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Apoptosis is regulated cell death that depends on caspases. A specific initiator caspase is involved upstream of each apoptotic signaling pathway. Characterized in nematode, fly, and mammals, intrinsic apoptosis is considered to be ancestral, conserved among animals, and depends on shared initiators: caspase-9, Apaf-1 and Bcl-2. However, the biochemical role of mitochondria, the pivotal function of cytochrome c and the modality of caspase activation remain highly heterogeneous and hide profound molecular divergence among apoptotic pathways in animals. Uncovering the phylogenetic history of apoptotic actors, especially caspases, is crucial to shed light on the evolutionary history of intrinsic apoptosis. Here, we demonstrate with phylogenetic analyses that caspase-9, the fundamental key of intrinsic apoptosis, is deuterostome-specific, while caspase-2 is ancestral to bilaterians. Our analysis of Bcl-2 and Apaf-1 confirms heterogeneity in functional organization of apoptotic pathways in animals. Our results support emergence of distinct intrinsic apoptotic pathways during metazoan evolution. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) is one of the most common cancers among women. Effective treatment requires precise tailoring to the genetic makeup of the cancer for improved efficacy. Numerous research studies have concentrated on natural compounds and their anti-breast cancer properties to improve the existing treatment options. Chromolaena tacotana (Klatt) R.M. King and H. Rob (Ch. tacotana) is a notable source of bioactive hydroxy-methylated flavonoids. However, the specific anti-BC mechanisms of these flavonoids, particularly those present in the plant's inflorescences, remain partly undefined. This study focuses on assessing a chalcone derivative extracted from Ch. tacotana inflorescences for its potential to concurrently activate regulated autophagy and intrinsic apoptosis in luminal A and triple-negative BC cells. We determined the chemical composition of the chalcone using ultraviolet (UV) and nuclear magnetic resonance (NMR) spectroscopy. Its selective cytotoxicity against BC cell lines was assessed using the MTT assay. Flow cytometry and Western blot analysis were employed to examine the modulation of proteins governing autophagy and the intrinsic apoptosis pathway. Additionally, in silico simulations were conducted to predict interactions between chalcone and various anti-apoptotic proteins, including the mTOR protein. Chalcone was identified as 2′,4-dihydroxy-4′,6′-dimethoxy-chalcone (DDC). This compound demonstrated a selective inhibition of BC cell proliferation and triggered autophagy and intrinsic apoptosis. It induced cell cycle arrest in the G0/G1 phase and altered mitochondrial outer membrane potential (∆ψm). The study detected the activation of autophagic LC3-II and mitochondrial pro-apoptotic proteins in both BC cell lines. The regulation of Bcl-XL and Bcl-2 proteins varied according to the BC subtype, yet they showed promising molecular interactions with DDC. Among the examined pro-survival proteins, mTOR and Mcl-1 exhibited the most favorable binding energies and were downregulated in BC cell lines. Further research is needed to fully understand the molecular dynamics involved in the activation and interaction of autophagy and apoptosis pathways in cancer cells in response to potential anticancer agents, like the hydroxy-methylated flavonoids from Ch. tacotana. [ABSTRACT FROM AUTHOR]

Abstract Background Mycobacterium tuberculosis is the causative agent of tuberculosis (TB), and its pathogenicity is associated with its ability to evade the host defense system. The secretory form of the chorismate mutase of M. tuberculosis (TBCM, encoded by Rv1885c) is assumed to play a key role in the pathogenesis of TB; however, the mechanism remains unknown. Methods A tbcm deletion mutant (B∆tbcm) was generated by targeted gene knockout in BCG to investigate the pathogenic role of TBCM in mice or macrophages. We compared the pathogenesis of B∆tbcm and wild-type BCG in vivo by measuring the bacterial clearance rate and the degree of apoptosis. Promotion of the intrinsic apoptotic pathway was evaluated in infected bone marrow-derived macrophages (BMDMs) by measuring apoptotic cell death, loss of mitochondrial membrane potential and translocation of pore-forming proteins. Immunocytochemistry, western blotting and real-time PCR were also performed to assess the related protein expression levels after infection. Furthermore, these findings were validated by complementation of tbcm in BCG. Results Deletion of the tbcm gene in BCG leads to reduced pathogenesis in a mouse model, compared to wild type BCG, by promoting apoptotic cell death and bacterial clearance. Based on these findings, we found that intrinsic apoptosis and mitochondrial impairment were promoted in B∆tbcm-infected BMDMs. B∆tbcm down-regulates the expression of Bcl-2, which leads to mitochondrial outer membrane permeabilization (MOMP), culminating in cytochrome c release from mitochondria. Consistent with this, transcriptome profiling also indicated that B∆tbcm infection is more closely related to altered mitochondrial-related gene expression than wild-type BCG infection, suggesting an inhibitory role of TBCM in mitochondrial dysfunction. Moreover, genetic complementation of B∆tbcm (C∆tbcm) restored its capacity to inhibit mitochondria-mediated apoptotic cell death. Conclusions Our findings demonstrate the contribution of TBCM to bacterial survival, inhibiting intrinsic apoptotic cell death of macrophages as a virulence factor of M. tuberculosis complex (MTBC) strains, which could be a potential target for the development of TB therapy.

Background: Mycobacterium tuberculosis is the causative agent of tuberculosis (TB), and its pathogenicity is associated with its ability to evade the host defense system. The secretory form of the chorismate mutase of M. tuberculosis (TBCM, encoded by Rv1885c) is assumed to play a key role in the pathogenesis of TB; however, the mechanism remains unknown. Methods: A tbcm deletion mutant (B∆tbcm) was generated by targeted gene knockout in BCG to investigate the pathogenic role of TBCM in mice or macrophages. We compared the pathogenesis of B∆tbcm and wild-type BCG in vivo by measuring the bacterial clearance rate and the degree of apoptosis. Promotion of the intrinsic apoptotic pathway was evaluated in infected bone marrow-derived macrophages (BMDMs) by measuring apoptotic cell death, loss of mitochondrial membrane potential and translocation of pore-forming proteins. Immunocytochemistry, western blotting and real-time PCR were also performed to assess the related protein expression levels after infection. Furthermore, these findings were validated by complementation of tbcm in BCG. Results: Deletion of the tbcm gene in BCG leads to reduced pathogenesis in a mouse model, compared to wild type BCG, by promoting apoptotic cell death and bacterial clearance. Based on these findings, we found that intrinsic apoptosis and mitochondrial impairment were promoted in B∆tbcm-infected BMDMs. B∆tbcm down-regulates the expression of Bcl-2, which leads to mitochondrial outer membrane permeabilization (MOMP), culminating in cytochrome c release from mitochondria. Consistent with this, transcriptome profiling also indicated that B∆tbcm infection is more closely related to altered mitochondrial-related gene expression than wild-type BCG infection, suggesting an inhibitory role of TBCM in mitochondrial dysfunction. Moreover, genetic complementation of B∆tbcm (C∆tbcm) restored its capacity to inhibit mitochondria-mediated apoptotic cell death. Conclusions: Our findings demonstrate the contribution of TBCM to bacterial survival, inhibiting intrinsic apoptotic cell death of macrophages as a virulence factor of M. tuberculosis complex (MTBC) strains, which could be a potential target for the development of TB therapy. [ABSTRACT FROM AUTHOR]

This study looked at a few confirmed cases of chronic lymphocytic leukemia (CLL) that may have had mutations in the human B lymphocyte genome's P-53 gene. The ELISA technique was used to determine the frequency of p-53 protein expression in twenty CLL patients undergoing evaluation in stages II–III / IV. In 17 of the 20 cases, the average amounts of p-53 proteins were found to be 16.76 μg/dl, with a probability index of p = 0.034 and a CV of 0.5%. It was discovered that as the illness progressed, the proportion of p-53 positive isoform proteins rose above normal. The percentage was 15% ± 2 in stages 1-2 and 100% in stages 3-4. Recent studies have shown that the p-53 protein inhibits protein kinase B, the AMPK protein, and the mTOR complex, hence mediating genes that trigger autophagy and stimulating autophagy. One potential use of the p-53 protein's role in cancer cell autophagy is the development of a novel anti-cancer medicinal approach. When a patient develops resistance to the initial line of treatment, the ELISA approach has shown to be an invaluable prognostic tool for CLL, enabling the administration of customized medication. [ABSTRACT FROM AUTHOR]

Chromolaena tacotana (Klatt) R. M. King and H. Rob (Ch. tacotana) contains bioactive flavonoids that may have antioxidant and/or anti-cancer properties. This study investigated the potential anti-cancer properties of a newly identified chalcone isolated from the inflorescences of the plant Chromolaena tacotana (Klatt) R. M. King and H. Rob (Ch. tacotana). The chalcone structure was determined using HPLC/MS (QTOF), UV, and NMR spectroscopy. The compound cytotoxicity and selectivity were evaluated on prostate, cervical, and breast cancer cell lines using the MTT assay. Apoptosis and autophagy induction were assessed through flow cytometry by detecting annexin V/7-AAD, active Casp3/7, and LC3B proteins. These results were supported by Western blot analysis. Mitochondrial effects on membrane potential, as well as levels of pro- and anti-apoptotic proteins were analyzed using flow cytometry, fluorescent microscopy, and Western blot analysis specifically on a triple-negative breast cancer (TNBC) cell line. Furthermore, molecular docking (MD) and molecular dynamics (MD) simulations were performed to evaluate the interaction between the compounds and pro-survival proteins. The compound identified as 2′,3,4-trihydroxy-4′,6′-dimethoxy chalcone inhibited the cancer cell line proliferation and induced apoptosis and autophagy. MDA-MB-231, a TNBC cell line, exhibited the highest sensitivity to the compound with good selectivity. This activity was associated with the regulation of mitochondrial membrane potential, activation of the pro-apoptotic proteins, and reduction of anti-apoptotic proteins, thereby triggering the intrinsic apoptotic pathway. The chalcone consistently interacted with anti-apoptotic proteins, particularly the Bcl-2 protein, throughout the simulation period. However, there was a noticeable conformational shift observed with the negative autophagy regulator mTOR protein. Future studies should focus on the molecular mechanisms underlying the anti-cancer potential of the new chalcone and other flavonoids from Ch. tacotana, particularly against predominant cancer cell types. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) is one of the most common cancers among women. Effective treatment requires precise tailoring to the genetic makeup of the cancer for improved efficacy. Numerous research studies have concentrated on natural compounds and their anti-breast cancer properties to improve the existing treatment options. Chromolaena tacotana (Klatt) R.M. King and H. Rob (Ch. tacotana) is a notable source of bioactive hydroxy-methylated flavonoids. However, the specific anti-BC mechanisms of these flavonoids, particularly those present in the plant’s inflorescences, remain partly undefined. This study focuses on assessing a chalcone derivative extracted from Ch. tacotana inflorescences for its potential to concurrently activate regulated autophagy and intrinsic apoptosis in luminal A and triple-negative BC cells. We determined the chemical composition of the chalcone using ultraviolet (UV) and nuclear magnetic resonance (NMR) spectroscopy. Its selective cytotoxicity against BC cell lines was assessed using the MTT assay. Flow cytometry and Western blot analysis were employed to examine the modulation of proteins governing autophagy and the intrinsic apoptosis pathway. Additionally, in silico simulations were conducted to predict interactions between chalcone and various anti-apoptotic proteins, including the mTOR protein. Chalcone was identified as 2′,4-dihydroxy-4′,6′-dimethoxy-chalcone (DDC). This compound demonstrated a selective inhibition of BC cell proliferation and triggered autophagy and intrinsic apoptosis. It induced cell cycle arrest in the G0/G1 phase and altered mitochondrial outer membrane potential (∆ψm). The study detected the activation of autophagic LC3-II and mitochondrial pro-apoptotic proteins in both BC cell lines. The regulation of Bcl-XL and Bcl-2 proteins varied according to the BC subtype, yet they showed promising molecular interactions with DDC. Among the examined pro-survival proteins, mTOR and Mcl-1 exhibited the most favorable binding energies and were downregulated in BC cell lines. Further research is needed to fully understand the molecular dynamics involved in the activation and interaction of autophagy and apoptosis pathways in cancer cells in response to potential anticancer agents, like the hydroxy-methylated flavonoids from Ch. tacotana.

The hypothalamic neurohormone kisspeptin-10 (KP-10) was inherently implicated in cholinergic pathologies when aberrant fluctuations of expression patterns and receptor densities were discerned in neurodegenerative micromilieus. That said, despite variable degrees of functional redundancy, KP-10, which is biologically governed by its cognate G-protein-coupled receptor, GPR54, attenuated the progressive demise of α-synuclein (α-syn)-rich cholinergic-like neurons. Under explicitly modeled environments, in silico algorithms further rationalized the surface complementarities between KP-10 and α-syn when KP-10 was unambiguously accommodated in the C-terminal binding pockets of α-syn. Indeed, the neuroprotective relevance of KP-10's binding mechanisms can be insinuated in the amelioration of α-syn-mediated neurotoxicity; yet it is obscure whether these extenuative circumstances are contingent upon prior GPR54 activation. Herein, choline acetyltransferase (ChAT)-positive SH-SY5Y neurons were engineered ad hoc to transiently overexpress human wild-type or E46K mutant α-syn while the mitigation of α-syn-induced neuronal death was ascertained via flow cytometric and immunocytochemical quantification. Recapitulating the specificity observed on cell viability, exogenously administered KP-10 (0.1 µM) substantially suppressed wild-type and E46K mutant α-syn-mediated apoptosis and mitochondrial depolarization in cholinergic differentiated neurons. In particular, co-administrations with a GPR54 antagonist, kisspeptin-234 (KP-234), failed to abrogate the robust neuroprotection elicited by KP-10, thereby signifying a GPR54 dispensable mechanism of action. Consistent with these observations, KP-10 treatment further diminished α-syn and ChAT immunoreactivity in neurons overexpressing wild-type and E46K mutant α-syn. Overall, these findings lend additional credence to the previous notion that KP-10's binding zone may harness efficacious moieties of neuroprotective intent. [ABSTRACT FROM AUTHOR]

Abstract Background The bladder cancer (BC) pathology is caused by both exogenous environmental and endogenous molecular factors. Several genes have been implicated, but the molecular pathogenesis of BC and its subtypes remains debatable. The bioinformatic analysis evaluates high numbers of proteins in a single study, increasing the opportunity to identify possible biomarkers for disorders. Methods The aim of this study is to identify biomarkers for the identification of BC using several bioinformatic analytical tools and methods. BC and normal samples were compared for each probeset with T test in GSE13507 and GSE37817 datasets, and statistical probesets were verified with GSE52519 and E-MTAB-1940 datasets. Differential gene expression, hierarchical clustering, gene ontology enrichment analysis, and heuristic online phenotype prediction algorithm methods were utilized. Statistically significant proteins were assessed in the Human Protein Atlas database. GSE13507 (6271 probesets) and GSE37817 (3267 probesets) data were significant after the extraction of probesets without gene annotation information. Common probesets in both datasets (2888) were further narrowed by analyzing the first 100 upregulated and downregulated probesets in BC samples. Results Among the total 400 probesets, 68 were significant for both datasets with similar fold-change values (Pearson r: 0.995). Protein-protein interaction networks demonstrated strong interactions between CCNB1, BUB1B, and AURKB. The HPA database revealed similar protein expression levels for CKAP2L, AURKB, APIP, and LGALS3 both for BC and control samples. Conclusion This study disclosed six candidate biomarkers for the early diagnosis of BC. It is suggested that these candidate proteins be investigated in a wet lab to identify their functions in BC pathology and possible treatment approaches.

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) remains one of the most fatal malignancies. Several chemotherapies employing fluorouracil (5-FU) and gemcitabine were attempted, but the survival rate was extremely low. Resveratrol (RVT), known as a polyphenol compound and phytoalexin, was demonstrated to induce intrinsic apoptosis in cancer cells. However, its low delivery performance and efficiency at tumor sites remain an obstacle to exploit RVT as a drug. To address these problems, we bio-conjugated resveratrol with gold nanoparticles (GNPs) via polyvinylpyrrolidone as a cross-linker (RVT@PVP-GNPs) and investigated whether the fabrications could enhance the delivery performance and anti-tumor efficacy of RVT. Results The fabrication of gold nanoparticles (GNPs) and bio-conjugated with resveratrol (RVT@PVP-GNPs) was conducted firstly. TEM image, spectrophotometry and zeta-potential revealed that the GNPs and RVT@PVP-GNPs having a size of approximately 40 nm were successfully synthesized and exhibited moderate stability. GNPs alone represented no damage in PANC-1 cells and moreover diminished the cytotoxicity of RVT in Raw264.7 murine macrophage cells, demonstrating the superiority of gold nanoparticles as a drug carrier. Evaluation using dialysis showed a burst release rate of RVT within 96 h at pH 5.0, demonstrating the possibility of enhanced efficiency of RVT delivery through blood vessels to the tumor. The RVT@PVP-GNPs induced increased rates of S-phase cell cycle arrest and apoptosis compared with free RVT. Notably, RVT@PVP-GNPs diminished the proportion of necrotic cells, whereas free RVT increased it. We also demonstrated that the RVT@PVP-GNPs may induce an apoptosis via intrinsic mitochondria with higher degree compared with free RVT, indicating the possibility of enhanced anti-tumor agents. In animal studies, RVT@PVP-GNPs conjugated with AS1411 aptamer induced efficient tumor volume suppression without accumulation in or damage to the kidneys in vivo. Conclusions The results demonstrate that RVT@PVP-GNPs enhance the anti-tumor efficacy of free RVT by activating the intrinsic apoptotic pathway and could be considered as potential anti-tumor drug candidates against pancreatic cancer cells.

Chromolaena tacotana (Klatt) R. M. King and H. Rob (Ch. tacotana) contains bioactive flavonoids that may have antioxidant and/or anti-cancer properties. This study investigated the potential anti-cancer properties of a newly identified chalcone isolated from the inflorescences of the plant Chromolaena tacotana (Klatt) R. M. King and H. Rob (Ch. tacotana). The chalcone structure was determined using HPLC/MS (QTOF), UV, and NMR spectroscopy. The compound cytotoxicity and selectivity were evaluated on prostate, cervical, and breast cancer cell lines using the MTT assay. Apoptosis and autophagy induction were assessed through flow cytometry by detecting annexin V/7-AAD, active Casp3/7, and LC3B proteins. These results were supported by Western blot analysis. Mitochondrial effects on membrane potential, as well as levels of pro- and anti-apoptotic proteins were analyzed using flow cytometry, fluorescent microscopy, and Western blot analysis specifically on a triple-negative breast cancer (TNBC) cell line. Furthermore, molecular docking (MD) and molecular dynamics (MD) simulations were performed to evaluate the interaction between the compounds and pro-survival proteins. The compound identified as 2′,3,4-trihydroxy-4′,6′-dimethoxy chalcone inhibited the cancer cell line proliferation and induced apoptosis and autophagy. MDA-MB-231, a TNBC cell line, exhibited the highest sensitivity to the compound with good selectivity. This activity was associated with the regulation of mitochondrial membrane potential, activation of the pro-apoptotic proteins, and reduction of anti-apoptotic proteins, thereby triggering the intrinsic apoptotic pathway. The chalcone consistently interacted with anti-apoptotic proteins, particularly the Bcl-2 protein, throughout the simulation period. However, there was a noticeable conformational shift observed with the negative autophagy regulator mTOR protein. Future studies should focus on the molecular mechanisms underlying the anti-cancer potential of the new chalcone and other flavonoids from Ch. tacotana, particularly against predominant cancer cell types.

Background: The bladder cancer (BC) pathology is caused by both exogenous environmental and endogenous molecular factors. Several genes have been implicated, but the molecular pathogenesis of BC and its subtypes remains debatable. The bioinformatic analysis evaluates high numbers of proteins in a single study, increasing the opportunity to identify possible biomarkers for disorders. Methods: The aim of this study is to identify biomarkers for the identification of BC using several bioinformatic analytical tools and methods. BC and normal samples were compared for each probeset with T test in GSE13507 and GSE37817 datasets, and statistical probesets were verified with GSE52519 and E-MTAB-1940 datasets. Differential gene expression, hierarchical clustering, gene ontology enrichment analysis, and heuristic online phenotype prediction algorithm methods were utilized. Statistically significant proteins were assessed in the Human Protein Atlas database. GSE13507 (6271 probesets) and GSE37817 (3267 probesets) data were significant after the extraction of probesets without gene annotation information. Common probesets in both datasets (2888) were further narrowed by analyzing the first 100 upregulated and downregulated probesets in BC samples. Results: Among the total 400 probesets, 68 were significant for both datasets with similar fold-change values (Pearson r: 0.995). Protein-protein interaction networks demonstrated strong interactions between CCNB1, BUB1B, and AURKB. The HPA database revealed similar protein expression levels for CKAP2L, AURKB, APIP, and LGALS3 both for BC and control samples. Conclusion: This study disclosed six candidate biomarkers for the early diagnosis of BC. It is suggested that these candidate proteins be investigated in a wet lab to identify their functions in BC pathology and possible treatment approaches. [ABSTRACT FROM AUTHOR]

Acrylamide (ACR) is a potential neurotoxin commonly found in the environment, as well as in food repeatedly exposed heat processing, but the mechanism underpinning ACR-induced neurotoxicity remains unclear. This study investigated the potential association and underlying signal transduction of oxidative stress, apoptosis, and autophagy associated with ACR-triggered neurotoxicity. Therefore, U87-MG cells were treated with varying ACR concentrations, while the cell activity reduction depended on the specific dosage and time parameters. Biochemical analyses showed that ACR significantly increased the reactive oxygen species (ROS), malondialdehyde (MDA), and Ca2+ levels while decreasing the glutathione (GSH) levels and mitochondrial membrane potential (ΔΨm), finally leading to a higher cell apoptotic rate. Moreover, ACR induced U87-MG cell apoptosis and autophagy via ROS-triggered expression in the mitochondrial apoptosis pathway, NF-κB activation, and autophagosome accumulation. In addition, the autophagosome accumulation induced by ACR could probably be ascribed to blocked autophagic flux, inhibiting the autophagosomes from combining with lysosomes, while the inhibition of autophagy caused by ACR further promoted the initiation of apoptosis. In conclusion, the results indicated that the apoptotic and autophagic pathways responded to ACR-induced neurotoxicity. However, inhibited protective autophagy further promoted apoptotic progression. New insights may be derived from these cellular responses that can help develop diverse pathway strategies for assessing the risk posed by ACR. ACR induced mitochondrial- and caspase-dependent apoptosis in U87-MG cells. ACR regulated the autophagic markers and blocked autophagic flux in U87-MG cells. ACR inhibited protective autophagy and promoted apoptotic initiation in U87-MG cells. [ABSTRACT FROM AUTHOR]

Background: Pancreatic ductal adenocarcinoma (PDAC) remains one of the most fatal malignancies. Several chemotherapies employing fluorouracil (5-FU) and gemcitabine were attempted, but the survival rate was extremely low. Resveratrol (RVT), known as a polyphenol compound and phytoalexin, was demonstrated to induce intrinsic apoptosis in cancer cells. However, its low delivery performance and efficiency at tumor sites remain an obstacle to exploit RVT as a drug. To address these problems, we bio-conjugated resveratrol with gold nanoparticles (GNPs) via polyvinylpyrrolidone as a cross-linker (RVT@PVP-GNPs) and investigated whether the fabrications could enhance the delivery performance and anti-tumor efficacy of RVT. Results: The fabrication of gold nanoparticles (GNPs) and bio-conjugated with resveratrol (RVT@PVP-GNPs) was conducted firstly. TEM image, spectrophotometry and zeta-potential revealed that the GNPs and RVT@PVP-GNPs having a size of approximately 40 nm were successfully synthesized and exhibited moderate stability. GNPs alone represented no damage in PANC-1 cells and moreover diminished the cytotoxicity of RVT in Raw264.7 murine macrophage cells, demonstrating the superiority of gold nanoparticles as a drug carrier. Evaluation using dialysis showed a burst release rate of RVT within 96 h at pH 5.0, demonstrating the possibility of enhanced efficiency of RVT delivery through blood vessels to the tumor. The RVT@PVP-GNPs induced increased rates of S-phase cell cycle arrest and apoptosis compared with free RVT. Notably, RVT@PVP-GNPs diminished the proportion of necrotic cells, whereas free RVT increased it. We also demonstrated that the RVT@PVP-GNPs may induce an apoptosis via intrinsic mitochondria with higher degree compared with free RVT, indicating the possibility of enhanced anti-tumor agents. In animal studies, RVT@PVP-GNPs conjugated with AS1411 aptamer induced efficient tumor volume suppression without accumulation in or damage to the kidneys in vivo. Conclusions: The results demonstrate that RVT@PVP-GNPs enhance the anti-tumor efficacy of free RVT by activating the intrinsic apoptotic pathway and could be considered as potential anti-tumor drug candidates against pancreatic cancer cells. [ABSTRACT FROM AUTHOR]

Age-related macular degeneration (AMD) is the leading cause of vision loss among the elderly, which is primarily attributed to oxidative stress-induced damage to the retinal pigment epithelium (RPE). Human amniotic mesenchymal stem cells (hAMSC) were considered to be one of the most promising stem cells for clinical application due to their low immunogenicity, tissue repair ability, pluripotent potential and potent paracrine effects. The conditional medium (hAMSC-CM) and exosomes (hAMSC-exo) derived from hAMSC, as mediators of intercellular communication, play an important role in the treatment of retinal diseases, but their effect and mechanism on oxidative stress-induced retinal degeneration are not explored. Here, we reported that hAMSC-CM alleviated H 2 O 2 -induced ARPE-19 cell death through inhibiting mitochondrial-mediated apoptosis pathway in vitro. The overproduction of reactive oxygen species (ROS), alteration in mitochondrial morphology, loss of mitochondrial membrane potential and elevation of Bax/Bcl2 ratio in ARPE-19 cells under oxidative stress were efficiently reversed by hAMSC-CM. Moreover, it was found that hAMSC-CM protected cells against oxidative injury via PI3K/Akt/FoxO3 signaling. Intriguingly, exosome inhibitor GW4869 alleviated the inhibitory effect of hAMSC-CM on H 2 O 2 -induced decrease in cell viability of ARPE-19 cells. We further demonstrated that hAMSC-exo exerted the similar protective effect on ARPE-19 cells against oxidative damage as hAMSC-CM. Additionally, both hAMSC-CM and hAMSC-exo ameliorated sodium iodate-induced deterioration of RPE and retinal damage in vivo. These results first indicate that hAMSC-CM and hAMSC-exo protect RPE cells from oxidative damage by regulating PI3K/Akt/FoxO3 pathway, suggesting hAMSC-CM and hAMSC-exo will be a promising cell-free therapy for the treatment of AMD in the future. • HAMSC-CM ameliorated H 2 O 2 -induced mitochondrial dysfunction in ARPE-19 cells. • HAMSC-CM suppressed H 2 O 2 -induced intrinsic apoptosis by PI3K/Akt/FoxO3 signaling. • HAMSC-CM alleviated oxidative stress-induced retinal degeneration via hAMSC-exo. • HAMSC-CM and hAMSC-exo will be a promising cell-free therapy for the treatment of AMD. [ABSTRACT FROM AUTHOR]

Through oxidative phosphorylation, mitochondria play a central role in energy production and are an important production source of reactive oxygen species (ROS). Not surprisingly, viruses have evolved to exploit this organelle in order to support their infection cycle. Beyond its role in the cellular antiviral response, induction of oxidative stress has emerged as a common strategy employed by many viruses to promote their replication. Here, we review the key molecular mechanisms employed by viruses to interact with mitochondria and induce oxidative stress. Furthermore, we discuss how viruses benefit from increased ROS levels, how they control ROS production to maintain a favorable redox environment, and how they cope with ROS-mediated cell death. Many viruses manipulate mitochondrial respiratory and apoptotic functions to ensure a successful intracellular life cycle. Viral interactions with mitochondrial membranes and other mitochondria-associated components lead to increased production of reactive oxygen species (ROS). Virus-induced mitochondrial ROS (mtROS) benefit viral replication through modulation of host pathways and covalent changes in viral components. Viruses control the oxidative status of the host cell during the course of infection. Manipulation of mtROS-induced apoptosis (intrinsic apoptosis) represents an important viral strategy for optimal intracellular viral replication and timely release of viral progeny. Antioxidant treatments have emerged as a promising antiviral strategy, although further understanding of the complex interplay between viruses and the cellular redox response is needed. [ABSTRACT FROM AUTHOR]

Esophageal squamous cell carcinoma (ESCC) is one of the deadliest digestive system cancers worldwide lacking effective therapeutic strategies. Recently, it has been found that the natural product celastrol plays an anti-cancer role in several human cancers by inducing cell cycle arrest and apoptosis. However, it remains elusive whether and how celastrol suppresses tumor growth of ESCC. In the present study, for the first time, we demonstrated that celastrol triggered both extrinsic and intrinsic apoptosis pathways to diminish the tumor growth of ESCC in vivo and in vitro. Mechanistic studies revealed that celastrol coordinatively induced DR5-dependent extrinsic apoptosis and Noxa-dependent intrinsic apoptosis through transcriptional activation of ATF4 in ESCC cells. Furthermore, we found that the FoxO3a-Bim pathway was involved in the intrinsic apoptosis of ESCC cells induced by celastrol. Our study elucidated the tumor-suppressive efficacy of celastrol on ESCC and revealed a previously unknown mechanism underlying celastrol-induced apoptosis, highlighting celastrol as a promising apoptosis-inducing therapeutic strategy for ESCC. [ABSTRACT FROM AUTHOR]

Abstract Objective Elamipretide (SS31) is a mitochondria-targeted peptide that has reported functions of stabilizing mitochondrial cristae structure and improving mitochondrial bioenergetics. Several studies have documented cell protective features of this peptide, including impairment of intrinsic apoptosis by inhibiting the recruitment and activation of the pro-apoptotic BAX protein. We used live-cell imaging of ARPE-19 cells expressing fluorescently labeled BAX, cytochrome c, and a mitochondrial marker to investigate the effect of elamipretide on the kinetics of BAX recruitment, mitochondrial outer membrane permeabilization (as a function of cytochrome c release), and mitochondrial fragmentation, respectively. Result In nucleofected and plated ARPE-19 cells, elamipretide accelerated the formation of larger mitochondria. In the presence of the apoptotic stimulator, staurosporine, cells treated with elamipretide exhibited moderately slower rates of BAX recruitment. Peptide treatment, however, did not significantly delay the onset of BAX recruitment or the final total amount of BAX that was recruited. Additionally, elamipretide showed no impairment or delay of cytochrome c release or mitochondrial fragmentation, two events associated with normal BAX activation during cell death. These results indicate that the protective effect of elamipretide is not at the level of BAX activity to induce pro-apoptotic mitochondrial dysfunction after the initiation of staurosporine-induced apoptosis.

Esophageal squamous cell carcinoma (ESCC) is one of the deadliest digestive system cancers worldwide lacking effective therapeutic strategies. Recently, it has been found that the natural product celastrol plays an anti-cancer role in several human cancers by inducing cell cycle arrest and apoptosis. However, it remains elusive whether and how celastrol suppresses tumor growth of ESCC. In the present study, for the first time, we demonstrated that celastrol triggered both extrinsic and intrinsic apoptosis pathways to diminish the tumor growth of ESCC in vivo and in vitro. Mechanistic studies revealed that celastrol coordinatively induced DR5-dependent extrinsic apoptosis and Noxa-dependent intrinsic apoptosis through transcriptional activation of ATF4 in ESCC cells. Furthermore, we found that the FoxO3a-Bim pathway was involved in the intrinsic apoptosis of ESCC cells induced by celastrol. Our study elucidated the tumor-suppressive efficacy of celastrol on ESCC and revealed a previously unknown mechanism underlying celastrol-induced apoptosis, highlighting celastrol as a promising apoptosis-inducing therapeutic strategy for ESCC.

The hypothalamic neurohormone kisspeptin-10 (KP-10) was inherently implicated in cholinergic pathologies when aberrant fluctuations of expression patterns and receptor densities were discerned in neurodegenerative micromilieus. That said, despite variable degrees of functional redundancy, KP-10, which is biologically governed by its cognate G-protein-coupled receptor, GPR54, attenuated the progressive demise of α-synuclein (α-syn)-rich cholinergic-like neurons. Under explicitly modeled environments, in silico algorithms further rationalized the surface complementarities between KP-10 and α-syn when KP-10 was unambiguously accommodated in the C-terminal binding pockets of α-syn. Indeed, the neuroprotective relevance of KP-10’s binding mechanisms can be insinuated in the amelioration of α-syn-mediated neurotoxicity; yet it is obscure whether these extenuative circumstances are contingent upon prior GPR54 activation. Herein, choline acetyltransferase (ChAT)-positive SH-SY5Y neurons were engineered ad hoc to transiently overexpress human wild-type or E46K mutant α-syn while the mitigation of α-syn-induced neuronal death was ascertained via flow cytometric and immunocytochemical quantification. Recapitulating the specificity observed on cell viability, exogenously administered KP-10 (0.1 µM) substantially suppressed wild-type and E46K mutant α-syn-mediated apoptosis and mitochondrial depolarization in cholinergic differentiated neurons. In particular, co-administrations with a GPR54 antagonist, kisspeptin-234 (KP-234), failed to abrogate the robust neuroprotection elicited by KP-10, thereby signifying a GPR54 dispensable mechanism of action. Consistent with these observations, KP-10 treatment further diminished α-syn and ChAT immunoreactivity in neurons overexpressing wild-type and E46K mutant α-syn. Overall, these findings lend additional credence to the previous notion that KP-10’s binding zone may harness efficacious moieties of neuroprotective intent.

Tibial dyschondroplasia (TD) is a common skeletal disease occurred in growth plate of fast-growing broilers. Thiram is a sort of chemical used for pesticide and fungicide. The excessive use of thiram increased the threat to animal and human health. In this study, we aimed to investigate the therapeutic mechanism of chlorogenic acid (CGA) on thiram-induced tibial dyschondroplasia. Broiler chickens were divided into three different groups, e.g., control, TD, and CGA. CGA was administrated after the induction of TD from 4th day to 7th day. Biochemical analysis was performed to detect the content of calcium (Ca) and phosphorus (P). Histological changes and degradation of extracellular matrix were observed through hematoxylin-eosin (H & E) and Masson staining. To further determine the mechanism, TUNEL staining and western blot were also performed to detect the apoptosis changes in growth plate of all groups. The results showed the disproportionation of Ca and P content and upregulation of apoptosis during the development of TD. But, after the administration of CGA, the ratio of Ca:P was upregulated, and the apoptosis was also downregulated. The current study shows the toxic effect of thiram on chickens and suggests that CGA is associated with a mechanism that plays a significant role in apoptosis induced by thiram in poultry industry. [ABSTRACT FROM AUTHOR]

Qing Fang,* Siyi Jiang,* Chengyuan Li Department of Hematology, The Third Xiangya Hospital of Central South University, Changsha, People’s Republic of China*These authors contributed equally to this workCorrespondence: Chengyuan LiThe Third Xiangya Hospital of Central South University, Tongzipo Road 138, Changsha 410013, People’s Republic of ChinaTel/Fax +86 073188618511Email lcy800097@163.comIntroduction: Evodiamine (Evo) is one of the main bioactive components derived from the drying mature fruit of the genus Evodia rutaecarpa (Juss.) Benth. Although Evo has shown its anti-cancer activity in several cancers, the effects on multiple myeloma (MM) remain unknown. In this study, we aim to investigate the cytotoxic role of Evo on MM cells.Methods: CCK-8 assay, apoptotic cell analysis, xenografted mice model, caspase activity assay and mitochondrial membrane potential assay were performed.Results: We found that Evo selectively inhibits cell proliferation and increases apoptosis rate in MM cells, but not in healthy B lymphocytes, in a time and dose-dependent manner. Evo treatment significantly activated caspase-3 and −9 in MM cells. Evo also increased cytochrome C expression and ROS production in cytosol in a dose-dependent manner, which was abolished by MitoTEMPO cotreatment. In addition, co-treatment with bortezomib and Evo showed a more potent reduction of cell viability and a higher apoptosis than that of bortezomib single treatment in U266 and RPMI8226 cells.Conclusion: We provided evidence to demonstrate that Evo selectively suppresses cell growth and increases apoptosis rate in MM cells through the intrinsic apoptosis pathway. Application of Evo and bortezomib might enhance the anti-cancer effect on MM cells.Keywords: evodiamine, mitochondria, intrinsic apoptosis, bortezomib, resistance

Conserved molecular signatures in multidrug-resistant Salmonella typhi can serve as novel therapeutic targets for mitigation of infection. In this regard, we present the S. typhi cell division activator protein (StCAP) as a conserved target across S. typhi variants. From in silico and fluorimetric assessments, we found that StCAP is a DNA-binding protein. Replacement of the identified DNA-interacting residue Arg 34 of StCAP with Ala 34 showed a dramatic (15-fold) increase in K d value compared to the wild type ( K d 546 nm) as well as a decrease in thermal stability (10 °C shift). Out of the two screened molecules against the DNA-binding pocket of StCAP, eltrombopag, and nilotinib, the former displayed better binding. Eltrombopag inhibited the stand-alone S. typhi culture with an IC 50 reduced further to 10 μM. Apoptotic protease activating factor1 (Apaf1), a key molecule for intrinsic apoptosis, was identified as an StCAP-interacting partner by pull-down assay against T1Mac. Further, StCAP-transfected T1Mac showed a significant increase in LC3 II (autophagy marker) expression and downregulation of caspase 3 protein. From these experiments, we conclude that StCAP provides a crucial survival advantage to S. typhi where colony formation was severely hindered with IC 50 reduced further to 10 μM. Apoptotic protease activating factor1 (Apaf1), a key molecule for intrinsic apoptosis, was identified as an StCAP-interacting partner by pull-down assay against T1Mac. Further, StCAP-transfected T1Mac showed a significant increase in LC3 II (autophagy marker) expression and downregulation of caspase 3 protein. From these experiments, we conclude that StCAP provides a crucial survival advantage to S. typhi during infection, thereby making it a potent alternative therapeutic target.

Head and neck squamous cell carcinoma (HNSCC) has been characterized by a low therapeutic response and poor prognosis. Currently, there are no reliable predictive models for HNSCC progression and therapeutic efficacy. This study explores the role of diverse patterns of cell death in tumor development, positing them as predictive factors of HNSCC prognosis. We utilized bulk transcriptome and single-cell transcriptome, align with clinical information from TCGA and GEO database, to analyze genes associated with 15 types of cell death and construct a cell death index (CDI) signature. The associations of CDI with tumor-infiltrating immune cells and immunotherapy-related biomarkers were also evaluated using various algorithms. The CDI signature emerged as a robust prognosis biomarker that could identify patients who can benefit potentially from immunotherapy, thus improving diagnostic accuracy and optimizing clinical decisions in HNSCC management. Notably, we discovered that CAAP1 deficiency not only induced apoptosis but also enhanced anti-tumor immunity, suggesting its potential as a target for clinical drug development., Competing Interests: None., (AJCR Copyright © 2024.)

Apoptotic cell death is implicated in both physiological and pathological processes. Since many types of cancerous cells intrinsically evade apoptotic elimination, induction of apoptosis has become an attractive and often necessary cancer therapeutic approach. Conversely, some cells are extremely sensitive to apoptotic stimuli leading to neurodegenerative disease and immune pathologies. However, due to several challenges, pharmacological inhibition of apoptosis is still only a recently emerging strategy to combat pathological cell loss. Here, we describe several key steps in the intrinsic (mitochondrial) apoptosis pathway that represent potential targets for inhibitors in disease contexts. We also discuss the mechanisms of action, advantages and limitations of small‐molecule and peptide‐based inhibitors that have been developed to date. These inhibitors serve as important research tools to dissect apoptotic signalling and may foster new treatments to reduce unwanted cell loss. [ABSTRACT FROM AUTHOR]

Esophageal squamous cell carcinoma (ESCC) is a recalcitrant cancer. The Chinese herbal monomer fangchinoline (FCL) has been reported to have anti-tumor activity in several human cancer cell types. However, the therapeutic efficacy and underlying mechanism on ESCC remain to be elucidated. In the present study, for the first time, we demonstrated that FCL significantly suppressed the growth of ESCC both in vitro and in vivo. Mechanistic studies revealed that FCL-induced G1 phase cell-cycle arrest in ESCC which is dependent on p21 and p27. Moreover, we found that FCL coordinatively triggered Noxa-dependent intrinsic apoptosis and DR5-dependent extrinsic apoptosis by transactivating ATF4, which is a novel mechanism. Our findings elucidated the tumor-suppressive efficacy and mechanisms of FCL and demonstrated FCL is a potential anti-ESCC agent.

Esophageal squamous cell carcinoma (ESCC) is a recalcitrant cancer. The Chinese herbal monomer fangchinoline (FCL) has been reported to have anti-tumor activity in several human cancer cell types. However, the therapeutic efficacy and underlying mechanism on ESCC remain to be elucidated. In the present study, for the first time, we demonstrated that FCL significantly suppressed the growth of ESCC both in vitro and in vivo. Mechanistic studies revealed that FCL-induced G1 phase cell-cycle arrest in ESCC which is dependent on p21 and p27. Moreover, we found that FCL coordinatively triggered Noxa-dependent intrinsic apoptosis and DR5-dependent extrinsic apoptosis by transactivating ATF4, which is a novel mechanism. Our findings elucidated the tumor-suppressive efficacy and mechanisms of FCL and demonstrated FCL is a potential anti-ESCC agent. [ABSTRACT FROM AUTHOR]

Objective: Elamipretide (SS31) is a mitochondria-targeted peptide that has reported functions of stabilizing mitochondrial cristae structure and improving mitochondrial bioenergetics. Several studies have documented cell protective features of this peptide, including impairment of intrinsic apoptosis by inhibiting the recruitment and activation of the pro-apoptotic BAX protein. We used live-cell imaging of ARPE-19 cells expressing fluorescently labeled BAX, cytochrome c, and a mitochondrial marker to investigate the effect of elamipretide on the kinetics of BAX recruitment, mitochondrial outer membrane permeabilization (as a function of cytochrome c release), and mitochondrial fragmentation, respectively. Result: In nucleofected and plated ARPE-19 cells, elamipretide accelerated the formation of larger mitochondria. In the presence of the apoptotic stimulator, staurosporine, cells treated with elamipretide exhibited moderately slower rates of BAX recruitment. Peptide treatment, however, did not significantly delay the onset of BAX recruitment or the final total amount of BAX that was recruited. Additionally, elamipretide showed no impairment or delay of cytochrome c release or mitochondrial fragmentation, two events associated with normal BAX activation during cell death. These results indicate that the protective effect of elamipretide is not at the level of BAX activity to induce pro-apoptotic mitochondrial dysfunction after the initiation of staurosporine-induced apoptosis. [ABSTRACT FROM AUTHOR]

Schematic representation of intrinsic apoptotic pathway induced by Sinularin relied on FOXO3 in prostate cancer cells. Sinularin upregulates FOXO3 via inhibiting the activity of AKT and ERK which phosphorylate FOXO3 at Ser253 and Ser294 respectively. Phosphorylation at these sites leads to FOXO3 binding to 14-3-3 protein, FOXO3 translocation to cytoplasm from nucleus, and subsequent ubiquitin–proteasome degradation. The upregulated FOXO3 increased its target PUMA, a pro-apoptotic protein belonging to the BH3 sub-family of Bcl-2 family. PUMA binds and antagonizes Bcl-2, then leads to mitochondrial outer membrane permeabilization and mitochondrial membrane potential collapses, promoting cytochrome c release and apoptosis. [Display omitted] Sinularin, a natural product that purified from soft coral, exhibits anti-tumor effects against various human cancers. However, the mechanisms are not well understood. In this study, we demonstrated that Sinularin inhibited the viability of human prostate cancer cells in a dose-dependent manner and displayed significant cytotoxicity only at high concentration against normal prostate epithelial cell RWPE-1. Flow cytometry assay demonstrated that Sinularin induced tumor cell apoptosis. Further investigations revealed that Sinularin exerted anti-tumor activity through intrinsic apoptotic pathway along with up-regulation of pro-apoptotic protein Bax and PUMA, inhibition of anti-apoptotic protein Bcl-2, mitochondrial membrane potential collapses, and release of mitochondrial proteins. Furthermore, we illustrated that Sinularin induced cell apoptosis via up-regulating PUMA through inhibition of FOXO3 degradation by the ubiquitin–proteasome pathway. To explore how Sinularin suppress FOXO3 ubiquitin–proteasome degradation, we tested two important protein kinases AKT and ERK that regulate FOXO3 stabilization. The results revealed that Sinularin stabilized and up-regulated FOXO3 via inhibition of AKT- and ERK1/2-mediated FOXO3 phosphorylation and subsequent ubiquitin–proteasome degradation. Our findings illustrated the potential mechanisms by which Sinularin induced cell apoptosis and Sinularin may be applied as a therapeutic agent for human prostate cancer. [ABSTRACT FROM AUTHOR]

Abstract Background A major limitation in the treatment for malignant mesothelioma is related to serious side effects caused by chemotherapeutics and to the development of cancer-resistance. Advances in cancer therapies have been reached thanks to the introduction of alternative approaches, such as the use of phytochemicals. Curcumin-C3complex®/Bioperine® is a commercially standardized extract containing a ratio-defined mixture of three curcuminoids and piperine that greatly increase its bioavailability. Interestingly, the anticancer effect of this formulation has been described in different studies and several clinical trials have been started, but to our knowledge none refers to human mesothelioma. Methods Curcumin-C3complex®/Bioperine® anticancer effect was evaluated in vitro in different human mesothelioma cell lines analysing cell proliferation, colony-forming assay, wound healing assays, invasion assay and FACS analysis. In vivo anticancer properties were analysed in a mesothelioma xenograft mouse model in CD1 Nude mice. Results Curcumin-C3complex®/Bioperine® in vitro induced growth inhibition in all mesothelioma cell lines analysed in a dose- and time-depended manner and reduced self-renewal cell migration and cell invasive ability. Cell death was due to apoptosis. The analysis of the molecular signalling pathway suggested that intrinsic apoptotic pathway is activated by this treatment. This treatment in vivo delayed the growth of the ectopic tumours in a mesothelioma xenograft mouse model. Conclusions Curcumin-C3complex®/Bioperine® treatment strongly reduces in vitro tumorigenic properties of mesothelioma cells by impairing cellular self-renewal ability, proliferative cell rate and cell migration and delays tumor growth in xenograft mouse model by reducing angiogenesis and increasing apoptosis. Considering that curcumin in vivo synergizes drug effects, its administration to treatment regimen may help to enhance drug therapeutic efficacy in mesothelioma. Our results suggest that implementation of standard pharmacological therapies with novel compounds may pave the way to develop alternative approaches to mesothelioma.

Apoptosis (type of programmed cell death) is an active process of cellular self-destruction in multicellular organisms. It is characterized by distinctive histomorphological, biochemical, and molecular features. Multiple cellular pathways trigger apoptosis, two of them are the best known: intrinsic and extrinsic. Multiple cellular signals and interactions can influence the course of apoptotic pathways. Bcl-2 family proteins play a key role in regulatory mechanisms of intrinsic apoptosis. Mitochondrial outer membrane permeabilization (MOMP) is an essential step for intrinsic apoptosis that is controlled by pro-apoptotic and anti-apoptotic members of Bcl-2 protein family. Pro-apoptotic effector proteins Bax and Bak represent the only Bcl-2 proteins inducing formation of MOMP, whose pores facilitate the subsequent releasing of several pro-apoptotic proteins from mitochondrial intermembrane space into cytosol. These proteins initiate a caspase cascade, resulting in rapid elimination of the doomed cells.

Abstract Toads have high medicinal value and have been used for medicinal purposes since the Tang Dynasty period (7th‐10th Century AD). Bufarenogin, an active anti‐tumor constituent of toad venom, shows anti‐tumor activity. In this study, we investigated the inhibitory effects of bufarenogin on the growth and metastasis of colorectal cancer (CRC), particularly its effects on mediating intrinsic signaling pathways that initiate apoptosis. An orthotopic CRC model was established in nude mice via surgical orthotopic implantation to investigate tumor growth. Immunohistochemistry, immunofluorescence, and Western blotting assays were performed to evaluate protein expression. The in vitro results revealed the anti‐proliferative effect of bufarenogin against CRC cells. Bufarenogin caused cell death via apoptosis, as revealed by Annexin V/7‐amino‐actinomycin D double staining, which was verified using a pan‐caspase inhibitor. Bufarenogin induced B‐cell lymphoma 2‐associated X protein (Bax)‐dependent intrinsic apoptosis, as demonstrated by mitochondrial translocation of Bax and cytoplasm release of HCT116 wild‐type cells and cytochrome C (soluble pro‐apoptotic factors). Additionally, we showed that adenine‐nucleotide translocator interacted with Bax. Bufarenogin induced intrinsic apoptosis through the cooperation of Bax and adenine‐nucleotide translocator and inhibited the metastasis and growth of orthotopical CRC cells.

Globally, breast cancer is a serious concern that exhibits a persistent rise in its incidence and related mortality even after significant advancement in the field of cancer research. To find an alternative cure for the disease from natural resources we selected Bacopa monniera, a perennial ethnomedicinal plant popularly used for boosting memory and mental health. We isolated four different types of dammarane saponins, namely bacopasaponins C–F (1–4) from the plant and evaluated their toxic effects on two different types of human breast cancer cell lines—a hormone-responsive MCF7 and a triple-negative MDA-MB-231. Interestingly, MTT assay revealed a dose-dependent toxic effect of all four types of bacopasaponins on both of these cell lines, 4 being the most effective with 48 h-inhibitory concentration (IC50) of 32.44 and 30 µM in MCF7 and MDA-MB-231 respectively. Further, 4 caused significant alterations in normal cytomorphology and induction of apoptosis in both of these cell lines after 48 h of treatment. No caspase-8 activity was detected in these cell lines when exposed to 4 for 2, 24, and 48 h; instead, Western blotting analysis confirmed involvement of either caspase-9 (MCF7) or both caspase-9 and caspase-3 (MDA-MB-231) in the process of apoptosis indicating the occurrence of intrinsic mode. Additionally, at comparable effective doses to cancer, bacopasaponins showed much less toxicity in normal human peripheral blood lymphocytes (≥ 85% cell survival). Overall, the findings project bacopasaponin F, a natural constituent of Bacopa monniera, as an efficient and safer alternative for breast cancer therapeutics. [ABSTRACT FROM AUTHOR]

Recent advancements in live cell imaging technologies have identified the phenomenon of intracellular propagation of late apoptotic events, such as cytochrome c release and caspase activation. The mechanism, prevalence, and speed of apoptosis propagation remain unclear. Additionally, no studies have demonstrated propagation of the pro-apoptotic protein, BAX. To evaluate the role of BAX in intracellular apoptotic propagation, we used high speed live-cell imaging to visualize fluorescently tagged-BAX recruitment to mitochondria in four immortalized cell lines. We show that propagation of mitochondrial BAX recruitment occurs in parallel to cytochrome c and SMAC/Diablo release and is affected by cellular morphology, such that cells with processes are more likely to exhibit propagation. The initiation of propagation events is most prevalent in the distal tips of processes, while the rate of propagation is influenced by the 2-dimensional width of the process. Propagation was rarely observed in the cell soma, which exhibited near synchronous recruitment of BAX. Propagation velocity is not affected by mitochondrial volume in segments of processes, but is negatively affected by mitochondrial density. There was no evidence of a propagating wave of increased levels of intracellular calcium ions. Alternatively, we did observe a uniform increase in superoxide build-up in cellular mitochondria, which was released as a propagating wave simultaneously with the propagating recruitment of BAX to the mitochondrial outer membrane. [ABSTRACT FROM AUTHOR]

B cell lymphoma 2 (BCL-2) family proteins play an important role in intrinsic apoptosis. Overexpression of BCL-2 proteins in acute myeloid leukemia can circumvent resistance to apoptosis and chemotherapy. Considering this effect, the exploration of anti-apoptotic BCL-2 inhibitors is considered to have tremendous potential for the discovery of novel pharmacological modulators in cancer. This review outlines the impact of BCL-2 family proteins on intrinsic apoptosis and the development of acute myeloid leukemia (AML). Furthermore, we will also review the new combination therapy with venetoclax that overcomes resistance to venetoclax and discuss biomarkers of treatment response identified in early-phase clinical trials.

Human telomerase is a specialized DNA polymerase whose catalytic core includes both TERT and human telomerase RNA (hTR). Telomerase in humans, which is silent in most somatic cells, is activated to maintain the telomere length (TEL) in various types of cancer cells, including melanoma. In the vast majority of tumor cells, the TERT promoter is mutated to promote proliferation and inhibit apoptosis. Here, we exploited NG-ABEmax to revert TERT -146 T to -146 C in melanoma, and successfully obtained TERT promoter revertant mutant cells. These TERT revertant mutant cells exhibited significant growth inhibition both in vitro and in vivo. Moreover, A375−146C/C cells exhibited telomere shortening and the downregulation of TERT at both the transcription and protein levels, and migration and invasion were inhibited. In addition, TERT promoter revertant mutation abrogated the inhibitory effect of mutant TERT on apoptosis via B-cell lymphoma 2 (Bcl-2), ultimately leading to cell death. Collectively, the results of our work demonstrate that reverting mutations in the TERT promoter is a potential therapeutic option for melanoma.

B cell lymphoma 2 (BCL-2) family proteins play an important role in intrinsic apoptosis. Overexpression of BCL-2 proteins in acute myeloid leukemia can circumvent resistance to apoptosis and chemotherapy. Considering this effect, the exploration of anti-apoptotic BCL-2 inhibitors is considered to have tremendous potential for the discovery of novel pharmacological modulators in cancer. This review outlines the impact of BCL-2 family proteins on intrinsic apoptosis and the development of acute myeloid leukemia (AML). Furthermore, we will also review the new combination therapy with venetoclax that overcomes resistance to venetoclax and discuss biomarkers of treatment response identified in early-phase clinical trials. [ABSTRACT FROM AUTHOR]

Colorectal cancer is the third leading cause of cancer related-death in the United States. Search for new alternatives to treat this type of cancer is necessary. In a previous report, auransterol from Penicillium aurantiacobrunneum showed cytotoxicity in HT-29 cancer cells. Thus, the goal of this study was to examine the potential cytotoxic mechanism of auransterol in HT-29 cells. Real-time cytotoxicity of auransterol was determined in HT-29 colon cancer cells, using the SRB assay. Loss of MTP, overproduction of ROS, cell cycle, cell migration, and caspase activity were analyzed. Western blot analysis was used to evaluate protein expression. Auransterol reduced cell proliferation rate in a time and concentration-dependent manner, with an IC50 value > 100, 49.1 and 23.8 μM at 24, 48 and 72 h of treatment, respectively. After 24 h of treatment, 50 μM of auransterol induced loss of MTP, overproduction of ROS, increased caspase activity, induced cell cycle G1 phase accumulation and inhibition of migration in HT-29 cells compared to control. These results were supported by protein upregulation of Cyt c, BAX, PARP-1, p21 and procaspase-3, and downregulation of Bcl-2 with no modifications in procaspase-7 and p53. The cytotoxic effect of auransterol in HT-29 colon cancer cells is mediated by mitochondrial apoptosis independent of p53 activation, cell cycle G1 phase arrest, and inhibition of cell migration. This work encourages further preclinical and clinical studies of auransterol and suggests auransterol as a good candidate for colorectal cancer treatment.

Abstract Background Previous studies showed sanguinarine induced apoptosis in CRC cells but did not define the underlying mechanisms. The purpose of this work was to determine the in vivo and in vitro effects of sanguinarine on CRC tumors and to elucidate the mechanism in regulating the intrinsic apoptosis. Methods Cell viability of CRC cell lines treated with sanguinarine was measured by MTT assay. Apoptotic cells stained with Annexin V and 7-AAD were detected by flow cytometry. Mitochondrial membrane potential and reactive oxygen species (ROS) were analyzed by JC-1 and DCFH-DA staining, respectively. The in vitro kinase activity of MELK was analyzed by using HTRF® KinEASE™-STK kit. The expression of proteins were determined using Western blotting and immunohistochemistry. Co-immunoprecipitation and immunofluorecence were used to study the interaction between STRAP and MELK. The anti-neoplastic effect of sanguinarine was observed in vivo in an orthotopic CRC model. Results Sanguinarine decreased the tumor size in a dose-dependent manner in orthotopical colorectal carcinomas through intrinsic apoptosis pathway in BALB/c-nu mice. It significantly increased cleavage of caspase 3 and PARP in implanted colorectal tissues. Sanguinarine increased mitochondrial ROS and triggered mitochondrial outer membrane permeabilization in multiple colorectal cancer (CRC) cell lines. NAC pretreatment lowered ROS level and downregulated apoptosis induced by sanguinarine. The intrinsic apoptosis induced by sanguinarine was Bax-dependent. The elevated expression and association between serine-threonine kinase receptor-associated protein (STRAP) and maternal embryonic leucine zipper kinase (MELK) were observed in Bax positive cells but not in Bax negative cells. Sanguinarine dephosphorylated STRAP and MELK and disrupted the association between them in HCT116 and SW480 cells. The expression and association between STRAP and MELK were also attenuated by sanguinarine in the tumor tissues. Importantly, we found that STRAP and MELK were overexpressed and highly phosphorylated in colorectal adenocarcinomas and their expression were significantly correlated with tumor stages. Furthermore, the expression of MELK, but not STRAP, was associated with lymph node metastasis. Conclusions Sanguinarine dephosphorelates STRAP and MELK and disassociates the interaction between them to trigger intrinsic apoptosis. Overexpression of STRAP and MELK may be markers of CRC and their disassociation may be a determinant of therapeutic efficacy.

The heme protein cytochrome c (Cyt c) plays pivotal roles in cellular life and death processes. In the respiratory chain of mitochondria, it serves as an electron transfer protein, contributing to the proliferation of healthy cells. In the cell cytoplasm, it activates intrinsic apoptosis to terminate damaged cells. Insight into these mechanisms and the associated physicochemical properties and biomolecular interactions of Cyt c informs on the anticancer therapeutic potential of the protein, especially in its ability to subvert the current limitations of small molecule-based chemotherapy. In this review, we explore the development of Cyt c as an anticancer drug by identifying cancer types that would be receptive to the cytotoxicity of the protein and factors that can be finetuned to enhance its apoptotic potency. To this end, some information is obtained by characterizing known drugs that operate, in part, by triggering Cyt c induced apoptosis. The application of different smart drug delivery systems is surveyed to highlight important features for maintaining Cyt c stability and activity and improving its specificity for cancer cells and high drug payload release while recognizing the continuing limitations. This work serves to elucidate on the optimization of the strategies to translate Cyt c to the clinical market.

Copy number gains and increased expression levels of cellular Inhibitor of Apoptosis protein (cIAP)1 and cIAP2 have been identified in primary diffuse large B‐cell lymphoma (DLBCL) tissues. Second mitochondria‐derived activator of caspases (Smac) mimetics were designed to antagonize IAP proteins. However, since their effect as single agents is limited, combination treatment represents a strategy for their clinical development. Therefore, we investigated the Smac mimetic BV6 in combination with proteasome inhibitors and analyzed the molecular mechanisms of action. We discovered that BV6 treatment sensitizes DLBCL cells to proteasome inhibition. We show a synergistic decrease in cell viability and induction of apoptosis by BV6/Carfilzomib (CFZ) treatment, which was confirmed by calculation of combination index (CI) and Bliss score. BV6 and CFZ acted together to trigger activation of BAX and BAK, which facilitated cell death, as knockdown of BAX and BAK significantly reduced BV6/CFZ‐mediated cell death. Activation of BAX and BAK was accompanied by loss of mitochondrial membrane potential (MMP) and activation of caspases. Pretreatment with the caspase inhibitor N‐benzyloxycarbonyl‐Val‐Ala‐Asp‐fluoromethylketone (zVAD.fmk) rescued BV6/CFZ‐induced cell death, confirming caspase dependency. Treatment with CFZ alone or in combination with BV6 caused accumulation of NOXA, which was required for cell death, as gene silencing by siRNA or Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/Cas9‐mediated NOXA inactivation inhibited BV6/CFZ‐induced cell death. Together, these experiments indicate that BV6 and CFZ cooperatively induce apoptotic cell death via the mitochondrial pathway. These findings emphasize the role of Smac mimetics for sensitizing DLBCL cells to proteasome inhibition with important implications for further (pre)clinical studies. What's new? Diffuse large B‐cell lymphoma (DLBCL) is a heterogenous disease, in which existing immunochemotherapy fails in about 40 percent of patients. In particular, poor outcome in DLBCL is correlated with elevated expression of X‐chromosome‐linked inhibitor of apoptosis (XIAP) protein. Here, the Smac mimetic BV6, designed to antagonize XIAP, was found to sensitize DLBCL cells to proteasome inhibition. Combination treatment using BV6 and proteasome inhibitors synergistically induced cell death, which relied on BAX/BAK activation and NOXA accumulation. The findings suggest that combined use of Smac mimetics and proteasome inhibitors is a promising strategy to improve the clinical management of DLBCL. [ABSTRACT FROM AUTHOR]

Gedunin is a natural tetranorterpenoid secondary metabolite found in plants of the Meliaceae family, which has been reported for its antiparasitic, antifungal and anticancer activities. Here, we describe the molecular mechanisms underlying the in vitro anti proliferative activity of gedunin (isolated from the mangrove plant Xylocarpus granatum) in human ovarian cancer cells. We observed that gedunin triggered severe ROS generation leading to DNA damage and cell cycle arrest in G2/M phase thus inhibiting cell proliferation. ROS upregulation also led to mitochondrial stress and membrane depolarization, which eventually resulted in mitochondria-mediated apoptosis following cytochrome C release, caspase 9, 3 activation, and PARP cleavage. Transmission electron microscopy of gedunin treated cells revealed sub-cellular features typical of apoptosis. Moreover, an upregulation in stress kinases like phospho-ERK 1/2, phospho-p38 and phospho-JNK was also observed in gedunin treated cells. Free radical scavenger N-Acetyl-L-Cysteine (NAC) reversed all these effects resulting in increased cell survival, abrogation of cell cycle arrest, rescue of mitochondrial membrane potential and suppression of apoptotic markers. Interestingly, gedunin is also an inhibitor of the evolutionarily conserved molecular chaperone Heat Shock Protein 90 (hsp90) responsible for maintaining cellular homeostasis. Targeting this chaperone could be an attractive strategy for developing cancer therapeutics since many oncogenic proteins are also client proteins of hsp90. Collectively, our findings provide insights into the molecular mechanism of action of gedunin, which may aid drug development efforts against ovarian cancer. [ABSTRACT FROM AUTHOR]

With the incessant rise in the cancer burden worldwide it is a dire need to develop anticancer agents that will offer negligible or no side effects and at the same time will be economically feasible. In this study, we utilized the principle of green chemistry where tyrosine and chitosan were used as reducer and stabilizer respectively to synthesize biocompatible silver nanoparticles. They were characterized by ultraviolet–visible spectroscopy, transmission electron microscopy and dynamic light scattering technique and found to be spherical with average diameter of 13–22 nm. Their toxicity was evaluated in MCF7 and MDA-MB-231 human breast cancer cell lines. MTT assay revealed excellent cytotoxic effect with IC50 values as low as 6.4 and 6.56 ppb respectively after 48 h of treatment. Intriguingly, they showed minimum toxicity in normal human peripheral blood lymphocytes at these effective concentrations. Cytomorphological alteration, ROS generation (DCFDA analysis) and nuclear fragmentation (Hoechst staining) were pronounced in both cancer cell lines following treatment. These nanoparticles also promoted expression and nuclear translocation of Nrf2 as an antioxidant response which was revealed by Western blot and immunofluorescence studies respectively. 'Apoptosis assay' confirmed the presence of apoptosis and 'Caspase-8 activity assay' revealed absence of the extrinsic apoptosis pathway. Western blot data (upregulation of p21, Bax/Bcl2 ratio, Caspase-9, Caspase-3 and cleaved PARP1) established the occurrence of intrinsic apoptosis pathway following cell cycle arrest. To conclude, the green synthesized silver nanoparticles are cytotoxic to cancer cells and can be considered as effective and safe cytotoxic agents in breast cancer therapeutics. [ABSTRACT FROM AUTHOR]

Propofol is widely applied in general anesthesia owing to its short effect and rapid recovery. Apart from its anesthetic advantages, propofol has also been observed to inhibit the growth of several types of cancer cells. Breast cancer is the most diagnosed cancer in females worldwide and triple negative breast cancer (TNBC) constitutes 15–20% of all breast cancer cases. TNBC is characterized by a high recurrence rate, which is associated with its high mortality rate. The present study aimed to evaluate apoptosis in MDA-MB-468 cells treated with propofol. The Cell Counting Kit-8 assay was used to assess proliferation in cells treated with different concentrations of propofol. In addition, Annexin V-FITC was used to detect apoptosis. Furthermore, the generation of reactive oxygen species (ROS) was examined. The relative expression of proteins in the intrinsic apoptosis pathway, such as Bak, Bax, Bcl-2, Cytochrome c, apoptotic peptidase-activating factor 1 (Apaf-1), Caspase 3 and Caspase 9, were calculated relative to GAPDH with western blot analysis. A wound healing assay was performed to examine the effect of propofol on MDA-MB-468 cell migration. The present study revealed that propofol inhibited the proliferation and increased the level of ROS in MDA-MB-468 cells. The expression levels of Cytochrome c, Apaf-1, Bax, Bak and cleaved Caspase 3/9 were upregulated compared with GAPDH. The level of Bcl-2 protein was upregulated by propofol at a concentration of 5 µM and downregulated at concentrations of 10 and 20 µM. In the wound-healing assay, propofol reduced the scratch distance and area. Taken together, the results of the present study suggested that propofol may induce ROS-mediated intrinsic apoptosis and promote migration in TNBC cells. [ABSTRACT FROM AUTHOR]

Bio‐fabrication of gold nanoparticles (AuNPs) has several advantages like biocompatibility, less toxicity, and eco‐friendly in nature over their chemical and physical methods. Currently, the authors fabricated AuNPs using aqueous root extract of Momordica dioica (M. dioica) and explored their anticancer application with mechanistic approaches. Different biophysical techniques such as UV–visible spectroscopy, Fourier transform infrared, X‐ray diffraction, transmission electron microscopy, selected area electron diffraction, and dynamic light scattering were employed for AuNPs characterisation. The synthesised AuNPs were mono‐dispersed, crystalline in nature, anionic surface (−23.9 mV), and spherical particle of an average diameter of 9.4 nm. In addition, the AuNPs were stable in buffers solutions and also biocompatible towards normal human cells (human vascular endothelial cells and human lung cells). The AuNPs were exhibited anticancer activity against different cancer cell lines such as human breast cancer cells, human cervical cancer cells (HeLa) and human lung cancer cells. Further, the pro‐apoptotic genes such as Bcl2 were down‐regulated and BAX, Caspase‐3, −8, and −9 were up‐regulated in HeLa cells as compared to untreated cells. Annexin‐V‐FITC assay results showed that the AuNPs were induced apoptosis by accumulation of intracellular reactive oxygen species. To their knowledge, this is the first report on the synthesis of bioactive metal nanoparticles from M. dioica and it may open up new avenues in therapeutic applications. [ABSTRACT FROM AUTHOR]