Discovery of a Meisoindigo-Derived PROTAC as the ATM Degrader: Revolutionizing Colorectal Cancer Therapy via Synthetic Lethality with ATR Inhibitors.

Meisoindigo (Mei) has long been recognized in chronic myeloid leukemia (CML) treatment. To elucidate its molecular target and mechanisms, we embarked on designing and synthesizing a series of Mei-derived PROTACs. Through this endeavor, VHL-type PROTAC 9b was identified to be highly cytotoxic against SW620, SW480, and K562 cells. Employing DiaPASEF-based quantitative proteomic analysis, in combination with extensive validation assays, we unveiled that 9b potently and selectively degraded ATM across SW620 and SW480 cells in a ubiquitin-proteasome-dependent manner. 9b-induced selective ATM degradation prompted DNA damage response cascades, thereby leading to the cell cycle arrest and cell apoptosis. This pioneering discovery renders the advent of ATM degradation for anti-cancer therapy. Notably, 9b-induced ATM degradation synergistically enhanced the efficacy of ATR inhibitor AZD6738 both in vitro and in vivo. This work establishes the synthetic lethality-inducing properties of ATR inhibitors in the ATM-deficient context, thereby providing new avenues to innovative therapies for colorectal cancer.

Research advance in lipid nanoparticle-mRNA delivery system and its application in CAR-T cell therapy.

Chimeric antigen receptor (CAR) T cell therapy has shown significant efficacy for hematological malignancies, however, it needs to be further optimized. Recently, the lipid nanoparticle (LNP)-mRNA delivery system as a nonviral gene transfer vector has gained rapid progress in CAR-T cell therapy. The claudin-6 (CLDN6) mRNA is delivered to antigen presenting cells (APCs) through LNP system, thereby enhancing the function of CLDN6 CAR-T cells for the clearance of solid tumor cells. For treatment of acute cardiac injury, the fibroblast activation protein (FAP) CAR mRNA can be delivered to T cells through LNP system for the in vivo production of FAP CAR-T cells, thereby blocking the process of myocardial fibrosis. The LNP-mRNA delivery system has advantages including having no integration in host genome, inexpensiveness, low toxicity and modifiability; on the other hand, it has certain disadvantages such as limited cell persistence caused by transient protein expression and limitations in preparation techniques. This article reviews the research advance in LNP-mRNA in vivo delivery system and its application in CAR-T cell therapy.

Early detection and intervention of clonal hematopoiesis for preventing hematological malignancies.

Clonal hematopoiesis (CH) is a clonal expansion of single hematopoietic stem cells (HSC) with germline or somatic mutations accumulated in specific genes, which usually leads to clonal dominance via multiple biological pathways and increases the risk of developing hematological malignancies. With the advancement of Next Generation Sequencing (NGS) technology, CH can be widely detected in healthy individuals, many patients complicated with bone marrow failure (BMF), or even in those with myeloproliferative neoplasm (MPN) and therapy-related MDS/AML (t-MDS/AML). Recently, several proof-of-concept studies showed that it is likely to discriminate the CH with high risk developing malignancy through predictive models many years before its onset. Additionally, it has been shown that the CH-related premalignant clones can be abated or eradicated through chemical or genetic measures in animal models, thereby providing an insightful idea for preventing leukemogenesis. However, in despite of these advancements, the clinical implication and early diagnosis of CH for predicting hematological malignancies remain to be more investigated. In this review, we will first review the brief history, risk factors and molecular mechanisms of CH. Then, we will discuss the involved biological process of CH in bone marrow failure diseases, MPN and t-MDS/AML, pointing to its clinical implication. Finally, we will discuss the advancement of early detection of CH at premalignant stage for predicting hematological malignancies, and express perspectives and challenges for early intervention of CH in the future.

Retinoic acid inducible gene-I slows down cellular senescence through negatively regulating the integrin ß3/p38 MAPK pathway.

Retinoic acid inducible gene-I (Rig-I) has been well documented as a cytosolic pattern recognition receptor that can sense viral RNA ligands to initiate the interferon-mediated antiviral immunity. However, little is known about the biological behaviors of Rig-I devoid of viral infection. Herein, we investigated the roles of Rig-I in the regulation of cellular senescence. In comparison to wild-type counterparts, Rig-I-/- mice displayed the accelerated loss of hair, less responsiveness to gentle physical stimuli and shorten survival time. Likewise, Rig-I deficiency rendered mouse embryonic fibroblasts (MEFs) more susceptible to the serial passages-associated replicative senescence. By performing a transcriptome analysis, we identified integrins at the intersections of biological pathways affected by Rig-I. Among these, integrin ß3 was negatively regulated by Rig-I, and significantly upregulated with the occurrence of senescence. Gene silencing of Itgb3 (encoding integrin ß3) retarded the progression of cellular senescence in both WT and Rig-I-/- MEFs. Notably, this effect was more prominent in Rig-I-/- MEFs. Furthermore, p38 MAPK was a key downstream molecule for integrin ß3-mediated senescence, and overactivated in senescent Rig-I-/- MEFs. Taken together, Rig-I deficiency contributes to cellular senescence through amplifying integrin ß3/p38 MAPK signaling. Our findings provide the evidence that Rig-I is a key regulator of cellular senescence, which will be helpful in better understanding its function without viral infection.Abbreviations: Rig-I: retinoic acid inducible gene-I; SASP: senescence-associated secretory phenotype; ECM: extracellular matrix; Itgb3: integrin beta 3; PRR: pattern recognition receptor; MEFs: mouse embryonic fibroblasts; Il-1ß: interleukin-1 beta; Il-6: interleukin-6; Il-8: interleukin-8; Cxcl1: chemokine (C-X-C motif) ligand 1; Ccl2: chemokine (C-C motif) ligand 2; WT, wild type; BM: bone marrow; MAPK: mitogen-activated protein kinase; ERK: extracellular signal-regulated kinases; JNK: Jun N-terminal kinases; SA-ß-gal: senescence-associated ß-galactosidase; qPCR: quantitative reverse-transcription PCR; PBS: phosphate-buffered saline.

Meisoindigo Protects Against Focal Cerebral Ischemia-Reperfusion Injury by Inhibiting NLRP3 Inflammasome Activation and Regulating Microglia/Macrophage Polarization via TLR4/NF-κB Signaling Pathway.

Ischemic stroke is a devastating disease with long-term disability. However, the pathogenesis is unclear and treatments are limited. Meisoindigo, a second-generation derivative of indirubin, has general water solubility and is well-tolerated. Previous studies have shown that meisoindigo reduces inflammation by inhibiting leukocyte chemotaxis and migration. In the present study, we investigated the hypothesis that meisoindigo was also protective against ischemic stroke, then evaluated its underlying mechanisms. In vivo, adult male C57BL/6J wild-type mice were used to produce a middle cerebral artery occlusion (MCAO) stroke model. On day three after reperfusion, obvious improvement in neurological scores, infarct volume reduction and cerebral edema amelioration were observed in meisoindigo treatment. Moreover, immunofluorescence staining and western-blot showed that the expression of NLRP3 inflammasome and its associated proteins in neurons and microglia was inhibited by meisoindigo. The effects of Meisoindigo on NLRP3 inflammasome inactivation and increased the M2 phenotype of microglia/macrophage through shifting from a M1 phenotype, which was possibly mediated by inhibition of TLR4/NF-κB. Furthermore, we verified the inhibitory effect of meisoindigo on TLR4/NF-κB signaling pathway, and found that meisoindigo treatment could significantly suppressed the expression of TLR4/NF-κB pathway-associated proteins in a dose-dependent manner, meanwhile, which resulted in downregulation of HMGB1 and IL-1ß. Next, we established an in vitro oxygen glucose deprivation/Reperfusion (OGD/R) model in HT-22 and BV2 cells to simulate ischemic conditions. Cytotoxicity assay showed that meisoindigo substantially improved relative cell vitality and in HT-22 and BV2 cells following OGD/R in vitro. After suffering OGD/R, the TLR4/NF-κB pathway was activated, the expression of NLRP3 inflammasome-associated proteins and M1 microglia/macrophage were increased, but meisoindigo could inhibit above changes in both HT-22 and BV2 cells. Additionally, though lipopolysaccharide stimulated the activation of TLR4 signaling in OGD/R models, meisoindigo co-treatment markedly reversed the upregulation of TLR4 and following activation of NLRP3 inflammasome and polarization of M1 microglia/macrophages mediated by TLR4. Overall, we demonstrate for the first time that meisoindigo post-treatment alleviates brain damage induced by ischemic stroke in vivo and in vitro experiments through blocking activation of the NLRP3 inflammasome and regulating the polarization of microglia/macrophages via inhibition of the TLR4/NF-κB signaling pathway.

[Research Progress on the Role of Pyroptosis in the Pathogenesis of Myelodysplastic Syndrome -Review].

Pyroptosis is a novel type of programmed cell death, which is closely related with the pathogenesis of myelodysplastic syndromes (MDS). The recent studies showed that all of S100A9/TLR4, S100A9/CD33 and Nox/ROS signaling pathways can activate oxygen-sensitivity NLRP3 inflammasome and then induce the pyroptosis of hematopoeitic stem cells (HSC) / hematopeitic pregenitor cells (HPC), resulting in ineffective hematopoiesis in patients with MDS. Further studies on the role and molecular mechanism of pyroptosis in the pathogenesis of MDS will provide the potential opportunity for the diagnosis and treatment of MDS. Here, the recent advances in the role and mechnism of pyroptosis in the pathogenesis of MDS are reviewed.

Engineering chimeric antigen receptor-T cells for cancer treatment.

Intratumor heterogeneity of tumor clones and an immunosuppressive microenvironment in cancer ecosystems contribute to inherent difficulties for tumor treatment. Recently, chimeric antigen receptor (CAR) T-cell therapy has been successfully applied in the treatment of B-cell malignancies, underscoring its great potential in antitumor therapy. However, functional challenges of CAR-T cell therapy, especially in solid tumors, remain. Here, we describe cancer-immunity phenotypes from a clonal-stromal-immune perspective and elucidate mechanisms of T-cell exhaustion that contribute to tumor immune evasion. Then we assess the functional challenges of CAR-T cell therapy, including cell trafficking and infiltration, targeted-recognition and killing of tumor cells, T-cell proliferation and persistence, immunosuppressive microenvironment and self-control regulation. Finally, we delineate tumor precision informatics and advancements in engineered CAR-T cells to counteract inherent challenges of the CAR-T cell therapy, either alone or in combination with traditional therapeutics, and highlight the therapeutic potential of this approach in future tumor precision treatment.

High-throughput sequencing of the immune repertoire in oncology: Applications for clinical diagnosis, monitoring, and immunotherapies.

The diagnostic, monitoring and therapeutic options for cancers currently remain limited. These limitations represent a large threat to human health. Adaptive immunity, which is dependent on diverse repertoires of B cell receptors (BCRs) and T cell receptors (TCRs), plays a critical role in the anti-tumor immune response. Modulation and surveillance of adaptive immunity has become a powerful weapon to combat cancers. Recently, the high-throughput sequencing of immune repertoire (HTS-IR) technology, which provides a robust tool for deep sequencing repertoires of BCRs or TCRs, has been applied in the development of tumor biomarkers and immunotherapeutics for cancers. This review will first provide an overview of the advancement of HTS-IR technology at the population-cell and single-cell levels. It will then provide a current summary of the applications of HTS-IR technology in the diagnosis and monitoring of minimal residual disease (MRD), focusing on immune reconstitution after the treatment of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in B/T-cell malignancies, and the precise detection of tumor-infiltrating lymphocytes (TILs) in non-B/T-cell malignancies. Finally, current advances of HTS-IR technology in cancer immunotherapeutic applications, such as therapeutic antibodies, CAR-T cell based-adoptive immunotherapies, and neoantigen-specific TCR-T cell-based adoptive immunotherapies, will be introduced.

Design, Synthesis, and Biological Activities of Vibsanin B Derivatives: A New Class of HSP90 C-Terminal Inhibitors.

Previously, vibsanin B (ViB) was found to preferentially target HSP90ß compared to HSP90α. In this study, multiple experiments, including pull-down assays of biotin-ViB with recombinant HSP90ß-NTD, MD, CTD, and full-length HSP90ß, molecular docking of ViB and its derivatives to the HSP90 CTD, and a inhibition assay of interaction of the HSP90ß CTD with GST-tagged cyclophilin 40 (Cyp40) by ViB derivatives, suggest that ViB can directly bind to the HSP90 C-terminus. On the basis of the docking predictions and primary structure-activity relationships (SARs), a series of ViB analogues devised with focus on the C18 position, along with compounds derivatized at the C4, C7, and C8 positions, were designed and chemically synthesized. Compound 12f (IC50 = 1.12 µM against SK-BR-3) exhibits great potency with drug-like properties. Overall, our findings demonstrate that compounds with the vibsanin B scaffold are a new class of HSP90 C-terminal inhibitors with considerable potential as anticancer agents.

Genetically Modified T-Cell-Based Adoptive Immunotherapy in Hematological Malignancies.

A significant proportion of hematological malignancies remain limited in treatment options. Immune system modulation serves as a promising therapeutic approach to eliminate malignant cells. Cytotoxic T lymphocytes (CTLs) play a central role in antitumor immunity; unfortunately, nonspecific approaches for targeted recognition of tumor cells by CTLs to mediate tumor immune evasion in hematological malignancies imply multiple mechanisms, which may or may not be clinically relevant. Recently, genetically modified T-cell-based adoptive immunotherapy approaches, including chimeric antigen receptor (CAR) T-cell therapy and engineered T-cell receptor (TCR) T-cell therapy, promise to overcome immune evasion by redirecting the specificity of CTLs to tumor cells. In clinic trials, CAR-T-cell- and TCR-T-cell-based adoptive immunotherapy have produced encouraging clinical outcomes, thereby demonstrating their therapeutic potential in mitigating tumor development. The purpose of the present review is to (1) provide a detailed overview of the multiple mechanisms for immune evasion related with T-cell-based therapies; (2) provide a current summary of the applications of CAR-T-cell- as well as neoantigen-specific TCR-T-cell-based adoptive immunotherapy and routes taken to overcome immune evasion; and (3) evaluate alternative approaches targeting immune evasion via optimization of CAR-T and TCR-T-cell immunotherapies.

Meisoindigo, but not its core chemical structure indirubin, inhibits zebrafish interstitial leukocyte chemotactic migration.

CONTEXT: Inflammatory disease is a big threat to human health. Leukocyte chemotactic migration is required for efficient inflammatory response. Inhibition of leukocyte chemotactic migration to the inflammatory site has been shown to provide therapeutic targets for treating inflammatory diseases. OBJECTIVE: Our study was designed to discover effective and safe compounds that can inhibit leukocyte chemotactic migration, thus providing possible novel therapeutic strategy for treating inflammatory diseases. MATERIALS AND METHODS: In this study, we used transgenic zebrafish model (Tg:zlyz-EGFP line) to visualize the process of leukocyte chemotactic migration. Then, we used this model to screen the hit compound and evaluate its biological activity on leukocyte chemotactic migration. Furthermore, western blot analysis was performed to evaluate the effect of the hit compound on the AKT or ERK-mediated pathway, which plays an important role in leukocyte chemotactic migration. RESULTS: In this study, using zebrafish-based chemical screening, we identified that the hit compound meisoindigo (25 µM, 50 µM, 75 µM) can significantly inhibit zebrafish leukocyte chemotactic migration in a dose-dependent manner (p = 0.01, p = 0.0006, p < 0.0001). Also, we found that meisoindigo did not affect the process of leukocyte reverse migration (p = 0.43). Furthermore, our results unexpectedly showed that indirubin, the core structure of meisoindigo, had no significant effect on zebrafish leukocyte chemotactic migration (p = 0.6001). Additionally, our results revealed that meisoindigo exerts no effect on the Akt or Erk-mediated signalling pathway. DISCUSSION AND CONCLUSION: Our results suggest that meisoindigo, but not indirubin, is effective for inhibiting leukocyte chemotactic migration, thus providing a potential therapeutic agent for treating inflammatory diseases.

Single-Cell Sequencing Technology in Oncology: Applications for Clinical Therapies and Research.

Cellular heterogeneity is a fundamental characteristic of many cancers. A lack of cellular homogeneity contributes to difficulty in designing targeted oncological therapies. Therefore, the development of novel methods to determine and characterize oncologic cellular heterogeneity is a critical next step in the development of novel cancer therapies. Single-cell sequencing (SCS) technology has been recently employed for analyzing the genetic polymorphisms of individual cells at the genome-wide level. SCS requires (1) precise isolation of the single cell of interest; (2) isolation and amplification of genetic material; and (3) descriptive analysis of genomic, transcriptomic, and epigenomic data. In addition to targeted analysis of single cells isolated from tumor biopsies, SCS technology may be applied to circulating tumor cells, which may aid in predicting tumor progression and metastasis. In this paper, we provide an overview of SCS technology and review the current literature on the potential application of SCS to clinical oncology and research.

USP10 Expression in Normal Adrenal Gland and Various Adrenal Tumors.

Ubiquitin-specific protease 10 (USP10), a novel deubiquitinating enzyme, is associated with androgen receptor transcriptional activity and pathological processes of tumor. However, information between USP10 and the adrenal gland is limited. In particular, the role of USP10 in adrenal tumors has not been elucidated yet. This study aims to investigate the expression of USP10 in the human normal adrenal gland and various adrenal tumors. Tissue samples were obtained from 30 adrenocortical adenomas, nine adrenocortical adenocarcinomas, and 20 pheochromocytomas following laparoscopic surgery. Twenty normal adrenal glands were obtained from kidney surgical resection conducted due to renal cell carcinomas. USP10 expression was investigated on protein levels using immunohistochemistry and on mRNA levels using bioinformatics analysis in the Gene Expression Omnibus (GEO) Datasets. In the 20 cases of normal adrenal glands analyzed, USP10 protein was constantly expressed in situ in the cortex of the adrenal glands, but in the medulla of the gland, only the sustentacular cells were detected positive. In adrenal tumors, detectable levels of USP10 protein were found in 100 % (30/30) adrenocortical adenomas, 88.89 % (8/9) adrenocortical carcinomas, and 10 % (2/20) pheochromocytomas. Bioinformatics analysis did not show a significant difference in USP10 messenger RNA (mRNA) expression between adrenal tumors and normal adrenal gland tissues. A positive USP10 immunoreaction can be useful in distinguishing adrenal cortical tumors from pheochromocytoma.

Vibsanin B preferentially targets HSP90ß, inhibits interstitial leukocyte migration, and ameliorates experimental autoimmune encephalomyelitis.

Interstitial leukocyte migration plays a critical role in inflammation and offers a therapeutic target for treating inflammation-associated diseases such as multiple sclerosis. Identifying small molecules to inhibit undesired leukocyte migration provides promise for the treatment of these disorders. In this study, we identified vibsanin B, a novel macrocyclic diterpenoid isolated from Viburnum odoratissimum Ker-Gawl, that inhibited zebrafish interstitial leukocyte migration using a transgenic zebrafish line (TG:zlyz-enhanced GFP). We found that vibsanin B preferentially binds to heat shock protein (HSP)90ß. At the molecular level, inactivation of HSP90 can mimic vibsanin B's effect of inhibiting interstitial leukocyte migration. Furthermore, we demonstrated that vibsanin B ameliorates experimental autoimmune encephalomyelitis in mice with pathological manifestation of decreased leukocyte infiltration into their CNS. In summary, vibsanin B is a novel lead compound that preferentially targets HSP90ß and inhibits interstitial leukocyte migration, offering a promising drug lead for treating inflammation-associated diseases.

Cannabinoid receptor 2 suppresses leukocyte inflammatory migration by modulating the JNK/c-Jun/Alox5 pathway.

BACKGROUND: The role of cannabinoid receptor type 2 (Cnr2) in regulating immune function had been widely investigated, but the mechanism is not fully understood. RESULTS: Cnr2 activation down-regulates 5-lipoxygenase (Alox5) expression by suppressing the JNK/c-Jun activation. CONCLUSION: The Cnr2-JNK-Alox5 axis modulates leukocyte inflammatory migration. SIGNIFICANCE: Linking two important regulators in leukocyte inflammatory migration and providing a potential therapeutic strategy for treating human inflammation-associated diseases. Inflammatory migration of immune cells is involved in many human diseases. Identification of molecular pathways and modulators controlling inflammatory migration could lead to therapeutic strategies for treating human inflammation-associated diseases. The role of cannabinoid receptor type 2 (Cnr2) in regulating immune function had been widely investigated, but the mechanism is not fully understood. Through a chemical genetic screen using a zebrafish model for leukocyte migration, we found that both an agonist of the Cnr2 and inhibitor of the 5-lipoxygenase (Alox5, encoded by alox5) inhibit leukocyte migration in response to acute injury. These agents have a similar effect on migration of human myeloid cells. Consistent with these results, we found that inactivation of Cnr2 by zinc finger nuclease-mediated mutagenesis enhances leukocyte migration, while inactivation of Alox5 blocks leukocyte migration. Further investigation indicates that there is a signaling link between Cnr2 and Alox5 and that alox5 is a target of c-Jun. Cnr2 activation down-regulates alox5 expression by suppressing the JNK/c-Jun activation. These studies demonstrate that Cnr2, JNK, and Alox5 constitute a pathway regulating leukocyte migration. The cooperative effect between the Cnr2 agonist and Alox5 inhibitor also provides a potential therapeutic strategy for treating human inflammation-associated diseases.

Inhibition of the replication of hepatitis B virus in vitro by a novel 2,6-diaminopurine analog, beta-LPA.

Antiviral therapy of chronic hepatitis B remains a major clinical problem worldwide. Like lamivudine, nucleoside analogs have become the focus of investigation of anti-hepatitis B virus (anti-HBV) drugs. Here, beta-LPA is a novel 2,6-diaminopurine analog found to possess potent anti-HBV activity. In HepG2.2.15 cell line, beta-LPA had a 50% effective concentration (EC(50)) of 0.01 microM against HBV, as determined by analysis of secreted and intracellular episomal HBV DNA. Levels of HBV surface antigen (HBsAg) and e antigen (HBeAg) in drug-treated cultures revealed that beta-LPA had no significant inhibitory effects on HBsAg and HBeAg. beta-LPA didn't show any cytotoxicity up to 0.4 microM with a 50% cytotoxic concentration (CC(50)) of 50 microM. Furthermore, treatment with beta-LPA resulted in no apparent inhibitory effects on mitochondrial DNA content. Considering the potent inhibition of HBV DNA synthesis and no obvious toxicity of beta-LPA, this compound should be further explored for development as an anti-HBV drug.