Effect of suramin (Bayer 205) on renal ornithine decarboxylase activity and polyamine concentrations in rats

Inhibitory effects of suramin on a human renal cell carcinoma line, causing nephrogenic hepatic dysfunction

A sarcomatoid renal cell carcinoma has been isolated from a patient with Stauffer's syndrome. The tumor, designated BA1119, has been established in tissue culture over 80 passages. Subcutaneous deposition of BA1119 in athymic mice induced splenomegaly and hepatic dysfunction which became fatal within four weeks without metastasis. Suramin is a synthetic polyanionic compound which is capable of altering the function of a number of biologic systems and inhibiting the activity of a variety of protein and growth factors. In this study we attempted to study the effect of suramin on growth of BA1119 in culture and in nude mice. Suramin, at 300 micrograms/ml., had a profound inhibitory effect on cell growth during a six-day culture period. Suramin given i.p. weekly to nude mice at clinically relevant doses (200 mg./kg.) caused significant shrinkage of subcapsular tumor deposits. Splenic hypertrophy secondary to BA1119-induced Stauffer's syndrome was inhibited by suramin. Synergistic effect with enhanced cytotoxicity on BA1119 cells was observed when suramin (100 micrograms/ml.) was used in combination with lymphokines, such as gamma interferon (500 units/ml.) and alpha tumor necrosis factor (300 ng./ml.). These results may suggest a therapeutic efficacy of suramin in renal cell carcinoma patients with Stauffer's syndrome.

Modulation by suramin of NK and monocytic cell-mediated cytotoxicity in human and murine cells

The in vitro effects of suramin, a compound recently tested in AIDS treatment, were investigated on human and murine NK and monocyte macrophage cytotoxicity and monocyte migratory ability. In a short-term, TNF-dependent assay, pre-exposure (4-18 h) to 100-400 micrograms/ml suramin was associated with a markedly increased cytotoxicity by human monocytes and murine-elicited peritoneal macrophages, paralleled by a greater cytotoxic capacity in the supernates of these effectors. Preincubation with the same pharmacological suramin concentrations also resulted in enhanced spontaneous and directed migration in monocytic cells. Suramin-preincubated human PBL and murine splenocytes were unchanged in their basal NK cytotoxicity but exhibited a deficient response to IFN. Pre- and post-incubations with suramin resulted in increased macrophagic cytotoxicity for TNF-insensitive targets. Conversely, postincubation of effectors with the drug at 100-400 micrograms/ml was associated with profound decreases in both NK and TNF-mediated macrophagic cytotoxicities, and prior exposure to suramin of macrophagic supernates resulted in reduced cytotoxic activity. The mechanisms involved in the complex modulatory activity of suramin for monocyte macrophages and NK cells and the possible therapeutic implications of these findings are discussed.

Organomegaly and histopathology in an animal model of mucopolysaccharidosis induced by suramin

The trypanocidal drug suramin causes glycosaminoglycan and sphingolipid accumulation in the rat, thus simulating a mucopolysaccharidosis (Constantopoulos et al. 1980). In this paper we report on the extent and nature of the morphological changes that occur in the liver, kidneys, spleen, heart, lung and brain as a result of short or long term suramin administration. The first group of rats received a single intravenous injection of suramin (500 mg/kg) and was sacrificed 3-9 days after the injection. The second group received low doses of suramin (50-90 mg/kg) at 2-3 weekly intervals over 3 months. Samples of the above mentioned organs were processed for light and electronmicroscopy and the remainder of the tissue weighed and assayed for total protein, DNA and RNA content. In both groups of rats, suramin caused an abnormal enlargement of the spleen, kidney, lung and liver, splenomegaly being the most pronounced. The total protein, and DNA content did not alter in the treated rats, however, the RNA content of the spleen increased 100%, 9 days after injection and there was a small but consistent increase in RNA content of the liver, kidney and lung. Significant pathological changes were observed in these organs and also in the brain and heart. The changes were similar in many respects to the pathology seen in the lysosomal storage disorder, mucopolysaccharidosis and further support the proposition that the suramin treated rat might be a useful experimental animal model of the disease. Several mechanisms by which suramin might produce organomegaly in the rat are discussed.

Effect of unilateral ureteral obstruction on renal polyamine levels in rats

Unilateral ureteral obstruction in rats, resulted in considerable alterations of polyamine levels in the obstructed kidney during a 72-h observation period, as compared with respective values for the contralateral control kidney.