Epigenetic activation of METTL14 promotes docetaxel resistance in prostate cancer by promoting pri-microRNA-129 maturation.

The development of resistance to Docetaxel (DTX) compromises its therapeutic efficacy and worsens the prognosis of prostate cancer (PCa), while the underlying regulatory mechanism remains poorly understood. In this study, METTL14 was found to be upregulated in DTX-resistant PCa cells and PCa tissues exhibiting progressive disease during DTX therapy. Furthermore, overexpression of METTL14 promoted the development of resistance to DTX in both in vitro and in vivo. Interestingly, it was observed that the hypermethylation of the E2F1 targeting site within DTX-resistant PCa cells hindered the binding ability of E2F1 to the promoter region of METTL14, thereby augmenting its transcriptional activity. Consequently, this elevated expression level of METTL14 facilitated m6A-dependent processing of pri-miR-129 and subsequently led to an increase in miR-129-5p expression. Our study highlights the crucial role of the E2F1-METTL14-miR-129-5p axis in modulating DTX resistance in PCa, underscoring METTL14 as a promising therapeutic target for DTX-resistant PCa patients.

Network pharmacology, molecular docking, and molecular dynamics simulation analysis reveal the molecular mechanism of halociline against gastric cancer.

Halociline, a derivative of alkaloids, was isolated from the marine fungus Penicillium griseofulvum by our group. This remarkable compound exhibits promising antineoplastic activity, yet the precise molecular mechanisms underlying its anticancer properties remain enigmatic. To unravel these mechanisms, we employed an integrated approach of network pharmacology analysis, molecular docking simulations, and molecular dynamics simulations to explore halociline therapeutic targets for gastric cancer. The data from network pharmacology indicate that halociline targets MAPK1, MMP-9, and PIK3CA in gastric cancer cells, potentially mediated by diverse pathways including cancer, lipid metabolism, atherosclerosis, and EGFR tyrosine kinase inhibitor resistance. Notably, molecular docking and dynamics simulations revealed a high affinity between halociline and these targets, with free binding energies (ΔEtotal) of - 20.28, - 27.94, and - 25.97 kcal/mol for MAPK1, MMP-9, and PIK3CA, respectively. This study offers valuable insights into the potential molecular mechanism of halociline's inhibition of gastric cancer cells and serves as a valuable reference for future basic research efforts.

Biologically Driven In Vivo Occlusion Design Provides a Reliable Experimental Glaucoma Model.

Fluid flow transport through the trabecular meshwork tissues is a major regulator of intraocular pressure (IOP) modulation in healthy and glaucomatous individuals. Microbead occlusion models of ocular hypertension regulate aqueous humor drainage to induce high IOP to allow for in vivo study of pressure-related glaucomatous pathology. However, the reliability and application of current injectable microbeads are hindered by inadequate design of the beads-tissue interfaces to maintain a stable IOP elevation over the long term. Considering the graded, porous architecture and fluid transport of the trabecular meshwork, we developed a tailored, injectable "viscobeads" technique, which induced a sustained elevation of IOP for at least 8 weeks. These composite viscobeads contain a non-degradable polystyrene (PS) core for structural support and a biodegradable polylactic-co-glycolic acid (PLGA) viscoelastic surface. This approach enhances the obstruction of aqueous humor drainage through heterogeneous sizes of trabecular meshwork fenestrations and reliably modulates the magnitude and duration of ocular hypertension. In a mouse model, a single viscobeads injection resulted in sustained IOP elevation (average 21.4±1.39 mm Hg), leading to a 34% retinal ganglion cell (RGC) loss by 56 days. In an earlier stage of glaucoma progression, we conducted non-invasive electroretinography (ERG) recording and revealed glaucomatous progression by analyzing high-frequency oscillatory potentials. To further explore the application of the viscobeads glaucoma models, we assayed a series of genes through adeno-associated virus (AAV)-mediated screening in mice and assessed the impact of genetic manipulation on RGC survivals. CRISPR mediated disruption of the genes, PTEN, ATF3 and CHOP enhanced RGC survival while LIN 28 disruption negatively impacted RGC survival. This biologically driven viscobeads design provides an accessible approach to investigate chronic intraocular hypertension and glaucoma-like neurodegeneration and ultimately tenders the opportunity to evaluate genetic and pharmacological therapeutics.

Marine Fungi: A Prosperous Source of Novel Bioactive Natural Products.

As the number of viruses, bacteria, and tumors that are resistant to drugs continues to rise, there is a growing need for novel lead compounds to treat them. Marine fungi, due to their unique secondary metabolic pathways and vast biodiversity, have become a crucial source for lead compounds in drug development. This review utilizes bibliometric methods to analyze the research status of natural products from marine fungi in the past decade, revealing the hotspots and trends in this field from Web of Science database. Furthermore, this review summarizes the biological activities and effects on molecular mechanisms of novel natural compounds isolated from marine fungi in the past five years. These novel compounds belong to six different structural classes, such as alkaloids, terpenoids, anthraquinones, polyketones, etc. They also exhibited highly potent biological properties, including antiviral, antitumor, antibacterial, antiinflammatory, and other properties. This review demonstrates the hotspots and trends of marine fungi research in recent years, as well as the variety of chemical structure and biological activities of their natural products, and it may provide guidance for those interested in discovering new drugs from marine fungi and specific targeting mechanisms.

Gliotransmission and adenosine signaling promote axon regeneration.

How glia control axon regeneration remains incompletely understood. Here, we investigate glial regulation of regenerative ability differences of closely related Drosophila larval sensory neuron subtypes. Axotomy elicits Ca2+ signals in ensheathing glia, which activates regenerative neurons through the gliotransmitter adenosine and mounts axon regenerative programs. However, non-regenerative neurons do not respond to glial stimulation or adenosine. Such neuronal subtype-specific responses result from specific expressions of adenosine receptors in regenerative neurons. Disrupting gliotransmission impedes axon regeneration of regenerative neurons, and ectopic adenosine receptor expression in non-regenerative neurons suffices to activate regenerative programs and induce axon regeneration. Furthermore, stimulating gliotransmission or activating the mammalian ortholog of Drosophila adenosine receptors in retinal ganglion cells (RGCs) promotes axon regrowth after optic nerve crush in adult mice. Altogether, our findings demonstrate that gliotransmission orchestrates neuronal subtype-specific axon regeneration in Drosophila and suggest that targeting gliotransmission or adenosine signaling is a strategy for mammalian central nervous system repair.

Silencing LINC00491 inhibits prostate cancer development through the miR-384/TRIM44 axis.

Accumulating evidence has demonstrated the key role of long noncoding (lnc)RNAs in tumorigenesis. Prostate cancer (PCa) is a cancer with high mortality that requires further exploration of the underlying molecular mechanisms. In the present study, we aimed to discover novel potential biomarkers for diagnosing PCa and targeting treatment. Overexpression of the lncRNA, LINC00491, was verified in PCa tumor tissues and cell lines using the real-time polymerase chain reaction. Cell proliferation and invasion were then analyzed via the Cell Counting Kit-8, colony formation, and transwell assays in vitro, and tumor growth in vivo. The interaction of miR-384 with LINC00491, as well as TRIM44, was investigated via bioinformatics analyses, subcellular fractionation, luciferase reporter gene assays, radioimmunoprecipitation, pull-down, and western blot analyses. LINC00491 was overexpressed in PCa tissues and cell lines. LINC00491 knockdown resulted in impaired cell proliferation and invasion in vitro and decreased tumor growth in vivo. Moreover, LINC00491 acted as a sponge for miR-384 and its downstream target, TRIM44. Additionally, miR-384 expression was downregulated in PCa tissues and cell lines, and its expression was negatively correlated with LINC00491. A miR-384 inhibitor restored the inhibitory effects of LINC00491 silencing on PCa cell proliferation and invasion. LINC00491 is a tumor promoter in PCa via enhancing TRIM44 expression by sponging miR-384 to facilitate the development of PCa. LINC00491 plays a significant role in PCa and could serve as both a biomarker for early diagnosis and a novel treatment target.

Spatiotemporal Dynamics of the Molecular Expression Pattern and Intercellular Interactions in the Glial Scar Response to Spinal Cord Injury.

Nerve regeneration in adult mammalian spinal cord is poor because of the lack of intrinsic regeneration of neurons and extrinsic factors - the glial scar is triggered by injury and inhibits or promotes regeneration. Recent technological advances in spatial transcriptomics (ST) provide a unique opportunity to decipher most genes systematically throughout scar formation, which remains poorly understood. Here, we first constructed the tissue-wide gene expression patterns of mouse spinal cords over the course of scar formation using ST after spinal cord injury from 32 samples. Locally, we profiled gene expression gradients from the leading edge to the core of the scar areas to further understand the scar microenvironment, such as neurotransmitter disorders, activation of the pro-inflammatory response, neurotoxic saturated lipids, angiogenesis, obstructed axon extension, and extracellular structure re-organization. In addition, we described 21 cell transcriptional states during scar formation and delineated the origins, functional diversity, and possible trajectories of subpopulations of fibroblasts, glia, and immune cells. Specifically, we found some regulators in special cell types, such as Thbs1 and Col1a2 in macrophages, CD36 and Postn in fibroblasts, Plxnb2 and Nxpe3 in microglia, Clu in astrocytes, and CD74 in oligodendrocytes. Furthermore, salvianolic acid B, a blood-brain barrier permeation and CD36 inhibitor, was administered after surgery and found to remedy fibrosis. Subsequently, we described the extent of the scar boundary and profiled the bidirectional ligand-receptor interactions at the neighboring cluster boundary, contributing to maintain scar architecture during gliosis and fibrosis, and found that GPR37L1_PSAP, and GPR37_PSAP were the most significant gene-pairs among microglia, fibroblasts, and astrocytes. Last, we quantified the fraction of scar-resident cells and proposed four possible phases of scar formation: macrophage infiltration, proliferation and differentiation of scar-resident cells, scar emergence, and scar stationary. Together, these profiles delineated the spatial heterogeneity of the scar, confirmed the previous concepts about scar architecture, provided some new clues for scar formation, and served as a valuable resource for the treatment of central nervous system injury.

Investigation of the bactericidal mechanism of Penicilazaphilone C on Escherichia coli based on 4D label-free quantitative proteomic analysis.

There is an urgent need to find new antibiotics to fight against the increasing drug resistance of microorganisms. A novel natural compound, Penicilazaphilone C (PAC), was isolated from a marine-derived fungus. It has displayed broad bactericidal activities against Gram-negative and Gram-positive bacteria. However, its bactericidal mechanism is still unknown. Herein, time-kill assays verified that PAC is a fast and efficient bactericidal agent. Furthermore, data from 4D label-free quantitative proteome assays revealed that PAC significantly influences over 898 proteins in Escherichia coli. Combining the results of biofilm formation, ß-galactosidase measurement, TEM observation, soft agar plate swimming, reactive oxygen species measurement, qRT-PCR, and west-blotting, the mode of PAC action against E. coli was to block respiration, inhibit assimilatory nitrate reduction and dissimilar sulfur reduction, facilitate assimilatory sulfate reduction, suppress cysteine and methionine biosynthesis, down-regulate antioxidant protein expression and induced intracellular ROS accumulation, weaken bacterial chemotaxis, destroy flagellar assembly, etc., and finally cause the bacteria's death. Our findings suggest that PAC could have a multi-target regulatory effect on E. coli and could be used as a new antibiotic in medicine.

S-3'-hydroxy-7', 2', 4'-trimethoxyisoxane, a novel ferroptosis inducer, promotes NSCLC cell death through inhibiting Nrf2/HO-1 signaling pathway.

Background: Ferroptosis is a newly discovered and promising non-apoptotic programmed cell death (PCD), and inducing ferroptosis in cancer cells could open up a novel avenue for drug screening and cancer therapy. S-3'-hydroxy-7', 2', 4'-trimethoxyisoxane (ShtIX), a new isoflavane compound, has been reported to possess cytotoxicity in non-small cell lung cancer (NSCLC). The aim of this research is to explore the ShtIX-induced cell death form and its underlying molecular mechanism in NSCLC cells. Methods: Cell proliferation, cell cycle arrest, and cell death tests were used to assess the ability of ShtIX to kill NSCLC cells. Iron metabolism, Fe2+ content, reactive oxygen species (ROS) production, lipid peroxide (MDA) level, glutathione (GSH) level, and glutathione peroxidase 4 (GPX4) level were used to determine ferroptosis caused by ShtIX. We employed western blot, quantitative real-time PCR, and Nrf2 interference in NSCLC cells to investigate the roles of Nrf2/HO-1 in ShtIX-induced ferroptosis. In a xenograft nude mouse model, the anticancer efficacy of ShtIX and the function of ferroptosis were studied. Results: Our research shows that ShtIX can selectively kill NSCLC cells while sparing normal cells and that ShtIX-induced cell death can be efficiently reversed by the ferroptosis inhibitors and the iron chelator, but not by other cell death inhibitors. After cells were treated with ShtIX, there was an increase in Fe2+ content and lipid peroxidation accumulation, as well as a drop in GSH and GPX4 levels, all of which are indicators of ferroptosis. ShtIX also reduced the expression of Nrf2 and HO-1, and genetic Nrf2 silencing in NSCLC enhanced the effect of ShtIX-induced ferroptosis. Additionally, ShtIX retards tumor growth and induced ferroptosis through Nrf2/HO-1 signal pathway in the A549 xenograft model, whereas Fer-1 lessens the anticancer effect. Conclusion: This work provided the evidence that ShtIX caused ferroptosis in NSCLC cells, and inhibiting the Nrf2/HO-1 pathway can considerably exacerbate the effect of ShtIX-induced ferroptosis. The study establishes ShtIX as a promising natural ferroptosis inducer for the treatment of NSCLC.

Genistein attenuates LPS-induced inflammatory injury of rat dorsal root ganglion neuron via down-regulating HDAC6. / é‡‘é›€å¼‚é»„ç´ é€šè¿‡ä¸‹è°ƒHDAC6减轻LPSè¯±å¯¼çš„å¤§é¼ èƒŒæ ¹ç¥žç»èŠ‚ç¥žç»å ƒç‚Žæ€§æŸä¼¤.

OBJECTIVES: Neuropathic pain (NP) is a chronic pain caused by somatosensory neuropathy or disease, and genistein (Gen) might be a potential drug for the treatment of NP. Therefore, this study aims to investigate the effect of Gen on lipopolysaccharide (LPS)-induced inflammatory injury of dorsal root ganglion neuron (DRGn) in rats and the possible molecular mechanism. METHODS: The DRGn of 1-day-old juvenile rats were taken for isolation and culture. The DRGn in logarithmic growth phase were divided into a control group, a LPS group, a tubastatin hydrochloride (TSA)+LPS group, a Gen1+LPS group, a Gen2+LPS group, a Gen2+LPS+TSA group, a Gen2+pcDNA-histone deacetylase 6 (HDAC6)+LPS group, and a Gen2+pcDNA3.1+LPS group. The LPS group was treated with 1 µg/mL LPS for 24 h; the TSA+LPS group, the Gen1+LPS group, the Gen2+LPS group were treated with 5 µmol/L TSA, 5 µmol/L Gen, 10 µmol/L Gen respectively for 0.5 h, and then added 1 µg/mL LPS for 24 h; the Gen2+TSA+LPS group was treated with 10 µmol/L Gen and 5 µmol/L TSA for 0.5 h and then added 1 µg/mL LPS for 24 h; the Gen2+pcDNA-HDAC6+LPS group and the Gen2+pcDNA3.1+LPS group received 100 nmol/L pcDNA-HDAC6 and pcDNA3.1 plasmids respectively, and 24 h after transfection, 10 µmol/L Gen was pretreated for 0.5 h, and then added 1 µg/mL LPS for 24 h. Real-time RT-PCR was used to detect the HDAC6 mRNA expression in DRGn; CCK-8 method was used to detect cell viability of DRGn; flow cytometry was used to detect cell apoptosis of DRGn; ELISA was used to detect the levels of IL-1ß, IL-6, and TNF-α in DRGn culture supernatant; Western blotting was used to detect the protein expression of HDAC6, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and NF-κB p65 in DRGn. RESULTS: Compared with the control group, the expression levels of HDAC6 mRNA and protein, the expression levels of TLR4 and MyD88 protein in DRGn of LPS group rats were significantly up-regulated, the ratio of p-NF-κB p65/NF-κB p65 was significantly increased, and the activity of DRGn was significantly decreased, the apoptosis rate was significantly increased, and the levels of IL-1ß, IL-6 and TNF-α in the DRGn culture supernatant were significantly increased (all P<0.05). Compared with the LPS group, the expression levels of HDAC6 mRNA and protein, TLR4 and MyD88 protein expression levels in DRGn of the TSA+LPS group, the Gen1+LPS group, the Gen2+LPS group and the Gen2+TSA+LPS group were significantly down-regulated, the ratio of p-NF-κB p65/NF-κB p65 was significantly decreased, the activity of DRGn was significantly increased, the apoptosis rate was significantly decreased, and the levels of IL-1ß, IL-6 and TNF-α in the DRGn culture supernatant were significantly decreased (all P<0.05), and the above changes were most obvious in the Gen2+TSA+LPS group. Compared with the Gen2+LPS group, the expression levels of HDAC6 mRNA and protein, TLR4 and MyD88 protein expression levels in DRGn of the Gen2+pcDNA-HDAC6+LPS group were significantly up-regulated, the ratio of p-NF-κB p65/NF-κB p65 was significantly increased, the activity of DRGn was significantly decreased, and the apoptosis rate was significantly increased, and the levels of IL-1ß, IL-6 and TNF-α in the DRGn culture supernatant were significantly increased (all P<0.05). CONCLUSIONS: Gen can alleviate LPS-induced DRGn inflammatory injury in rats, which might be related to down-regulating the expression of HDAC6 and further inhibiting the activation of TLR4/MyD88/NF-κB signaling pathway.

Gas5 inhibition promotes the axon regeneration in the adult mammalian nervous system.

Neurons in the peripheral nervous system (PNS) have robust regenerative capacity after axon injury, but the regenerative capacity is generally absent in the neurons of the central nervous system (CNS) in mammals. Increasing evidence highlighted the pivotal roles of long-noncoding RNAs (lncRNAs) in development and disease, but the role of LncRNA in triggering the regenerative capacity in CNS and PNS is not well studied. Here, we reported that lncRNA Gas5 is a suppressor for axon regeneration. Bioinformatics analysis shows that Gas5 is age-dependent up-regulated during DRG neurons development and down-regulated after sciatic nerve injury. In vitro, inhibiting the expression of Gas5 promotes the neurite growth of DRG neurons both in mice and rats. Consistently, Gas5 overexpression inhibits axon growth of mice DRG neurons. In vivo, Gas5 knockout(Gas5-/-) mice display enhanced nerve regeneration ability after sciatic nerve injury. RNA pull-down analysis indicates that Gas5 can interacts with soluble Vimentin, which is essential for peripheral nerve development and regeneration. Vimentin knockdown reverses the Gas5 silence-regulated axon pro-regeneration demonstrating that the function of Gas5 depending on Vimentin. Besides, inhibition of Gas5 expression can also enhance optic nerve regeneration indicating a potential pro-regenerative ability of Gas5 silence in CNS. Our study for the first time provides direct evidence in vivo that lncRNA plays a role in regulating central axon regrowth and Gas5 might be a novel therapeutic target for axon regeneration in both PNS and CNS.

The acetylome of adult mouse sciatic nerve.

Lysine acetylation is a reversible post-translational modification (PTM) involved in multiple physiological functions. Recent studies have demonstrated the involvement of protein acetylation in modulating the biology of Schwann cells (SCs) and regeneration of the peripheral nervous system (PNS). However, the mechanisms underlying these processes remain partially understood. Here, we characterized the acetylome of the mouse sciatic nerve (SN) and investigated the cellular distribution of acetylated proteins. We identified 483 acetylated proteins containing 1442 acetylation modification sites in the SN of adult C57BL/6 mice. Bioinformatics suggested that these acetylated SN proteins were mainly located in the myelin sheath, mitochondrial inner membrane, and cytoskeleton, and highlighted the significant differences between the mouse SN and brain acetylome. Manual annotation further indicated that most acetylated proteins (> 45%) were associated with mitochondria, energy metabolism, and cytoskeleton and cell adhesion. We verified three newly discovered acetylation-modified proteins, including neurofilament light polypeptide (NEFL), neurofilament medium/high polypeptide (NFM/H), and periaxin (PRX). Immunofluorescence illustrated that the acetylated proteins, including acetylated alpha-tubulin, were mainly co-localized with S100-positive SCs. Herein, we provided a comprehensive acetylome for the mouse SN and demonstrated that acetylated proteins in the SN were predominantly located in SCs. These results will extend our understanding and promote further study of the role and mechanism of protein acetylation in SC development and PNS regeneration.

Identification of Neuronal Cells in Sciatic Nerves of Adult Rats.

Prior research generally confirms that there are no neuronal cell bodies in the adult sciatic nerve. However, we occasionally find some neuronal cells in adult rat sciatic nerves, either intact or crush-injured. By whole-mount staining and optical imaging of the hyalinized sciatic nerves for Stmn2 (a specific marker for neuronal cells), we found those neuronal cells with irregular distribution in the sciatic nerves in both crushed model and normal rats. We investigated the identity of those cells and established a cultured sciatic nerve model. Immunohistochemistry evidence both in vivo and in vitro illustrated that some of those cells are mature neurons in sciatic nerves. With single-cell sequencing of neuronal cells in adeno-associated virus (AAV)-infected sciatic nerves, we identified that some of those cells are a kind of neuronal stem-like cells. Then we constructed a Nestin-CreERT 2 rat line and traced those cells with fluorescence labeling which was induced by tamoxifen. Interesting, we proved that neuronal stem-like cells could proliferate by combination of EdU incorporation with staining in the sciatic nerves of transgenic rats. Together, the discovery of neuronal cells in adult sciatic nerves will make us aware of the distribution of neurons in the peripheral nervous system. Especially our data suggest that neuronal stem-like cells could proliferate in the sciatic nerves of adult rats.

Unfolded protein response-induced expression of long noncoding RNA Ngrl1 supports peripheral axon regeneration by activating the PI3K-Akt pathway.

In mammals, long noncoding RNA (LncRNA) contributes to neuronal development and injury repair mediated by the spatiotemporal regulation of gene expression. However, the pivotal role of lncRNA in intrinsic axon regeneration control following a nerve injury remains unknown. In this article, we report a neurite growth-related lncRNA termed Ngrl1, which supported peripheral axon regeneration post sciatic nerve crush (SNC). A rapid increase in Ngrl1 expression was detected following SNC, and knockdown of Ngrl1 impaired axon regeneration both in vitro and in vivo. The unfolded protein response (i.e., the upstream modulator of Ngrl1 expression) improved the impairment of neurite growth induced by Ngrl1 inhibition in matured dorsal root ganglion neurons. Meanwhile, interference with Ngrl1 impacts the PI3K-Akt pathway, leading to a marked decrease in Akt phosphorylation. Furthermore, the activation of Akt by insulin-like growth factor 1 (IGF-1) or SC79 reversed the reduction of axon regeneration in dorsal root ganglion neuron following inhibition of Ngrl1. In conclusion, unfolded protein response-induced Ngrl1 expression supports the intrinsic control of peripheral axon regeneration by modulating the activation of the PI3K-Akt pathway following SNC.

Ethanol Extract of Eryngium Foetidum Leaves Induces Mitochondrial Associated Apoptosis via ROS Generation in Human Gastric Cancer Cells.

Background: Eryngium foetidum has long been used as a food ingredient and folk medicine in tropical regions. The anticancer activity of EF extract and the mechanisms remains unclear. Herein, we prepared four solvent extracts of EF leaves, detected the cytotoxic effects, and explored the potential mechanism by which these extracts induce cell death. Methods: The anticancer activity of the EF extracts was measured by MTT, CCK-8 and BrdU assays. The cell cycle was evaluated by flow cytometry and western blot. Apoptotic events were investigated with Hoechst, Annexin V/PI assays and western blot. The mitochondrial membrane potential was monitored using JC-1 staining, and ROS production was assessed with immunofluorescence. Results: The ethanol extract of EF leaves exhibited the strongest cytotoxic effect against SGC-7901 cells. The EFE extract significantly inhibited the SGC-7901 cells viability, arrested the cell cycle, increased the numbers of apoptotic cells, caused the loss of MMP, increased the Bax/Bcl-2 ratio, and led to cytochrome c release, and triggered ROS production. Conclusion: Our findings demonstrated for the first time that EFE extract induces mitochondrial associated apoptosis via ROS generation in SGC-7901 cells. Thus, EFE extract could be identified as a potential edible phytotherapy for the treatment of human gastric cancer.

Stigmasterol Simultaneously Induces Apoptosis and Protective Autophagy by Inhibiting Akt/mTOR Pathway in Gastric Cancer Cells.

BACKGROUND: Stigmasterol (SS) has been proven to possess potential anticancer activities in several cancer cell lines, but its molecular mechanism is still unknown. Thus, we investigated whether SS has the capabilities of inducing autophagy and its molecular mechanisms in gastric cancer cells. METHODS: We used CCK8 assay, clone formation assay, and EdU proliferation assay to assess the effects of SS on cell proliferation in SGC-7901 and MGC-803 cells in vitro, and its inhibition on the tumor growth of gastric cancer was observed in vivo. Apoptosis induced by SS was demonstrated using Hoechst and TUNEL staining, annexin V-FITC/PI assay. Immunofluorescence staining is used to detect the formation of autophagosomes triggered by SS. Apoptosis and autophagy related proteins were analyzed by western blot. RESULTS: The results indicated that SS treatment inhibited cell proliferation in SGC-7901 and MGC-803 cells. Furthermore, SS treatment induced apoptosis and autophagy by blocking Akt/mTOR signaling pathway. The pretreatment with the Akt inhibitor MK-2206 could promote apoptosis and autophagy induced by SS, predicting that Akt/mTOR pathway is involved in SS-induced apoptosis and autophagy. In addition, blockade of autophagy with 3-MA (an inhibitor of autophagy) enhanced SS-induced apoptosis in SGC-7901 and MGC-803 cells, implying that autophagy mediated by SS plays a cytoprotective role against apoptosis. Finally, an in vivo study demonstrated that tumor growth of gastric cancer was suppressed by SS in a xenograft model. CONCLUSION: Our findings illustrate for the first time that SS simultaneously induces apoptosis and protective autophagy by inhibiting Akt/mTOR pathway in gastric cancer cells, and SS may become a potential anticancer drug in treating gastric cancer in the future.

Reprogramming to recover youthful epigenetic information and restore vision.

Ageing is a degenerative process that leads to tissue dysfunction and death. A proposed cause of ageing is the accumulation of epigenetic noise that disrupts gene expression patterns, leading to decreases in tissue function and regenerative capacity1-3. Changes to DNA methylation patterns over time form the basis of ageing clocks4, but whether older individuals retain the information needed to restore these patterns-and, if so, whether this could improve tissue function-is not known. Over time, the central nervous system (CNS) loses function and regenerative capacity5-7. Using the eye as a model CNS tissue, here we show that ectopic expression of Oct4 (also known as Pou5f1), Sox2 and Klf4 genes (OSK) in mouse retinal ganglion cells restores youthful DNA methylation patterns and transcriptomes, promotes axon regeneration after injury, and reverses vision loss in a mouse model of glaucoma and in aged mice. The beneficial effects of OSK-induced reprogramming in axon regeneration and vision require the DNA demethylases TET1 and TET2. These data indicate that mammalian tissues retain a record of youthful epigenetic information-encoded in part by DNA methylation-that can be accessed to improve tissue function and promote regeneration in vivo.

Green Biosynthesized Silver Nanoparticles With Aqueous Extracts of Ginkgo Biloba Induce Apoptosis via Mitochondrial Pathway in Cervical Cancer Cells.

Biosynthetic silver nanoparticles (AgNPs), specifically formed using medicinal plant extracts, have recently exhibited a remarkable therapeutic effect due to their anticancer potential. Here, we synthesized AgNPs using an aqueous extract of Ginkgo biloba leaves and evaluated its activity against cervical cancer (CCa) and the related molecular mechanisms. The physiochemical properties of the AgNPs were measured by ultraviolet-visible spectrophotometry, nanometre particle size analyzer and transmission electron microscopy. The AgNPs effects on cell proliferation and apoptosis were investigated through MTT, MTS, and colony formation assay; Hoechst 33258 staining; and flow cytometry. The intracellular ROS and oxidative stress levels were assessed using the appropriate commercial kits. Apoptosis-related protein levels were determined by western blotting. We prepared a series of different sized ginkgo extract synthesized AgNPs (GB-AgNPs), and the smallest mean particle size was 40.2 ± 1.2 nm with low polydispersity (0.091 ± 0.011), zeta potential values showed -34.56 mV. Compared to the controls, the GB-AgNP treatment inhibited the cell proliferation and induced the apoptosis of HeLa and SiHa cells. In addition, GB-AgNP treatment led to markedly increased levels of intracellular ROS, the release of cytochrome c (Cyt C) from mitochondria into the cytosol and the cleavage of caspase -9 and -3 in both CCa cell lines. Moreover, NAC, an ROS scavenger, eliminated the effect of GB-AgNPs on the HeLa and SiHa cells. This study reveals that GB-AgNPs suppresses cancer cell proliferation and induces apoptosis by upregulating intracellular ROS generation and inducing the activation of the caspase-dependent mitochondrial apoptotic pathway in CCa cells. Thus, GB-AgNPs may be a potential alternative drug for CCa therapy.

Nomograms for predicting overall survival and cancer-specific survival of chondroblastic osteosarcoma patients.

BACKGROUND: The establishment of precise and personalized prediction systems for chondroblastic osteosarcoma patients is important for guiding the treatment. METHODS: The univariate logrank test and multivariate Cox regression analysis were performed to identify independent prognostic factors for overall survival (OS) and cancer-specific survival (CSS). Nomograms were constructed to estimate the OS and CSS based on these factors. Internal and external validation was performed. The predictive power of the nomograms was determined by C-index and calibration plots. RESULTS: A total of 401 chondroblastic osteosarcoma cases were identified. Univariate and multivariate analysis revealed that age at diagnosis, histological grade, tumor size, Surveillance, Epidemiology, and End Results stage, and surgical resection were independent prognostic factors for OS and CSS. The five factors were incorporated to construct the nomograms for estimating the 3- and 5-year OS and CSS. The C-index values for the internal validation of the OS and CSS nomogram were 0.732 and 0.746, respectively, and for the external validation were 0.780 and 0.808, respectively. The calibration curves revealed that the predicted OS and CSS could well match the actual survival rate. CONCLUSIONS: The nomograms for predicting 3- and 5-year OS and CSS were constructed and were proved to be accurate and reliable by the internal and external validation.

Penicilazaphilone C, a New Azaphilone, Induces Apoptosis in Gastric Cancer by Blocking the Notch Signaling Pathway.

Penicilazaphilone C (PAC) is a novel azaphilonidal derivative isolated by our group that demonstrates good anticancer activities. Considering that its molecular mechanisms remain largely unknown, here we explore the molecular mechanisms of the anticancer activities of PAC against gastric cancer. The in vitro effects of PAC on cell growth, proliferation, and apoptosis were evaluated by MTT, BrdU, MTS, colony formation assays, Hoechst 33258 staining, and flow cytometry. Related proteins were examined by western blotting. Notch receptor expression was analyzed by RT-PCR. In vivo antitumor activities of PAC were observed in a nude mouse model. We found that compared to the controls, PAC treatment suppressed cell proliferation and promoted apoptosis in MGC-803 and SGC-7901 cells, and the Notch/PTEN/AKT axis was involved in the activating PAC-induced apoptosis. PAC treatment led to decreased levels of Notch (NTM), NICD, pPTEN, and pAKT compared to controls. PAC-induced inhibition of Notch-related protein expression levels and the resulting apoptosis were reversed by overexpression of Notch1 (NTM) or/and Notch2 (NTM). Moreover, PAC treatment clearly inhibited tumor growth in mice both bearing tumors derived from both MGC-803 and SGC-7901 cells. This work reveals that PAC induces the apoptosis by suppressing activation of Notch receptor proteolytic cleavage and subsequently blocking the PTEN/AKT signaling axis in gastric cancer cells. Thus, PAC is a potential alternative agent for the treatment of gastric cancer.