MEK1 and AKT2 Mutations in Japanese Lung Cancer

Background: Recently, to identify potential somatic mutations in genes of epidermal growth factor receptor (EGFR) signaling pathway, MEK1 gene mutation at exon 2 and mutation of the AKT2 (v-akt murine thymoma viral oncogene homologue 2) gene at kinase domain have been reported in non-small cell lung cancer. Methods: We investigated the MEK1 mutation (n = 280) and AKT2 mutation (n = 273) in surgically treated non-small cell lung cancer cases. The presence or absence of MEK1 mutation (exon 2) and AKT2 mutation at kinase domain was analyzed by direct sequences. Results: MEK1 mutation (K57K) was found from 1 of 280 patients with lung cancer (0.4%) and detected only one case (0.4%) of AKT2 mutation (R371H) in our cohort. MEK1 mutation was exclusive with EGFR, K-ras, and B-raf mutations at kinase domain. However, AKT2 mutation was coexisted with EGFR and PIK3CA mutations. Conclusion: This study demonstrated that mutation in the kinase domain of AKT2 and MEK1 exon 2 mutation occurred in a small fraction of Japanese lung cancers.