title: Paclitaxel probably enhances cytotoxicity of natural killer cells against breast carcinoma cells by increasing perforin production.
abstract: Paclitaxel, a semisynthetic taxane, is one of the most active chemotherapeutic agents for the treatment of patients with breast cancer. We focused on the effect of paclitaxel on the cytotoxicity of natural killer (NK) cells. NK cells were purified by negative selection with magnetic beads from peripheral blood mononuclear cells of healthy volunteers. A human breast carcinoma cell line BT-474 and an NK cell-sensitive erythroleukemia cell line K562 were used as targets. Cytotoxicity of NK cells was determined by 51Cr-release assay with labeled target cells. Paclitaxel (1-100 nM) did not affect cellular viability, and significantly enhanced cytotoxicity of NK cells in a dose-dependent manner. Although paclitaxel did not affect Fas-ligand expression of NK cells, paclitaxel induced mRNA and protein production of perforin, an effector molecule in NK cell-mediated cytotoxicity. Concanamycin A, a potent inhibitor of the perforin-mediated cytotoxic pathway, inhibited paclitaxel-dependent NK cell-mediated cytotoxicity. Furthermore, paclitaxel induced activation of nuclear factor kappa B (NF-kappa B) in NK cells. NF-kappa B inhibitor pyrrolidine dithiocarbamate significantly suppressed both paclitaxel-induced perforin expression and NK cell cytotoxicity. Our results show for the first time that paclitaxel enhances in vitro cytotoxicity of human NK cells. Moreover, our results suggest a significant association between enhanced NK cell cytotoxicity, increased perforin production, and NF-kappa B activation.
authors.affiliation: Department of Cancer Therapy and Research, Graduate School of Medical Sciences, 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: Kotaro
authors.initials: K
authors.lastname: Matsumoto
authors.forename: Akira
authors.initials: A
authors.lastname: Tasaki
authors.forename: Naoki
authors.initials: N
authors.lastname: Yamanaka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakashima
authors.forename: Hideo
authors.initials: H
authors.lastname: Kuroki
authors.forename: Katsuya
authors.initials: K
authors.lastname: Nakamura
authors.forename: Masafumi
authors.initials: M
authors.lastname: Nakamura
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Katano
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology*; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000276:immunology*; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic / Q000187:drug effects*; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D016328:NF-kappa B / Q000378:metabolism; D017239:Paclitaxel / Q000494:pharmacology*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D011392:Proline / Q000031:analogs & derivatives* / Q000494:pharmacology; D013859:Thiocarbamates / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D052899:Pore Forming Cytotoxic Proteins; D013859:Thiocarbamates; D054353:Perforin; C066229:prolinedithiocarbamate; D011392:Proline; D017239:Paclitaxel