Combination therapy with CuDIPS, Tween 80 and cyclophosphamide: effects on survival and tumor incidence in SJL/J mice.

Combinations of Cu(II)2(3,5-diisopropylsalicylate)4 (CuDIPS), polyoxyethylenesorbitan monooleate (Tween 80) and cyclophosphamide (CY) were tested for their long-term effects on survival rate and incidence of reticulum cell sarcoma (RCS) in female SJL/J mice. Animals treated with CuDIPS + Tween 80 (72 hours later) exhibited a reduction in survival rate and an accelerated rate of tumorigenesis; the combination of CuDIPS + saline (24 or 72 hours later) proved of no value. Reductions in tumor incidence were achieved by treatment with Tween 80 + CY (72 hours later), Tween 80 + polyvinyl alcohol (PVA) or saline (72 hours later), or CY + PVA or saline (24 or 72 hours later); one of these combinations (CY + PVA or saline) also had a beneficial effect on survival rate. Results were most impressive among mice receiving the combination of CuDIPS + CY (24 hours later). Survival rate was not enhanced, but incidence of RCS was reduced to the lowest level (38%) of all experimental groups. Implications of these findings are discussed.