Study Of A Novel Estrogen Receptor GPER1 In The Proliferation Of EGFR-TKIs Resistant Lung Cancer Cells

[Purposes]Examine the expression of the novel estrogen receptor GPER1 in lung cancer cells and its effect on the proliferation of EGFR-TKIs resistant lung cancer cells.[Methods]Q-PCR was used to compare the expression of GPER1 and ER? in lung cancer cells A549,PC-9 and breast cancer cells MCF-7(positive control).TKIs resistant lung cancer PC9-GR and PC9-OR cell lines were constructed.PCR and ddPCR were used to detect the EGFR mutation in the constructed drug-resistant cell lines.The expression of GPER1 in PC9?PC9-GR and PC9-OR cells was detected by immunofluorescence technique.To further investigate the role of GPER1,a novel estrogen receptor,in drug resistance,western blot was used to detect the effects of E2 and G1 on the expression of GPER1 in lung cancer cells A549?PC-9OR.Cell Counting Kit-8(cck-8)was used to detect the effect of estrogen receptor GPER1 on the proliferation of lung cancer A549 and PC9-OR cells.[Results]1.The expression of GPER1 and ER? in A549 cells was significantly higher than that in PC9 cells,and the expression level in A549 cells was close to MCF-7 cells.2.PCR and ddPCR sequencing were used to detect the lung cancer cell lines PC9,PC9-GR and PC9-OR.It was found that there was no T790M mutation in PC9,T790M mutation in PC9-GR,and T790M mutation disappeared again in PC9-OR cell lines.3.Immunofluorescence confirmed that GPER1 was mainly expressed in the nucleus of PC9?PC9-GRcells,while in the cytoplasm and nucleus of PC9-OR.4.Western blot assay showed that E2 and G1 promoted the up-regulation of GPER1 expression in A549?PC9-OR cell lines.5.Cell Count Kit-8 detected that both E2 and G1 via GPER1 promoted the proliferation of drug-resistant cells A549 and PC9-OR.[Conclusions]1.Novel estrogen receptor GPER1 is expressed in lung cancer cells.2.E2 and G1 promoted the expression of GPER1 in lung cancer cells A549 and PC9-OR.3.Novel estrogen receptor GPER1-mediated E2 and G1 promoted the proliferation of EGFR-TKIs resistant lung cancer cells.