目的：探讨浆细胞瘤变异体易位1（plasmacytoma variant translocation 1,PVT1）和MYC基因在泛癌组织中的表达水平,及其对患者生存期的预测价值。方法：从癌症基因组图谱（The Cancer Genome Atlas, TCGA）数据库获取31种共计10 016例癌症患者的临床资料以及转录组RNA测序数据,其中23种癌症组织标本有相应的癌旁正常组织对照。应用t检验比较PVT1、MYC基因在23种癌症组织与癌旁正常对照样本中的表达水平差异。采用Spearman相关性分析PVT1与MYC基因在31种癌症中表达的相关性。应用Kaplan-Meier方法和Cox比例风险模型,分别在31种癌症中分析PVT1、MYC基因的表达水平与患者总体生存期的关系。结果：PVT1的表达水平在19种癌症组织中显著增高（P<0.05）;在2种癌症组织中显著降低（P<0.05）。MYC的表达水平在7种癌症组织中显著升高（P<0.05）;在6种癌症组织中降低（P<0.05）。相关性分析发现,在约87%（27/31）的癌症类型中,PVT1与MYC基因的表达水平呈正相关（Rho>0, P<0.01）。总体生存期分析表明,PVT1相对高表达在膀胱尿路上皮细胞癌、乳腺浸润癌、肾上腺皮质癌、肾透明细胞癌、乳头状肾细胞癌、低级别胶质瘤、前列腺癌、睾丸生殖细胞肿瘤以及葡萄膜黑色素瘤中与较短的总体生存期显著相关（log-rank P<0.05）;MYC基因相对高表达在肾上腺皮质癌、膀胱尿路上皮细胞癌、宫颈鳞状细胞癌、头颈部鳞状细胞癌、乳头状肾细胞癌、卵巢浆液性囊腺癌、胰腺癌以及肉瘤中与较短的总体生存期显著相关（log-rank P<0.05）,而在低级别胶质瘤及直肠腺癌中,MYC基因相对高表达组的总体生存期显著长于相对低表达组（log-rank P<0.05）。结论：PVT1在癌症组织中表达升高相比MYC基因而言更具有普遍性。在多种癌症中,PVT与MYC基因的表达相关,提示两者在功能调控中可能存在联系。此外,在9种癌症中,PVT1相对高表达患者的总体生存期较短,而MYC基因的表达情况在不同癌症中对患者总体生存期的影响存在差异。

Objective: To explore the expression levels and survival prediction of plasmacytoma variant translocation 1 (PVT1) and MYC gene in pan-cancer. Methods: The clinic data and RNA-seq data from 31 types of cancer tissues totaling 10 016 cases were retrieved from The Cancer Genome Atlas (TCGA) database, among which 23 types of cancer with adjacent tissues as normal controls. Student t-tests were used to analyze the significant differences of PVT1 or MYC gene expression levels between cancer tissues and corresponding normal controls. Spearman correlation was used to analyze the expression correlation between PVT1 and MYC in 31 types of cancer. The relationship between PVT1 or MYC expression and overall survival of 31 types of cancer patients was depicted by the Kaplan-Meier curve and Cox proportional hazards model. Results: =PVT1 expression was highly expressed in 19 types of cancer(P<0.05) and lowly expressed in 2 types of cancer (P<0.05). MYC expression was significantly upregulated in 7 types of cancer (P<0.05) and downregulated in 6 types of cancer (P<0.05). Expression correlation analysis presented that PVT1 expression was positively correlated with MYC in about 87% (27/31) types of cancer (Rho>0, P<0.01). Finally, survival analysis showed that relatively high expression of PVT1 was significantly associated with shorter overall survival in bladder urothelial carcinoma, breast invasive carcinoma, adrenocortical carcinoma, renal clear cell carcinoma, renal papillary cell carcinoma, lower grade glioma, prostate adenocarcinoma, testicular germ cell tumors and uveal melanoma (log-rank P<0.05). The relatively high expression group of MYC was significantly correlated with shorter overall survival in adrenocortical carcinoma, bladder urothelial carcinoma, cervical squamous cell carcinoma, head and neck squamous cell carcinoma, renal papillary cell carcinoma, ovarian serous cystadenocarcinoma, pancreatic adenocarcinoma and sarcoma (log-rank P<0.05), while was associated with long-time survival in lower grade glioma and rectum adenocarcinoma (log-rank P<0.05). Conclusions: The increased expression of PVT1 in pan-cancer is more prevalent than that of MYC. The positive correlation between PVT1 and MYC indicates a potential regulatory relationship in cancers. Furthermore, the relatively high expression of PVT1 has a poor effect on the overall survival of patients in 9 types of cancer, while the expression level of MYC presents different effects on the overall survival of patients in various cancers.