BCL9 Knockout Research Effect On Invasion And Migration Ability Of Breast Cancer Cell Lines

Objective: To study the expression of BCL9 gene in three breast cancer cell lines.To study the three different breast cancer cell line cell biological characteristics: proliferation,invasion and migration ability of difference and its significance.and to investigate the effects of BCL9 gene knockdown on the invasion and migration of breast cancer cell lines.Methods:1 Three different phenotypes of breast cancer cell lines were analyzed.mRNA and protein expression of BCL9 in human breast cancer cell lines,including MDA-MB-231,MCF-7 and MDA-MB-453,were detected by real-time fluorescent quantitative PCR and Western blot.Then,the cell lines with high expression of BCL9 were screened.2 Using flow cytometry to detect the cell cycle,proliferation index calculation,comparison between three kinds of cell lines proliferation ability.By adopting the scratch experiment and transwell cell invasion experiment to compare the three cell migration and invasion ability.3 Constructing BCL9 lentiviral plasmid shRNA and BCL9 gene knockdown experiments were performed for riched BCL9 cell lines.4 Transwell cell compartment and cell scratch test were conducted for BCL9 gene knockdown effect on breast cancer cell invasion and migration.Results:1 The results about mRNA expression of BCL9 by RT-PCR MDA-MB-231(0.016±0.004)>MCF-7(0.008±0.002)>MDA-MB-453(0.004±0.002)(Comparison among groups,P <0.05),and the difference was statistically significant.Expression quantity of BCL9 protein in the cell was MDA-MB-231(0.629 ± 0.101)>MCF-7(0.397 ± 0.19 6)>MDA-MB-453(0.204 ±0.990)(Comparison among groups,P <0.05)and thedifference was statistically significant.2 The flow cytometry proliferation index of MDA-MB-231 cells was higher than MDA-MB-453 and MCF-7(P < 0.05),the difference was statistically significant.Trans well cell invasion experiment: count: the MDA-MB-231 > MCF-7 > MDA-MB-453 cells(P < 0.05),the difference was statistically significant.Cell scratch experiments: the MDA-MB-231 >MCF-7 > MDA-MB-453 cells(P < 0.05),the difference was statistically significant.3 MDA-MB-231 cell lines were transfected with BCL9 gene by lentivirus transfection technique.4 Number of cells by transwell cell compartment assay : blank group(420.50±3.704)/negative control group(417.00±5.310)> experimental group(151.50±7.580)(P<0.05).The difference was statistically significant.The healing rate by cell scratch test: blank group(0.712±0.127)/ negative control group(0.709±0.015)> experimental group(0.382±0.012)(P<0.05).The difference was statistically significant.Conclusions:1 BCL9 expression level is different between in human breast cancer cell lines: triple-negtive breast cancer MDA-MB-231 cell line BCL9 expression level is relatively higher than MCF-7 or MDA-MB-453.2 Through the analysis of three different phenotype breast cancer cell lines,cell proliferation,invasion and migration ability all have differences,three negative breast cancer in vitro on behalf of the MDA-MB-231 cells proliferation,invasion and migration ability are the highest.3 Knockdown of BCL9 gene can effectively inhibit the invasion and migration of breast cancer cell line MDA-MB-231.It suggests that BCL9 may be a new molecular target for inhibiting invasion and metastasis of breast cancer cells.