ITGB1 Expression Research Articles

G9A promotes gastric cancer metastasis by upregulating ITGB3 in a SET domain-independent manner

Tumor metastasis is the leading cause of death in patients with advanced gastric cancer (GC). Limited therapeutic regimens are available for this condition, which is associated with a poor prognosis, and the mechanisms underlying tumor metastasis remain unclear. In the present study, increased histone methyltransferase G9A expression in GC tissues correlated with advanced stage and shorter overall survival, and in vitro and in vivo experiments revealed that G9A promoted tumor invasion and metastasis. Moreover, we observed that Reg IV induced G9A via the p-ERK/p-SP1 pathway. SP1 directly binds the G9A promoter and enhances G9A expression, and upregulated G9A then forms a transcriptional activator complex with P300 and GR, thereby promoting ITGB3 expression induced by dexamethasone (DEX) and contributing to GC metastasis. However, the G9A-mediated increase in ITGB3 expression was not dependent on the SET domain and methyltransferase activity of G9A. This study demonstrates that G9A is an independent prognostic marker and promotes metastasis in GC, thus suggesting that it may be a tumor biomarker and potential therapeutic target in GC.

MiR-199a-3p enhances cisplatin sensitivity of ovarian cancer cells by targeting ITGB8.

Drug resistance remains a large obstacle for the treatment of ovarian cancer. miRNAs have been reported to be involved in cisplatin (CDDP) resistance in ovarian cancer. The aim of the present study was to investigate the function and mechanism of miR-199a-3p in the CDDP resistance in ovarian cancer. We found that miR-199a-3p was significantly downregulated in chemoresistant ovarian cancer tissues, as well as CDDP-resistant SKOV3/CDDP cells, compared to chemosensitive carcinomas and SKOV3 cells. Restoration of miR-199a-3p in SKOV3/CDDP cells reduced cell proliferation, G1 phase cell cycle arrest, cell invasion, and increased cell apoptosis, resulting in enhanced CDDP sensitivity, while miR-199a-3p inhibition resulted in the opposite effects. Luciferase reporter assay showed that integrin β8 (ITGB8), one of the integrins that is involved in the regulation of cell cycle and motility, was a direct target of miR-199a-3p. Overexpression of miR-199a-3p downregulated ITGB8 expression via binding to its 3′-UTR. In addition, overexpression of ITGB8 restored CDDP resistance inhibited by miR-199a-3p. Moreover, orthotopic ovarian cancer mouse model showed that miR-199a-3p enhanced CDDP sensitivity of ovarian cancer in vivo. Therefore, our results indicate that miR-199a-3p enhances CDDP sensitivity of ovarian cancer cells through downregulating ITGB8 expression, and miR-199a-3p may serve as a therapeutic target for the treatment of ovarian cancer patients with CDDP-resistance.

Role of Corneal Stromal Cells on Epithelial Cell Function during Wound Healing.

Following injury, corneal stromal keratocytes transform into repair-phenotype of activated stromal fibroblasts (SFs) and participate in wound repair. Simultaneously, ongoing bi-directional communications between corneal stromal-epithelial cells also play a vital role in mediating the process of wound healing. Factors produced by stromal cells are known to induce proliferation, differentiation, and motility of corneal epithelial cells, which are also subsequently the main processes that occur during wound healing. In this context, the present study aims to investigate the effect of SFs conditioned medium (SFCM) on corneal epithelial cell function along with substance P (SP). Antibody microarrays were employed to profile differentially expressed cell surface markers and cytokines in the presence of SFCM and SP. Antibody microarray data revealed enhanced expression of the ITGB1 in corneal epithelial cells following stimulation with SP whereas SFCM induced abundant expression of IL-8, ITGB1, PD1L1, PECA1, IL-15, BDNF, ICAM1, CD8A, CD44 and NTF4. All these proteins have either direct or indirect roles in epithelial cell growth, movement and adhesion related signaling cascades during tissue regeneration. We also observed activation of MAPK signaling pathway along with increased expression of focal adhesion kinase (FAK), paxillin, vimentin, β-catenin and vasodilator-stimulated phosphoprotein (VASP) phosphorylation. Additionally, epithelial-to-mesenchymal transition (EMT) regulating transcription factors Slug and ZEB1 expression were enhanced in the presence of SFCM. SP enriched the expression of integrin subunits α4, α5, αV, β1 and β3 whereas SFCM increased α4, α5, αV, β1 and β5 integrin subunits. We also observed increased expression of Serpin E1 following SP and SFCM treatment. Wound healing scratch assay revealed enhanced migration of epithelial cells following the addition of SFCM. Taken together, we conclude that SFCM-mediated sustained activation of ZEB1, Slug in combination with upregulated migration-associated integrins and ERK (Extracellular signal-regulated kinase)-FAK-paxillin axis, may lead to induce type 2 EMT-like changes during corneal epithelial wound healing.

Epigenetic regulation of integrin β6 transcription induced by TGF-β1 in human oral squamous cell carcinoma cells.

Overexpression of integrin αvβ6 is believed to play an important role in the invasion and metastasis of oral squamous cell carcinoma (OSCC). However, little is known about the molecular mechanisms leading to αvβ6 upregulation in OSCC. As the integrin β6 (ITGB6) is the only partner with αv, the expression of αvβ6 is dependent on ITGB6, it is, therefore, pivotal to investigate the mechanisms underlying ITGB6 overexpression in OSCC. We previously reported the cloning and characterization of human ITGB6 gene. In the current study, we further investigated the molecular mechanisms of ITGB6 expression and the upregulation by carcinogenesis related cytokine-transforming growth factor-β1 (TGF-β1) in OSCC cells. We first demonstrated that TGF-β1 can induce ITGB6 mRNA and protein express in a time and concentration dependent manner, and the induced-ITGB6 mRNA was not due to increase the mRNA stability, but regulated at transcriptional level. By using a luciferase reporter assay, site-mutation, RNA interference, and chromatin immunoprecipitation assay, we revealed for the first time that JunB, a member of the activator protein-1 (AP-1) family, is involved in the positive regulation to the ITGB6 transcription induced by TGF-β1 in OSCC cells. Furthermore, our data also demonstrated that histone acetyltransferase (HAT) CBP mediated histone H3 and H4 hyperacetylation, and RNA Polymerase II recruitment to ITGB6 promoter, facilitated the binding of transcription factor JunB to ITGB6 promoter after TGF-β1 stimulation. Collectively, these findings demonstrate that JunB and CBP-mediated histone hyperacetylation are responsible for TGF-β1 induced ITGB6 transcription in OSCC cells, suggesting that epigenetic mechanisms are responsible for the active transcription expression of ITGB6 induced by TGF-β1 in OSCC cells.

The Role of YB1 in Renal Cell Carcinoma Cell Adhesion.

Background: Y-box binding protein 1 (YB1) is a multifunctional protein involved in many processes related to cancer progression and metastasis.Methods: In this study, we constructed YB1 knockdown stable renal cell carcinoma (RCC) cell line 786-0. The gene expression profile of 786-0 was performed by DNA microarray analysis to identify genes that were regulated by YB1. Real-time PCR and western blotting were used to test the genes and proteins expression. Transforming growth factor-β (TGF-β) activity was detected by dual-luciferase reporter assay. Cell adhesion assay was used to determine RCC cell adhesion ability.Results: Pathway analysis revealed that YB1 knockdown influenced cell adhesion molecules (CAMs). We further verified four genes (CLDN4, NRXN3, ITGB8, and VCAN) related to CAMs by real-time PCR, and confirmed that YB1 regulated the expression of ITGB8 in RCC. Functional assays demonstrated that knockdown of YB1 significantly inhibited the cell adhesion of 786-0 cells in vitro. In addition, YB1 affected TGF-β activation.Conclusion: Our study demonstrated that YB1 modulated the adhesion ability of renal cell carcinoma cells by regulating ITGB8 and TGF-β.

Influence on proliferation and adhesion of human gingival fibroblasts from different titanium surface decontamination treatments: An in vitro study

ObjectivesTo investigate the effects of different decontamination treatments on microstructure of titanium (Ti) surface as well as proliferation and adhesion of human gingival fibroblasts (HGFs). Material and methodsTi discs with machined (M) and sand blasted, acid etched (SAE) surfaces were treated with five different decontamination treatments: (1) stainless steel curette (SSC), ultrasonic system with (2) straight carbon fiber tip (UCF) or (3) metal tip (UM), (4) rotating Ti brush (RTB), and (5) Er:YAG laser (30 mJ/pulse at 30 Hz). Surface roughness was analyzed under optical interferometry. HGFs were cultured on each disc. Proliferation and adhesive strength were analyzed. qRT-PCR and ELISA were performed to detect the RNA and protein expression of FAK, ITGB1, COL1A1, and FN1 respectively from different Ti surfaces. ResultsSurface roughness increased on M surface. Proliferation, adhesive strength and gene expression were higher on M surface than SAE surface. Decontamination treatments affected surface parameters significantly (P < 0.001), making M surface less smooth while SAE surface became less rough. SSC, UCF, UM and RTB decreased proliferation on M surfaces significantly (P < 0.05). UCF, RTB and laser increased proliferation on SAE surface significantly (P < 0.05). UM decreased adhesive strength on M surface significantly and laser increased adhesive strength on SAE surface significantly (P < 0.05). Gene expression increased with time and was altered by decontamination treatments significantly (P < 0.001). ConclusionsDecontamination treatments influence surface roughness and cell behavior of HGFs. Laser might be an optimal decontamination treatment which has the least negative effect on M surface and the most positive effect on SAE surface.

SNRK (Sucrose Nonfermenting 1-Related Kinase) Promotes Angiogenesis In Vivo.

SNRK (sucrose nonfermenting 1-related kinase) is a novel member of the AMPK (adenosine monophosphate-activated protein kinase)-related superfamily that is activated in the process of angiogenesis. Currently, little is known about the function of SNRK in angiogenesis in the physiological and pathological conditions. In this study, in Snrk global heterozygous knockout mice, retina angiogenesis and neovessel formation after hindlimb ischemia were suppressed. Consistently, mice with endothelial cell (EC)-specific Snrk deletion exhibited impaired retina angiogenesis, and delayed perfusion recovery and exacerbated muscle apoptosis in ischemic hindlimbs, compared with those of littermate wide-type mice. Endothelial SNRK expression was increased in the extremity vessel samples from nonischemic human. In ECs cultured in hypoxic conditions, HIF1α (hypoxia inducible factor 1α) bound to the SNRK promoter to upregulate SNRK expression. In the nuclei of hypoxic ECs, SNRK complexed with SP1 (specificity protein 1), and together, they bound to an SP1-binding motif in the ITGB1 (β1 integrin) promoter, resulting in enhanced ITGB1 expression and promoted EC migration. Furthermore, SNRK or SP1 deficiency in ECs ameliorated hypoxia-induced ITGB1 expression and, consequently, inhibited EC migration and angiogenesis. Taken together, our data have revealed that SNRK/SP1-ITGB1 signaling axis promotes angiogenesis in vivo.

Inhibition of integrin β1-mediated oncogenic signalling by the antitumor microRNA-29 family in head and neck squamous cell carcinoma.

Due to their aggressive behavior, local recurrence and distant metastasis, survival rate of advanced stage of the patients with head and neck squamous cell carcinoma (HNSCC) is very poor. Currently available epidermal growth factor receptor (EGFR)-targeted therapies are not considered curative for HNSCC. Therefore, novel approaches for identification of therapeutic targets in HNSCC are needed. All members of the miRNA-29 family (miR-29a, miR-29b, and miR-29c) were downregulated in HNSCC tissues by analysis of RNA-sequencing based microRNA (miRNA) expression signature. Ectopic expression of mature miRNAs demonstrated that the miR-29 family inhibited cancer cell migration and invasion by HNSCC cell lines. Comprehensive gene expression studies and in silico database analyses were revealed that integrin β1 (ITGB1) was regulated by the miR-29 family in HNSCC cells. Overexpression of ITGB1 was confirmed in HNSCC specimens, and high expression of ITGB1 significantly predicted poor survival in patients with HNSCC (p = 0.00463). Knockdown of ITGB1 significantly inhibited cancer cell migration and invasion through regulating downstream of ITGB1-mediated oncogenic signalling. In conclusion, regulation of the antitumor miR-29 family affected integrin-mediated oncogenic signalling to modulate HNSCC pathogenesis; these molecules may be novel therapeutic targets for HNSCC.

Regulator of G-protein signaling 5 enhances portal vein invasion in hepatocellular carcinoma.

Portal vein invasion (PVI) is a major prognostic factor in hepatocellular carcinoma (HCC). The aim of the present study was to identify molecules that regulate PVI. Sections of cancerous tissue, paired noncancerous tissue and the PVI area were collected from 3 frozen HCC sections, using laser microdissection. The present study focused on 3 upregulated molecules, integrin β3 (ITGB3), secreted phosphoprotein 1 (SPP1) and regulator of G-protein signaling 5 (RGS5), and 2 molecules that were downregulated in PVI tissue compared with cancer tissue, metallothionein 1G (MT1G) and metallothionein 1H (MT1H), as determined by cDNA microarray analysis. Reverse transcription-quantitative polymerase chain reaction analysis of 32 HCC cases revealed that RGS5 mRNA levels were significantly increased and MT1 G and MT1H mRNA levels were significantly decreased in cancerous tissue compared with noncancerous tissue. However, there was no significant difference in ITGB3 and SPP1 expression. There were no significant differences between the expression of these molecules and any clinicopathologic factors, including PVI. Immunohistochemical staining for RGS5 in 60 HCC cases demonstrated that RGS5 protein levels were higher in cancerous tissue compared with paired noncancerous tissue in 63.3% of HCC cases. Furthermore, high expression of RGS5 in cancerous tissue was significantly associated with PVI and tended to be associated with intrahepatic metastasis. Confluent multinodular type was significantly more frequent in cases with high expression of RGS5 in the cancerous tissue. Therefore, RGS5 may be a useful prognostic biomarker as well as a potential target of molecular therapy to treat HCC.

The Role of Nephronectin on Proliferation and Differentiation in Human Dental Pulp Stem Cells.

Aim The purpose of the current study was to investigate the effects of nephronectin (Npnt) in human dental pulp stem cells (hDPSCs). Methodology Npnt was coated to nontissue culture-treated polystyrene (non-PS) plates. The presence of immobilized protein on the surface was detected by polyclonal rabbit primary anti-Npnt antibody. Then the cell number was counted and compared with PBS-, bovine serum albumin- (BSA-), fish scale type I collagen- (FCOL1-), and human fibronectin- (Fn-) coated wells. Cell proliferation was assessed using CCK-8 assay. Cell morphology was observed under light microscopy and fluorescence microscopy. Lastly, the mRNA expression profiles of integrins, dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), and mineralization capacity of hDPSCs were investigated by real time RT-PCR and alizarin red staining, respectively. Results Npnt mediates hDPSC adhesion and spreading partially via the Arg-Gly-Asp (RGD) motif. Npnt enhanced the mRNA expression of ITGA1, ITGA4, ITGA7, and ITGB1 on day five. Npnt downregulated DSPP but significantly upregulated BSP mRNA expression at day 28. Further, Npnt and FCOL1 accelerated the matrix mineralization in hDPSCs. Conclusions The current findings implicate that Npnt would be favorable to recruit hDPSCs and conducive to mineralization in hDPSCs. The combination of Npnt with hDPSCs may offer a promising approach for hard tissue regeneration.

Systemic inhibition of BMP1-3 decreases progression of CCl4-induced liver fibrosis in rats

Liver fibrosis is a progressive pathological process resulting in an accumulation of excess extracellular matrix proteins. We discovered that bone morphogenetic protein 1-3 (BMP1-3), an isoform of the metalloproteinase Bmp1 gene, circulates in the plasma of healthy volunteers and its neutralization decreases the progression of chronic kidney disease in 5/6 nephrectomized rats. Here, we investigated the potential role of BMP1-3 in a chronic liver disease. Rats with carbon tetrachloride (CCl4)-induced liver fibrosis were treated with monoclonal anti-BMP1-3 antibodies. Treatment with anti-BMP1-3 antibodies dose-dependently lowered the amount of collagen type I, downregulated the expression of Tgfb1, Itgb6, Col1a1, and Acta2 and upregulated the expression of Ctgf, Itgb1, and Dcn. Mehanistically, BMP1-3 inhibition decreased the plasma levels of transforming growth factor beta 1(TGFβ1) by prevention of its activation and lowered the prodecorin production further suppressing the TGFβ1 profibrotic effect. Our results suggest that BMP1-3 inhibitors have significant potential for decreasing the progression of fibrosis in liver cirrhosis.

Electron Microscopy Visualization of Vitronectin Adsorbed on COOH and NH2 Functionalized Surfaces: Distinctive Spatial Alignment and Regulated Cellular Responses

AbstractAdsorption of proteins associating with their conformational changes plays crucial roles in regulating biomaterial–cell interactions and consequent tissue responses to implanted biomaterials. This study reports direct visualization of typical serum protein, vitronectin, one of the key adhesive proteins that participate in mediating cell behaviors, upon adsorption on typically designed surfaces. Carbon films with their surfaces being plasma grafted functional groups COOH and NH2 are used as the model substrata for this study. Negative‐staining electron microscopy technique is employed for visualizing the adsorbed protein and 2D image classification is made and interpreted. Results show that adsorbed vitronectin tends to form multimer aggregate on the COOH‐grafted surfaces, exposing extensively its cell‐binding RGD (arginine‐glycine‐aspartic acid) motif for enhanced cell adhesion. The adsorbed vitronectin on the NH2‐grafted surface forms dimer aggregate with the binding sites being enwrapped. The COOH‐grafting triggers enhanced expressions of ITGA5, ITGAV, ITGB1, and ITGB3 of the adhered cells and this is likely attributed to the special spatial alignment of vitronectin upon adsorption. The conformational information of adsorbed vitronectin gained from the single particle electron microscopy analyses would shed light on design and construction of appropriate biomaterials surfaces for desired cellular behaviors.

The lncRNA HULC functions as an oncogene by targeting ATG7 and ITGB1 in epithelial ovarian carcinoma

Highly upregulated in liver cancer (HULC) is a long noncoding RNA (lncRNA), which has recently been identified as a key regulator in the progression of hepatocellular carcinoma, gliomas and gastric cancer. However, its role in epithelial ovarian carcinoma (EOC) remains unknown. In this study, HULC expression was examined in EOC, borderline and benign ovarian tumors, and normal ovarian tissues by RT-PCR. Ovarian cancer cell phenotypes, as well as autophagy-associated proteins were examined after HULC overexpression or downregulation by plasmid or small interfering RNA (siRNA) transfection, respectively. LncRNA–protein interactions were examined by ribonucleoprotein immunoprecipitation (RIP) assays. We found that HULC expression levels were higher in EOC tissues than normal samples. HULC overexpression induced cell proliferation, migration, invasion, whereas reduced cell apoptosis in vitro and induced tumor growth in vivo. In contrast, downregulation of HULC by siRNA transfection reduced cell proliferation, migration and invasion, and induced cell apoptosis and autophagy. Our results showed that HULC overexpression reduced ATG7, LC3-II and LAMP1 expression, while inducing SQSTM1 (P62) and ITGB1 expression. HULC downregulation had the opposite effects. Furthermore, RIP indicated that ATG7 interacted with HULC; ATG7 downregulation also induced cell proliferation, reduced apoptosis and inhibited autophagy in vitro by reducing LC3-II and LAMP1 expression, while inducing SQSTM1 expression. Furthermore, ATG7 co-transfection with HULC reversed the oncogenic effects of HULC both in vitro and in vivo; however, downregulating ATG7 did not affect cell migration and invasive ability. We found that ITGB1 siRNA co-transfection with HULC reversed the function of HULC in inducing ovarian cancer cell migration and invasive ability. Taken together, our results show that HULC may promote ovarian carcinoma tumorigenesis by inhibiting ATG7 and inducing progression by regulating ITGB1.

NFIX as a Master Regulator for Lung Cancer Progression.

About 40% of lung cancer cases globally are diagnosed at the advanced stage. Lung cancer has a high mortality and overall survival in stage I disease is only 70%. This study was aimed at finding a candidate of transcription regulator that initiates the mechanism for metastasis by integrating computational and functional studies. The genes involved in lung cancer were retrieved using in silico software. 10 kb promoter sequences upstream were scanned for the master regulator. Transient transfection of shRNA NFIXs were conducted against A549 and NCI-H1299 cell lines. qRT-PCR and functional assays for cell proliferation, migration and invasion were carried out to validate the involvement of NFIX in metastasis. Genome-wide gene expression microarray using a HumanHT-12v4.0 Expression BeadChip Kit was performed to identify differentially expressed genes and construct a new regulatory network. The in silico analysis identified NFIX as a master regulator and is strongly associated with 17 genes involved in the migration and invasion pathways including IL6ST, TIMP1 and ITGB1. Silencing of NFIX showed reduced expression of IL6ST, TIMP1 and ITGB1 as well as the cellular proliferation, migration and invasion processes. The data was integrated with the in silico analyses to find the differentially expressed genes. Microarray analysis showed that 18 genes were expressed differentially in both cell lines after statistical analyses integration between t-test, LIMMA and ANOVA with Benjamini-Hochberg adjustment at p-value < 0.05. A transcriptional regulatory network was created using all 18 genes, the existing regulated genes including the new genes PTCH1, NFAT5 and GGCX that were found highly associated with NFIX, the master regulator of metastasis. This study suggests that NFIX is a promising target for therapeutic intervention that is expected to inhibit metastatic recurrence and improve survival rate.

Abstract 3031: PHIP is a therapeutic target for triple negative solid tumors

Abstract Targeted therapy relies on the classification of tumors according to the major molecular drivers of the malignant phenotype, which can then help decide the therapeutic treatment. However, a substantial subset of solid tumors does not express these markers, exemplified by the triple-negative subtype of breast cancer. Shared molecular factors that promote the progression of these tumors, and that represent a target for their therapy, are missing. We previously described a role for PHIP (Pleckstrin Homology domain-Interacting Protein) in the progression of melanoma, and demonstrated PHIP activation in triple-negative melanomas. Analysis of the TCGA profiling efforts in melanoma, breast and lung cancer revealed PHIP expression to be enriched in triple-negative breast cancer and in the bronchiad subtype of triple-negative lung cancer. Here we show the broad-based role of PHIP in the progression of triple-negative subtypes of three solid tumors (breast and lung cancer, and melanoma) defined by different mutational drivers and targeted therapies. By using a shRNA-based targeting of PHIP in in vitro and in vivo models, we have suppressed the malignant phenotype of triple-negative MDA-MB-231 and MDA-MB-436 human breast carcinoma cells. In addition, PHIP knockdown resulted in significant anti tumor effects in H1703 and Calu3 human lung cancer cells lacking mutations in EGFR, KRAS, and ALK, and in two short-term triple wild type melanoma cultures lacking mutations in BRAF, NRAS, and NF1. Suppression of PHIP expression resulted in inhibition of both tumor cell proliferation by cell survival and colony formation assays and invasion into matrigel in each of the tumor models examined, and was accompanied by suppression of pAKT, CCND1, TLN1, and ITGβ1 expression when assessed by western-blot or quantitative immunofluorescence. The PHIP protein contains two bromodomains that can be therapeutically targeted by small molecules. However, the functional activity of the PHIP bromodomains has been poorly characterized. We show that PHIP co-localizes with and binds to the acetylated histone modification H4K91ac, and that both are coordinately regulated upon growth factor stimulation suggesting a new function for PHIP as a chromatin remodeler. To conclude, our results identify a novel role for PHIP in the progression of solid tumors lacking the major molecular drivers, and suggest PHIP as a druggable target for the therapy of these malignancies. Citation Format: David De Semir, Vladimir Bezrookove, Mehdi Nosrati, Altaf A. Dar, Nathan Salomonis, Richard W. Sagebiel, Pierre Desprez, Robert J. Debs, Dirk Schadendorf, Mohammed Kashani-Sabet. PHIP is a therapeutic target for triple negative solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3031. doi:10.1158/1538-7445.AM2017-3031

Hypoxia Selectively Enhances Integrin α5β1 Receptor Expression in Breast Cancer to Promote Metastasis.

Metastasis is the leading cause of breast cancer mortality. Previous studies have implicated hypoxia-induced changes in the composition and stiffness of the extracellular matrix (ECM) in the metastatic process. Therefore, the contribution of potential ECM-binding receptors in this process was explored. Using a bioinformatics approach, the expression of all integrin receptor subunits, in two independent breast cancer patient datasets, were analyzed to determine whether integrin status correlates with a validated hypoxia-inducible gene signature. Subsequently, a large panel of breast cancer cell lines was used to validate that hypoxia induces the expression of integrins that bind to collagen (ITGA1, ITGA11, ITGB1) and fibronectin (ITGA5, ITGB1). Hypoxia-inducible factors (HIF-1 and HIF-2) are directly required for ITGA5 induction under hypoxic conditions, which leads to enhanced migration and invasion of single cells within a multicellular 3D tumor spheroid but did not affect migration in a 2D microenvironment. ITGB1 expression requires HIF-1α, but not HIF-2α, for hypoxic induction in breast cancer cells. ITGA5 (α5 subunit) is required for metastasis to lymph nodes and lungs in breast cancer models, and high ITGA5 expression in clinical biopsies is associated with an increased risk of mortality.Implications: These results reveal that targeting ITGA5 using inhibitors that are currently under consideration in clinical trials may be beneficial for patients with hypoxic tumors. Mol Cancer Res; 15(6); 723-34. ©2017 AACR.

Non-catalytic region of tyrosine kinase adaptor protein 2 (NCK2) pathways as factor promoting aggressiveness in ovarian cancer.

In this study we investigated the function of the non-catalytic region of tyrosine kinase adaptor protein 2 (NCK2) and its correlation with ITGB1 and ITGB4 integrins in driving ovarian cancer (OvCa) aggressiveness. We also evaluated whether NCK2 may influence prognosis in OvCa patients. Nanofluidic technology was used to analyze expression of NCK2 in 332 OvCa patients. To evaluate mRNA expression of NCK2, integrins and VEGFA in OvCa cell lines, qRT-PCR was performed. Stable NCK2 overexpression was obtained in OVCAR3. qRT-PCR and Western blot were performed to evaluate expression changes of VEGFA, vimentin, ITGB1, ITGB4, MMP2 and MMP9 under normoxia and hypoxia conditions. Coimmunoprecipitation (Co-IP) was performed in the A2780 cell line to study the interaction between NCK2 and proteins of interest. To investigate whether NCK2 can influence anchorage-independent growth, a soft agar assay was completed. Transwell invasion assay was performed on stable-transfected OVCAR-3 cell lines. Nanofluidic data showed NCK2 can play an important role as a factor promoting tumor aggressiveness and survival in OvCa. This role was also linked to the behaviors of ITGB1 and ITGB4. Moreover, in cells overexpressing NCK2, the expression of vimentin, MMP2, MMP9, VEGFA and ITGB1, but not of ITGB4 was induced by hypoxia. Co-IP showed that NCK2 can directly bind ITGB1, but not VEGFA. NCK2 may be involved in mediating cell-extracellular matrix interactions in OvCa cells by influencing tumor aggressiveness. This study provides evidence of a possible role of NCK2 as biomarker of OvCa progression.

High expression of miR-493-5p positively correlates with clinical prognosis of non small cell lung cancer by targeting oncogene ITGB1.

Increasing evidence supports that microRNA (miRNA)-mediated gene regulation plays a significant functional role in cancer progression. To investigate the expression and clinical significance of ITGB1 in non small cell lung cancer (NSCLC), the expression levels of ITGB1 in NSCLC tissues and human normal lung tissues were analyzed in silico using genes microarray, KEGG pathway and hierarchical clustering analysis followed by validation with quantitative RT-PCR. Our results showed that ITGB1 was upregulated in NSCLC tissues when compared with normal lung tissues. Survival analysis based on the qRT-PCR data established that ITGB1 expression was attentively related to the prognosis of NSCLC, and patients with higher ITGB1 expression had shorter overall survival (OS). Moreover, ITGB1 was confirmed to be a direct target of miR-493-5p. Furthermore, concomitant high expression of ITGB1 and low expression of miR-493-5p correlated with a shorter median OS and PFS in NSCLC patients. In conclusion, our results provide the first evidence that ITGB1 is a direct target of miR-493-5p suggesting that ITGB1 and miR-493-5p may have potential prognostic value and may be useful as tumor biomarkers for the diagnosis of NSCLC patients.

Expression of FOXJ1 and ITGB4 is Activated upon KLH and LTA Stimulation in the DT40 Cell Line

Expression of FOXJ1 and ITGB4 is Activated upon KLH and LTA Stimulation in the DT40 Cell Line

N-myc downstream-regulated gene 1 inhibits the proliferation and invasion of hepatocellular carcinoma cells via the regulation of integrin β3.

N-myc downstream-regulated gene 1 (NDRG1) is a multifunctional protein associated with carcinogenesis and tumor progression. The function of NDRG1 in hepatocellular carcinoma (HCC) cells remains controversial. The present study investigated the role of NDRG1 in HCC as well as its molecular mechanism using a range of techniques, including western blot analysis, cellular proliferation test, wound healing assay and Transwell assay. In HCC, the levels of NDRG1 expression were highest in the cytoplasm, followed by the membrane, and were lowest in the nucleus. NDRG1 was revealed to inhibit the proliferation and invasion of BEL7402 cells, which facilitated the hypothesis that NDRG1 expression levels may be lower in cell line with a high metastatic potential compared with those in cell lines with a low metastatic potential. However, the present study identified that NDRG1 expression was higher in detached BEL7402 cells and MHCC-97H cells compared with that in attached BEL7402 cells and MHCC-97L cells. Thus, this finding was contrary to what was expected, suggesting that NDRG1 overexpression in the HCC with a high metastatic potential may be the compensatory mechanism. The human HCC BEL7402 cell line demonstrated a significant increase in the capability of motility, invasion and cellular proliferation following NDRG1-short hairpin RNA transfection. Integrin β3 (ITGB3) protein expression was increased in NDRG1-downregulated BEL7402 cells and SMMC7721 cells compared with that in the control cells. The present study suggested that NDRG1 may be a potential anti-tumor target for the treatment of patients with HCC. A potential mechanism for these roles of NDRG1 is by regulating ITGB3 expression; however, this requires additional investigation.