Differential alternative splicing expressions of thymidylate synthase isoforms.

We identified two novel deletion variants of the thymidylate synthase transcript in gastric cell lines. Sequence analyses indicate that none of these variants results in introduction of a premature stop-codon or a frame shifts. In 39 gastric cancer samples, both the full-length and one-deletion variant messages were detected in cancerous as well as non-cancerous tissues. However, another isoform was found in only seven of 39 cancerous tissues. Our results provide important information to assist more detailed studies on the regulation of thymidylate synthase activity.