Screening And Identification Of The Gene ATP/GTP Binding Protein 1 Related To Gastric Cancer

Gastric cancer is one of the most common malignant tumors, the second cause of death for patients with malignant tumor. Every year the number of patients dying of gastric cancer amounts to nearly 650,000 and the increase of new patients amounts to 880,000. The occurrence and development of gastric cancer is a complex multi-step process involving multiple genes, multiple causes and multiple steps. The discovery of oncogene and tumor suppressor genes has furthered human beings understand the mechanisms of cell cycle and cell apoptosis as well as mechanisms of tumorgenesis. It is the basis of understanding of the molecular mechanism of tumorgenesis, however, the right reason of occurrence and development of gastric cancer has been unknown up to now. In addition, the new tumor-related-genes should be explored.In this study, mRNA differential display (DD-PCR) was employed to search for differently expressed fragments, some of which were cloned and sequenced. By homology analysis in GenBank, corresponding homologous genes of those fragments were found. The corresponding genes of those differently expressed fragments were validated by semi-Real-time and Real-time quantitative PCR.Ten cDNA fragments were screened by performing FDD-PCR reactions with gastric cancer tissues and their respective normal tissues adjacent to the tumor in gastric cancer. These fragments were cloned and sequenced, and two cDNA fragments were obtained. By DD-PCR, one EST has highest homology (99%) with A/GTP binding protein 1 gene (A/GTPBP1). The ORF of A/GTP binding protein 1 gene was 3561 base pair long and encodes 1186 amino acids. The molecular weight was about 84.4 KD. The result of semi- Real-time and Real-time quantitative PCR showed that the expression level of A/GTP binding protein 1 gene both in the gastric cancer (P<0.01, t-test, n=12) and esophageal carcinoma(P<0.01, t-test, n=9) was significantly higher than that in normal tissues.At the same time, real-time quantitative PCR was employed to search differently expressed of A/GTP binding protein 1 gene in six different cell lines (AGS, SGC, Hela, K562, U937, EIF-4), the results showed that there is no significant differential expression in these six cell lines.