Sy. Im et al., PREVENTION OF TUMOR-GROWTH AND METASTASIS BY INTERLEUKIN (IL)-10 TRANSFECTION - A POTENT INHIBITORY ROLE OF IL-10 ON ANGIOGENESIS, Molecules and cells, 6(4), 1996, pp. 473-480
The influence of interleukin-10 (IL-10) on tumor growth and metastasis
was evaluated in murine melanoma and sarcoma cells manipulated by gen
e transfer to secrete IL-10. IL-10 gene transfection of the tumor cell
s resulted in antimetastatic and antitumor effects, which correlated w
ith the amount of IL-10 secretion; mice given injection of the highest
IL-10-secretors developed neither subcutaneous growth nor pulmonary m
etastasis. This effect of IL-10 transfection was inhibited by anti-IL-
10 antibodies. In addition, IL-10-secreting cells suppressed the subcu
taneous growth of coinjected parental tumor cells. Immunohistology wit
h anti-CD68 and anti-CD34 antibodies revealed that macrophage infiltra
tion and neovasculization within parental sarcoma tumors were profound
ly inhibited in IL-10-transfected tumors. These findings strongly sugg
est that IL-10 suppresses the tumor growth by inhibiting the formation
of new blood vessels within the tumors, the formation of which is ach
ieved by tumor infiltrating macrophages.