Somatostatin suppresses growth of murine myeloid leukemia in vivo.

Daily injections of somatostatin into mice with myeloid leukemia retarded the tumor growth. This myeloid leukemia is an insulin-dependent tumor (in that it grows more slowly in hypoinsulinemic diabetic mice than in nondiabetic animals). Since somatostatin decreased the level of immunoreactive insulin in mice with myeloid leukemia, and since the treatment with insulin abrogated the antileukemic effect of somatostatin, we attribute retarded growth of this leukemia to decreased secretion of insulin, caused by somatostatin.