The increase in the frequency of MICA gene A6 allele in oral squamous cell carcinoma.
BACKGROUND
Oral squamous cell carcinoma (OSCC) was reported to be associated with immune function. The MICA (MHC class I chain-related gene A) is expressed by keratinocytes and other epithelial cells, and its encoded protein interacts with gamma/delta T cells localized in submucosa. The MICA also influences the heat shock protein function. We speculated that the alterations of MICA might influence the pathogenesis of OSCC through the aberration in presenting tumor antigens or heat shock protein. MICA gene has a triplet repeat (GCT) polymorphism in the transmembrane domain, resulting in five distinctive allelic patterns.


METHODS
We analysed this MICA polymorphism in 67 OSCC patients and 351 randomly selected unrelated controls. By using the ABI Prism 377-18 DNA sequencer (Applied Biosystems, Foster City, CA, USA) to analyse the sample DNA PCR products. The number of micro-satellite repeats was estimated with Genescan 672 software (Applied Biosystems) with a standard size marker of GS-350 TAMRA (N,N,N,N-tetramethyl-6-carbohydroxyl rhodamine; Applied Biosystems).


RESULTS
The phenotype frequency of allele A6 of MICA in subjects with OSCC was significantly higher than that in controls (RR = 3.46, 95% CI = 1.73-6.94, P = 0.0002), as was the frequency of allele (RR = 2.64, 95% CI = 1.39-5.02, P = 0.002).


CONCLUSIONS
The results suggest that allele A6 in MICA might confer the risk of OSCC.
Department of Dentistry, Taipei Medical University, Taipei, Taiwan.
Liu
L
Chung-Ji
Lee
L
Yann-Jinn
Liu
L
Hsin-Fu
Dang
D
Ching-Wen
Chang
C
Che-Shoa
Leu
L
Yi-Shing
Chang
C
Kuo-Wei
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000276:immunology; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005787:Gene Frequency; D005805:Genes, MHC Class I; D015235:HLA-B Antigens / Q000235:genetics; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000235:genetics* / Q000276:immunology; D009857:Oncogenes; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018709:Statistics, Nonparametric
D015235:HLA-B Antigens; D015395:Histocompatibility Antigens Class I; C099187:MHC class I-related chain A