RESUMO
Aim To investigate the apoptosis of human gastric carcinoma AGS cells induced by cecropinXJ. Methods Human gastric carcinoma AGS cells and human normal epithelial cells GES-1 were co-cultured with different concentrations of cecropinXJ ranging from 0. 01 to 1 000 mg·L-1 for 24 h. MTT assay was used to observe the effects of cecropinXJ on the proliferation of AGS cells and GES-1 cells. The ultrastructural changes of the AGS cells were observed by transmission electron microscopy. Hoechst staining was used to de-tect cell apoptosis. The changes of intracellular reac-tive oxygen species ( ROS) and mitochondrial potential were analysed by flow cytometery. The expression of Bax, Bcl-2, caspase-3 and cytochrome C in mRNA level was investigated by qRT-PCR. Western blot was used to determine the protein expression of Bax, Bcl-2, caspase-3 and cytochrome C. Results CecropinXJ significantly suppressed the proliferation of AGS cells in vitro (P<0. 05) in a dose-dependent manner, IC50 =61. 19 mg·L-1 , but had no inhibitive effects on the proliferation of GES-1 cells. After treatment for 24 h, cecropinXJ induced AGS cells nuclear condensation, and increased ROS production, disrupted mitochondri-al integrity. The results of qRT-PCR and Western blot demonstrated cecropinXJ could up-regulate the expres-sion of Bax and down-regulate the expression of Bcl-2 , promote the release of cytochrome C and activate caspase-3. Meanwhile, cecropinXJ promoted caspase-3 activity in a dose-dependent manner, and cell death ratio of AGS cells induced by cecropinXJ was signifi-cantly reduced by caspase-3 and caspase-9 specific in-hibitors treatment. Conclusion CecropinXJ can in-duce apoptosis of AGS cells by downregulating Bcl-2 , upregulating Bax and activating caspase-3 , which may be one of its anti-tumor mechanisms.
RESUMO
Objective To explore the effects of lycium barbarum polysaccharide (LBP) on restraining the mouse pancre?atic cancer cells LTPA by the polarization of macrophages to type 1 macrophages (M1). Methods LTPA tumor model of the subcutaneous CB-17SCID mice was constructed. Model mice were randomly divided into tumor-bearing model group (n=10) and LBP treatment group (n=10). The LBP treatment group was fed 10mg/kg LBP every day, and the tumor-bearing model group was fed the same dose of normal saline. The same amount of macrophages Raw264.7 was randomly divided into the control group and experimental groups (different concentrations of LBP). MTT assay was used to detect the optical density (OD) of Raw264.7 in experimental groups and control group. ELISA was used to detect the levels of the interleukin (IL)-12 and IL-10 in experimental group (LBP was 100 mg/L) and the control group. Flow cytometry was used to test the levels of the membrane protein CD16/32 and CD206 in experimental group (LBP was 100 mg/L) and the control group. The tumor mass was weighted and the volume was calculated after three weeks. The effects of LBP on the growth of subcutaneous tumor were detected. HE staining and KI-67 staining were used to detect the microscopic changes of tumor and the proliferation of the LTPA. Results The dose of 100 mg/L LBP can promote the growth of the macrophages Raw264.7 (P<0.01), and induced the high expression of CD16/32 and low expression of CD206, high secretion of IL-12 and low secretion of IL-10. The weight, volume of the tumor and the expression of KI-67 were significantly lower in experimental group than those in the con?trol group (P<0.01). The microscopic necrosis area range of tumor was larger than that of control group. Conclusion The LBP has the effect of restraining LTPA by the polarization of macrophages to M1.