title: HLA-DR and melanoma-associated antigen (p97) expression during the cell cycle in human melanoma cell lines, and the effects of recombinant gamma-interferon: two-color flow cytometric analysis.
abstract: Using monoclonal antibodies, recombinant human gamma-interferon, and fluorescence-activated cell sorter, 2 human melanoma cell lines (KHm-1/4 and A101D) were examined quantitatively for HLA-DR and 97-kD melanoma-associated antigen (p97) expression throughout the cell cycle. Two-color flow cytometric analysis showed that the mean cell volume increased (KHm-1/4, 2.6 times; A101D, 3.6 times) during the progression of the cell cycle, and that fluorescence intensity of HLA-DR and p97 correlated well with cell volume, i.e., both antigens were maximally detected during the G2-M phase. The density of HLA-DR and p97 on the cell surface remained relatively constant throughout the cell cycle with the exception that cells in S phase showed a slightly lower density compared with those in G0/G1 and G2-M phases. gamma-Interferon treatment (500 IU/ml, 72 h) increased HLA-DR+ cells (KHm-1/4, 65% to 89%; A101D, 34% to 84%) and p97+ cells (KHm-1/4, 8% to 12%; A101D, 19% to 35%). Increased antigen densities were also relatively constant throughout the cell cycle as in nontreated cells. Cells treated with gamma-interferon tended to accumulate at G0/G1 phase (KHm-1/4, 21% to 37%; A101D, 17% to 53%), and had a reduced cell volume (0.82-0.95 times) throughout cell cycle. This study revealed that both melanoma cell lines showed heterogeneity in the expression of HLA-DR and p97, and that this heterogeneity was influenced, at least in part, by cell cycle and immunologic events such as gamma-interferon treatment.
mesh_terms: D000951:Antigens, Neoplasm; D002452:Cell Count / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects*; D002460:Cell Line; D004273:DNA, Neoplasm / Q000032:analysis; D005434:Flow Cytometry / Q000379:methods*; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D008545:Melanoma / Q000473:pathology*; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins / Q000276:immunology*; D011994:Recombinant Proteins / Q000494:pharmacology*
chemical_list: D000951:Antigens, Neoplasm; D004273:DNA, Neoplasm; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D011994:Recombinant Proteins; D007371:Interferon-gamma