mTOR regulates cocaine-induced behavioural sensitization through the SynDIG1-GluA2 interaction in the nucleus accumbens.

Behavioral sensitization is a progressive increase in locomotor or stereotypic behaviours in response to drugs. It is believed to contribute to the reinforcing properties of drugs and to play an important role in relapse after cessation of drug abuse. However, the mechanism underlying this behaviour remains poorly understood. In this study, we showed that mTOR signaling was activated during the expression of behavioral sensitization to cocaine and that intraperitoneal or intra-nucleus accumbens (NAc) treatment with rapamycin, a specific mTOR inhibitor, attenuated cocaine-induced behavioural sensitization. Cocaine significantly modified brain lipid profiles in the NAc of cocaine-sensitized mice and markedly elevated the levels of phosphatidylinositol-4-monophosphates (PIPs), including PIP, PIP2, and PIP3. The behavioural effect of cocaine was attenuated by intra-NAc administration of LY294002, an AKT-specific inhibitor, suggesting that PIPs may contribute to mTOR activation in response to cocaine. An RNA-sequencing analysis of the downstream effectors of mTOR signalling revealed that cocaine significantly decreased the expression of SynDIG1, a known substrate of mTOR signalling, and decreased the surface expression of GluA2. In contrast, AAV-mediated SynDIG1 overexpression in NAc attenuated intracellular GluA2 internalization by promoting the SynDIG1-GluA2 interaction, thus maintaining GluA2 surface expression and repressing cocaine-induced behaviours. In conclusion, NAc SynDIG1 may play a negative regulatory role in cocaine-induced behavioural sensitization by regulating synaptic surface expression of GluA2.

The synthesis, structure-toxicity relationship of cisplatin derivatives for the mechanism research of cisplatin-induced nephrotoxicity.

Cisplatin is a widely used antineoplastic drug, while its nephrotoxicity limits the clinical application. Although several mechanisms contributing to nephrotoxicity have been reported, the direct protein targets are unclear. Herein we reported the synthesis of 29 cisplatin derivatives and the structure-toxicity relationship (STR) of these compounds with MTT assay in human renal proximal tubule cells (HK-2) and pig kidney epithelial cells (LLC-PK1). To the best of our knowledge, this study represented the first report regarding the structure-toxicity relationship (STR) of cisplatin derivatives. The potency of biotin-pyridine conjugated derivative 3 met the requirement for target identification, and the preliminary chemical proteomics results suggested that it is a promising tool for further target identification of cisplatin-induced nephrotoxicity.

Utilization of Caenorhabditis elegans in laboratory teaching of genetics.

Caenorhabditis elegans is one of the most important model organisms in the study of biology. It is ideal for laboratory teaching due to its short life cycle and low cost. It enriches the teaching content and can motivate students' interest of learning. In this article, we have shown cased C. elegans for the observation of life cycle and mating, as well as the investigation of single nucleotide polymorphism (SNP) and RNA interfere. In addition, we also discuss the details of the experimental design, basic requirement, preparations and related information. We conclude that C. elegans can be used as the experimental materials for teaching college laboratory courses, such as genetic, cell biology, model biology and developmental biology.

Tissue metabolic profiling of human gastric cancer assessed by (1)H NMR.

BACKGROUND: Gastric cancer is the fourth most common cancer and the second most deadly cancer worldwide. Study on molecular mechanisms of carcinogenesis will play a significant role in diagnosing and treating gastric cancer. Metabolic profiling may offer the opportunity to understand the molecular mechanism of carcinogenesis and help to identify the potential biomarkers for the early diagnosis of gastric cancer. METHODS: In this study, we reported the metabolic profiling of tissue samples on a large cohort of human gastric cancer subjects (n = 125) and normal controls (n = 54) based on (1)H nuclear magnetic resonance ((1)H NMR) together with multivariate statistical analyses (PCA, PLS-DA, OPLS-DA and ROC curve). RESULTS: The OPLS-DA model showed adequate discrimination between cancer tissues and normal controls, and meanwhile, the model excellently discriminated the stage-related of tissue samples (stage I, 30; stage II, 46; stage III, 37; stage IV, 12) and normal controls. A total of 48 endogenous distinguishing metabolites (VIP > 1 and p < 0.05) were identified, 13 of which were changed with the progression of gastric cancer. These modified metabolites revealed disturbance of glycolysis, glutaminolysis, TCA, amino acids and choline metabolism, which were correlated with the occurrence and development of human gastric cancer. The receiver operating characteristic diagnostic AUC of OPLS-DA model between cancer tissues and normal controls was 0.945. And the ROC curves among different stages cancer subjects and normal controls were gradually improved, the corresponding AUC values were 0.952, 0.994, 0.998 and 0.999, demonstrating the robust diagnostic power of this metabolic profiling approach. CONCLUSION: As far as we know, the present study firstly identified the differential metabolites in various stages of gastric cancer tissues. And the AUC values were relatively high. So these results suggest that the metabolic profiling of gastric cancer tissues has great potential in detecting this disease and helping to understand its underlying metabolic mechanisms.

Synthesis and biological evaluation of novel (E)-N'-(2,3-dihydro-1H-inden-1-ylidene) benzohydrazides as potent LSD1 inhibitors.

Lysine specific demethylase 1 (LSD1) plays an important role in regulating histone lysine methylation at residues K4 and K9 on histone H3 and is recognized as an attractive therapeutic target in multiple malignancies. In this study, a series of novel (E)-N'-(2,3-dihydro-1H-inden-1-ylidene) benzohydrazides were synthesized and biologically evaluated for their potential LSD1 inhibitory effect. Among them, compounds 5a and 5n showed the most potent LSD1 inhibitory activity with IC50 values of 1.4 and 1.7nM, respectively, which were about 10 times more potent compared with (E)-N-(1-(5-chloro-2-hydroxyphenyl) ethylidene)-3-(morpholinosulf-only) benzohydrazide (J. Med. Chem.2013, 56, 9496-9508; as reference compound). Compounds 5a and 5n also exhibited marked anti-proliferation activities against cancer cell lines that highly expressed LSD1. These results suggest that these optimized compounds might be served as promising LSD1 inhibitors against cancer, which merit further study.

5-Methoxyquinoline Derivatives as a New Class of EZH2 Inhibitors.

A series of quinoline derivatives was synthesized and biologically evaluated as Enhancer of Zeste Homologue 2 (EZH2) inhibitors. Structure-activity relationship (SAR) studies led to the discovery of 5-methoxy-2-(4-methyl-1,4-diazepan-1-yl)-N-(1-methylpiperidin-4-yl)quinolin-4-amine (5k), which displayed an IC50 value of 1.2 µM against EZH2, decreased global H3K27me3 level in cells and also showed good anti-viability activities against two tumor cell lines. Due to the low molecular weight and the fact that no quinoline derivative has been reported as an EZH2 inhibitor, this compound could serve as a lead compound for further optimization.

Synthesis and biological evaluation of novel benzamide derivatives as potent smoothened antagonists.

A series of novel benzamide derivatives were prepared and evaluated using cell-based measurements. Among these compounds, 10f significantly inhibited Hedgehog signaling and showed equivalent or more potency than GDC-0449 in different tests. Furthermore, compound 10f potently inhibited the proliferation of Daoy, a medulloblastoma cell line that is reported to be resistant to GDC-0449, which indicated a promising prospect in the treatment of Hedgehog signaling pathway related cancer in clinical trial.

Study on biopharmaceutics classification and oral bioavailability of a novel multikinase inhibitor NCE for cancer therapy.

Specific biopharmaceutics classification investigation and study on phamacokinetic profile of a novel drug candidate (2-methylcarbamoyl-4-{4-[3- (trifluoromethyl) benzamido] phenoxy} pyridinium 4-methylbenzenesulfonate monohydrate, NCE) were carried out. Equilibrium solubility and intrinsic dissolution rate (IDR) of NCE were estimated in different phosphate buffers. Effective intestinal permeability (P(eff)) of NCE was determined using single-pass intestinal perfusion technique in rat duodenum, jejunum and ileum at three concentrations. Theophylline (high permeability) and ranitidine (low permeability) were also applied to access the permeability of NCE as reference compounds. The bioavailability after intragastrical and intravenous administration was measured in beagle dogs. The solubility of NCE in tested phosphate buffers was quite low with the maximum solubility of 81.73 µg/mL at pH 1.0. The intrinsic dissolution ratio of NCE was 1 × 10⁻4 mg·min⁻¹·cm⁻². The P(eff) value of NCE in all intestinal segments was more proximate to the high-permeability reference theophylline. Therefore, NCE was classified as class II drug according to Biopharmaceutics Classification System due to its low solubility and high intestinal permeability. In addition, concentration-dependent permeability was not observed in all the segments, indicating that there might be passive transportation for NCE. The absolute oral bioavailability of NCE in beagle dogs was 26.75%. Therefore, dissolution promotion will be crucial for oral formulation development and intravenous administration route will also be suggested for further NCE formulation development. All the data would provide a reference for biopharmaceutics classification research of other novel drug candidates.

Erratum: [Corrigendum] Chloroquine potentiates the anticancer effect of sunitinib on renal cell carcinoma by inhibiting autophagy and inducing apoptosis.

[This corrects the article DOI: 10.3892/ol.2017.7635.].

1H-NMR based metabonomic profiling of human esophageal cancer tissue.

BACKGROUND: The biomarker identification of human esophageal cancer is critical for its early diagnosis and therapeutic approaches that will significantly improve patient survival. Specially, those that involves in progression of disease would be helpful to mechanism research. METHODS: In the present study, we investigated the distinguishing metabolites in human esophageal cancer tissues (n = 89) and normal esophageal mucosae (n = 26) using a (1)H nuclear magnetic resonance ((1)H-NMR) based assay, which is a highly sensitive and non-destructive method for biomarker identification in biological systems. Principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and orthogonal partial least-squares-discriminant analysis (OPLS-DA) were applied to analyse (1)H-NMR profiling data to identify potential biomarkers. RESULTS: The constructed OPLS-DA model achieved an excellent separation of the esophageal cancer tissues and normal mucosae. Excellent separation was obtained between the different stages of esophageal cancer tissues (stage II = 28; stage III = 45 and stage IV = 16) and normal mucosae. A total of 45 metabolites were identified, and 12 of them were closely correlated with the stage of esophageal cancer. The downregulation of glucose, AMP and NAD, upregulation of formate indicated the large energy requirement due to accelerated cell proliferation in esophageal cancer. The increases in acetate, short-chain fatty acid and GABA in esophageal cancer tissue revealed the activation of fatty acids metabolism, which could satisfy the need for cellular membrane formation. Other modified metabolites were involved in choline metabolic pathway, including creatinine, creatine, DMG, DMA and TMA. These 12 metabolites, which are involved in energy, fatty acids and choline metabolism, may be associated with the progression of human esophageal cancer. CONCLUSION: Our findings firstly identify the distinguishing metabolites in different stages of esophageal cancer tissues, indicating the attribution of metabolites disturbance to the progression of esophageal cancer. The potential biomarkers provide a promising molecular diagnostic approach for clinical diagnosis of human esophageal cancer and a new direction for the mechanism study.

¹H NMR-based metabolic profiling of human rectal cancer tissue.

BACKGROUND: Rectal cancer is one of the most prevalent tumor types. Understanding the metabolic profile of rectal cancer is important for developing therapeutic approaches and molecular diagnosis. METHODS: Here, we report a metabonomics profiling of tissue samples on a large cohort of human rectal cancer subjects (n = 127) and normal controls (n = 43) using 1H nuclear magnetic resonance (1H NMR) based metabonomics assay, which is a highly sensitive and non-destructive method for the biomarker identification in biological systems. Principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA) and orthogonal projection to latent structure with discriminant analysis (OPLS-DA) were applied to analyze the 1H-NMR profiling data to identify the distinguishing metabolites of rectal cancer. RESULTS: Excellent separation was obtained and distinguishing metabolites were observed among the different stages of rectal cancer tissues (stage I = 35; stage II = 37; stage III = 37 and stage IV = 18) and normal controls. A total of 38 differential metabolites were identified, 16 of which were closely correlated with the stage of rectal cancer. The up-regulation of 10 metabolites, including lactate, threonine, acetate, glutathione, uracil, succinate, serine, formate, lysine and tyrosine, were detected in the cancer tissues. On the other hand, 6 metabolites, including myo-inositol, taurine, phosphocreatine, creatine, betaine and dimethylglycine were decreased in cancer tissues. These modified metabolites revealed disturbance of energy, amino acids, ketone body and choline metabolism, which may be correlated with the progression of human rectal cancer. CONCLUSION: Our findings firstly identify the distinguishing metabolites in different stages of rectal cancer tissues, indicating possibility of the attribution of metabolites disturbance to the progression of rectal cancer. The altered metabolites may be as potential biomarkers, which would provide a promising molecular diagnostic approach for clinical diagnosis of human rectal cancer. The role and underlying mechanism of metabolites in rectal cancer progression are worth being further investigated.

Knockdown of core 1 beta 1, 3-galactosyltransferase prolongs skin allograft survival with induction of galectin-1 secretion and suppression of CD8+ T cells: T synthase knockdown effects on galectin-1 and CD8+ T cells.

Core 1 beta 1,3-galactosyltransferase also known as T-antigen-synthase or T-synthase is a key enzyme for the synthesis of the common core 1 O-glycan structure (T-antigen). Although T-synthase is known to be important in human immune-related diseases, the effects of T-synthase and T-antigen on host immune responses remain poorly defined. In this study, a T-synthase-specific short hairpin RNA (shRNA) was transfected into murine colon carcinoma CT26 cells or mouse muscle tissues via intramuscular electroporation to assess the effects of T-synthase on T cells and cytokines. T-synthase knockdown significantly induced galectin-1 secretion both in vivo and in vitro and strongly enhanced Th2 cytokine (IL-10 and IL-4) production in vivo. Further, the increased production of galectin-1 induced by T-synthase knockdown promoted CD8(+) T-cell apoptosis, which, when combined with the increased production of CD4(+) T cell-derived Th2 cytokines prolonged the survival of skin allografts in mice. Our data suggest core 1 beta 1,3-galactosyltransferase-shRNA could serve not only as a useful tool in organ transplantation but also as a powerful tool for investigating O-glycans and glycoprotein synthesis and function.

A novel anticancer agent, SKLB70359, inhibits human hepatic carcinoma cells proliferation via G0/G1 cell cycle arrest and apoptosis induction.

Hepatocellular carcinoma is one of the most common cancers in worldwide. We previously reported a novel thienopyridine derivative 3-amino-6-(3,4-dichlorophenyl) thieno[2,3-b]pyridine-2-carboxamide (SKLB70359) which possesses anticancer activity against hepatocellular carcinoma. In present study, we further investigated its anticancer activity and possible mechanism. The SKLB70359 treatment decreased the viability of a panel of hepatocellular carcinoma cell lines in a concentration- and time-dependent manner with IC(50) 0.4 ~ 2.5 µM. The mechanism study showed that SKLB70359 induced G0/G1 cell cycle arrest and then led to apoptotic cell death of HepG2 cell. The SKLB70359 induced G0/G1 cell cycle arrest was characterized by down-regulation of cyclin-dependent kinase 2 (CDK2), CDK4, CDK6 expression and up-regulation of p53, p21(WAF1). Activating of caspase-3 and caspase-9 was also observed. Meanwhile, proliferation inhibitory effect of SKLB70359 was associated with decreased level of phosphorylated p44/42 mitogen activated protein kinase (p44/42 MAPK) and phosphorylated retinoblastoma protein (Rb). Moreover, SKLB70359 exhibit less toxicity to non-cancer cells than tumor cells. In conclusion, the findings in this study suggested that SKLB70359 have potential anticancer efficacy via G0/G1 cell cycle arrest and apoptosis induction. Its potential to be a candidate of anticancer agent is worth being further investigated.

Novel benzothiazole, benzimidazole and benzoxazole derivatives as potential antitumor agents: synthesis and preliminary in vitro biological evaluation.

In a previous hit-to-lead research program targeting anticancer agents, two promising lead compounds, 1a and 1b, were found. However, the poor solubility of 1a and 1b made difficult further in vivo studies. To solve this problem, a lead optimization was conducted through introducing N-methyl-piperazine groups at the 2-position and 6-position. To our delight, the optimized analogue 1d showed comparable antiproliferative activity in vitro with better solubility, compared with 1a. Based on this result, the replacement of the benzothiazole scaffold with benzimidazole and benzoxazole moieties afforded 1f and 1g, whose activities were fundamentally retained. In the preliminary in vitro biological evaluation, the immunofluorescence staining of HCT116 cells indicated that 1d, 1f and 1g led to cytosolic vacuolization which was not induced by 1a at low micromolecular concentrations. These results suggest that these optimized compounds might potentially constitute a novel class of anticancer agents, which merit further studies.

Syntheses and cell-based phenotypic screen of novel 7-amino pyrido[2,3-d]pyrimidine-6-carbonitrile derivatives as potential antiproliferative agents.

A series of N-3-substituted 7-aminopyrido[2,3-d]pyrimidin-6-carbonitrile derivatives was readily synthesized and their anti-proliferative activities on five types of tumor cells were evaluated through a cell-based phenotypic screening approach. Compound 3k was found to be potent on human colon cancer SW620 cells with an IC(50) value of 12.5 mM. Structural optimization of compound 3k led to compound 4a with improved anti-proliferative potency on SW620 cells with an IC(50) value of 6.9 mM. Further cell-cycle analyses suggested that compound 4a induced apoptosis of SW620 cells in a concentration-dependent manner.

Deltonin, a steroidal saponin, inhibits colon cancer cell growth in vitro and tumor growth in vivo via induction of apoptosis and antiangiogenesis.

Deltonin, a steroidal saponin, isolated from Dioscorea zingiberensis Wright (DZW), has shown high-cytotoxic activity in cancer cells. However, its mechanisms and in vivo anti-cancer effects remain unknown. In the present study, we evaluated the effects and explored the anti-tumor mechanisms of deltonin on a panel of colon cancer cell lines and in a mouse model of murine colon cancer C26. Deltonin had more cytotoxic effect on C26 cells than 5-fluorouracil had, promoting dramatic G2-M phase arrest and apoptosis in C26 cells in a concentration-dependent manner; oral administration of deltonin significantly inhibited the tumor growth and prolonged survival of the tumor bearing mice. The deltonin treatment caused a noticeable apoptosis in tumor tissue, which associated with increased levels of Bax, activated caspase-3, caspase-9, and cleaved poly (ADPribose) polymerase, decreased pro-caspase-8, pro-caspase-9, Bcl-2 expression levels and extracellular signal-regulated kinase-1/2 activity; and dose-dependently inhibit angiogenesis. In conclusion, the findings in this study demonstrated that deltonin is an effective natural agent for cancer therapy, which may be mediated, in part, by induction of apoptosis, as well as involve mitogen-activated protein kinase pathways, and inhibition of angiogenesis.

SKLB610: a novel potential inhibitor of vascular endothelial growth factor receptor tyrosine kinases inhibits angiogenesis and tumor growth in vivo.

Antagonizing angiogenesis-related receptor tyrosine kinase is a promising therapeutic strategy in oncology. In present study, we designed and synthesized a novel vascular endothelial growth factor receptor (VEGFR) inhibitor N-methyl-4-(4-(3-(trifluoromethyl) benzamido) phenoxy) picolinamide SKLB610 that potently suppresses human tumor angiogenesis. SKLB610 inhibited angiogenesis-related tyrosine kinase VEGFR2, fibroblast growth factor receptor 2 (FGFR2) and platelet-derived growth factor receptor (PDGFR) at rate of 97%, 65% and 55%, respectively, at concentration of 10µM in biochemical kinase assays. In vitro, SKLB610 showed more selective inhibition of VEGF-stimulated human umbilical vein endothelial cells (HUVECs) proliferation, and this proliferation inhibitory effect was associated with decreased phosphorylation of VEGFR2 and p42/44 mitogen-activated protein kinase (p42/44 MAPK). Antiangiogenic evaluation showed that SKLB610 inhibited the HUVECs capillary-tube formation on Matrigel in vitro and the sub-intestinal vein formation of zebrafish in vivo. Moreover, SKLB610 inhibited a panel of human cancer cells proliferation in a concentration-dependent manner and human non-small cell lung cancer cell line A549 and human colorectal cancer cell line HCT116 were most sensitive to SKLB610 treatment. In vivo, chronic intraperitoneally administration of SKLB610 at dose of 50mg/kg/d resulted in significant inhibition in the growth of established human A549 and HCT116 tumor xenografts in nude mice without exhibit toxicity. Histological analysis showed significant reductions in intratumoral microvessel density (CD31 staining) of 43-55% relative to controls depending on the specific tumor xenografts. In conclusion, the present study demonstrated that SKLB610 exhibited its antitumor activity as a multi-targeted inhibitor with more potent inhibition of VEGFR2 activity. Its potential to be a candidate of anticancer agent is worth being further investigated.

Synthesis, structure-activity relationships and preliminary antitumor evaluation of benzothiazole-2-thiol derivatives as novel apoptosis inducers.

A series of novel benzothiazole-2-thiol derivatives were synthesized, and their anti-proliferative activities on HepG2 and MCF-7 cells were investigated. Most compounds had inhibitory effects on cell growth, and some of them were more effective than cisplatin. Compounds 6m and 6t displayed good inhibitory activities against a panel of different types of human cancer cell lines, with IC(50) values in the low micromolar range. Further biological evaluation indicated that 6m induced apoptosis in HepG2 cancer cells. Structure-activity relationships were also proposed.

Synthesis, antiproliferative activities and in vitro biological evaluation of novel benzofuransulfonamide derivatives.

In a cell-based screen of novel antiproliferative agents, the hit compound 1a, which bears a benzofuransulfonamide scaffold, exhibited broad-spectrum antiproliferative activities against a panel of tumor cell lines. The promising in vitro antiproliferative activity and structural novelty of 1a prompted us to investigate the synthesis of five analogs of 1a and test their antiproliferative activities. The most potent analogue, 1h, exhibited enhanced antiproliferative activities compared with the parent 1a, and exhibited an IC(50) value against NCI-H460 cells of 4.13 µM compared with 4.52 µM for the positive control cisplatin. Flow cytometric analysis revealed that 1h induces significant levels of apoptosis in NCI-H460 cells in vitro at low micromolar concentrations. These results suggest that 1a and analogs based on its benzofuransulfonamide scaffold may constitute a novel class of antiproliferative agents, which deserve further study.