[Bioinformatics analysis of core differentially expressed genes in hepatitis B virus-related hepatocellular carcinoma].

OBJECTIVE: To identify the core genes associated with the development and progression of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC), so as to provide insights into the elucidation of pathogenesis of HBV-related HCC. METHODS: GSE55092 and GSE121248 datasets were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) between HCC and peri-cancer tissues were screened using the R package, and the volcano map of DEGs were plotted. The DEGs were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, and a protein-protein interaction (PPI) network was created. The hub DEGs were screened using Molecular Complex Detection (MCODE) and cytoHubba plugins in the open-access platform Cytoscape 3.9.0. Then, the screened hub DEGs were validated for differential expression and survival analysis using clinical sample data captured from the UALCAN and Kaplan Meier-plotter databases. RESULTS: A total of 1 148 and 686 DEGs were screened between HCC and peri-cancer tissues in GSE55092 and GSE121248 datasets, including 703 and 477 down-regulated genes and 445 and 209 up-regulated genes, respectively. A total of 557 common DEGs were screened between GSE55092 and GSE121248 datasets, including 384 down-regulated genes and 173 up-regulated genes. GO enrichment analysis showed that these DEGs were significantly enriched in biological processes of cell division, cell proliferation, redox process, immune response and proteolysis, cellular components of cell nucleus, cytoplasm, extracellular vesicle and endoplasmic reticulum membrane, and molecular functions of binding to calcium ion, protein kinase, DNA and heme. KEGG pathway analysis revealed that these DEGs were significantly enriched in pathways of cell cycle, oocyte meiosis, metabolic pathway, antibiotic biosynthesis and p53 signaling. PPI network analysis identified 10 DEGs, including CDK1, CCNB1, CCNA2, TOP2A, AURKA, CCNB2, KIF11, CDC20, KIF20A and BUB1B, and CDK1, KIF11 and KIF20A were found to be differentially expressed and correlate with poor prognosis among HBV-related HCC patients following clinical sample data validation. CONCLUSIONS: CDK1, KIF11 and KIF20A may play a critical role in the development and progression of HBV-related HCC, which may be potential diagnostic biomarkers and therapeutic targets of HBV-related HCC.

Regenerating gene IA predicts radiosensitivity and survival in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is a common malignancy in Southern China and Southeast Asia. Radiotherapy is the main treatment option. However, radiotherapy does not benefit all patients because there is no known precise biomarker that can be used for screening radioresistant patients. Genetic predisposition is closely related to tumor development, therapeutic response, and prognosis. The relationship between regenerating gene IA (REGIA) and NPC is unclear. This study aimed to retrospectively analyze the association between REGIA expression and metastasis, radiosensitivity, and survival in patients with NPC as well as assess the effect of radiation on REGIA expression in vitro. Immunohistochemical staining was used to detect REGIA. The relationship between REGIA expression in radioresistant NPC and the prognosis of CNE1 NPC cells were analyzed using quantitative real-time polymerase chain reaction and Western blotting. We found that increased doses of radiation in CNE1 cells significantly decreased REGIA expression (P<0.05). The overall rate of REGIA-positive expression was 47.15% in NPC tissues and 45.00% and 61.02% in radiosensitive and radioresistant cases, respectively, showing significant differences (P<0.05). A REGIA-positive protein expression rate had a negative correlation with radiosensitivity in NPC (r= -0.109, P=0.047). Both REGIA-positive and REGIA-negative expression strongly predicted the overall survival rate and progression-free survival of NPC patients (P<0.01). A multivariate analysis indicated that REGIA was an inverse prognostic factor in NPC patients (REGIA-positive expression: hazard ratio (HR)=2.139, 95% confidence interval (CI)=1.56-2.94, P<0.001 and REGIA-negative expression: HR=1.958, 95% CI=1.42-2.69, P<0.001). In conclusion: Radiation can affect REGIA expression. The REGIA expression level correlated with radioresistance and a poor prognosis. In addition, REGIA expression might act as a potential therapeutic target and prognostic predictor in NPC patients.

MiR-18a upregulation enhances autophagy in triple negative cancer cells via inhibiting mTOR signaling pathway.

OBJECTIVE: We investigated the involvement of miR-18a upregulation in autophagy regulation and paclitaxel (PTX) resistance in triple negative breast cancer (TNBC) cells. MATERIALS AND METHODS: PTX resistant MDA-MMB-231/PTX cells were generated using an intermittent, stepwise method. MiR-18a expression was assessed using qRT-PCR. The level of autophagy was assessed by Western blot analysis of LC3B expression and observation of LC3-GFP puncta formation under a fluorescence microscope. The effect of miR-18a mediated autophagy on PTX sensitivity was assessed by measuring IC50 and PTX induced cell apoptosis. RESULTS: MDA-MB-231/PTX cells had both higher miR-18a expression and basal autophagy than MDA-MB-231 cells. Enforced miR-18a overexpression directly led to increased autophagy in MDA-MB-231 cells, the effect of which was similar to that of rapamycin, a mTOR signaling inhibitor. Following Western blot analysis showed that miR-18a overexpression decreased the expression of p-mTOR and p-p70S6. Therefore, we infer that miR-18a increases autophagy level in MDA-MB-231 cells via inhibiting mTOR signaling pathway. Both drug sensitivity assay and flow cytometry analysis confirmed that the effect of miR-18a on increasing IC50 and decreasing PTX induced apoptosis in MDA-MB-231 cells could largely be abrogated by treatment with bafilomycin A1 (Baf. A1). CONCLUSIONS: MiR-18a upregulation results in enhanced autophagy via inhibiting mTOR signaling pathway in TNBC cells, which is a mechanism contributing to paclitaxel resistance.