KRAS突变对肺损伤大鼠蛋白激酶信号途径的影响

目的 研究鼠类肉瘤病毒癌(KRAS)基因突变对肺损伤大鼠蛋白激酶信号途径的影响。方法 建立大鼠急性肺损伤模型。根据组织芯片KRAS蛋白表达分组,KRAS阴性组:KRAS蛋白表达H-score计分<3分),KRAS阳性组(KRAS蛋白表达H-score计分> 3分)。KRAS突变型组:突变型KRAS蛋白的表达H-score计分<3分,KRAS野生型组:突变型KRAS蛋白的表达H-score计分> 3分。采用免疫组化法检测10种肺损伤相关蛋白磷脂酰肌醇-3-激酶(PI3K),KRAS,KRAS突变蛋白,NRAS,BRAF,丝裂原活化的细胞外信号调节激酶(MEK),细胞外信号调节激酶(ERK),磷酸化MEK1(p MEK1),磷酸化MEK2(p MEK2)和磷酸化ERK1/2(p ERK1/2)]的阳性表达,采用组织化学评分法(H-score)对蛋白表达情况进行定量并分组,比较各组KRAS下游蛋白及MEK2/ERK通路蛋白的表达情况。结果①与KRAS阴性组相比,KRAS阳性组该基因下游蛋白中BRAF、MEK、ERK表达显著上升(P <0. 05),而NRAS无显著差异(P> 0. 05);②与KRAS野生型相比,KRAS突变型基因下游蛋白中BRAF、MEK、ERK表达显著上升(P <0. 05),而NRAS无显著差异(P> 0. 05);③与KRAS阴性组相比,KRAS阳性组pMEK2,pERK1/2蛋白表达显著上升(P <0. 05),而p MEK1无显著差异(P> 0. 05)。结论 KRAS蛋白阳性大鼠肺损伤组织中,该蛋白下游蛋白BRAF、MEK和ERK(RAS/RAF/MEK/ERK信号通路的下游蛋白)在KRAS基因突变的肺损伤组织中的表达量显著增加,且MEK2/ERK通路蛋白MEK、p MEK2和ERK表达率也显著增加,提示KRAS蛋白通过调控其下游蛋白表达调控肺组织损伤,该过程可能与MEK2/ERK通路相关。

The effect of KRAS gene mutation on protein kinase signaling pathway in rats with lung injury

Objective To investigate the effect of KRAS gene mutation on protein kinase signaling pathway in rats with lung injury.Methods According to KRAS protein expression,the rats were divided into KRAS negative group(KRAS protein expression H-score score<3 points),KRAS positive group(KRAS protein expression H-score score>3 points),KRAS mutant group(mutant KRAS protein expression H-score score<3 points),KRAS wild type group(mutant KRAS protein expression H-score score>3 points).Immunohistochemistry was used to detect the positive expression of 10 lung injury-related proteins(P13K,KRAS,mutant KRAS,NRAS,BRAF,MEK,ERK,pMEK1,pMEK2,and pERK1/2),and histochemical score method(H-score)was used to quantify protein expression and group patients,that was,KRAS positive group and KRAS negative group(detecting KRAS mutant patients in this group),and comparing the KRAS downstream proteins and MEK2/ERK pathway proteins in each group expression.Results①Compared with the KRAS-negative group,the expression of BRAF,MEK,and ERK in the downstream proteins of the gene in the KRAS-positive group increased significantly(P<0.05),while NRAS had no significant difference(P>0.05).②Compared with KRAS wild type,the expression of BRAF,MEK and ERK in KRAS mutant downstream proteins was significantly increased(P<0.05),while NRAS had no significant difference(P>0.05).③Compared with the KRAS-negative group,the expression of pMEK2 and pERK1/2 protein in the KRAS-positive group increased significantly(P<0.05),but there was no significant difference in the pMEK1 expression between the two groups(P>0.05).Conclusion In lung injury tissues of KRAS protein-positive rats,the downstream proteins BRAF,MEK and ERK(the downstream proteins of the RAS/RAF/MEK/ERK signaling pathway)are significantly increased in lung injury tissues with KRAS mutations.It is shown that KRAS protein regulates lung tissue damage by regulating its downstream protein expression,which may be related to the MEK2/ERK pathway.