The Melanoma Inhibitory protein (MIA) was identified as an inhibitor of in vitro growth of malignant melanoma cells. The protein contains a SH3 domain.
MIA acts as a potent tumor cell growth inhibitor for malignant melanoma cells and some other neuroectodermal tumors,including gliomas,in an autocrine fashion. In a study of human melanoma cell lines with different metastatic capacity MIA mRNA expression appeared to be inversely correlated with pigmentation. MIA has been shown to represent a very sensitive and specific serum marker for systemic malignant melanoma that might be useful for staging of primary melanomas,detection of progression from localized to metastatic disease during follow-up,and monitoring therapy of advanced melanomas.