Interaction Between IGF1 Polymorphisms and the Risk of Acute Lymphoblastic Leukemia in Chinese Children.

BACKGROUND/AIMS IGF1 is a key regulator in cell proliferation and apoptosis, and the 3' un-translated region (3'UTR) of the gene plays an important role in gene expression. For the first time, we explored the relationship between polymorphisms in the IGF1 3'UTR region and the risk of childhood acute lymphoblastic leukemia (ALL). METHODS Questionnaires were applied to collect epidemiological data. The genotypes of IGF1 polymorphisms were tested in a population of 744 ALL patients and 1088 cancer-free controls utilizing Taqman. Cell functional studies included real-time PCR, cell culture and transfection and luciferase assays. RESULTS We found that rs6214 homozygous AA genotype and rs6218 homozygous CC genotype were significantly associated with increased risk of childhood ALL. In addition, rs6218 CC genotype was associated with increased level of IGF1 mRNA in bone marrow, and the mutation in rs6218 led to aberrant binding capacity of hsa-miR-603 and hsa-miR-3941 in the 3'UTR of IGF1. CONCLUSION Polymorphisms of rs6214 and rs6218 in the 3'UTR of IGF1 are associated with childhood ALL susceptibility, and the polymorphism of rs6218 is related with IGF1 expression at mRNA level.