Hepatocellular carcinoma (HCC) resistant to both chemotherapy and immunotherapy is among the deadliest malignancies. Doxorubicin widely used in transarterial chemotherapy in HCC can induce immunogenic cell death (ICD), but the resulting immunogenicity is still weak. We aim to seek a strategy for improving the efficacy of ICD in HCC based on an immunoregulatory drug called icaritin. Icaritin induced mitophagy and apoptosis to provoke ICD both in mouse Hepa1−6 and human Huh7 HCC cells. A combination of icaritin and doxorubicin with a molar ratio of 1:2 played a synergistic role in ICD induction. The poly lactic-co-glycolic acid (PLGA)-polyethylene glycol (PEG)-aminoethyl anisamide (AEAA) nanoparticle (NP) targeted codelivery of icaritin and doxorubicin remodeled the immunosuppressive tumor microenvironment and triggered a robust immune memory response, which efficiently improved anti-HCC effect at an early stage in mouse HCC model. In addition, the combo PLGA-PEG-AEAA NP together with lenvatinib significantly prolonged survival time of mice at the advanced stage of HCC. Collectively, our findings reveal an anti-HCC mechanism of icaritin on mitophagy and provide an effective immune-based therapeutic strategy for HCC.

The development and progression of colorectal cancer (CRC) is closely related to gut microbiome. Here we investigated the impact of lipopolysaccharide (LPS), one of the most prevalent products in the gut microbiome, on CRC immunotherapy. We found that LPS was abundant in orthotopic CRC tissue and was associated with low responses to anti-PD-L1 mAb therapy, and clearance of Gram-negative bacteria from the gut using polymyxin B (PmB), or blockade of Toll-like receptor 4 using TAK-242, would both relieve the immunosuppressive microenvironment and boost T-cell infiltration into the CRC tumor. Further, we designed an engineered LPS-targeting fusion protein and loaded its coding sequence into a lipid-protamine-DNA (LPD) nanoparticle system for selectively expression of LPS trap protein and blocking LPS inside the tumor, and this nano-trapping system significantly relieved the immunosuppressive microenvironment and boosted anti-PD-L1 mAb therapy against CRC tumor. This LPS trap system even attenuated CRC liver metastasis when applied, suggesting the importance of blocking LPS in the gut-liver axis. The strategy applied here may provide a useful new way for treating CRC as well as other epithelial cancers that interact with mucosa microbiome.

Activated hepatic stellate cell (aHSC)-mediated liver fibrosis is essential to the development of liver metastasis. Here, we discover intra-hepatic scale-up of relaxin (RLN, an anti-fibrotic peptide) in response to fibrosis along with the upregulation of its primary receptor (RXFP1) on aHSCs. The elevated expression of RLN serves as a natural regulator to deactivate aHSCs and resolve liver fibrosis. Therefore, we hypothesize this endogenous liver fibrosis repair mechanism can be leveraged for liver metastasis treatment via enforced RLN expression. To validate the therapeutic potential, we utilize aminoethyl anisamide-conjugated lipid-calcium-phosphate nanoparticles to deliver plasmid DNA encoding RLN. The nanoparticles preferentially target metastatic tumor cells and aHSCs within the metastatic lesion and convert them as an in situ RLN depot. Expressed RLN reverses the stromal microenvironment, which makes it unfavorable for established liver metastasis to grow. In colorectal, pancreatic, and breast cancer liver metastasis models, we confirm the RLN gene therapy results in significant inhibition of metastatic progression and prolongs survival. In addition, enforced RLN expression reactivates intra-metastasis immune milieu. The combination of the RLN gene therapy with PD-L1 blockade immunotherapy further produces a synergistic anti-metastatic efficacy. Collectively, the targeted RLN gene therapy represents a highly efficient, safe, and versatile anti-metastatic modality, and is promising for clinical translation.

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