ABSTRACT
Objective: To investigate the effects of miR-200a on the proliferation of lung cancer cells and to identify its direct target genes. Methods:Real-time PCR was performed to analyze the miR-200a expression in 15 paired clinical specimens of non-small cell lung cancer and adjacent noncancerous tissues, human lung cancer cell lines (A549, NCI-H520, and SK-MES-1), and one human normal lung bronchial epithelial cell line (16HBE). The effects of miR-200a on the proliferation of A549 lung cancer cells were detected through CCK-8 method. The candidate target genes of miR-200a were identified by bioinformatics screening and then verified by dual luciferase reporter gene assay, real-time PCR, and Western blot. The effects of YAP1 downregulation on the proliferation of A549 lung cancer cell line were also observed through CCK-8 method. Results:The miR-200a expression in non-small cell lung cancer tissues and lung cancer cell lines was significantly decreased (P<0.01). The upregulation of miR-200a expression could significantly inhibit the pro-liferation of A549 lung cancer cells (P<0.01). Dual luciferase reporter gene indicated that miR-200a could directly affect the 3′-untrans-lated region of the YAP1 gene to inhibit luciferase activity (P<0.01). Real-time PCR and Western blot revealed that the upregulation of miR-200a expression could significantly reduce the mRNA and protein expression levels of YAP1 in A549 lung cancer cells (P<0.01). CCK-8 method indicated that the downregulation of YAP1 could significantly prevent the proliferation of A549 lung cancer cells (P<0.01). Conclusion:MiR-200a inhibits the proliferation of lung cancer cells by targeting YAP1. Thus, miR-200a elicits tumor suppression effects.
ABSTRACT
Objective: To observe the expression of hMLH1 protein in esophagus squamous cell carcinoma, atypical hyperplasia tissue and normal esophagus tissue, so as to discuss the relationship between hMLH1 expression and esophagus carcinogenesis. Methods: The specimens of esophagus squamous cell carcinoma, atypical hyperplasia and normal esophagus tissue were obtained from 92 esophagus carcinoma patients. Immunohistochemistry (IHC) staining technique was used to detect expression of hMLH1 protein. The relationship between hMLH1 expression with clinical parameters, such as gender, age, cancer differentiation level, infiltration depth, tumor stage, lymphatic metastasis, was analyzed. Results: The positive rates of hMLH1 protein in esophagus squamous cell carcinoma, and atypical hyperplasia tissue and normal esophagus tissue were 36.96%,56.52%, and 84.78%,respectively,with the former 2 significantly lower than the latter (P