Ou J, Rasmussen M, Westers H, Andersen SD, Jager PO, Kooi KA, Niessen RC, Eggen BJL, Nielsen FC, Kleibeuker JH, Sijmons RH, Rasmussen LJ, Hofstra RMW. Biochemical characterization of MLH3 missense mutations does not reveal an apparent role of MLH3 in Lynch syndrome.
Genes Chromosomes Cancer 2009;
48:340-50. [PMID:
19156873 DOI:
10.1002/gcc.20644]
[Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
So far 18 MLH3 germline mutations/variants have been identified in familial colorectal cancer cases. Sixteen of these variants are amino acid substitutions of which the pathogenic nature is still unclear. These substitutions are known as unclassified variants or UVs. To clarify a possible role for eight of these MLH3 UVs identified in suspected Lynch syndrome patients, we performed several biochemical tests. We determined the protein expression and stability, protein localization and interaction of the mutant MLH3 proteins with wildtype MLH1. All eight MLH3 UVs gave protein expression levels comparable with wildtype MLH3. Furthermore, the UV-containing proteins, in contrast to previous studies, were all localized normally in the nucleus and they interacted normally with wildtype MLH1. Our different biochemical assays yielded no evidence that the eight MLH3 UVs tested are the cause of hereditary colorectal cancer, including Lynch syndrome.
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