Anticancer research
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Anticancer research · Jul 1992
Differential effects of the spermine analog, N1, N12-bis(ethyl)-spermine, on polyamine metabolism and cell growth in human melanoma cell lines and melanocytes.
We have previously found that in one of two human melanoma cell lines, potent increase in the polyamine catabolizing enzyme, spermidine/spermine N1-acetyltransferase (SSAT), correlate with growth sensitivity to the spermine analog, N1, N12-bis(ethyl) spermine (BESPM). Herein, we examine the generality of this SSAT response among seven human melanoma cell lines (LOX, SH-1, STO-1, HO, PANUT-3, MALME-3 and Ebey) and normal melanocytes and further evaluate its possible correlation with growth sensitivity. Following treatment with 10 microM BESPM for 48 hr, SSAT activity among the various cell lines increased from basal levels of 20-90 pmol/min/mg to levels ranging from 170 to 30,470 pmol/min/mg. ⋯ The polyamine biosynthetic enzyme activities, ornithine and S-adenosylmethionine decarboxylase, were similarly suppressed in all cell lines, presumably via analog activation of inherent regulatory mechanisms. Polyamine pool reduction occurred to a greater extent than predicted in cell lines where SSAT was increased to greater than 2500 pmol/min/mg suggesting a possible role for the enzyme in enhancing polyamine excretion and/or catabolism. The occurrence of potent SSAT induction among several human melanoma cell lines and the growth sensitivity of these same lines to BESPM suggests that the enzyme response may represent a determinant of drug action in this particular malignancy.