Expression of beta 2-microglobulin by premalignant epithelium.
Many human tumors express low amounts of HLA class I molecules relative to the normal cells from which they are derived. From experimental work it is clear that the malignant behavior of a tumor cell may depend on its MHC class I expression. Therefore, it is of obvious interest to study the HLA class I expression of human tumors in their various stages. We have studied the HLA class I expression by the cells in premalignant epithelial lesions and invasive carcinoma of the bladder and uterine cervix using immunoperoxidase staining for beta 2-microglobulin of paraffin-embedded tissue. We here assume that beta 2-microglobulin expression by malignant and premalignant cells equals HLA class I expression. Thirty-two of the 36 invasive tumors expressed less overall beta 2-microglobulin than cells from the normal epithelium. In contrast, approximately two-thirds of 34 premalignant bladder epithelia and 47 premalignant cervix epithelia displayed higher overall beta 2-microglobulin expression than the normal epithelium. Thus, a systematic large-scale elimination of HLA class I high-expressing tumor cell variants may take place only after the tumor penetrates the basement membrane.
Petersen
B L
BL
Department of Pathology, KAS Glostrup, Denmark.
Petersen
C L
CL
Braendstrup
O
O
Mouritsen
S
S
Engel
A M
AM
Svane
I M
IM
Werdelin
O
O
D002278:Carcinoma in Situ / Q000378:metabolism / Q000473:pathology*; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000032:analysis / Q000096:biosynthesis; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D009361:Neoplasm Invasiveness; D011230:Precancerous Conditions / Q000378:metabolism / Q000473:pathology*; D001749:Urinary Bladder Neoplasms / Q000378:metabolism / Q000473:pathology*; D002578:Uterine Cervical Dysplasia / Q000378:metabolism / Q000473:pathology; D002583:Uterine Cervical Neoplasms / Q000378:metabolism / Q000473:pathology*; D001613:beta 2-Microglobulin / Q000032:analysis / Q000096:biosynthesis
D015395:Histocompatibility Antigens Class I; D001613:beta 2-Microglobulin