Treatment Of Cells Research Articles

Ferroptosis-related gene signature predicts prognosis and immune microenvironment in prostate cancer.

Ferroptosis, an iron-dependent form of programmed cell death, significantly impacts cancer, yet its link to prostate cancer (PCa) prognosis remains underexplored. This study aims to develop and validate a ferroptosis-related gene signature to predict PCa prognosis and immune microenvironment differences, potentially identifying therapeutic targets. RNA-sequencing data of 478 PCa patients and corresponding clinical data were downloaded from The Cancer Genome Atlas (TCGA) database. We investigated the disease-free survival (DFS) rates of the high- and low-risk groups using the Kaplan-Meier method. Functional differences between the high- and low-risk groups were investigated by a gene set enrichment analysis (GSEA), and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The link between ferroptosis risk score and immune status was examined using CIBERSORT. The expression levels of core prognostic genes in benign prostatic hyperplasia (BPH) and PCa were verified using quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, and immunohistochemistry (IHC). A novel ferroptosis-related prognostic gene signature was established and tested in the Gene Expression Omnibus (GEO) database based on univariate and multivariate Cox regression analyses. Patients with PCa were classified into high- and low-risk groups based on this ferroptosis signature. Patients in the high-risk group had worse outcomes than those in the low-risk group. The predictive accuracy of the model was demonstrated by a receiver operating characteristic (ROC) analysis. An additional enrichment analysis of TCGA cohort revealed the immune-related pathways were significantly upregulated in the high-risk group, with areas under the curve (AUCs) of 0.85 at 1 year, 0.82 at 3 years, and 0.76 at 5 years. In the GEO cohort, the AUCs reached 0.69 at 1 year, 0.74 at 3 years, and 0.75 at 5 years. An additional enrichment analysis indicated a significant upregulation of cytokine-related pathways, immune receptor activity, and other immune-related pathways in the high-risk group. Furthermore, the analysis revealed that the proportions of mast cells and plasma cells were significantly lower in the high-risk group compared to the low-risk group of PCa patients. Conversely, the proportion of regulatory T cells (Tregs) was significantly higher in the high-risk group than in the low-risk group. According to the qRT-PCR, Western blot, and IHC results, DRD4, SRC, AKR1C2, and AIFM2 expression was significantly higher in PCa than BPH. We also showed that the ferrostatin 1-treated LNCaP cells had higher expression levels of DRD4, SRC, and AKR1C2. A prognostic signature of eight ferroptosis-related genes (FRGs) that may accurately predict PCa patient outcomes was constructed and validated. FRGs may contribute to anti-tumor immunity and serve as therapeutic targets in PCa.

Lathyrane diterpenoids from Euphorbia lathyris induce cell-cycle arrest and apoptosis in human hypertrophic scar cells

One new lathyrane-type diterpenoid, euphlathin A (1), and 11 known analogues (2–12), were isolated from the fruits of Euphorbia lathyris. Their structures were elucidated by spectroscopic data. The absolute configurations of 1 were established by single-crystal X-ray crystallography. All diterpenoids (1–12) were evaluated for antiproliferative activity against the human hypertrophic scar (HTS) cells. Compound 1 exhibited significantly against HTS cells growth with an IC50 value of 6.33 μM. Morphological features of apoptosis were evaluated in 1-treated HTS cells. Wound healing assays indicated that 1 significantly inhibited the migration of HTS at 24 h and 48 h. Compound 1 effectively induced apoptosis of HTS, which was associated with G2/M or S phase cell cycle arrest. Flow cytometric analysis showed that the treatment by 1 significantly induced HTS cell apoptosis in a dose-dependent manner. Overall, euphlathin A (1) has the potential to be a therapeutic agent for the treatment of hyperplastic scar therapy.

History and performance of the Everglades STA-3/4 periphyton-based stormwater treatment area (PSTA)

The Everglades Stormwater Treatment Areas (STAs) retain phosphorus (P) from stormwater runoff before it enters the Everglades Protection Area. These large treatment wetlands are extremely efficient in reducing total P (TP) concentrations. However, in some cases, the STAs may require additional measures to reach and/or maintain mandated discharge TP concentrations. One such option, a Periphyton-based Stormwater Treatment Area (PSTA) Cell, was constructed in 2005 on 40 ha at the outflow region of one flow-way in STA-3/4. This PSTA Cell was built to determine operational and engineering requirements associated with the implementation of this technology on a large scale. The PSTA Cell has supported an oligotrophic, periphyton-rich treatment wetland over its operational period of record. This system has consistently produced annual flow-weighted mean (FWM) outflow TP concentrations at or near the mandated outflow TP levels. The PSTA Cell maintained optimal treatment performance when subjected to hydraulic conditions observed in other full-scale STA cells (i.e., deeper water depths, pulsed flows, and major storm events). The PSTA Cell's treatment performance appeared to be better (FWM outflow concentrations ∼9 μg L−1) during continuous flows for 21 days compared to intermittent flow periods. Daily PSTA Cell outflows often were ≤ 13 μg L−1 when inflow TP concentrations were ≤ 22 μg L−1. The PSTA Cell also removed additional P from very low inflow concentrations (< 15 μg L−1). Seepage into the PSTA Cell occurred when its stage was lower than stages in adjacent water bodies, but seepage was greatly reduced when stages in the PSTA Cell were increased and the difference in stage between the PSTA Cell and adjacent bodies was reduced. TP concentrations in seepage water were usually higher than the PSTA Cell's inflow or surface water TP concentrations, therefore, the PSTA Cell performance did not benefit from seepage inflows. Over the 13 water years of operation, accretion of new soil (TP < 300 mg kg−1) did not result in nutrient gradients within the PSTA Cell that might affect P performance. Overall, the PSTA Cell study achieved its goal of providing operational and engineering insights for the implementation of this technology on a larger scale, and the PSTA Cell consistently attained ultra-low-P concentrations (mean ± standard deviation) of 10 ± 3 μg L−1 over its operational period of record.

Novel benzotriazole-benzimidazole metal complexes: structure-activity relationship, synthesis, characterization, and antidiabetic activity

To investigate the relationship between structure and antidiabetic activity, four novel metal complexes [Cu2(ebmb)2Cl4] (1), [Zn2(ebmb)Cl4] (2), [Cu(ebmb)SO4]n (3) and [Cu(mbmb)SO4]n (4) have been synthesized by 1-[(2-ethyl-1H-benzimidazole- 1-yl)methyl]-1H-benzotriazole (ebmb) and 1-[(2-methyl-1H-benzimidazole-1-yl) methyl]-1H-benzotriazole (mbmb), and the antidiabetic activities of them have been evaluated. The X-ray single crystal diffraction analysis reveals that complexes 1-2 are binuclear complexes and isostructural expect the different central metal. Complexes 3-4 possess the same central metal but different ligands, and they have very similar structure and they both possess one-dimensional chain structure. We assessed the in vitro antidiabetic activities of the complexes. The results of the α-amylase and α-glucosidase inhibition assays showed that complexes 1 and 4 possessed strongest inhibitory activities with the IC50 values of 1.29mM±0.04 (1) and 4.69mM±0.43 (4) for α-amylase, 0.75±0.04μM (1) and 1.63±0.11μM (4) for α-glucosidase. Finally, we evaluated the effect of complexes 1 and 4 on the glucose consumption of insulin resistant (IR) HepG2 cells, the results showed that both two complexes can improve the IR state of HepG2 cells, the glucose consumption of complex 1-treated IR-HepG2 cells and complex 4-treated IR-HepG2 cells were 1.3 times and 1.18 times as much as the model group, respectively. What's more, the structure-function relationship of complexes had also been discussed in this paper.

A Novel Role for Histatin 5 in Combination with Zinc to Promote Commensalism in C. albicans Survivor Cells.

Candida albicans is maintained as a commensal by immune mechanisms at the oral epithelia. Oral antifungal peptide Histatin 5 (Hst 5) may function in innate immunity, but the specific role Hst 5 plays in C. albicans commensalism is unclear. Since Zn-binding potentiates the candidacidal activity of Hst 5, we hypothesized that Hst 5+Zn would elicit a unique fungal stress response to shape interactions between C. albicans and oral epithelial cells (OECs). We found that Hst 5+Zn but not Hst 5 alone resulted in the activation of cell wall integrity (CWI) signaling, and deletion mutants were then used to determine that CWI-mediated chitin synthesis was protective against killing. Using flow cytometry, we confirmed that Hst 5+Zn-treated cells had significantly elevated levels of cell-wall chitin, mannan and β-1,3 glucan compared to Hst 5-treated cells. We then tested the activation of host signaling components involved in C. albicans cell-wall recognition. The immunoblot assay of C. albicans-exposed oral epithelial cells showed increased activation of EphA2 and NF-κB but not EGFR. Interestingly, C. albicans treated with Hst 5+Zn induced the global suppression of pro-inflammatory cytokine release from OECs, but an increase in negative regulator IL-10. Hst 5+Zn-treated cells were more adherent but ultimately less invasive to OECs than control cells, thus indicating lowered virulence. Therefore, Hst 5+Zn-treated C. albicans cells are discerned by epithelial monolayers, but are less virulent and promote anti-inflammatory signaling, suggesting that Hst 5+Zn in combination could play a role in regulating commensalism of oral C. albicans through cell wall reorganization.

Steroidal Glycosides from the Aerial Parts of Avena sativa L. and Their Cytotoxic Activity.

Twelve steroidal glycosides (1-12) were isolated from the aerial parts of Avena sativa L. (Poaceae). Among the isolated compounds, 1 was directly isolated from the plant for the first time, and 2-6 were new steroidal glycosides. The structures of 1-6 were determined by analysis of their spectroscopic data, chemical transformations, and chromatographic and spectroscopic analyses of the hydrolyzed products. Compounds 5 and 6 were novel steroidal glycosides with a B-ring contracted skeleton (B-nor steroid). Compounds 1, 9, 11, and 12 were cytotoxic to HL-60 human promyelocytic leukemia cells, MIA PaCa-2 human pancreatic carcinoma cells, and A549 human lung adenocarcinoma cells with IC50 values ranging from 0.79 to 13.5 μM. HL-60 cells treated with 1 exhibited apoptotic characteristics, namely, condensed nuclear chromatin, accumulation of sub-G1 cells, and activation of caspase-3. Additionally, the loss of the mitochondrial membrane potential and the release of cytochrome c into the cytoplasm in 1-treated HL-60 cells suggested that 1 induced apoptosis through a mitochondrial-dependent apoptotic pathway.

Protective effects of a small molecule inhibitor ligand against hyperphosphorylated tau-induced mitochondrial and synaptic toxicities in Alzheimer disease

The purpose of our study is to understand the protective effects of small molecule ligands for phosphorylated tau (p-tau) in Alzheimer's disease (AD) progression. Many reports show evidence that phosphorylated tau is reported to be an important contributor to the formation of paired helical filaments (PHFs) and neurofibrillary tangles (NFTs) in AD neurons. In AD, glycogen synthase kinase-3 beta (GSK3β), cyclin-dependent kinase-5 and dual specificity tyrosine-phosphorylation-regulated kinase 1A (DYRK1A), are the three important kinases responsible for tau hyperphosphorylation. Currently, there are no drugs and/or small molecules that reduce the toxicity of phosphorylated tau in AD. In the present study, we rationally selected and validated small molecule ligands that bind to the phosphorylated tau at SER23 (Ser 285) and TYR44 (Tyr310). We also assessed the molecular dynamics and validated molecular docking sites for the three best ligands. Based on the best docking scores -8.09, -7.9 and -7.8kcal/mol, we found that ligand 1 binds to key hyperphosphorylation residues of phosphorylated tau that inhibit abnormal PHF-tau, DYRK1A and GKS3β that reduce phosphorylated tau levels in AD. Using biochemical, molecular, immunoblotting, immunofluorescence and transmission electron microscopy analyses, we studied the ligand 1 inhibition as well as mitochondrial and synaptic protective effects in immortalized primary hippocampal neuronal (HT22) cells. We found interactions between NAT10-262501 (ligand 1) and phosphorylated tau at key phosphorylation sites and these ligand-based inhibitions decreased PHF-tau, DYRK1A and GSK3β levels. We also found increased mitochondrial biogenesis, mitochondrial fusion and synaptic activities and reduced mitochondrial fission in ligand 1-treated mutant tau HT22 cells. Based on these results, we cautiously conclude that phosphorylated tau NAT10-262501 (ligand 1) reduces hyperphosphorylation of tau based GKS3β and CDK5 kinase regulation in AD, and aids in the maintenance of neuronal structure, mitochondrial dynamics and biogenesis with a possible therapeutic drug target for AD.

A novel derivative of picolinic acid induces endoplasmic reticulum stress-mediated apoptosis in human non-small cell lung cancer cells: synthesis, docking study, and anticancer activity

Thirteen new derivatives of picolinic acid (4–7) were designed and synthesized from the starting parent molecule, picolinic acid. The new compounds were characterized by ATR-FTIR, 1HNMR, and CHNS analysis. A molecular docking study was performed to evaluate the binding affinity of the synthesized compounds toward EGFR kinase domain that indicated occupation of the critical site of EGFR kinase pocket and excellent positioning of the compounds in the pocket. The cytotoxic activity of the compounds against two human cancer cell lines (A549 and MCF-7), the non-tumorigenic MCF10A cell line, and white blood cells (WBC) was evaluated using the MTT assay. Compound 5 showed anticancer activity against A549 lung cancer cells (IC50 = 99.93 µM) but not against MCF-7 breast cancer cells or normal cells. Compound 5 mediated cytotoxicity in A549 lung cancer cells by inducing apoptotic cell death, as suggested by fragmented nuclei after DAPI staining, and agarose gel electrophoresis. Moreover, compound 5 triggered the activation of caspases 3, 4 and 9. However, compound 5 treatment did not affect the release of cytochrome c from the mitochondria to the cytosol, as compared to the vehicle-treated control cells. Nevertheless, compound 5-treated cells reported greater release of smac/DIABLO to the cytosol. In the same context, both compound 5 and thapsigargin (specific inhibitor of sarco/endoplasmic reticulum Ca2+-ATPase (SERCA)) enhanced eIF2 phosphorylation, reflecting the activation of the atypical ER stress pathway and the potential applicability of compound 5 in lung cancer treatment.

Aspergilfuranones A-D, four norlignanolides from the Peucedanum praeruptorum endophytic fungus Aspergillus udagawae

Abstract Aspergilfuranones A-D, four unpredicted norlignanolides (1–4), along with eight known compounds (5–12) were isolated from the endophytic fungus Aspergillus udagawae which was cultured on solid rice medium isolated from Peucedanum praeruptorum. The structures of these new compounds (1–4) were elucidated via comprehensive 1D/2D NMR, HRESIMS data analysis and the absolute configuration were determined by ECD calculations. New compounds were evaluated for their in vitro cytotoxic activity and aspergilfuranone A (1) exhibited a potent cytotoxic effect on human malignant melanoma A375 cells, with an IC50 value of 10.8 μM, being more active than the positive control, 5-FU (IC50 = 16.2 μM). Morphological features of apoptosis activities were evaluated in 1-treated melanoma A375 cells. Morphological changes analysis showed that aspergilfuranone A significantly induced A375 cell apoptosis in a dose-dependent manner.

Lathyrane diterpenoids from Jatropha podagrica and their antitumor activities in human osteosarcoma cells

Two new lathyrane-type diterpenoids, jatropodagins A and B (1 and 2), and five known analogues (3–7), were isolated from the stems of Jatropha podagrica. Their structures and absolute configurations were elucidated by spectroscopic data and calculated ECD analyses. The cytotoxicities of all the lathyrane-type diterpenoids (1–7) were evaluated against two human osteosarcoma cell lines (Saos-2 and MG-63). Compound 1 exhibited significant cytotoxic effects against Saos-2 and MG-63 with IC50 values of 8.08 and 14.64 μM, respectively. The IC50 values for the positive control 5-FU against the Saos-2 and MG-63 cell lines were 19.01 and 25.00 μM, respectively. Morphological features of apoptosis activities were evaluated in 1-treated Saos-2 cells and the results confirmed apoptosis in a dose-dependent manner.

High cell density increases glioblastoma cell viability under glucose deprivation via degradation of the cystine/glutamate transporter xCT (SLC7A11)

The cystine/glutamate transporter system xc- consists of the light-chain subunit xCT (SLC7A11) and the heavy-chain subunit CD98 (4F2hc or SLC3A2) and exchanges extracellular cystine for intracellular glutamate at the plasma membrane. The imported cystine is reduced to cysteine and used for synthesis of GSH, one of the most important antioxidants in cancer cells. Because cancer cells have increased levels of reactive oxygen species, xCT, responsible for cystine-glutamate exchange, is overexpressed in many cancers, including glioblastoma. However, under glucose-limited conditions, xCT overexpression induces reactive oxygen species accumulation and cell death. Here we report that cell survival under glucose deprivation depends on cell density. We found that high cell density (HD) down-regulates xCT levels and increases cell viability under glucose deprivation. We also found that growth of glioblastoma cells at HD inactivates mTOR and that treatment of cells grown at low density with the mTOR inhibitor Torin 1 down-regulates xCT and inhibits glucose deprivation-induced cell death. The lysosome inhibitor bafilomycin A1 suppressed xCT down-regulation in HD-cultured glioblastoma cells and in Torin 1-treated cells grown at low density. Additionally, bafilomycin A1 exposure or ectopic xCT expression restored glucose deprivation-induced cell death at HD. These results suggest that HD inactivates mTOR and promotes lysosomal degradation of xCT, leading to improved glioblastoma cell viability under glucose-limited conditions. Our findings provide evidence that control of xCT protein expression via lysosomal degradation is an important mechanism for metabolic adaptation in glioblastoma cells.

Ruxolitinib Alleviates Renal Interstitial Fibrosis in UUO Mice.

Ruxolitinib is a selective inhibitor of Jak1/2. Downstream signaling pathways of Jak, such as Stat3 and Akt/mTOR, are overactivated and contribute to renal interstitial fibrosis. Therefore, we explored the effect of Ruxolitinib on this pathological process. Unilateral ureteral obstruction (UUO) models and TGF-β1-treated fibroblasts and renal tubular epithelial cells were adopted in this study. Ruxolitinib was administered to UUO mice and TGF-β1-treated cells. Kidneys from UUO mice with Ruxolitinib treatment displayed less tubular injuries compared with those without Ruxolitinib treatment. Ruxolitinib treatment suppressed fibroblast activation and extracellular matrix (ECM) production in UUO kidneys and TGF-β1-treated fibroblasts. Ruxolitinib treatment also blocked epithelial-mesenchymal transition (EMT) in UUO kidneys and TGF-β 1-treated renal tubular epithelial cells. Moreover, Ruxolitinib treatment alleviated UUO-induced inflammation, oxidative stress and apoptosis. Mechanistically, Ruxolitinib treatment attenuated activation of both Stat3 and Akt/mTOR/Yap pathways. In conclusion, Ruxolitinib treatment can ameliorate UUO-induced renal interstitial fibrosis, suggesting that Ruxolitinib may be potentially used to treat fibrotic kidney disease.

Arylquin 1, a potent Par-4 secretagogue, induces lysosomal membrane permeabilization-mediated non-apoptotic cell death in cancer cells.

Arylquin 1, a small-molecule prostate-apoptosis-response-4 (Par-4) secretagogue, targets vimentin to induce Par-4 secretion. Secreted Par-4 binds to its receptor, 78-kDa glucose-regulated protein (GRP78), on the cancer cell surface and induces apoptosis. In the present study, we investigated the molecular mechanisms of arylquin 1 in cancer cell death. Arylquin 1 induces morphological changes (cell body shrinkage and cell detachment) and decreases cell viability in various cancer cells. Arylquin 1-induced cell death is not inhibited by apoptosis inhibitors (z-VAD-fmk, a pan-caspase inhibitor), necroptosis inhibitors (necrostatin-1), and paraptosis inhibitors. Furthermore, arylquin 1 significantly induces reactive oxygen species levels, but antioxidants [N-acetyl-l-cysteine and glutathione ethyl ester] do not inhibit arylquin 1-induced cell death. Furthermore, Par-4 knock-down by small interfering RNA confers no effect on cytotoxicity in arylquin 1-treated cells. Interestingly, arylquin 1 induces lysosomal membrane permeabilization (LMP), and cathepsin inhibitors and overexpression of 70-kDa heat shock protein (HSP70) markedly prevent arylquin 1-induced cell death. Therefore, our results suggest that arylquin 1 induces non-apoptotic cell death in cancer cells through the induction of LMP.

Dihydrochalcone Derivative Induces Breast Cancer Cell Apoptosis via Intrinsic, Extrinsic, and ER Stress Pathways but Abolishes EGFR/MAPK Pathway.

Dihydrochalcone derivatives are active compounds that have been purified from the Thai medicinal plant Cyathostemma argenteum. The objectives of this study were to investigate the effects of two dihydrochalcone derivatives on human breast cancer MDA-MB-231 and MCF-7 cell proliferation and to study the relevant mechanisms involved. The two dihydrochalcone derivatives are 4′,6′-dihydroxy-2′,4-dimethoxy-5′-(2″-hydroxybenzyl)dihydrochalcone (compound 1) and calomelanone (2′,6′-dihydroxy-4,4′-dimethoxydihydrochalcone, compound 2), both of which induced cytotoxicity toward both cell lines in a dose-dependent manner by using MTT assay. Treatment with both derivatives induced apoptosis as determined by annexin V-FITC/propidium iodide employing flow cytometry. The reduction of mitochondrial transmembrane potential (staining with 3,3′-dihexyloxacarbocyanine iodide, DiOC6, employing a flow cytometer) was established in the compound 1-treated cells. Compound 1 induced caspase-3, caspase-8, and caspase-9 activities in both cell lines, as has been determined by specific colorimetric substrates and a spectrophotometric microplate reader which indicated the involvement of both the extrinsic and intrinsic pathways. Calcium ion levels in mitochondrial and cytosolic compartments increased in compound 1-treated cells as detected by Rhod-2AM and Fluo-3AM intensity, respectively, indicating the involvement of the endoplasmic reticulum (ER) stress pathway. Compound 1 induced cell cycle arrest via enhanced atm and atr expressions and by upregulating proapoptotic proteins, namely, Bim, Bad, and tBid. Moreover, compound 1 significantly inhibited the EGFR/MAPK signaling pathway. In conclusion, compound 1 induced MDA-MB-231 and MCF-7 cell apoptosis via intrinsic, extrinsic, and ER stress pathways, whereas it ameliorated the EGFR/MAPK pathway in the MCF-7 cell line. Consequently, it is believed that compound 1 could be effectively developed for cancer treatments.

Protective effects of BACE1 inhibitory ligand molecules against amyloid beta-induced synaptic and mitochondrial toxicities in Alzheimer's disease.

Amyloid-β (Aβ) peptides are the major drivers of Alzheimer's disease (AD) pathogenesis, and are formed by successive cleavage of the amyloid precursor protein (APP) by the beta and gamma secretases. Mounting evidence suggests that Aβ and mitochondrial structural and functional abnormalities are critically involved in the loss of synapses and cognitive decline, in patients with AD. In AD brain, state the sequential proteolytic cleavage of APP by beta secretase 1 enzyme (BACE1) and γ-secretase leads to the production and release of Aβ40 and 42. BACE1 expression and activity increased in the brains of AD patients. Structurally, β-secretase has a very large binding site (1000Å) with fewer hydrophobic domains that makes a challenge to identify the specific targets/binding sites of BACE1. In the present study, we constructed a BACE1 pharmacophore with pepstatin and screened through molecular docking studies. We found one potential candidate (referred as ligand 1) that binds to the key catalytic residues of BACE1 and predicts to inhibit abnormal APP processing and reduce Aβ levels in AD neurons. Using biochemical, molecular, transmission electron microscopy, immunoblotting and immunofluorescence analyses, we studied the protective effects of ligand 1 against Aβ-induced synaptic and mitochondrial toxicities in mouse neuroblastoma (N2a) cells that express mutant APP. We found interaction between ligand 1 and BACE1 and this interaction decreased BACE1 activity, Aβ40 and 42 levels. We also found increased mitochondrial biogenesis, mitochondrial fusion and synaptic activity and reduced mitochondrial fission in ligand 1-treated mutant APP cells. Based on these results, we cautiously conclude that ligand 1 reduces Aβ-induced mitochondrial and synaptic toxicities, and maintains mitochondrial dynamics and neuronal function in AD.

New cytotoxic ergostane-type sterols from the Chinese soft coral Sinularia sp.

Two new highly oxygenated ergostane-type sterols (1, 2) together with one known related compound sinugrandisterol A (3) were isolated from the soft coral Sinularia sp. collected from the water area near the Xisha Islands, South China Sea. Their structures were elucidated on the basis of detailed spectroscopic analysis, chemical transformations, and by comparison with those reported in literature. In bioassays, compounds 1 and 2 showed in vitro antiproliferative activity against a panel of cancer cell lines, including MDA-MB-436, A549, Hep3B, HT-29 and H157. Morphological observation and Hoechst 33,258 staining assays showed that compound 1-treated H157 cells displayed apoptosis characteristics. Moreover, western blot assays suggested that 1 could increase the expression of Bax and down-regulate expression of Bcl-2.

γ-Glutamyltranspeptidase-Triggered Intracellular Gadolinium Nanoparticle Formation Enhances the T2-Weighted MR Contrast of Tumor.

Magnetic resonance imaging (MRI) is advantageous in the diagnosis of deep internal cancers, but contrast agents (CAs) are always needed to improve MRI sensitivity. Gadolinium (Gd)-based agents are routinely used as T1-dominated CAs in clinic but using intracellularly formed Gd nanoparticles to enhance the T2-weighted MRI of tumor in vivo at high magnetic field has not been reported. Herein, we rationally designed a "smart" Gd-based probe Glu-Cys(StBu)-Lys(DOTA-Gd)-CBT (1), which was subjected to γ-glutamyltranspeptidase (GGT) cleavage and an intracellular CBT-Cys condensation reaction to form Gd nanoparticles (i.e., 1-NPs) to enhance the T2-weighted MR contrast of tumor in vivo at 9.4 T. Living cell experiments indicated that the 1-treated HeLa cells had an r2 value of 27.8 mM-1 s-1 and an r2/r1 ratio of 10.6. MR imaging of HeLa tumor-bearing mice indicated that the T2 MR contrast of the tumor enhanced 28.6% at 2.5 h post intravenous injection of 1. We anticipate that our probe 1 could be employed for T2-weighted MRI diagnosis of GGT-related cancers in the future when high magnetic field is available in clinic.

Stable Isotope-Labeled Lipidomics to Unravel the Heterogeneous Development Lipotoxicity.

Non-alcoholic fatty liver disease (NAFLD) as a global health problem has clinical manifestations ranging from simple non-alcoholic fatty liver (NAFL) to non-alcoholic steatohepatitis (NASH), cirrhosis, and cancer. The role of different types of fatty acids in driving the early progression of NAFL to NASH is not understood. Lipid overload causing lipotoxicity and inflammation has been considered as an essential pathogenic factor. To correlate the lipid profiles with cellular lipotoxicity, we utilized palmitic acid (C16:0)- and especially unprecedented palmitoleic acid (C16:1)-induced lipid overload HepG2 cell models coupled with lipidomic technology involving labeling with stable isotopes. C16:0 induced inflammation and cell death, whereas C16:1 induced significant lipid droplet accumulation. Moreover, inhibition of de novo sphingolipid synthesis by myriocin (Myr) aggravated C16:0 induced lipoapoptosis. Lipid profiles are different in C16:0 and C16:1-treated cells. Stable isotope-labeled lipidomics elucidates the roles of specific fatty acids that affect lipid metabolism and cause lipotoxicity or lipid droplet formation. It indicates that not only saturation or monounsaturation of fatty acids plays a role in hepatic lipotoxicity but also Myr inhibition exasperates lipoapoptosis through ceramide in-direct pathway. Using the techniques presented in this study, we can potentially investigate the mechanism of lipid metabolism and the heterogeneous development of NAFLD.

Pyran-2-one derivatives from Croton crassifolius as potent apoptosis inducers in HepG2 cells via p53-mediated Ras/Raf/ERK pathway

Chemical investigation of the roots of Croton crassifolius led to the isolation of five pyran-2-one derivatives, including two brand new compounds (1–2), one new natural product (3) and two known compounds (4–5). Their structures and absolute configurations were established by spectroscopic analyses as well as comparison between the calculated optical rotation (OR) values with the experimental data. Interestingly, the new compound 1 showed an unusual negative chemical shift at H-11. It is well known that negative chemical shift values of 1H NMR spectrum are extremely rare in natural products. Such a negative chemical shift of 1H NMR spectrum was reproduced by density functional theory (DFT) calculations and explained by the shielding effect from the pyran-2-one ring over the hydrogen atom in the 3D conformations. Then, MTT assay was applied to evaluate the cytotoxicity of the isolated compounds (1–5) against two liver cancer cell lines (HepG2 and MHCC97H). The results suggested that compound 1 displayed the highest cytotoxicity with an IC50 value of 9.8 μM against HepG2 cells. Moreover, there was no obvious cytotoxicity of compounds 1–5 on normal liver cell line LO2. Furthermore, the mechanism of apoptosis induction in compound 1-treated HepG2 cells was investigated. The results showed that compound 1 could induce apoptosis via p53-mediated Ras/Raf/ERK suppression in HepG2 cells.

Alkaloids from Juglans Mandshurica maxim induce distinctive cell death in hepatocellular carcinoma cells

The aim of this work was to further investigate the anticancer potential of Juglans mandshurica Maxim, including the separation of active constituents and their anti-proliferative effects with underlying mechanism of action. Five alkaloids (1–5) were isolated from the bark of J. mandshurica. Among them, 1 showed the highest cytotoxic activities against Hep3B and HepG2 cells with an IC50 values of 61.80 and 56.24 μM, respectively. Therefore, the cellular mechanism involved 1 was subsequently studied. Our results showed that 1 markedly caused apoptosis and autophagy, but without cell cycle arrest in HepG2 cells. Interestingly, only autophagic cell death was induced in 1-treated Hep3B cells. It is concluded that the isolated alkaloids exerted a certain anti-hepatoma potential, and our results may provide a basis for the further investigation of the alkaloids extracted from J. mandshurica.