miR-615 Inhibits Prostate Cancer Cell Proliferation and Invasion by Directly Targeting Cyclin D2

Previous studies have reported that miR-615 exerts a tumor suppressor role in some tumors, such as esophageal squamous cell carcinoma and non-small cell lung cancer. However, the role of miR-615 in prostate cancer has not been defined. Here we found that miR-615 was downregulated in prostate cancer tissues and cell lines. Overexpression of miR-615 in PC-3 cells significantly inhibited cellular proliferation, migration, and invasion. Moreover, overexpression of miR-615 delayed tumor growth in vivo. In terms of mechanism, we found that cyclin D2 (CCND2) is a target gene of miR-615 in prostate cancer. We showed that miR-615 could bind to the 3 -UTR region of CCND2 mRNA and inhibit its expression. There was a negative correlation between the expression of miR-615 and CCND2 in prostate cancer tissues. Moreover, restoration of cyclin D2 abolished the inhibitory effects of miR-615 on the proliferation, migration, and invasion of prostate cancer cells. Taken together, our study identified miR-615 as a tumor suppressor by targeting cyclin D2 in prostate cancer.     

miR-29a对人胃癌细胞增殖、迁移的影响及其机制研究

目的：探讨微小RNA-29a（miR-29a）对人胃癌细胞增殖、迁移的影响及其机制。方法：胃癌SGC-7901细胞随机分为miR-29a转染组、质粒对照组、空白对照组、信号转导子与转录激活子3（STAT3）抑制组。miR-29a转染组、质粒对照组采用脂质体转染法分别将has-miR-29a mimics质粒、siRNA对照质粒转染至人胃癌SGC-7901细胞,STAT3抑制组细胞加入STAT3抑制剂溶液,空白对照组不做处理。实时荧光定量聚合酶链反应（qPCR）和Western blot法检测转染后细胞中miR-29a、血管内皮生长因子（VEGF）、STAT3、细胞周期蛋白D1（cyclin D1）mRNA和蛋白的表达情况;MTT、划痕实验分别检测细胞增殖和迁移情况。结果：qPCR和Western blot实验结果显示,与空白对照组和质粒对照组比较,miR-29a转染组的miR-29a相对表达水平升高,VEGF、cyclin D1 mRNA及蛋白相对表达水平与p-STAT3/STAT3比值均下降（P < 0.01）。MTT实验与划痕实验结果显示,与空白对照组和质粒对照组比较,miR-29a转染组细胞在培养24、48、72 h的细胞相对增殖率及迁移率降低（P < 0.01）。与空白对照组比较,STAT3抑制组细胞的cyclin D1 mRNA及蛋白相对表达水平、p-STAT3/STAT3比值均降低,细胞相对增殖率与迁移率降低（P < 0.01）。结论：miR-29a能降低VEGF mRNA、蛋白的表达,抑制人胃癌细胞增殖和迁移,其机制可能与下调p-STAT3及cyclin D1的表达有关。     

miR-29a对人胃癌细胞增殖、迁移的影响及其机制研究

目的：探讨微小RNA-29a（miR-29a）对人胃癌细胞增殖、迁移的影响及其机制。方法：胃癌SGC-7901细胞随机分为miR-29a转染组、质粒对照组、空白对照组、信号转导子与转录激活子3（STAT3）抑制组。miR-29a转染组、质粒对照组采用脂质体转染法分别将has-miR-29a mimics质粒、siRNA对照质粒转染至人胃癌SGC-7901细胞，STAT3抑制组细胞加入STAT3抑制剂溶液，空白对照组不做处理。实时荧光定量聚合酶链反应（qPCR）和Western blot法检测转染后细胞中miR-29a、血管内皮生长因子（VEGF）、STAT3、细胞周期蛋白D1（cyclin D1）mRNA和蛋白的表达情况；MTT、划痕实验分别检测细胞增殖和迁移情况。结果：qPCR和Western blot实验结果显示，与空白对照组和质粒对照组比较，miR-29a转染组的miR-29a相对表达水平升高，VEGF、cyclin D1 mRNA及蛋白相对表达水平与p-STAT3/STAT3比值均下降（P < 0.01）。MTT实验与划痕实验结果显示，与空白对照组和质粒对照组比较，miR-29a转染组细胞在培养24、48、72 h的细胞相对增殖率及迁移率降低（P < 0.01）。与空白对照组比较，STAT3抑制组细胞的cyclin D1 mRNA及蛋白相对表达水平、p-STAT3/STAT3比值均降低，细胞相对增殖率与迁移率降低（P < 0.01）。结论：miR-29a能降低VEGF mRNA、蛋白的表达，抑制人胃癌细胞增殖和迁移，其机制可能与下调p-STAT3及cyclin D1的表达有关。     

MicroRNA-561 Affects Proliferation and Cell Cycle Transition Through PTEN/AKT Signaling Pathway by Targeting P-REX2a in NSCLC

MicroRNAs (miRNAs) play crucial roles in tumorigenesis and tumor progression. miR-561 has been reported to be downregulated in gastric cancer and affects cancer cell proliferation and metastasis. However, the role and underlying molecular mechanism of miR-561 in human non-small cell lung cancer (NSCLC) remain unknown and need to be further elucidated. In this study, we discovered that miR-561 expression was downregulated in human NSCLC tissues and cell lines. The overexpression of miR-561 inhibited NSCLC cell proliferation and cell cycle G1 /S transition and induced apoptosis. The inhibition of miR-561 facilitated cell proliferation and G1 /S transition and suppressed apoptosis. miR-561 expression was inversely correlated with P-REX2a expression in NSCLC tissues. P-REX2a was confirmed to be a direct target of miR-561 using a luciferase reporter assay. The overexpression of miR-561 decreased P-REX2a expression, and the suppression of miR- 561 increased P-REX2a expression. Particularly, P-REX2a silencing recapitulated the cellular and molecular effects observed upon miR-561 overexpression, and P-REX2a overexpression counteracted the effects of miR-561 overexpression on NSCLC cells. Moreover, both exogenous expression of miR-561 and silencing of P-REX2a resulted in suppression of the PTEN/AKT signaling pathway. Our study demonstrates that miR-561 inhibits NSCLC cell proliferation and G1 /S transition and induces apoptosis through suppression of the PTEN/ AKT signaling pathway by targeting P-REX2a. These findings indicate that miR-561 plays a significant role in NSCLC progression and serves as a potential therapeutic target for NSCLC.     

The Downregulation of MicroRNA-10b and its Role in Cervical Cancer

It has been demonstrated that microRNAs (miRNAs) act as oncogenes or tumor suppressors in a variety of cancers. Our previous work suggested that miR-10a/b functioned as a tumor suppressor in gastric cancer, and miR-10b was also reported to be significantly downregulated in advanced stage cervical cancer tissues. However, the aberrant expression of miR-10b in cervical cancer and its possible role in cervical carcinogenesis was largely unknown. In this study, we investigated the expression of miR-10b in cervical cancer tissues, carcinoma in situ tissues, mild dysplasia, moderate dysplasia, severe dysplasia tissues, and normal controls. We found that miR-10b was significantly downregulated during cervical cancer progression, and the lower level of miR-10b in cervical cancer was significantly associated with a more aggressive tumor phenotype. Moreover, overexpression of miR-10b in cervical cancer cells could inhibit the cell proliferation and invasion, and the further mechanism study suggested that its role was possibly through directly targeting HOXA1. These results suggested that the downregulation of miR-10b and the resulting elevated HOXA1 level in cervical cancer tissues might play critical roles in cervical cancer progression.     

MicroRNA-mediated upregulation of integrin-linked kinase promotes Src-induced tumor progression

The tyrosine kinase c-Src is upregulated in various human cancers; however, the molecular mechanisms underlying c-Src-mediated tumor progression remain unclear. Here we show that downregulation of microRNA (miR)-542-3p is tightly associated with tumor progression via c-Src-related oncogenic pathways. In c-Src-transformed fibroblasts and human cancer cells that overexpress c-Src, miR-542-3p is substantially downregulated, and the ectopic expression of miR-542-3p suppresses tumor growth. We identified the integrin-linked kinase (ILK) as a conserved target of miR-542-3p. ILK upregulation promotes cell adhesion and invasion by activating the integrin-focal adhesion kinase (FAK)/c-Src pathway, and can also contribute to tumor growth via the AKT and glycogen synthase kinase 3β pathways. MiR-542-3p expression is downregulated by the activation of c-Src-related signaling molecules, including epidermal growth factor receptor, K-Ras and Ras/Raf/mitogen-activated protein kinase/extracellular signal-regulated kinase. In human colon cancer tissues, downregulation of miR-542-3p is significantly correlated with the upregulation of c-Src and ILK. Our results suggest that the novel c-Src-miR-542-3p-ILK-FAK circuit plays a crucial role in controlling tumor progression.     

The microRNA-520a-3p inhibits proliferation,apoptosis and metastasis by targeting MAP3K2 in non-small cell lung cancer

Growing evidence indicates that miR-520a was involved in the complement attack and migration of tumor cells, but nonetheless, the role of miR-520a-3p in non-small cell lung cancer (NSCLC) is not clear. Mitogen-activated protein kinase kinase kinase 2 (MAP3K2) is a kinase belonging to the serine/threonine protein kinase family. To develop potential therapy targeting MAP3K2, we studied the roles of miR-520a-3p in the proliferation, apoptosis and metastasis of NSCLC. The expression levels of miR-520a-3p were quantified in tumor tissues of NSCLC by qRT-PCR, and the mimics and inhibitors were used to verify the function of miR-520a-3p. The cell proliferation was evaluated by MTT assay, and the migration and invasion was evaluated by transwell assay. The athymic mice subcutaneous injection was used to research NSCLC cell tumor formation. The bioinformatics tools and luciferase assay was applied to detect the relationship between miR-520a-3p and its target. Protein levels of miR-520a-3p target was determined by western blot analysis. MiR-520a-3p expression was decreased in the NSCLC tissues compared with their normal counterparts and lower expression of miR-520a-3p in NSCLC tissues was associated with a higher clinical stage, NSCLC metastasis and poor prognosis. Inhibition of expression of miR-520a-3p can reduce in vitro NSCLC cell migration and invasion as well as in vivo metastasis. MAP3K2 mRNA contains a binding site for miR-520a-3p in the 3’UTR. MAP3K2 is one of target of miR-520a-3p. Together, our data demonstrated that miR-520a-3p inhibits proliferation, apoptosis and metastasis in NSCLC by targeting MAP3K2, and miR-520a-3p may be used as a prognosis marker for NSCLC in clinical research.     

miR-1290通过抑制干扰素调节因子-2调控非小细胞肺癌的增殖

  目的  探讨微小RNA-1290（miR-1290）在非小细胞肺癌（non-small cell lung cancer,NSCLC）组织中的表达及其相关调控机制。  方法  采用实时荧光定量PCR检测成都市双流区第一人民医院2014年6月至2017年6月41例NSCLC患者癌组织、癌旁组织以及NSCLC细胞株A549、H460及正常支气管上皮细胞BEAS-2B中miR-1290表达;qPCR、Western blot检测癌组织、癌旁组织IRF2 mRNA和蛋白表达;将A549和H460细胞分为miR-1290 mimic组（转染miR-1290 mimic）、miR-1290 inhibit组（转染miR-1290 inhibit）和miR- 1290 NC组（不转染）。分别于转染24、48、72、96 h后采用CCK-8法检测细胞增殖能力,平板克隆形成实验检测细胞克隆形成数,Transwell小室检测细胞侵袭数,双荧光素酶报告基因实验检测miR-1290与干扰素调节因子-2（interferon regulatory factor,IRF2）3′-UTR结合情况,qPCR检测不同miR-1290表达水平的A549和H460细胞IRF2 mRNA表达。  结果  癌组织miR-1290相对表达量明显高于癌旁组织,IRF2 mRNA和蛋白相对表达量明显低于癌旁组织,差异具有统计学意义（P < 0.05）;NSCLC组织miR-1290表达与IRF2 mRNA、蛋白表达呈显著负相关（P < 0.05）。NSCLC患者中,淋巴结转移者miR-1290表达明显高于无淋巴结转移者,Ⅲ/Ⅳ期患者miR-1290表达明显高于Ⅰ/Ⅱ期,差异具有统计学意义（P < 0.05）。转染72、96 h后,A549和H460细胞miR-1290 mimic组增殖能力明显高于miR- 1290 NC组,miR-1290 inhibit组增殖能力明显低于miR-1290 NC组,差异具有统计学意义（P < 0.05）。A549和H460细胞中miR-1290 mimic组细胞克隆数和侵袭细胞数明显高于miR-1290 NC组,miR-1290 inhibit组克隆数和侵袭细胞数明显低于miR-1290 NC组,差异具有统计学意义（P < 0.05）。双荧光素酶报告基因实验显示miR-1290能与IRF2 3′-UTR结合,明显降低荧光值（P < 0.05）。A549和H460细胞中,miR-1290 mimic组IRF2相对表达量明显低于miR-1290 NC组,miR-1290 inhibit组IRF2相对表达量明显高于miR-1290 NC组,差异具有统计学意义（P < 0.05）。  结论  miR-1290在NSCLC组织和细胞中高表达,miR-1290可能通过与IRF2结合,促进肿瘤细胞的增殖和侵袭。      

JAK1、p-STAT3和bcl-2在胃癌中的表达及意义

 目的 研究JAK1、p-STAT3和bcl-2在胃癌中的表达及与胃癌发生、发展的关系。 方法 采用免疫组织化学二步法检测JAK1、p-STAT3和bcl-2在60例胃癌组织和60例胃镜标本中的表达。 结果 (1)JAK1、p-STAT3和bcl-2 的阳性表达率在胃癌中最高,其次是不典型增生和癌旁胃黏膜,再次是慢性萎缩性胃炎伴肠上皮化生,浅表性胃炎中最低（P<0.05）;(2)胃癌JAK1、p-STAT3和bcl-2蛋白的阳性表达强度与分化程度、浸润深度、淋巴结转移、远端转移和临床分期有关（P<0.05）;(3)胃癌中三种蛋白的阳性表达强度呈正相关(P<0.05)。 结论 JAK1、p-STAT3和bcl-2在胃癌组织中存在异常高表达并与胃癌发生、浸润、转移和临床分期有关。     

MiR-206 inhibits gastric cancer proliferation in part by repressing CyclinD2

In this study, we detected miR-206 expression in gastric cancer (GC) and further investigated its effects on GC cell growth in vitro and in vivo. MiR-206 expression was found to be significantly decreased in 30 GC samples and GC cell lines by Real time-PCR. Restoration of miR-206 reduced cell growth and colony forming ability in GC cells with G0/G1 cell cycle arrest. Further studies demonstrated that miR-206 could suppress GC cells proliferation at least partially through targeting the CyclinD2 (CCND2). Therefore, we provided evidence that miR-206 was a potential tumor suppressor and may be used as a therapeutic target for gastric cancer.     

MicroRNA-34a affects the occurrence of laryngeal squamous cell carcinoma by targeting the antiapoptotic gene survivin

Survivin has been shown to be an ideal target for cancer gene therapy because of its strong antiapoptotic effect. MicroRNA-34a (miR-34a) can function as a tumor suppressor in some cancers through negative regulation of gene expression. However, the relationship between miR-34a and survivin in larynx squamous cell carcinoma (LSCC) has not been explored. The abundance of survivin mRNA and miR-34a in LSCC tissues were measured using quantitative real-time polymerase chain reaction. Their expression levels were analyzed and correlated with tumor differentiation, lymphatic metastasis, clinical stages, and survival rates. MiR-34a mimic was transfected using liposomes to increase its level in LSCC cancer cell line, Hep-2. The effects of miR-34a on survivin protein expression were tested using western blot analysis. Cell cycle analyses were performed using flow cytometry. The results showed that transfection of miR-34a mimic significantly suppressed cell proliferation with decreased survivin protein expression, but did not affect mRNA expression level. The results from LSCC tissue samples showed that miR-34a was downregulated, while survivin expression was upregulated. The miR-34a levels were negatively correlated with histologic differentiation and were positively correlated with survival rate. MiR-34a significantly suppressed cell proliferation by arresting cells at G(0)/G(1) phase in Hep-2 cells. These results indicated that miR-34a may affect the occurrence of LSCC by targeting survivin.     

miR-124 在乳腺癌中的表达及其作用机制研究

目的：探讨m iR- 124 表达与乳腺癌发生、发展的相关性及机制。方法：运用实时定量聚合酶链反应（qRT-PCR）检测乳腺癌细胞系以及52例患者乳腺癌癌组织和对应的癌旁正常组织样本中miR-124 的表达水平。在乳腺癌细胞株MDA-MB-231和T-47D 中过表达miR-124 后,测定细胞增殖活性以及侵袭转移能力。构建荧光素酶报告载体pMIR- 特异性蛋白1（specificityprotein 1,SP1）的3'UTR,利用荧光素酶活性检测鉴定miR-124 的预测靶基因SP1。qRT-PCR和Westernblot法分别检测SP1 的mRNA 和蛋白质的表达水平。结果：miR-124 在乳腺癌细胞系和癌组织中表达量下调,差异具有统计学意义（P < 0.01）,并与肿瘤的转移、分期、分级和预后相关。在乳腺癌细胞株MDA-MB-231 和T-47D 中过表达miR-124 后抑制乳腺癌细胞系的增殖、侵袭以及迁移（P < 0.01）。 转染miR-124 模拟物显著抑制荧光素酶的活性（P < 0.05）。 转染miR-124 模拟物显著下调MDA-MB-231 和T-47D 细胞中SP1 的mRNA（P < 0.05）和蛋白质的表达水平。结论：miR-124 在乳腺癌癌组织中低表达,miR-124 低表达与乳腺癌不良预后有关,且miR-124 可通过调控转录因子SP1 抑制乳腺癌癌细胞的增殖、侵袭和转移。miR-124 表达异常减少可能是乳腺癌发生、发展的重要因素。     

MiR-145 regulates cancer stem-like properties and epithelial-to-mesenchymal transition in lung adenocarcinoma-initiating cells

MicroRNA-145 (MiR-145) is an important regulator of tumorigenesis. Our previous work indicated that miR-145 reduced the proliferation and invasion as well as the tumorosphere growth capacity in lung adenocarcinoma cells. However, the underlying molecular mechanisms remain elusive. Here, we reported that the expression level of miR-145 was downregulated in lung adenocarcinoma tissues and negatively correlated with the expression level of Oct4. MiR-145 inhibited the proliferation of lung cancer-initiating cells (LCICs), partially by regulating Oct4 expression. Furthermore, we found that miR-145 exerted repressive effect on cancer stem cell properties and inhibited epithelial-mesenchymal transition (EMT) in vitro, also partially by regulating Oct4. Finally, we confirmed the repressive effect of miR-145 on cancer stem cell properties and EMT in vivo. Taken together, these evidences suggest that miR-145 serves as a tumor suppressor which downregulates LCICs’ cancer stem cell properties and EMT process by targeting Oct4, leading to the inhibition of tumor growth and metastasis.     

Low miR-145 silenced by DNA methylation promotes NSCLC cell proliferation,migration and invasion by targeting mucin 1

MiR-145 has been implicated in the progression of non-small cell lung cancer (NSCLC); however, its exact mechanism is not well established. Here, we report that miR-145 expression is decreased in NSCLC cell lines and tumor tissues and that this low level of expression is associated with DNA methylation. MiR-145 methylation in NSCLC was correlated with a more aggressive tumor phenotype and was associated with poor survival time, as shown by Kaplan-Meier analysis. Additional multivariate Cox regression analysis indicated that miR-145 methylation was an independent prognostic factor for poor survival in patients with NSCLC. Furthermore, we found that restoration of miR-145 expression inhibited proliferation, migration and invasion of NSCLC by the direct targeting of mucin 1 by miR-145. Our results indicate that low miR-145 expression, due to methylation, promotes NSCLC cell proliferation, migration and invasion by targeting mucin 1. Therefore, miR-145 may be a valuable therapeutic target for NSCLC.     

JAK2 inhibitor TG101348 overcomes erlotinib-resistance in non-small cell lung carcinoma cells with mutated EGF receptor

Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations are responsive to EGFR-tyrosine kinase inhibitor (EGFR-TKI). However, NSCLC patients with secondary somatic EGFR mutations are resistant to EGFR-TKI treatment. In this study, we investigated the effect of TG101348 (a JAK2 inhibitor) on the tumor growth of erlotinib-resistant NSCLC cells. Cell proliferation, apoptosis, gene expression and tumor growth were evaluated by diphenyltetrazolium bromide (MTT) assay, flow cytometry, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining, Western Blot and a xenograft mouse model, respectively. Results showed that erlotinib had a stronger impact on the induction of apoptosis in erlotinib-sensitive PC-9 cells but had a weaker effect on erlotinib-resistant H1975 and H1650 cells than TG101348. TG101348 significantly enhanced the cytotoxicity of erlotinib to erlotinib-resistant NSCLC cells, stimulated erlotinib-induced apoptosis and downregulated the expressions of EGFR, p-EGFR, p-STAT3, Bcl-xL and survivin in erlotinib-resistant NSCLC cells. Moreover, the combined treatment of TG101348 and erlotinib induced apoptosis, inhibited the activation of p-EGFR and p-STAT3, and inhibited tumor growth of erlotinib-resistant NSCLC cells in vivo. Our results indicate that TG101348 is a potential adjuvant for NSCLC patients during erlotinib treatment.