KIF17 maintains the epithelial phenotype of breast cancer cells and curbs tumour metastasis.

Kinesin superfamily motor protein 17 (KIF17) was previously identified downregulated in breast cancer and correlated with patient prognosis. However, its pathophysiological role in tumours remains unknown. Here, we confirmed that KIF17 was significantly under-expressed in breast cancer tissues and low KIF17 expression correlated with poor outcomes in patients with breast cancer. In vitro and in vivo experiments demonstrated that KIF17 overexpression in breast cancer cell lines significantly inhibited breast cancer invasion and metastasis. By establishing the lung metastatic MDA-MB-231 cell lines, we found a transient silence of KIF17 during the initiation of breast cancer metastasis. Further experiments revealed that KIF17 might suppress metastasis by regulating the level of acetylated tubulin to maintain cytoskeleton stability. Eventually, we found that the low expression of KIF17 in breast cancer is regulated by DNMT1-mediated 5-mC DNA methylation and epigenetic silencing. Decitabine can effectively improve the expression level of KIF17 in breast cancer cells. Our study demonstrates that KIF17 mediates microtubule acetylation to maintain the stability of microtubules, thereby inhibiting tumour invasion and metastasis.

LINC01194 recruits NUMA1 to promote ubiquitination of RYR2 to enhance malignant progression in triple-negative breast cancer.

Long intergenic nonprotein coding RNA 1194 (LINC01194) has been reported as an oncogene in several cancer types, but its expression and potential role in triple-negative breast cancer (TNBC) are still unclear. We found that LINC01194 was significantly highly expressed in TNBC based on The Cancer Genome Atlas (TCGA) database. Data from in vitro experiments and in vivo assays demonstrated that LINC01194 promoted TNBC progression. Through bioinformatics prediction, mass spectrometry, and mechanical experiments, we found that LINC01194 could recruit nuclear mitotic apparatus protein 1 (NUMA1) to bind to the untranslated region (3'UTR) of ubiquitin-conjugating enzyme E2 C (UBE2C) 3' and stabilize UBE2C mRNA. Moreover, we found that UBE2C acted as an ubiquitin ligase to promote the ubiquitination and degradation of ryanodine receptor type 2 (RYR2) that inhibited the progression of TNBC by inhibiting the Wnt/ß-catenin signaling pathway. In summary, LINC01194 activate the Wnt/ß-catenin signaling pathway and accelerates the malignant progression of TNBC by recruiting NUMA1 to stabilize UBE2C mRNA and thus promotes RYR2 ubiquitination and degradation. These findings might provide a more effective therapeutic strategy for TNBC patients.

LncRNA LGALS8-AS1 Promotes Breast Cancer Metastasis Through miR-125b-5p/SOX12 Feedback Regulatory Network.

BACKGROUND: Metastasis is a major factor weakening the long-term survival of breast cancer patients. Increasing evidence revealed that long non-coding RNAs (lncRNAs) were involved in the occurrence and development of breast cancer. In this study, we aimed to investigate the role of LGALS8-AS1 in the metastatic progression of breast cancer cells and its potential mechanisms. RESULTS: The lncRNA LGALS8-AS1 was highly expressed in breast cancer and associated with poor survival. LGALS8-AS1 functioned as an oncogenic lncRNA that promoted the metastasis of breast cancer both in vitro and in vivo. It upregulated SOX12 via competing as a competing endogenous RNA (ceRNA) for sponging miR-125b-5p and acted on the PI3K/AKT signaling pathway to promote the metastasis of breast cancer. Furthermore, SOX12, in turn, activated LGALS8-AS1 expression via direct recognition of its sequence binding enrichment motif on the LGALS8-AS1 promoter, thereby forming a positive feedback regulatory loop. CONCLUSION: This study manifested a novel mechanism of LGALS8-AS1 facilitating the metastasis of breast cancer. The LGALS8-AS1/miR-125b-5p/SOX12 reciprocal regulatory loop dyscrasia promoted the migration and invasion of breast cancer cells. This signaling axis could be applicable to the design of novel therapeutic strategies against this malignancy.

Patient-Derived Organoids Can Guide Personalized-Therapies for Patients with Advanced Breast Cancer.

Most breast cancers at an advanced stage exhibit an aggressive nature, and there is a lack of effective anticancer options. Herein, the development of patient-derived organoids (PDOs) is described as a real-time platform to explore the feasibility of tailored treatment for refractory breast cancers. PDOs are successfully generated from breast cancer tissues, including heavily treated specimens. The microtubule-targeting drug-sensitive response signatures of PDOs predict improved distant relapse-free survival for invasive breast cancers treated with adjuvant chemotherapy. It is further demonstrated that PDO pharmaco-phenotyping reflects the previous treatment responses of the corresponding patients. Finally, as clinical case studies, all patients who receive at least one drug predicate to be sensitive by PDOs achieve good responses. Altogether, the PDO model is developed as an effective platform for evaluating patient-specific drug sensitivity in vitro, which can guide personal treatment decisions for breast cancer patients at terminal stage.

ZIPK activates the IL-6/STAT3 signaling pathway and promotes cisplatin resistance in gastric cancer cells.

Gastric cancer is one of the most common malignant cancers globally. Chemotherapy resistance remains a major obstacle in the treatment of gastric cancer, and the molecular mechanisms underlying drug resistance are still not well understood. We previously reported that Zipper interacting protein kinase (ZIPK), also known as death-associated protein kinase3, exerts an oncogenic effect on gastric cancer via activation of Akt/NF-κB signaling and promotion of stemness. Here, we explored the roles of ZIPK in cisplatin resistance. We report that ZIPK enhances cell proliferation and invasion and reduces the antitumor activity of cisplatin in gastric cancer. In addition, our western blot data suggest that ZIPK activated the IL-6/STAT3 signaling pathway. Furthermore, ZIPK increased the expression of IL-6 and multidrug-resistance genes. Using the STAT3 inhibitor stattic to block the IL-6/STAT3 signaling pathway strongly increased the sensitivity of ZIPK-expressed cells to cisplatin. In conclusion, ZIPK may play a role in cisplatin resistance through activation of the IL-6/ STAT3 signaling pathway. Inhibition of STAT3 in gastric cancer overexpressing ZIPK might have potential to improve the efficacy of cisplatin.

METTL1/WDR4-mediated m7G tRNA modifications and m7G codon usage promote mRNA translation and lung cancer progression.

Mis-regulated epigenetic modifications in RNAs are associated with human cancers. The transfer RNAs (tRNAs) are the most heavily modified RNA species in cells; however, little is known about the functions of tRNA modifications in cancers. In this study, we uncovered that the expression levels of tRNA N7-methylguanosine (m7G) methyltransferase complex components methyltransferase-like 1 (METTL1) and WD repeat domain 4 (WDR4) are significantly elevated in human lung cancer samples and negatively associated with patient prognosis. Impaired m7G tRNA modification upon METTL1/WDR4 depletion resulted in decreased cell proliferation, colony formation, cell invasion, and impaired tumorigenic capacities of lung cancer cells in vitro and in vivo. Moreover, gain-of-function and mutagenesis experiments revealed that METTL1 promoted lung cancer growth and invasion through regulation of m7G tRNA modifications. Profiling of tRNA methylation and mRNA translation revealed that highly translated mRNAs have higher frequencies of m7G tRNA-decoded codons, and knockdown of METTL1 resulted in decreased translation of mRNAs with higher frequencies of m7G tRNA codons, suggesting that tRNA modifications and codon usage play an essential function in mRNA translation regulation. Our data uncovered novel insights on mRNA translation regulation through tRNA modifications and the corresponding mRNA codon compositions in lung cancer, providing a new molecular basis underlying lung cancer progression.

DAPK3 inhibits gastric cancer progression via activation of ULK1-dependent autophagy.

Dysregulation of the balance between cell proliferation and cell death is a central feature of malignances. Death-associated protein kinase 3 (DAPK3) regulates programmed cell death including apoptosis and autophagy. Our previous study showed that DAPK3 downregulation was detected in more than half of gastric cancers (GCs), which was related to tumor invasion, metastasis, and poor prognosis. However, the precise molecular mechanism underlying DAPK3-mediated tumor suppression remains unclear. Here, we showed that the tumor suppressive function of DAPK3 was dependent on autophagy process. Mass spectrometry, in vitro kinase assay, and immunoprecipitation revealed that DAPK3 increased ULK1 activity by direct ULK1 phosphorylation at Ser556. ULK1 phosphorylation by DAPK3 facilitates the ULK1 complex formation, the VPS34 complex activation, and autophagy induction upon starvation. The kinase activity of DAPK3 and ULK1 Ser556 phosphorylation were required for DAPK3-modulated tumor suppression. The coordinate expression of DAPK3 with ULK1 Ser556 phosphorylation was confirmed in clinical GC samples, and this co-expression was correlated with favorable survival outcomes in patients. Collectively, these findings indicate that the tumor-suppressor roles of DAPK3 in GC are associated with autophagy and that DAPK3 is a novel autophagy regulator, which can directly phosphorylate ULK1 and activate ULK1. Thus, DAPK3 might be a promising prognostic autophagy-associated marker.

Low expression of CDK12 in gastric cancer is correlated with advanced stage and poor outcome.

BACKGROUND: Cyclin-dependent kinase 12 (CDK12) belongs to the cyclin-dependent kinase (CDK) family, modulating multiple cellular functions including DNA damage response (DDR), development and cellular differentiation, transcription, mRNA processing, splicing and pre-mRNA processing. CDK12 has been reported as both tumor suppressor and oncogene in various kinds of tumor. The function of CDK12 in gastric cancer (GC) remains unclear. METHODS/RESULTS: CDK12 mRNA expression was decreased in GC compared with non-tumor tissue based on GEO database. Also, low mRNA expression of CDK12 was detected in GC cell lines by qPCR. Similarly, CDK12 protein expression was also reduced in GC tissues compared with adjacent non-tumor tissues in 177 GC patients as shown by immunohistochemistry. Low expression of CDK12 was associated with organ metastasis, poorly differentiated adenocarcinoma and advanced stage. Consistent with human protein atlas database analysis, Low expression of CDK12 was correlated with worse overall survival (P < 0.001). Multivariate Cox regression indicated that low expression of CDK12 was an independent prognostic factor for GC patients (P < 0.001). Finally, a gene set enrichment analysis was performed to detect underlying internal mechanisms and biological processes. CONCLUSIONS: CDK12 is down-regulated in GC and its expression is negatively correlated with advanced stage, poorly differentiated adenocarcinoma and poor outcomes. Our findings suggest that CDK12 may be a potential tumor suppressor in GC.

ZNF367-induced transcriptional activation of KIF15 accelerates the progression of breast cancer.

Breast cancer (BC) is one of the most common female cancers, and its incidence has been increasing in recent years. Although treatments are continuously improving, the prognosis of patients in the advanced stage is still unsatisfactory. Thus, an in-depth understanding of its molecular mechanisms is necessary for curing breast cancer. KIF15 is a tetrameric spindle motor which can regulate mitosis in cellular process and exert the crucial functions in several cancers. The purpose of our research was to investigate the functions of KIF15 in breast cancer. We tested the expression of KIF15 in breast cancer tissues and the survival rate of breast cancer patients with high or low level of KIF15 through TCGA data. What's more, western blot and immunohistochemistry assay were utilized to evaluate the protein level and mRNA level of KIF15 in breast cancer tissues. Then CCK-8, wound healing, transwell and flow cytometry experiments were adopted separately to test cell viability, migration, invasion and cell cycle distribution. We discovered that KIF15 was highly expressed in breast cancer tissues and high level KIF15 was associated with a low survival rate of breast cancer patients. Moreover, silence of KIF15 suppressed cell viability, migration, invasion and cell cycle distribution. Following, we discovered that ZNF367 was the upstream transcription factor of KIF15. In addition, silenced ZNF367 could also repress the growth of breast cancer cells. And rescue experiments indicated that overexpressed KIF15 could counteract the inhibition effect of silencing ZNF367 on the progression of breast cancer. Importantly, we discovered that KIF15 and ZNF367 were associated with the regulation of cell cycle. In short, ZNF367-activated KIF15 accelerated the progression of breast cancer by regulating cell cycle progress.

Nudix hydrolase 1 is a prognostic biomarker in hepatocellular carcinoma.

We investigated the prognostic significance of Nudix hydrolase 1 (NUDT1) in hepatocellular carcinoma (HCC). NUDT1 mRNA and protein levels were significantly higher in HCC tissues than normal liver tissues. The level of NUDT1 expression correlated with tumor grade, stage, size, differentiation, degree of vascular invasion, overall survival (OS), and disease-free survival (DFS) in HCC patients. Multivariate analysis showed that NUDT1 expression was an independent prognostic factor for OS and DFS in HCC patients. We constructed a prognostic nomogram with NUDT1 expression, AFP levels, vascular invasion, Child-Pugh classification, age, sex, AJCC staging, and tumor differentiation as variables. This nomogram was highly accurate in predicting the 5-year OS of HCC patients (c-index= 0.709; AUC= 0.740). NUDT1 silencing in HCC cells significantly reduced their survival, colony formation, migration, and invasiveness. Gene set enrichment analysis showed that biological pathways related to cell cycle, fatty acid metabolism, bile acid and bile salt metabolism, and PLK1 signaling were associated with NUDT1, as were the gene ontology terms "DNA binding transcription activator activity," "RNA polymerase II," "nuclear division," and "transmembrane transporter activity." Our study thus demonstrates that NUDT1 is a prognostic biomarker with therapeutic potential in HCC patients.

Expression of autophagy-related factor p62 for lung cancer diagnosis and prognosis: A systematic review and meta-analysis.

p62/SQSTM1 is the scaffold protein implicated in selective autophagy, which is induced by cellular stress. Research has shown that p62 is highly expressed in cancer. Moreover, p62 can easily promote tumor metastasis. However, studies have not reached a consensus on the relationship of p62 expression with the diagnosis and prognosis of lung cancer. We conducted a systematic review and meta-analysis of studies on p62 expression in the prognosis and clinical-pathological parameters of lung cancer patients. Literature search was performed with PubMed, Web of Science, EMBASE, Cochrane Library, and SpringerLink databases. Fixed-effects and random-effects models were used to study the relationship of p62 expression with patients' overall survival (OS) and clinical-pathological parameters. I2 was used to test for heterogeneity. Egger's test was used to assess publication bias. The meta-analysis collected and considered 13 articles, which included 1393 lung cancer patients. The studies show that the high expression of p62 is associated with poor OS in lung cancer patients. The clinical-pathological parameters of patients show that p62 is more highly expressed in high TNM stage (II + III + IV VS. I), Lymph node metastasis (N1 VS. N0), and distant metastases (D1 VS. D0). However, there is no correlation between the p62 expression and the Beclin 1 and LC3B in lung cancer patients. In conclusion, the over-expression of p62 is associated with poor OS in lung cancer patients and can be used as a biomarker for lung cancer diagnosis and prognosis.

ACE2 inhibits breast cancer angiogenesis via suppressing the VEGFa/VEGFR2/ERK pathway.

BACKGROUND: Breast cancer angiogenesis is key for metastasis and predicts a poor prognosis. Angiotensin-converting enzyme 2 (ACE2), as a member of the renin-angiotensin system (RAS), was reported to restrain the progression of hepatocellular carcinoma (HCC) and non-small cell lung cancer (NSCLC) through inhibiting angiogenesis. However, the relationship between ACE2 and breast cancer angiogenesis remains unclear. METHODS: The prognosis and relative gene selection were analysed using the GEPIA, GEO, TCGA and STRING databases. ACE2 expression in breast cancer tissue was estimated by reverse transcription-quantitative polymerase chain reaction (qPCR). Breast cancer cell migration, proliferation and angiogenesis were assessed by Transwell migration, proliferation, tube formation, and wound healing assays. The expression of vascular endothelial growth factor A (VEGFa) was detected by qPCR and Western blotting. The phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2), mitogen-activated protein kinase 1/2 (MEK1/2), and extracellular signal-regulated protein kinase 1/2 (ERK1/2) was examined by Western blotting. Breast cancer metastasis and angiogenesis in vivo were measured using a zebrafish model. RESULTS: ACE2 was downregulated in breast cancer patients. Patients with higher ACE2 expression had longer relapse-free survival (RFS). In vitro, ACE2 inhibited breast cancer migration. Meanwhile, ACE2 in breast cancer cells inhibited human umbilical vascular endothelial cell (HUVEC) proliferation, tube formation and migration. In the zebrafish model, ACE2 inhibited breast cancer cell metastasis, as demonstrated by analyses of the number of disseminated foci and the metastatic distance. Neo-angiogenesis was also decreased by ACE2. ACE2 downregulated the expression of VEGFa in breast cancer cells. Furthermore, ACE2 in breast cancer cells inactivated the phosphorylation of VEGFR2, MEK1/2, and ERK1/2 in HUVECs. CONCLUSIONS: Our findings suggest that ACE2, as a potential resister to breast cancer, might inhibit breast cancer angiogenesis through the VEGFa/VEGFR2/ERK pathway. TRIAL REGISTRATION: Retrospectively registered.

Evaluation of the prognostic value of paraoxonase 1 in the recurrence and metastasis of hepatocellular carcinoma and establishment of a liver-specific predictive model of survival.

BACKGROUND: Hepatocellular carcinoma is a malignant tumor with a highly invasive and metastatic phenotype, and the detection of potential indicators associated with its recurrence and metastasis after surgical resection is critical for patient survival. METHODS: Transcriptome data for large cohorts (n = 1432) from multicenter sources were comprehensively analyzed to explore such potential signatures. The prognostic value of the selected indicators was investigated and discussed, and a comparison with conventional clinicopathological features was performed. A survival predictive nomogram for 5-year survival was established with the selected indicator using the Cox proportional hazards regression. To validate the indicator at the protein level, we performed immunohistochemical staining with paraffin-embedded slides of hepatocellular carcinoma samples (n = 67 patients) from our hospital. Finally, a gene set enrichment analysis (GSEA) was performed to detect the underlying biological processes and internal mechanisms. RESULTS: The liver-specific protein paraoxonase 1 (PON1) was found to be the most relevant indicator of tumor recurrence, invasiveness, and metastasis in the present study, and the downregulation of PON1 might reveal poor survival for patients with hepatocellular carcinoma. The C-index of the PON1-related nomogram was 0.714, thus indicating a more effective predictive performance than the 7th American Joint Committee on Cancer (AJCC) tumor stage (0.534), AJCC T stage (0.565), or alpha-fetoprotein (0.488). The GSEA revealed that PON1 was associated with several hepatocellular carcinoma-related pathways, including the cell cycle, DNA replication, gap junction and p53 downstream pathways. CONCLUSIONS: The downregulation of paraoxonase 1 may suggest worse outcomes and a higher recurrence rate. Thus, paraoxonase 1 might represent an indicator for predicting the survival of patients with hepatocellular carcinoma.

miR-300 regulates the epithelial-mesenchymal transition and invasion of hepatocellular carcinoma by targeting the FAK/PI3K/AKT signaling pathway.

Several microRNAs (miRNAs) have been closely correlated with the development of hepatocellular carcinoma (HCC). However, the involvement of miR-300 in the development of HCC remains unknown. This study elucidated the potential molecular mechanisms of miR-300 in the modulation of the epithelial-mesenchymal transition (EMT) and invasion of HCC. The expression levels of miR-300 in HCC cells and clinical samples were detected by quantitative real-time PCR and in situ hybridization. The in vitro function of miR-300 in HCC was evaluated using a migration/invasion assay. Quantitative real-time PCR, western blotting, immunofluorescence and immunohistochemistry were used to validate the roles of miR-300 and FAK/PI3K/AKT in EMT progression. A dual-luciferase reporter assay was performed to confirm the target gene. miR-300 was down-regulated in HCC and significantly correlated with a poor prognosis in HCC patients. The down-regulation of miR-300 increased the invasiveness of the HCC cells, and promoted the EMT in both HCC tissues and HCC cells. In contrast, up-regulation of miR-300 led to the opposite results. Ectopic overexpression of miR-300 reversed TGF-ß1-induced EMT in SMMC-7721 cells, and according to a dual-luciferase reporter assay and rescue assay, miR-300 inhibits the EMT-mediated migration and invasion of HCC cells via the targeted modulation of FAK and the downstream PI3K/AKT signaling pathway. miR-300 targeting modulates FAK, and the PI3K/AKT signaling pathway inhibits the EMT and suppresses the migration and invasion of HCC cells. Thus, miR-300 represents a promising therapeutic target for HCC.

Frizzled7 Promotes Epithelial-to-mesenchymal Transition and Stemness Via Activating Canonical Wnt/ß-catenin Pathway in Gastric Cancer.

Aberrant activation of Wnt signaling is a crucial event in tumor development and metastasis. Wnt signaling is commonly divided into canonical and non-canonical signaling pathways based on whether ß-catenin is activated (canonical). The two signaling pathways are initiated by Wnt ligand binding to the surface Frizzled (FZD) receptors, and regulate cancer stem cell self-renewal and epithelial-mesenchymal transition (EMT). Frizzled 7 (FZD7), a member of Frizzled family, promotes cell proliferation and invasiveness in many cancers, suggesting that FZD7 transmitting Wnt signaling is important for driving cancer growth. FZD7 expression has been reported to be up-regulated in human primary gastric cancer tissues. However, the molecular mechanism by which FZD7 promotes gastric cancer(GC) development and progression is not fully understood. Our present study showed that FZD7 was overexpressed in clinical GC samples, and thus was correlated with tumor invasion, lymphatic and organ metastasis, late TNM stages and poor patient survival. The endogenous expression of FZD7 was significantly increased in cancer stem cell-enriched spheres compared with adherent cells. Furthermore, RNA interference-mediated silencing of FZD7 inhibited proliferation, migration and invasion in gastric cancer cells. Moreover, ablation of FZD7 down-regulated EMT and the expression levels of cancer stem cell markers, and these inhibitions were associated with attenuated canonical Wnt/ß-catenin signaling. The results suggest that Wnt canonical pathway may contribute to tumorigenesis and metastasis, indicating that FZD7 could be a potential therapeutic target for gastric cancer.

miR-17-5p suppresses cell proliferation and invasion by targeting ETV1 in triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) is the malignancy with the worst outcome among all breast cancer subtypes. We reported that ETV1 is a significant oncogene in TNBC tumourigenesis. Consequently, investigating the critical regulatory microRNAs (miRNAs) of ETV1 may be beneficial for TNBC targeted therapy. METHODS: We performed in situ hybridization (ISH) and immunohistochemistry (IHC) to detect the location of miR-17-5p and ETV1 in TNBC patient samples, respectively. miR-17-5p expression in TNBC tissues and cell lines was assessed by quantitative real-time PCR (qRT-PCR). ETV1 expression was evaluated by qRT-PCR, western blotting and IHC. Cell Counting Kit-8 (CCK-8), colony formation, Transwell and wound closure assays were utilized to determine the TNBC cell proliferation and migration capabilities. In vivo tumour metastatic assays were performed in a zebra fish model. RESULTS: The abundance of miR-17-5p was significantly decreased in TNBC cell lines and clinical TNBC tissues. The miR-17-5p expression levels were closely correlated with tumour size (P < 0.05) and TNM stage (P < 0.05). By contrast, the expression of ETV1 was significantly up-regulated in TNBC cell lines and tissues. There is an inverse correlation between the expression status of miR-17-5p and ETV1 (r = -0.28, P = 3.88 × 10-3). Luciferase reporter assay confirmed that ETV1 was a direct target of miR-17-5p. Forced expression of miR-17-5p in MDA-MB-231 or BT549 cells significantly decreased ETV1 expression and suppressed cell proliferation, migration in vitro and tumour metastasis in vivo. However, rescuing the expression of ETV1 in the presence of miR-17-5p significantly recovered the cell phenotype. High miR-17-5p expression was associated with a significantly favourable prognosis, in either the ETV1-positive or ETV1-negative groups (log-rank test, P < 0.001; P < 0.001). Both univariate and multivariate analyses showed that miR-17-5p and ETV1 were independent risk factors in the prognosis of TNBC patient. CONCLUSIONS: Our data indicate that miR-17-5p acts as a tumour suppressor in TNBC by targeting ETV1, and a low-abundance of miR-17-5p may be involved in the pathogenesis of TNBC. These findings indicate that miR-17-5p may be a therapeutic target for TNBC.

miR-338-3p inhibits epithelial-mesenchymal transition and metastasis in hepatocellular carcinoma cells.

Down-regulation of the miRNA miR-338-3p correlates with the invasive ability of hepatocellular carcinoma (HCC) cells. However, it is currently unclear whether down-regulation of miR-338-3p induces epithelial-mesenchymal transition (EMT), which may be the underlying mechanism governing HCC invasion. Here, we demonstrate that restoration of miR-338-3p expression via transfection of a miR-338-3p mimic reversed EMT and inhibited the motility and invasiveness of HCC cells. Conversely, silencing of endogenous miR-338-3p expression with a miR-338-3p-specific inhibitor induced EMT and enhanced HCC cell motility. Additionally, Snail1 (an upstream regulatory protein of EMT) and Gli1 (a key transcription factor in the sonic hedgehog (SHH) signaling pathway) expression was up-regulated in cells treated with the miR-338-3p inhibitor and down-regulated by the miR-338-3p mimic. Further analyses demonstrated that miR-338-3p inhibitor-induced EMT in HCC cells was blocked by treatment with a small interfering RNA (siRNA) targeting Snail1, that the SHH signaling pathway was required for both miR-338-3p inhibitor-induced EMT and up-regulation of Snail1, and that miR-338-3p targeted a sequence within the 3'-untranslated region of N-cadherin mRNA. Notably, miR-338-3p expression was significantly down-regulated in HCC samples from patients with metastases and was associated with poor metastasis-free survival rates. Lastly, correlations between the expression levels of miR-338-3p and E-cadherin, Smoothened (SMO), Gli1, Snail1, N-cadherin, and vimentin were confirmed in HCC xenograft tumors and HCC patient specimens. Our findings suggest that miR-338-3p suppresses EMT and metastasis via both inhibition of the SHH/Gli1 pathway and direct binding of N-cadherin. miR-338-3p is a potential therapeutic target for metastatic HCC.

Nuclear receptor NR4A1 is a tumor suppressor down-regulated in triple-negative breast cancer.

The nuclear receptor (NR) superfamily contains hormone-inducible transcription factors that regulate many physiological and pathological processes through regulating gene expression. NR4A1 is an NR family member that still does not have an identified endogenous ligand, and its role in cancer is also currently unclear and controversial. In this study, we aimed to define the expression profiles and specific role of NR4A1 in the highly malignant triple-negative breast cancer (TNBC), which still lacks available targeted therapies. Bioinformatic analysis revealed a decrease of NR4A1 mRNA expression in human TNBC samples. Semi-quantitative analysis of NR4A1 protein expression by immunohistochemistry also identified a progressive NR4A1 reduction during the development of mouse basal-like mammary tumors and a significant NR4A1 downregulation in human TNBC samples. Furthermore, the expression levels of NR4A1 in human TNBC were negatively associated with tumor stage, lymph node metastasis and disease recurrence. Moreover, ectopic expression of NR4A1 in MDA-MB-231, a TNBC cell line with little endogenous NR4A1, inhibited the proliferation, viability, migration and invasion of these cells, and these inhibitions were associated with an attenuated JNK1-AP-1-cyclin D1 pathway. NR4A1 expression also largely suppressed the growth and metastasis of these cell-derived tumors in mice. These results demonstrate that NR4A1 is downregulated in TNBC and restoration of NR4A1 expression inhibits TNBC growth and metastasis, suggesting that NR4A1 is a tumor suppressor in TNBC.

PSCA acts as a tumor suppressor by facilitating the nuclear translocation of RB1CC1 in esophageal squamous cell carcinoma.

Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy; its mechanisms of development and progression are poorly understood. By high-throughput transcriptome sequencing (RNA-Seq) profiling of three pairs of primary ESCCs and their corresponding non-tumorous tissues, we identified that prostate stem cell antigen (PSCA), a gene that encodes a glycosylphosphatidylinositol-anchored protein, is significantly downregulated in ESCC. Here, we reported decreased expression of PSCA in 188/218 (86.2%) of primary ESCC cases and was negatively regulated by its transcription factor sex-determining region Y-box5 that was significantly associated with the poor differentiation (P = 0.003), increased lymph node metastasis (P < 0.0001), advanced stage (P = 0.007), and disease-specific survival (P < 0.0001), but not associated with the recently reported transcrible rs2294008 (C > T) polymorphism in ESCC. Functional studies showed that PSCA could arrest cell cycle progression and promote cell differentiation independent of the start codon polymorphism. Further mechanistic studies revealed that retinoblastoma 1-inducible coiled-coil 1 (RB1CC1), a key signaling node to regulate cellular proliferation and differentiation, interacted specifically with PSCA in ESCC cells. Binding of PSCA and RB1CC1 in cytoplasm resulted in stabilization and translocation of RB1CC1 into nucleus, thereby activating key factors involved in cell cycle arrest and differentiation. Collectively, our data provide a novel molecular mechanism for the tumor suppressor role of PSCA and may help design effective therapy targeting PSCA-RB1CC1 pathway to control esophageal cancer growth and differentiation.

CD68 and interleukin 13, prospective immune markers for esophageal squamous cell carcinoma prognosis prediction.

PURPOSE: Oncology immunity was reported to play a key role in cancer development and progression, so we investigated the prediction role of several immune markers in esophageal squamous cell carcinoma (ESCC) patients after operation in this study. PATIENTS AND METHODS: 66 primary ESCC tumor tissues and four sets of tissue microarrays including 705 primary ESCC tumor tissues from four centers were collected and analyzed. Expressions of several immune markers in ESCC tumor tissue were detected with immunohistochemistry staining. Their distribution densities were analyzed with InForm™ 2.0.1 software. All statistic analyses were performed with SPSS16.0 and Stata version 10.0. RESULTS: Survival analyses assessed by Kaplan-Meier plots and log-rank tests demonstrated that densities of CD68 and interleukin 13 (IL-13) in tumor stroma were positively correlated with the overall survival of ESCC patients after operation (p < 0.01 for CD68, p < 0.001 for IL-13). Further, a model based on tumor stroma densities of CD68 and IL-13 was constructed and it could significantly classify patients with poor or good prognosis. This model could further identify high-risk group and low-risk group at the same Tumor lymph Nodes Metastases (TNM) stage. Lastly, a more accuracy model based on TNM stage, densities of CD68 and IL-13 was constructed to predict the prognosis of ESCC patient after operation. CONCLUSION: Combining the TNM staging system and densities of CD68 and IL-13 could substantially improve the prognosis prediction accuracy of ESCC patient after operation, which might be an excellent tool for selecting patients for individualized therapy in future.