Effects of lentivirus-mediated CC chemokine ligand 5 (CCL5)-RNAi on biological behaviors of human breast cancer cells (MDA-MB-231) / 中华普通外科杂志

ABSTRACT

Objective To study the effect of lentivirus-mediated CCL5-RNAi on the biological behaviors of human breast cancer cells. Methods CCL5-specific siRNA gene was synthesized and cloned into the recombinant lentiviral vector, pGCSIL-GFP. Human high-metastatic breast cancer cells, MDA-MB-231, were infected by CCL5-siRNA recombinant lentivirus, which was set as KD group. Cells infected with CCL5-NC was as NC group, and cells cultured was as CON group. The expression of CCL5 mRNA and protein in MDA-MB-231 cells was detected by RT-PCR and western blot, respectively. Cell growth suppression and cell cycle was observed by MTT assay and fluorescence activated cell sorting (FACS). Colony formation and migration ability were determined by colony-rorming assay and Boyden chamber method. Results After infection of CCL5-siRNA recombinant lentivirus, the expression level of CCL5 mRNA and protein in MDA-MB-231 cells as well as the colony formation and migration ability decreased significantly, but cell's proliferation was not affected obviously. Compared with MDA-MB-231 (0.88± 0.15) and MDA-MB-231/CCL5-NC (1.00±0.07) cells, the expression of CCL5 mRNA in MDA-MB-231/ CCL5-siRNA decreased to 0.18±0.03, P<0.01. Compared with MDA-MB-231/CCL5-NC (1.82±0.18) cells, the expression of CCL5 protein in MDA-MB-231/CCL5-siRNA decreased to 0.33±0.13, P <0.01. Colony-forming assay and Boyden chamber method showed that the colony formation and migration ability of MDA-MB-231/CCL5-siRNA decreased markedly (P<0.05). The clone count in KD group was (0.33± 0.10), which was a significant decrease from (0.97±0.09) (NC group) and (1.04±0.07) (CON group), P<0.05. The number of cells that migrated through the chamber membrane of KD group (38± 15) was less than that of NC group (77±11, P <0.05) and CON group (69±9, P <0.05). However, MTT assay and FACS revealed that the proliferation of MDA-MB-231/CCL5-siRNA was not different from MDA-MB-231/CCL5-NC and MDA-MB-231 (P>0.05), the proliferation index (PI) of group KD, NC and CON were (0.48±0.02), (0.44±0.05) and (0.47±0.02) respectively. The difference was not statistically significant by multiple comparison (P>0.05). Conclusion CCL5-specific siRNA can specifically suppress the colony formation and migration of human high-matastatic breast cancer cells.