Association between dense CADM1 promoter methylation and reduced protein expression in high-grade CIN and cervical SCC.
We previously showed that silencing of TSLC1, recently renamed CADM1, is functionally involved in high-risk HPV-mediated cervical carcinogenesis. CADM1 silencing often results from promoter methylation. Here, we determined the extent of CADM1 promoter methylation in cervical (pre)malignant lesions and its relation to anchorage-independent growth and gene silencing to select a CADM1-based methylation marker for identification of women at risk of cervical cancer. Methylation-specific PCRs targeting three regions within the CADM1 promoter were performed on high-risk HPV-containing cell lines, PBMCs, normal cervical smears, and (pre)malignant lesions. CADM1 protein expression in cervical tissues was analysed by immunohistochemistry. All statistical tests were two-sided. Density of methylation was associated with the degree of anchorage-independent growth and CADM1 gene silencing in vitro. In cervical squamous lesions, methylation frequency and density increased with severity of disease. Dense methylation (defined as >or= 2 methylated regions) increased from 5% in normal cervical samples to 30% in CIN3 lesions and 83% in squamous cell carcinomas (SCCs) and was significantly associated with decreased CADM1 protein expression (p < 0.00005). The frequency of dense methylation was significantly higher in >or= CIN3 compared with <or= CIN1 (p = 0.005), as well as in SCCs compared with adenocarcinomas (83% versus 23%; p = 0.002). Detection of dense CADM1 promoter methylation will contribute to the assembly of a valuable marker panel for the triage of high-risk HPV-positive women at risk of >or= CIN3.
Overmeer
R M
RM
Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands.
Henken
F E
FE
Snijders
P J F
PJ
Claassen-Kramer
D
D
Berkhof
J
J
Helmerhorst
T J M
TJ
Heideman
D A M
DA
Wilting
S M
SM
Murakami
Y
Y
Ito
A
A
Meijer
C J L M
CJ
Steenbergen
R D M
RD
D014408:Biomarkers, Tumor / Q000032:analysis*; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000378:metabolism; D016022:Case-Control Studies; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules; D002461:Cell Line, Transformed; D019175:DNA Methylation; D005260:Female; D020868:Gene Silencing; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis / Q000235:genetics*; D007150:Immunohistochemistry; D016015:Logistic Models; D008565:Membrane Proteins / Q000032:analysis / Q000235:genetics*; D011401:Promoter Regions, Genetic; D020133:Reverse Transcriptase Polymerase Chain Reaction; D025521:Tumor Suppressor Proteins / Q000032:analysis / Q000235:genetics*; D002583:Uterine Cervical Neoplasms / Q000235:genetics* / Q000378:metabolism; D002578:Uterine Cervical Dysplasia / Q000235:genetics* / Q000378:metabolism
D014408:Biomarkers, Tumor; C403514:CADM1 protein, human; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; D008565:Membrane Proteins; D025521:Tumor Suppressor Proteins