[LncRNA SNHG11 promotes malignant progression of colorectal cancer cells through the PI3K/Akt/mTOR signaling pathway].

Objective: To investigate the effects of lncRNA SNHG11 on proliferation, migration, invasion and apoptosis of colorectal cancer cancer cells and possible mechanisms. Methods: qRT-PCR was performed to detect the expression level of lncRNA SNHG11 in colorectal cancer tissues and its related cell lines. The correlation between SNHG11 expression and clinical prognosis of patients was assessed by bioinformatics techniques. Cultured CRC cell lines were transfected with shCtrl (shCtrl group), shSNHG11#1 (shSNHG11#1 group), shSNHG11#2 (shSNHG11#2 group), Control cDNA (Control cDNA group), and SNHG11 cDNA (SNHG11 cDNA), respectively. Thiazolyl blue (MTT), clone formation assay, Transwell assay, cell scratch assay, and flow cytometry were used to detect the proliferation, migration, invasion, and apoptosis of CRC cells in each group. Western protein blotting was used to detect the expression of relevant proteins in each group, and the effect of lncRNA SNHG11 knockdown on the growth of tumour cells in vivo was analysed by nude mice tumouring assay. Phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signalling pathway inhibitor LY294002 was used for rescue experiments. Results: The expression of lncRNA SNHG11 was significantly higher in colorectal cancer cells and tissues than in normal tissues (P<0.05). Survival analysis showed that the expression level of SNHG11 was not statistically associated with CRC survival (P>0.05). shSNHG11#2 group compared with shCtrl group. MTT OD490/570 values decreased, the number of CRC cell clones decreased, the number of Transwell cells decreased, the area of cell scratch decreased, and the apoptosis rate increased (P<0.05). The mesenchymal markers matrix metalloproteinase (MMP9), N-cadherin and vimentin were significantly reduced, and the expression of the epithelial marker E-cadherin was upregulated. The expression of anti-apoptotic proteins Bcl-2 and Bcl-xl was decreased, and the expression of pro-apoptotic protein Bax was increased (P<0.05).In vivo experiments showed that lncRNA SNHG11 knockdown inhibited the growth of colorectal cancer cells, and the expression of Ki67 was reduced in tumours (P<0.05). LncRNA SNHG11 knockdown inhibited the expression of p-PI3K, p-Akt and p-mTOR.The PI3K/Akt/mTOR signaling pathway inhibitor LY294002 was able to restore the malignant cytological progression of colorectal cancer cells induced by the overexpression of lncRNA SNHG11. Conclusions: LncRNA SNHG11 is highly expressed in colorectal cancer. lncRNA SNHG11 can promote the malignant progression of colorectal cancer cells by regulating the PI3K/Akt/mTOR signaling pathway, and this finding provides a new theoretical basis for targeted therapy of colorectal cancer.

Ulipristal acetate, a selective progesterone receptor modulator, induces cell death via inhibition of STAT3/CCL2 signaling pathway in uterine sarcoma.

Ulipristal acetate (UPA) is a selective progesterone receptor modulator and is used for the treatment of uterine leiomyoma (a benign tumor). Uterine sarcoma which is highly malignant cancer with a poor prognosis is clinically resembled with uterine leiomyoma. There has been no experimental research on the effect of UPA on uterine sarcoma. In this study, we examined the efficacy of UPA in uterine sarcoma with in vitro and in vivo animal models. Cytotoxicity of UPA was determined in uterine sarcoma cell lines (MES-SA, SK-UT-1, and SK-LMS-1). Apoptotic genes and signaling pathways affected by UPA were analyzed by complementary DNA (cDNA) microarray of uterine sarcoma cell lines and western blot, respectively. An in vivo efficacy of UPA was examined with uterine sarcoma cell line- and patient-derived xenograft (PDX) mice models. UPA inhibited cell growth in uterine sarcoma cell lines and primary culture cells from a PDX mouse (PDX-C). cDNA microarray analysis revealed that CCL2 was highly down-regulated by UPA. Phosphorylation and the total expression of STAT3 were inhibited by UPA. UPA also inhibited CCL2 and STAT3 in PDX-C. The inhibitory effect of UPA had not changed in the overexpression of PR and treatment of progesterone. In vivo efficacy studies with cell line-derived xenografts and a PDX model with leiomyosarcoma, a typical uterine sarcoma, demonstrated that UPA significantly decreased tumor growth. UPA had significant anti-tumor effects in uterine sarcoma through the inhibition of STAT3/CCL2 signaling pathway and might be a potential therapeutic agent to treat this disease.

Identification of an Arylnaphthalene Lignan Derivative as an Inhibitor against Dengue Virus Serotypes 1 to 4 (DENV-1 to -4) Using a Newly Developed DENV-3 Infectious Clone and Replicon.

Dengue virus (DENV) is the most widespread arbovirus, causing symptoms ranging from dengue fever to severe dengue, including hemorrhagic fever and shock syndrome. Four serotypes of DENV (DENV-1 to -4) can infect humans; however, no anti-DENV drug is available. To facilitate the study of antivirals and viral pathogenesis, here we developed an infectious clone and a subgenomic replicon of DENV-3 strains for anti-DENV drug discovery by screening a synthetic compound library. The viral cDNA was amplified from a serum sample from a DENV-3-infected individual during the 2019 epidemic; however, fragments containing the prM-E-partial NS1 region could not be cloned until a DENV-3 consensus sequence with 19 synonymous substitutions was introduced to reduce putative Escherichia coli promoter activity. Transfection of the resulting cDNA clone, plasmid DV3syn, released an infectious virus titer of 2.2 × 102 focus-forming units (FFU)/mL. Through serial passages, four adaptive mutations (4M) were identified, and addition of 4M generated recombinant DV3syn_4M, which produced viral titers ranging from 1.5 × 104 to 6.7 × 104 FFU/mL and remained genetically stable in transformant bacteria. Additionally, we constructed a DENV-3 subgenomic replicon and screened an arylnaphthalene lignan library, from which C169-P1 was identified as exhibiting inhibitory effects on viral replicon. A time-of-drug addition assay revealed that C169-P1 also impeded the internalization process of cell entry. Furthermore, we demonstrated that C169-P1 inhibited the infectivity of DV3syn_4M, as well as DENV-1, DENV-2, and DENV-4, in a dose-dependent manner. This study provides an infectious clone and a replicon for the study of DENV-3 and a candidate compound for future development against DENV-1 to -4 infections. IMPORTANCE Dengue virus (DENV) is the most prevalent mosquito-transmitted virus, and there is no an anti-dengue drug. Reverse genetic systems representative of different serotype viruses are invaluable tools for the study of viral pathogenesis and antiviral drugs. Here, we developed an efficient infectious clone of a clinical DENV-3 genotype III isolate. We successfully overcame the instability of flavivirus genome-length cDNA in transformant bacteria, an unsolved issue for construction of cDNA clones of flaviviruses, and adapted this clone to efficiently produce infectious viruses following plasmid transfection of cell culture. Moreover, we constructed a DENV-3 subgenomic replicon and screened a compound library. An arylnaphthalene lignan, C169-P1, was identified as an inhibitor of virus replication and cell entry. Finally, we demonstrated that C169-P1 exhibited a broad-spectrum antiviral effect against the infections with DENV-1 to -4. The reverse genetic systems and the compound candidate described here facilitate the study of DENV and related RNA viruses.

[Investigation of Efflux Pump Genes in Resistant Mycobacterium tuberculosis Complex Clinical Isolates Exposed to First Line Antituberculosis Drugs and Verapamil Combination]. / Birinci Seçenek Antitüberküloz Ilaçlara ve Verapamil Kombinasyonuna Maruz Birakilan Dirençli Mycobacterium tuberculosis Kompleks Klinik Izolatlarindaki Efluks Pompa Genlerinin Arastirilmasi.

Tuberculosis (TB) is caused by Mycobacterium tuberculosis, still one of the most common life-threatening infectious diseases worldwide. Although drug resistance in M.tuberculosis is mainly due to spontaneous chromosomal mutations in genes encoding drug target or drug activating enzymes, the resistance cannot be explained only by these mutations. Low permeability of the cell wall, drug inactivating enzymes and especially efflux pumps (EPs) are other mechanisms of drug resistance in mycobacteria. Efflux pump inhibitors (EPIs) binding to M.tuberculosis EPs were shown to inhibit efflux of anti-TB drugs, to enhance M.tuberculosis killing, to reduce drug resistance and to produce synergistic effects with first line anti-TB drugs. In this study, we aimed to determine the minimum inhibitory concentration (MIC) of first-line anti-TB drugs in the presence of verapamil (VER) and the expression of 21 putative EP genes belonged to the ATP-binding cassette (ABC), major facilitator superfamily (MFS) and resistance-nodulation-division (RND) families which might have caused the resistance in nine M.tuberculosis complex clinical isolates resistant to all of the first line anti-TB drugs. MIC values of the isolates were determined in 96-well U-bottom plates by the resazurin microtiter test (REMA) method based on the color change principle. According to the determined MIC values of each isolate, freshly grown cultures in Middlebrook 7H9 broth were exposed to first-line anti-TB drugs and MIC of first-line anti-TB drugs in the presence of VER (½ MIC) at 37°C for 48 hours for RNA extraction. The non-drug exposed cultures were used as control. Total RNA was extracted using the RNeasy Mini Kit (Qiagen GmbH, Hilden, Germany) and then treated with DNase I (Thermo Fischer Scientific Inc., Waltham, MA). Complementary DNA (cDNA) from the extracted RNAs was synthesized with the "First strand cDNA synthesis kit" (Thermo Fischer Scientific Inc., Waltham, MA) using oligo primers. The expression levels of efflux pump genes by quantitative realtime polymerase chain reaction (qRt-PCR) were performed using the QuantiTect SYBR Green Rt-PCR Kit (Qiagen, Germany). The housekeeping sigma factor gene sigA (Rv2703) was used as internal control in qRt­PCR assays. Relative quantification of the clinical isolates was determined by the 2-∆∆Ct method by comparing the expression levels of efflux genes in cultures exposed to primary anti-TB drugs and VER with those of non-drug exposed cultures. MIC values of nine isolates by REMA method was determined between 32-512 µg/mL, 1-128 µg/mL, 2-32 µg/mL, 4-16 µg/mL and 15.62-250 µg/mL for streptomycin (SM), isoniazid (INH), rifampicin (RIF), ethambutol (EMB) and VER, respectively. In the presence of ½ MIC VER, it was determined that the MIC of SM decreased 2-32 fold in eight isolates, the MIC of INH decreased by 2-8 fold in nine isolates, the MIC of RIF decreased by 2-16 fold in eight isolates, and the MIC of EMB decreased 2-4 fold in only five isolates. There was an increase in the expression of Rv1273c, Rv1456c, Rv1457 and Rv1819 efflux pump genes from the ABC family, Rv1634 and Rv0842 from the MFS family and Rv3823 efflux from the RND family in isolates exposed to ½ MIC of first-line anti-TB drugs stress. Rv1456c and Rv1819 were found to be associated with SM resistance, Rv1273c with EMB resistance, Rv1457, Rv0842 and Rv3823 with both RIF and EMB resistance, and Rv1634 with INH, RIF and EMB resistance. It was determined that there was a decrease in the expression levels of eight efflux pump genes from the ABC family (Rv1456c, Rv1457c, Rv1458c, Rv0194, Rv1272c, Rv1686c, Rv1687c, Rv1819c), six from MFS family (Rv0842, Rv0849, Rv1634, Rv2265, Rv2456c, Rv0876c) and two from RND family (Rv0507, Rv0676c) in isolates exposed to MIC of first-line anti-TB drugs in the presence of VER (½ MIC). Further studies with clinical isolates are needed to investigate the EPIs that can be used in alternative therapy and to determine the contribution of EPs to the development of resistance due to the increasing TB resistance.

Influence of Extracellular Vesicles from the Follicular Fluid of Young Women and Women of Advanced Maternal Age with Different miRNA Profiles on Sperm Functional Properties.

We studied the effect of co-culturing of extracellular vesicles in the follicular fluid of young women and women of advanced maternal age on sperm motility. Vesicles were obtained by differential centrifugation. The sperm fraction was isolated from the seminal fluid of 18 patients (age 28-36 years). The spermatozoa were incubated with vesicles (1:2 ratio) for 60 or 120 min at 37°C in a CO2 incubator. A fraction of spermatozoa incubated without vesicles served as the control. After the incubation, the sperm samples were sedimented by centrifugation, fixed in 2.5% glutaraldehyde, and analyzed by transmission electron microscopy. RNA was isolated from the follicular fluid vesicles by column method followed by cDNA synthesis in a reaction mixture according to miScript II RT Kit protocol (Qiagen). After 60-min incubation with extracellular vesicles from the follicular fluid of women of advanced maternal age, the sperm motility and hyperactivation slightly changed in comparison with the group where incubation was performed with follicular fluid vesicles from young women and control group. Follicular fluid miRNA profiles in women of different ages varied, which suggests different functional compositions and effects of follicular fluid vesicles of different age groups on sperm characteristics. Transmission electron microscopy revealed differences in the interaction of follicular fluid vesicles from women of different age groups with spermatozoa. Further study of the effect of extracellular vesicles from the follicular fluid and analysis of their transcriptomic, proteomic, and metabolomic composition on sperm mobility and fertilizing ability will improve the effectiveness of assisted reproductive technology programs in patients with male infertility.

Long Noncoding RNA TPRG1-AS1 Suppresses Migration of Vascular Smooth Muscle Cells and Attenuates Atherogenesis via Interacting With MYH9 Protein.

BACKGROUND: Migration of human aortic smooth muscle cells (HASMCs) contributes to the pathogenesis of atherosclerosis. This study aims to functionally characterize long noncoding RNA TPRG1-AS1 (tumor protein p63 regulated 1, antisense 1) in HASMCs and reveal the underlying mechanism of TPRG1-AS1 in HASMCs migration, neointima formation, and subsequent atherosclerosis. METHODS: The expression of TPRG1-AS1 in atherosclerotic plaques was verified a series of in silico analysis and quantitative real-time polymerase chain reaction analysis. Northern blot, rapid amplification of cDNA ends and Sanger sequencing were used to determine its full length. In vitro transcription-translation assay was used to investigate the protein-coding capacity of TPRG1-AS1. RNA fluorescent in situ hybridization was used to confirm its subcellular localization. Loss- and gain-of-function studies were used to investigate the function of TPRG1-AS1. Furthermore, the effect of TPRG1-AS1 on the pathological response was evaluated in carotid balloon injury model, wire injury model, and atherosclerosis model, respectively. RESULTS: TPRG1-AS1 was significantly increased in atherosclerotic plaques. TPRG1-AS1 did not encode any proteins and its full length was 1279nt, which was bona fide a long noncoding RNA. TPRG1-AS1 was mainly localized in cytoplasmic and perinuclear regions in HASMCs. TPRG1-AS1 directly interacted with MYH9 (myosin heavy chain 9) protein in HASMCs, promoted MYH9 protein degradation through the proteasome pathway, hindered F-actin stress fiber formation, and finally inhibited HASMCs migration. Vascular smooth muscle cell-specific transgenic overexpression of TPRG1-AS1 significantly reduced neointima formation, and attenuated atherosclerosis in apolipoprotein E knockout (Apoe-/-) mice. CONCLUSIONS: This study demonstrated that TPRG1-AS1 inhibited HASMCs migration through interacting with MYH9 protein and consequently suppressed neointima formation and atherosclerosis.

Poplar leaf abscission through induced chlorophyll breakdown by Mg-dechelatase.

Chlorophyll breakdown is observed during senescence. The first step in chlorophyll breakdown is the removal of central Mg by Mg-dechelatase. This reaction is the rate-limiting step in the chlorophyll breakdown pathway. We evaluated the effect of induced chlorophyll breakdown on abscission through the removal of Mg by Mg-dechelatase. Poplar transformants carrying the dexamethasone-inducible Mg-dechelatase gene were prepared using the Arabidopsis Stay-Green1 cDNA. When leaves were treated with dexamethasone, chlorophyll was degraded, photosynthetic capacity was reduced, and an abscission zone was formed, resulting in leaf abscission. In addition, ethylene, which plays an important role during senescence, was produced in this process. Thus, chlorophyll breakdown induces the phenotype in the same way as commonly observed during leaf senescence. This study suggests a physiological role of chlorophyll breakdown in the leaf abscission of deciduous trees. Furthermore, this study shows that the dexamethasone-inducible gene expression system is an available option for deciduous tree studies.

Preparation and optimisation of anionic liposomes for delivery of small peptides and cDNA to human corneal epithelial cells.

Drug delivery to corneal epithelial cells is challenging due to the intrinsic mechanisms that protect the eye. Here, we report a novel liposomal formulation to encapsulate and deliver a short sequence peptide into human corneal epithelial cells (hTCEpi). Using a mixture of Phosphatidylcholine/Caproylamine/Dioleoylphosphatidylethanolamine (PC/CAP/DOPE), we encapsulated a fluorescent peptide, resulting in anionic liposomes with an average size of 138.8 ± 34 nm and a charge of -18.2 ± 1.3 mV. After 2 h incubation with the peptide-encapsulated liposomes, 66% of corneal epithelial (hTCEpi) cells internalised the FITC-labelled peptide, demonstrating the ability of this formulation to effectively deliver peptide to hTCEpi cells. Additionally, lipoplexes (liposomes complexed with plasmid DNA) were also able to transfect hTCEpi cells, albeit at a modest level (8% of the cells). Here, we describe this novel anionic liposomal formulation intended to enhance the delivery of small cargo molecules in situ.

Antisense vimentin cDNA combined with chondroitinase ABC promotes axon regeneration and functional recovery following spinal cord injury in rats.

The formation of glial scar restricts axon regeneration after spinal cord injury (SCI) in adult mammalian. Chondroitin sulfate proteoglycans (CSPGs) are mostly secreted by reactive astrocytes, which form dense scar tissues after SCI. Chondroitinase ABC (ChABC), which can digest CSPGs, is a promising therapeutic strategy for SCI. However, to date ChABC has exhibited only limited success in the treatment of chronic SCI. The intermediate filament protein vimentin underpins the cytoskeleton of reactive astrocytes. We targeted glial scar in injured spinal cord by sustained infusion of ChABC and antisense vimentin cDNA. Using anterograde tracing, BBB scoring and hind limb placing response, we found that this combined treatment promoted axon regeneration and functional recovery after SCI in rats. Our results indicate that axon regeneration may be promoted by modified physical and biochemical characteristics of intra- and extracellular architecture in glial scar tissues. Theses findings could potentially help us to understand better the composition of glial scar in central nervous system injury.

Protein nanocages for self-triggered nuclear delivery of DNA-targeted chemotherapeutics in Cancer Cells.

A genetically engineered apoferritin variant consisting of 24 heavy-chain subunits (HFn) was produced to achieve a cumulative delivery of an antitumor drug, which exerts its cytotoxic action by targeting the DNA at the nucleus of human cancer cells with subcellular precision. The rationale of our approach is based on exploiting the natural arsenal of defense of cancer cells to stimulate them to recruit large amounts of HFn nanoparticles loaded with doxorubicin inside their nucleus in response to a DNA damage, which leads to a programmed cell death. After demonstrating the selectivity of HFn for representative cancer cells compared to healthy fibroblasts, doxorubicin-loaded HFn was used to treat the cancer cells. The results from confocal microscopy and DNA damage assays proved that loading of doxorubicin in HFn nanoparticles increased the nuclear delivery of the drug, thus enhancing doxorubicin efficacy. Doxorubicin-loaded HFn acts as a "Trojan Horse": HFn was internalized in cancer cells faster and more efficiently compared to free doxorubicin, then promptly translocated into the nucleus following the DNA damage caused by the partial release in the cytoplasm of encapsulated doxorubicin. This self-triggered translocation mechanism allowed the drug to be directly released in the nuclear compartment, where it exerted its toxic action. This approach was reliable and straightforward providing an antiproliferative effect with high reproducibility. The particular self-assembling nature of HFn nanocage makes it a versatile and tunable nanovector for a broad range of molecules suitable both for detection and treatment of cancer cells.

An improved and robust DNA immunization method to develop antibodies against extracellular loops of multi-transmembrane proteins.

Multi-transmembrane proteins are especially difficult targets for antibody generation largely due to the challenge of producing a protein that maintains its native conformation in the absence of a stabilizing membrane. Here, we describe an immunization strategy that successfully resulted in the identification of monoclonal antibodies that bind specifically to extracellular epitopes of a 12 transmembrane protein, multi-drug resistant protein 4 (MRP4). These monoclonal antibodies were developed following hydrodynamic tail vein immunization with a cytomegalovirus (CMV) promoter-based plasmid expressing MRP4 cDNA and were characterized by flow cytometry. As expected, the use of the immune modulators fetal liver tyrosine kinase 3 ligand (Flt3L) and granulocyte-macrophage colony-stimulating factor positively enhanced the immune response against MRP4. Imaging studies using CMV-based plasmids expressing luciferase showed that the in vivo half-life of the target antigen was less than 48 h using CMV-based plasmids, thus necessitating frequent boosting with DNA to achieve an adequate immune response. We also describe a comparison of plasmids, which contained MRP4 cDNA with either the CMV or CAG promoters, used for immunizations. The observed luciferase activity in this comparison demonstrated that the CAG promoter-containing plasmid pCAGGS induced prolonged constitutive expression of MRP4 and an increased anti-MRP4 specific immune response even when the plasmid was injected less frequently. The method described here is one that can be broadly applicable as a general immunization strategy to develop antibodies against multi-transmembrane proteins, as well as target antigens that are difficult to express or purify in native and functionally active conformation.

Gene delivery of bone morphogenetic protein-2 plasmid DNA promotes bone formation in a large animal model.

In the field of bone regeneration, BMP-2 is considered one of the most important growth factors because of its strong osteogenic activity, and is therefore extensively used in clinical practice. However, the short half-life of BMP-2 protein necessitates the use of supraphysiological doses, leading to severe side-effects. This study investigated the efficiency of bone formation at ectopic and orthotopic sites as a result of a low-cost, prolonged presence of BMP-2 in a large animal model. Constructs consisting of alginate hydrogel and BMP-2 cDNA, together acting as a non-viral gene-activated matrix, were combined with goat multipotent stromal cells (gMSCs) and implanted in spinal cassettes or, together with ceramic granules, intramuscularly in goats, both for 16 weeks. Bone formation occurred in all cell-seeded ectopic constructs, but the constructs containing both gMSCs and BMP-2 plasmid DNA showed higher collagen I and bone levels, indicating an osteogenic effect of the BMP-2 plasmid DNA. This was not seen in unseeded constructs, even though transfected, BMP-2-producing cells were detected in all constructs containing plasmid DNA. Orthotopic constructs showed mainly bone formation in the unseeded groups. Besides bone, calcified alginate was present in these groups, acting as a surface for new bone formation. In conclusion, transfection of seeded or resident cells from this DNA delivery system led to stable expression of BMP-2 during 16 weeks, and promoted osteogenic differentiation and subsequent bone formation in cell-seeded constructs at an ectopic location and in cell-free constructs at an orthotopic location in a large animal model.

cDNA cloning, overexpression, purification and pharmacologic evaluation for anticancer activity of ribosomal protein L23A gene (RPL23A) from the Giant Panda.

RPL23A gene encodes a ribosomal protein that is a component of the 60S subunit. The protein belongs to the L23P family of ribosomal proteins, which is located in the cytoplasm. The purpose of this paper was to explore the structure and anti-cancer function of ribosomal protein L23A (RPL23A) gene of the Giant Panda (Ailuropoda melanoleuca). The cDNA of RPL23A was cloned successfully from the Giant Panda using RT-PCR technology. We constructed a recombinant expression vector containing RPL23A cDNA and over-expressed it in Escherichia coli using pET28a plasmids. The expression product obtained was purified by using Ni chelating affinity chromatography. Recombinant protein of RPL23A obtained from the experiment acted on Hep-2 cells and human HepG-2 cells, then the growth inhibitory effect of these cells was observed by MTT (3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide) assay. The result indicated that the length of the fragment cloned is 506 bp, and it contains an open-reading frame (ORF) of 471 bp encoding 156 amino acids. Primary structure analysis revealed that the molecular weight of the putative RPL23A protein is 17.719 kDa with a theoretical pI 11.16. The molecular weight of the recombinant protein RPL23A is 21.265 kDa with a theoretical pI 10.57. The RPL23A gene can be really expressed in E. coli and the RPL23A protein, fusioned with the N-terminally His-tagged protein, gave rise to the accumulation of an expected 22 KDa polypeptide. The data showed that the recombinant protein RPL23A had a time- and dose-dependency on the cell growth inhibition rate. The data also indicated that the effect at low concentrations was better than at high concentrations on Hep-2 cells, and that the concentration of 0.185 µg/mL had the best rate of growth inhibition of 36.31%. All results of the experiment revealed that the recombinant protein RPL23A exhibited anti-cancer function on the Hep-2 cells. The study provides a scientific basis and aids orientation for the research and development of cancer protein drugs as well as possible anti-cancer mechanisms. Further research is on going to determine the bioactive principle(s) of recombinant protein RPL23A responsible for its anticancer activity.

Emergence of intratreatment resistance to oseltamivir in pandemic influenza A H1N1 2009 virus.

BACKGROUND: Pandemic influenza A H1N1 2009 virus presents a new challenge to health authorities and communities worldwide. In Argentina, the outbreak was at its peak by the end of June 2009, during the southern winter. A systematic analysis of samples from patients with pandemic H1N1 2009 studied in our laboratory (Virology Laboratory, Hospital de Niños R Gutiérrez, Buenos Aires, Argentina) detected two patients presenting intratreatment emergence of the H275Y neuraminidase mutation, which confers resistance to oseltamivir. METHODS: Complementary DNAs, including the 275 codon, were obtained by reverse transcriptase PCR using viral RNAs extracted from nasopharyngeal or tracheal aspirates. Conventional sequencing and pyrosequencing were performed on each sample. In order to measure the virus susceptibility to oseltamivir, 50% inhibitory concentration determinations were performed by chemiluminescence. RESULTS: Sequential samples of two paediatric patients under oseltamivir treatment were analysed. Pretreatment samples were composed of 100% oseltamivir-sensitive variants. In case 1, the oseltamivir-resistant variant was found 8 days after the beginning of treatment. In case 2, the viral population became resistant on the second day of treatment, with 83% of the viral population bearing the mutation and this reached 100% on the seventh day. CONCLUSIONS: We describe the intratreatment emergence of oseltamivir resistance in two paediatric patients. Pyrosequencing allowed us to detect variant mixtures, showing the transition of the viral population from sensitive to resistant.

In vitro and in vivo inhibitory effect evaluation of cyclooxygenase-2 inhibitors, antisense cyclooxygenase-2 cDNA, and their combination on the growth of human bladder cancer cells.

Overexpression of cyclooxygenase (COX)-2 is associated with the progression of various malignancies, but the contribution of COX-2 expression, bioactivity or their cooperation to bladder cancer growth calls for further clarification. In this study, we investigated the inhibitory effect of COX-2 inhibitors, antisense COX-2 nucleotide, and their combination on the growth of bladder cancer cells (5637, 5637-P and 5637-AS). Suppression of either COX-2 expression or activity caused reduced cell proliferation, enhanced cell numbers in G(1) phase, and increased apoptosis; the joint suppression of COX-2 expression and bioactivity enhanced the degree of cell growth inhibition. COX-2 antisense-expressing 5637-AS tumors showed a 41.42+/-3.08% growth inhibition as compared with 5637 controls. Oral administration of indomethacin (3mg/kg) or celecoxib (15 mg/kg) caused tumor growth inhibition by 31.5+/-14.87% or 83.17+/-1.17%, respectively. When COX-2 antisense cDNA and COX-2 inhibitor celecoxib were combined, the tumor growth inhibition rate was further increased up to 88.78+/-3.10%. These results provide evidence that celecoxib has potential therapeutic effect on bladder cancer, and the joint use of COX-2 antisense cDNA with celecoxib may improve their individual therapeutic effect, especially significantly increase the growth inhibitory effect of COX-2 antisense cDNA.

Molecular structure of the largemouth bass (Micropterus salmoides) Myf5 gene and its effect on skeletal muscle growth.

Myogenic Regulatory Factors (MRFs), a family of basic helix-loop-helix (bHLH) transcription factors, play important roles in regulating skeletal muscle development and growth. Myf5, the primary factor of MRFs, initiates myogenesis. Its expression pattern during somitomyogenesis in some fish has been revealed. To further study its effect on fish muscle during postembryonic growth, characterization and function analysis of myf5 cDNA were carried out in largemouth bass. The 1,093 bp cDNA sequence was identified by RT-PCR and 3'RACE, then the ORF of Myf5 cDNA was cloned into the expression vector pcDNA3.1(-)/mycHisB. The recombinant plasmid pcDNA3.1(-)/mycHisB-Myf5 was injected into the dorsal muscle of tilapias. RT-PCR and histochemical results showed that the exogenous gene was transcribed and translated in vivo. Its effect on muscle growth focused on myofiber hypertrophy in white muscle 60 days post injection. This indicated that overexpression of Myf5 can promote myogenesis during the fish muscle postembryonic growth period.

Long-term stable expression of antisense cDNA of cyclin B1 profoundly inhibits the proliferation of tumor cells and suppresses tumorigenicity in implanted mice.

BACKGROUND: Cyclin B1 (CLB1) is necessary for mitotic initiation in mammalian cells and plays important roles in cancer development. Therefore, a potential strategy in cancer therapy is to suppress the activity of CLB1 by delivering antisense constructs of CLB1 into tumor cells. In previous CLB1 studies, antisense constructs with a short half life were often used and these constructs might not persistently inhibit CLB1. METHODS: We successfully created a recombinant plasmid encoding the full-length antisense cDNA of mouse cyclin B1 (AS-mCLB1) and transfected this construct to the murine Lewis lung carcinoma (LL/2) and CT-26 colon carcinoma (CT-26) cells. We isolated clones of LL/2 and CT-26 transfectants with stable expression of AS-mCLB1. Reverse transcriptional polymerase chain reaction (RT-PCR) and Western blot were applied to detect the expression of the mRNA and protein levels of CLB1. To further test the efficacy of this strategy in vivo, AS-mCLB1-expressing LL/2 and CT-26 transfectants were implanted into mice. RESULTS: We found the expression of the mRNA and protein levels of CLB1 decrease in these transfectants. The inhibition of CLB1 caused prominent G1 arrest, abnormal morphology, retarded cell growth and an increase in apoptosis. In AS-mCLB1-expressing LL/2 and CT-26 transfectants implanted mice, tumorigenicity was effectively suppressed compared with the controls. In addition, the expression of AS-mCLB1 also significantly increases the survival duration of implanted animals. CONCLUSION: AS-mCLB1 is likely to be useful in future cancer therapy, which may be associated with its ability to down-regulate the expression of CLB1 and then induce G1arrest and apoptosis in tumor cells.

Adenovirus and adeno-associated virus-mediated delivery of human myophosphorylase cDNA and LacZ cDNA to muscle in the ovine model of McArdle's disease: expression and re-expression of glycogen phosphorylase.

At present there is no satisfactory treatment for McArdle's disease, deficiency of myophosphorylase. Injection of modified adenovirus 5 (AdV5) and adeno-associated virus 2 (AAV2) vectors containing myophosphorylase expression cassettes, into semitendinosus muscle of sheep with McArdle's disease, produced expression of functional myophosphorylase and some re-expression of the non-muscle glycogen phosphorylase isoforms (both liver and brain) in regenerating fibres. Expression of both non-muscle isoforms was also seen after control injections of AdV5LacZ vectors. There was up to an order of magnitude greater expression of phosphorylase after myophosphorylase vector injection than after LacZ controls (62% of sections with over 1000 positive muscle fibres, versus 7%). The results presented here suggest that the use of viral vector-mediated phosphorylase gene transfer may be applicable to the treatment of McArdle's disease and that sustained re-expression of the brain and liver isoforms should also be investigated as a possible treatment.

An automated system for intracellular and intranuclear injection.

The Xenopus oocyte expression system has played an important role in the study of cellular proteins, particularly in the field of membrane physiology; expression of transporters and ion channels has significantly advanced our knowledge of these membrane proteins and the rapid and easy expression of mutants has been crucial in many structure-function studies. Xenopus oocytes are an expression system in many ligand-binding assays and in functional screening for ion channel modulators. Several commercially available automated technologies use this system, generating a demand for large numbers of oocytes injected with ion channel genes. Injection of oocytes with genetic material is generally carried out manually. Here we describe an automated system capable of injecting up to 600 oocytes per hour. Oocytes are contained in microplates with conical wells, a simple calibration procedure by the operator is required and pipette filling and oocyte injection are carried out automatically. Following intracellular injection of mRNA coding for ligand-gated ion channels close to 100% of oocytes tested positive for expression, and intranuclear injection of cDNA gave a rate of expression >50%. Moreover, we demonstrate that this method can also be successfully applied to inject zebrafish embryos and could be extended to other cell types.