Induction of potent anti-tumor immunity by direct injection of Ad-LIGHT at the site of tumor inoculation

BACKGROUND

The aim of this study was to observe the therapeutic effects of adenovirus-mediated LIGHT gene transfer in murine B16 melanoma in vivo.

METHODS

C57BL/6 mice were inoculated subcutaneously with B16 cells to establish the murine melanoma model. The tumor-bearing mice were injected at the site of tumor inoculation with recombinant adenoviral vectors expressing the murine LIGHT gene. The tumor growth and survival period of tumor-bearing mice were observed. The splenic NK and CTL activity were measured in vitro by lactate dehydrogenase (LDH) release assay. The amounts of cytokines were determined with ELISA kits.

RESULTS

The LIGHT gene could be efficiently transduced into tumor tissue after injection of Ad-LIGHT. Treatment with Ad-LIGHT significantly inhibited the tumor growth and prolonged the survival period of the tumor-bearing mice. The splenic NK and CTL activity of the mice was also enhanced after LIGHT gene transfer. The production of IL-2 and IFN-gamma from lymphocytes derived from mice treated with Ad-LIGHT was increased significantly compared with control groups.

DISCUSSION

Our results indicate that local expression of the LIGHT gene can induce potent anti-tumor immunity and may be a promising treatment strategy for melanoma.

Mapping of hereditary mixed polyposis syndrome (HMPS) to chromosome 10q23 by genomewide high-density single nucleotide polymorphism (SNP) scan and identification of BMPR1A loss of function

BACKGROUND

Hereditary mixed polyposis syndrome (HMPS) is characterised by colonic polyps of mixed histological types that are autosomal dominantly inherited and eventually lead to colorectal cancer (CRC). Study of the molecular basis of HMPS will enhance our knowledge of the genetic basis of the mixed polyposis-carcinoma sequence in both hereditary and sporadic CRC.

METHODS/RESULTS

We performed a genomewide linkage search on 15 members of a three-generation HMPS family using the GeneChip Human Mapping 10K Array and identified a 7 cM putative linkage interval on chromosome 10q23. Subsequently, 32 members from two HMPS families were typed with nine microsatellite markers spanning the region and the linkage was confirmed with a maximum multi-point logarithm of the odds (LOD) score of 4.6 (p<0.001). The 10q23.1-10q23.31 haplotypes segregate with the disease in both families. We screened for mutations in four candidate genes within the linkage region and identified an 11 bp deletion in the bone morphogenesis protein receptor 1A (BMPR1A) gene in one family.

CONCLUSIONS

Our results indicate that BMPR1A mutation accounts for HMPS. The data suggest that inactivating BMPR1A can initiate colorectal tumourigenesis via the mixed polyposis-carcinoma sequence.

Regulation of Nur77 nuclear export by c-Jun N-terminal kinase and Akt

Proapoptotic nuclear receptor family member Nur77 translocates from the nucleus to the mitochondria, where it interacts with Bcl-2 to trigger apoptosis. Nur77 translocation is induced by certain apoptotic stimuli, including the synthetic retinoid-related 6-[3-(1-adamantyl)-4-hydroxyphenyl]-2-naphthalenecarboxylic acid (AHPN)/CD437 class. In this study, we investigated the molecular mechanism by which AHPN/CD437 analog (E)-4-[3-(1-adamantyl)-4-hydroxyphenyl]-3-chlorocinnamic acid (3-Cl-AHPC) induces Nur77 nuclear export. Our results demonstrate that 3-Cl-AHPC effectively activated Jun N-terminal kinase (JNK), which phosphorylates Nur77. Inhibition of JNK activation by a JNK inhibitor suppressed 3-Cl-AHPC-induced Nur77 nuclear export and apoptosis. In addition, several JNK upstream activators, including the phorbol ester TPA, anisomycin and MAPK kinase kinase-1 (MEKK1), phosphorylated Nur77 and induced its nuclear export. However, Nur77 phosphorylation by JNK, although essential, was not sufficient for inducing Nur77 nuclear export. Induction of Nur77 nuclear export by MEKK1 required a prolonged MEKK1 activation and was attenuated by Akt activation. Expression of constitutively active Akt prevented MEKK1-induced Nur77 nuclear export. Conversely, transfection of dominant-negative Akt or treatment with a phosphatidylinositol 3-kinase (PI3-K) inhibitor accelerated MEKK1-induced Nur77 nuclear export. Furthermore, mutation of an Akt phosphorylation residue Ser351 in Nur77 abolished the effect of Akt or the PI3-K inhibitor. Together, our results demonstrate that both activation of JNK and inhibition of Akt play a role in translocation of Nur77 from the nucleus to the cytoplasm.

Coupling mitochondrial respiratory chain to cell death: an essential role of mitochondrial complex I in the interferon-β and retinoic acid-induced cancer cell death

Combination of retinoic acids (RAs) and interferons (IFNs) has synergistic apoptotic effects and is used in cancer treatment. However, the underlying mechanisms remain unknown. Here, we demonstrate that mitochondrial respiratory chain (MRC) plays an essential role in the IFN-beta/RA-induced cancer cell death. We found that IFN-beta/RA upregulates the expression of MRC complex subunits. Mitochondrial-nuclear translocation of these subunits was not observed, but overproduction of reactive oxygen species (ROS), which causes loss of mitochondrial function, was detected upon IFN-beta/RA treatment. Knockdown of GRIM-19 (gene associated with retinoid-interferon-induced mortality-19) and NDUFS3 (NADH dehydrogenase (ubiquinone) Fe-S protein 3), two subunits of MRC complex I, by siRNA in two cancer cell lines conferred resistance to IFN-beta/RA-induced apoptosis and reduced ROS production. In parallel, expression of late genes induced by IFN-beta/RA that are directly involved in growth inhibition and cell death was also repressed in the knockdown cells. Our data suggest that the MRC regulates IFN-beta/RA-induced cell death by modulating ROS production and late gene expression.

Model development of human sarcomas for identification and validation of new targets

13080

Background: Soft tissue sarcomas are malignant tumors that can develop from a variety of tissues. There is a lack of targeted therapies directed specifically against sarcomas with surgery, radiation, and chemotherapy being the standard of care. By employing multiple strategies, new targets that may advance sarcoma therapy can be identified. Methods: Profiling of secreted cytokines that may drive tumor growth was performed on cell lines representing osteosarcomas, liposarcomas, fibrosarcomas, and rhabdomysarcomas. Of 27 cytokines analyzed from cultured media, the following were most highly expressed: IL-6, IL-8, IL-12p40, SDF-1, and MCP-1. Results: Results were compared against gene expression data from publicly available oligonucleotide microarrays derived from human tumors. Ewing’s sarcoma and rhabdomysarcoma samples confirmed higher expression levels of VEGF. Further analysis of array data from 16 classes of sarcomas and 181 tumors indicated that IL-7 was more predominantly expressed than IL-6 and IL-8. To evaluate efficacy of novel agents, xenograft models were established using human cell lines A673 rhabdomyosarcoma and SW872 liposarcoma. Tumor growth and response to therapy was characterized. Paclitaxel (75 mg/kg, days 7, 9, 11) delayed tumor growth for about one week following treatment in both models, however only SW872 liposarcoma tumors responded after dosing with anti-angiogenic agent, Avastin (5 mg/kg, days 4, 7, 11, 14, 17, and 21). Conclusions: In addition to killing cancer cells, destabilization of the vasculature/stroma may be beneficial. Immunohistochemical (IHC) analysis was performed on sarcoma tumors from the clinic. CD31 and SMA staining identified vasculature and stromal regions. Subsequent to identification of novel targets specific to sarcomas, IHC methods can further define localization of antigens between various tumor components. A variety of techniques are being utilized in order to recognize new targets in sarcomas. Cell-based assays and preclinical models are incorporated into the drug development pathway to evaluate novel drugs. Analysis of differential gene expression between tumor types and amongst sarcoma subtypes will be essential in identifying which patient population will gain the greatest benefits from targeted therapies.

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Exon deletions of parkin gene in patients with Parkinson disease

Mutations in the parkin gene have recently been identified in familial and isolated patients with early-onset Parkinson disease (PD) and that subregions between exon 2 and 4 of the parkin gene are hot spots of deletive mutations. To study the distribution of deletions in the parkin gene among variant subset patients with PD in China, and to explore the role of parkin gene in the pathogenesis of PD, 63 patients were divided into early onset and later onset groups. Exons 1-12 were amplified by PCR, templated by the genomic DNA of patients, and then the deletion distribution detected by agarose electrophoresis. Four patients were found to be carrier of exon deletions in 63 patients with PD. The location of the deletion was on exon 2 (1 case), exon 3 (2 cases) and exon 4 (1 case). All patients were belong to the group of early onset PD. The results showed that parkin gene deletion on exon 2, exon 3 and exon 4 found in Chinese population contributes partly to early onset PD.

Stat3 contributes to keloid pathogenesis via promoting collagen production, cell proliferation and migration

Keloids, partially considered as benign tumors, represent the most extreme example of cutaneous scarring that uniquely afflicts humans as a pathological response to wound healing. It is characterized by excessive deposition of collagen and other extracellular matrix components by dermal fibroblasts. Upon cutaneous injury, cocktails of chemokines, cytokines and growth factors are secreted temporally and spatially to direct appropriate responses from neutrophils, macrophages, keratinocytes and fibroblasts to facilitate normal wound healing. Signal transducer and activator of transcription 3 (Stat3) is an oncogene and a latent transcription factor activated by various cytokines and growth factors. We investigated the possible role of Stat3 in keloid scar pathogenesis by examining skin tissue and cultured fibroblasts from keloid-scarred patients. We observed enhanced expression and phosphorylation of Stat3 in keloid scar tissue, and in cultured keloid fibroblasts (KFs) in vitro. Increased activation of Janus kinase (Jak)2, but not Jak1, was detected in KFs, and suppression of Jak2 by its inhibitor repressed Stat3 Y705 phosphorylation. Inhibition of Stat3 expression and phosphorylation by short interfering RNA or Cucurbitacin I resulted in the loss of collagen production, impaired proliferation and delayed cell migration in KFs. We show, for the first time, a role of Stat3 in keloid pathogenesis. Inhibitors of Stat3 may be useful therapeutic strategies for the prospective treatment of keloid scars.

Haloperidol induces apoptosis via the sigma2 receptor system and Bcl-XS

Toxicity of the typical antipsychotic haloperidol (HAL) comprises an apoptotic component that we link to pro-apoptotic Bcl-XS in PC12 preneuronal and N2a neuroblastoma cells. The mitochondrial translocation of Bcl-XS and its interaction with the pore-forming voltage-dependent anion channel (VDAC) correlates with the redistribution of cytochrome c and the cleavage of Poly(ADP-ribose) polymerase. Haloperidol-induced apoptosis is mediated by the sigma2 (sigma2) receptor system and does not involve the expected antagonism of the dopamine D(2) receptor, nor is it influenced by Vitamin E- or p53/Bax-mediated events. Pathological relevance is demonstrated by the cytotoxic synergism between HAL and the Alzheimer disease-related peptide beta-amyloid(1-40), which correlates with Bcl-XS expression and its interaction with VDAC, and with cytosolic cytochrome c translocation. These data provide for a unique apoptotic mechanism that could underscore the clinical risks associated with HAL, particularly following chronic regimens or in the elderly.

Regulator of G-protein signaling 2 (RGS2) inhibits androgen-independent activation of androgen receptor in prostate cancer cells

Hormones acting through G protein-coupled receptors (GPCRs) can cause androgen-independent activation of androgen receptor (AR) in prostate cancer cells. Regulators of G-protein signaling (RGS) proteins, through their GTPase activating protein (GAP) activities, inhibit GPCR-mediated signaling by inactivating G proteins. Here, we identified RGS2 as a gene specifically downregulated in androgen-independent prostate cancer cells. Expression of RGS2, but not other RGS proteins, abolished androgen-independent AR activity in androgen-independent LNCaP cells and CWR22Rv1 cells. In LNCaP cells, RGS2 inhibited G(q)-coupled GPCR signaling. Expression of exogenous wild-type RGS2, but not its GAP-deficient mutant, significantly reduced AR activation by constitutively activated G(q)Q209L mutant whereas silencing endogenous RGS2 by siRNA enhanced G(q)Q209L-stimulated AR activity. RGS2 had no effect on RGS-insensitive G(q)Q209L/G188S-induced AR activation. Furthermore, extracellular signal-regulated kinase 1/2 (ERK1/2) was found to be involved in RGS2-mediated regulation of androgen-independent AR activity. In addition, RGS2 functioned as a growth suppressor for androgen-independent LNCaP cells whereas androgen-sensitive LNCaP cells with RGS2 silencing had a growth advantage under steroid-reduced conditions. Finally, RGS2 expression level was significantly decreased in human prostate tumor specimens. Taken together, our results suggest RGS2 as a novel regulator of AR signaling and its repression may be an important step during prostate tumorigenesis and progression.

Bioinformatics approaches for cross-species liver cancer analysis based on microarray gene expression profiling

Background

The completion of the sequencing of human, mouse and rat genomes and knowledge of cross-species gene homologies enables studies of differential gene expression in animal models. These types of studies have the potential to greatly enhance our understanding of diseases such as liver cancer in humans. Genes co-expressed across multiple species are most likely to have conserved functions. We have used various bioinformatics approaches to examine microarray expression profiles from liver neoplasms that arise in albumin-SV40 transgenic rats to elucidate genes, chromosome aberrations and pathways that might be associated with human liver cancer.

Results

In this study, we first identified 2223 differentially expressed genes by comparing gene expression profiles for two control, two adenoma and two carcinoma samples using an F-test. These genes were subsequently mapped to the rat chromosomes using a novel visualization tool, the Chromosome Plot. Using the same plot, we further mapped the significant genes to orthologous chromosomal locations in human and mouse. Many genes expressed in rat 1q that are amplified in rat liver cancer map to the human chromosomes 10, 11 and 19 and to the mouse chromosomes 7, 17 and 19, which have been implicated in studies of human and mouse liver cancer. Using Comparative Genomics Microarray Analysis (CGMA), we identified regions of potential aberrations in human. Lastly, a pathway analysis was conducted to predict altered human pathways based on statistical analysis and extrapolation from the rat data. All of the identified pathways have been known to be important in the etiology of human liver cancer, including cell cycle control, cell growth and differentiation, apoptosis, transcriptional regulation, and protein metabolism.

Conclusion

The study demonstrates that the hepatic gene expression profiles from the albumin-SV40 transgenic rat model revealed genes, pathways and chromosome alterations consistent with experimental and clinical research in human liver cancer. The bioinformatics tools presented in this paper are essential for cross species extrapolation and mapping of microarray data, its analysis and interpretation.

Polymorphic karyotypes and sex chromosomes in the tufted deer (Elaphodus cephalophus): cytogenetic studies and analyses of sex chromosome-linked genes

Different diploid chromosome numbers have been reported for the tufted deer Elaphodus cephalophus (female, 2n = 46/47; male, 2n = 47/48) in earlier reports. In the present study, chromosomal analysis of seven tufted deer (5 male symbol, 2 female symbol) revealed that the karyotype of these animals contains 48 chromosomes, including a pair of large heteromorphic chromosomes in the male. C-banding revealed these chromosomes to be very rich in constitutive heterochromatin. Chromosome banding and PCR of sex chromosome-linked genes (SRY, ZFX, ZFY) performed on DOP-PCR products of single microdissected X and Y chromosomes confirmed that the large telocentric chromosome without secondary constriction is the X chromosome whereas the subtelocentric chromosome is the Y. The increased size of both, the X and Y chromosome, appears to be at least partially attributable to the presence of substantial amounts of heterochromatin.

Resumption of oocyte meiosis in mammals: on models, meiosis activating sterols, steroids and EGF-like factors

De novo synthesis of meiosis activating sterols (MAS) was stimulated by LH- and AY-9944 in rat cultured follicles and cumulus oocyte complexes (COCs), but could not be measured in denuded oocytes. Thus, MAS synthesized by the somatic compartment of the follicle could serve as a signal for the resumption of meiosis. Nevertheless, the delay in germinal vesicle breakdown (GVB) after MAS or AY-9944 stimulation as compared with gonadotropins, obtained by several groups, remains the strongest evidence against the suggested role of MAS as an essential mediator of LH in meiosis resumption. Recently several studies using mammalian COCs in culture have implied that steroids, like in fish and amphibians, serve as signals in mediating the LH/hCG stimulation of meiosis. However, in these studies there was no clear distinction between the requirement for steroids for the acquisition of meiotic competence, oocyte and follicle wellbeing or as a signal for meiotic resumption. Further, some of the authors overlooked earlier studies showing that blocking ovarian or follicular steroidogenesis does not affect GVB, the first step of meiosis resumption. Finally, in vivo and in vitro studies in the rat confirm and extend recent studies showing that locally produced and released EGF-like factors, such as epiregulin, seem to mediate at least part of the LH/hCG actions on oocyte maturation and release of ova at ovulation.

Experimental study on induction of tolerance to experimental autoimmune myasthenia gravis by immature dendritic cells

To investigate the effect of immature dendritic cells (iDCs) on experimental autoimmune myasthenia gravis (MG), iDCs were generated in low dose of GM-CSF, and then they were pulsed with acetylcholine receptor (AchR) and transferred to allogeneic rats. After 3 weeks, all rats were immunized with AchR and complete Freund's adjuvant (CFA) and observed for the corresponding indices of MG for 7 weeks. Our results showed that compared with mature DCs (mDCs) generated at high dose of GM-CSF plus additional stimulation by lipopolysaccharide, iDCs expressed significantly lower levels of MHC-II, CD80 and CD86, and their ability to uptake FITC-Dextran was stronger but the ability of stimulating proliferation of allogeneic T cells were weaker. Like controls, after immunization, all rats transferred with iDCs, mDCs and AchR-pulsed mDCs showed typical symptoms in 4 to 7 weeks. The amplitude of electromyogram wave dropped obviously, the level of serum AchRab increased and neuromuscular junction showed typical damage of MG. In contrast, no conspicuous changes were noted in rats transferred with AchR-pulsed iDCs. The results suggest that iDCs could be generated by inducing bone marrow precursors in low dose of GM-CSF, AchR-pulsed iDCs could induce tolerance of EAMG. The dysfunction of DCs may play an important role in the initiation and maintenance of normal immune response in MG.

Epidermal growth factor family members: endogenous mediators of the ovulatory response

Previous studies showed that epidermal growth factor (EGF) and TGFalpha mimic the action of LH on the resumption of oocyte maturation. We tested whether EGF-like agents, such as amphiregulin (AR), epiregulin (ER), and betacellulin (BTC), also mediate the LH stimulation of the ovulatory response in the rat. LH induced transient follicular expression of AR, ER, and BTC mRNA, reaching a maximum after 3-h incubation. Furthermore, the addition of ER, AR, and BTC to the culture medium could mimic some of LH actions. AR and ER fully simulated LH-induced resumption of meiosis in vitro, whereas BTC was less effective. To study the putative involvement of EGF-like factors in mediation of LH signal, the effect of the EGF receptor kinase inhibitor AG1478 was tested. When added with LH, AG1478, but not its inactive analog AG43, reduced EGF receptor phosphorylation and oocyte maturation compared with follicles treated with LH only. In addition to the inhibition of resumption of meiosis, AG1478 administration into the bursa (3 microg/bursa) resulted in 51% (P < 0.0005) inhibition of ovulation in the treated ovaries, compared with the untreated contralateral ones, as well as to the vehicle-treated ovaries (P < 0.02). LH, as well as ER, induced the expression of genes associated with the ovulatory response like rat hyaluronan synthase-2, cyclooxygenase-2, and TNFalpha-stimulated gene 6 mRNA, whereas AG1478 inhibited this effect of LH. Release of EGF-like factors from the membrane is dependent on activated metalloproteases. Indeed, Galardin, a broad-spectrum metalloprotease inhibitor, but not a specific matrix metalloprotease 2 and 9 inhibitor, suppressed meiotic maturation induced by LH. Conversely, meiotic maturation induced by ER was not affected by Galardin, thus, supporting the notion that LH releases follicular membrane-bound EGF-like agents. In summary, EGF-like factors such as ER, AR, and BTC seem to mediate, at least partially, the LH stimulation of oocyte maturation, ovulatory enzyme expression, and ovulation.

Effect of PD I administration on dopamine receptors mRNAs expression in the lesioned striatum of PD rat model

To study the effect of PD I administration on dopamine receptors (DR1, DR2) mRNAs expression in the lesioned striatum of the PD rat model and confirm if PD I has the effect of dopamine receptor agonist. The PD rats with unilateral 6-hydroxydopamine lesioned were administrated with PD I, L-dopa methyl/benserazide, L-dopa methyl /benserazide/ PD I, normal saline respectively for 4 weeks and their behavioral changes were observed. Then the rats were sacrificed and RT-PCR technique was used to detect changes of dopamine receptors (DR1, DR2) mRNAs expression in the ipsilateral striatum 1 day after the last treatment. The results showed that treatment with PD I plus L-dopa resulted in a stable contralateral rotation behavior; treatment with L-dopa resulted in a progressively increased contralateral rotation behavior. Rotation behavior induced by anhydromorphine decreased with PD I or PD I plus L-dopa treatment. Treatment With L-dopa or PD I plus L-dopa, up-regulation of DR1 mRNA and down-regulation of DR2 mRNA were observed in the ipsilateral striatum which were more obvious than that treated with PD I or vehicle (P < 0.05). It was concluded that long-term treatment with PD I could alleviate the behavior of PD rats. PD I had no apparent effect on the dopamine receptors (DR1, DR2) mRNAs expression in the ipsilateral striatum and the PD I has no agonist effect on dopamine receptors.

Echocardiographic predictors of adverse clinical events in children with dilated cardiomyopathy: a prospective clinical study

OBJECTIVES

To compare tissue Doppler (TD) velocities between patients with dilated cardiomyopathy (DCM) and normal controls and to determine whether TD velocities, Tei index, right ventricular fractional area change, and left ventricular ejection fraction (LVEF) predict adverse clinical outcomes in children with DCM.

METHODS

Prospective evaluation of children with DCM.

RESULTS

54 children with DCM and 54 age and sex matched control group participants were studied. Mitral inflow velocities were similar for both groups except for decreased mitral deceleration time in patients with DCM. Systolic and diastolic TD velocities at the mitral annulus (septal and lateral sides) and tricuspid annulus were significantly reduced in children with DCM compared with controls (p < 0.001 for each). By multivariate analysis, after adjustment for Tei index and right ventricular fractional area change, decreased LVEF and tricuspid velocity during early diastole (Ea) were predictors of the primary end point (PEP), a composite end point consisting of need for hospitalisation or the outcome transplantation or death. Tricuspid Ea velocity < 8.5 cm/s had 87% specificity and 60% sensitivity for reaching the PEP. LVEF < 30% had 68% specificity and 74% sensitivity for the PEP. Combined LVEF < 30% and tricuspid Ea < 11.5 cm/s had 100% specificity and 44% sensitivity for the PEP.

CONCLUSIONS

Children with DCM have significantly lower TD velocities than normal controls. In such cases, lower LVEF (< 30%) is more sensitive but less specific than lower tricuspid Ea velocities (< 8.5 cm/s) in predicting which patients are at risk of hospitalisation, transplantation, or death.

Experimental study on heterograft of glomus cells of carotid body for hemiparkinsonian rats

To observe the effects of heterograft of glomus cells of carotid body on hemiparkinsonian rat models, rats with unilateral 6-hydroxydopamine (6-OHDA)-induced lesions of the right dopaminergic neurons of substantia nigra received intrastriatal glomus cells heterograft. Apomorphine-induced rotation was monitored for 30 min at various time points after grafting. The striata were cut and examined for dopamine content by HPLC and for immunohistochemical staining of tyrosine hydroxylase positive neurons (TH+) at the end of the experiments. The results showed that apomorphine-induced rotational behavior was significantly reduced for 12 weeks and the dopamine contents were significantly elevated after grafting (P < 0.01), and TH+ cells survived better. The present study demonstrates that intrastriatal heterograft of glomus cells within carotid body in rats with 6-OHDA-elicited lesions could reduce apomorphine-induced rotational behavior and elevate the dopamine contents and numbers of TH+ cell surviving within striatum, and can serve as a new and effective alternative for Parkinson disease.