Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:2.7.10.2 (focal adhesion kinase)
44,029 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Carcinogenesis is considered as a multistep process involving functional changes in the hemidesmosomal organization. In normal skin keratinocytes, expression of the alpha(6)beta(4) integrin is restricted to the proliferative basal layer and mediates stable adhesion to the underlying basement membrane. Observations in carcinoma cells show a functional and spatial dissociation of the alpha(6)beta(4) integrin from the hemidesmosomal complex, which stimulates cell migration and, therefore, may contribute to carcinoma invasion. We now have evaluated the adhesion behavior of epithelial cells at different stages of transformation in response to activation of the beta(4) integrin. It is demonstrated that ligation of the beta(4) integrin augmented adhesion of carcinoma and pre-carcinoma cells to non-modified plastic. In contrast, adhesion behavior of normal human keratinocytes was not influenced by ligation of the beta(4) integrin. In order to explain the mechanism of beta(4)-mediated adhesion, the hypothesis of an "inside-out" activation of integrins was tested. Evidence is given that for cells expressing the alpha(6)beta(4) integrin, ligation of the beta(4) integrin increased beta(1) integrin-mediated adhesion. Furthermore, ligation of the beta(4) integrin led to phosphorylation of PKB/Akt at both phosphorylation sites. Functional blocking of PKB/Akt by dominant-negative overexpression decreased cell adhesion in response to beta(4) integrin ligation. Taken together, the present data establish a link between the ligation of the beta(4) integrin and beta(1) integrin-mediated cell adhesion in carcinoma and pre-carcinoma cells. Hence, these findings provide further insight into the conversion processes during carcinogenesis and show the beta(4) integrin to be a key regulator of cellular adhesion.
...
PMID:Ligation of the beta4 integrin triggers adhesion behavior of human keratinocytes by an "inside-out" mechanism. 1530 80

Exposure to particulate matter (PM) is associated with several health effects including lung cancer. However, the mechanisms of particle-induced carcinogenesis are not fully understood. The main aim of this study was to investigate the genotoxicity of PM in relation to particle-cell interactions and to study the effect of removal of DNA-damaging substances by extraction of PM with different solvents. Genotoxicity was analyzed by means of the comet assay after exposure of cultured human fibroblasts to urban dust particles (SRM 1649). It was found that PM induced DNA damage in a dose-dependent manner and that cells interacting with PM suffered more DNA single-strand breaks relative to other cells. The genotoxicity of PM was significantly reduced after extraction with dichloromethane (DCM), dimethyl sulfoxide (DMSO) and water, but not with acetone and hexane. However, the insoluble particle core still induced DNA single-strand breaks. The extracts were further investigated in cell-free systems. Analysis of aromatic DNA adducts with 32P-HPLC showed that the DMSO and DCM extracts contained most of the DNA-reactive polyaromatic compounds (PACs). Further, the formation of 8-oxo-2'-deoxyguanosine (8-oxodG) upon incubation of the extracts with 2'-deoxyguanosine (dG) showed that the water extract contained most of the oxidizing substances. Thus, the genotoxicity of PM was caused both by adduct-forming PACs and oxidizing substances as well as the insoluble particle-core. This study showed that all these factors together contribute to explaining the mechanisms of PM genotoxicity.
...
PMID:Genotoxicity of airborne particulate matter: the role of cell-particle interaction and of substances with adduct-forming and oxidizing capacity. 1557 34

Macrophage inhibitory cytokine 1 (MIC-1), a divergent member of the transforming growth factor beta superfamily, plays a role in the progression of a number of cancers, including breast, gastric, prostate and colorectal carcinomas. Serum MIC-1 levels are elevated in patients with metastatic prostate, breast and colorectal carcinomas. In vitro studies have revealed a cell type-specific role for MIC-1 in senescence and apoptosis. MIC-1 activates the survival kinase AKT/PKB in neuronal cells. Depending on the cell type, it activates or represses the MAP kinases ERK1/2. Mechanisms responsible for an increased MIC-1 expression in cancers and the consequences of MIC-1 overexpression, however, are not known. In this study, we show that AKT/PKB directly regulates the expression of MIC-1 in breast cancer cells. Sequences within -88 to +30 of the MIC-1 promoter are required for the AKT-mediated induction of MIC-1. This region of the promoter contains two SP-1 binding sites (SP-1B and SP-1C), which bind to the SP-1 and SP-3 proteins. Mutation of SP-1C but not SP-1B reduced the AKT-mediated activation of MIC-1. MIC-1 increased the basal ERK1 phosphorylation and prolonged the estrogen-stimulated ERK1 phosphorylation in MCF-7 breast cancer cells without altering the phosphorylation status of AKT/PKB. Immunohistochemistry with MIC-1 antibody revealed an MIC-1 expression within the cancer cells of primary breast cancer and in the MCF-7 xenografts. Furthermore, a limited analysis of RNA from primary breast cancers revealed an overexpression of MIC-1 in tumors, compared with normal tissues. These results suggest that AKT/PKB through MIC-1 could regulate the ERK1 activity and the MIC-1 expression levels may serve as a surrogate marker for the AKT activation in tumors.
Carcinogenesis 2005 May
PMID:The macrophage inhibitory cytokine integrates AKT/PKB and MAP kinase signaling pathways in breast cancer cells. 1567 29

Increased extracellular pressure stimulates colon cancer cell adhesion by activating focal adhesion kinase (FAK) and Src. We investigated the role of the cytoskeleton in pressure-induced inside-out FAK and Src phosphorylation and pressure-stimulated adhesion. We perturbed actin polymerization with phalloidin, cytochalasin D and latrunculin B, and microtubule organization with colchicine and paclitaxol. We compared the effects of these agents on pressure-induced SW620 and human primary colon cancer cell adhesion and inside-out FAK/Src activation with outside-in adhesion-dependent FAK/Src activation. Cells pretreated with cytoskeletal inhibitors were subjected to 15 mmHg increased pressure and allowed to adhere to collagen I coated plates or prevented from adhesion to pacificated plates for 30 min. Phalloidin, cytochalasin D, latrunculin B and colchicine pretreatment completely prevented pressure-stimulated and significantly inhibited basal SW620 cell adhesion. Taxol did not inhibit pressure-induced colon cancer cell adhesion, but significantly lowered basal adhesion. Cytochalasin D and colchicine had similar effects in pressure-stimulated primary human malignant colonocytes. Phalloidin, cytochalasin D, latrunculin B and colchicine prevented pressure-induced SW620 FAK phosphorylation but not Src phosphorylation. FAK phosphorylation in response to collagen I adhesion was significantly attenuated but not completely prevented by these inhibitors. Although Src phosphorylation was not increased on adhesion, the cytoskeleton disrupting agents significantly lowered basal Src phosphorylation in adherent cells. These results suggest that both cytoskeleton-dependent FAK activation and cytoskeleton-independent Src activation may be required for extracellular pressure to stimulate colon cancer cell adhesion. Furthermore, the cytoskeleton plays a different role in pressure-activated FAK and Src signaling than in FAK and Src activation in adherent cells. We, therefore, hypothesize that cytoskeletal interactions with focal adhesion signals mediate the effects of extracellular pressure on colon cancer cell adhesion.
Carcinogenesis 2005 Oct
PMID:The role of the cytoskeleton in differentially regulating pressure-mediated effects on malignant colonocyte focal adhesion signaling and cell adhesion. 1591 11

Although the dioxin receptor, the aryl hydrocarbon receptor (AhR), is considered a major regulator of xenobiotic-induced carcinogenesis, its role in tumor formation in the absence of xenobiotics is still largely unknown. Trying to address this question, we have produced immortalized cell lines from wild-type (T-FGM-AhR+/+) and mutant (T-FGM-AhR-/-) mouse mammary fibroblasts by stable co-transfection with the simian virus 40 (SV-40) large T antigen and proto-oncogenic c-H-Ras. Both cell lines had a myofibroblast phenotype and similar proliferation, doubling time, SV-40 and c-H-Ras expression and activity, and cell cycle distribution. AhR+/+ and AhR-/- cells were also equally able to support growth factor- and anchorage-independent proliferation. However, the ability of T-FGM-AhR-/- to induce subcutaneous tumors (leimyosarcomas) in NOD/SCID-immunodeficient mice was close to 4-fold lower than T-FGM-AhR+/+. In culture, T-FGM-AhR-/- had diminished migration in collagen-I and decreased lamellipodia formation. VEGFR-1/Flt-1, a VEGF receptor that regulates cell migration and blood vessel formation, was also down-regulated in AhR-/- cells. Signaling through the ERK-FAK-PKB/AKT-Rac-1 pathway, which contributes to cell motility and invasion, was also significantly inhibited in T-FGM-AhR-/-. Thus, the lower tumorigenic potential of T-FGM-AhR-/- could result from a compromised adaptability of these cells to the in vivo microenvironment, possibly because of an impaired ability to migrate and to respond to angiogenesis.
...
PMID:Immortalized mouse mammary fibroblasts lacking dioxin receptor have impaired tumorigenicity in a subcutaneous mouse xenograft model. 1594 50

Small molecule inhibitors of signaling pathways have proven to be extremely useful for the development of therapeutic strategies for human cancers. Blocking the tumor-promoting effects of transforming growth factor-beta (TGF-beta) in advanced stage carcinogenesis provides a potentially interesting drug target for therapeutic intervention. Although very few TGF-beta receptor kinase inhibitors (TRKI) are now emerging in preclinical studies, nothing is known about how these inhibitors might regulate the tumor-suppressive or tumor-promoting effects of TGF-beta, or when these inhibitors might be useful for treatment during cancer progression. We have investigated the potential of TRKI in new therapeutic approaches in preclinical models. Here, we demonstrate that the TRKI, SB-431542, inhibits TGF-beta-induced transcription, gene expression, apoptosis, and growth suppression. We have observed that SB-431542 attenuates the tumor-promoting effects of TGF-beta, including TGF-beta-induced EMT, cell motility, migration and invasion, and vascular endothelial growth factor secretion in human cancer cell lines. Interestingly, SB-431542 induces anchorage independent growth of cells that are growth-inhibited by TGF-beta, whereas it reduces colony formation by cells that are growth-promoted by TGF-beta. However, SB-431542 has no effect on a cell line that failed to respond to TGF-beta. This represents a novel potential application of these inhibitors as therapeutic agents for human cancers with the goal of blocking tumor invasion, angiogenesis, and metastasis, when tumors are refractory to TGF-beta-induced tumor-suppressor functions but responsive to tumor-promoting effects of TGF-beta.
...
PMID:A specific inhibitor of TGF-beta receptor kinase, SB-431542, as a potent antitumor agent for human cancers. 1596 3

In human papillomavirus (HPV)-associated carcinogenesis, HPV infection characteristics such as viral load may play an important role in lesion development. The purpose of this study was to determine the association between quantitative assessment of oncogenic HPV viral load, and abnormal cytology among women residing along the United States-Mexico border. A cross-sectional study of 2,319 women was conducted between 1997 and 1998. Viral load of oncogenic HPV types (16, 18, 31, 39, 45, 51, 52, and 58) was measured among 173 HPV (+) women using quantitative real-time PCR. Overall, HPV 16, 31, 52 and 58 showed the highest viral load. Single type infection had higher viral loads compared to multiple type infections. HPV viral load declined significantly (p = 0.04) with age. No significant association was observed with other known HPV risk factors such as oral contraceptive use, parity, sexual and STD history. Viral load was independently associated with degree of cervical lesions. An adjusted odds ratio (AOR) of 4.7 for the association between increasing total viral load and Atypical Squamous Cells of Undetermined Significance (ASCUS)/Atypical Glandular Cells of Undetermined Significance (AGUS) was observed (p for trend <0.01). Increased risk of low-grade SIL was observed with higher viral load compared with HPV negative women (AOR = 47.7 for total viral load; AOR = 37.1 for HPV viral load not including HPV16, and AOR = 25.9 for HPV16 viral load). Likewise, increased risk of high-grade SIL with higher viral loads was observed (AOR = 58.4 for high total viral load compared with HPV negative women, AOR = 58.1 for HPV viral load not including HPV16, and AOR = 69.8 for HPV16 high viral load). Results from this study suggest a dose-response relationship between increasing oncogenic HPV viral load and risk of LSIL and HSIL.
...
PMID:Cross-sectional analysis of oncogenic HPV viral load and cervical intraepithelial neoplasia. 1615 19

We have found previously that human plasma-membrane-associated sialidase (NEU3), a key glycosidase for ganglioside degradation, was markedly up-regulated in human colon cancers, with an involvement in suppression of apoptosis. To elucidate the molecular mechanisms underlying increased NEU3 expression, in the present study we investigated its role in cell adhesion of human colon cancer cells. DLD-1 cells transfected with NEU3 exhibited increased adhesion to laminins and consequent cell proliferation, but decreased cell adhesion to fibronectin and collagens I and IV, compared with control cells. When triggered by laminins, NEU3 clearly stimulated phosphorylation of FAK (focal adhesion kinase) and ERK (extracellular-signal-regulated kinase), whereas there was no activation on fibronectin. NEU3 markedly enhanced tyrosine phosphorylation of integrin beta4 with recruitment of Shc and Grb-2 only on laminin-5, and NEU3 was co-immunoprecipitated by an anti-(integrin beta4) antibody, suggesting that association of NEU3 with integrin beta4 might facilitate promotion of the integrin-derived signalling on laminin-5. In addition, the promotion of phosphorylation of integrin beta1 and ILK (integrin-linked kinase) was also observed on laminins. G(M3) depletion as the result of NEU3 overexpression, assessed by TLC, appeared to be one of the causes of the increased adhesion on laminins and, in contrast, of the decreased adhesion on fibronectin - NEU3 probably having bimodal effects. These results indicate that NEU3 differentially regulates cell proliferation through integrin-mediated signalling depending on the extracellular matrix and, on laminins, NEU3 did indeed activate molecules often up-regulated in carcinogenesis, which may cause an acceleration of the malignant phenotype in cancer cells.
...
PMID:Plasma-membrane-associated sialidase (NEU3) differentially regulates integrin-mediated cell proliferation through laminin- and fibronectin-derived signalling. 1624 5

We cloned and characterized human WNT2B (WNT13) in 1996. Following our discovery of human WNT2B, others and we characterized mouse, rat, chicken and zebrafish WNT2B orthologs. Here, comparative integromics analyses on WNT2B and its clinical applications are reviewed. WNT2B-ST7L-CAPZA1 locus at human chromosome 1p13.2 and WNT2-ST7-CAPZA2 locus at human chromosome 7q31.2 are paralogous regions within the human genome. Two splicing variants occur from human WNT2B gene due to alternative promoters. WNT2B splicing variant 1 encodes secreted-type glycoprotein with WNT domain (WNT2B isoform 1), while WNT2B splicing variant 2 encodes transmembrane-type glycoprotein with WNT domain (WNT2B isoform 2). WNT2B splicing variant 2 is the evolutionarily conserved major transcript of human WNT2B gene. Mammalian WNT2B orthologs acquired the transmembrane domain and integrin-targeting RGD motif during vertebrate evolution. Human WNT2B isoform 2 and other vertebrate WNT2B orthologs are canonical WNTs to determine cell fate through the activation of beta-catenin/TCF signaling pathway and SNAIL/EMT signaling pathway. E box and CCAAT box are conserved within mammalian WNT2B promoters. WNT2B functions as the stem cell factor for neural or retinal progenitor cells during embryogenesis, and also for gastric cancer, esophageal cancer and skin basal cell carcinoma during carcinogenesis. Anti-WNT2B monoclonal antibody could be applied as selection marker of stem cells in the field of stem cell biology. Soluble WNT2B protein or small molecule WNT2B mimic compounds could be developed for stem cell expansion in the fields of tissue engineering and regenerative medicine. Anti-WNT2B monoclonal antibodies, WNT2B RNAi compounds, or small molecule WNT2B inhibitors could be developed as novel therapeutic agents for gastric cancer and esophageal cancer in the field of clinical oncology.
...
PMID:WNT2B: comparative integromics and clinical applications (Review). 1627 93

To identify novel methylation-silenced genes in gastric cancers, we carried out a chemical genomic screening, a genome-wide search for genes upregulated by treatment with a demethylating agent, 5-aza-2'-deoxycytidine (5-aza-dC). After 5-aza-dC treatment of a gastric cancer cell line (AGS) 579 genes were upregulated 16-fold or more, using an oligonucleotide microarray with 39,000 genes. From these genes, we selected 44 known genes on autosomes whose silencing in gastric cancer has not been reported. Thirty-two of these had CpG islands (CGI) in their putative promoter regions, and all of the CGI were methylated in AGS, giving an estimated number of 421+/-75 (95% confidence interval) methylation-silenced genes. Additionally, we analyzed the methylation status of 16 potential tumor-related genes with promoter CGI that were upregulated four-fold or more, and 14 of these were methylated in AGS. Methylation status of the 32 randomly selected and 16 potential tumor-related genes was analyzed in 10 primary gastric cancers, and 42 genes (ABHD9, ADFP, ALDH1A3, ANXA5, AREG, BDNF, BMP7, CAV1, CDH2, CLDN3, CTSL, EEF1A2, F2R, FADS1, FSD1, FST, FYN, GPR54, GREM1, IGFBP3, IGFBP7, IRS2, KISS1, MARK1, MLF1, MSX1, MTSS1, NT5E, PAX6, PLAGL1, PLAU, PPIC, RBP4, RORA, SCRN1, TBX3, TFAP2C, TNFSF9, ULBP2, WIF1, ZNF177 and ZNF559) were methylated in at least one primary gastric cancer. A metastasis suppressor gene, MTSS1, was located in a genomic region with frequent loss of heterozygosity (8q22), and was expressed abundantly in the normal gastric mucosa, suggesting its role in gastric carcinogenesis. (Cancer Sci 2006; 97: 64 -71).
...
PMID:Chemical genomic screening for methylation-silenced genes in gastric cancer cell lines using 5-aza-2'-deoxycytidine treatment and oligonucleotide microarray. 1636 23


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---