Raman spectroscopy detects melanoma and the tissue surrounding melanoma using tissue-engineered melanoma models

Invasion of melanoma cells from the primary tumour involves interaction with adjacent tissues and extracellular matrix. The extent of this interaction is not fully understood. In this study Raman spectroscopy was applied to cryo-sections of established 3D models of melanoma in human skin. Principal component analysis was used to investigate differences between the tumour and normal tissue and between the peri-tumour area and the normal skin. Two human melanoma cells lines A375SM and C8161 were investigated and compared in 3D melanoma models. Changes were found in protein conformations and tryptophan configurations across the entire melanoma samples, in tyrosine orientation and in more fluid lipid packing only in tumour dense areas, and in increased glycogen content in the peri-tumour areas of melanoma. Raman spectroscopy revealed changes around the perimeter of a melanoma tumour as well as detecting differences between the tumour and the normal tissue.