BCL2 family in DNA damage and cell cycle control

Extraction, physicochemical properties, bioactivities and application of natural sweeteners: A review

Natural sweeteners generally refer to a sweet chemical component directly extracted from nature or obtained through appropriate modifications, mainly secondary metabolites of plants. Compared to the first-generation sweeteners represented by sucrose and the second-generation sweeteners represented by sodium cyclamate, natural sweeteners usually have high sweetness, low-calorie content, good solubility, high stability, and rarely toxic side effects. Historically, researchers mainly focus on the function of natural sweeteners as substitutes for sugars in the food industry. This paper reviews the bioactivities of several typical natural sweeteners, including anti-cancer, anti-inflammatory, antioxidant, anti-bacterial, and anti-hyperglycemic activities. In addition, we have summarized the extraction, physicochemical properties, and application of natural sweeteners. The article aimed to comprehensively collate vital information about natural sweeteners and review the potentiality of tapping bioactive compounds from natural products. Hopefully, this review provides insights into the further development of natural sweeteners as therapeutic agents and functional foods.

In silico analysis shows slc1a4 as a potential target of hsa-mir-133a for regulating glutamine metabolism in gastric cancer

Cutting-edge research has spotlighted glutamine metabolism as a promising therapeutic target in managing gastric cancer. This investigation highlights the upregulated glutamine transporters by leveraging clinical data from the TCGA Database and the expression analysis of the transcriptome profile of stomach adenocarcinoma (STAD) patients. Notably, it identifies SLC1A4 as a potential glutamine transporter in STAD. The screening of human miRNAs conducted using the TargetScan database, and the subsequent docking analysis present multiple miRNAs with the potential of being explored as therapeutic agents. By integrating transcriptome profiling, miRNA screening, and molecular docking, this study reveals, for the first time, the potential of hsa-mir-133a-1 in targeting slc1a4, along with its known target mTOR, in stomach cancer. The myriad interactions that can be regulated by this silencing mechanism are anticipated to ultimately reduce glutamine uptake in STAD. This study provides compelling evidence of glutamine transport via SLC1A4 in stomach cancer and delves into how it might impact mTOR and some of its pivotal downstream molecules. Considering these findings, novel therapeutic strategies can be devised to further enhance existing methods for combating gastric cancer.

Synthesis, Anti-Cancer Activity, Cell Cycle Arrest, Apoptosis Induction, and Docking Study of Fused Benzo[h]chromeno[2,3-d]pyrimidine on Human Breast Cancer Cell Line MCF-7

Breast cancer is the predominant form of cancer among women and ranks as the second most prevalent cancer globally, affecting both developed and less developed countries. Presently, accessible cancer treatment methods either employ recently created, secure, and efficient chemotherapeutic medications or directly target innovative pathways that cause apoptosis. One of the indirect strategies for treating this fatal illness has mostly depended on its essential role in cell cycle arrest and apoptosis induction, as well as the antagonistic interaction between the Bcl-2 and Mcl-1 proteins, in order to avert major health repercussions. We reported that newly synthesized fused chromenopyrimidines (3a and 4a) showed potential cell cycle arrest and dual Bcl-2 and Mcl-1 inhibitory characteristics. Bcl-2 and Mcl-1 were the targets of a molecular docking procedure. The previous docking results are in line with the biological data and suggest that 3a may have promising anti-cancer activity.

Integrating network pharmacology, molecular docking and experimental verification to explore the therapeutic effect and potential mechanism of nomilin against triple-negative breast cancer

BACKGROUND

Nomilin is a limonoid compound known for its multiple biological activities, but its role in triple negative breast cancer (TNBC) remains unclear. This study aims to uncover the potential therapeutic effect of nomilin on TNBC and elucidate the specific mechanism of its action.

METHODS

We employed weighted gene co-expression network analysis (WGCNA), differential expression analysis, and the GeneCards database to identify potential targets for TNBC. Simultaneously, we utilized the Swiss Target Prediction, ChEMBL, and STITCH databases to identify potential targets of nomilin. The core targets and mechanisms of nomilin against TNBC were predicted through protein-protein interaction (PPI) network analysis, molecular docking, and enrichment analysis. The results of the network pharmacology were corroborated by conducting experiments.

RESULTS

A total of 17,204 TNBC targets were screened, and 301 potential targets of nomilin were identified. Through the PPI network, eight core targets of nomilin against TNBC were pinpointed, namely BCL2, Caspase3, CyclinD1, EGFR, HSP90AA1, KRAS, PARP1, and TNF. Molecular docking, molecular dynamics simulation and proteome microarray revealed that nomilin exhibits strong binding activity to these core proteins. Enrichment analysis results indicated that the anti-TNBC effect of nomilin is associated with PI3K/Akt pathway. In vitro and in vivo experiments have demonstrated that nomilin inhibits TNBC cell proliferation and migration while promoting cell apoptosis through the PI3K/Akt pathway.

CONCLUSION

For the first time, the research effectively discovered the objectives and mechanisms of nomilin in combating TNBC using network pharmacology, molecular docking, molecular dynamics simulation, proteome microarray and experimental confirmation, presenting a hopeful approach for treating TNBC.

Autophagy in aging-related diseases and cancer: Principles, regulatory mechanisms and therapeutic potential

Macroautophagy/autophagy is primarily accountable for the degradation of damaged organelles and toxic macromolecules in the cells. Regarding the essential function of autophagy for preserving cellular homeostasis, changes in, or dysfunction of, autophagy flux can lead to disease development. In the current paper, the complicated function of autophagy in aging-associated pathologies and cancer is evaluated, highlighting the underlying molecular mechanisms that can affect longevity and disease pathogenesis. As a natural biological process, a reduction in autophagy is observed with aging, resulting in an accumulation of cell damage and the development of different diseases, including neurological disorders, cardiovascular diseases, and cancer. The MTOR, AMPK, and ATG proteins demonstrate changes during aging, and they are promising therapeutic targets. Insulin/IGF1, TOR, PKA, AKT/PKB, caloric restriction and mitochondrial respiration are vital for lifespan regulation and can modulate or have an interaction with autophagy. The specific types of autophagy, such as mitophagy that degrades mitochondria, can regulate aging by affecting these organelles and eliminating those mitochondria with genomic mutations. Autophagy and its specific types contribute to the regulation of carcinogenesis and they are able to dually enhance or decrease cancer progression. Cancer hallmarks, including proliferation, metastasis, therapy resistance and immune reactions, are tightly regulated by autophagy, supporting the conclusion that autophagy is a promising target in cancer therapy.

Anti-apoptotic protein Bcl-2 contributes to the determination of reserve cells during myogenic differentiation of C2C12 cells

Skeletal muscle's regenerative ability is vital for maintaining muscle function, but chronic diseases like Duchenne muscular dystrophy can deplete this capacity. Muscle satellite cells, quiescent in normal situations, are activated during muscle injury, expressing myogenic regulatory factors, and producing myogenic progenitor cells. It was reported that muscle stem cells in primary culture and reserve cells in C2C12 cells express anti-apoptotic protein Bcl-2. Although the role of Bcl-2 expressed in myogenic cells has been thought to be to enhance cell viability, we hypothesized that Bcl-2 may promote the formation of reserve cells. The expression pattern analysis showed the expression of Bcl-2 in undifferentiated mononucleated cells, emphasizing its usefulness as a reserve cell marker and reminding us that cells expressing Bcl-2 have low proliferative potential. Silencing of Bcl-2 by transfection with siRNA decreased cell viability and the number of reserve cells, while overexpression of Bcl-2 not only increases cell viability but also inhibits muscle differentiation and proliferation. These results emphasize dual roles of Bcl-2 in protecting cells from apoptosis and contributing to reserve cell formation by regulating myoblast proliferation and/or differentiation. Overall, the study sheds light on the multifaceted role of Bcl-2 in the maintenance of skeletal muscle regeneration.

A culture method with berbamine, a plant alkaloid, enhances CAR-T cell efficacy through modulating cellular metabolism

Memory T cells demonstrate superior in vivo persistence and antitumor efficacy. However, methods for manufacturing less differentiated T cells are not yet well-established. Here, we show that producing chimeric antigen receptor (CAR)-T cells using berbamine (BBM), a natural compound found in the Chinese herbal medicine Berberis amurensis, enhances the antitumor efficacy of CAR-T cells. BBM is identified through cell-based screening of chemical compounds using induced pluripotent stem cell-derived T cells, leading to improved viability with a memory T cell phenotype. Transcriptomics and metabolomics using stem cell memory T cells reveal that BBM broadly enhances lipid metabolism. Furthermore, the addition of BBM downregulates the phosphorylation of p38 mitogen-activated protein kinase and enhanced mitochondrial respiration. CD19-CAR-T cells cultured with BBM also extend the survival of leukaemia mouse models due to their superior in vivo persistence. This technology offers a straightforward approach to enhancing the antitumor efficacy of CAR-T cells.

Myeloid Targeted Human MLL-ENL and MLL-AF9 Induces cdk9 and bcl2 Expression in Zebrafish Embryos

Acute myeloid leukemia (AML) accounts for greater than twenty thousand new cases of leukemia annually in the United States. The average five-year survival rate is approximately 30%, pointing to the need for developing novel model systems for drug discovery. In particular, patients with chromosomal rearrangements in the mixed lineage leukemia (MLL) gene have higher relapse rates with poor outcomes. In this study we investigated the expression of human MLL-ENL and MLL-AF9 in the myeloid lineage of zebrafish embryos. We observed an expansion of MLL positive cells and determined these cells colocalized with the myeloid markers spi1b, mpx, and mpeg. In addition, expression of MLL-ENL and MLL-AF9 induced the expression of endogenous bcl2 and cdk9, genes that are often dysregulated in MLL-r-AML. Co-treatment of lyz: MLL-ENL or lyz:MLL-AF9 expressing embryos with the BCL2 inhibitor, Venetoclax, and the CDK9 inhibitor, Flavopiridol, significantly reduced the number of MLL positive cells compared to embryos treated with vehicle or either drug alone. In addition, cotreatment with Venetoclax and Flavopiridol significantly reduced the expression of endogenous mcl1a compared to vehicle, consistent with AML. This new model of MLL-r-AML provides a novel tool to understand the molecular mechanisms underlying disease progression and a platform for drug discovery.

Joint Analysis of Genome-wide DNA Methylation and Transcription Sequencing Identifies the Role of BAX Gene in Heat Stress-Induced-Sertoli Cells Apoptosis

The problem of male infertility is a global health crisis and poses a serious threat to the well-being of families. Under heat stress (HS), the reduction of Sertoli cells (SCs) inhibits energy transport and nutrient supply to germ cells, leading to spermatogenesis failure. DNA methylation of genes is a central epigenetic regulatory mechanism in mammalian reproduction. However, it remains unclear how DNA methylation regulates gene expression in heat-stressed SCs. In this study, we investigated whether the decrease in SC levels during HS could be related to epigenetic DNA modifications. The cells exposed to HS showed changes in differential methylation cytosines and regions (DMCs/DMRs) and differential expression genes (DEGs), but not in global DNA methylations. One of the most important biological processes affected by HS is cell apoptosis induced by the intrinsic apoptotic signaling pathway (GO: 2,001,244, P < 0.05) by enrichment in the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The joint analysis showed that several gene expressions in RNA-seq and WGBS overlapped and the shortlisted genes BAX, HSPH1, HSF1B, and BAG were strongly correlated with stress response and apoptosis. Methylation-specific PCR (MSP) and flow cytometry (FCM) analyzes showed that reduced promoter methylation and enhanced gene expression of BAX with a consequence of apoptosis. The activity of BAX, as well as an increase in its expression, is likely to result in a reduction of SCs population which could further impair ATP supply and adversely affect membrane integrity. These findings provide novel insights into the molecular mechanisms through which stressors cause male reproductive dysfunction and a new molecular etiology of male infertility.

Therapeutic potential of targeting polo-like kinase 4

Polo-like kinase 4 (PLK4), a highly conserved serine/threonine kinase, masterfully regulates centriole duplication in a spatiotemporal manner to ensure the fidelity of centrosome duplication and proper mitosis. Abnormal expression of PLK4 contributes to genomic instability and associates with a poor prognosis in cancer. Inhibition of PLK4 is demonstrated to exhibit significant efficacy against various types of human cancers, further highlighting its potential as a promising therapeutic target for cancer treatment. As such, numerous small-molecule inhibitors with distinct chemical scaffolds targeting PLK4 have been extensively investigated for the treatment of different human cancers, with several undergoing clinical evaluation (e.g., CFI-400945). Here, we review the structure, distribution, and biological functions of PLK4, encapsulate its intricate regulatory mechanisms of expression, and highlighting its multifaceted roles in cancer development and metastasis. Moreover, the recent advancements of PLK4 inhibitors in patent or literature are summarized, and their therapeutic potential as monotherapies or combination therapies with other anticancer agents are also discussed.

Role of Apoptosis in the Pathogenesis of Osteoarthritis: An Explicative Review

Apoptosis is a complex regulatory, active cell death process that plays a role in cell development, homeostasis, and ageing. Cancer, developmental defects, and degenerative diseases are all pathogenic disorders caused by apoptosis dysregulation. Osteoarthritis (OA) is by far the most frequently diagnosed joint disease in the aged, and it is characterized by the ongoing breakdown of articular cartilage, which causes severe disability. Multiple variables regulate the anabolic and catabolic pathways of the cartilage matrix, which either directly or indirectly contribute to cartilage degeneration in osteoarthritis. Articular cartilage is a highly specialized tissue made up of an extracellular matrix of cells that are tightly packed together. As a result, chondrocyte survival is crucial for the preservation of an optimal cartilage matrix, and chondrocyte characteristics and survival compromise may result in articular cartilage failure. Inflammatory cytokines can either promote or inhibit apoptosis, the process of programmed cell death. Pro-apoptotic cytokines like TNF-α can induce cell death, while anti-apoptotic cytokines like IL-4 and IL-10 protect against apoptosis. The balance between these cytokines plays a critical role in determining cell fate and has implications for tissue damage and disease progression. Similarly, they contribute to the progression of OA by disrupting the metabolic balance in joint tissues by promoting catabolic and anabolic pathways. Their impact on cell joints, as well as the impacts of cell signalling pathways on cytokines and inflammatory substances, determines their function in osteoarthritis development. Apoptosis is evident in osteoarthritic cartilage; however, determining the relative role of chondrocyte apoptosis in the aetiology of OA is difficult, and the rate of apoptotic chondrocytes in osteoarthritic cartilage is inconsistent. The current study summarises the role of apoptosis in the development of osteoarthritis, the mediators, and signalling pathways that trigger the cascade of events, and the other inflammatory features involved.

Single-cell morphological and transcriptome analysis unveil inhibitors of polyploid giant breast cancer cells in vitro

Considerable evidence suggests that breast cancer therapeutic resistance and relapse can be driven by polyploid giant cancer cells (PGCCs). The number of PGCCs increases with the stages of disease and therapeutic stress. Given the importance of PGCCs, it remains challenging to eradicate them. To discover effective anti-PGCC compounds, there is an unmet need to rapidly distinguish compounds that kill non-PGCCs, PGCCs, or both. Here, we establish a single-cell morphological analysis pipeline with a high throughput and great precision to characterize dynamics of individual cells. In this manner, we screen a library to identify promising compounds that inhibit all cancer cells or only PGCCs (e.g., regulators of HDAC, proteasome, and ferroptosis). Additionally, we perform scRNA-Seq to reveal altered cell cycle, metabolism, and ferroptosis sensitivity in breast PGCCs. The combination of single-cell morphological and molecular investigation reveals promising anti-PGCC strategies for breast cancer treatment and other malignancies.

Mild heat treatment in vitro potentiates human adipose stem cells: delayed aging and improved quality for long term culture

BACKGROUND

Mesenchymal stem cells (MSCs) have gained significant attention for diverse biomedical applications, including cell-based therapy. Hence, in vitro expansion of MSCs is critical; however, in vitro MSC culture, especially long-term culture, inevitably leads to significant loss of stemness, growth, and differentiation potential.

METHOD

Effects of mild heat treatment (HT) conditions (temperature, duration, and repetition) on the characteristics of adipose tissue-derived MSCs in vitro were systematically investigated. Characteristics of the MSCs subjected to the predetermined HT conditions (41 or 44ºC, 1 h, and 2X HT) were first analyzed in a single passage using various assays. In addition, the feasibility of HT for long-term MSC culture was studied. The RNA sequencing analyses were performed to elucidate the mechanism of HT effects on MSCs.

RESULTS

A comprehensive exploration of various HT conditions revealed that specific mild HT at 41ºC or 44ºC for 1 h upregulated the expression of heat shock proteins and stemness markers and enhanced differentiation potentials. Furthermore, periodic mild HT extended the maintenance of growth rate and stemness of MSCs up to an additional 10 passages, which substantially retarded their spontaneous aging during subsequent in vitro culture. RNA sequencing analyses unveiled that HT downregulated genes associated with aging and apoptosis.

CONCLUSION

Our study successfully demonstrated that mild HT of MSCs has positive effects on their application in various biomedical fields, enhancing their capabilities and slowing down the aging process.

Oxytocin as neuro-hormone and neuro-regulator exert neuroprotective properties: A mechanistic graphical review

BACKGROUND

Neurodegeneration is progressive cell loss in specific neuronal populations, often resulting in clinical consequences with significant medical, societal, and economic implications. Because of its antioxidant, anti-inflammatory, and anti-apoptotic properties, oxytocin has been proposed as a potential neuroprotective and neurobehavioral therapeutic agent, including modulating mood disturbances and cognitive enchantment.

METHODS

Literature searches were conducted using the following databases Web of Science, PubMed, Elsevier Science Direct, Google Scholar, the Core Collection, and Cochrane from January 2000 to February 2023 for articles dealing with oxytocin neuroprotective properties in preventing or treating neurodegenerative disorders and diseases with a focus on oxidative stress, inflammation, and apoptosis/cell death.

RESULTS

The neuroprotective effects of oxytocin appears to be mediated by its anti-inflammatory properties, inhibition of neuro inflammation, activation of several antioxidant enzymes, inhibition of oxidative stress and free radical formation, activation of free radical scavengers, prevent of mitochondrial dysfunction, and inhibition of apoptosis.

CONCLUSION

Oxytocin acts as a neuroprotective agent by preventing neuro-apoptosis, neuro-inflammation, and neuronal oxidative stress, and by restoring mitochondrial function.

The mechanistic role of cardiac glycosides in DNA damage response and repair signaling

Cardiac glycosides (CGs) are a class of bioactive organic compounds well-known for their application in treating heart disease despite a narrow therapeutic window. Considerable evidence has demonstrated the potential to repurpose CGs for cancer treatment. Chemical modification of these CGs has been utilized in attempts to increase their anti-cancer properties; however, this has met limited success as their mechanism of action is still speculative. Recent studies have identified the DNA damage response (DDR) pathway as a target of CGs. DDR serves to coordinate numerous cellular pathways to initiate cell cycle arrest, promote DNA repair, regulate replication fork firing and protection, or induce apoptosis to avoid the survival of cells with DNA damage or cells carrying mutations. Understanding the modus operandi of cardiac glycosides will provide critical information to better address improvements in potency, reduced toxicity, and the potential to overcome drug resistance. This review summarizes recent scientific findings of the molecular mechanisms of cardiac glycosides affecting the DDR signaling pathway in cancer therapeutics from 2010 to 2022. We focus on the structural and functional differences of CGs toward identifying the critical features for DDR targeting of these agents.

Multiparametric senescent cell phenotyping reveals targets of senolytic therapy in the aged murine skeleton

Senescence drives organismal aging, yet the deep characterization of senescent cells in vivo remains incomplete. Here, we apply mass cytometry by time-of-flight using carefully validated antibodies to analyze senescent cells at single-cell resolution. We use multiple criteria to identify senescent mesenchymal cells that are growth-arrested and resistant to apoptosis. These p16 + Ki67-BCL-2+ cells are highly enriched for senescence-associated secretory phenotype and DNA damage markers, are strongly associated with age, and their percentages are increased in late osteoblasts/osteocytes and CD24high osteolineage cells. Moreover, both late osteoblasts/osteocytes and CD24high osteolineage cells are robustly cleared by genetic and pharmacologic senolytic therapies in aged mice. Following isolation, CD24+ skeletal cells exhibit growth arrest, senescence-associated β-galactosidase positivity, and impaired osteogenesis in vitro. These studies thus provide an approach using multiplexed protein profiling to define senescent mesenchymal cells in vivo and identify specific skeletal cell populations cleared by senolytics.

Therapeutic advancements in targeting BCL-2 family proteins by epigenetic regulators, natural, and synthetic agents in cancer

Cancer is amongst the deadliest and most disruptive disorders, having a much higher death rate than other diseases worldwide. Human cancer rates continue to rise, thereby posing the most significant concerns for medical health professionals. In the last two decades, researchers have gone past several milestones in tackling cancer while gaining insight into the role of apoptosis in cancer or targeting various biomarker tools for prognosis and diagnosis. Apoptosis which is still a topic full of complexities, can be controlled considerably by B-cell lymphoma 2 (BCL-2) and its family members. Therefore, targeting proteins of this family to prevent tumorigenesis, is essential to focus on the pharmacological features of the anti-apoptotic and pro-apoptotic members, which will help to develop and manage this disorder. This review deals with the advancements of various epigenetic regulators to target BCL-2 family proteins, including the mechanism of several microRNAs (miRNAs) and long non-coding RNAs (lncRNAs). Similarly, a rise in natural and synthetic molecules' research over the last two decades has allowed us to acquire insights into understanding and managing the transcriptional alterations that have led to apoptosis and treating various neoplastic diseases. Furthermore, several inhibitors targeting anti-apoptotic proteins and inducers or activators targeting pro-apoptotic proteins in preclinical and clinical stages have been summarized. Overall, agonistic and antagonistic mechanisms of BCL-2 family proteins conciliated by epigenetic regulators, natural and synthetic agents have proven to be an excellent choice in developing cancer therapeutics.

miR-126 mitigates the osteogenic differentiation of human bone marrow-derived mesenchymal stem cells by targeting the ERK1/2 and Bcl-2 pathways

Human bone marrow mesenchymal stem cells (hBMMSCs) are a promising cell source for bone engineering owing to their high potential to differentiate into osteoblasts. The objective of the present study is to assess microRNA-126 (miR-126) and examine its effects on the osteogenic differentiation of hBMMSCs. In this study, we investigate the role of miR-126 in the progression of osteogenic differentiation (OD) as well as the apoptosis and inflammation of hBMMSCs during OD induction. OD is induced in hBMMSCs, and matrix mineralization along with other OD-associated markers are evaluated by Alizarin Red S (AR) staining and quantitative PCR (qPCR). Gain- and loss-of-function studies are performed to demonstrate the role of miR-126 in the OD of hBMMSCs. Flow cytometry and qPCR-based cytokine expression studies are performed to investigate the effect of miR-126 on the apoptosis and inflammation of hBMMSCs. The results indicate that miR-126 expression is downregulated during the OD of hBMMSCs. Gain- and loss-of function assays reveal that miR-126 upregulation inhibits the differentiation of hBMMSCs into osteoblasts, whereas the downregulation of miR-126 promotes hBMMSC differentiation, as assessed by the determination of osteogenic genes and alkaline phosphatase activity. Furthermore, the miR-126 level is positively correlated with the production of inflammatory cytokines and apoptotic cell death. Additionally, our results suggest that miR-126 negatively regulates not only B-cell lymphoma 2 (Bcl-2) expression but also the phosphorylation of extracellular signal‑regulated protein kinase (ERK) 1/2. Moreover, restoring ERK1/2 activity and upregulating Bcl-2 expression counteract the miR-126-mediated suppression of OD in hBMMSCs by promoting inflammation and apoptosis, respectively. Overall, our findings suggest a novel molecular mechanism relevant to the differentiation of hBMMSCs into osteoblasts, which can potentially facilitate bone formation by counteracting miR-126-mediated suppression of ERK1/2 activity and Bcl-2 expression.

Synthetic lethality of drug-induced polyploidy and BCL-2 inhibition in lymphoma

Spontaneous whole genome duplication and the adaptive mutations that disrupt genome integrity checkpoints are infrequent events in B cell lymphomas. This suggests that lymphomas might be vulnerable to therapeutics that acutely trigger genomic instability and polyploidy. Here, we report a therapeutic combination of inhibitors of the Polo-like kinase 4 and BCL-2 that trigger genomic instability and cell death in aggressive lymphomas. The synthetic lethality is selective for tumor cells and spares vital organs. Mechanistically, inhibitors of Polo-like kinase 4 impair centrosome duplication and cause genomic instability. The elimination of polyploid cells largely depends on the pro-apoptotic BAX protein. Consequently, the combination of drugs that induce polyploidy with the BCL-2 inhibitor Venetoclax is highly synergistic and safe against xenograft and PDX models. We show that B cell lymphomas are ill-equipped for acute, therapy-induced polyploidy and that BCL-2 inhibition further enhances the removal of polyploid lymphoma cells.

`Targeted pharmacologic inhibition of S-phase kinase-associated protein 2 (SKP2) mediated cell cycle regulation in lung and other RB-Related cancers: A brief review of current status and future prospects

Small cell lung cancer (SCLC) often exhibits Rb deficiency, TRβ and p130 deletion, and SKP2 amplification, suggesting TRβ inactivation and SKP2 activation. It is reported that SKP2 targeted therapy is effective in some cancers in vitro and in vivo, but it is not reported for the treatment of SCLC and retinoblastoma. SKP2 is the synthetic lethal gene in SCLC and retinoblastoma, so SKP2 can be used for targeted therapy in SCLC and retinoblastoma. RB1 knockout mice develop several kinds of tumors, but Rb1 and SKP2 double knockout mice are healthy, suggesting that SKP2 targeted therapy may have significant effects on Rb deficient cancers with less side effects, and if successful in SCLC and retinoblastoma in vitro and in animal model, such compounds may be promising for the clinical treatment of SCLC, retinoblastoma, and variety of Rb deficient cancers. Previously our studies showed that retinoblastomas exhibit retinal cone precursor properties and depend on cone-specific thyroid hormone receptor β2 (TRβ2) and SKP2 signaling. In this study, we sought to suppress SCLC and retinoblastoma cell growth by SKP2 inhibitors as a prelude to targeted therapy in vitro and in vivo. We knocked down TRβ2 and SKP2 or over-expressed p27 in SCLC and retinoblastoma cell lines to investigate SKP2 and p27 signaling alterations. The SCLC cell lines H209 as well as retinoblastoma cell lines Y79, WERI, and RB177 were treated with SKP2 inhibitor C1 at different concentrations, following which Western blotting, Immunostaining, and cell cycle kinetics studies were performed to study SKP2 and p27 expression ubiquitination, to determine impact on cell cycle regulation and growth inhibition. TRβ2 knockdown in Y79, RB177 and H209 caused SKP2 downregulation and degradation, p27 up-regulation, and S phase arrest, whereas, SKP2 knockdown or p27 over-expression caused p27 accumulation and G1-S phase arrest. In the cell lines Y79, WERI, RB177, and H209 treatment with C1 caused SKP2 ubiquitination and degradation, p27 de-ubiquitination and accumulation, and cell growth arrest. SKP2 inhibitor C1 significantly suppressed retinoblastoma as well as SCLC cell growth by SKP2 degradation and p27 accumulation. In vivo study also showed inhibition of tumor growth with C1 treatment. Potential limitations of the success of such a therapeutic approach and its translational application in human primary tumors, and alternative approaches to overcome such limitations are briefly discussed for the treatment of retinoblastoma, SCLC and other RB-related cancers.

G-quadruplex-mediated specific recognition, stabilization and transcriptional repression of bcl-2 by small molecule

The presence of the G-quadruplex (G4) structure in the promoter region of the human bcl-2 oncogenes makes it a promising target for developing anti-cancer therapeutics. Bcl-2 inhibits apoptosis, and its frequent overexpression in cancer cells contributes to tumor initiation, progression, and resistance to therapy. Small molecules that can specifically bind to bcl-2 G4 with high affinity and selectivity are remaining elusive. Here, we report that small molecule 1,3-bis-) furane-2yl-methylidene-amino) guanidine (BiGh) binds to bcl-2 G4 DNA structure with very high affinity and selectivity over other genomic G4 DNA structures and duplex DNA. BiGh stabilizes folded parallel conformation of bcl-2 G4 via non-covalent and electrostatic interactions and increases the thermal stabilization up to 15 °C. The ligand significantly suppresses the bcl-2 transcription in HeLa cells by a G4-dependent mechanism and induces cell cycle arrest which promotes apoptosis. The in silico ADME profiling confirms the potential 'drug-likeness' of BiGh. Our results showed that BiGh stabilizes the bcl-2 G-quadruplex motif, downregulates the bcl-2 gene transcription as well as translation process in cervical cancer cells, and exhibits potential anti-cancer activity. This work provides a potential platform for the development of lead compound(s) as G4 stabilizers with drug-like properties of BiGh for cancer therapeutics.

Multiparametric senescent cell phenotyping reveals CD24 osteolineage cells as targets of senolytic therapy in the aged murine skeleton

Senescence drives organismal aging, yet the deep characterization of senescent cells in vivo remains incomplete. Here, we applied mass cytometry by time-of-flight (CyTOF) using carefully validated antibodies to analyze senescent cells at single-cell resolution. We used multiple criteria to identify senescent mesenchymal cells that were growth arrested and resistant to apoptosis (p16+/Ki67-/BCL-2+; "p16KB" cells). These cells were highly enriched for senescence-associated secretory phenotype (SASP) and DNA damage markers and were strongly associated with age. p16KB cell percentages were also increased in CD24+ osteolineage cells, which exhibited an inflammatory SASP in aged mice and were robustly cleared by both genetic and pharmacologic senolytic therapies. Following isolation, CD24+ skeletal cells exhibited growth arrest, SA-βgal positivity, and impaired osteogenesis in vitro . These studies thus provide a new approach using multiplexed protein profiling by CyTOF to define senescent mesenchymal cells in vivo and identify a highly inflammatory, senescent CD24+ osteolineage population cleared by senolytics.

miR-450-5p and miR-202-5p Synergistically Regulate Follicle Development in Black Goat

Follicle maturation is a complex biological process governed by numerous factors, and researchers have observed follicle development by studying the proliferation and apoptosis of follicular granulosa cells (GCs). However, the regulatory mechanisms of GCs proliferation and death during follicle development are largely unknown. To investigate the regulatory mechanisms of lncRNAs, mRNAs, and microRNAs, RNA sequencing (RNA-seq) and small RNA-seq were performed on large (>10 mm) and small follicles (<3 mm) of Leizhou black goat during estrus. We discovered two microRNAs, miR-450-5p and miR-202-5p, which can target GCs in goats and may be involved in follicle maturation, and the effects of miR-450-5p and miR-202-5p on ovarian granulosa cell lines were investigated (KGN). Using cell counting kit-8 (CCK-8) assays, 5-Ethynyl-2’-deoxyuridine (EdU) assay and flow cytometry, miR-202-5p overexpression could suppress the proliferation and induce apoptosis of GCs, whereas miR-450-5p overexpression induced the opposite effects. The dual-luciferase reporter assay confirmed that miR-450-5p could directly target the BMF gene (a BCL2 modifying factor), and miR-202-5p targeted the BCL2 gene. A considerable rise in phosphorylated Akt (p-AKT) protein was observed following the downregulation of BMF by miR-450-5p mimics. After BMF gene RNAi therapy, a notable elevation in p-AKT was detected. Mimics of miR-202-5p inhibited BCL2 protein expression, significantly decreasing p-AMPK protein expression. These results imply that during the follicular development in black goats, the miR-450-5p-BMF axis favored GC proliferation on a wide scale, while the miR-202-5p-BCL2 axis triggered GC apoptosis.

Modulation of Ca2+ signaling by antiapoptotic Bcl-2 versus Bcl-xL: From molecular mechanisms to relevance for cancer cell survival

Members of the Bcl-2-protein family are key controllers of apoptotic cell death. The family is divided into antiapoptotic (including Bcl-2 itself, Bcl-xL, Mcl-1, etc.) and proapoptotic members (Bax, Bak, Bim, Bim, Puma, Noxa, Bad, etc.). These proteins are well known for their canonical role in the mitochondria, where they control mitochondrial outer membrane permeabilization and subsequent apoptosis. However, several proteins are recognized as modulators of intracellular Ca²⁺ signals that originate from the endoplasmic reticulum (ER), the major intracellular Ca²⁺-storage organelle. More than 25 years ago, Bcl-2, the founding member of the family, was reported to control apoptosis through Ca²⁺ signaling. Further work elucidated that Bcl-2 directly targets and inhibits inositol 1,4,5-trisphosphate receptors (IP₃Rs), thereby suppressing proapoptotic Ca²⁺ signaling. In addition to Bcl-2, Bcl-xL was also shown to impact cell survival by sensitizing IP₃R function, thereby promoting prosurvival oscillatory Ca²⁺ release. However, new work challenges this model and demonstrates that Bcl-2 and Bcl-xL can both function as inhibitors of IP₃Rs. This suggests that, depending on the cell context, Bcl-xL could support very distinct Ca²⁺ patterns. This not only raises several questions but also opens new possibilities for the treatment of Bcl-xL-dependent cancers. In this review, we will discuss the similarities and divergences between Bcl-2 and Bcl-xL regarding Ca²⁺ homeostasis and IP₃R modulation from both a molecular and a functional point of view, with particular emphasis on cancer cell death resistance mechanisms.

Potassium Channel KCNH1 Activating Variants Cause Altered Functional and Morphological Ciliogenesis

The primary cilium is a non-motile sensory organelle that extends from the surface of most vertebrate cells and transduces signals regulating proliferation, differentiation, and migration. Primary cilia dysfunctions have been observed in cancer and in a group of heterogeneous disorders called ciliopathies, characterized by renal and liver cysts, skeleton and limb abnormalities, retinal degeneration, intellectual disability, ataxia, and heart disease and, recently, in autism spectrum disorder, schizophrenia, and epilepsy. The potassium voltage-gated channel subfamily H member 1 (KCNH1) gene encodes a member of the EAG (ether-à-go-go) family, which controls potassium flux regulating resting membrane potential in both excitable and non-excitable cells and is involved in intracellular signaling, cell proliferation, and tumorigenesis. KCNH1 missense variants have been associated with syndromic neurodevelopmental disorders, including Zimmermann-Laband syndrome 1 (ZLS1, MIM #135500), Temple-Baraitser syndrome (TMBTS, MIM #611816), and, recently, with milder phenotypes as epilepsy. In this work, we provide evidence that KCNH1 localizes at the base of the cilium in pre-ciliary vesicles and ciliary pocket of human dermal fibroblasts and retinal pigment epithelial (hTERT RPE1) cells and that the pathogenic missense variants (L352V and R330Q; NP_002229.1) perturb cilia morphology, assembly/disassembly, and Sonic Hedgehog signaling, disclosing a multifaceted role of the protein. The study of KCNH1 localization, its functions related to primary cilia, and the alterations introduced by mutations in ciliogenesis, cell cycle coordination, cilium morphology, and cilia signaling pathways could help elucidate the molecular mechanisms underlying neurological phenotypes and neurodevelopmental disorders not considered as classical ciliopathies but for which a significant role of primary cilia is emerging.

Identification of bicyclic compounds that act as dual inhibitors of Bcl-2 and Mcl-1

Elevated expression of anti-apoptotic proteins, such as Bcl-2 and Mcl-1 contributes to poor prognosis and resistance to current treatment modalities in multiple cancers. Here, we report the design, synthesis and characterization of benzimidazole chalcone and flavonoid scaffold-derived bicyclic compounds targeting both Bcl-2 and Mcl-1 by optimizing the structural differences in the binding sites of both these proteins. Initial docking screen of Bcl-2 and Mcl-1 with pro-apoptotic protein Bim revealed possible hits with optimal binding energies. All the optimized bicyclic compounds were screened for their in vitro cytotoxic activity against two oral cancer cell lines (AW8507 and AW13516) which express high levels of Bcl-2 and Mcl-1. Compound 4d from the benzimidazole chalcone series and compound 6d from the flavonoid series exhibited significant cytotoxic activity (IC₅₀ 7.12 μM and 17.18 μM, respectively) against AW13516 cell line. Time Resolved-Fluorescence Resonance Energy Transfer (TR-FRET) analysis further demonstrated that compound 4d and compound 6d could effectively inhibit the Bcl-2 and Mcl-1 proteins by displacing their BH3 binding partners. Both compounds exhibited potent activation of canonical pathway of apoptosis evident from appearance of cleaved Caspase-3 and PARP. Further, treatment of oral cancer cells with the inhibitors induced dissociation of the BH3 only protein Bim from Mcl-1 and Bak from Bcl-2 but failed to release Bax from Bcl-xL thereby confirming the nature of compounds as BH3-mimetics selectively targeting Bcl-2 and Mcl-1. Our study thus identifies bicyclic compounds as promising candidates for anti-apoptotic Bcl-2/Mcl-1 dual inhibitors with a potential for further development.

Single Nucleotide Polymorphisms of EXOC1, BCL2, CCAT2, and CARD8 Genes and Susceptibility to Cervical Cancer in the Northern Chinese Han Population

Cervical cancer (CC) is one of the main malignant tumors that threaten the health and lives of women around the world, and its morbidity and mortality rate ranks fourth. At present, most studies on the genetic background of CC focus on genetic polymorphisms. Single nucleotide polymorphisms (SNPs) are considered clinically as potential diagnostic and therapeutic biomarkers for a variety of tumors. Therefore, we aimed to explore the association between SNPs in different genes (EXOC1 gene, BCL2 gene, CCAT2 gene and CARD8 gene) and susceptibility to CC. This study is a case-control study based on women in northern Chinese, which included 492 women with CC and 510 healthy women. This study used multiplex PCR combined with next-generation sequencing to genotype the selected SNPs (rs13117307(C/T) in EXOC1 gene, rs2279115(C/A) in BCL2 gene, rs6983267(G/T) in CCAT2 gene and rs7248320(G/A) in CARD8 gene). The results of the study showed that there was no significant association between the four SNPs and the susceptibility to CC. However, in further stratified analysis, we found that rs13117307 and rs2279115 were significantly related to squamous cell carcinoma antigen (SCC-Ag) levels in women with CC, and rs6983267 was significantly related to the menopausal status of women with CC. Specifically, alleles T of rs13117307 and genoytpe AA of rs2279115 when SCC-Ag is greater than 1.5 ng/ml increase the risk of CC. The genotype TG/TG+TT of rs6983267 increases the risk of CC in premenopausal women. In conclusion, although we did not directly find a significant correlation between four SNPs, rs13117307 in EXOC1 gene,rs2279115 in BCL2 gene, rs6983267 in CCAT2 gene and rs7248320 in CARD8 gene, and CC susceptibility, we found that SNPs rs13117307, rs2279115, rs6983267 were associated with the clinical characteristics of several patients' CC patients. Therefore, this study provides us with new ideas for understanding CC and the diagnosis and treatment of CC in the future.

Whole-Genome Analyses Reveal Genomic Characteristics and Selection Signatures of Lincang Humped Cattle at the China-Myanmar Border

The location on the Yunnan border with Myanmar and its unique cultural landscape has shaped Lincang humped cattle over time. In the current study, we investigated the genetic characteristics of 22 Lincang humped cattle using whole-genome resequencing data. We found that Lincang humped cattle derived from both Indian indicine and Chinese indicine cattle depicted higher levels of genomic diversity. Based on genome-wide scans, candidate genomic regions were identified that were potentially involved in local thermal and humid environmental adaptions, including genes associated with the body size (TCF12, SENP2, KIF1C, and PFN1), immunity (LIPH, IRAK3, GZMM, and ELANE), and heat tolerance (MED16, DNAJC8, HSPA4, FILIP1L, HELB, BCL2L1, and TPX2). Missense mutations were detected in candidate genes IRAK3, HSPA4, and HELB. Interestingly, eight missense mutations observed in the HELB gene were specific to the indicine cattle pedigree. These mutations may reveal differences between indicine and taurine cattle adapted to variable climatic conditions. Our research provides new insights into the genetic characteristics of Lincang humped cattle representing Lincang and Pu'er areas as an important channel for the migration of Indian indicine from domestication centers toward southwestern China.

Casein kinase II activates Bik to induce death of hyperplastic mucous cells in a cell cycle-dependent manner

Extensive inflammation causes epithelial cell hyperplasia in the airways and Bcl-2-interacting killer (Bik) reduces epithelial cell and mucous cell hyperplasia without affecting resting cells to restore homeostasis. These observations suggest that Bik induces apoptosis in a cell cycle-specific manner, but the mechanisms are not understood. Mice were exposed to an allergen for 3, 14, or 30 days and Bik expression was induced in airway epithelia of transgenic mice. Bik reduced epithelial and mucous cell hyperplasia when mice were exposed to an allergen for 3 or 14 days, but not when exposure lasted for 30 days, and Ki67-positivity was reduced. In culture, Bik expression killed proliferating cells but not quiescent cells. To capture the stage of the cell cycle when Bik induces cell death, airway cells that express fluorescent ubiquitin cell cycle indicators were generated that fluoresce red or green during the G0/G1 and S/G2/M phases of the cells cycle, respectively. Regardless of the cell cycle stage, Bik expression eliminated green-fluorescent cells. Also, Bik, when tagged with a blue-fluorescent protein, was only detected in green cells. Bik phosphorylation mutants at threonine 33 or serine 35 demonstrated that phosphorylation activated Bik to induce death even in quiescent cells. Immunoprecipitation and proteomic approaches identified casein kinase IIα to be responsible for phosphorylating and activating Bik to kill cells in S/G2/M. As casein kinase 2 alpha (CKIIα) is expressed only during the G2/M phase, we conclude that Bik activation in airway epithelial cells selectively targets hyperplastic epithelial cells, while leaving resting airway cells unaffected.

Integrating network pharmacology deciphers the action mechanism of Zuojin capsule in suppressing colorectal cancer

BACKGROUND AND PURPOSE

Zuojin capsule (ZJC), a classical prescription, is outstanding in improving the conditions of patients with gastrointestinal diseases and colorectal cancer (CRC). Although ZJC has multi-ingredient and multi-target characteristics, its pharmacological effect on colorectal cancer and the underlying mechanism remain unclear.

METHOD

Here, the activity of ZJC against CRC was evaluated by the experiments with CRC cells and HCT-116 xenografted mice. The key genes of CRC were obtained from the cancer genome atlas (TCGA). The genes potentially targeted by ZJC were collected from traditional Chinese medicine systems pharmacology (TCMSP) database. The underlying pathways related to selected targets were analyzed through gene ontology (GO) and pathway enrichment analyses. Western blot (WB), cellular thermal shift assay (CETSA), molecular docking and quantitative real-time PCR (QRT-PCR) were carried out to confirm the validity of the targets.

RESULTS

In vitro and in vivo results indicated that ZJC may inhibit CRC cells and tumor growth. The network pharmacological analysis indicated that 22 compounds, 51 targets and 20 pathways were involved in the compound-target-pathway network. Our results confirmed that ZJC inhibited cycle progression, migration and induced apoptosis by targeting candidate genes (CDKN1A, Bcl2, E2F1, PRKCB, MYC, CDK2, and MMP9). We found that ZJC could directly change the protein level by regulating the protein stability and transcriptional activity of the target.

CONCLUSIONS

In summary, combined network pharmacology and biological experiments proved that the main ingredients of ZJC such as quercetin, (R)-Canadine, palmatine, rutaecarpine, evodiamine, beta-sitosterol and berberine can target CDKN1A, Bcl2, E2F1, PRKCB, MYC, CDK2 and MMP9 to combat colorectal cancer. The results of this study provide a basic theory for the clinical trials of Zuojin Capsules against colorectal cancer.

Growth Inhibition and Apoptotic Effect of Pine Extract and Abietic Acid on MCF-7 Breast Cancer Cells via Alteration of Multiple Gene Expressions Using In Vitro Approach

In vitro anti-proliferative activity of Pinus palustris extract and its purified abietic acid was assessed against different human cancer cell lines (HepG-2, MCF-7 and HCT-116) compared to normal WI-38 cell line. Abietic acid showed more promising IC50 values against MCF-7 cells than pine extract (0.06 µg/mL and 0.11 µM, respectively), with insignificant cytotoxicity toward normal fibroblast WI-38 cells. Abietic acid triggered both G2/M cell arrest and subG0-G1 subpopulation in MCF-7, compared to SubG0-G1 subpopulation arrest only for the extract. It also induced overexpression of key apoptotic genes (Fas, FasL, Casp3, Casp8, Cyt-C and Bax) and downregulation of both proliferation (VEGF, IGFR1, TGF-β) and oncogenic (C-myc and NF-κB) genes. Additionally, abietic acid induced overexpression of cytochrome-C protein. Furthermore, it increased levels of total antioxidants to diminish carcinogenesis and chemotherapy resistance. P. palustris is a valuable source of active abietic acid, an antiproliferative agent to MCF-7 cells through induction of apoptosis with promising future anticancer agency in breast cancer therapy.

Structural, biological and computational study of oxamide derivative

A dicarboxylato-diamide-type compound 2,2'-[(1,2-dioxoethane-1,2- -diyl)diimino]dibenzoic acid (H4obbz) (1) was synthesized and characterized. The crystal structure of K2H2obbz?2H2O (2) was determined by X-ray diffracttion analysis. The cytotoxic activities of the compounds were tested against four different cancer cell lines MCF-7, A549, HT-29, HeLa and a human normal cell line MRC-5. The results indicate reasonable dose-dependent cytotoxicity of the ligands that show selectivity against the tested carcinoma and healthy cell lines. Flow cytometric analysis and fluorescence microscopy showed that the most active compound, H4obbz, induced apoptosis and G0/G1 cell cycle arrest, indicating blockage of DNA synthesis as a possible mechanism that triggers apoptosis. Docking and molecular dynamics simulations gave similar responses regarding interactions (binding) between their ligands and chaperon Grp78. The MMGBSA determined ?G binding energies were in the range from -104 to -140 kJ mol-1.

Differential gene expression of BCL-2, ZEB2-AS1 and BALR-2 in prostate cancer and benign prostatic hyperplasia

Prostate cancer (PCa) and benign prostate hyperplasia (BPH) are highly prevalent heterogeneous disorders among men. Whereas PCa and BPH underline common pathological features, apoptotic-related genes might be differentially expressed in these diseases. This study was aimed at testing BCL-2 as well as BALR-2 and ZEB2-AS1 apoptosis-related long non-coding RNA (lncRNA) in patients with PCa and BPH. The expression levels of the BCL-2 gene and ZEB2-AS1 lncRNA were upregulated in tumoural tissues in comparison to adjacent non-cancerous tissues (ANCTs) and BPH tissues. In contrast, the expression level of BALR-2 lncRNA was significantly higher in BPH compared with tumoural tissues. Furthermore, while no association was noticed between the relative expression of ZEB2-AS1 and the tumour grade, the relative expression of BCL-2 and BALR-2 is strongly associated with a higher grade of the tumour in PCa samples compared with the ANCTs. The receiver operating characteristic (ROC) curve analysis indicated the highest specificity and diagnostic value in distinguishing PCa and ANCTs as well as PCa and BPH, respectively. In conclusion, altered expression of BCL-2 and BALR-2 was observed to be associated with tumoural progression and could be used as potential candidates for distinguishing PCa tissues from ANCTs or BPH samples.

Paradoxical implication of BAX/BAK in the persistence of tetraploid cells

Pro-apoptotic multi-domain proteins of the BCL2 family such as BAX and BAK are well known for their important role in the induction of mitochondrial outer membrane permeabilization (MOMP), which is the rate-limiting step of the intrinsic pathway of apoptosis. Human or mouse cells lacking both BAX and BAK (due to a double knockout, DKO) are notoriously resistant to MOMP and cell death induction. Here we report the surprising finding that BAX/BAK DKO cells proliferate less than control cells expressing both BAX and BAK (or either BAX or BAK) when they are driven into tetraploidy by transient exposure to the microtubule inhibitor nocodazole. Mechanistically, in contrast to their BAX/BAK-sufficient controls, tetraploid DKO cells activate a senescent program, as indicated by the overexpression of several cyclin-dependent kinase inhibitors and the activation of β-galactosidase. Moreover, DKO cells manifest alterations in ionomycin-mobilizable endoplasmic reticulum (ER) Ca2+ stores and store-operated Ca2+ entry that are affected by tetraploidization. DKO cells manifested reduced expression of endogenous sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a (Serca2a) and transfection-enforced reintroduction of Serca2a, or reintroduction of an ER-targeted variant of BAK into DKO cells reestablished the same pattern of Ca2+ fluxes as observed in BAX/BAK-sufficient control cells. Serca2a reexpression and ER-targeted BAK also abolished the tetraploidy-induced senescence of DKO cells, placing ER Ca2+ fluxes downstream of the regulation of senescence by BAX/BAK. In conclusion, it appears that BAX/BAK prevent the induction of a tetraploidization-associated senescence program. Speculatively, this may contribute to the low incidence of cancers in BAX/BAK DKO mice and explain why human cancers rarely lose the expression of both BAX and BAK.

Stress Relief Techniques: p38 MAPK Determines the Balance of Cell Cycle and Apoptosis Pathways

Protein signaling networks are formed from diverse and inter-connected cell signaling pathways converging into webs of function and regulation. These signaling pathways both receive and conduct molecular messages, often by a series of post-translation modifications such as phosphorylation or through protein-protein interactions via intrinsic motifs. The mitogen activated protein kinases (MAPKs) are components of kinase cascades that transmit signals through phosphorylation. There are several MAPK subfamilies, and one subfamily is the stress-activated protein kinases, which in mammals is the p38 family. The p38 enzymes mediate a variety of cellular outcomes including DNA repair, cell survival/cell fate decisions, and cell cycle arrest. The cell cycle is itself a signaling system that precisely controls DNA replication, chromosome segregation, and cellular division. Another indispensable cell function influenced by the p38 stress response is programmed cell death (apoptosis). As the regulators of cell survival, the BCL2 family of proteins and their dynamics are exquisitely sensitive to cell stress. The BCL2 family forms a protein-protein interaction network divided into anti-apoptotic and pro-apoptotic members, and the balance of binding between these two sides determines cell survival. Here, we discuss the intersections among the p38 MAPK, cell cycle, and apoptosis signaling pathways.

Betulinic Acid-Doxorubicin-Drug Combination Induced Apoptotic Death via ROS Stimulation in a Relapsed AML MOLM-13 Cell Model

In this study, cell death regulation and induction in AML cell line from a relapsed MLL-rearranged cell model (MOLM-13) was investigated with doxorubin (Dox) and betulinic acid (BetA), singly and in combination. CyQUANT Direct^® and Annexin V/propidium iodide double staining were used to measure the cytotoxic and cell death induction effects of the compounds, respectively. Reactive oxygen species (ROS) generation was measured using 2′,7′-dichlorofluorescin diacetate staining. Expressions of proteins and genes were examined by Western blot and reverse transcription polymerase chain reaction analysis, respectively. BetA (20 μM) and Dox (1 μM) indicated a synergistic growth inhibitory effect on MOLM-13 cells. The combined drug caused more cells to reside in irreversible late apoptotic stage compared to the single treatments (p < 0.05). Elevation in ROS may be the synergistic mechanism involved in MOLM-13 cell death since ROS can directly disrupt mitochondrial activity. In contrast, in leukaemic U-937 cells, the combination treatments attenuated Dox-induced cell death. Dox and the drug combination selectively reduced (p < 0.05) a recently reported anti-apoptotic Bcl-2 protein isoform p15-20-Bcl-2 in MOLM-13 by our group, without affecting the usually reported p26-Bcl-2-α. Further studies using known inhibitors of apoptosis are required to confirm the potential of Dox-BetA combination to modulate these pathways.

The multiple mechanisms of MCL1 in the regulation of cell fate

MCL1 (myeloid cell leukemia-1) is a widely recognized pro-survival member of the Bcl-2 (B-cell lymphoma protein 2) family and a promising target for cancer therapy. While the role MCL1 plays in apoptosis is well defined, its participation in emerging non-apoptotic signaling pathways is only beginning to be appreciated. Here, we synthesize studies characterizing MCL1s influence on cell proliferation, DNA damage response, autophagy, calcium handling, and mitochondrial quality control to highlight the broader scope that MCL1 plays in cellular homeostasis regulation. Throughout this review, we discuss which pathways are likely to be impacted by emerging MCL1 inhibitors, as well as highlight non-cancerous disease states that could deploy Bcl-2 homology 3 (BH3)-mimetics in the future.

In this review Widden and Placzek synthesize studies characterizing the influence that myeloid cell leukemia-1 (MCL1) has on cell proliferation, DNA damage response, autophagy, calcium handling, and mitochondrial quality control to highlight the broader scope that it plays in cellular homeostasis regulation. They discuss which pathways are likely to be impacted by emerging MCL1 inhibitors, as well as highlight non-cancerous disease states that could deploy BH3-mimetics in the future.

Prognostic influences of BCL1 and BCL2 expression on disease-free survival in breast cancer

We investigated the prognostic influences of BCL1 and BCL2 expression on disease-free survival in breast cancer patients. BCL1 and BCL2 expression statuses were assessed by immunohistochemistry using tissue microarrays from 393 breast cancer patients. The Kaplan–Meier estimator and log-rank test were used for survival analyses. The Cox proportional hazards model was used to calculate hazard ratio (HR) and the 95% confidence interval (CI) of survival analyses. BCL1 expression revealed no impact on survival. The high BCL2 group showed superior disease-free survival compared with the low BCL2 group (p = 0.002), especially regarding local recurrence-free survival (p = 0.045) and systemic recurrence-free survival (p = 0.002). BCL2 expression was a significant prognostic factor by univariable analysis (HR, 0.528; 95% CI, 0.353–0.790; p = 0.002) and by multivariable analysis (HR, 0.547; 95% CI, 0.362–0.826; p = 0.004). High BCL2 expression was associated with higher disease-free survival in the hormone receptor (HRc)-positive and human epidermal growth factor receptor 2 (HER2)-negative (HRc(+)/HER2(−)) subtype only (p = 0.002). The high BCL2 group was associated with positive estrogen receptor (ER), positive progesterone receptor (PR), low histologic grade, and age ≤ 50 years. BCL1 expression had no prognostic impact, but BCL2 expression was a significant independent prognostic factor. High BCL2 expression was associated with higher disease-free survival, especially regarding local recurrence and systemic recurrence. The prognostic effect of BCL2 expression was effective only in the HRc(+)/HER2(−) subtype. Favorable clinicopathologic features and a strong association with the ER/PR status could partly explain the superior prognosis of the high BCL2 group. BCL2 expression could be utilized to assess the prognosis of breast cancer patients in clinical settings.

Role of Glycans on Key Cell Surface Receptors That Regulate Cell Proliferation and Cell Death

Cells undergo proliferation and apoptosis, migration and differentiation via a number of cell surface receptors, most of which are heavily glycosylated. This review discusses receptor glycosylation and the known roles of glycans on the functions of receptors expressed in diverse cell types. We included growth factor receptors that have an intracellular tyrosine kinase domain, growth factor receptors that have a serine/threonine kinase domain, and cell-death-inducing receptors. N- and O-glycans have a wide range of functions including roles in receptor conformation, ligand binding, oligomerization, and activation of signaling cascades. A better understanding of these functions will enable control of cell survival and cell death in diseases such as cancer and in immune responses.

Acute toxicity analysis of an inhibitor of BCL2, Disarib, in rats

Apoptosis or programmed cell death is a highly regulated process, which eliminates unwanted and damaged cells. Inhibition of apoptosis is a hallmark of cancer cells. BCL2 family proteins are known to play a vital role in the regulation of apoptosis. Overexpression of BCL2, an antiapoptotic protein, provides the advantage of prolonged survival to cancer cells. Over the years, several BCL2 inhibitors have been investigated extensively for their anticancer potential. However, most of them were abolished before clinical use due to their side effects. Previously, we had identified and characterized a novel BCL2 inhibitor, Disarib, with the potential to eliminate tumor cells in a BCL2 specific manner leading to reduction in tumor burden in multiple mouse models. Notably, a head-to-head comparison of Disarib to ABT199, the only FDA approved BCL2 inhibitor revealed that Disarib is as potent as ABT199. Recent studies using mice revealed that Disarib did not invoke significant side effects in mice. In the present study, we have investigated the acute toxicity of Disarib in Wistar rats. The bioavailability studies following exposure of Disarib in Wistar rats revealed its maximum availability in serum at 24 h following oral administration. Acute toxicity analysis revealed that even a dose as high as 2000 mg/kg of Disarib did not cause significant toxicity in rats. There was no significant variation in blood parameters or kidney and liver functions following administration of Disarib. Histological analysis of different tissues from Disarib treated groups revealed standard architecture with no observable cellular damage. Importantly, exposure to Diasrib did not result in genotoxicity as determined by micronucleus assay. Further, solubility assays revealed that besides DMSO, Disarib is also soluble in alcohol. While the high acidic condition can increase the solubility of Disarib, even a lower percentage of alcohol with acidic conditions can improve its solubility. Thus, the toxicological profile in the current study revealed no significant side effects when Disarib was administered orally to rats.

Ten-Eleven Translocation 1 Promotes Malignant Progression of Cholangiocarcinoma With Wild-Type Isocitrate Dehydrogenase 1

BACKGROUND AND AIMS

Cholangiocarcinoma (CCA) is a highly lethal disease without effective therapeutic approaches. The whole-genome sequencing data indicate that about 20% of patients with CCA have isocitrate dehydrogenase 1 (IDH1) mutations, which have been suggested to target 2-oxoglutarate (OG)-dependent dioxygenases in promoting CCA carcinogenesis. However, the clinical study indicates that patients with CCA and mutant IDH1 have better prognosis than those with wild-type IDH1, further complicating the roles of 2-OG-dependent enzymes.

APPROACH AND RESULTS

This study aimed to clarify if ten-eleven translocation 1 (TET1), which is one of the 2-OG-dependent enzymes functioning in regulating 5-hydroxymethylcytosine (5hmC) formation, is involved in CCA progression. By analyzing The Cancer Genome Atlas (TCGA) data set, TET1 mRNA was found to be substantially up-regulated in patients with CCA when compared with noncancerous bile ducts. Additionally, TET1 protein expression was significantly elevated in human CCA tumors. CCA cells were challenged with α-ketoglutarate (α-KG) and dimethyl-α-KG (DM-α-KG), which are cosubstrates for TET1 dioxygenase. The treatments with α-KG and DM-α-KG promoted 5hmC formation and malignancy of CCA cells. Molecular and pharmacological approaches were used to inhibit TET1 activity, and these treatments substantially suppressed 5hmC and CCA carcinogenesis. Mechanistically, it was found that knockdown of TET1 may suppress CCA progression by targeting cell growth and apoptosis through epigenetic regulation. Consistently, targeting TET1 significantly inhibited CCA malignant progression in a liver orthotopic xenograft model by targeting cell growth and apoptosis.

CONCLUSIONS

Our data suggest that expression of TET1 is highly associated with CCA carcinogenesis. It will be important to evaluate TET1 expression in CCA tumors before application of the IDH1 mutation inhibitor because the inhibitor suppresses 2-hydroxyglutarate expression, which may result in activation of TET, potentially leading to CCA malignancy.

Two Distinct Faces of Vitamin C: AA vs. DHA

Historically, vitamin C has been associated with many regulatory processes that involve specific signaling pathways. Among the most studied signaling pathways are those involved in the regulation of aging, differentiation, neurotransmission, proliferation, and cell death processes in cancer. This wide variety of regulatory effects is due to the fact that vitamin C has a dual mechanism of action. On the one hand, it regulates the expression of genes associated with proliferation (Ccnf and Ccnb1), differentiation (Sox-2 and Oct-4), and cell death (RIPK1 and Bcl-2). At the same time, vitamin C can act as a regulator of kinases, such as MAPK and p38, or by controlling the activation of the NF-kB pathway, generating chronic responses related to changes in gene expression or acute responses associated with the regulation of signal transduction processes. To date, data from the literature show a permanent increase in processes regulated by vitamin C. In this review, we critically examine how vitamin C regulates these different cellular programs in normal and tumor cells.

Transcriptional repression of NFKBIA triggers constitutive IKK- and proteasome-independent p65/RelA activation in senescence

The IκB kinase (IKK)‐NF‐κB pathway is activated as part of the DNA damage response and controls both inflammation and resistance to apoptosis. How these distinct functions are achieved remained unknown. We demonstrate here that DNA double‐strand breaks elicit two subsequent phases of NF‐κB activation in vivo and in vitro, which are mechanistically and functionally distinct. RNA‐sequencing reveals that the first‐phase controls anti‐apoptotic gene expression, while the second drives expression of senescence‐associated secretory phenotype (SASP) genes. The rapidly activated first phase is driven by the ATM‐PARP1‐TRAF6‐IKK cascade, which triggers proteasomal destruction of inhibitory IκBα, and is terminated through IκBα re‐expression from the NFKBIA gene. The second phase, which is activated days later in senescent cells, is on the other hand independent of IKK and the proteasome. An altered phosphorylation status of NF‐κB family member p65/RelA, in part mediated by GSK3β, results in transcriptional silencing of NFKBIA and IKK‐independent, constitutive activation of NF‐κB in senescence. Collectively, our study reveals a novel physiological mechanism of NF‐κB activation with important implications for genotoxic cancer treatment.

Individual-oocyte transcriptomic analysis shows that genotoxic chemotherapy depletes human primordial follicle reserve in vivo by triggering proapoptotic pathways without growth activation

Gonadotoxic chemotherapeutics, such as cyclophosphamide, can cause early menopause and infertility in women. Earlier histological studies showed ovarian reserve depletion via severe DNA damage and apoptosis, but others suggested activation of PI3K/PTEN/Akt pathway and follicle ‘burn-out’ as a cause. Using a human ovarian xenograft model, we performed single-cell RNA-sequencing on laser-captured individual primordial follicle oocytes 12 h after a single cyclophosphamide injection to determine the mechanisms of acute follicle loss after gonadotoxic chemotherapy. RNA-sequencing showed 190 differentially expressed genes between the cyclophosphamide- and vehicle-exposed oocytes. Ingenuity Pathway Analysis predicted a significant decrease in the expression of anti-apoptotic pro-Akt PECAM1 (p = 2.13E-09), IKBKE (p = 0.0001), and ANGPT1 (p = 0.003), and reduced activation of PI3K/PTEN/Akt after cyclophosphamide. The qRT-PCR and immunostaining confirmed that in primordial follicle oocytes, cyclophosphamide did not change the expressions of Akt (p = 0.9), rpS6 (p = 0.3), Foxo3a (p = 0.12) and anti-apoptotic Bcl2 (p = 0.17), nor affect their phosphorylation status. There was significantly increased DNA damage by γH2AX (p = 0.0002) and apoptosis by active-caspase-3 (p = 0.0001) staining in the primordial follicles and no change in the growing follicles 12 h after chemotherapy. These data support that the mechanism of acute follicle loss by cyclophosphamide is via apoptosis, rather than growth activation of primordial follicle oocytes in the human ovary.

Apoptosis of lung cells regulated by mitochondrial signal pathway in crotonaldehyde-induced lung injury

Crotonaldehyde, a highly toxic α, β-unsaturated aldehyde, is a ubiquitous hazardous pollutant. Because of its extreme toxicity and ubiquity in all types of smoke, most current research focuses on the lung toxicity of such air pollutants. However, the specific mechanism of pulmonary toxicity caused by crotonaldehyde remains unclear, especially after long-term exposure to crotonaldehyde at low dose. Therefore, the aim of the present study is to determine whether crotonaldehyde-induced oxidative damage and inflammation promote apoptosis in rats via the mitochondrial pathway using histopathology, immunohistochemistry, biochemistry analysis and Western blot analysis. The results show that crotonaldehyde elicited oxidative damage and inflammation in rats in a concentration-dependent manner. Crotonaldehyde-induced lung injury which was confirmed by H&E, Masson's trichrome staining and TUNEL. And crotonaldehyde-induced lung cell apoptosis showed a concentration-response relationship. Immunohistochemistry and Western blot results showed that apoptotic mitochondrial signaling pathway is abnormally activated in crotonaldehyde-induced lung injury. Collectively, this study demonstrates that exposure of rats to crotonaldehyde induces lung injury by inducing apoptosis, which is related to oxidative damage and inflammation through mitochondrial pathway.

Folate-Targeted Cholesterol-Grafted Lipo-Polymeric Nanoparticles for Chemotherapeutic Agent Delivery

Docetaxel (DTX), an FDA approved chemotherapeutic agent, is used as a first-line treatment for triple-negative breast cancer (TNBC). Its poor aqueous solubility, rapid metabolism, short half-life, and effective targeting to the cancer cells limits its optimal therapeutic use. Herein, we report folate targeted amphiphilic lipopolymer grafted with cholesterol conjugated carbonate and DL-lactide prepared by microwave assisted ring opening polymerization, for the efficient actively targeted delivery of DTX. The DTX-loaded folate-targeted lipopolymeric nanoparticles (F-DTX-LPNs) prepared by the emulsion solvent evaporation method exhibited a smaller size of ∼115.17 nm with a PDI of 0.205 and encapsulation efficiency of >80%. Further, these lipopolymeric nanoparticles (F-DTX-LPNs) showed a good on-bench stability and sustained DTX release for 7 days. Cell-based assays in MDA-MB-231 cells revealed a significant enhancement in the intracellular uptake of folate-targeted lipopolymeric nanoparticles compared to non-targeted nanoparticles. Further, methyl beta-cyclodextrin (Mβ-CD) completely inhibited the uptake of these nanoparticles in the cells, indicating a lipid raft-mediated uptake mechanism. The developed F-DTX-LPNs showed improved cytotoxicity, apoptosis, and significant fold-change in expression levels of Bcl-2, BAX and Ki-67 as compared to non-targeted DTX-LPNs and free DTX. Further, F-DTX-LPNs showed an improved in vivo pharmacokinetic profile in Sprague Dawley rats as compared to the free DTX. The bio-imaging of ex vivo tissues demonstrated that the DiR loaded folate targeted LPNs exhibited intense signals after 24 h because of slow release of DiR dye from the nanoparticles.

The Hepatic Microenvironment Uniquely Protects Leukemia Cells through Induction of Growth and Survival Pathways Mediated by LIPG

Due to the disseminated nature of leukemia, malignant cells are exposed to many different tissue microenvironments, including a variety of extramedullary sites. In the present study, we demonstrate that leukemic cells residing in the liver display unique biological properties and also contribute to systemic changes that influence physiologic responses to chemotherapy. Specifically, the liver microenvironment induces metabolic adaptations via upregulating expression of endothelial lipase in leukemia cells, which not only stimulates tumor cell proliferation through polyunsaturated fatty acid-mediated pathways, but also promotes survival by stabilizing antiapoptotic proteins. Additionally, hepatic infiltration and tissue damage caused by malignant cells induces release of liver-derived enzymes capable of degrading chemotherapy drugs, an event that further protects leukemia cells from conventional therapies. Together, these studies demonstrate a unique role for liver in modulating the pathogenesis of leukemic disease and suggest that the hepatic microenvironment may protect leukemia cells from chemotherapeutic challenge. SIGNIFICANCE: The studies presented herein demonstrate that the liver provides a microenvironment in which leukemia cells acquire unique metabolic properties. The adaptations that occur in the liver confer increased resistance to chemotherapy. Therefore, we propose that therapies designed to overcome liver-specific metabolic changes will yield improved outcomes for patients with leukemia.This article is highlighted in the In This Issue feature, p. 211.

Upregulation of Mcl-1S Causes Cell-Cycle Perturbations and DNA Damage Accumulation

As an important regulator of apoptosis, Mcl-1 protein, a member of the Bcl-2 family, represents an attractive target for cancer treatment. The recent development of novel small molecule compounds has allowed Mcl-1-inhibitory therapy to proceed to clinical trials in cancer treatment. However, the possible adverse effects of either direct inhibition of Mcl-1 or upregulation of Mcl-1S, proapoptotic isoform resulting from alternative splicing of Mcl-1, remain unclear. Here, we investigated changes in Mcl-1S levels during cell cycle and the cell cycle-related functions of Mcl-1 isoforms to address the above-mentioned concerns. It was shown that an anti-mitotic agent monastrol caused accumulation of Mcl-1S mRNA, although without increasing the protein level. In contrast, both mRNA and protein levels of Mcl-1S accrued during the premitotic stages of the normal cell cycle progression. Importantly, Mcl-1S was observed in the nuclear compartment and an overexpression of Mcl-1S, as well as knockdown of Mcl-1, accelerated the progression of cells into mitosis and resulted in DNA damage accumulation. Surprisingly, a small molecule inhibitor of Mcl-1, BH3-mimetic S63845, did not affect the cell cycle progression or the amount of DNA damage. In general, upregulated Mcl-1S protein or genetically inhibited Mcl-1L were associated with the cell cycle perturbations and DNA damage accumulation in normal and cancer cells. At the same time, BH3-mimetic to Mcl-1 did not affect the cell cycle progression, suggesting that direct inhibition of Mcl-1 is devoid of cell-cycle related undesired effects.