Mitochondria-Judges and Executioners of Cell Death Sentences

Discovery and antitumor evaluation of a mitochondria-targeting ruthenium complex for effective cancer therapy

Ruthenium-based metallodrugs have garnered attention as a promising alternative for anticancer therapy, aiming to overcome chemoresistance and severe side effects linked to platinum-based drugs. However, ruthenium complexes tested in clinical trials to date have yielded unsatisfactory results. This study synthesized a positively charged ruthenium complex (Ru-2) that effectively penetrated cancer cells and exhibited superior cytotoxicity to cisplatin in vitro against cancer cell lines and organoids. Ru-2 selectively targeted mitochondria, disrupting their function by depolarizing mitochondrial membrane potential, elevating reactive oxygen species production, and impairing both oxidative phosphorylation and the tricarboxylic acid cycle. Furthermore, Ru-2 triggered endoplasmic reticulum (ER) stress and apoptosis. Integrative transcriptomic and proteomic analyses, performed using RNA sequencing and mass spectrometry, identified key molecular changes in cancer cells treated with Ru-2. For enhanced in vivo application, we developed a transferrin-based nanomedicine formulation, TF/Ru-2, incorporating Ru-2 into transferrin. In vivo studies demonstrated that both Ru-2 and TF/Ru-2 exhibited superior antitumor efficacy and improved biosafety compared to cisplatin. This study presents a novel ruthenium complex and a transferrin-based drug delivery platform with significant potential for future cancer therapies.

MIS18BP1 promotes bladder cancer cell proliferation and growth via inactivating P53 signaling pathway

MIS18 bonding protein 1 (MIS18BP1) is a subunit of MIS18 complex, accumulated specifically at telophase-G1 centromere and regulated apoptosis, proliferation and migration in cancer cells. The mechanisms about how MIS18BP1 regulate Bladder Cancer (BCa) cell development have not been previously unknown. We analyzed MIS18BP1 differential expression in BCa by The Cancer Genome Atlas (TCGA), Gene-Expression Omnibus (GEO) and Universal Protein database. The expression of MIS18BP1 mRNA was tested using qRT-PCR. The expression of MIS18BP1 protein was examined by western blot and immunohistochemistry (IHC) staining. T24 cells were transfected with an LV -MIS18BP1 -RNAi vector to decrease the MIS18BP1 expression. We used a series of experiments to detect the survival, proliferation and migration of T24. The apoptosis was analyzed by Flow cytometry assays. The expression of P53, BAX and Cleaved Casepase-3 was detected by western blot. P53 apoptosis-related proteins, proliferation and migration of cells were analyzed before and after treatment with P53 inhibitors. The expression of MIS18BP1 was higher in BCa tissues compared with control group. Its expression was in relation to clinical stage, depth of invasion and lymph node metastasis. We found that genes closely related to MIS18BP1 are mainly associated with cell cycle, chromosome separation and DNA repair in biological processes. After transfection, we found the proliferative capacity of T24 was significantly reduced. Transwell migration and scratch experiment demonstrated decreased migration. Meanwhile, downregulation of MIS18BP1 resulted in an increase in cell apoptosis. In addition, P53, BAX and Cleaved Casepase-3 were increased, whereas BCL2 protein was decreased in the MIS18BP1-downregulated T24. After treatment with Pifithrin-α, the phenotype of cell proliferation inhibition was restored. MIS18BP1 overexpression may be regulated to poor prognosis in BCa patients. MIS18BP1 may associated with cell apoptosis and proliferation in BC cells. This process may be mediated by P53 signal pathway.

Programmed mitophagy at the oocyte-to-zygote transition promotes species immortality

The quality of mitochondria inherited from the oocyte determines embryonic viability, metabolic health throughout progeny lifetime, and future generation endurance. High levels of endogenous reactive oxygen species and exogenous toxicants are threats to mitochondrial DNA (mtDNA) in fully developed oocytes. Deleterious mtDNA is commonly detected in developed oocytes, but is absent in embryos, suggesting the existence of a cryptic purifying selection mechanism. Here we discover that in C. elegans, the onset of oocyte-to-zygote transition (OZT) developmentally triggers a rapid mitophagy event. We show that mitophagy at OZT (MOZT) requires mitochondrial fragmentation, the macroautophagy pathway, and the mitophagy receptor FUNDC1, but not the prevalent mitophagy factors PINK1 and BNIP3. Impaired MOZT leads to increased deleterious mtDNA inheritance and decreases embryonic survival. Inherited mtDNA damage accumulates across generations, leading to the extinction of descendent populations. Thus, MOZT represents a strategy that preserves mitochondrial health during the mother-to-offspring transmission and promotes species continuity.

Incidence of Tumour Lysis Syndrome in Patients with Acute Myeloid Leukemia During Initiation of Therapy with Azacitidine and Venetoclax: A Retrospective Chart Review from a Canadian Single-Centre Perspective

Azacitidine and venetoclax (Aza-Ven) are part of a new standard of care for elderly patients with Acute Myeloid Leukemia (AML) [In line with recommendations, patients with AML at our centre were routinely admitted during initiation of Aza-Ven for close monitoring for tumour lysis syndrome (TLS). However, hospitalization impacts patient experience and is a significant resource burden. The objectives of this study were to evaluate the incidence of TLS in this population and identify patients who could safely initiate therapy in our outpatient facility. Of the 48 patients who commenced Aza-Ven as inpatients, the incidence of TLS was 25% using Cairo-Bishop (CB) diagnostic criteria but was mostly due to transient increases in uric acid, phosphate or potassium that remained within the normal laboratory reference range. Using Howard diagnostic criteria, TLS incidence was only 2%. Patients who developed CB TLS had a significantly higher baseline white blood count (WBC; p = 0.01). Patients with WBC of less than 30 × 109/L subsequently completed outpatient initiation of Aza-Ven (n = 15). Only one of these patients developed mild, transient TLS by CB criteria but not by Howard criteria. Our results demonstrate that a significant portion of patients could safely initiate Aza-Ven in our outpatient facility and avoid unnecessary hospitalization.

Combined inhibition of ribonucleotide reductase and WEE1 induces synergistic anticancer activity in Ewing's sarcoma cells

BACKGROUND

Ewing's sarcoma is a childhood bone and soft tissue cancer with poor prognosis. Treatment outcomes for Ewing's sarcoma patients have improved only modestly over the past decades, making the development of new treatment strategies paramount. In this study, the combined targeting of ribonucleotide reductase (RNR) and WEE1 was explored for its effectiveness against Ewing's sarcoma cells.

METHODS

The RNR inhibitor triapine and the WEE1 inhibitors adavosertib and ZN-c3 were tested in p53 wild-type and p53 mutant Ewing's sarcoma cells. The combination of adavosertib with the PARP inhibitors olaparib and veliparib was tested for comparison. Combinatorial effects were determined by flow cytometric analyses of cell death, loss of mitochondrial membrane potential and DNA fragmentation as well as by caspase 3/7 activity assay, immunoblotting and real-time RT-PCR. The drug interactions were assessed using combination index analysis.

RESULTS

RNR and WEE1 inhibitors were weakly to moderately effective on their own, but highly effective in combination. The combination treatments were similarly effective in p53 wild-type and p53 mutant cells. They synergistically induced cell death and cooperated to elicit mitochondrial membrane potential decay, to activate caspase 3/7 and to trigger DNA fragmentation, evidencing the induction of the apoptotic cell death cascade. They also cooperated to boost CHK1 phosphorylation, indicating augmented replication stress after combination treatment. In comparison, the combination of adavosertib with PARP inhibitors produced weaker synergistic effects.

CONCLUSION

Our findings show that combined inhibition of RNR and WEE1 was effective against Ewing's sarcoma in vitro. They thus provide a rationale for the evaluation of the potential of combined targeting of RNR and WEE1 in Ewing's sarcoma in vivo.

BCL-B Promotes Lung Cancer Invasiveness by Direct Inhibition of BOK

Expression of BCL-B, an anti-apoptotic BCL-2 family member, is correlated with worse survival in lung adenocarcinomas. Here, we show that BCL-B can mitigate cell death initiation through interaction with the effector protein BOK. We found that this interaction can promote sublethal mitochondrial outer membrane permeabilization (MOMP) and consequently generate apoptosis-flatliners, which represent a source of drug-tolerant persister cells (DTPs). The engagement of endothelial-mesenchymal-transition (EMT) further promotes cancer cell invasiveness in such DTPs. Our results reveal that BCL-B fosters cancer cell aggressiveness by counteracting complete MOMP.

Molecular Insights in the Anticancer Activity of Natural Tocotrienols: Targeting Mitochondrial Metabolism and Cellular Redox Homeostasis

The role of mitochondria as the electric engine of cells is well established. Over the past two decades, accumulating evidence has pointed out that, despite the presence of a highly active glycolytic pathway (Warburg effect), a functional and even upregulated mitochondrial respiration occurs in cancer cells to meet the need of high energy and the biosynthetic demand to sustain their anabolic growth. Mitochondria are also the primary source of intracellular ROS. Cancer cells maintain moderate levels of ROS to promote tumorigenesis, metastasis, and drug resistance; indeed, once the cytotoxicity threshold is exceeded, ROS trigger oxidative damage, ultimately leading to cell death. Based on this, mitochondrial metabolic functions and ROS generation are considered attractive targets of synthetic and natural anticancer compounds. Tocotrienols (TTs), specifically the δ- and γ-TT isoforms, are vitamin E-derived biomolecules widely shown to possess striking anticancer properties since they regulate several intracellular molecular pathways. Herein, we provide for the first time an overview of the mitochondrial metabolic reprogramming and redox homeostasis perturbation occurring in cancer cells, highlighting their involvement in the anticancer properties of TTs. This evidence sheds light on the use of these natural compounds as a promising preventive or therapeutic approach for novel anticancer strategies.

Targeting regulated cell death (RCD) with naturally derived sesquiterpene lactones in cancer therapy

Regulated cell death (RCD) is a type of cell death modulated by specific signal transduction pathways. Currently, known RCD types include apoptosis, autophagy, ferroptosis, necroptosis, cuproptosis, pyroptosis, and NETosis. Mutations in cancer cells may prevent the RCD pathway; therefore, targeting RCD in tumors has become a promising therapeutic approach. Sesquiterpene lactones represent a diverse and extensive class of plant-derived phytochemicals that serve as potential sources for developing various drugs. Recent studies have shown that sesquiterpene lactones have promising potential in cancer treatment. This review systematically summarizes recent progress in the study of sesquiterpene lactones as antitumor agents, highlighting their role in targeting various RCD pathways, including those involved in apoptosis, autophagy, ferroptosis, necroptosis, and cuproptosis. The primary purpose of the present review is to provide a clear picture of the regulation of RCD by sesquiterpene lactones against different targets in various cancers, which will facilitate the development of new strategies for cancer therapy.

Mitochondria-associated programmed cell death: elucidating prognostic biomarkers, immune checkpoints, and therapeutic avenues in multiple myeloma

Background

Multiple myeloma (MM) is a hematological malignancy characterized by the abnormal proliferation of plasma cells. Mitochondrial dysfunction and dysregulated programmed cell death (PCD) pathways have been implicated in MM pathogenesis. However, the precise roles of mitochondria-related genes (MRGs) and PCD-related genes (PCDRGs) in MM prognosis remain unclear.

Methods

Transcriptomic data from MM patients and healthy controls were analyzed to identify differentially expressed genes (DEGs). Candidate genes were selected by intersecting DEGs with curated lists of MRGs and PCDRGs. Univariate Cox, least absolute shrinkage and selection operator (LASSO), multivariate Cox, and stepwise regression analyses identified prognostic genes among the candidates. A risk model was constructed from these genes, and patients were stratified into high- and low-risk groups for survival analysis. Independent prognostic factors were incorporated into a nomogram to predict MM patient outcomes. Model performance was evaluated using calibration curves, receiver operating characteristic (ROC) analysis, and decision curve analysis (DCA). Finally, associations between prognostic genes and immune cell infiltration/drug responses were explored.

Results

2,192 DEGs were detected between MM and control samples. 30 candidate genes were identified at the intersection of DEGs, 1,136 MRGs, and 1,548 PCDRGs. TRIAP1, TOMM7, PINK1, CHCHD10, PPIF, BCL2L1, and NDUFA13 were selected as prognostic genes. The risk model stratified patients into high- and low-risk groups with significantly different survival probabilities. Age, gender, ISS stage, and risk score were independent prognostic factors. The nomogram displayed good calibration and discriminative ability (AUC) in predicting survival, with clinical utility demonstrated by DCA. 9 immune cell types showed differential infiltration between MM and controls, with significant associations to risk scores and specific prognostic genes. 57 drugs, including nelarabine and vorinostat, were predicted to interact with the prognostic genes. Ultimately, qPCR in clinical samples from MM patients and healthy donors validated the expression levels of the seven key prognostic genes, corroborating the bioinformatic findings.

Conclusion

Seven genes (TRIAP1, TOMM7, PINK1, CHCHD10, PPIF, BCL2L1, NDUFA13) involved in mitochondrial function and PCD pathways were identified as prognostic markers in MM. These findings provide insights into MM biology and prognosis, highlighting potential therapeutic targets.

BET inhibitors (BETi) influence oxidative phosphorylation metabolism by affecting mitochondrial dynamics leading to alterations in apoptotic pathways in triple-negative breast cancer (TNBC) cells

Repressing BET proteins' function using bromodomain inhibitors (BETi) has been shown to elicit antitumor effects by regulating the transcription of genes downstream of BRD4. We previously showed that BETi promoted cell death of triple-negative breast cancer (TNBC) cells. Here, we proved that BETi induce altered mitochondrial dynamics fitness in TNBC cells falling in cell death. We demonstrated that BETi treatment downregulated the expression of BCL-2, and proteins involved in mitochondrial fission and increased fused mitochondria. Impaired mitochondrial fission affected oxidative phosphorylation (OXPHOS) inducing the expression of OXPHOS-related genes, SDHa and ATP5a, and increased cell death. Consistently, the amount of mitochondrial DNA and mitochondrial membrane potential (∆Ψm) increased in BETi-treated cells compared to control cells. Lastly, BETi in combination with Metformin reduced cell growth. Our results indicate that mitochondrial dynamics and OXPHOS metabolism support breast cancer proliferation and represent novel BETi downstream targets in TNBC cells.

Deciphering the mechanistic impact of acupuncture on the neurovascular unit in acute ischemic stroke: Insights from basic research in a narrative review

Ischemic stroke(IS), a severe acute cerebrovascular disease, not only imposes a heavy economic burden on society but also presents numerous challenges in treatment. During the acute phase, while thrombolysis and thrombectomy serve as primary treatments, these approaches are restricted by a narrow therapeutic window. During rehabilitation, commonly used neuroprotective agents struggle with their low drug delivery efficiency and inadequate preclinical testing, and the long-term pharmacological and toxicity effects of nanomedicines remain undefined. Meanwhile, acupuncture as a therapeutic approach is widely acknowledged for its effectiveness in treating IS and has been recommended by the World Health Organization (WHO) as an alternative and complementary therapy, even though its exact mechanisms remain unclear. This review aims to summarize the known mechanisms of acupuncture and electroacupuncture (EA) in the treatment of IS. Research shows that acupuncture treatment mainly protects the neurovascular unit through five mechanisms: 1) reducing neuronal apoptosis and promoting neuronal repair and proliferation; 2) maintaining the integrity of the blood-brain barrier (BBB); 3) inhibiting the overactivation and polarization imbalance of microglia; 4) regulating the movement of vascular smooth muscle (VSM) cells; 5) promoting the proliferation of oligodendrocyte precursors. Through an in-depth analysis, this review reveals the multi-level, multi-dimensional impact of acupuncture treatment on the neurovascular unit (NVU) following IS, providing stronger evidence and a theoretical basis for its clinical application.

Unfolded proteins in the mitochondria activate HRI and inhibit mitochondrial protein translation

The mitochondrial unfolded protein response (UPRmt) is triggered through eIF2α phosphorylation in mammals. However, the mechanisms of UPRmt activation and the influence of eIF2α phosphorylation on mitochondrial protein translation remain unclear. In this study, we confirmed that the UPRmt is a rapid and specific stress response that occurs through pharmacological induction of eIF2α phosphorylation, along with the phosphorylation of eIF2α, ATF4, and CHOP. Moreover, with the upregulation of the expression of some chaperones, cytochrome P450 enzymes, and DDIT4, as determined by RNA-Seq and ribosome profiling, eIF2α phosphorylation was found to be essential for the expression of ATF4 and CHOP, after which ATF4 trafficked into the nucleus and initiated CHOP expression. In addition, the generation of ROS and mitochondrial morphology were not affected by the GTPP-induced UPRmt. Furthermore, we investigated the mechanism by which HRI kinase-mediated UPRmt is induced by mitochondrial unfolded proteins via CRISPR-Cas9 technology, mitochondrial recruitment of HRI and interaction with other proteins. Moreover, we confirmed that mitochondrial protein translation and mitochondrial protein import were inhibited through eIF2α phosphorylation with the accumulation of unfolded mitochondrial proteins. These findings reveal the molecular mechanism of the UPRmt and its impact on cellular protein translation, which will offer novel insights into the functions of the UPRmt, including its implications for human disease and pathobiology.

The Effects of Resveratrol, Gallic Acid, and Piperine on the Expression of miR-17, miR-92b, miR-181a, miR-222, BAX, BCL-2, MCL-1, WT1, c-Kit, and CEBPA in Human Acute Myeloid Leukemia Cells and Their Roles in Apoptosis

MicroRNAs (miRs) play a crucial role in the leukemogenesis and the prognosis of acute myeloid leukemia (AML). This study investigated the therapeutic effects of resveratrol, gallic acid, and piperine as natural anticancer agents on the HL-60 cell line and their roles in apoptosis. In this experimental study, quantitative analysis of miRs, including miR-17, miR-92b, miR-181a, and miR-222, were performed in 150 newly diagnosed patients with AML by real-time PCR assay. HL-60 cell viability as well as the expression of miRs, BAX, BCL-2, MCL-1, WT1, c-Kit, and CEBPA, were also assessed after transfection with the LNA-miRs and treatment with resveratrol, gallic acid, and piperine. The expression of miR-17 and miR-181a decreased significantly in LNA-anti-miRs. Although HL-60 cell viability decreased in LNA-anti-miR-222, miR-17, and miR-92b, blockade of miR-181a increased the cell viability. Besides, the cell viability increased merely in the piperine-treated group. Compared to untreated cells, miR-17 and miR-92b expression significantly increased in gallic acid- and resveratrol-treated cells. In HL-60 cells treated with resveratrol, gallic acid, and piperine, the expression of miR-181a was also increased significantly. The expression of BAX was also increased in resveratrol and piperine-treated groups. Compared to untreated cells, the expression of c-Kit increased significantly in the piperine-treated group; however, it decreased in the resveratrol-treated group. LNA-anti-miRs may be a promising agent for the treatment of AML. All three compounds used in this study showed anticancer effects, which can exert the desired outcome in patients with AML.

Mitochondrial bioenergetics as a cell fate rheostat for responsive to Bcl-2 drugs: New cues for cancer chemotherapy

Pro-survival BCL-2 proteins prevent the initiation of intrinsic apoptosis (mitochondria-dependent pathway) by inhibiting the pro-apoptotic proteins BAX and BAK, while BH3-only proteins promote apoptosis by blocking pro-survival BCL-2 proteins. Disruptions in this delicate balance contribute to cancer cell survival and chemoresistance. Recent advances in cancer therapeutics involve a new generation of drugs known as BH3-mimetics, which are small molecules designed to mimic the action of BH3-only proteins. Promising effects have been observed in patients with hematological and solid tumors undergoing treatment with these agents. However, the rapid emergence of mitochondria-dependent resistance to BH3-mimetics has been reported. This resistance involves increased mitochondrial respiration, altered mitophagy, and mitochondria with higher and tighter cristae. Conversely, mutations in isocitrate dehydrogenase 1 and 2, catalyzing R-2-hydroxyglutarate production, promote sensitivity to venetoclax. This evidence underscores the urgency for comprehensive studies on bioenergetics-based adaptive responses in both BH3 mimetics-sensitive and -resistant cancer cells. Ongoing clinical trials are evaluating BH3-mimetics in combination with standard chemotherapeutics. In this article, we discuss the role of mitochondrial bioenergetics in response to BH3-mimetics and explore potential therapeutic opportunities through metabolism-targeting strategies.

Mammalian integrated stress responses in stressed organelles and their functions

The integrated stress response (ISR) triggered in response to various cellular stress enables mammalian cells to effectively cope with diverse stressful conditions while maintaining their normal functions. Four kinases (PERK, PKR, GCN2, and HRI) of ISR regulate ISR signaling and intracellular protein translation via mediating the phosphorylation of eukaryotic translation initiation factor 2 α (eIF2α) at Ser51. Early ISR creates an opportunity for cells to repair themselves and restore homeostasis. This effect, however, is reversed in the late stages of ISR. Currently, some studies have shown the non-negligible impact of ISR on diseases such as ischemic diseases, cognitive impairment, metabolic syndrome, cancer, vanishing white matter, etc. Hence, artificial regulation of ISR and its signaling with ISR modulators becomes a promising therapeutic strategy for relieving disease symptoms and improving clinical outcomes. Here, we provide an overview of the essential mechanisms of ISR and describe the ISR-related pathways in organelles including mitochondria, endoplasmic reticulum, Golgi apparatus, and lysosomes. Meanwhile, the regulatory effects of ISR modulators and their potential application in various diseases are also enumerated.

Decreased apoptotic priming and loss of BCL-2 dependence are functional hallmarks of Richter's syndrome

Richter's syndrome (RS) is the transformation of chronic lymphocytic leukemia (CLL) into a high-grade B-cell malignancy. Molecular and functional studies have pointed out that CLL cells are close to the apoptotic threshold and dependent on BCL-2 for survival. However, it remains undefined how evasion from apoptosis evolves during disease transformation. Here, we employed functional and static approaches to compare the regulation of mitochondrial apoptosis in CLL and RS. BH3 profiling of 17 CLL and 9 RS samples demonstrated that RS cells had reduced apoptotic priming and lower BCL-2 dependence than CLL cells. While a subset of RS was dependent on alternative anti-apoptotic proteins and was sensitive to specific BH3 mimetics, other RS cases harbored no specific anti-apoptotic addiction. Transcriptomics of paired CLL/RS samples revealed downregulation of pro-apoptotic sensitizers during disease transformation. Albeit expressed, effector and activator members were less likely to colocalize with mitochondria in RS compared to CLL. Electron microscopy highlighted reduced cristae width in RS mitochondria, a condition further promoting apoptosis resistance. Collectively, our data suggest that RS cells evolve multiple mechanisms that lower the apoptotic priming and shift the anti-apoptotic dependencies away from BCL-2, making direct targeting of mitochondrial apoptosis more challenging after disease transformation.

It comes from the sea: macroalgae-derived bioactive compounds with anti-cancer potential

Nature derived compounds represent a valuable source of bioactive molecules with enormous potential. The sea is one of the richest environments, full of skilled organisms, where algae stand out due to their unique characteristics. Marine macroalgae adapt their phenotypic characteristics, such as chemical composition, depending on the environmental conditions where they live. The compounds produced by these organisms show tremendous potential to be used in the biomedical field, due to their antioxidant, anti-inflammatory, immunomodulatory, and anti-cancer properties.Cancer is one of the deadliest diseases in the world, and the lack of effective treatments highlights the urgent need for the development of new therapeutic strategies. This review provides an overview of the current advances regarding the anti-cancer activity of the three major groups of marine macroalgae, i.e., red algae (Rhodophyta), brown algae (Phaeophyceae), and green algae (Chlorophyta) on pancreatic, lung, breast, cervical, colorectal, liver, and gastric cancers as well as leukemia and melanoma. In addition, future perspectives, and limitations regarding this field of work are also discussed.

Terpenes and Terpenoids Conjugated with BODIPYs: An Overview of Biological and Chemical Properties

Advancements in small-molecule research have created the need for sensitive techniques to accurately study biological processes in living systems. Fluorescent-labeled probes have become indispensable tools, particularly those that use boron-dipyrromethene (BODIPY) dyes. Terpenes and terpenoids are organic compounds found in nature that offer diverse biological activities, and BODIPY-based probes play a crucial role in studying these compounds. Monoterpene-BODIPY conjugates have exhibited potential for staining bacterial and fungal cells. Sesquiterpene-BODIPY derivatives have been used to study sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA), indicating their potential for drug development. Owing to their unique properties, diterpenes have been investigated using BODIPY conjugates to evaluate their mechanisms of action. Triterpene-BODIPY conjugates have been synthesized for biological studies, with different spacers affecting their cytotoxicity. Fluorescent probes, inspired by terpenoid-containing vitamins, have also been developed. Derivatives of tocopherol, coenzyme Q10, and vitamin K1 can provide insights into their oxidation-reduction abilities. All these probes have diverse applications, including the study of cell membranes to investigate immune responses and antioxidant properties. Further research in this field can help better understand and use terpenes and terpenoids in various biological contexts.

SF3A2 promotes progression and cisplatin resistance in triple-negative breast cancer via alternative splicing of MKRN1

Triple-negative breast cancer (TNBC) is the deadliest subtype of breast cancer owing to the lack of effective therapeutic targets. Splicing factor 3a subunit 2 (SF3A2), a poorly defined splicing factor, was notably elevated in TNBC tissues and promoted TNBC progression, as confirmed by cell proliferation, colony formation, transwell migration, and invasion assays. Mechanistic investigations revealed that E3 ubiquitin-protein ligase UBR5 promoted the ubiquitination-dependent degradation of SF3A2, which in turn regulated UBR5, thus forming a feedback loop to balance these two oncoproteins. Moreover, SF3A2 accelerated TNBC progression by, at least in part, specifically regulating the alternative splicing of makorin ring finger protein 1 (MKRN1) and promoting the expression of the dominant and oncogenic isoform, MKRN1-T1. Furthermore, SF3A2 participated in the regulation of both extrinsic and intrinsic apoptosis, leading to cisplatin resistance in TNBC cells. Collectively, these findings reveal a previously unknown role of SF3A2 in TNBC progression and cisplatin resistance, highlighting SF3A2 as a potential therapeutic target for patients with TNBC.

Mitochondria-mediated Ferroptosis in Diseases Therapy: From Molecular Mechanisms to Implications

Ferroptosis, a type of cell death involving iron and lipid peroxidation, has been found to be closely associated with the development of many diseases. Mitochondria are vital components of eukaryotic cells, serving important functions in energy production, cellular metabolism, and apoptosis regulation. Presently, the precise relationship between mitochondria and ferroptosis remains unclear. In this study, we aim to systematically elucidate the mechanisms via which mitochondria regulate ferroptosis from multiple perspectives to provide novel insights into mitochondrial functions in ferroptosis. Additionally, we present a comprehensive overview of how mitochondria contribute to ferroptosis in different conditions, including cancer, cardiovascular disease, inflammatory disease, mitochondrial DNA depletion syndrome, and novel coronavirus pneumonia. Gaining a comprehensive understanding of the involvement of mitochondria in ferroptosis could lead to more effective approaches for both basic cell biology studies and medical treatments.

Targeting eIF5A2 reduces invasion and reverses chemoresistance in SCC-9 cells in vitro

BACKGROUND AND AIMS

Eukaryotic translation initiation factor 5A2 (EIF5A2) has been reported to be involved in metastasis and chemotherapy resistance in many human cancers. However, the effect and mechanism of EIF5A2 in oral cancer cells are unknown. Here, we investigated the effects of targeting EIF5A2 on chemotherapy resistance in oral cancer cells in vitro.

METHODS

By using a lentiviral system, we investigated the effects of targeting EIF5A2 on the invasion, migration, growth, and chemosensitivity of SCC-9 cells to CDDP in vitro. Through the method of gene intervention, we explore the role of pro-apoptotic Bim and epithelial and mesenchymal marker E-cadherin protein in this process and the regulation of EIF5A2 on Bim and E-cadherin.

RESULTS

Targeting EIF5A2 reduces invasion and migration in SCC-9 cells partly through upregulation of E-cadherin expression; Targeting EIF5A2 promotes cell apoptosis and inhibits cell survival as well as increasing chemosensitivity in SCC-9 cells through upregulation of Bim expression.

CONCLUSION

EIF5A2 may be a novel potential therapeutic target for oral cancer by upregulation of Bim and E-cadherin.

Novel Therapeutic Targets in Acute Myeloid Leukemia (AML)

PURPOSE OF REVIEW

This review seeks to identify and describe novel genetic and protein targets and their associated therapeutics currently being used or studied in the treatment of acute myeloid leukemia (AML).

RECENT FINDINGS

Over the course of the last 5-6 years, several targeted therapies have been approved by the FDA, for the treatment of both newly diagnosed as well as relapsed/refractory AML. These novel therapeutics, as well as several others currently under investigation, have demonstrated activity in AML and have improved outcomes for many patients. Patient outcomes in AML have slowly improved over time, though for many patients, particularly elderly patients or those with relapsed/refractory disease, mortality remains very high. With the identification of several molecular/genetic drivers and protein targets and development of therapeutics which leverage those mechanisms to target leukemic cells, outcomes for patients with AML have improved and continue to improve significantly.

NcRNAs: A synergistically antiapoptosis therapeutic tool in Alzheimer's disease

AIMS

The aim of this review is to systematically summarize and analyze the noncoding RNAs (ncRNAs), especially microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), in the cell apoptosis among Alzheimer's disease (AD) in recent years to demonstrate their value in the diagnosis and treatment of AD.

METHODS

We systematically summarized in vitro and in vivo studies focusing on the ncRNAs in the regulation of cell apoptosis among AD in PubMed, ScienceDirect, and Google Scholar.

RESULTS

We discover three patterns of ncRNAs (including 'miRNA-mRNA', 'lncRNA-miRNA-mRNA', and 'circRNA-miRNA-mRNA') form the ncRNA-based regulatory networks in regulating cell apoptosis in AD.

CONCLUSIONS

This review provides a future diagnosis and treatment strategy for AD patients based on ncRNAs.

Extracellular vesicles of Weizmannia coagulans lilac-01 reduced cell death of primary microglia and increased mitochondrial content in dermal fibroblasts in vitro

We investigated the properties of extracellular vesicles from the probiotic Weizmannia coagulans lilac-01 (Lilac-01EVs). The phospholipids in the Lilac-01EV membrane were phosphatidylglycerol and mitochondria-specific cardiolipin. We found that applying Lilac-01EVs to primary rat microglia in vitro resulted in a reduction in primary microglial cell death (P < .05). Lilac-01EVs, which contain cardiolipin and phosphatidylglycerol, may have the potential to inhibit cell death in primary microglia. The addition of Lilac-01EVs to senescent human dermal fibroblasts suggested that Lilac-01 EVs increase the mitochondrial content without affecting their membrane potential in these cells.

Aureusidin ameliorates 6-OHDA-induced neurotoxicity via activating Nrf2/HO-1 signaling pathway and preventing mitochondria-dependent apoptosis pathway in SH-SY5Y cells and Caenorhabditis elegans

Movement disorder Parkinson's disease (PD) is the second most common neurodegenerative disease in the world after Alzheimer's disease, which severely affects the quality of patients' lives and imposes an increasingly heavy socioeconomic burden. Aureusidin is a kind of natural flavonoid compound with anti-inflammatory and anti-oxidant activities, while its pharmacological action and mechanism are rarely reported in PD. This study aimed to explore the neuroprotective effects and potential mechanisms of Aureusidin in PD. The present study demonstrated that Aureusidin protected SH-SY5Y cells from cell damage induced by 6-hydroxydopamine (6-OHDA) via inhibiting the mitochondria-dependent apoptosis and activating the Nrf2/HO-1 antioxidant signaling pathway. Additionally, Aureusidin diminished dopaminergic (DA) neuron degeneration induced by 6-OHDA and reduced the aggregation toxicity of α-synuclein (α-Syn) in Caenorhabditis elegans (C. elegans.) In conclusion, Aureusidin showed a neuroprotective effect in the 6-OHDA-induced PD model via activating Nrf2/HO-1 signaling pathway and prevented mitochondria-dependent apoptosis pathway, and these findings suggested that Aureusidin may be an effective drug for the treatment of PD.

Steamed daylily flower (Hemerocallis fulva L.) protected cardiac and hepatic cells against ethanol induced apoptotic and oxidative damage

Our previous study examined the phytochemical composition and bio-activities of raw daylily flower (Hemerocallis fulva L.). However, this plant food is usually served via heat process such as cooking in a soup. This study aimed to investigate the phytochemical profile and biofunctions of steamed daylily flower (SDF). The content of total phenolic acids, total flavonoids, total carotenoids, total anthocyanins and total triterpenoids in SDF aqueous extract was assessed. Normal cardiac and hepatic cells, H9c2 and L-02 cells, were used to evaluate the protective effects of SDF against ethanol. SDF concentrations of 0.25%, 0.5%, and 1% were applied to treat H9c2 or L-02 cells for 48 h at 37 °C initially, followed by exposure to ethanol at 150 mM for 24 h at 37 °C. Results showed that the content of assessed phytochemicals was in the range of 1019-2045 mg/100 g dry weight. Flavonoids and triterpenoids were two major detected phytochemicals in SDF. SDF treatments at 0.5% and 1% increased the viability of H9c2 cells, but at three concentrations enhanced the survival of L-02 cells. SDF at 0.5% and 1% up-regulated Bcl-2 messenger RNA (mRNA) expression and down-regulated Bax mRNA expression. Ethanol increased reactive oxygen species production, decreased glutathione content, as well as lowered glutathione peroxidase and catalase activities. SDF treatments reversed these changes. SDF at 0.5% and 1% reduced the activity of cytochrome P450 2E1 and nicotinamide adenine dinucleotide phosphate oxidase, limited p47phox mRNA expression, as well as enhanced factor E2-related factor 2 and heme oxygenase-1 mRNA expression. SDF at three concentrations decreased gp91phox mRNA expression. In conclusion, these novel findings indicated that SDF aqueous extract was rich in phytochemicals and provided anti-apoptotic and anti-oxidative actions to protect cardiac and hepatic cells against ethanol. Thus, SDF might be considered as a functional food with multiple bio-activities.

Influence of Fatty Acid Modification on the Anticancer Activity of the Antimicrobial Peptide Figainin 1

Antimicrobial peptides derived from the skin secretions of amphibians have made important progress in tumor therapy due to their unique mechanism of destroying cell membranes. Figainin 1 (F1) is an 18-amino acid antimicrobial peptide from the skin secretions of Boana raniceps frogs. In a previous study, F1 was shown to inhibit cancer cell proliferation. F1 is composed entirely of natural amino acids; therefore, it is easily degraded by a variety of proteases, resulting in poor stability and a short half-life. In the present study, we used a fatty acid modification strategy to improve the stability of Figainin 1. Among the 8 peptides synthesized, A-10 showed the strongest antiproliferative activity against K562 cells and the other four tumor cell lines, and its stability against serum and proteinase K was improved compared with F1. We found that A-10 works through two mechanisms, cell membrane destruction and apoptosis, and can arrest the cell cycle in the G0/G1 phase. Moreover, A-10 exhibited self-assembly behavior. Overall, it is necessary to select a fatty acid with a suitable length for modification to improve the stability and antiproliferative activity of antimicrobial peptides. This study provides a good reference for the development of antimicrobial peptides as effective anticancer compounds.

A novel mitochondria-targeting compound exerts therapeutic effects against melanoma by inducing mitochondria-mediated apoptosis and autophagy in vitro and in vivo

Melanoma is the most invasive skin cancer, with a high mortality rate. However, existing therapeutic drugs have side effects, low reactivity, and lead to drug resistance. As the power source in cells, mitochondria play an important role in the survival of cancer cells and are an important target for tumor therapy. This study aimed to develop a new anti-melanoma compound that targets mitochondria, evaluate its effect on the proliferation and metastasis of melanoma cells, and explore its mechanism of action. The novel mitochondria-targeting compound, SCZ0148, was synthesized by modifying the structure of cyanine. Then, A375 and B16 cells were incubated with different concentrations of SCZ0148, and different doses of SCZ0148 were administered to A375 and B16 xenograft zebrafish. The results showed that SCZ0148 targeted mitochondria, had dose- and time-dependent effects on the proliferation of melanoma cell lines, and had no obvious side effects on normal cells. In addition, SCZ0148 induced melanoma cell apoptosis through the reactive oxygen species-mediated mitochondrial pathway of apoptosis and promoted autophagy. SCZ0148 significantly inhibited the migration of melanoma cells via a matrix metalloprotein 9-mediated pathway. Similarly, SCZ0148 inhibited melanoma cell proliferation in a concentration-dependent manner in vivo. In summary, SCZ0148 may be a novel anti-melanoma compound that targets mitochondria.

Pseudomonas aeruginosa quorum-sensing molecule N-(3-oxododecanoyl)-L-homoserine lactone mediates Ca+2 dysregulation, mitochondrial dysfunction, and apoptosis in human peripheral blood lymphocytes

N-(3-oxododecanoyl)-l-homoserine lactone is a Pseudomonas aeruginosa secreted quorum-sensing molecule that mediates the secretion of virulence factors, biofilm formation and plays a pivotal role in proliferation and persistence in the host. Apart from regulating quorum-sensing, the autoinducer signal molecule N-(3-oxododecanoyl)-l-homoserine lactone (3O-C12-HSL or C12) of a LasI-LasR circuit exhibits immunomodulatory effects and induces apoptosis in various host cells. However, the precise pathophysiological impact of C12 on human peripheral blood lymphocytes and its involvement in mitochondrial dysfunction remained largely elusive. In this study, the results suggest that C12 (100 μM) induces upregulation of cytosolic and mitochondrial Ca+2 levels and triggers mitochondrial dysfunction through the generation of mitochondrial ROS (mROS), disruption of mitochondrial transmembrane potential (ΔΨm), and opening of the mitochondrial permeability transition pore (mPTP). Additionally, it was observed that C12 induces phosphatidylserine (PS) exposure and promotes apoptosis in human peripheral blood lymphocytes. However, apoptosis plays a critical role in the homeostasis and development of lymphocytes, whereas enhanced apoptosis can cause immunodeficiency through cell loss. These findings suggest that C12 exerts a detrimental effect on lymphocytes by mediating mitochondrial dysfunction and enhancing apoptosis, which might further impair the effective mounting of immune responses during Pseudomonas aeruginosa-associated infections.

Morphological changes of mitochondria-related to apoptosis during postmortem aging of beef muscles

This study aimed to investigate how postmortem muscle cells' mitochondria changed in morphology from three aspects: the outer membrane, cristae, and fission/fusion. Atomic force microscopy (AFM) results showed that mitochondria underwent a morphology transformation from normal to swelling and collapse. Meanwhile, the cleavage of OPA1, upregulation of OMA1, downregulation of Mic60 and transmission electron microscope micrographs revealed that mitochondrial cristae ruptured with an aging time extended. Additionally, the increased expressions of Fis1 and Drp1, and the AFM topographic images mutually confirmed mitochondrial fission. These results further proved from the perspective of mitochondrial morphology that the degree of mitochondrial damage increased with the postmortem aging time extended, which was consistent with the results of the release of cytochrome c caused by the increase of mitochondrial permeability transition pore opening and the decrease of mitochondrial membrane permeability, and further induced the apoptosis of postmortem muscle cells.

Contribution of mitochondria to postmortem muscle tenderization: a review

Postmortem meat tenderization is a process mediated by a series of biochemical reactions related to muscle cell death. Cell death is considered a sign that muscle has started to transform into meat. Mitochondria play a significant role in regulating and executing cell death, as they are an aggregation point for many cell death signals and are also the primary target organelle damaged by tissue anoxia. Mitochondrial damage is likely to have an expanded role in postmortem meat tenderization. This review presents current findings on mitochondrial damage induced by the accumulation of reactive oxygen species during postmortem anaerobic metabolism and on the impact of mitochondrial damage on proteolysis and discusses how this leads to improved tenderness during aging. The underlying mechanisms of mitochondrial regulation of postmortem muscle tenderization likely focus on the mitochondria's role in postmortem cell death and energy metabolism. The death process of postmortem skeletal muscle cells may exhibit multiple types, possibly involving transformation from autophagy to apoptosis and, ultimately, necroptosis or necrosis. Mitochondrial characteristics, especially membrane integrity and ATP-related compound levels, are closely related to the transformation of multiple types of dead postmortem muscle cells. Finally, a possible biochemical regulatory network in postmortem muscle tenderization is proposed.

Regulation of defective mitochondrial DNA accumulation and transmission in C. elegans by the programmed cell death and aging pathways

The heteroplasmic state of eukaryotic cells allows for cryptic accumulation of defective mitochondrial genomes (mtDNA). 'Purifying selection' mechanisms operate to remove such dysfunctional mtDNAs. We found that activators of programmed cell death (PCD), including the CED-3 and CSP-1 caspases, the BH3-only protein CED-13, and PCD corpse engulfment factors, are required in C. elegans to attenuate germline abundance of a 3.1-kb mtDNA deletion mutation, uaDf5, which is normally stably maintained in heteroplasmy with wildtype mtDNA. In contrast, removal of CED-4/Apaf1 or a mutation in the CED-4-interacting prodomain of CED-3, do not increase accumulation of the defective mtDNA, suggesting induction of a non-canonical germline PCD mechanism or non-apoptotic action of the CED-13/caspase axis. We also found that the abundance of germline mtDNAuaDf5 reproducibly increases with age of the mothers. This effect is transmitted to the offspring of mothers, with only partial intergenerational removal of the defective mtDNA. In mutants with elevated mtDNAuaDf5 levels, this removal is enhanced in older mothers, suggesting an age-dependent mechanism of mtDNA quality control. Indeed, we found that both steady-state and age-dependent accumulation rates of uaDf5 are markedly decreased in long-lived, and increased in short-lived, mutants. These findings reveal that regulators of both PCD and the aging program are required for germline mtDNA quality control and its intergenerational transmission.

Multifunctional Au@AgBiS2 Nanoparticles as High-Efficiency Radiosensitizers to Induce Pyroptosis for Cancer Radioimmunotherapy

Radiotherapy (RT), a widely used clinical treatment modality for cancer, uses high-energy irradiation for reactive oxygen species (ROS) production and DNA damage. However, its therapeutic effect is primarily limited owing to insufficient DNA damage to tumors and harmful effects on normal tissues. Herein, a core-shell structure of metal-semiconductors (Au@AgBiS2 nanoparticles) that can function as pyroptosis inducers to both kill cancer cells directly and trigger a robust anti-tumor immune against 4T1 triple-negative murine breast cancer and metastasis is rationally designed. Metal-semiconductor composites can enhance the generation of considerable ROS and simultaneously DNA damage for RT sensitization. Moreover, Au@AgBiS2 , a pyroptosis inducer, induces caspase-3 protein activation, gasdermin E cleavage, and the release of damage-associated molecular patterns. In vivo studies in BALB/c mice reveal that Au@AgBiS2 nanoparticles combined with RT exhibit remarkable antitumor immune activity, preventing tumor growth, and lung metastasis. Therefore, this core-shell structure is an alternative for designing highly effective radiosensitizers for radioimmunotherapy.

Particle-induced osteolysis is mediated by endoplasmic reticulum stress-associated osteoblast apoptosis

Osteoblast dysfunction plays a crucial role in periprosthetic osteolysis and aseptic loosening, and endoplasmic reticulum (ER) stress is recognized as an important causal factor of wear particle-induced osteolysis. However, the influence of ER stress on osteoblast activity during osteolysis and its underlying mechanisms remain elusive. This study aims to investigate whether ER stress is involved in the detrimental effects of wear particles on osteoblasts. Through our investigation, we observed elevated expression levels of ER stress and apoptosis markers in particle-stimulated bone specimens and osteoblasts. To probe further, we employed the ER stress inhibitor, 4-PBA, to treat particle-stimulated osteoblasts. The results revealed that 4-PBA effectively alleviated particle-induced osteoblast apoptosis and mitigated osteogenic reduction. Furthermore, our study revealed that wear particle-induced ER stress in osteoblasts coincided with mitochondrial damage, calcium overload, and oxidative stress, all of which were effectively alleviated by 4-PBA treatment. Encouragingly, 4-PBA administration also improved bone formation and attenuated osteolysis in a mouse calvarial model. In conclusion, our results demonstrate that ER stress plays a crucial role in mediating wear particle-induced osteoblast apoptosis and impaired osteogenic function. These findings underscore the critical involvement of ER stress in wear particle-induced osteolysis and highlight ER stress as a potential therapeutic target for ameliorating wear particle-induced osteogenic reduction and bone destruction.

Menaquinone-4 prevents medication-related osteonecrosis of the jaw through the SIRT1 signaling-mediated inhibition of cellular metabolic stresses-induced osteoblast apoptosis

Long-term usage of bisphosphonates, especially zoledronic acid (ZA), induces osteogenesis disorders and medication-related osteonecrosis of the jaw (MRONJ) in patients, thereby contributing to the destruction of bone remodeling and the continuous progression of osteonecrosis. Menaquinone-4 (MK-4), a specific vitamin K2 isoform converted by the mevalonate (MVA) pathway in vivo, exerts the promotion of bone formation, whereas ZA administration suppresses this pathway and results in endogenous MK-4 deficiency. However, no study has evaluated whether exogenous MK-4 supplementation can prevent ZA-induced MRONJ. Here we showed that MK-4 pretreatment partially ameliorated mucosal nonunion and bone sequestration among ZA-treated MRONJ mouse models. Moreover, MK-4 promoted bone regeneration and inhibited osteoblast apoptosis in vivo. Consistently, MK-4 downregulated ZA-induced osteoblast apoptosis in MC3T3-E1 cells and suppressed the levels of cellular metabolic stresses, including oxidative stress, endoplasmic reticulum stress, mitochondrial dysfunction, and DNA damage, which were accompanied by elevated sirtuin 1 (SIRT1) expression. Notably, EX527, an inhibitor of the SIRT1 signaling pathway, abolished the inhibitory effects of MK-4 on ZA-induced cell metabolic stresses and osteoblast damage. Combined with experimental evidences from MRONJ mouse models and MC3T3-E1 cells, our findings suggested that MK-4 prevents ZA-induced MRONJ by inhibiting osteoblast apoptosis through suppression of cellular metabolic stresses in a SIRT1-dependent manner. The results provide a novel translational direction for the clinical application of MK-4 for preventing MRONJ.

Synergistic anticancer activity of combined ATR and ribonucleotide reductase inhibition in Ewing's sarcoma cells

PURPOSE

Ewing's sarcoma is a highly malignant childhood tumour whose outcome has hardly changed over the past two decades despite numerous attempts at chemotherapy intensification. It is therefore essential to identify new treatment options. The present study was conducted to explore the effectiveness of combined inhibition of two promising targets, ATR and ribonucleotide reductase (RNR), in Ewing's sarcoma cells.

METHODS

Effects of the ATR inhibitor VE821 in combination with the RNR inhibitors triapine and didox were assessed in three Ewing's sarcoma cell lines with different TP53 status (WE-68, SK-ES-1, A673) by flow cytometric analysis of cell death, mitochondrial depolarisation and cell cycle distribution as well as by caspase 3/7 activity determination, by immunoblotting and by real-time RT-PCR. Interactions between inhibitors were evaluated by combination index analysis.

RESULTS

Single ATR or RNR inhibitor treatment produced small to moderate effects, while their combined treatment produced strong synergistic ones. ATR and RNR inhibitors elicited synergistic cell death and cooperated in inducing mitochondrial depolarisation, caspase 3/7 activity and DNA fragmentation, evidencing an apoptotic form of cell death. All effects were independent of functional p53. In addition, VE821 in combination with triapine increased p53 level and induced p53 target gene expression (CDKN1A, BBC3) in p53 wild-type Ewing's sarcoma cells.

CONCLUSION

Our study reveals that combined targeting of ATR and RNR was effective against Ewing's sarcoma in vitro and thus rationalises an in vivo exploration into the potential of combining ATR and RNR inhibitors as a new strategy for the treatment of this challenging disease.

The role of epithelial-mesenchymal transition and autophagy in pancreatic ductal adenocarcinoma invasion

Of all pancreatic cancer (PC) cases, approximately 90% are pancreatic ductal adenocarcinoma (PDAC), which progress rapidly due to its high degree of invasiveness and high metastatic potential. Epithelial-mesenchymal transition (EMT) is a prerequisite for cancer cell invasion and spread, and it is mediated by the specific cellular behaviors and the tumor microenvironment. Autophagy has long been a target of cancer therapy, and it has been considered to play a dual and contradictory role, particularly regarding EMT-mediated PDAC invasion. This review discusses the characteristics and the biological role of EMT and autophagy from a cellular perspective, explaining invasion as a survival behavior of PDAC, with the aim of providing novel insights into targeting EMT and autophagy to overcome PDAC invasion.

siRNA drug delivery across the blood-brain barrier in Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disease with a few FDA-approved drugs that provide modest symptomatic benefits and only two FDA-approved disease-modifying treatments for AD. The advancements in understanding the causative genes and non-coding sequences at the molecular level of the pathophysiology of AD have resulted in several exciting research papers that employed small interfering RNA (siRNA)-based therapy. Although siRNA is being sought by academia and biopharma industries, several challenges still need to be addressed. We comprehensively report the latest advances in AD pathophysiology, druggable targets, ongoing clinical trials, and the siRNA-based approaches across the blood-brain barrier for addressing AD. This review describes the latest delivery systems employed to address this barrier. Critical insights and future perspectives on siRNA therapy for AD are also provided.

Novel BCL-2 Inhibitor Lisaftoclax in Relapsed or Refractory Chronic Lymphocytic Leukemia and Other Hematologic Malignancies: First-in-Human Open-Label Trial

PURPOSE

This global phase I trial investigated the safety, efficacy, pharmacokinetics, and pharmacodynamics of lisaftoclax (APG-2575), a novel, orally active, potent selective B-cell lymphoma 2 (BCL-2) inhibitor, in patients with relapsed or refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (R/R CLL/SLL) and other hematologic malignancies (HMs).

PATIENTS AND METHODS

Maximum tolerated dose (MTD) and recommended phase II dose were evaluated. Outcome measures were safety and tolerability (primary) and pharmacokinetic variables and antitumor effects (secondary). Pharmacodynamics in patient tumor cells were explored.

RESULTS

Among 52 patients receiving lisaftoclax, MTD was not reached. Treatment-emergent adverse events (TEAEs) included diarrhea (48.1%), fatigue (34.6%), nausea (30.8%), anemia and thrombocytopenia (28.8% each), neutropenia (26.9%), constipation (25.0%), vomiting (23.1%), headache (21.2%), peripheral edema and hypokalemia (17.3% each), and arthralgia (15.4%). Grade ≥ 3 hematologic TEAEs included neutropenia (21.2%), thrombocytopenia (13.5%), and anemia (9.6%), none resulting in treatment discontinuation. Clinical pharmacokinetic and pharmacodynamic results demonstrated that lisaftoclax had a limited plasma residence and systemic exposure and elicited rapid clearance of malignant cells. With a median treatment of 15 (range, 6-43) cycles, 14 of 22 efficacy-evaluable patients with R/R CLL/SLL experienced partial responses, for an objective response rate of 63.6% and median time to response of 2 (range, 2-8) cycles.

CONCLUSIONS

Lisaftoclax was well tolerated, with no evidence of tumor lysis syndrome. Dose-limiting toxicity was not reached at the highest dose level. Lisaftoclax has a unique pharmacokinetic profile compatible with a potentially more convenient daily (vs. weekly) dose ramp-up schedule and induced rapid clinical responses in patients with CLL/SLL, warranting continued clinical investigation.

Eltrombopag directly activates BAK and induces apoptosis

Small molecule direct BAK activators can potentially be used for the development of anti-cancer drugs or as tools to study BAK activation. The thrombopoietin receptor agonist eltrombopag (Eltro) inhibits BAX activation and BAX-mediated apoptosis. Here we report that, in contrast to its function as a BAX inhibitor, Eltro directly binds BAK but induces its activation in vitro. Moreover, Eltro induces or sensitizes BAK-dependent cell death in mouse embryonic fibroblasts (MEFs) and Jurkat cells. Chemical shift perturbation analysis by NMR indicates that Eltro binds to the BAK α4/α6/α7 groove to initiate BAK activation. Further molecular docking by HADDOCK suggests that several BAK residues, including R156, F157, and H164, play an important role in the interaction with Eltro. The introduction of an R156E mutation in the BAK α4/α6/α7 groove not only decreases Eltro binding and Eltro-induced BAK activation in vitro but also diminishes Eltro-induced apoptosis. Thus, our data suggest that Eltro directly induces BAK activation and BAK-dependent apoptosis, providing a starting point for the future development of more potent and selective direct BAK activators.

Sequential apoptotic and multiplexed proteomic evaluation of single cancer cells

A potential cause of cancer relapse is pretreatment chemoresistant subpopulations. Identifying targetable features of subpopulations that are poorly primed for therapy-induced cell death may improve cancer therapy. Here, we develop and validate real-time BH3 profiling, a live and functional single-cell measurement of pretreatment apoptotic sensitivity that occurs upstream of apoptotic protease activation. On the same single cells, we perform cyclic immunofluorescence, which enables multiplexed immunofluorescence of more than 30 proteins on the same cell. Using cultured cells and rapid ex vivo cultures of colon cancer patient-derived xenograft (PDX) models, we identify Bak as a univariate correlate of apoptotic priming, find that poorly primed subpopulations can correspond to specific stages of the cell cycle, and, in some PDX models, identify increased expression of Bcl-XL, Mcl-1, or Her2 in subpopulations that are poorly primed for apoptosis. Last, we generate and validate mathematical models of single-cell priming that describe how targetable proteins contribute to apoptotic priming.

LncRNAs and regulated cell death in tumor cells

Regulated Cell Death (RCD) is a mode of cell death that occurs through drug or genetic intervention. The regulation of RCDs is one of the significant reasons for the long survival time of tumor cells and poor prognosis of patients. Long non-coding RNAs (lncRNAs) which are involved in the regulation of tumor biological processes, including RCDs occurring on tumor cells, are closely related to tumor progression. In this review, we describe the mechanisms of eight different RCDs which contain apoptosis, necroptosis, pyroptosis, NETosis, entosis, ferroptosis, autosis and cuproptosis. Meanwhile, their respective roles in the tumor are aggregated. In addition, we outline the literature that is related to the regulatory relationships between lncRNAs and RCDs in tumor cells, which is expected to provide new ideas for tumor diagnosis and treatment.

The Role of Venetoclax in Relapsed/Refractory Acute Myeloid Leukemia: Past, Present, and Future Directions

Relapsed and/or refractory (R/R) acute myeloid leukemia (AML) is hallmarked by dramatic prognosis. Treatment remains challenging, with allogeneic hematopoietic stem cell transplantation (HSCT) as the only curative option. The BCL-2 inhibitor venetoclax (VEN) has proven to be a promising therapy for AML and is currently the standard of care in combination with hypomethylating agents (HMAs) for newly diagnosed AML patients ineligible for induction chemotherapy. Given its satisfactory safety profile, VEN-based combinations are increasingly being investigated as a part of the therapeutic strategy for R/R AML. The current paper aims to provide a comprehensive review of the main evidence regarding VEN in the setting of R/R AML, with a specific focus on combinational strategies, including HMAs and cytotoxic chemotherapy, as well as different clinical settings, especially in view of the crucial role of HSCT. A discussion of what is known about drug resistance mechanisms and future combinational strategies is also provided. Overall, VEN-based regimes (mainly VEN + HMA) have provided unprecedented salvage treatment opportunities in patients with R/R AML, with low extra-hematological toxicity. On the other hand, the issue of overcoming resistance is one of the most important fields to be addressed in upcoming clinical research.

Dual mTORC1/2 Inhibition Synergistically Enhances AML Cell Death in Combination with the BCL2 Antagonist Venetoclax

PURPOSE

Acute myelogenous leukemia (AML) is an aggressive disease with a poor outcome. We investigated mechanisms by which the anti-AML activity of ABT-199 (venetoclax) could be potentiated by dual mTORC1/TORC2 inhibition.

EXPERIMENTAL DESIGN

Venetoclax/INK128 synergism was assessed in various AML cell lines and primary patient AML samples in vitro. AML cells overexpressing MCL-1, constitutively active AKT, BAK, and/or BAX knockout, and acquired venetoclax resistance were investigated to define mechanisms underlying interactions. The antileukemic efficacy of this regimen was also examined in xenograft and patient-derived xenograft (PDX) models.

RESULTS

Combination treatment with venetoclax and INK128 (but not the mTORC1 inhibitor rapamycin) dramatically enhanced cell death in AML cell lines. Synergism was associated with p-AKT and p-4EBP1 downregulation and dependent upon MCL-1 downregulation and BAK/BAX upregulation as MCL-1 overexpression and BAX/BAK knockout abrogated cell death. Constitutive AKT activation opposed synergism between venetoclax and PI3K or AKT inhibitors, but not INK128. Combination treatment also synergistically induced cell death in venetoclax-resistant AML cells. Similar events occurred in primary patient-derived leukemia samples but not normal CD34+ cells. Finally, venetoclax and INK128 co-treatment displayed increased antileukemia effects in in vivo xenograft and PDX models.

CONCLUSIONS

The venetoclax/INK128 regimen exerts significant antileukemic activity in various preclinical models through mechanisms involving MCL-1 downregulation and BAK/BAX activation, and offers potential advantages over PI3K or AKT inhibitors in cells with constitutive AKT activation. This regimen is active against primary and venetoclax-resistant AML cells, and in in vivo AML models. Further investigation of this strategy appears warranted.

Antimicrobial peptides CS-piscidin-induced cell death involves activation of RIPK1/PARP, and modification with myristic acid enhances its stability and tumor-targeting capability

Ovarian cancer (OC) is a highly lethal gynecological malignancy, often diagnosed at advanced stages with limited treatment options. Here, we demonstrate that the antimicrobial peptide CS-piscidin significantly inhibits OC cell proliferation, colony formation, and induces cell death. Mechanistically, CS-piscidin causes cell necrosis by compromising the cell membrane. Furthermore, CS-piscidin can activate Receptor-interacting protein kinase 1 (RIPK1) and induce cell apoptosis by cleavage of PARP. To improve tumor targeting ability, we modified CS-piscidin by adding a short cyclic peptide, cyclo-RGDfk, to the C-terminus (CS-RGD) and a myristate to the N-terminus (Myr-CS-RGD). Our results show that while CS-RGD exhibits stronger anti-cancer activity than CS-piscidin, it also causes increased cytotoxicity. In contrast, Myr-CS-RGD significantly improves drug specificity by reducing CS-RGD toxicity in normal cells while retaining comparable antitumor activity by increasing peptide stability. In a syngeneic mouse tumor model, Myr-CS-RGD demonstrated superior anti-tumor activity compared to CS-piscidin and CS-RGD. Our findings suggest that CS-piscidin can suppress ovarian cancer via multiple cell death forms and that myristoylation modification is a promising strategy to enhance anti-cancer peptide performance.

Mitochondria as disease-relevant organelles in rheumatoid arthritis

Mitochondria are the controllers of cell metabolism and are recognized as decision makers in cell death pathways, organizers of cytoplasmic signaling networks, managers of cellular stress responses, and regulators of nuclear gene expression. Cells of the immune system are particularly dependent on mitochondrial resources, as they must swiftly respond to danger signals with activation, trafficking, migration, and generation of daughter cells. Analogously, faulty immune responses that lead to autoimmunity and tissue inflammation rely on mitochondria to supply energy, cell building blocks and metabolic intermediates. Emerging data endorse the concept that mitochondrial fitness, and the lack of it, is of particular relevance in the autoimmune disease rheumatoid arthritis (RA) where deviations of bioenergetic and biosynthetic flux affect T cells during early and late stages of disease. During early stages of RA, mitochondrial deficiency allows naïve RA T cells to lose self-tolerance, biasing fundamental choices of the immune system toward immune-mediated tissue damage and away from host protection. During late stages of RA, mitochondrial abnormalities shape the response patterns of RA effector T cells engaged in the inflammatory lesions, enabling chronicity of tissue damage and tissue remodeling. In the inflamed joint, autoreactive T cells partner with metabolically reprogrammed tissue macrophages that specialize in antigen-presentation and survive by adapting to the glucose-deplete tissue microenvironment. Here, we summarize recent data on dysfunctional mitochondria and mitochondria-derived signals relevant in the RA disease process that offer novel opportunities to deter autoimmune tissue inflammation by metabolic interference.

Inhibition of multiple CDKs potentiates colon cancer chemotherapy via p73-mediated DR5 induction

Targeting cyclin-dependent kinases (CDKs) has recently emerged as a promising therapeutic approach against cancer. However, the anticancer mechanisms of different CDK inhibitors (CDKIs) are not well understood. Our recent study revealed that selective CDK4/6 inhibitors sensitize colorectal cancer (CRC) cells to therapy-induced apoptosis by inducing Death Receptor 5 (DR5) via the p53 family member p73. In this study, we investigated if this pathway is involved in anticancer effects of different CDKIs. We found that less-selective CDKIs, including flavopiridol, roscovitine, dinaciclib, and SNS-032, induced DR5 via p73-mediated transcriptional activation. The induction of DR5 by these CDKIs was mediated by dephosphorylation of p73 at Threonine 86 and p73 nuclear translocation. Knockdown of a common target of these CDKIs, including CDK1, 2, or 9, recapitulated p73-mediated DR5 induction. CDKIs strongly synergized with 5-fluorouracil (5-FU), the most commonly used CRC chemotherapy agent, in vitro and in vivo to promote growth suppression and apoptosis, which required DR5 and p73. Together, these findings indicate p73-mediated DR5 induction as a potential tumor suppressive mechanism and a critical target engaged by different CDKIs in potentiating therapy-induced apoptosis in CRC cells. These findings help better understand the anticancer mechanisms of CDKIs and may help facilitate their clinical development and applications in CRC.

Emerging treatments for myelodysplastic syndromes: Biological rationales and clinical translation

Myelodysplastic syndromes (MDSs) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized by myeloid dysplasia, peripheral blood cytopenias, and increased risk of progression to acute myeloid leukemia (AML). The standard of care for patients with MDS is hypomethylating agent (HMA)-based therapy; however, nearly 50% of patients have no response to the treatment. Patients with MDS in whom HMA therapy has failed have a dismal prognosis and no approved second-line therapy options, so enrollment in clinical trials of experimental agents represents these patients' only chance for improved outcomes. A better understanding of the molecular and biological mechanisms underpinning MDS pathogenesis has enabled the development of new agents that target molecular alterations, cell death regulators, signaling pathways, and immune regulatory proteins in MDS. Here, we review novel therapies for patients with MDS in whom HMA therapy has failed, with an emphasis on the biological rationale for these therapies' development.