RESUMO
Objective Long non-coding RNA(lncRNA) are aberrantly expressed in breast cancer(BC) and strongly associated with its survival prognosis. The aim of this study is to investigate the expression and effect of IncRNA SPATA31D5P on the invasion and migration capacity of breast cancer cells through adsorption of miR-320a. Methods Totally 30 cases of BC tissues and paraneoplastic tissues were collected, and the expression levels of SPATA31D5P in BC tissues and BC cell lines were detected by Real-time PCR. MDA-MB-231 cells were transfected with SPATA31D5P siRNA interference vector, and cell proliferation, invasion and migration capacity were determined using the cell counting kit-8 assay (CCK-8), 5-ethynyl-2'- deoxyuridine(EdU), Transwell and wound-healing assay respectively. And cell cycle and apoptosis were detected by flow cytometry. Bioinformatics approachs were used to screen for miRNAs that could bind complementarily to SPATA31D5P, and the regulatory effect of SPATA31D5P on miR-320a was detected by Real-time PCR and dual luciferase reporter assay. Results SPATA31D5P levels were significantly higher in BC tissues than in adjacent normal breast tissues, and SPATA31D5P expression was higher in each BC cell line than in normal breast epithelial cells MCF10 A. The level of SPATA31D5P in the interference group was 0. 288±0. 052, which was lower than that of the blank control group 1. 114±0. 096 and negative control (NC) group 1. 079±0. 128 (P< 0. 01). The proliferation activity of MDA- MB-231 cells in the interfered group was significantly reduced and apoptotic rate was obviously increased compared to the NC and control groups (P<0. 01) ;the Gj phase block was observed in the interfered group; the scratch healing rate and number of perforated cells in the interference group were (14. 36 ± 1. 75) % and (26±1.52), which were lower than (52. 25± 1.87)% and ( 67. 33 ± 2. 91 ) of the NC group (PcO.Ol). Dual luciferase experiments confirmed that SPATA31D5P could directly regulate miR-320a expression and luciferase activity. Conclusion SPATA31D5P is highly expressed in BC, interfering with SPATA31D5P expression effectively inhibits the proliferation, migration and invasion of MDA-MB-231 cells, and the mechanism may be related to the targeted regulation of miR-320a.
RESUMO
<p><b>OBJECTIVE</b>To investigate the time course of let-7a microRNA expression in the cell cycle of HeLa cells.</p><p><b>METHODS</b>HeLa cells were synchronized in G(1), S and G(2)/M phases using double-thymidine block, and the cell cycle phases were defined by flow cytometry. Real-time quantitative RT-PCR was used to examine the expression of let-7a in HeLa cells in different cell cycle phases.</p><p><b>RESULTS</b>The synchronization rates of G(1), S and G(2)/M phases were 84.81%, 83.65% and 77.69%, respectively. Let-7a was constitutively expressed throughout the cell cycle in HeLa cells, but the expression levels in G(1) and S phases were lower than those in G(2)/M phase.</p><p><b>CONCLUSIONS</b>Cell cycle can significantly influence the expression level of let-7a, which may provide new clues to the understanding of the cell cycle control mechanisms.</p>