Expression of a catalytically inactive H118Y mutant of nm23-H2 suppresses the metastatic potential of line IV Cl 1 human melanoma cells.
Nm23-H1 and nm23-H2 are putative metastasis suppressor genes that encode nucleoside diphosphate kinase (NDPK) A and B. NDPKs form oligomers distributed between soluble and particulate fractions of cells and therefore may exert their effects as either soluble or bound proteins. To determine whether metastasis-related functions of NDPKs are mediated by their catalytic activity in membrane bound or soluble complexes, we have stably transfected highly metastatic human melanoma Line IV Cl 1 cells with wild-type and catalytically inactive (H118Y) nm23-H1 and nm23-H2 genes and assayed their metastatic potential in nude mice. Transfection with wild-type nm23-H1 and nm23-H2 genes and catalytically inactive nm23-H1 did not significantly (all p > 0.10) alter the metastatic potential of Line IV Cl 1 cells while transfection with catalytically inactive nm23-H2 significantly (p < 0.01) reduced their metastatic potential. The lack of effect of transfection with wild-type and catalytically inactive nm23-H1 suggests that neither soluble nor membrane bound NDPK A affect the metastatic potential of Line IV Cl 1 cells. The metastasis suppressive effect of catalytically inactive NDPK B overexpression suggests that competition with bound complexes containing catalytically active NDPK B inhibits metastasis of Line IV Cl 1 cells. These results imply that bound NDPK B promotes metastasis and suggest that inhibition of its function or of its binding to critical sites may be a useful approach to limit the development of metastases in human melanoma.
Hamby
C V
CV
Department of Microbiology and Immunology, New York Medical College, Valhalla, NY 10595, USA. hamby@nymc.edu
Abbi
R
R
Prasad
N
N
Stauffer
C
C
Thomson
J
J
Mendola
C E
CE
Sidorov
V
V
Backer
J M
JM
D019943:Amino Acid Substitution; D000818:Animals; D014408:Biomarkers, Tumor / Q000235:genetics; D020134:Catalytic Domain; D016147:Genes, Tumor Suppressor; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D008545:Melanoma / Q000235:genetics* / Q000473:pathology*; D051379:Mice; D008819:Mice, Nude; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics* / Q000502:physiology; D054778:NM23 Nucleoside Diphosphate Kinases; D009362:Neoplasm Metastasis / Q000235:genetics*; D009701:Nucleoside-Diphosphate Kinase / Q000235:genetics*; D010766:Phosphorylation; D017354:Point Mutation; D011994:Recombinant Proteins / Q000096:biosynthesis; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology; D014162:Transfection; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
D014408:Biomarkers, Tumor; D007527:Isoenzymes; D054778:NM23 Nucleoside Diphosphate Kinases; D011994:Recombinant Proteins; D014157:Transcription Factors; C119009:NBR-A isoenzyme; C119010:NBR-B isoenzyme; C517938:NME1 protein, human; C517939:Nme1 protein, mouse; D009701:Nucleoside-Diphosphate Kinase; D020559:Monomeric GTP-Binding Proteins