Specification of epibranchial placodes in zebrafish

In all vertebrates, the neurogenic placodes are transient ectodermal thickenings that give rise to sensory neurons of the cranial ganglia. Epibranchial (EB) placodes generate neurons of the distal facial, glossopharyngeal and vagal ganglia, which convey sensation from the viscera, including pharyngeal endoderm structures, to the CNS. Recent studies have implicated signals from pharyngeal endoderm in the initiation of neurogenesis from EB placodes; however, the signals underlying the formation of placodes are unknown. Here, we show that zebrafish embryos mutant for fgf3 and fgf8 do not express early EB placode markers, including foxi1 and pax2a. Mosaic analysis demonstrates that placodal cells must directly receive Fgf signals during a specific crucial period of development. Transplantation experiments and mutant analysis reveal that cephalic mesoderm is the source of Fgf signals. Finally, both Fgf3 and Fgf8 are sufficient to induce foxi1-positive placodal precursors in wild-type as well as Fgf3-plus Fgf8-depleted embryos. We propose a model in which mesoderm-derived Fgf3 and Fgf8 signals establish both the EB placodes and the development of the pharyngeal endoderm, the subsequent interaction of which promotes neurogenesis. The coordinated interplay between craniofacial tissues would thus assure proper spatial and temporal interactions in the shaping of the vertebrate head.

The mother superior mutation ablates foxd3 activity in neural crest progenitor cells and depletes neural crest derivatives in zebrafish

The zebrafish mutation mother superior (mosm188) leads to a depletion of neural crest (NC) derivatives including the craniofacial cartilage skeleton, the peripheral nervous system (sympathetic neurons, dorsal root ganglia, enteric neurons), and pigment cells. The loss of derivatives is preceded by a reduction in NC-expressed transcription factors, snail1b, sox9b, sox10, and a specific loss of foxd3 expression in NC progenitor cells. We employed genetic linkage analysis and physical mapping to place the mosm188 mutation on zebrafish chromosome 6 in the vicinity of the foxd3 gene. Furthermore, we found that mosm188 does not complement the sym1/foxd3 mutation, indicating that mosm188 resides within the foxd3 locus. Injection of PAC clones containing the foxd3 gene into mosm188 embryos restored foxd3 expression in NC progenitors and suppressed the mosm188 phenotype. However, sequencing the foxd3 transcribed area in mosm188 embryos did not reveal nucleotide changes segregating with the mosm188 phenotype, implying that the mutation most likely resides outside the foxd3-coding region. Based on these findings, we propose that the mosm188 mutation perturbs a NC-specific foxd3 regulatory element. Further analysis of mosm188 mutants and foxd3 morphants revealed that NC cells are initially formed, suggesting that foxd3 function is required to maintain the pool of NC progenitors.

Possible involvement of endogenous nociceptin/orphanin FQ in the pain-related behavioral responses induced by its own metabolite, nociceptin/orphanin FQ(14-17)

Nociceptin/orphanin FQ(14-17) (N/OFQ(14-17)) is one of the major fragments that are released from N/OFQ, an endogenous ligand for the opioid receptor like-1 (ORL-1) receptor by endopeptidase 24.11. In the present study, we determined the pharmacological profiles of N/OFQ(14-17) on pain-related behavioral responses in the mouse. Intrathecal (i.t.) administration of N/OFQ(14-17) (5-160 pmol) evoked pain-related behaviors, and these behavioral responses were reduced by i.t. co-administration of an ORL-1 receptor antagonist, [Nphe(1)]N/OFQ(1-13)NH2 (4 pmol). However, in the ligand-binding receptor assay, N/OFQ(14-17) had no affinity for the ORL-1 receptor. Furthermore, i.t. pretreatment with an antiserum against N/OFQ (1:50) diminished the N/OFQ(14-17)-induced pain-related behaviors, suggesting that endogenous N/OFQ is involved in their expression. Therefore, N/OFQ(14-17)-induced pain-related behaviors may be mediated through the release of endogenous N/OFQ in the mouse spinal cord.

Identification of metastasis candidate proteins among HCC cell lines by comparative proteome and biological function analysis of S100A4 in metastasis in vitro

Widespread metastasis of hepatocellular carcinoma (HCC) was a complex cascade of events, which is still beyond full appreciation. Screening key proteins, which play a critical role in metastasis, using high-throughput proteomics approach help discover valuable biomarkers and elucidate the mechanism of metastasis. This study was to find out some metastasis candidate proteins among HCC cell lines with various metastatic potential by comparative proteomics, and then further validate the biological function of these proteins in metastasis in vitro. The protein profiles of metastatic HCC cell lines (MHCC97H and MHCC97L) displayed obvious differences compared with nonmetastatic ones (Hep3B). Twenty-six metastasis candidate proteins, which were identified by on-line LC-ESI-MS/MS, such as S100 calcium-binding protein A4 (S100A4), annexin 1, etc., might have much application in diagnostic procedures and prognosis evaluation. S100A4, as a leading different metastasis candidate protein, which overexpressed only in the metastatic cells, was selected for further investigation. A series of assays related to invasion and metastasis in vitro, including cell motility, invasion, and matrix metalloproteinases (MMPs) secretion, were performed in MHCC97H/antisense recombinant plasmid to S100A4 (pcDNA3.1(+) AS S100A4) and the mock controls. All the data in the present study suggested that S100A4 might contribute to HCC invasion and metastasis through two paths of matrix metalloproteinase (MMP9) secretion regulation and strengthened motility and invasion properties.

The maternally localized RNA fatvg is required for cortical rotation and germ cell formation

Fatvg is a localized maternal transcript that translocates to the vegetal cortex of Xenopus laevis oocytes through both the METRO and Late RNA localization pathways. It is a member of a gene family that functions in vesicular trafficking. Depletion of the maternal store of fatvg mRNA results in a dual phenotype in which embryos are ventralized and also lack primordial germ cells. This complex fatvg loss of function phenotype is the result of stabilization of the dorsalizing factor beta-catenin at the vegetal pole and the inability of the germ cell determinants to move to their proper locations. This is coincident with the inhibition of cortical rotation and the abnormal aggregation of the germ plasm. Fatvg protein is located at the periphery of vesicles in the oocyte and embryo, supporting its proposed role in vesicular trafficking in the embryo. These results point to a common fundamental mechanism that is regulated by fatvg through which germ cell determinants and dorsalizing factors segregate during early development.

Beta-1 adrenergic receptor antisense-oligodeoxynucleotides ameliorates left ventricular remodeling in 2-Kidney, 1-Clip rats

Gene therapy has been applied to reduce blood pressure in rats. However, little is known about the effects of gene therapy on both blood pressure and left ventricular (LV) remodeling. This study was designed to compare the antihypertensive effect of ss(1) adrenergic receptor antisense oligodeoxynucleotides (ss(1)- AS-ODN) by delivery with the different charge ratios cationic liposomes DOTAP/DOPE and its impact on the LV remodeling in rats with 2-Kidney, 1-Clip (2K1C) Hypertension. Five charge ratios of liposome/ODN were tested in 2K1C rats. There was hypertension, cardiac dysfunction, LV hypertrophy and LV collagen deposition in 2K1C rats. On the basis of the magnitude and duration of hypotension, 2.0 was determined to be the optimal charge ratio, which decreased blood pressure by up to 39 mm Hg for 27 days. ss(1)-AS-ODN preserved cardiac function and inhibited LV mass and LV interstitial collagen deposition. In conclusion, cationic liposomes DOTAP/DOPE improve the antihypertensive effects of ss(1)-AS-ODN in renovascular hypertension and 2.0 were determined to be the optimal charge ratio. This study demonstrated that cardiac ss(1)-AR played a key role in LV remodeling and ss1-AS-ODN ameliorates cardiac dysfunction and LV remodeling.

Critical role of PTEN in the coupling between PI3K/Akt and JNK1/2 signaling in ischemic brain injury

JNK pathway is an important pro-apoptotic kinase cascade mediating cell death in response to a variety of extracellular stimuli including excitotoxicity, which results in selective and delayed neuronal death in the hippocampal CA1. On the contrary, activation of the protein kinase Akt, which is controlled by the opposing actions of PI3K and PTEN, contributes to enhanced resistance to apoptosis through multiple mechanisms. We here demonstrate that the temporal pattern of Akt activation reversely correlates with JNK1/2 activation following various time points of ischemic reperfusion. However, the activation of JNK1/2 could be decreased by the elevation of Akt activation via increasing the tyrosine phosphorylation of PTEN by bpv(pic), a potent PTPases inhibitor for PTEN, or by intracerebroventricular infusion of PTEN antisense oligodeoxynucleotides (AS-ODNs). In contrast, JNK1/2 activation was significantly increased by preventing PTEN degradation after pretreatment with proteasome inhibitor. The neuroprotective effects of bpv(pic) and PTEN AS-ODNs were significant in the CA1 subfield after transient global ischemia. In conclusion, the present results clearly show that PTEN plays a key regulatory role in the cross-talk between cell survival PI3K/Akt pathway and pro-death JNK pathway, and raise a new possibility that agents targeting phosphatase PTEN may offer a great promise to expand the therapeutic options in protecting neurons form ischemic brain damage.

Suppression of tumor growth using antisense oligonucleotide against survivin in an orthotopic transplant model of human hepatocellular carcinoma in nude mice

Survivin, an inhibitor of apoptosis protein, deserves attention as a selective target for cancer therapy because it is overexpressed in many cancers, including human hepatocellular carcinoma (HCC). Here, we report a novel antisense oligonucleotide (ASO) against survivin for its effectiveness against tumor growth both in vitro and in vivo, and providing evidence in treatment for HCC. Initially, transfection of liver tumor cells HepG2 with ASO resulted in significant cells growth inhibition and reduction expression of survivin mRNA and protein, in a dose-dependent manner. Using caspase-3 protease activation assays, we observed that ASO has induced significantly greater apoptosis rate compared to control oligonucleotides. Furthermore, we used an orthotopic transplant model of HCC in nude mice to investigate the effect of ASO on tumor growth in vivo, and ASO reagents were delivered by intravenous injection. Interestingly, this systemic treatment also resulted in significant inhibition in tumor growth. Tumor growth in mice treated with ASO (50 and 75 mg/kg per day) was significantly inhibited (45.31% and 60.94%, respectively) compared with saline-injected group (p < 0.01), in a dose-dependent manner, and the effect of ASO on tumor growth was associated with downregulation of survivin in tumor xenografts. Moreover, the level of serum alpha-fetoprotein in ASO-treated groups was also decreased in a dose-dependent manner. Taken together, these data suggest that the usefulness of survivin ASO could potentially be a promising gene therapy approach to treatment of HCC.

Targeted delivery of antisense oligodeoxynucleotide and small interference RNA into lung cancer cells

Selective gene inhibition by antisense oligodeoxynucleotide (AS-ODN) or by small interference RNA (siRNA) therapeutics promises the treatment of diseases that cannot be cured by conventional drugs. However, antisense therapy is hindered due to poor stability in physiological fluids and limited intracellular uptake. To address these problems, a ligand targeted and sterically stabilized nanoparticle formulation has been developed in our lab. Human lung cancer cells often overexpress the sigma receptor and, thus, can be targeted with a specific ligand such as anisamide. AS-ODN or siRNA against human survivin was mixed with a carrier DNA, calf thymus DNA, before complexing with protamine, a highly positively charged peptide. The resulting particles were coated with cationic liposomes consisting of DOTAP and cholesterol (1:1, molar ratio) to obtain LPD (liposome-polycation-DNA) nanoparticles. Ligand targeting and steric stabilization were then introduced by incubating preformed LPD nanoparticles with DSPE-PEG-anisamide, a PEGylated ligand lipid developed earlier in our lab, by the postinsertion method. Nontargeted nanoparticles coated with DSPE-PEG were also prepared as a control. Antisense activities of nanoparticles were determined by survivin mRNA down-regulation, survivin protein down-regulation, ability to trigger apoptosis in tumor cells, tumor cell growth inhibition, and chemosensitization of the treated tumor cells to anticancer drugs. We found that tumor cell delivery and antisense activity of PEGylated nanoparticles were sequence dependent and rely on the presence of anisamide ligand. The uptake of oligonucleotide in targeted, PEGylated nanoparticles could be competed by excess free ligand. Our results suggest that the ligand targeted and sterically stabilized nanoparticles can provide a selective delivery of AS-ODN and siRNA into lung cancer cells for therapy.

[Effects of ST6Gal I antisense oligonucleotide-mediated gene silencing on cell adhesion and invasiveness of hela cells]

OBJECTIVE

To study the effects of antisense oligonucleotide (ASODN) targeting ST6Gal I on cell adhesion and invasiveness of human cervical carcinoma cell line HeLa which over-expressed ST6Gal I .

METHODS

ASODN and sense oligonucleotide (SODN) targeting ST6Gal I were designed and constructed, and transfected into a cervical cancer cell line, HeLa, by lipofectmine 2000. HeLa cells were cultured and divided into 4 groups: blank control group, liposome group, SODN group and ASODN group. RT-PCR was used to examine the ST6Gal I mRNA expression. Flow cytometry was used to examine the amount of alpha2, 6-sialylation on the HeLa cell surface. The HeLa cell adhesion and invasiveness to extracellular matrix ( ECM) were analyzed by using CytoMatrixTM kit and cell invasion assay kit, respectively.

RESULTS

The expression of ST6Gal I mRNA in HeLa cells at 48 hrs after transfection in the ASODN group was significantly decreased in comparison with that in the blank control group, liposome group, and SODN group(P <0. 01). The amount of alpha2,6-sialylation on cell surface in ASODN group was significantly lower than that of the other 3 groups ( P <0. 05). The adhesion and invasiveness of the cells in the ASODN group decreased remarkably, both significantly lower than those of the other 3 groups ( all P < 0. 05).

CONCLUSION

Specific ASODN targeting ST6Gal I effectively inhibits HeLa cell ST6Gal I expression, decreases the amount of alpha2,6-sialylation on cell surface and leads to a decline of cell adhesion and invasiveness to ECM. This result also established a fine base for further studying on anti-tumor treatment with antisense oligonucleotide.

Leptin represses matrix metalloproteinase-1 gene expression in LX2 human hepatic stellate cells

BACKGROUND/AIMS

Collagen accumulation in liver fibrosis is due in part to decreased expression of matrix metalloproteinase (MMP)-1 relative to TIMP-1. LX-2 hepatic stellate cells produce increased amounts of collagen and tissue inhibitor of metalloproteinase (TIMP)-1 in response to leptin. The effect of leptin on MMP-1 production has not been reported.

METHODS

LX-2 cells were treated with leptin with or without inhibitors. We determined: phosphorylation of Janus kinase (JAK) 1 and -2, signal transducer and activator of transcription (STAT)3 and -5, extracellular signal-regulated kinase (ERK)1/2 and p38 by Western blot; H2O2 concentration by a colorimetric method; MMP-1 mRNA levels and stability by Northern blot; MMP-1 promoter activity as well as pro-MMP-1 by ELISA; and active MMP-1 by fluorescence.

RESULTS

LX-2 cells constitutively expressed the MMP-1 gene and leptin repressed the basal level of MMP-1 mRNA and its promoter activity. The repression was mediated by JAK/STAT pathway in synergism with JAK-mediated H2O2-dependent ERK1/2 and p38 pathways. ERK1/2 inhibited MMP-1 promoter activity, whereas p38 decreased the message stability, contributing to mRNA down-regulation. Inhibition of MMP-1 gene diminished secreted pro-MMP-1 and active MMP-1.

CONCLUSIONS

Leptin represses MMP-1 gene expression via the synergistic actions of the JAK/STAT pathway and JAK-mediated H2O2-dependent ERK1/2 and p38 pathways.

Efficacy of c-erbB-2 antisense oligonucleotide transfection on uterine endometrial cancer HEC-1A cell lines

OBJECTIVE

Antigene therapy targeting only one oncogene has made much progress although it still has some limitations. To explore the potential for antigene therapy in uterine endometrial cancer, we examined the in vitro inhibitory effects of liposmal anti-sense phosphorothioate oligonucleotides targeting c-erbB-2 in the human uterine endometrial cancer HEC-1A cell line.

METHODS

1) To detect c-erbB-2 protein expression on HEC-1A cell membranes by immunohisto- chemistry. 2) To assay cellular growth inhibition by MTT after transfecting 0.1-0.6 microM ASODN. 3) To observe cellular and ultra-structural changes under transmission electron microscope and to assay the cellular apoptotic rate by flow cytometry and c-erbB-2 mRNA, and protein expression by RT-PCR and Western blot after transfecting 0.3 microM ASODN.

RESULTS

1) c-erbB-2 protein expression was positive on HEC-1A cell membranes. 2) With the increase of the transfecting ASODN concentration from 0.1-0.6 microM, HEC-1A cellular growth inhibition was also enhanced. The results of MTT showed that when the transfecting concentration of ASODN was 0.3 microM, the HEC-1A cellular growth inhibition rate was 50% while when the transfecting concentration of ASODN was 0.6 microM, the HEC-1A cell growth inhibition rate was 75%. 3) When the concentration of transfecting ASODNs was 0.3 microM, there were obvious vacuolar degenerations in the plasma of HEC-1A cells, disappearance of organelle and nuclear structure and obvious shrinkage of nuclei under transmission electron microscope. The cellular apoptotic rate was 62.80%, while c-erbB-2 mRNA and protein expression were 47.18% and 33.60%, respectively, compared with those of the normal control cells.

CONCLUSION

Transfecting c-erbB-2 ASODNs can obviously suppress the mRNA and protein expression in HEC-1A cells, cause cellular apoptosis and inhibit cell growth. It may be a more useful gene therapy for endometrial cancer.

An NF-kappaB and slug regulatory loop active in early vertebrate mesoderm

Background

In both Drosophila and the mouse, the zinc finger transcription factor Snail is required for mesoderm formation; its vertebrate paralog Slug (Snai2) appears to be required for neural crest formation in the chick and the clawed frog Xenopus laevis. Both Slug and Snail act to induce epithelial to mesenchymal transition (EMT) and to suppress apoptosis.

Methodology & Principle Findings

Morpholino-based loss of function studies indicate that Slug is required for the normal expression of both mesodermal and neural crest markers in X. laevis. Both phenotypes are rescued by injection of RNA encoding the anti-apoptotic protein Bcl-xL; Bcl-xL's effects are dependent upon IκB kinase-mediated activation of the bipartite transcription factor NF-κB. NF-κB, in turn, directly up-regulates levels of Slug and Snail RNAs. Slug indirectly up-regulates levels of RNAs encoding the NF-κB subunit proteins RelA, Rel2, and Rel3, and directly down-regulates levels of the pro-apopotic Caspase-9 RNA.

Conclusions/Significance

These studies reveal a Slug/Snail–NF-κB regulatory circuit, analogous to that present in the early Drosophila embryo, active during mesodermal formation in Xenopus. This is a regulatory interaction of significance both in development and in the course of inflammatory and metastatic disease.

Ribosomal protein gene knockdown causes developmental defects in zebrafish

The ribosomal proteins (RPs) form the majority of cellular proteins and are mandatory for cellular growth. RP genes have been linked, either directly or indirectly, to various diseases in humans. Mutations in RP genes are also associated with tissue-specific phenotypes, suggesting a possible role in organ development during early embryogenesis. However, it is not yet known how mutations in a particular RP gene result in specific cellular changes, or how RP genes might contribute to human diseases. The development of animal models with defects in RP genes will be essential for studying these questions. In this study, we knocked down 21 RP genes in zebrafish by using morpholino antisense oligos to inhibit their translation. Of these 21, knockdown of 19 RPs resulted in the development of morphants with obvious deformities. Although mutations in RP genes, like other housekeeping genes, would be expected to result in nonspecific developmental defects with widespread phenotypes, we found that knockdown of some RP genes resulted in phenotypes specific to each gene, with varying degrees of abnormality in the brain, body trunk, eyes, and ears at about 25 hours post fertilization. We focused further on the organogenesis of the brain. Each knocked-down gene that affected the morphogenesis of the brain produced a different pattern of abnormality. Among the 7 RP genes whose knockdown produced severe brain phenotypes, 3 human orthologs are located within chromosomal regions that have been linked to brain-associated diseases, suggesting a possible involvement of RP genes in brain or neurological diseases. The RP gene knockdown system developed in this study could be a powerful tool for studying the roles of ribosomes in human diseases.

Zebrafish orthopedia (otp) is required for isotocin cell development

Several behavioral and physiological processes such as social, sexual, and maternal behaviors, learning and memory, and parturition are influenced by the neurohypophysial peptide oxytocin. Studies in knockout mice have identified four transcriptional regulatory genes that are required for oxytocin neuronal development in the hypothalamus. These are the basic helix-loop-helix PAS genes Single-minded 1 (Sim1) and Arylhydrocarbon receptor nuclear translocator 2 (Arnt2), the POU homeobox gene Pou3f2, and the paired homeobox gene Orthopedia (Otp). Overall, however, the molecular control of oxytocin cell development is poorly understood. Studies in zebrafish provide a complementary view to mouse knockout experiments and facilitate understanding of neuroendocrine cell development. Isotocin, which is orthologous to oxytocin, is expressed early in the developing zebrafish brain. In this paper we show that zebrafish otp mRNA expression in the embryonic forebrain is dynamic and complex, and that it overlaps with isotocin expression in the dorsal preoptic area. Additionally, these studies demonstrate that otp is required for isotocin cell development. Evidence is also provided that otp and sim1 function in parallel to direct the differentiation of isotocin cells, and that otp is unlikely to affect brain patterning. Overall, these studies support the hypothesis that the role of otp in zebrafish neuroendocrine cell development is evolutionarily conserved with that of mammals.

Fibin, a novel secreted lateral plate mesoderm signal, is essential for pectoral fin bud initiation in zebrafish

We identified a novel secreted protein, fibin, in zebrafish, mice and humans. We inhibited its function in zebrafish embryos by injecting antisense fibin morpholino oligonucleotides. A knockdown of fibin function in zebrafish resulted in no pectoral fin bud initiation and abolished the expression of tbx5, which is involved in the specification of pectoral fin identification. The lack of pectoral fins in fibin-knockdown embryos was partially rescued by injection of fibin RNA. fibin was expressed in the lateral plate mesoderm of the presumptive pectoral fin bud regions. Its expression region was adjacent to that of tbx5. fibin expression temporally preceded tbx5 expression in presumptive pectoral fin bud regions, and not abolished in tbx5-knockdown presumptive fin bud regions. In contrast, fibin expression was abolished in retinoic acid signaling-inhibited or wnt2b-knockdown presumptive fin bud regions. These results indicate that fibin is a secreted signal essential for pectoral fin bud initiation in that it potentially acts downstream of retinoic acid and wnt signaling and is essential for tbx5 expression. The present findings have revealed a novel secreted lateral plate mesoderm signal essential for fin initiation in the lateral plate mesoderm.

Vhnf1 acts downstream of Bmp, Fgf, and RA signals to regulate endocrine beta cell development in zebrafish

Bmp, Fgf, and retinoic acid (RA) signals have been implicated as regulators of pancreas development. However, the integration of these signaling pathways in vivo is not fully understood. Variant hnf1 (Vhnf1) is a transcription factor involved in pancreas, liver, and kidney development and its mutation in zebrafish causes underdeveloped pancreas and liver. We investigated the signaling pathways that regulate vhnf1 expression during pancreas development. First, we showed that Bmp activity is required for vhnf1 expression in the endoderm. In chordin (a Bmp antagonist) morpholino (MO)-injected embryos, vhnf1 expression in endoderm and in endocrine beta cells is expanded. On the other hand, in alk8 (a type I TGFbeta receptor) MO-injected embryos, vhnf1 expression in the endoderm is significantly reduced. Second, we showed that Fgf signaling participates in regulation of pancreas development through the vhnf1 pathway. Third, we demonstrated that RA fails to rescue reduction of insulin expression in vhnf1 mutants, whereas overexpression of vhnf1 restores insulin expression that is repressed by treatment with a RA receptor inhibitor. And finally, we revealed that both Bmp and Fgf signals act genetically upstream of RA in directing pancreas development. Taken together, our data establish that vhnf1 acts downstream of the signaling pathways of RA, Bmp, and Fgf to regulate pancreas development in zebrafish.

Antisense oligonucleotides targeting midkine induced apoptosis and increased chemosensitivity in hepatocellular carcinoma cells

AIM

Overexpression of midkine (MK) has been observed in many malignancies. This aim of this study is to screen for suitable antisense oligonucleotides (ASODN) targeting MK in hepatocellular carcinoma (HCC) cells and evaluate its antitumor activity.

METHODS

Ten ASODN targeting MK were designed and synthesized. After transfection with ASODN, cell proliferation was analyzed with MTS[3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] assay. In addition, MK mRNA, protein levels, as well as apoptosis and caspase-3 activity were also examined in HepG2 cells. Cell proliferation was then analyzed after treatment with both ASODN and chemotherapeutic drugs.

RESULTS

In this experiment, the ASODN5 among the 10 ASODN showed higher inhibitory activity against proliferation of hepatocellular carcinoma cells in a dose-dependent manner. In HepG2 cells, ASODN5 could significantly reduce the MK mRNA level and protein content. After transfection with ASODN5 for 48 h, accompanied with a decline of survivin and Bcl-2 protein content, a remarkable increase of apoptosis and caspase-3 activity was observed in HepG2 cells. Furthermore, ASODN5 transfer can significantly increase chemosensitivity in HepG2 cells.

CONCLUSION

Antisense oligonucleotides targeting MK shows therapeutic effects on HCC; ASODN5 has the possibility to be developed as an effective antitumor agent.

The myosin co-chaperone UNC-45 is required for skeletal and cardiac muscle function in zebrafish

The assembly of myosin into higher order structures is dependent upon accessory factors that are often tissue-specific. UNC-45 acts as such a molecular chaperone for myosin in the nematode Caenorhabditis elegans, in both muscle and non-muscle contexts. Although vertebrates contain homologues of UNC-45, their requirement for muscle function has not been assayed. We identified a zebrafish gene, unc45b, similar to a mammalian unc-45 homologue, expressed exclusively in striated muscle tissue, including the somites, heart and craniofacial muscle. Morpholino-oligonucleotide-mediated knockdown of unc45b results in paralysis and cardiac dysfunction. This paralysis is correlated with a loss of myosin filaments in the sarcomeres of the trunk muscle. Morphants lack circulation, heart looping and display severe cardiac and yolk-sac edema and also demonstrate ventral displacement of several jaw cartilages. Overall, this confirms a role for unc45b in zebrafish motility consistent with a function in myosin thick filament assembly and stability and uncovers novel roles for this gene in the function and morphogenesis of the developing heart and jaw. These results suggest that Unc45b acts as a chaperone that aids in the folding of myosin isoforms required for skeletal, cranial and cardiac muscle contraction.

Mechanisms of co-modified liver-targeting liposomes as gene delivery carriers based on cellular uptake and antigens inhibition effect

In order to deliver antisense oligonucleotides (asODN) into hepatocytes orientedly in the treatment of hepatitis B virus (HBV) infection, the liver-targeting cationic liposomes was developed as a gene carrier, which was co-modified with the ligand of the asialoglycoprotein receptor (ASGPR), beta-sitosterol-beta-d-glucoside (sito-G) and the nonionic surfactant, Brij 35. Flow cytometry (FCM) analysis and enzyme-linked immunosorbent assay (ELISA) showed that the asODN-encapsulating cationic liposomes exhibited high transfection efficiency and strong antigens inhibition effect in primary rat hepatocytes and HepG2.2.15 cells, respectively. With the help of several inhibitors acting on different steps during the targeting lipofection, the cellular uptake mechanisms of the co-modified liver-targeting cationic liposomes were investigated through antigens inhibition effect assay and confocal laser scanning microscopy (CLSM) analysis. The cellular uptake with high transfection efficiency seemed to involve both endocytosis and membrane fusion. The ligand sito-G was confirmed to be able to enhance ASGPR-mediated endocytosis, the nonionic surfactant Brij 35 seemed to be able to facilitate membrane fusion, and the co-modification resulted in the most efficient transfection but no enhanced cytotoxicity. These results suggested that the co-modified liver-targeting cationic liposomes would be a specific and effective carrier to transfer asODN into hepatocytes infected with HBV orientedly.

NPAS1 regulates branching morphogenesis in embryonic lung

Drosophila trachealess (Trl), master regulator of tracheogenesis, has no known functional mammalian homolog. We hypothesized that genes similar to trachealess regulate lung development. Quantitative (Q)RT-PCR and immunostaining were used to determine spatial and temporal patterns of npas1 gene expression in developing murine lung. Immunostaining for alpha-smooth muscle actin demonstrated myofibroblasts, and protein gene product (PGP)9.5 identified neuroendocrine cells. Branching morphogenesis of embryonic lung buds was analyzed in the presence of antisense or sense oligodeoxynucleotides (ODN). Microarray analyses were performed to screen for changes in gene expression in antisense-treated lungs. QRT-PCR was used to validate the altered expression of key genes identified on the microarrays. We demonstrate that npas1 is expressed in murine embryonic lung. npas1 mRNA peaks early at Embryonic Day (E)10.5-E11.5, then drops to low levels. Sequencing verifies the identity of npas1 transcripts in embryonic lung. NPAS1 immunostaining occurs in nuclei of parabronchial mesenchymal cells, especially at the tracheal bifurcation. Arnt, the murine homolog of Tango (the heterodimerization partner for Trl) is also expressed in developing lung but at constant levels. npas1- or arnt-antisense ODN inhibit lung branching morphogenesis, with altered myofibroblast development and increased pulmonary neuroendocrine cells. On microarrays, we identify > 50 known genes down-regulated by npas1-antisense, including multiple genes regulating cell migration and cell differentiation. QRT-PCR confirms significantly decreased expression of the neurogenic genes RBP-Jk and Tle, and three genes involved in muscle development: beta-ig-h3, claudin-11, and myocardin. Npas1 can regulate myofibroblast distribution, branching morphogenesis, and neuroendocrine cell differentiation in murine embryonic lung.

Contribution of mGluR and Fmr1 functional pathways to neurite morphogenesis, craniofacial development and fragile X syndrome

Fragile X Syndrome is a leading heritable cause of mental retardation that results from the loss of FMR1 gene function. Studies in mouse and Drosophila model organisms have been critical in understanding many aspects of the loss of function of the FMR1 gene in the human syndrome. Here, we establish that the zebrafish is a useful model organism for the study of the human fragile X syndrome and can be used to examine phenotypes that are difficult or inaccessible to observation in other model organisms. Using morpholino knockdown of the fmr1 gene, we observed abnormal axonal branching of Rohon-Beard and trigeminal ganglion neurons and guidance and defasciculation defects in the lateral longitudinal fasciculus. We demonstrate that this axonal branching defect can be rescued by treatment with MPEP [2-methyl-6-(phenylethynyl) pyridine]. This is consistent with an interaction between mGluR signalling and fmr1 function in neurite morphogenesis. We also describe novel findings of abnormalities in the abundance of trigeminal ganglion neurons and of craniofacial abnormalities apparently due to dysmorphic cartilage formation. These abnormalities may be related to a role for fmr1 in neural crest cell specification and possibly in migration.

Combinatorial function of ETS transcription factors in the developing vasculature

Members of the ETS family of transcription factors are among the first genes expressed in the developing vasculature, but loss-of-function experiments for individual ETS factors in mice have not uncovered important early functional roles for these genes. However, multiple ETS factors are expressed in spatially and temporally overlapping patterns in the developing vasculature, suggesting possible functional overlap. We have taken a comprehensive approach to exploring the function of these factors during vascular development by employing the genetic and experimental tools available in the zebrafish to analyze four ETS family members expressed together in the zebrafish vasculature; fli1, fli1b, ets1, and etsrp. We isolated and characterized an ENU-induced mutant with defects in trunk angiogenesis and positionally cloned the defective gene from this mutant, etsrp. Using the etsrp morpholinos targeting each of the four genes, we show that the four ETS factors function combinatorially during vascular and hematopoietic development. Reduction of etsrp or any of the other genes alone results in either partial or no defects in endothelial differentiation, while combined reduction in the function of all four genes causes dramatic loss of endothelial cells. Our results demonstrate that combinatorial ETS factor function is essential for early endothelial specification and differentiation.

[Functional study of progesterone receptor isoforms in endometrial cancer cell lines]

OBJECTIVE

To study the functional differences between the two progestrone receptor isoforms(PR-A and PR-B) in human endometrial cancer,using antisense oligodeoxynucleotide(AS-ODN) to downregulate isoform B of progestrone receptor in endometrial carcinoma cell lines, After transfection of the oligodeoxynucleotide, several kinds of hormones were added in the cells to observe the different response, where to study the functional differences between the two isoforms.

METHODS

The well-differentiated endometrial cancer cell line Ishikawa and moderate-differentiated endometrial cancer cell line Hec-1B were cultured in vitro. The cells were transfected with antisense, sense, and scramble-ODN. After 48 hours, the expressions of two progesterone receptor isoforms were detected by Western blot using specific antibody. Then the cells were planted in 96-well plates, transfected with antisense, sense, scramble-ODN and added in several hormones to search for the response in distinct hormones and oligodeoxynucleotides.

RESULTS

After transfecting antisense-ODN, two cell lines were down-regulated in progesterone receptor isoform B,but progesterone receptor isoform A was not down-regulated,and the progesterone receptor isoform B of cells transfected with sense and scramble-ODN was not changed. When stimulated by 17beta-estradiol(E2)for 72 hours,the growth of Ishikawa cells was significantly higher than that of the control, Hec-1B cells only grew higher than control,but it was to significant in statistics.R5020 inhibited Ishikawa cells significantly after stimulating for 72 hours. There was the same effect in Hec-1B cells after stimulating for 96 hours. On the bases of E2 and R5020, we added mifepristone (RU486) . The cells developed after 96 hours in Ishikawa cells and developed after 48 hours in Hec-1B cells. When PR-B was down-regulated,the stimulating effect of E2 was enhanced, but the inhibitory effect of R5020 was decreased, RU486 antagonized R5020 weaklier than the control.

CONCLUSION

AS-ODN directed against the human PR-B can inhibit the expression of PR-B effectively,through which the PR-A expresses predominantly. E2 can cause endometrial carcinoma cell growth, PR-B is associated with the stimulating effect of E2 in endometrial carcinoma cells. Progestin (R5020) inhibits the hyperplasia induced by E2,PR-B is involved in the inhibitory effect of R5020. RU486 antagonizes the effect of R5020,inhibiting cell growth, PR-B is involved in the antagonizing effect of RU486.

Inhibition of the VEGF expression and cell growth in hepatocellular carcinoma by blocking HIF-1alpha and Smad3 binding site in VEGF promoter

In order to investigate the inhibitory effects on the vascular endothelial growth factor (VEGF) expression and cell growth in hapatocellular carcinoma (HCC) by blocking HIF-1alpha and Smad3 binding site in the VEGF promoter, antisense oligodeoxynucleotides (ASODN) were designed to block HIF-1alpha and Smad3 binding site in the VEGF promoter. Different concentrations of ASODN and ODN were transfected into HCC cells respectively. The expression of VEGF mRNA and protein was detected by SABC, Western blot and RT-PCR techniques and the inhibitory effects on the expression of VEGF and cell growth of the HCC cells stimulated by the supernatants were determined by using MTT method. Immunohistochestry revealed that after co-inoculation of hepatocellular carcinoma cells with different concentrations of ODN and ASODN for 48 h, there was no significant difference in the expression of VEGF protein between ODN group and control group (P > 0.05), but there was significant difference between ASODN group and control group (P < 0.05). At a concentration of 10 micromol/L ASODN, the difference was very significant (P < 0.01). Western blot and RT-PCR revealed that, after treatment for 48 h at a concentration of 10 micromol/L. the integral gray levels and RNA odds were 59743.2 +/- 10412.5 and 0.783 +/- 0.032 in ODN group, and 38694.5 +/- 10925.1 and 0.468 +/- 0.015 in ASODN group, respectively, with the difference being very significant (P < 0.01). Antisense ODN could inhibit the growth of HCC cells in a concentration-dependent manner. It was concluded that anti-gene technique of aiming at HIF-1alpha action site in the VEGF promoter could suppress the VEGF expression and inhibit HCC cell growth, and it is promising that anti-gene technique works as a new gene therapeutic tool for anti-angiogenesis of HCC.