title: Analysis of HLA class I expression in different metastases from two melanoma patients undergoing peptide immunotherapy.
abstract: We characterized the HLA class I alterations in five metastases obtained from two patients with melanoma immunized with Melan A/MART-1, tyrosinase and gp100 tumor peptides. All three metastases analyzed in the first patient (NW145) showed a similar HLA class I alteration with a dual population of melanoma cells. One population was HLA class I antigen positive and the other had loss of heterozygosity (LOH) in the short arm of chromosome 6 leading to an HLA haplotype loss (A02011, B4007, Cw1). The absence of HLA-A2 antigen may explain why this patient did not develop HLA-A2 restricted, Melan A/MART-1 specificity immunization, since this HLA molecule is the restriction element for the tumor peptides used. However, this HLA-deficient population was not selected after peptide immunotherapy. The primary tumor in this patient presented LOH in region 6q, but only in the vertical growth phase of the lesion, whereas LOH at 6p was observed only in DNA from metastatic material. The second patient (NW16) also presented two metastatic lesions with an identical HLA molecular defect, i.e. HLA B locus downregulation (HLA B51011: serological B51; B1503: serological B70). One lesion expressed the tumor antigen (Melan A/ MART-1), but the other did not. Interestingly, the antigen-positive metastasis regressed after peptide immunotherapy, whereas the other progressed rapidly. These findings provide the first indication that multiple metastases generated in the same host can have identically altered HLA class I phenotypes.
authors.affiliation: Departamento de Analisis Clinicos, Hospital Universitario Virgen de las Nieves, Universidad de Granada, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Mendez
authors.forename: A
authors.initials: A
authors.lastname: Serrano
authors.forename: E
authors.initials: E
authors.lastname: Jäger
authors.forename: I
authors.initials: I
authors.lastname: Maleno
authors.forename: F
authors.initials: F
authors.lastname: Ruiz-Cabello
authors.forename: A
authors.initials: A
authors.lastname: Knuth
authors.forename: F
authors.initials: F
authors.lastname: Garrido
mesh_terms: D000368:Aged; D000951:Antigens, Neoplasm; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics; D017809:Fatal Outcome; D005260:Female; D005805:Genes, MHC Class I / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D016233:Immunotherapy, Active; D019656:Loss of Heterozygosity / Q000235:genetics; D058965:MART-1 Antigen; D008297:Male; D008545:Melanoma / Q000235:genetics* / Q000556:secondary* / Q000628:therapy; D008562:Membrane Glycoproteins / Q000276:immunology; D014442:Monophenol Monooxygenase / Q000276:immunology; D009363:Neoplasm Proteins / Q000276:immunology*; D058951:gp100 Melanoma Antigen
chemical_list: D000951:Antigens, Neoplasm; D058965:MART-1 Antigen; C548667:MLANA protein, human; D008562:Membrane Glycoproteins; D009363:Neoplasm Proteins; C548637:PMEL protein, human; D058951:gp100 Melanoma Antigen; D014442:Monophenol Monooxygenase