The Expression and Functional Roles of Epoxide Hydrolase 2 in Hepatocellular Carcinoma / 中国生物化学与分子生物学报

The expression, function and prognostic significance of epoxide hydrolase 2 (EPHX2) in hepatocellular carcinoma (HCC) were comprehensively analyzed through collecting HCC tissues and public database. The GEO and MitoCarta databases were used to identify the mitochondria-related differentially expressed genes (DEGs) in HCC. The Cancer Genome Atlas (TCGA) database was applied to analyze the expression levels of DEGs in HCC, including EPHX2 and its co-expressed genes. The R package was applied to draw the Kaplan-Meier survival curve and gene function enrichment analysis. The STRING database and GSEA software were used to analyze the protein-protein interaction (PPI) network and gene set enrichment analysis. qPCR and GEO database were applied to verify the expression level of EPHX2 in HCC. In the present study, a total of 15 mitochondria-related DEGs were identified in HCC. The expression of EPHX2 in HCC was significantly decreased compared to the normal liver tissues (P < 0. 01). The expression of EPHX2 was related to gender, tumor stage and grade in HCC, but not associated with age, T stage, et al in HCC. Moreover, compared with the patients with lower expression of EPHX2, patients with higher expression of EPHX2 had a better prognosis. EPHX2 was associated with fatty acid degradation. In addition, PPI results indicated that HAO1, AGXT, ACOX1, GSTκ1, SCP-2, CAT, CYP2C8, CYP2C9, CYP2B6, and CYP2J2 were co-expressed with EPXH2 in HCC. Furthermore, GSEA results showed that the group with lower expression of EPHX2 was positively correlated with the gene set of liver cancer cell proliferation and liver cancer recurrence. qPCR and GEO database results verified that the expression of EPHX2 was significantly decreased in HCC. The expression of EPHX2 was decreased in HCC, strongly suggesting that EPHX2 might function as a tumor suppressor gene in HCC. However, the potential mechanism of EPHX2 in HCC needs to be further verified.

Overexpression of TCF2 ameliorates insulin resistance in human hepatocellular carcinoma cells HepG2 / 基础医学与临床

Objective To investigate the effects of transcription factor 2(TCF2) overexpression on insulin resistance in HepG2 cells. Methods HepG2 cells were treated with high concentration of insulin(1×10-8mol/L) for 24 hours to induce insulin resistance (IR). Cells were divided into four groups:control group,IR group,IR+vector group and IR+TCF2 overexpression group. RT-qPCR and Western blot were performed to detect the expres-sion of TCF2. Glucose consumption and glycogen synthesis were assayed by glucose oxidase method and anthrone method respectively. Cell viability was evaluated by MTT assay. The activities of hexokinase and pyruvate kinase were detected by colorimetry. The protein level of IRS-1 and GLUT4 was detected by Western blot.Results Com-pared with control group,the decreased glucose consumption was observed in IR group(P＜0.05),indicating that insulin-resistance model was established successfully. The mRNA and protein expression of TCF2 was remarkably down-regulated in IR group as compared with control group. Compared with IR group,overexpression of TCF2 sig-nificantly improved glucose consumption, liver glycogen content, and the activities of hexokinase and pyruvate kinase (P＜0.05). Moreover,TCF2 overexpression up-regulated the protein expression of IRS-1 and GLUT4 (P＜0.05).Conclusions TCF2 overexpression ameliorates insulin resistance of HepG2 cells.

Mapping of BRCT1 domain of BRCA1 with chromatin unfolding activity / 生物工程学报

Breast cancer susceptibility gene 1(BRCA1) plays an important role in breast cancer development and progression. BRCA1 encodes a 1863-amino acid protein with two BRCA1 C-terminal (BRCT) domains at its C-terminus, BRCT1 and BRCT2. Many cancer-predisposing mutations are located in the BRCT domains, which have been shown to induce chromatin unfolding by use of an approach that allows visualization of large-scale chromatin structure through lac repressor/lac operator recognition. To map the important region of BRCT domain (amino acid residues 1642-1736), six deletion mutant constructs were made. The chromatin structure assay showed that amino acid residues 1691-1721 are involved in the induction of chromatin unfolding. To further localize the critical amino acid residues, ten alanine scanning mutant constructs were made. The chromatin structure assay demonstrated that the 1707IAGGK1711 region is critical for the chromatin unfolding activity. Based on the mapped important region, Blast analysis identified a novel homologous protein. Mapping of the BRCT1 domain may aid in the presymptomatic risk assessment and provide a valuable tool for further study on the BRCT1 structure and function.

The probability of microbiological contamination during the collection and processing of umbilical cord blood / 中国实验血液学杂志

To study the pathogens incidences in cord blood and the efficiency of different detective methods, 60 samples were drawn and reserved from collected and processed cord blood, respectively. The BACTEC 9050 system, improved Martin/thioglycollate broth (22 degrees C) and thioglycollate broth (35 degrees C) were employed to detected bacteria (including fungus) at the same time. Two hundred and six cord blood serum samples were used to detect the HBV DNA and HCV RNA by molecular biology technique, HBsAg, Anti-HBC, Anti-HCV, Anti-HCMV-IgM, HTLV-1, HTLV-2, HIV-1 and HIV-2 by ELISA and RBC agglutination test were used to detect the TPHA. Results showed that using BACTEC 9050 system, the incidence of bacteria and fungus was 3.33% and 0% respectively in collected cord blood; in processed cord blood, the rates increased to 6.67% and 1.67%, respectively. The sensitivity of BACTEC 9050 was higher than that of Martin/thioglycollate broth (22 degrees C/35 degrees C) culture. In 206 serum samples, the positive rate of HBV DNA was 5.8%, HCV RNA was 2.4%, HBsAg was 2.4%, HCMV-IgM was 1.89%, HCV was 2.4% and Anti-HBC was 29.4%. In those samples that Anti-HBC was positive, the positive rate of HBV DNA was 6.7%. It was concluded that the incidences of microbiological contamination in cord blood were high. The routine culture system would lead to false negative results of obligate anaerobes. It was necessary to replace the current culture system with improved system, such as BACTEC 9050 system. The molecular biology technique would make up for the default of ELISA.