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

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

Studies on signal transduction pathways have generated various promising molecular targets for therapeutic inhibition in cancer therapy. Receptor tyrosine kinases represent an important class of such therapeutic targets. c-Met is a receptor tyrosine kinase that has been shown to be overexpressed and/or mutated in a variety of malignancies. A number of c-Met activating mutations, many of which are located in the tyrosine kinase domain, have been detected in various solid tumors and have been implicated in invasion and metastasis of tumor cells. It is known that stimulation of c-Met via its natural ligand, hepatocyte growth factor (also known as scatter factor, HGF/SF) results in a plethora of biological and biochemical effects in the cell. Activation of c-Met signaling can lead to scattering, angiogenesis, proliferation, enhanced cell motility, invasion, and eventual metastasis. In this review, the role of c-Met dysregulation in tumor progression and metastasis is discussed in detail with particular emphasis on c-Met mutations. Moreover, we summarize current knowledge on various pathways of c-Met signal transduction, highlighting the central role in the cytoskeletal functions. In this summary is included recent data in our laboratory indicating that phosphorylation of focal adhesion proteins, such as paxillin, p125FAK, and PYK2, occurs in response to c-Met stimulation in lung cancer cells. Most importantly, current data on c-Met suggest that when mutated or overexpressed in malignant cells, c-Met would serve as an important therapeutic target.
Cancer Metastasis Rev 2003 Dec
PMID:c-Met: structure, functions and potential for therapeutic inhibition. 1288 8

Since its initial discovery as a substrate and binding partner for the Src oncogene, a role for the focal adhesion kinase (FAK) in cancer has been speculated. In this review the clinical evidence correlating FAK overexpression with cancer and the experimental evidence demonstrating that FAK can control some phenotypes associated with cancer will be discussed. In addition, the emerging theme of interactions between the FAK and growth factor signaling pathways will be described. The evidence presented in this review provides a compelling case for a role for FAK in the pathology of human cancer.
Cancer Metastasis Rev 2003 Dec
PMID:FAK regulates biological processes important for the pathogenesis of cancer. 1288 11

Integrin-linked kinase (ILK) is an intracellular protein, which interacts with the cytoplasmic domains of integrin beta and beta3 subunits. ILK is a 59 kDa protein containing a phosphoinositide phospholipid-binding domain flanked by an N-terminal ankyrin repeat domain and a C-terminal serine/threonine protein kinase domain. Genetic and biochemical evidence have established an essential role of ILK in connecting integrins to the actin cytoskeleton. Apart from integrins, ILK interacts with several adaptor and signaling proteins resulting in its activation and localization to focal adhesion plaques. The kinase activity of ILK is stimulated upon integrin engagement, as well as by growth factors and chemokines in a PI-3Kinase-dependent manner. ILK can mediate the phosphorylation of a variety of intracellular substrates, most notable of which are: protein kinase B (PKB/Akt), glycogen synthase kinase-3 (GSK-3) and myosin light chain. Gain and loss of function strategies have shown that overexpression, and/or constitutive activation of ILK results in oncogenic transformation and progression to invasive and metastatic phenotypes. In addition ILK expression and activity are upregulated in several types of cancers. In this review, we summarize the adaptor and signaling properties ofILK, and also progress in the identification of therapeutic strategies for inhibition of ILK activity.
Cancer Metastasis Rev 2003 Dec
PMID:The role of integrin-linked kinase (ILK) in cancer progression. 1288 12

CLCA (chloride channel, calcium-activated) proteins are novel pulmonary vascular addresses for blood-borne, lung-metastatic cancer cells. They facilitate vascular arrest of cancer cells via adhesion to beta4 integrin and promote early, intravascular, metastatic growth. Here we identify the interacting binding domains of endothelial CLCA proteins (e.g. hCLCA2, mCLCA5, mCLCA1, and bCLCA2) and beta4 integrin. Endothelial CLCAs share a common beta4-binding motif (beta4BM) in their 90- and 35-kDa subunits of the sequence F(S/N)R(I/L/V)(S/T)S, which is located in the second extracellular domain of the 90-kDa CLCA and near the N terminus of the 35-kDa CLCA, respectively. Using enzyme-linked immunosorbent, pull-down, and adhesion assays, we showed that glutathione S-transferase fusion proteins of beta4BMs from the 90- and 35-kDa CLCA subunits bind to the beta4 integrin in a metal ion-dependent manner. Fusion proteins from fibronectin and the integrins beta1 and beta3 served as negative controls. beta4BM fusion proteins competitively blocked the beta4/CLCA adhesion and prevented lung colonization of MDA-MB-231 breast cancer cells. A disrupted beta4BM in hCLCA1, which is not expressed in endothelia, failed to interact with beta4 integrin. The corresponding CLCA-binding domain of the beta4 integrin is localized to the specific determining loop (SDL). Again enzyme-linked immunosorbent, pull-down, and adhesion assays were used to confirm the interaction with CLCA proteins using a glutathione S-transferase fusion protein representing the C-terminal two-thirds of beta4 SDL (amino acids 184-203). A chimeric beta4 integrin in which the indicated SDL sequence had been replaced with the corresponding sequence from the beta1 integrin failed to bind hCLCA2. The dominance of the CLCA ligand in beta4 activation and outside-in signaling is discussed in reference to our previous report that beta4/CLCA ligation elicits selective signaling via focal adhesion kinase to promote metastatic growth.
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PMID:The interacting binding domains of the beta(4) integrin and calcium-activated chloride channels (CLCAs) in metastasis. 1451 19

Askin tumor is a malignant small round cell tumor that originates from the thoracopulmonary region and is a member of Ewing sarcoma family of tumors (ESFT). Only a few Askin tumor cell lines have been established. An Askin tumor cell line, designated MP-ASKIN-SA, was established from the left thoracic tumor of a 13-year-old Japanese boy. ESFT is known to have a high rate of distant metastases at diagnosis. The genes controlling the spread of ESFT cells, however, have not been elucidated. G-banding chromosome analysis revealed that the MP-ASKIN-SA cell line has complex chromosomal abnormalities including trisomy 8. The EWS/FLI1 chimeric transcript and c-myc overexpression were revealed by the reverse transcriptase-polymerase chain reaction and Northern blot analysis. Furthermore, we investigated the expression of the focal adhesion kinase (FAK) gene in the ESFT cell lines using Northern blot analysis. In addition to the MP-ASKIN-SA cell line, six Ewing sarcoma cell lines, one peripheral nerve sheath tumor cell line, and two Askin tumor cell lines were analyzed. All ESFT cell lines, including MP-ASKIN-SA, expressed five- to twenty-eight-fold-increased values of FAK, as compared with fibroblasts obtained from the bone marrow of a healthy volunteer. These results raise the possibility that the overexpression of c-myc and FAK are involved in the poor prognosis of ESFT.
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PMID:Newly established Askin tumor cell line and overexpression of focal adhesion kinase in Ewing sarcoma family of tumors cell lines. 1455 43

In vivo models utilizing orthotopic injection of tumor cells into nude mice have proven valuable for the study of metastasis. However, breast cancers are among the more difficult of human tumors to grow in immunodeficient mice, with a relatively low tumor take. Fewer still develop spontaneous metastases. The injection of GI101A breast cancer cells into the mammary fatpad (mfp) produced lung metastases in 25% of tumor-bearing mice. Selecting cells from the lung metastases and recycling in vivo resulted in the isolation of a series of variant cell lines. These cell lines were tested for tumorigenicity and metastasis in nude mice following mfp injection compared with the original cell line, and in vitro expression of factors associated with the metastatic phenotype measured. The in vivo selected cell lines were more aggressive, with higher tumor take, faster local growth rate and increased incidence (> or = 85%) and extent of lung metastasis. However, the metastasis-selected variants showed no increases in expression of the growth factor receptors EGFR or HER-2, and the pro-angiogenic factors VEGF-A and IL-8. Immunohistochemistry of mfp tumors revealed no differences in microvessel density (counting CD-31 positive structures) and cell proliferation (PCNA-positive cells) comparing the GI101A line with selected variants. No TUNEL-positive cells were detected in the tumors of the metastasis-derived variant, with a small number of cells undergoing apoptosis detected in sections of GI101A tumors. In vitro, the metastasis-derived variants were found to have a more robust expression of phosphorylated PKB/Akt, with or without EGF or serum stimulation, suggesting an association between Akt activation and metastatic ability. This new series of isogenic cell lines may be valuable for identifying molecular mechanisms involved in the metastatic progression of breast cancer.
Clin Exp Metastasis 2003
PMID:Selection of more aggressive variants of the gI101A human breast cancer cell line: a model for analyzing the metastatic phenotype of breast cancer. 1459 85

Over the past 20 years, combined treatment with radiotherapy and second-generation chemotherapy drugs was extensively studied in patients with locally advanced NSCLC and became the standard over radiotherapy alone in patients with good performance status. Radiosensitizing properties of cisplatin have been identified in the laboratory. Close temporal administration of cisplatin and radiation is mandatory for enhanced antitumor efficacy, but results in significant toxicity to normal tissues. Early clinical studies demonstrated that the concurrent administration of cisplatin during STD-RT was feasible, with acceptable esophageal toxicity, and had the potential of significantly improving locoregional control. Carboplatin administered concurrently with accelerated HFX-RT was responsible for a higher rate of esophageal toxicity. Further improvement in survival also requires an effective treatment of micro-metastatic disease through full-dose delivery of cytotoxic drugs and the addition of at least one more active drug in conjunction with cisplatin and radiotherapy to further improve locoregional control of the disease. In most clinical studies, etoposide was the second drug of choice because of its own radiosensitizing properties and possible synergy with cisplatin. In numerous phase II studies, concurrent radiotherapy and PE resulted in reproducible results in terms of local control (30%-40%), median survival (15-18 months), survival at 2 years (35%-40%), and survival at 5 years (25%-30%). In phase III studies, these results were shown to be superior to radiotherapy alone and to induction chemotherapy followed by STD-RT. The question of the potential benefit of HFX-RT combined with PE has been addressed in phase II and III studies. At this time, there is no firm evidence that concurrent chemotherapy with HFX-RT is superior to concurrent chemotherapy with STD-RT in terms of local control and survival. Only a significant benefit in terms of local control or survival would justify the significant increase of esophageal toxicity observed with HFX-RT, which remains the main limiting factor of concurrent chemoradiotherapy with PE. Studies on postinduction surgery after concurrent chemoradiotherapy have been of major interest, demonstrating that a complete pathologic response rate of 25% to 30% could be achieved with a relatively low dose of radiation (45 Gy) and that downstaging was a major determinant for improved long-term survival. Long-term survival after trimodality treatment, however, does not appear to be significantly different from what can be achieved with concurrent chemoradiotherapy alone in phase II studies. Whether postinduction surgery is beneficial to patients with histologically proved stage III (N2) and stage IIIB patients was the question addressed in a large, recently completed phase III intergroup trial and of which the results are eagerly awaited. Over the past 10 years, further progress in radiation technology has been accomplished through three-dimensional treatment planning, multileaf collimators, and electronic portal imaging devices, leading to high-precision conformal radiotherapy and dose escalation and (it is hoped) to improved local control. Intensity-modulated radiotherapy and respiratory gating remain to be evaluated. Accurate delineation of critical organs and pretreatment analysis of toxicity-predicting factors allow for better protection of normal intrathoracic tissues such as lung and esophagus and, it is hoped, will lead to a significant reduction in the incidence of radiation esophagitis and pneumonitis. Third-generation drugs such as taxanes, vinorelbine, and gemcitabine have demonstrated high response rates in NSCLC patients with favorable toxicity profiles. These drugs have also shown major radiosensitizing properties in the laboratory and in the clinical setting, often leading, however, to excessive radiosensitization and unacceptable normal tissue toxicities when administered at full dose concurrently with radiotherapy. Weekly administration of these drugs at reduced doses during a full course of conformational radiotherapy up to 70 Gy or more, however, resulted in encouraging results in several phase II studies, with median survival in excess of 20 months and 2- and 3-year survival rates near 50% and 40%, respectively. The respective benefits of either induction or consolidation full-dose chemotherapy with these drugs, before or after concurrent chemoradiotherapy with second- or third-generation chemotherapy, are presently being evaluated in phase III studies. As a result of improved survival and enhanced local control, most of these studies show a significant increase in the incidence of brain metastases. Because the brain is often the first site of relapse after concurrent chemoradiotherapy with or without surgery, the issue of prophylactic cranial irradiation is currently being addressed in a phase III trial.
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PMID:Radiotherapy and chemotherapy in locally advanced non-small cell lung cancer: preclinical and early clinical data. 1500 80

We have previously developed a quantitative PCR (QPCR) technique for the detection of cytokeratin 19 (CK19) transcripts in blood and bone marrow and compared this to immunocytochemistry (ICC). Together, both have shown promise for monitoring therapeutic efficacy in patients with metastatic breast cancer. The aim of this study was to determine the feasibility and value of these assays for minimal residual disease (MRD) in monitoring efficacy of adjuvant therapy following surgery for primary breast cancer. Bone marrow aspirates and peripheral blood samples were taken at the time of surgery from patients with primary breast cancer and no evidence of metastases on conventional scans. These were tested for the presence of CK19 mRNA transcripts and cytokeratin positive cells. Follow-up bone marrow aspirates were taken at 3, 6, 12, 24, 36 and 48 months. Prior to surgery, 51% of patients displayed evidence of disseminated cancer cells in the bone marrow by either or both QPCR and ICC. Of 91 patients who had repeat samples assayed, 87% and 65% had positive results at some time using QPCR and ICC, respectively. All patients received adjuvant systemic therapy and in 44 cases where there was a positive result in either the pretreatment or 3-month aspirate, 32/44 (73%) showed a fall in CK19:ABL ratio (QPCR) and 15/24 (63%) showed a reduction in the number of cytokeratin-positive cells (ICC) during follow-up. These results indicate that MRD persists despite adjuvant therapy in a majority of patients with primary breast cancer up to 4 years following surgery.
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PMID:Persistence of bone marrow micrometastases in patients receiving adjuvant therapy for breast cancer: results at 4 years. 1552 96

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors of the gastrointestinal tract characterized by the expression of a receptor that activates tyrosine kinase called c-kit. Since malignant GISTs are resistant to conventional radiation therapy and chemotherapy, recurrent or malignant GIST has an extremely poor prognosis even after surgical resection. The development of a tyrosine kinase inhibitor, STI571 (imatinib mesylate, Glivec, Gleevec), which inhibits the BCR-ABL, PDGF-R alpha and c-kit receptors, has changed the management of unresectable malignant GIST and has improved the survival of patients with metastatic disease. We report a patient with GIST and diffused peritoneal metastases, whose tumor initially responded to STI571 and eventually became resistant. A 45-year-old woman underwent partial jejunostomy on September 3, 1998, under a diagnosis of submucosal tumor of the jejunum. Pathological examination of the primary tumor revealed a strong c-kit expression and GIST was diagnosed. The patient underwent an excision of peritoneal recurrences on October 31, 2000; April 17, 2001; and August 28, 2001. A treatment with STI571 (400 mg/day) was initiated on October 15, 2001, and she was free from peritoneal masses for 8 months after the fourth operation. However, the patient herself suspended the STI571 therapy for one month and multiple peritoneal metastases developed. Although the treatment with STI571 was restarted at 400 mg/day, the peritoneal masses did not respond this time. She died of liver, lung, and peritoneal metastases after the seventh cytoreductive operation on February 11, 2004. Several mechanisms of the resistance to STI571 have been identified. Amplification or an overexpression of KIT has been proposed to be involved in the resistance development. Several mutations of KIT were also correlated with the clinical outcome. Her tumors showed mutations in exons 9 or 11 of KIT, which had longer event-free and overall survival times than those tumors that had mutations of exons 13 or 17. In this case, an exon 11 mutation of KIT was initially noted. After the interruption of the treatment, an additional point mutation arose in exon 13 that caused a resistance to STI571. Currently STI571 is the first-line therapy for non-resectable GISTs, but a single-agent therapy often leads to tumor resistance. It is our hope that we will be able to design an alternative treatment to overcome such resistance.
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PMID:[A case of metastatic gastrointestinal stromal tumor developing a resistance to STI571 (imatinib mesylate)]. 1555 17

Studies assessed if the serine/threonine protein phosphatase-2A (PP-2A) maintains cytoskeletal integrity of normal keratinocytes and if this differs in malignant cells. Murine and human keratinocyte cell lines contained more PP-2A activity than did the murine SCC VII/SF squamous cell carcinoma cells or primary cultures of human head and neck squamous cell carcinoma (HNSCC) cells. Since tyrosine phosphorylation of the focal adhesion proteins paxillin and FAK is indicative of more stable focal adhesions, cells were immunostained for phosphotyrosine plus either paxillin or FAK, and then examined by confocal microscopy. In non-malignant keratinocytes, phosphotyrosine staining co-localized with paxillin and FAK. This co-localization occurred at the cell periphery in a pattern resembling focal adhesions. In contrast, the co-localization of phosphotyrosine with either paxillin or FAK along the cell periphery was almost absent in the SCC cells or in keratinocytes that were treated with okadaic acid to inhibit PP-2A activity. Consistent with this was a rounded cellular morphology with less extended processes as compared to control keratinocytes. These studies indicate PP-2A maintains the organization and tyrosine-phosphorylated state of the focal adhesion proteins FAK and paxillin, and that the loss of PP-2A activity results in a loss of cytoskeletal organization, as is seen in SCC.
Clin Exp Metastasis 2004
PMID:Protein phosphatase-2A maintains focal adhesion complexes in keratinocytes and the loss of this regulation in squamous cell carcinomas. 1555 94


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