Study on the influence of metformin on castration-resistant prostate cancer PC-3 cell line biological behavior by its inhibition on PLCε gene-mediated Notch1/Hes and androgen receptor signaling pathway.

OBJECTIVE To study the regulation of metformin on the biological behaviors of the castration-resistant prostate cancer (CRPC) PC-3 cell such as proliferation, invasion, apoptosis through influencing Notch1/Hes and androgen receptor (AR) signaling pathway activity by its inhibition on the expression of PLCε gene. MATERIALS AND METHODS Human prostate cancer-3 (PC-3) cell line was divided into PC-3 cell line (group A), PC-3 cell line + metformin (10 mM) (group B), PC-3 cell line + metformin (20 mM) (group C), PLCε gene knockout cell line (group D), PLCε knockout cell line + metformin (10 mM)_ (group E) and PLCε knockout cell line + metformin (20 mM) (group F), which were respectively tested at 24 h, 48 h and 72 h, and five duplicate wells were set at each time point in each group. Western blot assay and RT-PCR assay were used to test the relative expressions of PLCε, Notch1, Hes, AR protein and mRNA; MTT assay was used to test the cell proliferation. Transwell chamber was used to test the invasion capability. The scratch test was used to test the migration capability and the flow cytometer was used to test cell apoptosis. RESULTS The relative expressions of PLCε, Notch1, Hes, AR protein and mRNA in Group A were increased gradually with time, but those values in group B and group C were decreased gradually with time and also significantly lower than those in group A (p <0.05) at each time point. The relative expressions of PLCε, Notch1, Hes, AR protein and mRNA in-group D, group E and group F were not changed at each time point (p>0.05). The proliferation, invasion and migration capabilities of the cells in group A, group D, group E and group F were gradually increased with time, but those in group B and group C were rapidly decreased with time and also significantly lower than those in group A, group D, group E and group F (p<0.05) at each time point. The apoptosis rates of group B and group C were increased gradually with time, and there was no other significant change in each group (p<0.05). CONCLUSIONS Metformin can regulate the biological behaviors of CRPC PC-3 cell line such as proliferation, invasion, migration and apoptosis through influencing Notch1/Hes and AR signaling pathway activity by its inhibition on the expression of PLCε gene.