Wenqiao Zang

MiR-429 up-regulation induces apoptosis and suppresses invasion by targeting Bcl-2 and SP-1 in esophageal carcinoma

PurposeMicroRNAs (miRNAs) may act as oncogenes or tumor suppressor genes and, as such, they may play a role in cancer development. We investigated miR-429 expression levels in a cohort of esophageal carcinomas (EC) to assess its impact on EC cell growth, apoptosis and invasion.MethodsqRT-PCR assays were used to quantify miR-429 expression levels in 32 paired EC samples and adjacent non-neoplastic tissues. Assays for cell growth, apoptosis, caspase activity and trans-well invasion were used to evaluate the effects of miR-429 expression on EC cells. Luciferase reporter and Western blotting assays were used to test whether the Bcl-2 and specificity protein 1 (SP1) mRNAs serve as major targets of miR-429.ResultsThe expression levels of miR-429 in EC tissues were found to be lower than those in adjacent non-neoplastic tissues (P < 0.05). This relatively low expression was found to be significantly associated with the occurrence of lymph node metastases (P < 0.05). Apoptosis and migration rates were found to be significantly higher in two EC-derived cell lines (EC9706 and KYSE30) transfected with a miR-429 agomir (P < 0.05). Subsequent Western blotting and luciferase reporter assays showed that miR-429 can bind to putative binding sites within the Bcl-2 and SP1 mRNA 3′ untranslated regions (UTRs) to reduce their expression.ConclusionsIn primary EC tissues miR-429 is expressed at low levels. Up-regulation of miR-429 inhibits invasion and promotes apoptosis in EC cells by targeting Bcl-2 and SP1. Our findings suggest that Bcl-2 and SP1 may serve as major targets of miR-429. This study paves the way for a better understanding of the mechanism underlying EC pathogenesis and the development of novel, targeted therapies.

MiR-144 inhibits proliferation and induces apoptosis and autophagy in lung cancer cells by targeting TIGAR.

Background: MiRNAs are noncoding RNAs of 20-24 nucleotides that function as post-transcriptional negative regulators of gene expression. MiRNA genes are usually transcribed by RNA polymerase II in the nucleus. Their initial products are pre-miRNAs which have cap sequences and polyA tails. The p53-induced glycolysis and apoptosis regulator (TIGAR) was discovered through microarray analysis of gene expression following activation of p53. However, little is known about the effect of miR-144 on cell proliferation and apoptosis and how it interacts with TIGAR. Methods: We performed real-time PCR, western blotting, CCK8, colony formation, tumor growth, flow cytometry, Caspase3/7 activity, Hoechst 33342 staining, MDC staining of autophagic cells and luciferase reporter assays to detect the influence of miR-144 to lung cancer cells. Results: miR-144 targeted TIGAR, inhibited proliferation, enhanced apoptosis, and increased autophagy in A549 and H460 cells. Conclusions: Our study improves our understanding of the mechanisms underlying lung cancer pathogenesis and may promote the development of novel targeted therapies.

miR-21 Down-Regulation Suppresses Cell Growth, Invasion and Induces Cell Apoptosis by Targeting FASL, TIMP3, and RECK Genes in Esophageal Carcinoma

BackgroundmiR-21 is overexpressed in esophageal squamous cell carcinoma (ESCC) and is thought to be correlated with the development of the cancer. The target gene of miR-21 including FASL, TIMP3 and RECK is revealed by researchers. miR-21 may be involved in the tumorgenesis of ESCC by targeting FASL, TIMP3 and RECK.AimsThe purpose of this study was to explore the mechanism of miR-21 in the development of ESCC.MethodsmiR-21 expression in ESCC and the matched non-malignant adjacent tissues (NMATs) was examined by qRT-PCR. Cell growth, cell apoptosis and cell invasion ability of EC9706 and EC-1 cells was examined after the cells were transfected with miR-21 inhibitor. The potential target genes of miR-21 including FASL, TIMP3 and RECK were examined by western blot and Luciferase reporter assay.ResultsmiR-21 expression was increased significantly in ESCC tissues compared with NMAT. miR-21 down-regulation inhibits cell growth, cell invasion and induces cells to apoptosis. FASL, TIMP3 and RECK are direct targets of miR-21.ConclusionsmiR-21 down-regulation inhibits cell growth, invasion and induces cells to apoptosis by targeting FASL, TIMP3 and RECK genes.

MicroRNA-124 inhibits cellular proliferation and invasion by targeting Ets-1 in breast cancer.

MicroRNAs (miRNAs) are small non-coding RNAs that, by targeting certain messenger RNAs (mRNAs) for translational repression or cleavage, can regulate the expression of these genes. In addition, miRNAs may also function as oncogenes and tumor-suppressor genes, as the abnormal expression of miRNAs is associated with various human tumors. However, the effects of the expression of miR-124 in breast cancer remain unclear. The present study was conducted to study the expression of miR-124 in breast cancer, paying particular attention to miR-124’s relation to the proliferation, invasion, and apoptosis in breast cancer cell MCF-7 and MDA-MB-231. Real-time quantitative RT-PCR (qRT-PCR) was performed to identify miR-124 that was down-regulated in breast cancer tissues. We also showed E26 transformation specific-1 (Ets-1) and miR-124 expression levels in breast cancer tissues that were associated with lymph node metastases. With transfected synthetic miR-124 agomir into MCF-7 and MDA-MB-231, a significant reduction (P < 0.05) in MCF-7 and MDA-MB-231 cell proliferation and colony forming potential was observed after treatment with miR-124. Apoptosis and migration rates were found to be significantly higher in two breast-derived cell lines transfected with a miR-124 agomir (P < 0.05). Luciferase reporter assay and Western blot were used to verify Ets-1 as a potential major target gene of miR-124, and the result showed that miR-124 can bind to putative binding sites within the Ets-1 mRNA 3′ untranslated region (UTR) to reduce its expression. Based on these findings, we propose that miR-124 and Ets-1 may serve as a therapeutic agent in breast cancer.

Effect of miR-335 upregulation on the apoptosis and invasion of lung cancer cell A549 and H1299.

MicroRNAs are small non-coding RNAs that may also function as oncogenes and tumor-suppressor genes, as the abnormal expression of microRNAs is associated with various human tumors. However, the effect of miR-335 on the lung cancer cells remains unclear. The aim of the paper was to study the expression of miR335 in non-small cell lung cancer (NSCLC) and miR335’s relation to the metastasis, invasion, and apoptosis in lung cancer cells A549 and H1299. qRT-PCR was used to identify the miR-335 expression. The effects of miR-335 on cell proliferation, apoptosis, and invasion were further analyzed. Luciferase reporter assay and Western blot were to verify Bcl-w and SP1 as potential major target genes of miR-335. Finally, the effect of Bcl-w on miR-335-induced cell survival was determined. Our results showed that miR-335 expression was significantly lower in NSCLC tissue, which was significantly associated with lymph node metastasis. In contrast to cells in blank and negative control groups, incidence of apoptosis was significantly higher (P < 0.05) and the number of cells migrating through matrigel was significantly lower (P < 0.05) in miR-335 mimics transfected group. Western blot and luciferase reporter assay demonstrated that miR-335 could bind to the putative binding sites in Bcl-w (or SP1) mRNA 3′-untranslated region to visibly lower the expression of Bcl-w (or SP1). The introduction of Bcl-w cDNA without 3′-untranslated region abrogated miR-335-induced cell survival. These results indicated that upregulation of miR-335 can simultaneously suppress the invasiveness and promote apoptosis of lung cancer cell A549 and H1299 by targeting Bcl-w and SP1. Therefore, miR-335 may be a potential therapeutic target in NSCLC treatment.

miR-663 attenuates tumor growth and invasiveness by targeting eEF1A2 in pancreatic cancer

BackgroundmiR-663 is associated with many important biologic processes, such as the evolution, development, viral infection, inflammatory response, and carcinogenesis among vertebrates. However, the molecular function and mechanism of miR-663 in pancreatic cancer growth and invasion is still unclear.MethodsWestern blot and real-time PCR were used to study the expression level of eEF1A2 protein and miR-663 in pancreatic cancer tissues and cell lines. The Pearson χ2 test was used to determine the correlation between miR-663 expression and clinicopathologic features of patients. Patients’ survival was analyzed using the Kaplan–Meier method, using the log-rank test for comparison. The biological function of miR-663 was examined by measuring cell growth, cell invasion and apoptosis analysis in vitro and in vivo. miR-663 target gene and signaling pathway was identified by luciferase activity assay and western blot.ResultsWe found that, in pancreatic cancer, eEF1A2 was significantly upregulated but miR-663 was significantly downregulated. Further results showed that the expression level of eEF1A2 and miR-663 was strongly associated with TNM stage and node metastasis status of the patients. miR-663 and eEF1A2 were inversely correlated with each other, and the changes in the expression levels of each can also predict the survival of patients with pancreatic cancer. We identified miR-663 as a tumor attenuate molecular that attenuated the proliferation and invasion of pancreatic cancer cells both in vitro and in vivo. Finally, we confirmed that the expression of eEF1A2 can partially restore the pro-apoptotic and anti-invasion functions of miR-663.ConclusionsmiR-663 attenuated the proliferation and invasion of pancreatic cells both in vitro and in vivo by directly targeting eEF1A2. miR-663 and eEF1A2 might be potential targets for the treatment of pancreatic cancer in the future.

MiR-148a regulates the growth and apoptosis in pancreatic cancer by targeting CCKBR and Bcl-2

Our previous studies have revealed that miR-148a is downregulated in pancreatic cancer. Bioinformatics analysis has shown cholecystokinin-B receptor (CCKBR) and B cell lymphoma (Bcl-2) to be potential targets of miR-148a. But the pathophysiologic role of miR-148a and its relevance to the growth and development of pancreatic cancer are yet to be investigated. The purpose of this study is to elucidate the molecular mechanisms where miR-148a acts as a tumor suppressor in pancreatic cancer. Our results showed significant downregulation of miR-148a in 28 pancreatic cancer tissue samples and five pancreatic cancer cell lines, compared with their non-tumor counterparts by qRT-PCR. MiR-148a was found to not only inhibit the proliferation of pancreatic cancer cells (PANC-1 and AsPC-1) in vitro by MTT assay and colony formation assay, but also to promote cells apoptosis in vitro by Annexin V-FITC apoptosis detection and caspase activity assay. Using western blot and luciferase activity assay, CCKBR and Bcl-2 were identified as targets of miR-148a. Moreover, we also found that the expression of Bcl-2 lacking in 3′UTR could abrogate the pro-apoptosis function of miR-148a. These findings suggest the importance of miR-148a’s targeting of CCKBR and Bcl-2 in the regulation of pancreatic cancer growth and apoptosis.

Effect of miR-451 on the Biological Behavior of the Esophageal Carcinoma Cell Line EC9706

BackgroundMicroRNAs play important roles in coordinating a variety of cellular processes. Abnormal expression of miRNAs has been linked to several cancers. However, the functional role of miR-451 in esophageal squamous cell carcinoma remains unclear.AimsThe present study explored the effects of miR-451 on the biological behavior of the esophageal carcinoma cell line EC9706.MethodsSynthetic miR-451 mimics were transfected into EC9706 cells using Lipofectamine™ 2000. The expression of miR-451 was analyzed by RT–PCR and the expressions of Bcl-2, AKT and phosphorylated AKT were analyzed by Western blotting. The MTT assay, soft agar colony formation assay, transwell assay and FACS were used to assess the effect of miR-451 on EC9706 cell proliferation, invasion, metastasis and apoptosis. Tumor growth was assessed by subcutaneous inoculation of cells into BALB/c nude mice.ResultsIn comparison to the controls, a significant increase in the expression of miR-451 was associated with significantly decreased expressions of Bcl-2, AKT and p-AKT, and a significant increase in the apoptosis rate. The number of cell clones was significantly decreased by miR-451 expression, which also caused the inhibition of cell proliferation. The average number of cells penetrating the matrigel was significantly lower than the controls. Injection of miR-451 inhibited tumor growth in a xenograft model.ConclusionsUpregulated expression of miR-451 induced apoptosis and suppressed cell proliferation, invasion and metastasis in the esophageal carcinoma cell line EC9706. In addition, injection of miR-451 inhibited tumor growth in a xenograft model of esophageal cancer.

MiR-495 regulates proliferation and migration in NSCLC by targeting MTA3

Our previous studies have showed that metastasis-associated protein 3 (MTA 3) is overexpressed in non-small cell lung cancer (NSCLC) tissue, and increased MTA3 mRNA levels is a risk factor of lymph node metastasis. Using bioinformatics analyses, we found that MTA3 was a potential target of miR-495. However, the pathophysiological role of miR-495 and its relevance to the growth and development of NSCLC have yet to be investigated. The purpose of this study was to elucidate the molecular mechanisms by which miR-495 acts as a tumor suppressor in NSCLC. qRT-PCR data showed significant downregulation of miR-495 in 56 NSCLC tissue samples and 5 lung cancer cell lines, compared with their adjacent normal tissue; furthermore, western blotting analysis revealed MTA3 protein was overexpressed in the tumor samples compared with the matched adjacent normal tissue. MiR-495 was shown to not only inhibit the proliferation of lung cancer cells (A549 and Calu-3) but also to inhibit cell migration in vitro. Using western blotting and luciferase assays, MTA3 was identified as a target of miR-495. These findings suggest the importance of miR-495 targeting of MTA3 in the regulation of lung cancer growth and migration.

Expression analysis of serum microRNAs in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology with considerable morbidity and mortality. Seeking informative diagnostic markers with greater clinical significance is essential for the early diagnosis of IPF. microRNAs (miRNAs or miRs) have emerged as novel serum diagnostic biomarkers for various diseases. In this study, we performed microarray analysis of the miRNA expression profile in the serum of patients with IPF compared to that of control subjects. We then performed a preliminary analysis of biological functions for the most differentially expressed miRNAs. Some of the microarray results were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The results from this study provide evidence to link the biological role of miRNAs to IPF, and suggest that miRNAs may undertake a variety of functions. Additionally, we found that the altered expression levels of miR-21, miR-155 and miR-101-3p were associated with forced vital capacity (FVC) and radiological features in IPF. Our data may serve as a basis for further investigation, preferably in large prospective studies, before miRNA can be used as a non-invasive screening tool for IPF in routine clinical practice.