Mutation And Expression Of DNA Polymerase Beta Gene In Gastric Carcinama

Oncogene, tumor suppressor gene and DNA repair gene constitute the molecular foundation of cell carcinogenesis . To study the development mechanism of turner from molecular level has become a more and more hot topic for many biologists and oncologists. DNA polymerase beta (DNA polβ )is a housekeeping gene and one member of DNA polymerase family. DNA sequence of DNA polβ is high conservative. DNA polβ gene exists extensively in mammalian cells. It's main function is to repair damaged DNA. The expression level of DNA polβ is relatively stable in the whole cell cycle without being regulated by proliferation of cell cycle. As an important repairing enzyme, DNA polβ excises and repairs DNA base mutations ranged from 1 to 4 bases especially, that is the function of BER. Transleisional DNA synthesis is another function. Recently, it has been reported that DNA polβ gene mutations have been discovered in colorectal cancer, esophageal cancer, breast cancer, liver cancer, lung cancer, bladder cancer and prostate cancer. The mutation rate of DNA polβ is much higher in colorectal cancer, approximately 70-80%. The mutations usually occur in mucous malignant cancer and the mutation rate is increased significantly. Gastric carcinoma is one of the most common malignant tumors and it's mortality rate is the highest in China. Of course, it belongs to mucosa malignant tumors. But there is no exploration on DNA polβ in gastric cancer except one report made by Japanese researchers. The expressions of DNA polβ have been detected in many tumors, such as: prostate cancer, breast cancer, ovarian cancer, colon cancer, and so on. Expression level is much higher in tumor tissue than that in corresponding...