Su Jinfang, Huang Yongbiao, Wang Yali, Li Rui, Deng Wanjun, Zhang Hao, Xiong Huihua
Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Cancer Cell Int. 2022 Feb 9;22(1):67. doi: 10.1186/s12935-022-02485-2.
Copine1 (CPNE1), the first discovered CPNE1 family member, participates in the process of carcinogenesis and development of diverse tumors. Our study aimed to investigate the expression and prognostic value of CPNE1 gene in hepatocellular carcinoma (HCC), to explore its functional network in HCC and its effects on biological behaviors.
HCCDB, CCLE, HPA and LinkedOmics online databases were used to explore the expression of CPNE1 gene and analyze the co-expression network of CPNE1 in hepatocellular carcinoma. Gene set enrichment analysis (GSEA) was used for GO functional annotation, KEGG pathway enrichment analysis and regulators of CPNE1 networks in LIHC. HepG2 and MHCC-97H cells were selected to construct CPNE1 knockdown cell lines by transfection with siRNA, and Hep3B cell was selected to construct CPNE1 overexpression cell line by transfection with plasmid. The effect of CPNE1 on the proliferation of hepatocellular carcinoma cells was examined by CCK8 assay and clone formation assay; the effect of CPNE1 on the migration ability of hepatocellular carcinoma cells was assessed by cell scratch assay and Transwell cell migration assay; finally, the expression of related signaling pathway proteins was examined by Western Blot. The correlation of CPNE1 expression with immune infiltration and immune checkpoint molecules in HCC tissues was analyzed using TIMER online database and GSEA.
CPNE1 was highly expressed in HCC tissues and significantly correlated with sex, age, cancer stage and tumor grade. Overall survival (OS) was significantly lower in patients with high CPNE1 expression than in patients with low CPNE1 expression, and CPNE1 could be used as an independent prognostic indicator for HCC. Knockdown of CPNE1 gene inhibited the AKT/P53 pathway, resulting in decreased proliferation, migration and invasion of HCC cells. Overexpression of CPNE1 gene showed the opposite results. The level of CPNE1 expression in HCC was significantly and positively correlated with the level of infiltration of B cells, CD8 T cells, CD4 T cells, macrophages, neutrophils, and dendritic cells (P < 0.001). GSEA results also showed that CPNE1 of LIHC was involved in some immune response regulating signaling pathways.
Our study firstly found the expression of CPNE1 was significantly higher in LIHC tissues than in normal liver tissues, and high CPNE1 expression was associated with poor prognosis. In addition, we identified the possible mechanism by which CPNE1 functioned in LIHC. CPNE1 influenced AKT/P53 pathway activation and LIHC cell proliferation and migration. There was a significant correlation between CPNE1 expression and tumor immune infiltration in LIHC.
Copine1（CPNE1）是首个被发现的CPNE家族成员，参与多种肿瘤的发生发展过程。本研究旨在探讨CPNE1基因在肝细胞癌（HCC）中的表达及预后价值，探索其在HCC中的功能网络及其对生物学行为的影响。
利用HCCDB、CCLE、HPA和LinkedOmics在线数据库探索CPNE1基因的表达，并分析CPNE1在肝细胞癌中的共表达网络。采用基因集富集分析（GSEA）对LIHC中的CPNE1网络进行GO功能注释、KEGG通路富集分析及调控因子分析。选用HepG2和MHCC-97H细胞，通过转染siRNA构建CPNE1基因敲低细胞系；选用Hep3B细胞，通过转染质粒构建CPNE1过表达细胞系。采用CCK8法和克隆形成试验检测CPNE1对肝癌细胞增殖的影响；采用细胞划痕试验和Transwell细胞迁移试验评估CPNE1对肝癌细胞迁移能力的影响；最后，通过蛋白质免疫印迹法检测相关信号通路蛋白的表达。利用TIMER在线数据库和GSEA分析CPNE1表达与HCC组织中免疫浸润及免疫检查点分子的相关性。
CPNE1在HCC组织中高表达，且与性别、年龄、癌症分期和肿瘤分级显著相关。CPNE1高表达患者的总生存期（OS）显著低于CPNE1低表达患者，CPNE1可作为HCC的独立预后指标。敲低CPNE1基因可抑制AKT/P53通路，导致肝癌细胞增殖、迁移和侵袭能力下降。CPNE1基因过表达则呈现相反结果。HCC中CPNE1表达水平与B细胞、CD8 T细胞、CD4 T细胞、巨噬细胞、中性粒细胞和树突状细胞的浸润水平显著正相关（P＜0.001）。GSEA结果还显示，LIHC的CPNE1参与了一些免疫反应调节信号通路。
本研究首次发现CPNE1在LIHC组织中的表达显著高于正常肝组织，且CPNE1高表达与预后不良相关。此外，我们还确定了CPNE1在LIHC中发挥作用的可能机制。CPNE1影响AKT/P53通路激活以及LIHC细胞的增殖和迁移。CPNE1表达与LIHC中的肿瘤免疫浸润显著相关。
