| Summary: | 碩士 === 國立成功大學 === 微生物及免疫學研究所 === 91 === Ras transduces multiple signals to modulate gene expression for cell proliferation, transformation and death. The cell death induced by Ras may play a critical role in preventing neoplasia formation. Mitochondria Ras interacts with Bcl-2 and regulates the death of cells. BNIP3 (Bcl-2 and Nineteen kDa Interacting Protein-3) belongs the BH3 domain only protein of Bcl-2 family. BNIP3 can bind with Bcl-2 and induces the death of mammalian cells. Our data showed that the expression of Ras correlated with the expression of BNIP3 in breast cancer cell MCF7-ras, mouse fibroblast NIH/3T3 cells Bcl2-3A, and bladder cancer cells, UB37, and UB40. Expression vector of BNIP3 was constructed, and overexpression of BNIP3 gene in 293 cells resulted in cell death and increase of mitochondria membrane permeability. Further study revealed that BNIP3 caused cell death is without release of cytochrome C. Our data also demonstrated that Ras interacted with BNIP3 on mitochondria. In conclusion, whether BNIP3 overexpression can induce the apoptosis of bladder cancer cell and whether the interaction among Ras, BNIP3 and Bcl-2 on mitochondria is involved in the cell death triggered by Ras-related BNIP3 remain unclear.
Different mutation types of three major Ras proteins (H-Ras, K-Ras and N-Ras) may lead to diverse carcinogenesis. For rapid screen of amino acid 12 mutants of Ras in clinical samples, a method using fluorescent probes and Real-Time PCR was established. A total of 8 mutations of K-ras and 9 mutations of H-ras were detected in 38 colon cancer samples. In addition, a total of 8 mutations of H-ras and no mutation of K-ras were detected in 25 bladder cancer samples. Compare to traditional methodology (SSCP), here we demonstrated a rapid and more precise method to screen codon 12 Ras mutations.
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