School of Food and Biology Engineering, Key Laboratory of Fermentation Engineering, Hubei University of Technology , Wuhan 430068, China.
Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH) and the Center for Biotechnology & Genomics, Texas Tech University , Lubbock, Texas 79416, United States.
ACS Nano. 2018 Feb 27;12(2):1250-1261. doi: 10.1021/acsnano.7b07384. Epub 2018 Jan 31.
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.
开发针对晚期肿瘤的有效治疗方法仍然是癌症免疫治疗的主要挑战。大约 50%的人类黑色素瘤是由 B-Raf 原癌基因突变（BRAF 突变）驱动的。具有这种突变的肿瘤是促结缔组织的，高度免疫抑制的，并且经常对免疫检查点疗法产生抗性。我们已经表明，低剂量多柔比星诱导的免疫原性细胞死亡介导的免疫疗法对此类肿瘤仅部分有效，并且不能有效抑制肿瘤进展的长期抑制。Wnt 家族成员 5A（Wnt5a）是一种由 BRAF 突变黑色素瘤细胞高度产生的信号蛋白，已被牵连诱导树突状细胞耐受和肿瘤纤维化，从而阻碍有效的抗原呈递和 T 细胞浸润。我们假设 Wnt5a 是控制转移性黑色素瘤中免疫抑制性肿瘤微环境的关键分子。相应地，我们设计并生成了三聚体陷阱蛋白，该蛋白包含与 Wnt5a 结合的 K ∼ 278 nM 的 Fizzled 7 受体的细胞外结构域。编码 Wnt5a 陷阱的质粒 DNA 通过阳离子脂质-鱼精蛋白-DNA 纳米粒递送到肿瘤中。尽管 Wnt5a 陷阱在肿瘤中的表达是短暂的，但大于包括肝脏在内的任何其他主要器官，导致肿瘤微环境中的 Wnt5a 水平显着降低，而没有系统性毒性。重要的是，Wnt5a 捕获与低剂量多柔比星的联合使用显示出对肿瘤生长的显著抑制和宿主存活时间的延长。我们的研究结果表明，有效的局部 Wnt5a 捕获显着重塑了免疫抑制性肿瘤微环境，以促进免疫原性细胞死亡介导的免疫疗法。
