Effects of adipocytes on the proliferation and differentiation of prostate cancer cells in a 3-D culture model

Objective: To investigate how the mechanism of adipocyte-prostate cancer cell interaction affects the proliferation and differentiation of prostate cancer cells. Methods: An androgen-dependent cell line (LNCaP), two androgen-independent cell lines (PC-3, DU145), and mature adipocytes harvested from male Wistar rats were used. Cancer cells were co-cultured with the isolated mature adipocytes in 3-D collagen gel matrix culture. The morphology and proliferative ability of the prostate cancer cells were examined. With regard to the activation of the phosphatidylinositol 3-kinase (PI3K) pathway, the expression of phosphatase and tensin homologue deleted on chromosome ten (PTEN), Akt and Bad were determined by immunohistochemistry. Results: LNCaP cells co-cultured with adipocytes formed larger clusters than those of the control. PC-3 cells co-cultured with adipocytes did not form larger clusters, but formed spherical and spindle-shaped cells. The phosphorylation of Akt in PC-3 cells was greater in the co-cultured group compared with the controls, but there were no significant differences in the phosphorylation of Akt with regard to LNCaP and DU145 cells. Conclusions: Adipocytes could modulate the proliferation and differentiation of prostate cancer cell lines. Activation of the PI3K pathway might be involved in the prostate cancer cell-adipocyte interaction.