In vitro 実験系による肺がん化学療法レジメンの抗腫瘍効果の評価

Lung cancer is the leading cause of cancer mortality.There are 3 major types of lung cancer therapy-surgery,chemotherapy and radiotherapy.In most cases,chemotherapy is the first choice and cisplatin-based combination therapy plays a major role in lung cancer chemotherapy.As the anticancer effects of lung cancer chemotherapy regimens have not been evaluated in vitro ,we evaluated the effects of combination therapy with cisplatin and irinotecan (IP therapy) and that with cisplatin and etoposide (EP therapy),using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in human lung adenocarcinoma A 549 epithelial cell line cells.In the MTT assay,drug solutions were added according to the same schedule as for the regimens.The exposure times of the drugs were their half-lives,and drug concentrations were the IC50 values of the half-lives.Our results suggested that cisplatin had a much stronger antiproliferative effect than irinotecan and etoposide,and that all agents had a strong anticancer effect.It has been shown that in these combination therapies,together,the drugs have a stronger anticancer effect than they do when given alone.For IP therapy,cell viability returned at day 28,while it returned at day 15 for EP therapy.These results suggested that the MTT assay can be used in vitro to evaluate cancer chemotherapy regimens as well as dosing schedules for IP therapy and EP therapy.