ABSTRACT
Introduction: Single nucleotide polymorphisms (SNPs) in DNA repair genes are mainly correlated with the response to radiotherapy in nasopharyngeal cancer (NPC). In NPC patients, previous research has studied the association between X-ray repair cross-complementing group 1 and 3 (XRCC1 and XRCC3) polymorphisms and radio-therapeutic response. The objective of our study was to test the association between XRCC1 Arg399Gln and XRCC3 Thr241Met polymorphisms and the response to radiotherapy in the NPC Moroccan population. Material and methods: A total of 100 patients with NPC were genotyped for polymorphisms in XRCC1 and XRCC3 genes. Results: The results revealed that the genotypes and alleles of both SNPs did not show any significant association with clinical stages (for XRCC1 Arg399Gln: p [genotype] = 0.559; p [allele] = 0.440) and (for XRCC3 Thr241Met: p [genotype] = 0.638; p [allele] = 0.567). Moreover, in the study of the association between the polymorphisms and radiotherapy, the response to radiation therapy between genotypes and alleles was not statistically significant (for XRCC1 Arg399Gln p [genotype] = 0.583; p [allele] = 0.459) and (for XRCC3 Thr241Met p [genotype] = 0.660; p [allele] = 0.590). Conclusions: The present study suggests that XRCC1 Arg399Gln polymorphism does not have any impact on the radio-therapeutic response in Moroccan NPC patients whereas XRCC3 Thr241Met polymorphism may act as a prognostic indicator for NPC patients treated with radiotherapy. However, studies with a larger sample are needed to confirm our results.
ABSTRACT
OBJECTIVE: Nasopharyngeal carcinoma (NPC) is a severe malignant disease. Despite its low frequency, NPC is very common in North African population. Radiotherapy is the standard therapeutic treatment of NPC. However, radioresistance hampers the success of treatment. At the molecular scale, radioresistance is due to genetic variations involved in DNA repair pathways in NPC patients. Several studies reported that single nucleotide polymorphisms (SNPs) in excision repair cross complementing group 1 (ERCC1) could be associated with radioresistance. In this optic, the present study aimed to evaluate the association between DNA repair gene polymorphisms ERCC1 C8092A and ERCC1 C118T and radiotherapy response of patients with NPC. METHODS: A total of 95 patients with confirmed NPC were recruited at the Mohammed VI Center for Cancer Treatment, Casablanca - Morocco between 2016 and 2018. Two single nucleotide polymorphisms in ERCC1 gene were genotyped. Multiple analysis software was used to assess the correlation between these SNPs and radio-therapeutic response. RESULTS: Sequencing of ERCC1 C8092A polymorphism revealed that CC and CA genotypes were found in 51.6% and 45.3% of cases, respectively, whereas the homozygote AA genotype was reported in only 3.1% of cases. For ERCC1 C118T polymorphism, the heterozygote CT genotype was identified in 49.5% of cases. Homozygotes genotypes CC and TT were detected in 17.9% and 32.6% respectively of NPC cases. Of note, no significant association was found between the ERCC1 C8092A polymorphism and response to radiation therapy (p=0.81). Similarly, there was no significant association between the response to radiotherapy and allelic distribution (p=0.56). Likewise, no correlation was observed neither with genotypes (p=0.07) nor with alleles (p=0.09) of ERCC1 C118T polymorphism and response to radiation therapy. CONCLUSION: Our results clearly showed that ERCC1 C8092A and ERCC1 C118T polymorphisms were not associated with response to radiotherapy in Moroccan NPC patients. Large studies are warranted to confirm the role of these SNPs in therapeutic response of NPC patients.
