Electrospun P34HB fibres: a scaffold for tissue engineering

OBJECTIVES

Amongst the fourth generation of PHAs is bio-plasticpoly3-hydroxybutyrate4-hydroxybutyrate (P34HB); it is thus appropriate to perform novel research on its uses and applications. The main objective of this study was to determine whether electrospun P34HB fibres would accommodate viability, growth and differentiation of mouse adipose-derived stem cells (mASCs).

MATERIALS AND METHODS

In the present study, we looked at P34HB in two forms, electrospun P34HB fibres and P34HB film. Morphology of electrospun P34HB fibres and P34HB film were characterized using scanning electron microscopy, fluorescence microscopy and confocal laser scanning microscopy, after cell seeding. Cell adhesion, proliferation and cytotoxicity tests were conducted on both by MTT and CCK-8 assays, respectively. After being cultured with osteogenic induction, expression of adipogenic genes Runx2, OPN and OCN, were examined by real-time PCR.

RESULTS

By scanning electron microscopy, light microscopy and confocal laser scanning microscopy, we observed that the mASCs grew well associated with the P34HB materials. After MTT and CCK-8 assay, we concluded that P34HB would, indeed, be a material suitable for further cell adhesion and proliferation studies. More importantly, we found that the P34HB matrices promoted expression of Runx2, OPN and OCN with osteogenic induction.

CONCLUSIONS

In this investigation, we can confirm that the electrospun P34HB fibres accommodated survival, proliferation and differentiation of mASCs, and we have been able to draw the conclusion that fibre scaffolds produced by the electrospinning process are promising for application of bone tissue engineering.

Effects of VEGF suppression by small hairpin RNA interference combined with radiotherapy on the growth of cervical cancer

This study aimed to investigate the inhibition of vascular endothelial growth factor (VEGF) by small hairpin RNA (shRNA) interference combined with radiotherapy on the growth of cervical cancer SiHa cell xenografts in nude mice. The effective pVEGF-shRNA plasmid was screened by reverse transcription-polymerase chain reaction (RT-PCR), and the cell apoptosis rate was estimated by flow cytometry. A nude mouse cervical xenograft model was established and all models were divided into four groups: blank control, VEGF shRNA, radiotherapy, and combined treatment. We calculated the tumor growth curve and the inhibitory rate. The histopathological changes of the microvascular density and VEGF protein expression were observed by immunohistochemistry. The expressions of VEGF and hypoxia inducible factor-1α (HIF-1α) proteins in the tumor tissue were analyzed via Western blot. VEGF shRNA interference inhibited the expression of radiation-induced VEGF (P < 0.05), induced apoptosis (P < 0.05), downregulated the HIF-1α protein, and reduced angiogenesis. Compared with the other three groups, the combined treatment group showed the most significant effects (P < 0.01). VEGF shRNA interference combined with radiotherapy promotes the radiosensitivity of tumors via improvement of the hypoxic microenvironment.

A novel decoy receptor fusion protein for FGF-2 potently inhibits tumour growth

BACKGROUND

Antiangiogenic therapies have been proven effective in cancer treatment. Fibroblast growth factor-2 (FGF-2) has been functionally implicated in tumour angiogenesis and is an important target of antiangiogenic therapies. The aim of this work was to develop a novel FGF-2 inhibitor for cancer therapy.

METHODS

Eleven fusion proteins were developed by fusing various truncated extracellular regions of FGFR1 with the Fc region of IgG1. The optimal decoy receptor fusion protein with the highest binding affinity for FGF-2 was identified by an FGF-2-binding assay and its potential antitumour effects were investigated.

RESULTS

We obtained a soluble decoy receptor fusion protein with the highest binding activity for FGF-2, named FGF-Trap. Fibroblast growth factor-Trap significantly abolished FGF-2-stimulated activation of FGF signalling as demonstrated by its suppression of FGF-2-mediated phosphorylation of Erk1/2 and Akt, upregulation of cyclins D1 and E and the increase in mRNA levels of vascular endothelial growth factor R1 and R2 (VEGFR1 and VEGFR2). Furthermore, FGF-Trap effectively suppressed FGF-2-induced proliferation and migration of human umbilical vein endothelial cells (HUVECs) in vitro. Most importantly, FGF-Trap potently inhibited tumour growth and angiogenesis in Caki-1 and A549 xenograft models in vivo.

CONCLUSIONS

Fibroblast growth factor-Trap potently inhibits tumour growth by blocking FGF-2 signalling pathways and could be an effective therapeutic agent for cancer patients.

Investigation of mutations in the SRY, SOX9, and DAX1 genes in sex reversal patients from the Sichuan region of China

We investigated the molecular genetic mechanism of sex reversal by exploring the relationship between mutations in the sex-determining genes SRY, SOX9, and DAX1 with genetic sex reversal disease. Mutations in the three key genes were detected by polymerase chain reaction (PCR) and sequencing after karyotype analysis. The mutations detected were then aligned with a random sample of 100 normal sequences and the NCBI sequence database in order to confirm any new mutations. Furthermore, the copy number of SOX9 was measured by fluorescence quantitative PCR. Seven of the 10 male sex reversal patients (46, XX) contained an excess copy of the SRY gene, while one of the eight female sex reversal patients (46, XY) was lacking the SRY gene. Additionally, a new mutation (T-A, Asp24Lys) was detected in one female sex reversal patient (46, XY). No other mutation was detected in the analysis of SOX9 and DAX1, with the exception of an insertion mutation (c.35377791insG) found in the testicular-specific enhancer (TESCO) sequences in an SRY-positive female sex reversal patient (46, XY). Eight of the 18 sex reversal cases (44.4%) showed obvious connections with SRY gene translocations, mutations, or deletions, which was significantly higher than that reported previously (33.3%), indicating a need to further expand the range of sample collection. Overall, these results indicated that the main mechanism of sex reversal are not associated with mutations in the coding regions of SOX9 and DAX1 or copy number variations of SOX9, which is consistent with results of previous studies.

Incremental cost-effectiveness of improving treatment results among migrant tuberculosis patients in Shanghai

SETTING

Two projects were introduced in October 2007 to improve treatment completion among rural-to-urban migrant tuberculosis (TB) patients in Shanghai. The Communicable Disease Research Consortium (COMDIS) project provided financial incentives to poor patients, whereas the Global Fund to Fight AIDS, Tuberculosis and Malaria (Global Fund) project provided incentives to all patients and increased staff time.

OBJECTIVE

To assess the incremental cost-effectiveness of these two projects.

METHODS

Case study. Costs were assessed from a societal perspective. The primary measure of effectiveness was the treatment completion rate. The incremental cost-effectiveness ratio was calculated as the additional cost of the intervention divided by the additional percentage of patients completing treatment compared to controls.

RESULTS

Post intervention, the treatment completion rates in the COMDIS and Global Fund projects were respectively 89% and 88%, 17% and 16% higher than in the control district (76%). For one additional per cent of patients to complete treatment, the additional cost of the COMDIS intervention was US$1891, 91% lower than that of the Global Fund intervention (US$21,904).

CONCLUSION

The intervention that addressed the financial barriers of poor patients was more cost-effective than the comprehensive intervention that provided assistance to both patients and providers. Further study is needed to understand the process of interventions prior to wider scale-up.

Effects of bone morphogenetic protein-4 (BMP-4) on adipocyte differentiation from mouse adipose-derived stem cells

OBJECTIVES

As mesenchymal stem cells (MSCs) can be isolated easily from adipose tissues while retaining their self-renewal and multi-potential differentiation capacities, they hold promising possibilities for being applied extensively in tissue engineering. Bone morphogenetic protein (BMP) family members have been reported to provide instructive signals to MSCs for them to differentiate into several different cell lineages. The study described here aims to investigate whether BMP-4 could promote adipose-derived stem cell (ASC) differentiation into adipocytes under various concentrations.

MATERIALS AND METHODS

ASCs were isolated from mouse inguinal adipose pads and cultured in vitro. 10 ng/ml and 50 ng/ml BMP-4 were added to adipogenic media for 8 days. Oil red-O staining, reverse transcription/polymerase chain reaction and immunocytofluorescence staining were performed to examine differentiation of the ASCs.

RESULTS

As indicated by increased expression of adipogenic and lipogenic genes (PPAR-γ, APN and LPL) and proteins, 50 ng/ml BMP-4 seemed to induce mASCs to differentiate into the adipo-lineage compared to 10 ng/ml BMP-4, and control groups. In addition, lipid droplets accumulated within the adipocytes under 50 ng/ml BMP-4 stimulation, as shown by oil red-O staining.

CONCLUSIONS

Our present study suggests that BMP-4, as an adipo-inducing factor, promoted adipogenesis of ASCs at higher concentrations (50 ng/ml) and can perhaps be considered as a candidate for use in adipose tissue engineering.

Etazolate abrogates the lipopolysaccharide (LPS)-induced downregulation of the cAMP/pCREB/BDNF signaling, neuroinflammatory response and depressive-like behavior in mice

Increasing evidence has indicated that immune challenge by bacterial lipopolysaccharide (LPS) induces depressive-like behavior, neuroinflammatory response and upregulates phosphodiesterase-4 (PDE4), an enzyme that specifically hydrolyzes cyclic adenosine monophosphate (cAMP). However, whether the potential PDE4 inhibitor etazolate prevents the LPS-induced depressive-like behavior remains unclear. Here using a model of depression induced by the repeated administration of LPS during 16days, and then investigated the influence of LPS on the expression of PDE4, interleukin-1β (IL-1β) and antidepressant action of etazolate in mice through forced swimming, novelty suppressed feeding, sucrose preference and open-field tests. Our results showed that etazolate pretreatment facilitated the recovery from weight loss and prevented the depressive-like behavior induced by repeated LPS administration. Moreover, the antidepressant action of etazolate was paralleled by significantly reducing the expression levels of PDE4A, PDE4B, PDE4D and IL-1β and up-regulating the cAMP/phosphorylated cAMP response-element binding protein (pCREB)/brain-derived neurotrophic factor (BDNF) signaling in the hippocampus and prefrontal cortex of mice. These results indicate that the effects of etazolate on the depressive-like behavior induced by repeated LPS treatment may partially depend on the inhibition of PDE4 subtypes, the activation of the cAMP/pCREB/BDNF signaling and the anti-inflammatory responses in the hippocampus and prefrontal cortex.

Posterior hemivertebra resection and monosegmental fusion in the treatment of congenital scoliosis

INTRODUCTION

Posterior hemivertebra resection combined with multisegmental or bisegmental fusion has been applied successfully for congenital scoliosis. However, there are several immature bones and their growth can be influenced by long segmental fusion in congenital patients. Posterior hemivertebra resection and monosegmental fusion was therefore suggested for treatment of congenital scoliosis caused by hemivertebra.

METHODS

Between June 2001 and June 2010, 60 congenital scoliosis patients (aged 2-18 years) who underwent posterior hemivertebra resection and monosegmental fusion were enrolled in our study. A standing anteroposterior x-ray of the whole spine was obtained preoperatively, postoperatively and at the last follow-up appointment to analyse the Cobb angle in the coronal and sagittal planes as well as the trunk shift.

RESULTS

The mean preoperative coronal plane Cobb angle was 41.6°. This was corrected to 5.1° postoperatively and 5.3° at the last follow-up visit (correction 87.3%). The compensatory cranial curve was improved from 18.1° preoperatively to 7.1° postoperatively and 6.5° at the last follow-up visit while the compensatory caudal curve was improved from 21.5° to 6.1° after surgery and 5.6° at the last follow-up visit. The mean sagittal plane Cobb angle was 23.3° before surgery, 7.3° after surgery and 6.8° at the last follow-up visit (correction 70.1%). The trunk shift of 18.5mm was improved to 15.2mm.

CONCLUSIONS

Posterior hemivertebra resection and monosegmental fusion seems to be an effective approach for treatment of congenital scoliosis caused by hemivertebra, allowing for excellent correction in both the frontal and sagittal planes.

Abstract P1-07-11: ERa regulates epithelial-mesenchymal transition in breast cancers through suppressing Bmi1 expression

Background: Bmi1, a polycomb-group protein, maintains stem cell self-renewal and is frequently overexpressed in cancers. Upregulation of Bmi1 by Twist1 can promote tumor-initiating capability and Epithelial-mesenchymal transition (EMT) by repressing E-cadherin expression. It has been demonstrated that Post-EMT breast cancer cells express cancer stem cell (CSC) markers including Bmi1, but display decreased ERα expression. ERα is a ligand-activated nuclear hormone receptor that regulates the transcription of E2-responsive genes in diverse target cells. It's reported that ligand-activated ERα could repress slug transcription by binding to the half-site ERE element in its promoter, and then regulate E-cadherin and EMT. Herein, we hypothesized that ERα signaling might regulate E-cadherin and EMT through Bmi1.

Methods: First, we determined Bmi1 and ERα expression at both mRNA and protein levels by quantitative RT-PCR and Western blot in various breast cancer cell lines. Further, we quantitatively analyzed mRNA and protein levels of Bmi1 as well as its down-stream genes including E-cadherin after silencing ERα in T47D cells with siRNA, or after overexpressing ERα in BT549 cells. The chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA) were also performed to investigate whether ERα binds directly to Bmi1 promoter region. Luciferase assay with Bmi1 reporter was performed to ERα mediated regulation. To identify whether ERα regulates EMT, transwell and matrigel invasion, flow cytometry, mammosphere assay and wound healing assay were performed to invasion, metastases and characterize stem-cell properties of EMT. Finally, we analyzed the expression of ERα, Bmi1 and E-cadherin in human breast cancer specimens with immunohistochemistry.

Results: The study showed that Bmi1 inversely correlated with ERα expression in different subtypes of breast cancer cells. We further confirmed that Bmi1 was upregulated at both mRNA and protein levels and E-cadherin was downregulated with siRNA against ERα in T47D cells, and Bmi1 was downregulated and E-cadherin was upregulated when overexpressing ERα in BT549 cells with qRT-PCR and western blot analyses. The present study also demonstrated that ERα could directly binds to the half-ERE region of the Bmi1 gene and repressing Bmi1 expression transcriptionally with CHIP/EMSA and reporter analyses. Overexpression of ERα in BT549 cell significantly decreased levels of migration of transwell and wounding healing, invasiveness, CD44high/CD24low population, and the capabilities of mammosphere formation.

Conclusions: Our results demonstrated that ERα can suppress EMT through transcriptionally down-regulating Bmi-1 and its down-stream genes in human breast cancer cells. The inverse relationship between ERα and Bmi1 expression further supports the epithelial phenotype of ERα positive tumors or mesenchymal phenotype of ERα negative tumors. Our findings provide a novel mechanistic insight into how ERα regulates EMT, and is of valuable for developing biomarkers to predict prognosis and targeted therapies in breast cancers in the future.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-07-11.

Analysis of interventional treatments of Budd-Chiari Syndrome and the related complications: a study of 1006 cases

AIM

The aim of this paper was to investigate the cause of intraoperative and postoperative complications in Budd-Chiari syndrome (BCS) and its prevention.

METHODS

BCS Patients (1035) who were treated between 1990 and 2009 were included in the present study. Among these patients, there were 651 cases with inferior vena cava occlusion, 273 cases with hepatic vein obstruction and 111 cases with both the symptoms. Treatment for 28 patients failed due to various causes and 1 case diagnosed of obstruction in the right hepatic vein was not treated due to the compensation from the middle and left hepatic vein. The remaining 1006 cases were resolved by the percutaneous transluminal angioplasty (PTA), of which 746 cases had only PTA and 260 cases had both PTA and stent.

RESULTS

There were complications in 66 (6.56%) cases after intervention and 2 patients (0.199%) died. Accidental surgical penetration of the pericardium or cardiac tamponade (0.99%) led to the death of 10 patients, among which 4 cases had cardiac tamponade and one died due to the tamponade. In 2 (0.199%) patients there was stent migration into the right atrium from inferior vena cava. Pleural bleeding was seen in 1 case (0.099%) and abdominal bleeding in 2 cases (0.199%). Two cases (0.199%) had pulmonary obstruction. A single (0.099%) case had chocolate cyst rupture in thrombolytic process. Twenty-seven patients had acute re-stenosis after the surgery, among which 22 (2.95%, 22/746) had the stenosis after only PTA and 5 (1.92%, 5/260) had the stenosis after receiving both PTA and stent. 3 (0.298%) cases had pseudoaneurysm at the puncturing site. Puncture site bleeding and local hematoma was seen in 10 cases (0.99%), whereas 4 cases (0.398%) had leg phlebothrombosis on the same side of the puncture site.

CONCLUSION

Interventional treatment is a safe and effective way to treat BCS. Various effective measures should be taken to avoid and lower the incidence of complications.

Suppression of hepatoma tumor growth by systemic administration of the phytotoxin gelonin driven by the survivin promoter

Hepatocellular carcinoma (HCC) is one of the most common types of cancer worldwide. However, there is currently no effective therapy strategy in the clinical practice. Recombinant phytotoxin gelonin fused to other factors have been used to treat different cancers. But there have been no reports of gelonin gene therapy. In this study, we have constructed a recombinant plasmid which contained a tumor-specific survivin promoter to drive phytotoxin gelonin (pSur-Gel). And the cytotoxicity effects of pSur-Gel in HCC were also validated both in vitro and in vivo. The expression level of survivin was detected in different liver cancer cell lines and normal liver cell lines by western blot analysis, and a survivin promoter-driven green fluorescent protein (GFP) expression vectors (pSur-GFP) was also tested in liver cancer cell line HepG2 and normal liver cell line LO2. Moreover, phytotoxin gelonin expression experiment and cytotoxicity experiment of pSur-Gel was performed in HepG2 cells and LO2 cells in vitro. Furthermore, anti-tumor effect of pSur-Gel against HepG2 xenografts and toxicity of this gene were evaluated in the mice model. Finally, LDH release assay, apoptosis assay and immunoblot analyse LC3 conversion (LC3-I to LC3-II) were tested. We found that the expression of survivin protein was higher in liver cancer cell lines compared with the normal liver cells. Further study showed that the pSur-GFP and pSur-Gel was expressed specially in liver cancer cell other than in normal liver cells. pSur-Gel plasmid could effectively inhibit the proliferation of liver cancer cells (*P<0.05), and significantly repress the growth of HepG2 xenografts via intravenous in vivo (*P<0.05). Otherwise, compared to cytomegalovirus promoter-driven gelonin expression vectors (pCMV-Gel), no significantly systemic toxicity or organ injuries had been observed in pSur-Gel treated mice. Further studies revealed that the phytotoxin gelonin induced cell death might be mediated by apoptosis and the damage of cell membrane. Taken together, treating hepatocellular carcinoma with the pSur-Gel may be a novel and interesting cancer gene therapy protocol and is worthy of further development for future clinical trials.

KEYWORDS

liver cancer, gelonin, survivin promoter, gene therapy.

Blood plasma concentrations of endocrine disrupting chemicals in Hong Kong populations

In this study we report the human plasma concentrations of some common endocrine disrupting chemicals (EDCs) in the Hong Kong population. We have analyzed 153 plasma samples for the contaminants by methods involving labeled standards spiked into the samples. Quantification was performed using high performance liquid chromatography tandem mass spectrometry for bisphenol-A (BPA) and perfluorinated compounds (PFCs), and gas chromatography mass spectrometry methods for phthalates. We found BPA, several types of PFCs and phthalates in over 90% of the plasma samples. Perfluorooctane sulfonate (PFOS) was the dominant PFC, followed by perfluroroctanoic acid (PFOA) and perfluorohexane sulfonate (PFHxS). Eight out of ten phthalates were detected, with bis(2-ethylhexyl) phthalate (DEHP) as the most abundant, followed by bis(2-methoxyethyl) phthalate (DMEP) and dioctyl phthalate (DnOP). The levels of PFOS, PFOA, PFHxS and perfluorohexanoic acid (PFHxA) were significantly higher in the male plasma samples (p<0.05), while the mean plasma levels of DEHP and n-butyl benzyl phthalate (BBP) were significantly higher in the young age group (p<0.02). The presence of the selected EDCs in human blood plasma indicates common exposure routes among different population cohorts. Although the plasma levels of the EDCs were comparable to other countries, regular monitoring of human blood EDC contamination levels is necessary to provide a time-trend database for the estimation of exposure risk and to formulate appropriate public health policy.