Inverse correlation between expression of HLA-B and c-myc in uveal melanoma.
HLA class I is expressed in 75-85 per cent of uveal melanoma and cytoplasmic c-myc expression has been reported in 78 per cent of uveal melanoma. In skin melanoma, an inverse relationship has been observed between HLA class I expression and c-myc. The purpose of this study was to determine whether a similar correlation occurred between high expression of c-myc and low expression of HLA class I in uveal melanoma. The expression of c-myc, HLA-A, and HLA-B was determined by immunohistochemistry on formalin-fixed and paraffin-embedded sections of 30 uveal melanomas. Cell cultures from four primary uveal melanomas (lines 92-1, MEL 202, OCM-1, and EOM-3) and one uveal melanoma metastasis (line OMM-1) were tested for mRNA levels of c-myc and HLA-A and HLA-B in Northern blot assays. The high level of expression of cytoplasmic c-myc was significantly correlated with low expression of HLA-B (P = 0.03) and vice versa. High expression of HLA-B was significantly correlated with the presence of epithelioid cells (P = 0.004). The inverse correlation observed between c-myc and HLA-B expression is similar to previous observations in cutaneous melanoma. By downregulating HLA-B expression, c-myc may influence the immune response in uveal melanoma. Tumours containing epithelioid cells showed a significantly higher expression of HLA-B than tumours of the spindle cell type.
Blom
D J
DJ
Department of Ophthalmology, Leiden University Hospital, The Netherlands.
Mooy
C M
CM
Luyten
G P
GP
Kerkvliet
S
S
Ouwerkerk
I
I
Zwinderman
A H
AH
Schrier
P I
PI
Jager
M J
MJ
D000293:Adolescent; D000328:Adult; D000368:Aged; D015152:Blotting, Northern; D015536:Down-Regulation; D005260:Female; D015234:HLA-A Antigens / Q000378:metabolism; D015235:HLA-B Antigens / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008545:Melanoma / Q000378:metabolism*; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism*; D012189:Retrospective Studies; D014407:Tumor Cells, Cultured; D014604:Uveal Neoplasms / Q000378:metabolism*
D015234:HLA-A Antigens; D015235:HLA-B Antigens; D009363:Neoplasm Proteins; D016271:Proto-Oncogene Proteins c-myc