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Implications of mismatch repair genes h MLH1 and h MSH2 in patients with sporadic renal cell carcinoma
Author(s) -
RubioDelCampo Antonio,
SalinasSánchez Antonio S.,
SánchezSánchez Francisco,
GiménezBachs José M.,
DonateMoreno María J.,
PastorNavarro Héctor,
CarriónLópez Pedro,
Escribano Julio
Publication year - 2008
Publication title -
bju international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.773
H-Index - 148
eISSN - 1464-410X
pISSN - 1464-4096
DOI - 10.1111/j.1464-410x.2008.07581.x
Subject(s) - microsatellite instability , mlh1 , msh2 , biology , dna mismatch repair , loss of heterozygosity , microsatellite , cancer research , microbiology and biotechnology , genetics , germline mutation , gene , mutation , dna repair , allele
OBJECTIVES To analyse the implications of DNA mismatch repair genes h MLH1 and h MSH2 in sporadic renal cell carcinoma (RCC). MATERIALS AND METHODS Specimens of tumour and healthy renal tissue were collected from 89 patients treated for sporadic RCC. Another 95 blood samples taken from individuals with no history of cancer were also analysed. After DNA extraction and PCR amplification, microsatellite instability (MSI) was determined using the Bethesda microsatellite panel, two exonic microsatellites of the TGFbRII and BAX genes, and the microsatellite D3S1611. The promoter methylation status of h MLH1 was investigated using the Hpa II and Msp I restriction enzymes. In addition, a sequencing analysis of complete coding region of h MLH1 and h MSH2 genes was performed .RESULTS MSI and promoter hypermethylation of h MLH1 were not detected. Interestingly, loss of heterozygosity (LOH) was common among patients with RCC, particularly in microsatellite D3S1611 (34.9%). Mutations were identified in eight patients: K618A and V716M in gene h MLH1 ; and I145V, G322D, and the novel mutation P349A, in gene h MSH2 . The mutations also appeared in healthy renal tissue and therefore, were considered as germline DNA sequence variations. There were G322D and K618A changes in >1% of the healthy control subjects, suggesting that they are DNA polymorphisms. CONCLUSIONS Our data show that loss of function of both h MLH1 and h MSH2 is not involved in sporadic RCC, either by promoter methylation or mutation in their exons. However, LOH indicated that chromosomal instability affecting large fragments of DNA was the main genetic alteration we detected associated with RCC.