蛋白酶活化受体2在卵巢上皮性癌中的表达及意义

The expression and significance of protease activated receptor 2 in ovarian epithelial carcinoma

目的探讨蛋白酶活化受体2(PAR2)在卵巢上皮性癌中的表达及意义。方法收集癌症基因组图谱(TCGA)数据库(410例卵巢上皮性癌患者)和组织基因型表达(GTEx)数据库(88例正常人)中PAR2 mRNA的表达水平。收集2009—2019年于中国医学科学院肿瘤医院接受手术治疗卵巢癌患者(149例)的癌组织及临床病理资料,对患者肿瘤组织进行PAR2蛋白免疫组化染色,分析PAR2 mRNA及蛋白表达与临床病理特征及预后的关系,通过富集分析研究PAR2参与的基因功能及相关信号通路。生存分析采用Kaplan-Meier法和Log rank检验,影响因素分析采用Cox比例风险回归模型。结果 TCGA和GTEx数据库结果显示,卵巢上皮性癌组织中PAR2 mRNA的表达水平(3.05±0.72)高于正常卵巢组织(0.33±0.16,P=0.004)。149例患者的免疫组化结果显示,PAR2呈强阳性19例,阳性77例,弱阳性21例,阴性32例。初始手术减瘤效果及初始治疗效果与PAR2 mRNA及PAR2蛋白的表达有关(均P<0.05)。PAR2 mRNA高表达组(PAR2 mRNA≥0.88)患者的中位无进展生存时间(14.9个月)低于低表达组(PAR2 mRNA<0.88;17.1个月,P=0.033);PAR2 mRNA高表达组患者的中位总生存时间(36个月)低于低表达组(40个月,P=0.011)。多因素分析显示,初始手术减瘤效果、初始治疗效果是无进展生存和总生存的独立影响因素(均P<0.05)。PAR2蛋白高表达组(PAR2≥0.90)患者的中位无进展生存时间(6.5个月)低于PAR2蛋白低表达组(PAR2<0.90;9.5个月,P=0.016)。PAR2高表达组患者的中位总生存时间(43个月)低于低表达组(55个月,P=0.038)。多因素分析显示,PAR2蛋白表达水平、初始手术减瘤效果、化疗耐药是无进展生存和总生存的独立影响因素(均P<0.05)。基因本体论(GO)及京都基因与基因组百科全书(KEGG)分析显示,PAR2的靶基因主要富集于细胞间连接相关的功能上,占40.0%(6/15)。基因富集分析表明,在PAR2 mRNA高表达卵巢癌患者中Wnt/β-catenin信号通路(P=0.023)、MAPK通路(P=0.029)及糖酵解相关通路(P=0.018)存在富集。结论 PAR2表达与卵巢癌初始手术满意减瘤、初始治疗效果及患者预后有关,PAR2可能参与Wnt/β-catenin信号通路调控细胞间连接来促进卵巢癌侵袭及转移。

Objective To investigate the expression and significance of protease activated receptor 2(PAR2)in ovarian epithelial carcinoma.Methods PAR2 mRNA expression levels in 410 cases of epithelial ovarian carcinoma and 88 cases of human normal ovary were analyzed from cancer Genome Atlas(TCGA)database and tissue genotypic expression database(GTEx).Immunohistochemical(IHC)staining of PAR2 protein was performed in 149 patients with ovarian cancer who underwent primary surgical treatment at Cancer Hospital of Chinese Academy of Medical Sciences.Then the relationship between mRNA/protein expression of PAR2 and clinicopathological features and prognosis was analyzed.Gene functions and related signaling pathways involved in PAR2 were studied by enrichment analysis.Results The mRNA expression of PAR2 in epithelial ovarian carcinoma was significantly higher than that in normal ovarian tissue(3.05±0.72 vs.0.33±0.16,P=0.004).There were 77 cases showing positive and 19 showing strong positive of PAR2 IHC staining among the 149 patients,accounting for 64.4%in total.PAR2 mRNA/protein expression was closely correlated with tumor reduction effect and initial therapeutic effect(P<0.05).Survival analysis showed that the progression free survival time(P=0.033)and overall survival time(P=0.011)in the group with high PAR2 mRNA expression was significantly lower than that in the low PAR2 mRNA group.Multivariate analysis showed tumor reduction effect,initial therapeutic effect were independent prognostic factors on both progression-free survival and overall survival(P<0.05).The progression-free survival(P=0.016)and overall survival(P=0.038)of the PAR2 protein high expression group was significantly lower than that of the low group.Multivariate analysis showed PAR2 expression,initial treatment effect and chemotherapy resistance were independent prognostic factors on both progression-free survival and overall survival(P<0.05).Based on Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG),PAR2 target genes were mainly enriched in function related to intercellular connection,accounting for 40%.Gene enrichment analysis(GSEA)showed that the Wnt/β-catenin signaling pathway(P=0.023),the MAPK signaling pathway(P=0.029)and glycolysis related pathway(P=0.018)were enriched in ovarian cancer patients with high PAR2 mRNA expression.Conclusions PAR2 expression is closely related to tumor reduction effect,initial treatment effect and survival of ovarian cancer patients.PAR2 may be involved in Wnt/β-catenin signaling pathway and intercellular connection promoting ovarian cancer invasion and metastasis.