RETRACTED ARTICLE: MiR-200 suppresses metastases of colorectal cancer through ZEB1

Poor prognosis of some colorectal cancer (CRC) cases largely results from early metastases of CRC to the distal organs. Thus, suppression of the invasion of CRC appears to be crucial therapy. Since microRNAs (miRNAs) play critical roles in the regulation of cancer metastases, identification of the involved miRNAs may provide novel therapeutic targets for CRC treatment. Here, we showed that the levels of miR-200 were significantly decreased and the levels of ZEB1 were significantly increased in the CRC specimens from patients, compared to the paired non-tumor tissue. Moreover, the levels of miR-200 and ZEB1 are inversely correlated. Bioinformatics analyses showed that miR-200 targeted the 3′-UTR of ZEB1 mRNA to inhibit its translation, which was confirmed by luciferase reporter assay. Moreover, miR-200 overexpression inhibited ZEB1-mediated cell invasiveness, while miR-200 depletion increased ZEB1-mediated cell invasiveness in CRC cells. Together, our data suggest that miR-200 suppression in CRC cells may promote ZEB1-mediated cancer metastasis. Our work thus highlights a novel molecular regulatory machinery that regulates metastases of CRC.     

microRNA-320a inhibits tumor invasion by targeting neuropilin 1 and is associated with liver metastasis in colorectal cancer

MicroRNAs (miRNAs) have been implicated in regulating diverse cellular pathways. Although there is emerging evidence that various miRNAs function as oncogenes or tumor suppressors in colorectal cancer (CRC), the role of miRNAs in mediating liver metastasis remains unexplored. The expression profile of miRNAs in liver metastasis and primary CRC tissues was analyzed by miRNA microarrays and verified by real-time polymerase chain reaction (PCR). In 62 CRC patients, the expression levels of miR-320a were determined by real-time PCR, and the effects on migration and invasion of miR-320a were determined using a transwell assay. miR-320a target genes were confirmed by luciferase assay, real-time PCR and western blot analysis. A set of miRNAs was found to be dysregulated in the liver metastasis tissues compared to matched primary CRC tissues, and the expression levels of miR-320a were significantly decreased in the liver metastasis tissues examined. miR-320a was correlated with tumor progression in CRC. miR-320a was downregulated in liver metastatic colon cancer cells and inhibited liver metastatic colon cancer cell migration and invasion. miR-320a directly binds to the 3'UTR of neuropilin 1 (NRP-1), a protein that functions as a co-receptor of vascular epithelial growth factor. miR-320a downregulated the expression of NRP-1 at both the mRNA and protein levels. These data demonstrated that miR-320a may be useful for identifying CRC patients that are at an elevated risk for developing liver metastasis. Our findings suggest that miR-320a may be a novel therapeutic candidate for the treatment of colorectal cancer.     

宫颈癌及癌前病变组织中microRNAs的差异表达

目的 寻找与宫颈癌及宫颈癌前病变相关的microRNA。 方法 利用miRNA芯片,筛查宫颈 癌组织、宫颈上皮内瘤变及正常宫颈组织中差异表达的miRNA,并用实时定量RT-PCR在60份宫颈组 织标本中对4个miRNA进行验证。利用生物信息学对部分差异表达的miRNA的靶基因进行功能分析。 结果 与正常宫颈组织比较,宫颈癌及高级别宫颈病变（HSIL）中存差异表达的miRNAs,其中在宫 颈癌中下调最明显的是miR-218（下调倍数为0.175）,上调最明显的是miR-21（上调倍数为5.68）。 实时定量RT-PCR验证结果与miRNA芯片结果基本一致。功能分析显示预测的miR-218及miR-21的靶基 因与肿瘤的生长、侵袭转移有关。结论 宫颈癌及癌前病变中存在异常表达的miRNA,它们在宫颈癌 发生过程中可能起癌基因或抑癌基因的作用。     

MicroRNA-510 Plays Oncogenic Roles in Non-Small Cell Lung Cancer by Directly Targeting SRC Kinase Signaling Inhibitor 1

An increasing number of studies have demonstrated that microRNAs (miRNAs) may play key roles in various cancer carcinogenesis and progression, including non-small cell lung cancer (NSCLC). However, the expressions, roles, and mechanisms of miR-510 in NSCLC have, up to now, been largely undefined. In vivo assay showed that miR-510 was upregulated in NSCLC tissues compared with that in adjacent nontumor lung tissues. miR-510 expression was significantly correlated with TNM stage and lymph node metastasis. In vitro assay indicated that expressions of miR-510 were also increased in NSCLC cell lines. Downregulation of miR-510 suppressed NSCLC cell proliferation and invasion in vitro. We identified SRC kinase signaling inhibitor 1 (SRCIN1) as a direct target gene of miR-510 in NSCLC. Expression of SRCIN1 was downregulated in lung cancer cells and negatively correlated with miR-510 expression in tumor tissues. Downregulation of SRCIN1, leading to inhibition of miR-510 expression, reversed cell proliferation and invasion in NSCLC cells. These results showed that miR-510 acted as an oncogenic miRNA in NSCLC, partly by targeting SRCIN1, suggesting that miR-510 can be a potential approach for the treatment of patients with malignant lung cancer.     

MicroRNA-494 inhibits cell proliferation and invasion of chondrosarcoma cells in vivo and in vitro by directly targeting SOX9

Accumulating evidence indicates that dysregulation of miRNAs could contribute to tumor growth and metastasis of chondrosarcoma by infuencing cell proliferation and invasion. In the current study, we are interested to examine the role of miRNAs in the carcinogenesis and progression of chondrosarcoma. Here, using comparative miRNA profiling of tissues and cells of chondrosarcoma and cartilage, we identified miR-494 as a commonly downregulated miRNA in the tissues of patients with chondrosarcoma and chondrosarcoma cancer cell line, and upregulation of miR-494 could inhibit proliferation and invasion of chondrosarcoma cancer cells in vivo and in vitro. Moreover, our data demonstrated that SOX9, the essential regulator of the process of cartilage differentiation, was the direct target and functional mediator of miR-494 in chondrosarcoma cells. And downregulation of SOX9 could also inhibit migration and invasion of chondrosarcoma cells. In the last, we identified low expression of miR-494 was significantly correlated with poor overall survival and prognosis of chondrosarcoma patients. Thus, miR-494 may be a new common therapeutic target and prognosis biomarker for chondrosarcoma.     

The novel miR-9501 inhibits cell proliferation,migration and activates apoptosis in non-small cell lung cancer

Accumulating evidences suggest that lots of microRNAs (miRNAs) play crucial roles in (patho-)physiological processes of lung cancer, including metastasis, drug-resistance or tumorigenesis. They mediate the progression of cell growth, migration and invasion by regulating the expression of special genes. MiRNA expression patterns could also serve as diagnostic/prognostic biomarkers. Cancer therapies mediated by miRNAs remain tremendous potential and challenges. Our previous small RNA-seq assay found that the novel miR-9501 was down-regulated in lung cancer tissues compared with adjacent non-cancer tissues. In this study, our results verified that miR-9501 was significantly down-regulated in lung cancer tissues and its expression levels were remarkably suppressed in non-small cell lung cancer cell lines. Then, we characterized and investigated the novel miR-9501 in A549 cells. Transient transfection of miR-9501 into cultured A549 cells led to remarkable decrease in cell proliferation, migration and increase apoptosis. These data demonstrated that miR-9501 might be a tumor suppressor for lung cancer therapy.     

miR-192-5p通过靶向ZEB2调控胰腺癌PANC-1细胞的恶性生物学行为

目的：探讨miR-192-5p靶向E盒锌指结合同源框2(ZEB2)对胰腺癌PANC-1细胞增殖、迁移、侵袭和上皮间质转化（EMT）的影响及其作用机制。方法：利用TCGA数据库数据分析miR-192-5p和ZEB2在胰腺癌组织中的表达及两者的相关性。采用qPCR法和WB法分别检测人正常胰腺上皮细胞HPNE和胰腺癌PANC-1细胞中miR-192-5p和ZEB2的表达水平。利用脂质体转染技术转染PANC-1细胞,实验分为miR-192-5p mimic组、Mimic NC组、miR-192-5p inhibitor组、Inhibitor NC组、Mimic NC+pcDNA3.1组、miR-192-5p mimic+pcDNA3.1组、miR-192-5p mimic+pcDNA3.1-ZEB2组。CCK-8法、克隆形成、划痕愈合、Transwell实验分别检测转染PANC-1细胞的增殖、克隆形成、迁移和侵袭能力。qPCR法、WB法、双重免疫荧光实验检测PANC-1细胞中ZEB2、E-cadherin、vimentin的表达水平。通过生物信息学网站预测miR-192-5p的靶基因,并利用双...     

Aberrant Expression of miR-20a and miR-203 in Cervical Cancer

MicroRNAs (miRNAs) are small, non-coding RNAs that are critical regulators of various diseases. MicroRNA-20a (miR-20a) and microRNA-203 (miR-203) have previously shown significant alteration in a range of cancers.In this study, the expression levels of miR-20a and miR-203 in 100 cervical cancer tissues were detected byqRT–PCR and compared to patient matched-nontumor cervical tissues. Correlations between expression leveland clinicopathologic characteristics of cervical cancer were also analyzed. Finally, we studied the effect of miR-20a and miR-203 on cell proliferation in cervical cancer cell lines by MTT. We found that the expression levelof miR-20a (P<0.001) was significantly higher in cervical cancer patients than in healthy controls, while thatof miR-203 (P<0.001) was lower. Aberrant expression of miR-20a was correlated with lymph node metastasis(LNM), histological grade and tumor diameter, but down-regulated miR-203 was correlated with LNM only.Furthermore, we found that over-expression of miR-203 decreased cell proliferation, while reduction of miR-20a also prevented tumor progression. Our results support the involvement of miR-20a and miR-203 in cervicaltumorigenesis. We propose that miRNAs might be used as therapeutic agents for cervical cancer.     

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.     

miR-27 promotes human gastric cancer cell metastasis by inducing epithelial-to-mesenchymal transition

microRNAs (miRNAs) play an important role in tumorigenesis. However, the mechanisms by which miRNAs regulate gastric cancer metastasis remain poorly understood. In the current study, we defined the target genes and biological functions of miR-27 with a luciferase reporter assay and Western blot analysis. We verified that miR-27 levels were increased in gastric cancer tissues. The overexpression of miR-27 promoted the metastasis of AGS cells, whereas its depletion decreased cell metastasis. Up-regulation of miR-27 increased the levels of the epithelial-mesenchymal transition (EMT)-associated genes ZEB1, ZEB2, Slug, and Vimentin, as well as decreased E-cadherin levels. We demonstrated that miR-27 promoted EMT by activating the Wnt pathway. Finally, the APC gene was identified as the direct and functional target of miR-27. These results suggest an important role of miR-27 in regulating metastasis of gastric cancer and implicate the potential application of miR-27 in gastric cancer therapy.     

MiR-125a suppresses tumor growth,invasion and metastasis in cervical cancer by targeting STAT3

MiR-125a has been characterized as a tumor suppressor in several cancers. However, the role of miR-125a in cervical cancer is unknown. In this study, we found the expression of miR-125a was downregulated in cervical cancer patients, and negatively correlated with the tumor size, FIGO stage, and preoperative metastasis. Kaplan-Meier analysis showed that miR-125a expression predicted favorable outcome for cervical cancer patients. Dual luciferase assays identified the STAT3 gene as a novel direct target of miR-125a. Functional studies showed that miR-125a overexpression significantly suppressed the growth, invasion and epithelial-mesenchymal transition (EMT) of cervical cancer cells both in vitro and in vivo via decreasing STAT3 expression. Moreover, miR-125a conferred to G2/M cell cycle arrest, accompanied by inhibition of several G2/M checkpoint proteins. Mechanistically, inactivation of miR-125a during cervical carcinogenesis was caused by HPV suppression of p53 expression. Clinically, STAT3, the expression of which, predicted poorer outcome, was inversely correlated with miR-125a in cervical cancer. These data highlight the importance of miR-125a in the cell proliferation and progression of cervical cancer, and indicate that miR-125a may be a useful therapeutic target for cervical cancer.     

MicroRNA-432 Acts as a Prognostic Biomarker and an Inhibitor of Cell Proliferation,Migration, and Invasion in Breast Cancer

BackgroundAccumulating studies have demonstrated that microRNAs (miRNAs) are involved in the progression of various cancers. This study aimed to investigate the potential clinical and functional role of miR-432 in breast cancer.Materials and MethodsWe evaluated the expression of miR-432 in 117 breast cancer samples and paired nontumor tissue samples, as well as 4 breast cancer cell lines using RT-qPCR analysis. Kaplan-Meier survival curve and multivariate Cox regression analysis were used to evaluate the prognostic significance of miR-432 in breast cancer patients. CCK-8 assay and Transwell assays were used to evaluate the biological function of miR-432 in the progression of breast cancer.ResultsmiR-432 was downregulated in breast cancer tissues and cell lines, and its exotic expression was associated with tumor size, lymph node metastasis, and TNM stage. In addition, breast cancer patients with low miR-432 expression exhibited a shorter overall survival outcome. Further experiments revealed that overexpression of miR-432 inhibited the cell proliferation, migration, and invasion of breast cancer cells, while knockdown of miR-432 promoted these cellular activities. AXL was a direct target of miR-432 in breast cancer cells.ConclusionThe present study suggested that miR-432 may be a tumor suppressor in the progression of breast cancer through inhibiting cell proliferation, migration, and invasion by targeting AXL. And miR-432 might be a prognostic biomarker and therapeutic target for the treatment of breast cancer. This study provided a novel insight into breast cancer prognosis and treatment.     

MicroRNA-99a inhibits tumor aggressive phenotypes through regulating HOXA1 in breast cancer cells

MicroRNAs (miRNAs) are key regulators of tumor progression. Based on microarray data, we identified miR-99a as a potential tumor suppressor in breast cancer. Expression of miR-99a is frequently down-regulated in breast cancer tissues relative to normal breast tissues. Reduced miR-99a expression was highly associated with lymph node metastasis and shorter overall survival of patients with breast cancer. Gain- and loss-of-function studies revealed that, miR-99a significantly inhibits breast cancer cell proliferation, migration, and invasion. An integrated bioinformatics analysis identified HOXA1 mRNA as the direct functional target of miR-99a, and this regulation was confirmed by luciferase reporter assay. Furthermore, we showed for the first time that HOXA1 expression is elevated in breast cancer tissues. Knockdown of HOXA1 significantly inhibited breast cancer cell proliferation, migration and invasion, and restoration of HOXA1 partially rescued the inhibitory effect of miR-99a in breast cancer cells. Collectively, our data indicate that miR-99a plays a tumor-suppressor role in the development of breast cancer, and could serve as a potential therapeutic target for breast cancer treatment.     

MicroRNA-152 Inhibits Cell Proliferation,Migration, and Invasion in Breast Cancer

The aim of the present study was to investigate the roles of microRNA-152 (miR-152) in the initiation and progression of breast cancer. The expression level of miR-152 was detected in human breast cancer tissue and a panel of human breast cancer cell lines using qRT-PCR. Results found that miR-152 expression was significantly downregulated in breast cancer tissue samples compared to adjacent noncancerous tissues as well as in breast cancer cell lines. Overexpression of miR-152 significantly suppressed breast cancer cell proliferation, migration, and invasion. Luciferase reporter assay results found that ROCK1 is a direct and functional target gene of miR-152 in breast cancer. In addition, downexpression of ROCK1 could inhibit breast cancer cell proliferation, migration, and invasion. These findings indicate that miR-152 inhibited breast cancer growth and metastasis through negative regulation of ROCK1 expression. These data suggest that miR-152/ROCK1 pathway may be a useful therapeutic target for breast cancer treatment.     

miR-26b-3p对乳腺癌细胞生物学行为的影响及作用机制研究

背景与目的：miRNA是一类长度为21~23个核苷酸的单链非编码RNA分子,其作用机制主要为靶向于mRNA的3’非翻译区（3’ untranslated region,3’UTR）从而抑制其靶基因的表达。miRNA在肿瘤的发生、发展过程中发挥着关键作用,探讨miR-26b-3p对乳腺癌生物学行为的影响及作用机制。方法：通过实时荧光定量聚合酶链反应（real-time fluorescence quantitative polymerase chain reaction,RTFQ-PCR）检测miR-26b-3p在三种乳腺癌细胞系MCF-7、MDA-MB-231和MDA-MB-453中的表达,选取miR-26b-3p表达水平最低的乳腺癌细胞转染miR-26b-3p mimics后,采用细胞计数试剂盒（cell counting kit-8,CCK-8）法检测细胞的增殖,采用transwell迁移和侵袭实验检测细胞迁移和侵袭能力,通过小动物活体成像及裸鼠移植瘤模型检测miR-26b-3p对乳腺癌细胞裸鼠移植瘤生长和转移的影响,采用双荧光素酶报告基因分析检测miR-26b-3p与锌指E盒结合同源盒基因1（zinc finger E-box binding homeobox 1,ZEB1）的相互作用,采用RTFQ-PCR和蛋白质印迹法（Western blot）检测ZEB1的表达。结果：乳腺癌细胞系MDA-MB-453中miR-26b-3p表达最低,在MDA-MB-453细胞中转染miR-26b-3p mimics后,miR-26b-3p的表达水平显著升高（P<0.05）,细胞的增殖能力显著降低（P<0.05）,细胞的迁移（P<0.001）和侵袭能力（P<0.01）显著降低。过表达miR-26b-3p可抑制裸鼠体内乳腺癌移植瘤的生长和转移。miR-26b-3p可与ZEB1的3’UTR结合,抑制ZEB1的表达。结论：miR-26b-3p可靶向于ZEB1,抑制乳腺癌细胞的增殖、迁移和侵袭,抑制乳腺癌的生长和转移。     

Methylation-associated silencing of MicroRNA-335 contributes tumor cell invasion and migration by interacting with RASA1 in gastric cancer

MicroRNAs (miRNAs) are small non-coding RNAs that function as endogenous silencers of target genes, previous studies have shown that miR-335 play an important role in suppressing metastasis and migration in human cancer including gastric cancer (GC). However, the mechanisms which result in aberrant expression of miR-335 in GC are still unknown. Recent studies have shown that the silencing of some miRNAs is associated with DNA hypermethylation. In this study, we find the promoter of miR-335 we embedded in CpG island by accessing to bioinformatics data and the low expression of miR-335 in 5 gastric cell lines can be restored by 5-aza-2’-deoxycytidine (5-Aza-dC) treatment. So we postulated that the miR-335 genes undergo epigenetic inactivation in GC. Subsequently, in GC cells and tissues, we performed quantitative real-time PCR (RTQ-PCR) to assess the expression of miR-335, and methylation-specific PCR (MSP) and bisulfite sequence-PCR (BSP) to evaluate the DNA methylation status in the CpG islands upstream of MiR-335. The result showed that the expression of miR-335 was significantly reduce in gastric cancer cell lines and tumor tissues compared to matched normal gastric tissues, and cell lines, and which is inverse correlation with DNA hypermethylation of miR-335 both in GC cells lines and tissues, but not in normal tissues. In addition, we found that the lower miR-335 expression induced by abnormal methylation may be mainly involved in gastric cell invasion and metastasis in GC tissues. No statistical significance was found about miR-335 expression and methylation level between healthy individuals with and without H. pylori (HP) infection. Finally, we carry out miRNA transfection, RTQ-PCR and western blot assay to find the RAS p21 protein activator (GTPase activating protein) 1 (RASA1) may be the possible target genes which lead to the gastric cell invasion and metastasis, furthermore, the re-expression of endogenous miR-335 by 5-Aza-dC treatment can exert effects similar to exogenous miRNAs transfection. Taken together, our results suggest that miR-335 may be silenced by promoter hypermethylation and play important roles in gastric cell invasion and metastasis through its target genes, such as RASA1. Its methylation level might be a predictive epigenetic marker of GC and remodeling on the expression by demethylation can provided a potential therapeutic strategy.