title: A novel drug delivery system using IL-2 activated NK cells and Zyn-linked doxorubicin.
abstract: Adoptively transferred IL-2 activated NK (A-NK) cells selectively accumulate within tumor metastases which recommends them as vehicles for locoregional drug delivery. Zyn-Linkers are membrane-binding lipophilic dyes which can be coupled by a variety of conjugation chemistries to therapeutic agents. We have previously demonstrated that A-NK cells labeled with PKH26 are able to accumulate within established B16 melanoma pulmonary metastases by 16 h at a concentration of over 600 cells/mm2 of tumor tissue (Basse et al. J. Exp. Med. 174: 479 1991). Zyn-205 is a prodrug in which doxorubicin is attached to a similar Zyn-Linker through an acid-sensitive bond. We have optimized the ex vivo labeling conditions and found that a 10 min incubation with 25 microM Zyn-205 results in the uptake of over 10(8) drug molecules per cell with no effect on either cell viability or cytolytic activity up to 24 h after labeling. Given these parameters, the amount of drug which may be carried to and concentrated in metastatic lesions represents a local concentration of approximately 15 microM. In addition, A-NK cells carrying Zyn-Linked doxorubicin at an equivalent dose of 25 micrograms/kg was therapeutically comparable to a systemic dose of 8 mg/kg (320x more) in the 3LL model of experimental metastasis. These data indicate that A-NK cells bearing Zyn-Linked chemotherapeutic agents represent a unique and feasible method to target chemotherapeutic agents to cancer metastases and that therapeutic doses can be attained without unwanted systemic exposure.
authors.affiliation: Department of Molecular Biology, University of North Texas Health Science Center at Fort Worth 76107-2118, USA. rgoldfar@hsc.unt.edu
authors.forename: R H
authors.initials: RH
authors.lastname: Goldfarb
authors.forename: R
authors.initials: R
authors.lastname: Koelemij
authors.forename: K A
authors.initials: KA
authors.lastname: Muirhead
authors.forename: B M
authors.initials: BM
authors.lastname: Ohlsson-Wilhelm
authors.forename: B D
authors.initials: BD
authors.lastname: Gray
authors.forename: P J
authors.initials: PJ
authors.lastname: Kuppen
authors.forename: P H
authors.initials: PH
authors.lastname: Basse
authors.forename: G
authors.initials: G
authors.lastname: al-Atrash
authors.forename: R P
authors.initials: RP
authors.lastname: Kitson
mesh_terms: D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000737:chemistry; D002452:Cell Count / Q000187:drug effects; D004317:Doxorubicin / Q000008:administration & dosage* / Q000737:chemistry; D016503:Drug Delivery Systems; D005456:Fluorescent Dyes / Q000737:chemistry; D016219:Immunotherapy, Adoptive; D007376:Interleukin-2 / Q000494:pharmacology*; D015979:Killer Cells, Lymphokine-Activated / Q000166:cytology / Q000187:drug effects / Q000276:immunology*; D008175:Lung Neoplasms / Q000188:drug therapy / Q000276:immunology / Q000556:secondary; D008546:Melanoma, Experimental / Q000188:drug therapy / Q000276:immunology / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D016019:Survival Analysis; D016896:Treatment Outcome; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D005456:Fluorescent Dyes; D007376:Interleukin-2; D004317:Doxorubicin