KRT7 promotes epithelial-mesenchymal transition in ovarian cancer via the TGF-β/Smad2/3 signaling pathway

Keratin 7 (KRT7) is a member of the keratin gene family. KRT7 is abnormally expressed in various types of cancer and promotes the malignant progression of tumors. However, the role of KRT7 in ovarian cancer remains unclear. The present study aimed to validate the role of KRT7 in ovarian cancer progression. KRT7 expression levels in patients with ovarian cancer were analyzed using data obtained from the Human Protein Atlas and The Cancer Genome Atlas databases. KRT7 mRNA and protein expression levels were upregulated in ovarian cancer tissue compared with normal tissue. KRT7 expression was associated with the grading, staging and poor prognosis of ovarian cancer. The differentially expressed genes affected by KRT7 were primarily enriched in the functions of cell migration, cell adhesion and cell growth. In vitro studies, including a CCK8 assay, were used to detect cell proliferation. In addition, wound healing and transwell assays were performed to analyze cell migration. The results demonstrated that KRT7 overexpression was associated with increased proliferation, migration and epithelial-mesenchymal transition (EMT) of ovarian cancer cells, and the migration and EMT of ovarian cancers cells were decreased following knockdown with KRT7 small interfering RNA. In vivo, knockdown of KRT7 inhibited tumor growth of ovarian cancer. Furthermore, KRT7 regulated EMT in ovarian cancer via the TGF-β/Smad2/3 pathway, and regulated cell-matrix adhesion through integrin-β1-focal adhesion kinase signaling. These results suggest that KRT7 may be a potential molecular marker for prognosis prediction in patients with ovarian cancer.