Relationship between PAK6 expression and radiosensitivity in breast cancer patients undergoing radiotherapy

Abstract

Objective To investigate the relationship between P21-activated kinase 6 (PAK6) expression and radiosensitivity of breast cancer patients undergoing radiotherapy. Methods MDA-MB-453 breast cancer cell line, small interfering RNA (siRNA), and cells transfected with PAK6 siRNA were set as untransfected group, control group and observation group, respectively. Western blot and quantitative real time polymerase chain reaction were used to detect the expression of PAK6 in each group. Every group was given 0, 1, 3 and 5 Gy radiotherapies, respectively, with one radiation dose for once. Thereafter, cell proliferation was detected by cell counting kit-8, and apoptosis was monitored by flow cytometry. Western blotting was used to detect the level of Caspase-3 protein in cells of three groups. Results The PAK6 protein and PAK6 mRNA expression levels of the untransfected group and control group were higher than those of the observation group (P<0.05). The proliferation of breast cancer cells , with the radiotherapy doses of 0, 1, 3 and 5 Gy, in the untransfected group and the control group were higher than that in the observation group (P<0.05); while untransfected group and control group had lower levels of apoptosis than observation group (P<0.05). The expression level of caspase-3 in the observation group was higher than that in the control group and untransfected group (P<0.05). Compared with the untransfected group and control group, the cell inventory score of the observation group was reduced, and the sensitization ratio of radiotherapy was 1.774. Conclusions Interference on PAK6 expression in breast cancer cells can inhibit the proliferation of breast cancer cells, promote the apoptosis of breast cancer cells and increase the radiosensitivity of breast cancer patients. The mechanism may be related to the effects of PAK6 on caspase-3 protein. Key words: Breast cancer; P21-activated kinase 6; Radiotherapy; Sensitivity