Microphthalmia-associated transcription factor and tyrosinase as markers of melanoma cells in blood of patients with melanoma.
OBJECTIVE
To investigate whether analysis of microphthalmia-associated transcription factor (MITF) as an additional marker to tyrosinase in melanoma patients can improve the detection of circulating melanoma cells by reverse-transcription-polymerase chain reaction (RT-PCR).


METHODS
Blood samples were taken from 33 patients with metastatic melanoma. RNA was isolated from mononuclear cell fraction of the blood and reversely transcribed into the complementary DNA (cDNA). The cDNA was assayed by PCR for the expression of tyrosinase and MITF. Peripheral blood samples from 15 healthy subjects were used as controls.


RESULTS
The threshold for detection of both tyrosinase and MITF was set low enough to detect 50 melanoma cells in 10 mL of healthy volunteer blood in the relative ratio of one melanoma cell in 0.82 x 106 peripheral blood leukocytes. Out of 33 blood samples from metastatic melanoma patients, 5 were positive for both tyrosinase and MITF, 7 for tyrosinase only, and 5 for MITF only. All samples from healthy volunteers were negative for both tyrosinase and MITF.


CONCLUSIONS
Determination of MITF marker in addition to tyrosinase improved the detection of circulating melanoma cells in patients with metastatic melanoma.
Samija
Ivan
I
Department of Oncology and Nuclear Medicine, Sisters of Mercy University Hospital, Zagreb, Croatia. isamija@kbsm.hr
Lukac
Josip
J
Marić-Brozić
Jasmina
J
Kusić
Zvonko
Z
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D016022:Case-Control Studies; D004268:DNA-Binding Proteins / Q000097:blood; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000097:blood* / Q000175:diagnosis / Q000201:enzymology / Q000473:pathology; D051739:Microphthalmia-Associated Transcription Factor; D008875:Middle Aged; D014442:Monophenol Monooxygenase / Q000097:blood; D009362:Neoplasm Metastasis / Q000175:diagnosis; D009367:Neoplasm Staging; D009360:Neoplastic Cells, Circulating; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000097:blood
D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; C497234:MITF protein, human; D051739:Microphthalmia-Associated Transcription Factor; D014157:Transcription Factors; D014442:Monophenol Monooxygenase