Porcine growth differentiation factor 9 gene polymorphisms and their associations with litter size

Growth differentiation factor 9 （GDF9） is expressed in oocytes and is thought to be required for ovarian folliculogenesis. Given this function, GDF9 may be considered as a candidate gene controlling pig ovulate rate. In this study, the complete coding sequence was cloned （encoding a 444 amino acid）, intron sequence and partial 5＇-UTR of pig GDF9. RT-PCR results showed that GDF9 mRNA is expressed in a wide range of tissues of the ruttish Erhualian pig. The expression levels of GDF9 mRNA in pituitary, ovary, uterus and oviduct are higher in the Erhualian pigs than those in Duroc pigs, especially in pituitary with a significant difference （P 〈 0.05）. Comparative sequencing revealed 12 polymorphisms, including 8 single nucleotide polymorphisms （SNPs） and one 314 bp indel in noncoding regions, and the other 3 SNPs in coding regions. Four polymorphisms, G359C, C1801T, T1806C and 314 bp indel, were developed as markers for further use in population variation and association studies. The G359C polymorphism segregates only in Chinese native pigs, Erhualian and Dahuabai, on the contrary, 314 bp indel segregates only in Duroc and Landrace. C1801T and T1806C sites seem to be completely linked and segregate in Erhualian, Dahuabai and Landrace. In a word, GDF9 may be not associated with pig litter size in extensive populations as per the studies of allele distributions of the four polymorphisms and pilot association in four breeds.

Effect of transforming growth factor beta and bone morphogenetic proteins on rat hepatic stellate cell proliferation and transdifferentiation

AIM: To explore different roles of TGF-β (transforming growth factor beta) and bone morphogenetic proteins (BMPs)in hepatic stellate cell proliferation and trans-differentiation.METHODS: Hepatic stellate cells were isolated from male Sprague-Dawley rats. Sub-cultured hepatic stellate cells were employed for cell proliferation assay with WST-1 reagent and Western blot analysis with antibody against smooth muscle alpha actin (SMA).RESULTS: The results indicated that TGF-β1 significantly inhibited cell proliferation at concentration as low as 0.1 ng/ml, but both BMP-2 and BMP-4 did not affect cell proliferation at concentration as high as 10 ng/ml. The effect on hepatic stellate cell trans-differentiation was similar between TGFβ1 and BMPs. However, BMPs was more potent at transdifferentiation of hepatic stellate cells than TGF-β1. In addition, we observed that TGF-β1 transient reduced the abundance of SMA in hepatic stellate cells.CONCLUSION: TGF-β may be more important in regulation of hepatic stellate cell proliferation while BMPs may be the major cytokines regulating hepatic stellate cell transdifferentiation.

Hepatogenic differentiation of mesenchymal stem cells induced by insulin like growth factor-Ⅰ

AIM:To improve hepatic differentiation of human mesenchymal stem cell(MSC)using insulin growth factor 1(IGF-Ⅰ),which has important role in liver development,hepatocyte differentiation and function.METHODS:Bone marrow of healthy donors was aspirated from the iliac crest.The adherent cells expanded rapidly and were maintained with periodic passages until a relatively homogeneous population was established.The identification of these cells was carried out by immunophenotype analysis and differentiation potential into osteocytes and adipocytes.To effectively induce hepatic differentiation,we designed a protocol based on a combination of IGF-Ⅰ and liver specificfactors(hepatocyte growth factor,oncostatin M and dexamethasone).Morphological features,hepatic functions and cytological staining were assessed to evaluate transdifferentiation of human marrow-derived MSCs.RESULTS:Flow cytometric analysis and the differentiation potential into osteoblasts and adipocytes showed that more than 90% of human MSCs which were isolated and expanded were positive by specif ic markers and functional tests.Morphological assessment and evaluation of glycogen storage,albumin and α-feto protein expression,as well as albumin and urea secretion revealed a statistically signif icant difference between the experimental groups and control.CONCLUSION:In vitro differentiated MSCs using IGF-Ⅰwere able to display advanced liver metabolic functions,supporting the possibility of developing them as potential alternatives to primary hepatocytes.

Transfection of the glial cell line-derived neurotrophic factor gene promotes neuronal differentiation

Glial cell line-derived neurotrophic factor recombinant adenovirus vector-transfected bone marrow mesenchymal stem cells were induced to differentiate into neuron-like cells using inductive medium containing retinoic acid and epidermal growth factor. Cell viability, micro- tubule-associated protein 2-positive cell ratio, and the expression levels of glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein-43 protein in the su- pernatant were significantly higher in glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells compared with empty virus plasmid-transfected bone marrow mes- enchymal stem cells. Furthermore, microtubule-associated protein 2, glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein743 mRNA levels in cell pellets were statistically higher in glial cell line-derived neurotrophic factor/bone marrow mesen- chymal stem cells compared with empty virus plasmid-transfected bone marrow mesenchymal stem cells. These results suggest that glial cell line-derived neurotrophic factor/bone marrow mesenchymal stem cells have a higher rate of induction into neuron-like cells, and this enhanced differentiation into neuron-like cells may be associated with up-regulated expression of glial cell line-derived neurotrophic factor, nerve growth factor and growth-associated protein-43.

Macrophage inhibitory cytokine-1/growth differentiation factor-15 in premalignant and neoplastic tumours in a high-risk pancreatic cancer cohort

BACKGROUND Pancreatic cancer(PC)is a leading cause of cancer related mortality worldwide,with poor survival due to late diagnosis.Currently,biomarkers have limited use in early diagnosis of PC.Macrophage inhibitory cytokine-1 or growth differentiation factor-15(MIC-1/GDF15)has been implicated as a potential serum biomarker in PC and other malignancies.AIM To determine the role of MIC-1/GDF15 in detecting pre-malignant pancreatic lesions and neoplastic tumours in an asymptomatic high-risk cohort part of Australian Pancreatic Cancer Screening Program.METHODS A feasibility prospective single centre cohort study was performed.Participants recruited for yearly surveillance with endoscopic ultrasound(EUS)had serial fasting blood samples collected before EUS for MIC-1/GDF15,C-reactive protein and carbohydrate antigen 19-9.Patients were stratified into five groups based on EUS findings:Normal;pancreatic cysts,branch-duct intraductal papillary mucinous neoplasm;diffuse non-specific abnormalities;and neoplastic tumours.MIC-1/GDF15 serum levels were quantified using ELISA.Participants in whom EUS demonstrated abnormalities but not malignancy were closely followed up with magnetic resonance imaging(MRI)or computed tomography.RESULTS One hundred twenty participants were prospectively recruited from 2011-2018.Forty-seven participants(39.2%)had an abnormal EUS and five participants(4.2%)were diagnosed with neoplastic tumours,three by EUS(two pancreatic and one liver)and two by MRI/computed tomography(breast cancer,bladder cancer),which were performed for follow up of abnormal EUS.Baseline serum MIC-1/GDF15 was a significant predictor of neoplastic tumours on receiver operator characteristic curve analysis[area under curve(AUC)=0.814,P=0.023].Baseline serum MIC-1/GDF15 had moderate predictive capacity for branch-duct intraductal papillary mucinous neoplasm(AUC=0.644)and neoplastic tumours noted on EUS(AUC=0.793),however this was not significant(P=0.188 and 0.081 respectively).Serial serum MIC-1/GDF15 did not demonstrate a significant percentage change between a normal and abnormal EUS(P=0.213).Median baseline MIC-1/GDF15 was greater in those with neoplastic tumours(Median=1039.6,interquartile range=727.0-1977.7)compared to those diagnosed with a benign lesion(Median=570.1,interquartile range=460.7-865.2)on EUS and MRI(P=0.012).CONCLUSION In this pilot study MIC-1/GDF15 has predictive capacity for neoplastic tumours in asymptomatic individuals with a genetic predisposition for PC.Further imagining may be warranted in patients with abnormal EUS and raised serum MIC-1/GDF15.Larger multicentric prospective studies are required to further define the role of MIC-1/GDF15 as a serological biomarker in pre-malignant pancreatic lesions and neoplastic tumours.

Changes in expression and secretion patterns of fibroblast growth factor 8 and Sonic Hedgehog signaling pathway molecules during murine neural stem/progenitor cell differentiation in vitro

In the present study, we investigated the dynamic expression of fibroblast growth factor 8 and Sonic Hedgehog signaling pathway related factors in the process of in vitro hippocampal neural stem/progenitor cell differentiation from embryonic Sprague-Dawley rats or embryonic Kunming species mice, using fluorescent quantitative reverse transcription-PCR and western blot analyses. Results demonstrated that the dynamic expression of fibroblast growth factor 8 was similar to fibroblast growth factor receptor 1 expression but not to other fibroblast growth factor receptors. Enzyme-linked immunosorbent assay demonstrated that fibroblast growth factor 8 and Sonic Hedgehog signaling pathway protein factors were secreted by neural cells into the intercellular niche. Our experimental findings indicate that fibroblast growth factor 8 and Sonic Hedgehog expression may be related to the differentiation of neural stem/progenitor cells.

Fibroblast Growth Factor-2 Counteracts the Effect of Ciliary Neurotrophic Factor on Spontaneous Differentiation in Adult Hippocampal Progenitor Cells

Neural stem/progenitor cells (NSCs) can spontaneously differentiate into neurons and glial cells in the absence of mitogen fibroblast growth factor-2 (FGF-2) or epidermal growth factor (EGF) in medium and the spontaneous differentiation of NSCs is mediated partially by endogenous ciliary neuro-trophic factor (CNTF). This study examined the relationship of FGF-2 and CNTF in the spontaneous differentiation of adult hippocampal progenitor cells (AHPs). AHPs were cultured in the medium containing different concentration of FGF-2 (1–100 ng/mL). Western blotting and immunofluorescence staining were applied to detect the expression of the astrocytic marker GFAP, the neuronal marker Tuj1, the oligodendrocytic marker CNPase and, Nestin, the marker of AHPs. The expression of endogenous CNTF in AHPs at early (passage 4) and late stage (passage 22) was also measured by Western blotting. The results showed that FGF-2 increased the expression of Nestin, dramatically inhibited the expression of GFAP and Tuj1 and slightly suppressed the expression of CNPase. FGF-2 down-regulated the expression of endogenous CNTF in AHPs at both early (passage 4) and late stage (passage 22). These results suggested that FGF-2 could inhibit the spontaneous differentiation of cultured AHPs by negatively regulating the expression of endogenous CNTF in AHPs.

Noggin versus basic fibroblast growth factor on the differentiation of human embryonic stem cells

The difference between Noggin and basic fibroblast growth factor for the neural precursor differen- tiation from human embryonic stem cells has not been studied. In this study, 100 tJg/L Noggin or 20 IJg/L basic fibroblast growth factor in serum-free neural induction medium was used to differen- tiate human embryonic stem cells H14 into neural precursors using monolayer differentiation. Two weeks after induction, significantly higher numbers of neural rosettes formed in the Noggin-induced group than the basic fibroblast growth factor-induced group, as detected by phase contrast micro- scope. Immunofluorescence staining revealed expression levels of Nestin, [3-111 Tubulin and Sox-1 were higher in the induced cells and reverse-transcription PCR showed induced cells expressed Nestin, Sox-1 and Neurofilament mRNA. Protein and mRNA expression in the Noggin-induced group was increased compared with the basic fibroblast growth factor-induced group. Noggin has a greater effect than basic fibroblast growth factor on the induction of human embryonic stem cell differentiation into neural precursors by monolayer differentiation, as Noggin accelerates and in- creases the differentiation of neural precursors.

Transforming growth factor-β and smooth muscle differentiation

Transforming growth factor(TGF)-β family members are multifunctional cytokines regulating diverse cel- lular functions such as growth,adhesion,migration, apoptosis,and differentiation.TGF-βs elicit their effects via specific typeⅠand typeⅡserine/threonine kinase receptors and intracellular Smad transcription factors. Knockout mouse models for the different components of the TGF-β signaling pathway have revealed their critical roles in smooth muscle cell(SMC)differentia- tion.Genetic studies in humans have linked mutations in these signaling components to specific cardiovascular disorders such as aorta aneurysm and congenital heart diseases due to SMC defects.In this review,the current understanding of TGF-β function in SMC differentiation is highlighted,and the role of TGF-βsignaling in SMC- related diseases is discussed.

Significance of 125I radioactive seed implantation on growth differentiation factor and programmed death receptor-1 during treatment of oral cancer

BACKGROUND Oral cancer(OC)is the most common malignant tumor in the oral cavity,and is mainly seen in middle-aged and elderly men.At present,OC is mainly treated clinically by surgery or combined with radiotherapy and chemotherapy;but recently,more and more studies have shown that the stress trauma caused by surgery and the side effects of radiotherapy and chemotherapy seriously affect the prognosis of patients.AIM To determine the significance of 125I radioactive seed implantation on growth differentiation factor 11(GDF11)and programmed death receptor-1(PD-1)during treatment of OC.METHODS A total of 184 OC patients admitted to The Second Affiliated Hospital of Jiamusi University from May 2015 to May 2017 were selected as the research subjects for prospective analysis.Of these patients,89 who received 125I radioactive seed implantation therapy were regarded as the research group(RG)and 95 patients who received surgical treatment were regarded as the control group(CG).The clinical efficacy,incidence of adverse reactions and changes in GDF11 and PD-1 before treatment(T0),2 wk after treatment(T1),4 wk after treatment(T2)and 6 wk after treatment(T3)were compared between the two groups.RESULTS The efficacy and recurrence rate in the RG were better than those in the CG(P<0.05),while the incidence of adverse reactions and survival rate were not different.There was no difference in GDF11 and PD-1 between the two groups at T0 and T1,but these factors were lower in the RG than in the CG at T2 and T3(P<0.05).Using receiver operating characteristic(ROC)curve analysis,GDF11 and PD-1 had good predictive value for efficacy and recurrence(P<0.001).CONCLUSION 125I radioactive seed implantation has clinical efficacy and can reduce the recurrence rate in patients with OC.This therapy has marked potential in clinical application.The detection of GDF11 and PD-1 in patients during treatment showed good predictive value for treatment efficacy and recurrence in OC patients,and may be potential targets for future OC treatment.

Growth differentiation factor 5:a neurotrophic factor with neuroprotective potential in Parkinson’s disease

Parkinson’s disease is the most common movement disorder worldwide,affecting over 6 million people.It is an age-related disease,occurring in 1%of people over the age of 60,and 3%of the population over 80 years.The disease is characterized by the progressive loss of midbrain dopaminergic neurons from the substantia nigra,and their axons,which innervate the striatum,resulting in the characteristic motor and non-motor symptoms of Parkinson’s disease.This is paralleled by the intracellular accumulation ofα-synuclein in several regions of the nervous system.Current therapies are solely symptomatic and do not stop or slow disease progression.One promising disease-modifying strategy to arrest the loss of dopaminergic neurons is the targeted delivery of neurotrophic factors to the substantia nigra or striatum,to protect the remaining dopaminergic neurons of the nigrostriatal pathway.However,clinical trials of two well-established neurotrophic factors,glial cell line-derived neurotrophic factor and neurturin,have failed to meet their primary end-points.This failure is thought to be at least partly due to the downregulation byα-synuclein of Ret,the common co-receptor of glial cell line-derived neurorophic factor and neurturin.Growth/differentiation factor 5 is a member of the bone morphogenetic protein family of neurotrophic factors,that signals through the Ret-independent canonical Smad signaling pathway.Here,we review the evidence for the neurotrophic potential of growth/differentiation factor 5 in in vitro and in vivo models of Parkinson’s disease.We discuss new work on growth/differentiation factor 5’s mechanisms of action,as well as data showing that viral delivery of growth/differentiation factor 5 to the substantia nigra is neuroprotective in theα-synuclein rat model of Parkinson’s disease.These data highlight the potential for growth/differentiation factor 5 as a disease-modifying therapy for Parkinson’s disease.

Elevated serum growth differentiation factor 15 in multiple system atrophy patients:A case control study

BACKGROUND Multiple system atrophy(MSA) is a serious progressive neurodegenerative disease. Early diagnosis of MSA is very difficult, and diagnostic biomarkers are limited. Growth differentiation factor 15(GDF15) is involved in the differentiation and progression of the central nervous system, and is widely distributed in peripheral blood, which may be a novel biomarker for MSA.AIM To determine serum GDF15 levels, related factors and their potential diagnostic value in MSA patients, compared with Parkinson’s disease(PD) patients and healthy controls.METHODS A case-control study was conducted, including 49 MSA patients, 50 PD patients and 50 healthy controls. Serum GDF15 levels were measured by human enzymelinked immunosorbent assay, and the differences between the MSA, PD and control groups were analyzed. Further investigations were performed in different MSA subgroups according to age of onset, sex, clinical subtypes, diagnostic criteria, and disease duration. Receiver-operating characteristic curve analysiswas used to evaluate the diagnostic value of GDF15, especially for the differential diagnosis between MSA and PD.RESULTS Serum GDF15 levels were significantly higher in MSA patients than in PD patients and healthy controls(P = 0.000). Males and those with a disease duration of more than three years showed higher serum GDF15 levels(P = 0.043 and 0.000;respectively). Serum GDF15 levels may be a potential diagnostic biomarker for MSA patients compared with healthy controls and PD patients(cutoff: 470.42 pg/m L, sensitivity: 85.7%, specificity: 88.0%;cutoff: 1075.91 pg/m L, sensitivity:51.0%, specificity: 96.0%;respectively).CONCLUSION Serum GDF15 levels are significantly higher in MSA patients and provide suggestions on the etiology of MSA.

Growth differentiation factor 11 promotes macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway

Background:Myocardial infarctions(MI)is a major threat to human health especially in people exposed to cold environment.The polarization of macrophages towards different functional phenotypes(M1 macrophages and M2 macrophages)is closely related to MI repairment.The growth differentiation factor 11(GDF11)has been reported to play a momentous role in inflammatory associated diseases.In this study,we examined the regulatory role of GDF11 in macrophage polarization and elucidated the underlying mechanisms in MI.Methods:In vivo,the mice model of MI was induced by permanent ligation of the left anterior descending coronary artery(LAD),and mice were randomly divided into the sham group,MI group,and MI+GDF11 group.The protective effect of GDF11 on myocardial infarction and its effect on macrophage polarization were verified by echocardiography,triphenyl tetrazolium chloride staining and immunofluorescence staining of heart tissue.In vitro,based on the RAW264.7 cell line,the effect of GDF11 in promoting macrophage polarization toward the M2 type by inhibiting the Notch1 Signaling pathway was validated by qRT-PCR,Western blot,and flow cytometry.Results:We found that GDF11 was significantly downregulated in the cardiac tissue of MI mice.And GDF11 supplementation can improve the cardiac function.Moreover,GDF11 could reduce the proportion of M1 macrophages and increase the accumulation of M2 macrophages in the heart tissue of MI mice.Furthermore,the cardioprotective effect of GDF11 on MI mice was weakened after macrophage clearance.At the cellular level,application of GDF11 could inhibit the expression of M1 macrophage(classically activated macrophage)markers iNOS,interleukin(IL)-1β,and IL-6 in a dose-dependent manner.In contrast,GDF11 significantly increased the level of M2 macrophage markers including IL-10,CD206,arginase 1(Arg1),and vascular endothelial growth factor(VEGF).Interestingly,GDF11 could promote M1 macrophages polarizing to M2 macrophages.At the molecular level,GDF11 significantly down-regulated the Notch1 signaling pathway,the activation of which has been demonstrated to promote M1 polarization in macrophages.Conclusions:GDF11 promoted macrophage polarization towards M2 to attenuate myocardial infarction via inhibiting Notch1 signaling pathway.

Growth differentiation factor 15 as an emerging novel biomarker in SARS-CoV-2 infection

BACKGROUND Growth differentiation factor(GDF)-15 is a member of a transforming growth factor-βcytokine superfamily that regulates metabolism and is released in response to inflammation,hypoxia and tissue injury.It has evolved as one of the most potent cytokines for predicting the severity of infections and inflammatory conditions,such as severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection.AIM To investigate the utility of GDF-15 in predicting the severity of SARS-CoV-2 infection.METHODS PubMed,Reference Citation Analysis,CNKI,and Goggle Scholar were explored by using related MeSH keywords and data such as the first author’s name,study duration,type and place of study,sample size and subgroups of participants if any,serum/plasma GDF-15 level in pg/mL,area under the curve and cut-off value in receiver operating characteristic analysis,method of measurement of GDF-15,and the main conclusion were extracted.RESULTS In all studies,the baseline GDF-15 level was elevated in SARS-CoV-2-infected patients,and it was significantly associated with severity,hypoxemia,viral load,and worse clinical consequences.In addition,GDF-15 levels were correlated with C-reactive protein,D-dimer,ferritin and procalcitonin,and it had superior discriminatory ability to detect severity and in-hospital mortality of SARS-CoV-2 infection.Hence,GDF-15 might be used to predict the severity and prognosis of hospitalized patients with SARS-CoV-2.CONCLUSION Serial estimation of GDF-15 levels in hospitalized patients with SARS-CoV-2 infection appeared to have useful prognostic value and GDF-15 can be considered a clinically prominent sepsis biomarker for SARS-CoV-2 infection.

GROWTH DIFFERENTIATION FACTOR-5 STIMULATES THE GROWTH AND ANABOLIC METABOLISM OF ARTICULAR CHONDROCYTES

Objective To observe the effect of growth differentiation factor-5 (GDF-5) on the growth and anabolic metabolism of articular chondrocytes. Methods The articular chondrocytes isolated from rats were treated with various concentrations of rmGDF-5, and the growth of chondrocytes measured by MTT assay, the cellular cartilage matrices formation detected sulfated glycosaminoglycan by Alcian blue staining and type Ⅱcollagen by RT-PCR. Results After 7 days culture, MTT assay showed that GDF-5 enhanced the growth of chondrocytes in a dose-dependent manner, RT-PCR showed that GDF-5 clearly induced the synthesis of type Ⅱ collagen because of the col2a1 mRNA band more and more strong in a dose-dependent. Chondrocytes were cultured with GDF-5 for 14 days, the intensity of Alcian blue staining was greatly enhanced, especially, at a high concentration of 1000ng/mL, and GDF-5 enhanced the accumulation of the Alcian blue-stainable material in a concentration-dependent manner and in a does-dependent manner. Conclusion GDF-5 enhanced the growth of mature articular chondrocytes, and stimulated the cellular cartilage matrices formation in mono-layer culture.

Chondrogenic differentiation of human bone mesenchymal stem cells treated with growth differentiation factor 5 under hypoxia

Objective To explore the feasibility and effectiveness of the self-assembly cartilage tissue engineered with chondrogenically differentiated human bone mesenchymal stem cells (hBMCs) induced by growth differentiation factor-5 (GDF-5)

Gene expression of hepatocyte growth factor and its receptor in HCC and nontumorous liver tissues

AIM To study the changes of gene expression of hepatocyte growth factor (HGF) and hepatocyte growth factor receptor (HGFr) in hepatocellular carcinoma (HCC) tissue and nontumorous liver tissue and the relationship between these changes and the biological behavior of the tumor.METHODS Gene expression of HGF and HGFr in 26 cases of HCC tissue and their adjacent nontumorous liver tissues was determined with digoxigenin-labeled DNA probes.RESULTS Positive expression of HGF in HCC tissue was similar to that in the adjacent nontumorous liver tissue, but positive rate of HGF expression was lower than HGFr gene expression. However, HGFr expression was higher in the metastatic cases than in those without metastasis. It was found that HGFr was overexpressed in HCC tissue as well as in the adjacent nontumorous liver tissue.CONCLUSION There seems to be a close relationship between overexpression of HGFr gene and tumor metastasis, and the HGF and HGFr system plays an important role in regulating tumor growth and metastasis.

Reduction of tumorigenicity of SMMC-7721 hepatoma cells by vascular endothelial growth factor antisense gene therapy

AIM: To test the hypothesis to block VEGF expression of SMMC-7721 hepatoma cells may inhibit tumor growth using the rat hepatoma model. METHODS: Amplify the 200 VEGF cDNA fragment and insert it into human U6 gene cassette in the reverse orientation transcribing small antisense RNA which could specifically interact with VEGF165, and VEGF121 mRNA. Construct the retroviral vector containing this antisense VEGF U6 cassette and package the replication-deficient recombinant retrovirus. SMMC-7721 cells were transduced with these virus and positive clones were selected with G418. PCR and Southern blot analysis were performed to determine if U6 cassette integrated into the genomic DNA of positive clone. Transfected tumor cells were evaluated for RNA expression by ribonuclease protection assays. The VEGF protein in the supernatant of parental tumor cells and genetically modified tumor cells was determined with ELISA. In vitro and in vivo growth properties of antisense VEGF cell clone in nude mice were analyzed. RESULTS: Restriction enzyme digestion and PCR sequencing verified that the antisense VEGF RNA retroviral vector was successfully constructed.After G418 selection, resistant SMMC-7721 cell clone was picked up. PCR and Southern blot analysis suggested that U6 cassette was integrated into the cell genomic DNA. Stable SMMC-7721 cell clone transduced with U6 antisense RNA cassette could express 200 bp small antisense VEGF RNA and secrete reduced levels of VEGF in culture condition. Production of VEGF by antisense transgene-expressing cells was 65+/-10 ng/L per 10(6) cells, 42045 ng/L per 10(6) cells in sense group and 485+/-30 ng/L per 10(6) cells in the negative control group, (P【 0.05). The antisense-VEGF cell clone appeared phenotypically indistinguishable from SMMC-7721 cells and SMMC-7721 cells transfected sense VEGF. The growth rate of the antisense-VEGF cell clone was the same as the control cells. When S.C. was implanted into nude mice, growth of antisense-VEGF cell lines was greatly inhibited compared with control cells. CONCLUSION: Expression of antisense VEGF RNA in SMMC-7721 cells could decrease the tumorigenicity, and antisense-VEGF gene therapy may be an adjuvant treatment for hepatoma.

Expression of vascular endothelial growth factor and its role in oncogenesis of human gastric carcinoma

AIM: To establish the role of vascular endothelial growth factor (VEGF) in the oncogenesis of human gastric carcinoma more directly. METHODS: The expression of VEGF and its receptor kinase-domain insert containing receptor (KDR) in human gastric cancer tissue were observed by immunohistochemical staining. VEGF levels were manipulated in human gastric cancer cell using eukaryotic expression constructs designed to express the complete VEGF(165) complimentary DNA in either the sense or antisense orientation. The biological changes of the cells were observed in which VEGF was up-regulated or down-regulated. RESULTS: VEGF-positive rate was 50%, and VEGF was mainly localized in the cytoplasm and membrane of the tumor cells, while KDR was mainly located in the membrane of vascular endothelial cells in gastric cancer tissues and peri-cancerous tissue. In 2 cases of 50 specimens, the gastric cancer cells expressed KDR, localized in both the cytoplasm and membrane. Introduction of VEGF(165) antisense into human gastric cancer cells (SGC-7901, immunofluorescence intensity, 31.6%)) resulted in a significant reduction in VEGF-specific messenger RNA and total and cell surface VEGF protein (immunofluorescence intensity, 8.9%) (P【0.05). Conversely, stable integration of VEGF(165) in the sense orientation resulted in an increase in cellular and cell surface VEGF (immunofluorescence intensity, 75.4%) (P【0.05). Lowered VEGF levels were associated with a marked decrease in the growth of nude mouse xenografted tumor (at 33 days postimplantation, tumor volume: 345.40 +/- 136.31 mm3)(P【0.05 vs control SGC-7901 group: 1534.40 +/- 362.88 mm3), whereas up-regulation of VEGF resulted in increased xenografted tumor size (at 33 days postimplantation, tumor volume: 2350.50 +/- 637.70 mm3) (P【0.05 vs control SGC-7901 group). CONCLUSION: This study provides direct evidence that VEGF plays an important role in the oncogenesis of human gastric cancer.

Keratinocyte growth factor gene therapy ameliorates ulcerative colitis in rats

AIM:To investigate the effect of keratinocyte growth factor(KGF) gene therapy in acetic acid-induced ulcerative colitis in rat model.METHODS:The colitis of Sprague-Dawley rats was induced by intrarectal infusion of 1 mL 5%(v/v) acetic acid.Twenty-four hours after exposed to acetic acid,rats were divided into three experimental groups:control group,attenuated Salmonella typhimurium Ty21a strain(SP) group and SP strain carrying human KGF gene(SPK) group,and they were separately administered orally with 10% NaHCO3,SP or SPK.Animals were sacrificed and colonic tissues were harvested respectively on day 3,5,7 and 10 after administration.Weights of rats,colonic weight/length ratio and stool score were evaluated.Histological changes of colonic tissues were examined by hematoxylin and eosin(HE) staining method.The expression of KGF,KGF receptor(KGFR) and TNF-α were measured either by enzyme-linked immunosorbent assay or Western blotting.Immunohistochemistry was used to detect the cellular localization of KGFR and Ki67.In addition,superoxide dismutase(SOD) activity and malondialdehyde(MDA) contents in the homogenate were measured.RESULTS:Body weight and colonic weight/length ratio were declined in SPK group compared with SP and control groups(body weight:272.78 ± 17.92 g vs 243.72 ± 14.02 g and 240.68 ± 12.63 g,P < 0.01;colonic weight/length ratio:115.76 ± 7.47 vs 150.32 ± 5.99 and 153.67 ± 5.50 mg/cm,P < 0.01).Moreover,pathological changes of damaged colon were improved in SPK group as well.After administration of SPK strain,KGF expression increased markedly from the 3rd d,and remained at a high level till the 10th d.Furthermore,KGFR expression and Ki67 expression elevated,whereas TNF-α expression was inhibited in SPK group.In the group administered with SPK,SOD activity increased significantly(d 5:26.18 ± 5.84 vs 18.12 ± 3.30 and 18.79 ± 4.74 U/mg,P < 0.01;d 7:35.48 ± 3.35 vs 22.57 ± 3.44 and 21.69 ± 3.94 U/mg,P < 0.01;d 10:46.10 ± 6.23 vs 25.35 ± 4.76 and 27.82 ± 6.42 U/mg,P < 0.01) and MDA contents decreased accordingly(d 7:7.40 ± 0.88 vs 9.81 ± 1.21 and 10.45 ± 1.40 nmol/mg,P < 0.01;d 10:4.36 ± 0.62 vs 8.41 ± 0.92 and 8.71 ± 1.27 nmol/mg,P < 0.01),compared with SP and control groups.CONCLUSION:KGF gene therapy mediated by attenuated Salmonella ameliorates ulcerative colitis induced by acetic acids,and it may be a safe and effective treatment for ulcerative colitis.