Microsatellite instability (MSI) due to alterations in DNA repair genes leads to carcinogenesis, but it also correlates with better prognosis and therapy response. Little is known of the contribution of altered noncoding sequences to MSI tumorigenesis. This report identifies a deletion in an MSI intronic region leading to the expression of a truncated chaperone, which shows dominant-negative effects on its wild-type counterpart. Acting as an endogenous inhibitor of a protumorigenic chaperone, the expression of the truncated variant associates with better prognosis in humans and may contribute to the overall limited malignancy of MSI tumors.
- Coralie Dorard
- Aurélie de Thonel
- Alex Duval
