Studies On Amplification Of Gene Copies And Its Effects On Expression In The Malignant Transformation Of Bronchial Epithelial Cells

Genomic instability is an early event in the development of lung cancer, Gene amplifications and deletions frequently may be the important molecular mechanism contributing to malignant transformation of bronchial epithelial cells. Our work aims at screening amplified genes in the malignant transformation of bronchial epithelial cells and analyzing the effect of gene amplification on the expression level. By cDNA microarray-CGH, we detected the alterations of gene copy in the immortalized cell line and cancer cell line that derived from bronchial epithelial cells. The result revealed that the amplified chromosome regions found in the immortalized cell line included 5q31.3, 9q32~33.1, 14q22.2~23.1, 19p13.12-13.13, and 20q13.12-13.31; the amplified regions in cancer cell line were found in 1p12~13.1, 5q33.1, 5q31.3, 9q32 and 19pl3.12-13.13.The amplified regions in the both two cell lines were 5q31.3 , 9q32 , and 19pl3.12~13.13. 496 genes in total were amplified among 646 abnormal copy genes in both two lines. The amplification and over-expression of PCNA, p53 and GADD45A were conformed further by real-time PCR and cell immunohistochemistry. In addition, the result of gene sequence ananlysis showed that a point mutation was found at 13811bp in the 8th exon of p53.Our study indicates the amplification of gene copies may be one of the important factors...