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Immunorcacdve fractions ranged from 0.59 to 0.50. Cultured TKB-2 cells expressed 1. I x 1V binding sites/cell for MAb 15 IgG in vitro. The binding of a control antibody and the binding of its fragments to TKB- 2 cells were ~3% of the input doses. The mice with the TKB-2 tumors were given simultaneous injections of 10 ??Ci of i3iI-labeled MAb 15 or its fragments and 10 ??Ci of lUI-labeled control IgG or its fragments. With MAb 15 IgG, the percentage of the injected dose bound per gram of tissue (ID/g) of the tumor was 3.68% at day 7, when the localization index (LI) was 4.38. At day 2 after MAb 15 F(ab’), injection, 1.12% of the ID/g was localized in the tumor and the LI was 3.04. After MAb 15 Fabinjcction,thepercentageoftheID/gofthe tumor was0.3l%andthe LI was 2.58 at day 1. MAb 15 IgG, F(ab’),, and Fab cleared from the blood early, with a half-life of 33, 16, and 9 hours, respectively. The distributions of MAb 15 and its fragments in the normal organs did not differ from those of the control. Radioimaging with 100 ??Ci of ‘rlI- labeled MAb 15 and its fragments showed that 42%. 44%. and 32% of the total-body count were localized in the tumor with IgG at day 7, F(ab’), at day 2, or Fab at day 1, respectively. Because the radioactivity remaining in the tumor with Fab was low, the image was insufficient. Throughout the period, ~10% of the control IgG and its fragments remained in the tumor. Microautoradiography confirmed the binding of MAb 15 and its fragments to the tumor cells. In this study the F(ab’), was the best compromise between the slowly cleared IgG and the poorly Incnliwrl Fah in tnmnr imaeinr.

Antitumor activity of regional lymph node lymphocytes in patients with lung cancer. Yaita H, Yasumoto K, Nagashima A, Sugimachi K, Nomoto K. Second Department of Surgery, Faculty of Medicine, Kyushu University. Hi- gashi-ku. Fukuoka 812. J Surg Gncol 1988;38:165-72.

Cytotoxic activities of regional lymph node lymphocytes (RLNL) and peripheral blood lymphocytes (PBL) of 49 primary lung cancer patients who were subjected to surgical resection were examined by 4 h “Cr release assay. PBL showed significantly lower cytotoxicity against autologous tumor cells than against K562 and QG-56. On the other hand, RLNL exhibited the same level of cytotoxicity against autologous tumorcellsasPBL,althoughthecytotoxicitiesagainstK562 and QG-56 were low. Cytotoxicity of RLNL against autologous tumor cells exhibited a significant degree of depression with the advance of stage, Tand N factors. Cytotoxicity of PBL did not significantly change as the stage progressed. When both PBL and RLNL were cultured with purified interleukin-2 @-IL2) in vitro, their cytotoxic activities were markedly augmented and the cytotoxicities could not be diminished by the treatment with anti-Leu-7 + anti-Leu- 11 b + C’. These facts indicate that the augmented cytotoxicity may be due to lymphokine activated killer (LAK) cells.

Evidence for autocrine mitogenic stimulation by somatomedin-C/ insulin-likegrowthfactor Ionanestablished humanlungcancercell line. Minuto F, Del Monte P, Barreca A, Alama A, Cariola G, Giordano G. Catledra di Fisioparologia Endocrina, Istituto Scientifico di Medicina Inferna, t-16132 Genova. Cancer Res 1988;48:3716-9.

The production of immunoreactive somatomedin-C/insulin-like growth factor I (Sm-C/IGF-I) by the established cell line derived from a human lung carcinoma CALU-6 has been evidenced in the serum-free medium in increasing concentrations as a function of the incubation time. Gel filtration in acid conditions of cell-conditioned medium collected after 72 h showed peeks of immunoreactive Sm-C/IGF-I in the elution volume corresponding to the molecular weight of the synthetic Sm-C/IGF-I, and in the high molecular weight region, where specific binding sites for Sm-C/IGF-I could bc also demonstrated. These results indicate that this established cell line produces high amounts of im-

munoreactive Sm-C/IGF-I and of Sm-C/IGF-I carrier protein. The pooled fractionscorresponding to themolecularweight of synthetic Sm- C/IGF-I showed a competitive binding curve parallel to the standard in the Sm-C/IGF-I RIA system, and a mitogenic activity on cells from the same line similar to the one observed using two different pure Sm-C/ IGF-I preparations, obtained by chemical synthesis or by DNA recom- binanttechnology. Whenamonoclonalantibody(sm-1.2)raisedagainst Sm-C/IGF-I was added into the medium, the mitogenic effect observed by both synthetic and cell derived Sm-CflGF-I peptide was completely abolished; the monoclonal antibody also partially inhibited the effect of 10% fetal calf serum and the thymidine incorporation observed in serum-free medium without growth factors. In serum-free medium the monoclonal antibody produced a 45% reduction of cells in S phase by thymidine labeling index without modification of the growth fraction as determined by primer-dependent _-DNA polymerase labeling index. In conclusion it seems that Sm-C/IGF-I has a critical role in the autocrine stimulation of the replication of this cell line.

Induction of in vitro tumoricidal activity in alveolar macrophages and monocytes from patients with lung cancer. Thomassen MJ, Wiedemann HP, Bama BP, Farmer M, Ahmad M. Department of Pulmonary Disease, Cleveland Clinic Foundation, Cleveland, OH 44106. Cancer Res 1988;48:3949-53.

Human alveolar macrophages (AMs) and blood monocytes were obtained from 65 smoking and nonsmoking normal volunteers and 29 patients with lung cancer. The oxidative metabolic response of these cells was measured by superoxide anion production after incubation with lipopolysaccharide. In addition, tumoricidal activity of AMs and monocytes was assessed against [3H]thymidine-labeled tumor target cells. Smoking was associated with depressed AM superoxide anion responses in normals but not in patients. In contrast, smoking appeared to slightly elevate monocyte superoxide anion activity. AMs and monocytes exposed to lipopolysaccharide or recombinant gamma- interferon showed tumoricidal activity in all groups. Mean cytotoxicity values of smoking patients versus smoking normals and exsmoking patients versus nonsmoking normals were not significantly different. Smoking, however, in both patients and normals was associated with significantly (P c 0.00s) depressed AM cytotoxicity levels (< 40%) compared to nonsmoking volunteers andexsmoking patients. Activated AMs from cancer patients and normals were cytotoxic against three different tumorigenic cell lines but not against a nontumorigenic line. No correlation between monocyte and AM cytotoxic activity within single individuals was found. We conclude that AM and monocytes from smoking and exsmoking patients can be activated after exposure to immunomodulators; however, smoking may be slightly suppressive to cytotoxic responses. These studies provide a rationale for clinical trials of immunomodulators in patients with lung cancer.

Production of immunoreactive insulin-like growth factor I and response to exogenous IGF-I in small cell lung cancer cell lines. Jaques G, Rotsch M, Wegmann C, Worsch U, Maasberg M, Havemann K. PhilippsUniversityMedical Center,DivisionofHematologylOncol- ogy, 3550 Marburg. Exp Cell Res 1988;176:336-43.

Small cell lung cancer (SCLC) cell lines were examined for the presence of insulin-like growth factor I-related protein (IGF-I) in ceil pellets and culture media. IGF-I immunoreactivity was detected in 1 I/ 14 pellets, ranging from 12 to 76 mIU/mg soluble protein. The IGF-I levels in the cell pellets showed a correlation to the corresponding culture media. IGF-I binding sites were found in all tested cell lines. The maximum binding (B(max)) ranged from 131 to 1230 fmovmg protein and the dissociation constant (K(D)) from 0.89 to 5.21 nM. The incorporation of [‘Hlthymidine in the presence of recombinant human IGF-I resulted in aclearly increased DNA synthesis in twoof seven cell lines. Thus, IGF-I may be an important growth factor in SCLC.