Enhanced antitumor activity of a combination treatment with a mouse/human chimeric anti-MK-1 antibody and lymphokine-activated killer cells in vitro and in a severe combined immunodeficient mouse xenograft model

Abstract

Mouse monoclonal antibody FU-MK-1, raised against a human gastric adenocarcinoma, recognizes a glycoprotein antigen (termed MK-1 antigen) present on most carcinomas and seems to be valuable in immunodiagnosis and immunotherapy of various cancers. In a recent study, we constructed a mouse/human chimeric antibody, designated Ch FU-MK-1, by fusing the FU-MK-1 V(H) and Vkappa genes to the human Cgamma1 and Ckappa genes, respectively. In the present study, we tested combination immunotherapy of Ch FU-MK-1 with human lymphokine-activated killer (LAK) cells in vitro and in mice with severe combined immunodeficiency (SCID) bearing human MK-1-expressing tumors. In in vitro experiments, Ch FU-MK-1 effectively mediated antibody-dependent cell-mediated cytotoxicity (ADCC) against MK-1-expressing MKN-74 cells, which was completely blocked by an anti-FcR antibody. Since the apoptotic pathway as well as the necrotic pathway have been shown to be utilized in various cytotoxic effector mechanisms, we investigated the role of apoptosis in ADCC mediated by LAK cells and Ch FU-MK-1 against MKN-74 cells. The implication of the apoptosis during ADCC was demonstrated by means of both a terminal-deoxynucleotidyltransferase-mediated dUTP-biotin nick-end-labeling assay and a propidium iodide staining method. In vivo antitumor activity of combination treatment with LAK cells and Ch FU-MK-1 was estimated using SCID mice inoculated s.c. with MKN-74 cells. The i.v. administration of LAK cells and i.p. administration of Ch FU-MK-1 and interleukin-2 (IL-2) produced a marked growth inhibition of MKN-74 tumors in SCID mice. When the actual tumor weights were measured 16 days after initiation of treatment, more than 70% reduction was observed in the group receiving LAK cells plus Ch FU-MK-1 plus IL-2 as compared to the control untreated group. Together these results suggest that Ch FU-MK-1 may serve as a potentially useful immunotherapeutic reagent for human MK-1-expressing tumors.

Prevention of Peritoneal Carcinomatosis from Human Gastric Cancer Cells by Adjuvant-Type Intraperitoneal Immunotherapy in a SCID Mouse Model

“…In addition, a mouse/human chimeric anti-MK-1 antibody in combination with IL-2 was injected intravenously. Sixteen days later the animals were sacrificed and a reduction in subcutaneous tumor mass of approximately 70% was found compared to the untreated controls [22]. In keeping with these findings, tumor mass reduction after immunotherapy with 17-1A mAb could also be realized in the presented model.…”

“…From cell lines of gastric cancer used so far, we chose the line MKN-45 as this cell line expresses 17-1A antigen, and has also been established for the induction of peritoneal carcinomatosis [2, 17, 22]. The antigen 17-1A is a membrane-glycoprotein and belongs to the family of epithelial cellular adhesion molecules (Ep-CAM).…”

SCID mouse models to study human cancer pathogenesis and approaches to therapy: potential, limitations, and future directions

“…In some cases, chimeric mouse-human antibodies (129)(130)(131)(132), consisting of murine variable (V)regions and human constant (C)-regions, are employed since "humanized" antibodies are thought to be preferable for treating cancer patients clinically. The mechanism responsible for the anti-tumor effect observed in these systems is antibody-dependent cellular cytotoxicity (ADCC), mediated either by resident host cells (e.g.…”

“…The mechanism responsible for the anti-tumor effect observed in these systems is antibody-dependent cellular cytotoxicity (ADCC), mediated either by resident host cells (e.g. NK, macrophage, eosinophils) (126-128, 130, 131), or by adoptively-transferred human effector cells (PBL,LAK) (129,132) or a combination of both. Of specific note is the use of anti-human CD40 antibodies for the treatment of human B-cell lymphoma xenografts, since ligation of CD40 on lymphoma cells has direct anti-proliferative effects in addition to mediating ADCC (126, 133).…”

Molecular Identification of a Human Carcinoma‐associated Glycoprotein Antigen Recognized by Mouse Monoclonal Antibody FU‐MK‐1

“…2) In combination with human lymphokine-activated killer cells, Ch FU-MK-1 showed a marked growth inhibition of human MK-1-producing tumor cells in vitro and in severe combined immunodeficiency mice. 3) The histochemical distribution of the MK-1 antigen is similar to the known distributions of a number of carcinoma-associated antigens, such as the 17-1A antigen defined by MAb CO17-1A, 4,5) the Trop-1 antigen 6,7) iden-tified by MAb 162-21.2, the KS1/4 antigen or KSA recognized by MAb KS1/4, [8][9][10] the GA733-2 antigen specified by MAb GA733, 11,12) epithelial glycoprotein-2 (EGP-2) defined by MAb HEA125, 13,14) and the C215 antigen identified by MAb C215. 15,16) These antigens are expressed to varying degrees in epithelial carcinomas such as gastric, colonic, pancreatic, and mammary cancers.…”