Evaluation of BAT-26 as an indicator of microsatellite instability in gallbladder carcinomas.

BACKGROUND/AIMS: The genetic pathways of gallbladder cancer are not yet well defined, since the contribution of genetic abnormalities, clarified in other organs, remains questionable. Our aim was to evaluate the role of microsatellite instability in this organs carcinogenesis.

METHODOLOGY: We investigated a group of 20 gallbladder carcinomas from Greek patients with regard to alterations in length of the BAT-26 mononucleotide marker--as an indicator of microsatellite instability. The findings were correlated with the presence of p53 and ras mutations, alterations of the bax and TGF-beta RII genes and tumors' clinicopathological features. Polymerase chain reaction and electrophoretic analysis in a non-denaturating 25% polyacrylamide gel was performed for the detection of BAT-26 size variations.

RESULTS

None of our specimens showed microsatellite instability at the BAT-26 marker.

CONCLUSIONS

BAT-26, an indicator of high-level microsatellite instability, may not be sufficient, when used alone, for determining the microsatellite instability status of gallbladder carcinomas, since these may be characterized by low-level instability. Bax and TGF-beta RII genes may not also be targets of instability in this type of tumors.