%0 Journal Article
%T Genetic Heterogeneity of Breast Cancer Metastasis May Be Related to miR-21 Regulation of TIMP-3 in Translation
%A Jianyi Li
%A Yang Zhang
%A Wenhai Zhang
%A Shi Jia
%A Rui Tian
%A Ye Kang
%A Yan Ma
%A Dan Li
%J International Journal of Surgical Oncology
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/875078
%X Purpose. MicroRNAs are noncoding RNA molecules that posttranscriptionally regulated expression of target gene and implicate the progress of cancer proliferation, differentiation, and apoptosis. The aim of this study is to determine whether microRNA-21 (miR-21), a specific microRNA implicated in multiple aspects of carcinogenesis, promoted breast cancer metastasis by regulating the tissue inhibitor of metalloproteinase 3 (TIMP-3) gene. Methods. miR-21 of serum and tissue from 40 patients (30 patients with breast cancer) were detected by real-time quantitative reverse transcriptase polymerase chain reaction (RT-qPCR). TIMP-3 of tissue from the patient was tested by real-time RT-qPCR. Protein expression of TIMP-3 was evaluated by western blotting. Correlation analysis was performed between miR-21 and TIMP-3. Results. Of the 40 samples from tissue and serum analyzed, the miR-21 expression was significantly higher in high invasion metastasis group (HIMG) that in low invasion metastasis group (LIMG); the latter was higher than that in normal group (NG). Additionally, the TIMP-3 expression was significantly lower in HIMG than in LIMG; the latter was lower than that in NG. There was significantly inverse correlation between miR-21 and TIMP-3 extracted from tissue. Conclusion. Our data suggest that miR-21 could promote metastasis in breast cancer via the regulation of TIMP3 translation, and there was consistency between miR-21 of serum and miR-21 in tissue. 1. Introduction Metastasis is the main reason which cause the treatment failure and death in patients with breast cancer [1]. In clinical work, even in the same pathological type, histological grade, clinical stages and molecular typing, differences between the metastatic probability in patients are huge [2]. In fact, tumor metastasis is still poorly understood for researchers, and deconstruction of genetic heterogeneity is the right way. According to findings previously, endogenous inhibitors of matrix metalloproteinases (MMPs) play an important role in extracellular matrix (ECM) homeostasis and deregulate ECM remodeling which contributes to cancer metastasis [3, 4]. Tissue inhibitor of metalloproteinase (TIMP) balanced the role of MMPs involved in organizing remodeling, thus having an impact on cancer metastasis [5]. On the other hand, the discovery of microRNA regulation of tumor metastasis was considered to be the molecular basis of the genetic heterogeneity of mechanism¡¯s important part [6]. Specifically, miR-21 is overexpressed in diverse types of malignancy [7]. Further, recent experiments suggest that
%U http://www.hindawi.com/journals/ijso/2013/875078/