A. Guclu

Immunochemotherapy of human malignant melanoma with chlorambucil-carrying antibody

Abstract Heterologous anti-melanoma sera produced against any one patients tumour cross-react, to varying degrees, with both the cytoplasmic and surface antigens of melanoma cells from other patients. Intravenous injections of cross-reacting antimelanoma antibodies bound to chlorambucil were followed by the regression of a considerable number of skin metastases in a patient with disseminated malignant melanoma. When immunochemotherapy had to be discontinued because of anaphylaxis, many of the metastases which had almost completely regressed, reappeared and grew progressively in spite of chemotherapy. One metastatic nodule which had not regressed and another which appeared during immunochemotherapy contained a much larger proportion of tumour cells lacking the cross-reacting surface antigen, when compared to tumour cells in metastatic nodules excised before immunochemotherapy.

Antibody as carrier of 131I in cancer diagnosis and treatment

Cell‐surface localizing heterologous antibodies against mouse EL4 lymphoma, Ehrlich ascites carcinoma, and several human malignant tumors could be bound to varying amounts of131I without interfering with the reactivity of these antibodies with their respective tumor cells. Exposure of the mouse tumor cells to radio‐iodinated antitumor antibodies in vitro, or the injection of radioiodinated antitumor antibodies into mice preinoculated with tumor cells resulted in either partial or complete tumor inhibition depending upon the amount of 131I activity carried by the antibodies. Injecten of comparable amounts of the immunoglobulin alone or of 131I bound to normal globulin did not cause any tumor inhibition. Intraperitoneally injected radio‐iodinated anti‐EL4 antibody was found to localize preferentially in the subcutaneous transplants of EL4 lymphoma. Similar localization of intravenously injected radio‐iodinated antibodies was observed in the metastases of two cancer patients.

Tumor Localization of 131I-Labeled Antibodies by Radionuclide Imaging

Intravenous injections of 131I-Iabeled anti-EL4 lymphoma antibodies showed progressive localization of radioactivity in EL4 transplants but not in B16 melanoma in mice carrying both tumors. Normal rabbit globulin labeled with 131I did not localize in either tumor and cleared more slowly from the internal organs. Metastatic localization of intravenous 131I-labeled anti-tumor antibodies was also observed in 2 cancer patients.

Binding of Chlorambucil with Antitumor Globulins and its Effect on Drug and Antibody Activities

Abstract A method for noncovalently binding chlorambucil to antitumor globulins (ATG) at a pH of about 2·0 is described. Binding of chlorambucil to ATG by this method did not impair either the alkylating activity of chlorambucil or the immunological reactivity of ATG and led to more consistent binding and better retention of both drug and antibody activities than binding at alkaline pH. Variations of temperature between 0°–37° C had no effect on the binding. Gammaglobulins from different species showed different patterns of binding with chlorambucil. Chlorambucil to y-globulin ratio and the concentration of chlorambucil in the reaction mixture were important factors in determining the amount of drug which bound to ATG. Up to 3000 moles of chlorambucil could be bound to each mole of a goat anti-EL 4 IgG, however, there was substantial reduction of antibody activity when 20 moles of chlorambucil bound to a mole of the ATG. Binding of chlorambucil also changed the immunoelectrophoretic mobility of the ATG. Chlorambucil bound anti-EL 4 globulin carried more chlorambucil to target EL 4 cells in vitro than equivalent amounts of chlorambucil bound to normal goat globulin.

Immunoprophylaxis and immunotherapy of EL4 lymphoma

Abstract Injections of appropriate numbers of irradiated, but not iodoacetate treated, EL4 lymphoma cells into C57BL/6J mice were effective in immunoprophylaxis against 106 EL4 cells and in immunotherapy against 102 EL4 cells per mouse. The addition of BCG injections made immunotherapy with irradiated EL4 cells effective against a load of 104 EL4 cells/mouse. Though inoculation of BCG into BALB/c mice inhibited the growth of the allogeneic Ehrlich carcinoma, immunoprophylaxis with BCG only was ineffective against EL4 in C57BL/6J mice. Coating irradiated EL4 cells with concanavalin A did not increase their immunogenicity. Immunotherapy with vibrio cholera neuraminidase and mitomycin treated EL4 cells or with sensitized syngeneic lymphoid cells did not protect EL4 inoculated C57BL/6J mice. However, injections of several rabbit anti-EL4 globulins completely suppressed EL4 lymphoma in a proportion of mice even when treatment was started 120 hr after i.p. inoculation of 104 EL4 cells per mouse. When administered within 72 hr of tumour inoculation 131I or chlorambucil noncovalently bound to nontumour inhibitory anti-EL4 globulins were at least as effective tumour inhibitors as the inhibitory anti-EL4 globulins.

Tumor Localization of 131I-Labeled Antibodies by Radionuclide Imaging1

Intravenous injections of 131I-Iabeled anti-EL4 lymphoma antibodies showed progressive localization of radioactivity in EL4 transplants but not in B16 melanoma in mice carrying both tumors. Normal rabbit globulin labeled with 131I did not localize in either tumor and cleared more slowly from the internal organs. Metastatic localization of intravenous 131I-labeled anti-tumor antibodies was also observed in 2 cancer patients.

Inhibition of a mouse hepatoma by the alkylating agent trenimon linked to immunoglobulins.

SummaryTrenimon was conjugated in active alkylating form to rabbit anti-mouse H6 hepatoma globulin (AHG) with retention of antibody activity. H6 hepatoma-inoculated mice were given various combinations of conjugates, free Trenimon, and unconjugated immunoglobulins in daily injections for 5 days. Linkage of Trenimon to immunoglobulins reduced systemic toxicity of the drug, with comparative retention of its antitumor activity. The antitumor action of Trenimon was potentiated by AHG irrespective of whether the drug was directly linked to AHG or free AHG was administered along with Trenimon linked to normal rabbit globulin (NRG).In vitro, Trenimon bound to AHG was less inhibitory to hepatoma cells than free Trenimon, but more inhibitory than Trenimon-NRG conjugates. There was no significant endocytosis of conjugates by the hepatoma cells. This suggests that unlike free Trenimon, the target molecules of Trenimon-immunoglobulin conjugates are not intracellular DNA but are located on the surface of the hepatoma cells.

Inhibition of pulmonary metastases of B16 melanoma with irradiated tumor cells and BCG

SummaryWhen the tumor-bearing leg of C57BL/6J mice was amputated 16 days after SC inoculation of 106B16 melanoma cells, all the amputated mice died of pulmonary metastases. Transfer of lungs from the amputated to normal syngeneic mice revealed tumor cells in the lungs just after amputation. Repeated weekly injections of BCG and irradiated tumor cells, beginning 24 h after amputation of the tumor-bearing limb, prolonged the survival only of mice presensitized to BCG. Injections of BCG or irradiated melanoma cells alone, of neuraminidase- and mitomycin C-treated tumor cells or of Levamisole had no effect, but injections of ConA-coated tumor cells slightly prolonged the survival of the amputated mice. Both BCG and B16 cells induced humoral and cell-mediated immunity but there was no cross-reactivity between BCG and B16 cells.