利用加权基因共表达网络挖掘乳腺癌相关疾病靶标

目的 利用公共数据库癌症基因组图谱（TCGA），通过加权基因共表达网络分析（WGCNA）挖掘乳腺癌诊断年龄和肿瘤分期相关疾病靶标。方法 利用TCGA得到53例亚洲人种和126例非洲人种乳腺癌基因芯片表达数据及相应的临床指标，然后用R软件的WGCNA包分别构建这2个人群的共表达网络，得到与诊断年龄和肿瘤分期的相关显著性模块，并用在线网站DAVID进行功能富集，用在线网站UALCAN进行生存分析。结果 WGCNA分析得到11个与肿瘤分期和诊断年龄显著相关的模块。将11个模块取交集后得到42个候选基因，利用在线网站DAVID进行基因本体（GO）富集分析，发现这些候选基因主要富集在蛋白质结合功能方面。取42个候选基因中9个由WGCNA识别出的核心基因，输入在线网站UALCAN上行差异分析和生存分析，最终筛选出2个（ERLIN2和ASH2L）候选生物标志物，这2个基因在正常组织和癌组织中的表达差异有统计学意义（P<0.01），且表达水平影响乳腺癌患者的生存期（P<0.05）。结论 利用数据挖掘寻找生物标志物或疾病靶标是一种高效、经济的研究方式。本研究通过数据挖掘发现ERLIN2和ASH2L为乳腺癌的候选生物标志物，可用于大样本临床验证及机制探讨。

Weighted gene co-expression network analysis for data mining of breast cancer biomarkers

Objective To explore the disease targets of breast cancer related to age at diagnosis and tumor stage by weighted gene co-expression network analysis (WGCNA) from public database The Cancer Genome Atlas (TCGA). Methods We obtained the breast cancer gene chip expression data and corresponding clinical data of 53 Asians and 126 Africans from TCGA database. R software WGCNA package was used to construct the co-expression network of the two populations, and the significant modules related to age at diagnosis and cancer stage were obtained. Online website DAVID was used for function enrichment and online website UALCAN for survival analysis. Results WGCNA yielded 11 modules significantly related to cancer stage and age at diagnosis. Forty-two candidate genes were obtained after 11 modules were intersected. Gene ontology (GO) enrichment analysis was carried out using online website DAVID and these genes were mainly involved in protein binding function. Nine of the 42 candidate genes were identified as hub genes by WGCNA, the 9 genes were used in UALCAN for differential analysis and survival analysis, and 2 candidate biomarkers (ERLIN2 and ASH2L) were screened out. The expression of the 2 genes in normal tissues and breast cancer tissues was significantly different (P<0.01), and the expression level significantly influenced the survival of breast cancer patients (P<0.05). Conclusion Data mining from public databases for biomarkers or therapeutic targets is a cost-effective research method. In this study ERLIN2 and ASH2L have been found to be candidate biomarkers for breast cancer through data mining, which needs large sample study and mechanism exploration.