Down-regulation of Hsp90 could change cell cycle distribution and increase drug sensitivity of tumor cells

AIM:To construct Hsp90 antisense RNA eukaryotic expression vector, transfect it into SGC7901 and SGC7901/VCR of MDR-type human gastric cancer cell lines, HCC7402 of human hepatic cancer and Ec109 of human esophageal cancer cell lines, and to study the cell cycle distribution of the gene transected cells and their response to chemotherapeutic drugs.METHODS:A 1.03kb cDNA sequence of Hsp90beta was obtained from the primary plasmid phHSP90 by EcoR I and BamH I nuclease digestion and was cloned to the EcoR I and BamH I site of the pcDNA by T4DNA ligase and an antisense orientation of Hsp90beta expression vector was constructed. The constructs were transfected with lipofectamine and positive clones were selected with G418. The expression of RNA was determined with dot blotting and RNase protection assay, and the expression of Hsp90 protein determined with western blot. Cell cycle distribution of the transfectants was analyzed with flow cytometry, and the drug sensitivity of the transfectants to Adriamycin (ADR), vincrinstine (VCR), mitomycin (MMC) and cyclophosphamide (CTX) with MTT and intracellular drug concentration of the transfectants was determined with flow cytometry.RESULTS:In EcoR I and BamH I restriction analysis, the size and the direction of the cloned sequence of Hsp90beta remained what had been designed and the gene constructs were named pcDNA-Hsp90.AH-SGC7901, AH-SGC7901/VCR, AH-HCC7402 and AH-Ec109 cell clones all expressed Hsp90 anti-sense RNA. The expression of Hsp90 was down-regulated in AH-SGC7901, AH-SGC7901/VCR, AH-HCC7402 and AH-Ec109 cell clones. Cell cycle distribution was changed differently. In AH-SGC7901/VCR and AH-Ec109 cells, G(1) phase cells were increased; S phase and G(2) phase cells were decreased as compared with their parental cell lines. In AH-SGC7901 cell, G(1)phase cells were decreased, G(2) phase cells increased and S phase cells were not changed, and in AH-HCC7402 cells G(1), S and G(2) phase cells remained unchanged as compared with their parental cell lines. The sensitivity of AH-SGC7901, AH-SGC7901/VCR, AH-HCC7402 and AH-Ec109 to chemotherapeutic drugs, the sensitivity of AH-SGC7901/VCR to ADR, VCR, MMC and CTX the sensitivity of AH-HCC7402 to ADR and VCR, and the sensitivity of Ec109 to ADR, VCR and CTX all increased as compared with their parental cell lines. The mean fluorescence intensity of ADR in AH-SGC7901, AH-SGC7901/VCR, AH-HCC7402 and AH-Ec109 was also significantly elevated (P 【 0.05).CONCLUSION: Down-regulation of Hsp90 could change cell cycle distribution and increase the drug sensitivity of tumor cells.

Bisoprolol reverses down-regulation of potassium channel proteins in ventricular tissues of rabbits with heart failure

Remodeling of ion channels is an important mechanism of arrhythmia induced by heart failure （HF）. We investigated the expression of potassium channel encoding genes in the ventricles of rabbit established by volumeoverload operation followed with pressure-overload. The reversible effect of these changes with bisoprolol was also evaluated. The HF group exhibited left ventricular enlargement, systolic dysfunction, prolongation of corrected QT interval （QTc）, and increased plasma brain natriuretic peptide levels in the HF rabbits. Several potassium channel subunit encoding genes were consistently down-regulated in the HF rabbits. After bisoprolol treatment, heart function was improved significantly and QTc was shortened. Additionally, the mRNA expression of potassium channel subunit genes could be partially reversed. The down-regulated expression of potassium channel subunits Kv4.3, Kv1.4, KvLQT1, minK and Kir 2.1 may contribute to the prolongation of action potential duration in the heart of rabbits induced by volume combined with pressure overload HF. Bisoprolol could partially reverse these down-regulations and improve heart function.

Inactivated Sendai Virus Induces Apoptosis in Murine Melanoma Cells by IGF-1R Down-regulation

The mortality of cancer patients has considerably improved due to progress in surgery, chemotherapy and radiotherapy. However, some types of cancers, such as melanoma, remain refractory to conventional strategies. Although melanoma accounts for only 4% of all dermatological malignancies, it is responsible for 80% of mortalities from skin tumors[11. The reported survival rate of melanoma over 5 years is not yet encouraging due to its chemo-resistance and rapid metastasis. Therefore, it is necessary to develop new drugs with potent activity and weak side-effect against melanoma.

LncRNA LUCAT1 Activation Mediated by theDown-regulation of DNMT1 Is Involved inCell Apoptosis Induced by PM2.5

Particulate matter （PM）, which is a great environmental concern, has been classified as a Group 1 human carcinogen by the International Agency for Research on Cancer （IARC）;.Epidemiological and experimental studies have indicated that chronic exposure to PM, especially PM;(particles with an aerodynamic diameter less than

Down-regulation of glucocorticoid receptor mRNA by glucocorticoids in rats

The effect of glucocorticoids on the down-regulation of glucocorticoidreceptor (GR) mRNA was studied in intact rats.GR mRNA was characterized byNorthern blot hybridization and quantitated by dot blot hybridization using a hu-man GR cDNA fragment as a probe.Administration of hydrocortisone (F) inpolyvinyl alcohol (PVA) resulted in a rapid increase in plasma glucocorticoidswhich maintained at stress levels (20 to 40μg/dl) for about 3 d.HepaticGR mRNA decreased significantly to 73.5±6.3% of control values 6h followingF treatment,after which the decline of GR mRNA was gradual,reaching a mini-mum of 44.0±5.0% of control levels 3d after the treatment.The effect of F onthe down-regulation of hepatic GR mRNA lasted up to 11 d.In contrast,F treat-ment had no effect on GR mRNA in rat brain.These results are consistent withthe changes in GR in rats as reported previously,except that even though thehepatic cytosol GR decreased markedly,no significant changes in hepatic GRmRNA were found 1h after F treatment,strongly suggesting that thedown-regulation of GR by its ligands in vivo occurs at both transcriptional andposttranscriptional levels and is of tissue-specific fashion.

Maternal Lead Exposure Induces Down-regulation of Hippocampal Insulin-degrading Enzyme and Nerve Growth Factor Expression in Mouse Pups

Lead exposure is a known potential risk factor for neurodegenerative diseases such as Alzheimer’s disease （AD）. Exposure to lead during the critical phase of brain development has been linked with mental retardation and hypophrenia in later life.

Glypican 4 down-regulation in pluripotent stem cells as a potential strategy to improve differentiation and to impair tumorigenicity of cell transplants

Recent advances in stem cell technologies have opened new avenues for the treatment of a number of diseases still lacking effective therapeutic options.Cell transplantation has emerged as among the most promising clinical intervention for disorders such as injuries,diabetes,liver diseases, neurodegeneration and heart failure （Lee et al., 2013; Forbes and Rosenthal, 2014; Tabar and Studer, 2014）.

Down-regulation of Notch-1 gene expression inhibits growth of TJ-905 glioblastoma

Objective To study the inhibitory effect of siRNA on glioblastoma (GBM) Notch-1 gene expression in addition to the growth of TJ-905 glioblastoma. Methods Three small interference RNAs (siRNAs) targeting Notch1 gene,named siRNA1,siRNA2,siRNA3,synthesized chemically in vitro with gene bank BLAST. TJ-905 cells were transfected twice with the siRNA by using Oligofectamine

Modified super-long down-regulation protocol improves fertilization and pregnancy in patients with poor ovarian responses

Background The successful end-point of in vitro fertilization （IVF） treatment is for a woman to give live birth. This outcome is based on various factors including adequate number of retrieved eggs. Failure to recruit adequate follicles, from which the eggs are retrieved, is called a ＂poor response＂. How to improve the clinical pregnancy rates of poor responders was one of the tough problems for IVF. Methods The study involved 51 patients who responded poorly to high dose gonadotropin treatment in their previous cycles at our reproductive center, between April 2010 and February 2012. The previous cycle （group A） received routine long protocol; the subsequent cycle （group B） received modified super-long down-regulation protocol. The primary outcome of the study was the number of oocytes fertilized. The increase in the pregnancy rate was the secondary outcome. Differences between the groups were assessed by using Student＇s t test and Z2 test where appropriate. Results The patients＇ average age was （36.64±3.85） years. The mean duration of ovarian stimulation cycles of the group A patients was longer than those of the group B patients. The total dose of follicle-stimulating hormone （FSH） was significantly lower in the subsequent cycle. The peak value of serum estradiol on human chorionic gonadotrophin （hCG） day was lower in group A as compared with group B. The number of metaphase II oocytes recovered was significantly higher in group B. The cleavage rate in group A was significantly lower than in group B, 49 patients in group B reached embryo transfer stage, while 46 patients in group A reached this stage. Patients in group B received significantly more embryos per transfer as compared with group A. More pregnancies and more clinical pregnancies with fetal heart activity were achieved in group B. Conclusions This comparative trial shows that poor responder women undergoing repeated assisted reproduction treatment using modified super-long down-regulation protocol achieve more oocytes, leading to higher fertilization rate, compared to women receiving routine long protocol. Our study also showed that clinical pregnancy rate was significantly improved.

Down-regulation of PTH/PTHrP receptor in the kidney of patients with renal impairment

OBJECTIVE: To investigate whether the down-regulation of renal parathyroid hormone/parathyroid hormone related protein (PTH/PTHrP) receptor messenger ribonucleic acid (mRNA) expression is a general phenomenon in patients with different stages of renal disease, besides chronic renal failure. METHODS: Twenty-five patients were divided into the following groups: (1) chronic glomerulonephritis with normal renal function (GNN) (2) chronic glomerulonephritis with moderate renal insufficiency (GNI) (3) severe chronic renal failure undergoing maintenance dialysis (CRF) (4) acute renal failure during oliguric phase (ARF) (5) normal control without renal suffering (NC). Using relatively quantitative reverse transcription/polymerase chain reaction (RT/PCR) method, we investigated PTH/PTHrP receptor mRNA expression in renal specimens obtained through biopsy or operation. The levels of plasma C-terminal PTH, serum phosphorus and calcium were also observed at the same time. RESULTS: Plasma C-terminal PTH levels in GNI, CRF and ARF patients were 1.90, 9.73 and 8.63 times higher than those in NC. However, the difference between GNN and NC was insignificant. CRF and ARF patients also presented obviously elevated serum phosphorus (1.61, 1.86 vs 1.14 mmol/L) and reduced serum calcium (1.82, 1.71 vs 2.26 mmol/L) compared with that in the control. These two parameters for GNN and GNI patients were normal. The levels of PTH/PTHrP receptor mRNA (corrected by beta-actin mRNA) in the kidney of GNN, GNI, CRF and ARF patients was markedly decreased by up to 35.7%, 68.5%, 77.9% and 92.2%, respectively. CONCLUSIONS: The down-regulation of renal PTH/PTHrP receptor mRNA occurs much earlier than the changes of renal function, plasma PTH, serum phosphorus and calcium in the course of human renal disease.

Revised Super-long Down-regulation Protocol Improves the Outcome of Infertile Patients with Repeated Implantation Failure in IVF/ICSI-ET

Objective To investigate the outcome of revised super-long down-regulation protocol （RSDP） for in vitro fertilization / intracytoplasmic sperm injection-embryo transfer （1VF/1CS1-ET） in the special infertile patients with repeated implantation failure （RIF）. Methods Patients with RIF were divided into RSDP group and routine long downregulation protocol （RLDP） group. In RSDP group, gonadotropin releasing hormone agonist （GnRHa） was injected intramuscularly by 2.5 mg in mid-luteal phase for the ftrst time and 1.25 mg after 28 d; gonadotropin （Gn） was started 14 d later after the second GnRHa dose. IVF/ICSI-ET was performed according to the routine procedure. The clinical outcomes of RSDP group were compared with those of RLDP group. Results In RSDP group, the number of retrieved oocytes and valid embryos was significantly lower （P〈0.05）; there were no significant differences about fertilization rate （P〉0. 05）; both good-quality embryo rate and implantation rate were significantly increased （P〈0. 005）; clinical pregnancy rate was obviously improved （P〈0. 05）, as compared with RLDP group.Conclusion RSDP can improve the IVF outcomes significantly in RIF patients.

AduoLa Fuzhenglin Down-regulates Microwave-induced Expression of β_1-adrenergic Receptor and Muscarinic Type 2 Acetylcholine Receptor in Myocardial Cells of Rats

This paper is aimed to study the effect of ADL on expression of ~z-AR and Mz-AchR in myocardial cells of rats exposed to microwave radiation. Immunohistochemistry, Western blot and image analysis were used to detect the expression of ~I-AR and Mz-AchR in myocardial cells at 7 and 14 d after microwave exposure. The results show that the expression level was higher in microwave exposure group and 0.75 g/（kg.d） ADL group than in sham operation group and significantly lower in 1.5 and 3.0 g/（kg.d） ADL groups than in microwave group. So we have a conclusion that the expression of I^z-AR and Mz-AchR is down-regulated in myocardial cells of rats exposed to microwave radiation. ADL can protect rats against microwave-induced heart tissue injury.

Expression and Biological Function of N-myc Down-regulated Gene 1 in Human Cervical Cancer

The expression of N-myc down-regulated gene 1 (NDRG1) has previously been reported to be involved in the proliferation,differentiation,invasion and metastasis of cancer cells,but its role in cervical cancer is still unclear.This study aimed to investigate the expression of NDRG1gene in human cervical cancer and its effect on aggressive tumor behaviors.The NDRG1 expression in cervical tissues and cells was detected by RT-PCR.Specific expression plasmid pEGFP-N1-NDRG1-GFP was used to enhance the expression of NDRG1 in human cervical cancer cell lines.The mRNA and protein level of NDRG1 was assessed by RT-PCR and Western blotting,respectively.Its effects on cell proliferation,migration,invasion,cell cycle and apoptosis were detected by MTT,transwell migration assay and flow cytometry (FCM),respectively.The results showed that the expression of NDRG1 in cervical cancer tissues and cells was significantly lower than in normal cervical tissues (P【0.001).After transfection with pEGFP-N1-NDRG1-GFP,the mRNA and protein expression of NDRG1 was up-regulated in Siha cells,which suppressed cell proliferation (P【0.001),induced cell cycle arrest (P【0.05),reduced invasion and migration of Siha cells (P【0.05),but caused no cell apoptosis.Moreover,vascular endothelial growth factor (VEGF),a tumor-induced angiogenesis factor,was markedly reduced and E-cadherin,a cell adhesion molecule,was increased in the cells transfected with pEGFP-N1-NDRG1-GFP.It was concluded that up-regulated NDRG1 may play a role in the suppression of malignant cell growth,invasion and metastasis of human cervical cancer.

The Effect of Lumbrokinase on P-selectin and E-selectin in Cerebral Ischemia Model of Rat

Purpose: To find the effect of lumbrokinase (LK) on P-selectin and E-selectin in ischemic rats. Methods: Male healthy Spragur-Dawley rats weighing 180-220 g (n=90) were divided into 4 groups: (1) normal control group (n=5), (2) sham-operated group (n=35), (3) ischemic group (n=35), (4) LK group (n=15). LK 10mg/kg (2000UK activity of LK) was given by intraperitoneal injection in the LK group 30 minutes before experiment. Same volume of normal saline was given in the sham-operated group and ischemic group. The ischemic model was made by modified Haruo Nagasawa's method. Immunohistochemistry was used to observe the P-selectin and E-selectin positive cells in the ischemic region. Results: P-selectin and E-selectin positive cells in ischemic regions were observed in the ischemic group, and the peak of expression was at 6 hours and 12 hours, respectively. The similar changes were not observed in normal control group. There were only a few positive cells in the sham-operated group. In LK group, the P-selectin and E-selectin positive cells were significantly less than those in the ischemic group (P<0.05 at 3 hours after the onset, P<0.01 at 6 hours and P<0.01 at 12 hours, respectively). Conclusions: LK might significantly decrease the immunoreactions of P-selectin and E-selectin in ischemic lesion.

Effects of Batroxobin on Spatial Learning and Memory Disorder of Rats with Temporal Ischemia and the Expression of HSP32 and HSP70

The effect of Batroxobin on spatial memory disorder of left temporal ischemic rats and the expression of HSP32 and HSP70 were investigated with Morri`s water maze and immunohistochemistry methods. The results showed that the mean reaction time and distance of temporal ischemic rats in searching a goal were significantly longer than those of the sham-operated rats and at the same time HSP32 and HSP70 expression of left temporal ischemic region in rats was significantly increased as compared with the sham-operated rats. However, the mean reaction time and distance of the Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of HSP32 and HSP70 immune reactive cells of Batroxobin-treated rats was also less than that of the ischemic group. In conclusion, Batroxobin can improve spatial memory disorder of temporal ischemic rats; and the down-regulation of the expression of HSP32 and HSP70 is probably related to the attenuation of ischemic injury.

Correlation of genomic and expression alterations of AS3 with esophageal squamous cell carcinoma

Androgen-induced proliferation shutoff gene AS3, also known as APRIN, is a growth inhibitory gene that is initially implicated in prostate cancer. This gene is required for androgen-dependent growth arrest and is a primary target for 1,25（OH）2D3 and androgens. Allelic loss at AS3 locus has been linked to a variety of cancers. However, the correlation of genomic and expression alterations of AS3 with esophageal squamous cell carcinoma （ESCC） is not well established. In this study, the genornic and expression alterations of AS3 in ESCC and their clinical significance are evaluated. Loss of heterozygosity （LOH） analysis using an AS3 intragenic microsatellite marker D13S171 revealed 72% allelic loss at AS3 locus in ESCC, which is significantly correlated with higher pathological grade （P=0.042）. RT-PCR examination showed that AS3 mRNA obviously decreased in 44% tumors and its down-regulation was correlated with the sex of patients （P=0.03）. Furthermore, the correlation between genornic and expression alterations of AS3 gene was analyzed in 18 ESCC specimens, which indicated that the consistency between allelic loss and decreased mRNA expression of AS3 was relatively poor. The results of this study indicate that the aberrant expression of AS3 may be involved in the tumorigenesis of esophagus and is responsible for the male predominance of ESCC.

TGF-β receptors in mouse ES-5 cells and their differentiated derivatives

By radioreceptor binding studies with iodinated TGF-β1, it has been shown that an undifferentiated ES-5 cell expresses approximately 3270 receptors with a dissociation constant Kd=130pM, but after the induction of differenti-ation by retinoic acid and dBcAMP, the receptor number of a differentiated RA-ES-5 cell was increased about 80% and the Kd was also increased to 370 pM. Furthermore,more direct evidence supporting the expression of TGF-βtype Ⅰand type Ⅱ receptors in both ES-5 and RA-ES-5 cells has come from dot blot hybridization of cellular mRNA with cDNA probes for type Ⅰ and type Ⅱ recep-tors. Meanwhile, mRNA expression level of types Ⅰ and Ⅱreceptors in RA-ES-5 cells were higher than that in ES-5 cells. Down regulation of TGF-β receptors with a signifi-cant decrease in the rate of cell proliferation in both cells, was found by employing a pretreatment with neutralizing antibody to TGF-β1. The possible role of receptors for TGF-β in cen differentiation is discussed here.

Differential Expression of miRNAs in Sorghum bicolor under Drought and Salt Stress

The regulatory mechanisms of drought and salt-associated miRNAs have not been fully understood in Sorghum bicolor. In this study, we investigated the effect of salinity stress (200 and 300 mM NaCl) and drought stress at pre- and post-flowering stages on the expression pattern of small regulatory RNAs in six Sorghum genotypes using semi-quantitative reverse transcriptase PCR (RT-qPCR). The results indicated that both drought and salt stresses altered the expression pattern of miRNAs in a dose-dependent manner. However, each miRNA responded to drought and salt stress in a different pattern among the six sorghum genotypes. miR156, miR167, miR168 and miR399 give different expressions levels compared to other studied miRNAs which may attribute to the adaption of sorghum to drought and salt stress and are good candidates for improving sorghum by transgenic technology.

Is NEDD4-1 a negative regulator of phosphatase and tensin homolog in gastric carcinogenesis?

The expression of phosphatase and tensin homolog (PTEN ), a tumor suppressor gene, is frequently downregulated in gastric carcinomas due to mutation, loss of heterozygosity, and promoter hypermethylation. However, it is unknown if additional mechanisms may account for the down-regulation of PTEN expression. While neuronal precursor cell-expressed developmentally down-regulated 4-1 (NEDD4-1) is believed to be a potential dual regulator of PTEN, there are conflicting reports regarding their interaction. To gain further insight into the role of NEDD4-1 and its association with PTEN in gastric carcinoma development, we measured the protein expression of NEDD4-1 and PTEN in gastric mucosae with various pathological lesions and found that NEDD4-1 increased from normal gastric mucosa to intestinal metaplasia and decreased from dysplasia to gastric carcinoma. These changes did not correlate with PTEN expression changes during gastric carcinogenesis. Moreover, we found similar results in protein levels in the primary tumors and adjacent non-tumorous tissues. These results differ from a previous report showing that expression of NEDD4-1 is up-regulated in gastric carcinomas, and show a more complex pattern of NEDD4-1 gene expression during gastric carcinogenesis.

A Synonymous Polymorphism of APCDD1 Affects Translation Efficacy and is Associated with Androgenic Alopecia

The APCDDI （adenomatosis polyposis coli down-regulated 1） gene is an inhibitor of the Wnt signaling pathway, and a rare mutation of this gene has been associated with hereditary hypotrichosis simplex. In this study, the authors aimed to investigate whether common APCDD1 gene polymorphisms contribute to the development of androgenic alopecia. Patients （n = 210） with androgenic alopecia and 98 controls were investigated. SNPs （Single nucleotide polymorphisms） in the coding region of the gene were sequenced. A significant difference in genotype distribution was found for the c. 1781C/T, p.L476L SNP （rs3185480） of the APCDD1 gene. This SNP is located in exon 5 and is associated with a 3.5- and a 2.8-fold increase in risk for the development of androgenic alopecia for homozygote （CI 0.933-13.125; nominal regression P = 0.063） and heterozygote （CI 1.086-7.217; nominal regression P = 0.033） carriers, respectively. These data suggest that the rs3185480 polymorphism contributes to the development of androgenic alopecia. Protein expression experiments revealed that the polymorphism is associated with reduced APCDDI protein abundance. This reduction is likely due to altered codon usage for leucine from a preferred codon （CTC） to a rare codon （CTT）, which might influence translation efficiency and, thus, APCDDI protein level.