The characteristic genetic abnormality of neuroendocrine neoplasms (NENs), a heterogeneous group of tumors found in various organs, remains to be identified. Here, based on the analysis of the splicing variants of an oncogene Focal Adhesion Kinase (FAK) in The Cancer Genome Atlas datasets that contain 9193 patients of 33 cancer subtypes, we found that Box 6/Box 7-containing FAK variants (FAK^6/7) were observed in 7 (87.5%) of 8 pancreatic neuroendocrine carcinomas and 20 (11.76%) of 170 pancreatic ductal adenocarcinomas (PDACs). We tested FAK variants in 157 tumor samples collected from Chinese patients with pancreatic tumors, and found that FAK^6/7 was positive in 34 (75.6%) of 45 pancreatic NENs, 19 (47.5%) of 40 pancreatic solid pseudopapillary neoplasms, and 2 (2.9%) of 69 PDACs. We further tested FAK splicing variants in breast neuroendocrine carcinoma (BrNECs), and found that FAK^6/7 was positive in 14 (93.3%) of 15 BrNECs but 0 in 23 non-NEC breast cancers. We explored the underlying mechanisms and found that a splicing factor serine/arginine repetitive matrix protein 4 (SRRM4) was overexpressed in FAK^6/7-positive pancreatic tumors and breast tumors, which promoted the formation of FAK^6/7 in cells. These results suggested that FAK^6/7 could be a biomarker of NENs and represent a potential therapeutic target for these orphan diseases.
Female ; Humans ; Alternative Splicing ; Breast Neoplasms/metabolism* ; Carcinoma, Pancreatic Ductal/pathology* ; Focal Adhesion Protein-Tyrosine Kinases/therapeutic use* ; Nerve Tissue Proteins/genetics* ; Neuroendocrine Tumors/genetics* ; Oncogenes ; Pancreatic Neoplasms/metabolism*

Objective To investigate how the neutrophil extracellular traps (NETs) affect the proliferation and migration of mouse MC38 colorectal cancer cells and its mechanism. Methods Spleen neutrophils were extracted in mouse, followed by collection of NETs after ionomycin stimulation in vitro. The proliferation of MC38 cell was detected by CCK-8 assay, and migration ability were detected by Transwell^TM and cell scratch assay, after co-incubation with MC38 cells. The mRNA expression of cellular matrix metalloproteinase 2 (MMP2) and MMP9 were detected by real-time fluorescence quantitative PCR, and the expression of MMP2, MMP9 and focal adhesion kinase (FAK), phosphorylated FAK protein were detected by Western blot. After silencing MMP9 using small interfering RNA (siRNA), the effect of NETs on the proliferation and migration ability of MC38 cells and the altered expression of related molecules were examined by previous approach. Results NETs promoted the proliferation and migration of MC38 cells and up-regulated the MMP9 expression and FAK phosphorylation. Silencing MMP9 inhibited the promotion of MC38 proliferation and migration by NETs and suppressed FAK phosphorylation. Conclusion NETs up-regulates MMP9 expression in MC38 cells, activates FAK signaling pathway and promotes tumor cell proliferation and migration.
Animals ; Mice ; Focal Adhesion Protein-Tyrosine Kinases/metabolism* ; Matrix Metalloproteinase 2/metabolism* ; Matrix Metalloproteinase 9/metabolism* ; Extracellular Traps/metabolism* ; Cell Movement ; Cell Proliferation ; RNA, Small Interfering/genetics* ; Colorectal Neoplasms/genetics* ; Cell Line, Tumor

OBJECTIVETo investigate the effect of Ganfukang (GFK) on connective tissue growth factor (CTGF) and focal adhesion kinase (FAK)/protein kinase B (PKB or Akt) signal pathway in a hepatic fibrosis rat model and to explore the underlying therapeutic molecular mechanisms of GFK.

METHODSFifty SD rats were randomly divided into five groups as follows: the control group, the model group (repeated subcutaneous injection of CCl4), and the three GFK treatment groups (31.25, 312.5, and 3125 mg/kg, intragastric administration). Reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting, and immunohistochemistry were used to examine the expression of CTGF, integrin α5, integrin β1, FAK/Akt signal pathway, cyclinD1, and collagen in the different-treated rats.

RESULTSGFK attenuated the up-regulation of CTGF, integrin α5, and integrin β1 in hepatic fibrosis rats and suppressed both the phosphorylation of FAK and the phosphorylation of Akt simultaneously (P<0.01). At the same time, the expression of cyclinD1, collagen I, and collagen III was decreased by GFK significantly (P<0.01).

CONCLUSIONSCTGF and FAK/Akt signal pathway were activated in the CCl4-induced hepatic fibrosis rats, which contribute to increased expression of cyclinD1 and collagen genes. The mechanisms of the anti-fibrosis activity of GFK may be due to its effects against CTGF and FAk/Akt signal pathway.

Animals ; Collagen ; genetics ; metabolism ; Connective Tissue Growth Factor ; genetics ; metabolism ; Cyclin D1 ; genetics ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Female ; Focal Adhesion Protein-Tyrosine Kinases ; metabolism ; Gene Expression Regulation ; drug effects ; Integrin alpha5 ; genetics ; metabolism ; Integrin beta1 ; genetics ; metabolism ; Liver ; drug effects ; enzymology ; pathology ; Liver Cirrhosis ; drug therapy ; enzymology ; genetics ; pathology ; Male ; Phosphorylation ; drug effects ; Proto-Oncogene Proteins c-akt ; metabolism ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects

BACKGROUNDThe initial osteoblastic adhesion to materials characterizes the first phase of cell-material interactions and influences all the events leading to the formation of new bone. In a previous work, we developed a novel amorphous calcium phosphate (ACP)/poly(L-lactic acid) (PLLA) material that demonstrated morphologic variations in its microstructure. The aim of this study was to investigate the initial interaction between this material and osteoblastic cells. Cellular attachment and the corresponding signal transduction pathways were investigated.

METHODSA porous ACP/PLLA composite and PLLA scaffold (as a control) were incubated in fetal bovine serum (FBS) containing phosphate-buffered saline (PBS), and the protein adsorption was determined. Osteoblastic MG63 cells were seeded on the materials and cultured for 1, 4, 8, or 24 hours. Cell attachment was evaluated using the MTS method. Cell morphology was examined using scanning electron microscopy (SEM). The expression levels of the genes encoding integrin subunits α1, α5, αv, β1, focal adhesion kinase (FAK), and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were determined using real-time reverse transcription polymerase chain reaction (RT-PCR).

RESULTSThe ACP/PLLA material significantly increased the protein adsorption by 6.4-fold at 1 hour and 2.4-fold at 24 hours, compared with the pure PLLA scaffold. The attachment of osteoblastic cells to the ACP/PLLA was significantly higher than that on the PLLA scaffold. The SEM observation revealed a polygonal spread shape of cells on the ACP/ PLLA, with the filopodia adhered to the scaffold surface. In contrast, the cells on the PLLA scaffold exhibited a spherical or polygonal morphology. Additionally, real-time RT-PCR showed that the genes encoding the integrin subunits α1, αv, β1, and FAK were expressed at higher levels on the ACP/PLLA composite.

CONCLUSIONSThe ACP/PLLA composite promoted protein adsorption and osteoblastic adhesion. The enhanced cell adhesion may be mediated by the binding of integrin subunits α1, αv, and β1, and subsequently may be regulated through the FAK signal transduction pathways.

Biocompatible Materials ; chemistry ; Calcium Phosphates ; chemistry ; Cell Adhesion ; physiology ; Cells, Cultured ; Focal Adhesion Protein-Tyrosine Kinases ; metabolism ; Humans ; Integrin alpha1 ; metabolism ; Integrin alpha5 ; metabolism ; Integrin alphaV ; metabolism ; Integrin beta1 ; metabolism ; Integrins ; genetics ; metabolism ; Lactic Acid ; chemistry ; Osteoblasts ; cytology ; Porosity ; Tissue Engineering ; methods

Syntenin is a PDZ domain-containing adaptor protein that has been recently shown to regulate migration and invasion in several tumors. Small cell lung cancer (SCLC) is notorious for its invasiveness and strong potential for metastasis. We therefore studied the influence of syntenin on the invasiveness of SCLC. Immunohistochemistry in tumor tissues showed that syntenin was more frequently expressed in small cell carcinomas than other neuroendocrine tumors, such as carcinoids and neuroblastomas, suggesting that syntenin expression may be related to more aggressive forms of neuroendocrine tumors. In SCLC patients, syntenin overexpression in tumor cells was significantly associated with more extensive and advanced disease at the time of diagnosis (P=0.029). Overexpression of syntenin in SCLC cells that were intrinsically syntenin-low increased the invasiveness of cells and led to the induction of extracellular matrix (ECM)-degrading membrane type 1-matrix metalloproteinase (MT1-MMP) and matrix metalloproteinase 2 (MMP2). In contrast, suppression of syntenin in syntenin-high cells was associated with the downregulation of MT1-MMP. Contrary to the results of previous studies using malignant melanomas and breast carcinomas, signaling cascades were shown to be further transduced through p38 MAPK and PI3K/AKT, with activation of SP1 rather than NF-kappaB, under circumstances not involving ECM interaction. In addition, the upstream molecule focal adhesion kinase was induced by syntenin activation, in spite of the absence of ECM interaction. These results suggest that syntenin might contribute to the invasiveness of SCLC and could be utilized as a new therapeutic target for controlling invasion and metastasis in SCLC.
Cell Line, Tumor ; Focal Adhesion Protein-Tyrosine Kinases/*metabolism ; Humans ; Matrix Metalloproteinase 14/genetics/metabolism ; Matrix Metalloproteinase 2/genetics/metabolism ; Neoplasm Invasiveness ; Phosphatidylinositol 3-Kinases/*metabolism ; Proto-Oncogene Proteins c-akt/*metabolism ; Signal Transduction ; Small Cell Lung Carcinoma/*metabolism/pathology ; Sp1 Transcription Factor/*metabolism ; Syntenins/genetics/*metabolism ; p38 Mitogen-Activated Protein Kinases/*metabolism

Protein tyrosine phosphatase (PTP)-proline-, glutamate-, serine-, and threonine-rich sequence (PEST) is ubiquitously expressed and is a critical regulator of cell adhesion and migration. PTP-PEST activity can be regulated transcriptionally via gene deletion or mutation in several types of human cancers or via post-translational modifications, including phosphorylation, oxidation, and caspase-dependent cleavage. PTP-PEST interacts with and dephosphorylates cytoskeletal and focal adhesion-associated proteins. Dephosphorylation of PTP-PEST substrates regulates their enzymatic activities and/or their interaction with other proteins and plays an essential role in the tumor cell migration process.
Cell Adhesion ; Cell Movement ; Focal Adhesion Protein-Tyrosine Kinases ; metabolism ; Humans ; Neoplasms ; metabolism ; pathology ; Oxidation-Reduction ; Phosphorylation ; Protein Processing, Post-Translational ; Protein Tyrosine Phosphatase, Non-Receptor Type 12 ; metabolism ; Shc Signaling Adaptor Proteins ; metabolism ; rho GTP-Binding Proteins ; metabolism ; src-Family Kinases ; metabolism

Tumor angiogenesis induced by vascular endothelial cells (VECs) migration is a necessary condition for tumor growth and metastasis. The purpose of this study is to investigate the effect of focal adhesion kinase (FAK) inhibitor (50nmol/mL) on the adhesion and migration of endothelial cells(ECs) and the expression of focal adhesion proteins vinculin, talin and paxillin. Scratch wound migration assay was performed to examine the effect of FAK inhibitor with 50nmol/mL on ECs migration at 0, 5, 10, 30, 60 and 120min, respectively. And immunofluorescence analysis was performed to detect the expression of F-actin in ECs treated with FAK inhibitor within 2h. Western blot was carried out to determine the effect of FAK inhibitor on expression of vinculin, talin and paxillin proteins. The results showed that the migration distance and the expression of F-actin in ECs treated with FAK inhibitor decreased significantly compared with that of the controls, and the level of vinculin showed no significant difference with increasing of treated time of FAK inhibitor. However, the talin and paxillin showed an identical decreasing tendency in 5-10min, but slowly going up in 30min and then after subsequently decreasing. The results of this study proved that blocking phosphorylation of FAK could inhibit VECs adhesion and migration by downregulating focal adhesion proteins so that it may inhibit tumor angiogenesis. This may provide a new approach for tumor therapy.
Cell Adhesion ; Cell Movement ; physiology ; Cells, Cultured ; Endothelial Cells ; cytology ; metabolism ; Focal Adhesion Protein-Tyrosine Kinases ; antagonists & inhibitors ; metabolism ; Focal Adhesions ; metabolism ; physiology ; Humans ; Neoplasms ; blood supply ; Neovascularization, Pathologic ; Paxillin ; metabolism ; Talin ; metabolism ; Vinculin ; metabolism

Focal adhesion kinase (FAK) plays a critical role in the process of cell adhesion and migration by regulating the expression of downstream small G proteins. A kind of focal adhesion kinase (FAK) inhibitor was used to inhibit the phosphorylation of Y397 site of FAK, and scratch wound migration assay was used to examine the effect of FAK inhibitor with different concentrations (0-250 nmol/mL) on the migration of hepatomal cells (Hep G2 cells) at 0, 2, 4, 8 and 24h. Immunofluorescence analysis and Western blot analysis were performed to detect the expression of F-actin and small G proteins Rac1, RhoA and Cdc42 in Hep G2 cells treated with FAK inhibitor for 120 min. The results indicated that the FAK inhibitor can inhibit the migration of Hep G2 cells with a dose- and time-dependent manner. F-actin was down-regulated in Hep G2 cells treated with FAK inhibitor for 120 min, and expression of small G proteins were inhibited at different durations. The inhibition of FAK phosphorylation could inhibit cell adhesion and migration by down-regulating small G proteins. These results suggested that FAK inhibitor can inhibit the migration of tumor cells by blocking FAK phosphorylation. This means that FAK inhibitor can block the metastasis of tumor cells to surrounding tissues. It may be a potential application in the prevention and treatment of cancer.
Cell Adhesion ; drug effects ; Cell Movement ; drug effects ; Focal Adhesion Protein-Tyrosine Kinases ; antagonists & inhibitors ; metabolism ; physiology ; Hep G2 Cells ; Humans ; Liver Neoplasms ; pathology ; Neoplasm Metastasis ; prevention & control

OBJECTIVETo investigate the effects of Matrigel on expression of focal adhesion kinase and on proliferation and apoptosis of alveolar epithelial cell II of premature rat exposed to hyperoxia.

METHODSThe primary premature rat AECII (gestation 19 d) were cultured in vitro. For establishing hyperoxia-exposed cell model, purified AECII were cultured for 12 hours after culture flasks were filled with 95% oxygen-5% CO2 at 5 L/min, and then sealed for 12 hours. DNA content, phosphor and total protein of FAK were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting respectively after 12 hours of air or hyperoxia exposure in the presence or absence of Matrigel. To investigate the relationship between FAK activated and proliferation or apoptosis of type II alveolar epithelial cells, levels of proliferation and apoptosis of AECII were measured by immunohistochemical assay of proliferating cell nuclear antigen (PCNA) and TUNEL method respectively.

RESULTSFAK and FAK-Tyr(397) activity of AECII on Matrigel-coated substrate increased: compared with air group, the expression of PCNA decreased and apoptotic index increased markedly in hyperoxia group (0.1498 ± 0.009 vs. 0.0953 ± 0.006, P < 0.05; 1.232 ± 0.6 vs. 13.40 ± 3.2, P < 0.01), but the expression of PCNA of AECII on Matrigel-coated substrate increased significantly (0.1498 ± 0.009 vs. 0.1921 ± 0.008, P < 0.01) and apoptotic index did not change. The expression of PCNA increased significantly (0.0953 ± 0.006 vs. 0.1125 ± 0.012, P < 0.05) and apoptotic index decreased markedly in hyperoxia + Matrigel group as compared with hyperoxia group (13.40 ± 3.2 vs. 7.641 ± 1.6, P < 0.05).

CONCLUSIONHyperoxia decreased the level of FAK and FAK-Tyr(397) in AECII, which may be a contributory mechanism of impaired proliferation and apoptosis of AECII in hyperoxia induced lung injury in premature rat. Matrigel could inhibit apoptosis and promote proliferation of AECII resulted from hyperoxia in vitro. Matrigel may play a protective role in hyperoxia-induced lung injury partly due to activated FAK.

Alveolar Epithelial Cells ; Animals ; Animals, Newborn ; Apoptosis ; Cell Proliferation ; Cells, Cultured ; Collagen ; pharmacology ; Drug Combinations ; Epithelial Cells ; drug effects ; enzymology ; Focal Adhesion Protein-Tyrosine Kinases ; metabolism ; Hyperoxia ; Laminin ; pharmacology ; Male ; Proteoglycans ; pharmacology ; Pulmonary Alveoli ; cytology ; enzymology ; pathology ; Rats ; Rats, Sprague-Dawley

PURPOSE: To investigate the role of focal adhesion kinase (FAK) in transforming growth factor (TGF)-beta-induced myofibroblast transdifferentiation of human Tenon's fibroblasts. METHODS: Primary cultured human Tenon's fibroblasts were exposed to TGF-beta1 for up to 48 hours. The mRNA levels of FAK, alpha smooth muscle actin (alphaSMA), and beta-actin were determined by quantitative real time reverse transcription polymerase chain reaction. The protein levels of collagen type I, FAK, phospho-FAK, alphaSMA, and beta-actin were determined by Western immunoblots. After the small interfering RNA targeting FAK (siRNA(FAK)) molecules were delivered into the cells, the expressions of alphaSMA proteins were determined by Western immunoblots. RESULTS: In human Tenon's fibroblasts, TGF-beta1 significantly increased the mRNA and protein expressions of alphaSMA. However, when the action of FAK was inhibited using siRNAFAK, the TGF-beta1-induced expression of alphaSMA was attenuated. CONCLUSIONS: Our data suggest that FAK may be associated with the TGF-beta1-induced transdifferentiation of human Tenon's fibroblasts to myofibroblasts, which is the essential step of subconjunctival fibrosis.
Actins/metabolism ; Analysis of Variance ; Blotting, Western ; Cell Transdifferentiation/drug effects ; Cells, Cultured ; Collagen/metabolism ; Fibroblasts/cytology/drug effects/metabolism ; Focal Adhesion Protein-Tyrosine Kinases/*metabolism ; Humans ; Myofibroblasts ; RNA, Messenger/metabolism ; RNA, Small Interfering/metabolism ; Real-Time Polymerase Chain Reaction ; Transforming Growth Factor beta/*pharmacology