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Updated: Jun 19, 2026
A Robust Discovery Platform for the Identification of Novel Mediators of Melanoma Metastasis
Published on: March 8, 2022
The expression of MT1 melatonin receptor and Ki-67 antigen in melanoma malignum
Karolina Danielczyk1, Piotr Dziegiel
1Department of Histology, Wroclaw Medical University, ul. Chałubińskiego 6a, 50-368 Wrocław, Poland. karolka_d@poczta.fm
Background:
Melatonin, the principal hormone produced by the pineal gland, manifests strong potency of inhibiting growth of dermal melanoma cells both under in vitro and in vivo conditions. Although the mechanism of the phenomenon has not been fully clarified yet, melatonin receptors seem to play a key role in the inhibition. In humans, two main types of high affinity membrane melatonin receptors have been identified, including MT1 (Mel1a) and MT2 (Mel1b) receptors, and their expression increases efficacy of the oncostatic melatonin activity. The principal aim of this study involved determination of location and intensity of expression of MT1 melatonin receptors and of Ki-67 proliferation-associated antigen in dermal melanoma using an immunohistochemical technique and an examination of their reciprocal correlation and their relationship with clinical advancement of the tumour, i.e. with its depth of infiltration.
Patients And Methods:
Immunohistochemical studies were conducted on the material of 48 cases of dermal melanoma, including 38 primary tumours and 10 metastatic lymph nodes, fixed in formalin and embedded in paraffin.
Results:
In all the examined cases, positive immunohistochemical reactions were obtained with antibodies to MT1 and Ki-67. Expression of MT1 receptor was more pronounced in primary tumours than in lymph nodes (p<0.05). Depth of tumour infiltration demonstrated a moderate positive correlation with the intensity of MT1 expression (r=0.45; p<0.05) and a strongly positive correlation with the expression of Ki-67 antigen (r=0.79; p<0.05). Moreover, both in primary tumours and in metastatic lymph nodes, a weak correlation was detected between the expression of MT1 receptor and expression of Ki-67 antigen.
Conclusion:
Confirmation of positive correlation between the expression of MT1 receptor and depth of melanoma infiltration may point to future use of MT1 as a prognostic index for such tumours.
Insights
Melatonin receptor MT1 expression correlates with melanoma depth. Higher MT1 levels indicate deeper tumor infiltration, suggesting MT1 as a potential prognostic marker for dermal melanoma.
Area of Science:
- Oncology
- Endocrinology
- Dermatology
Background:
- Melatonin, a pineal gland hormone, inhibits dermal melanoma growth.
- Melatonin receptors, particularly MT1 and MT2, are crucial for this oncostatic activity.
- Understanding MT1 receptor expression is key to clarifying melatonin's anti-melanoma mechanisms.
Purpose of the Study:
- To determine the location and expression intensity of MT1 receptors and Ki-67 antigen in dermal melanoma.
- To examine the correlation between MT1 expression, Ki-67, and tumor infiltration depth.
- To evaluate the relationship between these markers and clinical advancement of melanoma.
Main Methods:
- Immunohistochemical analysis of 48 dermal melanoma samples (38 primary tumors, 10 metastatic lymph nodes).
- Quantification of MT1 receptor and Ki-67 proliferation antigen expression.
- Statistical analysis to assess correlations between marker expression and tumor depth.
Main Results:
- MT1 receptor expression was higher in primary tumors than in metastatic lymph nodes.
- Tumor infiltration depth showed a moderate positive correlation with MT1 expression (r=0.45, p<0.05).
- Tumor infiltration depth strongly correlated with Ki-67 expression (r=0.79, p<0.05).
Conclusions:
- A positive correlation exists between MT1 receptor expression and melanoma infiltration depth.
- MT1 receptor expression may serve as a future prognostic index for dermal melanoma.
- Further research can explore MT1's role in melanoma progression and treatment.
