Iridium(III) complex induces apoptosis in HeLa cells by regulating mitochondrial and PI3K/AKT signaling pathways: In vitro and in vivo experiments.

Cyclometalated iridium complexes with mitochondrial targeting show great potential as substitutes for platinum-based complexes because of their strong anti-cancer properties. Three novel cyclometalated iridium(III) compounds were synthesized and evaluated in five different cell lines as part of the ongoing systematic investigations of these compounds. The complexes were prepared using 4,7-dichloro-1,10-phenanthroline ligands. The cytotoxicity of complexes Ir1-Ir3 towards HeLa cells was shown to be high, with IC50 values of 0.83±0.06, 4.73±0.11, and 4.95±0.62 µM, respectively. Complex Ir1 could be ingested by HeLa cells in 3 h and has shown high selectivity toward mitochondria. Subsequent investigations demonstrated that Ir1 triggered apoptosis in HeLa cells by augmenting the generation of reactive oxygen species (ROS), reducing the mitochondrial membrane potential, and depleting ATP levels. Furthermore, the movement of cells was significantly suppressed and the progression of the cell cycle was arrested in the G0/G1 phase following the administration of Ir1. The Western blot analysis demonstrated that the induction of apoptosis in HeLa cells by Ir1 involves the activation of the mitochondria-dependent channel and the PI3K/AKT signaling pathway. No significant cytotoxicity was observed in zebrafish embryos at concentrations less than or equal to 16 µM, e.g., survival rate and developmental abnormalities. In vivo, antitumor assay demonstrated that Ir1 suppressed tumor growth in mice. Therefore, our work shows that complex Ir1 could be a promising candidate for developing novel antitumor drugs.

Structure-Based Bioisosterism Design, Synthesis, Biological Activity and Toxicity of 1,2,4-Oxadiazole Substituted Benzamides Analogues Containing Pyrazole Rings.

In order to discover pesticidal lead compounds with high activity and low toxicity, a series of novel benzamides substituted with pyrazole-linked 1,2,4-oxadiazole were designed via bioisosterism. The chemical structures of the target compounds were confirmed via 1H NMR, 13C NMR and HRMS analysis. The preliminary bioassay showed that most compounds exhibited good lethal activities against Mythimna separate, Helicoverpa armigera, Ostrinia nubilalis and Spodoptera frugiperda at 500 mg/L. Particularly in the case of Mythimna separate, compound 14q (70%) exhibited obvious insecticidal activity. In addition, compound 14h demonstrated good fungicidal activity against Pyricularia oryae with an inhibition rate of 77.8%, and compounds 14e, 14k, 14n and 14r also showed certain antifungal activities (55.6-66.7%). The zebrafish toxicity test showed that the LC50 of compound 14h was 14.01 mg/L, which indicated that it may be used as a potential leading compound for further structural optimization.

Benzamides Substituted with Quinoline-Linked 1,2,4-Oxadiazole: Synthesis, Biological Activity and Toxicity to Zebrafish Embryo.

To develop new compounds with high activity, broad spectrum and low-toxicity, 17 benzamides substituted with quinoline-linked 1,2,4-oxadiazole were designed using the splicing principle of active substructures and were synthesized. The biological activities were evaluated against 10 fungi, indicating that some of the synthetic compounds showed excellent fungicidal activities. For example, at 50 mg/L, the inhibitory activity of 13p (3-Cl-4-Cl substituted, 86.1%) against Sclerotinia sclerotiorum was superior to that of quinoxyfen (77.8%), and the inhibitory activity of 13f (3-CF3 substituted, 77.8%) was comparable to that of quinoxyfen. The fungicidal activities of 13f and 13p to Sclerotinia sclerotiorum were better than that of quinoxyfen (14.19 mg/L), with EC50 of 6.67 mg/L and 5.17 mg/L, respectively. Furthermore, the acute toxicity of 13p was 19.42 mg/L, classifying it as a low-toxic compound.

Correction: Shao et al. AKT Axis, miR-21, and RECK Play Pivotal Roles in Dihydroartemisinin Killing Malignant Glioma Cells. Int. J. Mol. Sci. 2017, 18, 350.

The authors wish to make the following corrections to this paper [...].

AKT Axis, miR-21, and RECK Play Pivotal Roles in Dihydroartemisinin Killing Malignant Glioma Cells.

Dihydroartemisinin (DHA), a semi-synthetic derivative of artemisinin, is known to play important roles in inhibiting proliferation rate, inducing apoptosis, as well as hindering the metastasis and invasion of glioma cells, but the underlying mechanisms are still unclear so far. In this study, methyl thiazolyl tetrazolium (MTT), colony-forming, wound healing, invasion, and apoptosis assays were performed to investigate the effect of DHA on malignant glioma cells. Results showed that DHA induced apoptosis of malignant glioma cells through Protein Kinase B (AKT) axis, induced death of malignant glioma cells by downregulating miR-21, and inhibited the invasion of malignant glioma cells corresponding with up-regulation of the reversion-inducing-cysteine-rich protein with kazal motifs (RECK). These results revealed that AKT axis, miR-21, and RECK play pivotal roles in DHA killing malignant glioma cells, suggesting that DHA is a potential agent for treating glioma.

Interindividual epigenetic variation in ABCB1 promoter and its relationship with ABCB1 expression and function in healthy Chinese subjects.

AIM: Interindividual epigenetic variation is likely to be an important mechanism contributing to the interindividual variability in the expression and function of ATP-binding cassette, sub-family B, member 1 (ABCB1). The aim of the present study was to explore the effect of interindividual epigenetic variability in the ABCB1 promoter on ABCB1 expression and function in healthy Chinese subjects. METHODS: Using bisulfite sequencing polymerase chain reaction (PCR) and chromatin immunoprecipitation assays, the DNA methylation and histone acetylation status of the ABCB1 promoter in stool DNA and exfoliated colonic epithelial cells of 157 healthy Chinese male volunteers was analysed. ABCB1 mRNA levels in colonic epithelial cells were detected by real-time PCR. The digoxin pharmacokinetics in subjects with different epigenetic profiles was investigated after a single oral administration of digoxin (0.5 mg). RESULTS: The methylation levels of ABCB1 promoter in stool DNA showed a significant interindividual variation, from 0.84% to 18.05%. A high methylation level of the ABCB1 promoter was closely related to the low levels of acetylated histone H3 and ABCB1 mRNA expression. In the high methylation group, the area under the concentration-time curves (AUC(0-4 h) and AUC(0-10 h) ) of digoxin was increased by 19% [95% confidence interval (CI) 10%, 31%; P = 0.024] and 13% (95% CI 8%, 26%; P = 0.026), respectively, and the peak concentration (Cmax ) of digoxin was increased by 30% (95% CI 12%, 41%; P = 0.021) compared with the low methylation group. CONCLUSIONS: The epigenetic modifications of the ABCB1 promoter show high interindividual variability in healthy Chinese subjects, and are closely related to the interindividual variation in ABCB1 mRNA expression and digoxin 0-4 h plasma concentrations in vivo.

Hyperprins A and B, Two Complex Meroterpenoids from Hypericum przewalskii.

Hyperprins A (1) and B (2), two polyprenylated acylphloroglucinol related meroterpenoids with undescribed carbon skeletons, were isolated from Hypericum przewalskii. Compound 1 possesses a new 6/6/6/6/5/5 hexacyclic system with an unprecedented tetracyclo[10.3.1.03,8.08,12]hexadecane motif. Compound 2 features a unique 6/8/6/6 tetracyclic scaffold. Their structures were determined by spectroscopic data, chemical method, and X-ray crystallography. Compound 1 showed antiproliferation activity against the MV-4-11 cell line, and the p-bromobenzoate derivative of 2 displayed PTP1B inhibition.

Identification of glutathione-S-transferase genes by transcriptome analysis in Meteorus pulchricornis (Hymenoptera: Braconidae) and their expression patterns under stress of phoxim and cypermethrin.

Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae) is a preponderant endoparasitoid wasp, attacking the larvae of many lepidopteran pests. We present the first body transcriptome dataset for M. pulchricornis. In total, 50,781,796 clean reads were obtained and 33,144 unigenes were assembled; 15,458 unigenes showed a significant similarity (E value < 10-5) to known proteins in the NCBI non-redundant protein database. Gene ontology and cluster of orthologous group analyses were performed to classify the functions of genes. To better understand the role of glutathione-S-transferases (GSTs) in detoxification mechanism in M. pulchricornis, we identified seventeen GST genes (MpulGSTs) from the body transcriptome. Among these, fifteen MpulGSTs belonged to cytosolic GSTs and the other two belonged to microsomal classes. The cytosolic GSTs were classified into four different clades: four in delta, three in omega, seven in sigma, and one in zeta. The expression levels of these MpulGSTs after exposure to sub-lethal concentrations of phoxim and cypermethrin were determined using real-time quantitative polymerase chain reaction: seven MpulGSTs (MpulGSTD3, MpulGSTS1, MpulGSTS2, MpulGSTS4, MpulGSTS6 MpulGSTO3, and MpulGSTmic1) and 11 MpulGSTs (MpulGSTD1, MpulGSTD2, MpulGSTD3, MpulGSTO2, MpulGSTS1, MpulGSTS2, MpulGSTS3, MpulGSTS4, MpulGSTS5, MpulGSTS7, and MpulGSTmic1) were highly expressed, respectively. These results suggested that GST genes may play a pivotal role in detoxification process in M. pulchricornis. Our findings would provide a theoretical base for elucidating insecticide susceptibility and should promote functional research on specific GST genes in parasitoid wasps.

Enhanced photoreduction degradation of polybromodiphenyl ethers with Fe3O4-g-C3N4 under visible light irradiation.

As typical persistent organic pollutants, polybrominated diphenyl ethers (PBDEs) have aroused high environmental concern due to their toxicity and recalcitrant degradation. Herein, we report the enhanced photoreduction degradation of polybromodiphenyl ethers with Fe3O4-g-C3N4 under visible light irradiation (>420 nm). A series of high activity photocatalysts Fe3O4-g-C3N4 (named FeOCN-x) have been synthesized by an in situ growth method. The characterization of the prepared FeOCN-x nanocomposites has been examined by SEM, TEM, ultraviolet-visible diffuse reflectance spectroscopy, a vibrating sample magnetometer, X-ray diffraction, X-ray photoelectron spectroscopy and Brunauer-Emmer-Teller surface area analysis. FeOCN-x hybrids all exhibit good magnetic separation properties with the saturation magnetization at 300 K varying from 0.4 to 6.3 emu g-1. Under visible light irradiation, FeOCN-x hybrids show enhanced photocatalytic activity for the debromination of PBDEs compared with g-C3N4. Among all the hybrids, FeOCN-4 with a 4 wt% Fe3O4 content gives the highest reaction rate, which is 6.7 times as high as that in pure g-C3N4. The FeOCN-x nanocomposites not only exhibit good photostability, but could also be easily recovered by magnetism. The results of the kinetic isotope effects (KIE) and the trapping agent experiments show that the rate determining step in the degradation reaction of PBDEs with FeOCN-x is the rate of electron accumulation in the conductive band. A possible photoreductive mechanism has been proposed. This study shows that the easily magnetically separable recycled photocatalyst FeOCN-x, with high visible light activity, could be an excellent candidate for dealing with halogen pollutants.

DNA hypermethylated status and gene expression of PAX1/SOX1 in patients with colorectal carcinoma.

BACKGROUND: Colorectal cancer (CRC) is a widespread and aggressive carcinoma with poor prognosis. Hypermethylation of specific gene promoters is an important mechanism of CRC. In this study, we investigated the hypermethylation of paired boxed gene 1 (PAX1) and sex-determining region Y-related high-mobility group box 1 (SOX1) genes in CRC tissues. METHODS: DNA methylation at cg2,09,07,471 PAX1 and cg0,66,75,478 SOX1 from 166 cancer tissues and 37 normal tissues from CRC patients were compared using datasets downloaded from The Cancer Genome Atlas. Quantitative methylation-specific polymerase chain reaction and assay of PAX1 and SOX1 were performed in dissected tumor and paracancerous tissues by surgery from 41 CRC patients. Quantitative reverse transcription polymerase chain reaction and immunohistochemistry assay were performed in both CRC and paired normal tissues to detect mRNA and protein expression, respectively. RESULTS: Methylation levels of PAX1/SOX1 genes were significantly higher in cancer tissues than in paired normal tissues. PAX1 and SOX1 genes were methylated in 28 (68.3%) of the 41 CRC samples but in 5 (12.2%) and 0 (0%) of the paired normal control samples (both P<0.001), respectively. Sensitivities and specificities of PAX1 methylation for the detection of cancer were 68.3% and 87.8%, respectively, whereas the corresponding values for SOX1 were 68.3% and 100%. However, the Kaplan-Meier analysis illustrated no significant difference in the overall survivals between patients with high and low methylation levels of SOX1 or PAX1 (P>0.5). In addition, the methylation level of PAX1/SOX1 was significantly higher in CRC patients with high TNM stage (TNM stage III/IV, 3.11±2.43) than those with low TNM stage (TNM stage I/II, 1.26±2.94, P<0.05). Relative RNA and protein expression levels of PAX1/SOX1 were both significantly lower in CRC tissues than in their paired normal tissue. CONCLUSIONS: This study is the first analysis of the methylation of PAX1/SOX1, which may be new biomarkers for CRC screening.

Pseudogenes of annexin A2, novel prognosis biomarkers for diffuse gliomas.

Diffuse gliomas is a kind of common malignant primary brain tumor. Pseudogenes have multilayered biological function in the progression of human cancers. In this study, Differentially Expressed Pseudogenes (DEPs) between glioblastomas and non-tumor controls were found by bioinformatics analysis, of which the annexin A2 pseudogenes (ANXA2P1, ANXA2P2 and ANXA2P3) were significantly up-regulated, along with the parent gene annexin A2 (ANXA2). Among four glioblastoma subtypes, ANXA2P1 and ANXA2P2 were preferentially expressed in mesenchymal subtype and less expressed in proneural subtype. Meanwhile, Pearson's correlation analysis revealed that the expression level of ANXA2 was positively correlated with ANXA2 pseudogenes expression. Then, the expression patterns of ANXA2 and its pseudogenes were validated in diffuse glioma specimens (n=99) and non-tumor tissues (n=12) by quantitative real-time PCR (qRT-PCR). Additionally, Kaplan-Meier analysis revealed that highly expressed ANXA2 and annexin A2 pseudogenes were associated with the poor survival outcome of glioma patients. Cox regression analyses suggested that ANXA2, ANXA2P1 and ANXA2P2 were the independent prognosis factors for gliomas. Furthermore, down-regulation of ANXA2 and ANXA2 pseudogenes might contribute to the improvement of patients' survival who received chemotherapy and radiotherapy. These results demonstrated that ANXA2 pseudogenes and ANXA2 could be used as the novel biomarkers for diagnosis, prognosis and target therapy of gliomas.

Combined Influence of Genetic Polymorphism and DNA Methylation on ABCB1 Expression and Function in Healthy Chinese Males.

BACKGROUND AND OBJECTIVES: It is well known that the expression and function of ATP-binding cassette transporter B1 (ABCB1) show high interindividual variability, but the reasons have not yet been fully elucidated. In this study, combined influence of genetic polymorphism and DNA methylation on ABCB1 mRNA expression and digoxin pharmacokinetics in healthy Chinese males was analyzed. METHODS: A total of 93 subjects who were homozygous for the ABCB1 1236-2677-3435 TTT or CGC haplotype were enrolled in this study. DNA methylation status of the ABCB1 promoter and ABCB1 mRNA expression level in exfoliated intestinal epithelial cells were analyzed using bisulfite sequencing PCR and real-time PCR. The pharmacokinetics of digoxin in subjects were investigated after administration of a single oral dose of digoxin 0.5 mg. RESULTS: The DNA methylation levels of ABCB1 promoter showed no significant difference between TTT/TTT and CGC/CGC carriers (P = 0.54). Subjects with TTT/TTT haplotype pair and high methylation status (TTT/TTT-HM) showed a significantly lower ABCB1 mRNA level compared to other subjects. Compared with TTT/TTT-HM subgroup, the area under the plasma concentration-time curve from time zero to 72 h (AUC0-72) of digoxin was decreased by 26.9 %, the maximum plasma concentration (C max) was decreased by 25 % and the apparent oral clearance (CL/F) was increased by 21.2 % in CGC/CGC-LM subgroup. The values of time to maximum concentration (t max) and terminal elimination half-life (t 1/2) showed no significant difference. CONCLUSIONS: Both genetic polymorphism and DNA methylation variation should be taken into consideration to explain the interindividual variability in ABCB1 expression and function more clearly.