CFTR suppresses tumor progression through miR-193b targeting urokinase plasminogen activator (uPA) in prostate cancer

Cystic fibrosis (CF) transmembrane conductance regulator (CFTR) is expressed in the epithelial cells of a wide range of organs/tissues from which most cancers are derived. Although accumulating reports have indicated the association of cancer incidence with genetic variations in CFTR gene, the exact role of CFTR in cancer development and the possible underlying mechanism have not been elucidated. Here, we report that CFTR expression is significantly decreased in both prostate cancer cell lines and human prostate cancer tissue samples. Overexpression of CFTR in prostate cancer cell lines suppresses tumor progression (cell growth, adhesion and migration), whereas knockdown of CFTR leads to enhanced malignancies both in vitro and in vivo. In addition, we demonstrate that CFTR knockdown-enhanced cell proliferation, cell invasion and migration are significantly reversed by antibodies against either urokinase plasminogen activator (uPA) or uPA receptor (uPAR), which are known to be involved in various malignant traits of cancer development. More interestingly, overexpression of CFTR suppresses uPA by upregulating the recently described tumor suppressor microRNA-193b (miR-193b), and overexpression of pre-miR-193b significantly reverses CFTR knockdown-enhanced malignant phenotype and abrogates elevated uPA activity in prostate cancer cell line. Finally, we show that CFTR gene transfer results in significant tumor repression in prostate cancer xenografts in vivo. Taken together, the present study has demonstrated a previously undefined tumor-suppressing role of CFTR and its involvement in regulation of miR-193b in prostate cancer development.

[A study on relationship between single nucleotide polymorphisms of vascular endothelial growth factor gene and susceptibility to systemic lupus erythematosus in China north Han population]

AIM

To investigate relationship between single nucleotide polymorphism(SNP) of VEGF gene and susceptibility to systemic lupus erythematosus(SLE) in China north population.

METHODS

Six VEGF SNPs (rs2010963, rs3024994, rs3025000, rs3025010, rs3025035 and rs833070) of forty-four patients with SLE and one hundred healthy controls were examined by Sequenom chip-based MALDI-TOF mass spectomery platform. Different genotypes were analyzed statistically by SPSS 11.5.

RESULTS

There was no significant difference between SLE patients and controls in frequency of rs2010963, rs3024994, rs3025000, rs3025010, rs3025035 genotype and allele (P>0.05). The frequency of rs833070 A allele was significantly higher in SLE than that in controls. (31.2% vs 20%, x(2);=4.547, P=0.033, OR=1.818 , 95% CI 1.045-3.162). In the patient with SLE, rs833070 G decreased the susceptibility of arthritis(56% vs 80.4%, x(2);=5.613, P=0.018, OR=0.336, 95% CI 0.134-0.843), while the genotype of rs833070 GG significantly decreased the susceptibility to arthritis(GGvsAG+AA: 28% vs 65.2%, x(2);=6.684, P=0.010, OR=0.207, 95% CI 0.061-0.705).

CONCLUSION

VEGF rs833070 A may represent an inreased susceptibility to SLE in China north Han population. VEGF rs833070 G and rs833070 GG may play protective roles in the case of lupus arthritis.

Assessment of soil contamination with Cd, Pb and Zn and source identification in the area around the Huludao Zinc Plant

The distribution characteristics of heavy metals (cadmium (Cd), lead (Pb) and zinc (Zn)) in the natural soil profiles around the Huludao Zinc Plant (HZP), an old industrial base in Northeast China, were analyzed. The pollutant source was identified using (210)Pb isotope technique to evaluate the geochemical characteristics of Pb and the historical production records of HZP. The results indicated: dust precipitation from HZP was the primary source of the pollutants. The average deposition rates of Cd, Pb and Zn were 0.33, 1.75, and 30.97 g/m(2)year, respectively at 1 km away after HZP, and 0.0048, 0.035, and 0.20 g/m(2) year, respectively at 10 km away after HZP. There is a risk of secondary pollution to the environment as well as the food chain in seriously polluted areas used for cultivation.

[Relationship between the level of MCP-1 expression in sera of RA patients and ILD]

AIM

To investigate the function and clinical significance of monocyte chemoattractant protein-1 MCP-1 in the pathogenesis of rheumatoid arthritis(RA)and the relation ship between the expression of MCP-1 in serum and interstitial lung disease (ILD) secondary from RA.

METHODS

60 patients with RA were divided into two groups: 30 cases with simple RA group and 30 cases with ILD secondary from RA (RA+ILD group). The control group incuided 20 healthy cases. Enzyme linked immunosorbent assay (ELISA ) was used to determine the serum expression of MCP-1 in patients healthy controls. The differences of MCP-1 level and other laboratory indexes (IgG, IgA, IgM, alpha2-G, gamma-G, RF, ESR, CRP, and the number of arthrocele) in different groups were compared with software spss13.0.

RESULTS

The expression of MCP-1 in simple RA patients was significantly higher than that in the control group (P>0.05) and significantly lower than that in the RA+ILD group (P>0.01). The level of MCP-1 in serum of RA patieuts was positively correlated with IgG, IgM, and gamma-G.

CONCLUSION

MCP-1 plays an important role in the pathogenesis of RA and may contribute to the promotion of lung fibrosis in ILD secondary from RA.

CCR3, CCR2A and macrophage inflammatory protein (MIP)-1a, monocyte chemotactic protein-1 (MCP-1) in the mouse hippocampus during and after pilocarpine-induced status epilepticus (PISE)

AIMS

To investigate protein and gene expressions of chemokine subtypes CCR3, CCR2A and their respective ligands macrophage inflammatory protein 1-alpha (MIP-1alpha), monocyte chemotactic protein-1 (MCP-1) in the normal mouse central nervous system (CNS) and in the hippocampus at different time points during and after pilocarpine-induced status epilepticus (PISE).

METHODS

CCR3 and MIP-1alpha protein expressions were mapped in the mouse CNS. The protein and gene expressions of CCR3 and CCR2A and their respective ligands MIP-1alpha, MCP-1 in the hippocampus were studies by immunocytochemical and quantitative real-time RT-PCR during and after PISE.

RESULTS

CCR3 and MIP-1alpha gene expression and immunopositive neurones were broadly distributed in the CNS. CCR3 and CCA2A gene and their protein expression were downregulated in the hippocampus at 1 h during PISE. The protein expression of MIP-1alpha, MCP-1 decreased but gene expression increased at 2 h during PISE. In the hilus of the dentate gyrus, significant reduction of the numbers of CCR3, CCR2A, MCP-1 immunopositive neurones occurred from 1 h during to 2 months after PISE, but the number of MIP-1alpha neurones reduced from 2 h during to 2 months after PISE. Induced expression of CCR3 at 1 week, CCR2A, MCP-1 or MIP-1alpha at 1 week and 2 months after PISE was found in reactive astrocytes. MCP-1 was also demonstrated in the blood vessels of the hippocampus at 2 months after PISE.

CONCLUSIONS

CCR3 and MIP-1alpha may play important functional roles in the mouse brain. The downregulation of CCR3, CCR2A, MIP-1alpha and MCP-1 in the hippocampal neurones at the acute stage during and after PISE may weaken the neuroprotective mechanisms. However, induced expression of MCP-1 in hippocampal blood vessel may be related to changes in permeability of the blood-brain barrier during epileptogenesis.

[Sustainable electricity generation in microbial fuel cells using Fe(III)-EDTA as cathodic electron shuttle]

The rate of oxygen reduction reaction (ORR) at the cathode is a major factor affecting the performance of the microbial fuel cells (MFC). Results showed that when using Fe(III)-EDTA solution as catholyte, the ORR rate was significantly increased and the internal resistance was reduced, consequently leading to an increase in power output. With a concentration of Fe(III )-EDTA at 20.0 mmol/L in the catholyte, the MFC produced the voltage and power density at approximate 200.1 mV and 16.0 mW/m2, respectively, which was increased by 73.2% and 70.1% contrary to the MFC without the presence of Fe(III)-EDTA. The further experiment suggested that Fe(III)-EDTA functioned as electron shuttle to accelerate electron transfer. Fe(III)-EDTA received electron and got reduced to Fe(III)-EDTA, which further provided electrons to oxygen and got reoxidized at the same time. Therefore Fe(III)-EDTA can act as recyclable electron shuttles between cathode electrode and oxygen. The optimum condition in the case of using Fe(III)-EDTA as cathode electron shuttles was tested to be Fe(III)-EDTA concentration at 20.0 mmol/L and pH at 5.0, which allowed MFC produced the maximum power density of 100.9 mW/m2.

[Mechanisms of bioelectricity generation in Enterobacter aerogenes-based microbial fuel cells]

Microbial fuel cells (MFCs) using hydrogen-producing bacteria (HPB) could utilize a large number of substrates to generate power. However, the coulombic efficiency is limited by the fact that only suspended cells are used as biocatalyst in anodic medium. MFCs using Fe (III)-reducing bacteria have high energy recovery efficiency, but can only utilize some simple organic matters. In this study, Enterobacter aerogenes XM02, a hydrogen-producing strain with Fe(III)-reducing activity, was selected as biocatalyst for MFCs, which could produce electricity by digesting lots of carbohydrates even starch. Graphite felt, a material with high specific surface area and hydrogen catalysis, instead of carbon paper supported platinum, was used as anode material. The coulombic efficiency had been substantially improved from 1.68% to 42.49%, higher than other HPB-based MFCs previously reported. The SEM image proved the ability of XM02 strain to colonize on the anode surface. Power generation of MFCs could restore quickly when anodic medium was completely replaced with non-growth medium containing glucose. This suggested that the attached cells contributed to electricity production because planktonic cells had been removed during the medium replacement. This study proposed the mechanism of power generated from in situ oxidation of hydrogen produced by the XM02 strain biofilm.

[Electricity generation from corn steepwater using microbial fuel cell technology]

Corn steepwater containing 49,732.2 mg/L of chemical oxygen demand (COD) was used as fuel for a membrane electrode assembly microbial fuel cell (MEA-MFC), which could generate electricity and treat the wastewater at the same time. During a batch experiment of 94 days with a fixed 1,000 Omega external resistance, the maximum voltage output of 525.0 mV and power density of 169.6 mW/m2 were obtained after 17 days, corresponding to the current density, internal resistance and open voltage of 440.2 mA/m2, 350 Omega and 619.5 mV, respectively. However, data showed that the coulombic efficiency was only 1.6%, suggesting very limited COD was utilized for electricity generation. At the conclusion of the test, the removals of COD and ammonia-nitrogen were achieved 51.6% and 25.8%, respectively. This study demonstrates that corn steepwater can be used for power generation in MFC with simultaneous accomplishments of wastewater treatment, providing a novel approach for the safe disposal and recycle of corn steepwater.

Preclinical pharmacokinetics and tissue distribution of a natural cardioprotective agent astragaloside IV in rats and dogs

Astragaloside IV, a natural product purified from the Chinese medical herb Astragalus membranaceus (Fisch) Bge, is now being developed as a cardioprotective agent for treating cardiovascular diseases. The purpose of the present study was to examine in vivo pharmacokinetics and tissue distribution in both rats and dogs by using an established high-performance liquid chromatography (HPLC) coupled with tandem mass spectrometry quantitative detection method. Astragaloside IV showed moderate to fast elimination; the elimination half-life of astragaloside IV was 98.1, 67.2 and 71.8 min in male rats, and 34.0, 66.9 and 131.6 min in female rats at doses of 0.75, 1.5 and 3.0 mg/kg, respectively. There was no significant difference in systemic clearance at three dose levels, suggesting that astragaloside IV may have linear pharmacokinetic characteristics in rats within the dose ranges tested. The highest concentration of astragaloside IV was detected in the lung and liver. However, limited distribution to the brain, indicates that astragaloside IV may have difficulty penetrating the blood brain barrier. In addition, only about 50% of the parent astragaloside IV was recovered in both urine and feces. These results indicate that there was about 83% astragaloside IV binding to plasma protein and that the binding to the plasma is linear at the concentration range of 250-1000 ng/ml. As in rats, astragaloside IV may have linear pharmacokinetic characteristics in dogs within the dose ranges tested. Astragaloside IV was slowly cleared via hepatic clearance with a systemic clearance (CL) of about 0.004 l/kg/min. Based on the favorable pharmacokinetic properties in both rats and dogs, astragaloside IV warrants further investigation for the prevention of cardiovascular diseases.

[Molecular cloning of full-long cDNA sequences encoding hairless gene in the Kunming mouse]

The mouse hairless gene is a crucial nuclear receptor gene associated with the structure of hair and skin. It encodes a putative zinc finger transcription factor, and is a transcriptional corepressor for thyroid hormone receptors. Hairless gene plays a critical role in maintaining the delicate balance between cell proliferation, differentiation, and apoptosis in the hair follicle as well as in the interfollicular epidermis, and is concerned with the control of hair growth cycling. This study was designed to clone and analyze the cDNA encoding Hr from Kunming mouse. The RT-PCR method was developed to clone the Hr cDNA. A full-length cDNA and CDS sequences of Kunming mouse were 4104bp and 3546bp, respectively, which has been accepted by GenBank (Accession Number: AY547391). Accession number of protein encoded by AY547391 sequence in GenBank is AAT45233 , composed of 1181 amino acid residues. The Hr cDNA of Kunming mouse was cloned and sequenced for the first time. The identities of CDS of Hr gene were 99.9%, 94.4%, 83.1%, 78.1%, 81.9% and 82.1% by homologous comparison among Kunming mouse and other six species, and that were 99.9%, 92.2%, 81.7%, 70.8%, 79.9% and 80.1% respectively in amino acid sequences. The results suggested a high degree of conservation and thus functional significance of the Hr gene among different mammalian taxons. The results derived from information searching by Blast program revealed that there were 4 SNP sites and one deletion mutation in the sequences of hairless gene mRNAs between Kunming mice and that collected in GenBank. Three SNP sites did not alter the related amino acids encoded. Two SNP proved to be polymorphism mutant sites with amino acids changes. The results provided new data for SNPs in Hr gene.

A Novel Nonsense Mutation and Polymorphisms in the Mouse Hairless Gene

A novel autosomal recessive mutation arose spontaneously in a breeding colony of Chinese Kunming mice. The characteristics of these mutant mice include progressive irreversible hair loss soon after birth, rhinocerotic appearance, and shorter life span. Histological evaluation of skin revealed the homogeneous enlargement of utriculi, and the formation of several rows of large cysts. Sequencing the complete cDNA of the hairless gene identified two polymorphisms and a homozygous transition for a G-->A at nucleotide position 3110 (exon 12) leading to the substitution of tryptophan by a nonsense codon, designated W911X. This allele was named rhinocerotic and short-lived, with the symbol hr(rhsl). Addition of hairless gene mutation into the expanding hairless mutation database allows further development of genotype/phenotype correlations towards understanding inherited atrichia.

[Establishment of segregating inbred strain of Yuyi hairless mice and its monitoring of genetic characteristics]

Using brother-sister inbreeding with forced heterozygosity to breed a new segregating inbred strain which carry mutant hairless gene. Then, genetic monitoring was conducted by the skin grafting test, coat color test and biochemical marker analysis, and its basic biological characteristics were studied with corresponding methods. The Results are that the Yuyi Hairless Mice (YYHL) with unique biological characteristics have been bred successfully and have progressed to 30th generation since 1991. Thirteen biochemical markers loci on nine chromosomes coding biochemical markers measured with electrophoresis were all homogenous. The skin grafting test showed that no dropping graft was found during 100 days after transplanting, implying the YYHL was of isohistogeneicity. Analysis of coat color genes indicated that the hair color of first generation hybrid crossed between YYHL and DBA/2 was all agouti suggesting that the coat color genes of the YYHL were homogenous. The gene type is AABBccDD. All these showed that the YYHL have been an inbred strain reaching the international standards.

New drugs derived from medicinal plants

In China, increasing emphasis has been laid in recent years on research on natural products. About 140 new drugs have been developed from Chinese medicinal plants. For example, anisodamine possesses good effects in the treatment of septic shock and morphine addiction; 3-n-butylphthalide isolated from seeds of celery was shown to be a new cerebral anti-ischemic agent; indirubin was identified as an anti-leukemic drug with no inhibition of bone marrow; huperzine is a potent and reversible inhibitor of acetylcholinesterase (AChE) and its selective action is superior to that of donepezil; clausenamide was shown to be a potassium channel blocker, its nootropic effect was 50-100 times more potent than that of piracetam; bicyclol was synthesized from schizandrin C isolated from Fructus schizandrae. It has remarkable hepatoprotective and certain anti-hepatitis virus actions; salvianolic acid B is a very strong antioxidant agent with potential anti-dementia effects; yingzhaosu A and artemisinin are anti-malaria drugs containing a peroxide ring which is very rarely seen in natural substances.

NO mediates ginsenoside Rg1-induced long-term potentiation in anesthetized rats

AIM

To investigate the effect of ginsenoside Rg1 on synaptic transmission in anesthetized rats and the effect of NOS inhibitor, 7-nitroindazole (7-NI), on long-term potentiation (LTP) induced by Rg1.

METHODS

Extracellular recording technique was used to record the population spike (PS) in the dentate gyrus (DG) of anesthetized rats. Drug or vehicle injections were delivered via a cannula in the lateral cerebral ventricle.

RESULTS

Rg1 (10 and 100 nmol/L) enhanced the basic synaptic transmission and the magnitude of LTP induced by high frequency stimulation (HFS). Selective nNOS inhibitor 7-NI (5 nmol) icv could inhibit the induction of perforant path-dentate gyrus LTP elicited by Rg1 (P<0.05), and L-arginine 250 g/L ip prevented the action of 7-nitroindazole (P<0.05).

CONCLUSION

Rg1-accelerated synaptic transmission and nitric oxide produced by nNOS played a role in the induction of PP-DG LTP in anesthetized rats.