Methylation of multiple genes as diagnostic and therapeutic markers in primary head and neck squamous cell carcinoma.
OBJECTIVE
To examine epigenetic events of aberrant promoter methylation as diagnostic markers in primary head and neck squamous cell carcinoma using a novel multigene approach. Promoter methylation-mediated silencing is a hallmark of several established tumor suppressor genes. Changes in DNA methylation have been reported to occur early in carcinogenesis and therefore are potentially important early indicators of existing disease.


METHODS
A multicandidate gene probe panel interrogated DNA for aberrant methylation status in 22 cancer genes using the methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay. Aberrant promoter hypermethylation was confirmed using methylation-specific polymerase chain reaction after bisulfite treatment.


METHODS
Primary care medical center.


METHODS
We examined fresh-frozen primary head and neck tumor specimens from 28 patients, including 21 late-stage (19 stage IV and 2 stage III) and 7 early-stage (6 stage II and 1 stage I) tumors.


RESULTS
Promoter hypermethylation was observed in 14 of the 28 patients (50%). Genes for RARB, APC, and CHFR were most frequently hypermethylated, occurring in 11 (39%) for RARB, 7 (25%) for CHFR, and 6 (21%) for APC. Aberrant methylation of CHFR was solely a stage IV event. Methylation-specific polymerase chain reaction after bisulfite treatment with conventional and real-time polymerase chain reaction confirmed aberrant methylation for RARB and CHFR.


CONCLUSIONS
Promoter methylation profiling of primary head and neck squamous cell carcinoma using multiple target genes identified RARB, APC, and CHFR as frequent epigenetic events. The clinical implications of these genes as diagnostic and treatment biomarkers are highly relevant as attractive targets for cancer therapy, given the reversible nature of epigenetic gene silencing.
Chen
Kangmei
K
Department of Otolaryngology-Head and Neck Surgery, Henry Ford Health System, 1 Ford Pl., Detroit, MI 48202, USA.
Sawhney
Raja
R
Khan
Mumtaz
M
Benninger
Michael S
MS
Hou
Zizheng
Z
Sethi
Seema
S
Stephen
Josena K
JK
Worsham
Maria J
MJ
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000502:physiology*; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D019175:DNA Methylation; D044127:Epigenesis, Genetic / Q000502:physiology; D005260:Female; D052138:Genes, Neoplasm / Q000502:physiology*; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011401:Promoter Regions, Genetic / Q000502:physiology*
D014408:Biomarkers, Tumor