目的:筛选与结直肠癌(colorectal cancer,CRC)诊断预后相关的piRNA通路相关基因。方法:基于癌症基因组图谱(the cancer genome atlas, TCGA)数据库中647个结直肠肿瘤样本和51个非肿瘤样本,分析39个piRNA通路相关基因在组织水平的表达情况,并构建风险预后模型。利用生存曲线(KM曲线)和受试者工作特征曲线(ROC曲线)评估测量模型的预测性能、效果。最后,结合临床病理特征挑选候选分子,在细胞水平进行验证并分析其在免疫微环境中的作用。结果:37个有显著差异的piRNA通路相关基因中有8个基因共同构建风险预后模型。KM曲线分析显示模型与肠癌预后的关系:CRC高危组患者总生存期(OS)显著降低;ROC曲线显示模型的诊断效能:在1、3、5年范围内该模型的曲线下面积分别为0.624、0.669、0.670。肠癌中POLR2F和PAICS在分子水平及蛋白水平均呈现高表达,且表达水平与临床病理学特征相关。尤其PAICS表达水平与CRC中肿瘤免疫浸润细胞呈正相关,在癌相关成纤维细胞中显著低表达。结论:piRNA通路相关基因,尤其是POLR2F和PAICS,可能是CRC潜在的癌症诊断和预后生物标志物。
Objective: To screen piRNA pathway related genes associated with diagnosis and prognosis of colorectal cancer (CRC). Methods: The expression of 39 piRNA pathpathy-related genes at the tissue level was analyzed based on 647 colorectal tumor samples and 51 non-tumor samples from the Cancer Genome Atlas (TCGA) database, and the risk prediction model was constructed. KM and ROC were used to evaluate the prediction performance and effect of the measurement model. Finally, candidate molecules were selected based on clinicopathological features and validated at the cellular level. Results: Among 37 piRNA pathway related genes with significant differences, 8 genes co-constructed the risk prediction model. KM analysis showed that OS decreased significantly in high-risk group. The ROC curve showed that the area under the curve of the model was 0.624, 0.669, and 0.670 in 1, 3, and 5 years respectively. The expression levels of POLR2F and PAICS were overexpressed in colorectal cancer cells and CTPAC Database data, and correlated with clinicopathological features. In particular, the expression level of PAICS was positively correlated with tumor immune infiltrating cells in CRC, and significantly lower in cancer-associated fibroblasts. Conclusion: piRNA pathway related genes, especially POLR2F and PAICS, may be the potential biomarkers for cancer diagnosis and prognosis in CRC.
[1] Mattiuzzi C, Lippi G. Current cancer epidemiology[J]. J Epidemiol Glob Health, 2019, 9(4): 217-222.
[2] Ross RJ, Weiner MM, Lin H. PIWI proteins and PIWI-interacting RNAs in the soma[J]. Nature, 2014, 505(7483): 353-359.
[3] He J, Chen MM, Xu JC, et al. Identification and characterization of piwi-interacting RNAs in human placentas of preeclampsia[J]. Sci Rep, 2021, 11(1): 15766.
[4] Vychytilova-Faltejskova P, Stitkovcova K, Radova L, et al. Circulating PIWI-interacting RNAs piR-5937 and piR-28876 are promising diagnostic biomarkers of colon cancer[J]. Cancer Epidemiol Biomarkers Prev, 2018, 27(9): 1019-1028.
[5] Wang ZF, Yang H, Ma DG, et al. Serum PIWI-interacting RNAs piR-020619 and piR-020450 are promising novel biomarkers for early detection of colorectal cancer[J]. Cancer Epidemiol Biomarkers Prev, 2020, 29(5): 990-998.
[6] German SD, Lee JH, Campbell KH, et al. Actin depolymerization is associated with meiotic acceleration in cycloheximide-treated ovine oocytes[J]. Biol Reprod, 2015, 92(4): 103.
[7] Barrett T, Wilhite SE, Ledoux P, et al. NCBI GEO: archive for functional genomics data sets: update[J]. Nucleic Acids Res, 2013, 41(Database issue): D991-D995.
[8] Belinky F, Nativ N, Stelzer G, et al. PathCards: multi-source consolidation of human biological pathways[J]. Database (Oxford), 2015, 2015: bav006.
[9] Li CW, Tang ZF, Zhang WJ, et al. GEPIA2021: integrating multiple deconvolution-based analysis into GEPIA[J]. Nucleic Acids Res, 2021, 49(W1): W242-W246.
[10] Kato T, Uemura M. Period analysis using the least absolute shrinkage and selection operator (lasso)[J]. Publ Astron Soc Jpn Nihon Tenmon Gakkai, 2012, 64(6): 122.
[11] Szklarczyk D, Gable AL, Nastou KC, et al. The STRING database in 2021: customizable protein-protein networks, and functional characterization of user-uploaded gene/measurement sets[J]. Nucleic Acids Res, 2021, 49(D1): D605-D612.
[12] Li TW, Fu JX, Zeng ZX, et al. TIMER2.0 for analysis of tumor-infiltrating immune cells[J]. Nucleic Acids Res, 2020, 48(W1): W509-W514.
[13] Ferreira HJ, Heyn H, Garcia Del Muro X, et al. Epigenetic loss of the PIWI/PiRNA machinery in human testicular tumorigenesis[J]. Epigenetics, 2014, 9(1): 113-118.
[14] Ray SK, Mukherjee S. Piwi-interacting RNAs (piRNAs) and colorectal carcinoma: emerging non-invasive diagnostic biomarkers with potential therapeutic target based clinical implications[J]. Curr Mol Med, 2022, online ahead of print.
[15] Agarwal S, Chakravarthi BVSK, Behring M, et al. PAICS, a purine nucleotide metabolic enzyme, is involved in tumor growth and the metastasis of colorectal cancer[J]. Cancers, 2020, 12(4): 772.
[16] Pusch C, Wang Z, Roe B, et al. Genomic structure of the RNA polymerase II small subunit (hRPB14.4) locus (POLRF) and mapping to 22q13.1 by sequence identity[J]. Genomics, 1996, 34(3): 440-442.
[17] Jia Z M, Ai X, Sun FL, et al. Identification of new hub genes associated with bladder carcinoma via bioinformatics analysis[J]. Tumori, 2015, 101(1): 117-122.
[18] Chakravarthi BVSK, Rodriguez Pena MDC, Agarwal S, et al. A role for de novo purine metabolic enzyme PAICS in bladder cancer progression[J]. Neoplasia, 2018, 20(9): 894-904.
[19] Qu ZY, Cui GY, Shi PJ, et al. Potential suppressive functions of microRNA-504 in cervical cancer cells malignant process were achieved by targeting PAICS and regulating EMT[J]. Arch Gynecol Obstet, 2020, 302(1): 173-182.
[20] Sample KM. DNA repair gene expression is associated with differential prognosis between HPV16 and HPV18 positive cervical cancer patients following radiation therapy[J]. Sci Rep, 2020, 10(1): 2774.
[21] Du BS, Zhang ZY, Di WY, et al. PAICS is related to glioma grade and can promote glioma growth and migration[J]. J Cell Mol Med, 2021, 25(16): 7720-7733.
[22] Kobayashi Y, Kumamoto K, Okayama H, et al. Downregulation of PAICS due to loss of chromosome 4q is associated with poor survival in stage III colorectal cancer[J]. PLoS One, 2021, 16(2): e0247169.
