Bong R. Oh

FREQUENT GENOTYPE CHANGES AT −308, AND 488 REGIONS OF THE TUMOR NECROSIS FACTOR - α (TNF-α) GENE IN PATIENTS WITH PROSTATE CANCER

Purpose: Tumor necrosis factor-alpha (TNF-α) is involved in oncogenesis of several cancers. The purpose of this study was to investigate whether genotype changes of TNF-α promoter regions (−238, −308) and at the 488 region are associated with human prostate cancer. Materials and Methods: The DNA from 73 cases of human prostate cancer was analyzed by allele-specific polymerase chain reaction to characterize the genotype changes of three regions of the TNF-α gene in prostate cancer patients. We also determined the genotype frequency in these patients. The relative risk of variant genotype was calculated by comparing with our previous data from healthy controls. Results: Genetic changes were detected in 15.1% (11/73) of prostate cancer samples at 488 region of TNF-α. Seventy-three percent (53/73) of the patients showed genotype GA at −308 region of TNF-α. Genotype GA at 488 region in TNF-α was observed in 73% (53/73) of the cancer and 71% (52/73) of the normal tissue. The relative risks of incidence for prostate cancer was14-fold higher in people with genotype GA at −308 region of TNF-α. The relative incidence for prostate cancer was a 17-fold higher in-patient with genotype GA at 488 region of TNF-α. Genotype GA at −308 of TNF-α was related to higher clinical tumor stage of prostate cancer than genotype G (p Conclusions: The present study demonstrates, for the first time, that the genotype changes in −308 and 488 regions of TNF-α are associated with prostate cancer.

Late presentation of ureteral injury after laparoscopic surgery

Objective To describe clinical presentation, etiology, and treatment of ureteral injuries recognized late in women who had gynecologic laparoscopies. Methods We reviewed the charts of 12 women who had delayed recognition of ureteral injuries between January 1991 and December 1998. Results Patients presented with fever, hematuria, flank pain, or peritonitis between 3 and 33 days postoperatively. The mechanism of ureteral injuries was electrocoagulation in seven women, laser ablation in one, and stapler ligation in four. The sites of injury were near the inferior margin of the sacroiliac joint on excretory urogram in eight women and near the ureterovesical junction in four. Three women initially treated with internal ureteral stents were subsequently treated with ureteroneocystostomy because of progression of urinary ascites in two and a delayed ureteral stricture in one. In nine patients, attempts at ureteral stenting were unsuccessful and immediate ureteral reconstruction was done. Outcomes were good in all cases. Conclusion Delayed recognition of ureteral injury after gynecologic laparoscopy was associated with serious complications, and initial treatment with ureteral stenting was not useful. We advocate early open repair for those injuries.

Inactivation of the human androgen receptor gene is associated with CpG hypermethylation in uterine endometrial cancer

Androgens mediate their effects through the androgen receptor (AR) and have antiproliferative effects on uterine endometrial cells. In this report, we investigated methylation status and the expression of the AR gene in normal endometrium and uterine endometrial cancer (UEC) tissues using methylation‐specific polymerase chain reaction (MSP) and immunohistochemical staining. Seventy of 89 cancer samples were AR negative, although 39 of 46 normal samples were AR positive by immunohistochemistry. By MSP, 64 of 89 cancer samples showed only methylated AR alleles, although all normal tissues showed both unmethylated and methylated AR alleles. To determine whether similar changes occurred in methylation status in the UEC carcinogenesis, we studied AR methylation using pairs of cancerous and normal samples from 28 patients. Twenty‐three of 28 cancer samples showed only methylated AR alleles, although all normal samples showed both unmethylated and methylated alleles. All of the 23 cancer samples that lost unmethylated alleles were negative for AR by immunohistochemical analysis. Reverse transcription–polymerase chain reaction was performed by using UEC cell lines with and without treatment by the demethylating reagent 5‐aza‐2′‐deoxycytidine. No AR expression was found in any of the UEC cell lines, except for MFE‐296 without 5‐aza‐2′‐deoxycytidine. Treatment with 5‐aza‐2′‐deoxycytidine restored AR expression in all of the UEC cell lines that showed no AR expression before treatment. This study is the first to report that the possible mechanism of AR inactivation in endometrial cancer is through hypermethylation of the AR gene CpG islands. Mol. Carcinog. 29:59–66, 2000.

TUMOR NECROSIS FACTOR-α GENE MUTATIONS AND GENOTYPE CHANGES IN RENAL CELL CARCINOMA

Purpose: We tested the hypothesis that genotype changes in the promoter region of tumor necrosis factor-α and exon 1 are associated with renal cell carcinoma.Materials and Methods: We analyzed genotypic changes at the 3 polymorphic loci of tumor necrosis factor-α −238, −308 and 488 using tumor and normal tissues from 81 Japanese patients with renal cell carcinoma.Results: Of the 81 patients 14 (17%) had point mutations from G to A, including 8 (57%) with point mutations at multiple loci. Six of the 8 patients (75%) with point mutations at multiple loci were classified with stage 4 renal cell carcinoma. Of the 81 patients 14 were classified with stage 4 carcinoma, including 9 (64%) with point mutation from G to A. Normal tissue from cancer patients showed an increased frequency of the GA genotype at loci −238 and 488 compared to healthy controls (37% versus 9% and 30% versus 12%, respectively). The relative risk of renal cell carcinoma was 6.5-fold higher in patients with the GA genotype at locus −238 (p <...

Nitric oxide synthase gene and protein expression are upregulated by Bacille Calmette-Guérin in the rat bladder.

Objective: We hypothesize that Bacille Calmette–Guérin (BCG) may act through the regulation of various isoforms of nitric oxide synthase (NOS) [inducible (iNOS), endothelial (eNOS), and neuronal (nNOS)] genes and protein expression in rat bladder. Methods: Adult female Sprague–Dawley rats (200–250 g) were injected transurethrally with BCG (22 rats) and phosphate–buffered saline (22 control rats), and after 2, 4, 6, and 12 h, and 1, 2, 3, 5, 7, 10, and 14 days, the bladders were harvested. Normal and BCG–treated rat bladders were analyzed for mRNA expression for iNOS, eNOS, and nNOS by reverse–transcriptase polymerase chain reaction. Protein expression was determined by Western blotting and immunohistochemistry. Results: mRNA expression for iNOS was induced after 2 h of BCG injection in the rat bladder. Gene expression for iNOS was highest at 6 h to 1 day followed by decreased expression, reaching its lowest level at 5 days. eNOS mRNA expression was detected in control bladders, but its level was higher in the BCG–treated animals. nNOS mRNA expression was present in all samples, but did not change after BCG treatment. Western blotting confirmed these findings. Immunohistochemistry analysis demonstrated that eNOS was present mainly in endothelium, while iNOS was detected in stroma and nNOS in epithelium and smooth muscle of the rat bladder. Conclusion: The present study demonstrates, for the first time, that BCG treatment up–regulates gene and protein expression of iNOS and eNOS in normal rat bladders, suggesting that BCG action may be mediated through NOS pathways.