title: A novel vaccine targeting gastrin-releasing peptide: efficient inhibition of breast cancer growth in vivo.
abstract: Gastrin-releasing peptide (GRP), a bombesin-like peptide, is an autocrine growth factor that can stimulate the growth of various cancer cells. We developed a novel protein vaccine HSP65-(GRP-10)(6) (HG6) that consists of six copies of a 10-amino acid residue epitope of GRP C-terminal fragment carried by mycobacterial 65 kDa HSP65 and then immunized mice via subcutaneous injection. Strong humoral and cell-mediated immune responses were induced. High titer of anti-GRP antibodies was detected in immunized mice sera by ELISA and verified by Western blot analysis. Activity of CD4+T lymphocytes, especially high levels of interferon (INF)-gamma, were developed in mice immunized with HG6 when compared with HSP65 or PBS. We found that immunogene tumor therapy with a vaccine based on GRP was effective at both protective and therapeutic antitumor immunity in breast tumor models in mice. The purified GRP monoclonal antibody (McAb) was proved to be potential in inhibiting EMT-6 tumor cell proliferation in vitro. The attenuation induced by active immune responses on tumor-induced angiogenesis was observed with an intradermal tumor model in mice. Taken together, we demonstrate for the first time that immune responses that are elicited by a novel chimeric protein vaccine targeting GRP can suppress the proliferation of breast tumor cell EMT-6 in mice, and it may be of importance in the further exploration of the applications of other autocrine growth factor identified in human and other animal in cancer therapy.
authors.affiliation: Minigene Pharmacy Laboratory of the Biopharmaceutical College, China Pharmaceutical University, Nanjing, PR China.
authors.forename: Wu
authors.initials: W
authors.lastname: Guojun
authors.forename: Guo
authors.initials: G
authors.lastname: Wei
authors.forename: Ouyan
authors.initials: O
authors.lastname: Kedong
authors.forename: He
authors.initials: H
authors.lastname: Yi
authors.forename: Xie
authors.initials: X
authors.lastname: Yanfei
authors.forename: Chen
authors.initials: C
authors.lastname: Qingmei
authors.forename: Zhang
authors.initials: Z
authors.lastname: Yankai
authors.forename: Wu
authors.initials: W
authors.lastname: Jie
authors.forename: Fan
authors.initials: F
authors.lastname: Hao
authors.forename: Li
authors.initials: L
authors.lastname: Taiming
authors.forename: Liu
authors.initials: L
authors.lastname: Jingjing
authors.forename: Cao
authors.initials: C
authors.lastname: Rongyue
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015153:Blotting, Western; D001839:Bombesin / Q000276:immunology*; D001943:Breast Neoplasms / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D019496:Cancer Vaccines / Q000008:administration & dosage*; D049109:Cell Proliferation; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay; D007114:Immunization; D007371:Interferon-gamma / Q000378:metabolism; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D009389:Neovascularization, Pathologic; D010446:Peptide Fragments / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D023041:Xenograft Model Antitumor Assays
chemical_list: D000911:Antibodies, Monoclonal; D019496:Cancer Vaccines; D017931:DNA Primers; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; C040794:neuromedin C; D007371:Interferon-gamma; D001839:Bombesin