INTERLEUKIN-4 INHIBITS GROWTH OF A HUMAN LUNG-TUMOR CELL-LINE IN-VITRO AND HAS THERAPEUTIC ACTIVITY AGAINST XENOGRAFTS OF THIS CELL-LINE IN-VIVO

In the present study we report that recombinant human (rh) interleukin 4 (IL-4) has direct, dose-dependent antiproliferative effects on the human lung cancer cell line CCL 185 in vitro as measured by a human tu mor cloning assay (HTCA). The biological response of the tumor cells t o rhIL-4 is correlated with expression of specific binding sites for h uman (h) IL-4 on the cell surface. Furthermore, we have xenotransplant ed CCL 185 into BALB/c nu/nu mice. Subsequently, the mice were treated for 17 days with twice 0.5 mg/m2 rhIL-4 or control vehicle subcutaneo usly per day. Treatment with rhIL-4 yielded a significant inhibition o f tumor growth versus control. Histology of the tumors in both groups showed no marked infiltration of the tumors with murine hematopoietic and lymphocytic cells consistent with the species specificity of IL-4. We conclude that rhIL-4 has direct antiproliferative effects on the g rowth of a human lung tumor cell line in vitro and in vivo which toget her with its regulatory effects on various effector cell populations m akes this cytokine a possible candidate for experimental cancer treatm ent.