ABSTRACT
Objective: To explore the relationship between plasma Jagged1 protein level and coronary collateral circulation (CCC) formation in patients with coronary artery disease(CAD). Methods: According to coronary angiography (CAG) examination, our research was categorized in 2 groups: CAD group, n=89 patients with at least one of left anterior descending (LAD), left circumflex(LCX) or right coronary artery(RCA) stenosis ≥ 95％ and Control group, n=30 subjects without abnormal findings by CAG. Based on Rentrop grading system, CAD group was further divided into 2 subgroups: Good CCC subgroup, n=42 patients with Rentrop grade ≥ 2 and Poor CCC subgroup, n=47 patients with Rentrop grade≤1. Plasma levels of Jagged1 protein,vascular endothelial growth factor (VEGF) were measured by ELISA and the relevant correlation study was conducted by multivariate regression analysis. Results: Compared with Control group, CAD group had increased plasma levels of Jagged1 protein (38.74±10.60)ng/L vs (23.04±8.97)ng/L and elevated VEGF (113.98±30.80)pg/L vs (72.73±14.55)pg/L. Compared with Poor CCC subgroup, Good CCC subgroup presented increased Jagged1 protein (46.77±8.49)ng/L vs (31.56±6.26)ng/L and elevated VEGF (128.10±20.24) pg/L vs (92.43±21.09)pg/L. Correlation study showed that Jagged1 protein was positively related to VEGF in CAD patients (r=0.730, P<0.01); multivariate regression analysis indicated that Jagged1 protein (OR=1.318, P=0.000) and VEGF (OR=1.043, P=0.043) were the independent predictors for CCC processing.Conclusion: CAD patients with good CCC had the higher plasma Jagged1 protein level than the patients with poor CCC which implied that Jagged1 protein played important role in CCC processing, such finding may provide a new direction for treating CAD patients in clinical practice.
ABSTRACT
<p><b>BACKGROUND</b>O(6)-methylguanine-DNA-methyltransferase (MGMT) is a specific DNA revising enzyme transferring alkylated groups from DNA to its cysteine residue to avoid the abnormal twisting of DNA. Therefore, it is one of the drug resistant genes targeted in the treatment of cancer. This study explored the protective effect of MGMT gene transferred into mammalian cells.</p><p><b>METHODS</b>Mammalian expression vector containing the MGMT gene cloned from human hepatocytes by RT-PCR was constructed and transferred into K562 cells and human peripheral blood mononuclear cells (PBMCs) via liposome, then assayed for gene expression at RNA and protein levels. MTT assay was used to check the drug resistance of cells transfected with MGMT gene.</p><p><b>RESULTS</b>MGMT gene was successfully cloned. Real-time PCR showed that the mRNA expression in gene transfected groups in K562 cell line and PBMC were 13.4 and 4.0 times that of the empty vector transfected groups respectively.</p><p><b>RESULTS</b>of Western blotting showed distinct higher expression of MGMT in gene transfected group than in other two groups. The IC(50) values increased to 7 and 2 times that of the original values respectively in stable transfected K562 cells and transient transfected PBMC.</p><p><b>CONCLUSION</b>The alkylating resistance of eukaryotic cells is enhanced after being transfected with MGMT gene which protein product performs the protective function, and may provide the reference for the protective model of peripheral blood cells in cancer chemotherapy.</p>