DataSheet_1_Identification of CDCA2 as a Diagnostic and Prognostic Marker for Hepatocellular Carcinoma.zip

ObjectiveHepatocellular carcinoma (HCC) is one of the most common and malignant tumors with an insidious onset, difficult early diagnosis, and limited therapy options, resulting in a poor prognosis. Cell division cycle associated 2 (CDCA2), also known as Repo-Man, plays an important role in regulating mitosis and DNA repair, but the involvement of CDCA2 in HCC remains unclear.
MethodsThe differentially expressed genes that were significantly upregulated in multiple RNA sequencing datasets of HCC were screened. Receiver operating characteristic (ROC) curve analysis was performed to identify diagnostic markers for HCC. Least absolute shrinkage and selection operator Cox regression analysis was performed to screen the prognosis-related genes. The screening and analyses identified CDCA2 as the target gene in this study. The expression of CDCA2 was analyzed in public databases and clinical specimens, and CDCA2 involvement in HCC was explored by both bioinformatic analysis and in vitro experiments.
ResultsThe level of CDCA2 was enhanced in HCC compared with healthy livers. Overexpression of CDCA2 positively correlated with the pathological grade and TNM stage of the diseases. Furthermore, CDCA2 was found to be an independent prognostic predictor. An excellent prognostic model of HCC was successfully constructed with CDCA2 in combination with TNM stage. Bioinformatic analysis revealed that CDCA2 was closely associated with the cell cycle, apoptosis, and p53 signaling pathway. Silencing CDCA2 in Huh7 cells resulted in significant upregulation of p53 and the downstream PUMA and NOXA and a subsequently increased apoptosis. Inhibition of p53 signaling and apoptosis was found after overexpression of CDCA2 in L02 cells. Strikingly, the proliferation of cells was not affected by CDCA2.
ConclusionsCDCA2 was a novel diagnostic marker for HCC, and overexpression of this gene reflected poor pathological grade, stage, and clinical prognosis. CDCA2 promoted the pathogenesis of HCC by suppressing the p53-PUMA/NOXA signaling and the subsequent apoptosis.

研究目标
肝细胞癌（Hepatocellular carcinoma, HCC）是最常见的恶性肿瘤之一，其起病隐匿、早期诊断困难且治疗手段有限，因此预后极差。细胞分裂周期相关蛋白2（Cell division cycle associated 2, CDCA2），又称Repo-Man，在调控有丝分裂与DNA修复过程中发挥重要作用，但目前CDCA2在肝细胞癌中的参与机制仍不明确。
研究方法
本研究首先筛选出多组肝细胞癌RNA测序数据中显著上调的差异表达基因。通过受试者工作特征（Receiver operating characteristic, ROC）曲线分析鉴定肝细胞癌的诊断标志物；采用最小绝对收缩和选择算子Cox回归分析筛选预后相关基因。经上述筛选与分析流程，确定CDCA2为本研究的靶基因。随后，在公共数据库与临床标本中检测分析CDCA2的表达水平，并通过生物信息学分析与体外实验探究CDCA2在肝细胞癌中的作用。
研究结果
相较于正常肝脏组织，肝细胞癌组织中CDCA2的表达水平显著升高。CDCA2过表达与患者的病理分级及TNM分期呈显著正相关。进一步分析显示，CDCA2可作为独立的预后预测因子。本研究成功构建了CDCA2联合TNM分期的肝细胞癌预后模型。生物信息学分析表明，CDCA2与细胞周期、细胞凋亡及p53信号通路密切相关。在Huh7细胞中沉默CDCA2后，p53及其下游靶基因PUMA、NOXA的表达显著上调，进而引发细胞凋亡水平升高。而在L02细胞中过表达CDCA2，则会抑制p53信号通路与细胞凋亡进程。值得注意的是，CDCA2对细胞增殖无显著影响。
研究结论
CDCA2可作为肝细胞癌新型诊断标志物，其过表达提示患者存在不良病理分级、分期与临床预后。CDCA2通过抑制p53-PUMA/NOXA信号通路及后续细胞凋亡，促进肝细胞癌的发生发展。