Non-fused imidazole-biphenyl analogs repress triple-negative breast cancer growth by mainly stabilizing the c-MYC G-quadruplex via a multi-site binding mode.

As oncogene c-MYC is abnormally expressed during TNBC pathogenesis, stabilizing its promoter G-quadruplex (G4), which may thus inhibit c-MYC expression and promote DNA damage, may be a potential anti-TNBC strategy. However, large quantities of potential G4-forming sites exist in the human genome, which represents a potential drug selectivity problem. In order to achieve better recognition for c-MYC G4, we herein presented a new approach of designing small-molecule ligands by linking tandem aromatic rings with the c-MYC G4 selective binding motifs. Thus, a series of non-fused, conformation-tunable imidazole-biphenyl analogs were designed and synthesized. Among them, the optimal ligand appeared more effective on stabilizing c-MYC G4 than other types of G4s possibly through an adaptive, multi-site binding mode involved of end-stacking, groove-binding and loop-interacting. Then, the optimal ligand exerted good inhibitory activity on c-MYC expression and induced remarkable DNA damage, leading to the occurrence of G2/M phase arrest, apoptosis and autophagy. Furthermore, the optimal ligand exhibited potent antitumor effects in a TNBC xenograft tumor model. To sum up, this work offers new insights for the development of selective c-MYC G4 ligands against TNBC.

Drug-like biimidazole derivatives dually target c-MYC/BCL-2 G-quadruplexes and inhibit acute myeloid leukemia.

Chemotherapy is the main approach for treating acute myeloid leukemia (AML). However, this therapy can cause severe side effects as well as drug resistance, hence calling for new therapeutic strategies. As c-MYC and BCL-2 are often overexpressed in AML, and synergism between c-MYC and BCL-2 promotes tumorigenesis, therefore, dual targeting of c-MYC/BCL-2 promoter G-quadruplexes (G4s) and then inhibiting the targeted gene expression would be a potential strategy in ALM treatment. In this work, in the search of dual ligands, we performed a screening assay with an in-house, imidazole-based compound library. Consequently, two drug-like biimidazole derivatives were identified as selective c-MYC/BCL-2 G4 binders, of which, BIM-2 was selected as the candidate for inhibiting AML cell growth. Then, BIM-2 was demonstrated to downregulate both c-MYC and BCL-2 expression, and thereby cause cell cycle arrest at G0/G1 phase and apoptosis in AML cells. Furthermore, the possible end-stacking binding modes between BIM-2 and c-MYC/BCL-2 G4s were revealed by NMR and molecular docking studies. Accordingly, this study provides a new class of drug-like dual-selective c-MYC/BCL-2 G4 ligands for the potential treatment of AML.

Synthesis and Photodynamic Activity of Peri-xanthenoxanthene Derivatives.

Photodynamic therapy (PDT) is a modern cancer therapy. But it is still difficult to obtain ideal photosensitizers. We synthesized six new peri-xanthenoxanthene derivatives rapidly and efficiently using solid-phase carbon-bath microwave irradiation technology, and investigated their in vitro photodynamic antitumor activity with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Our results showed that all compounds exhibited extremely low dark cytotoxicity and good phototoxicity against four human cancer cell lines. In particular, compound 3c showed the best in vitro PDT activity against Hela cells and Bel-7402 cells with IC50 values of 91 and 74 nmol/L, respectively. Its value of 1-octanol/water partition coefficient (log Kow) was 0.5309, suggesting that it is a promising photosensitizer for PDT due to its low dark cytotoxicity, high phototoxicity, and potential water solubility.

Kai-Xin-San, a traditional Chinese medicine formulation, exerts antidepressive and neuroprotective effects by promoting pCREB upstream pathways.

Kai-Xin-San (KXS) is a traditional Chinese medicine that has been widely used for the treatment of emotion-related disease. However, the underlying mechanism remains largely unknown. The present study aimed to examine whether phospho-cAMP response element-binding protein (pCREB) and upstream components, such as extracellular signal-regulated kinase (ERK), phospho-ERK (pERK), phosphatidylinositol-3-kinase (PI3K), protein kinase B (Akt), glycogen synthase kinase 3ß (GSK3ß) and pGSK3ß are associated with the antidepressive effect of KXS. In total, 24 male Wistar rats were randomly divided into three groups, including control (n=8, no treatment), induced with chronic unpredictable mild stress (CMS) (n=8), and CMS rats treated with KXS at dosage of 370 mg/kg/day orally. Primary hippocampal neuronal cultures were prepared from Wistar rats for cell survival and proliferation assays. In KXS rats, increased protein expression levels of pCREB, BDNF and tyrosine receptor kinase B (TrkB) were observed in the hippocampus and prefrontal cortex, compared with the CMS model group. Furthermore, increased expression levels of ERK, pERK, PI3K, Akt, and GSK3ß were also detected in the hippocampus and prefrontal cortex of KXS-treated rats compared with CMS model rats and in primary hippocampal neuronal cells treated with KXS. These results suggest that pCREB and upstream components, including TrkB/ERK/CREB and TrkB/PI3 K/CREB, may contribute to the antidepressive effect induced by KXS. Further studies are required to confirm these findings.

Effect of Tenuifoliside A isolated from Polygala tenuifolia on the ERK and PI3K pathways in C6 glioma cells.

Tenuifoliside A (TFSA) is a bioactive oligosaccharide ester component of Polygala tenuifolia Wild, a traditional Chinese medicine which was used to manage mental disorders effectively. The neuroprotective and anti-apoptotic effects of TFSA have been demonstrated in our previous studies. The present work was designed to study the molecular mechanism of TFSA on promoting the viability of rat glioma cells C6. We exposed C6 cells to TFSA (or combined with ERK, PI3K and TrkB inhibitors) to examine the effects of TFSA on the cell viability and the expression and phosphorylation of key proteins in the ERK and PI3K signaling pathway. TFSA increased levels of phospho-ERK and phospho-Akt, enhanced release of BDNF, which were blocked by ERK and PI3K inhibitors, respectively (U0126 and LY294002). Moreover, the TFSA caused the enhanced phosphorylation of cyclic AMP response element binding protein (CREB) at Ser133 site, the effect was revoked by U0126, LY294002 and K252a. Furthermore, when C6 cells were pretreated with K252a, a TrkB antagonist, known to significantly inhibit the activity of brain-derived neurotrophic factor (BDNF), blocked the levels of phospho-ERK, phospho-Akt and phosphor-CREB. Taking these results together, we suggested the neuroprotection of TFSA might be mediated through BDNF/TrkB-ERK/PI3K-CREB signaling pathway in C6 glioma cells.

Antidepressant and neuroprotective effect of the Chinese herb kaixinsan against lentiviral shRNA knockdown brain-derived neurotrophic factor-induced injury in vitro and in vivo.

Depression has been associated with reduced expression of brain-derived neurotrophic factor (BDNF) in the hippocampus. Previous studies have demonstrated that the herbal medicine formula, 'kaixinsan' (KXS), could ameliorate the severity of depression and increase cAMP response element-binding protein expression. There is direct evidence suggesting that the reduction of the BDNF protein in specific brain sites can provoke depressive-like behaviour or affect neurogenesis in vivo. However, the biological mechanisms between the antidepressant and neuroprotective effect of KXS and the alterations in BDNF levels in in vivo and in vitro models remain unclear. Using BDNF knockdown mediated by lentiviral vectors (LV-shBDNF-3) transfected with primary hippocampal neurons and following injection into the dentate gyrus of the hippocampus, it was demonstrated that a reduction in BDNF expression affects cell viability and animal behaviours associated with depression. During treatment with KXS after the lentiviral shRNA silencing of BDNF in cell and animal, cell viability, body weight, the sucrose preference test (SPT), the open field test (OFT) the Morris Water Maze (MWM) task and BDNF expression were measured. KXS attenuated LV-shBDNF-3-induced cell death in primary hippocampal neurons and also improved the sucrose intake in SPT, ambulatory response in OFT and learning ability in MWM against LV-shBDNF-3-induced depressive-like syndromes. Moreover, immunoblot analysis confirmed that KXS could reverse LV-shBDNF-induced BDNF reduction either in vitro or in vivo. These findings provide substantial evidence for supporting a neurotrophic hypothesis of depression and specify BDNF targets for potential antidepressant interventions. Moreover, the antagonism between LV-shRNA BDNF knockdown and KXS may depend on multiple compounds with synergistic mechanisms that modulate the different signal transduction networks directly or indirectly, increasing BDNF expression and exerting its neuroprotective and antidepressant-like effects.

Effect of kai xin san on learning and memory in a rat model of paradoxical sleep deprivation.

The present study aimed to evaluate the effect of kai xin san (KXS, at doses of 500, 250, and 125 mg/kg body weight per day), a well-known traditional Chinese medicine, on learning and memory in paradoxical sleep deprivation (PSD)-induced cognition deficit rats. Two behavior tests (the Open Field test and the Morris water maze task) were used for testing the effects of KXS on a PSD-induced learning and memory deficit model. Furthermore, its effect on the glutamic acid (GLU) and γ-amino-butyric acid (GABA) levels in the brain tissue, brain-derived neurotrophic factor (BDNF), cyclic AMP response element binding protein (CREB), and phosphorylated-CREB (p-CREB) expression in the hippocampus was also tested. KXS exerted the greatest cognition against the 48 h PSD-induced cognitive deficit and these effects may be mediated by decreasing the GLU and GABA levels and increasing the levels of BDNF, CREB, and p-CREB. This study indicates that the effect of KXS on learning and memory in a rat model of PSD could be associated with the modulation of neurotransmitter levels and the expression of some genes in the brain that contribute to memory functions.

[Study on several ultrasound markers combined maternal serum biochemical markers to screen fetal chromosomal aneuploidy at 11 to 13(+)6 weeks of gestation].

OBJECTIVE: To evaluate the efficiency of combined screening for chromosomal abnormalities in the first trimester and the ultrasound characteristics of these fetuses. METHODS: Retrospective study for 5000 singleton pregnancies by combined screening of trisomies 21, 18, 13 and Turner syndrome.Risk algorithms were developed for calculation of patient-specific risks for each of the three trisomies based on maternal age, fetal nuchal translucency, free ß human chorionic gonadotropin and serum pregnancy associated plasma protein A at 11 to 13(+6) weeks of pregnant. The value of nuchal translucency (NT) and ß-hCG and pregnancy-associated plasma protein A (PAPP-A) level were inputted computer, and calculate the risk value ( ≥ 1: 270) by automatic analysis software. Two hundred and four cases with high risk were performed transabdominal chorionic villus biopsy to detect the fetal chromosomal karyotypes. Meanwhile, other ultrasonic characteristics of fetal were elevated. RESULTS: (1) Five thousand cases of pregnant women were detected, including 4983 normal cases, 62 cases were induced labor for a variety of reasons in the second trimester, including 40 cases with normal karyotype but with congenital heart disease, 17 cases of chromosome abnormalities (9 cases trisomy 21, 2 cases trisomy 18, 1 cases trisomy 13, 4 cases 45X), 2 cases spina bifida, 2 cases digestive tract obstruction, 1 cases giant bladder.One case with low risk of fetal chromosomal abnormalities in combined screening, but high risk of age (maternal age were over 40 years old), it was 21 trisomy syndrome after the prenatal diagnosis.(2) Five cases of nasal bone loss in 9 cases of trisomy 21 (5/9), 5 cases with three tricuspid regurgitation (5/9), 4 cases of venous ductus a wave flow reverse (4/9), 3 cases of fetal nasal bone loss accompanied by tricuspid regurgitation and venous ductus a wave flow reverse (3/9).One case of nasal bone loss in 2 cases of trisomy 18, 2 cases were tricuspid regurgitation and venous ductus a wave flow reverse. Two cases in 4 cases of 45X had venous ductus a wave flow reverse. There were 8 cases (0.16%) nasal bone absence in 4983 cases of normal karyotype fetus, 48 cases (0.96%) of tricuspid regurgitation and 44 cases (0.88%) of venous ductus a wave flow reverse. Thirty-two cases in 40 cases (80%) of fetal congenital heart disease were tricuspid regurgitation, 30 cases of venous ductus a wave flow reverse (75%).Eight cases of nasal bone absence normal karyotype fetus were found the nasal bone at 20 weeks gestation. CONCLUSION: Combination screening of nuchal translucency with serum markers in the first trimester were high detection rate and low false positive rate; a wave reversion and fetal nasal bone absence accompanied by tricuspid regurgitation can improve the detection rate of abnormal karyotype; abnormalities ultrasound marker may be associated with fetal congenital heart disease at 11-13(+6) weeks of pregnancy.

[Effect and mechanism of dingzhixiao wan on scopolamine-induced learning-memory impairment in mice].

OBJECTIVE: To investigate the effect of Dingzhixiao Wan (DZXW), a classic traditional Chinese medicine formula consisting of Acorus tatarinowii, Polygala tenuifolia, Poria cocos and Panax ginseng in a proportion of 2: 2: 3: 3, on learning-memory impairment induced by scopolamine and its possible mechanisms. METHOD: The mice were randomly divided into six groups: the control group, the model group, the positive huperzine A (0.05 mg x kg(-1)) group, DZXW 700 mg x kg(-1), 350 mg x kg(-1) and 175 mg kg(-1) groups. DZXW extracts were orally administrated to the mice for 7 days. Scopolamine (1.5 mg x kg(-1), ip) was injected to establish the learning and memory impairment model in mice. Morris water maze (MWM) test was used to assess the learning and memory ability of each group. After the test, the activities of glutamic acid (Glu), gamma-amino-butyric acid (GABA), serotonin (5-HT), dopamine (DA), acetylcholine (Ach) and acetyl cholinesterase (AchE) in brain tissue were measured. RESULT: The praxiology test showed that DZXW significantly decreased the average latency of model mice in the place navigation test, and enhanced the frequency for passing through the platform in the spatial probe test, the percentage between target quadrant swimming distance and time. Moreover, DZXW could significantly increase the contents of Glu and 5-HT, DA and Ach, while reducing the levels of GABA and AchE in mice brain. CONCLUSION: DZXW could significantly ameliorate the scopolamine-induced learning-memory impairment in mice and improve their learning-memory capacity, which may be related to its effect on adjusting Glu/GABA system and increasing Ach and monoamine neurotransmitter contents in mice brain.