Summary: | 碩士 === 輔仁大學 === 生命科學系碩士班 === 94 === Lung cancer is currently the leading cause of cancer death worldwide as well as in Taiwan. Identifying the causal perturbations that confer lung carcinogenesis may significantly advance the detection and the treatment of cancer. Recently, we have analyzed the lung adenocarcinoma by Affymetrix microarray profiling, and proposed to investigate one novel gene, FLJ20152, by its’ down-regulation in lung cancer tissue as compared to adjacent normal part (p < 0.0001) and its positioned near LOH region. Using Q-RT-PCR analysis, we also validate the expression of FLJ20152 mRNA is indeed lower in lung tumor tissues (p = 0.002), indicating it may at least, in part, plays roles on tumor suppression. In attempt to know whether FLJ20152 gene was mutated in tumor tissues, the coding sequences of FLJ20152 in 15 lung cancer patients and 13 lung cancer lines were sequenced. So far, I didn’t find any non-synonymous mutations in tumor tissues. Only one heterozygous synonymous mutation on exon 6 (T180T/C) and one synonymous mutation on exon 8 (C393C/T or C393T), which also be mentioned in NCBI SNP database were found, indicating no mutation of FLJ20152 was obviously linked to lung cancer formation. To elucidate the role of FLJ20152, I firstly established a yeast two-hybrid system to identify its interacting protein(s). I have identified eight proteins were shown to interact with FLJ20152 including THY1, MAGED4, OLFML3, ATP1B1, NUDC, P2Y5, BF and ATP1A1. Among these candidate interacting proteins, ATP1A1 and THY1 were shown to regulate cell proliferation by different ways, indicating the interacting of them and FLJ20152 may also play roles in regulating cell growth, which is one of the characteristics of cancer formation. As indicated above, FLJ20152 stably expressed H1299 cells show increase of G0/G1 phase cells as compared to the control cells, indicating this protein might indeed play a role in G1/S progression. I have found that FLJ20152 displays tiny speckled morphology within cytoplasm, however, how it functions and corrects with its down-regulation in lung cancer cells still to be further resolved. In the present thesis, I have used shRNA and siRNA for knock-down the expression of FLJ20152, generate the GST-FLJ20152 fusion protein for immunizing animals, which will form the basis for our further studying the function of FLJ20152 and its link in lung cancer formation.
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