Yuang Chen

Targeted lipid nanoparticles (LNPs) offer a nonviral approach for in vivo cell engineering but efficient programming of natural killer (NK) cells remains underexplored. Here we develop NK cell-targeted LNPs (NtLNPs) using engineered biparatopic NK cell ligands to drive receptor-specific uptake and mRNA delivery. Lead NtLNPs achieve up to ~80% NK cell transfection with minimal off-target effects in mice. Systemic delivery of chimeric antigen receptor (CAR) mRNA using NtLNPs generates CAR NK cells in vivo. CD19-targeted CAR NKs completely deplete circulating B cells in healthy mice and CD3-targeted CAR NKs eliminate nearly all autoreactive T cells in an autoimmune hepatitis model, highlighting a potential advantage over CAR T therapies for T cell-driven disease. In solid tumors, NtLNPs targeting the inhibitory checkpoint NKG2A enhance antitumor efficacy by relieving Qa-1^b-mediated immunosuppression. Lastly, we optimized NtLNPs for in vivo engineering of human CAR NK cells, enabling regression of two humanized hematologic malignancy models and establishing NtLNPs as a modular immunotherapy system.

Emerging evidence suggests that MYC binds RNAs, but its functional consequences remain unclear. Here, we integrate multiomics data and reveal that MYC broadly binds enhancer RNAs (eRNAs), which exhibit high cancer- and tissue-specific expression in cancer cell lines and patient tumors. Moreover, we developed a computational pipeline to identify potential cis-regulatory MYC-eRNA target genes, with most predicted eRNA-target pairs supported by RNA polymerase II–mediated chromatin interaction data. Among these, we functionally characterized MERG1 as an oncogenic eRNA that promotes breast cancer tumorigenesis. Mechanistically, MERG1 interacts with MYC to enhance its occupancy at the GREB1 promoter, driving chromatin remodeling and epigenetic activation. This process specifically amplifies GREB1 expression and promotes tumor progression. Last, nanoparticle-mediated delivery of antisense oligonucleotides targeting MERG1 suppresses MYC-mediated breast cancer growth. These results advance our understanding of the enhancer-driven regulation of gene expression and tumorigenesis and provide insights into the regulatory landscape of MYC in cancer.

Increases in retroelement-derived double-stranded RNAs (dsRNAs) in various types of cancer cells facilitate the activation of antitumor immune responses. The long noncoding RNA EPIC1 interacts with the histone methyltransferase EZH2 and contributes to tumor immune evasion. Here, we found that EPIC1 in tumor cells suppressed cytoplasmic dsRNA accumulation, type I interferon (IFN) responses, and antitumor immunity. In various cancer cell lines, knockdown of EPIC1 stimulated the production of dsRNA from retroelements and an antiviral-like type I IFN response that activated immune cells. EPIC1 inhibited the expression of LINE, SINE, and LTR retroelements that were also repressed by EZH2, suggesting a potential role for the EPIC1-EZH2 interaction in regulating dsRNA production. In a humanized mouse model, in vivo delivery of EPIC1-targeting oligonucleotides enhanced dsRNA accumulation in breast cancer xenografts, reduced tumor growth, and increased the infiltration of T cells and inflammatory macrophages into tumors. Furthermore, EPIC1 knockdown improved the therapeutic efficacy of the immunotherapy drug pembrolizumab, a PD-1 inhibitor, in the humanized mouse model. Together, our findings establish EPIC1 as a key regulator of dsRNA-mediated type I IFN responses and highlight its potential as a therapeutic target to improve the efficacy of immunotherapy.

SERPINB9, an endogenous inhibitor of granzyme B (GzmB), has emerged as a critical factor in the resistance to immunotherapy by protecting cancer cells from GzmB-induced cytotoxicity. However, its role in chemosensitivity remains unknown. In this study, we show that gemcitabine (GEM) treatment upregulates SERPINB9 through transcription factor ATF-3. Interestingly, GEM also induces the expression of GzmB and knockout or knockdown of SERPINB9 results in enhanced response of tumor cells to GEM, suggesting a role of GzmB/SERPINB9 axis in regulating chemosensitivity. To facilitate the therapeutic translation of these findings, we engineer POEM nanocarrier (consisting of lipid-derivatized polylysine (PEG-PLL-Oleic acid, PPO), and GEM-conjugated polylysine (PEG-PLL-OA-GEM, PPOGEM), PPO/PPOGEM (POEM)) that is highly effective in codelivery of built-in GEM and loaded SERPINB9 short interfering RNA (siSPB9). GEM conjugation introduces an additional mechanism of carrier/siRNA interaction in addition to charge-mediated interaction and enables efficient i.v. delivery at lower N/P ratios. Here, we show that co-delivery of GEM and siSPB9 significantly improves antitumor efficacy and remodels the tumor immune microenvironment in pancreatic cancer models, supporting a promising therapeutic strategy.

The multifaceted chemo-immune resistance is the principal barrier to achieving cure in cancer patients. Identifying a target that is critically involved in chemo-immune-resistance represents an attractive strategy to improve cancer treatment. iRhom1 plays a role in cancer cell proliferation and its expression is negatively correlated with immune cell infiltration. Here we show that iRhom1 decreases chemotherapy sensitivity by regulating the MAPK14-HSP27 axis. In addition, iRhom1 inhibits the cytotoxic T-cell response by reducing the stability of ERAP1 protein and the ERAP1-mediated antigen processing and presentation. To facilitate the therapeutic translation of these findings, we develop a biodegradable nanocarrier that is effective in codelivery of iRhom pre-siRNA (pre-siiRhom) and chemotherapeutic drugs. This nanocarrier is effective in tumor targeting and penetration through both enhanced permeability and retention effect and CD44-mediated transcytosis in tumor endothelial cells as well as tumor cells. Inhibition of iRhom1 further facilitates tumor targeting and uptake through inhibition of CD44 cleavage. Co-delivery of pre-siiRhom and a chemotherapy agent leads to enhanced antitumor efficacy and activated tumor immune microenvironment in multiple cancer models in female mice. Targeting iRhom1 together with chemotherapy could represent a strategy to overcome chemo-immune resistance in cancer treatment.

The majority of lncRNAs’ roles in tumor immunology remain elusive. This project performed a CRISPR activation screening of 9744 lncRNAs in melanoma cells cocultured with human CD8⁺T cells. We identified 16 lncRNAs potentially regulating tumor immune response. Further integrative analysis using tumor immunogenomics data revealed thatIL10RB-DTandLINC01198are significantly correlated with tumor immune response and survival in melanoma and breast cancer. Specifically,IL10RB-DTsuppresses CD8⁺T cells activation via inhibiting IFN-γ–JAK–STAT1 signaling and antigen presentation in melanoma and breast cancer cells. On the other hand,LINC01198’s up-regulation sensitizes the killing of tumor cells by CD8⁺T cells. Mechanistically,LINC01198interacts and activates NF-κB component p65 to trigger the type I and type II interferon responses in melanoma and breast cancer cells. Our study systematically characterized novel lncRNAs involved in tumor immune response.

Activation of scramblases is one of the mechanisms that regulates the exposure of phosphatidylserine to the cell surface, a process that plays an important role in tumour immunosuppression. Here we show that chemotherapeutic agents induce overexpression of Xkr8, a scramblase activated during apoptosis, at the transcriptional level in cancer cells, both in vitro and in vivo. Based on this finding, we developed a nanocarrier for co-delivery of Xkr8 short interfering RNA and the FuOXP prodrug to tumours. Intravenous injection of our nanocarrier led to significant inhibition of tumour growth in colon and pancreatic cancer models along with increased antitumour immune response. Targeting Xkr8 in combination with chemotherapy may represent a novel strategy for the treatment of various types of cancers.