High MHC class I expression correlates with slow growth in UV-induced skin carcinomas in hairless mice.
An experiment was set up to investigate the relationship, if any, between cell surface MHC class I expression and the growth rate for skin tumors induced by two different UV radiation regimens in hairless mice. Two groups of 20 hairless mice were each irradiated with either a UVA radiation source (2 SED per session) or broad-spectrum UV radiation (UVB) (8.1 SED per session) 5 days a week during the entire experiment. In the UVA group, 17 out of 20 animals developed tumors, and 10 of these grew to a diameter of > or = 5 mm. In the UVB group, 19 out of 20 animals developed tumors, and 15 of these grew to a diameter of > or = 5 mm. The tumor induction time, i.e. the time from the start of UV treatment to tumor appearance, was found to be significantly longer (p<0.01) in the UVA than in the UVB group. This is in accordance with previous findings. Of the 25 tumors growing to a diameter of > or = 5 mm, 11 were established as cultured cell lines (4 UVA and 7 UVB tumors). These uncloned cell lines were analyzed for surface expression of major histocompatibility complex class I by FACS analysis. There was a clear correlation between high MHC class I expression and slow growth of the individual tumors (p<0.05). This suggests a role for the MHC class I governed, i.e. cytotoxic T-cell-mediated, reactions in deciding the fate of UV-induced skin cancers. No correlation was found between MHC class I expression and tumor induction time.
Svane
I M
IM
Institute of Medical Microbiology and Immunology, University of Copenhagen, Denmark.
Engel
A M
AM
Thomsen
N B
NB
Wulf
H C
HC
Werdelin
O
O
D000818:Animals; D002277:Carcinoma / Q000276:immunology* / Q000473:pathology; D002455:Cell Division / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000096:biosynthesis / Q000276:immunology*; D007150:Immunohistochemistry; D051379:Mice; D008812:Mice, Hairless; D009374:Neoplasms, Experimental / Q000276:immunology* / Q000473:pathology; D012878:Skin Neoplasms / Q000276:immunology* / Q000473:pathology; D014466:Ultraviolet Rays; D001613:beta 2-Microglobulin / Q000276:immunology
D015395:Histocompatibility Antigens Class I; D001613:beta 2-Microglobulin