Related Experiment Videos
alpha-Melanotropin immunoreactivity in human melanoma exudate is related to necrosis
B Loir1, F Sales, R Deraemaecker
1Laboratory of Oncology and Experimental Surgery, Université Libre de Bruxelles, Belgium.
Abstract:
We have previously reported high immunoreactive alpha-MSH (IR-alpha-MSH) concentrations in melanoma patients' plasma, as well as significant amounts in melanoma metastases and cells grown in culture. Necrosis within the melanoma tumour leads to a massive proteolysis of intracellular proteins and release of cell content: this might significantly contribute to the elevated IR-alpha-MSH plasma levels measured in melanoma patients. To test this hypothesis, we studied the necrosis-related release of MSH from human melanoma cells, using a specific radioimmunoassay. The studies of fine-needle biopsies indicated that most of the human melanoma tumour exudates tested contained very high MSH concentrations (> 500 pg/ml; 14/15), while plasma levels were generally normal (< or = 25 pg/ml; 10/15). The level in an exudate from a non-melanoma tumour type was < 40 pg/ml. In vitro studies showed that release of the IR-alpha-MSH was time- and temperature-dependent, and related to cell death.
Insights
Melanoma cell death releases alpha-melanocyte-stimulating hormone (MSH). This finding suggests tumor necrosis contributes to elevated MSH levels in melanoma patients, aiding in understanding disease markers.
Area of Science:
- Oncology
- Biochemistry
- Cell Biology
Background:
- Elevated immunoreactive alpha-MSH (IR-alpha-MSH) has been observed in melanoma patients' plasma.
- Significant IR-alpha-MSH levels are also found in melanoma metastases and cultured cells.
Purpose of the Study:
- To investigate the hypothesis that melanoma tumor necrosis contributes to elevated plasma IR-alpha-MSH levels.
- To study the release of MSH from human melanoma cells related to necrosis.
Main Methods:
- Utilized a specific radioimmunoassay to quantify MSH concentrations.
- Analyzed fine-needle biopsies from melanoma tumors and exudates.
- Conducted in vitro studies on human melanoma cells to assess MSH release.
Main Results:
- Melanoma tumor exudates showed very high MSH concentrations ( > 500 pg/ml; 14/15 cases).
- Plasma MSH levels in melanoma patients were generally normal ( <= 25 pg/ml; 10/15 cases).
- Exudates from non-melanoma tumors had significantly lower MSH levels (< 40 pg/ml).
- In vitro studies demonstrated that IR-alpha-MSH release is time- and temperature-dependent and linked to cell death.
Conclusions:
- Melanoma tumor necrosis is a significant source of MSH release.
- The findings support the hypothesis that necrosis-driven MSH release contributes to elevated plasma levels in melanoma patients.
- MSH release from necrotic melanoma cells could serve as a potential biomarker.