Expression of NM23 protein in acquired melanocytic nevi, malignant melanoma and metastases of malignant melanoma: an immunohistological assessment in human skin.

BACKGROUND

It has been suggested that nm23 may exert metastasis suppressor function in human tumors.

OBJECTIVE

We have analyzed expression of nm23 polypeptide in acquired melanocytic nevi (n = 19), dysplastic nevi (n = 19), malignant melanomas (n = 22) and metastases of malignant melanomas (n = 47) in situ.

METHODS

Nm23 protein was detected immunohistochemically on paraffin sections using the highly sensitive labeled avidin-biotin technique.

RESULTS

We found that (1) nm23 polypeptide is predominantly expressed in the cytoplasmic but also in nuclear and membrane compartments of melanocytic human cells, (2) expression of nm23 protein does not correlate with benign or malignant phenotype in melanocytic tumors of human skin.

CONCLUSION

Our study challenges the hypothesis that nm23 may function in malignant melanomas as a tumor suppressor gene.