Downregulation of HLA Class I Molecules in Primary Oral Squamous Cell Carcinomas and Cell Lines
Received 6 December 2008; accepted 30 March 2009. published online 22 May 2009.
Background and Aims
Loss or downregulation of human leukocyte antigen (HLA) class I expression has been reported in a variety of human tumors including oral squamous cell carcinoma (OSCC).
Methods
Expression of HLA class I molecules were evaluated by immunohistochemistry, flow cytometry, semi-quantitative Western blot and RT-PCR in 43 tissue samples of primary oral squamous cell carcinomas (pOSCC) from Chinese patients and two OSCC cell lines.
Results
HLA class I heavy chain of B/C locus and A locus and β2-microglobulin were obviously lost or downregulated in pOSCC with the percentage of 31, 55 and 35% respectively. The expression of HLA B/C, LMP2, LMP7, LMP10 and PA28β in OSCC cell lines was also presumably reduced in comparison with normal epithelial cell line.
Conclusions
These data suggested that the downregulation of HLA class I molecules in OSCC was closely associated with the low–efficient transcription and abnormality of post-transcription regulation of HLA class I genes and antigen presentation-related genes. These results can add more light to the mechanism by which OSCC escape from immunological surveillance.
aThe Key Laboratory of Developmental Genes and Human Disease of Education Ministry, Department of Genetics and Developmental Biology, Southeast University Medical School, Nanjing, Jiangsu Province, China
bDepartment of Pathology, Oral Hospital of Jiangsu Province, Nanjing, Jiangsu Province, China
Address reprint requests to: Wei Xie, Ph.D., The Key Laboratory of Developmental Genes and Human Disease of Education Ministry, Department of Genetics and Developmental Biology, Southeast University Medical School, 87 Dingjiaqiao Rd, Nanjing, Jiangsu Province, China 210009.
ABSTRACT