Tyrosinase Immunoreactivity in Formalin-Fixed, Paraffin-Embedded Primary and Metastatic Melanoma: Frequency and Distribution

J Cutan Pathol. 1998 Apr;25(4):204-9. doi: 10.1111/j.1600-0560.1998.tb01720.x.

Abstract

Monoclonal antibody T311 specifically detects tyrosinase protein expression. Tyrosinase-derived peptides are recognized by CD8+ T-cells and applied in immunotherapy. We examined formalin-fixed paraffin-embedded tissue of 50 melanoma (primary n=31, metastatic n=19) and 41 control cases (junctional, dermal, compound, Spitz, Reed, balloon-cell nevi) by immunochemistry using the alkaline phosphatase-anti-alkaline phosphatase method after antigen retrieval. Staining with mAb T311 showed a sensitivity of 94% for melanoma with a very high specificity for melanocytic cells. Immunopositivity (94% of melanomas overall) correlated inversely with clinical stage: clinical stage I and stage II showed 100%, stage III and stage IV 86% immunoreactivity each. Staining changed from an exclusively homogeneous pattern in early stages to a more heterogeneous pattern in later stages. Melanocytic control tissue like nevi of different subtypes all showed weak to moderate, homogeneous immunoreactivity with polarity towards the epidermis. RT-PCR ELISA analysis of short-term melanoma cell cultures displayed mRNA expression in only half of the originally immunopositive tumors only, suggesting rapid mRNA expression loss in culture. mAb T311 allows detection of melanoma-associated tyrosinase protein expression and thus profiling of melanomas using routine archival tissue suited for immunotherapy approaches involving tyrosinase derived epitopes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal
  • DNA Primers / chemistry
  • Enzyme-Linked Immunosorbent Assay
  • Formaldehyde
  • Humans
  • Hutchinson's Melanotic Freckle / enzymology
  • Hutchinson's Melanotic Freckle / pathology
  • Immunoenzyme Techniques
  • Melanoma / enzymology*
  • Melanoma / secondary
  • Monophenol Monooxygenase / genetics
  • Monophenol Monooxygenase / metabolism*
  • Nevus / enzymology
  • Nevus / pathology
  • Paraffin Embedding
  • Polymerase Chain Reaction
  • RNA, Messenger / metabolism
  • Skin Neoplasms / enzymology*
  • Skin Neoplasms / pathology
  • Tissue Fixation / methods

Substances

  • Antibodies, Monoclonal
  • DNA Primers
  • RNA, Messenger
  • Formaldehyde
  • Monophenol Monooxygenase