目的 探讨缺氧活化钙敏感受体（CaSR）在人非小细胞肺癌细胞A549细胞增殖中的信号转导途径。 方法 将A549细胞随机分为对照组、缺氧组（H）、缺氧+ CaSR激动剂组（H+Gd）、缺氧+ CaSR抑制剂组（H+NPS）与磷脂酶C（PLC）通路抑制剂组（H+Gd+U73122）。应用Western blotting分析不同处理情况下CaSR、增殖细胞核抗原（PCNA）在A549细胞中的表达；采用激光扫描共焦显微镜技术检测不同处理情况下细胞内钙离子浓度的变化；利用流式细胞术检测不同药物处理对细胞周期及增殖指数的影响；HE染色观察不同药物处理后细胞数量的变化。 结果 缺氧导致A549细胞的CaSR与PCNA表达增加，细胞增殖指数上调，细胞数量增加，氯化钆（GdCl3）（CaSR激动剂）能够放大缺氧的作用，NPS2390（CaSR抑制剂）可以减弱缺氧的作用，上述效应均可被U73122（PLC通路抑制剂）抑制。 结论 缺氧活化的CaSR通过Gq-PLC-IP3信号通路介导A549的增殖。

Objective To explore the signal transduction pathway of calcium-sensing receptor (CaSR) mediating hypoxia-induced proliferation of A549 cells of human non-small cell lung cancer. Methods The A549 cells were randomly divided into several groups which conclude control group, hypoxia group (H), hypoxia + CaSR agonist group (H+Gd), hypoxia + CaSR inhibitor group (H+NPS) and phospholipase C(PLC) pathway inhibitor group (H+Gd+U73122). Expression of CaSR and proliferating cell nuclear antigen (PCNA) in A549 cells under different treatments was analyzed by Western blotting. The changes of intracellular calcium ion concentration were detected by confocal laser scanning microscope. The effects of cell proliferation cycle and proliferation index were gauged by flow cytometry under different drugs. HE staining was used to observe the changes of cell number with different drugs. Results The expression levels of CaSR and PCNA in A549 cells increased by hypoxia. Meanwhile, cell proliferation index and cell number were also upregulated. GdCl3 (CaSR agonist) could amplify the effect of hypoxia, and NPS2390 (CaSR inhibitor) could reduce the effect of hypoxia. All effects mentioned above could be inhibited by U73122 (PLC pathway inhibitor). Conclusion Hypoxia-induced CaSR can mediate the proliferation of A549 cells through Gq-PLC-IP3 signal transduction pathway.