ABSTRACT
Recently much interest has been expressed for the use of biological response modifiers and growth factor antagonists in the treatment or radiation and chemotherapeutic drug-refractory renal cell carcinoma. Herein antiproliferative effects of Suramin, human recombinanl tumor necrosis factor alpha (TNF-alpha) and human recombinant interferon alpha (IFN-alpha) as a single and in combination were studied in vito on human renal carcinoma cell line (Caki-1). Antiproliferative effect was evaluated by trypan blue dye exclusion assay after 3 days exposure to Suramin at 10, 30, 100, 300, 1,000 mcg/ ml. TNF-alpha at 1, 10, 50, 100, 500, 1,000 units/ml and IFN-alpha at 10, 100, 1,000. 10,000 units/ml concentration, respectively. In addition, effects of combined administration in tolerable peak plasma level or suramin (300 mcg/ml). TNF-alpha (500 units/ml) and IFN-alpha (1000 units/ml) were comparatively analyzed to those of single drug administration. The results were as follows: 1. Significant dose dependent antiproliferative effects were shown by Suramin at above 100 mcg/ml. TNF-alpha at above 500 units/ml and IFN-alpha at above 10 units/ml, respectively (p<0.05). 2. At peak plasma level, suramin, TNF-alpha and IFN-alpha showed less than 50% inhibition of proliferation. 3. On combined administration, suramin plus TNF-alpha (61.0%), Suramin plus IFN-alpha(71.7%) and TNF-alpha plus IFN-alpha (57.2%) induced significantly greater inhibition of proliferation (p<0.005). These results suggest that further in vivo study using combination of Suramin plus TNF-alpha Suramin plus IFN-alpha and TNF-alpha plus IFN-alpha is necessary and that these combination trials may become one of the treatment options for renal cell carcinoma.