Altered Secretory Activity of APE1/Ref-1 D148E Variants Identified in Human Patients With Bladder Cancer / 대한배뇨장애요실금학회지

PURPOSE: Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein involved in DNA repair and redox modulation. Recently, serum and urinary APE1/Ref-1 levels were reported to be increased in patients with bladder cancer. Genetic variations of APE/Ref-1 are associated with the risk of cancer. However, the effect of APE1/Ref-1 variants on its secretory activity is yet unknown. METHODS: APE1/Ref-1 variants were evaluated by DNA sequencing analysis of reverse transcription polymerase chain reaction products in coding DNA sequences (CDS) of APE1/Ref-1 in bladder tissue samples from patients with bladder cancer (n=10). Secretory activity of APE1/Ref-1 variants was evaluated with immunoblot and enzyme-linked immunosorbent assay of the culture medium supernatants. RESULTS: Four different substitution mutants (D148E, I64V/D148E, W67R/D148E, and E86G/D148E) of APE1/Ref-1 were identified in bladder cancer specimens. However, deletion mutants of APE1/Ref-1 CDS were not found. The secretory activity of the APE1/Ref-1 variants (D148E, I64V/D148E, and E86G/D148E) was increased compared to that of wild type APE1/Ref-1. Furthermore, the secretory activity in basal or hyperacetylated conditions was much higher than that in APE1/Ref-1 D148E-transfected HEK293 cells. CONCLUSIONS: Taken together, our data suggest that the increased secretory activity of D148E might contribute to increased serum levels of APE1/Ref-1 in patients with bladder cancer.

Relationship between APE1 single nucleotide polymorphism and prognosis of primary small cell carcinoma of esophagus / 中国综合临床

Objective To examine the single nucleotide polymorphism(SNP) of apurinic/apyrimidinic endonuclease1 (APE1) in primary small cell carcinoma of esophagus(PSEC) ,then investigate the relationship between these SNPs and the prognosis.Methods Sixty cases first-treated patients with PSEC were recruited, patients with esophageal squamous cell carcinoma (ESCC) and healthy blood donors were recruited as positive and negative controls.APE1 (Asp148Glu) of the patients with PSEC and controls were genotyped by the TaqMan method.Every patient was treated with platinum-based chemotherapy(EP regimen for PSEC and TP regimen for ESCC)and radiotherapy(3D-CRT) ,then every case was followed-up for 2 years.The relationship between these SNPs and the follow-up outcome was analyzed.Results Compared with the ESCC group and control group, APE1 148 pure mutant(Glu/Glu) of PSEC group increased significantly(PSEC group was 40％ (12/30), ESCC group was 13.3％ (4/30) , control group was 10％ (2/20)), the difference was statistically significant (x2 =7.248,P =0.027).According to data of following-up, there was a significant increase in rate of progress (1year:40.0％ (12/30) vs 16.7％ (5/30), x2 =4.022, P =0.045;2 years: 86.7％ (26/30) vs 40.0％ (12/30) ,P =0.004) and a significant decrease in survival (33.3％ (10/30) vs 76.7％ (23/30)) of PSEC compared with ESCC.The SNPs of APE1 Asp148Glu was significantly correlated with frequency of progress, a significant increase was found in rate of progress of the patients with mutant type(Asp/Glu±Glu/Glu) compared with wild genotype(1 year: 50.0％(11/22) ,x2 =3.854,P=0.05;2 years: 81.8％ (19/22) ,x2 =10.519,P =0.001) ,the survival of the patients with mutant genotype was significantly lower than wild type (22.7％ (5/22) ,x2=10.77,P=0.001).Conclusion The most of polymorphisms of APE1(Asp148Glu) are mutation type in PSEC.Pure mutant genotype (APE1 148Glu/Glu) carry significant enhancement of progression.The polymorphisms of APE1 (Asp148Glu) maybe one of those molecular mechanisms of high frequency of progress and poor prognosis in PSEC.

APE1/Ref-1 as a Serological Biomarker for the Detection of Bladder Cancer / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Apurinic/apyrimidinic endonuclease 1/redox factor-1 (APE1/Ref-1) is a multifunctional protein that shows elevated expression in a number of cancers. We attempted to determine whether serum APE1/Ref-1 is elevated in patients with bladder cancer. MATERIALS AND METHODS: Serum APE1/Ref-1 levels were determined using enzyme-linked immunosorbent assay in serum from patients with bladder cancer who had not received chemotherapy or radiotherapy (n=51) and non-tumor controls (n=55). The area under the receiver operating characteristic area under the curve was applied to determine the correlation between clinical factors and the serum levels of APE1/Ref-1. RESULTS: Serum levels of APE1/Ref-1 in bladder cancer patients were significantly elevated compared to those of the control group (3.548+/-0.333 ng/100 muL [n=51] for bladder cancer vs. 1.547+/-0.319 ng/100 muL [n=55] for the control group), with a sensitivity and specificity of 93% and 59%, respectively. Serum APE1/Ref-1 levels are associated with tumor stage, grade, muscle invasion, and recurrence. CONCLUSION: Serum APE1/Ref-1 might be useful as a potential serologic biomarker for bladder cancer.

Overexpression of Ref-1 Inhibits Lead-induced Endothelial Cell Death via the Upregulation of Catalase

The role of apurinic/apyrimidinic endonuclease1/redox factor-1 (Ref-1) on the lead (Pb)-induced cellular response was investigated in the cultured endothelial cells. Pb caused progressive cellular death in endothelial cells, which occurred in a concentration- and time-dependent manner. However, Ref-1 overexpression with AdRef-1 significantly inhibited Pb-induced cell death in the endothelial cells. Also the overexpression of Ref-1 significantly suppressed Pb-induced superoxide and hydrogen peroxide elevation in the endothelial cells. Pb exposure induced the downregulation of catalase, it was inhibited by the Ref-1 overexpression in the endothelial cells. Taken together, our data suggests that the overexpression of Ref-1 inhibited Pb-induced cell death via the upregulation of catalase in the cultured endothelial cells.

Expression of DNA repair gene apurinic/apyrimidinic endonuclease 1 and its correlation with the expression of mutant p53 in hepatocellular carcinoma / 中华消化外科杂志

Objective To detect the expression of apurinic/apyrimidinic endonuclease 1 (APEI) and explore its correlation with the expression of mutant p53 in hepatocellular carcinoma (HCC). Methods The expression of APE1 and mutant p53 was detected by SP immunohistochemical method in 10 specimens of normal liver tissue, 40 specimens of liver cirrhosis tissue and 103 specimens of HCC tissue which were collected at the Department of Pathology of Daping Hospital from 1991 to 2004. All data were analyzed by chi-square test, correla-tion analysis and K Independent-Samples Tests. Results The expression rate of APE1 in HCC was 100.0%, which was significantly higher than that in normal liver tissue (40.0%) and liver cirrhosis tissue (82.5%) (χ~2= 47.852, P < 0.01). The expression of APE1 was only detected in the nucleus in normal liver tissue. Ectopic expression of APE1 in cytoplasm was detected in liver cirrhosis tissue and HCC tissue, with the rate of 20.0% and 53.4%, respectively (χ~2=20.757, P <0.01). There was statistical difference in clinical staging and pathological grading of HCC with different combinations of APE1 expression (intranuclear or ectopic expression) and mutant p53 expression (positive or negative expression) (χ~2=12.910, 14.481, P < 0.01), and HCC with ectopic expression of APE1 and positive expression of p53 had high malignant degree. Conclusion Overexpression and ectopic expression of APE1 in cytoplasm may play important roles in the genesis and progression of HCC, and the ectopic expression of APE1 and p53 mutation may have synergistic effect.

Expression feature of APE1 and its clinical implication in colorectal carcinoma / 解放军医学杂志

Objective To investigate the role of APE1 in the carcinogenesis and progression of colorectal carcinoma (CRC). Methods Expression of APE1 was determined with SP immunohistochemical technique in 40 specimens of normal colorectal mucosa, 60 specimens of colorectal mucosa adjacent to CRC, 72 specimens of colorectal adenoma, and 125 specimens of colorectal carcinoma. Results In normal colorectal mucosa, APE1 was detected in nuclei of epithelial cells. Shift of APE1 from nucleus to cytoplasm was observed in 6 of 60 (10%) specimens of mucosa adjacent to cancer. Such shift was observed in 92 of 125 (73.6%) CRC tissues and 60 of 72 (83.3%) colorectal adenoma, the incidence of both of them was significantly higher than that observed in normal colorectal mucosa and colorectal mucosa adjacent to CRC (P