An anti-apoptotic protein human survivin is a direct inhibitor of caspase-3 and -7

Oxidative tryptamine dimers from Corynebacterium durum directly target survivin to induce AIF-mediated apoptosis in cancer cells

Accumulating evidence indicates that microbial communities in the human body crucially affect health through the production of chemical messengers. However, the relationship between human microbiota and cancer has been underexplored. As a result of a biochemical investigation of the commensal oral microbe, Corynebacterium durum, we identified the non-enzymatic transformation of tryptamine into an anticancer compound, durumamide A (1). The structure of 1 was determined using LC-MS and NMR data analysis as bis(indolyl)glyoxylamide, which was confirmed using one-pot synthesis and X-ray crystallographic analysis, suggesting that 1 is an oxidative dimer of tryptamine. Compound 1 displayed cytotoxic activity against various cancer cell lines with IC50 values ranging from 25 to 35 μM. A drug affinity responsive target stability assay revealed that survivin is the direct target protein responsible for the anticancer effect of 1, which subsequently induces apoptosis-inducing factor (AIF)-mediated apoptosis. Inspired by the chemical structure and bioactivity of 1, a new derivative, durumamide B (2), was synthesized using another indole-based neurotransmitter, serotonin. The anticancer properties of 2 were similar to those of 1; however, it was less active. These findings reinforce the notion of human microbiota-host interplay by showing that 1 is naturally produced from the human microbial metabolite, tryptamine, which protects the host against cancer.

Derivation of a novel antimicrobial peptide from the Red Sea Brine Pools modified to enhance its anticancer activity against U2OS cells

Cancer associated drug resistance is a major cause for cancer aggravation, particularly as conventional therapies have presented limited efficiency, low specificity, resulting in long term deleterious side effects. Peptide based drugs have emerged as potential alternative cancer treatment tools due to their selectivity, ease of design and synthesis, safety profile, and low cost of manufacturing. In this study, we utilized the Red Sea metagenomics database, generated during AUC/KAUST Red Sea microbiome project, to derive a viable anticancer peptide (ACP). We generated a set of peptide hits from our library that shared similar composition to ACPs. A peptide with a homeodomain was selected, modified to improve its anticancer properties, verified to maintain high anticancer properties, and processed for further in-silico prediction of structure and function. The peptide's anticancer properties were then assessed in vitro on osteosarcoma U2OS cells, through cytotoxicity assay (MTT assay), scratch-wound healing assay, apoptosis/necrosis detection assay (Annexin/PI assay), RNA expression analysis of Caspase 3, KI67 and Survivin, and protein expression of PARP1. L929 mouse fibroblasts were also assessed for cytotoxicity treatment. In addition, the antimicrobial activity of the peptide was also examined on E coli and S. aureus, as sample representative species of the human bacterial microbiome, by examining viability, disk diffusion, morphological assessment, and hemolytic analysis. We observed a dose dependent cytotoxic response from peptide treatment of U2OS, with a higher tolerance in L929s. Wound closure was debilitated in cells exposed to the peptide, while annexin fluorescent imaging suggested peptide treatment caused apoptosis as a major mode of cell death. Caspase 3 gene expression was not altered, while KI67 and Survivin were both downregulated in peptide treated cells. Additionally, PARP-1 protein analysis showed a decrease in expression with peptide exposure. The peptide exhibited minimal antimicrobial activity on critical human microbiome species E. coli and S. aureus, with a low inhibition rate, maintenance of structural morphology and minimal hemolytic impact. These findings suggest our novel peptide displayed preliminary ACP properties against U2OS cells, through limited specificity, while triggering apoptosis as a primary mode of cell death and while having minimal impact on the microbiological species E. coli and S. aureus.

Cleaved caspase-3 is present in the majority of glial cells in the intact rat spinal cord during postnatal life

Cell death is an essential process that occurs during the development of the central nervous system. Despite the availability of a wide range of commercially produced antibodies against various apoptotic markers, data regarding apoptosis in intact spinal cord during postnatal development and adulthood are mostly missing. We investigated apoptosis in rat spinal cord at different stages of ontogenesis (postnatal days 8, 29, and 90). For this purpose, we applied immunofluorescent detection of two widely used apoptotic markers, cleaved caspase-3 (cC3) and cleaved poly(ADP-ribose) polymerase (cPARP). Surprisingly, we found significant discrepancy between the number of cC3+ cells and PARP+ cells, with a ratio between 500:1 and 5000:1 in rat spinal cord at all postnatal time points. The majority of cC3+ cells were glial cells and did not exhibit an apoptotic phenotype. In contrast with in vivo results, in vitro analysis of primary cell cultures derived from neonatal rat spinal cord and treated with the apoptotic inductor staurosporine revealed a similar onset of occurrence of both cC3 and cPARP in cells subjected to apoptosis. Gene expression analysis of spinal cord revealed elevated expression of the Birc4 (XIAP), Birc2, and Birc5 (Survivin) genes, which are known potent inhibitors of apoptosis. Our data indicate that cC3 is not an exclusive marker of apoptosis, especially in glial cells, owing its possible presence in inhibited forms and/or its participation in other non-apoptotic roles. Therefore, cPARP appears to be a more appropriate marker to detect apoptosis.

Small Molecule Inhibitors Targeting the "Undruggable" Survivin: The Past, Present, and Future from a Medicinal Chemist's Perspective

Survivin, a homodimeric protein and a member of the IAP family, plays a vital function in cell survival and cycle progression by interacting with various proteins and complexes. Its expression is upregulated in cancers but not detectable in normal tissues. Thus, it has been regarded and validated as an ideal cancer target. However, survivin is "undruggable" due to its lack of enzymatic activities or active sites for small molecules to bind/inhibit. Academic and industrial laboratories have explored different strategies to overcome this hurdle over the past two decades, with some compounds advanced into clinical testing. These strategies include inhibiting survivin expression, its interaction with binding partners and homodimerization. Here, we provide comprehensive analyses of these strategies and perspective on different small molecule survivin inhibitors to help drug discovery targeting "undruggable" proteins in general and survivin specifically with a true survivin inhibitor that will prevail in the foreseeable future.

Cancer Resistance Is Mediated by the Upregulation of Several Anti-Apoptotic Gene Products via the Inducible Nitric Oxide Synthase/Nitric Oxide Pathway: Therapeutic Implications

Significance: Several therapeutic strategies for cancer treatments have been developed with time, and significant milestones have been achieved recently. However, with these novel therapies, not all cancer types respond and in the responding cancer types only a subset is affected. The failure to respond is principally the result that these cancers develop several mechanisms of resistance. Thus, a focus of current research investigations is to unravel the various mechanisms that regulate resistance and identify suitable targets for new therapeutics. Recent Advances: Hence, many human cancer types have been reported to overexpress the inducible nitric oxide synthase (iNOS) and it has been suggested that iNOS/nitric oxide (NO) plays a pivotal role in the regulation of resistance. We have postulated that iNOS overexpression or NO regulates the overexpression of pivotal anti-apoptotic gene products such as B-cell lymphoma 2 (Bcl-2), B-cell lymphoma extra large (Bcl-xL), myeloid cell leukemia-1 (Mcl-1), and survivin. In this report, we describe the various mechanisms, transcriptional, post-transcriptional, and post-translational, by which iNOS/NO regulates the expression of the above anti-apoptotic gene products. Critical Issues: The iNOS/NO-mediated regulation of the four gene products is not the same with both specific and overlapping pathways. Our findings are, in large part, validated by bioinformatic analyses demonstrating, in several cancers, several direct correlations between the expression of iNOS and each of the four examined anti-apoptotic gene products. Future Directions: We have proposed that targeting iNOS may be highly efficient since it will result in the underexpression of multiple anti-apoptotic proteins and shifting the balance toward the proapoptotic gene products and reversal of resistance. Antioxid. Redox Signal. 39, 853-889.

Identification of functional genes regulating gastric cancer progression using integrated bioinformatics analysis

BACKGROUND

Gastric cancer (GC) is one of the most common cancers and has a poor prognosis. Treatment of GC has remained unchanged over the past few years.

AIM

To investigate the potential therapeutic targets and related regulatory biomarkers of GC.

METHODS

We obtained the public GC transcriptome sequencing dataset from the Gene Expression Omnibus database. The datasets contained 348 GC tissues and 141 healthy tissues. In total, 251 differentially expressed genes (DEGs) were identified, including 187 down-regulated genes and 64 up-regulated genes. The DEGs' enriched functions and pathways include Progesterone-mediated oocyte maturation, cell cycle, and oocyte meiosis, Hepatitis B, and the Hippo signaling pathway. Survival analysis showed that BUB1, MAD2L1, CCNA2, CCNB1, and BIRC5 may be associated with regulation of the cell cycle phase mitotic spindle checkpoint pathway. We selected 26 regulated genes with the aid of the protein-protein interaction network analyzed by Molecular Complex Detection.

RESULTS

We focused on three critical genes, which were highly expressed in GC, but negatively related to patient survival. Furthermore, we found that knockdown of BIRC5, TRIP13 or UBE2C significantly inhibited cell proliferation and induced cell apoptosis. In addition, knockdown of BIRC5, TRIP13 or UBE2C increased cellular sensitivity to cisplatin.

CONCLUSION

Our study identified significantly upregulated genes in GC with a poor prognosis using integrated bioinformatics methods.

Apoptotic proteins with non-apoptotic activity: expression and function in cancer

Apoptosis is a process of programmed cell death in which a cell commits suicide while maintaining the integrity and architecture of the tissue as a whole. Apoptosis involves activation of one of two major pathways: the extrinsic pathway, where extracellular pro-apoptotic signals, transduced through plasma membrane death receptors, activate a caspase cascade leading to apoptosis. The second, the intrinsic apoptotic pathway, where damaged DNA, oxidative stress, or chemicals, induce the release of pro-apoptotic proteins from the mitochondria, leading to the activation of caspase-dependent and independent apoptosis. However, it has recently become apparent that proteins involved in apoptosis also exhibit non-cell death-related physiological functions that are related to the cell cycle, differentiation, metabolism, inflammation or immunity. Such non-conventional activities were predominantly reported in non-cancer cells although, recently, such a dual function for pro-apoptotic proteins has also been reported in cancers where they are overexpressed. Interestingly, some apoptotic proteins translocate to the nucleus in order to perform a non-apoptotic function. In this review, we summarize the unconventional roles of the apoptotic proteins from a functional perspective, while focusing on two mitochondrial proteins: VDAC1 and SMAC/Diablo. Despite having pro-apoptotic functions, these proteins are overexpressed in cancers and this apparent paradox and the associated pathophysiological implications will be discussed. We will also present possible mechanisms underlying the switch from apoptotic to non-apoptotic activities although a deeper investigation into the process awaits further study.

The asymmetric and long-run effect of energy productivity on environmental quality in Ireland

This study aims to examine the long-run asymmetric impact of energy productivity on environmental quality in Ireland. The data set covers the period from 1990Q1 to 2019Q4. Although the border issue has been the source of contention and terrorism for decades in Ireland, the country is conscious of modern innovations and has a coherent body of environmental law. Ireland's goal is to achieve 80% of its electricity as renewable energy and reduce carbon emissions by 51% in 2030. Unlike earlier studies, the novelty of this study lies in the thorough analysis of how energy productivity affects the quality of the environment in Ireland while controlling for financial development, primary energy consumption, and economic growth utilizing the nonlinear ARDL approach and other robust econometric techniques. Precisely, the results indicate that (i) energy productivity benefits the environment by lowering CO2 emissions (CO2E) in the long term; (ii) financial sector development enhances the quality of the environment in Ireland; (iii) increase in primary energy consumption and economic growth without eco-friendly protocols propel an increase in CO2E. These findings support the economic theory that energy productivity can stimulate steady green living and green technological growth. We recommend that policymakers in Ireland invest in energy productivity and prioritize R&D that embraces cleaner technologies and cross-cutting eco-friendly policies to combat environmental challenges in Ireland and the world at large.

Simultaneous Imaging and Visualizing the Association of Survivin mRNA and Telomerase in Living Cells by Using a Dual-Color Encoded DNA Nanomachine

Simultaneous imaging and especially visualizing the association of survivin mRNA and telomerase in living cells are of great value for the diagnosis and prognosis of cancer because their co-expression facilitates the development of cancer and identifies patients at high risk of tumor-related death. The challenge is to develop methods that enable visualizing the association of multiplex targets and avoid the distorted signals due to the different delivery efficiency of probes. Herein, we engineered a DNA triangular prism nanomachine (DTPN) for simultaneous multicolor imaging of survivin mRNA and telomerase and visualizing their association in living cells. Two recognizing probes targeted survivin mRNA and telomerase, and the reporter probe was assembled on the DTP in equal amounts, ensuring the same delivery efficiency of the probes to the living cells. The results showed that this DTPN could quantify intracellular survivin mRNA expression and telomerase activity. Moreover, it also enabled us to visualize the effect of the down-regulation of one target on the expression of another target under different drug stimulations. The results implied that our DTPN provided a promising platform for cancer diagnosis, prognosis, drug screening, and related biological research.

Design, Synthesis, and Investigation of Cytotoxic Effects of 5-Hydroxyindole-3-Carboxylic Acid and Ester Derivatives as Potential Anti-breast Cancer Agents

Breast cancer is a deadly disease with a high prevalence rate among females. Despite several treatments, scientists are still engaged in finding less invasive treatments for this disease. The cellular proliferation rate and cell viability survey are critical to assess the drug's effect on both normal and malignant cell populations. Indole derivatives are promising candidates for their cytotoxic effect causing on breast cancer cells; however, they are less toxic on normal cells. This study synthesized 23 novel 5-hydroxyindole-3-carboxylic acids and related esters featuring various linear, cyclic, and primary aromatic amines. The MTT assay indicated the cytotoxicity of all acid and ester derivatives against the MCF-7 cells with no significant cytotoxicity on normal human dermal fibroblasts cells. Compound 5d, an ester derivative possessing a 4-methoxy group, was the most potent compound, with a half-maximal effective concentration of 4.7 µM. Compounds 5a, 5d, and 5l bearing ester group in their structure demonstrated cytotoxicity values < 10 µM against the MCF-7 cell line and were safe for advanced screening.

Mechanisms of Drug Resistance in Ovarian Cancer and Associated Gene Targets

In the United States, over 100,000 women are diagnosed with a gynecologic malignancy every year, with ovarian cancer being the most lethal. One of the hallmark characteristics of ovarian cancer is the development of resistance to chemotherapeutics. While the exact mechanisms of chemoresistance are poorly understood, it is known that changes at the cellular and molecular level make chemoresistance challenging to treat. Improved therapeutic options are needed to target these changes at the molecular level. Using a precision medicine approach, such as gene therapy, genes can be specifically exploited to resensitize tumors to therapeutics. This review highlights traditional and novel gene targets that can be used to develop new and improved targeted therapies, from drug efflux proteins to ovarian cancer stem cells. The review also addresses the clinical relevance and landscape of the discussed gene targets.

Preclinical evaluation of the ROCK1 inhibitor, GSK269962A, in acute myeloid leukemia

Acute myeloid leukemia (AML) is an aggressive hematologic malignancy with high mortality that urgently requires new treatments. ROCK1 plays an essential role in regulating growth and survival in AML cells. In this study, we evaluated GSK269962A, a selective ROCK1 inhibitor, in preclinical models of AML. Compared with solid tumors, GSK269962A selectively inhibited cell growth and clonogenicity of AML cells. Furthermore, GSK269962A arrested AML cells in the G2 phase and induced apoptosis by regulating multiple cell cycle- and apoptosis-associated proteins. Strikingly, GSK269962A could eliminate leukemia cells from bone marrow, liver, and spleen in an animal model of AML and significantly prolong mouse survival. Mechanistically, GSK269962A could inhibit the growth of AML by blocking ROCK1/c-Raf/ERK signaling pathway. Notably, a correlation was found between the expression levels of ROCK1 protein and the sensitivity of GSK269962A in AML. These data highlight the potential role of ROCK1 as an attractive target for treating AML, as well as the potential of GSK269962A for use in clinical trials of AML.

Resveratrol Enhances the Radiosensitivity by Inducing DNA Damage and Antitumor Immunity in a Glioblastoma Rat Model under 3 T MRI Monitoring

Glioblastoma (GBM) is the most common intracranial tumor with characteristic of malignancy. Resveratrol, a natural originated polyphenolic compound, has been reported to act as a potential radiosensitizer in cancer therapy. Magnetic resonance imaging (MRI) is the first choice for the diagnosis, pathological grading, and efficacy evaluation of GBM. In this study, MRI was applied to observe whether resveratrol could intensify the anti-GBM tumor effect by enhancing antitumor immunity during radiotherapy. We established an intracranial C6 GBM model in SD rats, treated with radiation and resveratrol. The increased body weight, the inhibition on mortality, and tumor volume in radiated- GBM rats were further enhanced by resveratrol addition, while the pathological damage of brain was alleviated. The modulation of radiation on inflammation, cell cycle, and apoptosis was strengthened by resveratrol; and Ki-67, PD-L1, and cell cycle- and apoptosis-related protein expressions were also improved by cotreatment. Besides, cotreatment attenuated DNA damage and induced G0/G1-phase cell arrest of GBM rats, accompanied with the changed expression of ATM-AKT-STAT3 pathway-related proteins. Moreover, the percentages of CD3⁺CD8⁺T cells and IFN-γ⁺CD8⁺T cells were enhanced, while (CD4⁺CD25⁺Foxp3)/CD4⁺T cells were decreased by radiation or resveratrol, which was strengthened by cotreatment. The modulation effect of cotreatment on CD3, Foxp3, and IFN-γ levels was also stronger than radiation or resveratrol alone. To conclude, resveratrol enhanced the effect of radiotherapy by inducing DNA damage and antitumor immunity in the intracranial C6 GBM.

Serum Survivin in Oral Submucosal Fibrosis and Squamous Cell Carcinoma

Survivin, an inhibitor of apoptosis protein is a biomarker of significance in prognostication of many malignancies. In the current study we investigated the serum survivin levels in patients with oral submucosal fibrosis (OSMF) and squamous cell carcinoma (OSCC). Serum was isolated from, peripheral blood collected of clinically and histopathologically confirmed OSMF and OSCC patients. Circulating level of survivin was measured in patients and control subjects by ELISA and analyzed further using Kruskal-Wallis test and two-sample Wilcoxon rank-sum (Mann-Whitney) test. Serum Survivin levels were significantly reduced in the OSCC group as compared to the control group. No significant correlation was noted between the serum survivin level and various clinicopathological characteristics of OSCC and OSMF patients. Our study suggests that free, wild form of circulating survivin probably has no role in predicting the prognosis of oral cancer or the malignant transformation potential of oral submucosal fibrosis.

Crucial Role of Oncogenic KRAS Mutations in Apoptosis and Autophagy Regulation: Therapeutic Implications

KRAS, one of the RAS protein family members, plays an important role in autophagy and apoptosis, through the regulation of several downstream effectors. In cancer cells, KRAS mutations confer the constitutive activation of this oncogene, stimulating cell proliferation, inducing autophagy, suppressing apoptosis, altering cell metabolism, changing cell motility and invasion and modulating the tumor microenvironment. In order to inhibit apoptosis, these oncogenic mutations were reported to upregulate anti-apoptotic proteins, including Bcl-xL and survivin, and to downregulate proteins related to apoptosis induction, including thymine-DNA glycosylase (TDG) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). In addition, KRAS mutations are known to induce autophagy in order to promote cell survival and tumor progression through MAPK and PI3K regulation. Thus, these mutations confer resistance to anti-cancer drug treatment and, consequently, result in poor prognosis. Several therapies have been developed in order to overcome KRAS-induced cell death resistance and the downstream signaling pathways blockade, especially by combining MAPK and PI3K inhibitors, which demonstrated promising results. Understanding the involvement of KRAS mutations in apoptosis and autophagy regulation, might bring new avenues to the discovery of therapeutic approaches for CRCs harboring KRAS mutations.

ILP-2: A New Bane and Therapeutic Target for Human Cancers

Inhibitor of apoptosis protein-related-like protein-2 (ILP-2), also known as BIRC-8, is a member of the inhibitor of apoptosis protein (IAPs) family, which mainly encodes the negative regulator of apoptosis. It is selectively overexpressed in a variety of human tumors and can help tumor cells evade apoptosis, promote tumor cell growth, increase tumor cell aggressiveness, and appears to be involved in tumor cell resistance to chemotherapeutic drugs. Several studies have shown that downregulation of ILP-2 expression increases apoptosis, inhibits metastasis, reduces cell growth potential, and sensitizes tumor cells to chemotherapeutic drugs. In addition, ILP-2 inhibits apoptosis in a unique manner; it does not directly inhibit the activity of caspases but induces apoptosis by cooperating with other apoptosis-related proteins. Here, we review the current understanding of the various roles of ILP-2 in the apoptotic cascade and explore the use of interfering ILP-2, and the combination of related anti-tumor agents, as a novel strategy for cancer therapy.

Increase in ADAR1p110 activates the canonical Wnt signaling pathway associated with aggressive phenotype in triple negative breast cancer cells

Triple-negative breast cancer (TNBC) represents a challenge in the search for new therapeutic targets. TNBCs are aggressive and generate resistance to chemotherapy. Tumors of TNBC patients with poor prognosis present a high level of adenosine deaminase acting on RNA1 (ADAR1). We explore the connection of ADAR1 with the canonical Wnt signaling pathway and the effect of modulation of its expression in TNBC. Expression data from cell line sequencing (DepMap) and TCGA samples were downloaded and analyzed. We lentivirally generated an MDA-MB-231 breast cancer cell line that overexpress (OE) ADAR1p110 or an ADAR knockdown. Abundance of different proteins related to Wnt/β-catenin pathway and activity of nuclear β-catenin were analyzed by Western blot and luciferase TOP/FOP reporter assay, respectively. Cell invasion was analyzed by matrigel assay. In mice, we study the behavior of tumors generated from ADAR1p110 (OE) cells and tumor vascularization immunostaining were analyzed. ADAR1 connects to the canonical Wnt pathway in TNBC. ADAR1p110 overexpression decreased GSK-3β, while increasing active β-catenin. It also increased the activity of nuclear β-catenin and increased its target levels. ADAR1 knockdown has the opposite effect. MDA-MB-231 ADAR1 (OE) cells showed increased capacity of invasion. Subsequently, we observed that tumors derived from ADAR1p110 (OE) cells showed increased invasion towards the epithelium, and increased levels of Survivin and CD-31 expressed in vascular endothelial cells. These results indicate that ADAR1 overexpression alters the expression of some key components of the canonical Wnt pathway, favoring invasion and neovascularization, possibly through activation of the β-catenin, which suggests an unknown role of ADAR1p110 in aggressiveness of TNBC tumors.

Effects of caspase activity of yak meat and internal environment changing during aging

The objective of this study was to investigate the protease family caspases in skeletal muscle and their potential contribution to postmortem proteolysis and meat tenderization. Nine yaks were slaughtered, and samples of Longissimus dorsal were injected with AC-DEVD-CHO at a ratio of 1:1 (w/v) and then stored at 4 °C for 2, 6, 12, 24, 72, and 120 h. Results indicate that the morphological changes of the muscle fibers are significantly obstructed, which is not conducive to the subsequent degradation of proteins. After inhibiting the activity of Caspase- 3, the activity of Caspase-8 and 9 and the energy metabolism was affected. In the case of without inhibition of caspase, the pH value decreased and then increased. The meat color and the water retention are better, the muscle fiber skeleton protein degradation is remarkable, the tenderness is improved. Furthermore, yak meat tenderness was improved by apoptotic pathway during aging.

A Review of the Current Impact of Inhibitors of Apoptosis Proteins and Their Repression in Cancer

Simple Summary

The Inhibitor of Apoptosis (IAP) family of proteins has emerged as a potential pharmacological target in cancer. Abnormal expression of IAPs can lead to dysregulated cell suicide, promoting the development of different pathologies. In several cancer types, members of this protein family are overexpressed while their natural antagonist (Smac) appears to be downregulated, contributing to the acquisition of resistance to traditional therapy. The development of compounds that mimic the action of Smac showed promise in the re-sensitization of the cell suicide defense mechanism in cancer cells, particularly in combination with other treatments. Interaction with other molecules, such as tumor necrosis factor-α, in the tumor microenvironment reveals a complex interplay between IAPs and cancer.

Abstract

The Inhibitor of Apoptosis (IAP) family possesses the ability to inhibit programmed cell death through different mechanisms; additionally, some of its members have emerged as important regulators of the immune response. Both direct and indirect activity on caspases or the modulation of survival pathways, such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), have been implicated in mediating its effects. As a result, abnormal expression of inhibitor apoptosis proteins (IAPs) can lead to dysregulated apoptosis promoting the development of different pathologies. In several cancer types IAPs are overexpressed, while their natural antagonist, the second mitochondrial-derived activator of caspases (Smac), appears to be downregulated, potentially contributing to the acquisition of resistance to traditional therapy. Recently developed Smac mimetics counteract IAP activity and show promise in the re-sensitization to apoptosis in cancer cells. Given the modest impact of Smac mimetics when used as a monotherapy, pairing of these compounds with other treatment modalities is increasingly being explored. Modulation of molecules such as tumor necrosis factor-α (TNF-α) present in the tumor microenvironment have been suggested to contribute to putative therapeutic efficacy of IAP inhibition, although published results do not show this consistently underlining the complex interaction between IAPs and cancer.

Dysregulation of Survivin-Targeting microRNAs in Autoimmune Diseases: New Perspectives for Novel Therapies

It has been well established that the etiopathogenesis of diverse autoimmune diseases is rooted in the autoreactive immune cells' excessively proliferative state and impaired apoptotic machinery. Survivin is an anti-apoptotic and mitotic factor that has sparked a considerable research interest in this field. Survivin overexpression has been shown to contribute significantly to the development of autoimmune diseases via autoreactive immune cell overproliferation and apoptotic dysregulation. Several microRNAs (miRNAs/miRs) have been discovered to be involved in survivin regulation, rendering the survivin-miRNA axis a perspective target for autoimmune disease therapy. In this review, we discuss the role of survivin as an immune regulator and a highly implicated protein in the pathogenesis of autoimmune diseases, the significance of survivin-targeting miRNAs in autoimmunity, and the feasibility of targeting the survivin-miRNA axis as a promising therapeutic option for autoimmune diseases.

The Potential Hepatoprotective Effect of Paeoniae Radix Alba in Thioacetamide-Induced Acute Liver Injury in Rats

Aim

Acute liver injury (ALI) can occur for various reasons by induced inflammation and apoptosis of liver cells including hepatocytes, Kupffer cells, and hepatic stellate cells. Thioacetamide (TAA), which is a classic hepatotoxin, causes oxidative stress, membrane damage, and accumulation of lipid droplets and subsequently provokes consecutive liver injury. In the current study, we tested whether Paeoniae Radix Alba (PR) could alleviate TAA-induced ALI.

Methods

Thirty-five male rats were equally separated into five groups. The first group was the normal group, which received distilled water only. The remaining four groups received intraperitoneal TAA (200 mg/kg) for 3 days to induce ALI. The four groups were divided into the control group (no treatment), silymarin-treated, 100 mg/kg PR-treated, and 200 mg/kg PR-treated. The efficacy of PR against hepatotoxicity was evaluated in terms of the serum biochemical index and protein expression associated with inflammation and apoptosis. Moreover, the dissected livers were analyzed by hematoxylin and eosin stain.

Results

PR alleviated liver dysfunction as evidenced by decreased levels of aspartate aminotransferase, alanine aminotransferase, and ammonia. Phosphorylated AMP-activated protein kinase (AMPK) and Sirtuin 1 (Sirt1) levels were obviously decreased in the TAA control group, whereas PR reversed these changes. PR also prevented deteriorative effects through inhibition of inflammation and apoptosis via nuclear transcription factor-kappa Bp65 (NF-κBp65) inactivation. Moreover, we found that the hepatoprotective effect of PR pretreatment was mediated by restoration of histopathological changes.

Conclusion

PR efficiently blocked both the inflammatory response and apoptosis through activating the AMPK/Sirt1/NF-κBp65 pathway. Therefore, PR is considered a potential therapeutic agent against ALI.

Research on the mechanisms of taraxerol for the treatment of gastric cancer effect based on network pharmacology

BACKGROUND

Modern pharmacological studies have shown that traditional Chinese medicine (TCM) Taraxacum mongolicum possesses anti-cancer activity. Taraxerol (TRX) is a pentacyclic triterpene isolated from T. mongolicum, which is widely used in clinical treatment, and its anti-cancer effects have been extensively studied. However, the effects and molecular mechanism of TRX in gastric cancer (GC) have not been fully explicated.

METHODS

We used public databases to derive information on potential targets of TRX and proteins related to GC. Also, STRING and R3.6.2 software were used to analyze the protein-protein interaction (PPI). The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were done to explain the potential mechanism underlying the regulatory role of TRX in GC. The role of TRX in GC was verified by 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide (MTT) assay, apoptosis analysis, Transwell assay, and wound healing assay, and the key signaling pathways were verified.

RESULTS

We identified 135 potential targets for the treatment of GC via network pharmacological analysis. GO and KEGG enrichment analysis showed that steroid hormone receptor activity and the PI3K/AKT signaling pathway were the biological processes and pathways with the highest degree of enrichment. Additionally, cellular experiments revealed that TRX inhibited the proliferation, migration, and invasion of GC cells as well as induced G1 phase arrest and apoptosis in GC cells.

CONCLUSION

Here, we used multi-target and multi-pathway network pharmacological analysis to verify the anti-cancer activity of TRX in GC. Also, in vitro experimental data were used to derive the potential molecular mechanism.

Deletion of SA β-Gal+ cells using senolytics improves muscle regeneration in old mice

Systemic deletion of senescent cells leads to robust improvements in cognitive, cardiovascular, and whole-body metabolism, but their role in tissue reparative processes is incompletely understood. We hypothesized that senolytic drugs would enhance regeneration in aged skeletal muscle. Young (3 months) and old (20 months) male C57Bl/6J mice were administered the senolytics dasatinib (5 mg/kg) and quercetin (50 mg/kg) or vehicle bi-weekly for 4 months. Tibialis anterior (TA) was then injected with 1.2% BaCl2 or PBS 7- or 28 days prior to euthanization. Senescence-associated β-Galactosidase positive (SA β-Gal+) cell abundance was low in muscle from both young and old mice and increased similarly 7 days following injury in both age groups, with no effect of D+Q. Most SA β-Gal+ cells were also CD11b+ in young and old mice 7- and 14 days following injury, suggesting they are infiltrating immune cells. By 14 days, SA β-Gal+/CD11b+ cells from old mice expressed senescence genes, whereas those from young mice expressed higher levels of genes characteristic of anti-inflammatory macrophages. SA β-Gal+ cells remained elevated in old compared to young mice 28 days following injury, which were reduced by D+Q only in the old mice. In D+Q-treated old mice, muscle regenerated following injury to a greater extent compared to vehicle-treated old mice, having larger fiber cross-sectional area after 28 days. Conversely, D+Q blunted regeneration in young mice. In vitro experiments suggested D+Q directly improve myogenic progenitor cell proliferation. Enhanced physical function and improved muscle regeneration demonstrate that senolytics have beneficial effects only in old mice.

The effects of Acyclovir administration to NCI-H1975 non-small cell lung cancer cells

The biochemical mechanisms by which the antiviral drug Acyclovir (ACV) may induce anticancer effects even without detecting human herpesviruses (HHVs) are still poorly understood. Herein, we investigated for the first time how NCI-H1975 non-small cell lung cancer cells responded in vitro to ACV administration by exploring mitochondrial damage and apoptosis induction. We confirmed ACV ability to cause the inhibition of cancer cell growth even without detecting intracellular HHVs; the drug also significantly inhibited the colony formation capacity of NCI-H1975 cells. Cell cycle analysis revealed an increase of the sub-G1 hypodiploid peak after ACV treatment; the activation of caspase-3 and the presence of DNA laddering sustained the capacity of the drug to induce apoptotic cell death. Regarding mitochondrial toxicity, a reduction of mitochondrial membrane potential, altered mitochondrial size and shape, and mtDNA damage were found after ACV administration. Furthermore, an increment of intracellular reactive oxygen species levels as well as the upregulation of NudT3 involved in DNA repair mechanisms were observed. Altogether, these findings suggest that mitochondria may be possible initial targets and/or sites of ACV cytotoxicity within cancer cells in the absence of intracellular HHVs.

LncRNA SFTA1P mediates positive feedback regulation of the Hippo-YAP/TAZ signaling pathway in non-small cell lung cancer

Long non-coding RNAs (lncRNAs) regulate numerous biological processes involved in both development and carcinogenesis. Hippo-YAP/TAZ signaling, a critical pathway responsible for organ size control, is often dysregulated in a variety of cancers. However, the nature and function of YAP/TAZ-regulated lncRNAs during tumorigenesis remain largely unexplored. By profiling YAP/TAZ-regulated lncRNAs, we identified SFTA1P as a novel transcriptional target and a positive feedback regulator of YAP/TAZ signaling. Using non-small cell lung cancer (NSCLC) cell lines, we show that SFTA1P is transcriptionally activated by YAP/TAZ in a TEAD-dependent manner. Functionally, knockdown of SFTA1P in NSCLC cell lines inhibited proliferation, induced programmed cell death, and compromised their tumorigenic potential. Mechanistically, SFTA1P knockdown decreased TAZ protein abundance and consequently, the expression of YAP/TAZ transcriptional targets. We provide evidence that this phenomenon could potentially be mediated via its interaction with TAZ mRNA to regulate TAZ translation. Our results reveal SFTA1P as a positive feedback regulator of Hippo-YAP/TAZ signaling, which may serve as the molecular basis for lncRNA-based therapies against YAP/TAZ-driven cancers.

L-asparaginase from Dickeya chrysanthemi: expression, purification and cytotoxicity assessment

Microbial L-asparaginases are aminohydrolases that hydrolyze L-asparagine to L-aspartate. They are used to treat acute lymphoblastic leukemia and Hodgkin's lymphomas and in food industries. Increasing demand for L-ASNases is therefore needed. In the current study, the recombinant L-ASNase from Dickeya chrysanthemi (DcL-ASNase) was cloned into pET28a (+) expression vector and expressed in Escherichia coli as a 6His-tagged fusion protein and purified using Ni²⁺ chelated Sepharose chromatography resin, yielding a highly purified enzyme. Kinetics analysis allowed the determination of its substrate specificity and the physicochemical parameters that affect enzyme activity. The enzyme showed operational stability at 37 °C and 45 °C. The immunogenicity of the purified DcL-ASNase was evaluated by measuring the IgG and IgM levels in rats after injection. The cytotoxicity DcL-ASNase in selected cancer cell lines and peripheral blood monocytes was determined. The results showed that the enzyme induces pleiotropic effects, including significant morphological changes and the formation of apoptotic bodies. No cytotoxic effects were observed in peripheral blood monocytes at the same concentrations. In addition, gene expression analysis by RT-PCR of apoptotic biomarkers (Bax, survivin, and Ki-67) allowed the study of the apoptotic mechanism induced by DcL-ASNase on THP-1 cells.

Survivin' Acute Myeloid Leukaemia-A Personalised Target for inv(16) Patients

Despite recent advances in therapies including immunotherapy, patients with acute myeloid leukaemia (AML) still experience relatively poor survival rates. The Inhibition of Apoptosis (IAP) family member, survivin, also known by its gene and protein name, Baculoviral IAP Repeat Containing 5 (BIRC5), remains one of the most frequently expressed antigens across AML subtypes. To better understand its potential to act as a target for immunotherapy and a biomarker for AML survival, we examined the protein and pathways that BIRC5 interacts with using the Kyoto Encyclopedia of Genes and Genomes (KEGG), search tool for recurring instances of neighbouring genes (STRING), WEB-based Gene Set Analysis Toolkit, Bloodspot and performed a comprehensive literature review. We then analysed data from gene expression studies. These included 312 AML samples in the Microarray Innovations In Leukemia (MILE) dataset. We found a trend between above median levels of BIRC5 being associated with improved overall survival (OS) but this did not reach statistical significance (p = 0.077, Log-Rank). There was some evidence of a beneficial effect in adjusted analyses where above median levels of BIRC5 were shown to be associated with improved OS (p = 0.001) including in Core Binding Factor (CBF) patients (p = 0.03). Above median levels of BIRC5 transcript were associated with improved relapse free survival (p < 0.0001). Utilisation of a second large cDNA microarray dataset including 306 AML cases, again showed no correlation between BIRC5 levels and OS, but high expression levels of BIRC5 correlated with worse survival in inv(16) patients (p = 0.077) which was highly significant when datasets A and B were combined (p = 0.001). In addition, decreased BIRC5 expression was associated with better clinical outcome (p = 0.004) in AML patients exhibiting CBF mainly due to patients with inv(16) (p = 0.007). This study has shown that BIRC5 expression plays a role in the survival of AML patients, this association is not apparent when we examine CBF patients as a cohort, but when those with inv(16) independently indicating that those patients with inv(16) would provide interesting candidates for immunotherapies that target BIRC5.

Strategies to Improve the Efficiency of Transplantation with Mesenchymal Stem Cells for the Treatment of Ischemic Stroke: A Review of Recent Progress

Cerebral ischemia is a common global disease that is characterized by a loss of neurological function and a poor prognosis in many patients. However, only a limited number of treatments are available for this condition at present. Given that the efficacies of these treatments tend to be poor, cerebral ischemia can create a significant burden on patients, families, and society. Mesenchymal stem cell (MSC) transplantation treatment has shown significant potential in animal models of ischemic stroke; however, the specific mechanisms underlying this effect have yet to be elucidated. Furthermore, clinical trials have yet to yield promising results. Consequently, there is an urgent need to identify new methods to improve the efficiency of MSC transplantation as an optimal treatment for ischemic stroke. In this review, we provide an overview of recent scientific reports concerning novel strategies that promote MSC transplantation as an effective therapeutic approach, including physical approaches, chemical agents, traditional Chinese medicines and extracts, and genetic modification. Our analyses showed that two key factors need to be considered if we are to improve the efficacy of MSC transplantation treatments: survival ability and homing ability. We also highlight the importance of other significant mechanisms, including the enhanced activation of MSCs to promote neurogenesis and angiogenesis, and the regulation of permeability in the blood-brain barrier. Further in-depth investigations of the specific mechanisms underlying MSC transplantation treatment will help us to identify effective methods that improve the efficiency of MSC transplantation for ischemic stroke. The development of safer and more effective methods will facilitate the application of MSC transplantation as a promising adjuvant therapy for the treatment of poststroke brain damage.

CCT245718, a dual FLT3/Aurora A inhibitor overcomes D835Y-mediated resistance to FLT3 inhibitors in acute myeloid leukaemia cells

BACKGROUND

Activating mutations in the Fms-like tyrosine kinase 3 (FLT3) are among the most prevalent oncogenic mutations in acute myeloid leukaemia. Inhibitors selectively targeting FLT3 kinase have shown promising clinical activity; their success in the clinic, however, has been limited due to the emergence of acquired resistance.

METHODS

CCT245718 was identified and characterised as a dual Aurora A/FLT3 inhibitor through cell-based and biochemical assays. The ability of CCT245718 to overcome TKD-mediated resistance was evaluated in a cell line-based model of drug resistance to FLT3 inhibitors.

RESULTS

CCT245718 exhibits potent antiproliferative activity towards FLT3-ITD + AML cell lines and strongly binds to FLT3-ITD and TKD (D835Y) mutants in vitro. Activities of both FLT3-ITD and Aurora A are also inhibited in cells. Inhibition of FLT3 results in reduced phosphorylation of STAT5, downregulation of survivin and induction of apoptotic cell death. Moreover, CCT245718 overcomes TKD-mediated resistance in a MOLM-13-derived cell line containing FLT3 with both ITD and D835Y mutations. It also inhibits FLT3 signalling in both parental and resistant cell lines compared to FLT3-specific inhibitor MLN518, which is only active in the parental cell line.

CONCLUSIONS

Our results demonstrate that CCT245718 is a potent dual FLT3/Aurora A inhibitor that can overcome TKD-mediated acquired resistance.

Ginkgolic Acid Suppresses Nasopharyngeal Carcinoma Growth by Inducing Apoptosis and Inhibiting AKT/NF-κB Signaling

Even though nasopharyngeal carcinoma (NPC) is not common worldwide, it is a major public health burden in endemic areas. Distant metastasis often leads to a poor prognosis for NPC; therefore, new and effective anticancer strategies are needed. Ginkgolic acid (GA) is small-molecule compound existing in Ginkgo biloba that has various biologically relevant activities, including antitumor properties; however, its effects and mechanism of action in NPC are unknown. The effects of GA on NPC and such underlying mechanisms were investigated using 5-8F and CNE2 cells and NP69 human immortalized nasopharyngeal epithelial cells in this study. Moreover, the xenograft models were built to examine GA's effection in vivo. GA treatment decreased the survival and invasive capacity of 5-8F and CNE2 and induced their apoptosis, which varied with dose; this was accompanied by downregulation of B cell lymphoma (Bcl)2, upregulation of Bcl2-associated X protein, and activation of poly-ADP ribose polymerase, and caspase-9/-3. G0/G1 phase arrest was induced by GA in NPCs. It also reduced the expression of cyclin-dependent kinase 6 and its regulators cyclin D2 and cyclin D3. GA inhibited the activation of protein kinase B/nuclear factor signaling; this effect was potentiated with GA and 5-fluorouracil (5-FU), which also enhanced 5-FU-induced apoptosis. In summary, GA may be effective as an adjuvant to conventional chemotherapy drugs in preventing the progression of NPC.

Prognostic value of baculoviral IAP repeat containing 5 expression as a new biomarker in lung adenocarcinoma: a meta-analysis

BACKGROUND

BIRC5 is associated with the prognosis of a variety of tumors. This meta-analysis aimed to identify whether BIRC5 is associated with the prognosis of lung adenocarcinoma (LUAD).

RESEARCH DESIGN AND METHODS

We conducted an in-depth review of seven Chinese and English databases and two high-throughput sequencing databases according to inclusion and exclusion criteria to find relevant studies. The pooled standardized mean differences (SMDs) and 95% confidence intervals (CIs) for the associations between the BIRC5 expression level and clinicopathological characteristics were calculated, and the pooled hazard ratios (HRs) and 95% CIs were calculated to estimate associations between the BIRC5 expression level and survival outcomes.

RESULTS

In total, 17 studies involving 2887 LUAD patients whose BIRC5 expression level was known were included in this meta-analysis. The BIRC5 expression level was higher in younger patients, males, and smokers and correlated with advanced AJCC, T and N stages but not M stage. A high BIRC5 expression level also correlated with poor overall survival (OS) and progression-free survival (PFS). There was no publication bias in this study.

CONCLUSIONS

This meta-analysis indicates that BIRC5 is a significant biomarker for a poor prognosis and poor clinicopathological outcomes in patients with LUAD.

Insulin reverses choriocarcinoma 5- fluorouracil resistance

Choriocarcinoma (CC) is a gestational trophoblastic tumor secondary to a gravid or non-gravid pregnancy. It is characterized by rapid growth, high invasion, and high metastatic potential and chemotherapy resistance that significantly affect survival rate of CC patients. Insulin is implicated in alleviation of chemotherapy resistance in CC. However, the mechanism of reversing resistance in CC has not been explored. Our purpose was to explore insulin effect on 5-fluorouracil (5-FU) resistance in CC and elucidate its potential mechanism in vitro and in vivo. CKK-8, colony formation, Transwell, and flow cytometry were used to detect the effect of insulin on 5-FU resistance in CC cells JEG-3 and JARS. Xenograft mice were used to evaluate the effect of insulin on 5-FU resistance. Results showed that insulin combined with 5-FU suppressed cell viability by 30% in JEG-3 and 43% in JAR compared with 5-FU alone in 72 h. What’s more, insulin combined with 5-FU promoted cell apoptosis, inhibited cell proliferation, migration, and phosphorylation of survivin at residue threonine 34 (Thr34) and drug resistance-related proteins, P-GP and MRP1 levels (p < 0.05). In vivo experiment showed Insulin combined with 5-FU suppressed tumor volume by 35% compared with 5-FU alone and 73% compared with control in CC xenograft mice. In summary, the findings of this study show that insulin reversed chemoresistance of CC cells to 5-FU by inhibiting phosphorylation of survivin. Development of a therapeutic strategy that combines insulin with the chemotherapeutic agent 5-FU has a great potential in improving survival of CC patients.

Systematic Analysis of the Transcriptome Profiles and Co-Expression Networks of Tumour Endothelial Cells Identifies Several Tumour-Associated Modules and Potential Therapeutic Targets in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common cancer and the third most common cause of cancer-related death, with tumour associated liver endothelial cells being thought to be major drivers in HCC progression. This study aims to compare the gene expression profiles of tumour endothelial cells from the liver with endothelial cells from non-tumour liver tissue, to identify perturbed biologic functions, co-expression modules, and potentially drugable hub genes that could give rise to novel therapeutic targets and strategies. Gene Set Variation Analysis (GSVA) showed that cell growth-related pathways were upregulated, whereas apoptosis induction, immune and inflammatory-related pathways were downregulated in tumour endothelial cells. Weighted Gene Co-expression Network Analysis (WGCNA) identified several modules strongly associated to tumour endothelial cells or angiogenic activated endothelial cells with high endoglin (ENG) expression. In tumour cells, upregulated modules were associated with cell growth, cell proliferation, and DNA-replication, whereas downregulated modules were involved in immune functions, particularly complement activation. In ENG⁺ cells, upregulated modules were associated with cell adhesion and endothelial functions. One downregulated module was associated with immune system-related functions. Querying the STRING database revealed known functional-interaction networks underlying the modules. Several possible hub genes were identified, of which some (for example FEN1, BIRC5, NEK2, CDKN3, and TTK) are potentially druggable as determined by querying the Drug Gene Interaction database. In summary, our study provides a detailed picture of the transcriptomic differences between tumour and non-tumour endothelium in the liver on a co-expression network level, indicates several potential therapeutic targets and presents an analysis workflow that can be easily adapted to other projects.

PLK1-mediated S369 phosphorylation of RIPK3 during G2 and M phases enables its ripoptosome incorporation and activity

Receptor-interacting protein kinase 3 executes a form of regulated necrosis called necroptosis. Upon induction of an altered conformation by chemical inhibitors or via mutations in its kinase site, RIPK3 associates with a multiprotein complex called the ripoptosome-a signaling platform containing FADD, RIPK1, caspase 8, and cFLIP-and becomes decisive in the execution of apoptosis. Surprisingly, in contexts not completely understood, the ripoptosome itself cleaves RIPK3, highlighting an apparent conundrum on how RIPK3 fulfills its role via the complex responsible for its own degradation. Recently, ripoptosome assembly was found to occur in mitosis where we found elevated RIPK3 levels. We now report that PLK1 directly associates with RIPK3 and phosphorylates it at S369 as cells enter mitosis. G2/M phase RIPK3 has pro-apoptotic activity but upon release from ripoptosome, can trigger necroptosis. Taken together, phosphorylation of RIPK3 at S369 prevents its ripoptosome-mediated cleavage thereby retaining its pro-death activity during mitosis.

A novel prognostic factor TIPE2 inhibits cell proliferation and promotes apoptosis in pancreatic ductal adenocarcinoma (PDAC)

Background: Tumor necrosis factor (TNF)-alpha-induced protein 8-like 2 (TIPE2 or TNFAIP8L2) is a newly discovered negative immune regulator. Studies have shown that TIPE2 causes significant malignant biological effects and is differentially expressed in various malignant tumors. However, the expression and roles of TIPE2 in pancreatic ductal adenocarcinoma (PDAC) are largely unknown. Materials and Methods: The expression of TIPE2 in PDAC tissues was assessed by immunohistochemistry, qPCR and western blot analysis and related clinicopathological parameters including survival time were analyzed. After overexpression of TIPE2, cell proliferation and apoptosis analysis were conducted, and the associated underlying molecular mechanism was also explored. Results: In the present study, TIPE2 was upregulated in early PDAC tissues, and TIPE2 expression decreased as the tumor progressed (P<0.001). TIPE2 expression was negatively associated with tumor size, TNM stage and metastasis of lymph nodes. Furthermore, as an independent risk factor, TIPE2 could be used to predict the survival of patients with PDAC (P=0.035). TIPE2 overexpression significantly suppressed the viability, proliferation and induced apoptosis of PDAC cells by inhibiting survivin and increasing the activity of caspase3/7. Conclusions: For the first time, this study demonstrated that TIPE2 is an independent prognostic factor in PDAC. TIPE2 inhibited the proliferation and induced apoptosis via regulating survivin/caspase3/7 signaling pathway. These results indicated that TIPE2 is a potential biomarker for predicting the prognosis of PDAC patients and plays a pivotal role in the progression of PDAC.

Therapeutic targeting of FOS in mutant TERT cancers through removing TERT suppression of apoptosis via regulating survivin and TRAIL-R2

The telomerase reverse transcriptase (TERT) has long been pursued as a direct therapeutic target in human cancer, which is currently hindered by the lack of effective specific inhibitors of TERT. The FOS/GABPB/(mutant) TERT cascade plays a critical role in the regulation of mutant TERT, in which FOS acts as a transcriptional factor for GABPB to up-regulate the expression of GABPB, which in turn activates mutant but not wild-type TERT promoter, driving TERT-promoted oncogenesis. In the present study, we demonstrated that inhibiting this cascade by targeting FOS using FOS inhibitor T-5224 suppressed mutant TERT cancer cells and tumors by inducing robust cell apoptosis; these did not occur in wild-type TERT cells and tumors. Mechanistically, among 35 apoptotic cascade-related proteins tested, the apoptosis induced in this process specifically involved the transcriptional activation of tumor necrosis factor-related apoptosis-inducing ligand receptor 2 (TRAIL-R2) and inactivation of survivin, two key players in the apoptotic cascade, which normally initiate and suppress the apoptotic cascade, respectively. These findings with suppression of FOS were reproduced by direct knockdown of TERT and prevented by prior knockdown of TRAIL-R2. Further experiments demonstrated that TERT acted as a direct transcriptional factor of survivin, up-regulating its expression. Thus, this study identifies a therapeutic strategy for TERT promoter mutation-driven cancers by targeting FOS in the FOS/GABPB/(mutant) TERT cascade, circumventing the current challenge in pharmacologically directly targeting TERT itself. This study also uncovers a mechanism through which TERT controls cell apoptosis by transcriptionally regulating two key players in the apoptotic cascade.

Self-Assembled DNA Nanostructure as a Carrier for Targeted siRNA Delivery in Glioma Cells

INTRODUCTION

RNA interference is a promising therapy in glioma treatment. However, the application of RNA interference has been limited in glioma therapy by RNA instability and the lack of tumor targeting. Here, we report a novel DNA tetrahedron, which can effectively deliver small interfering RNA to glioma cells and induce apoptosis.

METHODS

siRNA, a small interfering RNA that can suppress the expression of survivin in glioma, was loaded into the DNA tetrahedron (TDN). To enhance the ability of active targeting of this nanoparticle, we modified one side of the DNA nanostructure with aptamer as1411 (As-TDN-R), which can selectively recognize the nucleolin in the cytomembrane of tumor cells. The modified nanoparticles were characterized by agarose gel electrophoresis, dynamic light scattering, and transmission electron microscopy. The serum stability was evaluated by agarose gel electrophoresis. Nucleolin was detected by Western blot and immunofluorescence, and targeted cellular uptake was examined by flow cytometry. The TUNEL assay, flow cytometry, and Western Blot were used to detect apoptosis in U87 cells. The gene silencing of survivin was examined by qPCR, Western Blot, and immunofluorescence.

RESULTS

As-TDN-R alone showed better stability towards siRNA, indicating that TDN was a good siRNA protector. Compared with TDN alone, there was increased intercellular uptake of As-TDN-R by U87 cells, evidenced by overexpressed nucleolin in glioma cell lines. TUNEL assay, flow cytometry, and Western Blot revealed increased apoptosis in the As-TDN-R group. The downregulation of survivin protein and mRNA expression levels indicated that As-TDN-R effectively silenced the target gene.

CONCLUSION

The novel nanoparticle can serve as a good carrier for targeting siRNA delivery in glioma. Further exploration of the DNA nanostructure can greatly promote the application of DNA-based drug systems in glioma.

Shengxian decoction decreases doxorubicin‑induced cardiac apoptosis by regulating the TREM1/NF‑κB signaling pathway

Shengxian decoction (SXT) is a traditional Chinese medicine that is clinically used for treating cardiovascular diseases. It is known for its beneficial effect on cardiomyocyte injuries, some of which can be induced by anticancer agents including doxorubicin (DOX). To determine the molecular mechanisms involved in the cardioprotective effects of SXT, DOX‑induced H9c2 cells were analyzed for apoptosis and expression levels of apoptosis biomarkers. Cell viability and apoptosis were measured by CCK‑8 and flow cytometry. Triggering receptors expressed on myeloid cells 1 (TREM1), cleaved caspase‑3, survivin and NF‑κBp65 expression levels were measured by reverse transcription‑quantitative PCR and/or western blotting. A total of 30 adult male Sprague‑Dawley rats were randomly allocated into five groups (n=6 each); control group receiving 0.9% saline, 1 DOX group receiving 2.5 mg/kg of DOX and 3 DOX + SXT groups, receiving a DOX dose equivalent to the DOX‑only group and either 0.4, 0.8 or 1.6 g/kg of SXT. It was found that DOX increased apoptosis and NF‑κB activation of H9c2 cells by increasing TREM1 expression and that SXT inhibited apoptosis and NF‑κB activation of H9c2 cells induced by DOX or Trem1 overexpression. SXT also significantly reversed DOX‑induced cardiotoxicity in rats. The results suggested that the protective effects of SXT against DOX‑induced apoptosis may be attributed to its downregulation of TREM1.

Crosstalk of the Caspase Family and Mammalian Target of Rapamycin Signaling

Cell can integrate the caspase family and mammalian target of rapamycin (mTOR) signaling in response to cellular stress triggered by environment. It is necessary here to elucidate the direct response and interaction mechanism between the two signaling pathways in regulating cell survival and determining cell fate under cellular stress. Members of the caspase family are crucial regulators of inflammation, endoplasmic reticulum stress response and apoptosis. mTOR signaling is known to mediate cell growth, nutrition and metabolism. For instance, over-nutrition can cause the hyperactivation of mTOR signaling, which is associated with diabetes. Nutrition deprivation can inhibit mTOR signaling via SH3 domain-binding protein 4. It is striking that Ras GTPase-activating protein 1 is found to mediate cell survival in a caspase-dependent manner against increasing cellular stress, which describes a new model of apoptosis. The components of mTOR signaling-raptor can be cleaved by caspases to control cell growth. In addition, mTOR is identified to coordinate the defense process of the immune system by suppressing the vitality of caspase-1 or regulating other interferon regulatory factors. The present review discusses the roles of the caspase family or mTOR pathway against cellular stress and generalizes their interplay mechanism in cell fate determination.

Liberibacter, A Preemptive Bacterium: Apoptotic Response Repression in the Host Gut at the Early Infection to Facilitate Its Acquisition and Transmission

“Candidatus Liberibacter solanacearum” (Lso) is a phloem-limited Gram-negative bacterium that infects crops worldwide. In North America, two haplotypes of Lso (LsoA and LsoB) are transmitted by the potato psyllid, Bactericera cockerelli (Šulc), in a circulative and persistent manner. Both haplotypes cause damaging plant diseases (e.g., zebra chip in potatoes). The psyllid gut is the first organ Lso encounters and could be a barrier for its transmission. However, little is known about the psyllid gut immune responses triggered upon Lso infection. In this study, we focused on the apoptotic response in the gut of adult potato psyllids at the early stage of Lso infection. We found that there was no evidence of apoptosis induced in the gut of the adult potato psyllids upon infection with either Lso haplotype based on microscopic observations. However, the expression of the inhibitor of apoptosis IAPP5.2 gene (survivin-like) was significantly upregulated during the period that Lso translocated into the gut cells. Interestingly, silencing of IAPP5.2 gene significantly upregulated the expression of two effector caspases and induced apoptosis in the psyllid gut cells. Moreover, RNA interference (RNAi) of IAPP5.2 significantly decreased the Lso titer in the gut of adult psyllids and reduced their transmission efficiency. Taken together, these observations suggest that Lso might repress the apoptotic response in the psyllid guts by inducing the anti-apoptotic gene IAPP5.2 at an early stage of the infection, which may favor Lso acquisition in the gut cells and facilitate its transmission by potato psyllid.

Influence of Microgravity on Apoptosis in Cells, Tissues, and Other Systems In Vivo and In Vitro

All life forms have evolved under the constant force of gravity on Earth and developed ways to counterbalance acceleration load. In space, shear forces, buoyance-driven convection, and hydrostatic pressure are nullified or strongly reduced. When subjected to microgravity in space, the equilibrium between cell architecture and the external force is disturbed, resulting in changes at the cellular and sub-cellular levels (e.g., cytoskeleton, signal transduction, membrane permeability, etc.). Cosmic radiation also poses great health risks to astronauts because it has high linear energy transfer values that evoke complex DNA and other cellular damage. Space environmental conditions have been shown to influence apoptosis in various cell types. Apoptosis has important functions in morphogenesis, organ development, and wound healing. This review provides an overview of microgravity research platforms and apoptosis. The sections summarize the current knowledge of the impact of microgravity and cosmic radiation on cells with respect to apoptosis. Apoptosis-related microgravity experiments conducted with different mammalian model systems are presented. Recent findings in cells of the immune system, cardiovascular system, brain, eyes, cartilage, bone, gastrointestinal tract, liver, and pancreas, as well as cancer cells investigated under real and simulated microgravity conditions, are discussed. This comprehensive review indicates the potential of the space environment in biomedical research.

Gene Expression Alterations Associated with Oleuropein-Induced Antiproliferative Effects and S-Phase Cell Cycle Arrest in Triple-Negative Breast Cancer Cells

It is known that the Mediterranean diet is effective in reducing the risk of several chronic diseases, including cancer. A critical component of the Mediterranean diet is olive oil, and the relationship between olive oil consumption and the reduced risk of cancer has been established. Oleuropein (OL) is the most prominent polyphenol component of olive fruits and leaves. This compound has been shown to have potent properties in various types of cancers, including breast cancer. In the present study, the molecular mechanism of OL was examined in two racially different triple-negative breast cancer (TNBC) cell lines-African American (AA, MDA-MB-468) and Caucasian American (CA, MDA-MB-231). The data obtained showed that OL effectively inhibits cell growth in both cell lines, concomitant with S-phase cell cycle arrest-mediated apoptosis. The results also showed that OL-treated MDA-MB-468 cells were two-fold more sensitive to OL antiproliferative effect than MDA-MB-231 cells were. At lower concentrations, OL modified the expression of many apoptosis-involved genes. OL was more effective in MDA-MB-468, compared to MDA-MB-231 cells, in terms of the number and the fold-change of the altered genes. In MDA-MB-468 cells, OL induced a noticeable transcription activation in fourteen genes, including two members of the caspase family: caspase 1 (CASP1) and caspase 14 (CASP14); two members of the TNF receptor superfamily: Fas-associated via death domain (FADD) and TNF receptor superfamily 21 (TNFRSF21); six other proapoptotic genes: growth arrest and DNA damage-inducible 45 alpha (GADD45A), cytochrome c somatic (CYCS), BCL-2 interacting protein 2 (BNIP2), BCL-2 interacting protein 3 (BNIP3), BH3 interacting domain death agonist (BID), and B-cell lymphoma/leukemia 10 (BCL10); and the CASP8 and FADD-like apoptosis regulator (CFLAR) gene. Moreover, in MDA-MB-468 cells, OL induced a significant upregulation in two antiapoptotic genes: bifunctional apoptosis regulator (BFAR) and B-Raf proto-oncogene (BRAF) and a baculoviral inhibitor of apoptosis (IAP) repeat-containing 3 (BIRC3). On the contrary, in MDA-MB-231 cells, OL showed mixed impacts on gene expression. OL significantly upregulated the mRNA expression of four genes: BIRC3, receptor-interacting serine/threonine kinase 2 (RIPK2), TNF receptor superfamily 10A (TNFRSF10A), and caspase 4 (CASP4). Additionally, another four genes were repressed, including caspase 6 (CASP6), pyrin domain (PYD), and caspase recruitment domain (CARD)-containing (PAYCARD), baculoviral IAP repeat-containing 5 (BIRC5), and the most downregulated TNF receptor superfamily member 11B (TNFRSF11B, 16.34-fold). In conclusion, the data obtained indicate that the two cell lines were markedly different in the anticancer effect and mechanisms of oleuropein's ability to alter apoptosis-related gene expressions. The results obtained from this study should also guide the potential utilization of oleuropein as an adjunct therapy for TNBC to increase chemotherapy effectiveness and prevent cancer progression.

Paclitaxel-Loaded Colloidal Silica and TPGS-Based Solid Self-Emulsifying System Interferes Akt/mTOR Pathway in MDA-MB-231 and Demonstrates Anti-tumor Effect in Syngeneic Mammary Tumors

A solid self-emulsifying drug delivery system (SEDDS) of paclitaxel (PTX) was developed that could enhance its oral bioavailability and neutralize other niggles associated with conventional delivery systems of PTX. TPGS-centered SEDDS containing PTX was optimized by Box-Behnken experimental design and then formulated as fumed colloidal silica-based solid SEDDS microparticles (Si-PTX-S-SEDDS). AFM analysis exhibited round-shaped microparticles of approximately 2-3 μM diameter, whereas after reconstitution, particle size measurement showed nanoemulsion droplets of 30.00 ± 2.00 nm with a zeta potential of 17.38 ± 2.88 mV. Si-PTX-S-SEDDS displayed improved efficacy proven by reduced IC₅₀ of 0.19 ± 0.03 μM against MDA-MB-231 cells and a 45.83-fold higher cellular uptake in comparison to free PTX. Molecular mechanistic studies showed mitochondria-mediated intrinsic pathway of apoptosis following Akt/mTOR pathway, which is accompanied by survivin downregulation. Rhodamine 123 assay and chylomicron flow blocking studies revealed P-gp inhibition potential and lymphatic uptake of Si-PTX-S-SEDDS, responsible for over 4-fold increment in oral bioavailability compared to PTX administered as Taxol. In vivo anti-tumor studies in syngeneic mammary tumor model in SD rats revealed higher efficacy of Si-PTX-S-SEDDS as evident from significant reduction in tumor burden. In total, the developed Si-PTX-S-SEDDS formulation was found as an appropriate option for oral delivery of PTX.

Curcusone C induces apoptosis in endometrial cancer cells via mitochondria-dependent apoptotic and ERK pathway

OBJECTIVE

Jatropha curcashas been used in traditional medicine in Africa to treat cancer for thousands of years. This study aimed to examine the anti-endometrial cancer effect of Curcusone C, a naturally occurring rhamnofolane diterpene, isolated from J. curcas and reveal its molecular mechanism of action.

RESULTS

Curcusone C treatment caused significant anti-proliferative and apoptotic effects in human endometrial cancer (EC) Ishikawa and HEC-1A cells in a dose-dependent manner. Exposure of EC cells to Curcusone C resulted in apoptosis, which was associated with cytochrome c release, caspase-3 and caspase-9 activation, Bcl-xL/Bax dysregulation, and decreased expression of inhibitors of apoptosis proteins, such as XIAP and survivin. The inhibitory effect induced by Curcusone C was greatly impaired by the overexpression of survivin or Bax^-/- MEFs or the knockdown of Bim expression. Moreover, Curcusone C activated mitogen-activated protein kinases, and the ERK inhibitor U0126 significantly attenuated the growth-inhibitory and apoptotic effects of Curcusone C in Ishikawa cells.

CONCLUSION

Taken together, the results demonstrate the anti-endometrial cancer potential of Curcusone C for the treatment of endometrial cancer.

Rosmarinic acid-induced apoptosis and cell cycle arrest in triple-negative breast cancer cells

Rosmarinic acid (RA) is a polyphenolic compound with various pharmacological properties, including, anti-inflammatory, immunomodulatory, and neuroprotective, as well as having antioxidant and anticancer activities. This study evaluated the effects and mechanisms of RA in two racially different triple-negative breast cancer (TNBC) cell lines. Results obtained show that RA significantly caused cytotoxic and antiproliferative effects in both cell lines in a dose- and time-dependent manner. Remarkably, RA induced cell cycle arrest-related apoptosis and altered the expression of many apoptosis-involved genes differently. In MDA-MB-231 cells, RA arrested the cells in the G0/G1 phase. In contrast, the data suggest that RA causes S-phase arrest in MDA-MB-468 cells, leading to a 2-fold increase in the apoptotic effect compared to MDA-MB-231 cells. Further, in MDA-MB-231 cells, RA significantly upregulated the mRNA expression of three genes: harakiri (HRK), tumor necrosis factor receptor superfamily 25 (TNFRSF25), and BCL-2 interacting protein 3 (BNIP3). In contrast, in the MDA-MB-468 cell line, the compound induced a significant transcription activation in three genes, including TNF, growth arrest and DNA damage-inducible 45 alpha (GADD45A), and BNIP3. Furthermore, RA repressed the expression of TNF receptor superfamily 11B (TNFRSF11B) in MDA-MB-231 cells in comparison to the ligand TNF superfamily member 10 (TNFSF10) and baculoviral IAP repeat-containing 5 (BIRC5) in MDA-MB-468 cells. In conclusion, the data suggest that the polyphenol RA may have a potential role in TNBC therapies, particularly in MDA-MB-468 cells.

Novel Survivin Peptides Screened With Computer Algorithm Induce Cytotoxic T Lymphocytes With Higher Cytotoxic Efficiency to Cancer Cells

The identification of novel biomarkers and therapeutic targets in advanced cancer is critical for improving cancer diagnosis and therapeutics. Survivin (SV) is highly expressed predominantly in most cancer cells and tissues but is absent or undetectable in terminally differentiated normal adult tissues. Therefore, it functions as an almost universal tumor antigen. Peptides are short chains of amino acids linked by peptide bonds. To obtain novel SV decamers that are able to induce SV-specific cytotoxic T lymphocytes (CTLs) with a higher cytotoxic efficiency against cancer cells, major histocompatibility complex (MHC) peptide binding algorithms were conducted to predict nine modified SV₉₅ decamers (from SV_95–2 to SV_95–10) based on the natural SV_95–104 peptide sequence of ELTLGEFLKL (here defined as SV_95–1). The fluorescent density of each SV₉₅ peptide was determined by a MHC stability assay, followed by the generation of SV₉₅-specific CTLs with each SV₉₅ peptide (from SV_95–1 to SV_95–10) and human dendritic cells (DCs) loaded with Poly(lactic-co-glycolic) acid (PLGA) nanoparticles encapsulated with SV₉₅ peptide. Finally, IFN-γ ELISpot and CytoTox 96^® Non-Radioactive Cytotoxicity Assays were employed to verify their cytotoxic efficiency of the SV₉₅-specific CTLs generated with the corresponding artificial antigen presenting cells (aAPCs) containing SV₉₅ (SV_95–1 to SV_95–10) peptide. Furthermore, the cytotoxicity of the SV₉₅ specific CTLs generated with nine mutated SV₉₅ peptides was compared to the one generated with natural SV_95–1 peptide and TIL2080 cells. The results indicated that the HLA-A2-restricted mutated SV₉₅ epitope decamers (SV_95–6 and SV_95–7) showed significant higher binding ability compared to natural peptide SV_95–1 in MHC stability assay. More importantly, SV_95–specific CTLs with higher cytotoxicity were successfully induced with both SV_95–6 and SV_95–7 peptides, which significantly eliminated target cells (not only SV_95–1 peptide pulsed T2 cells, but also both HLA-A2 and SV positive cancer cells) when compared to those generated with natural SV_95–1 peptide and TIL2080 cells. These findings suggest that the SV_95–6 and SV_95–7 peptides are two novel HLA-A2-restricted CTL epitopes and may be useful for the immunotherapy for patients with survivin expressing cancer.