Ubiquitin E3 ligase SPOP is a host negative regulator of enterovirus 71-encoded 2A protease.

IMPORTANCE: EV71 poses a significant health threat to children aged 5 and below. The process of EV71 infection and replication is predominantly influenced by ubiquitination modifications. Our previous findings indicate that EV71 prompts the activation of host deubiquitinating enzymes, thereby impeding the host interferon signaling pathway as a means of evading the immune response. Nevertheless, the precise mechanisms by which the host employs ubiquitination modifications to hinder EV71 infection remain unclear. The present study demonstrated that the nonstructural protein 2Apro, which is encoded by EV71, exhibits ubiquitination and degradation mediated by the host E3 ubiquitin ligase SPOP. In addition, it is the first report, to our knowledge, that SPOP is involved in the host antiviral response.

Hypoxia promotes metastasis by relieving miR-598-3p-restricted glycolysis in gastric cancer.

The activation of glycolysis, particularly in the context of reprogrammed energy metabolism, is increasingly recognized as a significant characteristic of cancer. However, the precise mechanisms by which glycolysis is promoted in metastatic gastric cancer cells under normal oxygen conditions remain poorly understood. MicroRNAs (miRNAs) play a crucial role in the development of malignant phenotypes in gastric cancer. Nevertheless, our understanding of the specific involvement of miRNAs in hypoxia-induced metabolic shifting and the subsequent metastatic processes is limited. Hypoxia-induced downregulation of miR-598-3p mechanistically leads to the upregulation of RMP and IGF1r, thereby promoting glycolysis. Either overexpression of miR-598-3p or R406 treatment effectively suppresses the metastasis of gastric cancer cells both in vitro and in vivo. Collectively, the depletion of miR-598-3p alters glucose metabolism from oxidative phosphorylation to glycolysis, thereby exacerbating the malignancy of gastric cancer cells. The present findings indicate a potential target for the development of therapeutics against gastric cancers with increased miR-598-3p expression.

Erbium-doped ZBLAN fiber laser pumped at 1.7 µm for emission at 2.8 µm.

In this paper, a novel, to the best of our knowledge, efficient pump scheme for an erbium-doped fluoride fiber laser with emission at 2.8 µm in the mid-infrared region is proposed and demonstrated. A singular pump source at 1.7 µm is used to excite Er3+ ions from ground state 4I15/2 to lower laser level 4I13/2, and then further boost the ions to 4I9/2, where a non-radiation transition occurs for the Er3+ ions to reach upper laser level 4I11/2. This scheme can efficiently recycle ions on the lower laser level 4I13/2 by excited-state absorption, therefore realizing population inversion and enhancing laser efficiency. In our demonstration, a 660-mW laser output at 2.8 µm is achieved from a 1.7-µm core-pumped erbium-doped fluoride fiber laser, where the slope efficiency versus launched pump power is 23.7%. The proposed innovative pump scheme shows great potential to realize high-power, high-efficiency erbium-doped fiber lasers at 2.8 µm.

Hyperoside: A Review of Its Structure, Synthesis, Pharmacology, Pharmacokinetics and Toxicity.

Hyperoside is an active ingredient in plants, such as Hypericum monogynum in Hypericaceae, Crataegus pinnatifida in Rosaceae and Polygonum aviculare in Polygonaceae. Its pharmacologic effects include preventing cancer and protecting the brain, neurons, heart, kidneys, lung, blood vessels, bones, joints and liver, among others. Pharmacokinetic analysis of hyperoside has revealed that it mainly accumulates in the kidney. However, long-term application of high-dose hyperoside should be avoided in clinical practice because of its renal toxicity. This review summarises the structure, synthesis, pharmacology, pharmacokinetics and toxicity of hyperoside.

Insights into Q-markers of honey-fried licorice in treating spleen deficiency based on substance and energy metabolism regulation.

BACKGROUND: Honey-fried Licorice (HFL) is a dosage form of Glycyrrhizae Radix et Rhizome processed with honey, which has been recorded to exhibit better efficacy in tonifying the spleen compared to the raw product. In contrast, different processing methods of Glycyrrhizae Radix et Rhizome exhibit different efficacies and applications, but their current quality control index components remain consistent. PURPOSE: Based on the discovery and research strategy of traditional Chinese medicine decoction piece quality marker (Q-marker), this study aimed to conduct a multidimensional integration of constituents absorbed into the body and metabolomics based on the tonifying spleen and stomach effects of HFL to effectively identify the Q-marker of HFL. METHODS: In this study, a spleen deficiency rat model was established using the "exhausted swimming + poor diet" method to investigate the pharmacodynamics of tonifying the spleen and stomach by HFL. The constituents absorbed into blood was conducted using UPLC-Q-TOF/MS, correlation analysis between metabolomics and constituents absorbed into blood recognized the Q-Marker of HFL. RESULTS: The pharmacodynamic data demonstrated that HFL exhibited a significant regulatory effect on the disordered levels of PP, trypsin, chymase, PL, α-Glu, MTL, GAS, VIP, IL-2, IFN-γ, and IgA in the spleen deficiency model. Furthermore, HFL was found to improve the pathological changes in the spleen and intestine in the spleen deficiency model, highlighting its significant "tonifying spleen and stomach" effect. In the serum containing HFL, a total of 17 constituents were identified as being absorbed into the blood. Among these, 11 were prototypical components, while 6 were metabolites. Metabolomics data revealed that 9 differentially expressed metabolic markers were observed. Furthermore, the analysis of endogenous metabolic markers indicated that 10 components exhibited significant correlations with these biomarkers. CONCLUSION: The effect of "tonifying spleen and stomach" of HFL is closely related to the regulation of the material and energy metabolism pathway. The Q-Marker of HFL is glycyrrhizic acid and 18ß-glycyrrhetinic acid as the main control standards and liquiritin, isoliquiritin, liquiritin, isoliquiritin, isolicorice flavonol, licorice chalcone C and Formononetin were used as auxiliary standards.

Research progress on ethnobotany, phytochemistry, pharmacological action, and applications of Engelhardia roxburghiana Wall: a review.

OBJECTIVES: Engelhardia roxburghiana Wall is a plant of the Juglandaceae family, and its leaves is the main part used as a medicine. It is used to relieve heat and pain, gasification, and dampness. The purpose of this review is to provide a systematic review about the botany, traditional uses, phytochemistry, pharmacology, and toxicology of this plant. KEY FINDINGS: Many compounds have been isolated and identified from the plant, including flavonoids, triterpenoids, steroids, quinones, essential oils, and other types of chemical constituents. Extensive pharmacological activities of the extracts or compounds of E. roxburghiana Wall in vivo and in vitro were mainly confirmed, including anti-cancer, anti-diabetic, anti-inflammatory, and anti-allergic effects. SUMMARY: In this paper, the botany, traditional uses, phytochemistry, and pharmacology of E. roxburghiana Wall were reviewed. In the future, E. roxburghiana Wall needs further study, such as paying more attention to quality control and the utilization on agriculture. In addition, discussing the medicinal components of decoction as well as the toxicity will also contribute to the progress of clinical trial studies.

Neurexin dysfunction in neurodevelopmental and neuropsychiatric disorders: a PRIMSA-based systematic review through iPSC and animal models.

Background: Neurexins, essential synaptic proteins, are linked to neurodevelopmental and neuropsychiatric disorders like autism spectrum disorder (ASD) and schizophrenia. Objective: Through this systematic review, we aimed to shed light on the relationship between neurexin dysfunction and its implications in neurodevelopmental and neuropsychiatric manifestations. Both animal and human-induced pluripotent stem cell (hiPSC) models served as our primary investigative platforms. Methods: Utilizing the PRISMA 2020 guidelines, our search strategy involved scouring articles from the PubMed and Google Scholar databases covering a span of two decades (2003-2023). Of the initial collection, 27 rigorously evaluated studies formed the essence of our review. Results: Our review suggested the significant ties between neurexin anomalies and neurodevelopmental and neuropsychiatric outcomes, most notably ASD. Rodent-based investigations delineated pronounced ASD-associated behaviors, and hiPSC models derived from ASD-diagnosed patients revealed the disruptions in calcium dynamics and synaptic activities. Additionally, our review underlined the integral role of specific neurexin variants, primarily NRXN1, in the pathology of schizophrenia. It was also evident from our observation that neurexin malfunctions were implicated in a broader array of these disorders, including ADHD, intellectual challenges, and seizure disorders. Conclusion: This review accentuates the cardinal role neurexins play in the pathological process of neurodevelopmental and neuropsychiatric disorders. The findings underscore a critical need for standardized methodologies in developing animal and hiPSC models for future studies, aiming to minimize heterogeneity. Moreover, we highlight the need to expand research into less studied neurexin variants (i.e., NRXN2 and NRXN3), broadening the scope of our understanding in this field. Our observation also projects hiPSC models as potent tools for bridging research gaps, promoting translational research, and fostering the development of patient-specific therapeutic interventions.

Dormant origin firing promotes head-on transcription-replication conflicts at transcription termination sites in response to BRCA2 deficiency.

BRCA2 is a tumor suppressor protein responsible for safeguarding the cellular genome from replication stress and genotoxicity, but the specific mechanism(s) by which this is achieved to prevent early oncogenesis remains unclear. Here, we provide evidence that BRCA2 acts as a critical suppressor of head-on transcription-replication conflicts (HO-TRCs). Using Okazaki-fragment sequencing (Ok-seq) and computational analysis, we identified origins (dormant origins) that are activated near the transcription termination sites (TTS) of highly expressed, long genes in response to replication stress. Dormant origins are a source for HO-TRCs, and drug treatments that inhibit dormant origin firing led to a reduction in HO-TRCs, R-loop formation, and DNA damage. Using super-resolution microscopy, we showed that HO-TRC events track with elongating RNA polymerase II, but not with transcription initiation. Importantly, RNase H2 is recruited to sites of HO-TRCs in a BRCA2-dependent manner to help alleviate toxic R-loops associated with HO-TRCs. Collectively, our results provide a mechanistic basis for how BRCA2 shields against genomic instability by preventing HO-TRCs through both direct and indirect means occurring at predetermined genomic sites based on the pre-cancer transcriptome.

Oncopreventive and Oncotherapeutic Potential of Licorice Chalcone Compounds: Molecular Insights.

BACKGROUND: Licorice is an important traditional Chinese medicine commonly used in clinical practice and contains more than 300 flavonoids. Chalcone is one of the main types of flavonoids with a wide range of biological functions and pharmacological activities. In the anticancer research, chalcone compounds have shown excellent performance. OBJECTIVE: This review aims to summarize the biosynthetic pathway and pharmacokinetics of chalcone from licorice and provide evidence for the anticancer effects of chalcone and the underlying mechanisms involved. METHODS: For this review, the following databases were consulted: the PubMed Database (https://pubmed.ncbi.nlm.nih.gov), Chinese National Knowledge Infrastructure (http:// www.cnki.net), National Science and Technology Library (http://www.nstl.gov.cn/), Wanfang Data (http://www.wanfangdata.com.cn/), and the Web of Science Database (http:// apps.webofknowledge.com/). RESULTS: To date, about 56 chalcones have been isolated and identified from licorice, 14 of which have antitumor effects. These chalcones have a wide range of biological activities and can inhibit the viability, proliferation, and migration of cancer cells by blocking the cancer cell cycle, thus inducing apoptosis and autophagy. However, the molecular mechanism of the anticancer effects of chalcone is not fully understood. CONCLUSION: In this paper, the molecular mechanism of chalcone regulating different types of cancer is reviewed in detail from the biosynthetic pathway. This comprehensive review article summarizes the biosynthetic pathway and pharmacokinetics of chalcone from the traditional Chinese medicine licorice and provides evidence for the potential anticancer effects of chalcone and the respective mechanisms of action. This paper also provides a basis for structural modification, biosynthesis, and new drug development of chalcone compounds in Glycyrrhiza uralensis.

Regulation of external electric field on sensitivity of ICM energetic materials.

CONTEXT: [2,2'-Bi(1,3,4-oxadiazole)]-5,5'-dinitramide (ICM-101), 2,4,6-triamino-5-nitropyrimidine-1,3-dioxide (ICM-102), and 6-nitro-7-azido-pyrazol[3,4-d][1,2,3]triazine-2-oxide (ICM-103) are excellent China-made explosives, but their performance under external electric fields (EEF) has never been explored, especially sensitivity. To study the induction effect of EEF on it, the chemical reactivity, electron localization function (ELF), spectrum, and other parameters were calculated by density functional theory. The results show that the increasing EEF can weaken the △EHOMO-LUMO (△EHOMO-LUMO = EHOMO-ELUMO) materials, making the stability worse and the sensitivity higher. The proportion of the positive electrostatic surface potential area is also smaller under the increasing EEF, indicating that ICM molecules are becoming more and more unstable. The ELF and localized orbital locator (LOL) decrease with the increase of EEF strength, which suggests that the trigger bond length increases, the EBDE decreases, and the molecular sensitivity increases. When the intensity of EEF increases, the absorption peak of the molecular spectrum gradually redshifts, and even a weak new absorption peak appears, indicating that the color of the material may change. Finally, EEF strength affects electron density, nitro charge, and chemical reactivity parameters. METHODS: Gaussian 16 software was used for calculation. The calculation levels are B3LYP/6-311G+ (d, p) and B3LYP/Def2-TZVPP. The optimized structure has a local true minimum energy on the potential energy surface and no imaginary frequency. Multiwfn 3.8 and VMD 1.9.3 were used in this work to analyze the ICM series of energetic material wave functions. The strength range of EEF is 0.000-0.016 a.u., and the increasing gradient is 0.002 a.u.

Investigation of the Effects of Glabridin on the Proliferation, Apoptosis, and Migration of the Human Colon Cancer Cell Lines SW480 and SW620 and Its Mechanism Based on Reverse Virtual Screening and Proteomics.

Colon cancer is a relatively common malignant tumor of the digestive tract. Currently, most colon cancers originate from adenoma carcinogenesis. By screening various licorice flavonoids with anticancer effects, we found that glabridin (GBN) has a prominent anticolon cancer effect. First, we initially explored whether GBN can inhibit proliferation, migration, and invasion and induce apoptosis in SW480 and SW620 cells. Next, we exploited reverse virtual and proteomics technologies to screen out closely related target pathways on the basis of a drug and target database. At the same time, we constructed the structure of the GBN target pathway in colon cancer. We predicted that GBN can regulate the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT)-mammalian target of the rapamycin pathway (mTOR) pathway to fight colon cancer. Finally, through Western blot analysis and qRT-PCR, we verified that the expression levels of the PI3K, AKT, and mTOR proteins and genes in this pathway were significantly reduced after GBN administration. In short, the promising discovery of the anticolon cancer mechanism of GBN provides a reliable experimental basis for subsequent new drug development.

mTOR inhibition suppresses Myc-driven polyposis by inducing immunogenic cell death.

Myc is a key driver of colorectal cancer initiation and progression, but remains a difficult drug target. In this study, we show that mTOR inhibition potently suppresses intestinal polyp formation, regresses established polyps, and prolongs lifespan of APCMin/+ mice. Everolimus in diet strongly reduces p-4EBP1, p-S6, and Myc levels, and induces apoptosis of cells with activated ß-catenin (p-S552) in the polyps on day 3. The cell death is accompanied by ER stress, activation of the extrinsic apoptotic pathway, innate immune cell recruitment, and followed by T-cell infiltration on day 14 persisting for months thereafter. These effects are absent in normal intestinal crypts with physiologic levels of Myc and a high rate of proliferation. Using normal human colonic epithelial cells, EIF4E S209A knockin and BID knockout mice, we found that local inflammation and antitumor efficacy of Everolimus requires Myc-dependent induction of ER stress and apoptosis. These findings demonstrate mTOR and deregulated Myc as a selective vulnerability of mutant APC-driven intestinal tumorigenesis, whose inhibition disrupts metabolic and immune adaptation and reactivates immune surveillance necessary for long-term tumor control.

Mume Fructus (Prunus mume Sieb. et Zucc.) extract accelerates colonic mucosal healing of mice with colitis induced by dextran sulfate sodium through potentiation of cPLA2-mediated lysophosphatidylcholine synthesis.

BACKGROUND: Mume Fructus (MF) is the fruit of Prunus mume Sieb. et Zucc, a plant of Rosaceae family. Previous studies demonstrated that MF was capable of ameliorating ulcerative colitis (UC) in mice, its action mechanism needs to be clarified. PURPOSE: This study deciphered whether and how MF extract accelerates colonic mucosal healing, the therapeutic endpoint of UC. METHODS: Biochemical, histopathological and qRT-PCR analyses were utilized to define the therapeutic efficacy of MF on dextran sulfate sodium (DSS)-induced colitis in mice. UHPLC-QTOF-MS/MS-based metabolomics technique was adopted to explore the changes of endogenous metabolites associated with UC and responses to MF intervention. qRT-PCR analysis was performed to confirm the molecular pathway in vivo. The effects of MF and lysophosphatidylcholine (LPC) on cell viability, wound healing, proliferation, and migration were examined through a series of in vitro experiments. Moreover, the effects of different subtypes of phospholipase A2 (PLA2) inhibitors on MF-treated colonic epithelial cells were detected by wound healing test and transwell assay. RESULTS: Orally administered MF could alleviate colitis in mice mainly by accelerating the healing of colonic mucosa. Guided by an unbiased metabolomics screen, we identified LPC synthesis as a major modifying pathway in colitis mice after MF treatment. Notably, MF facilitated the synthesis of LPC by enhancing the expression of PLA2 in colitis mice. Mechanistically, MF and LPC accelerated wound closure by promoting cell migration. Moreover, the promotion of MF on wound healing and migration of colonic epithelial cells was blunted by a cytosolic phospholipase A2 (cPLA2) inhibitor. CONCLUSION: MF can facilitate colonic mucosal healing of mice with colitis through cPLA2-mediated intestinal LPC synthesis, which may become a novel therapeutic agent of UC.

Isolation, phytochemistry, characterization, biological activity, and application of Morinda officinalis How oligosaccharide: a review.

Morinda officinalis How oligosaccharide (MOO) stands as one of the principal active constituents of M. officinalis How, widely employed in traditional Chinese medicine. The methods for MOO extraction predominantly encompass hot water extraction, ethanol extraction, ultrasonic-assisted extraction, and microwave-assisted extraction. Distinct extraction techniques yield varying MOO quantities. MOO encompasses a diversity of oligosaccharides, including bajijiasu, sucrose, 1-kestose, nystose, mannose, 1F-fructofuranosylnystose, 1,1,1,1-kestohexose, fructoheptasaccharide, inulin-type hexasaccharide, inulin-type heptasaccharide, inulotriose, inulotetraose, inulopentaose, and mannose. MOO exhibits a wide spectrum of biological activities, exerting specific effects on the nervous system, cardiovascular system, motor system, reproductive system, and immune system. It demonstrates antidepressant properties, offers potential in mitigating Alzheimer's disease, stimulates angiogenesis, and possesses anti-osteoporotic and other pharmacological effects. Clinically, when combined with various antidepressants, MOO exhibits specific therapeutic efficacy across multiple forms of depression. As a naturally occurring plant oligosaccharide, MOO holds diverse pharmaceutical applications. This article conducts a review of the latest extraction and purification methodologies, structural characterization analysis, biological activity assessment, and clinical applications of MOO. Such a comprehensive analysis yields innovative insights for advancing the research and application of MOO in the future.

Cholinergic dysfunction-induced insufficient activation of alpha7 nicotinic acetylcholine receptor drives the development of rheumatoid arthritis through promoting protein citrullination via the SP3/PAD4 pathway.

Both cholinergic dysfunction and protein citrullination are the hallmarks of rheumatoid arthritis (RA), but the relationship between the two phenomena remains unclear. We explored whether and how cholinergic dysfunction accelerates protein citrullination and consequently drives the development of RA. Cholinergic function and protein citrullination levels in patients with RA and collagen-induced arthritis (CIA) mice were collected. In both neuron-macrophage coculture system and CIA mice, the effect of cholinergic dysfunction on protein citrullination and expression of peptidylarginine deiminases (PADs) was assessed by immunofluorescence. The key transcription factors for PAD4 expression were predicted and validated. Cholinergic dysfunction in the patients with RA and CIA mice negatively correlated with the degree of protein citrullination in synovial tissues. The cholinergic or alpha7 nicotinic acetylcholine receptor (α7nAChR) deactivation and activation resulted in the promotion and reduction of protein citrullination in vitro and in vivo, respectively. Especially, the activation deficiency of α7nAChR induced the earlier onset and aggravation of CIA. Furthermore, deactivation of α7nAChR increased the expression of PAD4 and specificity protein-3 (SP3) in vitro and in vivo. Our results suggest that cholinergic dysfunction-induced deficient α7nAChR activation, which induces the expression of SP3 and its downstream molecule PAD4, accelerating protein citrullination and the development of RA.

Study on regulation effect of external electric field on energetic material 1-methyl-2,4,5-Trinitroimidazole.

In this work, in order to explore the regulation effect of external electric field (EEF) on various properties of 1-methyl-2,4,5-trinitroimidazole (MTNI), density functional theory (DFT) was used to investigate the molecular structure, electronic structure, frontier molecular orbital (FMO) and ultraviolet-visible (UV-Vis) spectroscopy of MTNI under EEF. The results show that: (1) EEF significantly affects the geometric and electronic structure of MTNI, which in turn affects the sensitivity of MTNI. (2) When the EEF in the positive direction increases, the energy gap of MTNI decreases significantly and the total density of states (TDOS) turns to be dominated by the nitro groups. (3) EEF makes MTNI appear new absorption peak in visible light region and thus makes the MTNI display color. The generation of new absorption peaks is also dominated by the nitro groups. We also carefully analyzed how EEF deforms structure of the MTNI from the perspective of atomic forces and decomposition of energy variation.

Theoretical study on BTF-based cocrystals: effect of external electric field.

The external electric field plays an important role in the sensitivity of cocrystal energetic materials. To reveal the influence of external electric field on benzotrifuroxan/2,4,6-trinitroaniline (BTF/TNA), benzotrifuroxan/trinitroazetidine (BTF/TNAZ), benzotrifuroxan/1,3,5-trinitrobenzene (BTF/TNB), and benzotrifuroxan/trinitrotoluene (BTF/TNT) cocrystals' sensitivity, atoms in molecules (AIM), frontier molecular orbitals, nitro group charges (QNO2), electron density values (ρ), electrostatic surface potentials (ESPs), bond dissociation energy (EBDE), and interaction energy (Eint) of the C-NO2 bond were calculated by density functional theory at M062X-D3/ma-def2 TZVPP and B3LYP-D3/6-311 + G (d, p) levels in this article. The results indicate that both negative and positive electric fields reduce the energy gap of the BTF-based cocrystals, and BTF/TNAZ is the most sensitive cocrystal among the four cocrystals. For BTF/TNA and BTF/TNB, the EBDE and the negative charge of the nitro group decreases with increasing positive electric field strength, the Vs max increases with positive electric field strength, and the sensitivity of cocrystal eventually tends to increase under the positive electric field. For BTF/TNAZ and BTF/TNT, the EBDE and the negative charge of the nitro group decrease with increasing negative electric field strength, the Vs max increases with negative electric field strength, and the sensitivity of cocrystal eventually tends to increase under the negative electric field. Finally, the variation in bond length, nitro charge, and AIM electron density values are well correlated with the strengths of the external electric field.

Pulsatilla chinensis (Bge.) Regel: A Systematic Review on Anticancer of Its Pharmacological Properties, Clinical Researches and Pharmacokinetic Studies.

Pulsatilla chinensis (Bge.) Regel (PC) is one of the most commonly used Chinese medicines and has a history of thousands of years. This article reviews the research results of anti-cancer activity and its mechanism of action obtained from experimental, clinical, pharmacokinetic and bioinformatic studies in recent years. A large number of studies have shown that PC exerts had anti-cancer effects on different types of tumor cells by inhibiting cell proliferation, inducing apoptosis, inhibiting cell cycle and energy metabolism, inducing autophagy, and inhibiting angiogenesis. The literature has shown that PC can trigger the expression of autophagy-related molecules, activate the mitochondrial apoptotic pathway, inhibit the phosphorylation of PI3K downstream factors, down-regulate the expression of glycolysis-related proteins, and regulate a series of cancer-related signal pathways and proteins. The molecular mechanisms involved in PC include signal pathways such as Notch, PI3K/AKT/m TOR, AKT/mTOR, and MEK/ERK. The article also discusses the derivatives of the active ingredients in PC, which greatly improved the anti-cancer effect. In conclusion, this review provides a comprehensive overview of the biological effects and mechanisms of PC against cancer. The analysis of the literature shows that PC can be used as a potential drug candidate for the treatment of cancer.

Saikosaponin B4 Suppression Cancer Progression by Inhibiting SW480 and SW620 Cells Proliferation via the PI3K/AKT/mTOR Pathway in Colon Cancer.

BACKGROUND: Colon cancer is a gastrointestinal malignancy with high incidence and poor prognosis. OBJECTIVE: Saikosaponin B4 (SSB4) is a monomeric component of the Traditional Chinese medicine (TCM), Bupleurum. The current study investigates the therapeutic effect and mechanisms of SSB4 in colon cancer. METHODS: The proliferation of two colon cancer cell lines, SW480 and SW620, were assessed using CCK8 and expression of regulatory molecules, including Bax, Caspase3, Caspase9, Cleaved Caspase3, Cleaved Caspase9 and Bcl2 by flow cytometry and Western blotting. RESULTS: Survival rates, assessed by CCK8, of SW480 and SW620 cells decreased significantly when the SSB4 concentration was in the range 12.5-50 µg/ml. Flow cytometry measurements indicated apoptosis rates of 55.07% ± 1.63% for SW480 cells and 33.07% ± 1.28% for SW620 cells treated with 25 µg/ml SSB4. Western blotting revealed upregulation of the proapoptotic proteins, Bax, Caspase3, Caspase9, Cleaved Caspase3 and Cleaved Caspase9, and downregulation of the anti-apoptotic protein, Bcl2, in the presence of SSB4. Network pharmacology and molecular docking predicted that the PI3K/Akt/mTOR pathway might be the main regulatory target for the antitumor effect of SSB4. Further Western blotting experiments showed that SSB4 downregulated (p < 0.01) expression of PI3K, Akt, mTOR and the phosphorylated proteins, P-PI3K, P-Akt and P-MTOR. Expression of PI3K, Akt and mTOR mRNA was found to be downregulated by SSB4 (P < 0.01) as the result of RT-PCR measurements. CONCLUSION: SSB4 is a potent anti-colon cancer agent. Its effects are likely to be mediated by suppression of the PI3K/AKT/mTOR pathway.

Structural transformation of methyl urotropine perchlorate under high pressure.

Based on the first-principles calculations of density functional theory (DFT), the crystal structure, molecular structure, electronic properties, and optical absorption properties of methyl urotropine perchlorate under hydrostatic compression in the range of 0 ~ 100 GPa were calculated. The results show that the crystal structure of methyl urotropine perchlorate undergoes two structural transformations under hydrostatic compression. The H1A-H1B bond breaks at 25 GPa, generating two new covalent bonds N3-H1A and O1-H1B. The covalent bonds of O2A-C1 and Cl1-H3A are formed at 85 GPa. The compression ratio of lattice constants (a, b, c) and unit cell volume change abruptly at 25 GPa and 85 GPa, respectively. The conclusion that new bonds are formed under high pressure is further demonstrated by analyzing the partial density of states (PDOS) of N3, H1A, O1, H1B, O2A, C1, Cl1, and H3A atoms. The absorption spectrum showed that the absorption peak of methyl urotropine perchlorate gradually enhanced with the increase of pressure and the highest absorption peak shifted to high frequency.