Relation between DNA ploidy status and the expression of the DNA-mismatch repair genes MLH1 and MSH2 in cytological specimens of melanoma lymph node and liver metastases

ISSN
8755-1039
Date Issued
2001
Author(s)
Korabiowska, M.
Ruschenburg, I.
Schlott, T.
Kubitz, A.
Brinck, Ulrich
DOI
10.1002/1097-0339(200103)24:3<157::AID-DC1033>3.0.CO;2-A
Abstract
DNA-mismatch repair is essential for preventing genetic instability, and its important protective role has been demonstrated in several tumors. The main aim of this study was to investigate the expression of MLH1 and MSH2 (on the RNA level) in melanoma liver and lymph node metastases, and to define the relation between DNA ploidy status and mismatch repair gene expression. MLH1 was found in 29/33 melanoma lymph node and in 5/17 melanoma liver metastases. MSH2 was present in 26/33 lymph node and 5/17 liver metastases. A comparison of MLH1 and MSH2 positive and negative melanoma metastases showed that there were highly significant differences in the percentages of diploid cells, aneuploid cells between 4c and 8c, octaploid cells, and 5c exceeding rate. This fact confirms the strong relation between the loss of DNA-mismatch repair gene expression and advanced DNA aneuploidy status in melanoma metastases. (C) 2001 Wiley-Liss, Inc.