Wu Wei, Wu Fan, Wang Zaozao, Di Jiabo, Yang Jie, Gao Pin, Jiang Beihai, Su Xiangqian
Key laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Gastrointestinal Surgery IV, Peking University Cancer Hospital & Institute, Beijing 100142, China.
J Cancer. 2017 Jul 15;8(12):2163-2172. doi: 10.7150/jca.19940. eCollection 2017.
Centromere protein H (CENPH) is known as a fundamental component of the active centromere complex, and its overexpression is correlated with poor prognosis in various solid tumors. mTOR inhibitor rapamycin has been shown to possess antitumor activity, as well as prevent intestinal tumorigenesis. However, the prognostic value of CENPH in colorectal cancer (CRC) and the role of CENPH in rapamycin sensitivity remain unknown. The effect of CENPH on the cell proliferation, clonogenicity, and cell response to rapamycin in CRC were evaluated by MTT and/or colony formation assays. For the underlying mechanisms, the interaction between CENPH and GOLPH3 were detected by co-immunoprecipitation, GST pull-down, and His-tag pull-down assays, as well as the laser scanning confocal microscopy. The status of kinases in mTOR signaling was determined by Western blot. Finally, the clinical significance of CENPH was analyzed using public CRC datasets with CENPH transcripts and clinical information. CENPH inhibited CRC malignant phenotypes, conferred reduced sensitivity to rapamycin, and attenuated both mTORC1 and mTORC2 in mTOR signaling pathway through the interaction with golgi phosphoprotein 3 (GOLPH3), which has been identified as a potential oncogene and modulates the response to rapamycin. Moreover, elevated levels of CENPH were detected in CRC tissues, compared with normal colorectal tissues. High levels of CENPH expression gradually decreased according to CRC tumor stages. Patients with high CENPH expression had favorable survival. Our results suggest that CENPH inhibits rapamycin sensitivity by regulating GOLPH3 dependent mTOR pathway. High CENPH expression is associated with better prognosis in CRC patients. Taken together, CENPH may serve as a potential predictor for rapamycin sensitivity and therapeutic target for CRC patients.
着丝粒蛋白H（CENPH）是活性着丝粒复合体的一种基本成分，其过表达与多种实体瘤的不良预后相关。mTOR抑制剂雷帕霉素已显示具有抗肿瘤活性，并能预防肠道肿瘤发生。然而，CENPH在结直肠癌（CRC）中的预后价值以及CENPH在雷帕霉素敏感性中的作用仍不清楚。通过MTT和/或集落形成试验评估CENPH对CRC细胞增殖、克隆形成能力以及对雷帕霉素的细胞反应的影响。对于潜在机制，通过免疫共沉淀、GST下拉和His标签下拉试验以及激光扫描共聚焦显微镜检测CENPH与GOLPH3之间的相互作用。通过蛋白质印迹法确定mTOR信号通路中激酶的状态。最后，使用具有CENPH转录本和临床信息的公开CRC数据集分析CENPH的临床意义。CENPH抑制CRC恶性表型，降低对雷帕霉素的敏感性，并通过与高尔基体磷蛋白3（GOLPH3）相互作用减弱mTOR信号通路中的mTORC1和mTORC2，GOLPH3已被确定为一种潜在的癌基因并调节对雷帕霉素的反应。此外，与正常结直肠组织相比，在CRC组织中检测到CENPH水平升高。CENPH高表达水平根据CRC肿瘤分期逐渐降低。CENPH高表达的患者生存期良好。我们的结果表明，CENPH通过调节GOLPH3依赖的mTOR途径抑制雷帕霉素敏感性。CENPH高表达与CRC患者较好的预后相关。综上所述，CENPH可能作为雷帕霉素敏感性的潜在预测指标和CRC患者的治疗靶点。
