New perspectives for prostate cancer treatment: in vitro inhibition of LNCaP and PC3 cell proliferation by amnion-derived mesenchymal stromal cells conditioned media.

Abstract Aim: To determine whether normal human amnion-derived mesenchymal stromal cells (hAMSCs) secrete trophic mediators able to inhibit human prostate cancer cell lines growth. Methods: Human prostate cancer and normal cell lines were used. Mesenchymal stromal cells (MSC) were isolated through mechanical and enzymatic digestion from amniotic membranes and were evaluated for specific mesenchymal stromal cells antigens. Cell proliferation was examined by MTT assay. Staining with propidium iodide (PI) followed by flow cytometry was used to detect cell cycle phase. Results: hAMSC showed proper mesenchymal stem cells phenotype. We found that hAMSC conditioned media (CM) inhibited prostate cancer cells proliferation. Indeed, we demonstrated that hAMSC CM treatment increased percentage of G1 cancer cells and decreased percentage of cancer cells in S and G2M phases, suggesting that the hAMSC factors slow progression of prostate cancer cells through cell cycle inhibition. Conclusions: Our study provide evidences that hAMSC microenvironment secretes soluble factors able to inhibit prostate cancer cells growth. This may represent a novel strategy to control proliferation of prostate cancer through modulation of the host microenvironment.