Nanoparticle-Mediated Trapping of Wnt Family Member 5A in Tumor Microenvironments Enhances Immunotherapy for B-Raf Proto-Oncogene Mutant Melanoma

Abstract

Development of an effective treatment against advanced tumors remains a major challenge for cancer immunotherapy. Approximately 50% of human melanoma is driven by B-Raf proto-oncogene mutation (BRAF mutant). Tumors with such mutation are desmoplastic, highly immunosuppressive, and often resistant to immune checkpoint therapies. We have shown that immunotherapy mediated by low-dose doxorubicin-induced immunogenic cell death was only partially effective for this type of tumor and not effective in long-term inhibition of tumor progression. Wnt family member 5A (Wnt5a), a signaling protein highly produced by BRAF mutant melanoma cells, has been implicated in inducing dendritic cell tolerance and tumor fibrosis, thus hindering effective antigen presentation and T-cell infiltration. We hypothesized that Wnt5a is a key molecule controlling the immunosuppressive tumor microenvironment in metastatic melanoma. Accordingly, we have designed and generated a trimeric trap protein, containing the extracellular domain of Fizzled 7 receptor that binds Wnt5a with a K ∼ 278 nM. Plasmid DNA encoding for the Wnt5a trap was delivered to the tumor by using cationic lipid-protamine-DNA nanoparticles. Expression of Wnt5a trap in the tumor, although transient, was greater than that of any other major organs including liver, resulting in a significant reduction of the Wnt5a level in the tumor microenvironment without systematic toxicity. Significantly, combination of Wnt5a trapping and low-dose doxorubicin showed great tumor growth inhibition and host survival prolongation. Our findings indicated that efficient local Wnt5a trapping significantly remodeled the immunosuppressive tumor microenvironment to facilitate immunogenic cell-death-mediated immunotherapy.

Materials for Immunotherapy

“…Huang and co‐workers developed cationic liposome‐protamine‐HA nanoparticles to deliver siRNA to silence CD47 expression in solid tumors . Starting in 2017, the Huang group published a series of papers using a similar particle design (i.e., a liposome‐protamine‐DNA (LPD) nanoparticle) to deliver genes for various anticancer purposes, including those that encode for proteins that bind to (or trap): i) the immunosuppressive proteins PD‐L1 and C‐X‐C motif chemokine (CXCL)12, ii) the signaling protein Wnt family member 5A (Wnt5a), which has been implicated in inducing dendritic cell tolerance, iii) IL‐10, which is known to suppress dendritic cells from releasing IL‐12, to develop Th1 responses, iv) LPS, which relieved the immunosuppressive microenvironment and boosted anti‐PD‐L1 therapy against colorectal tumors, and v) CCR‐7, which is associated with the metastasis of breast cancer . The group also investigated the delivery of siRNA to silence high mobility group protein A1 (HMGA1), which is associated with immunosuppression .…”

Locally Trapping the C‐C Chemokine Receptor Type 7 by Gene Delivery Nanoparticle Inhibits Lymphatic Metastasis Prior to Tumor Resection

“…As shown in Figure b, CCR7 trap decreased the migration of HuT78 cells stimulated with mCCL19 (100 ng mL −1 ), with an IC 50 around 239 × 10 −9 m . To efficiently and preferentially deliver the CCR7 trap pDNA into the tumor site, we used LPD NPs that were previously well‐characterized (Figure c) . CCR7 trap pDNA was first condensed with the cationic protamine to form a complex with slight excess anions.…”

“…Using transmission electron microscopy (TEM), LPD NPs appeared as compacted spheres of ≈95 nm in diameter, slightly smaller than the hydrated value measured by DLS (Figure d). Aminoethyl anisamide (AEAA) has been exploited in the Huang lab for tumor‐targeted delivery of LPD NPs on many epithelial cancers overexpressing the sigma‐1 receptor including 4T1 murine breast cancer . The AEAA functionalized LPD NPs labeled with DiD mainly accumulated in the tumor as revealed with IVIS imaging system 24 h after intravenous (i.v.)…”

“…The small size of the CCR7 trap allows for efficient tumor penetration and rapid clearance, which could presumably result in significantly reduced immune‐related systemic toxicity. To achieve the local and transient expression in TME, we delivered a plasmid encoding CCR7 trap into the tumor site, by using a tumor targeting nanoparticle platform—lipid‐protamine‐DNA (LPD) nanoparticles (NPs) . Accordingly, CCR7 traps were produced by and secreted out of the tumor cells and took function locally at the TME (Scheme ).…”

A Chemical-genetics and Nanoparticle Enabled Approach forin vivoProtein Kinase Analysis

“…Nanoparticles have been widely used for therapeutic agent delivery in biomedical researches. For instance, the LCP nanoparticle has been used to deliver gene therapy agents such as siRNA and expression vectors (55,56). It has also been used to deliver many therapeutical chemicals such as gemcitabine triphosphate (20,21), doxorubicin and paclitaxel (57).…”