Background: Effective chemotherapy for advanced gastric cancer is yet to be established. Taxanes, novel anticancer drugs which bind to beta-tubulin and prevent disruption of microtubules, are newly approved and promising agents for advanced and recurrent gastric cancer. To predict the chemoresistance to a taxan in gastric cancer, we examined the genetic mutations of the beta-tubulin gene.
Methods: Fifty pairs of gastric tumor and normal mucosa tissues were obtained from operations and the genomic DNA was extracted from each specimen. The four exons of the beta-tubulin gene were amplified for DNA mutations by single-strand conformation polymorphism (SSCP) methods and sequencing analysis.
Results: Nine (18%) of 50 patients with gastric cancer had two kinds of silent variations of the beta-tubulin gene in exon 4. Three kinds of intronic variations were detected in exons 1, 2, and 3. However, no genetic alterations that would change the beta-tubulin protein structure were detected in any of the 50 gastric tumors.
Conclusion: Our findings indicate that mutations of the beta-tubulin gene, which might be a contraindication for chemotherapy based on taxans, were very rare events in gastric cancer.