Preliminary study on the effects of costimulatory molecule B7-H3 on the invasion and survival of human non-small cell lung cancer cell line A549 / 中华微生物学和免疫学杂志

ABSTRACT

Objective To investigate the effects of costimulatory molecule B7-H3 on the prolifera-tion and invasion of human non-small cell lung cancer cell line A549. Methods Flow cytometry was used to detect the expression of B7-H3 at protein level on A549 cells. B7-H3-targeting siRNA was transfected into A549 by lentivirus to construct B7-H3-A549 cells, which were identified with Western blot and qPCR. Differences in proliferation between B7-H3-A549 and B7-H3+A549 cells were analyzed by CCK8 assay. Flow cytometry was performed to detect the changes in apoptosis and cell cycle after AnnexinⅤ-PE/propidi-um iodide ( PI) staining. Transwell assay was used to evaluate the migration and invasion of B7-H3-A549 and B 7-H 3+ A 549 cells . Expression of apoptosis-related proteins was detected by Western blot . Results (1) B7-H3 was highly expressed on A549 cells. A stable B7-H3-A549 cell line and its control cell line B7-H3+A549 were successfully prepared. (2) A549 cell proliferation was significantly reduced after knocking down B7-H3 expression. (3) The percentage of early apoptotic cells in B7-H3-A549 cell group was higher than that in B7-H3+A549 cell group, but no significant difference in the percentages of cells undergoing late apoptosis was found between the two groups. B7-H3-A549 cells were arrested at the G0/G1 phase of cell cy-cle. (4) Compared with B7-H3+A549 cells, B7-H3-A549 cells showed suppressed migration and invasion. (5) Enhanced expression of Bad and Caspase-3 and decreased expression of Bcl-2, P-AKT and MMP-9 were detected in B7-H3-A549 cells as compared with those in B7-H3+A549 cells, but no significant difference in the total AKT was observed. Conclusions Knocking down the expression of B7-H3 molecule in A549 cells could inhibit cell proliferation and invasion, induce cell cycle arrest at G0/G1 phase and promote cell apoptosis.