Cell Movement ; genetics ; physiology ; Humans ; Microfilament Proteins ; genetics ; metabolism ; Models, Biological ; Neoplasm Metastasis ; genetics ; physiopathology ; Protein Binding ; genetics ; physiology ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Vesicular Transport Proteins ; genetics ; metabolism

BACKGROUNDGastric cancer (GC) is one of the most prevalent malignancies in the world today, with a high mortality rate. CDX2 is a Drosophila caudal-related homeobox transcription factor that plays an important role in GC. Phosphatase and tensin homologue deleted from chromosome 10 (PTEN) is an important tumor suppressor which is widely expressed in normal human tissues. The aim of the study was to determine the relationship and mechanism between CDX2 and PTEN in invasion and migration of GC cells.

METHODSpcDNA3-CDX2 plasmids were transfected into MGC-803 cells to up-regulate CDX2 protein, and small interfering RNA-CDX2 was transfected to down-regulate CDX2. The influence of CDX2 or PTEN on cell migration and invasion was measured by invasion, migration and wound healing assays. Western blotting assay and immunofluorescence were used to detect the expression of CDX2, PTEN, phosphorylation of Akt, E-cadherin and N-cadherin. Statistical significance was determined by one-way analysis of variance.

RESULTSThe results showed that CDX2 reduced the migration and invasion of GC cells (P < 0.05), and inhibited the activity of Akt through down-regulating PTEN expression (P < 0.05). CDX2 also restrained epithelial-mesenchymal transition of GC cells.

CONCLUSIONSCDX2 inhibited invasion and migration of GC cells by PTEN/Akt signaling pathway, and that may be used for potential therapeutic target.

CDX2 Transcription Factor ; Cell Line, Tumor ; Cell Movement ; genetics ; physiology ; Chromosomes, Human, Pair 10 ; genetics ; Epithelial-Mesenchymal Transition ; genetics ; physiology ; Homeodomain Proteins ; genetics ; metabolism ; Humans ; Microfilament Proteins ; genetics ; metabolism ; PTEN Phosphohydrolase ; genetics ; Phosphoric Monoester Hydrolases ; genetics ; metabolism ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Signal Transduction ; genetics ; physiology ; Stomach Neoplasms ; genetics ; metabolism ; pathology ; Tensins ; Wound Healing ; genetics ; physiology

The experiment was designed to investigate the function of SREBP cleavage-activating protein (SCAP) mutant (D443N) by constructing an eukaryotic expressive vector using a smooth muscle specific promoter SM22 (pGL3-SM22-SCAP(D443N)). SM22 promoter (pSM22) was amplified from genome DNA of mice by nested PCR, and then cloned into pMD-T vector. The SM22 promoter fragment released from the vector by Kpn I and Hind III digestion was sub-cloned into pGL3-control-Luc vector, to form pGL3-SM22-Luc. The activity of pSM22 in human vascular smooth muscle cells (VSMCs) was tested using Dual-Luciferase Reporter System. SCAP(D443) mutant amplified from plasmid pTK-HSV-SCAP(D443N) and pSM22 from mice liver were cloned into pGL3-control vector to construct pGL3-SM22-SCAP(D443N) which was transfected into Chinese hamster ovary cells (CHO) to test SCAP(D443) expression by real-time PCR and Western blot. The sequence and construction of pGL3-SM22-SCAP(D443N) were correct. SM22 promoter activity initiated the expression of luciferase in VSMCs and also drove SCAP(D443) expression in transfected CHO cells. The pGL3-SM22-SCAP(D443N) eukaryotic expression vector was successfully constructed and the recombinant vector provides a powerful approach in investigating the function and regulation of SCAP and also in producing vascular smooth muscle specific SCAP transgenic mice.
Animals ; CHO Cells ; Cricetinae ; Cricetulus ; Genetic Vectors ; genetics ; Humans ; Intracellular Signaling Peptides and Proteins ; genetics ; physiology ; Membrane Proteins ; biosynthesis ; genetics ; physiology ; Mice ; Mice, Transgenic ; Microfilament Proteins ; genetics ; Muscle Proteins ; genetics ; Mutant Proteins ; biosynthesis ; genetics ; Promoter Regions, Genetic ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; Transfection

AIMTo investigate the interaction between C-terminal domains of SM22alpha and cytoskeleton F-actin.

METHODSProkaryotic expression vector containing SM22alpha cDNA and GST sequence was constructed. The induction conditions were optimized to increase the product of soluble GST-SM22alpha fusion protein in E coli. Expression products were purified and rabbit anti-GST-SM22alpha polyclonal antibody was produced by the purified fusion protein. In order to explore the effect of SM22alpha on cytoskeleton reorganization, VSMCs were treated with serum withdrawal and then serum stimulation to induce contractile/synthetic phenotypic modulation. SM22alpha protein distribution in F-actin/G-actin fractions was detected by Western blotting. The interaction between SM22alpha and actin was examined by GST pull down assay and coimmunoprecipitation. Colocalization of endogenous SM22alpha with F-actin was observed by immunofluorescence.

RESULTSThe results showed that the expression of soluble GST-SM22alpha protein was the highest under condition induced by 30 degrees C, 0.5 mmol/L IPTG for 6 h. Immunofluorescence and Western blotting of protein extracts from F-actin/G-actin fractions revealed that SM22alpha colocalized with F-actin during VSMC redifferentiation. GST pull down assay and coimmunoprecipitation showed that SM22alpha interacted with F-actin by C-terminal domains to participate in cytoskeleton reorganization.

CONCLUSIONThe recombinant SM22alpha C-terminal domains have the ability to bind F-actin, by which SM22alpha interacts with actin and participates in cytoskeleton reorganization.

Actins ; metabolism ; Amino Acid Sequence ; Animals ; Cell Line ; Cytoskeleton ; metabolism ; physiology ; Microfilament Proteins ; genetics ; Molecular Sequence Data ; Muscle Proteins ; genetics ; Muscle, Smooth, Vascular ; cytology ; metabolism ; Myocytes, Smooth Muscle ; metabolism ; Protein Binding ; Rats ; Rats, Sprague-Dawley ; Recombinant Proteins ; genetics

OBJECTIVETo search and identify the non-steroid receptor binding cis-acting elements in the L-plastin promoter in prostate cancer, and the correlative regulation pathway and transcription factors.

METHODSOn the basis of construction of the L-plastin promoter luciferase vectors which were removed the steroid hormone receptor AR and ER binding elements, the promoter on the vector was nest-deleted by Exonuclease III and the relative luciferase plasmids were constructed. Transfected these twelve plasmids into prostate cancer cell line LNCaP under dihydrotestosterone-stimulated situation or not and test the intensity of luciferase, then we got the regulation message of every 200 bp part of the promoter in prostate cancer. After the analysis of relative programme, we got the possible regu- lation pathway of non-steroid hormone transcription factors. After removing the possible transcription factors binding site sequence by site-specific mutagenesis, the changes luciferase of activities proved our reasoning.

RESULTSWe succeed in segmental deletion of the L-plastin promoter, and constructing the relative plasmids containing part L-plastin promoter on luciferase vector pGL3-basic. After testing the luciferase activities of constructed plasmids, we found the sequence from 206 to 1 of L-plastin promoter had significant luciferase activity. The software TRANSFECT showed that there were binding elements for transcription factors AP-4 at seq-198 to 192 and SP-1 at seq-54 to 41 on the short part promoter (206 to 1). The recombinant plasmids deleted the AP-4 and SP-1 binding elements had lower luciferase activity than the wild-type.

CONCLUSIONThere are some other non-steroid hormone pathway to regulate the expression of L-plastin except the steroid hormone pathway in prostate cancer. The main binding sites of the non-steroid hormone regulator lies in the sequence from 206 to 1. Transcription factors AP4 and SP-1 may up-regulated the expression of L-plastin by binding these sites.

Animals ; DNA-Binding Proteins ; physiology ; Gene Expression Regulation, Neoplastic ; Luciferases ; metabolism ; Male ; Membrane Glycoproteins ; Mice ; Microfilament Proteins ; Phosphoproteins ; biosynthesis ; genetics ; Promoter Regions, Genetic ; genetics ; Prostatic Neoplasms ; metabolism ; Response Elements ; Transcription Factors ; physiology ; Transfection ; Tumor Cells, Cultured ; Up-Regulation

Animals ; Carrier Proteins ; genetics ; Immunohistochemistry ; Lacrimal Apparatus ; metabolism ; Lung ; metabolism ; Mice ; Mice, Inbred NOD ; Microfilament Proteins ; genetics ; RNA, Small Interfering ; genetics ; physiology ; Random Allocation ; Sjogren's Syndrome ; genetics ; immunology ; therapy

OBJECTIVETo understand the role that esophageal cancer related gene-1 (ECRG-1) plays and to search for ECRG-1-interacting proteins.

METHODSA DNA fragment encoding the carboxy-terminus of ECRG-1 (amino acids 40 - 418) was inserted into pGBKT7-DNA-BD vector and fused in-frame to the DNA-binding domain of GAL4. Then, it was used as a bait to screen the human fetal liver cDNA library by yeast two-hybrid, with the cDNA fragment inserted into pACT2 vector and fused in-frame to the Gal4 activation domain. If ECRG-1 interacted with a protein encoded by a cDNA fragmant in the yeast, the transcription of reporter Gene could be activated. With the false positive clonies eliminated, the inserts in the positive plasmids were sequenced and compared to those in the GenBank.

RESULTSIn approximately 3 x 10(6) independent tansformants screened, 23 clonies exhibited the expression of reporter gene. After eliminating the false positive clonies, two cDNA fragments were obtained. DNA sequencing revealed that one encoded Miz-1 (Myc-interacting Zn finger protein-1), and another encoded FLNA (actin-binding protein-280), Miz-1, being a Zn finger protein, could be bound to p15 promotor and activated the transcription. FLNA, being an actin-binding protein took part in the TGF-beta pathway via interaction with Smad.

CONCLUSIONECRG-1 is able to be specifically bound to Miz-1 and FLNA in the yeast. It may play a role in the regulation of cell cycle via interaction with Miz-1 and FLNA.

Contractile Proteins ; metabolism ; DNA-Binding Proteins ; metabolism ; Escherichia coli Proteins ; metabolism ; physiology ; Filamins ; Gene Library ; Humans ; Kruppel-Like Transcription Factors ; Liver ; embryology ; physiology ; Membrane Proteins ; Microfilament Proteins ; metabolism ; Recombinant Fusion Proteins ; metabolism ; physiology ; Serine Proteases ; Transcription Factors ; Two-Hybrid System Techniques ; Yeasts ; genetics

PURPOSE: Endothelial cells maintain the homeostasis of blood, which consists of plasma and cellular components, and regulate the interaction between blood and the surrounding tissues. They also have essential roles in vascular permeability, the circulation, coagulation, inflammation, wound healing, and tissue growth. The senescence of endothelial cells is closely related to the aging of the adjacent tissues and to age-related vascular disease. Recently, the expression of moesin was found to be decreased in elderly human dermal microvascular endothelial cells (HDMECs), and an association between moesin and senescence has been suggested. This study examined the functional role of moesin in cellular senescence. MATERIALS AND METHODS: To study the effects of decreased moesin expression on cellular senescence and metabolism, HDMECs were transfected with short hairpin-RNA (shRNA) lentivirus to silence moesin gene expression. In addition, specimens from young and old human skin were stained with anti-moesin and anti-p16 antibodies as an in vivo study. RESULTS: Using shRNAl-entivirus, moesin knock-down HDMECs developed characteristics associated with aging and expressed senescence associated-beta-galactosidase during early passages. They also showed increased p16 expression, decreased metabolic activity, and cell growth retardation. Human skin tissue from elderly persons showed decreased moesin expression and increased p16 expression. CONCLUSION: These findings suggest that there is a functional association between moesin expression and cellular senescence. Further study of the functional mechanism of moesin in the cytoskeleton and cellular senescence is needed. In addition, this study provides a useful model for developing anti-aging treatments.
Aged, 80 and over ; Antigens, CD31/metabolism ; Blotting, Western ; Cell Aging/genetics/*physiology ; Cell Line ; Child ; Endothelial Cells/*cytology/*metabolism ; Humans ; Immunohistochemistry ; Microfilament Proteins/genetics/*physiology ; Microscopy, Phase-Contrast ; Microvessels/*cytology ; RNA, Small Interfering/genetics/physiology ; Reverse Transcriptase Polymerase Chain Reaction ; Skin/*blood supply

AIMTo determine the effectiveness of the sk11, sk9 and sk11 TNUA5 Sertoli cell lines in binding germ cells in vitro.

METHODSThe immortalized Sertoli cell lines sk9, sk11 and sk11 TNUA5 were used in co-culture experiments with germ cells in media with or without reproductive hormones and incubated for 44 h at 32 degrees . The number of germ cells bound to Sertoli cells was then determined and statistically analyzed. Western blot analysis and reverse transcriptase-polymerase chain reaction (RT-PCR) studies were employed to investigate the presence of cell adhesion proteins and follicle stimulating hormone (FSH) receptor, respectively.

RESULTSNo statistical difference between the number of bound step-8 spermatids and bound pre-step 8 spermatids on Sertoli cells from any of the cell lines existed. After the addition of germ cells, Sertoli cells showed more lipid accumulation in their cytoplasm, indicating active phagocytosis. Western blot analysis in the sk11 TNUA5 line indicated the expression of N-cadherin. FSH-only and testosterone-only treatments increased N-cadherin expression, regardless of germ cell addition. The addition of germ cells to the sk11 TNUA5 Sertoli cells increased the expression of espin, as did the addition of FSH with germ cells. RT-PCR studies of the sk11 TNUA5 cells indicated that the mRNA for FSH receptor decreased with successive passages.

CONCLUSIONIn vitro binding between isolated germ cells and sk9, sk11 or sk11 TNUA5 Sertoli cells is not feasible, and therefore these cell lines are not useful for the in vitro investigation of Sertoli-germ cell interactions and primary Sertoli cell isolates must still be used.

Animals ; Cadherins ; genetics ; metabolism ; Cell Adhesion ; physiology ; Cell Line, Transformed ; cytology ; metabolism ; Coculture Techniques ; Gene Expression ; Image Processing, Computer-Assisted ; Male ; Mice ; Microfilament Proteins ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Receptors, FSH ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Sertoli Cells ; cytology ; metabolism ; Spermatids ; cytology ; metabolism

Oval cells have a potential to differentiate into a variety of cell lineages including hepatocytes and biliary epithelia. Several models have been established to activate the oval cells by incorporating a variety of toxins and carcinogens, alone or combined with surgical treatment. Those models are obviously not suitable for the study on human hepatic oval cells. It is necessary to establish a new and efficient model to study the human hepatic oval cells. In this study, the hepatocyte growth factor (HGF) and epidermal growth factor (EGF) were used to induce differentiation of mouse embryonic stem (ES) cells into hepatic oval cells. We first confirmed that hepatic oval cells derived from ES cells, which are bipotential, do exist during the course of mouse ES cells' differentiation into hepatic parenchymal cells. RT-PCR and transmission electron microscopy were applied in this study. The ratio of Sca-1+/CD34+ cells sorted by FACS in the induction group was increased from day 4 and reached the maximum on the day 8, whereas that in the control group remained at a low level. The differentiation ratio of Sca-1+/CD34+ cells in the induction group was significantly higher than that in the control group. About 92.48% of the sorted Sca-1+/CD34+ cells on the day 8 were A6 positive. Highly purified A6+/Sca-1+/CD34+ hepatic oval cells derived from ES cells could be obtained by FACS. The differentiation ratio of hepatic oval cells in the induction group (up to 4.46%) was significantly higher than that in the control group. The number of hepatic oval cells could be increased significantly by HGF and EGF. The study also examined the ultrastructures of ES-derived hepatic oval cells' membrane surface by atomic force microscopy. The ES-derived hepatic oval cells cultured and sorted by our protocols may be available for the future clinical application.
Animals ; Antigens, CD34 ; genetics ; metabolism ; Antigens, Ly ; genetics ; metabolism ; Cell Differentiation ; drug effects ; genetics ; physiology ; Cell Line ; Embryonic Stem Cells ; cytology ; metabolism ; ultrastructure ; Epidermal Growth Factor ; pharmacology ; Flow Cytometry ; Gene Expression Regulation, Developmental ; drug effects ; Hepatocyte Growth Factor ; pharmacology ; Liver ; cytology ; metabolism ; Membrane Proteins ; genetics ; metabolism ; Mice ; Mice, Inbred BALB C ; Microfilament Proteins ; metabolism ; Microscopy, Atomic Force ; Microscopy, Electron, Transmission ; Reverse Transcriptase Polymerase Chain Reaction ; Stem Cells ; cytology ; metabolism ; ultrastructure ; Time Factors