Wang Chunni, Li Zitong, Shao Fei, Yang Xueying, Feng Xiaoli, Shi Susheng, Gao Yibo, He Jie
Department of Thoracic Surgery, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China.
Department of Pathology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100021, China.
J Exp Clin Cancer Res. 2017 Jun 23;36(1):84. doi: 10.1186/s13046-017-0555-8.
Oesophageal cancer is one of the most common malignancies worldwide,and oesophageal squamous cell carcinoma (ESCC) is the predominant histological type both globally and in China. Collagen triple helix repeat containing 1 (CTHRC1) has been found to be upregulated in ESCC. However, its role in tumourigenesis and progression of ESCC remains unclear.
Using our previous ESCC mRNA profiling data, we screened upregulated genes to identify those required for proliferation. Immunohistochemistry was performed to determine the level of CTHRC1 protein expression in 204 ESCC patients. Correlations between CTHRC1 expression and clinicopathological characteristics were assessed. In addition, pyrosequencing and 5-aza-dC treatment were performed to evaluate methylation status of CTHRC1 promoter. In vitro and in vivo analyses were also conducted to determine the role of CTHRC1 in ESCC cell proliferation, migration and invasion, and RNA sequencing and molecular experiments were performed to study the underlying mechanisms.
Based on mRNA profiling data, CTHRC1 was identified as one of the most significantly upregulated genes in ESCC tissues (n = 119, fold change = 20.5, P = 2.12E-66). RNA interference screening also showed that CTHRC1 was required for cell proliferation. Immunohistochemistry confirmed markedly high CTHRC1 protein expression in tumour tissues, and high CTHRC1 expression was positively correlated with advanced T stage (P = 0.043), lymph node metastasis (P = 0.023), TNM stage (P = 0.024) and poor overall survival (P = 0.020). Promoter hypomethylation at cg07757887 may contribute to increased CTHRC1 expression in ESCC cells and tumours. Forced overexpression of CTHRC1 significantly enhanced cell proliferation, migration and invasion, whereas depletion of CTHRC1 suppressed these cellular functions in three ESCC cell lines and xenografts. CTHRC1 was found to activate FRA-1 (Fos-related antigen 1, also known as FOSL1) through the MAPK/MEK/ERK cascade, which led to upregulation of cyclin D1 and thus promoted cell proliferation. FRA-1 also induced snail1-mediated MMP14 (matrix metallopeptidase 14, also known as MT1-MMP) expression to facilitate ESCC cell invasion, migration, and metastasis.
Our data suggest that CTHRC1 may act as an oncogenic driver in progression and metastasis of ESCC, and may serve as a potential biomarker for prognosis and personalized therapy.
食管癌是全球最常见的恶性肿瘤之一，食管鳞状细胞癌（ESCC）是全球及中国最主要的组织学类型。已发现含胶原三螺旋重复序列1（CTHRC1）在ESCC中上调。然而，其在ESCC肿瘤发生和进展中的作用仍不清楚。
利用我们之前的ESCC mRNA谱数据，筛选上调基因以鉴定增殖所需的基因。对204例ESCC患者进行免疫组织化学检测以确定CTHRC1蛋白表达水平。评估CTHRC1表达与临床病理特征之间的相关性。此外，进行焦磷酸测序和5-氮杂-2'-脱氧胞苷处理以评估CTHRC1启动子的甲基化状态。还进行了体外和体内分析以确定CTHRC1在ESCC细胞增殖、迁移和侵袭中的作用，并进行了RNA测序和分子实验以研究潜在机制。
基于mRNA谱数据，CTHRC1被鉴定为ESCC组织中上调最显著的基因之一（n = 119，倍数变化 = 20.5，P = 2.12E-66）。RNA干扰筛选还表明CTHRC1是细胞增殖所必需的。免疫组织化学证实肿瘤组织中CTHRC1蛋白表达明显升高，且CTHRC1高表达与晚期T分期（P = 0.043）、淋巴结转移（P = 0.023）、TNM分期（P = 0.024）及总体生存率差（P = 0.020）呈正相关。cg07757887处的启动子低甲基化可能导致ESCC细胞和肿瘤中CTHRC1表达增加。CTHRC1的强制过表达显著增强细胞增殖、迁移和侵袭，而CTHRC1的缺失则抑制了三种ESCC细胞系和异种移植中的这些细胞功能。发现CTHRC1通过MAPK/MEK/ERK级联激活FRA-1（Fos相关抗原1，也称为FOSL1），这导致细胞周期蛋白D1上调，从而促进细胞增殖。FRA-1还诱导蜗牛1介导的MMP14（基质金属蛋白酶14，也称为MT1-MMP）表达以促进ESCC细胞侵袭、迁移和转移。
我们的数据表明CTHRC1可能是ESCC进展和转移中的致癌驱动因子，并且可能作为预后和个性化治疗的潜在生物标志物。
