Protective Effects of Pyridoxamine Against UVC-induced Programmed Cell Death in HaCaT Cells.

BACKGROUND: Exposure to ultraviolet (UV) light is closely related to human diseases, such as skin cancer, due to irreversible injuries to the skin cells. The UV-induced DNA damage and programmed cell death are important determinants for skin carcinogenesis. The aim of the present study was to investigate the anti-ultraviolet-C (UVC) effects of pyridoxamine in human keratinocyte HaCaT cells and its mechanisms of action. RESULTS: UVC-induced programmed cell death in HaCaT cells was abrogated by treated the cells immediately after UVC irradiation with 40, 80 and 160 µM of pyridoxamine. Monitoring the UVC-induced-specific reactive oxygen species, we found that 20, 40, 80 and 160 µM of pyridoxamine was also effective in suppressing the induction of reactive oxygen species by UVC. CONCLUSION: Overall, our results provided evidence showing that pyridoxamine was effective in protecting HaCaT cells from UVC-induced programmed cell death and may be a potential anti-UVC agent in life and clinical practice.

Significant Association of Cyclo-oxygenase 2 Genotypes with Upper Tract Urothelial Cancer.

AIM: Reliable biomarkers are in urgent need for diagnosis, outcome prediction and treatment-effect monitoring for upper tract urothelial carcinomas (UTUC). Although up-regulation of cyclo-oxygenase 2 (COX2) is found in stroma and tumor cells in more than half of the patients with UTUC investigated, the genomic contribution of COX2 to UTUC has not been studied. The study aimed to evaluate the association of six polymorphic genotypes of COX2 with UTUC within a Taiwanese population. MATERIALS AND METHODS: A total of 218 patients with UTUC and 580 healthy controls were genotyped for six COX2 polymorphisms, namely A-1195G, G-765C, T+8473C, intron 1, intron 5 and intron 6, and examined for their association with UTUC risk. RESULTS: The distribution of genotypes of COX2 G-765C and intron 5 were significantly different between patient and control groups (p=0.0001 and 0.0016, respectively), while others were not (p>0.05). The haplotype analysis showed that compared to the GG/TT haplotype of COX2 G-765C/intron 5, those carrying GG/AT variants have a significantly increased risk of UTUC (odds ratio=4.83, 95% confidence interval=1.79-13.06), while those carrying CG/TT variants have a decreased risk (odds ratio=0.26, 95% confidence interval=0.14-0.49). CONCLUSION: Our results suggest that individual and combined COX2 G-765C/intron 5 genotypes play a role in controlling COX2 expression and UTUC development.