title: Combination of adoptive immunotherapy with Herceptin for patients with HER2-expressing breast cancer.
abstract: Clinical use of Herceptin (trastuzumab), which is a humanized monoclonal antibody against HER2, started for patients with HER2-overexpressing breast cancer. To potentiate the efficacy of the Herceptin therapy, this study focused on the combination of Herceptin with activated immune lymphocytes. We used peripheral blood mononuclear cells (PBMCs) as effector cells and used HER2-unexpressing K562 cells, HER2-weakly-expressing breast carcinoma cells (Breast-M), or HER2-strongly-expressing breast carcinoma cells (BT-474) as target cells. Interleukin-2 (IL-2)-activated PBMCs, IL-2/OKT-3-activated PBMCs and a streptococcal preparation OK-432-activated PBMCs were generated and used as effector cells. Cytotoxic activity was determined with 4-hour 51Cr release assay. Both fresh PBMCs and activated PBMCs exhibited Herceptin-dependent cytotoxicity. Importantly, Herceptin-dependent cytotoxicity was found even at a lower effector to target cell ratio (E/T ratio) than that of Herceptin-independent cytotoxicity. In addition, Herceptin-dependent cytotoxicity by these activated PBMCs was observed even in HER2-weakly-expressing Breast-M cells. Since gamma-globulin or anti-CD16 antibody abrogated Herceptin-dependent cytotoxicity, it seems likely that antibody-dependent cellular cytotoxicity (ADCC) plays an important role in the Herceptin-dependent cytotoxicity. We present a recurrent breast cancer patient with malignant pleural effusion, in which HER2-strongly-expressing tumor cells were present, who was undergoing Herceptin therapy. Cluster formation between tumor cells and intrapleural mononuclear cells was induced 24 hours after intravenous injection of Herceptin (4 mg/kg). Mononuclear cells bound specifically to HER2-strongly-expressing tumor cells but not to other cells, such as mesothelial cells, suggested a Herceptin-mediated binding like ADCC in vivo. Taken together, these findings suggest that the combination of Herceptin with various types of activated lymphocytes may be a new therapeutic strategy, not only for HER2-strongly-expressing breast cancer but also for HER2-weakly-expressing cancer.
authors.affiliation: Department of Cancer Therapy and Research, Graduate School of Medical Science, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Kubo
authors.forename: Takashi
authors.initials: T
authors.lastname: Morisaki
authors.forename: Hideo
authors.initials: H
authors.lastname: Kuroki
authors.forename: Akira
authors.initials: A
authors.lastname: Tasaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamanaka
authors.forename: Kotaro
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Katsuya
authors.initials: K
authors.lastname: Nakamura
authors.forename: Hideya
authors.initials: H
authors.lastname: Onishi
authors.forename: Eishi
authors.initials: E
authors.lastname: Baba
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Katano
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology* / Q000628:therapy*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000276:immunology* / Q000628:therapy*; D045744:Cell Line, Tumor; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007376:Interleukin-2 / Q000276:immunology / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology*; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000276:immunology*; D011961:Receptors, Fc / Q000276:immunology; D000068878:Trastuzumab
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D007376:Interleukin-2; D018719:Erb-b2 Receptor Tyrosine Kinases; D011961:Receptors, Fc; D000068878:Trastuzumab