The activity of 5'-nucleotidase and ouabain-sensitive Na/K ATPase was determined in seven different mouse melanoma cell lines. Ouabain-sensitive Na/K ATPase activity was found in NP40-treated cell homogenates of all cell lines. However, 5'-nucleotidase activity was found in only one mouse melanoma cell line--JB/RH. The absence of expression of 5'-nucleotidase activity in the other six cell lines is not associated with pigmentation in melanoma cells, nor is the gene switched off in all transformed melanocytes of C57BL/6 origin.

5'-Nucleotidase↗

PubMedDate not supplied

Absence of murine melanoma 5'-nucleotidase activity is not attributable to a detectable inhibitor.

Previous observations indicated the absence of demonstrable 5'-nucleotidase activity in six of seven cultured murine melanoma cell lines. It could not be determined from those studies whether the enzyme was absent, or whether an inhibitor was present. The current studies indicate that no inhibitor can be demonstrated, therefore the enzyme is absent.

5'-Nucleotidase↗