Functional analysis of a lung adenocarcinoma down-regulated gene, MOSC2

• Main Authors: Tsung-Shin Fu, 傅綜信
• Other Authors: Jin-Mei Lai
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/92271778560234901175

碩士 === 輔仁大學 === 生命科學系碩士班 === 95 === Lung adenocarcinoma is the leading cause of female cancer death in Taiwan. It was noticed that 85 percent of them are nonsmokers, indicating the higher risk of these females may as least, in part, impute to their distinctive genome. Recently, 18 pairs of lung adenocarcinoma tissues and their adjacent normal tissues were analyzed by Affmatrix microarray. After data mining, we have found that MOSC2 is one of the genes whose mRNA expression is lower in tumor as compared to adjacent noncancerous part (p value<0.0001), which is also confirmed by quantitative RT-PCR(p value＝0.0001). MOSC2 is a novel gene. As MOSC2 is down-regulated in lung cancer tissues, and locates on LOH(loss of heterozygousity) region, we therefore investigate the function of MOSC2 by which may shed some light on the research of lung adenocarcinoma. In attempt to knowing whether MOSC2 gene was mutated in tumor tissue, the coding sequence of MOSC2 in genome of 13 lung cancer cell lines and 25 lung cancer patients were sequenced. In this thesis, six mutations (T297T/C; T360T/C, T360T; G528A /G, G528A; G730G/A, G730G; C827C/T and G933G/A) sites have been identified. However, five out of six mutations are demonstrated as SNP in NCBI SNPs database, only one site, C827C/T, is the new mutation found in lung cancer cell line H460. We conclude that mutation is not the cause which down-regulate MOSC2 gene in lung adenocarcinoma. To investigate the function of MOSC2, I have established a yeast two-hybrid system to identify its interacting protein(s). APOAI was identified as the interacting protein of MOSC2 interact with the N-terminal region of MOSC2. Subsequently, I also performed immunofluorescence to find the subcellular localization of MOSC2. Interestingly, MOSC2 seemed to locate in mitochondria, by which is colocalized with pEYFP-mito. To evaluate the role of MOSC2 in cell cycle regulation, we also over-expressed MOSC2 in H1299 cells. However, no obvious role was found in cell cycle distribution. Finally, I try to identify the promoter region of MOSC2 toward understanding the transcriptional control of it. From the transcription start site of MOSC2, we have constructed -1 to -512, -1 to -1003, -1 to -1512 and -1 to -2000 region from genomic sequence and analyzed their promoter activity. We have concluded that -512 to -1003 which existed putative TATA box and displayed higher promoter activity may be the promoter region of MOSC2.