Dataset Information

MicroRNA-125a represses cell growth by targeting HuR in breast cancer.

ABSTRACT: MicroRNAs (miRNAs) are a class of naturally occurring, small, non-coding RNAs that control gene expression during development,normal cell function and disease. Although there is emerging evidence that some miRNAs can function as oncogenes or tumor suppressors, there is limited understanding of the role of miRNAs in cancer. In this study, we observed that the expression of miR-125a was inversely correlated with HuR expression in several different breast carcinoma cell lines. HuR is a stress-induced RNA binding protein whose expression is elevated or localization perturbed in several different cancers. Increased cytoplasmic localization of HuR is a prognostic marker in breast cancer. Real time PCR and gene reporter assays indicated that HuR was translationally repressed by miR-125a. Re-establishing miR-125a expression in breast cancer cells decreased HuR protein level and inhibited cell growth. Using MCF-7 breast cancer cells, we further clarified that miR-125a inhibited cell growth via a dramatic suppression of cell proliferation and promotion of apoptosis.In addition, cell migration was also inhibited by miR-125a overexpression. Importantly, the repression of cell proliferation and migration engendered by miR-125a was partly rescued by HuR re-expression. Our results suggest that miR-125a may function as a tumor suppressor for breast cancer, with HuR as a direct and functional target.

SUBMITTER: Guo X

PROVIDER: S-EPMC3645467 | biostudies-literature | 2009 Nov-Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

MicroRNA-125a represses cell growth by targeting HuR in breast cancer.

Guo Xu X Wu Yuehan Y Hartley Rebecca S RS

RNA biology 20091101 5

MicroRNAs (miRNAs) are a class of naturally occurring, small, non-coding RNAs that control gene expression during development,normal cell function and disease. Although there is emerging evidence that some miRNAs can function as oncogenes or tumor suppressors, there is limited understanding of the role of miRNAs in cancer. In this study, we observed that the expression of miR-125a was inversely correlated with HuR expression in several different breast carcinoma cell lines. HuR is a stress-induc ...[more]

PMID: 19875930

Similar Datasets

Project description:To date, the role of hematopoietic-substrate-1-associated protein X-1 (HAX1) in liver cancer is rarely studied. The present study explored the role of HAX1 in liver cancer. The association between HAX1 expression and survival of patients with liver cancer was analyzed by a log-rank test. The target genes for HAX1 was predicted by TargetScan and verified by a dual-luciferase reporter assay. The protein and mRNA expressions of HAX1 in liver cancer and adjacent non-cancerous tissues were examined by immunohistochemistry and reverse transcription-quantitative PCR (RT-qPCR). The transfection efficiency of HAX1, small interfering RNA against HAX1, microRNA (miR)-125a mimics, miR-125a inhibitor, miR-223 mimics and miR-223 inhibitor in liver cancer cells was determined by RT-qPCR. The expression of HAX1, p53, VEGF, epithelial-to-mesenchymal transition (EMT)-related markers (E-cadherin, N-cadherin and vimentin) in the cancer cells were determined by western blotting and RT-qPCR. Cell viability, migration, invasion and colony formation rates were determined by Cell Counting Kot-8, wound healing, Transwell and colony formation assays, respectively. The results showed that high expression of HAX1 in liver cancer was found relate to poor prognosis in patients with liver cancer, and upregulation of HAX1 expression in liver cancer tissues was related to lower overall survival. miR-125a-5p directly binds to HAX1. Upregulation of miR-125a-5p expression inhibited cell viability, migration, invasion and colony formation of SK-Hep1 cells and reduced the expression of HAX1, VEGF, N-cadherin and vimentin, but increased cell apoptosis and the expression of p53 and E-cadherin. However, the effects miR-125a-5p upregulation were partially reversed by SK-Hep1 cells with HAX1 overexpression. Downregulated miR-125a-5p in SNU-387 cells produced opposite effects, which was partially reversed by HAX silencing. In conclusion, miR-125a-5p suppresses liver cancer growth via targeting HAX1 and concurrently modulating the expression of p53 and VEGF and EMT-related markers.

Project description:IntroductionMicroRNAs are small non-coding RNAs that are involved in the post-transcriptional negative regulation of mRNAs. MicroRNA 510 (miR-510) was initially shown to have a potential oncogenic role in breast cancer by the observation of its elevated levels in human breast tumor samples when compared to matched non-tumor samples. Few targets have been identified for miR-510. However, as microRNAs function through the negative regulation of their direct targets, the identification of those targets is critical for the understanding of their functional role in breast cancer.MethodsBreast cancer cell lines were transfected with pre-miR-510 or antisense miR-510 and western blotting and quantitative real time PCR were performed. Functional assays performed included cell growth, migration, invasion, colony formation, cytotoxicity and in vivo tumor growth. We performed a PCR assay to identify novel direct targets of miR-510. The study focused on peroxiredoxin 1 (PRDX1) as it was identified through our screen and was bioinformatically predicted to contain a miR-510 seed site in its 3' untranslated region (3'UTR). Luciferase reporter assays and site-directed mutagenesis were performed to confirm PRDX1 as a direct target. The Student's two-sided, paired t-test was used and a P-value less than 0.05 was considered significant.ResultsWe show that miR-510 overexpression in non-transformed and breast cancer cells can increase their cell growth, migration, invasion and colony formation in vitro. We also observed increased tumor growth when miR-510 was overexpressed in vivo. We identified PRDX1 through a novel PCR screen and confirmed it as a direct target using luciferase reporter assays. The reintroduction of PRDX1 into breast cancer cell lines without its regulatory 3'UTR confirmed that miR-510 was mediating its migratory phenotype at least in part through the negative regulation of PRDX1. Furthermore, the PI3K/Akt pathway was identified as a positive regulator of miR-510 both in vitro and in vivo.ConclusionsIn this study, we provide evidence to support a role for miR-510 as a novel oncomir. We show that miR-510 directly binds to the 3'UTR of PRDX1 and blocks its protein expression, thereby suppressing migration of human breast cancer cells. Taken together, these data support a pivotal role for miR-510 in breast cancer progression and suggest it as a potential therapeutic target in breast cancer patients.

Dataset Information

MicroRNA-125a represses cell growth by targeting HuR in breast cancer.

Publications

MicroRNA-125a represses cell growth by targeting HuR in breast cancer.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets