title: Dietary administration of the proapoptotic vitamin E analogue alpha-tocopheryloxyacetic acid inhibits metastatic murine breast cancer.
abstract: The ability of the vitamin E (RRR-alpha-tocopherol) derivatives alpha-tocopheryl succinate (alpha-TOS) and alpha-tocopheryloxyacetic acid (alpha-TEA) to suppress tumor growth in preclinical animal models has recently led to increased interest in their potential use for treating human cancer. To make the use of these vitamin E analogues more clinically relevant, we compared the antitumor efficacy of orally and i.p. delivered forms of alpha-TEA and alpha-TOS against a murine mammary cancer (4T1) that bears resemblance to human breast cancer because of its poor immunogenicity and high metastatic potential. In cell culture studies, we showed that both compounds inhibited tumor colony formation and induced apoptotic death of tumor cells. To avoid solubility concerns associated with the hydrophobicity of alpha-TEA and alpha-TOS, we used the vesiculated forms of alpha-TEA (V alpha-TEA) and alpha-TOS (V alpha-TOS) for the in vivo tumor studies. Both compounds inhibited the growth of preestablished 4T1 tumors when given i.p. However, when given by oral gavage, only the esterase-resistant V alpha-TEA was able to suppress primary tumor growth and reduce lung metastasis. To make this approach more translatable to the clinic, alpha-TEA was incorporated into the diet and fed to tumor-bearing mice. We report here for the first time that dietary alpha-TEA delivery significantly inhibited primary tumor growth and dramatically reduced spontaneous metastatic spread to the lung in prophylactic and therapeutic settings. This study suggests that dietary alpha-TEA could prove useful as a relatively easy and effective modality for treating metastatic breast cancer.
authors.affiliation: Department of Immunobiology, Arizona Cancer Center, BIO5 Institute for Collaborative Bioresearch, University of Arizona, Tucson, AZ 85724, USA.
authors.forename: Tobias
authors.initials: T
authors.lastname: Hahn
authors.forename: Lajos
authors.initials: L
authors.lastname: Szabo
authors.forename: Mikhal
authors.initials: M
authors.lastname: Gold
authors.forename: Lalitha
authors.initials: L
authors.lastname: Ramanathapuram
authors.forename: Laurence H
authors.initials: LH
authors.lastname: Hurley
authors.forename: Emmanuel T
authors.initials: ET
authors.lastname: Akporiaye
mesh_terms: D000284:Administration, Oral; D000821:Animal Feed; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects*; D045744:Cell Line, Tumor / Q000187:drug effects; D005260:Female; D057927:Hydrophobic and Hydrophilic Interactions; D007274:Injections, Intraperitoneal; D008325:Mammary Neoplasms, Experimental / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009362:Neoplasm Metastasis / Q000517:prevention & control*; D012995:Solubility; D024505:Tocopherols; D014410:Tumor Stem Cell Assay; D014810:Vitamin E / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000970:Antineoplastic Agents; D014810:Vitamin E; C488288:2,5,7,8-tetramethyl-2R-(4R,8R,12-trimethyltridecyl)chroman-6-yloxy acetic acid; D024505:Tocopherols