TY - JOUR
T1 - Mismatch repair deficiency in hematological malignancies with microsatellite instability
AU - Gu, Liya
AU - Cline-Brown, Brandee
AU - Zhang, Fujian
AU - Qiu, Lu
AU - Li, Guo Min
N1 - Funding Information:
We thank Steve Presnell and Cecilia Ramilo for helpful comments on the manuscript. This work was supported in part by grants CA85377 (from the National Cancer
PY - 2002
Y1 - 2002
N2 - Mutations in human mismatch repair (MMR) genes are the genetic basis for certain types of solid tumors displaying microsatellite instability (MSI). MSI has also been observed in hematological malignancies, but whether these hematological malignancies are associated with MMR deficiency is still unclear. Using both biochemical and genetic approaches, this study analysed MMR proficiency in 11 cell lines derived from patients with hematological malignancies and demonstrated that six out of seven hematological cancer cell lines with MSI were defective in strand-specific MMR. In vitro complementation experiments, using characterized MMR mutant extracts or purified proteins, showed that these hematological cancer cells were defective in either hMutSα (a heterodimer of hMSH2 and hMSH6) or hMutLα (a heterodimer of hMLH1 and hPMS2). Furthermore, cell lines deficient in hMutSα showed large deletions or point mutations in hMSH2, while those deficient in hMutLα exhibited point mutations in hMLH1 or a lack of expression of hPMS2. From these results, we conclude that, as in solid tumors, hematological malignancies with MSI are also associated with MMR deficiency, and that the cause of MMR deficiency in these cell lines is due to a defective MutSα or MutLα. We also report here, for the first time, that an MSI-positive cell line derived from Burkitt's lymphoma is proficient in MMR.
AB - Mutations in human mismatch repair (MMR) genes are the genetic basis for certain types of solid tumors displaying microsatellite instability (MSI). MSI has also been observed in hematological malignancies, but whether these hematological malignancies are associated with MMR deficiency is still unclear. Using both biochemical and genetic approaches, this study analysed MMR proficiency in 11 cell lines derived from patients with hematological malignancies and demonstrated that six out of seven hematological cancer cell lines with MSI were defective in strand-specific MMR. In vitro complementation experiments, using characterized MMR mutant extracts or purified proteins, showed that these hematological cancer cells were defective in either hMutSα (a heterodimer of hMSH2 and hMSH6) or hMutLα (a heterodimer of hMLH1 and hPMS2). Furthermore, cell lines deficient in hMutSα showed large deletions or point mutations in hMSH2, while those deficient in hMutLα exhibited point mutations in hMLH1 or a lack of expression of hPMS2. From these results, we conclude that, as in solid tumors, hematological malignancies with MSI are also associated with MMR deficiency, and that the cause of MMR deficiency in these cell lines is due to a defective MutSα or MutLα. We also report here, for the first time, that an MSI-positive cell line derived from Burkitt's lymphoma is proficient in MMR.
KW - Hematological malignancy
KW - Microsatellite instability
KW - hMLH1
KW - hMSH2
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U2 - 10.1038/sj.onc.1205695
DO - 10.1038/sj.onc.1205695
M3 - Article
C2 - 12173046
AN - SCOPUS:0037158899
SN - 0950-9232
VL - 21
SP - 5758
EP - 5764
JO - Oncogene
JF - Oncogene
IS - 37
ER -