Polyamines in human breast cancer, effects of an anticancer drug

ABSTRACT

The polyamines putrescine, spermidine and spermine are ubiquitous amines, involved in cell growth and tumourogenesis. Their catabolism occurs via acetylation by Polyamine acetyl transferase [PAT], a cytosolic enzyme. Methyl glyoxal Bis [guanyl hydrazone] MGBG, is an antineoplastic agent known to inhibit polyamine biosynthesis. We studied the effect of MGBG on cell growth, polyamine content and PAT enzyme in ZR-75-1 cells a breast cancer cell line in culture. The cells were grown in monolayer for up to 120h. Twe cell growth was determined by estimating total protein content by the method of Lowry et al [1951]. Polyamines were analysed using reversed phase high performance liquid chromatography. PAT activity was assayed using [H]3 acetyl CoA and spermidine [3mM] as substrate. PAT activity was significantly increased [P <0.001] in MGBG-treated cells. It could be that MGBG exerts its cytotoxic effect on breast cancer cells by induction of their catabolism along with inhibition of their biosynthesis: