BACKGROUND: Microsatellite instability (MSI) is a phenotypic characteristic of tumors with biallelic inactivation of mismatch repair genes, such as MSH2 or MLH1, and contributes to malignant transformation. AIMS: The aim of this study was to examine the prevalence of MSI in cutaneous squamous cell carcinoma (SCC) using a PCR and fluorescent-based detection system. These methods of analysis offer several advantages over the use of silver staining and autoradiographic techniques. We also aimed to determine if MSI status correlated with expression of the MSH2 and MLH1 mismatch repair proteins in these cutaneous SCC samples. METHODS: The MSI status of 22 histologically confirmed invasive cutaneous SCC samples were analyzed at five microsatellite markers (the National Cancer Institute's Bethesda panel of two mononucleotide and three dinucleotide markers) using a PCR and fluorescent-based detection system. Immunohistochemical analysis of MSH2 and MLH1 protein expression was also carried out on the SCC samples. RESULTS: Only one case of cutaneous SCC displayed MSI. This was found at just one of five markers, and thus was low frequency MSI. All 22 cutaneous SCC cases strongly expressed MSH2 protein. Eighteen (82%) of the cutaneous SCC cases showed moderate to strong expression of MLH1 protein. The remaining four cases of cutaneous SCC were negative for MLH1 protein. Therefore, the majority of the SCC patients analyzed showed a correlation between absence of MSI and expression of MSH2 and MLH1 proteins. CONCLUSIONS: MSI is uncommon in cutaneous SCC. In addition, MSH2 was strongly expressed in all SCC samples analyzed and appeared to be upregulated when compared with the corresponding normal tissue. MLH1 protein was not detected in 4 of 22 SCC cases, although it was expressed in the corresponding normal tissue, suggesting that inactivation of MLH1 may be a late event in a subset of invasive SCC cases.
BACKGROUND: Microsatellite instability (MSI) is a phenotypic characteristic of tumors with biallelic inactivation of mismatch repair genes, such as MSH2 or MLH1, and contributes to malignant transformation. AIMS: The aim of this study was to examine the prevalence of MSI in cutaneous squamous cell carcinoma (SCC) using a PCR and fluorescent-based detection system. These methods of analysis offer several advantages over the use of silver staining and autoradiographic techniques. We also aimed to determine if MSI status correlated with expression of the MSH2 and MLH1 mismatch repair proteins in these cutaneous SCC samples. METHODS: The MSI status of 22 histologically confirmed invasive cutaneous SCC samples were analyzed at five microsatellite markers (the National Cancer Institute's Bethesda panel of two mononucleotide and three dinucleotide markers) using a PCR and fluorescent-based detection system. Immunohistochemical analysis of MSH2 and MLH1 protein expression was also carried out on the SCC samples. RESULTS: Only one case of cutaneous SCC displayed MSI. This was found at just one of five markers, and thus was low frequency MSI. All 22 cutaneous SCC cases strongly expressed MSH2 protein. Eighteen (82%) of the cutaneous SCC cases showed moderate to strong expression of MLH1 protein. The remaining four cases of cutaneous SCC were negative for MLH1 protein. Therefore, the majority of the SCCpatients analyzed showed a correlation between absence of MSI and expression of MSH2 and MLH1 proteins. CONCLUSIONS: MSI is uncommon in cutaneous SCC. In addition, MSH2 was strongly expressed in all SCC samples analyzed and appeared to be upregulated when compared with the corresponding normal tissue. MLH1 protein was not detected in 4 of 22 SCC cases, although it was expressed in the corresponding normal tissue, suggesting that inactivation of MLH1 may be a late event in a subset of invasive SCC cases.
Authors: Y Wang; J Irish; C MacMillan; D Brown; Y Xuan; C Boyington; P Gullane; S Kamel-Reid Journal: Int J Cancer Date: 2001-08-01 Impact factor: 7.396
Authors: C Chapusot; L Martin; P Laurent Puig; T Ponnelle; N Cheynel; A M Bouvier; D Rageot; P Roignot; P Rat; J Faivre; F Piard Journal: Am J Surg Pathol Date: 2004-12 Impact factor: 6.394
Authors: C R Boland; S N Thibodeau; S R Hamilton; D Sidransky; J R Eshleman; R W Burt; S J Meltzer; M A Rodriguez-Bigas; R Fodde; G N Ranzani; S Srivastava Journal: Cancer Res Date: 1998-11-15 Impact factor: 12.701
Authors: L A Aaltonen; P Peltomäki; J P Mecklin; H Järvinen; J R Jass; J S Green; H T Lynch; P Watson; G Tallqvist; M Juhola Journal: Cancer Res Date: 1994-04-01 Impact factor: 12.701
Authors: K Ericson; B Halvarsson; J Nagel; E Rambech; M Planck; Z Piotrowska; H Olsson; M Nilbert Journal: Eur J Cancer Date: 2003-01 Impact factor: 9.162
Authors: Roman Miturski; Michał Bogusiewicz; Carmella Ciotta; Margherita Bignami; Marek Gogacz; Dominique Burnouf Journal: Exp Biol Med (Maywood) Date: 2002-09