title: Caprin-1 is a novel microRNA-223 target for regulating the proliferation and invasion of human breast cancer cells.
abstract: MicroRNAs (miRNAs) are 21-22 nucleotides regulatory small non-coding RNAs that inhibit gene expression by binding to complementary sequences especially the 3' untranslated region (3'UTR) of mRNA. One miRNA can target many messenger RNAs, leading to a complex metabolic network. Previous studies have shown that miRNA-223 regulates migration and invasion of tumor cells and targets cytoplasmic activation/proliferation-associated protein-1 (Caprin-1). In the present study, we detected the expression of miRNA-223 and Caprin-1 in MCF-7, T-47D and MDA-MB-231 cancer cell lines, and MCF-10A normal breast cell line, and analyzed the role of miRNA-223 in Caprin-1-induced proliferation and invasion of human breast cancer cells. We found that miRNA-223 expression levels are significantly lower in MCF-7, T-47D and MDA-MB-231 cancer cells than in MCF-10A normal breast cells, while Caprin-1 expression is higher in cancer cells than in normal breast cells. The most malignant cancer cell line MDA-MB-231 has the lowest expression of miR-223, but the highest expression of Caprin-1. Further, we found that miR-223 targets the 3'UTR of Caprin-1 miRNA and down-regulates the expression of Caprin-1. We also found that over-expression of Caprin-1 can promote the proliferation and the invasion of breast cancer cells, but miRNA-223 can inhibit the proliferation and the invasion. miRNA-223-induced inhibition can be reversed by ectopic over-expression of Caprin-1. These findings suggest that miR-223 may suppress the proliferation and invasion of cancer cells by directly targeting Caprin-1. Our study also indicates that expression levels of miR-223 and Caprin-1 can be used to predict the state of cancer in breast cancer patient.
authors: Shanghai Changning Maternity and Infant Health Hospital, No. 773 Wuyi Road, Changning District, Shanghai 200051, PR China.
authors: Bo
authors: B
authors: Gong
authors: Heyu
authors: H
authors: Hu
authors: Jia
authors: J
authors: Chen
authors: Shuang
authors: S
authors: Cao
authors: Jing
authors: J
authors: Yu
authors: Jianxiang
authors: J
authors: Xue
authors: Fuhua
authors: F
authors: Chen
authors: Ye
authors: Y
authors: Cai
authors: Hong
authors: H
authors: He
authors: Lei
authors: L
authors: Zhang
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology*; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D009361:Neoplasm Invasiveness / Q000235:genetics / Q000473:pathology
chemical_list: D018797:Cell Cycle Proteins; D035683:MicroRNAs; C486562:CAPRIN1 protein, human; C525067:MIR223, human
keywords: Caprin-1; Human breast cancer; Invasion; Proliferation; Viability; miRNA-223