Multiple truncated transcripts of TSG101 in gastrointestinal cancers.

The candidate tumour suppressor gene TSG101, located on chromosome 11p15, has been associated with frequent intragenic deletion in uncultured primary human breast cancers. Using paired tumour and normal tissues from surgical specimens, we performed nested reverse transcriptase-polymerase chain reaction and direct sequencing to analyse TSG101 exons 1-6 from 32 gastric, 30 colorectal and 16 oesophageal cancers. Truncated transcripts, were found in both tumour and normal tissues from the stomach (15.6 and 12.5%), colon (13.3 and 3.3%) and oesophagus (25 and 25%). Multiple truncated transcripts in individual specimens were also observed. Two types of splicing patterns, one with three to six bases homology at the deletion junction (25.9%), the other with donor site 5' GT and acceptor site 3' AG (55.6%), were the most common patterns. We conclude that in gastrointestinal cancers, truncated transcripts of TSG101 gene occur not uncommonly and do so with a specific splicing pattern.