Premium
Epigenetic abnormalities in cutaneous squamous cell carcinomas: frequent inactivation of the RB1/p16 and p53 pathways
Author(s) -
Murao K.,
Kubo Y.,
Ohtani N.,
Hara E.,
Arase S.
Publication year - 2006
Publication title -
british journal of dermatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.304
H-Index - 179
eISSN - 1365-2133
pISSN - 0007-0963
DOI - 10.1111/j.1365-2133.2006.07487.x
Subject(s) - cdh1 , pten , epigenetics , cancer research , biology , cdkn2a , carcinogenesis , dna methylation , methylation , cancer , gene , genetics , cell , gene expression , pi3k/akt/mtor pathway , cadherin , signal transduction
Summary Background Aberrant methylation of CpG islands in the promoter regions of cancer‐related genes has been demonstrated in many human tumours. However, the methylation profile of these regions in cutaneous squamous cell carcinomas (SCCs) has not been well studied. Objectives To examine epigenetic abnormalities of a wide range of cancer‐related genes in SCCs. Methods We investigated the methylation status of 11 candidate cancer‐related genes ( CDH1 , p 16 INK 4 a , p 14 ARF , DAPK1 , MGMT , RB1 , RASSF1 , p 15 INK 4 b , PTEN , PRDM2 and p 53) in 20 cases of SCC by methylation‐specific polymerase chain reaction, and comparatively examined the protein production of E‐cadherin (CDH1), p16, RB1, p14, BMI1 and cyclin A by immunohistochemical analysis. Results The frequency of cancer‐related gene methylation in SCCs was: CDH1 (95%), p 16 (20%), p 14 (15%), DAPK1 (15%), MGMT (15%), RB1 (5%), RASSF1 (5%), p 15 (0%), PTEN (0%), PRDM2 (0%) and p 53 (0%). Almost all cases with hypermethylation of CDH1 , p 16, RB1 and p 14 showed no obvious production of each protein, suggesting that promoter hypermethylation of these genes contributes to the loss of protein production. The results of methylation analysis, in combination with the results of our previous mutation analysis of CDKN2A locus and p 53, revealed that 70% of SCCs have alterations in the RB1/p16 or p53 pathway. Conclusions Our findings indicate that the promoter hypermethylation of cancer‐related genes, especially CDH1 , is frequently shown in SCCs, and dysregulation of the RB1/p16 and/or p53 pathway through either genetic or epigenetic mechanisms, except for epigenetic abnormalities of p 53 itself, should contribute to the carcinogenesis of SCCs.