miR-221 mediates epithelial-mesenchymal transition-related gene expressions via regulation of PTEN/Akt signaling in drug-resistant glioma cells / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the correlation between miR-221 and epithelial-mesenchymal transition (EMT) in drug-resistant glioma cells.</p><p><b>METHODS</b>The expression levels of miR-221, PTEN, p-Akt, E-cadherin, vimentin, and MRP1 were quantitatively analyzed in Z1 cells (primary drug-resistant cells), Z2 cells (drug-sensitive cells) and Z2-BCNU cells (drug-resistant cells) using fluorescent real-time PCR and Western blotting.</p><p><b>RESULTS</b>The expression levels of PTEN were significantly increased in Z2 cells compared with Z1 and Z2-BCNU cells which overexpressed miR-221 and vimentin. The expression levels of vimentin, p-Akt and MRP1 were significantly decreased in Z2 cells overexpressing E-cadherin.</p><p><b>CONCLUSION</b>MiR-221 regulates the expression of EMT-related genes through down-regulation of PTEN and activation of PI3-K/Akt signaling.</p>

Inhibitory effect of temozolomide combined with tetrandrine on human glioblastoma U87 cells / 中国药理学与毒理学杂志

OBJECTIVE Toobservetheeffectoftemozolomide(TMZ)incombinationwithtetran-drine(TET)on cell viability,colony formation,migration and cell apoptosis of human glioblastoma U87 cells.METHODS TheviabilityofU87cellstreatedwithTET(8-64μmol·L-1),TMZ(50-400 μmol·L-1 )and TMZ combined with TET (3.2,6.4 μmol·L-1 )was detected by cytotoxicity assays with Cell Counting Kit-8 (CCK-8),the colony formation was detected by Giemsa staining,cell migration ability was detected by Transwell migration assay,cell apoptosis was assayed by flow cytometry using Annexin Ⅴ /PI double staining,and the expression of apoptosis-related proteins expression was detec-tedbyWesternblotting.RESULTS ThedataofCCK-8showedthatTET(r=0.903,P<0.05)orTMZ (r=0.995,P<0.05)could inhibit U87 cell viability alone in a concentration-dependent manner.The cell viability inhibition rate of U87 cells by TMZ co mbined with TET was higher than by TMZ or TET alone. Data showed that the effect of TMZ combined with TET was additive.TMZ 100 μmol·L-1 inhibited U87 cell colony formation and migration ablility compared with normal control.The inhibition rate of U87 cells by TMZ 100 μmol·L-1 combined with TET (3.2 and 6.4 μmol·L-1 )was more significant than by TMZ alone (P<0.05).Compared with TMZ alone,TMZ combined with TET (3.2 and 6.4 μmol·L-1 )signifi-cantly down-regulated the expression of anti-apoptotic protein Bcl-XL,but significantly up-regulated the expression of cleaved caspase 3 protein and cleaved poly(ADP-ribose)polymerase.CONCLUSION TET combined with TMZ can inhibit U87 cell viability,colony formation and migration by activating caspase-dependent apoptotic pathway,resulting in apoptosis.

Glucagon-like peptide-1 regulates lipometabolism by down-regulating adipose triglyceride lipase in 3T3-L1 adipocytes / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of glucagon-like peptide-1 (GLP-1) on glycolipid metabolism in 3T3-L1 adipocytes and explore the mechanism.</p><p><b>METHODS</b>3T3-L1 adipocytes were treated with GLP-1, insulin, or both for 24 h, and Western blotting was used to analyze the expression levels of adipose triglyceride lipase (ATGL), glucose transporter type 4 (GLUT4), Akt1, Akt2 and phosphorylated Akt in the cells. Immunofluorescence was used to observe lipid content in 3T3-L1 adipocytes.</p><p><b>RESULTS</b>Akt1 and Akt2 were not activated by insulin stimulation in 3T3-L1 adipocytes. Akt was phosphorylated by GLP-1 stimulation, which inhibited the expression of ATGL and increased the translocation of GLUT4 from the intracellular membranes to plasma membranes. These changes were more obvious under the synergistic effect of insulin in 3T3-L1 adipocytes.</p><p><b>CONCLUSION</b>GLP-1 decreases lipolysis by inhibiting the expression of ATGL and improves insulin resistance by increasing the translocation of GLUT4 in 3T3-L1 adipocytes.</p>

Roles of microRNAs in glioma / 中国病理生理杂志

MicroRNAs (miRNAs) are critical regulators of gene expression. These small, non-coding RNAs are believed to regulate more than one third of protein-coding genes, and have been implicated in the control of many biological processes, including the biology of glioma. The functional significance in some of the miRNAs begins to emerge. This paper reviews the biogenesis of miRNAs, their roles in neuronal development and tumorigenesis of gliomas, and their contribution as tumor biomarkers. Research in this area is quickly gathering pace and is illuminating important aspects of the diseases that may ultimately lead to novel therapeutic interventions, as well as diagnostic and prognostic tools for brain tumors.

Relationship of Tumor Necrosis Factor Genetic Polymorphisms with the Clinical Course and Outcome of Non-Hodgkin's Lymphoma / 中国肿瘤临床

Objective:To investigate the relationship of-308bp polymorphism in tumor necrosis factor-α (TNFa)gene and+252bp in lymphotoxin-α(LTα)gene with the clinical course and outcome of non-Hodgkin's lymphoma(NHL).Methods:The single base change in TNFα gene and LTα gene was analyzed among 96 Chinese patients with NHL and 72 normal controls by using PCR-restrictive fragment length polymorphism (RFLP).The clinical data were collected and survival analysis was performed.Results:In NHL patients,no statistcally significant association was found between the presence of a given TNF/LT haplotype status and clinical variables such as age,seX,disease stage,and so on.The patients carrying low-risk haplotype achieved a more sensitive response to first-line therapy than that in patients with high-risk haplotype(70.4%v 45.2%:P=0.018).The estimated 1-year progression-free survival rates in the high-risk and low-risk groups were 66.67% and 87.5%,respectively(log-rank test,P=0.0231).Kaplan-Meier method showed that the estimated 2-year and 4-year overall survival rates were 39.95%and 8.32%in patents carrying high-risk haplotypes and 65.13%and 46.52%in patients carrying low-risk haplotypes,respectively(log-rank test,P=0.0012).In multivariate Cox regression models.the TNF/LT haplotype status was found to be a dsk factor for outcome of NHL (P=0.034).Conclusion:There is an association between TNF/LT haplotype status and response to therapy and outcomes of NHL in Canton area,China.Detecting TNF/LT haplotype may be a sensitive method to evaluate the outcome of NHL.

Expression of PTEN, p53, Ki-67 and its relationship with tumor histopathological grade and proliferation in astrocytoma / 肿瘤研究与临床

Objective To study the incidence of PTEN, p53 and Ki-67 expression in astrocytoma and show the relationship between PTEN, p53 expression and the proliferation activity. Methods The surgical specimens from 68 brain astrocytoma patients were analysed to detect PTEN, p53 and Ki-67 expression with immunohistochemical method. Results The incidence of PTEN, p53 and Ki-67 expression was 54.4 %,45.6 % and 48.5 % respectively in astrocytoma. With the grade of astrocytoma increasing the levels of PTEN protein decreased, on the other hand the levels of p53, Ki-67 increased. There was a negative correlation between PTEN expression and grade of astrocytoma while there was a positive correlation between p53, Ki-67 expression and grade of astrocytoma by using the Spearman Correlation test to analyse the data. The incidence of Ki-67 positive expression was 24.3 % in 37 cases exhibiting PTEN positive staining, whereas the incidence of Ki-67 positive expression was 77.4 % in 31 cases exhibiting PTEN negative staining. In statistics, there was an inverse correlation between PTEN and Ki-67 expression. Conclusion There is an inverse correlation between histopathological grades of astrocytoma and PTEN expression. A positive correlation is found between p53, Ki-67 expression and histopathological grades of astrocytoma. PTEN can inhibit tumor cell proliferation in astrocytoma.

Effects of serum from myocardial infarction rats on rat bone marrow mesenchymal stem cell differentiation into cardiomyocytes / 中国组织工程研究

BACKGROUND: Differentiation of bone marrow mesenchymal stem calls(BMSCs) is associated with their microenvironment. After acute myocardial infarction (AMI), the necrosis of cardiomyocytes caused activation of complement, generation of free radical, and secretion of various cell factors. As a result, the ingredients of patients' serum also changed, so does the changes will influence the differentiation of BMSCs into cardiomyocytes? And what influence it will be? OBJECTIVE: To investigative effects of AMI rat serum on the differentiation of BMSCs into cardiomyocytes. DESIGN, TIME AND SETTING: The in vitro controlled cytology experiment was performed at the Laboratory of Center for Stem cells and Tissue Engineering, Sun Yat-sen University from September in 2005 to June in 2006. MATERIALS: SPF Sprague Dawley rats, weighing 50-80 g, aged 3-4 weeks, were used for culture of BMSCs, and SpragueDawley rats, weighing 200-300 g, aged 6-8 weeks, were used for making AMI models. METHODS: BMSCs were isolated and cultured with the adherent method. After making AMI rat models by deligating anterior descending of the left coronary artery, the serum were collected and centrifuged from AMI and normal rats. Then the passage 3 of BMSCs were divided into six groups, non-induction group, 5-azacytidine (5-aza) group, 5-aza plus serum from AMI rat group, 5-aza plus serum from normal rat group, serum from AMI rat group, and serum from normal rat group. MAIN OUTCOME MEASURES: Morphology changes in rat BMSCs after induction; Expression of cardiac troponin T of BMSCs after induction; Expression of GATA-4 and desmin mRNA of BMSCs after induction. RESULTS: After being induced by 5-aza and two kinds of serum, some cells became elongated and thinner. Two to three weeks after induction, some cells had a ball-like or rod-like appearance, and connection were formed between adjacent cells. It showed that some BMSC have differentiated into cardiac like cells. The expression of cardiac troponin T, GATA-4 and desmin were positive in cells differentiated from BMSCs. The troponin T expression in control group and simple serum induction group were negative, but GATA-4 and desmin expressed weakly. CONCLUSION: Serum from AMI rat cannot induce BMSCs to differentiate into cardiomyocytes alone, but it promotes BMSCs induced by 5-aza differentiating into cardiomyocytes and facilitates the differentiated calls into mature.

Studies on the expression of Survivin in human leukemia K562 treated by cytarabine / 白血病·淋巴瘤

Objective To investigate the influences of cytarabine on Survivin gene expression in human leukemia K562 cell line and discuss the mechanism of drug resistance in chemotherapy. Methods The IC50 of cytarabine was chosen by MTr assay. The K562 cells were exposed to certain concentration of cytarabine for about 24 hours and 48 hours. The expression levels of Survivin gene were detected by RT-PCR and Western-blot. Results After exposed to cytarabine for 24 hours and 48 hours, the Survivin mRNA level of K562 cells was significantly elevated about 1.92 and 3.38-fold, and the protein expression level was elevated about 1.92 and 2.64-fold. Conclusion An elevated expression of Survivin was tested in K562 cells treated by cytarabine. Consequently, the elevated expression of Survivin could resist apoptosis induced by chemotherapeutic agent which probably associated with chemotherapeutic drug resistance.

In situ transplantation of autologous bone marrow stem cells mobilized by Granulocyte colony-stimulating factor for treatment of ischemic cerebral infarction in rats / 中国组织工程研究

BACKGROUND:Granulocyte colony-stimulating factor (G-CSF) can strongly mobilize bone marrow hematopoietic stem cells (HSCs). It has been proved that G-CSF has the ability to mobilize both HSCs and mesenchymal stem cells (MSCs).OBJECTIVE:To investigate the therapeutic effect of G-CSF in mobilizing autologous bone marrow stem cells entering cerebral infarction zone on ischemic cerebral infarction in rats.DESIGN:A randomized grouping design, animal experiment.SETYING: Center for Stem Cell Biology and Tissue Engineering of Sun Yat-sen University.MATERIALS: This experiment was carried out at the Animal Experimental Department of Sun Yat-sen University (North District) and Center for Stem Cell Biology and Tissue Engineering of Sun Yat-sen University from September 2004 to January 2005. Totally 200 male Wistar rats were chosen and randomly divided into autologous bone marrow stem cells transplantation group and control group, with 100 rats in each group.METHODS:Rats of two groups were made cerebral infarction models by line occlusion. Transplantation group introduced intraperitoneal injection of 60 μg/kg G-CSF one hour after operation. The control group introduced intraperitoneal injection of saline of the same dosage at the same time. ①All rats were weighed before operation and 24 hours, 48 hours, one week after operation to evaluate body mass loss rate. They were also given neurological grading. Grading criteria: Grade 0 is normal. Grade Ⅰ is that the right forelimb bends. Grade Ⅱ is that the right forelimb grasped weakly when the tail is lifted. Grade Ⅲ is that the rat has no directivity in automatic action and circumrotates to right when the tail is lifted. Grade Ⅳ is that the rat circumrotates to right in automatic action. ②15 rats in each group were selected. 24 hours, 48 hours, one week after operation, we opened the skulls, took out the brain and used 2,3,5-Triphenyltetrazoluim Chloride (TTC) staining to measure infarction volume, hematoxylin-eosin(HE) staining to observe the pathological change , and immunohistochemistry to detect the infiltration of CD34+ cells.MAIN OUTCOME MEASURES:Body mass loss rate, neurological grade,infarction volume, pathological change and infiltration of CD34+ cells.RESULTS: Totally 180 of 200 rats were successfully made cerebral infarction model. 48 rats died in seven days after operation. As a result, 132 rat models were alive and 120 rats were randomly selected for data analysis. ①Measurement of body mass and neurological grading: There was no significant difference in body mass loss rate between two groups 24 hours and 48 hours after operation (P ＜ 0.05);one week after operation, body mass loss rate was significantly lower in transplantation group [(10.5±8.2)%]than in control group [(17.8±7.1)%] (P ＜ 0.05). There was no significant difference in neurology grade between two groups. ②Infarction volume:Infarction volume and the percent of infarction volume in the whole brain in control group were all higher than those in the transplantation group,with significant difference [ (251.69±52.77) mm3 vs(145.72±28.05)mm3,(17.00±2.69)% vs (9.90±1.62)% ,P ＜ 0.01]. ③Pathological change: 24 hours after operation, the brain tissue of two groups got classical pathological change of cerebral ischemia infarction. There were some mono-nucleus cells infiltrating in transplantation group while none in control group. 48 hours after operation, most nerve cells disappeared and the glial cells were degenerated. There were many mono-nucleus cells infiltrating in transplantation group while a few in control group. One week after operation, tissues in the infarction zone were liquescent with many monocaryons and lymphocytes infiltrating around them in control group. In transplantation group, part of the infarction zone was plerosised through proliferation of newly born capillaries and glial cells and inflammatory cells were not evident. ④Immunohistochemistry: CD34+ mono-nucleus cells were detected in the ischemic territory in transplantation group 24 hours after operation while none in the brain of other side and control group. There were CD34+ mono-nucleus cells and pyramidate cells with mutations in transplantation group 48 hours after operation while none in the brain of other side and control group.CONCLUSION:The stem cell transplantation in situ therapy, which employs self-marrow stem cells mobilized by G-CSF can relieve the ischemic degree and reduce the infarction volume.

Recent advances in platelet growth factors / 中国病理生理杂志

Currently, platelet transfusion is the primary treatment for thrombocytopnia which results from intensive chemotherapy and radiotherapy of cancer. While repeated platelet transfusions are associated with several problems. The clinical availability of safe and effective platelet growth factors is eagerly awaited. Currently, a mumber of hematopoietic growth factors with thrombopoietic activity have been identified. This review discusses the biological characteristics and the clinical trial investigation development of platelet growth factors.

Effects of thrombopoietin and thrombopoietinⅡ on human platelet activation / 中国病理生理杂志

AIM:To investigate effects of thrombopoietin(TPO) and TPOⅡ on human platelet activation in vitro. METHODS:Human platelets were incubated in the phosphate-buffered saline containing rhTPO or TPOⅡ at the concentration of 100 μg/L for five minutes. In order to determine the rate of platelet activation. The CD62P and CD41 expressions on platelets were analysed by flow cytometry using fluorescence labelled monoclonal antibody to CD62P and CD41. RESULTS:The results demonstrated that expression of CD62P on platelets which were incubated with rhTPO or TPOⅡ didn't increase compared with that of contrast group. CONCLUSION:Both rhTPO and TPOⅡdidn't cause the disorder of platelet activation.

Accumulation of p53 and cytokeratin-18neo in non-small cell lung cancer and its clinicopathological significance / 中国病理生理杂志

AIM： To investigate the tumorigenicity of lung cancer by learning the accumulation of p53 and the exposure of cytokeratin 18 neo-epitope(CK-18neo) related to the clinicopathological parameters in non-small cell lung cancer(NSCLC). METHODS: To detect the monoclonal antibodies of p53 and M30 CytoDEATH(specific antibody for CK-18neo) in 62 cases of NSCLC (included 29 cases of squamous cell carcinoma and 33 cases of adenocarcinoma) and 10 cases of control group by adopting immunohistochemistry assay (LSAB). Moreover, the immunoreactivity of p53 was quantitatively evaluated with positive unit (PU). RESULTS: (1) p53 immunoreactivity was positive in 15 of 29 squamous cell carcinoma (51.72%), 15 of 33 adenocarcinoma (45.45%), 30 of 62 NSCLC (48.39%). In 10 control cases was negative. There were significant differences between these groups (P＜0.01). (2)In 62 cases of NSCLC, AI% of M30 is 1.10%, and in 29 cases of squamous cell carcinoma is 0.95%, and in 33 cases of adenocarcinoma is 1.24%. In 10 control cases, the AI% is 1.06%. There is not significant difference among these groups . (3) According to the results of Pearson's correlation analysis, we found positive linear correlation between the immunoreactivity of p53（-/+）, p53（5 degrees）and p53（PU）(P＜0.01). CONCLUSION: Our results suggested that the pathogenesis of NSCLC might be related to the mutation of gene p53 and cell excessive proliferation and insufficient apoptosis.

Effect of recombinant human thrombopoietin on exsanguine thrombocytopenia mice / 中国病理生理杂志

AIM:To investigate effect of recombinant human thrombopoietin on exsanguine thrombocytopenia mice. METHODS:Normal peripheral platelet counts were performed on sample obtained from the tail vein of purebred Babl/c mice including experimental and control groups before experimentation. rhTPO was injected into the mice by intraperitoneal injection once a day for 7 days. On the seventh and the fourteenth day, the mice were phlebotomized from the supra-obitalis vein in order to make exsanguine thrombocytopenia animal model. At the same time, we observed the biological activity of recombinant human thrombopoietin in vivo and the mice's death rate. RESULTS: On the seventh day and the fourteenth day, platelet counts of mice treated by rhTPO were higher than those by PBS (P＜0.05). Moreover the platelet counts of mice in experimental group of rhTPO showed increasing tendency following experimental days. In addition, death happened in two groups after those mice were phlebotomized from the supra-obitalis vein, but the death rate in negative control group was evidently higher than that in experimental group (P＜0.05). CONCLUSION:rhTPO had obvious biological activity in increasing platelet production, which resulted in the drop in thrombocytopenia mice's death rate.

Tumor stem cells and glioma initiating cells / 中国病理生理杂志

The tumor stem cell theory supposed that tumor stem cells are the origin of tumor abnormal proliferation,invasion,metastasis,drug resistance and recurrence.As the theory is put forward,it redefines the functions of classic stem cells in tumorigenesis.It is a great event for recent studies on glioma initiating cells as brain tumor stem cells were identified and isolated successfully.A lot of evidence from experiments in vivo and in vitro demonstrates that brain tumor stem cells might play an important role in glioma tumorigenesis.In this review,we discuss the relationship between tumor stem cells and tumorigenesis,and the research on the correlation between brain tumor stem cells and glioma genesis.

Function of I?B kinase links inflammation and cancer / 中国病理生理杂志

It has long been acknowledged that there is a link between inflammation and cancer, but its molecular mechanism remains unclear. A key player in inflammation is nuclear transcription factor NF-?B, that activity is triggered in response to infectious agents and proinflammatory cytokines via the I?B kinase. In parenchyma cells, inflammation through I?B kinase/NF-?B pathway suppresses apoptosis, accelerates cell cycle, then promote tumorigenesis. In mesenchyma cells inflammation through I?B kinase/NF-?B pathway produces cytokines and chemokines that may serve as tumor growth factors. To sum up, I?B kinase/NF -?B pathway represents a critical molecular link between inflammation and cancer.

Effect of zinc on sister chromatid exchange induced by cadmium in human lymphocytes / 中国病理生理杂志

AIM: To investigate the mutagenicity of cadmium and zinc and the effect of zinc on the mutagenicity of cadmium. METHODS: The frequency of sister chromatid exchange (SCE) induced by cadmium, zinc and the combination of cadmium and zinc were observed in cultured human lymphocytes. RESULTS: Cadmium induced the increase in frequency of SCE in human lymphocytes from the concentration 1?10~(-8) mol/L to 1?10~(-6) mol/L, but zinc had a negative result. Zinc reduced the frequency of SCE induced by cadmium at the concentration from 1?10~(-6) mol/L to 1?10~(-4) mol/L and a relationship between dose and effect was also observed. CONCLUSION: Zinc inhibits the mutagenicity of cadmium in cultured human lymphocytes.

Effect of inactivated SARS coronavirus vaccine on mouse organs / 中国病理生理杂志

AIM: To study the pathological change in mouse organs immunitied by inactivated SARS-CoV vaccine. METHODS: Inactivated SARS-CoV vaccine was injected into BALB/c and C57BL/6 mice. Anti-SARS antibody was analyzed by ELISA. After 8 weeks, the immunitied mice were killed and those organs were analyzed by pathological methods. RESULTS: Anti-SARS antibody in mice was positive after 8 days. Only minimal injury was observed in a few lungs and livers, but the other organs were not. CONCLUSIONS: Inactivated SARS-CoV vaccine induced mice to create antibody, whereas they did not cause severe injury. This result will be valuable for vaccine into clinical research. [

The plasticity of hematopoietic stem cells and clinical application / 中国病理生理杂志

Traditional concept has been that hematopoietic stem cells (HSC) are tissue-specific stem cells, which are restricted to generate the cell types of the blood and immune system. However, recent studies have shown that there is a higher plasticity of the HSC than previous expected, it can be induced to transdifferentiated into mature cells of other nonhematopoietic organs after transplantation in vivo. In this article, the recent advances in the plasticity of HSC and its potential clinical application are reviewed.

Whole cell screening of phage-display peptide library for mimicry peptides of glioma SWO-38 / 中国病理生理杂志

AIM and METHODS:The Ph.D.-7 phage display library was used to isolate peptides specific for glioma SWO-38 cell by whole cell screening.Moreover,binding efficiency analysis was carried out to test the binding specificity of the clones obtained. RESULTS: After three rounds of biopanning,a high concentration of phage clones was obtained and two of them were found to be highly specific to glioma SWO-38. CONCLUSION: Highly specific clones against neurtral glioma cells can be obtained from a phage display library by simple procedures.

Intervention therapy of MDS / 肿瘤研究与临床

Myelodysplastic syndromes(MDS) is a malignant disease of hematopoietic stem cell / progenitor cell clones. Therapies of MDS including immuno-suppressive drugs, chemotherapy, hemopoietic stem cell transplantation and drugs suppressing malignant clones have improved much in recent years. This review is about intervention therapy of MDS and the therapy effect.