Effect of claudin 1 on cell proliferation, migration and apoptosis in human cervical squamous cell carcinoma

Claudin 1 is a member of the claudin protein family that serves an important role in tight junctions. Increased or decreased expression levels of claudin 1 are found in several diseases, including breast cancer and viral infections. However, the function of claudin 1 in cervical cancer remains controversial. The aim of the present study was to investigate the biological functions of claudin 1 in different human cervical cancer cell lines. First, SiHa and ME-180 cells with stable claudin 1 overexpression or knockdown were established using lentiviral transduction, and the mRNA and protein levels were measured via reverse transcription-quantitative PCR and western blot analysis. Subsequently, cell proliferation, colony formation and migration experiments were performed in vitro using standard protocols, demonstrating that claudin 1 was able to inhibit cell proliferation and migration in both SiHa and ME-180 cells. Furthermore, cell cycle and apoptosis were detected via flow cytometry and western blotting, and the results revealed that claudin 1 inhibited cell cycle progression and promoted apoptosis. To further verify whether claudin 1 was involved in tumor growth in vivo, xenograft tumors were established in athymic mice via injecting SiHa cells overexpressing claudin 1, which was found to decrease tumor growth in vivo. Furthermore, the association between claudin 1 expression and prognosis was analyzed in different types of cancer in The Cancer Genome Atlas. Overall, the findings of the present study revealed that claudin 1 may serve an antitumor role in cervical squamous cell carcinoma and may be of value as a potential therapeutic target.