Comparison of natural killer (NK) sensitivities of two tumor cell lines established from a cancer patient before and after radiation therapy.
Major histocompatibility complex (MHC) class I positive tumor cells are generally resistant to natural killer (NK) cells. In this report, we compared the NK sensitivities of tumor cell lines H41 and H42, which were established from a cancer patient at surgery. H41 was established before radiation therapy and H42 was established after the radiation therapy in 1985. H41 was resistant to NK cells, whereas H42 was NK-sensitive. Both cell lines reacted with W6/32, which is an antibody to the HLA common epitope determinant. However, H42 did not react to anti-HLA-locus-specific antibodies, although H41 reacted to them. When these cell lines were treated with interferon-gamma, H41 showed an increase in HLA-locus-specific antigenicity, whereas H42 did not show such a tendency. This suggests that there may have been interference in the expression of the HLA-locus-specific determinants on H42. Therefore, it was assumed that the NK sensitivity of H42 may be due to depression of an HLA-locus-specific determinant, and this depression may be related to the radiation therapy. The patient recovered from the disease after the radiation therapy and the last surgery. He is now in a tumor-free state. We propose that his recovery may be related to the conversion of the tumor cells from NK-resistant to NK-sensitive.
Komatsu
F
F
School of Medicine, Tokyo Medical & Dental University, Yushima 1-5-45, Bunkyoku, Tokyo, 113, Japan.
Kajiwara
M
M
D002295:Carcinoma, Transitional Cell / Q000276:immunology* / Q000532:radiotherapy; D003602:Cytotoxicity, Immunologic / Q000528:radiation effects*; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology* / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000276:immunology* / Q000532:radiotherapy