OBJECTIVETo investigate the relationship between (GT)n polymorphism and esophageal cancer by analyzing the connection between microsatellite polymorphisms in the promoter of heme oxygenase-1 and the clinicopathological characteristics of esophageal squamous cell carcinoma (ESCC) in Han chinese population.

METHODSThe (GT)n repeats in HO-1 gene in 83 male and 43 female hospital-based patients with ESCC (aged between 40 and 79 years with a mean of (61 ± 8) years) and 134 healthy control individuals were obtained by DNA sequencing. Polymorphisms of the (GT)n repeats were generally grouped into three classes based on allele frequencies: class S alleles (<25 repeats), class M alleles (25 to 29 repeats), and class L alleles (≥30 repeats). The correlation between susceptibility and clinicopathological characteristics of ESCC were analyzed by χ2 test. For in vitro experiments, the transient-transfection assay was performed to explore the correlation between different lengths of (GT)n repeats and promoter activity by assessing the promoter activities of HO-1 gene in cultured Ecal09 cells treated with H2O2 by analysis of cariance.

RESULTSHigher frequencies of L-allele (25. 8% vs. 14. 9%, χ2 = 9. 520, P = 0. 002), L-allele carrier (41. 3% vs. 27. 6%, χ2 = 5. 381 , P = 0. 020) were found in patients with ESCC. Furthermore, the lymphatic metastasis rate (63. 5% vs. 41. 8%, χ = 5. 685, P = 0. 017) and the detection rate of poorly differentiated ESCC cell (53. 8% vs. 28. 4%, χ2 = 8. 335, P = 0. 004) was significantly higher in L-allele carriers compared to non-L-allele carriers. In transfection experiments, promoter activities of 5'-flanking regions of the HO-1 gene in Eca109 cells transfected with the recombinant gene carrying (GT)16 repeat after treatment with H2O2 increased (F = 23. 615,P = 0. 008). In H2O treated control group, compared to (GT)26 and (GT)36, the basal promoter activities of HO-1 gene carrying (GT)16 repeat increased (F =41. 376, P = 0. 003; F = 50. 761, P = 0. 002).

CONCLUSIONThe long (GT)n repeats of HO-1 gene promoter can increase the susceptibility of esophageal squamous cell carcinoma and the risk of lymphatic metastasis.

Alleles ; Asian Continental Ancestry Group ; Carcinoma, Squamous Cell ; etiology ; pathology ; Esophageal Neoplasms ; etiology ; pathology ; Female ; Gene Frequency ; Heme Oxygenase-1 ; genetics ; Humans ; Hydrogen Peroxide ; Lymphatic Metastasis ; Male ; Microsatellite Repeats ; Polymorphism, Genetic ; Promoter Regions, Genetic ; Risk Factors ; Transfection

OBJECTIVETo investigate the effect and mechanism of recombinant human erythropoietin (rhEPO) on angiogenesis in chronic ischemic porcine myocardium.

METHODSA ameroid constrictor was placed around the proximal circumflex branch of the left coronary artery in 12 Bama miniatures' swine artery by thoracoscopy. Electrocardiogram and coronary angiography were used to confirm the establishment of myocardial ischemia. The animals were divided into rhEPO treatment group (n = 6) and negative control group (n = 6). Treatment group received subcutaneous injection of rhEPO at 1, 3, 7, 14, 21 days, control group received saline. The expression of vascular endothelial growth factor (VEGF) in serum was assessed by ELISA. Ultrasonography and coronary angiography were assessed 28 days after therapy. Western blot was used to detect the expression of VEGF, phosphorylated protein kinase B (p-Akt) and phosphorylated extracellular signal regulated kinases (p-Erk). The degree of angiogenesis was assessed by immunohistochemical analysis.

RESULTSSerum VEGF rose significantly in both control and treatment groups, peaking at 3 days and then returning to the near-baseline level at 28 days, but the two groups showed no significant difference at each time point (P > 0.05). Echocardiographic measurements showed that the left ventricular systolic function of animals in treatment group increase significantly after rhEPO therapy. the expression levels of VEGF, p-Akt and p-Erk had markedly increased, which resulted in a 2.5-fold increased of VEGF, 1.1-fold increased of p-Akt, 1.5-fold increased of p-Erk (t = 37.721, 10.907, 12.957, all P = 0.000). there were significant increase in capillary density and arteriole density in the two groups ((944 ± 98) %/mm² vs. (569 ± 102) %/mm², (73 ± 13) %/mm² vs. (45 ± 10) %/mm², t = 4.214, 2.869, P = 0.016, 0.023).

CONCLUSIONSrhEPO can promote angiogenesis and arteriogenesis and improve the left ventricular systolic function in porcine model of chronic myocardial ischemia. The potential mechanism is to up-regulated the expression of p-Akt and p-Erk.

Animals ; Disease Models, Animal ; Epoetin Alfa ; Erythropoietin ; pharmacology ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Humans ; Male ; Myocardial Ischemia ; drug therapy ; metabolism ; pathology ; Neovascularization, Physiologic ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Recombinant Proteins ; pharmacology ; Swine ; Swine, Miniature ; Vascular Endothelial Growth Factor A ; metabolism