Li Wenjing, Xu Chang, Wang Kun, Ding Yuhan, Ding Lei
Department of Oncology, Beijing Shijitan Hospital, Capital Medical University, Beijing, People's Republic of China,
Binzhou Medical University Hospital, Binzhou, People's Republic of China.
Cancer Manag Res. 2019 Feb 13;11:1443-1451. doi: 10.2147/CMAR.S188020. eCollection 2019.
We conducted a preliminarily exploration of the role and possible mechanism of the non-tight junction-related function of claudin-7 in the occurrence and development of colorectal cancer.
We selected the colorectal cancer cell line HCT116, constructed a stably transfected claudin-7 knockdown cell line via RNAi and lentiviral infection, and determined the claudin-7 knockdown efficiency. We assessed the biological behavior changes (cell viability, apoptosis, and migration) in the stably transfected HCT116 cells and observed structural changes in the tight junction by transmission electron microscopy. We used a subcutaneous tumor formation model to assess the tumorigenicity of HCT116 cells after claudin-7 knockdown. We assessed the expression and localization of integrinβ1 in the stably transfected cell line by immunofluorescence staining and investigated the interaction between integrinβ1 and claudin-7 by co-immunoprecipitation.
After the knockdown of claudin-7 the expression, the viability and migration ability of HCT116 cells increased and apoptosis decreased. Transmission electron microscopy indicated that the intercellular tight junction structure did not change substantially. Furthermore, the tumor growth in nude mice was enhanced. Immunofluorescence staining showed that integrinβ1 and claudin-7 were co-expressed and co-localized on the cell membrane, and immunoprecipitation suggested that claudin-7 interacts with integrinβ1.
Claudin-7 may inhibit the proliferation and migration of tumor cells by interacting with integrinβ1, subsequently participating in the development of colorectal cancer.
我们对claudin-7的非紧密连接相关功能在结直肠癌发生发展中的作用及可能机制进行了初步探索。
我们选择了结直肠癌细胞系HCT116，通过RNA干扰和慢病毒感染构建了稳定转染的claudin-7敲低细胞系，并测定了claudin-7的敲低效率。我们评估了稳定转染的HCT116细胞的生物学行为变化（细胞活力、凋亡和迁移），并通过透射电子显微镜观察紧密连接的结构变化。我们使用皮下肿瘤形成模型评估claudin-7敲低后HCT116细胞的致瘤性。我们通过免疫荧光染色评估稳定转染细胞系中整合素β1的表达和定位，并通过免疫共沉淀研究整合素β1与claudin-7之间的相互作用。
claudin-7敲低后，HCT116细胞的表达、活力和迁移能力增加，凋亡减少。透射电子显微镜显示细胞间紧密连接结构没有实质性变化。此外，裸鼠体内肿瘤生长增强。免疫荧光染色显示整合素β1和claudin-7在细胞膜上共表达和共定位，免疫沉淀表明claudin-7与整合素β1相互作用。
claudin-7可能通过与整合素β1相互作用抑制肿瘤细胞的增殖和迁移，进而参与结直肠癌的发展。
