Domain-inlaid Nme2Cas9 adenine base editors with improved activity and targeting scope.

Nme2Cas9 has been established as a genome editing platform with compact size, high accuracy, and broad targeting range, including single-AAV-deliverable adenine base editors. Here, we engineer Nme2Cas9 to further increase the activity and targeting scope of compact Nme2Cas9 base editors. We first use domain insertion to position the deaminase domain nearer the displaced DNA strand in the target-bound complex. These domain-inlaid Nme2Cas9 variants exhibit shifted editing windows and increased activity in comparison to the N-terminally fused Nme2-ABE. We next expand the editing scope by swapping the Nme2Cas9 PAM-interacting domain with that of SmuCas9, which we had previously defined as recognizing a single-cytidine PAM. We then use these enhancements to introduce therapeutically relevant edits in a variety of cell types. Finally, we validate domain-inlaid Nme2-ABEs for single-AAV delivery in vivo.

Cantharidin induces apoptosis of human triple negative breast cancer cells through mir-607-mediated downregulation of EGFR.

BACKGROUND: Triple negative breast cancer (TNBC) is a major subtype of breast cancer, with limited therapeutic drugs in clinical. Epidermal growth factor receptor (EGFR) is reported to be overexpressed in various TNBC cells. Cantharidin is an effective ingredient in many clinical traditional Chinese medicine preparations, such as Delisheng injection, Aidi injection, Disodium cantharidinate and vitamin B6 injection. Previous studies showed that cantharidin had satisfactory pharmacological activity on a variety of tumors. In this study, we aimed to study the therapeutic potential of cantharidin for TNBC treatment by targeting EGFR, and expound its novel regulator miR-607. METHODS: The effect of cantharidin on breast cancer in vivo was evaluated by 4T1 mice model. Then the effects of cantharidin on TNBC cells was assessed by the MTT, colony formation, and AnnexinV-PE/7AAD staining. Cantharidin acts on EGFR were verified using the cell membrane chromatography, RT-PCR, Western blotting, MTT, and so on. Mechanistic studies were explored by dual-luciferase report assay, RT-PCR, western blotting, and immunofluorescence staining assay. RESULTS: Cantharidin inhibited TNBC cell growth and induce apoptosis by targeting EGFR. miR-607 was a novel EGFR regulator and exhibited suppressive functions on TNBC cell behaviors. Mechanistic study showed that cantharidin blocked the downstream PI3K/AKT/mTOR and ERK/MAPK signaling pathway. CONCLUSION: Our results revealed that cantharidin may be served as a potential candidate for TNBC treatment by miR-607-mediated downregulation of EGFR.

Role of NLRP3 inflammasome activation in HCC cell progression.

Hepatocellular carcinoma (HCC) is a globally prevalent and fatal malignancy worldwide, and identifying therapeutic strategies is time-consuming. Numerous reports have suggested the involvement of the NLRP3 inflammasome in the progression of various cancers. However, the detailed mechanisms underlying the role of NLRP3 inflammasome in HCC progression remain unclear. In this study, we observed low expression levels of the NLRP3 inflammasome in a subset of HCC cells. Furthermore, we demonstrated that the NLRP3 inflammasome can be activated by LPS + ATP through the nuclear factor kappa B signaling pathway, as confirmed by western blotting and immunofluorescence staining. To assess the impact of NLRP3 inflammasome activation on HCC cell behavior, we employed Edu staining, cell cycle assay, Annexin V/PI staining, and wound healing assay. Our results revealed that NLRP3 inflammasome activation inhibited the proliferation of Bel-7402 and SMMC-7721 cells, arrested the cell cycle at the G1 phase, and suppressed cell migration, while apoptosis remained unaffected. In summary, our findings suggest that targeting the NLRP3 inflammasome could have therapeutic potential for HCC.

CTLA-4 tail fusion enhances CAR-T antitumor immunity.

Chimeric antigen receptor (CAR)-T cells are powerful therapeutics; however, their efficacy is often hindered by critical hurdles. Here utilizing the endocytic feature of the cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) cytoplasmic tail, we reprogram CAR function and substantially enhance CAR-T efficacy in vivo. CAR-T cells with monomeric, duplex or triplex CTLA-4 cytoplasmic tails (CCTs) fused to the C terminus of CAR exhibit a progressive increase in cytotoxicity under repeated stimulation, accompanied by reduced activation and production of proinflammatory cytokines. Further characterization reveals that CARs with increasing CCT fusion show a progressively lower surface expression, regulated by their constant endocytosis, recycling and degradation under steady state. The molecular dynamics of reengineered CAR with CCT fusion results in reduced CAR-mediated trogocytosis, loss of tumor antigen and improved CAR-T survival. CARs with either monomeric (CAR-1CCT) or duplex CCTs (CAR-2CCT) have superior antitumor efficacy in a relapsed leukemia model. Single-cell RNA sequencing and flow cytometry analysis reveal that CAR-2CCT cells retain a stronger central memory phenotype and exhibit increased persistence. These findings illuminate a unique strategy for engineering therapeutic T cells and improving CAR-T function through synthetic CCT fusion, which is orthogonal to other cell engineering techniques.

Identification and analysis of anti-tumor effective substances in Yangzheng Mixture.

Yangzheng Mixture is a traditional Chinese medicine used in clinical practice as an adjuvant therapy for tumors. However, little is known about its active components in tumor treatment. The purpose of this study was to explore the potential anti-tumor components of Yangzheng Mixture to better promote its clinical application. Using LC-MS/MS, 43 components were detected in concentrated Yangzheng Mixture. Six components, comprising astragaloside, calycosin, formononetin, isoquercitrin, ononin, and calycosin-7-O-ß-D-glucoside, were identified in rat plasma. The cancer cell absorption assay showed that the intracellular concentration of four components, calycosin, calycosin-7-O-ß-D-glucoside, formononetin, and ononin, increased with extended incubation time and demonstrated potential anti-tumor effects. The MTT assay results confirmed that Yangzheng Mixture inhibited different tumor cells proliferation. Additionally, the colony formation assay, flow cytometry analysis and wound healing displayed that Yangzheng Mixture and a combination of four components could inhibit colony formation, arrest the cell cycle and impair cell migration of tumor cells, including HCT-116, MHCC-97L, MCF-7 and NCI-H1299. In summary, our study highlighted the plausible application of Yangzheng Mixture as a potential adjuvant treatment for tumors. Furthermore, it identified effective anti-tumor components and provided evidences for the further clinical application of Yangzheng Mixture.

CTLA-4 tail fusion enhances CAR-T anti-tumor immunity.

Chimeric antigen receptor (CAR) T cells are powerful therapeutics; however, their efficacy is often hindered by critical hurdles. Here, utilizing the endocytic feature of the cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) cytoplasmic tail (CT), we reprogram CAR function and substantially enhance CAR-T efficacy in vivo . CAR-T cells with monomeric, duplex, or triplex CTLA-4 CTs (CCTs) fused to the C-terminus of CAR exhibit a progressive increase in cytotoxicity under repeated stimulation, accompanied by reduced activation and production of pro-inflammatory cytokines. Further characterization reveals that CARs with increasing CCT fusion show a progressively lower surface expression, regulated by their constant endocytosis, recycling and degradation under steady state. The molecular dynamics of reengineered CAR with CCT fusion results in reduced CAR-mediated trogocytosis, loss of tumor antigen, and improved CAR-T survival. CARs with either monomeric (CAR-1CCT) or duplex CCTs (CAR-2CCT) have superior anti-tumor efficacy in a relapsed leukemia model. Single-cell RNA sequencing and flow cytometry analysis reveal that CAR-2CCT cells retain a stronger central memory phenotype and exhibit increased persistence. These findings illuminate a unique strategy for engineering therapeutic T cells and improving CAR-T function through synthetic CCT fusion, which is orthogonal to other cell engineering techniques.

Cas12a/Cpf1 knock-in mice enable efficient multiplexed immune cell engineering.

Cas9 transgenic animals have drastically accelerated the discovery of novel immune modulators. But due to its inability to process its own CRISPR RNAs (crRNAs), simultaneous multiplexed gene perturbations using Cas9 remains limited, especially by pseudoviral vectors. Cas12a/Cpf1, however, can process concatenated crRNA arrays for this purpose. Here, we created conditional and constitutive LbCas12a knock-in transgenic mice. With these mice, we demonstrated efficient multiplexed gene editing and surface protein knockdown within individual primary immune cells. We showed genome editing across multiple types of primary immune cells including CD4 and CD8 T cells, B cells, and bone-marrow derived dendritic cells. These transgenic animals, along with the accompanying viral vectors, together provide a versatile toolkit for a broad range of ex vivo and in vivo gene editing applications, including fundamental immunological discovery and immune gene engineering.

Shuanghua decoction exerts anticancer activity by activating NLRP3 inflammasome via ROS and inhibiting NF-κB signaling in hepatocellular carcinoma cells.

BACKGROUND: Hepatocellular carcinoma (HCC) is a major subtype of liver cancer, with a high mortality rate, and close relation to chronic hepatitis. The components of the NLRP3 inflammasome are poorly expressed or even lost in HCC. Downregulation of the NLRP3 inflammasome expression significantly affects the clinical stages and pathological grade of HCC. According to previous research, Shuanghua decoction (SHD), a traditional folk prescription, has an inhibitory effect on nasopharyngeal cancer. PURPOSE: This study aimed to reveal the therapeutic potential of the traditional folk recipe, SHD and its demolition recipe for HCC, and to explore the underlying mechanism. METHODS: The effect of SHD and its demolition recipe on HCC cell biological behaviors was assessed using the MTT assay, colony formation, LDH release assay, KFluor-Edu staining, annexin V-FITC/PI staining assay, Hoechst staining, wound-healing assay, transwell assay, reactive oxygen species (ROS) release assay, HPLC, nude mice model, HE staining, IHC, western blot, and immunofluorescence staining in vitro and in vivo. RESULTS: SHD was found to inhibit HCC, and Oldenlandia and OP (Oldenlandia: Prunella spike = 2.5:1) were identified as the main ingredients that inhibited the proliferation and migration of HCC cells via the activation of the ROS-mediated NLRP3 inflammasome and inhibition of the NF-κB signaling pathway in vitro and in vivo. CONCLUSION: Overall, Chinese medicine theory and pharmacology research revealed that SHD, Oldenlandia and OP may be promising traditional Chinese medicine for the treatment of HCC.

A genome-scale gain-of-function CRISPR screen in CD8 T cells identifies proline metabolism as a means to enhance CAR-T therapy.

Chimeric antigen receptor (CAR)-T cell-based immunotherapy for cancer and immunological diseases has made great strides, but it still faces multiple hurdles. Finding the right molecular targets to engineer T cells toward a desired function has broad implications for the armamentarium of T cell-centered therapies. Here, we developed a dead-guide RNA (dgRNA)-based CRISPR activation screen in primary CD8+ T cells and identified gain-of-function (GOF) targets for CAR-T engineering. Targeted knockin or overexpression of a lead target, PRODH2, enhanced CAR-T-based killing and in vivo efficacy in multiple cancer models. Transcriptomics and metabolomics in CAR-T cells revealed that augmenting PRODH2 expression reshaped broad and distinct gene expression and metabolic programs. Mitochondrial, metabolic, and immunological analyses showed that PRODH2 engineering enhances the metabolic and immune functions of CAR-T cells against cancer. Together, these findings provide a system for identification of GOF immune boosters and demonstrate PRODH2 as a target to enhance CAR-T efficacy.