Expression of tumor associated transcripts in malignant melanoma metastases : with methodological aspects

• Several antigens expressed in malignant melanoma are involved in the immunological surveillance of the tumor. The mRNAs of these antigens, especially tyrosinase, have also been used in the detection of minimal residual disease in the blood of melanoma patients. We have therefore analyzed the expression of tyrosinase, TRP-1, TRP-2, MART-1/Melan-A, MAGE-A3, MAGE-A12, S-100 and GD2 synthase by real-time PCR in snap frozen sections from 28 regional and systemic metastases. Treatment with cisplatinum, dacarbazine and interferon-α2b was given to 15 patients before surgery. The transcript concentrations varied widely between individual metastases. However, in general the pigment-related transcripts and that of S-100 were found at higher levels than those of MAGE-A3, MAGE-A12 and GD2 synthase. Significant correlations (p<0.001) were found between tyrosinase and MART-1/Melan-A and between MAGE-A3 and MAGE-A12. TRP-2 and GD2 synthase were both influenced by the treatment, TRP-2 expression was increased in the metastases from treated patients, whereas GD2 synthase expression was decreased. Furthermore, a decrease in tyrosinase expression was found in metastases without tumor-infiltrating lymphocytes. ln this work normalization by the section area contra normalization by housekeeping genes was also evaluated and similar results were obtained with both methods.

Nyckelord

MEDICINE

MEDICIN

Publikations- och innehållstyp

vet (ämneskategori)

ovr (ämneskategori)