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Exclusive mutation in epidermal growth factor receptor gene, HER-2, and KRAS, and synchronous methylation of nonsmall cell lung cancer
Article first published online: 5 APR 2006
Copyright © 2006 American Cancer Society
Volume 106, Issue 10, pages 2200–2207, 15 May 2006
How to Cite
Suzuki, M., Shigematsu, H., Iizasa, T., Hiroshima, K., Nakatani, Y., Minna, J. D., Gazdar, A. F. and Fujisawa, T. (2006), Exclusive mutation in epidermal growth factor receptor gene, HER-2, and KRAS, and synchronous methylation of nonsmall cell lung cancer. Cancer, 106: 2200–2207. doi: 10.1002/cncr.21853
- Issue published online: 27 APR 2006
- Article first published online: 5 APR 2006
- Manuscript Accepted: 12 DEC 2005
- Manuscript Revised: 17 NOV 2005
- Manuscript Received: 16 MAY 2005
- epidermal growth factor receptor gene;
- methylator phenotype;
- lung cancer
Both genetic and epigenetic changes in nonsmall cell lung cancer (NSCLC) are known to be a common event.
Mutations in the epidermal growth factor receptor gene (EGFR), HER-2, and KRAS and the methylation profile of 9 genes for NSCLC were analyzed and correlated with clinical and histologic data.
Thirty-nine EGFR, 4 HER-2, and 6 KRAS mutations were found in 150 NSCLC cases, with the methylation percentages of the genes ranging from 13% to 54%. Most mutations were present in adenocarcinomas, but mutations of the 3 genes were never found to be present in individual tumors. The frequency of methylation for all the genes was correlated with the Methylation Index, a reflection of the overall methylation pattern (all genes, P≤.01), supporting the presence of the CpG island methylator phenotype (CIMP) in NSCLC. On the basis of the methylation profile, CRBP1 and CDH13 methylation were good indicators of CIMP in NSCLC, and were correlated with a poorer prognosis in adenocarcinomas. Mutations in EGFR, HER-2, and KRAS were found to be present exclusively, whereas methylation tended to be present synchronously. A comparison of mutation and methylation demonstrated that the EGFR mutation had an inverse correlation with methylation of SPARC (secreted protein acidic and rich in cysteine), an extracellular Ca2+-binding matricellular glycoprotein associated with the regulation of cell adhesion and growth, and the p16INK4A gene.
The findings of the current study suggest that adenocarcinoma cases with CIMP have a poorer prognosis than adenocarcinoma cases without CIMP, and the EGFR mutation was shown to have an inverse correlation with methylation of SPARC and the p16INK4A gene in NSCLC. Cancer 2006. © 2006 American Cancer Society.