A comprehensive study of the association between the EGFR and ERBB2 genes and glioma risk

Abstract

Glioma is the most common type of adult brain tumor and glioblastoma, its most aggressive form, has a dismal prognosis. Receptor tyrosine kinases such as the epidermal growth factor receptor (EGFR, ERBB2, ERBB3, ERBB4) family, and the vascular endothelial growth factor receptor (VEGFR), play a central role in tumor progression. We investigated the genetic variants of EGFR, ERBB2, VEGFR and their ligands, EGF and VEGF on glioma and glioblastoma risk. In addition, we evaluated the association of genetic variants of a newly discovered family of genes known to interact with EGFR: LRIG2 and LRIG3 with glioma and glioblastoma risk. Methods. We analyzed 191 tag single nucleotide polymorphisms (SNPs) capturing all common genetic variation of EGF, EGFR, ERBB2, LRIG2, LRIG3, VEGF and VEGFR2 genes. Material from four case-control studies with 725 glioma patients (329 of who were glioblastoma patients) and their 1 610 controls was used. Haplotype analyses were conducted using SAS/Genetics software. Results. Fourteen of the SNPs were significantly associated with glioma risk at p< 0.05, and 17 of the SNPs were significantly associated with glioblastoma risk at p< 0.05. In addition, we found that one EGFR haplotype was related to increased glioblastoma risk at p=0.009, Odds Ratio [OR] = 1.67 (95% confidence interval (CI): 1.14, 2.45). The Bonferroni correction made all p-values non-significant. One SNP, rs4947986 next to the intron/exon boundary of exon 7 in EGFR, was validated in an independent data set of 713 glioblastoma and 2 236 controls, [OR] = 1.42 (95% CI: 1.06,1.91). Discussion. Previous studies show that regulation of the EGFR pathway plays a role in glioma progression but the present study is the first to find that certain genotypes of the EGFR gene may be related to glioblastoma risk. Further studies are required to reinvestigate these findings and evaluate the functional significance.

Acknowledgements

All centers were supported by the European Union Fifth Framework Program “Quality of life and Management of Living Resources” (contract number QLK4-CT-1999-01563), and the International Union against Cancer (UICC). The UICC received funds for this purpose from the Mobile Manufacturers’ Forum and GSM Association. Provision of funds to the INTERPHONE study investigators via the UICC was governed by agreements that guaranteed INTERPHONE’s complete scientific independence. These agreements are publicly available at http://www.iarc.fr/ENG/Units/RCAd.html. The Swedish center was also supported by the Swedish Research Council, the Cancer Foundation of Northern Sweden, the Swedish Cancer Society, and the Nordic Cancer Union. The Danish center was supported by the Danish Cancer Society, the Finnish center by the Emil Aaltonen Foundation and the Academy of Finland, The Cancer Society of Finland, and the UK center by the Mobile Telecommunications and Health Research (MTHR) Programme and NHS funding to the NIHR Biomedical Research Centre. The views expressed in the publication are those of the authors and not necessarily those of the funders. BM, UA and RH designed the study, and BM UA, JS, SS FW and RH conducted the genetic and statistical analyses and drafted the manuscript. AhA, AA, HCC, MF, CJ, KA, SL, MS and AS designed and conducted the original case control study and gave significant input to the manuscript.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.