Autophagy in cutaneous malignant melanoma
Article first published online: 14 JUL 2009
Copyright © 2009 John Wiley & Sons A/S
Journal of Cutaneous Pathology
Volume 37, Issue 2, pages 256–268, February 2010
How to Cite
Lazova, R., Klump, V. and Pawelek, J. (2010), Autophagy in cutaneous malignant melanoma. Journal of Cutaneous Pathology, 37: 256–268. doi: 10.1111/j.1600-0560.2009.01359.x
- Issue published online: 16 DEC 2009
- Article first published online: 14 JUL 2009
- Accepted for publication May 18, 2009
We show that malignant melanoma cells display high levels of autophagy, a cytoplasmic process of protein and organelle digestion that provides an energy source in times of nutrient deprivation. In a panel of 12 cases of cutaneous malignant melanoma of the superficial spreading type, cells in florid melanoma in situ (MIS) and invasive cells in the dermis appeared to be undergoing autophagy. Autophagosomes were detected through immunohistochemistry using the marker LC3B (microtubule-associated light chain 3B), and by electron microscopy. Some autophagosomes contained melanized melanosomes, accounting for the phenomenon of ‘coarse melanin’ in malignant melanoma. Autophagosomes also contained the Golgi 58k protein, a structural component of the Golgi apparatus, and β1, 6-branched oligosaccharides, indicating that at least some of the autophagosomal proteins were glycosylated with these structures. The findings suggest that autophagy could be a constitutive metabolic state for invasive and metastatic melanoma cells. Interestingly, a similar phenotype was also expressed by tumor-associated melanophages. The findings are consistent with previous reports that endoplasmic reticulum (ER) stress drives melanoma progression, since ER stress is known to trigger autophagy. The results suggest that therapies inhibiting autophagy may be effective for the treatment of malignant melanoma by depriving cells of an important energy source.
Lazova R, Klump V, Pawelek J. Autophagy in cutaneous malignant melanoma.