| Background:Hypoxia condition is the typical feature during the formation of tumor. Due to avariation of gastric mucosa epithelial cells, gastric cancer is regarded as malignanttumors with features of higher morbidity and mortality. And various genes are alteredduring the formation and development of malignant tumors. Hypoxia condition couldaffect gastric cancer cells’ biological characteristics significantly. GCRG213is anewly-found high expression gene sequence with complete open reading frame（ORF）in gastric cancer during recent years, and that is part of long interspersednuclear element-1family member, LINE-1endonuclease(L1-EN) variant. Preliminarystudy suggested that GCRG213may be related with the proliferation of gastric cancercell.Objective:To investigate the changes of gastric cancer cell proliferation, also the effect ofGCRG213and L-1EN expression during different hypoxia conditions.Methods:Normal gastric mucosa cell GES-1and gastric cancer cell BGC-823werecultured in20%,3%or0.3%oxygen concentrations, respectively. MTT test was usedto analyze the proliferation of the GES-1and BGC-823cells. The change ofGCRG213mRNA and protein expression in GES-1and BGC-823cells was detectedby using RT-PCR and Western blotting analysis. RT-PCR was used to study thechange of L1-EN mRNA expression. The senescence-associated beta-galactosidaseassay was used to detect cellular senescence.Results:（1）Compared with20%oxygencondition,3%oxygenconcentrationcouldpromote cell growth(P<0.01), The increase rate of GES-1cell proliferation was higherthan that of BGC-823cell(P<0.05), Cultured under the condition of0.3%oxygenconcentration for24and48hours, the cell proliferation of both BGC-823and GES-1cell decreased, and BGC-823cell proliferation decreased, and the rate of which was higher than that of GES-1cell (P<0.05);（2）Under20%oxygen condition, theexpression of GCRG213at mRNA and protein levels in BGC-823cell were higherthan in GES-1cell(P<0.05);（3）Compared with20%oxygen condition, theexpression of GCRG213at mRNA and protein levels were increased during3%oxygen conditions for48h(P<0.05), and GCRG213expression increased in BGC-823cell was more significant than in GES-1cell(P<0.05);（4）Cultivated under0.3%oxygen concentration for48h, compared with20%oxygen condition, there was nosignificant difference in the expression of GCRG213at mRNA and protein levels inGES-1cell and BGC-823cell. but the expression of L1-EN at mRNA level wasincreased apparently in both two cells(P<0.05), which was more significant in BGC-823cell than in GES-1cell(P<0.05);（5）Under3%oxygen conditions, theexpression of GCRG213at mRNA and protein levels in GES-1cell and BGC-823cellincreased more significantly than under0.3%oxygen conditions;（6）In0.3%oxygen concentration, the number of SA-β-Gal cells positive in BGC-823cell wassignificantly higher than the control group.Conclusion:Hypoxia condition can influence gastric cell proliferation; the expression ofGCRG213in gastric cancer cell changed during3%oxygen condition. In0.3%oxygen concentration, the expression of L1-EN at mRNA level was increased and atthe same time gastric gastric cancer cell BGC-823happened cell aging and the abilityof proliferation became low. |
