Neutralization of TNFα in tumor with a novel nanobody potentiates paclitaxel-therapy and inhibits metastasis in breast cancer

Metastatic disease is the major cause of death from cancer, and immunotherapy and chemotherapy have had limited success in reversing its progression. Researchers have suggested that inflammatory factors in the tumor environment can promote cancer invasion and metastasis, stimulating cancer progression. Thus, novel strategies that target cytokines and modulate the tumor microenvironment may emerge as important approaches for treating metastatic breast cancer. Specific neutralization of pathogenic TNF signaling using a TNF alpha antibody has gained increasing attention. Considering this, a selective human TNF alpha neutralized antibody was generated based on nanobody technology. A TNF alpha-specific nanobody was produced in Pichia pastoris with a molecular mass of 15 kDa and affinity constant of 2.05 nM. In the proliferation experiment, the TNF alpha nanobody could inhibit the proliferation of the breast cancer cell line MCF-7 induced by hTNF alpha in a dose-dependent manner. In the microinvasion model, the TNF alpha nanobody could inhibit the migration of the breast cancer cell lines MCF-7, MDA-MB-231 and the invasiveness of MDA-MB-231 induced by hTNFa in a dose-dependent manner. Drug administration of the combination of paclitaxel with the TNFa nanobody in vivo significantly enhanced the efficacy against 4T-1 breast tumor proliferation and lung metastasis; meanwhile, E-cadherin tumor epithelial marker expression was upregulated, supporting the anti-tumor therapeutic relevance of paclitaxel and the TNF alpha nanobody on EMT. This study highlights the importance of neutralizing low TNF alpha levels in the tumor microenvironment to sensitize the chemotherapeutic response, which has attractive potential for clinical applications. (C) 2016 Elsevier Ireland Ltd. All rights reserved.