Antitumor therapeutic effect of neurotropin on transplanted tumors in rats

The antitumor therapeutic effect of neurotropin (NSP) was examined using the moderately immunogenic KMT-17 tumor in WKA rats and the lower immunogenic 9098 tumor in ACI rats. Treatment with NSP was effective in causing tumor regression and of prolonging the mean survival time of animals which were inoculated with the KMT-17 tumor whereas it is ineffective with the 9098 tumor. Mitogen studies with 9098 tumor-bearing animals, which were treated with NSP, showed that the PHA-P mitogenic reactivity of spleen cells from NSP treated tumor bearing rats (TBR) was higher than that from NSP untreated TBR. When 9098 tumor bearing animals were given combination therapy with NSP and adriamycin (ADR), a beneficial therapeutic effect of NSP was observed. No adverse effect of NSP treatment was observed when it was given before, intermediate or after ADR treatment. These experiments demonstrate that immunomodulation by NSP may possibly have a beneficial therapeutic effect on tumor growth but the conditions to demonstrate this may be highly variable.