Mutational analysis of the β-tubulin gene in lung cancer

Recently, several studies have suggested that a major mechanism of resistance to paclitaxel might involve mutations in the beta-tubulin gene in tumor cells. To investigate the frequency of beta-tubulin mutations in Japanese patients with small and non-small cell lung cancer, direct sequence analysis following reverse transcription-polymerase chain reaction (RT-PCR) of the beta-tubulin gene was performed using total RNA from 20 lung cancer cell lines and 22 specimens from lung cancer patients. First-strand cDNA sequence analysis of the 42 samples showed silent mutations at codon 180 of the beta-tubulin gene, which encodes the GTP-binding site of the protein, and codons 195 and 217. However, neither missense nor non-sense mutations affecting microtubule dynamics, within or near the GTP-binding site of the beta-tubulin gene, were detected. These results indicate that beta-tubulin gene mutations might not play a major role in the mechanism of resistance to paclitaxel in Japanese lung cancer patients. Further investigations are needed to clarify the mechanism of drug resistance. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.