Abstract
The expression of human transfer ribonucleic acid (tRNA) methyltransferase 9-like (KIAA1456) protein in lung cancer tissue and its effects on certain genes involved in the proliferation, migration and invasion of lung cancer cells were investigated. Immunohistochemistry was applied to stain lung cancer tissue and adjacent tissue sections of 90 lung cancer patients, so as to evaluate the difference in the expression level of KIAA1456 between two tissues. The correlation of KIAA1456 expression with clinicopathological parameters of lung cancer was analyzed. Kaplan-Meier survival curves were used to analyze the relationship between KIAA1456 and postoperative survival in patients with lung cancer. KIAA1456 gene was overexpressed in lung cancer cell lines (A549 and GLC-15), and the influence of KIAA1456 gene on the expression of cyclin D1, neural cadherin (N-cadherin) and epithelial cadherin (E-cadherin) and their involvement in lung cancer cell proliferation, migration and invasion were observed. Compared with that in adjacent tissue, the expression of KIAA1456 in lung cancer tissue was significantly decreased (p<0.05). The low expression of KIAA1456 in lung cancer tissue was clearly associated with pathological tumor (pT) stage, pathological node (pN) stage, tumor-node-metastasis (TNM) stage and pathological stage, but had no correlation with sex, age, tumor size or histology of the patient. KIAA1456 low expression was related with poor prognosis of the lung cancer patient. According to Western blotting, the overexpression of KIAA1456 in lung cancer cells could inhibit the expressions of cyclin D1 and N-cadherin, and promote the expression of E-cadherin. The results show that KIAA1456 expression was low in lung cancer tissue, and was associated with poor prognosis in patients and was an independent prognostic factor in patients with lung cancer. Thus, KIAA1456 can be used as a tumor suppressor gene in lung cancer, suppressing the proliferation, migration and invasion of lung cancer cells.