Search

The present study aimed to investigate the molecular mechanisms and effect of Beclin-1 on autophagy, proliferation and apoptosis in the colorectal cancer (CRC) HCT116 and SW620 cells. Beclin-1 was silenced by RNA interference (RNAi) in HTC116 and SW620 cells. Reverse transcription-polymerase chain reaction and western blot were used to measure the expression of Beclin-1. The percentage of apoptotic cells was analyzed by cell counting kit-8 (CCK-8) and flow cytometry (FCM). Cell cycle and cell proliferation were analyzed by FCM and the MTT assay. The present study created 3 groups in the two cell lines, consisting of the targeting siRNA (TS) group, in which Beclin-1 was partially silenced, non-specific siRNA (NS) group and control group (CG; without transfection). By siRNA transfection, the mRNA and protein level of Beclin-1 in the TS group were significantly inhibited compared with the NS group and CG (P<0.05). After 0, 24, 48 and 72 h, the survival rate of the cells in the TS group was significantly decreased compared with the survival rate of the cells in the NS group and CG, as detected by CCK-8 methods (P<0.05). FCM and MTT results showed the apoptotic rate of the cells in the TS group was significantly decreased compared with the rate in the NS group and CG (P<0.05), and the proliferation of the cells in the NS group was evidently increased compared with the CG. In conclusion, Beclin-1 played an important role in regulating autophagy, proliferation and apoptosis in HCT116 and SW620 cells. The inhibition of Beclin-1 by RNAi suppressed the autophagic activity and proliferation, but promoted apoptosis in CRC cells. Beclin-1 was the new target of gene therapy for CRC. [ABSTRACT FROM AUTHOR]

Guan Chang Fu Fang (GCFF) is a natural compound, which is extracted from three medicinal plants, Agrimonia pilosa Ledeb., Patrinia scabiosaefolia and Solanum nigrum L. GCFF has demonstrated clinical efficacy in the treatment of colon cancer. At present, 5-fluorouracil (5-FU) is the primary active chemotherapeutic agent used for treating colon cancer. Using median-effect and apoptosis analyses, fluorescence microscopy and western blotting, the present study analyzed the association between GCFF and 5-FU in the human colon adenocarcinoma LoVo cell line. The effect of GCFF on the expression of chemotherapeutic agent-associated genes was also investigated. The results of the synergistic analysis revealed that GCFF exhibited a significant effect upon 5-FU-associated cytotoxicity within the LoVo cell line. This effect was observed over a broad dose-inhibition range (5-95%), but was particularly significant in the lower concentrations. The flow cytometry results revealed that low doses of GCFF or 5-FU induced S -phase arrest, as did a low-dose combination of the two drugs. After 48 h, GCFF significantly suppressed the expression levels of the chemotherapeutic agent resistance-associated genes within the colon cancer cells. The western blot analysis revealed that the combined effects of 5-FU and GCFF were due to a regulation of the B-cell lymphoma-2 family of proteins. The findings of the present study suggested that GCFF, when combined with 5-FU, has the potential to be a novel, chemotherapeutic compound for the treatment of colon cancer. [ABSTRACT FROM AUTHOR]