lower survival rate in diabetics, others report no association. Our own experience indicates that diabetes does not seem to worsen the prognosis once the tumor is present. Despite this controversy, there are no wide‐spectrum molecular studies that delve into the impact of T2DM‐related mechanisms in colon carcinogenesis. Here, we present a transcriptomic and proteomic profiling of paired tumor and normal colon mucosa samples in a cohort of 42 CC patients, 23 of which have T2DM. We used gene set enrichment and network approaches to extract relevant pathways in diabetics, referenced them to current knowledge, and tested them using in vitro techniques. Through our transcriptomics approach, we identified an unexpected overlap of pathways overrepresented in diabetics compared to nondiabetics, in both tumor and normal mucosa, including diabetes‐related metabolic and signaling processes. Proteomic approaches highlighted several cancer‐related signaling routes in diabetics found only in normal mucosa, not in tumors. An integration of the transcriptome and proteome analyses suggested the deregulation of key pathways related to colon carcinogenesis which converged on tumor initiation axis TEAD/YAP‐TAZ as a potential initiator of the process. In vitro studies confirmed upregulation of this pathway in nontumor colon cells under high‐glucose conditions. In conclusion, T2DM associates with deregulation of cancer‐related processes in normal colon mucosa adjacent to tissue which has undergone a malignant transformation. These data support that in diabetic patients, the local microenvironment in normal colon mucosa may be a factor driving field cancerization promoting carcinogenesis. Our results set a new framework to study links between diabetes and colon cancer, including a new role of the TEAD/YAP‐TAZ complex as a potential driver.

Together with its reported ability to modulate AKT phosphorylation (p-AKT) status in several tumor types, the oncoprotein CIP2A has been described to induce breast cancer progression and drug resistance. However, the clinical and therapeutic relevance of the CIP2A/AKT interplay in breast cancer remains to be fully clarified. Here, we found high p-AKT levels in 80 out of 220 cases (36.4%), which were associated with negative estrogen receptor expression (p = 0.049) and CIP2A overexpression (p < 0.001). Interestingly, p-AKT determined substantially shorter overall (p = 0.002) and progression-free survival (p = 0.003), and multivariate analyses showed its CIP2A-independent prognostic value. Moreover, its clinical relevance was further confirmed in the triple negative and HER2-positive subgroups after stratifying our series by molecular subtype. Functionally, we confirmed in vitro the role of CIP2A as a regulator of p-AKT levels in breast cancer cell lines, and the importance of the CIP2A/AKT axis was also validated in vivo. Finally, p-AKT also showed a higher predictive value of response to doxorubicin than CIP2A in ex vivo analyses. In conclusion, our findings suggest that CIP2A overexpression is a key contributing event to AKT phosphorylation and highlights the CIP2A/AKT axis as a promising therapeutic target in breast cancer. However, our observations highlight the existence of alternative mechanisms that regulate AKT signaling in a subgroup of breast tumors without altered CIP2A expression that determines its independent value as a marker of poor outcome in this disease.

The identification of robust prognostic markers still represents a need in locally advanced rectal cancer (LARC). MicroRNAs (miRs) have progressively emerged as promising circulating markers, overcoming some limitations that traditional biopsy comprises. Tissue miR-199b deregulation has been reported to predict outcome and response to neoadjuvant chemoradiotherapy (nCRT) in LARC, and was also found to be associated with disease progression in colorectal cancer. However, its biological and clinical relevance remains to be fully clarified. Thus, we observed here that miR-199b regulates cell migration, aggressiveness, and cell growth, and inhibits colonosphere formation and induces caspase-dependent apoptosis. Moreover, miR-199b expression was quantified by real-time PCR in plasma samples from LARC patients and its downregulation was observed in 22.7% of cases. This alteration was found to be associated with higher tumor size (p = 0.002) and pathological stage (p = 0.020) after nCRT. Notably, we observed substantially lower global miR-199b expression associated with patient downstaging (p = 0.009), as well as in non-responders compared to those cases who responded to nCRT in both pre- (p = 0.003) and post-treatment samples (p = 0.038). In concordance, we found that miR-199b served as a predictor marker of response to neoadjuvant therapy in our cohort (p = 0.011). Altogether, our findings here demonstrate the functional relevance of miR-199b in this disease and its potential value as a novel circulating marker in LARC.

Background Next-generation sequencing (NGS) is a high-throughput technology that has become widely integrated in molecular diagnostics laboratories. Among the large diversity of NGS-based panels, the Trusight Tumor 26 (TsT26) enables the detection of low-frequency variants across 26 genes using the MiSeq platform. Methods We describe the inter-laboratory validation and subsequent clinical application of the panel in 399 patients presenting a range of tumor types, including gastrointestinal (GI, 29%), hematologic (18%), lung (13%), gynecological and breast (8% each), among others. Results The panel is highly accurate with a test sensitivity of 92%, and demonstrated high specificity and positive predictive values (95% and 96%, respectively). Sequencing testing was successful in two-thirds of patients, while the remaining third failed due to unsuccessful quality-control filtering. Most detected variants were observed in the TP53 (28%), KRAS (16%), APC (10%) and PIK3CA (8%) genes. Overall, 372 variants were identified, primarily distributed as missense (81%), stop gain (9%) and frameshift (7%) altered sequences and mostly reported as pathogenic (78%) and variants of uncertain significance (19%). Only 14% of patients received targeted treatment based on the variant determined by the panel. The variants most frequently observed in GI and lung tumors were: KRAS c.35G > A (p.G12D), c.35G > T (p.G12V) and c.34G > T (p.G12C). Conclusions Prior panel validation allowed its use in the laboratory daily practice by providing several relevant and potentially targetable variants across multiple tumors. However, this study is limited by high sample inadequacy rate, raising doubts as to continuity in the clinical setting.

Downregulation of miR-33b has been documented in many types of cancers and is being involved in proliferation, migration, and epithelial–mesenchymal transition (EMT). Furthermore, the enhancer of zeste homolog 2-gene (EZH2) is a master regulator of controlling the stem cell differentiation and the cell proliferation processes. We aim to evaluate the implication of miR-33b in the EMT pathway in HER2+ breast cancer (BC) and to analyze the role of EZH2 in this process as well as the interaction between them. miR-33b is downregulated in HER2+ BC cells vs healthy controls, where EZH2 has an opposite expression in vitro and in patients’ samples. The upregulation of miR-33b suppressed proliferation, induced apoptosis, reduced invasion, migration and regulated EMT by an increase of E-cadherin and a decrease of ß-catenin and vimentin. The silencing of EZH2 mimicked the impact of miR-33b overexpression. Furthermore, the inhibition of miR-33b induces cell proliferation, invasion, migration, EMT, and EZH2 expression in non-tumorigenic cells. Importantly, the Kaplan–Meier analysis showed a significant association between high miR-33b expression and better overall survival. These results suggest miR-33b as a suppressive miRNA that could inhibit tumor metastasis and invasion in HER2+ BC partly by impeding EMT through the repression of the MYC–EZH2 loop.

Cutaneous squamous cell carcinoma (cSCC) is the second most common form of skin cancer, the incidence of which has risen over the last years. Although cSCC rarely metastasizes, early detection and treatment of primary tumours are critical to limit progression and local invasion. Several prognostic factors related to patients’ clinicopathologic profile and tumour features have been identified as high-risk markers and included in the stratification scales, but their association with regional control or survival is uncertain. Therefore, decision-making on the diagnosis and management of cSCC should be made based on each individual patient’s characteristics. Recent advances in non-invasive imaging techniques and molecular testing have enhanced clinical diagnostic accuracy. Surgical excision is the mainstay of local treatment, whereas radiotherapy (RT) is recommended for patients with inoperable disease or in specific circumstances. Novel systemic treatments including immunotherapies and targeted therapies have changed the therapeutic landscape for cSCC. The anti-PD-1 agent cemiplimab is currently the only FDA/EMA-approved first-line therapy for patients with locally advanced or metastatic cSCC who are not candidates for curative surgery or RT. Given the likelihood of recurrence and the increased risk of developing multiple cSCC, close follow-up should be performed during the first years of treatment and continued long-term surveillance is warranted.

A partir de casos confirmados de leucoencefalomalacia equina en el municipio de Juchitlán (estado de Jalisco), esta investigación tuvo como objetivo determinar la presencia y niveles de fumonisinas en el alimento. El área de estudio incluyó a los principales municipios en donde se concentra la población equina de Jalisco, teniendo en común el uso de prácticas similares en el manejo de la alimentación y conservación del alimento. Las determinaciones analíticas se realizaron mediante inmunoensayo de tipo competitivo y cromatografía de líquidos de alta resolución. Se detectó contaminación con fumonisinas en el 100 % de muestras analizadas de todos los municipios, los niveles fueron de 0.23 a 19.18 mg/kg. Se observó diferencia entre municipios (P

Stromal cell recruitment, activation and crosstalk with cancer cells is poorly understood. Here, the authors demonstrate that cancer cell-derived Hedgehog ligand triggers stromal remodeling that in turn induces a cancer-stem-cell like, drug-resistant phenotype of nearby cancer cells while treatment with smoothened inhibitors reverses these phenotypes.

INTRODUCTION: The coexpression of pIGF-1R and MMP-7 (double-positive phenotype, DP) correlates with poor overall survival (OS) in KRAS wild-type (WT) (exon 2) metastatic colorectal cancer (mCRC) patients treated with irinotecan-cetuximab in second/third line. METHODS: We analyzed two prospective biomarker design trials of newly diagnosed RAS-WT mCRC patients treated with panitumumab-FOLFOX6 (PULSE trial; NCT01288339) or cetuximab plus either FOLFOX6/FOLFIRI (POSIBA trial; NCT01276379). The main exposure was DP phenotype (DP/non-DP), as assessed by two independent pathologists. DP cases were defined by immunohistochemistry as >70% expression of moderate or strong intensity for both MMP-7 and pIGF-1R. Primary endpoint: progression-free survival (PFS); secondary endpoints: OS and response rate. PFS and OS were adjusted by baseline characteristics using multivariate Cox models. RESULTS: We analyzed 67 patients (30 non-DP, 37 DP) in the PULSE trial and 181 patients in the POSIBA trial (158 non-DP, 23 DP). Response rates and PFS were similar between groups in both studies. DP was associated with prolonged OS in PULSE (adjusted HR: 0.23; 95%CI: 0.11-0.52; P=.0004) and with shorter OS in POSIBA (adjusted HR: 1.67; 95%CI: 0.96-2.90; P=.07). CONCLUSION: A differential effect of anti-EGFRs on survival by DP phenotype was observed. Panitumumab might be more beneficial for RAS-WT mCRC patients with DP phenotype, whereas cetuximab might improve OS in non-DP.

The combination of trastuzumab plus pertuzumab plus docetaxel as a first-line therapy in patients with HER2-positive metastatic breast cancer has provided significant clinical benefits compared to trastuzumab plus docetaxel alone. However, despite the therapeutic success of existing therapies targeting HER2, tumours invariably relapse. Therefore, there is an urgent need to improve our understanding of the mechanisms governing resistance, so that specific therapeutic strategies can be developed to provide improved efficacy. It is well known that the tumour microenvironment (TME) has a significant impact on cancer behaviour. Cancer-associated fibroblasts (CAFs) are essential components of the tumour stroma that have been linked to acquired therapeutic resistance and poor prognosis in breast cancer. For this reason, it would be of interest to identify novel biomarkers in the tumour stroma that could emerge as therapeutic targets for the modulation of resistant phenotypes. Conditioned medium experiments carried out in our laboratory with CAFs derived from HER2-positive patients showed a significant capacity to promote resistance to trastuzumab plus pertuzumab therapies in two HER2-positive breast cancer cell lines (BCCLs), even in the presence of docetaxel. In order to elucidate the components of the CAF-conditioned medium that may be relevant in the promotion of BCCL resistance, we implemented a multiomics strategy to identify cytokines, transcription factors, kinases and miRNAs in the secretome that have specific targets in cancer cells. The combination of cytokine arrays, label-free LC-MS/MS quantification and miRNA analysis to explore the secretome of CAFs under treatment conditions revealed several up- and downregulated candidates. We discuss the potential role of some of the most interesting candidates in generating resistance in HER2-positive breast cancer.

The absence of established predictive markers with value to anticipate response to neoadjuvant 5-fluorouracil (5-FU)-based chemoradiotherapy (CRT) represents a current major challenge in locally advanced rectal cancer (LARC). The tumor suppressor microRNA (miR)-199b has been reported to play a key role determining 5-FU sensitivity of colorectal cancer cells through the regulation of several signaling pathways, and has emerged as a novel molecular target to overcome the 5-FU resistant phenotype. Moreover, miR-199b downregulation was described as a common alteration that predicts lack of response to preoperative CRT in LARC but this issue needs to be confirmed in independent larger cohorts. Here, we evaluate the clinical impact of miR-199b in LARC and perform additional analyses to further clarify its potential relevance as novel marker in this disease. Thus, miR-199b expression was quantified by real-time-PCR in a cohort of 185 LARC patients, observing this miR downregulated in 22.2% of cases and significantly associated with higher tumor size (p = 0.026) and positive lymph node after CRT (p = 0.005), and higher pathological stage (p = 0.004). Notably, this alteration showed a strong independent predictive value of poor pathological response to neoadjuvant CRT (p = 0.004). Moreover, the subgroup of cases with low miR-199b levels had a markedly shorter overall (p < 001) and event-free survival (p < 0.001), and multivariate analyses showed that miR-199b deregulation represents an independent prognosticator for patient outcome in LARC. Interestingly, the prognostic impact of this miR was strongly significant in both younger and elderly patients, and was very effective determining patient recurrence (p = 0.004). Finally, we compared miR-199b expression profiles in a set of cases with pre and post-treatment samples available, observing that only a minimal response leads to miR-199b increase levels, further suggesting its potential clinical and therapeutic relevance as a promising marker and novel molecular target for the management of LARC.

The PANGEA-Breast trial evaluated a new chemo-immunotherapeutic combination that would synergistically induce long-term clinical benefit in HER2-negative advanced breast cancer patients. Treatment consisted of 21-day cycles of 200 mg of pembrolizumab (day 1) plus gemcitabine (days 1 and 8). The primary objective was the objective response rate (ORR). The tumor infiltrating lymphocytes (TILs) density and PD-L1 expression in tumor, and the myeloid-derived suppressor cells (MDSCs) level in peripheral blood, were analyzed to explore associations with treatment efficacy. Considering a two-stage Simon’s design, the study recruitment was stopped after its first stage as statistical assumptions were not met. A subset of 21 triple-negative breast cancer (TNBC) patients was enrolled. Their median age was 49 years; 15 patients had visceral involvement, and 16 had ≤3 metastatic locations. Treatment discontinuation due to progressive disease (PD) was reported in 16 patients. ORR was 15% (95% CI 3.2–37.9). Four patients were on treatment >6 months before PD. Grade ≥3 treatment-related adverse events were observed in 8 patients, where neutropenia was the most common. No association was found between TILs density, PD-L1 expression or MDSCs levels and treatment efficacy. ORR in TNBC patients also did not meet the assumptions, but 20% were on treatment >6 months.

Solitary fibrous tumor is a rare subtype of soft-tissue sarcoma with a wide spectrum of histopathological features and clinical behaviors, ranging from mildly to highly aggressive tumors. The defining genetic driver alteration is the gene fusion NAB2–STAT6, resulting from a paracentric inversion within chromosome 12q, and involving several different exons in each gene. STAT6 (signal transducer and activator of transcription 6) nuclear immunostaining and/or the identification of NAB2–STAT6 gene fusion is required for the diagnostic confirmation of solitary fibrous tumor. In the present study, a new gene fusion consisting of Nuclear Factor I X (NFIX), mapping to 19p13.2 and STAT6, mapping to 12q13.3 was identified by targeted RNA-Seq in a 74-year-old female patient diagnosed with a deep-seated solitary fibrous tumor in the pelvis. Histopathologically, the neoplasm did not display nuclear pleomorphism or tumor necrosis and had a low proliferative index. A total of 378 unique reads spanning the NFIXexon8–STAT6exon2 breakpoint with 55 different start sites were detected in the bioinformatic analysis, which represented 59.5% of the reads intersecting the genomic location on either side of the breakpoint. Targeted RNA-Seq results were validated by RT-PCR/ Sanger sequencing. The identification of a new gene fusion partner for STAT6 in solitary fibrous tumor opens intriguing new hypotheses to refine the role of STAT6 in the sarcomatogenesis of this entity.

The use of anti-HER2 therapies has significantly improved clinical outcome in patients with HER2-positive breast cancer, yet a substantial proportion of patients acquire resistance after a period of treatment. The PI3K/AKT/mTOR pathway is a good target for drug development, due to its involvement in HER2-mediated signalling and in the emergence of resistance to anti-HER2 therapies, such as trastuzumab. This study evaluates the activity of three different PI3K/AKT/mTOR inhibitors, i.e., BEZ235, everolimus and TAK-228 in vitro, in a panel of HER2-positive breast cancer cell lines with primary and acquired resistance to trastuzumab. We assess the antiproliferative effect and PI3K/AKT/mTOR inhibitory capability of BEZ235, everolimus and TAK-228 alone, and in combination with trastuzumab. Dual blockade with trastuzumab and TAK-228 was superior in reversing the acquired resistance in all the cell lines. Subsequently, we analyse the effects of TAK-228 in combination with trastuzumab on the cell cycle and found a significant increase in G0/G1 arrest in most cell lines. Likewise, the combination of both drugs induced a significant increase in apoptosis. Collectively, these experiments support the combination of trastuzumab with PI3K/AKT/mTOR inhibitors as a potential strategy for inhibiting the proliferation of HER2-positive breast cancer cell lines that show resistance to trastuzumab.

The introduction of targeted treatments and more recently immune checkpoint inhibitors (ICI) to the treatment of metastatic non-small cell lung cancer (NSCLC) has dramatically changed the prognosis of selected patients. For patients with oncogene-addicted metastatic NSCLC harbouring an epidermal growth factor receptor (EGFR) or v-Raf murine sarcoma viral oncogene homologue B1 (BRAF) mutation or an anaplastic lymphoma kinase (ALK) or ROS proto-oncogene 1, receptor tyrosine kinase (ROS1) gene alteration (translocation, fusion, amplification) mutation-specific tyrosine kinase inhibitors (TKI) are already first-line standard treatment, while targeted treatment for other driver mutations affecting MET, RET, human epidermal growth factor receptor (HER) 2, tropomyosin receptor kinases (TRK) 1–3 and others are currently under investigation. The role of ICI in these patient subgroups is currently under debate. This article summarises a round-table discussion organised by ESMO Open in Vienna in July 2018. It reviews current clinical data on ICI treatment in patients with metastatic oncogene-addicted NSCLC and discusses molecular diagnostic assessment, potential biomarkers and radiological methods for response evaluation of ICI treatment. The round-table panel concluded ICI should only be considered in patients with oncogene-addicted NSCLC after exhaustion of effective targeted therapies and in some cases possibly after all other therapies including chemotherapies. More clinical trials on combination therapies and biomarkers for ICI therapy based on the specific differing characteristics of oncogene-addicted NSCLC need to be conducted.

The bromodomain-containing protein 4 (BRD4), a member of the bromodomain and extra-terminal domain (BET) protein family, has emerged in the last years as a promising molecular target in many tumors including breast cancer. The triple negative breast cancer (TNBC) represents the molecular subtype with the worst prognosis and a current therapeutic challenge, and TNBC cells have been reported to show a preferential sensitivity to BET inhibitors. Interestingly, BRD4 phosphorylation (pBRD4) was found as an alteration that confers resistance to BET inhibition and PP2A proposed as the phosphatase responsible to regulate pBRD4 levels. However, the potential clinical significance of pBRD4, as well as its potential correlation with the PP2A pathway in TNBC, remains to be investigated. Here, we evaluated the expression levels of pBRD4 in a series of 132 TNBC patients. We found high pBRD4 levels in 34.1% of cases (45/132), and this alteration was found to be associated with the development of patient recurrences (p = 0.007). Interestingly, BRD4 hyperphosphorylation predicted significantly shorter overall (p < 0.001) and event-free survival (p < 0.001). Moreover, multivariate analyses were performed to confirm its independent prognostic impact in our cohort. In conclusion, our findings show that BRD4 hyperphosphorylation is an alteration associated with PP2A inhibition that defines a subgroup of TNBC patients with unfavorable prognosis, suggesting the potential clinical and therapeutic usefulness of the PP2A/BRD4 axis as a novel molecular target to overcome resistance to treatments based on BRD4 inhibition.

The standard treatment for patients with locally advanced colorectal cancer (LARC) is neoadjuvant 5-fluorouracil (5-FU) based chemoradiotherapy (CRT) followed by surgical mesorectal excision. However, the lack of response to this preoperative treatment strongly compromises patient outcomes and leads to surgical delays and undesired toxicities in those non-responder cases. Thus, the identification of effective and robust biomarkers to predict response to preoperative CRT represents an urgent need in the current clinical management of LARC. The oncomiR microRNA-19b (miR-19b) has been reported to functionally play oncogenic roles in colorectal cancer (CRC) cells as well as regulate 5-FU sensitivity and determine outcome in CRC patients. However, its clinical impact in LARC has not been previously investigated. Here, we show that miR-19b deregulation is a common event in this disease, and its decreased expression significantly associates with lower tumor size after CRT (p = 0.003), early pathological stage (p = 0.003), and absence of recurrence (p = 0.001) in LARC patients. Interestingly, low miR-19b expression shows a predictive value of better response to neoajuvant CRT (p < 0.001), and the subgroup of LARC patients with low miR-19b levels have a markedly longer overall (p = 0.003) and event-free survival (p = 0.023). Finally, multivariate analyses determined that miR-19b independently predicts both patient outcome and response to preoperative CRT, highlighting its potential clinical usefulness in the management of LARC patients.

Deregulation of lipid metabolism in cancer cells is critical to the maintenance of certain malignant features. Here, the authors show that the proliferation of breast cancer cells depends upon the extracellular activity of the endothelial lipase enzyme LIPG whose expression is regulated by the FoxA family of transcription factors.

It is well-known that microRNAs (miRNAs) are critical mediators of initiation and disease progression in many human cancers. Rectal cancer is a highly prevalent tumor, accounting for around one third of newly diagnosed colorectal cancers. The usefulness of miRNAs as clinical biomarkers predictive of the outcome and response to chemoradiotherapy has been well-reported for rectal cancer. However, the existing literature on their functional and therapeutic impact needs to be put in context to clarify their role in disease pathogenesis. Therfore, this review is focused on the functional relevance of miRNAs as key regulators of signaling pathways in rectal cancer and their potential therapeutic value as novel molecular targets in this disease.

The endogenous PP2A inhibitor SET Nuclear Proto-Oncogene (SET) has been reported to play oncogenic roles and determines poor outcomes in colorectal cancer (CRC). Our group previously showed that miR-199b is deregulated in metastatic CRC, and reduced the cell viability and enhanced the sensitivity of CRC cells to standard induction chemotherapy drugs, mainly through direct negative SET regulation. Clinically, miR-199b downregulation was identified as the molecular mechanism responsible for SET overexpression in around half of metastatic CRC patients. However, the potential clinical value of miR-199b in early-stage CRC remains totally unknown. Thus, here we explored the expression levels of this microRNA in a cohort of 171 early-stage CRC patients using real-time polymerase chain reactions. MiR-199b downregulation was found in 21.6% of cases (37 out of 171) and was significantly associated with those patients with a worse Eastern Cooperative Oncology Group (ECOG) status (p = 0.045). Moreover, miR-199b downregulation predicted shorter overall (p < 0.001) and progression-free survival (p = 0.015). As expected, we next immunohistochemically analyzed SET, observing that it was significantly associated with miR-199b in our cohort. However, multivariate analyses showed that miR-199b was an independent biomarker of poor outcomes in early-stage CRC with a predictive value stronger than SET. In conclusion, our results highlight the potential clinical usefulness of miR-199b and suggest that it could represent a novel molecular target in this disease.

Neoadjuvant 5-fluorouracil (5-FU)-based chemoradiotherapy followed by mesorectal excision is the current standard treatment in locally advanced rectal cancer (LARC) and the lack of complete response represents a major problem that compromises long-term patient survival. However, there is a lack of robust established markers predictive of response to this preoperative treatment available in the clinical routine. The tumor suppressor microRNA (miR)-199b directly targets the PP2A inhibitor SET, which has been involved in 5-FU resistance, and its downregulation has been found to correlate with poor outcome in metastatic colorectal cancer. Here, we studied the functional effects of miR-199b on 5-FU sensitivity after its ectopic modulation, and its expression was quantified by real-time-PCR in a cohort of 110 LARC patients to evaluate its potential clinical significance. Interestingly, our findings demonstrate that miR-199b enhances the sensitivity of colorectal cancer cells to 5-FU in a SET-dependent manner, and that both miR-199b overexpression and SET inhibition are able to overcome resistance to this drug using an acquired 5-FU-resistant model. MiR-199b was found downregulated in 26.4% of cases and was associated with positive lymph node levels after chemoradiotherapy (CRT, p = 0.007) and high pathological stage (p = 0.029). Moreover, miR-199b downregulation determined shorter overall (p = 0.003) and event-free survival (p = 0.005), and was an independent predictor of poor response to preoperative CRT (p = 0.004). In conclusion, our findings highlight the clinical impact of miR-199b downregulation predicting poor outcome and pathological response in LARC, and suggest the miR-199b/SET signaling axis as a novel molecular target to prevent the development of resistance to 5-FU treatment.

The increasing number of recently published works regarding the role of circular RNAs (circRNAs) in oral cancer highlights the key contribution of this novel class of endogenous noncoding RNAs as regulators of critical signaling pathways and their clinical value as novel biomarkers. This review summarizes and puts into context the existing literature in order to clarify the relevance of circRNAs as novel mediators of oral cancer pathogenesis as well as their potential usefulness as predictors of clinical outcome and response to therapy in this disease.

Trastuzumab is the first-line targeted therapeutic drug for HER2-positive breast cancer, leading to improved overall survival. However, acquired resistance inevitably occurs. We aimed to identify, quantify, and assess the mechanisms of acquired resistance to trastuzumab. We established an acquired trastuzumab-resistant model in vitro from BT-474, a trastuzumab-sensitive, HER2-amplified breast-cancer cell line. A multi-omic strategy was implemented to obtain gene, proteome, and phosphoproteome signatures associated with acquired resistance to trastuzumab in HER2-positive breast cancer, followed by validation in human clinical samples. YAP1 dephosphorylation and TEAD2 overexpression were detected as significant alterations in the Hippo pathway in trastuzumab-resistant breast cancer. Because of the emerging role of these proteins as mediators of normal growth and tumorigenesis, we assessed the exogenous modulation of their activity, either by in vitro gene silencing or by pharmacological inhibition of the YAP1/TEAD complexes, both in vitro and in vivo. Moreover, we identified increased signaling through the Hippo pathway in human samples after progression following trastuzumab treatment. Finally, YAP1/TAZ nuclear accumulation in malignant cells in HER2 breast tumor was significantly associated with worse progression-free and overall survival in metastatic HER2-positive breast-cancer patients. Our results suggest the involvement of Hippo signaling in acquired trastuzumab resistance in breast cancer. Additionally, we provide novel evidence for a potential breast-cancer treatment strategy based on dual targeting of HER2 and Hippo pathway effectors, which may improve the antitumor activity of trastuzumab and help overcome resistance.

Overexpression of the human epidermal growth factor receptor 2 (HER2) defines a subgroup of breast tumors with aggressive behavior. The addition of HER2-targeted antibodies (i.e., trastuzumab, pertuzumab) to chemotherapy significantly improves relapse-free and overall survival in patients with early-stage and advanced disease. Nonetheless, considerable proportions of patients develop resistance to treatment, highlighting the need for additional and co-adjuvant therapeutic strategies. HER2-specific antibodies can trigger natural killer (NK) cell-mediated antibody-dependent cellular cytotoxicity and indirectly enhance the development of tumor-specific T cell immunity; both mechanisms contributing to their antitumor efficacy in preclinical models. Antibody-dependent NK cell activation results in the release of cytotoxic granules as well as the secretion of pro-inflammatory cytokines (i.e., IFNγ and TNFα) and chemokines. Hence, NK cell tumor suppressive functions include direct cytolytic killing of tumor cells as well as the regulation of subsequent antitumor adaptive immunity. Albeit tumors with gene expression signatures associated to the presence of cytotoxic lymphocyte infiltrates benefit from trastuzumab-based treatment, NK cell-related biomarkers of response/resistance to HER2-specific therapeutic antibodies in breast cancer patients remain elusive. Several variables, including (i) the configuration of the patient NK cell repertoire; (ii) tumor molecular features (i.e., estrogen receptor expression); (iii) concomitant therapeutic regimens (i.e., chemotherapeutic agents, tyrosine kinase inhibitors); and (iv) evasion mechanisms developed by progressive breast tumors, have been shown to quantitatively and qualitatively influence antibody-triggered NK cell responses. In this review, we discuss possible interventions for restoring/enhancing the therapeutic activity of HER2 therapeutic antibodies by harnessing NK cell antitumor potential through combinatorial approaches, including immune checkpoint blocking/stimulatory antibodies, cytokines and toll-like receptor agonists.

Mutations in Human Epidermal Growth Factor Receptors (HER) are associated with poor prognosis of several types of solid tumors. Although HER-mutation detection methods are currently available, such as Next-Generation Sequencing (NGS), alternative pyrosequencing allow the rapid characterization of specific mutations. We developed specific PCR-based pyrosequencing assays for identification of most prevalent HER2 and HER3 mutations, including S310F/Y, R678Q, L755M/P/S/W, V777A/L/M, 774-776 insertion, and V842I mutations in HER2, as well as M91I, V104M/L, D297N/V/Y, and E332E/K mutations in HER3. We tested 85 Formalin Fixed and Paraffin Embbeded (FFPE) samples and we detected three HER2-V842I mutations in colorectal carcinoma (CRC), ovarian carcinoma, and pancreatic carcinoma patients, respectively, and a HER2-L755M mutation in a CRC specimen. We also determined the presence of a HER3-E332K mutation in an urothelial carcinoma sample, and two HER3-D297Y mutations, in both gastric adenocarcinoma and CRC specimens. The D297Y mutation was previously detected in breast and gastric tumors, but not in CRC. Moreover, we found a not-previously-described HER3-E332E synonymous mutation in a retroperitoneal leiomyosarcoma patient. The pyrosequencing assays presented here allow the detection and characterization of specific HER2 and HER3 mutations. These pyrosequencing assays might be implemented in routine diagnosis for molecular characterization of HER2/HER3 receptors as an alternative to complex NGS approaches.

Protein phosphatase 2A (PP2A) is a tumor suppressor complex that has recently been reported as a novel and highly relevant molecular target in prostate cancer (PCa). However, its potential therapeutic value remains to be fully clarified. We treated PC-3 and LNCaP cell lines with the PP2A activators forskolin and FTY720 alone or combined with the PP2A inhibitor okadaic acid. We examined PP2A activity, cell growth, prostasphere formation, levels of PP2A phosphorylation, CIP2A and SET expression, and AKT and ERK activation. Interestingly, both forskolin and FTY720 dephosphorylated and activated PP2A, impairing proliferation and prostasphere formation and inducing changes in AKT and ERK phosphorylation. Moreover, FTY720 led to reduced CIP2A levels. Treatment with okadaic acid impaired PP2A activation thus demonstrating the antitumoral PP2A-dependent mechanism of action of both forskolin and FTY720. Levels of PP2A phosphorylation together with SET and CIP2A protein expression were studied in 24 PCa patients and both were associated with high Gleason scores and presence of metastatic disease. Altogether, our results suggest that PP2A inhibition could be involved in PCa progression, and the use of PP2A-activating drugs might represent a novel alternative therapeutic strategy for treating PCa patients.

BACKGROUND:Multiple observational studies suggest an increased risk of colon cancer in patients with diabetes mellitus (DM). This can theoretically be the result of an influence of the diabetic environment on carcinogenesis or the tumor biologic behavior. AIM:To gain insight into the influence of a diabetic environment on colon cancer characteristics and outcomes. MATERIAL AND METHODS:Retrospective analysis of clinical records in an academic tertiary care hospital with detailed analysis of 81 diabetic patients diagnosed of colon cancer matched with 79 non-diabetic colon cancer patients. The impact of streptozotocin-induced diabetes on the growth of colon cancer xenografts was studied in mice. RESULTS:The incidence of DM in 1,137 patients with colorectal cancer was 16%. The diabetic colon cancer cases and non-diabetic colon cancer controls were well matched for demographic and clinical variables. The ECOG Scale Performance Status was higher (worse) in diabetics (ECOG ≥1, 29.1% of controls vs 46.9% of diabetics, p = 0.02), but no significant differences were observed in tumor grade, adjuvant therapy, tumor site, lymphovascular invasion, stage, recurrence, death or cancer-related death. Moreover, no differences in tumor variables were observed between patients treated or not with metformin. In the xenograft model, tumor growth and histopathological characteristics did not differ between diabetic and nondiabetic animals. CONCLUSION:Our findings point towards a mild or negligible effect of the diabetes environment on colon cancer behavior, once cancer has already developed.

Pigment epithelium-derived factor (PEDF), a member of the serine protease inhibitor superfamily, has potent anti-metastatic effects in cutaneous melanoma through its direct actions on endothelial and melanoma cells. Here we show that PEDF expression positively correlates with microphthalmia-associated transcription factor (MITF) in melanoma cell lines and human samples. High PEDF and MITF expression is characteristic of low aggressive melanomas classified according to molecular and pathological criteria, whereas both factors are decreased in senescent melanocytes and naevi. Importantly, MITF silencing down-regulates PEDF expression in melanoma cell lines and primary melanocytes, suggesting that the correlation in the expression reflects a causal relationship. In agreement, analysis of Chromatin immunoprecipitation coupled to high throughput sequencing (ChIP-seq) data sets revealed three MITF binding regions within the first intron of SERPINF1, and reporter assays demonstrated that the binding of MITF to these regions is sufficient to drive transcription. Finally, we demonstrate that exogenous PEDF expression efficiently halts in vitro migration and invasion, as well as in vivo dissemination of melanoma cells induced by MITF silencing. In summary, these results identify PEDF as a novel transcriptional target of MITF and support a relevant functional role for the MITF-PEDF axis in the biology of melanoma.

Snail1 transcriptional repressor is a major inducer of epithelial-to mesenchymal transition but is very limitedly expressed in adult animals. We have previously demonstrated that Snail1 is required for the maintenance of mesenchymal stem cells (MSCs), preventing their premature differentiation. Now, we show that Snail1 controls the tumorigenic properties of mesenchymal cells. Increased Snail1 expression provides tumorigenic capabilities to fibroblastic cells; on the contrary, Snail1 depletion decreases tumor growth. Genetic depletion of Snail1 in MSCs that are deficient in p53 tumor suppressor downregulates MSC markers and prevents the capability of these cells to originate sarcomas in immunodeficient SCID mice. Notably, an analysis of human sarcomas shows that, contrarily to epithelial tumors, these neoplasms display high Snail1 expression. This is particularly clear for undifferentiated tumors, which are associated with poor outcome. Together, our results indicate a role for Snail1 in the generation of sarcomas.

Los adsorbentes han sido utilizados ampliamente para prevenir las micotoxicosis y la transferencia d e toxinas o sus metabolitos dentro de la cadena alimentaria. Particularmente, se unen a las aflatoxinas dentro del tracto gastrointestinal de los rumiantes, disminuyendo su biodisponibilidad y la transferencia de aflatoxin a M 1 (AFM 1 ) a la leche. El presente estudio se desarrolló para evaluar dos métodos de exposición a aflatoxina B 1 en vacas Holstein y monitorear la transferencia AFM 1 a la leche. Adicionalmente, se analizó el potencial de tres adsorbentes de aflatoxinas en ambos experimentos. Los resultados mostraron una tasa de trasferencia de AFB 1 a AFM 1 / día de 3.35 y 1.8 % en los dos experimentos respectivamente. La transferencia estimada de AFM 1 en la leche observada en el segundo método fue cercana a las obtenidas de vacas alimentadas con alimentos natura lmente contaminados con aflatoxinas. A diferencia de los glucomananos de paredes cel ulares de levaduras, ambos adsorbentes de aluminosilicatos disminuyeron significativamente los niveles de AFM 1 en la leche ( P