[Expression and anti-metastatic potential of nm 23/NDP kinase in human head and neck cancer cells]

Abstract

The nm23, encoding a protein identical to nucleoside diphosphate (NDP) kinase, is thought to be a candidate metastasis suppressor gene. Low expression of nm23 at the protein or/and mRNA levels was associated with metastatic potential of several types of rodent and human tumors. Expression and anti-metastatic action of nm23/NDP kinase gene products of human head and neck cancer (squamous cell carcinoma) cell lines were investigated. Among six cell lines examined, only those which showed metastatic potential exhibited reduced levels of nm23-H2 protein with no apparent change in nm23-H1 protein levels as compared with non-metastatic cells. When either nm23-H1 or nm23-H2 cDNA was transfected into a high metastatic cell line, only cell clones expressing higher levels of nm23-H2 protein above control levels displayed a reduced number of lung foci in an experimental metastasis assay. The data suggested that nm23-H2 gene product possesses the metastasis suppressor activity in human head and neck cancer cells.