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

UNLABELLED: AbstractObjective: To investigate the effect of the axon guidance factor Netrin-1 on the expression of VEGFA in T cell acute lymphoblastic leukemia(T-ALL) and its related mechanism. METHODS: ELISA assays were applied to detect the levels of Netrin-1 and VEGFA in the bone marrow (BM) samples from children in the T-ALL and control group. The level of Netrin-1 and VEGFA were compared between control children and patients, and the liner correlation between Netrin-1 and VEGFA was analyzed. The T-ALL cells Jurkat and Molt-4 were culture in vitro, and the cells were treated with different concentration of Netrin-1 (0, 25, 50, 100 ng/ml) for 24 h, quantitative RT-PCR (qRT-PCR) and Western blot were used to detect the VEGFA expression in Jurkat, Molt-4 cells. The expression of Netrin-1 receptors in T-ALL cells was detected by qRT-PCR and the interaction between Netrin-1 and receptor in each cells was detected by co-IP. Furthermore, Western blot was used to detect the phosphorylation level of key prateins of AKT signal transduction pathway including Akt and mTOR in T-ALL cells treated with Netrin-1 (100 ng/ml). The expression of VEGFA and phosphorylation of AKT pathway transducers were detected by Western blot, after T-ALL cells treated with Netrin-1 (100 ng/ml) combined with inhibitors specific to Akt or mTOR. RESULTS: The expression level of Netrin-1 and VEGFA in T-ALL patients BM samples were both signi-ficantly higher than that of control group. And the expression level of Netrin-1 was positively correlated with that of VEGFA（r2=0974). With the increase of Netrin-1 concentration, the expression level of VEGFA also increased(P<0.05）. Netrin-1 interacted with its receptor, integrin-β4 at the Netrin-1 concentration of 100 ng/ml. Further, the treatment of Netrin-1 could increase the phosphorylation of Akt and mTOR, which were the key transducers of AKT pathway. After treatment of T-ALL cells with Netrin-1 (100 ng/mL) and Akt inhibitor, the expression of VEGFA and phosphorylation of Akt or mTOR decreased. When the cells were treated with Netrin-1(100 ng/ml) and mTOR inbititor, the phosphorylation level of mTOR and the expression of VEGFA decreased, the phosphorylation level of Akt increased. CONCLUSION The expression of Netrin-1 and VEGFA in bone marrow of childred with T-ALL were abnormal, and there was a linear relationship between them. Netrin-1 can interact with its receptor, integrin-β4 and activate AKT transduction pathway to elevate the expression of VEGFA in T-ALL cells.
Child ; Humans ; Integrins ; Netrin-1/metabolism* ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; Proto-Oncogene Proteins c-akt/metabolism* ; T-Lymphocytes ; TOR Serine-Threonine Kinases/metabolism* ; Vascular Endothelial Growth Factor A

Integrin is a large family of cell adhesion molecules (CAMs) which involves in the interaction of cells/cells and cells/ extracellular matrix (ECM) to mediate cell proliferation, differentiation, adhesion, migration, etc. In recent years, aberrant expression of integrin has been clearly found in many tumor studies, indicating that integrin is closely related to tumor formation and development. Meanwhile, it has effects on tumor cell differentiation, cell migration, proliferation and tumor neovascularization. The study of drugs targeting integrins is of great significance for the clinical treatment of tumors. Because of its important role in tumorigenesis and development, integrin has become a promising target for the treatment of cancer. This review summarizes the role of integrin in tumor development and the current state of integrin inhibitors to provide a valuable reference for subsequent research.
Antineoplastic Agents ; pharmacology ; therapeutic use ; Biological Products ; pharmacology ; therapeutic use ; Cell Movement ; drug effects ; Cell Proliferation ; drug effects ; Extracellular Matrix ; metabolism ; Humans ; Integrins ; antagonists & inhibitors ; classification ; genetics ; metabolism ; Neoplasms ; drug therapy ; pathology ; Neovascularization, Pathologic ; drug therapy ; pathology ; Signal Transduction ; drug effects

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

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

Integrins such as αvβ3, α5β1 play a key role in angiogenesis regulation, invasion and metastasis, inflammation, wound healing, etc. The up-regulation of integrin αvβ3 after cerebral ischemic stroke can promote angiogenesis, which in turn improves functional recovery. In addition, the integrin αvβ3 inhibitor can block the blood-brain barrier (BBB) leakage induced by vascular endothelial growth factor (VEGF) and also can reduce inflammatory reaction, decrease the deposition of fibrinogen. Other studies showed that integrin αvβ3 is not essential in revascularization. Therefore, the effect of integrin αvβ3 in the whole process of brain function recovery merits further study.
Animals ; Blood Vessels ; drug effects ; physiopathology ; Blood-Brain Barrier ; drug effects ; metabolism ; physiopathology ; Humans ; Integrin alphaVbeta3 ; antagonists & inhibitors ; metabolism ; Integrins ; metabolism ; Models, Biological ; Peptides, Cyclic ; pharmacology ; Stroke ; metabolism ; physiopathology ; Vascular Endothelial Growth Factor A ; metabolism

The process of human embryo implantation is mediated not only by evolutionarily conserved mechanisms, but also by a mechanism unique to humans. Evidence suggests that the cell adhesion molecules, L-selectin and trophinin, play a unique role in human embryo implantation. Here, we describe the dual roles of mucin carbohydrate ligand for L-selectin and trophinin protein and of the trophinin-associated proteins bystin and tastin. We then describe trophinin-mediated signal transduction in trophectoderm cells and endometrial epithelial cells. This review also covers cadherin and integrin in human embryo implantation.
Cadherins ; physiology ; Cell Adhesion Molecules ; physiology ; Embryo Implantation ; Epithelial Cells ; metabolism ; Humans ; Integrins ; physiology ; L-Selectin ; physiology ; Signal Transduction

OBJECTIVETo investigate the effect of integrin α9β1 on corneal angiogenesis and the expression of vascular endothelial growth factor A (VEGF-A) in rats after corneal suture.

METHODSThirty-nine SD rats were randomly divided into normal control group, corneal suture model group, α9β1 group, and α9β1 suppression group, and in the latter 3 groups, the rats received topical administration of levofloxacin, levofloxacin + α9β1, and levofloxacin+ anti-α9β1 monoclonal antibody (Y9A2) twice daily after corneal suture, respectively. At 3, 5, 7, 14 days after the surgery, 3 rats were randomly selected from each group to observe corneal neovascularization (CNV) under slit lamp. RT-PCR and Western blotting were used to detect the expressions of VEGF-A.

RESULTSCNV was not observed in normal cornea. Neovascularization occurred in the corneal limbus in the 3 corneal suture groups, and the leak neovascularization count (CNVC), which occurred on the 7th postoperative day, was significantly increased after α9β1 treatment compared with that in the model group (4.57∓0.31 vs 3.21∓0.19, P<0.05) but markedly decreased after α9β1 suppression (2.03∓0.26, P<0.05). VEGF-A was expressed at a low level in normal cornea, and increased significantly in the model group, reaching the peak level on 7th day (P<0.05); corneal VEGF-A expression was further enhanced by α9β1 treatment (P<0.05) while significantly lowered by α9β1 suppression (P<0.05).

CONCLUSIONIntegrin α9β1 can promote CNV by up-regulating VEGF-A expression and α9β1 suppression produces the opposite effect after corneal suture in rats.

Animals ; Cornea ; drug effects ; metabolism ; Corneal Neovascularization ; metabolism ; Female ; Integrins ; antagonists & inhibitors ; Rats ; Rats, Sprague-Dawley ; Sutures ; Vascular Endothelial Growth Factor A ; metabolism

OBJECTIVETo determine the distribution of integrins and calcium channels on major human and mouse host cells of Leptospira species.

METHODSThe expression of β1, β2 and β3 integrins was detected with immunofluorescence assay on the surface of human monocyte line THP-1, mouse mononuclear-macrophage-like cell line J774A.1, human vascular endothelial cell line HUVEC, mouse vascular endothelial cell EOMA, human hepatocyte line L-02, mouse hepatocyte line Hepa1-6, human renal tubular epithelial cell line HEK-293, mouse glomerular membrane epithelial cell line SV40-MES13, mouse collagen blast line NIH/3T3, human and mouse platelets. The distribution of voltage gate control calcium channels Cav3.1, Cav3.2, Cav3.3 and Cav2.3, and receptor gate calcium channels P(2)X(1), P(2)2X(2), P(2)X(3), P(2)X(4), P(2)X(5), P(2)X(6) and P(2)X(7) were determined with Western blot assay.

RESULTSβ1 integrin proteins were positively expressed on the membrane surface of J774A.1, THP-1, HUVEC, EOMA, L-02, Hepa1-6 and HEK-239 cells as well as human and mouse platelets. β2 integrin proteins were expressed on the membrane surface of J774A.1, THP-1, HUVEC, EOMA, and NIH/3T3 cells. β3 integrin proteins were expressed on the membrane surface of J774A.1, THP-1, HUVEC, EOMA, Hepa1-6, HEK-239 and NIH/3T3 cells as well as human and mouse platelets. P(2)X(1) receptor gate calcium channel was expressed on the membrane surface of human and mouse platelets, while P(2)X(5) receptor gate calcium channel was expressed on the membrane surface of J774A.1, THP-1, L-02, Hepa1-6, HEK-239 and HUVEC cells. However, the other calcium channels were not detected on the tested cell lines or platelets.

CONCLUSIONThere is a large distribution diversity of integrins and calcium channel proteins on the major human and mouse host cells of Leptospira species, which may be associated with the differences of leptospira-induced injury in different host cells.

Animals ; Blood Platelets ; metabolism ; microbiology ; Calcium Channels ; metabolism ; Cell Line ; HEK293 Cells ; Host-Pathogen Interactions ; Human Umbilical Vein Endothelial Cells ; Humans ; Integrins ; metabolism ; Leptospira ; pathogenicity ; Macrophages ; metabolism ; microbiology ; Mice ; Monocytes ; metabolism ; microbiology ; NIH 3T3 Cells