MIA enhances liver metastasis of A-mel 3 melanoma cells

Introduction: Melanoma inhibitory activity (MIA) a 11 KD Protein expressed by melanoma cells is proposed to affect migration and invasion of melanoma cells. We therefore further investigated the role of MIA in the metastatic process of A-mel 3 melanoma cells. Methods: A-mel 3 cells with different levels of MIA expression were establi shed by stable transfection with rhMIAcDNA. Tumor cell attachment, extravas ation and metastasis were assessed by means of intravital microscopy. Liver metastasis after intraportal injection of variant A-mel 3 subclones was de terminated by counting superficial tumor nodes. Results: Overexpression of rhMIA in A-mel 3 melanoma cells enhanced extrava sation and liver metastasis of A-mel 3 cells in vivo. Conclusion: We therefore conclude, that MIA promotes liver metastases by fa cilitating extravasation and migration of melanoma cells in the liver.