Efficient growth inhibition of ErbB2-overexpressing tumor cells by anti-ErbB2 ScFv-Fc-IL-2 fusion protein in vitro and in vivo

Abstract

Aim: To investigate the antitumor activities of an anti-ErbB2 scFv-Fc-interleukin 2 (IL-2) fusion protein (HFI) in vitro and in vivo. Methods: Fusion protein HFI was constructed. The efficacy of HFI in mediating tumor cell lysis was determined by colorimetric lactate dehydrogenase release assays. The antitumor activity of HFI was evaluated in tumor xenograft models. Results: The fusion protein was folded as a homodimer formed by covalently linking Fc portions and it retained ErbB2 specificity and IL-2 biological activity. HFI mediated antibody-dependent cellmediated cytotoxicity (ADCC) at low effector-to-target ratios in vitro and improved the therapeutic efficacy of IL-2 in experiments in vivo. Conclusion: The genetically-engineered anti-ErbB2 scFv-Fc-IL-2 fusion protein exhibited high efficiency both in mediating ADCC in vitro and significant antitumor activity in tumor xenograft models.

Antibody–cytokine fusion proteins: applications in cancer therapy

“…BALB/c athymic nude mice received subcutaneous injections of the human ovarian carcinoma cell line SKOV-3, which expresses high levels of HER2/ neu. These mice treated intravenously with the antibody-cytokine fusion protein plus human LAK cells showed a reduction of tumor growth in comparison with treatment with rIL-2 plus LAK cells [74]. These results demonstrate the antitumor activity of this antibodycytokine fusion protein in xenograft models.…”

“…This antibody-cytokine fusion protein retained antigen binding, and retained the biological activity of the cytokine, which was evaluated by the induction of proliferation of CTLL-2 T-cell line [73]. Recent studies have shown that anti-erbB2 scFv-Fc-(IL-2) improved the ability of IL-2 to mediate ADCC activity in vitro [74]. BALB/c athymic nude mice received subcutaneous injections of the human ovarian carcinoma cell line SKOV-3, which expresses high levels of HER2/ neu.…”

ErbB-directed immunotherapy: Antibodies in current practice and promising new agents

“…This CD86(111)-IgG-scFv(FRP5) molecule is able to bind two ErbB2 targets on tumor cells and two CD28 proteins on T cells, providing a strong costimulatory signal in addition to mediating T cell-target interaction [170]. Along similar principles, Shi et al [171] have recently reported about an anti-ErbB2 scFv-Fc-IL2 fusion protein that was shown to mediate ADCC in vitro, and exhibited significant antitumor activity in vivo.…”

Stability of the recombinant anti-erbB2 scFv-Fc-interleukin-2 fusion protein and its inhibition of HER2-overexpressing tumor cells

“…When the signals of HER2 were blocked on the surface of the HER2 overexpression cells, the growth of cells was inhibited or the cells entered apoptosis. The three types of cells including SKBR3 cells (HER2 +++ ), SKOV3 cells (HER2 ++ ) and MCF7 cells (HER2 ± ) were provided by Professor N. Guo (Institute of Basic Medical Sciences, China), and were chosen to evaluate HFI antitumor activity in vitro (33). Firstly, the cells were placed on 96-well cell plates, then, serial dilution of the samples were added to the plates and incubated at 37˚C in a humidified atmosphere of 5% CO 2 .…”