Bovine serum albumin-stabilized nano-delivery system potentiates targeted anti-angiogenic therapy and synergistic photo-immunotherapy to restrict lung cancer metastasis.

Abstract

Tumor angiogenesis plays a crucial role in tumor metastasis as it provides uninterrupted supply of oxygen and nutrients to the rapidly growing tumor cells. The Food and Drug Administration (FDA) recommends that anti-angiogenesis should be used as a supplement along with other tumor treatment modalities, and therefore, anti-angiogenic therapy has recently become an attractive strategy to control tumor metastasis. In our previous work, we reported that glioma-associated oncogene 1 (Gli1) is involved in the angiogenesis of non-small cell lung cancer (NSCLC), and thus could serve as a novel target for anti-angiogenic therapy. Herein, we design a protein-based nano-delivery system (defined as BCRG) for 1) the tumor targeted delivery of angiogenic inhibitor (GANT61) of Gli1 gene to prevent angiogenesis in NSCLC and 2) collaborative photodynamic-immunotherapy to kill primary tumor cells and further restrict tumor recurrence through immune activation. A library of BCRG nanoparticles was developed by varying the ratios of different components, and the best formulation (1:4 ratio, 145 nm) was selected. Under laser activation, BCRG triggered the photodynamic killing of primary NSCLC tumor through singlet oxygen generation and further induced immunogenic cell death (ICD) in vivo. Simultaneously, the tumor targeted delivery of GANT61 by BCRG inhibit angiogenesis in NSCLC tumor-bearing mice by modulating tumor angiogenic pathway (down-regulating Snail and N-cadherin, up-regulating E-cadherin to reduce epithelial-mesenchymal transition through inhibiting Gli1 gene, and reducing the secretion of basic fibroblast growth factor by NSCLC tumor cells), thereby actively restricts tumor metastasis to the distant organs. Importantly, the robust immune activation by ICD during tumor PDT further prevent tumor recurrence and relapse. We anticipate that the collaborative anti-angiogenic/photodynamic-immunotherapy could be clinically applied as a standalone treatment for eliminating primary tumor and further restricting tumor metastasis and recurrence at the later stages. STATEMENT OF SIGNIFICANCE: Conventional anti-angiogenic agents for the treatment of lung cancer show poor solubility and no tumor targeting, whereas PDT treatment alone causes tumor hypoxia to promote angiogenesis. Herein, a bovine serum albumin-based targeted nano-delivery system (BCRG) is constructed by integrating a photodynamic drug (Ce6), a targeting peptide (RGD), and an anti-angiogenic agent (GANT61) for synergistic anti-angiogenic/photo-immunotherapy. The as-developed BCRG exhibits active tumor targeting, good biocompatibility, and pH-responsive drug release, thereby triggering PDT-induced immunogenic cell death to kill primary tumors, inhibiting Gli1 gene to block angiogenesis and EMT, alleviating tumor hypoxia, restricting distant metastasis, and activating anti-tumor immunity to prevent recurrence without any systemic toxicity. This work demonstrates a rational design strategy to develop a multifunctional nanoplatform for synergistic therapy against metastatic tumors.