The expression of DNA PK and DNA TOP I in liver cancer tissues

Objective To study the liver cancer specific DNA damage response/repair/recombination gene expression profile and the difference between liver cancer tissues and their adjacent normal tissues. Methods The cDNA probes labeled with α 32 P dATP were synthesized from total RNA of cancer tissue and adjacent liver tissues. The cDNA probes were differentially hybridized to two identical Atlas human cancer cDNA expression array membranes containing 588 known genes. A gene specific semiquantitative reverse transcription polymerase chain reaction (RT PCR) method and Northern blot were used to check the expression pattern of two known genes. Results Autoradiographic result analyzed by specific Atlas Image TM (version1.01a) showed among the 588 genes analyzed, 33 genes were related to damage response/repair/recombination and the expression of 4 genes including DNA dependent protein kinase, and DNA topoisomerase Ⅰ were found to be up regulated in liver cancer. The results of RT PCR and Northern blot confirmed the expression pattern of two genes which were detected by Atlas human cancer cDNA expression array. Conclusion The result obtained from Atlas microarray provides a liver cancer specific expression profile comprehensively and systematically. The findings about genes related to DNA damage response/repair/recombination may lead to understanding of the pathogenesis of liver cancer and the mechanism of drug resistant.