1899 Mitophagy-related genes.

BackgroundMitophagy is used by eukaryotic cells to eliminate damaged mitochondria. The deregulation of this process can lead to an accumulation of dysfunctional mitochondria and is implicated in carcinogenesis and tumorigenesis. Despite increasing evidence that mitophagy is involved in the development of colon cancer, the role of mitophagy-related genes (MRGs) in colon adenocarcinoma (COAD) prognosis and treatment remains largely unknown.MethodsDifferential analysis was used to identify differentially expressed mitophagy-related genes associated with COAD and conduct key module screening. Cox regression and least absolute shrinkage selection operator, and other analyses were used to characterize prognosis-related genes and verify the feasibility of the model. The model was tested using GEO data and a nomogram was constructed for future clinical application. The level of immune cell infiltration and immunotherapy were compared between the two groups, and sensitivity to treatment with many commonly used chemotherapeutic agents was assessed in individuals with different risk factors. Finally, qualitative reverse transcription polymerase chain reaction and western blotting were performed to assess the expression of prognosis-related MRGs.ResultsA total of 461 differentially expressed genes were mined in COAD. Four prognostic genes, PPARGC1A, SLC6A1, EPHB2, and PPP1R17, were identified to construct a mitophagy-related gene signature. The feasibility of prognostic models was assessed using Kaplan-Meier analysis, time-dependent receiver operating characteristics, risk scores, Cox regression analysis, and principal component analysis. At 1, 3, and 5 years, the area under the receiver operating characteristic curves were 0.628, 0.678, and 0.755, respectively, for TCGA cohort, and 0.609, 0.634, and 0.640, respectively, for the GEO cohort. Drug sensitivity analysis found that camptothecin, paclitaxel, bleomycin, and doxorubicin were significantly different between low- and high-risk patients. The qPCR and western blotting results of clinical samples further confirmed the public database results.ConclusionsThis study successfully constructed a mitophagy-related gene signature with significant predictive value for COAD, informing new possibilities for the treatment of this disease.

背景 线粒体自噬（mitophagy）是真核细胞用以清除受损线粒体的生物学过程。该过程失调可导致功能异常线粒体堆积，并与致癌作用及肿瘤发生密切相关。尽管已有越来越多的证据表明线粒体自噬参与结肠癌的发生发展，但线粒体自噬相关基因（MRGs）在结肠腺癌（COAD）的预后与治疗中的作用仍尚未完全明确。
方法 采用差异分析筛选与COAD相关的差异表达线粒体自噬相关基因，并开展关键模块筛选；通过Cox回归、最小绝对收缩和选择算子（LASSO）等分析对预后相关基因进行特征化，并验证模型的可行性。使用GEO数据集对模型进行外部验证，并构建列线图以用于后续临床应用。比较两组间的免疫细胞浸润水平与免疫治疗应答情况，同时评估不同风险分层患者对多种常用化疗药物的治疗敏感性。最后通过定性逆转录聚合酶链式反应与蛋白质印迹实验，检测预后相关MRGs的表达水平。
结果 本研究在COAD样本中共筛选得到461个差异表达基因。最终鉴定出PPARGC1A、SLC6A1、EPHB2及PPP1R17这4个预后基因，用于构建线粒体自噬相关基因特征模型。通过卡普兰-迈尔分析、时间依赖性受试者工作特征曲线、风险评分、Cox回归分析及主成分分析评估预后模型的可行性。TCGA队列中，1年、3年及5年的受试者工作特征曲线下面积分别为0.628、0.678和0.755；GEO队列中对应数值分别为0.609、0.634和0.640。药物敏感性分析显示，喜树碱、紫杉醇、博来霉素与多柔比星在低危与高危患者间的敏感性存在显著差异。临床样本的qPCR与蛋白质印迹实验结果进一步验证了公共数据库的分析结论。
结论 本研究成功构建了对COAD具有显著预测价值的线粒体自噬相关基因特征模型，为该疾病的治疗提供了新的思路与方向。