HRM screening of the UBC9 gene encoding the SUMO-E2-conjugating enzyme - case-control study in breast cancer.

AIM: UBC9 (E2) small ubiquitin-like modifier conjugating enzyme plays a key role in the post-translational modification of proteins named sumoylation. Defects in small ubiquitin-like modifier modification may contribute to breast carcinogenesis. In the present work, we examined UBC9 genetic variation. MATERIALS AND METHODS: UBC9 genetic variation was analyzed by using the high resolution melting (HRM) method. HRM study was conducted on 173-182 healthy women and 188-190 women with breast cancer. RESULTS: During HRM screening, we analysed three known single-nucleotide polymorphisms in introns: rs4984806, rs909916 and rs909917, and one known single nucleotide polymorphism rs8063 in exon 7, in a non-coding region. The genotype frequencies for all polymorphisms were in accordance with Hardy - Weinberg equilibrium among the control subjects and breast cancer patients. The linkage disequilibrium analysis displayed that there was one polymorphism block, which consisted of three single nucleotide polymorphisms: rs909916, rs909917 and rs4984806. We identified two common haplotypes CCG and TTC, but we did not find significant differences in the distribution of these haplotypes between cases and controls. CONCLUSION: Our study showed no differences in the occurrence of indicated polymorphisms in the UBC9 gene in a group of healthy women compared to women with breast cancer. These results suggest that the polymorphisms of the UBC9 gene - rs4984806, rs909916, rs909917 and rs8063 can be not associated with breast cancer risk.

Zinc differentially modulates DNA damage induced by anthracyclines in normal and cancer cells.

UNLABELLED: Zinc is one of the most essential trace elements in human organism. Low blood level of zinc is often noted in acute lymphocytic leukemia (ALL). Treatment with zinc adjuvant is hypothesized to accelerate recovery from ALL, and in conjunction with chemotherapy, cure ALL. AIM: We determined the effect of zinc on DNA damage induced by doxorubicin and idarubicin, two anthracyclines used in ALL treatment. METHODS: The experiment was performed on acute lymphoblastic leukemia cell line (CCRF-CEM) and lymphocytes from peripheral blood of healthy, adult subjects. To evaluate the level of DNA damage the comet assay in the alkaline version was used. RESULTS: We observed a significant difference in DNA damage level between normal and cancer cells in the presence of zinc. Cancer cells exhibited a significant increase of DNA damage in the presence of zinc, while in lymphocytes no such effect was observed. CONCLUSION: Our results suggest that zinc may protect normal cells against DNA-damaging action of anthracyclins and increase this action in cancer cells.