Regulation of non-AU-rich element containing c-fms proto-oncogene expression by HuR in breast cancer

The role of RNA-binding proteins in cancer biology is recognized increasingly. The nucleocytoplasmic shuttling and AU-rich RNA-binding protein HuR stabilizes several cancer-related target mRNAs. The proto-oncogene c-fms, whose 3'untranslated region (3'UTR) is not AU-rich, is associated with poor prognosis in breast cancer. Using a large breast-cancer tissue array (N=670), we found nuclear HuR expression to be associated with nodal metastasis and independently with poor survival (P=0.03, RR 1.45), as well as to be co-expressed with c-fms in the breast tumors (P=0.0007). We described c-fms mRNA as a direct target of HuR in vivo, and that HuR bound specifically to a 69-nt region containing 'CUU' motifs in 3'UTR c-fms RNA. Overexpressing or silencing HuR significantly up- or down-regulated c-fms RNA expression, respectively. We also found that known glucocorticoid stimulation of c-fms RNA and protein is largely dependent on the presence of HuR. HuR, by binding to the 69-nt wild type, but not mutant, c-fms sequence can regulate reporter gene expression post-transcriptionally. We are the first to describe that HuR can regulate gene expression by binding non-AU-rich sequences in 3'UTR c-fms RNA. Collectively, our findings suggest that HuR plays a supportive role for c-fms in breast cancer progression by binding a 69-nt element in its 3'UTR, thus regulating its expression.

Niche-specificity and the variable fraction of the Pectobacterium pan-genome

We compare genome sequences of three closely related soft-rot pathogens that vary in host range and geographical distribution to identify genetic differences that could account for lifestyle differences. The isolates compared, Pectobacterium atrosepticum SCRI1043, P. carotovorum WPP14, and P. brasiliensis 1692, represent diverse lineages of the genus. P. carotovorum and P. brasiliensis genome contigs, generated by 454 pyrosequencing ordered by reference to the previously published complete circular chromosome of P. atrosepticum genome and each other, account for 96% of the predicted genome size. Orthologous proteins encoded by P. carotovorum and P. brasiliensis are approximately 95% identical to each other and 92% identical to P. atrosepticum. Multiple alignment using Mauve identified a core genome of 3.9 Mb conserved among these Pectobacterium spp. Each core genome is interrupted at many points by species-specific insertions or deletions (indels) that account for approximately 0.9 to 1.1 Mb. We demonstrate that the presence of a hrpK-like type III secretion system-dependent effector protein in P. carotovorum and P. brasiliensis and its absence from P. atrosepticum is insufficient to explain variability in their response to infection in a plant. Additional genes that vary among these species include those encoding peptide toxin production, enzyme production, secretion proteins, and antibiotic production, as well as differences in more general aspects of gene regulation and metabolism that may be relevant to pathogenicity.

Theoretical and experimental study on PMD-supported transmission using polarization diversity in coherent optical OFDM systems

In this paper, we conduct theoretical and experimental study on the PMD-supported transmission with coherent optical orthogonal frequency-division multiplexing (CO-OFDM). We first present the model for the optical fiber communication channel in the presence of the polarization effects. It shows that the optical fiber channel model can be treated as a special kind of multiple-input multiple-output (MIMO) model, namely, a two-input two-output (TITO) model which is intrinsically represented by a two-element Jones vector familiar to the optical communications community. The detailed discussions on various coherent optical MIMO-OFDM (CO-MIMO-OFDM) models are presented. Furthermore, we show the first experiment of polarization-diversity detection in CO-OFDM systems. In particular, a CO-OFDM signal at 10.7 Gb/s is successfully recovered after 900 ps differential-group-delay (DGD) and 1000-km transmission through SSMF fiber without optical dispersion compensation. The transmission experiment with higher-order PMD further confirms the immunity of the CO-OFDM signal to PMD in the transmission fiber. The nonlinearity performance of PMD-supported transmission is also reported. For the first time, nonlinear phase noise mitigation based on receiver digital signal processing is experimentally demonstrated for CO-OFDM transmission.

Strain distributions in nano-onions with uniform and non-uniform compositions

Nano-onions are ellipsoidal or spherical particles consisting of a core surrounded by concentric shells of nanometre size. Nano-onions produced by self-assembly and colloidal techniques have different structures and compositions, and thus differ in the state of strains. The mismatch of the thermal expansion coefficients and lattice constants between neighbouring shells induces stress/strain fields in the core and shells, which in turn affect their physical/mechanical properties and/or the properties of the composites containing them. In this paper, the strains in embedded and free-standing nano-onions with uniform and non-uniform compositions are studied in detail. It is found that the strains in the nano-onions can be modified by adjusting their compositions and structures. The results are useful for the band structure engineering of semiconductor nano-onions.

Combining Steinernema carpocapsae and Bacillus thuringienis strains for control of diamondback moth (Plutella xylostella)

The diamondback moth (DBM), Plutella xylostella, is a major pest of crucifers and has developed resistance against all chemical insecticides, even against the biological insecticide Bacillus thuringiensis (Bt). Entomopathogenic nematodes (EPN) as novel biological insecticide were successfully used against DBM. We investigated the potential of Bt to enhance the virulence of EPN and the possibility to reduce the application density by exploiting synergistic effects. The interaction between different combinations of Bt and EPN were tested against early 3rd instar P. xylostella on 2 cm2 cabbage leaf discs. All of the combinations had additive effects. Synergistic results were exceptional. The result indicate that a joint application of Bt and EPN is not recommended. But alternating applications are a measure to manage resistance development against Bt.

Immunoscreening of Schistosoma japonicum egg cDNA library

AIM

To screen and identify genes encoding vaccine candidates and molecules with diagnostic potential from S. japonicum (S. j) egg cDNA library.

METHODS

S. j egg cDNA library was screened by sera from SEA-immunized rabbits. Positive clones were identified after three rounds of screening and were excised automatically in vivo with helper phage. Products of PCR were used to detect insert sizes by agarose gel electrophoresis. DNA samples were obtained by purification using mini-prep kit. Automatic sequencing was carried out and the sequence data were analysed using GCG software.

RESULTS

Twelve clones were identified as positive and the inserts were around 1.2 kb in size. Compared with DNA sequences in GenBank, eight clones were homologous to a 70 kDa S. j heatshock protein(S. j HsP70). C18 exhibited 97.8% homology with S. j23. C22 and C23 shared 82.4% and 89.5% homology with S. j calreticulin, respectively. C12 was homologous to S. mansoni(S. m.) immunophilin.

CONCLUSION

This paper first reported the results of immunoscreening S. j egg cDNA library by anti-SEA sera. Twelve positive clones were found to be related to protective immunity and/or immunodiagnosis of schistosomiasis.

[Cross-protection against Schistosoma japonicum infection in mice immunized with Trichinella spiralis muscle larva antigen]

AIM

To explore the cross-protection against S. japonicum cercaria challenge in mice immunized with T. spiralis larva antigen.

METHODS

Groups of BALB/c mice were immunized with 4 preparations of T. spiralis larva antigen, respectively. Vaccinated mice were then challenged with 30 and 100 S. japonicum cercariae, respectively. Forty-five days later, all mice were sacrificed and examined for adult worm burden, liver and stool egg count.

RESULTS

All groups of mice immunized with 4 preparations of T. spiralis larvae antigen without adjuvant showed significant protection against S. japonicum. Among these antigen preparations, the soluble antigen (TsLSA) presented highest protection with reductions in worm burden and liver and stool egg counts of 21.3%, 48.0% and 58.5%, respectively. When mice were immunized with TsLSA plus Freunds complete adjuvant (FCA) or with double-dose of the antigen, the worm reduction rate was increased to 29.3% and 39.6%, respectively.

CONCLUSION

Different preparations of T. spiralis muscle larva antigen could induce protection against S. japonicum in mice.

[Evaluation of therapeutic efficacy by detection of specific IgG and IgG4 against KLH in schistosomiasis japonica]

The specific IgG and IgG4 antibodies in the sera of patients with Schistosoma japonicum were determined by KLH-ELISA and SEA-ELISA. The results showed that KLH-ELISA was as sensitive and specific as SEA-ELISA. The negative conversion rates of IgG and IgG4 12 months after treatment detected by KLH-ELISA were significantly higher than those by SEA-ELISA. The negative conversion rate of IgG was 92.9%, and that of IgG4 was 97.6% 24 months after treatment. Therefore, it is regarded that detecting specific IgG and IgG4 by KLH has high value in both diagnosing schistosomiasis japonica and assessing its therapeutic efficacy. Particularly the specific IgG4 may be a short-duration antibody which can indicate successful chemotherapy of patients with chronic Schistosoma japonicum infection.

[Schistosoma japonicum: protective immunity induced in mice immunized with SjGST-Sj32]

Schistosoma japonicum glutathione-s-transferase (SjGST), Schistosoma japonicum 32,000 protein (Sj32) and SjGST - Sj32 were expressed and purified to study on protective immunity against Schistosoma japonicum. The result showed that compared with the adjuvant control group, the worm burden was decreased significantly in mice immunized with recombinant SjGST - Sj32, Sj32 and Sj32 + SjGST (P < 0.05). At the same time, the liver egg per gram(EPG) was decreased in mice immunized with SjGST - Sj32, Sj32, Sj32 + SjGST and SjGST. It is concluded that Sj32 significantly induces both protective immunity and anti-fecundity immunity, but SjGST only has an anti-fecundity effect.

The receptor docking segment and S-adenosyl-L-homocysteine bind independently to the methyltransferase of bacterial chemotaxis

To mediate adaptation to stimuli, the methyltransferase (CheR) catalyzes methyl group transfer from S-adenosyl-L-methionine (SAM) to glutamyl residues in the transmembrane receptors of the bacterial chemosensory signaling pathway. The interaction between receptors and CheR occurs at two sites: a methylation site-active site interaction, and a 'docking' site interaction that is separated both from the methylation sites and the CheR active site. It is not certain if the docking site interaction functions merely to localize the transferase in close proximity to the methylation sites, or if it also increases CheR catalytic activity. Isothermal titration calorimetry experiments are conducted to test for allosteric interactions between the docking and active sites on CheR, which are expected to be present if docking activates CheR. The binding parameters (DeltaG, DeltaH, DeltaS) of a substrate analog of SAM, S-adenosyl-L-homocysteine (SAH), are measured both in the absence and presence of saturating concentrations of a pentapeptide (NWETF) that defines the docking receptor docking segment. SAH binding is unaffected by the presence of saturating NWETF, providing evidence that an allosteric activation of CheR does not take place upon docking, and thus supports the idea that the CheR-NWETF interaction merely functions to localize CheR near the sites of methylation.

Simulation of Sand Production in Unconsolidated Heavy Oil Reservoirs

Abstract

Previous research on sand production prediction focused on when sand will be produced during depletion based on some mechanics analyses, but the amount of sand production was ignored. Recently, more and more researchers are focussing on the simulation of heavy oil sand production processes. For an unconsolidated heavy oil reservoir which employs sand production to enhance production, the amount of sand production is of great importance, because too much sand production may cause near wellbore instability, while too little sand production may not maximize well productivity. In view of this, based on both fluid flow modelling and reservoir mechanics concepts, a coupled heavy oil/sand particulate flow/reservoir elasto-plastic deformation model is used to simulate sand production, oil production, and reservoir deformation. With this model, we can determine an optimum flow rate which will not cause near wellbore instability while maximizing well productivity.

Introduction

Heavy oil sand production as an important production enhancement measure has been used in the primary development of heavy oil reservoirs in Canada for a long time.

The production of sand may lead to the change of formation flow-related parameters such as permeability, porosity and mechanical parameters such as cohesion, and it also causes near wellbore stress redistribution. Thus, sand production is a very complicated process involving both fluid flow and geomechanical problems. In order to simulate the effect of sand production and productivity enhancement, simulation of the physical process needs to be done. Because of the long history of cold production, the simulation of cold production is becoming mature and a lot of excellent work has been done by experts in Canada and elsewhere around the world(1–5).

Wang(1) developed a model to predict sand production in a heavy oil reservoir in Frog Lake at Lloydminster, Canada. It is believed that reservoir depletion induces stress concentrations around the wellbore, and large drawdown causes a foamy oil zone, in which large drawdown and seepage forces are created which causes sand production. A fully coupled geomechanical, foamy oil flow model was developed. Sand production is assumed to start when the effective radial stress is equal to the tensile strength. Later Wang(2) developed a coupled reservoir-geomechanical model to simulate the enhanced production phenomena in both heavy oil reservoirs (Northwestern Canada) and conventional oil reservoirs (North Sea). It is believed that the production enhancement is contributed:by the reservoir porosity and permeability improvement after a large amount of sand is produced, andby the higher mobility of the fluid due to the movement of the sand particles. Once the reservoir formation yields plastically, loose sand particles can be generated.

Sand production has been postulated as a critical condition when the effective radial stress reaches the tensile strength or when the plastic strain reaches the critical plastic strain. Recently, Papamichos et al.(3) and Stavropoulou et al.(4) also provided their model to simulate sand production. Later Papamichos et al.(5) applied successfully this model to interpret sand production from a North Sea reservoir.

Recombinant paramyosin (rec-Sj-97) tested for immunogenicity and vaccine efficacy against Schistosoma japonicum in mice and water buffaloes

A primary vaccine candidate antigen against schistosomiasis is paramyosin (pmy), a myofibrillar protein found exclusively in invertebrates. Here we report the results of vaccine trials against the Asian schistosome undertaken on inbred and outbred mice and water buffaloes using a bacterially expressed and purified form of Schistosoma japonicum pmy (rec-Sj-97). Vaccination of the mice resulted in high levels of specific anti-pmy IgG antibodies when compared with adjuvant controls and significant reduction in worm burdens and in liver eggs. Furthermore, a significant reduction in liver eggs was recorded in two of the three water buffalo vaccine trials undertaken and, in all three trials, high levels of specific anti-pmy IgG antibodies were generated. There was no evidence of any toxic effects and the vaccine preparations and Quil A adjuvant were clearly well tolerated. The development of a vaccine intended for livestock animals such as bovines would be beneficial in two ways; directly by blocking transmission of schistosomiasis to humans and economically by contributing to healthier livestock. We are encouraged by the consistent efficacy in the mouse and the buffalo vaccine trials that resulted in a significant decrease in liver eggs. Indeed, predictions from mathematical models indicate that an egg reduction effect of 42-45% in buffaloes would be sufficient when combined with human treatment to control schistosomiasis japonica in the marshes and lakes along the middle and upper reaches of the Yangtze River, the most highly endemic areas for the disease in China.

Quantitation of telomerase components and hTERT mRNA splicing patterns in immortal human cells

Telomerase is a reverse transcriptase that adds telomeric repeats to chromosomal ends. In most normal human somatic cells, telomerase is repressed and telomeres progressively shorten, leading to limited proliferative life-span. Telomerase reactivation is associated with cellular immortalization and is a frequent event during tumorigenesis. The telomerase ribonucleoprotein complex consists of two essential components, a catalytic protein subunit [human telomerase reverse transcriptase (hTERT)] and a template RNA (hTR). hTR is constitutively expressed, while hTERT is almost universally absent in telomerase-negative cells. Although repression of telomerase is transcriptional in telomerase-negative cells, post-transcriptional and assembly processes are likely to play important roles in regulating telomerase activity in those that are telomerase-positive. The telomerase transcript can also be alternatively spliced into a variety of non-functional forms. To establish the quantitative relationships between telomerase activity and its various components, we determined the numbers of molecules of hTR and hTERT mRNA, and the levels of alternatively spliced hTERT mRNA variants in normal, in vitro immortalized and cancer cell lines. We report here that there is surprisingly little variation in the proportion of alternatively spliced forms of hTERT in different cell lines. The only variation observed occurred when a change in splicing to non-functional forms appeared in response to conditions that repress telomerase activity in IDH4 cells. We also found that most telomerase-positive cell lines only contain a few molecules of potentially functional hTERT mRNA, and there is a correlation between telomerase activity and the levels of both hTR and hTERT +alpha+beta mRNA.

Hydrogen exchange reveals a stable and expandable core within the aspartate receptor cytoplasmic domain

Intensive study of bacterial chemoreceptors has not yet revealed how receptor methylation and ligand binding alter the interactions between the receptor cytoplasmic domain and the CheA kinase to control kinase activity. Both monomeric and dimeric forms of an Asp receptor cytoplasmic fragment have been shown to be highly dynamic, with a small core of slowly exchanging amide hydrogens (Seeley, S. K., Weis, R. M., and Thompson, L. K. (1996) Biochemistry 35, 5199-5206). Hydrogen exchange studies of the wild-type cytoplasmic fragment and an S461L mutant thought to mimic the kinase-inactivating state are used to investigate the relationship between the stable core and dimer dissociation. Our results establish that (i) decreasing pH stabilizes the dimeric state, (ii) the stable core is present also in the transition state for dissociation, and (iii) this core is expanded significantly by small changes in electrostatic and hydrophobic interactions. These kinase-inactivating changes stabilize both the monomeric and the dimeric states of the protein, which has interesting implications for the mechanism of kinase activation. We conclude that the cytoplasmic domain is a flexible region poised for stabilization by small changes in electrostatic and hydrophobic interactions such as those caused by methylation of glutamate residues and by ligand-induced conformational changes during signaling.

cDNA cloning and promoter analysis of rat caspase-9

Caspase-9 is the apex caspase of the mitochondrial pathway of apoptosis, which plays a critical role in apoptotic initiation and progression. However, gene regulation of caspase-9 is largely unknown. This is in part due to the lack of information on the gene promoter. Here we have cloned the full-length cDNA of rat caspase-9 and have isolated promoter regions of this gene. The rat caspase-9 cDNA of 2058 bp predicts a protein of 454 amino acids, which contains a caspase-recruitment domain ('CARD') at the N-terminus and enzymic domains at the C-terminus. The enzyme's active site, with a characteristic motif of QACGG, was also identified. Overall, rat and human caspase-9 have 71% identity. With the cDNA sequence, we subsequently isolated the proximal 5'-flanking regions of rat caspase-9 by the procedure of genomic walking. The 2270 bp genomic segment is 'TATA-less', but contains several GC boxes. Elements binding known transcription factors such as Sp-1, Pit-1, CCAAT-enhancer-binding protein (C/EBP), glucocorticoid receptor and hypoxia-inducible factor 1 (HIF-1) were also identified. When cloned into reporter gene vectors, the genomic segment showed significant promoter activity, indicating that the 5'-flanking regions isolated by genomic walking contain the gene promoter of rat caspase-9. Of significance is that the cloned promoter segments were activated by severe hypoxia, conditions inducing caspase-9 transcription. Thus, the genomic sequences reported here contain not only the basal promoter of rat caspase-9 but also regulatory elements responsive to pathophysiological stimuli including hypoxia.

[Clinical significance of the expression of lung resistance protein in non-small cell lung carcinomas]

OBJECTIVE

To investigate the expression of the lung resistance-related protein (LRP) in non-small cell lung carcinomas (NSCLC) and evaluate its clinical significance.

METHODS

Using immunohistochemistry, LRP was examined in 69 NSCLC specimens obtained by either transbronchial biopsy via fibrobronchoscopy or transcutaneous needle biopsy or surgical resection. Of the 69 patients from whom tumor specimens were obtained, 52 were male and 17 were female.

RESULTS

LRP expression was detected in 39/69 (57%) tumor specimens. There was no correlation between LRP expression and NSCLC histological classification (P > 0.05). No significant differences were found in gender and among age groups. The positive rates of LRP were 67% (18/27), 55% (17/31), 52% (23/44), 64% (16/25), 83% (5/6), 57% (36/63) and 50% (3/6) in adenocarcinoma, squamous, staging T1-2, T3-4, N3, M0 and M1 respectively. It was shown that LRP expression was not associated with primary tumor size and metastasis status (N,M). NSCLC patients with positive LRP expression responded more poorly to chemotherapy than those with negative LRP expression (P < 0.05).

CONCLUSIONS

The frequencies of multidrug resistance caused by LRP are similar between adenocarcinoma and squamous. Expression of LRP is related to multidrug resistance of NSCLC, which in turn related to the efficacy and prognosis of chemotherapy. The examination of LRP expression may be valuable for choice of chemotherapy regimen.

Anterior approach to the second thoracic vertebral body for surgical treatment (vertebrectomy, bone grafting, and titanium alloy plate fixation)

The surgical approach to the second thoracic vertebral body is difficult from the anterior side. A 38-year-old woman suffering from plasmacytoma in the second thoracic vertebra showed paraplegia for 2 weeks prior to surgery. X-ray, computed tomography (CT), and magnetic resonance imaging (MRI) examinations indicated breakdown of the second thoracic vertebral body and arch, associated with spinal cord compression. A 99mTc bone scintigram showed accumulation only in the second thoracic vertebra. After one course of chemotherapy with cyclophosphamide and prednisone (CP protocol), surgery was carried out. The incision was made on the right side of the anterior of the neck, from the middle half of the sternocleidomastoideus along the anterior edge to the jugular notch of the sternum. After cutting the platysma, severing the sternohyoideus, splitting the sternothyroid muscle, and forming a compartment between the esophagus and vagina carotica, we extended the incision to the sternum. Without wedging the sternum, we separated tissue from the posterior of the sternum to the second and third thoracic vertebrae, excised the second thoracic vertebra to expose the hard spinal meninges, and removed the tumor in the vertebral canal to release the compression on the spinal cord. An autogeneous bone graft, taken from the right ilium (1.5 x 1.5 x 3 cm in size), was implanted between the first and third thoracic vertebrae, and a spinal titanium alloy plate was used to increase fixation between the first and third thoracic vertebrae from the front. During the surgery, 800 ml of blood was transfused. On the fifth postsurgical day, the patient could walk normally with a neck collar, and the paraplegia was completely alleviated, with no complications.

[Three dimensional quantitative structure-activity relationship of farnesyl protein transferase inhibitors]

AIM

To build a three dimensional structure model that correlates the biological activities and the structures of a series of farnesyl protein transferase (FPT) inhibitors exemplified by the compound of 2, 3,4,5-tetrahydro-1-(1H-imidazol-4-ylmethyl)-4-(2-biphenylylcarbonyl)-1H-1, 4-benzodiazepine.

METHODS AND RESULTS

Thirty-two FPT inhibitors with two types of scaffold were analyzed. Active conformations of which were studied using system search, a 3D-QSAR model were constructed using the method of comparative molecular field analysis (CoMFA). The resulting of cross-validated RCV2 = 0.602, non-cross-validated R2 = 0.958, SE = 0.270 and F = 124.5 indicate that the 3D-model possesses an ability to predict activities of new inhibitors.

CONCLUSION

The information of CoMFA model offers an approach to designing new FPT inhibitors.

[Cardio-pulmonary pathology of sudden death in asthma]

OBJECTIVE

To elucidate the pathological characteristics of the heart and lung in asthmatics with sudden death.

METHOD

A detail analysis of pathological data was performed on 14 patients with sudden death in asthma.

RESULTS

There was no apparent gender difference among 14 patients. 9 patients were younger than 30 years old. Pathological examination showed that bronchial infiltration of eosinophils in 14 patient (100%), thickened basement membrane of the bronchial mucosa in 12 patients (85.7%), proliferation of smooth muscle cells in 11 patients (78.6%), proliferative mucous gland in 9 patients (64.3%), mucous plug in bronchiole in 8 patients (57.1%), and cicatvization of left ventricle in 10 patients (71.4%).

CONCLUSION

Severe nonspecific airway inflammation is demonstrated in asthmatic patients with sudden death. Lesions of the left ventricle and mucous plug in bronchiole may contribute to the main cause leading sudden death.

[Study on 3D-QSAR of PPAR gamma agonists with thiazolidinedione and arylketo-acid moieties]

AIM

To build a model of two series of PPAR gamma agonists--thiazolidinedione and aryketo-acid derivatives using 3D-QSAR method, and to reveal the structural features affecting the binding activity to PPAR gamma, which relates to antihyperglycemic and antihyperlipidemic activity and has a potential application to the treatment of type II diabetes.

METHODS AND RESULTS

48 agonists with selective activity for PPAR gamma were analyzed using CoMFA. Based upon the active conformation of rosiglitazone (BRL) extracted from its complex with PPAR gamma all agonists were aligned. The model from CoMFA showed a high ability to explain and predict the activity of PPAR gamma agonists with cross-validation correlation coefficient R2 = 0.656, that of non-cross-validation R2 = 0.982, F10,37 = 201.1, and SE = 0.115.

CONCLUSION

The CoMFA contour map indicates that the steric fields mainly contribute to the binding effect, and especially a bulk group in the arylketo-acid series favors in the increase of affinity for PPAR gamma, as compared to the thiazolidinedione.