线粒体核糖体蛋白五肽重复结构域3在前列腺癌中的表达及其临床意义

Expression and significance of pentapeptide repeat domain 3 in prostate cancer

目的:探讨五肽重复结构域3(PTCD3)在前列腺癌(PCa)中的表达及其临床意义。方法:下载癌症基因组图谱数据库PCa数据集,利用R语言包"ggsignif"、"survival"、"clusterProfiler"和"GSVA"分析PTCD3在PCa组织中的表达量及其与PCa患者临床特征和生存预后以及其发挥作用的相关机制;构建干扰PTCD3表达的PCa细胞株DU145,分别为空白组(DU145 si-NC)和干扰组(DU145 si-PTCD3),利用细胞增殖-毒性检测试剂盒、细胞体外侵袭实验和海马实验检测细胞的增殖、侵袭能力和线粒体功能。组间分析采用独立样本t检验。结果:PTCD3在PCa组织表达增多(PCa比良性前列腺为2.546±0.306比2.443±0.236,P<0.01)。PTCD3在PCa组织中的高表达与高Gleason评分(Gleason评分≥8分比Gleason评分<8分为2.631±0.324比2.485±0.277,P<0.01),肿瘤转移(转移比非转移为2.637±0.356比2.526±0.291,P<0.01)和高临床分期(≥T3A比<T3A为2.570±0.311比2.502±0.286,P<0.05)有关。高表达PTCD3的PCa患者总生存期[风险比(HR)=0.233,P<0.05]和无疾病进展生存期更短(HR=0.526,P<0.01)。PTCD3相关的生物学进程为细胞器裂变,参与组成浓缩的染色体,调控腺苷三磷酸酶活性。PTCD3高表达相关基因主要富集的信号通路为G 2M检测点和E2F靶点;低表达相关基因主要富集在活性氧通路和异生物质代谢相关通路。成功构建低表达PTCD3的DU145细胞株。沉默PTCD3后,DU145细胞的增殖(si-PTCD3比si-NC为1.267±0.037比2.057±0.069,t=22.480,P<0.01)和侵袭能力(si-PTCD3比si-NC为323.700±28.150比709.300±81.220,t=7.771,P<0.01)减弱;基础呼吸率[si-PTCD3比si-NC为(27.230±6.328)pmol/min比(50.010±4.134)pmol/min,t=5.221,P<0.01]、ATP相关呼吸率[si-PTCD3比si-NC为(20.510±4.542)pmol/min比(43.000±2.109)pmol/min,t=7.778,P<0.01]和最大呼吸率均下降[si-PTCD3比si-NC为(30.020±5.273)pmol/min比(60.070±4.364)pmol/min,t=7.602,P<0.01]。上述结果差异均有统计学意义。结论:PTCD3在PCa组织中表达升高,高表达PTCD3提示患者预后不佳,PTCD3可能参与调控PCa细胞线粒体的氧化磷酸化活性以及细胞分裂的生物学进程,进而调控PCa的进展。

Objective To investigate the expression and significance of pentapeptide repeat domain 3(PTCD3)in prostate cancer(PCa).Methods The PCa data set in the Cancer Genome Atlas(TCGA)database was downloaded.The expression of PTCD3 in PCa and its correlation with clinical characteristics,survival prognosis and its role in PCa were analyzed by R language packages"ggsign","survival","clusterprofiler"and"GSVA".PTCD3 down-regulated PCa cell line DU145 was constructed.The cell proliferation,invasion ability and mitochondrial function were detected by cell counting kit-8 assay,cell invasion assay and seahorse assay.Independent sample t-test was used for inter group analysis.Results The expression of PTCD3 increased in PCa(PCa vs.benign prostate:2.546±0.306 vs.2.443±0.236,P<0.01).The elevated expression of PTCD3 in PCa was associated with higher Gleason score(Gleason score≥8 vs.Gleason score<8:2.631±0.324 vs.2.485±0.277,P<0.01),tumor metastasis(metastasis vs.non-metastasis:2.637±0.356 vs.2.526±0.291,P<0.01)and advanced clinical stage(≥T3a vs.<T3a:2.570±0.311 vs.2.502±0.286,P<0.05).Patients with high expression of PTCD3 had shorter overall survival[hazard rate(HR)=0.233,P<0.05]and shorter progression free survival(HR=0.526,P<0.01).The biological process related to PTCD3 is organelle fission,which is involved in the formation of concentrated chromosomes and the regulation of adenosine triphosphatase activity.The main enriched signal pathways of PTCD3 overexpression related genes are G2M detection point and E2F target,and reactive oxygen species pathway and heterobiotic metabolism pathway of PTCD3 low expression related genes.After silencing PTCD3,the proliferation(si-PTCD3 vs.si-NC:1.267±0.037 vs.2.057±0.069,t=22.480,P<0.01),and the invasion of DU145(si-PTCD3 vs.si-NC:323.700±28.150 vs.709.300±81.220,t=7.771,P<0.01)decreased.The basal respiratory rate[si-PTCD3 vs.si-NC:(27.230±6.328)pmol/min vs.(50.010±4.134)pmol/min,t=5.221,P<0.01],the ATP related respiratory rate[si-PTCD3 vs.si-NC:(20.510±4.542)pmol/min vs.(43.000±2.109)pmol/min,t=7.778,P<0.01],and the maximum respiratory rate[si-PTCD3 vs.si-NC:(30.020±5.273)pmol/min vs.(60.070±4.364)pmol/min,t=7.602,P<0.01]decreased.The above differences were statistically significant.Conclusion Aberrant elevated PTCD3 in PCa indicated poor prognosis.PTCD3 may be involved in regulating the oxidative phosphorylation activity and cell division which plays a critic role in the progression of PCa.