Engineered Fenretinide- and Tocilizumab-Releasing Janus Nanoparticles for Site-Directed Immunochemoprevention of Squamous Cell Carcinoma of the Lung.

Background: Both clinical and research data support the contribution of IL6-mediated local immunosuppression coupled with IL6-initiated protumorigenic processes, e.g., sustained proliferation and angiogenesis in the development of many cancers, including lung cancer. By virtue of their pharmacologic advantage, controlled release, local delivery formulations can provide immunochemopreventive relevant agent levels at the target site with negligible systemic agent-related effects. Bioavailability is a major challenge with chemopreventive agents. Methods: Janus nanoparticles (JNPs), however, are a versatile drug delivery platform that addresses several major cancer preventive challenges including bioavailability and retention of bioactivity, with elimination of potential deleterious effects with systemic administration. Furthermore, JNPs feature two discrete compartments that enable concurrent delivery of two chemically distinct agents with complementary mechanisms of action. Results: Our data show that the synthetic vitamin A derivative, fenretinide (4HPR), and the IL6R inhibitor, tocilizumab (TCZ), inhibit pathways integral for the development of lung cancer. Initial molecular modeling and kinase activity assays confirmed that 4HPR serves as a competitive inhibitor for active-site ATP binding of two key IL6 downstream kinases (JAK1, CK2). Concurrent RNA-seq analyses that employed Qiagen Ingenuity Pathway Analysis showed significant inhibition of canonical pathways associated with DNA replication and division in conjunction with significant activation of immunogeneic cell death and TREM 1 signaling pathways and showed the immune-augmenting, cancer-preventive impact of 4HPR-TCZ treatment on gene expression in premalignant lung epithelial cells. Subsequent qRT-PCR analyses corroborated the RNA seq findings and demonstrated 3- to 6-fold increased expression of TREM 1 and immunogenic cell death genes, such as TREM1 and NLRC4 and HSPA6 and DDTT3, respectively. These data collectively guided the development of human serum albumin-chitosan JNPs for the co-delivery of 4HPR and TCZ, respectively. 4HPR-TCZ JNP characterization studies demonstrated high circularities and stability in suspension, as shown by consistency in diameter and minimal changes to the polydispersity index, while confocal microscopy confirmed their biocompartmental nature. Subsequent tertiary chemoprevention in vivo studies that employed a highly aggressive human lung cancer cell line showed that JNPs releasing 4HPR and 4HPR-TCZ significantly reduced tumor volume, as assessed by vital tumor tissue, suppressed proliferation, increased apoptosis, and promoted intratumor vascular instability. Conclusions: Collectively, these studies elucidate 4HPR-TCZ in vitro chemopreventive mechanisms of action and demonstrate proof of concept for JNP-4HPR-TCZ in vivo efficacy.