Podophyllotoxin Induces CREB Phosphorylation and CRE-Driven Gene Expression via PKA but Not MAPKs

Xin Xie,Ya Qiong Chen 한국분자세포생물학회 2010 Molecules and cells Vol.29 No.1

CRE-driven luciferase reporter is commonly used in drug screening systems involving G protein-coupled receptors (GPCRs). In a screen campaign designed to search for melanocortin-4 receptor (MC4R) agonists, podophyllotoxin, a microtubules disruptor, was found to induce cAMP-responsive element (CRE)-driven reporter expression. MC4R was not involved because podophyllotoxin induced CREB activation and CRE-driven transcription in cells not express-ing MC4R. Previous studies indicated that intracellular cal-cium, PKA, and MAPKs are involved in CREB phosphoryla-tion and activation. Our studies revealed that podophyl-lotoxin did not affect intracellular calcium level and the phosphorylation state of p38. Podophyllotoxin induced JNK and ERK activation, but blockade of JNK and ERK activation with specific inhibitors had no effect on podophyllotoxin-induced CREB activation and CRE-regulated gene expression. Further experiments revealed that H89, a specific inhibitor of PKA, significantly inhibited podophyllotoxin-induced CREB activation. Podophyllotoxin itself did not alter intracellular cAMP level. Taken together, podophyllotoxin induces CREB activation and CRE-driven gene expression via PKA activa-tion by a cAMP-independent mechanism.

Chemoenzymatic Synthesis of Dual-responsive Amphiphilic Block Copolymers and Drug Release Studies

Chen, Peng,Li, Ya-Peng,Wang, Shu-Wei,Meng, Xin-Lei,Zhu, Ming,Wang, Jing-Yuan Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

Dual-responsive amphiphilic block copolymers were synthesized by combining enzymatic ring-opening polymerization (eROP) of ${\varepsilon}$-caprolactone (CL) and ATRP of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA). The obtained block copolymers were characterized by gel permeation chromatography (GPC), $^1H$ NMR and FTIR-IR. The critical micelle concentration (CMC) of copolymer was determined by fluorescence spectra, it can be found that with hydrophilic block (PDMAEMA) increasing, CMC value of the polymer sample increased accordingly, and the CMC value was 0.012 mg/mL, 0.025 mg/mL and 0.037 mg/mL for $PCL_{50}$-b-$PDMAEMA_{68}$, $PCL_{50}$-b-$PDMAEMA_{89}$, $PCL_{50}$-b-$PDMAEMA_{112}$, $PCL_{50}$-b-$PDMAEMA_{89}$ was chosen as drug carrier to study in vitro release profile of anti-cancer drug (taxol). The temperature and pH dependence of the values of hydrodynamic diameter (Dh) of micelles, and self-assembly of the resulting block copolymers in water were evaluated by dynamic light scattering (DLS). The result showed that with the temperature increasing and pH decreasing, the Dh decreased. Drug-loaded nanoparticles were fabricated using paclitaxel as model. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) had been explored to study the morphology of the hollow micelles and the nanoparticles, revealing well-dispersed spheres with the average diameters both around 80 nm. In vitro release kinetics of paclitaxel from the nanoparticles was also investigated in different conditions (pH and temperature, etc.), revealing that the drug release was triggered by temperature changes upon the lower critical solution temperature (LCST) at pH 7.4, and at $37^{\circ}C$ by an increase of pH.

Podophyllotoxin Induces CREB Phosphorylation and CRE-Driven Gene Expression via PKA but Not MAPKs

Chen, Ya Qiong,Xie, Xin Korean Society for Molecular and Cellular Biology 2010 Molecules and cells Vol.29 No.1

CRE-driven luciferase reporter is commonly used in drug screening systems involving G protein-coupled receptors (GPCRs). In a screen campaign designed to search for melanocortin-4 receptor (MC4R) agonists, podophyllotoxin, a microtubules disruptor, was found to induce cAMP-responsive element (CRE)-driven reporter expression. MC4R was not involved because podophyllotoxin induced CREB activation and CRE-driven transcription in cells not expressing MC4R. Previous studies indicated that intracellular calcium, PKA, and MAPKs are involved in CREB phosphorylation and activation. Our studies revealed that podophyllotoxin did not affect intracellular calcium level and the phosphorylation state of p38. Podophyllotoxin induced JNK and ERK activation, but blockade of JNK and ERK activation with specific inhibitors had no effect on podophyllotox-ininduced CREB activation and CRE-regulated gene expression. Further experiments revealed that H89, a specific inhibitor of PKA, significantly inhibited podophyllotoxin-induced CREB activation. Podophyllotoxin itself did not alter intracellular cAMP level. Taken together, podophyllotoxin induces CREB activation and CRE-driven gene expression via PKA activation by a cAMP-independent mechanism.

Suppression of MED19 expression by shRNA induces inhibition of cell proliferation and tumorigenesis in human prostate cancer cells

( Xin Gang Cui ),( Dan Feng Xu ),( Chao Lv ),( Fa Jun Qu ),( Jin He ),( Ming Chen ),( Yu Shan Liu ),( Yi Gao ),( Jian Ping Che ),( Ya Cheng Yao ),( Hong Yu Yu ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.8

MED19 is a member of the Mediator that plays a key role in the activation and repression of signal transduction or the regulation of transcription in carcinomas. To tested the functional role of MED19 in human prostate cancer, we downregulated MED19 expression in prostate cancer cells (PC-3 and DU145) by lentivirus- mediated short hairpin (shRNA), and analyzed the effect of inhibition of MED19 on prostate cancer cell proliferation and tumorigenesis. The in vitro prostate cancer cell proliferation, colony formation, and in vivo tumor growth in nude mice xenografts was significantly reduced after the downregulation of MED19. Knock- down of MED19 caused S-phase arrest and induced apoptosis via modulation of Bid and Caspase 7. It was suggested that MED19 serves as a novel proliferation regulator that promotes growth of prostate cancer cells. [BMB reports 2011; 44(8): 547-552]

Risk Factors, Patterns, and Outcomes of Late Recurrence after Liver Resection for Patients with Hepatocellular Carcinoma (Analysis of a Multicenter Cohort over 15 Years)

( Xin-fei Xu ),( Jiong-jie Yu ),( Ju-dong Li ),( Hao Xing ),( Jun Han ),( Zhen-li Li ),( Han Wu ),( Han Zhang ),( Jian-hong Zhong ),( Yi- Sheng Huang ),( Ya-hao Zhou ),( Ting-hao Chen ),( Hong Wang ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1

Aims: Late recurrence (> 2 years) after liver resection of hepatocellular carcinoma (HCC) is usually considered as multi-centric tumors or de novo cancer formation. We aimed to investigate risk factors, patterns and outcomes of late recurrence after HCC resection. Methods: From a multicenter database from 2001 to 2015, 734 patients who were alive and recurrence-free at 2 years after curative resection of initial HCC were enrolled into this retrospective study. Univariate and multivariate Cox-regression analysis were used to identify independent risk factors of late recurrence. Patterns, treatments and outcomes of late recurrence were investigated and analyzed. Results: During a median follow-up of 78.0 months after surgery, 303 patients (41.3%) developed late recurrence. Multivariate analysis revealed that cirrhosis, macroscopic vascular invasion, satellites, and tumor size > 5cm were independent risk factors of late recurrence. Among them, 273 (90.1%) were sole intrahepatic recurrence, 30 (9.9%) were concurrent intrahepatic and extrahepatic recurrence, and none of them was sole extrahepatic recurrence; 165 (54.4%) patients received curative treatments for recurrent HCC, including re-resection, transplantation and local ablation. Multivariate analysis showed regular postoperative surveillance and receiving curative treatments were two independent protective factors of prolonging survival for those patients with late recurrence. Conclusions: Late recurrence is correlated with cirrhosis and certain tumor-related characteristics of initial HCC. The patterns of late recurrence suggest that postoperative surveillance after 2 years of surgery could be adjusted and more targeted. Regular postoperative surveillance improves the probability to receive curative treatments again, yielding to better outcomes for patients with late recurrence.

Molecular characterization of the sans fille gene in Antheraea pernyi: A highly conserved gene during the evolution of animals

Ya-Jie Li,Rui Mi,Nan Meng,Zhi-Xin Wen,Xue-Jun Li,Mo Chen,Yan-Qun Liu,Shu-Ying Li 한국응용곤충학회 2013 Journal of Asia-Pacific Entomology Vol.16 No.3

Sans-fille (SNF) is the Drosophila homologue ofmammalian general splicing factors U1A and U2B″, and plays an important role in sex determination in Drosophilamelanogaster. In this study, the snf gene fromAntheraea pernyi (Lepidoptera: Saturniidae), an economically important insect, was isolated and characterized. The obtained 925 bp cDNA sequence contains an open reading frame of 669 bp encoding a polypeptide of 222 amino acids,showing 78% sequence identity to that from D. melanogaster. A database search revealed that SNF protein homologs are present in many animals, including invertebrates and vertebrates, with more than 70% amino acid sequence identities, suggesting that they were highly conserved during the evolution of animals. Phylogenetic analysis revealed that A. pernyi SNF was closely related to Bombyx mori SNF. Quantitative real-time PCR (qRT-PCR) analysis showed that the A. pernyi snf gene was transcribed during five larval developmental stages,and in six tested tissues (ovaries, testes, silk glands, fat body, integument, and hemolymph),with the most abundance determined in the gonads (ovaries or testes). Investigation of expression changes throughout embryonic development indicated that A. pernyi snfmRNAwas expressed at a lowlevel fromdays 0 to 4, and reached amaximum level at day 10, but decreased to a low level before hatching. These results suggest that the product of the snf gene may play important roles in the development of A. pernyi.

H-형태 양친매성 펜타블록 공중합체의 화학효소적 합성과 자기회합거동 평가

Peng Chen,Ya Peng Li,Can Jin Li,Xin Lei Meng,Bao Zhang,Ming Zhu,Yan-jing Liu,Jing Yuan Wang 한국고분자학회 2013 폴리머 Vol.37 No.3

H-shaped amphiphilic pentablock copolymers (PSt)2-b-PCL-b-PEO-b-PCL-b-(PSt)2 was synthesized via chemoenzymatic method by combining enzyme-catalyzed ring-opening polymerization (eROP) of ε-caprolactone (ε-CL) and atom transfer radical polymerization (ATRP) of styrene. By this process, we obtained copolymers with controlled molecular weight and low polydispersity. The structure and composition of the obtained copolymers were characterized by nuclear magnetic resonance (NMR), gel permeation chromatography (GPC) and infrared spectroscopy analysis (IR). The crystallization behavior of the copolymers was analyzed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The crystallization behavior of the H-shaped block copolymers demonstrated a PCL dominate crystallization. The self-assembly behavior of the copolymers was investigated in aqueous media. The hydrodynamic diameters of the copolymer micelles in aqueous solution were measured by dynamic light scattering (DLS). The morphology of the copolymer micelles was observed by atomic force microscopy (AFM) and transmission electron microscopy (TEM). The hydrodynamic diameters of spherical micelles declined gradually with the increase of the hydrophobic chain lengths of the copolymers. The critical micelle concentration (CMC) values were determined from fluorescence emission, and it was found that the CMCs decreased with an increase of PSt hydrophobic block lengths.

Chemoenzymatic Synthesis of Dual-responsive Amphiphilic Block Copolymers and Drug Release Studies

Peng Chen,Ya-Peng Li,Shu-Wei Wang,Xin-Lei Meng,Ming Zhu,Jing-Yuan Wang 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.6

Dual-responsive amphiphilic block copolymers were synthesized by combining enzymatic ring-opening polymerization (eROP) of ε-caprolactone (CL) and ATRP of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA). The obtained block copolymers were characterized by gel permeation chromatography (GPC), 1H NMR and FTIR-IR. The critical micelle concentration (CMC) of copolymer was determined by fluorescence spectra, it can be found that with hydrophilic block (PDMAEMA) increasing, CMC value of the polymer sample increased accordingly, and the CMC value was 0.012 mg/mL, 0.025 mg/mL and 0.037 mg/ mL for PCL50-b-PDMAEMA68, PCL50-b-PDMAEMA89, PCL50-b-PDMAEMA112, PCL50-b-PDMAEMA89 was chosen as drug carrier to study in vitro release profile of anti-cancer drug (taxol). The temperature and pH dependence of the values of hydrodynamic diameter (Dh) of micelles, and self-assembly of the resulting block copolymers in water were evaluated by dynamic light scattering (DLS). The result showed that with the temperature increasing and pH decreasing, the Dh decreased. Drug-loaded nanoparticles were fabricated using paclitaxel as model. Transmission electron microscopy (TEM) and atomic force microscopy (AFM) had been explored to study the morphology of the hollow micelles and the nanoparticles, revealing well-dispersed spheres with the average diameters both around 80 nm. In vitro release kinetics of paclitaxel from the nanoparticles was also investigated in different conditions (pH and temperature, etc.), revealing that the drug release was triggered by temperature changes upon the lower critical solution temperature (LCST) at pH 7.4, and at 37 °C by an increase of pH.

Net micromineral requirements for maintenance and growth of ewe lambs at the latter fattening period

Jin Ya Qian,Ding Na,Diao Xiao Gao,Yu Sheng Chen,Zhao Jun Xing,Zhang Jian Xin 아세아·태평양축산학회 2020 Animal Bioscience Vol.33 No.9

Objective: The objective of this study was to investigate the net micromineral (Cu, Fe, Mn, Zn) requirements for maintenance and growth of Dorper×Jinzhong crossbred ewe lambs at their latter fattening period. Methods: Thirty 1/2 Dorper × 1/2 Jinzhong crossed F1 ewe lambs (35±0.5 kg of body weight [BW]) were used and divided into five groups in a randomized design for a comparative slaughter trial. At the beginning of the experiment, six lambs were randomly selected and slaughtered at 35 kg BW to determine their initial body composition. When their BWs reached 43 kg, another six lambs fed ad libitum were slaughtered to serve as an intermediate slaughter group. The retained eighteen lambs were randomly distributed into three groups and offered one type of feed at 100%, 65%, and 40% of the ad libitum intake. When the lambs fed ad libitum reached a BW of 50 kg, the three groups were slaughtered. The body composition (muscle, fat, bone, blood with viscera, skin, and wool) were weighted, ground, mixed, and subsampled for mineral content analysis. Results: The net maintenance requirements of Cu, Fe, Mn, and Zn were 0.017, 0.160, 0.004, and 0.067 mg/kg BW/d, respectively, and the net growth requirements per 100 grams of average daily gain ranged from 0.48 to 0.51 mg of Cu, 2.63 to 2.17 mg of Fe, 0.12 to 0.15 mg of Mn, and 2.07 to 2.00 mg of Zn, respectively, for Dorper × Jinzhong crossed ewes from 35 to 50 kg BW. Conclusion: Our results suggest that the micromineral requirements for both maintenance and growth of Dorper × Jinzhong crossbred ewe lambs were quite different from the recommendations of NRC (2007), except for Zn.

Radiation-induced Cochlea Hair Cell Death: Mechanisms and Protection

Tan, Pei-Xin,Du, Sha-Sha,Ren, Chen,Yao, Qi-Wei,Yuan, Ya-Wei Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Cochlea hair cell death is regarded to be responsible for the radiation-induced sensorineural hearing loss (SNHL), which is one of the principal complications of radiotherapy (RT) for head and neck cancers. In this mini-review, we focus on the current progresses trying to unravel mechanisms of radiation-induced hair cell death and find out possible protection. P53, reactive oxygen species (ROS) and c-Jun N-terminal kinase (JNK) pathways have been proposed as pivotal in the processes leading to radiation hair cell death. Potential protectants, such as amifostine, N-acetylcysteine (NAC) and epicatechin (EC), are claimed to be effective at reducing radiation-inducedhair cell death. The RT dosage, selection and application of concurrent chemotherapy should be pre-examined in order to minimize the damage to cochlea hair cells.