Protein Expression of BLM Gene and Its Apoptosis Sensitivity in Hematopoietic Tumor Cell Strains

Patients with Bloom syndrome （BS） show an immunodeficiency, an enhanced sister chromatid exchanges （SCEs）, a strong genetic instability and an increased predisposition to all. In order to investigate the differential expression of BLM protein in hematopoietic tumor cell strains and study the effects of BLM gene on ultraviolet （UV）- or hydroxyurea （HU）-induced apoptosis, Western blot was used to detect the expression of BLM protein in normal human bone marrow mononuclear cells and 4 kinds of hematopoietic tumor cell strains. The 4 kinds of hematopoietic tumor cells were exposed to UV light with a germicidal UV lamp or treated with 2 mmol/L hydroxyurea and the apoptotic rate was detected by using AnnexinV-FITC. The results showed that these tumor cells expressed BLM protein higher than the normal human bone marrow mononuclear cells （P〈0.01）. In the 4 hematopoietic tumor cells, BLM protein was all specially cleaved in response to UV- or HU-induced apoptosis. The increase of BLM protein expression may play an important role in the development of these tumors, and BLM proteolysis is likely to be a general feature of the apoptotic response.

Inhibitory effect of Fuzheng Yiliuyin in combination with chemotherapeutics on human gastric carcinoma cell strain

AIM： To study the inhibitory effects of Fuzheng Yiliuyin （Decoction for Suppressing Tumors by Strengthening the Body Resistance） in combination with chemotherapeutics on human gastric carcinoma cell strain. METHODS： Fuzheng Yiliuyin （ZY） combined with various kinds of chemotherapeutics was put into two kinds of cultivated human gastric carcinoma cell strains, then its inhibitory effects on human gastric carcinoma cell strains were determind by the MTT method. Flow cytorneter was used to assay the apoptosis rate, and the ultrastructure of gastric carcinoma cells was observed under transmission electron microscope. RESULTS： Obvious apoptosis was seen in gastric carcinoma cells after treatment with ZY for 72 h. ZY and chemical drugs had synergistic inhibition effects on the cultivated gastric carcinoma cells, but the effects were different on various cell strains. The inhibitory effects of ZY could be strengthened by cytotoxic action and apoptosis. ZY combined with tluorouracil, etoposide and cisplatin （EFP） chemotherapeutics had better inhibitory effects on SGC-7901, while ZY combined with EFP or with DDP chemotherapeutics had better inhibitory effects than other drugs on MGC-803. CONCLUSION： ZY induces apoptosis and inhibits the growth of gastric carcinoma cells. ZY has the synergistic function of chemotherapeutics.

O^6-METHYLGUANINE-DNA METHYLTRANSFERASE ACTIVITY AND SENSITIVITY OF 20 CHINESE TUMOR CELL STRAINS TO 1-(4-AMINO-2-METHYL-5-PYRIMIDINYL) METHYL-3-(2-CHLOROETHYL)-3-NITROSOUREA

O6-methylguanine-DNA methyltransferase (MGMT) plays an important role in repairing alkylated DNA. MGMT activity as well as cellular sensitivity to 1- ( 4- amino- 2-methyl-5-pyrimidinyl) methyl-3- ( 2-chloroethyl)-3-nitrosourea (ACNU) of 20 Chinese tumor cell strains were assayed. A linear response between MGMT activity and ACNU sensitivity (D10) was observed. The lower the MGMT activity In the cells, the more the sensitivity to ACNU killing. It suggested that assay of MGMT activity in tumor biopsy could be used as a guide to predict the effectiveness of ACNU treatment in chemotherapy of human cancer.

Expression of cyclooxygenase-2 mRNA in drug-sensitive cell and drug-resistant strains of ovarian cancer cell lines

Objective： To investigate the expression of cyclooxygenase-2 （COX-2） mRNA in drug-sensitive cell and drugresistant clones of ovarian cancer cell lines. Methods： RT-PCR and immunocytochemistry were used to investigate the expression of cyclooxygenase-2 in 3 clones drug-sensitive and 5 clones drug-resistant ovarian cancer cell. Results： Strong COX-2 mRNA expressions were detected in 3 clones of drug-sensitive cell and weak expressions were detected in 5 clones of drug-resistant cell. The protein expression of COX-2 in drug-sensitive cell was strongly positive reaction in immunocytochemistry stain and there was a weak positive reaction in 5 clones of drug-resistant cell. Conclusion： The expression of COX-2 mRNA in drug-sensitive cell strains is much higher than that in drugresistant strains of ovarian cancer cell lines, providing a basis of the chemoprevention for ovarian cancer.

GENOTOXIC EFFECT OF CIGARETTE SMOKE CONDENSATE (CSC) ON HUMAN DIPLOID CELL 2BS STRAIN

A series of bioassays such as sister chromatid exchange frequencies ( SCE.), chromosomal aberration ( CA ), micronuclel rate (MN) and cell-cycle delay have been used to detecting the genotoxic effect of cigarette smoke condensate (CSC) on human diploid cell 2BS strain. The results suggested that a higher SCE, ( 17. 0/ cell) was observed In 2BS cells treated with CSC at 100 μg/ml, as compared with 6. 9/cell of the background (P<0. 001). CA rate was significantly increased from 4% to 36% In cells treated with 10 μg/ml CSC (P< 0.001). MN rate varied from 9 -26‰ In cells treated with CSC compared to that of control (6‰). Meanwhile, the cell-cycle of cells was markedly delayed by CSC. The survival rate of 2BS cells declined to 59. 6% for treatment with CSC at 200 μg/ ml. There was a dose-effect response In SCE., CA, MN rate. We proposed that active oxygen might responsible for genotoxiclty of CSC on cells.

Sensing Traction Strain Induces Cell-Cell Distant Communications

Mechanobiology has been a highly recognized field in studying the importance of physical forces in physiologies at the molecular,cellular,tissue,organ and body-levels.Beside the intensive work focusing on the fine local biomechanical forces,the long-range force which can propagate through a relatively distant scale(in hundreds of micrometers and beyond)has been an intriguing topic with increasing attentions in recent years.The collective functions at cell population level often rely on cell-cell communications with or without direct contacts.Recent progresses including our own work indicate that the long-range biomechanical force propagating across scales far beyond single cell size may reserve the capability to trigger coordinative biological responses within cell population.Whether and how cells communicate mechanically in a distant manner remains largely to be explored.In respiratory system,the mechanical property of airway smooth muscle(ASM)is associated with asthma attack with prolonged contraction during airway hyper-responsiveness.In this work,we found that ASM cells rapidly self-assembled into a well-constructed network on 3D matrigel containing type I collagen(COL I),which required the collective functions and coordination of thousands of cells completed within 12-16 hours.Cells were assembled with aligned actin stress fibers and elongated nuclei.The assembling process relied on the long-range mechanical forces across the matrix to direct cell-cell distant interactions.We further found that single ASM cells could rapidly initiate multiple buds precisely pointing to neighboring cells in distance,which relied on cell traction force and force strain on the matrix.Beads tracking assay demonstrated the long-range transmission of cellular traction force to distant locations,and modeling of maximum strain distribution on matrix by finite element method predicted the consistency with cell directional protrusions and movements in experiments.Cells could sense each other in distance to move directionally on both non-fibrous matrigel and in much more efficient way when containing COL I.Cells recruited COL I from the hydrogel to build nearly identical COL I fibrous network to mechanically stabilize the cell network.Our results revealed that ASM cells can sense the traction strain transmitted through matrix to initiate distant communications and rapidly coordinate the network assembly at the population level through active cell-matrix interactions.As an interesting phenomenon,cells sound able to’make phone call’via the role of long-range mechanical force.In summary,this work demonstrated that long-range biomechanical force facilitates the collective functions of ASM cell population for network assembly.The cells reacted to traction strain on the matrix for distant communications,which resulted in directional budding and movement.Fibrous COL I had important roles in facilitating the efficiency of force transmission to induce the assembly and stabilizing the cell network.This work has helped advance the understanding of the feature andfunction of long-range biomechanical force at the cell population level.The observed high mechano-sensitivity of ASM cells might suggest a re-enforced feedback of enhanced contraction by excessive ASM under asthmatic condition.

ADVANCES IN THE STUDY ON LEUKEMIA STRAINS AND LEUKEMIA CELL LINES IN CHINA

The study and establishment of leukemia strains and leukemia cell lines have made great achievement in China.It has been extended from mice to rat model and related to explore human leukemia cell line and heterotransplantable tumor strains. The cellular types of leukemia strain have included Iymphocytic,tmyelocytic,ecythroleukmia and megakaryoblastic cell strain.

CD69+NK Cells Contribute to the Murine Hepatitis Virus Strain 3-Induced Murine Hepatitis

Summary： The role of hepatic CD69＋ natural killer （NK） cells in virus-induced severe liver injury and subsequent hepatic failure is not well defined. In this study, a mouse model of fulminant liver failure （FHF） induced by murine hepatitis virus strain 3 （MHV-3） was used to study the role of hepatic CD69＋NK cells in the development of FHF. The CD69 expression in NK cells in the liver, spleen, bone marrow and peripheral blood was detected by using flow cytometry. The correlation between the CD69 level in hepatic NK cells and liver injury was studied. The functional marker （CD107a）, and activating and inhibitory receptor （NKG2D and NKG2A） expressed on CD69＋NK cells and CD69-NK cells were detected by using flow cytometry. Pro-inflammatory cytokines （IL-9, IFN-y and TNF-a） were also examined by using intracellular staining. After MHV-3 infection, the number of CD69＋NK cells in the liver of BALB/cJ mice was increased markedly and peaked at 72 h post-infection. Similar changes were also observed in the spleen, bone marrow and peripheral blood. Meanwhile, the CD69 expression in hepatic NK cells was highly correlated with the serum level of ALT and AST. The expression of CD107a and NKG2D, as well as the production of TNF-a, IFN-7 and IL-9 in hepatic CD69＋NK cells was all significantly up-regulated during 48-72 h post-infection. In contrast, the NKG2A expression was increased in hepatic CD69-NK cells but not in CD69＋NK cells. These results suggested that hepatic CD69＋NK cells play a pivotal role in the pathogenesis of FHF by enhancing degranulation and cytotoxic ability of NK cells and increasing the production of pro-inflammatory cytokines.

Multiplication of the Recombinant Strain Re-7 of Avian Influenza Virus Subtype H5 in MDCK Cells

This study was conducted to explore the multiplication pattern of the recombinant strain Re-7 of avian influenza virus subtype H5 in Madin Darby Canine Kidney （MDCK） cells and to determine the optimal multiplicity of infection （MOI） and the optimal time for virus harvest. The recombinant strain Re-7 was inoculated at different MOIs into MDCK cells grown in serum-free medium in 100 L bioreactors for replication. Then, the hemagglutination（HA） titer, 50% tissue culture infectious dose （TCID50） and 50% embryo infectious dose （EID50） of culture medium were measured once every 12 h from 24 h after virus inoculation to determine the optimal MOI. After that, virus was inoculated at the optimal MOI determined above into MDCK cells for large-scale virus replication to determine the optimal time for virus harvest. The results showed that the optimal MOI was 10 2, and the optimal time for virus harvest was 60 h after inoculation. Under these conditions, the HA titer, TCIDso per 1 mL and EIDso per 0.1 mL were increased to 1：102 4, 10^7.33 and 10^6.83, respectively. This study provides relatively stable parameters for large-scale production of the recombinant strain Re-7 of avian influenza virus subtype H5.

Effects of serum containing natural cerebrolysin on glucose-regulated protein 78 and CCAAT enhancer-binding protein homologous protein expression in neuronal PC12 cells following tunicamycin-induced endoplasmic reticulum stress

BACKGROUND： Glucose-regulated protein 78 （GRP78）, a marker of endoplasmic reticulum stress, can prolong cell survival. Alternatively, CCAAT enhancer-binding protein homologous protein （CHOP）, a transcription factor specific for endoplasmic reticulum stress, can cause cell cycle arrest and cell apoptosis. OBJECTIVE： To study the protective effects of serum containing natural cerebrolysin on endoplasmic reticulum stress in tunicamycin-induced neuronal PC12 cells, and analyze the influence on GRP78 and CHOP expressions. DESIGN, TIME AND SETTING： A parallel controlled study was performed at the Institute of Integrated Western and Traditional Chinese Medicine, Shenzhen Hospital, Southern Medical University, between March 2006 and August 2008. MATERIALS： Adult Sprague-Dawley rats were perfused with natural Cerebrolysin aqueous extract （0.185 g/kg/d） to produce serum containing natural Cerebrolysin. Physiological saline was used to produce blank serum. PC12 cell line was provided by Shanghai Institute of Cell Biology, Chinese Academy of Science. Tunicamycin was provided by Sigma （St. Louis, USA）, and natural Cerebrolysin, containing ginseng, rhizoma gastrodiae, and gingko leaf （1：2：2）, by Shengzhen Institute of Integrated Western and Traditional Chinese Medicine. METHODS： PC12 cells were treated with DMEM culture media containing 10% blank serum （normal control group）, tunicamycin （1 μg/mL; model group）, and 5%, 10%, and 15% serum containing natural cerebrolysin and tunicamycin （1 μ g/mL; low-, moderate-, and high-dose serum containing natural cerebrotysin groups）, for 2 hours. MAIN OUTCOME MEASURES： PC12 cells were treated with tunicamycin for 48 hours after which apoptosis was measured using the TUNEL method to calculate apoptotic index. GRP78 expression was detected using immunocytochemistry. After 24 hours of treatment with tunicamycin, GRP78 and CHOP mRNA expressions were measured using RT-PCR. RESULTS： The apoptotic index and CHOP mRNA expression were in the model group and three cerebrolysin groups were significantly increased when compared to the normal control group （P 〈 0.05）. In contrast, GRP78 mRNA and protein expressions were significantly decreased （P 〈 0.05）. CONCLUSION： Serum containing natural cerebrolysin significantly reduced apoptosis in neuronal PC12 cells following tunicamycin-induced endoplasmic reticulum stress. These results may be related to an up-regulation of GRP78 expression and down-regulation of CHOP expression, both of which displayed dose-dependent effects.

Immortalized Rat Astrocyte Strain Genetically Modified by Rat Preprogalanin Gene

Summary: To construct an immortalized rat astrocyte strain genetically modified by rat preprogalanin gene (IAST/GAL) and detect its galanin (GAL) expression and secretion, a cDNA fragment of rat GAL in plasmid of pBS KS(+)-GAL was inserted into eukaryotic expression vector pcDNA3.1(+) by DNA recombinant technology, then the restriction enzyme digestion and DNA sequencing were carried out to evaluate the recombinant. The pcDNA3.1(+)-GAL and pcDNA3.1(+) construct were transfected into immortalized rat astrocyte strain (IAST) by lipofectamine and the population of cells which stably integrated the construct was selected with 600 μg/mL G418. Individual clones were screened and expanded into clonal cell strains. Detection of Neo gene was used to validate the success of the transfection. Immunocytochemical staining, RT-PCR and radioimmunoassay were used to detect the expression and secretion level of GAL. The recombinant had been successfully constructed by restriction enzyme digestion and DNA sequencing. Detection of Neo gene showed that the pcDNA3.1(+)-GAL and pcDNA3.1(+) have been successfully transfected into IAST. After selection by using G418, IAST/GAL and IAST/Neo cell strains were obtained. IAST/GAL, IAST/Neo and IAST were immunostained positively for GAL, but the GAL average optical density of IAST/GAL was significantly higher than that of IAST/Neo and IAST (P< 0.01). The level of GAL mRNA expression and the supernatant concentration of GAL in cultured IAST/GAL were significantly higher than those of IAST and IAST/Neo (P<0.01), but no significant differences were found between the IAST and IAST/Neo (P>0.05). It was concluded that IAST/GAL strain was constructed successfully and it might provide a basis for the further study of pain therapy.

Providencia rettgeri strain HNR菌株羟胺氧化酶超声波法提取的研究

为了更有效和便捷的提取菌株脱氮过程中的关键酶,本文利用超声波破碎法对异养脱氮菌Providencia rettgeri strain HNR进行破碎,通过单因素实验及正交试验,确定出最佳破碎条件,便于后续试验。实验结果表明:最佳超声破碎条件为菌液OD_(600)为1.996,工作次数为70次,工作/间歇为5/5s功率为400W的组合为最佳工作条件。在此工作条件下破碎后得到的酶粗提液对羟胺有降解,得到羟胺氧化酶。

Dauricine can inhibit the activity of proliferation of urinary tract tumor cells

Objective:To explore the anti-tumor effects of asiatic moonseed rhizome extraction-dauricine on bladder cancer EJ cell strain,prostate cancer PC-3Mcell strain and primary cell culture system.Methods:The main effective component-phenolic alkaloids of Menispermum dauricum was extracted and separated from asiatic moonseed rhizome by chemical method.MTT method was used to detect dauricine anti-tumor effect.Results:Dauricine had an obvious proliferation inhibition effect on the main tumor cells in urinary system.The minimum drug sensitivity concentration was between 3.81-S.ISμg/mL,and the inhibition ratio increased with the increase of concentration.Condusioiis:Dauricine,the main effective component extracted from asiatic moonseed rhizome,had a good inhibition effect on tumor cells in urinary system.At the same time,Dauricine has certain inhibition effects on the primary cultured tumor cell.

Effect of Helicobacter pylori infection on gastric epithelial cell proliferation

INTRODUCTION Helicobacter pylori(H.pylori)infection is one ofthe main pathogens of chronic gastritis and duodenalulcer(DU),and it may be considered as a riskfactor in the incidence of gastric cancer.H.pylori infection may lead to the anomaly of gastricepithelial cell proliferation which is closely relatedto the development of gastric cancer.Vacuolatingcytotoxin(VacA)is an important virulence andvacA subtype determines the toxic activity.According to its signal sequence,it can be groupedinto type sla,slb,slc and s2.Strains harboringvacAsla are more closely related with digestivediseases and may be the strains with high toxicity.The effect of H.pylori infection on

Mechanoresponse of stem cells for vascular repair

Stem cells have shown great potential in vascular repair.Numerous evidence indicates that mechanical forces such as shear stress and cyclic strain can regulate the adhesion,proliferation,migration,and differentiation of stem cells via serious signaling pathways.The enrichment and differentiation of stem cells play an important role in the angiogenesis and maintenance of vascular homeostasis.In normal tissues,blood flow directly affects the microenvironment of vascular endothelial cells(ECs);in pathological status,the abnormal interactions between blood flow and vessels contribute to the injury of vessels.Next,the altered mechanical forces are transduced into cells by mechanosensors to trigger the reformation of vessels.This process occurs when signaling pathways related to EC differentiation are initiated.Hence,a deep understanding of the responses of stem cells to mechanical stresses and the underlying mechanisms involved in this process is essential for clinical translation.In this the review,we provide an overview of the role of stem cells in vascular repair,outline the performance of stem cells under the mechanical stress stimulation,and describe the related signaling pathways.

Effects of cell size on compressive properties of aluminum foam

The effects of cell size on the quasi-static and dynamic compressive properties of open cell aluminum foams produced by infiltrating process were studied experimentally. The quasi-static and dynamic compressive tests were carried out on MTS 810 system and SHPB(split Hopkinson pressure bar) respectively. It is found that the elastic moduli and compressive strengths of the studied aluminum foam are not only dependent on the relative density but also dependent on the cell size of the foam under both quasi-static loading and dynamic loading. The foams studied show a significant strain rate sensitivity, the flow strength can be improved as much as 112%, and the cell size also has a sound influence on the strain rate sensitivity of the foams. The foams of middle cell size exhibit the highest elastic modulus, the highest flow strength and the most significant strain rate sensitivity.

Expression of Bone-related Genes in Bone Marrow MSCs after Cyclic Mechanical Strain: Implications for Distraction Osteogenesis

Aim Understanding the response of mesenchymal stem cells （MSCs） to mechanical strain and their consequent gene expression patterns will broaden our knowledge of the mechanobiology of distraction osteogenesis. Methodology In this study, a single period of cyclic mechanical stretch （0.5 Hz, 2,000 με） was performed on rat bone marrow MSCs. Cellular proliferation and alkaline phosphatase （ALP） activity was examined. The mRNA expression of six bone-related genes （Ets-1, bFGF, IGF-Ⅱ, TGF-β, Cbfal and ALP） was detected using real-time quantitative RT-PCR. Results The results showed that mechanical strain can promote MSCs proliferation, increase ALP activity, and up-regulate the expression of these genes. A significant increase in Ets-1 expression was detected immediately after mechanical stimulation, but Cbfal expression became elevated later. The temporal expression pattem of ALP coincided perfectly with Cbfal. Conclusion The results of this study suggest that mechanical strain may act as a stimulator to induce differentiation of MSCs into osteoblasts, and that these bone-related genes may play different roles in the response of MSCs to mechanical stimulation.

高频超声在构建SD大鼠皮下移植性乳腺癌模型中的应用

目的:应用MADB-106大鼠乳腺癌细胞悬液皮下移植法建立SD大鼠乳腺癌移植性肿瘤动物模型,并使用高频超声监测肿瘤生长情况。方法:选取7~8周龄雌性SD乳鼠16只,将处于对数生长期的MADB-106大鼠乳腺癌细胞悬液于大鼠腹股沟皮下接种,应用高频超声观察成瘤率、肿块大小、血供情况及其它声像图特征。结果:SD大鼠接种成功率为100%,死亡2只,剩余14只生长良好;超声检查肿块为类圆形,内部低回声且稍不均匀,边界尚清,后方回声衰减,彩色多普勒扫查肿块内部及周边可见较丰富血流信号;3周后切除瘤体组织,大体观肿块成灰白色,多呈椭圆形,部分边缘呈分叶状改变,肿瘤血管较丰富,镜下可见肿瘤细胞大小形状各异,核大深染,异型性明显。结论:通过MADB-106大鼠乳腺癌细胞接种于雌性SD大鼠腹股沟皮下,成功建立了大鼠乳腺癌移植性肿瘤动物模型。高频超声技术可以在SD大鼠乳腺癌皮下成瘤过程中对肿物的大小、形态、边界、内部回声及血流等生物学情况进行动态检测,是观察和评价瘤体动态变化过程的重要技术手段。

Identification and characterization of cell cultures with various embryogenic/regenerative potential in cotton based on morphological,cytochemical,and cytogenetical assessment

Somatic embryogenesis(SE) plays a vital role in genetic transformation and massive propagation of important agronomical and economical crops.Here,we conducted a systematic assessment of the morphological,cytochemical,and cytogenetical characteristics of six culture strains with various embryogenic/regenerative potential during SE process in cotton.Results indicated that the six cell culture strains had stable ploidy levels,and did not reveal any relationship between the cytogenetic state and their morphogenetic potential.Moreover,the six culture strains were compared via double staining with Evans blue and Acetocarmine to efficiently distinguish embryogenic and non-embryogenic cells and determine the embryogenic nature of the calli.In addition,the kind of auxins added in medium affected not only growth property,color,size of cell clumps but also ploidy level and regeneration ability.By combining analysis of morphological,cytochemical,and cytogenetical characteristics of the cell cultures,we are able to obtain and maintain homogeneous cell population with high morphogenic and regeneration ability and establish efficient somatic embryogenesis and regeneration system from short-term cell cultures in upland cotton,which highlight the application of biotechnological approaches in crop breeding,and above all,to better understand totipotency of cells in higher plants.

Effect of off-axis cell orientation on mechanical properties in smooth muscle tissue

The cell alignment in a smooth muscle tissue plays a significant role in determining its mechanical proper-ties. The off-axis cell orientation 'θ” not only effects the shortening strain but also modifies the shear stress relationship significantly. Both experiments and finite element analysis were carried out on a tracheal smooth muscle strip to study how the cell alignment in smooth muscle affects the shear stiffness and shear stresses as well as deformation. A simple model for shear stiffness is derived using the data from experiments. Shear stiffness results obtained from the model indicate that the muscle shear stiff-ness values increase non-linearly with strain and with higher off-axis alignment of cells. Results of deforma-tion and shear stresses obtained from finite element analsysis indicate that the maximum shear stress values of tracheal smooth muscle tissue at 45% of strain are 2.5 times the corresponding values at 20% of strain for all three off-axis cell orientation values θ = 15?, 30? and 45?.