Senescent Cells in Cancer Therapy: Friends or Foes?

Temporal regulation of gene expression and pathways in chemotherapy-induced senescence in HeLa cervical cancer cell line

Cellular senescence is the state of permanent growth arrest. Chemotherapeutic drugs induce senescence, known as therapy-induced senescence. Although there are studies deciphering processes in senescence, more studies providing detailed information on therapy-induced senescence at the transcriptome level are needed. In order to understand temporal molecular changes of doxorubicin treatment in the course of senescence formation, two data sets from HeLa cells at 16 h and 72 h doxorubicin treatment were analyzed. GO BP enrichment, KEGG pathways and hub genes specific to or shared between 16 h and 72 h doxorubicin treated HeLa cells were identified. Genes functioning in p53 signaling were upregulated only in 16 h, while genes functioning in extracellular matrix organization were upregulated only in 72 h doxorubicin treated HeLa cells. Wound healing genes were gradually upregulated from 16 h to 72 h doxorubicin treatment and metabolic pathways were downregulated at both. ncRNA processing and ribosome biogenesis GO BP terms were enriched in upregulated genes at 16 h, while these terms were enriched in downregulated genes at 72 h senescent HeLa cells. According to our results, genes functioning in p53 signaling may be involved in the induction of senescence, but may not be required to maintain senescence in HeLa cells.

Cellular senescence-driven transcriptional reprogramming of the MAFB/NOTCH3 axis activates the PI3K/AKT pathway and promotes osteosarcoma progression

Osteosarcoma is the most common primary malignancy of bones and primarily occurs in adolescents and young adults. However, a second smaller peak of osteosarcoma incidence was reported in the elderly aged more than 60. Elderly patients with osteosarcoma exhibit different characteristics compared to young patients, which usually results in a poor prognosis. The mechanism underlying osteosarcoma development in elderly patients is intriguing and of significant value in clinical applications. Senescent cells can accelerate tumor progression by metabolic reprogramming. Recent research has shown that methylmalonic acid (MMA) was significantly up-regulated in the serum of older individuals and played a central role in the development of aggressive characteristics. We found that the significant accumulation of MMA in elderly patients imparted proliferative potential to osteosarcoma cells. The expression of MAFB was excessively up-regulated in osteosarcoma specimens and was further enhanced in response to MMA accumulation as the patient aged. Specifically, we first confirmed a novel molecular mechanism between cellular senescence and cancer, in which the MMA-driven transcriptional reprogramming of the MAFB-NOTCH3 axis accelerated osteosarcoma progression via the activation of PI3K-AKT pathways. Moreover, the down-regulation of the MAFB-NOTCH3 axis increased the sensitivity and effect of AKT inhibitors in osteosarcoma through significant inhibition of AKT phosphorylation. In conclusion, we confirmed that MAFB is a novel age-dependent biomarker for osteosarcoma, and targeting the MAFB-NOTCH3 axis in combination with AKT inhibition can serve as a novel therapeutic strategy for elderly patients with osteosarcoma in experimental and clinical trials.

Correlates of frailty in older female cancer survivors

INTRODUCTION

Cancer survivors are at risk of frailty because of cancer and its treatment. Understanding the factors that increase the risk of frailty is an important aspect of cancer care for the development of interventions to prevent or manage frailty, thus improving cancer survival and overall quality of life of cancer survivors. This study aimed to identify demographic, clinical, and psychosocial correlates of frailty in older, female cancer survivors.

MATERIALS AND METHODS

This is a sub-study focusing on the exploratory aim of a larger cross-sectional study (NURS-IIR-IUSCC-0748). A total of 213 female cancer survivors aged 59-87 years old were included from the parent study in the current analysis. Frailty, the primary outcome, was measured using the Tilburg Frailty Indicator scale. The independent variables were age, relationship status, clinical stage of cancer, treatment type, comorbidity, depression, affect, optimism, stress, and social support. Stepwise linear regression modeling identified the independent variables that were significantly associated with frailty.

RESULTS

The final regression model revealed that high patient-reported stress and depression, comorbidity, not being married or living with a partner, and low positive affect were significantly associated with worsening frailty in this population.

DISCUSSION

Understanding the context of frailty is important for the design of interventions that target factors known to be associated with frailty in older cancer survivors. Further validation with a larger and a more diverse sample from a broad spectrum of sociodemographic and clinical population would fully account for the multiple independent variables influencing frailty in cancer survivors.

Diverse temporal and spatial mechanisms work, partially through Stanniocalcin-1, V-ATPase and senescence, to activate the extracellular ATP-mediated drug resistance in human cancer cells

Introduction

Resistance to drug therapies is associated with a large majority of cancer-related deaths. ATP-binding cassette (ABC) transporter-mediated drug efflux, epithelial-mesenchymal transition (EMT), cancer stem cells (CSCs), glutathione (GSH), senescence, and vacuole-type ATPase (V-ATPase) all contribute to the resistance. We recently showed that extracellular ATP (eATP) induces and regulates EMT, CSC formation, and ABC transporters in human cancer cells and tumors. eATP also consistently upregulates Stanniocalcin-1 (STC1), a gene that significantly contributes to EMT, CSC formation, and tumor growth. We also found that eATP enhances drug resistance in cancer cells through eATP internalization mediated by macropinocytosis, leading to an elevation of intracellular ATP (iATP) levels, induction of EMT, and CSC formation. However, these factors have never been systematically investigated in the context of eATP-induced drug resistance.

Methods

In this study, we hypothesized that eATP increases drug resistance via inducing ABC efflux, EMT, CSCs, STC1, and their accompanied processes such as GSH reducing activity, senescence, and V-ATPase. RNA sequencing, metabolomics, gene knockdown and knockout, and functional assays were performed to investigate these pathways and processes.

Results and discussion

Our study results showed that, in multiple human cancer lines, eATP induced genes involved in drug resistance, elevated ABC transporters' efflux activity of anticancer drugs; generated transcriptomic and metabolic profiles representing a drug resistant state; upregulated activities of GSH, senescence, and V-ATPase to promote drug resistance. Collectively, these newly found players shed light on the mechanisms of eATP-induced as well as STC1- and V-ATPase-mediated drug resistance and offer potential novel targets for combating drug resistance in cancers.

Senolytics: from pharmacological inhibitors to immunotherapies, a promising future for patients' treatment

The involvement of cellular senescence in the initiation and propagation of diseases is clearly characterized, making the elimination of senescent cells essential to treat age-related diseases. The development of senolytic drugs demonstrated that targeting these cells limits the deterioration of patients' condition, by inducing apoptosis. Nevertheless, the first generations of senolytics which has been developed displayed their activities through specific mechanisms and demonstrated several limitations during clinical development. However, the rational to eliminate senescent cells remains evident, with the necessity to develop specific therapies in a context of diseases and tissues. The evolutions in the field of drug discovery open the way to a new generation of senolytic therapies, such as immunological approaches (CAR-T cells, Antibody-Drug Conjugated or vaccines), which require preliminary steps of research to identify markers specifically expressed on senescent cells, demonstrating promising specific effects. Currently, the preclinical development of these strategies appears more challenging to avoid strong side effects, but the expected results are commensurate with patients' hopes for treatments. In this review, we highlight the fact that the classical senolytic approach based on drug repurposing display limited efficacy and probably reached its limits in term of clinical development. The recent development of more complex therapies and the extension of interest in the domain of senescence in different fields of research allow to extend the possibility to discover powerful therapies. The future of age-related diseases treatment is linked to the development of new approaches based on cell therapy or immunotherapy to offer the best treatment for patients.

Modeling of senescence-related chemoresistance in ovarian cancer using data analysis and patient-derived organoids

Background

Ovarian cancer (OC) is a malignant tumor associated with poor prognosis owing to its susceptibility to chemoresistance. Cellular senescence, an irreversible biological state, is intricately linked to chemoresistance in cancer treatment. We developed a senescence-related gene signature for prognostic prediction and evaluated personalized treatment in patients with OC.

Methods

We acquired the clinical and RNA-seq data of OC patients from The Cancer Genome Atlas and identified a senescence-related prognostic gene set through differential and cox regression analysis in distinct chemotherapy response groups. A prognostic senescence-related signature was developed and validated by OC patient-derived-organoids (PDOs). We leveraged gene set enrichment analysis (GSEA) and ESTIMATE to unravel the potential functions and immune landscape of the model. Moreover, we explored the correlation between risk scores and potential chemotherapeutic agents. After confirming the congruence between organoids and tumor tissues through immunohistochemistry, we measured the IC50 of cisplatin in PDOs using the ATP activity assay, categorized by resistance and sensitivity to the drug. We also investigated the expression patterns of model genes across different groups.

Results

We got 2740 differentially expressed genes between two chemotherapy response groups including 43 senescence-related genes. Model prognostic genes were yielded through univariate cox analysis, and multifactorial cox analysis. Our work culminated in a senescence-related prognostic model based on the expression of SGK1 and VEGFA. Simultaneously, we successfully constructed and propagated three OC PDOs for drug screening. PCR and WB from PDOs affirmed consistent expression trends as those of our model genes derived from comprehensive data analysis. Specifically, SGK1 exhibited heightened expression in cisplatin-resistant OC organoids, while VEGFA manifested elevated expression in the sensitive group (P<0.05). Intriguingly, GSEA results unveiled the enrichment of model genes in the PPAR signaling pathway, pivotal regulator in chemoresistance and tumorigenesis. This revelation prompted the identification of potential beneficial drugs for patients with a high-risk score, including gemcitabine, dabrafenib, epirubicin, oxaliplatin, olaparib, teniposide, ribociclib, topotecan, venetoclax.

Conclusion

Through the formulation of a senescence-related signature comprising SGK1 and VEGFA, we established a promising tool for prognosticating chemotherapy reactions, predicting outcomes, and steering therapeutic strategies. Patients with high VEGFA and low SGK1 expression levels exhibit heightened sensitivity to chemotherapy.

Identification of a novel macrophage-related prognostic signature in colorectal cancer

Colorectal cancer (CRC) is one of the most prevalent and deadliest illnesses all around the world. Growing proofs demonstrate that tumor-associated macrophages (TAMs) are of critical importance in CRC pathogenesis, but their mechanisms remain yet unknown. The current research was designed to recognize underlying biomarkers associated with TAMs in CRC. We screened macrophage-related gene modules through WGCNA, selected hub genes utilizing the LASSO algorithm and COX regression, and established a model. External validation was performed by expression analysis using datasets GSE14333, GSE74602, and GSE87211. After validating the bioinformatics results using real-time quantitative reverse transcription PCR, we identified SPP1, C5AR1, MMP3, TIMP1, ADAM8 as potential biomarkers associated with macrophages in CRC.

Context-dependent role of SIRT3 in cancer

Sirtuin 3 (SIRT3), an NAD+-dependent deacetylase, plays a key role in the modulation of metabolic reprogramming and regulation of cell death, as well as in shaping tumor phenotypes. Owing to its critical role in determining tumor-type specificity or the direction of tumor evolution, the development of small-molecule modulators of SIRT3, including inhibitors and activators, is of significant interest. In this review, we discuss recent studies on the oncogenic or tumor-suppressive functions of SIRT3, evaluate advances in SIRT3-targeted drug discovery, and present potential avenues for the design of small-molecule modulators of SIRT3 for cancer therapy.

PARP1 at the crossroad of cellular senescence and nucleolar processes

Senescent cells that occur in response to telomere shortening, oncogenes, extracellular and intracellular stress factors are characterized by permanent cell cycle arrest, the morphological and structural changes of the cell that include the senescence-associated secretory phenotype (SASP) and nucleoli rearrangement. The associated DNA lesions induce DNA damage response (DDR), which activates the DNA repair protein - poly-ADP-ribose polymerase 1 (PARP1). This protein consumes NAD+ to synthesize ADP-ribose polymer (PAR) on its own protein chain and on other interacting proteins. The involvement of PARP1 in nucleoli processes, such as rRNA transcription and ribosome biogenesis, the maintenance of heterochromatin and nucleoli structure, as well as controlling the crucial DDR protein release from the nucleoli to nucleus, links PARP1 with cellular senescence and nucleoli functioning. In this review we describe and discuss the impact of PARP1-mediated ADP-ribosylation on early cell commitment to senescence with the possible role of senescence-induced PARP1 transcriptional repression and protein degradation on nucleoli structure and function. The cause-effect interplay between PARP1 activation/decline and nucleoli functioning during senescence needs to be studied in detail.

Suppression of Bcl3 Disrupts Viability of Breast Cancer Cells through Both p53-Dependent and p53-Independent Mechanisms via Loss of NF-κB Signalling

The NF-κB co-factor Bcl3 is a proto-oncogene that promotes breast cancer proliferation, metastasis and therapeutic resistance, yet its role in breast cancer cell survival is unclear. Here, we sought to determine the effect of Bcl3 suppression alone on breast cancer cell viability, with a view to informing future studies that aim to target Bcl3 therapeutically. Bcl3 was suppressed by siRNA in breast cancer cell lines before changes in viability, proliferation, apoptosis and senescence were examined. Bcl3 suppression significantly reduced viability and was shown to induce apoptosis in all cell lines tested, while an additional p53-dependent senescence and senescence-associated secretory phenotype was also observed in those cells with functional p53. The role of the Bcl3/NF-κB axis in this senescence response was confirmed via siRNA of the non-canonical NF-κB subunit NFKB2/p52, which resulted in increased cellular senescence and the canonical subunit NFKB1/p50, which induced the senescence-associated secretory phenotype. An analysis of clinical data showed a correlation between reduced relapse-free survival in patients that expressed high levels of Bcl3 and carried a p53 mutation. Together, these data demonstrate a dual role for Bcl3/NF-κB in the maintenance of breast cancer cell viability and suggests that targeting Bcl3 may be more beneficial to patients with tumours that lack functional p53.

Y-Box Binding Protein 1: Unraveling the Multifaceted Role in Cancer Development and Therapeutic Potential

Y-box binding protein 1 (YBX1), a member of the Cold Shock Domain protein family, is overexpressed in various human cancers and is recognized as an oncogenic gene associated with poor prognosis. YBX1's functional diversity arises from its capacity to interact with a broad range of DNA and RNA molecules, implicating its involvement in diverse cellular processes. Independent investigations have unveiled specific facets of YBX1's contribution to cancer development. This comprehensive review elucidates YBX1's multifaceted role in cancer across cancer hallmarks, both in cancer cell itself and the tumor microenvironment. Based on this, we proposed YBX1 as a potential target for cancer treatment. Notably, ongoing clinical trials addressing YBX1 as a target in breast cancer and lung cancer have showcased its promise for cancer therapy. The ramp up in in vitro research on targeting YBX1 compounds also underscores its growing appeal. Moreover, the emerging role of YBX1 as a neural input is also proposed where the high level of YBX1 was strongly associated with nerve cancer and neurodegenerative diseases. This review also summarized the up-to-date advanced research on the involvement of YBX1 in pancreatic cancer.

Immunosenescence and immunotherapy in older NSCLC patients

Nonsmall cell lung cancer (NSCLC) predominantly affects the elderly since its incidence and mortality rates skyrocket beyond the age of 65. The landscape of NSCLC treatment has been revolutionized by immune checkpoint inhibitors (ICIs), which have emerged after a long and mostly inactive period of conventional treatment protocols. However, there is limited data on the exact effects of these chemicals on older patients, whose care can be complicated by a variety of conditions. This highlights the need to understand the efficacy of emerging cancer medicines in older patients. In this study, we will review the data of ICIs from clinical trials that were relevant to older people with NSCLC and poor performance status. We will also discuss the role of immunosenescence in immunotherapy and biomarkers in predicting the efficacy of ICIs in patients with advanced NSCLC.

Implications of cellular senescence in paediatric pituitary tumours

The long-standing view of senescent cells as passive and dysfunctional biological remnants has recently shifted into a new paradigm where they are main players in the development of many diseases, including cancer. The senescence programme represents a first line of defence that prevents tumour cell growth but also leads to the secretion of multiple pro-inflammatory and pro-tumourigenic factors that fuel tumour initiation, growth, and progression. Here, we review the main molecular features and biological functions of senescent cells in cancer, including the outcomes of inducing or targeting senescence. We discuss evidence on the role of cellular senescence in pituitary tumours, with an emphasis on adamantinomatous craniopharyngioma (ACP) and pituitary adenomas. Although senescence has been proposed to be a tumour-preventing mechanism in pituitary adenomas, research in ACP has shown that senescent cells are tumour-promoting in both murine models and human tumours. Future studies characterizing the impact of targeting senescent cells may result in novel therapies against pituitary tumours.

Epigenetic and inflammatory markers in older adults with cancer: A Young International Society of Geriatric Oncology narrative review

The number of adults aged ≥ 65 years with cancer is rapidly increasing. Older adults with cancer are susceptible to treatment-related acute and chronic adverse events, resulting in loss of independence, reduction in physical function, and decreased quality of life. Nevertheless, evidence-based interventions to prevent or treat acute and chronic adverse events in older adults with cancer are limited. Several promising blood-based biomarkers related to inflammation and epigenetic modifications are available to identify older adults with cancer who are at increased risk of accelerated aging and physical, functional, and cognitive impairments caused by the cancer and its treatment. Inflammatory changes and epigenetic modifications can be reversible and targeted by lifestyle changes and interventions. Here we discuss ways in which changes in inflammatory and epigenetic pathways influence the aging process and how these pathways can be targeted by interventions aimed at reducing inflammation and aging-associated biological markers. As the number of older adults with cancer entering survivorship continues to increase, it is becoming progressively more important to understand ways in which the benefit from treatment can be enhanced while reducing the effects of accelerated aging.

Beyond cell cycle regulation: The pleiotropic function of CDK4 in cancer

CDK4, along with its regulatory subunit, cyclin D, drives the transition from G1 to S phase, during which DNA replication and metabolic activation occur. In this canonical pathway, CDK4 is essentially a transcriptional regulator that acts through phosphorylation of retinoblastoma protein (RB) and subsequent activation of the transcription factor E2F, ultimately triggering the expression of genes involved in DNA synthesis and cell cycle progression to S phase. In this review, we focus on the newly reported functions of CDK4, which go beyond direct regulation of the cell cycle. In particular, we describe the extranuclear roles of CDK4, including its roles in the regulation of metabolism, cell fate, cell dynamics and the tumor microenvironment. We describe direct phosphorylation targets of CDK4 and decipher how CDK4 influences these physiological processes in the context of cancer.

Delayed Reaction of Radiation on the Central Nervous System and Bone System in C57BL/6J Mice

The aim of this study was to provide a suitable mouse model of radiation-induced delayed reaction and identify potential targets for drug development related to the prevention and treatment of radiation injury. C57BL/6J mice were subjected to singular (109 cGy/min, 5 Gy*1) and fractional (109 cGy/min, 5 Gy*2) total body irradiation. The behavior and activity of mice were assessed 60 days after ionizing radiation (IR) exposure. After that, the pathological changes and mechanism of the mouse brain and femoral tissues were observed by HE, Nissl, Trap staining micro-CT scanning and RNA sequencing (RNA-Seq), and Western blot. The results show that singular or fractional IR exposure led to a decrease in spatial memory ability and activity in mice, and the cognitive and motor functions gradually recovered after singular 5 Gy IR in a time-dependent manner, while the fractional 10 Gy IR group could not recover. The decrease in bone density due to the increase in osteoclast number may be relative to the down-regulation of RUNX2, sclerostin, and beta-catenin. Meanwhile, the brain injury caused by IR exposure is mainly linked to the down-regulation of BNDF and Tau. IR exposure leads to memory impairment, reduced activity, and self-recovery, which are associated with time and dose. The mechanism of cognitive and activity damage was mainly related to oxidative stress and apoptosis induced by DNA damage. The damage caused by fractional 10 Gy TBI is relatively stable and can be used as a stable multi-organ injury model for radiation mechanism research and anti-radiation medicine screening.

Cellular Senescence in Liver Cancer: How Dying Cells Become "Zombie" Enemies

Liver cancer represents the fourth leading cause of cancer-associated death worldwide. The heterogeneity of its tumor microenvironment (TME) is a major contributing factor of metastasis, relapse, and drug resistance. Regrettably, late diagnosis makes most liver cancer patients ineligible for surgery, and the frequent failure of non-surgical therapeutic options orientates clinical research to the investigation of new drugs. In this context, cellular senescence has been recently shown to play a pivotal role in the progression of chronic inflammatory liver diseases, ultimately leading to cancer. Moreover, the stem-like state triggered by senescence has been associated with the emergence of drug-resistant, aggressive tumor clones. In recent years, an increasing number of studies have emerged to investigate senescence-associated hepatocarcinogenesis and its derived therapies, leading to promising results. In this review, we intend to provide an overview of the recent evidence that unveils the role of cellular senescence in the most frequent forms of primary and metastatic liver cancer, focusing on the involvement of this mechanism in therapy resistance.

Prognostic significance of senescence-related tumor microenvironment genes in head and neck squamous cell carcinoma

The impact of the senescence related microenvironment on cancer prognosis and therapeutic response remains poorly understood. In this study, we investigated the prognostic significance of senescence related tumor microenvironment genes (PSTGs) and their potential implications for immunotherapy response. Using the Cancer Genome Atlas- head and neck squamous cell carcinoma (HNSC) data, we identified two subtypes based on the expression of PSTGs, acquired from tumor-associated senescence genes, tumor microenvironment (TME)-related genes, and immune-related genes, using consensus clustering. Using the LASSO, we constructed a risk model consisting of senescence related TME core genes (STCGs). The two subtypes exhibited significant differences in prognosis, genetic alterations, methylation patterns, and enriched pathways, and immune infiltration. Our risk model stratified patients into high-risk and low-risk groups and validated in independent cohorts. The high-risk group showed poorer prognosis and immune inactivation, suggesting reduced responsiveness to immunotherapy. Additionally, we observed a significant enrichment of STCGs in stromal cells using single-cell RNA transcriptome data. Our findings highlight the importance of the senescence related TME in HNSC prognosis and response to immunotherapy. This study contributes to a deeper understanding of the complex interplay between senescence and the TME, with potential implications for precision medicine and personalized treatment approaches in HNSC.

Protocol for examining the capability of senescent tumor cells to stimulate murine bone-marrow-derived dendritic cells by flow cytometry

Therapy-induced senescence (TIS) may contribute to therapy resistance; however, evidence also suggests that senescent cells (SnCs) may promote anti-tumor immunity. Here, we present a protocol for examining the capability of TIS to stimulate type 1 conventional CD103+ dendritic cells (DCs). We describe steps for isolating and differentiating CD103+ DCs from murine bone marrow, inducing senescence in murine colon carcinoma cell line CT26, and coculturing DCs with SnCs. We then detail the flow cytometric analysis of DC maturation and activation. For complete details on the use and execution of this protocol, please refer to Liu et al. (2022)1 and Liu et al. (2023).2.

Effects of radiation therapy on tumor microenvironment: an updated review

ABSTRACT

Cancer is a major threat to human health and causes death worldwide. Research on the role of radiotherapy (RT) in the treatment of cancer is progressing; however, RT not only causes fatal DNA damage to tumor cells, but also affects the interactions between tumor cells and different components of the tumor microenvironment (TME), including immune cells, fibroblasts, macrophages, extracellular matrix, and some soluble products. Some cancer cells can survive radiation and have shown strong resistance to radiation through interaction with the TME. Currently, the complex relationships between the tumor cells and cellular components that play major roles in various TMEs are poorly understood. This review explores the relationship between RT and cell-cell communication in the TME from the perspective of immunity and hypoxia and aims to identify new RT biomarkers and treatment methods in lung cancer to improve the current status of unstable RT effect and provide a theoretical basis for further lung cancer RT sensitization research in the future.

Therapy-induced senescent tumor cells in cancer relapse

Cellular senescence is characterized by a generally irreversible cell cycle arrest and the secretion of bioactive factors known as the senescence-associated secretory phenotype (SASP). In an oncogenic context, senescence is considered a tumor suppressive mechanism as it prevents cell proliferation and inhibits the progression from pre-malignant to malignant disease. However, recent studies have demonstrated that senescent tumor cells, which could spontaneously exist within cancer tissues or arise in response to various cancer interventions (the so-called therapy-induced senescence, TIS), can acquire pro-tumorigenic properties and are capable of driving local and metastatic relapse. This highlights the complex and multifaceted nature of cellular senescence in cancer biology. Here, we summarize the current knowledge of the pathological function of therapy-induced senescent tumor cells and discuss possible mechanisms by which tumor cell senescence contributes to cancer relapse. We also discuss implications for future studies toward targeting these less appreciated cells.

Identification of a venetoclax-resistance prognostic signature base on 6-senescence genes and its clinical significance for acute myeloid leukemia

Background

Satisfactory responses can be obtained for acute myeloid leukemia (AML) treated by Venetoclax (VEN)-based therapy. However, there are still quite a few AML patients (AMLs) resistant to VEN, and it is critical to understand whether VEN-resistance is regulated by senescence.

Methods

Here, we established and validated a signature for predicting AML prognosis based on VEN resistance-related senescence genes (VRSGs). In this study, 51 senescence genes were identified with VEN-resistance in AML. Using LASSO algorithms and multiple AML cohorts, a VEN-resistance senescence prognostic model (VRSP-M) was developed and validated based on 6-senescence genes.

Results

According to the median score of the signature, AMLs were classified into two subtypes. A worse prognosis and more adverse features occurred in the high-risk subtype, including older patients, non-de novo AML, poor cytogenetics, adverse risk of European LeukemiaNet (ELN) 2017 recommendation, and TP53 mutation. Patients in the high-risk subtype were mainly involved in monocyte differentiation, senescence, NADPH oxidases, and PD1 signaling pathway. The model's risk score was significantly associated with VEN-resistance, immune features, and immunotherapy response in AML. In vitro, the IC50 values of ABT-199 (VEN) rose progressively with increasing expression of G6PD and BAG3 in AML cell lines.

Conclusions

The 6-senescence genes prognostic model has significant meaning for the prediction of VEN-resistance, guiding personalized molecularly targeted therapies, and improving AML prognosis.

Resistomycin Inhibits Wnt/β-Catenin Signaling to Induce the Apoptotic Death of Human Colorectal Cancer Cells

Resistomycin is a natural antibiotic related to quinone that has been shown to exhibit robust antitumor activity. To further characterize the mechanistic basis for such activity, human colorectal cancer (CRC) cells were selected as a model to explore the role of Wnt/β-catenin signaling in the ability of resistomycin to induce apoptotic cell death. These analyses revealed that resistomycin was able to suppress β-catenin, TCF4, and GSK-3β expression, together with that of the downstream targets c-Myc and survivin. This coincided with elevated cleaved caspase-3 and Bax protein levels and a decline in Bcl-2 content. When β-catenin was silenced, this further enhanced the ability of resistomycin to induce apoptotic CRC cell death, whereas this apoptotic process was partially ablated when cells were treated using lithium chloride to activate Wnt/β-catenin signaling. Overall, these results support a model wherein resistomycin inhibits Wnt/β-catenin signaling within CRC cells, thereby inducing apoptotic death. Further research may be warranted to better clarify the potential utility of this compound as a candidate drug for use in the treatment of patients suffering from this form of cancer.

Cellular senescence in brain aging and cognitive decline

Cellular senescence is a biological aging hallmark that plays a key role in the development of neurodegenerative diseases. Clinical trials are currently underway to evaluate the effectiveness of senotherapies for these diseases. However, the impact of senescence on brain aging and cognitive decline in the absence of neurodegeneration remains uncertain. Moreover, patient populations like cancer survivors, traumatic brain injury survivors, obese individuals, obstructive sleep apnea patients, and chronic kidney disease patients can suffer age-related brain changes like cognitive decline prematurely, suggesting that they may suffer accelerated senescence in the brain. Understanding the role of senescence in neurocognitive deficits linked to these conditions is crucial, especially considering the rapidly evolving field of senotherapeutics. Such treatments could help alleviate early brain aging in these patients, significantly reducing patient morbidity and healthcare costs. This review provides a translational perspective on how cellular senescence plays a role in brain aging and age-related cognitive decline. We also discuss important caveats surrounding mainstream senotherapies like senolytics and senomorphics, and present emerging evidence of hyperbaric oxygen therapy and immune-directed therapies as viable modalities for reducing senescent cell burden.

The Combination of Radiation with PARP Inhibition Enhances Senescence and Sensitivity to the Senolytic, Navitoclax, in Triple Negative Breast Tumor Cells

Despite significant advances in the treatment of triple-negative breast cancer, this disease continues to pose a clinical challenge, with many patients ultimately suffering from relapse. Tumor cells that recover after entering into a state of senescence after chemotherapy or radiation have been shown to develop a more aggressive phenotype, and to contribute to disease recurrence. By combining the PARP inhibitor (PARPi), talazoparib, with radiation, senescence was enhanced in 4T1 and MDA-MB-231 triple-negative breast cancer cell lines (based on SA-β-gal upregulation, increased expression of CDKN1A and the senescence-associated secretory phenotype (SASP) marker, IL6). Subsequent treatment of the radiation- and talazoparib-induced senescent 4T1 and MDA-MB231 cells with navitoclax (ABT-263) resulted in significant apoptotic cell death. In immunocompetent tumor-bearing mice, navitoclax exerted a modest growth inhibitory effect when used alone, but dramatically interfered with the recovery of 4T1-derived tumors induced into senescence with ionizing radiation and talazoparib. These findings support the potential utility of a senolytic strategy in combination with the radiotherapy/PARPi combination to mitigate the risk of disease recurrence in triple-negative breast cancer.

Doxorubicin-induced senescence promotes resistance to cell death by modulating genes associated with apoptotic and necrotic pathways in prostate cancer DU145 CD133+/CD44+ cells

Cancer stem cells (CSCs) are the most important cause of cancer treatment failure. Traditional cancer treatments, such as chemotherapy and radiotherapy, damage healthy cells alongside malignant cells, leading to severe adverse effects. Therefore, inducing cellular senescence without triggering apoptosis, which further damages healthy cells, may be an alternative strategy. However, there is insufficient knowledge regarding senescence induction in CSCs that show resistance to treatment and stemness properties. The present study aims to elucidate the effects of senescence induction on proliferation, cell cycle, and apoptosis in prostate CSCs and non-CSCs. Prostate CSCs were isolated from DU145 cancer cells using the FACS method. Subsequently, senescence induction was performed in RWPE-1, DU145, prostate CSCs, and non-CSCs by using different concentrations of Doxorubicin (DOX). Cellular senescence was detected using the senescence markers SA-β-gal, Ki67, and senescence-associated heterochromatin foci (SAHF). The effects of senescence on cell cycle and apoptosis were evaluated using the Muse Cell Analyzer, and genes in signaling pathways associated with the apoptotic/necrotic pathway were analyzed by real-time PCR. Prostate CSCs were isolated with 95.6 ± 1.4% purity according to CD133+/CD44+ characteristics, and spheroid formation belonging to stem cells was observed. After DOX-induced senescence, we observed morphological changes, SA-β-gal positivity, SAHF, and the lack of Ki67 in senescent cells. Furthermore; we detected G2/M cell cycle arrest and downregulation of various apoptosis-related genes in senescent prostate CSCs. Our results showed that DOX is a potent inducer of senescence for prostate CSCs, inhibits proliferation by arresting the cell cycle, and senescent prostate CSCs develop resistance to apoptosis.

Cellular senescence and ophthalmic diseases: narrative review

PURPOSE

Cellular senescence is a state of permanent growth arrest whereby a cell reaches its replicative limit. However, senescence can also be triggered prematurely in certain stressors including radiation, oxidative stress, and chemotherapy. This stress-induced senescence has been studied in the context of promoting inflammation, tumor development, and several chronic degenerative diseases of aging. Emerging research has elucidated the role of senescence in various ocular diseases.

METHODS

The literature search was performed using PubMed with using the query (senescence OR aging) AND (eye disease OR ocular disease OR ophthalmic disease OR cornea OR glaucoma OR cataract OR retina) on October 20th, 2022. No time restriction was proposed. Articles were excluded if they were not referenced in English.

RESULTS

Overall, 51 articles regarding senescence and ocular diseases were found and summarized in this study. Several signaling pathways have been implicated in the development of senescence. Currently, senescence has been linked to various corneal and retinal pathologies, as well as cataract and glaucoma. Given the number of pathologies, senolytics, which are small molecules with the ability to selective targeting of senescent cells, can be used as therapeutic or prophylactic agents.

CONCLUSIONS

Senescence has been shown to underlie the pathogenesis of numerous ocular diseases. The overall literature on senescence and ocular disease is growing rapidly. There is an ongoing debate whether or not cellular senescence detected in experiments contributes in a significant way to diseases. Research on understanding the mechanism of senescence from ocular cells and tissues is just beginning. Multiple animal models are required to test potential senolytics. Currently, no studies exist to date which have demonstrated the benefits of senolytic therapies in human studies.

DNA damage-mediated cellular senescence promotes hand-foot syndrome that can be relieved by thymidine prodrug

Hand-foot syndrome (HFS) is a widely recognized dose-limiting cutaneous toxicity effect of fluoropyrimidine chemotherapy agents that impairs clinical benefits and treatment outcomes. Even though the cause and pathophysiology of HFS are relatively widely reported, how the toxicity of fluoropyrimidine translates into persistent inflammation has not been studied. Additionally, prevention and treatment strategies for HFS based on its mechanistic occurrence and development are scarce. In our study, we demonstrated that cGAS-STING signaling pathway-mediated cellular senescence played a critical role in the inflammatory reaction and provided a therapeutic solution for HFS. Mechanistically, DNA damage, as the primary cytotoxic cause, in keratinocytes induces cell cycle arrest, activates the cGAS-STING signaling pathway, and subsequently mediates cellular senescence, ultimately fueling a robust secondary inflammatory response that results in HFS. More importantly, the thymidine prodrug thymidine diacetate was proven to be effective in preventing HFS by compensating for thymidylate deficiency to facilitate the replication and repair of DNA and thus causing the escape from cellular senescence. These data highlight the importance of DNA damage-mediated cellular senescence in the etiology of HFS and provide a potential therapeutic anchor point for fluoropyrimidine-induced HFS.

TRDMT1-mediated RNA C-5 methylation as a novel target in anticancer therapy

Affected landscape of RNA modifications is frequently observed in different cancer cells that can be associated with the development of cancer cell phenotypic traits such as sustained proliferation, migration and invasion, apoptosis resistance and metabolic reprograming. DNMT2/TRDMT1 5-methylcytosine methyltransferase, initially classified as DNA methyltransferase, can methylate both tRNA and mRNA promoting tRNA stability and proper protein synthesis, and orchestrating DNA damage response (DDR) and DNA stability, respectively. TRDMT1 is associated with cancer progression as its levels can be elevated and its mutations can be observed in a number of cancer types. TRDMT1 gene knockout (KO) can sensitize cancer cells of different origin to radiotherapy and chemotherapy. In the present review paper, based on literature data, the physiological and pathophysiological roles of TRDMT1 in different biological systems are described with the emphasis on human normal and cancer cells. Potential TRDMT1 substrates, inhibitors and regulatory mechanisms of catalytic activity and cellular localization are also presented and evaluated. TRDMT1 as a novel promising target in anticancer therapy is proposed and discussed.

Therapy-induced senescence as a component of tumor biology: Evidence from clinical cancer

Therapy-Induced Senescence (TIS) is an established response to anticancer therapy in a variety of cancer models. Ample evidence has characterized the triggers, hallmarks, and functional outcomes of TIS in preclinical studies; however, limited evidence delineates TIS in clinical cancer (human tumor samples). We examined the literature that investigated the induction of TIS in samples derived from human cancers and highlighted the major findings that suggested that TIS represents a main constituent of tumor biology. The most frequently utilized approach to identify TIS in human cancers was to investigate the protein expression of senescence-associated markers (such as cyclins, cyclin-dependent kinase inhibitors, Ki67, DNA damage repair response markers, DEC1, and DcR1) via immunohistochemical techniques using formalin-fixed paraffin-embedded (FFPE) tissue samples and/or testing the upregulation of Senescence-Associated β-galactosidase (SA-β-gal) in frozen sections of unfixed tumor samples. Collectively, and in studies where the extent of TIS was determined, TIS was detected in 31-66% of tumors exposed to various forms of chemotherapy. Moreover, TIS was not only limited to both malignant and non-malignant components of tumoral tissue but was also identified in samples of normal (non-transformed) tissue upon chemo- or radiotherapy exposure. Nevertheless, the available evidence continues to be limited and requires a more rigorous assessment of in vivo senescence based on novel approaches and more reliable molecular signatures. The accurate assessment of TIS will be beneficial for determining its relevant contribution to the overall outcome of cancer therapy and the potential translatability of senotherapeutics.

Tumour-suppressive effects of curcumin analogs CCA-1.1 and Pentagamavunone-1 in colon cancer: In vivo and in vitro studies

This study aimed to evaluate the efficacy of Chemoprevention Curcumin Analog-1.1 (CCA-1.1) and Pentagamavunone-1 (PGV-1) in vivo and in vitro in colorectal cancer model. CCA-1.1 or PGV-1 was administered orally to 1,2-dimethylhydrazine (DMH)-induced rats for 16 weeks. The cytotoxicity of both compounds was tested on Caco-2, CT26, and NIH/3T3 cells using the MTT method. The cell cycle, apoptosis, and reactive oxygen species (ROS) levels were analyzed through flow cytometry. X-gal staining was used to examine the compound's effect on senescence. Oral co-administration of CCA-1.1 or PGV-1 significantly suppressed the carcinogenic characteristics and symptoms of premalignant colon cancer relative to DMH-only and untreated groups. CCA-1.1 and PGV-1 administration did not affect the blood profile. CCA-1.1 and PGV-1 demonstrated great cytotoxicity on Caco-2 and CT26 cells, with 50% inhibition concentration (IC50) values of 4.3 ± 0.2 and 3.1 ± 0.1 µM for CCA-1.1 and 11.2 ± 1.1 and 4.8 ± 0.1 µM for PGV-1, respectively, while not toxic against fibroblast cells. Both compounds instigated G2/M arrest and efficiently induced cell senescence and apoptosis. Moreover, these analogs selectively elevated oxidative stress in colon cancer cells without inducing noticeable changes in fibroblasts. In conclusion, PGV-1 and CCA-1.1 suppressed colorectal tumor formation and induced mitotic arrest.

Peficitinib ameliorates 5-fluorouracil-induced intestinal damage by inhibiting aging, inflammatory factors and oxidative stress

5-Fluorouracil (5-FU) is a conventional and effective drug for colorectal cancer patients, and it is an important part of combined chemotherapy and adjuvant chemotherapy. Chemotherapy intestinal mucositis (CIM) is a severe side effect caused by 5-FU that, induces cancer treatment failure and affects patients' quality of life. The mechanism of 5-FU-induced CIM is related to normal cell senescence induced by 5-FU. Peficitinib, a Janus Kinase (JAK) inhibitor, treats inflammatory disorders, including rheumatoid arthritis, psoriasis, and inflammatory bowel disease. However, the therapeutic role and underlying mechanism of peficitinib in CIM remain unclear. The main objective of our research was to investigate the effects of peficitinib on 5-FU-induced senescence and intestinal damage in human umbilical vein endothelial (HUVEC) cells, human intestinal epithelial (HIEC) cells and BABL/C mice. The results showed that 5-FU caused intestinal damage by inducing aging and increasing inflammation and oxidative stress. Peficitinib alleviated aging by reducing senescence-beta-galactosidase (SA-β-gal) activity and the protein levels of aging indicators (p53, p21, p16). Moreover, peficitinib reversed the changes in senescence-associated secretory phenotype (SASP) expression caused by 5-FU. Besides, 5-FU induced release of inflammatory factors and oxidative stress indicators was reversed by peficitinib. Additionally, the combination of peficitinib and 5-FU reinforced the anticancer curative intent of 5-FU in two colorectal cancer cell lines (HCT116 cells and SW620 cells). In conclusion, peficitinib alleviates mucositis by alleviating aging, reducing inflammatory accumulation and oxidative stress and enhancing the antitumor activity of 5-FU.

A mini-review on anticancer-related properties of azithromycin and its potential activities in overcoming the challenges of glioblastoma

The resistance, plasticity and heterogeneity of cancer cells, including glioblastoma (GB) cells, have prompted the investigation of various agents for possible adjuncts and alternatives to existing therapies. This includes a macrolide antibiotic, azithromycin (AZI). It possesses intriguing anticancer properties in a range of cancer models in vitro, such as antiproliferative, pro-apoptotic, anti-autophagy and anti-angiogenic effects. In fact, AZI is renowned for its ability to eradicate cancer stem cells by inhibiting mitochondrial biogenesis and respiration. AZI-containing regimens in cancer patients for different purposes have shown favourable (i.e., attributed to its antibacterial activity) and unfavourable outcomes. Whilst its direct anticancer effects have yet to be clinically proven. To that end, this review provides a summary of AZI anticancer studies and delineates its potential activities in overcoming the challenges of GB.

NOXA expression is downregulated in human breast cancer undergoing incomplete pathological response and senescence after neoadjuvant chemotherapy

Neoadjuvant chemotherapy (NAC) is a frequently utilized approach to treat locally advanced breast cancer, but, unfortunately, a subset of tumors fails to undergo complete pathological response. Apoptosis and therapy-induced senescence (TIS) are both cell stress mechanisms but their exact role in mediating the pathological response to NAC is not fully elucidated. We investigated the change in expression of PAMIP1, the gene encoding for the pro-apoptotic protein, NOXA, following NAC in two breast cancer gene datasets, and the change in NOXA protein expression in response to NAC in 55 matched patient samples (pre- and post-NAC). PAMIP1 expression significantly declined in post-NAC in the two sets, and in our cohort, 75% of the samples exhibited a downregulation in NOXA post-NAC. Matched samples that showed a decline in NOXA post-NAC were examined for TIS based on a signature of downregulated expression of Lamin-B1 and Ki-67 and increased p16INK4a, and the majority exhibited a decrease in Lamin B1 (66%) and Ki-67 (80%), and increased p16INK4a (49%). Since our cohort consisted of patients that did not develop complete pathological response, such findings have clinical implications on the role of TIS and NOXA downregulation in mediating suboptimal responses to the currently established NAC.

Cellular senescence: a double-edged sword in cancer therapy

Over the past few decades, cellular senescence has been identified in cancer patients undergoing chemotherapy and radiotherapy. Senescent cells are generally characterized by permanent cell cycle arrest as a response to endogenous and exogenous stresses. In addition to exiting the cell cycle process, cellular senescence also triggers profound phenotypic changes such as senescence-associated secretory phenotype (SASP), autophagy modulation, or metabolic reprograming. Consequently, cellular senescence is often considered as a tumor-suppressive mechanism that permanently arrests cells at risk of malignant transformation. However, accumulating evidence shows that therapy-induced senescence can promote epithelial-mesenchymal transition and tumorigenesis in neighboring cells, as well as re-entry into the cell cycle and activation of cancer stem cells, thereby promoting cancer cell survival. Therefore, it is particularly important to rapidly eliminate therapy-induced senescent cells in patients with cancer. Here we review the hallmarks of cellular senescence and the relationship between cellular senescence and cancer. We also discuss several pathways to induce senescence in tumor therapy, as well as strategies to eliminate senescent cells after cancer treatment. We believe that exploiting the intersection between cellular senescence and tumor cells is an important means to defeat tumors.

Resveratrol affects ccRCC cell senescence and macrophage polarization by regulating the stability of CCNB1 by RBM15

Aim: The present study sought to investigate the therapeutic effect of resveratrol on clear cell renal cell carcinoma. Materials & methods: Cell Counting Kit-8 and 5-ethynyl-2'-deoxyuridine assays were used to verify the cell proliferation. Transwell, real-time quantitative transcription PCR, western blot and β-galactosidase staining were used to verify the migration, macrophage polarization and senescence. The tumor inhibitory effect of resveratrol on clear cell renal cell carcinoma was verified in vivo. Results: This study confirmed that resveratrol could affect the stability of CCNB1 mRNA mediated by RBM15 and inhibit the cancer process by inhibiting the expression of EP300/CBP from the perspective of cell senescence. Conclusion: Resveratrol is able to treat clear cell renal cell carcinoma through RBM15-induced cell senescence.

LncRNA NEAT1 suppresses cellular senescence in hepatocellular carcinoma via KIF11-dependent repression of CDKN2A

BACKGROUND

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. Therapeutic options for advanced HCC are limited, which is due to a lack of full understanding of pathogenesis. Cellular senescence is a state of cell cycle arrest, which plays important roles in the pathogenesis of HCC. Mechanisms underlying hepatocellular senescence are not fully understood. LncRNA NEAT1 acts as an oncogene and contributes to the development of HCC. Whether NEAT1 modulates hepatocellular senescence in HCC is unknown.

METHODS

The role of NEAT1 and KIF11 in cellular senescence and tumor growth in HCC was assessed both in vitro and in vivo. RNA pulldown, mass spectrometry, Chromatin immunoprecipitation (ChIP), luciferase reporter assays, RNA FISH and immunofluorescence (IF) staining were used to explore the detailed molecular mechanism of NEAT1 and KIF11 in cellular senescence of HCC.

RESULTS

We found that NEAT1 was upregulated in tumor tissues and hepatoma cells, which negatively correlated with a senescence biomarker CDKN2A encoding p16INK4a and p14ARF proteins. NEAT1 was reduced in senescent hepatoma cells induced by doxorubicin (DOXO) or serum starvation. Furthermore, NEAT1 deficiency caused senescence in cultured hepatoma cells, and protected against the progression of HCC in a mouse model. During senescence, NEAT1 translocated into cytosol and interacted with a motor protein KIF11, resulting in KIF11 protein degradation and subsequent increased expression of CDKN2A in cultured hepatoma cells. Furthermore, KIF11 knockdown caused senescence in cultured hepatoma cells. Genetic deletion of Kif11 in hepatocytes inhibited the development of HCC in a mouse model.

CONCLUSIONS

Conclusively, NEAT1 overexpression reduces senescence and promotes tumor progression in HCC tissues and hepatoma cells, whereas NEAT1 deficiency causes senescence and inhibits tumor progression in HCC. This is associated with KIF11-dependent repression of CDKN2A. These findings lay the foundation to develop potential therapies for HCC by inhibiting NEAT1 and KIF11 or inducing senescence.

Cell Survival, Death, and Proliferation in Senescent and Cancer Cells: the Role of (Poly)phenols

Cellular senescence has long been considered a permanent state of cell cycle arrest occurring in proliferating cells subject to different stressors, used as a cellular defense mechanism from acquiring potentially harmful genetic faults. However, recent studies highlight that senescent cells might also alter the local tissue environment and concur to chronic inflammation and cancer risk by secreting inflammatory and matrix remodeling factors, acquiring a senescence-associated secretory phenotype (SASP). Indeed, during aging and age-related diseases, senescent cells amass in mammalian tissues, likely contributing to the inevitable loss of tissue function as we age. Cellular senescence has thus become one potential target to tackle age-associated diseases as well as cancer development. One important aspect characterizing senescent cells is their telomere length. Telomeres shorten as a consequence of multiple cellular replications, gradually leading to permanent cell cycle arrest, known as replicative senescence. Interestingly, in the large majority of cancer cells, a senescence escape strategy is used and telomere length is maintained by telomerase, thus favoring cancer initiation and tumor survival. There is growing evidence showing how (poly)phenols can impact telomere maintenance through different molecular mechanisms depending on dose and cell phenotypes. Although normally, (poly)phenols maintain telomere length and support telomerase activity, in cancer cells this activity is negatively modulated, thus accelerating telomere attrition and promoting cancer cell death. Some (poly)phenols have also been shown to exert senolytic activity, thus suggesting both antiaging (directly eliminating senescent cells) and anticancer (indirectly, via SASP inhibition) potentials. In this review, we analyze selective (poly)phenol mechanisms in senescent and cancer cells to discriminate between in vitro and in vivo evidence and human applications considering (poly)phenol bioavailability, the influence of the gut microbiota, and their dose-response effects.

Regulatory miRNAs in cancer cell recovery from therapy exposure and its implications as a novel therapeutic strategy for preventing disease recurrence

The desired outcome of cancer therapies is the eradication of disease. This can be achieved when therapy exposure leads to therapy-induced cancer cell death as the dominant outcome. Theoretically, a permanent therapy-induced growth arrest could also contribute to a complete response, which has the potential to lead to remission. However, preclinical models have shown that therapy-induced growth arrest is not always durable, as recovering cancer cell populations can contribute to the recurrence of cancer. Significant research efforts have been expended to develop strategies focusing on the prevention of recurrence. Recovery of cells from therapy exposure can occur as a result of several cell stress adaptations. These include cytoprotective autophagy, cellular quiescence, a reversable form of senescence, and the suppression of apoptosis and necroptosis. It is well documented that microRNAs regulate the response of cancer cells to anti-cancer therapies, making targeting microRNAs therapeutically a viable strategy to sensitization and the prevention of recovery. We propose that the use of microRNA-targeting therapies in prolonged sequence, that is, a significant period after initial therapy exposure, could reduce toxicity from the standard combination strategy, and could exploit new epigenetic states essential for cancer cells to recover from therapy exposure. In a step toward supporting this strategy, we survey the available scientific literature to identify microRNAs which could be targeted in sequence to eliminate residual cancer cell populations that were arrested as a result of therapy exposure. It is our hope that by successfully identifying microRNAs which could be targeted in sequence we can prevent disease recurrence.

Tissue factor is a critical regulator of radiation therapy-induced glioblastoma remodeling

Radiation therapy (RT) provides therapeutic benefits for patients with glioblastoma (GBM), but inevitably induces poorly understood global changes in GBM and its microenvironment (TME) that promote radio-resistance and recurrence. Through a cell surface marker screen, we identified that CD142 (tissue factor or F3) is robustly induced in the senescence-associated β-galactosidase (SA-βGal)-positive GBM cells after irradiation. F3 promotes clonal expansion of irradiated SA-βGal+ GBM cells and orchestrates oncogenic TME remodeling by activating both tumor-autonomous signaling and extrinsic coagulation pathways. Intratumoral F3 signaling induces a mesenchymal-like cell state transition and elevated chemokine secretion. Simultaneously, F3-mediated focal hypercoagulation states lead to activation of tumor-associated macrophages (TAMs) and extracellular matrix (ECM) remodeling. A newly developed F3-targeting agent potently inhibits the aforementioned oncogenic events and impedes tumor relapse in vivo. These findings support F3 as a critical regulator for therapeutic resistance and oncogenic senescence in GBM, opening potential therapeutic avenues.

P. aeruginosa interactions with other microbes in biofilms during co-infection

This review addresses the topic of biofilms, including their development and the interaction between different counterparts. There is evidence that various diseases, such as cystic fibrosis, otitis media, diabetic foot wound infections, and certain cancers, are promoted and aggravated by the presence of polymicrobial biofilms. Biofilms are composed by heterogeneous communities of microorganisms protected by a matrix of polysaccharides. The different types of interactions between microorganisms gives rise to an increased resistance to antimicrobials and to the host's defense mechanisms, with the consequent worsening of disease symptoms. Therefore, infections caused by polymicrobial biofilms affecting different human organs and systems will be discussed, as well as the role of the interactions between the gram-negative bacteria Pseudomonas aeruginosa, which is at the base of major polymicrobial infections, and other bacteria, fungi, and viruses in the establishment of human infections and diseases. Considering that polymicrobial biofilms are key to bacterial pathogenicity, it is fundamental to evaluate which microbes are involved in a certain disease to convey an appropriate and efficacious antimicrobial therapy.

IL-1β is involved in docetaxel chemoresistance by regulating the formation of polyploid giant cancer cells in non-small cell lung cancer

Docetaxel (Doc) is a cornerstone of chemotherapy; however, treatment with Doc often and inevitably leads to drug resistance and the formation of polyploid giant cancer cells (PGCCs). In this study, we investigated the effect of Doc on non-small cell lung cancer to explore the role of PGCCs in drug resistance and the molecular mechanisms that regulate this resistance. We found that Doc induced G2/M cell cycle arrest and cell death in A549 and NCI-H1299 cells. However, many cells remained alive and became PGCCs by decreasing the expression of key regulatory proteins related to the cell cycle and proliferation. Notably, the PGCCs showed typical features of senescence, especially upregulation of p21 and p-histone H2A.X expression. Moreover, the mRNA level of IL-1β in the senescence-associated secretory phenotype was increased significantly with the development of PGCCs. Inhibition of IL-1β reduced the expression of p-histone H2A.X and promoted polyploidy to enhance the proapoptotic effect of Doc. Taken together, our results suggested that IL-1β was involved in the formation of PGCCs and regulated the senescence of PGCCs, which contributed to drug resistance to Doc. Therefore, targeting IL-1β in PGCCs may be a novel approach to overcome drug resistance.

Inhibition of EZH2 alleviates SAHA-induced senescence-associated secretion phenotype in small cell lung cancer cells

Chemotherapy has been widely used in small cell lung cancer (SCLC) treatment in the past decades. However, SCLC is easy to recur after chemotherapy. The senescence of cancer cells during chemotherapy is one of the effective therapeutic strategies to inhibit the progression of cancer. Nevertheless, the senescence-associated secretion phenotype (SASP) promotes chronic inflammation of the cancer microenvironment and further accelerates the progression of tumors. Therefore, inducing the senescence of cancer cells and inhibiting the production of SASP factors during anticancer treatment have become effective therapeutic strategies to improve the anticancer effect of drugs. Here we reported that SCLC cells treated with an FDA-approved HDAC inhibitor SAHA underwent senescence and displayed remarkable SASP. In particular, SAHA promoted the formation of cytoplasmic chromatin fragments (CCFs) in SCLC cells. The increased CCFs in SAHA-treated SCLC cells were related to nuclear porin Tpr, which activated the cGAS-STING pathway, and promoted the secretion of SASP in cancer cells. Inhibition of EZH2 suppressed the increase of CCFs in SAHA-treated SCLC cells, weakened the production of SASP, and increased the antiproliferative effect of SAHA. Overall, our work affords new insight into the secretion of SASP in SCLC and establishes a foundation for constructing a new therapeutic strategy for SCLC patients.

Cellular senescence in glioma

INTRODUCTION

Glioma is the most common primary brain tumor and is often associated with treatment resistance and poor prognosis. Standard treatment typically involves radiotherapy and temozolomide-based chemotherapy, both of which induce cellular senescence-a tumor suppression mechanism.

DISCUSSION

Gliomas employ various mechanisms to bypass or escape senescence and remain in a proliferative state. Importantly, senescent cells remain viable and secrete a large number of factors collectively known as the senescence-associated secretory phenotype (SASP) that, paradoxically, also have pro-tumorigenic effects. Furthermore, senescent cells may represent one form of tumor dormancy and play a role in glioma recurrence and progression.

CONCLUSION

In this article, we delineate an overview of senescence in the context of gliomas, including the mechanisms that lead to senescence induction, bypass, and escape. Furthermore, we examine the role of senescent cells in the tumor microenvironment and their role in tumor progression and recurrence. Additionally, we highlight potential therapeutic opportunities for targeting senescence in glioma.

Modelling the dynamics of senescence spread

Cellular senescence is a cell surveillance mechanism that arrests the cell cycle in damaged cells. The senescent phenotype can spread from cell to cell through paracrine and juxtacrine signalling, but the dynamics of this process are not well understood. Although senescent cells are important in ageing, wound healing and cancer, it is unclear how the spread of senescence is contained in senescent lesions. In the absence of the immune system, senescence could theoretically spread infinitely from one cell to another, but this contradicts experimental evidence. To investigate this issue, we developed both a minimal mathematical model and a stochastic simulation of senescence spread. Our results suggest that differences in the number of signalling molecules secreted between subtypes of senescent cells can limit the spread of senescence. We found that dynamic, time-dependent paracrine signalling prevents the uncontrolled spread of senescence, and we demonstrate how model parameters can be determined using Bayesian inference in a proposed experiment.

Autophagy Inhibition with Chloroquine Increased Pro-Apoptotic Potential of New Aziridine-Hydrazide Hydrazone Derivatives against Glioblastoma Cells

Tumor therapy escape due to undesired side effects induced by treatment, such as prosurvival autophagy or cellular senescence, is one of the key mechanisms of resistance that eventually leads to tumor dormancy and recurrence. Glioblastoma is the most frequent and practically incurable neoplasm of the central nervous system; thus, new treatment modalities have been investigated to find a solution more effective than the currently applied standards based on temozolomide. The present study examined the newly synthesized compounds of aziridine-hydrazide hydrazone derivatives to determine their antineoplastic potential against glioblastoma cells in vitro. Although the output of our investigation clearly demonstrates their proapoptotic activity, the cytotoxic effect appeared to be blocked by treatment-induced autophagy, the phenomenon also detected in the case of temozolomide action. The addition of an autophagy inhibitor, chloroquine, resulted in a significant increase in apoptosis triggered by the tested compounds, as well as temozolomide. The new aziridine-hydrazide hydrazone derivatives, which present cytotoxic potential against glioblastoma cells comparable to or even higher than that of temozolomide, show promising results and, thus, should be further investigated as antineoplastic agents. Moreover, our findings suggest that the combination of an apoptosis inducer with an autophagy inhibitor could optimize chemotherapeutic efficiency, and the addition of an autophagy inhibitor should be considered as an optional adjunctive therapy minimizing the risk of tumor escape from treatment.

Reshaping of the tumor microenvironment by cellular senescence: An opportunity for senotherapies

Cellular senescence is a stress response associated with aging and disease, including cancer. Senescent cells undergo a stable cell cycle arrest, undergo a change in morphology and metabolic reprogramming, and produce a bioactive secretome termed the senescence-associated secretory phenotype (SASP). In cancer, senescence is an important barrier to tumor progression. Induction of senescence in preneoplastic cells limits cancer initiation, and many cancer therapies act in part by inducing senescence in cancer cells. Paradoxically, senescent cells lingering in the tumor microenvironment (TME) can contribute to tumor progression, metastasis, and therapy resistance. In this review, we discuss the different types of senescent cells present in the TME and how these senescent cells and their SASP reshape the TME, affect immune responses, and influence cancer progression. Furthermore, we will highlight the importance of senotherapies, including senolytic drugs that eliminate senescent cells and impede tumor progression and metastasis by restoring anti-tumor immune responses and influencing the TME.

Reduced YAP1 and FOLR1 in gliomas predict better response to chemotherapeutics

Gliomas harbouring mutations in IDH1 (isocitrate dehydrogenase 1) are characterized by greater sensitivity to chemotherapeutics. These mutants also exhibit diminished levels of transcriptional coactivator YAP1 (yes-associated protein 1). Enhanced DNA damage in IDH1 mutant cells, as evidenced by γH2AX formation (phosphorylation of histone variant H2A.X) and ATM (serine/threonine kinase; ataxia telangiectasia mutated) phosphorylation, was accompanied by reduced FOLR1 (folate receptor 1) expression. Diminished FOLR1, concomitant with heightened γH2AX levels, was also observed in patient-derived IDH1 mutant glioma tissues. Chromatin immunoprecipitation, overexpression of mutant YAP1, and treatment with YAP1-TEAD (TEA domain transcription factors) complex inhibitor verteporfin demonstrated regulation of FOLR1 expression by YAP1 and its partner transcription factor TEAD2. TCGA (The Cancer Genome Atlas) data analysis demonstrated better patient survival with reduced FOLR1 expression. Depletion of FOLR1 rendered IDH1 wild-type gliomas more susceptible to temozolomide-mediated death. Despite heightened DNA damage, IDH1 mutants exhibited reduced levels of IL6 (interleukin 6) and IL8 (interleukin 8) - pro-inflammatory cytokines known to be associated with persistent DNA damage. While both FOLR1 and YAP1 influenced DNA damage, only YAP1 was involved in regulating IL6 and IL8. ESTIMATE and CIBERSORTx analyses revealed the association between YAP1 expression and immune cell infiltration in gliomas. By identifying the influence of YAP1-FOLR1 link in DNA damage, our findings suggest that simultaneous depletion of both could amplify the potency of DNA damaging agents, while concomitantly reducing the release of inflammatory mediators and potentially affecting immune modulation. This study also highlights the novel role of FOLR1 as a probable prognostic marker in gliomas, predicting responsiveness to temozolomide and other DNA damaging agents.

WNT-Conditioned Mechanism of Exit from Postchemotherapy Shock of Differentiated Tumour Cells

BACKGROUND

the present study aims to prove or disprove the hypothesis that the state of copy number aberration (CNA) activation of WNT signalling pathway genes accounts for the ability of differentiated tumour cells to emerge from postchemotherapy shock.

METHODS

In the first step, the CNA genetic landscape of breast cancer cell lines BT-474, BT-549, MDA-MB-231, MDA-MD-468, MCF7, SK-BR-3 and T47D, which were obtained from ATCC, was examined to rank cell cultures according to the degree of ectopic activation of the WNT signalling pathway. Then two lines of T47D with ectopic activation and BT-474 without activation were selected. The differentiated EpCAM+CD44-CD24-/+ cells of these lines were subjected to IL6 de-differentiation with formation of mammospheres on the background of cisplatin and WNT signalling inhibitor ICG-001.

RESULTS

it was found that T47D cells with ectopic WNT signalling activation after cisplatin exposure were dedifferentiated to form mammospheres while BT-474 cells without ectopic WNT-signalling activation did not form mammospheres. The dedifferentiation of T47D cells after cisplatin exposure was completely suppressed by the WNT signalling inhibitor ICG-001. Separately, ICG-001 reduced, but did not abolish, the ability to dedifferentiate in both cell lines.

CONCLUSIONS

these data support the hypothesis that the emergence of differentiated tumour cells from postchemotherapy shock after chemotherapy is due to ectopic activation of WNT signalling pathway genes.