Objective: To uncover the time-dependent expression pattern of ptk2b gene and ptk2b-encoded protein, protein tyrosine kinase 2 beta(PTK2B), in the brain tissues of transgenic animal models of Alzheimer's disease (AD) and its relationship with the levels of Aβ_1-42, phosphorylation of Tau (p-Tau) and low density lipoprotein receptor-related protein-1(LRP-1) in blood and brain tissues. Methods: In this study, 5-, 10- and 15-month-old APPswe/PS1dE9 double-transgenic mice harboring the genotype of AD confirmed by the gene test were divided into the 5-, 10- and 15-month-old experiment groups, and simultaneously, age-matched C57BL/6J mice were placed into the corresponding control groups, with 8 mice in each group. All mice were subjected to the Morris Water Maze for test of cognitive and behavioral ability. Expression profiles of PTK2B, Aβ_1-42, p-Tau/Tau and LRP-1 in the hippocampus or blood of mice were quantified by using the immunohistochemistry staining, Western blot or enzyme-linked immunosorbent assay (ELISA), while the mRNA expression of ptk2b in the hippocampus was quantified by using the real-time quantitative polymerase chain reaction (qRT-PCR). Results: Results of experiment groups demonstrated that as mice aged, the expression levels of PTK2B, ptk2b mRNA, Aβ_1-42 and p-Tau/Tau in the hippocampus were increased, and the expression of LRP-1 was decreased gradually. While in the blood, the level of Aβ_1-42 was decreased, and the cognitive and behavioral ability was decreased in an age-dependent manner (all P＜ 0.05). However, comparisons among the control groups, only the age-dependent downregulation of LRP-1 were observed in hippocampus(P＜0.05), but other indicators had no significant differences (P＞0.05). Conclusion: In the hippocampus of APP/PS1 double-transgenic mice, the expressions of PTK2B, Aβ_1-42 and p-Tau/Tau are upregulated, LRP-1 is downregulated, while cognitive and behavioral ability is decreased, and such changes are presented in a time-dependent manner.
Alzheimer Disease/metabolism* ; Amyloid beta-Peptides ; Amyloid beta-Protein Precursor/genetics* ; Animals ; Focal Adhesion Kinase 2/metabolism* ; Hippocampus/metabolism* ; Low Density Lipoprotein Receptor-Related Protein-1 ; Maze Learning ; Mice ; Mice, Inbred C57BL ; Mice, Transgenic ; RNA, Messenger

This study was designed to evaluate ERK5 expression in lung cancer and malignant melanoma progression and to ascertain the involvement of ERK5 signaling in lung cancer and melanoma. We show that ERK5 expression is abundant in human lung cancer samples, and elevated ERK5 expression in lung cancer was linked to the acquisition of increased metastatic and invasive potential. Importantly, we observed a significant correlation between ERK5 activity and FAK expression and its phosphorylation at the Ser
A549 Cells ; Animals ; Cell Movement ; Epithelial-Mesenchymal Transition/genetics* ; Focal Adhesion Kinase 1/metabolism* ; Humans ; Lung Neoplasms/pathology* ; MAP Kinase Signaling System ; Mice ; Mitogen-Activated Protein Kinase 7/metabolism* ; Neoplasm Invasiveness ; Neoplasm Metastasis ; Neoplasm Proteins/metabolism*

OBJECTIVETo investigate the effects of sphingosine kinase 1 (SphK1) on the proliferation, migration and invasion of human colon cancer LoVo cells, and to explore the related mechanisms.

METHODSHuman colon cancer LoVo cells were divided into three groups: phorbol 12-myristate 13-acetate (PMA) was used to induce the activation of SphK1 in the PMA group, N,N-dimethylsphingosine (DMS) used to suppress the activity of SphK1 in DMS group, and the cells treated with equal amount of 0.9 % NaCl instead of drugs served as the control group. The activity of SphK1 was assayed by autoradiography, the cell proliferation was assessed by MTT assay, cell migration and invasion were examined by Boyden chamber assay, concentrations of sICAM-1 and sVCAM-1 were assayed by ELISA, and RT-PCR and Western blot were used to evaluate the mRNA and protein expression in the cells.

RESULTSThe activity of SphK1 was efficiently induced by PMA and significantly suppressed by DMS. PMA induced cell proliferation in a time- and dose-dependent manner. On the contrast, DMS suppressed cell proliferation in a time- and dose-dependent manner. After treating with PMA, the number of migrating and invasing cells were increased to 143.36 ± 8.73 and 118.46 ± 6.25, significantly higher than those of the control group (75.48 ± 6.12 and 64.19 ± 5.36). After treating with DMS, the number of migrating and invasing cells were decreased to 38.57 ± 3.24 and 32.48 ± 4.27, significantly lower than those of the control group (P < 0.01). The relative expression levels of FAK, ICAM-1 and VCAM-1 mRNA in the PMA group were 0.82 ± 0.06, 0.74 ± 0.05 and 0.89 ± 0.09, and those in the DMS group were 0.23 ± 0.02, 0.26 ± 0.03 and 0.37 ± 0.04, with significant differences between the PMA, DMS and control groups (P < 0.01). Compared with the control group, the relative expression levels of FAK and p-FAK proteins in the PMA group (0.52 ± 0.06 and 0.51 ± 0.06) were significantly elevated, and those of the DMS group (0.20 ± 0.03 and 0.09 ± 0.02) were significantly decreased. In addition, the concentrations of sICAM-1 and sVCAM-1 were significantly elevated with the activation of SphK1. On the contrary, those of the DMS group were significantly reduced with the suppression of SphK1 (Both P < 0.01).

CONCLUSIONSSphK1 may enhance the proliferation, migration and invasion of colon cancer LoVo cells through activating FAK pathway and up-regulating the expression of ICAM-1 and VCAM-1.

Cell Line, Tumor ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Colonic Neoplasms ; enzymology ; metabolism ; pathology ; Dose-Response Relationship, Drug ; Enzyme Inhibitors ; pharmacology ; Focal Adhesion Kinase 1 ; genetics ; metabolism ; Humans ; Intercellular Adhesion Molecule-1 ; genetics ; metabolism ; Neoplasm Invasiveness ; Phosphorylation ; drug effects ; Phosphotransferases (Alcohol Group Acceptor) ; metabolism ; RNA, Messenger ; metabolism ; Signal Transduction ; Sphingosine ; analogs & derivatives ; pharmacology ; Tetradecanoylphorbol Acetate ; pharmacology ; Vascular Cell Adhesion Molecule-1 ; genetics ; metabolism

Malignant melanoma still remains to be a serious health threat. Overexpression of focal adhesion kinase (FAK) in melanoma has suggested that FAK could be a promising target for therapeutic intervention. To further investigate the function of FAK in melanoma, FAK expression was down-regulated by stable transfection of plasmid harboring FAK small interfering RNA (siRNA) into melanoma cell line. Two stable cell lines, F10-siFAK and F10-control, have been constructed and screened. Compared with the F10-control, both the mRNA and protein levels of FAK decreased significantly, and the cell cycle of F10-siFAK was arrested at G1 phase. Furthermore, the tumor growth rate of F10-siFAK cells was notably slower than that of F10-control in in vivo tumor models. These results show that FAK is an important regulatory gene in melanoma. The stable FAK-knockdown melanoma cell line is an useful tool for further investigation of FAK's function in the progression of melanoma, and also an effective means of drug screening for anti-melanoma therapeutics.
Animals ; Cell Cycle ; Cell Line, Tumor ; Cell Proliferation ; Down-Regulation ; Focal Adhesion Protein-Tyrosine Kinases ; genetics ; metabolism ; G1 Phase ; Gene Knockdown Techniques ; Melanoma, Experimental ; enzymology ; pathology ; Mice ; Mice, Inbred C57BL ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Plasmids ; RNA, Messenger ; metabolism ; RNA, Small Interfering ; genetics ; Transfection

We previously reported that mice lacking JSAP1 (jsap1-/-) were lethal and the brain of jsap1-/- at E18.5 exhibited multiple types of developmental defects, which included impaired axon projection of the corpus callosum and anterior commissures. In the current study, we examined whether the early telencephalic commissures were formed abnormally from the beginning of initial development or whether they arose normally, but have been progressively lost their maintenance in the absence of JSAP1. The early corpus callosum in the brain of jsap1+/+ at E15.5-E16.5 was found to cross the midline with forming a distinct U-shaped tract, whereas the early axonal tract in jsap1-/- appeared to cross the midline in a diffuse manner, but the lately arriving axons did not cross the midline. In the brain of jsap1-/- at E17.5, the axon terminals of lately arriving collaterals remained within each hemisphere, forming an early Probst's bundle-like shape. The early anterior commissure in the brain of jsap1+/+ at E14.5-E15.5 crossed the midline, whereas the anterior commissure in jsap1-/- developed, but was deviated from their normal path before approaching the midline. The axon tracts of the corpus callosum and anterior commissure in the brain of jsap1-/- at E16.5-E17.5 expressed phosphorylated forms of FAK and JNK, however, their expression levels in the axonal tracts were reduced compared to the respective controls in jsap1+/+. Considering the known scaffolding function of JSAP1 for the FAK and JNK pathways, these results suggest that JSAP1 is required for the pathfinding of the developing telencephalic commissures in the early brains.
Adaptor Proteins, Signal Transducing/genetics/*metabolism ; Animals ; Brain/*embryology/*metabolism ; Female ; Focal Adhesion Kinase 1/genetics/metabolism ; Immunohistochemistry ; In Situ Nick-End Labeling ; JNK Mitogen-Activated Protein Kinases/genetics/metabolism ; Mice ; Mice, Knockout ; Nerve Tissue Proteins/genetics/*metabolism ; Pregnancy ; Telencephalon/*embryology/*metabolism

OBJECTIVETo investigate the effect of the wild type phosphatase and tensin homolog deleted on chromosome 10 (PTEN), a tumor-suppressor gene on the proliferation and apoptosis of human chronic myeloid leukemia (CML) cells line (K562) in vitro and explore the influence of PTEN-FAK signaling pathway on invasion and metastasis of leukemia cells.

METHODSThe recombinant Ad-PTEN gene containing green fluorescent protein gene (Ad-PTEN-GFP) or the empty vector (Ad-GFP) was transfected into K562 cells and fresh leukemia cells from CML patients in blast crisis. The growth of K562 cells was assayed by MTT assay; the apoptosis rate was assessed by flow cytometry (FCM). PTEN and FAK mRNA levels were detected by real-time fluorescent relative- quantification reverse transcriptional PCR (FQ-PCR) and its protein levels by Western blot. The metastasis and invasive ability was examined by transwell chamber assay.

RESULTSThe growth of K562 cells was suppressed markedly when Ad-PTEN-GFP was transfected into K562 cells at the 200 multiplicity of infection (MOI). The maximum growth inhibition rate was 35.2%. Transwell results showed the number of cells entered the lower chamber in Ad-GFP group was 9.1 fold more than that in Ad-PTEN-GFP group;The ability of metastasis and invasion of fresh leukemia cells was also suppressed after transfection with Ad-PTEN-GFP. FAK and p-FAK proteins were down-regulated by 0.72 and 0.16 fold lower after transfected with Ad-PTEN-GFP compared with Ad-GFP group.

CONCLUSIONSPTEN gene might inhibit the proliferation, metastasis and invasive ability of leukemia cells via down-regulating FAK expression.

Apoptosis ; Cell Movement ; Cell Proliferation ; Focal Adhesion Kinase 1 ; genetics ; metabolism ; Genetic Vectors ; Humans ; K562 Cells ; Leukemic Infiltration ; PTEN Phosphohydrolase ; genetics ; metabolism ; Signal Transduction ; Transfection

OBJECTIVETo investigate the role of focal adhesion kinase (FAK) in adhesion and migration of hepatic stellate cells (HSC).

METHODSTwo recombinant plasmids expressing short hairpin RNAs (shRNAs) targeting FAK were constructed and one plasmid substantially suppressing FAK expression in HSC was selected. Real-time PCR and Western blot were used to detect the knockdown effects of FAK gene. After 48-hour treatment with FAK shRNA, toluidine blue colorimetric assay was used to detect the cell adhesion. Wound-healing assay and improved Boyden double-chamber were used to detect the cell migration induced by FN.

RESULTSThe recombinant plasmid expressing FAK shRNA was successfully constructed and transfected into HSC. Compared with the controls, the expression of FAK mRNA and protein in HSC treated with FAK shRNA was markedly down-regulated by 76.82% and 72.53%, respectively. The expression of p-FAK (Tyr397) protein was also decreased by 62.71% 48 h posttransfection. The adhesion of HSC was inhibited by 58.69% at 48 h after shRNA transfection. FAK gene silencing could also dramatically inhibit FN-stimulated HSC migration, and the cell migration distance and the cell number of crossing membrane were decreased by 58.27% and 83.70%, respectively.

CONCLUSIONSFAK gene silencing suppresses adhesion and migration of HSC, and FAK may be a potential target for novel anti-fibrosis therapies.

Animals ; Blotting, Western ; Cell Adhesion ; Cell Line ; Cell Movement ; Down-Regulation ; Fibronectins ; Focal Adhesion Kinase 1 ; genetics ; metabolism ; Genetic Vectors ; Hepatic Stellate Cells ; cytology ; enzymology ; Liver Cirrhosis ; pathology ; prevention & control ; Plasmids ; genetics ; Polymerase Chain Reaction ; RNA Interference ; RNA, Messenger ; genetics ; metabolism ; Rats ; Transfection

Cell Adhesion ; drug effects ; Cell Movement ; drug effects ; Focal Adhesion Kinase 1 ; genetics ; metabolism ; Focal Adhesion Protein-Tyrosine Kinases ; Neoplasms ; Phosphorylation

OBJECTIVETo study the role of inhibition FAK expression by FAK siRNA in liver cancer cell (MHCC97-H) adhesion, invasion and cytoskeleton rearrangement.

METHODSFAK siRNA was transfected into MHCC97-H cell by Lipofectamine 2000; then, FAK expression was detected by Western blot analysis. The change of cell adhesive and invasive ability after RNAi was checked by cell adhesive assay and cell invasive assay respectively. Meanwhile, matrix metalloproteinase-2 secretion was checked by gelatin zymography. Cytoskeleton rearrangement labeled by immunofluorescence antibody was examined by confocal laser scanning microscope.

RESULTSFAK expression in MHCC97-H cell was obviously inhibited by specific FAK siRNA; However, it was not inhibited by negative siRNA. Adhesion rate between MHCC97-H cell and extracellular matrix decreased from 57.3% to 35.8% after RNA interference (P < 0.05). Compared with untreated group, the number of cell penetrating matrigel also decreased from 31.3 +/- 2.6 to 14.5 +/- 3.1 after transfection (P < 0.05). Besides, matrix metalloproteinase-2 secretion was significantly reduced for FAK expression inhibited by FAK siRNA. FAK inhibition influenced Vinculin rearrangement, blocked the formation of lamellipodium, delayed the time of focal adhesion formation.

CONCLUSIONDown-regulation the expression of FAK can reduce adhesive rate and invasive number of MHCC97-H cell by influencing cytoskeleton rearrangement and decreasing matrix metalloproteinase-2 secretion.

Blotting, Western ; Carcinoma, Hepatocellular ; enzymology ; genetics ; pathology ; Cell Adhesion ; Cell Line, Tumor ; Cell Movement ; Cytoskeleton ; metabolism ; Fluorescent Antibody Technique ; Focal Adhesion Kinase 1 ; genetics ; metabolism ; Humans ; Liver Neoplasms ; enzymology ; genetics ; pathology ; Matrix Metalloproteinase 2 ; metabolism ; Microscopy, Confocal ; RNA Interference ; RNA, Small Interfering ; genetics ; Transfection ; methods

Exposure of endothelial cells (ECs) to hypoxia leads to a decrease in EC proliferation. However, the mechanism by which hypoxia inhibits EC proliferation is unclear. Perlecan has been reported to play an important role in regulating EC proliferation. We hypothesized that perlecan was involved in the hypoxia-induced inhibition of EC proliferation. To test this hypothesis, rat cardiac microvascular ECs were cultured under normoxic or hypoxic conditions for 12 h and harvested for determination of perlecan mRNA expression using real-time reverse transcription-polymerase chain reaction (RT-PCR). The results showed that exposure of ECs to hypoxia for 12 h induced a decrease in perlecan mRNA expression (61.72%, P<0.05). Concomitantly, the down-regulation of endogenous perlecan induced by hypoxia or the neutralization of endogenous perlecan with anti-perlecan antibody significantly inhibited EC proliferation and responsiveness to basic fibroblast growth factor (bFGF), and decreased focal adhesion kinase (FAK) expression and extracellular signal-regulated kinase 1/2 (ERK1/2) activation. These data indicate that down-regulation of perlecan expression contributes to hypoxia-induced inhibition of rat cardiac microvascular EC proliferation by suppressing FAK-mediated and ERK1/2-dependent growth signals.
Animals ; Capillaries ; cytology ; Cell Hypoxia ; Cell Proliferation ; Cells, Cultured ; Coronary Circulation ; Down-Regulation ; Endothelial Cells ; cytology ; metabolism ; Focal Adhesion Kinase 1 ; metabolism ; Heparan Sulfate Proteoglycans ; genetics ; metabolism ; MAP Kinase Signaling System ; Male ; Oxygen ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Real-Time Polymerase Chain Reaction