NO EVIDENCE OF MICROSATELLITE INSTABILITY IN BONE-TUMORS

Microsatellite instability has recently been reported in sporadic and familial colorectal tumours and can be due to defects in DNA mismatch repair genes. Such instability has subsequently been detected in sever al other types of sporadic tumours. We studied 29 specimens of bone tu mours with different histopathological diagnoses and found no evidence of microsatellite instability. Our results suggest that mismatch repa ir defects are unlikely to play a significant part in the tumorigenesi s of bone neoplasms. Loss of heterozygosity with at least one marker w as detected in 11, i.e. in 38% of the tumour samples, most frequently with markers D2S136 at 2p (eight of 28 informative specimens, 29%) and D11S904 at 11p (four of 21 informative specimens, 19%).