A novel BMX variant promotes tumor cell growth and migration in lung adenocarcinoma

The non-receptor tyrosine kinase BMX has been reported in several solid tumors. However, the alternative splicing of BMX and its clinical relevance in lung cancer remain to be elucidated. Exon1.0 array was used to identify a novel alternative splicing of BMX, BMX Delta N, which was confirmed by rapid amplification of cDNA ends and reverse transcription-polymerase chain reaction. BMX Delta N, resulting from exon skipping with excluding exon 1 to exon 8 of BMX gene, was found in 12% human lung adenocarcinoma specimens. BMX Delta N is not found in paired pathologically normal lungs and positively correlated with EGFR mutation in lung adenocarcinomas. Moreover, BMX Delta N increases cell proliferation, neoplastic transformation, and migratory property of human non-small cell lung cancer cells. The function of BMX Delta N in lung cancer might be presumably due to enhanced ERK signaling.