Upregulated microRNA-301a in breast cancer promotes tumor metastasis by targeting PTEN and activating Wnt/β-catenin signaling

MicroRNAs (miRNAs) are strongly implicated in many cancers, including breast cancer. Recently, microRNA-301a (miR-301a) has been proved to play a substantial role in gastric cancer, but its functions in the context of breast cancer remain unknown. Here we report that miR-301a was markedly upregulated in primary tumor samples from patients with distant metastases and pro-metastatic breast cancer cell lines. Gain-of-function and loss-of-function studies showed that ectopic overexpression of miR-301a promoted breast cancer cell migration, invasion and metastasis both in vitro and in vivo. Notably, Wnt/β-catenin signaling was hyperactivated in metastatic breast cancer cells that express miR-301a, and mediated miR-301a-induced invasion and metastasis. Furthermore, miR-301a directly targeted and suppressed PTEN, one negative regulator of the Wnt/β-catenin signaling cascade. These results demonstrate that miR-301a maintains constitutively activated Wnt/β-catenin signaling by directly targeting PTEN, which promotes breast cancer invasion and metastasis. Taken together, our findings reveal a new regulatory mechanism of miR-301a and suggest that miR-301a might be a potential target in breast cancer therapy.     

Upregulated KDM4B promotes prostate cancer cell proliferation by activating autophagy

Castration-resistant prostate cancer (CRPC) causes most of the deaths in patients with prostate cancer (PCa). The androgen receptor (AR) axis plays an important role in castration resistance. Emerging studies showed that the lysine demethylase KDM4B is a key molecule in AR signaling and turnover, and autophagy plays an important role in CRPC. However, little is known about whether KDM4B promotes CRPC progression by regulating autophagy. Here we used an androgen-independent LNCaP (LNCaP-AI) cell line to assay aberrant KDM4B expression using qPCR and western blot analysis and investigated the function of KDM4B in regulating cell proliferation. We found that KDM4B was markedly increased in LNCaP-AI cells compared with LNCaP cells. KDM4B level was significantly correlated with the Gleason score in PCa tissues. In vitro, KDM4B overexpression in CRPC cells promoted cell proliferation, whereas knockdown of KDM4B significantly inhibited cell proliferation. Upregulated KDM4B contributed to activate Wnt/β-catenin signaling and autophagy. Moreover, KDM4B activated autophagy by regulating the Wnt/β-catenin signaling. Finally, we demonstrated that autophagy inhibition attenuated KDM4B-induced CRPC cell proliferation. Our results provided novel insights into the function of KDM4B-driven CRPC development and indicated that KDM4B may be served as a potential target for CRPC therapy.     

Long non-coding RNA ZFAS1 regulates the malignant progression of gastric cancer via the microRNA-200b-3p/Wnt1 axis

Gastric cancer is a common malignant tumor. Studies from our laboratory or others have shown that long non-coding RNA (lncRNA) zinc finger antisense (ZFAS)1 often acts as an oncogene. However, the molecular underpinnings of how ZFAS1 regulates gastric cancer remain to be elucidated. Results showed that ZFAS1 expression was upregulated, and microRNA-200b-3p (miR-200b) expression was downregulated in gastric cancer tissues. MiR-200b overexpression suppressed the proliferation, cell cycle process, and Wnt/β-catenin signaling of gastric cancer cells. Subsequently, we identified miR-200b is a target of ZFAS1 and Wnt1 is a target of miR-200b. Furthermore, promotion of cancer malignant progression and activation of Wnt/β-catenin signaling induced by ZFAS1 was counteracted by increasing miR-200b expression. In vivo, ZFAS1 knockdown suppressed the tumorigenesis with the upregulated miR-200b and the inactive Wnt/β-catenin signaling. Summarily, we demonstrated a critical role of miR-200b in gastric cancer, and ZFAS1 can promote malignant progression through regulating miR-200b mediated Wnt/β-catenin signaling.     

MicroRNA-107, an oncogene microRNA that regulates tumour invasion and metastasis by targeting DICER1 in gastric cancer

MicroRNAs are small non-coding RNA molecules that control expression of target genes. Previous studies showed that microRNA-107 (miR-107) is overexpressed in gastric cancer tissues compared with the matched normal tissues. However, it remains largely unclear as to how miR-107 exerts its function and modulates the malignant phenotypes of gastric cancer, because our understanding of miR-107 signalling pathways is limited. In this study, we demonstrate that miR-107 is frequently up-regulated in gastric cancers and its overexpression is significantly associated with gastric cancer metastasis. Furthermore, silencing the expression of miR-107 could inhibit gastric cancer cell migration and invasion in vitro and in vivo. Subsequent investigation characterized DICER1 as a direct target of miR-107. Up-regulation of DICER1 resulted in a dramatic reduction of in vitro migration, invasion, in vivo liver metastasis of nude mice, which is similar to that occurs with the silencing of miR-107, indicating that DICER1 functions as a metastasis suppressor in gastric cancer. Furthermore, the restoration of DICER1 can inhibit miR-107-induced gastric cancer cell invasion and metastasis. In conclusion, our results suggested that miR-107, an oncogene miRNA promoting gastric cancer metastasis through down-regulation of DICER1. Inhibition of miR-107 or restoration of DICER1 may represent a new potential therapeutic target for gastric cancer treatment.     

MicroRNA-137 Contributes to Dampened Tumorigenesis in Human Gastric Cancer by Targeting AKT2

MiRNAs play important roles in tumorigenesis. This study focused on exploring the effects and regulation mechanism of miRNA-137 on the biological behaviors of gastric cancer. Total RNA was extracted from tissues of 100 patients with gastric cancer and from four gastric cancer cell lines. Expression of miR-137 was detected by real-time PCR from 100 patients. The effects of miR-137 overexpression on gastric cancer cells’ proliferation, apoptosis, migration and invasion ability were investigated in vitro and in vivo. The target gene of miR-137 was predicted by Targetscan on line software, screened by dual luciferase reporter gene assay and demonstrated by western blot. As a result, the expression of miR-137 was significant reduced in gastric cancer cell line HGC-27, HGC-803, SGC-7901 and MKN-45 as well as in gastric cancer tissues compared with GES-1 cell or matched adjacent non-neoplastic tissues (p<0.001). The re-introduction of miR-137 into gastric cancer cells was able to inhibit cell proliferation, migration and invasion. The in vivo experiments demonstrated that the miR-137 overexpression can reduce the gastric cancer cell proliferation and metastasis. Bioinformatic and western blot analysis indicated that the miR-137 acted as tumor suppressor roles on gastric cancer cells through targeting AKT2 and further affecting the Bad and GSK-3β. In conclusion, the miR-137 which is frequently down-regulated in gastric cancer is potentially involved in gastric cancer tumorigenesis and metastasis by regulating AKT2 related signal pathways.     

Histone Demethylase KDM6B Promotes Epithelial-Mesenchymal Transition

Epithelial-mesenchymal transition (EMT) is a critical event that occurs in embryonic development, tissue repair control, organ fibrosis, and carcinoma invasion and metastasis. Although significant progress has been made in understanding the molecular regulation of EMT, little is known about how chromatin is modified in EMT. Chromatin modifications through histone acetylation and methylation determine the precise control of gene expression. Recently, histone demethylases were found to play important roles in gene expression through demethylating mono-, di-, or trimethylated lysines. KDM6B (also known as JMJD3) is a histone demethylase that might activate gene expression by removing repressive histone H3 lysine 27 trimethylation marks from chromatin. Here we report that KDM6B played a permissive role in TGF-β-induced EMT in mammary epithelial cells by stimulating SNAI1 expression. KDM6B was induced by TGF-β, and the knockdown of KDM6B inhibited EMT induced by TGF-β. Conversely, overexpression of KDM6B induced the expression of mesenchymal genes and promoted EMT. Chromatin immunoprecipitation (ChIP) assays revealed that KDM6B promoted SNAI1 expression by removing histone H3 lysine trimethylation marks. Consistently, our analysis of the Oncomine database found that KDM6B expression was significantly increased in invasive breast carcinoma compared with normal breast tissues. The knockdown of KDM6B significantly inhibited breast cancer cell invasion. Collectively, our study uncovers a novel epigenetic mechanism regulating EMT and tumor cell invasion, and has important implication in targeting cancer metastasis.     

Circ_0058106 promotes proliferation,metastasis and EMT process by regulating Wnt2b/β-catenin/c-Myc pathway through miR-185-3p in hypopharyngeal squamous cell carcinoma

Hypopharyngeal squamous cell carcinoma (HSCC) accounts 95% of hypopharyngeal cancer, which is characterized by high early metastasis rate and poor prognosis. It is reported that circular RNA is involved in the occurrence and development of cancer; however, the role of circRNA in hypopharyngeal cancer has little been investigated. We performed hypopharyngeal carcinoma circRNA microarray and qRT-PCR verification. The results showed circ_0058106 expression level was significantly upregulated in tumor tissues than in corresponding normal tissues. We found that circ_0058106 upregulation promoted proliferation, migration and invasion of HSCC cells, while knockdown of circ_0058106 inhibited proliferation, migration and invasion of HSCC cells both in vitro and in vivo. Bioinformatics predicted circ_0058106 may interact with miR-185-3p. We verified circ_0058106 directly bound miR-185-3p and downregulated miR-185-3p expression by using dual-luciferase reporter assay and qRT-PCR. Moreover, we proved circ_0058106 promoted HSCC cells tumorigenesis and EMT process by regulating Wnt2b/β-catenin/c-Myc pathway via miR-185-3p. In conclusion, our findings firstly confirmed the carcinogenic effect of circ_0058106 in promoting HSCC cells tumorigenesis, metastasis, invasion and EMT process by regulating Wnt2b/β-catenin/c-Myc pathway through sponging miR-185-3p, indicating that circ_0058106 may be a new therapeutic target and prognostic marker for HSCC.Subject terms: Head and neck cancer, Head and neck cancer     

MiR-125b regulates the proliferation and metastasis of triple negative breast cancer cells via the Wnt/β-catenin pathway and EMT

Background/aim: MiR-125b plays an important role in breast cancer. The current study was to explore the expression and function of miR-125b in triple negative breast cancer cells. Materials and methods: The expression of miR-125b in human TNBC samples and cell lines were examined by qRT-PCR. MTT, scratch assays and transwell assays were utilized to observe the proliferation, migration and invasion ability. MiR-125b’s target gene and downstream signaling pathways were investigated by Luciferase Reporter Assays, qRT-PCR, immunofluorescence assays and western bolt. Results: MiR-125b was highly expressed in human TNBC tissues and cell lines. Inhibiting miR-125b expression suppressed the proliferation, cell migration and invasion. The three-prime untranslated region (3´-UTR) of adenomatous polyposis coli (APC) mRNA contains miR-125b binding sites, and inhibiting miR-125b expression suppressed the activity of the intracellular Wnt/β-catenin pathways and EMT. Conclusion: Inhibiting miR-125b regulates the Wnt/β-catenin pathway and EMT to suppress the proliferation and migration of MDA-MB-468 TNBC cells.     

Alpha B‐crystallin promotes the invasion and metastasis of gastric cancer via NF‐κB‐induced epithelial‐mesenchymal transition

Alpha B‐crystallin (CRYAB) is overexpressed in a variety of cancers. However, little is known about its specific function and regulatory mechanism in gastric cancer. Here, we first explore the role of CRYAB in gastric cancer progression and metastasis. The expression of CRYAB was determined by western blot and immunohistochemistry in gastric cancer tissues. Besides, methods including stably transfected against CRYAB into gastric cancer cells, western blot, migration and invasion assays in vitro and metastasis assay in vivo were also conducted. The expression of CRYAB is up‐regulated in gastric cancer tissues compared with matched normal tissues. High expression level of CRYAB is closely correlated with cancer metastasis and shorter survival time in patients with gastric cancer. Additionally, CRYAB silencing significantly suppresses epithelial‐mesenchymal transition (EMT), migration and invasion of gastric cancer cells in vitro and in vivo, whereas CRYAB overexpression dramatically reverses these events. Mechanically, CRYAB facilitates gastric cancer cells invasion and metastasis via nuclear factor‐κ‐gene binding (NF‐κB)‐regulated EMT. These findings suggest that CRYAB expression predicts a poor prognosis in patients with gastric cancer. Besides, CRYAB contributes to gastric cancer cells migration and invasion via EMT, mediated by the NF‐κB signalling pathway, thus possibly providing a novel therapeutic target for gastric cancer.     

Down-regulated miR-625 suppresses invasion and metastasis of gastric cancer by targeting ILK

Accumulating evidence has shown that microRNAs are involved in multiple processes in cancer development and progression. Here, we report that expression of miR-625 is significantly down-regulated and negatively correlated with lymph node metastasis in gastric cancer. miR-625 significantly inhibits invasion and metastasis of gastric cancer cells both in vitro and in vivo. Moreover, we identify that ILK is a direct target gene for miR-625 and knockdown of ILK has a phenocopy of overexpression of miR-625. Taken together, our findings suggest that miR-625 plays an important role in the mechanism of tumor metastasis.     

miR-30b,Down-Regulated in Gastric Cancer,Promotes Apoptosis and Suppresses Tumor Growth by Targeting Plasminogen Activator Inhibitor-1

Background

Gastric cancer is one of the most common malignant diseases worldwide. Emerging evidence has shown that microRNAs (miRNAs) are associated with tumor development and progression. Our previous studies have revealed that H. pylori infection was able to induce the altered expression of miR-30b in gastric epithelial cells. However, little is known about the potential role of miR-30b in gastric cancer.

Methods

We analyzed the expression of miR-30b in gastric cancer cell lines and human gastric cancer tissues. We examined the effect of miR-30b mimics on the apoptosis of gastric cancer cells in vitro by flow cytometry (FCM) and caspase-3/7 activity assays. Nude mouse xenograft model was used to determine whether miR-30b is involved in tumorigenesis of gastric cancer. The target of miR-30b was identified by bioinformatics analysis, luciferase assay and Western blot. Finally, we performed the correlation analysis between miR-30b and its target expression in gastric cancer.

Results

miR-30b was significantly down-regulated in gastric cancer cells and human gastric cancer tissues. Enforced expression of miR-30b promoted the apoptosis of gastric cancer cells in vitro, and miR-30b could significantly inhibit tumorigenicity of gastric cancer by increasing the apoptosis proportion of cancer cells in vivo. Moreover, plasminogen activator inhibitor-1 (PAI-1) was identified as the potential target of miR-30b, and miR-30b level was inversely correlated with PAI-1 expression in gastric cancer. In addition, silencing of PAI-1 was able to phenocopy the effect of miR-30b overexpression on apoptosis regulation of cancer cells, and overexpression of PAI-1 could suppressed the effect of promoting cell apoptosis by miR-30b, indicating PAI-1 is potentially involved in miR-30b-induced apoptosis on cancer cells.

Conclusion

miR-30b may function as a novel tumor suppressor gene in gastric cancer by targeting PAI-1 and regulating the apoptosis of cancer cells. miR-30b could serve as a potential biomarker and therapeutic target against gastric cancer.     

miR-125b在前列腺癌1E8细胞运动转移中的作用及其分子机制的初步探讨

目的 研究 miR-125b在前列腺癌高低转移潜能细胞中的表达差异及其对高转移细胞株1E8细胞的运动转移中的作用和可能的分子机制.方法 realtime PCR法检测前列腺癌高低转移潜能配对细胞系中 miR-125b的表达差异.通过划痕实验及transwell实验观察1E8细胞及转染 miR-125b 抑制剂及其阴性对照后该细胞运动转移能力的变化.结果 realtime PCR结果显示高转移潜能1E8细胞中miR-125b表达水明显高于低转移潜能2B4细胞;下调miR-125b会减弱1E8细胞的运动转移能力.结论 miR-125b可促进前列腺癌细胞的运动转移能力.     

Long noncoding RNA LINC00629 restrains the progression of gastric cancer by upregulating AQP4 through competitively binding to miR-196b-5p

Gastric cancer continues to be a common cancer in the world with high incidence and mortality. Accumulating evidence has implicated long noncoding RNAs (lncRNAs) in gastric cancer progression. Here, this study identified the potential role of a novel lncRNA, LINC00629 in gastric cancer and to elucidate the underlying mechanism. Initially, microarray-based gene expression profiling of gastric cancer was employed to identify differentially expressed genes. Next, the expression of LINC00629, microRNA-196b-5p (miR-196b-5p) and aquaporin 4 (AQP4) in clinical gastric cancer tissues was determined and the cell line presenting with the lowest LINC00629 expression was selected. The interaction among LINC00629, miR-196b-5p, and AQP4 was identified. Expression of LINC00629, miR-196b-5p, and AQP4 in gastric cancer cells were altered and then biological behaviors of gastric cancer cells were assessed by 5-ethynyl-2′-deoxyuridine and Transwell assays. Tumor formation in vivo was evaluated in nude mice. In gastric cancer, expression of LINC00629 and AQP4 was downregulated, and expression of miR-196b-5p was upregulated. Proliferation, invasion, and migration of gastric cancer cells were reduced after overexpression of LINC00629. LINC00629 competitively bound to miR-196b-5p, while AQP4 was a target of miR-196b-5p. Either downregulating miR-196b-5p or upregulating AQP4 could restrain the development of gastric cancer in vitro. LINC00629 overexpression repressed the growth of transplanted tumors in vivo. Taken together, LINC00629 competitively bound to miR-196b-5p to upregulate AQP4 expression, thereby inhibiting gastric cancer progression. Therefore, understanding of this mechanism may help to improve gastric cancer treatment.     

miR-125b靶向MCL1抑制胃癌 MGC-803细胞增殖

探讨mi R-125b对胃癌MGC-803细胞增殖的影响及机制,为阐明胃癌发病的分子机制提供实验依据.采用q RT-PCR和原位杂交,检测mi R-125b在正常胃黏膜(NGM)和胃癌(GAC)组织中的表达.将mi R-125b导入胃癌MGC-803细胞,观察mi R-125b高表达对MGC-803细胞增殖的影响.利用Targetscan 6.2软件及荧光素酶报告基因检测,分析mi R-125b对MCL1基因的靶向性作用.构建MCL1干扰载体,观察干扰MCL1基因表达对MGC-803细胞增殖的影响.结果发现,mi R-125b在胃癌组织中低表达,其表达与胃癌的分化程度及患者预后呈正相关,与TNM分期、淋巴结转移呈负相关(P0.01).mi R-125b高表达后MGC-803细胞的增殖降低、凋亡率增加、裂解caspase-3与裂解PARP表达增加(P0.01);mi R-125b与MCL1基因的3′UTR(2 613~2 620)结合,抑制MCL1的m RNA及蛋白质表达(P0.01);沉默MCL1基因表达后MGC-803细胞的增殖降低、凋亡率增加、裂解caspase-3与裂解PARP表达增加(P0.01).从而得出结论,mi R-125b在胃癌组织中低表达,其表达与胃癌组织分化程度、TNM分期、淋巴结转移及患者预后密切相关;mi R-125b靶向抑制MCL1基因表达,活化caspase-3信号通路,抑制MGC-803细胞增殖.     

Up-regulated lnc-SNHG1 contributes to osteosarcoma progression through sequestration of miR-577 and activation of WNT2B/Wnt/β-catenin pathway

Long noncoding RNA small nucleolar RNA host gene 1 (lnc-SNHG1) was reported to play an oncogenic role in the progression of cancers. However, the roles of SNHG1 and its molecular mechanism in osteosarcoma (OS) cells are largely unknown. In present study, we found that the expression of SNHG1 was up-regulated in OS tissues and cell lines. OS patients with the high SNHG1 expression were positively correlated with tumor size, TNM stage and lymph node metastasis. In addition, SNHG1 overexpression promoted cell proliferation, cell migration and EMT process in U2OS and MG63 cells and tumor growth in vivo. Furthermore, we also found that miR-577 could act as a ceRNAof SNHG1 in OS cells and the promotion of OS progression induced by lnc-SNHG1 overexpression required the inactivity of miR-577. Besides, we identified that WNT2B acted as a target of miR-577, and WNT2B played the oncogenic role in OS cells by activating Wnt/β-catenin pathway. In short, our study suggested that lnc-SNHG1 could promote OS progression via miR-577 and WNT2B. The lnc-SNHG1/miR-577/WNT2B/Wnt/β-catenin axis regulatory network might provide a potential new therapeutic strategy for OS treatment.