Placenta-derived conditioned medium with anti-tumor properties on human NSCLC

The decidua of human term placenta contains a cell population with highly immunomodulatory properties regulating viability, growth and invasion important for the fetal development, remarkably resembling the tumor-microenvironment. Prompted by previously published data from our group demonstrating the pro-apoptotic potential of placenta-derived supernatant on human lung cancer in vitro, the anti-tumor activity of placenta-conditioned medium was studied in more detail. For this purpose, human NSCLC cell lines A549 and H838 were challenged for 17h with placenta-derived conditioned medium, obtained from human fresh term placenta incubated overnight in DMEM with 2%FCS. Viability was analysed either by MTT assay or FACS using 7-AAD. For tumor growth, expression of proliferation marker Ki-67 was analysed, induction of apoptosis was determined by expression of annexin V and/or cleaved caspase 3 using immunofluorescence or FACS analysis. Overall, both suppression of Ki-67 expression and increase of apoptotic cells were induced by all placentas (n=6), although to strikingly varying extent. Based on these preliminary but promising results demonstrating consistent inhibitory effects on lung tumor cells, placenta-derived anti-tumor activity will be further studied including human NSCLC specimens and by using fractionated placenta-derived supernatants that will be also analysed by mass spectrometry to identify potential immunosuppressive mediators. Thus, these studies could result in the development of new therapeutic agents for a more effective treatment of NSCLC.