Original Article Effect of rapamycin (RAPA) on the growth of lung cancer and its mechanism in mice with A549
Int J Clin Exp Pathol
Objective: To investigate the effects of rapamycin (RAPA) on the tumor growth of lung cancer in the mice bearing A549 and the mechanisms. Methods: 60 mice with A549 lung cancer models established were randomly divided into model group, low RAPA dose group and high RAPA dose group. The low dose group underwent intra-peritoneal injection of 1.5 mg/kg RAPA, while the high dose group underwent intraperitoneal injection of 4.5 mg/ kg RAPA, and the control group was given the same volume of PBS. 21 d
... volume of PBS. 21 d after the administration, the changes of the tumor growth and survival rates of three groups were observed. RT-PCR and Western blot were utilized to analyze Caspase-3 mRNA and protein levels in the tumor tissues of the mice, and TUNEL staining method was used to analyze the cellular apoptosis of tumor tissues. Results: Compared with the model group, the low and high dose groups significantly inhibit tumor growth and have remarkably higher survival rates (P<0.05). The high dose group has obviously better effects on inhibiting tumors and a higher survival rate than low dose group (P<0.05). Compared with the model group, the low and high dose groups have significantly increased Caspase-3 mRNA and protein levels in tumor tissues (P<0.05), and higher cellular apoptosis rates in tumor tissues (P<0.05); Caspase-3 mRNA and protein levels and apoptosis rates of the mice's tumor tissues of high dose group are markedly higher than those of low dose group (P<0.05). Conclusions: RAPA can significantly increase the expression of Caspase-3 in tumor tissues and promote the apoptosis of tumor tissue cells, and thus achieve good anti-tumor effects.