Studies On The Anti-tumor Effect Of Gambogenic Acid Effect On Small Cell Lung Cancer In Vivo And In Vitro

Objective:Based on exploring the anti-tumor effects and the mechanism of gambogenic acid(GNA)on small cell lung cancer cell line NCI-H446?NCI-H1688 cells in vivo and in vitro,our aim is to provide laboratorial evidences for later clinical drug trials.Methods: Studies in vitro:1.CCK8 assay was used to detect the growth inhibition of NCI-H446 and NCI-H1688 cells induced by GNA.2.Flow cytometry was used to detect cell cycle and apoptosis of two cell lines induced by GNA.3.Western Blot was used to detect cell-apoptotic protein Bax?Bcl-2? Cleaved-caspase3,8,9? PARP and p53 in protein expressive levels affected by GNA to further detect some apoptotic ways.Studies in vivo:1.A nude mice model of small cell lung cancer was established by subcutaneous inoculation of human small cell lung cancer cell line NCI-H446 in advance,formula method was used to calculate the inhibitory rate,apoptotic cells of the tumors were detected by means of TUNEL and HE stain was used to test the toxicity on normal tissues.2.Western Blot was similarly used to detect cell-apoptotic protein Bax ? Bcl-2 ? Cleaved-caspase3,8,9?PARP and p53 in protein expressive levels affected by GNA to further detect some apoptotic ways.Results:1.In NCI-H446 and NCI-H1688 cells,the IC50 of GNA were 1.43±0.09?g/ml and 2.36±0.19?g/ml,according to which two cell lines was proved having the growth inhibitory effects in a dose-and time-dependent manner.2.According to the flow cytometry,the lower concentration GNA can lead to significant apoptosis in both two cell lines.In addition,it can also exert cell cycle.Low doses of GNA arrested cell cycle progression in G0/G1 while higher concentration blocked it in S phase.Different concentration of GNA all blocked cell cycle in S phase for NCI-H1688(p<0.05).3.Compared to the control group,the expressions of Bax?Cleaved-caspase3,8,9?PARP and p53 were all obviously increased while the expression of Bcl-2 was decreased(p<0.05).4.On the basis of xenograft nude mouse models,GNA-treated mice showed higher inhibition rate compared to control group(p<0.05).TUNEL staining further validated that GNA induced apoptosis in a dose-related manner(p<0.05).Furthermore,according to the HE staining,apoptosis cells were not observed in GNA-treated groups in the lung,liver,kidney,spleen,and heart from xenograft models of SCLC(p<0.05).Conclusions:1.GNA significantly inhibited SCLC cell proliferation,cell cycle progression and induced cell apoptosis.2.GNA can significantly inhibited the growth of tumor tissue and promoted cell apoptosis.3.The apoptosis-related proteins were significantly by GNA,the expressions of pro-apoptotic protein was obviously increased while the expression of anti-apoptotic protein was decreased.4.GNA has a relatively low toxicity.