Induced Cell Death Research Articles

Immunogenicity of cell death and cancer immunotherapy with immune checkpoint inhibitors.

While immunotherapy with immune checkpoint inhibitors (ICIs) has revolutionized the clinical management of various malignancies, a large fraction of patients are refractory to ICIs employed as standalone therapeutics, necessitating the development of combinatorial treatment strategies. Immunogenic cell death (ICD) inducers have attracted considerable interest as combinatorial partners for ICIs, at least in part owing to their ability to initiate a tumor-targeting adaptive immune response. However, compared with either approach alone, combinatorial regimens involving ICD inducers and ICIs have not always shown superior clinical activity. Here, we discuss accumulating evidence on the therapeutic interactions between ICD inducers and immunotherapy with ICIs in oncological settings, identify key factors that may explain discrepancies between preclinical and clinical findings, and propose strategies that address existing challenges to increase the efficacy of these combinations in patients with cancer.

Regulatory factor X1 promotes sorafenib-induced ferroptosis in hepatocellular carcinoma by transcriptional regulation of BECN1.

Sorafenib is a commonly used first-line kinase-targeted drug for advanced hepatocellular carcinoma (HCC) patients suffering from limited efficacy. Emerging evidence indicates that sorafenib exerts anti-cancer activity through the induction of ferroptosis in HCC cells, but the underlying mechanism is still unclear. The whole transcriptome sequencing and bioinformatics analysis were used to screen for target genes. The expression and subcellular localization of regulatory factor X1 (RFX1) were determined through immunohistochemistry, immunofluorescence, PCR and western blot analyses. The impact of RFX1 on HCC cell growth was assessed using CCK8, colony formation assays, cell death assays, and animal experiments. Glutathione measurement, iron assay and lipid peroxidation detection assays were performed to investigate ferroptosis of HCC cells. The regulatory mechanism of RFX1 in HCC was investigated by sgRFX1, co-IP, ChIP and luciferase experiments. Immunohistochemical and survival analyses were performed to examine the prognostic significance of RFX1 in HCC. In this study, we found that RFX1 promote ferroptosis in HCC cells. Further, we showed that sorafenib induces cell death through RFX1-mediated ferroptosis in HCC cells. The enhancing effect of RFX1 on HCC cell ferroptosis is largely dependent on inhibition of cystine/glutamate antiporter (system Xc-) activity through the BECN-SLC7A11 axis, where RFX1 directly binds to the promoter region of BECN1 and upregulates BECN1 expression. In addition, a STAT3-RFX1-BECN1 signalling loop was found to promote RFX1 expression in HCC cells. Our study reveals a novel mechanism underlying sorafenib-induced HCC cell death.

A barley MLA immune receptor is activated by a fungal nonribosomal peptide effector for disease susceptibility.

The barley Mla locus contains functionally diversified genes that encode intracellular nucleotide-binding leucine-rich repeat receptors (NLRs) and confer strain-specific immunity to biotrophic and hemibiotrophic fungal pathogens. In this study, we isolated a barley gene Scs6, which is an allelic variant of Mla genes but confers susceptibility to the isolate ND90Pr (BsND90Pr) of the necrotrophic fungus Bipolaris sorokiniana. We generated Scs6 transgenic barley lines and showed that Scs6 is sufficient to confer susceptibility to BsND90Pr in barley genotypes naturally lacking the receptor. The Scs6-encoded NLR (SCS6) is activated by a nonribosomal peptide (NRP) effector produced by BsND90Pr to induce cell death in barley and Nicotiana benthamiana. Domain swaps between MLAs and SCS6 reveal that the SCS6 leucine-rich repeat domain is a specificity determinant for receptor activation by the NRP effector. Scs6 is maintained in both wild and domesticated barley populations. Our phylogenetic analysis suggests that Scs6 is a Hordeum-specific innovation. We infer that SCS6 is a bona fide immune receptor that is likely directly activated by the nonribosomal peptide effector of BsND90Pr for disease susceptibility in barley. Our study provides a stepping stone for the future development of synthetic NLR receptors in crops that are less vulnerable to modification by necrotrophic pathogens.

Design of a Magnetic Nanoplatform Based on CD26 Targeting and HSP90 Inhibition for Apoptosis and Ferroptosis-Mediated Elimination of Senescent Cells.

The accumulation of senescent cells, a hallmark of aging and age-related diseases, is also considered as a side effect of anticancer therapies, promoting drug resistance and leading to treatment failure. The use of senolytics, selective inducers of cell death in senescent cells, is a promising pharmacological antiaging and anticancer approach. However, more studies are needed to overcome the limitations of first-generation senolytics by the design of targeted senolytics and nanosenolytics and the validation of their usefulness in biological systems. In the present study, we have designed a nanoplatform composed of iron oxide nanoparticles functionalized with an antibody against a cell surface marker of senescent cells (CD26), and loaded with the senolytic drug HSP90 inhibitor 17-DMAG (MNP@CD26@17D). We have documented its action against oxidative stress-induced senescent human fibroblasts, WI-38 and BJ cells, and anticancer drug-induced senescent cutaneous squamous cell carcinoma A431 cells, demonstrating for the first time that CD26 is a valid marker of senescence in cancer cells. A dual response to MNP@CD26@17D stimulation in senescent cells was revealed, namely, apoptosis-based early response (2 h treatment) and ferroptosis-based late response (24 h treatment). MNP@CD26@17D-mediated ferroptosis might be executed by ferritinophagy as judged by elevated levels of the ferritinophagy marker NCOA4 and a decreased pool of ferritin. As 24 h treatment with MNP@CD26@17D did not induce hemolysis in human erythrocytes in vitro, this newly designed nanoplatform could be considered as an optimal multifunctional tool to target and eliminate senescent cells of skin origin, overcoming their apoptosis resistance.

Effects of autophagy on the selective death of human breast cancer cells exposed to plasma-activated Ringer’s lactate solution

Plasma-activated Ringer’s lactate (PAL) solution prepared by irradiating an intravenous solution with a non-equilibrium atmospheric pressure plasma is a potential new cancer therapy having no side effects. However, the induction of autophagy to avoid cell death has been confirmed to occur following exposure to PAL solution. It is thought that the antitumor effect of PAL solution could be weakened by this process, which is meant to maintain homeostasis in cells and assists tumorigenesis. Thus, it would be helpful to devise PAL-based cancer therapies that inhibit autophagy. Unfortunately, it is not yet clear which substances in PAL solution promote autophagy. The present work examined the mechanism by which PAL solution induces autophagy when treating MCF-7 human breast cancer cells. Autophagy was found to be temporarily induced upon exposure to PAL solution, suggesting that this effect contributes to cell proliferation. Although autophagy is associated with reactive oxygen and nitrogen species and/or acidic environments, in this study, significant autophagy was observed using a PAL solution diluted 1/256x without these stressors. Acetate, glyoxylate and 2,3-dimethyltartrate in the PAL solution were determined to promote autophagy. Interestingly, 2,3-dimethyltartrate was found to either induce cell death or autophagy depending on the concentration.

The anticancer effect of metformin targets VDAC1 via ER-mitochondria interactions-mediated autophagy in HCC.

Metformin (MetF) is used worldwide as a first-line therapy for type 2 diabetes. Recently, interest in the pleiotropic effects of MetF, such as its anticancer and antiaging properties, has increased. However, the molecular target of MetF and the detailed mechanism underlying its ability to inhibit cell growth through autophagy induction remain incompletely understood. In this study, using an innovative label-free drug affinity responsive target stability (DARTS)-LC-MS/MS method, we discovered that mitochondrial voltage-dependent anion channel 1 (VDAC1) is a novel binding protein involved in the induction of autophagy-related cell death by high-dose MetF in hepatocellular carcinoma (HCC). Computational alanine scanning mutagenesis revealed that MetF and VDAC1 (D9, E203) interact electrostatically. MetF disrupts the IP3R-GRP75-VDAC1 complex, which plays a key role in stabilizing mitochondria-associated ER membranes (MAMs), by binding to VDAC1. This disruption leads to increased cytosolic calcium levels, thereby contributing to autophagy induction. MetF also decreased the AMP/ATP ratio and activated the AMPK pathway. Cells with genetic knockdown of VDAC1 mimicked the activity of MetF. In conclusion, this study provides new insights into the involvement of MetF in ionic interactions with VDAC1, contributing to its anticancer effects in HCC. These findings help elucidate the diverse biological and pharmacological effects of MetF, particularly its influence on autophagy, as well as the potential of MetF as a therapeutic agent for diseases characterized by VDAC1 overexpression.

Green Synthesis Techniques for Sulphur Nanoparticles: Current Methods and Future Perspectives

Abstract: In recent years, cancer has emerged as a significant public health challenge, prompting extensive research into the development of innovative anticancer therapies capable of selectively inducing cell death or halting the proliferation of cancer cells. Harnessing the distinctive characteristics of nanomaterials, advancements in nanotechnology have played a pivotal role in the progression of nanomedicine for cancer treatment. Various nanomaterials, such as gold, silver, silica, and carbon nanoparticles, have been investigated for their potential in drug delivery systems. Meanwhile, sulfur, with its abundant chemically diverse organic and inorganic compounds exhibiting a range of biological functions from antioxidant properties to antibacterial and anticancer capabilities, has garnered significant attention. Sulphur nanoparticles (SNPs) find widespread application in diverse fields such as lithium sulfur batteries, sulphur-based photocatalysts, and antimicrobial agents. Despite their extensive utilization in non-biomedical domains, such as drug delivery and cancer prevention strategies, SNPs face challenges when employed for biomedical purposes. Concerns include toxicity, limited reactivity, and the substantial particle size of SNPs, which hinder their effectiveness as drug delivery carriers. To overcome these obstacles, surface modifications of SNPs are necessary to enhance their biomedical applicability.

TAT-PPA1 protects against oxidative stress-induced loss of dopaminergic neurons.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by the progressive loss of dopaminergic neurons in the substantia nigra (SN) of the midbrain, resulting in severe motor impairments. Inorganic pyrophosphatase 1 (PPA1) plays a key role in various biological processes, and this study introduces a cell-penetrating PPA1 fusion protein (TAT-PPA1) to explore its transduction into cells and brain tissues. TAT-PPA1 effectively penetrates SH-SY5Y cells and the SN region of PD animal models without toxicity, exhibiting protective effects against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP-)-induced cell death. TAT-PPA1 revealed an inhibitory influence on the MAPK signaling pathway and MPTP-induced reactive oxygen species (ROS) production. TAT-PPA1 suppresses JNK, AKT, p53, ERK, and p38 phosphorylation, showcasing its multifaceted role in cell survival pathways. In the MPTP-induced PD animal model, TAT-PPA1 prevents dopaminergic cell death and enhances motor function. This study shows that TAT-PPA1 protects against oxidative stress and cell death in neurodegenerative diseases, suggesting potential as a PD treatment.

Heterocycle-functional steroidal derivatives: Design, synthesis, bioevaluation and SARs of steroidal pyrazolo[1,5-a]pyrimidines as potential ALK inhibitors

Two series of heterocyclic steroidal pyrazolo[1,5-a]pyrimidines derived from dehydroepiandrosterone (DHEA) and epiandrosterone (EPIA) were designed and synthesized, and these compounds were screened for their potential antiproliferation activities. The preliminary bioassay indicated that some of target compounds exhibited significantly good antiproliferation activities against human melanoma cell line (A875) and human hepatocellular carcinoma (Huh-7) cell lines compared with 5-fluorouracil (5-FU), and some of which present good antiproliferative activities as potential ALK inhibitors. The detailed analysis of structure–activity relationships (SARs) based on the inhibition activities, kinase assay, and molecular docking demonstrated that the antiproliferation activities of these steroidal pyrazolo[1,5-a]pyrimidine might be affected by the β-hydroxyl group of steroidal scaffold and the N atom of pyridine heterocycle. Especially, compound 4c has certain inhibitory effects on the tyrosine protein kinases ALK, CDK2/CyclinE1, FAK, CDK5/P35, CDK9/CyclinT1, CDK5/P25, PIM2, CDK2/CyclinA2, CDK1/CyclinB1, et c., and which displayed highest inhibitory effect on the kinases of ALK with inhibition rate 40.63 % at the concentration of 10 μM, which induced cell death in A875 cells at least partly (initially), by apoptosis.

RNA 3′end tailing safeguards cells against products of pervasive transcription termination

Premature transcription termination yields a wealth of unadenylated (pA−) RNA. Although this can be targeted for degradation by the Nuclear EXosome Targeting (NEXT) complex, possible backup pathways remain poorly understood. Here, we find increased levels of 3′ end uridylated and adenylated RNAs upon NEXT inactivation. U-tailed RNAs are mostly short and modified by the cytoplasmic tailing enzymes, TUT4/7, following their PHAX-dependent nuclear export and prior to their degradation by the cytoplasmic exosome or the exoribonuclease DIS3L2. Longer RNAs are instead adenylated redundantly by enzymes TENT2, PAPOLA and PAPOLG. These transcripts are either degraded via the nuclear Poly(A) tail eXosome Targeting (PAXT) connection or exported and removed by the cytoplasmic exosome in a translation-dependent manner. Failure to do so decreases global translation and induces cell death. We conclude that post-transcriptional 3′ end modification and removal of excess pA− RNA is achieved by tailing enzymes and export factors shared with productive RNA pathways.

Inhibition of CDGSH iron‑sulfur domain 2 exhibits tumor-suppressing effects on diffuse large B-cell lymphoma (DLBCL) by inducing ferroptosis through the regulation of the NRF2/SLC7A11/GPX4 pathway

CDGSH iron‑sulfur domain 2 (CISD2) is recognized as a ferroptosis-related gene that has potential as a target for cancer treatment. However, it is still uncertain whether targeting CISD2 can modulate ferroptosis in diffuse large B-cell lymphoma (DLBCL) cells and exhibit cancer-suppressing effects. The present study thoroughly investigated the role of CISD2 in DLBCL. CISD2 was found to be overexpressed in DLBCL, and its inhibition resulted in substantial growth inhibition in DLBCL cells. The growth inhibition effect resulting from CISD2 silencing could be reversed by a ferroptosis inhibitor, whereas inhibitors of apoptosis and necrosis did not yield the same reversal. CISD2-silenced DLBCL cells exhibited increased sensitivity to growth inhibition induced by ferroptosis suppressors. The inhibition of CISD2 induced ferroptotic cell death in DLBCL cells, which was supported by the overproduction of lipid peroxides, depletion of glutathione, accumulation of iron, and increased presence of shrunken mitochondria. Further investigation revealed reduced levels of NRF2, GPX4, and SLC7A11 in CISD2-silenced DLBCL cells. The overexpression of NRF2 significantly reduced the occurrence of ferroptotic cell death in DLBCL cells in which CISD2 was silenced. Furthermore, CISD2 inhibition exhibited tumor-suppressing effects in vivo associated with the induction of ferroptotic cell death in xenografts. These findings suggest that CISD2inhibition has tumor-suppressing effects on DLBCL by promoting ferroptotic cell death via the NRF2/SLC7A11/GPX4 pathway. Therefore, CISD2 holds promise as a viable candidate target for treating DLBCL.

Self-delivered sonodynamic nanomedicine for enhanced tumor immunotherapy by simultaneously reversing the immunosuppression and immune resistance

Sonodynamic therapy (SDT) shows potential for noninvasive eradication of local solid tumors. However, its efficacy in suppressing metastatic tumors is limited by factors such as insufficient tumor accumulation, the immunosuppressive tumor microenvironment, and acquired immune tolerance. To address these challenges, we developed self-delivering sonodynamic nanomedicine incorporating Toll-like receptor (TLR) agonists R848 and programmed death-ligand 1 (PD-L1) inhibitors JQ1 for combined SDT and immunotherapy. These nanomedicines enhanced tumor accumulation of sonosensitizers, enabling potent SDT and induction of immunogenic cell death (ICD). Additionally, the co-encapsulated R848 and JQ1 alleviated tumor immunosuppression and immune tolerance, synergizing effectively with SDT to elicit a robust antitumor immune response. By integrating enhanced SDT with activated antitumor immunity, significant inhibition of primary, distant, and lung metastatic tumors was achieved. This study introduces a novel approach for combining SDT with immunotherapy using self-assembled active pharmaceutical ingredients.

CaCO3-complexed pH-responsive nanoparticles encapsulating mitoxantrone and celastrol enhance tumor chemoimmunotherapy

Modulating the immunosuppressive tumor microenvironment (TME) while enhancing antitumor immune responses is a promising strategy. In this study, we designed an acid-sensitive nanosystem (MCCaNPs) to demonstrate effective immunotherapy against cancer through the systemic delivery of immune-stimulating chemotherapy combinations. A pH-responsive nanoplatform containing CaCO3 was prepared by the double emulsion method, and mitoxantrone (MIT) and celastrol (CEL) were simultaneously encapsulated as immunogenic cell death (ICD) inducers. Due to the acid responsiveness of CaCO3, the nanoparticles rapidly consume H+ to relieve the acidic tumor microenvironment and explosively release CEL and MIT, showing inherent immunomodulatory activity in collaborative tumor chemoimmunotherapy. MIT and CEL synergistically trigger stronger ICD by inducing tumor cells to release calreticulin (CRT), high mobility group box 1 protein (HMGB1). Following the intravenous administration of MCCaNPs, the local tumor microenvironment(TME) was reprogrammed in mice-bearing tumors. This reprogramming was characterized by a significant increase in the density of tumor-infiltrating cytotoxic T lymphocytes(CTLs), ultimately prolonging survival. Therefore, this research proposes a promising approach to trigger immunogenic cell death collaboratively, aiming to boost the tumor CTLs infiltration for anticancer immunotherapy.

The type III effector RipBB from Ralstonia pseudosolanacearum inhibits plant immunity responses and contributes to virulence on peanut

AbstractRalstonia solanacearum species complex (RSSC) is a serious soilborne phytopathogen affecting over 310 plant species. R. pseudosolanacearum is one clade of RSSC, which infects the important oil crop peanut. A variety of virulence factors are employed by RSSC to promote disease, among which type III effectors (T3Es) are prominent. How T3Es manipulate the interaction between R. pseudosolanacearum and peanut is unclear. A T3E RipBB was previously found specifically in a more virulent peanut R. pseudosolanacearum PeaFJ1 strain. In the present study, the function of RipBB was analysed. Loss of RipBB from PeaFJ1 strain resulted in attenuated pathogenicity to peanut, and complementation with RipBB recovered the virulence of the mutant strain. Transient expression of RipBB induced cell death and inhibited flg22‐triggered reactive oxygen species (ROS) burst in the leaves of Nicotiana benthamiana. The expression of pattern‐triggered immunity (PTI)‐related genes were also suppressed by RipBB transient expression. Among the available sequenced 639 RSSC strains, RipBB is an infrequent T3E that is only present in eight strains. Two ankyrin (ANK) repeats were identified in RipBB, which play an important role in localizing the protein to the cytomembrane and nucleus. Altogether, we verified that RipBB contributes to infecting peanut by acting as a virulence T3E, and causes cell death and suppresses immunity in N. benthamiana. These results enhance the study of ANK‐containing effectors. Further elucidation of the molecular mechanisms underlying RipBB effect on immunity may reveal ANK‐containing effector functions in host cells, helping to understanding the mechanism of R. pseudosolanacearum–peanut interaction.

Arenobufagin Induces Ferroptosis in Glioblastoma Cells via Modulating the MiR‐149‐5p/AEBP1 Axis

ABSTRACTAccumulating evidences have proved Arenobufagin (ArBu) exhibited cytotoxic effects to multiple types of cancer. However, in glwioblastoma (GBM), which is easy to develop resistance to classic chemotherapy reagent, the therapeutic effects of ArBu have not been explored. In the current study, we found that GBM cells were sensitive to ArBu treatment and ArBu induced cell death both in a dose‐dependent and a time‐dependent manner. ArBu was observed to promote ROS accumulating and elevate Fe2+/MDA/GSH level, which lead to ferroptosis. Mechanistically, ArBu significantly downregulated AEBP1 expression and decreased the mRNA stability of AEBP1 without affecting its transcription. Then, AEBP1 mRNA was predicted to bind with miR‐149‐5p in GBM cells, which directly target its 3′UTR. At last, we found ArBu could upregulate miR‐149‐5p to suppress AEBP1 expression, and the rescue experiments confirmed miR‐149‐5p/AEBP1 axis regulated ferroptosis, which underlay the therapeutic effects of ArBu in GBM cells. This study revealed that ArBu induced ferroptosis in a dose‐dependent manner via modulating miR‐149‐5p/AEBP1 axis. It provides evidences for clinical application of ArBu for GBM.

Enhancing radiotherapy in triple-negative breast cancer with hesperetin-induced ferroptosis via AURKA targeting nanocomposites

Triple-negative breast cancer (TNBC) is an aggressive cancer type that lacks targeted treatment options. Ferroptosis, a novel therapeutic strategy, induces cell death by disrupting the oxidative-reductive balance. Hesperetin, a potential TNBC therapeutic drug, has unidentified regulatory targets. The objective of this study was to explore the potential targets of hesperetin in TNBC and investigate whether the nanocomposites carrier hesperetin-loaded ferroptosis-inducing nanocomposites (HFPN), which activates ferroptosis, can enhance the anti-tumor efficacy of hesperetin. Bioinformatics methods were employed to screen hesperetin targets in TNBC, and a molecular docking model between hesperetin and the core target aurora kinase A (AURKA) was successfully constructed. The stability and anti-tumor activity of HFPN were validated in cell and mouse models, including tumor suppression and increased radiation sensitivity. These results suggest that HFPN can regulate the core target AURKA in TNBC, disrupt tumor oxidative-reductive balance, promote ferroptosis in tumor cells, and ultimately enhance the effectiveness of radiation therapy for TNBC.Graphical abstract

Anti-cancer effect of sodium pentaborate in combination with cisplatin on lung cancer cell lines.

Despite the development of novel therapeutic modalities, lung cancer persists as the leading cause of cancer-related mortality. Platinum-based treatments represent the most prominent treatment option, with cisplatin being the most frequently utilized chemotherapeutic agent. However, cisplatin has several serious side effects. A substantial body of evidence has emerged in recent years indicating that boron compounds exhibit anti-cancer properties when administered as monotherapy or in combination with chemotherapy agents. The objective of this study is to examine the anti-cancer effects of Cisplatin (Cis) and sodium pentaborate pentahydrate (NaB), both individually and in combination, on non-small cell lung cancer (NSCLC) cell line A-549 cells and small cell lung cancer (SCLC) cell line DMS-114 cells under in vitro conditions. The effects of cisplatin and NAB on cell survival, apoptosis, the cell cycle, and the expression levels of apoptotic, anti-apoptotic, and tumor suppressor genes were determined by an MTS assay, an Annexin-V assay, a cell cycle analysis, and real-time PCR (qPCR). It was found that the IC-50 value of cisplatin, which was 10 µM when used alone, decreased to 2.5 µM when combined with a non-toxic dose of NaB on the A-549 cell line. BAX and TP53 gene expression levels were elevated by the Nab-Cisplatin combination in the A-549 cell line. The combination was observed to result in an approximately 19-fold increase in CDK2 gene expression in the A-549 cell line and an approximately 6-fold increase in the DMS-114 line, which resulted in S phase and/or G2 phase arrest on the cell cycle. Gene expression levels of Survivin and Ki-67 were decreased by the combination on both cell lines when compared with cisplatin alone. The findings demonstrate that NaB exerts an anti-cancer effect on the A-549 and DMS-114 cell lines. Moreover, when combined with cisplatin, it produces a synergistic anti-cancer effect on the A-549 cell line, whereby apoptosis is activated and cell proliferation is inhibited. The combination of NaB and cisplatin represents a novel approach to the treatment of NSCLC. This is due to the fact that it reduces the IC-50 value of cisplatin and also results in a greater inhibition of cell division and a stronger induction of cell death when used in the context of a combined treatment. Further insight into the effects of the NaB-cisplatin combination will be gained from in vivo experiments and clinical studies.

Dual specific STAT3/5 degraders effectively block acute myeloid leukemia and natural killer/T cell lymphoma.

The transcription factors STAT3, STAT5A, and STAT5B steer hematopoiesis and immunity, but their enhanced expression and activation promote acute myeloid leukemia (AML) or natural killer/T cell lymphoma (NKCL). Current therapeutic strategies focus on blocking upstream tyrosine kinases to inhibit STAT3/5, but these kinase blockers are not selective against STAT3/5 activation and frequent resistance causes relapse, emphasizing the need for targeted drugs. We evaluated the efficacy of JPX-0700 and JPX-0750 as dual STAT3/5 binding inhibitors promoting protein degradation. JPX-0700/-0750 decreased the mRNA and protein levels of STAT3/5 targets involved in cancer survival, metabolism, and cell cycle progression, exhibiting nanomolar to low micromolar efficacy. They induced cell death and growth arrest in both AML/NKCL cell lines and primary AML patient blasts. We found that both AML/NKCL cells hijack STAT3/5 signaling through either upstream activating mutations in kinases, activating mutations in STAT3, mutational loss of negative STAT regulators, or genetic gains in anti-apoptotic, pro-proliferative, or epigenetic-modifying STAT3/5 targets. This emphasizes a vicious cycle for proliferation and survival through STAT3/5. Both JPX-0700/-0750 treatment reduced leukemic cell growth in human AML or NKCL xenograft mouse models significantly, being well tolerated by mice. Synergistic cell death was induced upon combinatorial use with approved chemotherapeutics in AML/NKCL cells.

Development of an efficient NUPR1 inhibitor with anticancer activity

Pancreatic cancer is highly lethal and has limited treatment options available. Our team had previously developed ZZW-115, a promising drug candidate that targets the nuclear protein 1 (NUPR1), which is involved in pancreatic cancer development and progression. However, clinical translation of ZZW-115 was hindered due to potential cardiotoxicity caused by its interaction with the human Ether-à-go-go-Related Gene (hERG) potassium channel. To address this, we have performed a high-throughput screening of 10,000 compounds from the HitFinder Chemical Library, and identified AJO14 as a lead compound that binds to NUPR1, without having favorable affinity towards hERG. AJO14 induced cell death through apoptosis, necroptosis, and parthanatos (induced by the poly-ADP ribose polymerase (PARP) overactivation), driven by mitochondrial catastrophe and decreased ATP production. This process seemed to be mediated by the hyperPARylation (an excessive modification of proteins by PARP, leading to cellular dysfunction), as it could be reversed by Olaparib, a PARP inhibitor. In xenografted mice, AJO14 demonstrated a dose-dependent tumor reduction activity. Furthermore, we attempted to improve the anti-cancer properties of AJO14 by molecular modification of the lead compound. Among the 51 candidates obtained and tested, 8 compounds exhibited a significant increase in efficacy and have been retained for further studies, especially LZX-2-73. These AJO14-derived compounds offer potent NUPR1 inhibition for pancreatic cancer treatment, without cardiotoxicity concerns.

A Stinkbug Salivary Protein Is Indispensable for Insect Feeding and Activates Plant Immunity.

Salivary proteins secreted by phytophagous insects play pivotal roles in plant-insect interactions. A salivary protein RpSP27, from the stinkbug Riptortus pedestris, a devastating pest on soybean, was selected for studying due to its ability to induce cell death and activate immune responses in plants. RpSP27 localized to the endoplasmic reticulum and triggered reactive oxygen species burst. Virus-induced gene silencing assays showed RAR1 plays an essential role in RpSP27-induced cell death in Nicotiana benthamiana. Expression analyses revealed that RpSP27 is predominantly expressed in R. pedestris salivary glands. RNA interference-mediated silencing of RpSP27 in R. pedestris significantly reduced insect survival rates and altered feeding behavior by decreasing the formation of salivary sheaths on soybeans and reducing probing and feeding duration. Furthermore, the silencing of RpSP27 in R. pedestris mitigated the staygreen syndrome in soybeans, characterized by delayed senescence and pod abnormalities. This study elucidated the role of RpSP27 in the interaction between R. pedestris and soybean, presenting a potential target for pest management strategies to protect soybean crops from the detrimental effects of R. pedestris feeding.