Cell Survival Research Articles (Page 1)

Injectable PROTAC-loaded hydrogel remodels the tumor microenvironment to potentiate radio-immunotherapy.

Clinical and epidemiological studies suggest similarities in dysregulation of pathways in type 2 diabetes (T2DM) and Parkinson's disease (PD). Efficacy of several antidiabetic drugs has been tested in PD. Exenatide, a synthetic version of exendin-4, an incretin-mimetic drug, is an agonist of glucagon-like peptide 1 receptor (GLP1R) and is approved for the treatment of T2DM. Exenatide can cross the blood-brain barrier and exerts neuroprotective and neurorestorative effects via GLP1R at doses similar to those used in T2DM, resulting in improved motor performance, behaviour, learning and memory in different rodent PD models. Reports in human PD patients have also shown promise. In this work, we carried out substitution at the fourteenth position of exenatide (M14) with basic, acidic and nonpolar residues and investigated their effect on aggregation of recombinant human α-synuclein in vitro and in SH-SY5Y cells. Molecular dynamic (MD) simulation studies showed altered stability of α-synuclein upon substitution at M14 in exenatide. Exenatide had no effect on aggregation of α-synuclein in vitro. The M14K mutant, which stabilized α-synuclein, prolonged lag time and caused significant reduction in aggregation. On the contrary, aggregation of α-synuclein was significantly attenuated in SH-SY5Y cells in the presence of exenatide for all mutants tested, with a concomitant increase in cell survival. Flow cytometric analysis suggested induction of autophagy in the presence of the peptides, explaining the reduction in protein aggregation. Thus, mutants of exenatide could be investigated further as inhibitors of aggregation of α-synuclein.

We studied the distribution and survival of mesenchymal stem cells (MSCs) transplanted within a fibrin hydrogel into the spinal cord of immunocompetent rats without spinal cord injury (SCI) and with contusion SCI within the first hours after injury. MSC migration was monitored by MRI, and cell survival was assessed by immunofluorescence and immunohistochemistry on spinal cord sections. It was shown that transplanted allogeneic MSCs remain viable for at least 7 days in case of intrafocal administration 30 min after experimental contusion SCI and for at least 28 days in case of subdural and intramedullary transplantation into the intact spinal cord. MSCs are predominantly located at the injection site. Thus, our data demonstrate that allogeneic MSCs transplanted into the SCI site in the acute phase can survive for at least 7 days without migrating into surrounding tissues.

NF2-related schwannomatosis (NF2-SWN) is a genetic predisposition to develop multiple schwannomas that cause serious neurological disabilities for which there are no approved drug therapies. We previously reported that the MEK inhibitor trametinib slowed schwannoma growth in two mouse models, however, ERK reactivation was observed. Pathway analysis of the proteome of trametinib-treated mouse schwannoma model cells predicted activation of BRD4. To elucidate the adaptive mechanisms contributing to cell survival, we studied the trametinib response in novel immortalized and non-immortalized human schwannoma model cells (MD-HSCs). MD-HSCs exposed to trametinib avoid cell death by upregulating expression of ECM and cell adhesion proteins resulting in an increase in cell size, stress fiber formation, and a switch from c-Jun to Krox20/Egr2 nuclear expression. We demonstrate that BET proteins mediate the survival response to trametinib in MD-HSCs. Preventing this epigenetic adaptation to trametinib with BET inhibitors induces schwannoma cell death. However, this response is not observed when BET inhibitors are combined with brigatinib, a multi-kinase inhibitor in clinical use. These findings highlight the complex cellular adaptations in schwannomas and suggest that targeting BET alongside MEK inhibition prevents resistance mechanisms and promotes cell death.

Epstein-Barr virus (EBV) is a potent oncogenic virus capable of manipulating cell death and cell survival pathways in order to persist in human B cells. Since the discovery of EBV in Burkitt's lymphoma cells in 1964, cell culture has played an important role in uncovering EBV's ability to overcome cell death pathways such as apoptosis and ferroptosis. Whilst apoptosis is a genetically defined and developmentally regulated non-immunogenic cell death program, ferroptosis is a mode of necrotic cell death that is closely linked to amino acid, lipid, redox, energy, selenium, and iron metabolism. Such cell culture studies have not only played a pivotal role in our understanding of the role of EBV in growth transformation and cancer but have also enriched knowledge in the fields of cell death. Artificial in vitro cell culture conditions including (i) oxygen partial pressure, (ii) media composition, (iii) cell density, (iv) cell-, and (v) pH-homo- versus heterogeneity have profound effects on cell growth and responses to death stimuli. In fact, a search for pro-survival genes in Burkitt's lymphoma cells plated at low cell density in FCS-supplemented RPMI1640 medium had revealed two genes, glutathione peroxidase-4 (GPX4) and ferroptosis-suppressor protein-1 (FSP1), that are now well-known master regulators protecting cells from ferroptosis. Here we review those early fundamental studies and reflect on the subsequent literature that seeks to understand how EBV viral products can modulate cellular pathways during transformation and oncogenesis, reducing the requirement for mutations in cellular genes that are found more commonly in EBV-negative Burkitt's lymphomas.

The B-cell Lymphoma 2 (BCL-2) family of proteins plays a fundamental role in maintaining the balance between cell survival and apoptosis, processes that are frequently manipulated by oncogenic viruses. This review explores the contribution of BCL-2 family members to the pathogenesis of deltaretroviruses, with emphasis on Human T-cell Leukemia Virus type 1 (HTLV-1) and Bovine Leukemia Virus (BLV). Both viruses employ viral oncoproteins such as Tax and HBZ (HTLV-1) or their BLV homologs to upregulate anti-apoptotic proteins, including BCL-2, BCL-xL (B-cell Lymphoma-extra Large), MCL-1 (Myeloid Cell Leukemia 1), and Bfl-1, while suppressing pro-apoptotic counterparts such as BCL-2-Associated X Protein ( BAX ), BIM (BCL-2-Interacting Mediator of Cell Death), and BID (BH3-Interacting Domain Death Agonist). This dysregulation prolongs the survival of infected lymphocytes and promotes clonal expansion, genomic instability, and malignant transformation. Importantly, studies demonstrate that BLV and HTLV-1 infection induce resistance to programmed cell death in lymphoid and even non-lymphoid cells, highlighting apoptosis evasion as a central mechanism of viral persistence. Therapeutically, BCL-2 family inhibition has shown promise in sensitizing transformed cells to apoptosis. Small-molecule inhibitors such as ABT-737 and Navitoclax, kinase inhibitors targeting NF-κB (Nuclear Factor kappa-light-chain-enhancer of Activated B Cells) and JAK/STAT (Janus Kinase/Signal Transducer and Activator of Transcription) pathways, and natural compounds including fucoxanthin, peridinin, and thymoquinone have demonstrated the ability to overcome apoptosis resistance in preclinical models. Recent strategies combining MCL-1 inhibitors with antiretroviral therapy or immune checkpoint blockade further highlight the translational potential of targeting BCL-2 pathways. Collectively, the evidence positions the BCL-2 family as a critical determinant of deltaretroviral persistence and leukemogenesis, and as a promising therapeutic axis for the development of novel treatments for HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) and BLV-associated leukosis.

PI3Kα is a lipid kinase that regulates cell growth and survival via the PI3Kα/Akt pathway. As a peripheral membrane protein, PI3Kα is activated at the membrane, however, its active conformation remains unknown. To investigate how PI3Kα and its most prevalent oncogenic mutation, H1047R, interact with the membrane, we performed Molecular Dynamics simulations of active-like PI3Kα WT and H1047R mutant in complex with HRAS on a model membrane. Our simulations reveal that the H1047R mutation enhances substrate coordination, promotes catalytic interactions, and induces an open C-terminal conformation that stabilizes the protein on the membrane. Moreover, H1047R strengthens allosteric coupling between the C-terminus and membrane-binding loop 2 in both solution and membrane-bound states. WT and mutant proteins adopt distinct conformational ensembles on the membrane, enabling structure-based prediction of allosteric pockets at the protein-membrane interface. These findings offer a mechanistic basis for the H1047R enhanced membrane-binding ability and insights for new therapeutic strategies targeting the protein-membrane interface.

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality worldwide, highlighting the critical need for the development of innovative and effective therapeutic strategies. Baicalein, a bioactive flavonoid derived from Scutellaria baicalensis, has emerged as a promising anticancer agent with multifaceted effects against colorectal cancer. This work summarizes into the molecular and immunomodulatory mechanisms underlying baicalein's anticancer activity. Baicalein inhibits proliferation, suppresses metastasis, induces apoptosis, and modulates key pathways like PI3K/Akt, MAPK, and TLR4/NF-κB. It enhances the tumor microenvironment by promoting immune cell infiltration, regulating cytokines, and activating CD4 + and CD8 + T cells, amplifying antitumor immunity. By targeting critical oncogenic and immune pathways, baicalein disrupts tumor progression while simultaneously enhancing immune recognition and suppressing tumor-promoting mechanisms in CRC. Additionally, baicalein influences redox homeostasis by modulating reactive oxygen species (ROS) generation and restoring oxidative balance, thereby impacting cancer cell survival and proliferation. Its anti-oxidative properties further mitigate tumor-promoting oxidative stress while sensitizing CRC cells to apoptosis. Baicalein have poor solubility and rapid metabolism limits its effectiveness against colorectal cancer, where nanotechnology-based drug delivery can overcome these challenges. By using nanoparticles (NP) and other nano-carriers to improve stability, targeting, and controlled release, baicalein's anticancer potency and safety can be significantly enhanced for future CRC therapies. Thus, baicalein-NP conjugates can strengthen the immune defense and blocks cancer-promoting signals in colorectal cancer.

The pregnane X receptor (Pxr) regulates metabolism and inflammation, but its roles in bone homeostasis remain elusive. This study demonstrates that Pxr deficiency in bones induces osteoporotic phenotypes, with reduced trabecular bone mass, impaired osteogenesis, increased inflammation, and apoptosis. RNA sequencing reveals downregulation of the PI3K/Akt signaling pathway in Pxr-deficient bones, a key pathway linked to cell survival and differentiation. In vitro, primary bone marrow mesenchymal stem cells (BMSCs) with Pxr deficiency exhibited inhibited antioxidant enzyme activity, elevated intracellular reactive oxygen species level, activated pro-inflammatory cytokines, suppressed PI3K/Akt pathway, enhanced apoptosis, and decreased osteogenic differentiation. Conversely, Pxr overexpression in BMSCs from aged mice restores PI3K/Akt activation, mitigates apoptosis, and rescues osteogenic differentiation, with these multidirectional beneficial effects abrogated by a PI3K/Akt inhibitor. Moreover, both genetical overexpression of Pxr and pharmacological activation of Pxr improve bone quality in aged mice. These findings identify Pxr as a key regulator of bone homeostasis via the PI3K/Akt pathway, suggesting Pxr as a potential treatment target for age-related bone loss.

Parkinson's disease (PD) is a neurodegenerative pathology characterized by movement-associated symptoms due to the selective loss of dopaminergic neurons in the substantia nigra pars compacta. Autophagy is an essential mechanism that restores homeostasis and promotes cell survival. Mutations in the Leucine-Rich Repeat Kinase 2 (LRRK2) gene are among the most common in the familial cases. The LRRK2 E193K mutation falls in the Armadillo (ARM) domain and modifies LRRK2 interactome. The role of LRRK2 in autophagy has been widely explored, but the impact of E193K mutation on autophagy remains unknown. We found that the E193K variant increases autophagy in primary fibroblasts obtained from an E193K carrier. By cryo-based electron microscopy we observed that E193K fibroblasts present a higher amount of phagophores/autophagosomes. We showed that LRRK2 binds to the Dynein-1 complex, an essential regulator of retrograde transport of autophagosomes. Noteworthy, the E193K mutation jeopardizes this interaction and increases the cellular sensitivity to 1-methyl-4-phenylpyridinium (MPP+) toxin in fibroblasts as well as in a heterologous cell model. Our study reveals that the LRRK2 E193K variant influences the autophagic regulation and suggests that the dysregulation of the LRRK2-Dynein-1 complex causes autophagic defects and, eventually, cell death.

Alzheimer's disease (AD) is a neurodegenerative disorder that lacks effective treatments and urgently requires innovative therapeutic strategies. Although stem cell therapy has demonstrated efficacy in preclinical and clinical studies, it faces challenges such as low cell survival (<5%) and uncontrolled glial differentiation. This study aims to develop a 3D-bioprinted neural patch to enhance stem cell therapy for AD. The hypothesis is that a supportive bioengineered microenvironment would improve cell integration and neuronal differentiation, leading to functional recovery. A tri-component bioink (gelatin/alginate/fibrinogen) is created with tunable printability, biocompatibility, and biodegradation, establishing functional transplantation microenvironments for a 3D-printed human induced pluripotent stem cell (hiPSC)-derived neural progenitor cell (NPC) construct as a hippocampal patch. The system (TTBT) maintains NPC survival and promotes neuronal differentiation, neurite development, and calcium signaling in vitro. In AD-like rats, these constructs improved cell retention (3.41-fold over suspensions), enhanced neuron (79.21±6.67%vs 65.08±7.14%) and GABAergic neuron (29.85±7.69%vs 15.93±10.33%) differentiation, and restored long-term potentiation (LTP) to 97.89%±19.84% of healthy control levels. Behavioral tests also show memory improvement, particularly in the Morris water maze. This 3D-printed therapy not only holds potential for enhancing stem cell treatments but also addresses other 3D brain defects.

Phosphorus is one of the crucial elements required for the proper functioning of metabolic processes in microalgae. Despite the crucial role of phosphate (P), the dynamics of polyphosphate accumulation with respect to nutrient availability remain unknown in freshwater microalgae. We have investigated three freshwater microalgal strains - Chlorella pyrenoidosa, Scenedesmus obliquus, and Chlamydomonas reinhardtii under varied phosphate treatments to understand the phosphate metabolic responses and polyphosphate dynamics. Our results show that the accumulation of polyP in microalgae is very dynamic and mainly depends on the availability of extracellular phosphate. Reduced P availability showed algal species-specific reduction in the polyphosphate storage with a decline in growth and total chlorophyll content. Further, an increase in lipid and carbohydrate content with a substantial decrease in protein was observed under P stress, suggesting preferential utilization of stored polyP to support cell survival. Species-specific differences in the fatty acid profiles were also observed in the GC analysis among all three algal strains, indicating varied mechanisms happening among the species to adapt and protect themselves against cellular damage under P stress. Our results suggest the existence of natural variability among the selected algal strains in their ability to accumulate polyP and metabolites with respect to P-varied conditions. Among the three microalgal species, Scenedesmus obliquus showed notably enhanced accumulation of polyphosphate, highlighting its potential application as P-rich biofertilizer.

The variation of the oxygen enhancement ratio (OER) across linear energy transfer (LET) currently lacks a comprehensive mechanistic interpretation and a mechanistic model. Our earlier research revealed a significant correlation between the distribution of double-strand breaks (DSBs) within 3D genome and radiation-induced cell death, which offers valuable insights into the oxygen effect. We propose a model where the reaction of oxygen is represented as the probability of inducing DNA strand breaks. Then it is integrated into a track-structure Monte Carlo simulation to investigate the impact of oxygen on the distribution of DSBs within 3D genome. Using the parameters from our previous study, we calculate the OER values related to cell survival. Results show that the incidence ratios of clustered DSBs within a single topologically associating domain (TAD) (case 2) and within frequently interacting TADs (case 3) under aerobic and hypoxic conditions align with the trend in the OER of cell survival across LET. Our OER curves exhibit good correspondence with experimental data. This study provides a potentially mechanistic explanation for changes in OER across LET. High-LET irradiation leads to dense ionization events, resulting in an overabundance of lesions that readily induce case 2 and case 3, which have substantially higher probabilities of cell killing than other damage patterns. This may contribute to the main mechanism governing the variation of OER for high LET. Our study further underscores the importance of the DSB distribution within 3D genome in the context of radiation-induced cell death.

Metabolic pathways are typically dysregulated in cancer to support critical cellular processes. In response to metabolic disturbances, cancer cells preferentially manipulate stress sensors to enhance their adaptability. Sestrin 2 (SESN2), a highly conserved protein induced by various stressors, is implicated in this adaptation. Mutations and alterations of SESN2 are prevalent among cancer patients, suggesting a potential role in tumor progression. However, the functions and regulation of SESN2 in cancer, particularly in virus-induced cancer, remain largely unknown. In this study, we demonstrate that latent infection with Kaposi's sarcoma-associated herpesvirus (KSHV) stabilizes and upregulates SESN2 by inhibiting its proteasomal degradation across multiple cell lines. Notably, KSHV-encoded vCyclin, a homolog of cellular Cyclin D, directly interacts with SESN2 and promotes its stabilization by recruiting the deubiquitinase OTUB1, thereby blocking SESN2 polyubiquitination and proteasomal degradation. Moreover, vCyclin- and OTUB1-mediated stabilization of SESN2 activates AMP-activated protein kinase (AMPK), which supports the survival and growth of KSHV-driven primary effusion lymphoma cells. Importantly, the lysine at residue 74 of vCyclin is crucial for its cytosolic localization, OTUB1 recruitment, and subsequent SESN2 upregulation and AMPK activation. These findings unveil a regulatory mechanism for SESN2 involving vCyclin and OTUB1, positioning them as potential therapeutic targets for diseases associated with AMPK dysregulation.

Extrahepatic cholangiocarcinoma (eCCA) is a highly malignant tumor with a propensity for metastasis, reflected in its estimated 5-year survival rate of 11%. Metastasis greatly impairs the effectiveness of cancer therapies and increases cancer-related deaths. Therefore, gaining an understanding of the complex metastatic process is essential for development of effective treatments. Metastasis progression involves remodeling of the tumor microenvironment (TME) and the formation of pre-metastatic niches (PMNs), facilitating the migration and survival of tumor cells from the primary site to distant locations. As the eCCA progresses, immune cells, fibroblasts and endothelial cells in the TME are gradually converted to a tumor-supportive phenotype, coordinating tumor metastasis through intercellular interactions. Recent studies have confirmed that bile, a body fluid in close contact with eCCA, is also involved in the formation of supportive TME and tumor metastasis. On the other hand, primary tumors construct PMNs conducive to cancer cell colonization in distant organs prior to metastatic tumor formation through paracrine effects. This review aimed to summarize the mechanisms by which TME and PMNs drive eCCA metastasis, current treatment strategies for metastatic eCCA, and prospects for future research.

Acquisition of resistance to anti-cancer therapies is a multistep process initiated by the survival of drug-tolerant persister cells. Accessibility of drug-tolerant persister cells in patients is limited, which has hindered understanding the mechanisms driving their emergence. Here, using multiple patient-derived models to isolate persister cells, we showed that these cells are transcriptionally plastic in vivo and return to a common treatment naïve-like state upon relapse, regardless of treatment. Hallmarks of the persister state in TNBC across treatment modalities included high expression of basal keratins together with activation of stress response and inflammation pathways. These hallmarks were also activated in HER2+ breast and lung cancer cells in response to targeted therapies. Analysis of gene regulatory networks identified AP-1, NF-κB and IRF/STAT as the key drivers of this hallmark persister state. Functionally, FOSL1, an AP-1 member, drove cells to the persister state by binding enhancers and reprogramming the transcriptome of cancer cells. On the contrary, cancer cells without FOSL1 had a decreased ability to reach the persister state. By defining hallmarks of TNBC persistence on multiple therapies, this study provides a resource to design effective combination therapeutic strategies that limit resistance.

Small cell lung cancer (SCLC) is an aggressive neuroendocrine tumour with limited treatment options and a poor prognosis. Hypoxia, a hallmark of solid tumours, contributes to therapeutic resistance and tumour progression. Gastrin-releasing peptide receptor (GRPR) is known to be overexpressed in SCLC; however, its regulation under hypoxic conditions is not well described. In this study, we demonstrate that hypoxia significantly enhances GRPR expression in SCLC cell lines, COR-L24 and DMS79, as confirmed by Western blot, immunofluorescence, and flow cytometric analysis of binding with fluorescein isothiocyanate–labelled bombesin (BBN-FITC), a known GRPR ligand. To exploit this upregulation, we synthesised a previously discovered butylated neuropeptide antagonist (BU peptide) using a new method of solid-phase peptide synthesis (SPPS) by Boc chemistry and evaluated its therapeutic potential. BU peptide exhibited potent, dose-dependent cytotoxicity in both cell lines, with significantly greater efficacy under hypoxic conditions compared to normoxia. Mechanistic studies revealed that BU peptide inhibits GRP–GRPR-mediated activation of the PI3K/Akt and MAPK/ERK signalling pathways, known to be key regulators of tumour cell survival and proliferation. Moreover, BU peptide induced robust caspase 3/7-mediated apoptosis, especially under hypoxic conditions. These findings suggest that GRPR is a hypoxia-inducible target in SCLC and demonstrate that a synthetically optimised BU peptide antagonist exerts selective efficacy against hypoxic tumour cells, outperforming conventional chemotherapy agents. These findings provide new mechanistic insights into SCLC and suggest translational potential to inform the development of future treatment strategies for this and other hypoxia-driven malignancies.

Therapies targeting BRAF can inhibit the development of melanoma with BRAF mutations and enhance survival rates, though acquired resistance inevitably arises. The non-receptor tyrosine kinase Fyn, recognized for its role in regulating tumor cell survival and drug resistance, has emerged as a promising therapeutic target in melanoma treatment. In this study, we conducted a virtual screening and identified TAE684 as a potent inhibitor of Fyn. Utilizing in vitro assays, including assessments of cell viability, reactive oxygen species (ROS) production and DNA damage, alongside an in vivo melanoma xenograft model, we demonstrated that either TAE684 treatment or Fyn knockdown resulted in increased ROS levels and DNA damage, ultimately inducing cell cycle arrest at the G2/M phase and apoptosis in melanoma cells. Significantly, the application of TAE684 in melanoma cells demonstrated a capacity to counteract vemurafenib resistance, presumably through the down-regulation of the AP-1 pathway. Furthermore, the combination of TAE684 with vemurafenib exhibits a synergistic effect, leading to decreased cell viability in melanoma cells resistant to vemurafenib treatment. These results highlight the potential of TAE684 as a dual-function agent that not only inhibits melanoma proliferation but also reverses resistance to vemurafenib by targeting Fyn, thereby establishing it as a promising candidate for melanoma therapy.

Chromodomain helicase DNA-binding protein 8 (CHD8), a frequently mutated gene in autism spectrum disorder (ASD), is an ATP-dependent chromatin remodeler with emerging roles in hematopoiesis. While CHD8 is known to maintain hematopoietic stem and progenitor cells (HSPCs) in the bone marrow, its function during developmental hematopoiesis remains undefined. Here, using a zebrafish model, we demonstrate that chd8 loss severely depletes the HSPC pool in the caudal hematopoietic tissue through a p53-dependent apoptotic mechanism. Furthermore, chd8−/− embryos exhibit a p53-independent expansion of myelopoiesis. chd8 deficiency upregulates brd4, which promotes systemic inflammatory cytokine expression. Inhibiting brd4 alleviates cytokine expression, suppresses excessive myelopoiesis, and restores HSPC development. Our findings reveal a dual regulatory mechanism in which chd8 governs HSPC development by repressing p53-mediated apoptosis and constraining brd4-driven immune cell differentiation.

Abstract Bioprinting is a manufacturing method that enables the precise deposition of bioinks in the three-dimensional environment based on a digitally created model. In cancer modelling, bioprinting has the potential to produce complex, multicellular, and reproducible biological constructs. However, optimizing bioprinting processes remains a significant challenge. This study presents a new multi-technology bioprinter concept that combines the Extrusion-Based bioprinting (EBB) with Digital Light Processing (DLP), enabling the fabrication of highly accurate biological constructs. To validate the technology, various process parameters –including feed rate, flow rate and DLP curing time– were analysed. Hydrogels composed of a seaweed polysaccharide and gelatin methacryloyl (Bioink 1) and a tuber-derived polysaccharide and gelatin methacryloyl (Bioink 2) with MDA-MB-231 or MDA-MB-468 cells were prepared. Prior to printing, cytocompatibility was assessed through an MTT assay. Dimensional accuracy varying flow rate and feed rate was assessed on a bioink with similar viscosity. Based on previous results, Bioink 1 and MDA-MB-231 were used to print constructs with varying process parameters and cell viability was assessed. Results indicate that cytocompatibility is influenced by cell type, bioink composition and culture duration, while printing parameters have no relevant impact on cell viability, although lower feed rates slightly influence cell survival. Consequently, this study demonstrates that the optimization of printing parameters can significantly improve cell viability and structural integrity, highlighting the potential of this approach as a promising tool for advancing cancer modeling.