Malignant Melanoma and Its Stromal Nonimmune Microecosystem

The study highlighted the significant role of the stromal nonimmune microecosystem in the growth and progression of cutaneous malignant melanoma (CMM). It was found that the dermal extracellular matrix (ECM) and stromal cells, which store and release ECM components, had strong effects on CMM. The peri-CMM stroma exhibited specific changes, such as intracytoplasmic loads in Factor XIIIa, CD34, versican, and α (IV) collagen chains, which were linked to neoangiogenesis and metastatic spread. These migratory CMM cells, potentially CMM stem cells or cells with aberrant HOX gene expression, were associated with a higher risk of metastases in sentinel lymph nodes. The study concluded that the interaction between CMM and its stroma was crucial for the regulation of growth, invasiveness, and early metastatic spread of CMM cells.