Role Of Proton Sensing Receptor OGR1 In Lung Cancer Cells

Proton sensing OGR1(OGR1)is one of the four members of OGR subfamily(TDAG8,OGR1,G2 A and GPR4)in GPCR superfamily,which is activated under pathologic acidic conditions(such as tumor and inflammation)to regulate the physiological and pathological processes of the cells.The formation of pathological acidic microenvironment is related to the enhancement of glycolytic pathway in cells,which is determined by the over activation of hypoxia-inducible factor(HIF)and the multiple target genes are expressions induced by HIF.After analysis of tumor large data,we found that the HIFinduced gene also contains OGR1.So we speculated that OGR1 may be involved in the ability of tumor cells to adapt to hypoxic or acidic environment.In this study,we will explore the relationship between OGR1 and the biological characteristics of tumor survival,metastasis and apoptosis in acidic environment,elucidate the physiological function and pathological mechanism of OGR1,and propose new perspectives on the essential aspects of tumor cell resistance to acid resistance and tumor treatment strategies.In this study,human OGR1 gene was firstly cloned and a prokaryotic expression vector of OGR1 was constructed.Subsequently,OGR1 eukaryotic expression plasmid phblv-cmv-ef1 was constructed.Enzyme digestion and sequencing were used to confirm the accuracy.Lipofectamine2000 transfected the plasmid into A549 lung cancer cell line.The expression of exogenous ORG1 gene in A549 cells was detected by real-time fluorescence quantitative PCR.Protein expression was detected by Western Blot.To study the effect of OGR1 on the function of tumor cells,MTT assay was used to detect the proliferation activity of cells,trans-well assay was used to measure the migration ability,and flow cytometry assay was used to measure the apoptosis of cells.In order to demonstrate the effect of OGR1 on tumor growth in vivo,we compared tumors volume derived from OGR1 stable expression and empty vector transgenic A549 cells in tumor-bearing nude mouse models,respectively.As a result,we successfully constructed a lung cancer cell A549 model with stable expression of ORG1 gene.OGR1 experiments on the function of tumor cells showed that OGR1 had no significant effect on proliferation and migration of lung cancer cell A549.OGR1 can improve the anti-apoptotic ability of tumor cells and the development of tumors in vivo.Conclusion:OGR1 has no obvious effect on proliferation and migration of lung cancer cells after being activated under acidic conditions.However,it can improve the anti-apoptotic ability of tumor cells,so as to improve tumor growth in vivo and shown to be a tumor-promoting receptor.Our results suggest that neutralizing the acidic microenvironment of tumors and developing OGR1 receptor antagonists are expected to be new ideas in the treatment of lung tumors.