SNPs associated with the genetic predisposition to develop therapy-related acute myelogenous leukemia after chemotherapy for breast cancer

Abstract

8536 Background: t-AML is a syndrome occurring after exposure to chemo or radiotherapy. Since for similar treatments only some patients ends developing a secondary leukemia, it has been proposed a genetic predisposition associated to this syndrome. Methods: To analyse single nucleotide polymorphisms (SNPs) on genes that could be involved on risk of developing t-AML by means of RFLP and SNP genome screening using high density microarrays .Two groups of individuals were genotyped: Group A, composed by patients that develop t-AML after chemotherapy for breast cancer (BC) and Group B (control), formed by chemotherapy treated BC patients that after a period of more than 10 years have not developed t-AML. We have studied 12 polymorphisms on genes from drug detoxification pathways (NOQ1, GSTP1), DNA repair (XPC[3 ], XRCC1[2 ], NBS1, ERCC5 and XRCC3) and DNA synthesis (MTHFR[2 ]), in which the nucleotide change implies a change in the protein sequence (nA=16, nB=18) . Alternatively, for each patient, more than 10.000 SNPs were genotyped by means of of high density microarrays (Affymetrix) (nA=12, nB=18). The alele frequencies for each SNP between two groups were compared. Results: In RFLP study, we observe two SNPs on MTHFR gene displaying remarkably different allele frequencies between BC patients (Table). In microarray study, we found 12 SNPs with differences of allele frequency higher that 45% between A and B groups, located 6 on chromosome 8. Conclusions: The results suggest that the MHFTR gene is a candidate for being studied by its possible relation with the genetic predisposition to develop t-AML after BC treatment although its functional implication with the disease must still be elucidated. Moreover, data from SNP arrays suggest that the genome regions marked by those 12 SNPs, specially those on chromosome 8, are candidate for being studied by its possible relation with the genetic predisposition to develop t-AML after BC treatment. Financed by FIS G03/008. [Table: see text] No significant financial relationships to disclose.