Theranostics 2022; 12(14):6088-6105. doi:10.7150/thno.72509 This issue
1. The United Innovation of Mengchao Hepatobiliary Technology Key Laboratory of Fujian Province, Mengchao Hepatobiliary Hospital of Fujian Medical University, Fuzhou 350025, P. R. China.
2. Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou 350122, P.R. China.
3. Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, P. R. China.
4. Mengchao Med-X Center, Fuzhou University, Fuzhou 350116, P. R. China.
5. Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, P.R. China.
*These authors contributed equally to this work.
Colorectal cancer (CRC), mostly categorized as a low immunogenic microsatellite-stable phenotype bearing complex immunosuppressive tumor microenvironment (TME), is highly resistant to immunotherapy. Seeking safe and efficient alternatives aimed at modulating tumor immunosuppressive TME to improve outcome of CRC is highly anticipated yet remains challenging.
Methods: Enlightened from the drug complementary art in traditional Chinese medicine, we designed a self-assembled nanomedicine (termed LNT-UA) by the natural active ingredients of ursolic acid (UA) and lentinan (LNT) through a simple nano-precipitation method, without any extra carriers, for CRC immunotherapy.
Results: UA induces immunogenic cell death (ICD), while LNT further promotes dendritic cell (DC) maturation and repolarizes tumor-associated macrophage (TAM) from a protumorigenic M2 to an antitumor M1 phenotype. Co-delivery of UA and LNT by LNT-UA effectively reshapes the immunosuppressive TME and mobilizes innate and adaptive immunity to inhibit tumor progression in the CT26 CRC tumor model. Following the principle of integrative theoretical system of traditional Chinese medicine (TCM) on overall regulation, the further combination of LNT-UA and anti-CD47 antibody (αCD47) would reinforce the antitumor immunity by promoting phagocytosis of dying tumor cells and tumor-associated antigens (TAAs), leading to effective suppression of both primary and distant tumor growth with 2.2-fold longer of median survival time in the bilateral tumor model. Most notably, this combination effect is also observed in the spontaneous CRC model induced by chemical carcinogens, with much less and smaller size of tumor nodules after sequential administration of LNT-UA and αCD47 through gavage and intraperitoneal injection, respectively.
Conclusions: This study provides a promising self-assembled traditional Chinese nanomedicine to improve immunotherapy for CRC, which might be applicable for future clinical translation.
Keywords: lentinan, ursolic acid, traditional Chinese nanomedicine, colorectal cancer, immunotherapy