| Summary: | 碩士 === 國立東華大學 === 生命科學系 === 99 === In this study, the crude extract of Taiwanofungus camphoratus fruiting body was sequentially separated into six fractions, FK1 to FK6, according to the polarity of components by using column chromatography process. These fractions were used to treat human colorectal cancer cell line caco-2 with different doses. The result showed that the IC50 of FK6 was 20 μg / mL. By using PI staining, the data showed of subG1of cell cycle was increased 7.3% after treating 20 μg / mL of FK6 for 24 hr., and increased 8.9% after treating 48hr. in caco-2 cancer cell. Subsequently, the results of annexinV - FITC & PI double staining showed that the number of living cells was decreased, and the number of necrosis and apoptotic cells was increased along with the increasing dose of FK6 and treating time. Finally, the results of Western blot showed that FK6 induced FasL expression and interacted with Fas receptor to activate caspase 8 in extrinsic apoptosis pathway. In intrinsic apoptosis pathway, caspase 8 activated Bid into tBid, it caused the increase of Bax expression and decrease of Bcl-2 expression inmitochondria, afterward induced cytochrome c released from mitochondria to cytoplasm. The above results fully demonstrated the intrinsic apoptosis pathway in mitochondria. While cytochrome c released from mitochondria, it activated caspase 9, followed by activation of downstream caspase 3, caspase 7 and inhibited PARP performance. Therefore cell lossed DNA repaired capacity, and promoted cells to apoptosis.
This paper indicated that FK6 fraction of Taiwanofungus camphoratus extract induced colorectal cancer cell line caco-2 apoptosis through Fas / FasL signal pathway activation which inhibited DNA repair capability. Based on the results showed in this paper, the FK6 ingredient of Taiwanofungus camphoratus fruiting bodies should has the opportunity to further develop the effective medicine for treatment of colon cancer.
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