Proteasomes reactivator REG gamma enchances oncogenicity of mda-mb-231 cell line via promoting cell proliferation and inhibiting apoptosis

Abstract

To investigate the effect of proteasomes reactivator REG gamma (γ) on cell cycle and apoptosis in vitro and in vivo. In vitro, we first constructed recombinant plasmid of PcDNA3.1-REGγ and then transfected REGγ into MDA-MB-231 cell line. We confirmed the transfection efficiency by Western blot. Subsequently, we observed cell growth, cycle and colony formation. Specific proliferative molecule proliferating cell nuclear antigen (PCNA) and apoptosis related signal molecule Caspase-3 was assayed by immmunohistochemistry and absorption spectrometry, respectively. In vivo, we successfully established transplantation tumor nude mice model. We determined REGγ mRNA level in the transplantation tumor tissue. Then, FCM was used to determine cell cycle, apoptosis and CD16. Finally, we employed immunohistochemistry to determine P21 positive expression. However, the cells transfected with REGγ grew more rapidly compared with non-transfected ones. Increased cells were observed in S+G2+M phase and S phase in the REGγ transfected group. PCNA expression level in the transfected cells was higher than that in non-transfected ones. In vivo, we observed the similar phenomenon including more rapid tumor growth, higher REGγ mRNA expression, decreased cells number in G0/G1 phase and G2/M phase, increased cells in S phase and decreased apoptosis in the transfected group. In the study of related molecules, we also found related molecules P21 and CD16 positive expression rate were obviously lower than non-infected ones. In present study, we found oncogenicity of MDA-MB-231 cell transfected with REGγ was enhanced, which might be realized via REGγ promoting cell growth, inhibiting cell apoptosis, degrading P21 and suppressing activation of NK, suggesting REGγ promoting tumor growth is a process involving multiple factor mechanisms.