IntroductionThe present study aimed to explore the effects of pri-let-7a-1 rs10739971 and FAS-670 rs1800682 polymorphisms on the pathogenesis of radiation induced intestinal toxicity in prostate cancer (PC) patients.Material and methods380 PC patients with or without signs of intestinal toxicity were enrolled to study the effects of let-7a rs10739971 and FAS-670 rs1800682 polymorphisms on rectal volume and the risk of intestinal toxicity. In addition, real-time PCR, Western-blot analysis, immunohistochemistry, luciferase assays and computational analyses were performed to explore the mechanism underlying the role of let-7a rs10739971 polymorphism in radiation induced intestinal toxicity.ResultsThe let-7a rs10739971 polymorphism but not the FAS-670 rs1800682 polymorphism was closely related to the risk of radiation induced intestinal toxicity featured by a high rectal volume. In addition, there was no obvious association between the rectal volume and the genotype and allele frequencies of FAS -670 rs1800682 and Pri-let-7a-1 rs10739971 polymorphisms. The GG genotype of let-7a rs10739971 polymorphism reduced let-7a expression but enhanced FAS expression. In addition, the intestinal toxicity (-) group showed a much higher level of let-7a and a much lower level of FAS than the intestinal toxicity (+) group. FAS was a virtual target gene of let-7a, which decreased FAS protein expression in a dose-dependent manner.ConclusionsThe GG genotype of pri-let-7a-1 rs10739971 polymorphism could increase the risk of radiation induced intestinal toxicity in PC patients. Therefore, the pri-let-7a-1 rs10739971 polymorphism could be used as a putative marker to predict the risk of intestinal toxicity in PC patients undergoing radiotherapy.
Involvement of Multidrug Resistance-Associated Protein 1 in Intestinal Toxicity of Methotrexate
