Depression mechanism of survival signals induced by radiation

用2GyX射线或铁离子束照射携带突变型p53(Mp53)基因的人牙龈癌细胞(Ca9-22细胞)。当细胞受到高LET辐射时，AKT相关蛋白水平下降。此外，与低LET辐射相比，高LET辐射增加了G2/M期阻滞，并更有效地抑制了细胞周期的进展。这些结果表明，高LET辐射通过抑制Akt相关信号而促进细胞凋亡和细胞周期停滞，即使在携带mp53基因的癌细胞中也是如此。

Human gingival cancer cells (Ca9-22 cells) harboring mutated p53 (mp53) gene were irradiated with 2 Gy of X-rays or Fe-ion beams. Akt-related protein levels decreased when cells were irradiated with high LET radiation. In addition, high LET radiation increased G2/M phase arrests and suppressed the progression of the cell cycle much more efficiently when compared to low LET radiation. These results suggest that high LET radiation enhances apoptosis and cell cycle arrest by suppressing Akt-related signals,even in the cancer cells bearing mp53 gene.