Correlation between tumour and serum beta 2m expression in patients with breast cancer.
HLA class I antigens are composed of a major histocompatibility complex (MHC) encoded heavy chain that is associated non-covalently with a light chain beta-2 microglobulin (beta-2m). When the HLA complex is metabolized, beta-2m is shed into the serum. A large variety of human and experimental tumours have altered MHC class I expression. In a previous study we observed elevated mean beta-2m serum levels in breast cancer patients, as compared to controls. To study the relationship between tumour expression and serum levels, we examined 54 patients with breast cancer. Tumour beta-2m was determined by immunohistochemistry and serum levels by the ELISA technique. Of the 54 patients, 38 had low and 16 had high beta-2m expression on the tumour. There was a significant correlation between tumour beta-2m and serum beta-2m levels (P = 0.02), with patients whose tumours expressed high beta-2m having high serum beta-2m levels. There was an inverse correlation between tumour grade and tumour beta-2m expression which approached statistical significance (P = 0.06). These findings suggest that in a substantial number of patients the high serum levels derive from shedding of beta-2m from tumour cells. These levels may have implications for tumour growth and metastases due to influences on immunological responses.
Klein
T
T
Tissue Typing Laboratory, Beilinson Medical Center, Beer Sheva, Israel.
Levin
I
I
Niska
A
A
Koren
R
R
Gal
R
R
Schachter
J
J
Kfir
B
B
Narinski
R
R
Warchaizer
S
S
Klein
B
B
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000097:blood / Q000276:immunology* / Q000473:pathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D001613:beta 2-Microglobulin / Q000032:analysis*
D001613:beta 2-Microglobulin