title: Immunization against HIF-1α Inhibits the Growth of Basal Mammary Tumors and Targets Mammary Stem CellsIn Vivo.
abstract: Purpose:Triple-negative breast cancer (TNBC) represents a cancer stem cell-enriched phenotype. Hypoxia-inducible factor-1α (HIF-1α) induces the expression of proteins associated with stemness and is highly upregulated in TNBC. We questioned whether HIF-1α was immunogenic and whether vaccination targeting HIF-1α would impact the growth of basal-like mammary tumors in transgenic mice.Experimental Design:We evaluated HIF-1α-specific IgG in sera from controls and patients with breast cancer. Class II epitopes derived from the HIF-1α protein sequence were validated by ELISPOT. To assess therapeutic efficacy, we immunized Tg-MMTVneu and C3(1)Tag mice with HIF-1α Th1-inducing peptides. Stem cells were isolated via magnetic bead separation. Levels of HIF-1α and stem cells in the tumor were quantitated by Western blotting and flow cytometry.Results:The magnitude (P< 0.001) and incidence (P< 0.001) of HIF-1α-specific IgG were elevated in TNBC patients compared with controls. Both breast cancer patients and donors showed evidence of HIF-1α-specific Th1 and Th2 immunity. Three HIF-1α-specific Th1 class II restricted epitopes that were highly homologous between species elicited type I immunity in mice. After HIF-1α vaccination, mammary tumor growth was significantly inhibited in only C3(1)Tag (basal-like/stem cellhigh;P< 0.001) not TgMMTV-neu (luminal/neu/stem celllow;P= 0.859) murine models. Vaccination increased type I T cells in the tumor (P= 0.001) and decreased cells expressing the stem cell marker, Sca-1, compared with controls (P= 0.004).Conclusions:An HIF-1α vaccine may be uniquely effective in limiting tumor growth in TNBC. Inhibiting outgrowth of breast cancer stem cells via active immunization in the adjuvant setting may impact disease recurrence.Clin Cancer Res; 23(13); 3396-404. ©2016 AACR.
authors.affiliation: Tumor Vaccine Group, Center for Translational Medicine in Women's Health, University of Washington, Seattle, Washington. dcecil@uw.edu.
authors.forename: Denise L
authors.initials: DL
authors.lastname: Cecil
authors.affiliation: Tumor Vaccine Group, Center for Translational Medicine in Women's Health, University of Washington, Seattle, Washington.
authors.forename: Meredith
authors.initials: M
authors.lastname: Slota
authors.affiliation: Seattle Genetics, Inc., Bothell, Washington.
authors.forename: Megan M
authors.initials: MM
authors.lastname: O'Meara
authors.affiliation: Tumor Vaccine Group, Center for Translational Medicine in Women's Health, University of Washington, Seattle, Washington.
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Curtis
authors.affiliation: Tumor Vaccine Group, Center for Translational Medicine in Women's Health, University of Washington, Seattle, Washington.
authors.forename: Ekram
authors.initials: E
authors.lastname: Gad
authors.affiliation: Tumor Vaccine Group, Center for Translational Medicine in Women's Health, University of Washington, Seattle, Washington.
authors.forename: Yushe
authors.initials: Y
authors.lastname: Dang
authors.affiliation: Tumor Vaccine Group, Center for Translational Medicine in Women's Health, University of Washington, Seattle, Washington.
authors.forename: Daniel
authors.initials: D
authors.lastname: Herendeen
authors.affiliation: Tumor Vaccine Group, Center for Translational Medicine in Women's Health, University of Washington, Seattle, Washington.
authors.forename: Lauren
authors.initials: L
authors.lastname: Rastetter
authors.affiliation: Tumor Vaccine Group, Center for Translational Medicine in Women's Health, University of Washington, Seattle, Washington.
authors.forename: Mary L
authors.initials: ML
authors.lastname: Disis
mesh_terms: D000818:Animals; D019496:Cancer Vaccines / Q000008:administration & dosage* / Q000276:immunology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000097:blood / Q000235:genetics / Q000276:immunology*; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D015674:Mammary Neoplasms, Animal / Q000097:blood / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D051379:Mice; D009364:Neoplasm Recurrence, Local / Q000097:blood / Q000276:immunology / Q000628:therapy; D014411:Neoplastic Stem Cells / Q000276:immunology; D064726:Triple Negative Breast Neoplasms / Q000097:blood / Q000276:immunology / Q000473:pathology / Q000628:therapy*
chemical_list: D019496:Cancer Vaccines; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007074:Immunoglobulin G