ABSTRACT
BACKGROUND: Non-coding RNAs have attracted considerable attention for their vital role in cancer. The purpose of this study was to determine the effects of non-coding RNAs on hepatocellular carcinoma (HCC) and reveal their regulatory mechanism in the pathophysiological process. METHODS: We measured the expression of mucin 1 (MUC1) and miR-485-5p in tissues from 15 HCC patients and in liver cancer cell lines by quantitative real-time polymerase chain reaction and Western blot, screened for aberrantly expressed microRNAs (miRNAs) by miRNA microarrays. Bioinformatics tools were used to find the miRNA and circular RNA that regulated MUC1, which were validated by RNA immunoprecipitation assay and luciferase reporter assay. Cell counting kit-8, Transwell assays, and flow cytometry were used to conduct functional experiments. Proteins were examined by western blot and immunohistochemical staining assays. Significant differences between groups were estimated using the one-way analysis of variance. A Pâ<â0.05 was considered statistically significant. RESULTS: MUC1 was overexpressed in HCC tissues compared with that in paratumor tissues (normal vs. tumor, 1.007â±â0.215 vs. 75.213â±â18.403, t = 18.401, P < 0.001) while miR-485-5p was down-regulated (normal vs. tumor, 4.894â±â0.684 vs. 1.586â±â0.398, tâ=â16.191, P < 0.001). Inhibition of miR-485-5p promoted cell proliferation (73.33%â±â5.13% vs. 41.33%â±â3.51%, tâ=â8.913, P < 0.001), migration (102â±â8 cells vs. 46â±â8 cells, tâ=â8.681, P < 0.001), invasion (59â±â7 cells vs. 28â±â2 cells, tâ=â8.034, P < 0.01), and suppressed apoptosis (22.64%â±â6.97% vs. 36.33%â±â3.96%, tâ=â2.958, P < 0.05) of HepG2 cells with which MUC1 is knocked down. Mechanically, miR-485-5p binds to MUC1, while circHECTD1 binds to miR-485-5p, resulting in the indirect up-regulation of the MUC1 level. CONCLUSIONS: Our findings reveal that circHECTD1 facilitates HCC progression by sponging miR-485-5p to up-regulate MUC1.
Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , MicroRNAs , Mucin-1 , Carcinoma, Hepatocellular/genetics , Cell Line, Tumor , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic , Humans , Liver Neoplasms/genetics , MicroRNAs/genetics , Mucin-1/genetics , RNA, Circular , Ubiquitin-Protein LigasesABSTRACT
Metaplastic thymoma is an extremely rare tumor. To date, only 17 cases of metaplastic thymoma have been reported. To the best of the authors' knowledge, this is the second reported case of a sarcomatoid carcinoma arising in metaplastic thymoma; the carcinoma in this case is larger than that in the previous case. A 63-year-old woman with cough and asthenia for 2 weeks was admitted to the hospital. Computed tomography (CT) revealed a giant mass on the right side of the front mediastinum medium. The mediastinal tumor was excised, and additional pathological examinations, immunohistochemical tests, and electron-microscopic tests were performed. The tumor was diagnosed as a sarcomatoid carcinoma arising in metaplastic thymoma. Here, the authors discuss the clinical pathology of the sarcomatoid carcinoma arising in metaplastic thymoma and describe the biological behaviors with respect to the pathological features.
