Prognostic value of microphthalmia-associated transcription factor and tyrosinase as markers for circulating tumor cells detection in patients with melanoma

Abstract

The aim of this study was to analyze microphthalmia-associated transcription factor (MITF) as a marker for the detection of circulating melanoma cells, determine its prognostic value in melanoma patients, and compare it with tyrosinase. Blood samples from 201 melanoma patients in all stages of the disease and 40 healthy volunteers were analyzed. RNA was isolated from mononuclear cell fraction of the blood and assayed by reverse transcription-PCR for the expression of MITF and tyrosinase. All samples from healthy volunteers were negative for both MITF and tyrosinase. Out of 201 blood samples from melanoma patients 32 were positive for MITF, 20 for tyrosinase, and four for both MITF and tyrosinase. Analysis of MITF as an additional marker to tyrosinase allowed for detection of circulating melanoma cells in a larger number of melanoma patients in comparison to tyrosinase analysis alone (48 vs. 20 positive). A positive value of MITF was associated with shorter progression-free (P=0.005) and overall survival (P=0.042). A positive value of tyrosinase was associated with shorter overall survival (P=0.012), whereas there was no significant association between the value of tyrosinase and progression-free survival. The value of MITF was selected with multivariate analysis as the independent prognostic factor for progression-free survival, whereas the only independent prognostic factor for overall survival was the stage of disease. This study has shown that MITF is a specific marker for detection of circulating melanoma cells that has a prognostic value in melanoma patients. Determination of MITF in addition to tyrosinase improved the detection of circulating melanoma cells in melanoma patients.

Absolute quantitative PCR for detection of molecular biomarkers in melanoma patients: A preliminary report

“…Its detection after treatment is, in fact, a significant independent prognostic indicator for the patients' survival [25]. When it was assayed by RT-PCR along with TYR and MITF transcripts, an increase in the detection rate of CMCs, from 25% to 38% for stages III and IV, respectively, was found [26].…”

Detection of circulating melanoma cells in the blood of melanoma patients

“…Nevertheless, several studies have shown the detection of CMC may represent a biomarker that can identify metastatic disease spread. [8, 9, 11, 13, 16–18, 21, 24–26, 40–43] Polymerase chain reaction (PCR)-based techniques have been used to monitor CMCs for treatment response in metastatic melanoma patients receiving chemotherapy and biochemotherapy. [12, 14, 15, 20, 22, 23] However, the reproducibility of PCR-based detection methods is low,[44, 45] which hinders their reliability and implementation in routine clinical practice.…”

Circulating Biomarkers in Malignant Melanoma

“…Because MCAM promotes progression, it is associated with a more aggressive phenotype and more advanced disease. Alternatively, CMC can be purified by negative selection by lymphocyte depletion with [55,57,71] anti-CD45 antibody [66]. This approach is independent of malignant cell characteristics and appears to have better recovery versus positive selection methods [48].…”

“…To increase CMC detection rate, tyrosinase mRNA has been combined with other mRNA targets [84]. These include melanoma antigen recognized by T-cells (Melan-A/MART-1) [36], microphthalmia-associated transcription factor (MITF) [55], gp100, MAGE-3 [61], and p97 (melanotransferrin) ( Table 2).…”