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Long noncoding (lnc)RNAs are reported to be key regulators of tumor progression, including hepatocellular carcinoma (HCC). The lncRNA

Background Due to the difficulties in early diagnosing and treating hepatocellular carcinoma (HCC), prognoses for patients remained poor in the past decade. In this study, we established a screening model to discover novel prognostic biomarkers in HCC patients. Methods Candidate biomarkers were screened by liquid chromatography with tandem mass spectrometry (LC-MS/MS) analyses of five HCC normal (N)/tumor (T) paired tissues and preliminarily verified them through several in silico database analyses. Expression levels and functional roles of candidate biomarkers were respectively evaluated by immunohistochemical staining in N/T paired tissue (n = 120) and MTS, colony formation, and transwell migration/invasion assays in HCC cell lines. Associations of clinicopathological features and prognoses with candidate biomarkers in HCC patients were analyzed from GEO and TCGA datasets and our recruited cohort. Results We found that the transmembrane P24 trafficking protein 9 (TMED9) protein was elevated in HCC tissues according to a global proteomic analysis. Higher messenger (m)RNA and protein levels of TMED9 were observed in HCC tissues compared to normal liver tissues or pre-neoplastic lesions. The TMED9 mRNA expression level was significantly associated with an advanced stage and a poor prognosis of overall survival (OS, p = 0.00084) in HCC patients. Moreover, the TMED9 protein expression level was positively correlated with vascular invasion (p = 0.026), OS (p = 0.044), and disease-free survival (p = 0.015) in our recruited Taiwanese cohort. In vitro, manipulation of TMED9 expression in HCC cells significantly affected cell migratory, invasive, proliferative, and colony-forming abilities. Conclusions Ours is the first work to identify an oncogenic role of TMED9 in HCC cells and may provide insights into the application of TMED9 as a novel predictor of clinical outcomes and a potential therapeutic target in patients with HCC.

Renal cell carcinoma (RCC) is one of the most lethal genitourinary malignancies with poor prognoses, since it is largely resistant to chemotherapy, radiotherapy, and targeted therapy. The persistence of cancer stem cells (CSCs) is the major cause of treatment failure with RCC. Recent evidence showed that dopamine receptor D2 (DRD2)-targeting antipsychotic drugs such as penfluridol exert oncostatic effects on several cancer types, but the effect of penfluridol on RCC remains unknown. Here, we uncovered penfluridol suppressed in vitro cell growth and in vivo tumorigenicity of various RCC cell lines (Caki-1, 786-O, A498, and ACHN) and enhanced the Sutent (sunitinib)-triggered growth inhibition on clear cell (cc)RCC cell lines. Mechanistically, upregulation of endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) was critical for autophagy-mediated apoptosis induced by penfluridol. Transcriptional inhibition of OCT4 and Nanog via inhibiting GLI1 was important for penfluridol-induced stemness and proliferation inhibition. The anticancer activities of penfluridol on ccRCC partially occurred through DRD2. In clinical ccRCC specimens, positive correlations of DRD2 with GLI1, OCT4, and Nanog were observed and their expressions were correlated with worse prognoses. Summarizing, DRD2 antagonists such as penfluridol induce UPR signaling and suppress the GLI1/OCT4/Nanog axis in ccRCC cells to reduce their growth through inducing autophagy-mediated apoptosis and stemness inhibition. These drugs can be repurposed as potential agents to treat ccRCC patients.

Although new generations of EGFR-tyrosine kinase inhibitors (EGFR-TKI) have been developed for the treatment of patients with non–small cell lung cancer (NSCLC) with EGFR-mutant tumors, TKI resistance often returns as a result of additional EGFR mutations. In addition to seeking for next-generation EGFR-TKI, developing novel EGFR-targeting strategies may hold the key to overcome the vicious cycle of TKI resistance. Endocan is known as a receptor tyrosine kinase ligand enhancer in tumorigenesis, but the impact of endocan on EGFR-driven NSCLC progression remains unknown. In this study, higher endocan levels were found in lung tumors compared with cancer-free tissues and correlated with poor prognosis in patients with NSCLC harboring mutant EGFR; circulating endocan levels were also significantly higher in patients with mutant EGFR. Endocan facilitated EGFR signaling via direct binding and enhancing of the EGF–EGFR interaction and supported the growth of tumors driven by mutated EGFR. Activated EGFR in turn upregulated expression of endocan via JAK/STAT3 and ERK/ELK cascades, thus forming a positive regulatory loop of endocan-EGFR signaling. On the basis of the binding region between endocan and EGFR, we designed therapeutic peptides and demonstrated promising therapeutic effects in xenografts harboring EGFR mutations including TKI-resistant T790M. Together, our findings highlight the novel interaction between endocan and EGFR and new opportunities to effectively target endocan-EGFR regulatory axis in patients with TKI-resistant NSCLC. Significance: Endocan is a novel and critical regulator of EGF/EGFR signaling and serves as an alternative target of EGFR-TKI resistance in NSCLC.

N-α-Acetyltransferase 10 protein (Naa10p) was reported to be an oncoprotein in androgen-dependent prostate cancer (PCa; ADPC) through binding and increasing transcriptional activity of the androgen receptor (AR). PCa usually progresses from an androgen-dependent to an androgen-independent stage, leading to an increase in the metastatic potential and an incurable malignancy. At present, the role of Naa10p in androgen-independent prostate cancer (AIPC) remains unclear. In this study, in silico and immunohistochemistry analyses showed that Naa10 transcripts or the Naa10p protein were more highly expressed in primary and metastatic PCa cancer tissues compared to adjacent normal tissues and non-metastatic cancer tissues, respectively. Knockdown and overexpression of Naa10p in AIPC cells (DU145 and PC-3M), respectively, led to decreased and increased cell clonogenic and invasive abilities in vitro as well as tumor growth and metastasis in AIPC xenografts. From the protease array screening, we identified a disintegrin and metalloprotease 9 (ADAM9) as a potential target of Naa10p, which was responsible for the Naa10p-induced invasion of AIPC cells. Naa10p can form a complex with ADAM9 to maintain ADAM9 protein stability and promote AIPC’s invasive ability which were independent of its acetyltransferase activity. In contrast to the Naa10p-ADAM9 axis, ADAM9 exerted positive feedback regulation on Naa10p to modulate progression of AIPC in vitro and in vivo. Taken together, for the first time, our results reveal a novel cross-talk between Naa10p and ADAM9 in regulating the progression of AIPC. Disruption of Naa10p–ADAM9 interactions may be a potential intervention for AIPC therapy.

Oral squamous cell carcinoma (OSCC) is the most frequently encountered type of oral cancer. Histamine receptor H1 (

Endocan is known to be a circulating dermatan sulfate proteoglycan that regulates endothelial cell function. Dysregulation of endocan expression is observed not only in the tumor vasculature but also in cancer cells. Accumulating evidence has revealed that disordered endocan facilitates cancer progression via enhancing cancer cell proliferation, cell mobility, and cancer stemness properties. Recently, various interacting proteins and diverse subcellular localizations of endocan were identified in cancer cells. Herein, we summarize the application of endocan in cancer diagnoses and prognoses using serum and tumor specimens. We further discuss that the aberrant molecular characteristics of endocan may be due to the mislocalization of endocan in cancer cells. Defining the specific cellular roles of endocan will provide a promising diagnostic factor and therapeutic target for cancer patients.

Non-small cell lung cancer (NSCLC) is a typical inflammation-associated cancer, and lung adenocarcinoma (LUAD) is the most common histopathological subtype. Epidermal growth factor receptor (EGFR) mutations are the most common driver mutations of LUAD, and they have been identified as important therapeutic targets by EGFR tyrosine kinase inhibitors. Interleukin (IL)-17A secreted by T-helper 17 lymphocytes is a proinflammatory cytokine that plays an important role in cancer pathogenesis. The present study was designed to investigate the possible associations among IL-17A genetic polymorphisms, EGFR mutation status, and the clinicopathologic development of LUAD in a Taiwanese population. Our study population consisted of 277 LUAD patients harboring the wild-type (WT) EGFR or a mutant (MT) EGFR. Four single-nucleotide polymorphisms (SNPs) of IL-17A in the peripheral blood, including rs8193036(C > T), rs8193037(G > A), rs2275913(G > A), and rs3748067(C > T) loci, were genotyped using a TaqMan allelic discrimination assay. Our results showed that none of these IL-17A SNPs were correlated with the risk of developing mutant EGFR. However, patients with a smoking habit who carried the GA genotype of IL-17A rs8193037 had a significantly lower susceptibility to EGFR mutations (adjusted odds ratio (AOR): 0.225; 95% confidence interval (CI): 0.056~0.900, p = 0.035). Moreover, compared to individuals carrying the CC genotype of rs8193036 at IL-17A, T-allele carriers (CT + TT) were at higher risk of developing more-advanced stages (stage III or IV; p = 0.020). In the WT EGFR subgroup analysis, IL-17A rs8193036 T-allele carriers had higher risks of developing an advanced tumor stage (p = 0.016) and lymphatic invasion (p = 0.049). Further analyses of clinical datasets revealed correlations of IL-17 receptor A (IL-17RA) and IL-17RC expressions with a poor prognosis of LUAD patients with a smoking history or with higher levels of tumor-infiltrating lymphocytes. In conclusion, our results suggested that two functional promoter polymorphisms of IL-17A, i.e., rs8193036 and rs8193037, were associated with the EGFR mutation status and progression in LUAD patients, indicating that these two genetic variants might act as possible markers for predicting patients’ clinical prognoses.

Wnt/β‐catenin signaling is frequently activated in advanced prostate cancer and contributes to therapy resistance and metastasis. However, activating mutations in the Wnt/β‐catenin pathway are not common in prostate cancer, suggesting alternative regulations may exist. Here, we report that the expression of endothelial cell‐specific molecule 1 (ESM1), a secretory proteoglycan, is positively associated with prostate cancer stemness and progression by promoting Wnt/β‐catenin signaling. Elevated ESM1 expression correlates with poor overall survival and metastasis. Accumulation of nuclear ESM1, instead of cytosolic or secretory ESM1, supports prostate cancer stemness by interacting with the ARM domain of β‐catenin to stabilize β‐catenin–TCF4 complex and facilitate the transactivation of Wnt/β‐catenin signaling targets. Accordingly, activated β‐catenin in turn mediates the nuclear entry of ESM1. Our results establish the significance of mislocalized ESM1 in driving metastasis in prostate cancer by coordinating the Wnt/β‐catenin pathway, with implications for its potential use as a diagnostic or prognostic biomarker and as a candidate therapeutic target in prostate cancer.

Metastasis of lung adenocarcinoma (LADC) is a crucial factor determining patient survival. Repurposing of the antipsychotic agent penfluridol has been found to be effective in the inhibition of growth of various cancers. As yet, however, the anti-metastatic effect of penfluridol on LADC has rarely been investigated. Herein, we addressed the therapeutic potential of penfluridol on the invasion/metastasis of LADC cells harboring different epidermal growth factor receptor (EGFR) mutation statuses.MTS viability, transwell migration and invasion, and tumor endothelium adhesion assays were employed to determine cytotoxic and anti-metastatic effects of penfluridol on LADC cells. Protease array, Western blot, immunohistochemistry (IHC), immunofluorescence (IF) staining, and expression knockdown by shRNA or exogenous overexpression by DNA plasmid transfection were performed to explore the underlying mechanisms, both in vitro and in vivo.We found that nontoxic concentrations of penfluridol reduced the migration, invasion and adhesion of LADC cells. Protease array screening identified matrix metalloproteinase-12 (MMP-12) as a potential target of penfluridol to modulate the motility and adhesion of LADC cells. In addition, we found that MMP-12 exhibited the most significantly adverse prognostic effect in LADC among 39 cancer types. Mechanistic investigations revealed that penfluridol inhibited the urokinase plasminogen activator (uPA)/uPA receptor/transforming growth factor-β/Akt axis to downregulate MMP-12 expression and, subsequently, reverse MMP-12-induced epithelial-mesenchymal transition (EMT). Subsequent analysis of clinical LADC samples revealed a positive correlation between MMP12 and mesenchymal-related gene expression levels. A lower survival rate was found in LADC patients with a SNAl1Our results indicate that MMP-12 may serve as a useful biomarker for predicting LADC progression and as a promising penfluridol target for treating metastatic LADC.

Monoamine oxidases (MAOs) including MAOA and MAOB are enzymes located on the outer membranes of mitochondria, which are responsible for catalyzing monoamine oxidation. Recently, increased level of MAOs were shown in several cancer types. However, possible roles of MAOs have not yet been elucidated in the progression and prognosis of colorectal carcinoma (CRC). We therefore analyzed the importance of MAOs in CRC by an in silico analysis and tissue microarrays. Several independent cohorts indicated that high expression of MAOB, but not MAOA, was correlated with a worse disease stage and poorer survival. In total, 203 colorectal adenocarcinoma cases underwent immunohistochemical staining of MAOs, and associations with clinicopathological parameters and patient outcomes were evaluated. We found that MAOB is highly expressed in CRC tissues compared to normal colorectal tissues, and its expression was significantly correlated with a higher recurrence rate and a poor prognosis. Moreover, according to the univariate and multivariate analyses, we found that MAOB could be an independent prognostic factor for overall survival and disease-free survival, and its prognostic value was better than T and N stage. Furthermore, significant positive and negative correlations of MAOB with mesenchymal-type and epithelial-type gene expressions were observed in CRC tissues. According to the highlighted characteristics of MAOB in CRC, MAOB can be used as a novel indicator to predict the progression and prognosis of CRC patients.

A disintegrin and metalloprotease with thrombospondin motifs (ADAMTS) family are widely implicated in tissue remodeling events manifested in cancer development. ADAMTS1, the most fully characterized ADAMTS, plays conflicting roles in different cancer types; however, the role of ADAMTS1 in renal cell carcinoma (RCC) remains unclear. Herein, we found that ADAMTS1 is highly expressed in RCC tissues compared to normal renal tissues, and its expression was correlated with an advanced stage and a poor prognosis of RCC patients. In vitro, we observed higher expression of ADAMTS1 in metastatic (m)RCC cells compared to primary cells, and manipulation of ADAMTS1 expression affected cell invasion and clonogenicity. Results from protease array showed that ADAMTS1 is modulated by melatonin through mechanisms independent of the MT1 receptor in mRCC cells, and overexpression of ADAMTS1 relieved the invasion/clonogenicity and growth/metastasis inhibition imposed by melatonin treatment in vitro and in an orthotopic xenograft model. The human microRNA (miR) OneArray showed that miR-181d and miR-let-7f were induced by melatonin and, respectively, targeted the 3'-UTR and non-3'-UTR of ADAMTS1 to suppress its expression and mRCC invasive ability. Clinically, RCC patients with high levels of miR-181d or miR-let-7f and a low level of ADAMTS1 had the most favorable prognoses. In addition, ubiquitin/proteasome-mediated degradation of ADAMTS1 can also be triggered by melatonin. Together, our study indicates that ADAMTS1 may be a useful biomarker for predicting RCC progression. The novel convergence between melatonin and ADAMTS1 post-transcriptional and post-translational regulation provides new insights into the role of melatonin-induced molecular regulation in suppressing RCC progression.

The aldolase family members involved in metabolism and glycolysis are present in three isoforms: ALDOA, ALDOB, and ALDOC. Aldolases are differentially expressed in human tissues, and aberrant expression has been observed in several human diseases and cancer types. However, non-enzymatic functions through protein-protein interactions or epigenetic modifications have been reported in recent years. Using high-throughput screening and -omics database integration, aldolase has been validated as an independent clinical prognostic marker of human cancers. Therefore, the aim of this review was to provide potential clinical value from in silico predictions and also summarize well-known signaling axes or phenotypes in various cancer types. Finally, we discuss the role of aldolase in the treatment of human diseases and cancers.

Background Metastasis rather than the primary cancer determines the survival of cancer patients. Activation of Akt plays a critical role in the epithelial-to-mesenchymal transition (EMT), the initial step in lung cancer metastasis. Apigenin (API), a flavonoid with a potent Akt-inhibitory effect, shows oncostatic activities in various cancers. However, the effects of API on metastasis of non-small cell lung cancer (NSCLC) remain unclear. Methods NSCLC cell lines with different epidermal growth factor receptor (EGFR) statuses and in vivo orthotopic bioluminescent xenograft model were employed to determine antitumor activity of API. Western blot and genetic knockdown by shRNA or genetic overexpression by DNA plasmids were performed to explore the underlying mechanisms. The Cancer Genome Atlas (TCGA) database was used to investigate the prognosis of API-targeted genes. Results API was demonstrated to inhibit the migration/invasion of NSCLC cells harboring different EGFR statuses via suppressing the Snail/Slug-mediated EMT. Mechanistic investigations showed that CD26/dipeptidyl peptidase IV (DPPIV) was downregulated by API following suppressive interplay of Akt and Snail/Slug signaling to modulate the EMT and the invasive ability of NSCLC cells. CD26 expression was positively correlated with the invasive abilities of NSCLC cells and a worse prognosis of lung cancer patients. Furthermore, we observed that patients with CD26high/Akthigh tumors had the shortest recurrence-free survival times. In vivo, API drastically reduced the growth and metastasis of A549 xenografts through targeting CD26. Conclusions CD26 may be a useful biomarker for predicting NSCLC progression. API effectively suppressed lung cancer progression by targeting the CD26-Akt-Snail/Slug signaling pathway. Electronic supplementary material The online version of this article (10.1186/s13046-018-0869-1) contains supplementary material, which is available to authorized users.

Cancer cells encounter metabolic stresses such as hypoxia and nutrient limitations because they grow and divide more quickly than their normal counterparts. In response to glucose restriction, we found that nuclear translocation of the glycolic enzyme, pyruvate kinase M2 (PKM2), helped cancer cells survive under the metabolic stress. Restriction of glucose stimulated AMPK activation and resulted in co-translocation of AMPK and PKM2 through Ran-mediated nuclear transport. Nuclear PKM2 subsequently bound to Oct4 and promoted the expression of cancer stemness-related genes, which might enrich the cancer stem cell population under the metabolic stress. Nuclear PKM2 was also capable of promoting cancer metastasis in an orthotopic xenograft model. In summary, we found that cytosolic AMPK helped PKM2 carry out its nonmetabolic functions in the nucleus under glucose restriction and that nuclear PKM2 promoted cancer stemness and metastasis. These findings suggested a potential new targeting pathway for cancer therapy in the future.

KH-type splicing regulatory protein (KSRP) is a single-strand RNA binding protein which regulates mRNA stability either by binding to AU-rich elements (AREs) of mRNA 3'UTR or by facilitating miRNA biogenesis to target mRNA. Unlike its well-characterized function at the molecular level in maintaining RNA homeostasis, the role of KSRP in cancer progression remains largely unknown. Here we investigate the role of KSRP in non-small cell lung cancer (NSCLC). We first examined KSRP expression by immunohistochemistry in a cohort containing 196 NSCLC patients and observed a strong positive correlation between KSRP expression and survival of NSCLC patients. Multivariate analysis further identified KSRP as an independent prognostic factor. Manipulating KSRP expression significantly affected in vitro cell mobility and in vivo metastatic ability of NSCLC cells. Microarray analysis identified an ARE-containing gene, EGR3, as a downstream effector of KSRP in NSCLC. Interestingly, we found that KSRP decreased EGR3 mRNA stability in an ARE-independent manner. By screening KSRP-regulated miRNAs in NSCLC cells, we further found that miR-23a directly binds to EGR3 3'UTR, reducing EGR3 expression and thereby inhibiting NSCLC cell mobility. Our findings implicate a targetable KSRP/miR-23a/EGR3 signaling axis in advanced tumor phenotypes.

Background Cisplatin is the first-line chemotherapy used against most upper aerodigestive tract carcinomas. In head and neck cancer, sensitivity to cisplatin remains the key issue in treatment response and outcome. Genetic heterogeneity and aberrant gene expression may be the intrinsic factors that cause primary cisplatin-resistance. Methods Combination of the HNSCC gene expression data and the cisplatin sensitivity results from public database. We found that aldo-keto reductase family 1 member C1 (AKR1C1) may be associated with cisplatin sensitivity in HNSCC treatment of naïve cells. We examined the AKR1C1 expression and its correlation with cisplatin IC50 and prognosis in patients. The in vitro and in vivo AKR1C1 functions in cisplatin-resistance through overexpression or knockdown assays, respectively. cDNA microarrays were used to identify the upstream regulators that modulate AKR1C1-induced signaling in HNSCC. Finally, we used the cigarette metabolites to promote AKR1C1 expression and ruxolitinib to overcome AKR1C1-induced cisplatin-resistance. Results AKR1C1 positively correlates to cisplatin-resistance in HNSCC cells. AKR1C1 is a poor prognostic factor for recurrence and death of HNSCC patients. Silencing of AKR1C1 not only reduced in vitro IC50 but also increased in vivo cisplatin responses and vise versa in overexpression cells. Cigarette metabolites also promote AKR1C1 expression. Transcriptome analyses revealed that STAT1 and STAT3 activation enable AKR1C1-induced cisplatin-resistance and can be overcome by ruxolitinib treatment. Conclusions AKR1C1 is a crucial regulator for cisplatin-resistance in HNSCC and also poor prognostic marker for patients. Targeting the AKR1C1-STAT axis may provide a new therapeutic strategy to treat patients who are refractory to cisplatin treatment. Electronic supplementary material The online version of this article (10.1186/s13046-019-1256-2) contains supplementary material, which is available to authorized users.

Background Prostate cancer (PCa) is considered one of the most prevalent malignancy globally, and metastasis is a major cause of death. Apigenin (API) is a dietary flavonoid which exerts an antimetastatic effect in various cancer types. Sparc/osteonectin, cwcv, and kazal-like domains proteoglycan 1 (SPOCK1) is a crucial modulator of tumor growth and metastasis in cancers. However, the role and underlying regulatory mechanisms of SPOCK1 in the API-mediated antimetastatic effects of PCa remain unclear. Methods MTS, colony formation, wound-healing, and transwell assays were conducted to evaluate the effects of API on PCa cell proliferative, migratory, and invasive potentials. In vivo orthotopic bioluminescent xenograft model were employed to determine antitumor activity of API. PCa cells were transfected with either Snail-, Slug-, SPOCK1-overexpressing vector, or small hairpin (sh)SPOCK1 to determine the invasive abilities and expression levels of SPOCK1 and epithelial-to-mesenchymal transition (EMT) biomarkers in response to API treatment. Immunohistochemical (IHC) assays were carried out to evaluate the expression level of SPOCK1 in PCa xenografts and a PCa tissue array. Associations of SPOCK1 expression with clinicopathological features and prognoses of patients with PCa were analyzed by GEO or TCGA RNA-sequencing data. Results API significantly suppressed in vitro PCa cell proliferation, migration, and invasion and inhibited in vivo PCa tumor growth and metastasis. Moreover, survival times of animals were also prolonged after API treatment. Mechanistic studies revealed that API treatment resulted in downregulation of SPOCK1, which was accompanied by reduced expressions of mesenchymal markers and subsequent attenuation of invasive abilities of PCa cells. Overexpression of SPOCK1 in PCa xenografts resulted in significant promotion of tumor progression and relieved the anticancer activities induced by API, whereas knockdown of SPOCK1 had opposite effects. In clinical, SPOCK1 levels were higher in tumor tissues compared to non-tumor tissues, which was also significantly correlated with shorter disease-free survival in PCa patients. Conclusions Levels of SPOCK1 increase with the progression of human PCa which suggests that SPOCK1 may act as a prognostic marker or therapeutic target for patients with PCa. Suppression of SPOCK1-mediated EMT signaling contributes to the antiproliferative and antimetastatic activities of API in vitro and in vivo. Electronic supplementary material The online version of this article (10.1186/s13046-019-1247-3) contains supplementary material, which is available to authorized users.

Background Chemotherapy is the main treatment for acute myeloid leukemia (AML), but the cure rates for AML patients remain low, and the notorious adverse effects of chemotherapeutic drugs drastically reduce the life quality of patients. Penfluridol, a long-acting oral antipsychotic drug, has an outstanding safety record and exerts oncostatic effects on various solid tumors. Until now, the effect of penfluridol on AML remains unknown. Methods AML cell lines harboring wild-type (WT) Fms-like tyrosine kinase 3 (FLT3) and internal tandem duplication (ITD)-mutated FLT3 were used to evaluate the cytotoxic effects of penfluridol by an MTS assay. A flow cytometric analysis and immunofluorescence staining were employed to determine the cell-death phenotype, cell cycle profile, and reactive oxygen species (ROS) and acidic vesicular organelle (AVO) formation. Western blotting and chemical inhibitors were used to explore the underlying mechanisms involved in penfluridol-mediated cell death. Results We observed that penfluridol concentration-dependently suppressed the cell viability of AML cells with FLT3-WT (HL-60 and U937) and FLT3-ITD (MV4–11). We found that penfluridol treatment not only induced apoptosis as evidenced by increases of nuclear fragmentation, the sub-G1 populations, poly (ADP ribose) polymerase (PARP) cleavage, and caspase-3 activation, but also triggered autophagic responses, such as the light chain 3 (LC3) turnover and AVO formation. Interestingly, blocking autophagy by the pharmacological inhibitors, 3-methyladenine and chloroquine, dramatically enhanced penfluridol-induced apoptosis, indicating the cytoprotective role of autophagy in penfluridol-treated AML cells. Mechanistically, penfluridol-induced apoptosis occurred through activating protein phosphatase 2A (PP2A) to suppress Akt and mitogen-activated protein kinase (MAPK) activities. Moreover, penfluridol’s augmentation of intracellular ROS levels was critical for the penfluridol-induced autophagic response. In the clinic, we observed that patients with AML expressing high PP2A had favorable prognoses. Conclusions These findings provide a rationale for penfluridol being used as a PP2A activator for AML treatment, and the combination of penfluridol with an autophagy inhibitor may be a novel strategy for AML harboring FLT3-WT and FLT3-ITD. Electronic supplementary material The online version of this article (10.1186/s12929-019-0557-2) contains supplementary material, which is available to authorized users.

An increasing number of enzymes involved in serine biosynthesis have been identified and correlated with malignant evolution in various types of cancer. Here we showed that the overexpression of phosphoserine aminotransferase 1 (PSAT1) is widely found in lung cancer tissues compared with nontumor tissues and predicts a poorer prognosis in patients with lung adenocarcinoma. PSAT1 expression was examined in a tissue microarray by immunohistochemistry. The data show that the knockdown of PSAT1 dramatically inhibits the in vitro and in vivo metastatic potential of highly metastatic lung cancer cells; conversely, the enforced expression of exogenous PSAT1 predominantly enhances the metastatic potential of lung cancer cells. Importantly, manipulating PSAT1 expression regulates the in vivo tumor metastatic abilities in lung cancer cells. Adjusting the glucose and glutamine concentrations did not alter the PSAT1-driven cell invasion properties, indicating that this process might not rely on the activation of its enzymatic function. RNA microarray analysis of transcriptional profiling from PSAT1 alternation in CL1-5 and CL1-0 cells demonstrated that interferon regulatory factor 1 (IRF1) acts as a crucial regulator of PSAT1-induced gene expression upon metastatic progression. Decreasing the IRF1-IFIH1 axis compromised the PSAT1-prompted transcriptional reprogramming in cancer cells. Our results identify PSAT1 as a key regulator by a novel PSAT1/IRF1 axis in lung cancer progression, which may serve as a potential biomarker and therapeutic target for the treatment of lung cancer patients.

Renal cell carcinoma (RCC) is the most lethal of all urological malignancies because of its potent metastasis potential. Melatonin exerts multiple tumor-suppressing activities through antiproliferative, proapoptotic, and anti-angiogenic actions and has been tested in clinical trials. However, the antimetastastic effect of melatonin and its underlying mechanism in RCC are unclear. In this study, we demonstrated that melatonin at the pharmacologic concentration (0.5-2 mm) considerably reduced the migration and invasion of RCC cells (Caki-1 and Achn). Furthermore, we found that melatonin suppressed metastasis of Caki-1 cells in spontaneous and experimental metastasis animal models. Mechanistic investigations revealed that melatonin transcriptionally inhibited MMP-9 by reducing p65- and p52-DNA-binding activities. Moreover, the Akt-mediated JNK1/2 and ERK1/2 signaling pathways were involved in melatonin-regulated MMP-9 transactivation and cell motility. Clinical samples revealed an inverse correlation between melatonin receptor 1A (MTNR1A) and MMP-9 expression in normal kidney and RCC tissues. In addition, a higher survival rate was found in MTNR1A(high) /MMP-9(low) patients than in MTNR1A(low) /MMP-9(high) patients. Overall, our results provide new insights into the role of melatonin-induced molecular regulation in suppressing RCC metastasis and suggest that melatonin has potential therapeutic applications for metastastic RCC.

Background The epidermal growth factor receptor (EGFR) plays important roles in cell survival, growth, differentiation, and tumorigenesis. Dysregulation of the EGFR is a common mechanism in cancer progression especially in non-small cell lung cancer (NSCLC). Main body Suppression of the EGFR-mediated signaling pathway is used in cancer treatment. Furthermore, reactive oxygen species (ROS)-induced oxidative stress from mitochondrial dysfunction or NADPH oxidase (NOX) overactivation and ectopic expression of antioxidative enzymes were also indicated to be involved in EGFR-mediated tumor progression (proliferation, differentiation, migration, and invasion) and drug resistance (EGFR tyrosine kinase inhibitor (TKI)). The products of NOX, superoxide and hydrogen peroxide, are considered to be major types of ROS. ROS are not only toxic materials to cells but also signaling regulators of tumor progression. Oxidation of both the EGFR and downstream phosphatases by ROS enhances EGFR-mediated signaling and promotes tumor progression. This review primarily focuses on the recent literature with respect to the roles of the EGFR and ROS and correlations between ROS and the EGFR in tumor progression and EGFR TKI resistance. Short conclusion The evidence discussed in this article can serve as a basis for basic and clinical research to understand how to modulate ROS levels to control the development and drug resistance of cancers.

Secondary mutation of epidermal growth factor receptor (EGFR) resulting in drug resistance is one of the most critical issues in lung cancer therapy. Several drugs are being developed to overcome EGFR tyrosine kinase inhibitor (TKI) resistance. Here, we report that pyruvate kinase M2 (PKM2) stabilized mutant EGFR protein by direct interaction and sustained cell survival signaling in lung cancer cells. PKM2 silencing resulted in markedly reduced mutant EGFR expression in TKI-sensitive or -resistant human lung cancer cells, and in inhibition of tumor growth in their xenografts, concomitant with downregulation of EGFR-related signaling. Mechanistically, PKM2 directly interacted with mutant EGFR and heat-shock protein 90 (HSP90), and thus stabilized EGFR by maintaining its binding with HSP90 and co-chaperones. Stabilization of EGFR relied on dimeric PKM2, and the protein half-life of mutant EGFR decreased when PKM2 was forced into its tetramer form. Clinical levels of PKM2 positively correlated with mutant EGFR expression and with patient outcome. These results reveal a previously undescribed non-glycolysis function of PKM2 in the cytoplasm, which contribute to EGFR-dependent tumorigenesis and provide a novel strategy to overcome drug resistance to EGFR TKIs.

Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world, especially, in eastern Asia, and its prognosis is poor once metastasis occurs. Niclosamide, a US Food and Drug Administration-approved antihelmintic drug, was shown to inhibit the growth of various cancers including HCC, but the effect of niclosamide on cell motility and the underlying mechanism have not yet been completely defined. The present study demonstrated that niclosamide, at 0-40 nM, concentration-dependently inhibited wound closure and the migratory/invasive capacities of human Huh7 and SK-Hep-1 HCC cells without exhibiting cytotoxicity. A protease array analysis showed that CD10 was dramatically downregulated in Huh7 cells after niclosamide treatment. Western blot and flow cytometric assays further demonstrated that CD10 expression was concentration-dependently downregulated in Huh7 and SK-Hep-1 cells after niclosamide treatment. Mechanistic investigations found that niclosamide suppressed Twist-mediated CD10 transactivation. Moreover, knockdown of CD10 expression by CD10 small interfering RNA in HCC cells suppressed cell migratory/invasive abilities and overexpression of CD10 relieved the migration inhibition induced by niclosamide. Taken together, our results indicated that niclosamide could be a potential agent for inhibiting metastasis of HCC, and CD10 is an important target of niclosamide for suppressing the motility of HCC cells.

Pyruvate kinase muscle isozymes (PKMs) have crucial roles in regulating metabolic changes during carcinogenesis. A switch from PKM1 to PKM2 isoform was thought to lead to aerobic glycolysis promoting carcinogenesis, and was considered as one of the cancer signatures. However, recent evidence has argued against the existence of PKM isoform switch and related metabolic effects during cancer progression. We compared the effects of PKM1 and PKM2 in cell invasiveness and metastasis of pancreatic ductal adenocarcinoma (PDAC). Both PKM1 and PKM2 expression affected cell migration and invasion abilities of PDAC cells, but only knockdown of PKM2 suppressed metastasis in a xenograft model. By comparing the established PKM2 mutants in the regulation of cell invasion, we found that PKM2 may control cell mobility through its protein kinase and phopho-peptide binding abilities. Further survey for PKM2-associated proteins identified PAK2 as a possible phosphorylation target in PDAC. In vitro binding and kinase assays revealed that PKM2 directly phosphorylated PAK2 at Ser20, Ser141, and Ser192/197. Knockdown of PKM2 decreased PAK2 protein half-life by increasing ubiquitin-dependent proteasomal degradation. Moreover, we identified PAK2 as an HSP90 client protein and the mutation at Ser192/197 of PAK2 reduced PAK2-HSP90 association. Knockdown of PAK2 diminished in vitro cell mobility and in vivo metastatic ability of PKM2 overexpressed PDAC cells. PKM2 and PAK2 protein expression also positively correlated with each other in PDAC tissues. Our findings indicate that PKM2-PAK2 regulation is critical for developing metastasis in PDAC, and suggest that targeting the PKM2/HSP90/PAK2 complex has a potential therapeutic value in this deadly disease.

Introduction DNA methyltransferase 3B (DNMT3B) contributes to de novo DNA methylation and its overexpression promotes tumorigenesis. However, whether DNMT3B is upregulated by transcriptional deregulation remains unclear. Methods We studied the transcriptional repression of DNMT3B by forkhead O transcription factor 3a (FOXO3a) in lung cancer cell, animal, and clinical models. Results The results of luciferase reporter assay showed that FOXO3a negatively regulated DNMT3B promoter activity by preferentially interacting with the binding element FOXO3a-E (+166 to +173) of DNMT3B promoter. Ectopically overexpressed FOXO3a or combined treatment with doxorubicin to induce FOXO3a nuclear accumulation further bound at the distal site, FOXO3a-P (−249 to −242) by chromatin-immunoprecipitation assay. Knockdown of FOXO3a resulted in an open chromatin structure and high DNMT3B mRNA and protein expression. Abundant FOXO3a repressed DNMT3B promoter by establishing a repressed chromatin structure. Note that FOXO3a is a degradation substrate of MDM2 E3-ligase. Cotreatment with doxorubicin and MDM2 inhibitor, Nutlin-3, further enforced abundant nuclear accumulation of FOXO3a resulting in decrease expression of DNMT3B leading to synergistic inhibition of tumor growth and decrease of methylation status on tumor suppressor genes in xenograft specimens. Clinically, lung cancer patients with DNMT3B high, FOXO3a low, and MDM2 high expression profile correlated with poor prognosis examined by immunohistochemistry and Kaplan-Meier survival analysis. Conclusions We reveal a new mechanism that FOXO3a transcriptionally represses DNMT3B expression and this regulation can be attenuated by MDM2 overexpression in human lung cancer model. Cotreatment with doxorubicin and Nutlin-3 is a novel therapeutic strategy through epigenetic modulation.

The rate of preterm birth has been increasing worldwide. Most preterm babies are at increased risk of central nervous system impairments as well as respiratory and gastrointestinal complications. The aim of this study was to investigate the trends in preterm birth and associated factors contributing to preterm delivery in Taiwan. Information on obstetric antecedents and risk factors of preterm birth of pregnant women was obtained from the Taiwan National Medical Birth Register database. All live births from 2001 to 2011 in Taiwan were included in this study. A total of 2,334,532 live births from 2001 to 2011 were included in this study. Overall, the proportion of preterm deliveries increased by 11.1% (from 8.2% in 2001 to 9.1% in 2011). Multiple logistic regression analyses showed that nulliparity, multiple births, maternal medical complications, maternal age

Hepatocellular carcinoma (HCC) relies on angiogenesis for growth and metastasis. Leukocyte cell-derived chemotaxin 2 (LECT2) is a cytokine and preferentially expressed in the liver. Previous studies have found that LECT2 targets to both immune and tumor cells to suppress HCC development and vascular invasion. Although LECT2 did not affect HCC cells growth in vitro, it still suppressed HCC xenografts growth in immune-deficient mice, suggesting other cells such as stroma cells may also be targeted by LECT2. Here, we sought to determine the role of LECT2 in tumor angiogenesis in HCC patients. We found that LECT2 expression inhibited tumor growth via angiogenesis in the HCC xenograft model. Specifically, we demonstrated that recombinant human LECT2 protein selectively suppressed vascular endothelial growth factor (VEGF)165-induced endothelial cell proliferation, migration, and tube formation in vitro and in vivo. Mechanistically, LECT2 reduced VEGF receptor 2 tyrosine phosphorylation and its downstream extracellular signal-regulated kinase and AKT phosphorylation. Furthermore, LECT2 gene expression correlated negatively with angiogenesis in HCC patients. Taken together, our findings demonstrate that LECT2 inhibits VEGF165-induced HCC angiogenesis through directly binding to VEGFR2 and has broad applications in treating VEGF-mediated solid tumors.

Overexpression of DNA 5′-cytosine-methyltransferases (DNMT), which are enzymes that methylate the cytosine residue of CpGs, is involved in many cancers. However, the mechanism of DNMT overexpression remains unclear. Here, we showed that wild-type p53 negatively regulated DNMT1 expression by forming a complex with specificity protein 1 (Sp1) protein and chromatin modifiers on the DNMT1 promoter. However, the stoichiometry between p53 and Sp1 determined whether Sp1 acts as a transcription activator or corepressor. Low level of exogenous Sp1 enhanced the repressive activity of endogenous p53 on the DNMT1 promoter whereas high level of Sp1 upregulated DNMT1 gene expression level in A549 (p53 wild-type) cells. In H1299 (p53 null) cells, exogenous Sp1 induced DNMT1 expression in a dose-dependent manner. We also discovered a new mechanism whereby high level of Sp1, via its COOH-terminal domain, induced interaction between p53 and MDM2, resulting in degradation of p53 by MDM2-mediated ubiquitination. Clinical data from 102 lung cancer patients indicated that overexpression of DNMT1 was associated with p53 mutation (P = 0.014) and high expression of Sp1 protein (P = 0.006). In addition, patients with overexpression of both DNMT1 and Sp1 proteins showed poor prognosis (P = 0.037). Our cell and clinical data provided compelling evidence that deregulation of DNMT1 is associated with gain of transcriptional activation of Sp1 and/or loss of repression of p53. DNMT1 overexpression results in epigenetic alteration of multiple tumor suppressor genes and ultimately leads to lung tumorigenesis and poor prognosis. Cancer Res; 70(14); 5807–17. ©2010 AACR.

Purpose: Overexpression of DNA 5′-cytosine-methyltransferase 3A (DNMT3A), which silences genes including tumor suppressor genes (TSG), is involved in many cancers. Therefore, we examined whether the transcriptional deregulation of RB/MDM2 pathway was responsible for DNMT3A overexpression and analyzed the therapeutic potential of MDM2 antagonist for reversing aberrant DNA methylation status in lung cancer. Experimental Design: The regulation of DNMT3A expression and TSG methylation status by RB/MDM2 was assessed in cancer cell lines and patients. The effects of Nutlin-3, an MDM2 antagonist, on tumor growth in relation to DNMT3A expression and TSG methylation status were examined by xenograft model. Results: We found that RB suppressed DNMT3A promoter activity and mRNA/protein expression through binding with E2F1 protein to the DNMT3A promoter, leading to the decrease of methylation level globally and TSG specifically. In addition, MDM2 dramatically induced DNMT3A expression by negative control over RB. In clinical study, MDM2 overexpression inversely correlated with RB expression, while positively associating with overexpression of DNMT3A in samples from patients with lung cancer. Patients with high MDM2 and low RB expression showed DNMT3A overexpression with promoter hypermethylation in TSGs. Treatment with Nutlin-3, an MDM2 antagonist, significantly suppressed tumor growth and reduced DNA methylation level of TSGs through downregulation of DNMT3A expression in xenograft studies. Conclusions: This study provides the first cell, animal, and clinical evidence that DNMT3A is transcriptionally repressed, in part, by RB/E2F pathway and that the repression could be attenuated by MDM2 overexpression. MDM2 is a potent target for anticancer therapy to reverse aberrant epigenetic status in cancers. Clin Cancer Res; 18(16); 4325–33. ©2012 AACR.

Existence of humoral immunity has been previously demonstrated in malignant ascitic fluids. However, only a limited number of immunogenic tumor-associated antigens (TAAs) were identified, and few of which are associated with ovarian cancer. Here, we identified salt-inducible kinase 3 (SIK3) as a TAA through screening of a random peptide library in the phage display system. Overexpression of SIK3 markedly promoted cell proliferation, attenuated p21(Waf/Cip1) and p27(Kip) expressions in low-grade OVCAR3 cells, and permitted the cells to grow in mice. Decrease in SIK3 expression in high-grade SK-OV3 cells consistently demonstrated its tumorigenic potency by modulating the protein levels of cell cycle regulators. When the expressions of SIK3 and CA125 were compared in cancer tissues, immunohistochemical (IHC) studies indicated that cytoplasm-localized SIK3 was highly expressed in 55% of the ovarian cancer samples. In contrast, it was rarely detected in adenomyosis, leiomyoma and normal ovary tissues, showing its higher specificity (97%) to CA125 (65%) in ovarian cancer. Moreover, experiments using pharmacological inhibitors to block SIK3-induced p21(Waf/Cip1) expression revealed that activation of c-Src and phosphoinositide-3-kinase were critically required for its biological activity, suggesting that they are the downstream signaling mediators of SIK3. These data were further supported by IHC studies, showing coexpression of c-Src with SIK3 in 85% of the ovarian tumor samples stained positive for SIK3. Collectively, our findings indicate that SIK3 is a novel ovarian TAA. Overexpression of SIK3 promotes G1/S cell cycle progression, bestows survival advantages to cancer cells for growth and correlates the clinicopathological conditions of patients with ovarian cancer.