Senescence and tumour clearance is triggered by p53 restoration in murine liver carcinomas

Exercise alleviates osteoporosis by regulating the secretion of the Senescent Associated Secretory Phenotype

As the elderly population grows, the number of patients with metabolic bone diseases such as osteoporosis has increased sharply, posing a significant threat to public health and social economics. Although pharmacological therapies for osteoporosis demonstrate therapeutic benefits, their prolonged use is associated with varying degrees of adverse effects. As a non-pharmacological intervention, exercise is widely recognized for its cost-effectiveness, safety, and lack of toxic side effects, making it a recommended treatment for osteoporosis prevention and management. Previous studies have demonstrated that exercise can improve metabolic bone diseases by modulating the Senescent Associated Secretory Phenotype (SASP). However, the mechanisms through which exercise influences SASP remain unclear. Therefore, this review aims to summarize the effects of exercise on SASP and elucidate the specific mechanisms by which exercise regulates SASP to alleviate osteoporosis, providing a theoretical basis for osteoporosis through exercise and developing targeted therapies.

Pharmacological modulation of cellular senescence: Implications for breast cancer progression and therapeutic strategies

Senescence, defined by the cessation of cell proliferation, plays a critical and multifaceted role in breast cancer progression and treatment. Senescent cells produce senescence-associated secretory phenotypes (SASP) comprising inflammatory cytokines, chemokines, and small molecules, which actively shape the tumor microenvironment, influencing cancer development, progression, and metastasis. This review provides a comprehensive analysis of the types and origins of senescent cells in breast cancer, alongside their markers and detection methods. Special focus is placed on pharmacological strategies targeting senescence, including drugs that induce or inhibit senescence, their molecular mechanisms, and their roles in therapeutic outcomes when combined with chemotherapy and radiotherapy. By exploring these pharmacological interventions and their impact on breast cancer treatment, this review underscores the potential of senescence-targeting therapies to revolutionize breast cancer management.

Design, synthesis, and activity evaluation of indole derivatives as potential stabilizers for p53 Y220C

The p53 Y220C mutation is frequently observed in human cancers. This mutation renders the p53 Y220C unstable at physiological temperatures, leading to a loss of its normal function and promoting tumor development. In this study, a total of eight compounds were designed and synthesized based on the active compound C8. The protein thermal shift assay revealed that both C8-3b and C8-6 exhibited similar activity of C8, with a ΔTm value of +0.5 °C. Compounds C8-1a, C8-1b, and C8-2b were found to enhance the thermostability of p53 Y220C (ΔTm: + 1.0 °C), the melting temperature exhibits an enhancement of 0.5 °C over the C8, indicating that these compounds possess the ability to stabilize p53 Y220C. The results of the cell viability assay revealed that C8-1b exhibited selective inhibitory effects on the proliferation of tumor cells harboring the p53 Y220C mutation. Furthermore, we utilized molecular docking and two-dimensional interaction analysis to elucidate the binding mode and key interactions of these compounds with p53 Y220C. Our study suggests that these compounds could potentially serve as lead compounds for enhancing the stability of p53 Y220C, thus providing a rational approach for designing small molecule stabilizers against p53 mutations.

Postoperative metastatic Krukenberg tumors with ARID1A and KRAS mutations in a patient with gastric cancer treated with oxaliplatin and tegafur: A case report

Krukenberg tumors are a notably rare type of metastatic ovarian malignant tumor, often originating from the stomach. Due to their low incidence rate and the short survival time of patients, there is currently a lack of consensus on the diagnosis and treatment of this disease, as well as a deficiency in genomic analyses and research into the pathogenetic molecular mechanisms. In the present study, the case of a patient with gastric cancer who, 2 years after curative surgery and chemotherapy with oxaliplatin and tegafur, developed recurrent metastatic bilateral Krukenberg tumors with distant metastasis in the ovaries. During treatment, a total hysterectomy and bilateral salpingo-oophorectomy were performed, and intraoperative intraperitoneal chemotherapy with cisplatin (70 mg) was administered. Additionally, ureteroscopy and bilateral ureteral stent placement were conducted transurethrally. Post-surgery, assessments of the genomic alterations and microsatellite instability of the tumor revealed an AT-rich interaction domain 1A (ARID1A) exon c.4720delC mutation and a KRAS exon c.35G>C mutation. The potential pathogenic mechanisms and clinical significance of these mutations were then further discussed. Mutations in the ARID1A gene could increase the sensitivity of the patient to immune checkpoint inhibitor therapy. Additionally, the successful application of KRASG12C inhibitors in other cancer types offers a new approach for the targeted therapy of Krukenberg tumors. Therefore, the present study provides further evidence regarding the genomics of Krukenberg tumors, which may aid in the development of targeted treatment strategies.

Combinatorial screen with apoptosis pathway targeted agents alrizomadlin, pelcitoclax, and dasminapant in multi-cell type tumor spheroids

Apoptosis, or programmed cell death, plays a critical role in maintaining tissue homeostasis by eliminating damaged or abnormal cells. Dysregulation of apoptosis pathways is a hallmark of cancer, allowing malignant cells to evade cell death and proliferate uncontrollably. Targeting apoptosis pathways has emerged as a promising therapeutic strategy in cancer treatment, aiming to restore the balance between cell survival and death. The MDM2 inhibitor alrizomadlin, the Bcl-2/Bcl-xL inhibitor pelcitoclax, and the IAP family inhibitor dasminapant were evaluated both individually and in combinations with standard of care and investigational anticancer small molecules in a spheroid model of solid tumors. The multi-cell type tumor spheroids were grown from human endothelial cells and mesenchymal stem cells combined with human malignant cells that were either established or patient-derived cell lines from the NCI Patient-Derived Models Repository. The malignant cell lines were derived from a range of solid tumors including uterine carcinosarcoma, synovial sarcoma, rhabdomyosarcoma, soft tissue sarcoma, malignant fibrous histiocytoma, malignant peripheral nerve sheath tumor (MPNST), pancreas, ovary, colon, breast, and small cell lung cancer. Interactions were observed from combinations of the apoptosis pathway targeted agents. Additionally, interactions were observed from combinations of the apoptosis pathway targeted agents with other agents, including PARP inhibitors, the XPO1 inhibitor eltanexor, and the PI3K inhibitor copanlisib. Enhanced activity was also observed from combinations of the apoptosis pathway targeted agents with MAPK pathway targeted agents, including the MEK inhibitor cobimetinib as well as adagrasib and MRTX1133, which specifically target the KRAS G12C and G12D variants, respectively.

Prolonged exposure to leisure screen time notably accelerates biological aging: Evidence from observational studies and genetic associations

LST is steadily increasing and is associated with various health issues. However, its impact on aging remains unclear. A total of 7212 participants from NHANES 1999-2002 were included. LTL, ALM, and FI were selected as aging phenotypes. Observational association between LST and aging traits was analyzed using linear regression models. MR analyses based on 112 genetic variants were performed to test the causal estimates from LST on aging. TWAS and PPI analyses were conducted to investigate underlying biological mechanisms. After adjusting for physical activity, per 1 ​h increase in LST, participants had a shorter LTL (β ​= ​-1.39, 95 ​% CI: -2.47 to -0.30), a lower ALM (β ​= ​-1.09, 95 ​% CI: -1.39 to -0.70), and an increased FI (β ​= ​8.22, 95 ​% CI: 4.29 to 12.30). Likewise, TSMR analyses indicated that genetically increased LST was significantly associated with shorter LTL (β ​= ​-2.63, 95 ​% CI: -4.86 to -0.35), lower ALM (β ​= ​-6.56, 95 ​% CI: -9.43 to -3.60), and increased FI (β ​= ​20.16, 95 ​% CI: 15.73 to 24.77). The trend remained robust after tests for pleiotropy and heterogeneity, consistent with the results of MVMR. 4 hub genes and 15 co-localized genes are identified, respectively, from PPI networks and TWAS. Pathways related to immune reactions, oxidative stress, and protein metabolism were significantly enriched. This study revealed that increased LST is significantly associated with adverse aging phenotypes. Reducing LST may help alleviate the burden of aging.

Exploring the double-edged role of cellular senescence in chronic liver disease for new treatment approaches

Cellular senescence is a fundamental yet complex defense mechanism that restricts excessive proliferation, maintains cellular homeostasis under various stress conditions-such as oncogenic activation and inflammation-and serves as a dynamic stress response program involved in development, aging, and immunity. Its reversibility depends on essential maintenance components. Cellular senescence is a "double-edged sword": on one hand, it limits the malignant proliferation of damaged cells, thereby preventing tumor development. However, by retaining secretory functions, senescent cells can also induce persistent changes in the microenvironment and disrupt homeostasis, leading to tissue inflammation, fibrosis, and carcinogenesis. Senescence plays a critical role in the pathogenesis of various chronic liver diseases, including chronic viral hepatitis, liver fibrosis, and hepatocellular carcinoma. It exerts a dual influence by facilitating immune evasion and inflammation in chronic viral hepatitis, modulating hepatic stellate cell activity in fibrosis, and reshaping the tumor microenvironment to accelerate hepatocarcinogenesis. This article reviews the characteristics of cellular senescence and its role in the pathogenesis of these chronic liver diseases while exploring potential treatment and prevention strategies. The aim is to provide a comprehensive reference for future clinical and research investigations into chronic liver disease.

The context-dependent effect of cellular senescence: From embryogenesis and wound healing to aging

Aging is characterized by a steady loss of physiological integrity, leading to impaired function and increased vulnerability to death. Cell senescence is a biological process that progresses with aging and is believed to be a key driver of age-related diseases. Senescence, a hallmark of aging, also demonstrates its beneficial physiological aspects as an anti-cancer, pro-regenerative, homeostatic, and developmental mechanism. A transitory response in which the senescent cells are quickly formed and cleared may promote tissue regeneration and organismal fitness. At the same time, senescence-related secretory phenotypes associated with extended senescence can have devastating effects. The fact that the interaction between senescent cells and their surroundings is very context-dependent may also help to explain this seemingly opposing pleiotropic function. Further, mitochondrial dysfunction is an often-unappreciated hallmark of cellular senescence and figures prominently in multiple feedback loops that induce and maintain the senescent phenotype. This review summarizes the mechanism of cellular senescence and the significance of acute senescence. We concisely introduced the context-dependent role of senescent cells and SASP, aspects of mitochondrial biology altered in the senescent cells, and their impact on the senescent phenotype. Finally, we conclude with recent therapeutic advancements targeting cellular senescence, focusing on acute injuries and age-associated diseases. Collectively, these insights provide a future roadmap for the role of senescence in organismal fitness and life span extension.

Inflammation and tumor immune escape in response to DNA damage

Senescent and cancer cells share common inflammatory characteristics, including factors of the senescence-associated secretory phenotype (SASP) and the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway. Inflammation in the tumor microenvironment not only provides an opportunity for immune cells to attack cancer cells, but also promotes cancer invasion and metastasis. Immune checkpoint molecule PD-L1 is transcriptionally induced by inflammation, and the immunological state of PD-L1-positive tumors influences the efficacy of Immune checkpoint inhibitors (ICIs). ICIs are effective against the PD-L1-positive "hot" tumors; however, the non-immunoactive "cold" tumors that express PD-L1 rarely respond to ICIs, suggesting that converting PD-L1-positive "cold" tumors into "hot" tumors would improve the efficacy of ICIs. To eliminate cancer via the innate immune system, a therapeutic strategy for manipulating inflammatory responses must be established. To date, the molecular mechanisms of inflammation-induced tumorigenesis are not yet fully understood. However, it is becoming clear that the regulatory mechanisms of inflammation in cancer via the cGAS-STING pathway play an important role in both cancer and sensescent cells. In this review, we focus on inflammation and immune escape triggered by DNA damage in cancer and senescent cells.

Saikosaponin A induces cellular senescence in triple-negative breast cancer by inhibiting the PI3K/Akt signalling pathway

Background

Breast cancer has now become the most prevalent cancer worldwide. Existing therapeutic agents are generally accompanied by significant side effects. Here, we highlight Saikosaponin A (SSA), a promising natural metabolite characterized by low toxicity, demonstrating significant efficacy against breast cancer through the induction of cellular senescence.

Methods

The antitumor property of SSA was determined via MTT colorimetric assay, 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay, colony formation, and propidium iodide (PI) staining in vitro, as well as xenograft in vivo model. A network approach was used to predict potential targets of SSA reevant for a potential anti-tumor effect and verified through senescence-associated β-galactosidase (SA-β-gal), flow-cytometry analysis, RT-PCR, Western blotting, and immuno-histochemistry assay.

Results

SSA significantly suppressed proliferation and triggered cell cycle arrest of SUM159PT and MDA-MB-231 cells. Revealed by network analysis, cellular senescence, and phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway were implemented in the anti-tumor effects of SSA. SSA-stimulated senescence was associated with increased ROS production, distinct senescence-associated secretory phenotype (SASP), and restricted PI3K/Akt signaling, as well as p21 and p53 accumulation. Furthermore, SSA displayed inhibitory effects on tumor growth with minimal toxicity in animal studies, accompanied by activated biomarkers of cellular senescence and decreased expression of p-Akt and p-PI3K.

Conclusion

Taken together, based on the preliminary results of network analysis and further experimental validation, this study revealed that SSA significantly induced cell cycle arrest and senescence, and the inhibition of ROS-mediated PI3K/Akt pathway may be the potential mechanism in this process.

HIV-Tat upregulates the expression of senescence biomarkers in CD4+ T-cells

Introduction

Current antiretroviral therapy (ART) for HIV infection reduces plasma viral loads to undetectable levels and has increased the life expectancy of people with HIV (PWH). However, this increased lifespan is accompanied by signs of accelerated aging and a higher prevalence of age-related comorbidities. Tat (Trans-Activator of Transcription) is a key protein for viral replication and pathogenesis. Tat is encoded by 2 exons, with the full-length Tat ranging from 86 to 101 aa (Tat101). Introducing a stop codon in position 73 generates a 1 exon, synthetic 72aa Tat (Tat72). Intracellular, full-length Tat activates the NF-κB pro-inflammatory pathway and increases antiapoptotic signals and ROS generation. These effects may initiate a cellular senescence program, characterized by cell cycle arrest, altered cell metabolism, and increased senescence-associated secretory phenotype (SASP) mediator release However, the precise role of HIV-Tat in inducing a cellular senescence program in CD4+ T-cells is currently unknown.

Methods

Jurkat Tetoff cell lines stably transfected with Tat72, Tat101, or an empty vector were used. Flow cytometry and RT-qPCR were used to address senescence biomarkers, and 105 mediators were assessed in cell supernatants with an antibody-based membrane array. Key results obtained in Jurkat-Tat cells were addressed in primary, resting CD4+ T-cells by transient electroporation of HIV-Tat-FLAG plasmid DNA.

Results

In the Jurkat cell model, expression of Tat101 increased the levels of the senescence biomarkers BCL-2, CD87, and p21, and increased the release of sCD30, PDGF-AA, and sCD31, among other factors. Tat101 upregulated CD30 and CD31 co-expression in the Jurkat cell surface, distinguishing these cells from Tat72 and Tetoff Jurkats. The percentage of p21+, p16+, and γ-H2AX+ cells were higher in Tat-expressing CD4+ T-cells, detected as a FLAG+ population compared to their FLAG- (Tat negative) counterparts. Increased levels of sCD31 and sCD26 were also detected in electroporated CD4+ T-cell supernatants.

Discussion

Intracellular, full-length HIV-Tat expression increases several senescence biomarkers in Jurkat and CD4+ T-cells, and SASP/Aging mediators in cell supernatants. Intracellular HIV-Tat may initiate a cellular senescence program, contributing to the premature aging phenotype observed in PWH.

Identification of Nitric Oxide Donating Dasatinib Derivatives with Intraocular Pressure Lowering and Senolytic Activities

Based on two major risk factors of glaucoma, elevated intraocular pressure (IOP) and senescence, two new series of nitric oxide (NO) donating dasatinib derivatives 1a-f, 2a-f were designed, synthesized, and biologically evaluated. The results demonstrated that the most active compound 2e effectively released NO and increased the concentration of 3',5'-cyclic guanosine monophosphate in human trabecular meshwork cells, as well as maintained senolytic activity. Topical administration of 2e in chronic ocular hypertension (COHT) glaucoma mice not only significantly eliminated senescent cells in retina but also exhibited potent retinal ganglion cells (RGCs) surviving, IOP lowering, and visual function protection activities, which were superior to those of dasatinib. Compared with younger adult mice, aged COHT mice resulted in more severe RGCs loss, while 2e demonstrated a greater capacity to improve RGCs survival. Our findings show that dual IOP lowering and senolytic functions could be a promising therapeutic strategy for glaucoma, particularly in older patients.

H, Elsayed Ahmed R, Muralidharan P, Paulsamy P. SASP Modulation for Cellular Rejuvenation and Tissue Homeostasis: Therapeutic Strategies and Molecular Insights

Cellular senescence regulates aging, tissue maintenance, and disease progression through the Senescence-Associated Secretory Phenotype (SASP), a secretory profile of cytokines, chemokines, growth factors, and matrix-remodeling enzymes. While transient SASP aids wound healing, its chronic activation drives inflammation, fibrosis, and tumorigenesis. This review examines SASP's molecular regulation, dual roles in health and pathology, and therapeutic potential. The following two main strategies are explored: senescence clearance, which eliminates SASP-producing cells, and SASP modulation, which refines secretion to suppress inflammation while maintaining regenerative effects. Key pathways, including NF-κB, C/EBPβ, and cGAS-STING, are discussed alongside pharmacological, immunotherapeutic, gene-editing, and epigenetic interventions. SASP heterogeneity necessitates tissue-specific biomarkers for personalized therapies. Challenges include immune interactions, long-term safety, and ethical considerations. SASP modulation emerges as a promising strategy for aging, oncology, and tissue repair, with future advancements relying on multi-omics and AI-driven insights to optimize clinical outcomes.

A bibliometric and visual analysis of the impact of senescence on tumor immunotherapy

Background

Recently, many studies have focused on the relationship between senescence and immunotherapy in cancer treatment. However, relatively few studies have examined the intrinsic links between the three. Whether these studies can act synergistically in the fight against cancer and the specific links between them are still unclear.

Methods

We extracted, quantified, and visualized data from the literature (n = 2396) for the period 2004-2023 after rigorous quality control using citespace, GraphPad Prism, the R software package, and VOSviewer.

Results

Linear fit analyses were generated to predict the number of annual publications and citations as a function of the top-performing authors, journals, countries, and affiliations academically over the past two decades such as Weiwei, Aging-us, China, and the UT MD Anderson Cancer Center. Vosviewer-based hierarchical clustering further categorized study characteristics into six clusters, including two major clusters of immunotherapy research, immunosenescence-related research factors, and timeline distributions suggesting that cellular senescence and tumor progression is a relatively new research cluster that warrants further exploration and development. Study characterization bursts and linear regression analyses further confirmed these findings and revealed other important results, such as aging (a = 1.964, R² = 0.6803) and immunotherapy (a = 16.38, R² = 0.8812). Furthermore, gene frequency analysis in this study revealed the most abundant gene, APOE, and SIRT1-7 proteins.

Conclusion

The combination of aging therapies with tumor immunotherapies is currently in its preliminary stages. Although senescence has the greatest impact on ICB therapies, mechanistic investigations, and drug development for APOE and sirt1-7 (Sirtuins family) targets may be the key to combining senescence therapies with immunotherapies in the treatment of tumors.

Changing landscape of hematopoietic and mesenchymal cells and their interactions during aging and in age-related skeletal pathologies

Aging profoundly impacts mesenchymal and hematopoietic lineage cells, including their progenitors-the skeletal stem cells (SSCs) and hematopoietic stem cells (HSCs), respectively. SSCs are crucial for skeletal development, homeostasis, and regeneration, maintaining bone integrity by differentiating into osteoblasts, adipocytes, and other lineages that contribute to the bone marrow (BM) microenvironment. Meanwhile, HSCs sustain hematopoiesis and immune function. With aging, SSCs and HSCs undergo significant functional decline, partly driven by cellular senescence-a hallmark of aging characterized by irreversible growth arrest, secretion of pro-inflammatory factors (senescence associated secretory phenotype, SASP), and impaired regenerative potential. In SSCs, senescence skews lineage commitment toward adipogenesis at the expense of osteogenesis, contributing to increased bone marrow adiposity (BMAd), reduced bone quality, and osteoporosis. Similarly, aged HSCs exhibit diminished self-renewal, biased differentiation, and heightened inflammation, compromising hematopoietic output and immune function. In this review, we examine the age-related cellular and molecular changes in SSCs and HSCs, their lineage decisions in the aging microenvironment, and the interplay between skeletal and hematopoietic compartments. We also discuss the role of senescence-driven alterations in BM homeostasis and how targeting cellular aging mechanisms may offer therapeutic strategies for mitigating age-related skeletal and hematopoietic decline.

Senescence, NK cells, and cancer: navigating the crossroads of aging and disease

Cellular senescence, a state of stable cell cycle arrest, acts as a double-edged sword in cancer biology. In young organisms, it acts as a barrier against tumorigenesis, but in the aging population, it may facilitate tumor growth and metastasis through the senescence-associated secretory phenotype (SASP). Natural killer (NK) cells play a critical role in the immune system, particularly in the surveillance, targeting, and elimination of malignant and senescent cells. However, age-related immunosenescence is characterized by declining NK cell function resulting in diminished ability to fight infection, eliminate senescent cells and suppress tumor development. This implies that preserving or augmenting NK cell function may be central to defense against age-related degenerative and malignant diseases. This review explores the underlying mechanisms behind these interactions, focusing on how aging influences the battle between the immune system and cancer, the implications of senescent NK cells in disease progression, and the potential of adoptive NK cell therapy as a countermeasure to these age-related immunological challenges.

STAT3/TGFBI signaling promotes the temozolomide resistance of glioblastoma through upregulating glycolysis by inducing cellular senescence

Glioblastoma (GBM) is the most lethal type of brain tumor. Recent studies have indicated that cellular senescence-targeted therapy is a promising approach for cancer treatment. However, the underlying mechanisms remain to be clarified. In this study, 101 unique combinations of 10 machine learning algorithms were used to construct prognostic models based on cellular senescence-related genes (CSRGs). We developed the CSRG signature (CSRGS) using machine learning models that exhibited optimal performance. GBM samples were stratified into high- and low-CSRGS groups based on CSRGS scores. Patients in the high-CSRGS group exhibited a worse prognosis, higher immune infiltration, and increased sensitivity to immune checkpoint blockade therapy. Furthermore, senescence-related pathways were significantly correlated with glycolysis, indicating upregulated glycolytic metabolism in senescent GBM cells. We identified TGFBI as a key regulator that played vital roles in both glycolysis and cellular senescence in GBM. TGFBI was overexpressed in GBM samples compared to normal brain tissues, and its knockdown via shRNA inhibited cellular senescence, glycolysis, and temozolomide resistance. Chromatin immunoprecipitation (ChIP) and luciferase reporter assays confirmed that TGFBI is a direct STAT3 target and is required for the STAT3-induced promotion of cellular senescence, glycolysis, and drug resistance. The STAT3-TGFBI axis could be a potential target for senescence-targeted GBM therapy.

Emerging Role of the p53 Pathway in Modulating NK Cell-Mediated Immunity

The p53 pathway plays an important role in role in cancer immunity. Mutation or downregulation of the proteins in the p53 pathway are prevalent in many cancers, contributing to tumor progression and immune dysregulation. Recent findings suggest that the activity of p53 within tumor cells, immune cells, and the tumor microenvironment can play an important role in modulating NK cell-mediated immunity. Consequently, efforts to restore p53 pathway activity are being actively pursued to modulate this form of immunity. This review focuses on p53 activity regulating the infiltration and activation of NK cells in the tumor immune microenvironment. Furthermore, the impact of p53 and its regulation of NK cells on immunogenic cell death within solid tumors and the abscopal effect are reviewed. Finally, future avenues for therapeutically restoring p53 activity to improve NK cell-mediated antitumor immunity and optimize the effectiveness of cancer therapies are discussed.

Modelling the spatiotemporal dynamics of senescent cells in wound healing, chronic wounds, and fibrosis

Cellular senescence is known to drive age-related pathology through the senescence-associated secretory phenotype (SASP). However, it also plays important physiological roles such as cancer suppression, embryogenesis and wound healing. Wound healing is a tightly regulated process which when disrupted results in conditions such as fibrosis and chronic wounds. Senescent cells appear during the proliferation phase of the healing process where the SASP is involved in maintaining tissue homeostasis after damage. Interestingly, SASP composition and functionality was recently found to be temporally regulated, with distinct SASP profiles involved: a fibrogenic, followed by a fibrolytic SASP, which could have important implications for the role of senescent cells in wound healing. Given the number of factors at play a full understanding requires addressing the multiple levels of complexity, pertaining to the various cell behaviours, individually followed by investigating the interactions and influence each of these elements have on each other and the system as a whole. Here, a systems biology approach was adopted whereby a multi-scale model of wound healing that includes the dynamics of senescent cell behaviour and corresponding SASP composition within the wound microenvironment was developed. The model was built using the software CompuCell3D, which is based on a Cellular Potts modelling framework. We used an existing body of data on healthy wound healing to calibrate the model and validation was done on known disease conditions. The model clearly shows how differences in the spatiotemporal dynamics of different senescent cell phenotypes lead to several distinct repair outcomes. These differences in senescent cell dynamics can be attributed to variable SASP composition, duration of senescence and temporal induction of senescence relative to the healing stage. The range of outcomes demonstrated strongly highlight the dynamic and heterogenous role of senescent cells in wound healing, fibrosis and chronic wounds, and their fine-tuned control. Further specific data to increase model confidence could be used to explore senolytic treatments in wound disorders.

Targeting senescence with radioactive 223Ra/Ba SAzymes enables senolytics-unlocked One-Two punch strategy to boost anti-tumor immunotherapy

Senescent cells are characterized by a persistent cessation of their cell cycle, rendering them valuable targets for anti-tumor strategies in cancer treatment. Numerous studies have explored induced senescence as a promising approach in tumor therapy. Nevertheless, these treatments often come with drawbacks, including adverse side effects and weaker senescence-inducing effects. To address these challenges, we synthesized 223Ra/Ba single-atom nanozyme (SAzyme), wherein Ba SAzyme acts concurrently as a carrier for 223RaCl2, facilitating targeted delivery and minimizing side effects. The 223Ra/Ba SAzyme complex enhances various enzyme-mimicking functions, including catalase (CAT) and peroxidase (POD) activities. Importantly, 223Ra/Ba SAzyme induces cellular senescence and boost anti-tumor immunity. The persistent presence of a senescence-associated secretory phenotype (SASP) in the tumor microenvironment presents risks of immune suppression and tumor recurrence, which can be effectively mitigated by senolytics. As a result, 223Ra/Ba SAzyme were combined with anti-PD-L1 checkpoint blockade to achieve a one-two punch therapy, wherein 223Ra/Ba SAzyme exploits senescence followed by anti-PD-L1 therapy to eradicate senescent cells. This one-two punch strategy approach presents a straightforward and potent intervention for both primary tumors and distant tumor.

Senescence-associated lineage-aberrant plasticity evokes T-cell-mediated tumor control

Cellular senescence is a stress-inducible state switch relevant in aging, tumorigenesis and cancer therapy. Beyond a lasting arrest, senescent cells are characterized by profound chromatin remodeling and transcriptional reprogramming. We show here myeloid-skewed aberrant lineage plasticity and its immunological ramifications in therapy-induced senescence (TIS) of primary human and murine B-cell lymphoma. We find myeloid transcription factor (TF) networks, specifically AP-1-, C/EBPβ- and PU.1-governed transcriptional programs, enriched in TIS but not in equally chemotherapy-exposed senescence-incapable cancer cells. Dependent on these master TF, TIS lymphoma cells adopt a lineage-promiscuous state with properties of monocytic-dendritic cell (DC) differentiation. TIS lymphoma cells are preferentially lysed by T-cells in vitro, and mice harboring DC-skewed Eμ-myc lymphoma experience significantly longer tumor-free survival. Consistently, superior long-term outcome is also achieved in diffuse large B-cell lymphoma patients with high expression of a TIS-related DC signature. In essence, these data demonstrate a therapeutically exploitable, prognostically favorable immunogenic role of senescence-dependent aberrant myeloid plasticity in B-cell lymphoma.

Identification of CCNB1 as a biomarker for cellular senescence in hepatocellular carcinoma: a bioinformatics and experimental validation study

BACKGROUND

Hepatocellular carcinoma (HCC), originating in the liver and often asymptomatic in early stages, frequently metastasises and recures post-surgery. Currently, reliable diagnostic biomarkers and therapeutic targets for HCC are lacking. This study investigates the influence of cellular senescence on HCC, employing bioinformatics analysis and in vitro experiments to identify potential biomarkers.

METHODS

We integrated data from GEO microarrays (GSE14520, GSE45267 and GSE64041) to analyse differentially expressed genes (DEGs) using the R package limma. WGCNA identified gene modules highly correlated to HCC. Then, ageing-highly related differentially expressed genes (AgHDEGs) were identified. Correlation analysis, GO and KEGG functional enrichment analysis, and gene co-expression network analysis further elucidated the functions of AgHDEGs. The STRING database identified hub AgHDEGs with CCNB1 subsequently evaluated for diagnostic value using ROC curve analysis. Additionally, we explored the correlation between CCNB1 and immune cells and assessed its biological functions via GSEA. Ultimately, the conclusions from bioinformatics analysis were confirmed via in vitro experiments, complemented by molecular docking simulations of gene-drug interactions.

RESULTS

Eight AgHDEGs (KPNA2, CCT3, CCNB1, RACGAP1, CDKN3, FEN1, MT1X and FOXM1) were identified. PPI network analysis highlighted CCNB1 as hub AgHDEGs with ROC analysis confirming its strong diagnostic potential. Analysis of immune infiltration revealed a significant correlation between CCNB1 and M0 macrophages. Subsequent studies showed CCNB1's critical role in regulating the cell cycle. Validation experiments illustrated an upregulation of CCNB1 expression in HCC, while inhibiting CCNB1 may reduce HepG2 cell proliferation by promoting cellular senescence. Moreover, molecular docking indicated CCNB1 as a potential therapeutic target.

CONCLUSION

Our study underscores CCNB1's potential impact on HCC senescence and progression, suggesting its candidacy as a biomarker for HCC.

Pharmacological rescue of mutant p53 triggers spontaneous tumor regression via immune responses

Tumor suppressor p53 is the most frequently mutated protein in cancer, possessing untapped immune-modulating capabilities in anticancer treatment. Here, we investigate the efficacy and underlying mechanisms of pharmacological reactivation of mutant p53 in treating spontaneous tumors in mice. In the p53 R279W (equivalent to the human hotspot R282W) mouse model developing spontaneous tumors, arsenic trioxide (ATO) treatment through drinking water significantly prolongs the survival of mice, dependent on p53-R279W reactivation. Transient regressions of spontaneous T-lymphomas are observed in 70% of the ATO-treated mice, accompanied by interferon (IFN) response. In allograft models, the tumor-suppressive effect of reactivated p53-R279W is detectably reduced in both immunodeficient Rag1-/- and CD8+ T cell-depleted mice. ATO also activates the IFN pathway in human cancer cells harboring various p53 mutations, as well as in primary samples derived from the p53-mutant patient treated with ATO. Together, p53 could serve as an alternative therapeutic target for the development of immunotherapies.

Wnt/B-catenin Activation and TP53 Mutations Associate With Distinct Immune Profiles in Advanced Thyroid Cancer

CONTEXT

Anaplastic thyroid carcinomas (ATCs) and poorly differentiated thyroid carcinomas (PDTCs) exhibit distinct immune-related gene expression profiles. Most ATCs are characterized by active immune interactions (hot or altered immunosuppressed immunophenotypes), while PDTCs are largely immunologically inert (cold immunophenotypes).

OBJECTIVE

This study aimed to elucidate the mechanisms driving these divergent immunological fates, focusing on the Wnt/β-catenin pathway and TP53 mutations.

RESULTS

Our data reveal that ATCs frequently harbor TP53 mutations (83.3%), which correlate with a hot immunophenotype, characterized by high expression of β-catenin-regulated cytokine CCL4 and recruitment of CD103 + dendritic cells. Conversely, PDTCs, with a lower incidence of TP53 mutations (12.5%), often exhibit a cold immunophenotype. In cold cancers and PDTCs, β-catenin is overexpressed, suggesting that Wnt/β-catenin pathway activation drives immune exclusion through CCL4 downregulation.Further analysis indicated that loss of p53 function is inversely correlated with β-catenin expression. P53-mutated cancers showed significantly higher expression of CCL4 and densities of CD103 + dendritic cells compared to their p53-wild-type counterparts. Additionally, p53-mutated ATCs expressed a higher number of immune-related genes, supporting the role of p53 loss in activating immune responses in cancer.

CONCLUSION

Our study indicates a potential correlation between the activation of the Wnt/β-catenin pathway and the development of cold thyroid cancers, which may be mediated by the suppression of CCL4 expression. Concurrently, mutations in the p53 gene appear to be linked with the occurrence of hot thyroid cancers. While these associations are compelling, they are based on observational data. Experimental research is necessary to determine the causal relationships underlying these findings.

Exosomal dynamics: Bridging the gap between cellular senescence and cancer therapy

Cancer remains one of the most devastating diseases, severely affecting public health and contributing to economic instability. Researchers worldwide are dedicated to developing effective therapeutics to target cancer cells. One promising strategy involves inducing cellular senescence, a complex state in which cells exit the cell cycle. Senescence has profound effects on both physiological and pathological processes, influencing cellular systems through secreted factors that affect surrounding and distant cells. Among these factors are exosomes, small extracellular vesicles that play crucial roles in cellular communication, development, and defense, and can contribute to pathological conditions. Recently, there has been increasing interest in engineering exosomes as precise drug delivery vehicles, capable of targeting specific cells or intracellular components. Studies have emphasized the significant role of exosomes from senescent cells in cancer progression and therapy. Notably, chemotherapeutic agents can alter the tumor microenvironment, induce senescence, and trigger immune responses through exosome-mediated cargo transfer. This review explores the intricate relationship between cellular senescence, exosomes, and cancer, examining how different therapeutics can eliminate cancer cells or promote drug resistance. It also investigates the molecular mechanisms and signaling pathways driving these processes, highlighting current challenges and proposing future perspectives to uncover new therapeutic strategies for cancer treatment.

Immune surveillance of senescence: potential application to age-related diseases

Several lines of evidence suggest that the age-dependent accumulation of senescent cells leads to chronic tissue microinflammation, which in turn contributes to age-related pathologies. In general, senescent cells can be eliminated by the host's innate and adaptive immune surveillance system, including macrophages, NK cells, and T cells. Impaired immune surveillance leads to the accumulation of senescent cells and accelerates the aging process. Recently, senescent cells, like cancer cells, have been shown to express certain types of immune checkpoint proteins as well as non-classical immune-tolerant MHC variants, leading to immune escape from surveillance systems. Thus, immune checkpoint blockade (ICB) may be a promising strategy to enhance immune surveillance of senescence, leading to the amelioration of some age-related diseases and tissue dysfunction.

Bidirectional regulation of the cyclic guanosine monophosphate-adenosine monophosphate synthase-stimulator of interferon gene pathway and its impact on hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) ranks as the fourth leading cause of cancer-related deaths in China, and the treatment options are limited. The cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS) activates the stimulator of interferon gene (STING) signaling pathway as a crucial immune response pathway in the cytoplasm, which detects cytoplasmic DNA to regulate innate and adaptive immune responses. As a potential therapeutic target, cGAS-STING pathway markedly inhibits tumor cell proliferation and metastasis, with its activation being particularly relevant in HCC. However, prolonged pathway activation may lead to an immunosuppressive tumor microenvironment, which fostering the invasion or metastasis of liver tumor cells.

AIM

To investigate the dual-regulation mechanism of cGAS-STING in HCC.

METHODS

This review was conducted according to the PRISMA guidelines. The study conducted a comprehensive search for articles related to HCC on PubMed and Web of Science databases. Through rigorous screening and meticulous analysis of the retrieved literature, the research aimed to summarize and elucidate the impact of the cGAS-STING pathway on HCC tumors.

RESULTS

All authors collaboratively selected studies for inclusion, extracted data, and the initial search of online databases yielded 1445 studies. After removing duplicates, the remaining 964 records were screened. Ultimately, 55 articles met the inclusion criteria and were included in this review.

CONCLUSION

Acute inflammation can have a few inhibitory effects on cancer, while chronic inflammation generally promotes its progression. Extended cGAS-STING pathway activation will result in a suppressive tumor microenvironment.

Multiple outcomes of the germline p16INK4a mutation affecting senescence and immunity in human skin

The integrated behaviour of multiple senescent cell types within a single human tissue leading to the development of malignancy is unclear. Patients with Familial Melanoma Syndrome (FMS) have heterozygous germline defects in the CDKN2A gene coding for the cyclin inhibitor p16INK4a. Melanocytes within skin biopsies from FMS patients express significantly less p16INK4a but express higher levels of the DNA-damage protein 𝛾H2AX a than fibroblastic cells. However, patient fibroblasts also exhibit defects since senescent cells do not increase in the skin during ageing and fibroblasts isolated from the skin of patients have increased replicative capacity compared to control fibroblasts in vitro, culminating in abnormal nuclear morphology. Patient derived fibroblasts also secreted less SASP than control cells. Predisposition of FMS patients to melanoma may therefore result from integrated dysregulation of senescence in multiple cell types in vivo. The inherently greater levels of DNA damage and the overdependence of melanocytes on p16 for cell cycle inhibition after DNA damage makes them exquisitely susceptible to malignant transformation. This may be accentuated by senescence-related defects in fibroblasts, in particular reduced SASP secretion that hinders recruitment of T cells in the steady state and thus reduces cutaneous immunosurveillance in vivo.

Immune therapeutic strategies for the senescent tumor microenvironment

Senescent cells can either to promote immunosuppressive tumor microenvironment or facilitate immune surveillance. Despite the revolutionary impact of cancer immunotherapy, durable responses in solid tumors, particularly in advanced stages, remain limited. Recent studies have shed light on the influence of senescent status within the tumor microenvironment (TME) on therapy resistance and major efforts are needed to overcome these challenges. This review summarizes recent advancements in targeting cellular senescence, with a particular focus on immunomodulatory approaches on the hallmarks of cellular senescence.

A ganglioside-based immune checkpoint enables senescent cells to evade immunosurveillance during aging

Although senescent cells can be eliminated by the immune system, they tend to accumulate with age in various tissues. Here we show that senescent cells can evade immune clearance by natural killer (NK) cells by upregulating the expression of the disialylated ganglioside GD3 at their surface. The increased level of GD3 expression on senescent cells that naturally occurs upon aging in liver, lung, kidney or bones leads to a strong suppression of NK-cell-mediated immunosurveillance. In mice, we found that targeting GD3+ senescent cells with anti-GD3 immunotherapy attenuated the development of experimentally induced or age-related lung and liver fibrosis and age-related bone remodeling. These results demonstrate that GD3 upregulation confers immune privilege to senescent cells. We propose that GD3 acts as a senescence immune checkpoint (SIC) that allows senescent cells to escape immunosurveillance and to trigger immune anergy during aging.

Breathing new insights into the role of mutant p53 in lung cancer

The tumour suppressor gene p53 is one of the most frequently mutated genes in lung cancer and these defects are associated with poor prognosis, albeit some debate exists in the lung cancer field. Despite extensive research, the exact mechanisms by which mutant p53 proteins promote the development and sustained expansion of cancer remain unclear. This review will discuss the cellular responses controlled by p53 that contribute to tumour suppression, p53 mutant lung cancer mouse models and characterisation of p53 mutant lung cancer. Furthermore, we discuss potential approaches of targeting mutant p53 for the treatment of lung cancer.

Accelerated Cellular Senescence in Progressive Multiple Sclerosis: A Histopathological Study

OBJECTIVE

The neurodegenerative processes driving the build-up of disability in progressive multiple sclerosis (P-MS) have not been fully elucidated. Recent data link cellular senescence (CS) to neurodegeneration. We investigated for evidence of CS in P-MS and sought to determine its pattern.

METHODS

We used 53BP1, p16, and lipofuscin as markers of CS in white matter lesions (WMLs), normal appearing white matter (NAWM), normal appearing cortical gray matter (NAGM), control white matter (CWM), and control gray matter (CGM) on autopsy material from patient with P-MS and healthy controls. Senescence-associated secretory phenotype (SASP) factors were quantified in cerebrospinal fluid (CSF).

RESULTS

P16+ cell counts were significantly increased in WMLs and GMLs, compared with NAWM, CWM, NAGM, and CGM and lipofuscin+ cells were significantly increased in WMLs, compared with NAWM and CWM, indicating more abundant CS in demyelinated lesions. The 53BP1+ cells in WMLs were significantly increased compared with NAWM and CWM. The 53BP1+ and p16+ cells were found significantly more abundant in acute active WMLs and GMLs, compared with chronic inactive lesions. Co-localization studies showed evidence of CS in neurons, astrocytes, oligodendrocytes, microglia, and macrophages. Among the quantified CSF SASP factors, IL-6, MIF, and MIP1a levels correlated with 53BP1+ cell counts in NAGM, whereas IL-10 levels correlated with p16+ cell counts in NAWM. P16+ cell counts in WMLs exhibited an inverse correlation with time to requiring a wheelchair and with age at death.

INTERPRETATION

Our data indicates that CS primarily affects actively demyelinating gray and WMLs. A higher senescent cell load in P-MS is associated with faster disability progression and death. ANN NEUROL 2025.

Telomeres, telomerase, and cancer: mechanisms, biomarkers, and therapeutics

Telomeres and telomerase play crucial roles in the initiation and progression of cancer. As biomarkers, they aid in distinguishing benign from malignant tissues. Despite the promising therapeutic potential of targeting telomeres and telomerase for therapy, translating this concept from the laboratory to the clinic remains challenging. Many candidate drugs remain in the experimental stage, with only a few advancing to clinical trials. This review explores the relationship between telomeres, telomerase, and cancer, synthesizing their roles as biomarkers and reviewing the outcomes of completed trials. We propose that changes in telomere length and telomerase activity can be used to stratify cancer stages. Furthermore, we suggest that differential expression of telomere and telomerase components at the subcellular level holds promise as a biomarker. From a therapeutic standpoint, combining telomerase-targeted therapies with drugs that mitigate the adverse effects of telomerase inhibition may offer a viable strategy.

Tp53 determines the spatial dynamics of M1/M2 tumor-associated macrophages and M1-driven tumoricidal effects

The spatial role of M1 and M2 tumor-associated macrophages (M1/M2 TAMs) in precision medicine remains unclear. EGFR and TP53 are among the most frequently mutated genes in lung adenocarcinoma. We characterized the mutation status and density of M1/M2 TAMs within tumor islets and stroma in 117 lung adenocarcinomas using next-generation sequencing and immunohistochemistry, respectively. Stromal M1 TAMs were positively correlated with disease progression and smoking history. In contrast, islet M1/M2 TAMs were predominantly found in tumors with wild-type TP53 (wtp53) but not associated with EGFR status. The presence of wtp53 was associated with the spatial distribution of M1/M2 TAMs in tumor islets and stroma. Additionally, dominance of islet M1 TAMs and M1-signature were significantly associated with improved survival in patients with wtp53 lung adenocarcinoma, unlike in those with mutant TP53. Conditioned medium from M1 macrophages (M1 CM) induced apoptosis in wtp53 cells through increased p53 accumulation. We found that interferons in M1 CM activate JAK1/TYK2 via IFNARs, leading to enhanced STAT1 expression and Y701 phosphorylation. This activation facilitates p53-STAT1 interactions, reduces the interaction between p53 and MDM2, and subsequently decreases p53 ubiquitination. M1 CM inhibited tumorigenesis, and silencing p53 reduced the anti-tumor efficacy of polyinosinic:polycytidylic acid (poly I:C) in vivo. Furthermore, higher M1-signature was significantly associated with better responses and survival following anti-PD1 treatment in wtp53 melanomas. IFNs/STAT1/p53 signaling was critical for the anti-tumor activity of M1 macrophages. These findings suggest that p53 modulates the spatial balance of M1/M2 TAMs, and the tumoricidal effects of M1 TAMs depend on p53 status. Thus, p53 companion diagnostics could facilitate the development of M1-oriented therapies, which may be particularly beneficial for wtp53 patients when combined with immunotherapy.

Tumor suppressor genotype influences the extent and mode of immunosurveillance in lung cancer

The impact of cancer driving mutations in regulating immunosurveillance throughout tumor development remains poorly understood. To better understand the contribution of tumor genotype to immunosurveillance, we generated and validated lentiviral vectors that create an epi-allelic series of increasingly immunogenic neoantigens. This vector system is compatible with autochthonous Cre-regulated cancer models, CRISPR/Cas9-mediated somatic genome editing, and tumor barcoding. Here, we show that in the context of KRAS-driven lung cancer and strong neoantigen expression, tumor suppressor genotype dictates the degree of immune cell recruitment, positive selection of tumors with neoantigen silencing, and tumor outgrowth. By quantifying the impact of 11 commonly inactivated tumor suppressor genes on tumor growth across neoantigenic contexts, we show that the growth promoting effects of tumor suppressor gene inactivation correlate with increasing sensitivity to immunosurveillance. Importantly, specific genotypes dramatically increase or decrease sensitivity to immunosurveillance independently of their growth promoting effects. We propose a model of immunoediting in which tumor suppressor gene inactivation works in tandem with neoantigen expression to shape tumor immunosurveillance and immunoediting such that the same neoantigens uniquely modulate tumor immunoediting depending on the genetic context.

One Sentence Summary

Here we uncover an under-appreciated role for tumor suppressor gene inactivation in shaping immunoediting upon neoantigen expression.

SMARCA4 regulates the NK-mediated killing of senescent cells

Induction of senescence by chemotherapeutic agents arrests cancer cells and activates immune surveillance responses to contribute to therapy outcomes. In this investigation, we searched for ways to enhance the NK-mediated elimination of senescent cells. We used a staggered screen approach, first identifying siRNAs potentiating the secretion of immunomodulatory cytokines to later test for their ability to enhance NK-mediated killing of senescent cells. We identified that genetic or pharmacological inhibition of SMARCA4 enhanced senescent cell elimination by NK cells. SMARCA4 expression is elevated during senescence and its inhibition derepresses repetitive elements, inducing the SASP via activation of cGAS/STING and MAVS/MDA5 pathways. Moreover, a PROTAC targeting SMARCA4 synergized with cisplatin to increase the infiltration of CD8 T cells and mature, activated NK cells in an immunocompetent model of ovarian cancer. Our results indicate that SMARCA4 inhibitors enhance NK-mediated surveillance of senescent cells and may represent senotherapeutic interventions for ovarian cancer.

Decoding T cell senescence in cancer: Is revisiting required?

Senescence is an inherent cellular mechanism triggered as a response to stressful insults. It associates with several aspects of cancer progression and therapy. Senescent cells constitute a highly heterogeneous cellular population and their identification can be very challenging. In fact, the term "senescence" has been often misused. This is also true in the case of immune cells. While several studies indicate the presence of senescent-like features (mainly in T cells), senescent immune cells are poorly described. Under this prism, we herein review the current literature on what has been characterized as T cell senescence and provide insights on how to accurately discriminate senescent cells against exhausted or anergic ones. We also summarize the major metabolic and epigenetic modifications associated with T cell senescence and underline the role of senescent T cells in the tumor microenvironment (TME). Moreover, we discuss how these cells associate with standard clinical therapeutic interventions and how they impact their efficacy. Finally, we underline the importance of precise identification and thorough characterization of "truly" senescent T cells in order to design successful therapeutic manipulations that would delay cancer incidence and maximize efficacy of immunotherapy.

Immune senescence: A key player in cancer biology

With the rapid development of immunological techniques in recent years, our understanding of immune senescence has gradually deepened, but the role of immune senescence in cancer biology remains incompletely elucidated. Understanding these mechanisms and interactions is crucial for the development of tumor biology. This review examines five key areas: the classification and main features of immune senescence, factors influencing immune cell senescence in cancer, the reciprocal causal cycle between immune senescence and malignancy, and the potential of immune senescence as a target for cancer immunotherapy.

Remodeling of tumor microenvironment by cellular senescence and immunosenescence in cervical cancer

Cellular senescence is a response to various stress signals, which is characterized by stable cell cycle arrest, alterations in cellular morphology, metabolic reprogramming and production of senescence-associated secretory phenotype (SASP). When it occurs in the immune system, it is called immunosenescence. Cervical cancer is a common gynecological malignancy, and cervical cancer screening is generally recommended before the age of 65. Elderly women (≥65 years) are more often diagnosed with advanced disease and have poorer prognosis compared to younger patients. Despite extensive research, the tumor microenvironment requires more in-depth exploration, particularly in elderly patients. In cervical cancer, senescent cells have a double-edged sword effect on tumor progression. Induction of preneoplastic cell senescence prevents tumor initiation, and several treatment approaches of cervical cancer act in part by inducing cancer cell senescence. However, senescent immune cell populations within the tumor microenvironment facilitate tumor development, recurrence, treatment resistance, etc. Amplification of beneficial effects and inhibition of aging-related pro-tumorigenic pathways contribute to improving antitumor effects. This review discusses senescent cancer and immune cells present in the tumor microenvironment of cervical cancer and how these senescent cells and their SASP remodel the tumor microenvironment, influence antitumor immunity and tumor initiation and development. Moreover, we discuss the significance of senotherapeutics that enable to eliminate senescent cells and prevent tumor progression and development through improving antitumor immunity and affecting the tumor microenvironment.

The crosstalk between senescence, tumor, and immunity: molecular mechanism and therapeutic opportunities

Cellular senescence is characterized by a stable cell cycle arrest and a hypersecretory, proinflammatory phenotype in response to various stress stimuli. Traditionally, this state has been viewed as a tumor-suppressing mechanism that prevents the proliferation of damaged cells while activating the immune response for their clearance. However, senescence is increasingly recognized as a contributing factor to tumor progression. This dual role necessitates a careful evaluation of the beneficial and detrimental aspects of senescence within the tumor microenvironment (TME). Specifically, senescent cells display a unique senescence-associated secretory phenotype that releases a diverse array of soluble factors affecting the TME. Furthermore, the impact of senescence on tumor-immune interaction is complex and often underappreciated. Senescent immune cells create an immunosuppressive TME favoring tumor progression. In contrast, senescent tumor cells could promote a transition from immune evasion to clearance. Given these intricate dynamics, therapies targeting senescence hold promise for advancing antitumor strategies. This review aims to summarize the dual effects of senescence on tumor progression, explore its influence on tumor-immune interactions, and discuss potential therapeutic strategies, alongside challenges and future directions. Understanding how senescence regulates antitumor immunity, along with new therapeutic interventions, is essential for managing tumor cell senescence and remodeling the immune microenvironment.

Senescence as a therapeutic target in cancer and age-related diseases

Cellular senescence is a stress response that restrains the growth of aged, damaged or abnormal cells. Thus, senescence has a crucial role in development, tissue maintenance and cancer prevention. However, lingering senescent cells fuel chronic inflammation through the acquisition of a senescence-associated secretory phenotype (SASP), which contributes to cancer and age-related tissue dysfunction. Recent progress in understanding senescence has spurred interest in the development of approaches to target senescent cells, known as senotherapies. In this Review, we evaluate the status of various types of senotherapies, including senolytics that eliminate senescent cells, senomorphics that suppress the SASP, interventions that mitigate senescence and strategies that harness the immune system to clear senescent cells. We also summarize how these approaches can be combined with cancer therapies, and we discuss the challenges and opportunities in moving senotherapies into clinical practice. Such therapies have the potential to address root causes of age-related diseases and thus open new avenues for preventive therapies and treating multimorbidities.

Illudin S inhibits p53-Mdm2 interaction for anticancer efficacy in colorectal cancer

The impairment of the p53 pathway was once regarded as inadequately druggable due to the specificity of the p53 structure, its flat surface lacking an ideal drug-binding site, and the difficulty in reinstating p53 function. However, renewed interest in p53-based therapies has emerged, with promising approaches targeting p53 and ongoing clinical trials investigating p53-based treatments across various cancers. Despite significant progress in p53-targeted therapies, challenges persist in identifying effective therapeutic targets within the p53 pathway. In this study, we implemented a molecular screening system to effectively discover p53 activator. As a result, illudin S was identified as a potential inhibitor of the p53-Mdm2 interaction. This compound is particularly intriguing due to its well-documented anti-cancer effects, despite the ambiguity surrounding its precise mechanism of action. Illudin S demonstrated a direct binding affinity to the Mdm2 binding site of p53 through hydrogen bonding, which enhanced the stability and transcriptional activity of p53. The inhibition of the p53-Mdm2 interaction by illudin S led to increased p53 expression. Moreover, this inhibition effectively induced apoptosis and cell cycle arrest in CT26 colorectal cancer cells. Administration of illudin S in a colorectal cancer mouse model resulted in prolonged survival and significant tumor growth inhibition. These findings elucidate the mechanism underlying the anti-cancer effects of illudin S, specifically through its targeting of the p53-Mdm2 interaction in colorectal cancer. Consequently, illudin S emerges as a promising candidate for the development of p53-targeted cancer therapies.

Navigating the complex role of senescence in liver disease

ABSTRACT

Cellular senescence, an irreversible state of cell cycle arrest characterized by phenotypic changes and a specific secretory profile, plays a dual role in liver health and disease. Under physiological conditions, senescence aids organ repair and regeneration, but its accumulation due to aging or pathological stress significantly contributes to chronic liver diseases, including alcoholic liver disease, metabolic dysfunction-associated steatohepatitis, liver fibrosis, and hepatocellular carcinoma. Senescence is identified by a range of cellular and molecular changes, such as morphological alterations, expression of cell cycle inhibitors, senescence-associated β-galactosidase activity, and nuclear membrane changes. The onset of senescence in organ cells can affect the entire organism, primarily through the senescence-associated secretory phenotype, which has autocrine, paracrine, and endocrine effects on tissue microenvironments. The objective of this review is to offer a contemporary overview of the pathophysiological events involving hepatic senescent cells and to elucidate their role in the onset and progression of liver diseases, particularly through mechanisms like telomere shortening, genomic and mitochondrial DNA damage, and inflammation. Additionally, this review discusses the emerging senolytic therapies aimed at targeting senescent cells to delay or mitigate liver disease progression. The therapeutic potential of these interventions, alongside their safety and effectiveness, highlights the need for further research to refine these approaches and address unresolved problems in the field of hepatic cellular senescence.

PP2C phosphatases-terminators of suicidal thoughts

Cell death and related signaling pathways are essential during development and in various physiological and pathological conditions. Post-translational modifications such as ubiquitination and phosphorylation play an important role in these signaling pathways. The involvement of kinases - enzymes that catalyze protein phosphorylation - in cell death signaling has been extensively studied. On the other hand, not many studies have been devoted to analyzing the role in cell death of phosphatases, enzymes involved in the removal of phosphorylated residues added to proteins by kinases. Obviously, the two opposite reactions, phosphorylation and dephosphorylation, are equally important in the regulation of protein functions and subsequently in the execution of the cell death program. Here, we have summarized recent work on the involvement of serine-threonine PP2C phosphatases in cell death pathways, senescence and autophagy, focusing in particular on the most studied phosphatase PPM1D (PP2Cδ) as an example of the regulatory role of PP2Cs in cell death. The review should help to draw attention to the importance of PP2C family phosphatases in cell death checkpoints and to discover new targets for drug development.

Identifying specific functional roles for senescence across cell types

Cellular senescence plays critical roles in aging, regeneration, and disease; yet, the ability to discern its contributions across various cell types to these biological processes remains limited. In this study, we generated an in vivo genetic toolbox consisting of three p16Ink4a-related intersectional genetic systems, enabling pulse-chase tracing (Sn-pTracer), Cre-based tracing and ablation (Sn-cTracer), and gene manipulation combined with tracing (Sn-gTracer) of defined p16Ink4a+ cell types. Using liver injury and repair as an example, we found that macrophages and endothelial cells (ECs) represent distinct senescent cell populations with different fates and functions during liver fibrosis and repair. Notably, clearance of p16Ink4a+ macrophages significantly mitigates hepatocellular damage, whereas eliminating p16Ink4a+ ECs aggravates liver injury. Additionally, targeted reprogramming of p16Ink4a+ ECs through Kdr overexpression markedly reduces liver fibrosis. This study illuminates the functional diversity of p16Ink4a+ cells and offers insights for developing cell-type-specific senolytic therapies in the future.

TPR is required for cytoplasmic chromatin fragment formation during senescence

During oncogene-induced senescence there are striking changes in the organisation of heterochromatin in the nucleus. This is accompanied by activation of a pro-inflammatory gene expression programme - the senescence-associated secretory phenotype (SASP) - driven by transcription factors such as NF-κB. The relationship between heterochromatin re-organisation and the SASP has been unclear. Here, we show that TPR, a protein of the nuclear pore complex basket required for heterochromatin re-organisation during senescence, is also required for the very early activation of NF-κB signalling during the stress-response phase of oncogene-induced senescence. This is prior to activation of the SASP and occurs without affecting NF-κB nuclear import. We show that TPR is required for the activation of innate immune signalling at these early stages of senescence and we link this to the formation of heterochromatin-enriched cytoplasmic chromatin fragments thought to bleb off from the nuclear periphery. We show that HMGA1 is also required for cytoplasmic chromatin fragment formation. Together these data suggest that re-organisation of heterochromatin is involved in altered structural integrity of the nuclear periphery during senescence, and that this can lead to activation of cytoplasmic nucleic acid sensing, NF-κB signalling, and activation of the SASP.

Discovery and Characterization of Brigimadlin, a Novel and Highly Potent MDM2-p53 Antagonist Suitable for Intermittent Dose Schedules

p53 is known as the guardian of the genome and is one of the most important tumor suppressors. It is inactivated in most tumors, either via tumor protein p53 (TP53) gene mutation or copy number amplification of key negative regulators, e.g., mouse double minute 2 (MDM2). Compounds that bind to the MDM2 protein and disrupt its interaction with p53 restore p53 tumor suppressor activity, thereby promoting cell cycle arrest and apoptosis. Previous clinical experience with MDM2-p53 protein-protein interaction antagonists (MDM2-p53 antagonists) has demonstrated that thrombocytopenia and neutropenia represent on-target dose-limiting toxicities that might restrict their therapeutic utility. Dosing less frequently, while maintaining efficacious exposure, represents an approach to mitigate toxicity and improve the therapeutic window of MDM2-p53 antagonists. However, to achieve this, a molecule possessing excellent potency and ideal pharmacokinetic properties is required. Here, we present the discovery and characterization of brigimadlin (BI 907828), a novel, investigational spiro-oxindole MDM2-p53 antagonist. Brigimadlin exhibited high bioavailability and exposure, as well as dose-linear pharmacokinetics in preclinical models. Brigimadlin treatment restored p53 activity and led to apoptosis induction in preclinical models of TP53 wild-type, MDM2-amplified cancer. Oral administration of brigimadlin in an intermittent dosing schedule induced potent tumor growth inhibition in several TP53 wild-type, MDM2-amplified xenograft models. Exploratory clinical pharmacokinetic studies (NCT03449381) showed high systemic exposure and a long plasma elimination half-life in patients with cancer who received oral brigimadlin. These findings support the continued clinical evaluation of brigimadlin in patients with MDM2-amplified cancers, such as dedifferentiated liposarcoma.

The senescence-associated secretory phenotype and its physiological and pathological implications

Cellular senescence is a state of terminal growth arrest associated with the upregulation of different cell cycle inhibitors, mainly p16 and p21, structural and metabolic alterations, chronic DNA damage responses, and a hypersecretory state known as the senescence-associated secretory phenotype (SASP). The SASP is the major mediator of the paracrine effects of senescent cells in their tissue microenvironment and of various local and systemic biological functions. In this Review, we discuss the composition, dynamics and heterogeneity of the SASP as well as the mechanisms underlying its induction and regulation. We describe the various biological properties of the SASP, its beneficial and detrimental effects in different physiological and pathological settings, and its impact on overall health span. Finally, we discuss the use of the SASP as a biomarker and of SASP inhibitors as senomorphic interventions to treat cancer and other age-related conditions.

The cell cycle inhibitor p21CIP1 is essential for irinotecan-induced senescence and plays a decisive role in re-sensitization of temozolomide-resistant glioblastoma cells to irinotecan

BACKGROUND AND PURPOSE

Standard of care for glioblastomas includes radio-chemotherapy with the monoalkylating compound temozolomide. Temozolomide induces primarily senescence, inefficiently killing glioblastoma cells. Recurrences are inevitable. Although recurrences presumably arise from cells evading/escaping TMZ-induced senescence, becoming resistant, they are often again treated with TMZ. As an alternative treatment, irinotecan could be used. Our aim was to examine to what extent and conditions the topoisomerase I inhibitor irinotecan induces senescence and to analyze the underlying mechanism.

RESULTS

Multiple glioblastoma lines with different genetic signatures for p53, p21CIP1, p16INK4A, p14ARF, and PTEN were used. By means of LN229 glioblastoma clones which escaped from temozolomide-induced senescence, thus, being potentially recurrence-forming, we show that this escape is accompanied by increased p21CIP1 protein levels in temozolomide-unexposed senescence-evading clones and inability of temozolomide to induce p21CIP1. In contrast, irinotecan was still able to induce p21CIP1 and could elevate senescence and cell death. In combination with the senolytic drug BV6, irinotecan-induced senescence was significantly reduced. Differential response clusters were also observed in paired samples of newly diagnosed and recurrent patients' tumors. This can partially explain a significantly prolonged progression-free time until surgery for recurrence in patients additionally treated with irinotecan after temozolomide consolidation and upon the first onset of recurrence.

CONCLUSIONS

p21CIP1 is essentially involved in induction and maintenance of irinotecan-induced senescence. Neither p16INK4A, p14ARF, nor PTEN contribute to senescence, if p21CIP1 cannot be induced. Based on the positive results of the irinotecan/BV6 treatment, combatting recurrent glioblastomas by targeting senescence cell antiapoptotic pathways (SCAPs) should be considered.

Decoding senescence of aging single cells at the nexus of biomaterials, microfluidics, and spatial omics

Aging has profound effects on the body, most notably an increase in the prevalence of several diseases. An important aging hallmark is the presence of senescent cells that no longer multiply nor die off properly. Another characteristic is an altered immune system that fails to properly self-surveil. In this multi-player aging process, cellular senescence induces a change in the secretory phenotype, known as senescence-associated secretory phenotype (SASP), of many cells with the intention of recruiting immune cells to accelerate the clearance of these damaged senescent cells. However, the SASP phenotype results in inducing secondary senescence of nearby cells, resulting in those cells becoming senescent, and improper immune activation resulting in a state of chronic inflammation, called inflammaging, in many diseases. Senescence in immune cells, termed immunosenescence, results in further dysregulation of the immune system. An interdisciplinary approach is needed to physiologically assess aging changes of the immune system at the cellular and tissue level. Thus, the intersection of biomaterials, microfluidics, and spatial omics has great potential to collectively model aging and immunosenescence. Each of these approaches mimics unique aspects of the body undergoes as a part of aging. This perspective highlights the key aspects of how biomaterials provide non-cellular cues to cell aging, microfluidics recapitulate flow-induced and multi-cellular dynamics, and spatial omics analyses dissect the coordination of several biomarkers of senescence as a function of cell interactions in distinct tissue environments. An overview of how senescence and immune dysregulation play a role in organ aging, cancer, wound healing, Alzheimer's, and osteoporosis is included. To illuminate the societal impact of aging, an increasing trend in anti-senescence and anti-aging interventions, including pharmacological interventions, medical procedures, and lifestyle changes is discussed, including further context of senescence.