TROP2通过内质网钙铁离子交换影响胃癌侵袭的分子机制

MOLECULAR MECHANISM OF TROP2 AFFECTING THE INVASION OF GASTRIC CANCER THROUGH CALCIUM AND IRON ION EXCHANGE IN ENDOPLASMIC RETICULUM

目的探讨人滋养层细胞表面糖蛋白2(TROP2)通过内质网钙铁离子交换影响胃癌侵袭的分子机制。方法构建TROP2与PLOD2过表达/敲减细胞株,WB、RT-qPCR检测TROP2、PLOD2、磷脂酰肌醇4,5-二磷酸(PIP2)、胶原蛋白I型(COL-I)、缺氧诱导因子-1α(HIF-1α)、蛋白激酶C(PKC)mRNA和蛋白的表达水平,ELISA法检测三磷酸肌醇受体(IP3R)含量,比色分析法检测Fe^(2+)和Ca^(2+)含量。结果随着TROP2的表达量的变化,PLOD2、PIP2、IP3等蛋白水平随之同步变化,在PLOD2的过表达和敲减模型中,无论PLOD2如何变化,TROP2、PIP2、IP3R、PKC并无明显变化,但COL-I、HIF-1α随着PLOD2的变化同步增减。在离子水平,内质网Ca^(2+)浓度与TROP2和PLOD2的表达量呈正相关,Fe^(2+)浓度与TROP2和PLOD2的表达量呈负相关。结论PLOD2上游受TROP2的钙离子信号转导通路“内质网Ca^(2+)-Fe^(2+)交换”调控,下游通过调控HIF1α和胶原纤维交联促进肿瘤的侵袭、转移。

Objective To investigate the molecular mechanism of human trophoblast cell surface glycoprotein 2(TROP2)affecting gastric cancer invasion through endoplasmic reticulum calcium-iron ion exchange.Methods TROP2 and PLOD2 overexpression/knockdown cell lines were constructed,WB,RT-qPCR detected the expression levels of TROP2,PLOD2,PIP2,COL-1,HIF-1α,PKC mRNA and protein,ELISA detected IP3 receptor(IP3R)content,colorimetric analysis detected Fe^(2+)and Ca^(2+)content.Results With the change of TROP2 expression,the levels of PLOD2,PIP2,IP3 and other proteins changed synchronously,and in the overexpression and knockdown model of PLOD2,no matter how PLOD2 changed,TROP2,PIP2,IP3R,PKC did not change significantly,but COL-I and hif-1αincreased and decreased simultaneously with the change of PLOD2.At the ionic level,the concentration of endoplasmic reticulum Ca^(2+)was positively correlated with the expression of TROP2 and PLOD2.Fe^(2+)concentration was negatively correlated with the expression of TROP2 and PLOD2.Conclusions The upstream of PLOD2 is regulated by the calcium signal transduction pathway"endoplasmic reticulum Ca^(2+)-Fe^(2+)exchange"in the upper reachesof PLOD2,and the downstream promotes tumor invasion and metastasis by regulating the crosslinking of HIF1αand collagen fibers.