Plasma-activated medium induced apoptosis on tumor cells

The non-equilibrium atmospheric pressure plasma (NEAPP) has attracted attention in cancer therapy. In this study, the fresh medium was treated with our developed NEAPP, ultra-high electron density (approximately 2 $\times$ 10$^{16}$ cm$^{-3}$) [1,2]. The medium called the plasma-activated medium (PAM) killed not normal cells but tumor cells through induction of apoptosis. Cell proliferation assays showed that the tumor cells were selectively killed by the PAM. Those cells induced apoptosis using an apoptotic molecular marker, cleaved Caspase3/7. The molecular mechanisms of PAM-mediated apoptosis in the tumor cells were also found that the PAM downregulated the expression of AKT kinase, a marker molecule in a survival signal transduction pathway. These results suggest that PAM may be a promising tool for tumor therapy by downregulating the survival signals in cancers.\\[4pt] [1] M. Iwasaki et al. Appl. Phys. Lett. 92, 081503 (2008);\\[0pt] [2] H. Tanaka, et al. Plasma Medicine 1(3-4) 265-277 (2011).