Integrins are a family of transmembrane receptors that connect the extracellular matrix and actin skeleton, which mediate cell adhesion, migration, signal transduction, and gene transcription. As a bi-directional signaling molecule, integrins can modulate many aspects of tumorigenesis, including tumor growth, invasion, angiogenesis, metastasis, and therapeutic resistance. Therefore, integrins have a great potential as antitumor therapeutic targets. In this review, we summarize the recent reports of integrins in human hepatocellular carcinoma (HCC), focusing on the abnormal expression, activation, and signaling of integrins in cancer cells as well as their roles in other cells in the tumor microenvironment. We also discuss the regulation and functions of integrins in hepatitis B virus-related HCC. Finally, we update the clinical and preclinical studies of integrin-related drugs in the treatment of HCC.
Humans ; Integrins/metabolism* ; Carcinoma, Hepatocellular/genetics* ; Liver Neoplasms/genetics* ; Cell Adhesion ; Carcinogenesis ; Cell Transformation, Neoplastic ; Tumor Microenvironment

Normal articular cartilage is composed of chondrocytes embedded within an extracellular matrix (ECM). The patterns of integrin expression determine the adhesive properties of cells by modulating interactions with specific ECMs. Our hypothesis is that chondrocyte integrin expression changes in response to changes in their microenvironment. Porcine articular chondrocytes were encapsulated in alginate beads with several ECMs (collagen type I, collagen type II and fibronectin) for 7 days, subjected to RT-PCR, western blot analysis and immunofluorescence staining. It was found that chondrocytes in different ECMs showed different patterns of integrin expression. Integrin alpha5 and beta1 were strongly expressed in all groups, but integrin alpha1 was strongly expressed only in collagen type I and fibronectin conjugated alginate beads, and integrin alpha2 was strongly expressed only in collagen type II conjugated alginate beads. These findings suggest that the addition of different ECMs to chondrocytes can modulate the patterns and levels of integrin expression possibly through a feedback mechanism. These finding suggest that the modulation of ECM interactions may play a critical role in the pathogenesis of osteoarthritis.
Animals ; Cartilage, Articular/cytology/*metabolism ; Chondrocytes/*metabolism ; Extracellular Matrix/*physiology ; Fluorescent Antibody Technique ; Integrins/genetics/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Support, Non-U.S. Gov't ; Swine

The purpose of this study was to investigate the growth characteristics and the expression level of integrin mRNA of the cultured bone marrow mesenchymal stem cells (BMMSCs) from patients with chronic myeloid leukemia (CML) in myeloid crisis (MC), and explore the role of BMMSCs in pathogenesis of CML. Five CML patients were enrolled in experimental group, five healthy persons were used as control. BMMSCs were cultured in vitro. The morphology of BMMSCs was observed every day and the growth curve were portrayed, and the ability of cell proliferation were detected according to the daily results of cell counting. Total RNA was extracted from third and fourth passages of BMMSCs, The expression of integrins mRNA of BMMSCs were measured by real-time PCR. The results showed that the BMMSCs of experimental and control groups had no difference in growth characterisctics, but the expression of integrins mRNA of the BMMSCs was higher in CML patients than in normal control group (p < 0.05). It is concluded that the abnormally high expression of integrins of BMMSC from the CML patients take part in pathogenesis of CML.
Adult ; Blast Crisis ; metabolism ; Bone Marrow Cells ; metabolism ; pathology ; Cell Proliferation ; Female ; Humans ; Integrins ; genetics ; metabolism ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive ; metabolism ; pathology ; Male ; Mesenchymal Stromal Cells ; metabolism ; pathology ; Middle Aged ; RNA, Messenger ; genetics ; metabolism ; Tumor Cells, Cultured

We have previously shown that the binding of integrins with extracellular matrix component fibronectin (Fn) can improve the ability of bronchial epithelial cells (BECs) in resisting oxidant injury by up-regulating the activity of catalase and increasing the content of GSH. However, the molecular mechanism or its signaling pathway of this protection is still unclear. In order to examine the intracellular signaling mechanism activated by Fn-integrin binding reaction, the present study investigated the mRNA expression of catalase in primary cultured rabbit BECs using RT-PCR based on a cell-injury model made with ozone exposure. The product bands of target gene CAT were checked with Southern blot and oligonucleotide probe hybridization. The results showed that Fn (10 microg/ml) promoted the catalase mRNA transcription (P<0.01). This effect was abolished either by protein-tyrosine kinase inhibitor genistein or calmodulin inhibitor W(7) (P<0.01). These results indicate that the promotion of catalase activity induced by Fn-integrin reaction is partly due to the elevation of catalase mRNA transcription, and that its signalling are possibly relevant to tyrosine phosphorylation or calmodulin pathway.
Animals ; Bronchi ; cytology ; metabolism ; Calmodulin ; metabolism ; Catalase ; biosynthesis ; genetics ; Cells, Cultured ; Epithelial Cells ; cytology ; metabolism ; Female ; Fibronectins ; physiology ; Integrins ; physiology ; Male ; Protein-Tyrosine Kinases ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Rabbits ; Signal Transduction ; Up-Regulation ; drug effects

AIMTo construct an efficient recombinant viral vector for gene therapy.

METHODSFirst-generation adenovirus (Ad) vector was modified with the RGD peptide inserted into the fiber. Both in vitro and in vivo experiments of gene expression in different tumor cells with conventional and recombinant vectors were conducted. RT-PCR was used for detecting the expression of coxackievirus and adenovirus receptor and integrin at the surface of Meth-A cells.

RESULTSFiber-mutant adenovirus vector showed a notably enhanced gene expression in A2058, B16BL6, OV-HM, and Meth-A tumor cells compared with that of conventional ones. In vivo study carried out using Meth-A tumor-bearing mice also demonstrated that the intra-tumoral injection of recombinant adenovirus induced strong gene expression in these CAR-deficient tumor cells.

CONCLUSIONThe recombinant vector can be a promising one for effective cancer gene therapy.

Adenoviridae ; genetics ; Amino Acid Sequence ; Animals ; Base Sequence ; Cell Line ; Cell Line, Tumor ; Enterovirus ; genetics ; Female ; Gene Expression Regulation, Neoplastic ; Genetic Therapy ; methods ; Genetic Vectors ; Green Fluorescent Proteins ; genetics ; metabolism ; Humans ; Integrins ; genetics ; metabolism ; Luciferases ; genetics ; metabolism ; Mice ; Mice, Inbred BALB C ; Microscopy, Fluorescence ; Mutation ; Neoplasm Transplantation ; Neoplasms, Experimental ; genetics ; pathology ; therapy ; Oligopeptides ; genetics ; Receptors, Virus ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Transfection

OBJECTIVESTo investigate the effects of Arg-Gly-Asp-Ser (RGDS) tetrapeptide on integrin signaling and apoptosis in fibronectin (FN) -stimulated hepatic stellate cells (HSCs).

METHODS3H-thymidine incorporation, annexin-V/propidium iodide double-labeled flow cytometry (FCM) and transmission electron microscopy were employed to estimate the influence of RGDS on the proliferation and apoptosis of HSCs. And the adhesion rates were observed by toluidine blue colorimetric assay. The expression of focal adhesion kinase (FAK) mRNA and protein in HSCs was detected using RT-PCR and western blotting analysis, respectively.

RESULTSRGDS tetrapeptide at the concentrations of 25 microg/ml, 50 microg/ml and 100 microg/ml inhibited the proliferation of HSCs and induced HSCs apoptosis in dose-dependent and time-dependent manners, with the apoptotic rates of 9.49%, 27.67%, 31.59%, and the necrotic rates of 3.47%, 5.38%, 9.10%, respectively. Both the rates were higher than those in FN group (apoptotic rate: 3.44%; necrotic rate: 2.39%), F=8.02, P<0.05. After adding RGDS tetrapeptide to HSCs for 2 hours, the adhesive inhibition rates were 8.82%, 29.41% and 45.59%, respectively, which were higher than that in FN group (F=20.58, P<0.01). After exposure of HSCs to RGDS tetrapeptide for 24 hours, FAK protein decreased, and FAK mRNA was down-regulated earlier, about 2 hours after exposure to RGDS tetrapeptide.

CONCLUSIONThese results suggest that RGDS tetrapeptide may induce apoptosis of HSC in both dose-dependent and time-dependent manners in vitro, which may be related to the disruption of cell matrix adhesion and down-regulation of FAK expression.

Apoptosis ; drug effects ; Fibronectins ; pharmacology ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Hepatocytes ; cytology ; physiology ; Humans ; Integrins ; metabolism ; physiology ; Liver ; cytology ; physiology ; Oligopeptides ; pharmacology ; Platelet Aggregation Inhibitors ; pharmacology ; Protein-Tyrosine Kinases ; biosynthesis ; genetics ; metabolism ; Signal Transduction

OBJECTIVETo study the effect of nadroparin in the migration of breast cancer cells MDA-MB-231 and its action mechanism.

METHODThe MTT test was adopted to observe the effect of different concentrations of naringenin on the growth capacity of breast cancer cells MDA-MB-231. Wound healing and transwell experiment analysis were conducted to detect the effect of naringenin on the migration of breast cancer cells MDA-MB-231. Western blotting was adopted to investigate the effect of naringenin on protein expressions of MDA-MB-231 cell Integrin β3, β1 and matrix metalloproteinase MMP-2 and MMP-9. The computer virtual docking technique was used to evaluate the combining capacity of naringenin and Integrin β3 in vitro.

RESULTNaringenin inhibited the migration of MDA-MB-231 cells in a dose-dependent manner. In wound healing and transwell experiments, with the increase in the concentration of naringenin, the number of migrant MDA-MB-231 cells and the invasion capacity of breast cancer cells decreased. Naringenin could inhibit the protein expression of Integrin β3 in a dose-dependent manner, but with unobvious effect on expression of Integrin β1. Besides, naringenin could significantly inhibit the protein expressions of MMP-2 and MMP-9. The results of the computer virtual docking showed a negative value in the combining capacity between naringenin and Integrin β3, indicating the high affinity between them.

CONCLUSIONNaringenin can inhibit the growth capacity of breast cancer cells MDA-MB-231 and block the migration and invasion of breast cancer cells MDA-MB-231. Its mechanism is to down-regulate MMP-2 and MMP-9 expressions after combining with Integrin β3.

Breast Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; Cell Line, Tumor ; Cell Movement ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Female ; Flavanones ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Integrins ; genetics ; metabolism ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Matrix Metalloproteinase 9 ; genetics ; metabolism ; Neoplasm Invasiveness

OBJECTIVETo study the expression of keratinocyte (KC) basement membrane (BM) related genes during the process of re-epithelialization of burn wound in scalded rats with cDNA microarray technique.

METHODSTwenty-four SD rats were inflicted with deep partial thickness scald with an area of 45 cm(2) on the back, and they were randomly divided into A [3 postscald day (PSD)], B (10 PSD), C (14 PSD) and D (re-epithelialization complete day) groups, with 6 rats in each group. Tissue samples were harvested from 1 cm of wound margin on 3, 10 and 14 PSD. On the re-epithelialization complete day, tissue samples were harvested from the center of the wound in D group and digested with enzyme into KC suspensions. Skin samples from the back of 6 uninjured rats were taken as normal control. The differential expression of KC BM related genes during different stages of re-epithelialization was assayed with cDNA microarray.

RESULTSThe expression of laminin (LN) gamma 1 (2.068) and integrin beta8 (2.200) was up-regulated on 3 PSD compared with that in control. The expression of integrin beta1 and LN receptor 1 was up-regulated on 10 and 14 PSD, (2.472 and 2.658), while that of integrin beta2 and beta1 (0.419 and 0.462) down-regulated on 10 and 14 PSD, and the expression of type IV collagen alpha1 and alpha3 was up-regulated during re-epithelialization.

CONCLUSIONThe expression of integrin beta1, LN gamma 1, LN receptor 1, type IV collagen alpha1 and alpha3 genes were up-regulated during re-epithelialization, which might be beneficial to the construction of BM in new skin and the formation of stable conjunction between KC and BM.

Animals ; Basement Membrane ; metabolism ; Burns ; metabolism ; pathology ; Collagen Type IV ; genetics ; Disease Models, Animal ; Epithelium ; metabolism ; Gene Expression ; Integrin beta1 ; genetics ; Integrins ; genetics ; Keratinocytes ; cytology ; metabolism ; Laminin ; genetics ; Oligonucleotide Array Sequence Analysis ; Rats ; Rats, Sprague-Dawley ; Regeneration ; Skin ; cytology ; Wound Healing

Celastrol is a type of quinone methyl triterpene isolated from traditional Chinese medicine Tripterygium wilfordii, with pharmacological activities, like anti-inflammatory, immunosuppression and anti-tumor. This study focused on the effects of celastrol on adhesion, migration and invasion of lung cancer cells. The migration inhibition of lung cancer cells induced by celastrol was detected by the scratch test. The invasion inhibition of lung cancer cells induced by celastrol was measured by the transwell experiment. RT-PCR and Western blot were used to determine the effect of different concentrations of celastrol in integrin family and Akt signaling pathway in lung cancer cells. The results showed that celastrol inhibited adhesion, migration and invasion of lung cancer cells and expressions of integrins β3, β4, αv and phosphorylated Akt, GSK-3β, c-Raf, PDK1 in Akt signal pathway in a dose-dependent manner. Therefore, the study implies that Celastrol could inhibit the metastasis of lung cancer cells by suppressing Akt signaling pathway and expression of integrins.
Apoptosis ; drug effects ; Cell Line, Tumor ; Drugs, Chinese Herbal ; pharmacology ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Integrins ; genetics ; metabolism ; Lung Neoplasms ; genetics ; metabolism ; pathology ; physiopathology ; Neoplasm Metastasis ; Proto-Oncogene Proteins c-akt ; genetics ; metabolism ; Signal Transduction ; drug effects ; Triterpenes ; pharmacology

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