Expression of transporter associated with antigen processing 1 and 2 (TAP1/2) in malignant melanoma cell lines.
TAP1 and TAP2 molecules are involved in the transport of peptides prior to their association with class I molecules and are mandatory for efficient antigen presentation. To investigate whether loss of expression of TAP1 or TAP2 is a likely mechanism of immune escape in malignant melanoma, TAP1 and TAP2 mRNA was analyzed by RT-PCR in 39 melanoma cell lines expressing at least 2 of the known melanoma-associated antigens, tyrosinase, Melan-A/MART-1, gp100, MAGE-1 and MAGE-3. All 39 cell lines expressed both TAP1 and TAP2 at the mRNA level. To investigate other factors potentially involved in immune escape, the expression of LMP2, LMP7, HLA class I molecules, beta2-microglobulin (beta2m) and specific HLA-A alleles was evaluated by RT-PCR and FACS analyses. All 39 cell lines expressed LMP2, LMP7 and beta2m. A single cell line (FM37) had lost the expression of class I molecules, and this same cell line showed loss of expression of the HLA-A2 heavy chain. No cell lines showed loss of expression of the HLA-A1 heavy chain. Based on our studies of in vitro established cell lines, loss of TAP1/2 or LMP2/7 expression does not appear to be a common mechanism of immune escape in malignant melanoma.
Thor Straten
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P
Department of Tumor Cell Biology, Danish Cancer Society, Copenhagen.
Kirkin
A F
AF
Seremet
T
T
Zeuthen
J
J
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism*; D026905:Amino Acid Transport Systems; D000951:Antigens, Neoplasm / Q000378:metabolism; D005095:Exoribonucleases; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D008545:Melanoma / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D026905:Amino Acid Transport Systems; D000951:Antigens, Neoplasm; D005656:Fungal Proteins; D015395:Histocompatibility Antigens Class I; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D029701:Saccharomyces cerevisiae Proteins; C429825:TAT2 protein, S cerevisiae; D015534:Trans-Activators; C071692:TAP2 protein, human; D005095:Exoribonucleases