Showing papers on "Growth factor receptor inhibitor published in 2008"
TL;DR: A review of the specific roles of these growth factors and cytokines during wound healing can be found in this article, where patients are treated by three growth factors: PDGF-BB, bFGF, and GM-CSF.
Abstract: Wound healing is an evolutionarily conserved, complex, multicellular process that, in skin, aims at barrier restoration. This process involves the coordinated efforts of several cell types including keratinocytes, fibroblasts, endothelial cells, macrophages, and platelets. The migration, infiltration, proliferation, and differentiation of these cells will culminate in an inflammatory response, the formation of new tissue and ultimately wound closure. This complex process is executed and regulated by an equally complex signaling network involving numerous growth factors, cytokines and chemokines. Of particular importance is the epidermal growth factor (EGF) family, transforming growth factor beta (TGF-beta) family, fibroblast growth factor (FGF) family, vascular endothelial growth factor (VEGF), granulocyte macrophage colony stimulating factor (GM-CSF), platelet-derived growth factor (PDGF), connective tissue growth factor (CTGF), interleukin (IL) family, and tumor necrosis factor-alpha family. Currently, patients are treated by three growth factors: PDGF-BB, bFGF, and GM-CSF. Only PDGF-BB has successfully completed randomized clinical trials in the Unites States. With gene therapy now in clinical trial and the discovery of biodegradable polymers, fibrin mesh, and human collagen serving as potential delivery systems other growth factors may soon be available to patients. This review will focus on the specific roles of these growth factors and cytokines during the wound healing process.
2,617 citations
TL;DR: It is demonstrated that a small regulatory microRNA, miR-296, has a major role in angiogenesis by directly targeting the hepatocyte growth factor-regulated tyrosine kinase substrate (HGS) mRNA, leading to decreased levels of HGS and thereby reducing HGS-mediated degradation of the growth factor receptors VEGFR2 and PDGFRbeta.
440 citations
TL;DR: This review will summarize the principal signaling pathways activated by IGF1R and the preclinical data that validated this receptor as a treatment target, and review clinical progress in the testing of IGF 1R inhibitory drug candidates.
Abstract: Research conducted over the past two decades has shown the importance of the type 1 insulin-like growth factor receptor (IGF1R) in tumorigenesis, metastasis, and resistance to existing forms of cancer therapy. The IGF1R itself has only recently been accepted as a credible treatment target, however, perhaps reflecting the potential problems for drug design posed by normal tissue IGF1R expression, and close homology with the insulin receptor. Currently approximately 12 anti-IGF1R therapeutics are undergoing clinical evaluation, including blocking antibodies and tyrosine kinase inhibitors. This review will summarize the principal signaling pathways activated by IGF1R and the preclinical data that validated this receptor as a treatment target. We will review clinical progress in the testing of IGF1R inhibitory drug candidates, the relative benefits and potential toxicities of coinhibition of the insulin receptor, and the rationale for combining IGF1R blockade with other cancer treatments. An understanding of IGF1R signaling is important because it will guide the incorporation of appropriate molecular markers into clinical trial design. This will be key to the identification of patients most likely to benefit, and so will influence the ability of IGF1R inhibition to make the transition from experimental intervention to clinical therapy.
422 citations
TL;DR: A systems approach to cancer treatment where the surface distribution of receptors is targeted through metabolism and N-glycan branching to induce growth arrest is suggested.
Abstract: N-Glycan branching in the medial-Golgi generates ligands for lattice-forming lectins (e.g., galectins) that regulate surface levels of glycoproteins including epidermal growth factor (EGF) and transforming growth factor-beta (TGF-beta) receptors. Moreover, functional classes of glycoproteins differ in N-glycan multiplicities (number of N-glycans/peptide), a genetically encoded feature of glycoproteins that interacts with metabolic flux (UDP-GlcNAc) and N-glycan branching to differentially regulate surface levels. Oncogenesis increases beta1,6-N-acetylglucosaminyltransferase V (encoded by Mgat5) expression, and its high-affinity galectin ligands promote surface retention of growth receptors with a reduced dependence on UDP-GlcNAc. Mgat5(-/-) tumor cells are less metastatic in vivo and less responsive to cytokines in vitro, but undergo secondary changes that support tumor cell proliferation. These include loss of Caveolin-1, a negative regulator of EGF signaling, and increased reactive oxygen species, an inhibitor of phosphotyrosine phosphatases. These studies suggest a systems approach to cancer treatment where the surface distribution of receptors is targeted through metabolism and N-glycan branching to induce growth arrest.
390 citations
TL;DR: It is demonstrated that fibroblast growth factor 21 (FGF21), a hormone induced by fasting, causes GH resistance and suggests a central role for FGF21 in inhibiting growth as part of its broader role in inducing the adaptive response to starvation.
357 citations
TL;DR: The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase receptor that is frequently expressed in epithelial tumors as discussed by the authors, and it was the first receptor to be proposed as a target for cancer therapy.
Abstract: The epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase receptor that is frequently expressed in epithelial tumors. The EGFR was the first receptor to be proposed as a target for cancer therapy, and after 2 decades of intensive research, there are several anti-EGFR agents available in the clinic. Recent advances in our understanding in the mechanisms of receptor activation and function, discovery of primary and secondary EGFR somatic mutations, as well as a new generation of anti-EGFR agents provide new leads on the clinical targeting of this receptor and may serve as a model for strategies aimed at targeting other receptors.
313 citations
TL;DR: The functional interaction between AR and an array of growth factor signal transduction events in prostate tumors and its value as a therapeutic forum targeting androgen-independent metastatic prostate cancer is discussed.
Abstract: Androgens promote the growth and differentiation of prostate cells through ligand activation of the androgen receptor (AR). Sensitization of the androgenic response by multifunctional growth factor signaling pathways is one of the mechanisms via which AR contributes to the emergence of androgen-independent prostate tumors. The ability of AR to cross-talk with key growth factor signaling events toward the regulation of cell cycle, apoptosis, and differentiation outcomes in prostate cancer cells is established. In this paper, we review the functional interaction between AR and an array of growth factor signal transduction events (including epidermal growth factor; fibroblast growth factor; IGF1; vascular endothelial growth factor; transforming growth factor-beta) in prostate tumors. The significance of this derailed cross-talk between androgens and key signaling networks in prostate cancer progression and its value as a therapeutic forum targeting androgen-independent metastatic prostate cancer is discussed.
270 citations
TL;DR: The unique role played by fibroblast growth factors might be organization of various angiogenic pathways and coordination of cell–cell interactions in this process of neovascularization.
Abstract: Purpose of review
Fibroblast growth factors (FGFs) are potent angiogenic inducers; however, their precise roles in angiogenesis have not been well understood. In this review, we will focus on specific roles played by FGFs in neovascularization.
255 citations
241 citations
TL;DR: The data preliminarily suggest treatment with an epithelial growth factor receptor inhibitor may improve survival after bone metastasis, as well as single and multiple variables indicated better prognoses for patients with adenocarcinoma, no evidence of appendicular bone metastases, and treatment withAn epithelialgrowth factor receptor inhibitors.
Abstract: The prognosis of patients with bone metastasis from lung cancer has not been well documented. We assessed the survival rates after bone metastasis and prognostic factors in 118 patients with bone metastases from lung cancer. The cumulative survival rates after bone metastasis from lung cancer were 59.9% at 6 months, 31.6% at 1 year, and 11.3% at 2 years. The mean survival was 9.7 months (median, 7.2 months; range, 0.1-74.5 months). A favorable prognosis was more likely in women and patients with adenocarcinoma, solitary bone metastasis, no metastases to the appendicular bone, no pathologic fractures, performance status 1 or less, use of systemic chemotherapy, and use of an epithelial growth factor receptor inhibitor. Analyses of single and multiple variables indicated better prognoses for patients with adenocarcinoma, no evidence of appendicular bone metastases, and treatment with an epithelial growth factor receptor inhibitor. The mean survival period was longer in a small group treated with an epithelial growth factor receptor inhibitor than in the larger untreated group. The data preliminarily suggest treatment with an epithelial growth factor receptor inhibitor may improve survival after bone metastasis.
222 citations
TL;DR: This work focuses on ectodomain shedding of the EGF family ligands, especially HB‐EGF by disintegrin and metalloproteases, which are not only key events of receptor cross talk, but also novel intercellular signaling by their carboxy‐terminal fragments to regulate gene expression directly.
Abstract: The epidermal growth factor (EGF) family and the EGF receptor (EGFR, ErbB) tyrosine kinase family have been spearheading the studies of signal transduction events that determine cell fate and behavior in vitro and in vivo. The EGFR family and their signaling pathways are giving us tremendous advantages in developing fascinating molecular target strategies for cancer therapy. Currently, two important types of EGFR inhibitors are in clinical use: neutralizing antibodies of EGFR or ErbB2, and synthetic small compounds of tyrosine kinase inhibitors designed for receptors. On the other hand, basic research of the EGF family ligands presents new challenges as membrane-anchored growth factors. All members of the EGF family have important roles in development and diseases and are shed from the plasma membrane by metalloproteases. The ectodomain shedding of the ligands has emerged as a critical component in the functional transactivation of EGFRs in interreceptor cross-talk in response to various shedding stimulants such as G-protein coupled receptor agonists, growth factors, cytokines, and various physicochemical stresses. Among the EGFR-ligands, heparin-binding EGF-like growth factor (HB-EGF) is a prominent ligand in our understanding of the pathophysiological roles of ectodomain shedding in cancer, wound healing, cardiac diseases, etc. Here we focus on ectodomain shedding of the EGF family ligands, especially HB-EGF by disintegrin and metalloproteases, which are not only key events of receptor cross talk, but also novel intercellular signaling by their carboxy-terminal fragments to regulate gene expression directly.
TL;DR: Removal of ZIP7 offers a means through which zinc-induced activation of growth factor receptors may be effectively suppressed and provides a mechanism of targeting multiple growth factor pathways, increasing tumor kill, and preventing further development of resistance in breast cancer.
Abstract: Antiestrogens such as tamoxifen are the mainstay of treatment for estrogen receptor-positive breast cancer. However, their effectiveness is limited by the development of endocrine resistance, allowing tumor regrowth and progression. Importantly, in vitro MCF7 cell models of acquired tamoxifen resistance (TamR cells) display an aggressive, invasive phenotype in which activation of epithelial growth factor receptor/IGF-I receptor/Src signaling plays a critical role. In this study, we report that TamR cells have increased levels of zinc and zinc transporter, ZIP7 [solute carrier family 39 (zinc transporter) member 7, also known as SLC39A7], resulting in an enhanced response to exogenous zinc, which is manifested as a greatly increased growth factor receptor activation, leading to increased growth and invasion. Removal of ZIP7, using small interfering RNA, destroys this activation of epithelial growth factor receptor/IGF-I receptor/Src signaling by reducing intracellular zinc levels. Similarly, it also blocks the activation of HER2, -3, and -4. These data suggest that intracellular zinc levels may be a critical factor in determining growth factor responses and that the targeting of zinc transporters may have novel therapeutic implications. We show that ZIP7 is a critical component in the redistribution of zinc from intracellular stores to the cytoplasm and, as such, is essential for the zinc-induced inhibition of phosphatases, which leads to activation of growth factor receptors. Removal of ZIP7 therefore offers a means through which zinc-induced activation of growth factor receptors may be effectively suppressed and provides a mechanism of targeting multiple growth factor pathways, increasing tumor kill, and preventing further development of resistance in breast cancer.
TL;DR: Resistance to inhibition of MEK, mTOR, and EGFR is associated with enhanced IGF-IR-directed Akt signaling, where all affect feedback loops converging at the level of IRS-1.
Abstract: Epidermal growth factor receptor (EGFR) and insulin-like growth factor-I receptor (IGF-IR) can cooperate to regulate tumor growth and survival, and synergistic growth inhibition has been reported for combined blockade of EGFR and IGF-IR. However, in preclinical models, only a subset of tumors exhibit high sensitivity to this combination, highlighting the potential need for patient selection to optimize clinical efficacy. Herein, we have characterized the molecular basis for cooperative growth inhibition upon dual EGFR and IGF-IR blockade and provide biomarkers that seem to differentiate response. We find for epithelial, but not for mesenchymal-like, tumor cells that Akt is controlled cooperatively by EGFR and IGF-IR. This correlates with synergistic apoptosis and growth inhibition in vitro and growth regression in vivo upon combined blockade of both receptors. We identified two molecular aspects contributing to synergy: (a) inhibition of EGFR or IGF-IR individually promotes activation of the reciprocal receptor; (b) inhibition of EGFR-directed mitogen-activated protein kinase (MAPK) shifts regulation of Akt from EGFR toward IGF-IR. Targeting the MAPK pathway through downstream MAPK/extracellular signal-regulated kinase kinase (MEK) antagonism similarly promoted IGF-driven pAkt and synergism with IGF-IR inhibition. Mechanistically, we find that inhibition of the MAPK pathway circumvents a negative feedback loop imposed on the IGF-IR- insulin receptor substrate 1 (IRS-1) signaling complex, a molecular scenario that parallels the negative feedback loop between mTOR-p70S6K and IRS-1 that mediates rapamycin-directed IGF-IR signaling. Collectively, these data show that resistance to inhibition of MEK, mTOR, and EGFR is associated with enhanced IGF-IR-directed Akt signaling, where all affect feedback loops converging at the level of IRS-1.
TL;DR: HCC patients with increased SULF2 expression in resected HCC tissues had a worse prognosis and a higher rate of recurrence after surgery, mainly through up‐regulation of FGF signaling and GPC3 expression.
TL;DR: G-CSF may promote tumor angiogenesis through a Bv8-dependent pathway that bypasses VEGF and renders tumors refractory to anti-VEGF therapy.
Abstract: CD11b+Gr1+ cells, which include neutrophils, macrophages, and myeloid-derived suppressor cells, have been shown to contribute to tumor angiogenesis. Recently, we found that accumulation of CD11b+Gr1+ in tumors renders them refractory to angiogenic blockade by vascular endothelial growth factor (VEGF) antibodies. This effect was traced to a pathway of CD11b+Gr1+-mediated angiogenesis that is, at least in part, driven by the secreted protein Bv8, which is up-regulated by the important myeloid growth factor granulocyte colony-stimulating factor (G-CSF). Thus, G-CSF may promote tumor angiogenesis through a Bv8-dependent pathway that bypasses VEGF and renders tumors refractory to anti-VEGF therapy.
TL;DR: The results indicate that maintenance of human brain tumor stem cells absolutely requires epidermal growth factor and that tyrosine kinase inhibitors of epiderm growth factor signaling potentially inhibit proliferation and induce apoptosis of these cells.
TL;DR: The data suggest that TF is regulated by both oncogenic and differentiation pathways, and that it functions in tumor initiation, tumor growth, angiogenesis, and metastasis, and could serve as a therapeutic target in EGFR-dependent malignancies.
Abstract: ErbB oncogenes drive the progression of several human cancers. Our study shows that in human carcinoma (A431) and glioma (U373) cells, the oncogenic forms of epidermal growth factor receptor (EGFR; including EGFRvIII) trigger the up-regulation of tissue factor (TF), the transmembrane protein responsible for initiating blood coagulation and signaling through interaction with coagulation factor VIIa. We show that A431 cancer cells in culture exhibit a uniform TF expression profile; however, these same cells in vivo exhibit a heterogeneous TF expression and show signs of E-cadherin inactivation, which is coupled with multilineage (epithelial and mesenchymal) differentiation. Blockade of E-cadherin in vitro , leads to the acquisition of spindle morphology and de novo expression of vimentin, features consistent with epithelial-to-mesenchymal transition. These changes were associated with an increase in EGFR-dependent TF expression, and with enhanced stimulation of vascular endothelial growth factor production, particularly following cancer cell treatment with coagulation factor VIIa. In vivo , cells undergoing epithelial-to-mesenchymal transition exhibited an increased metastatic potential. Furthermore, injections of the TF-blocking antibody (CNTO 859) delayed the initiation of A431 tumors in immunodeficient mice, and reduced tumor growth, vascularization, and vascular endothelial growth factor expression. Collectively, our data suggest that TF is regulated by both oncogenic and differentiation pathways, and that it functions in tumor initiation, tumor growth, angiogenesis, and metastasis. Thus, TF could serve as a therapeutic target in EGFR-dependent malignancies. [Cancer Res 2008;68(24):10068–76]
TL;DR: The role of the IGF-IR pathway is described in mediating resistance to both general cytotoxic therapies and targeted therapies, and it is argued that inhibition of IGF signaling, in conjunction with standard therapies, may enhance the response of cancer cells to multiple modalities.
Abstract: The insulin-like growth factor (IGF) ligands stimulate cellular proliferation and survival by activating the type I insulin-like growth factor receptor (IGF-IR). As a result, the IGF signaling system is implicated in a number of cancers, including those of the breast, prostate, and lung. In addition to mitogenic and anti-apoptotic roles that may directly influence tumor development, IGF-IR also appears to be a critical determinant of response to numerous cancer therapies. This review describes the role of the IGF-IR pathway in mediating resistance to both general cytotoxic therapies, such as radiation and chemotherapy, and targeted therapies, such as tamoxifen and trastuzumab. It concludes with a description of approaches to target IGF-IR and argues that inhibition of IGF signaling, in conjunction with standard therapies, may enhance the response of cancer cells to multiple modalities.
TL;DR: Key issues include identification of factors that influence sensitivity to IGF 1R blockade, and how most effectively to combine IGF1R inhibitors with other treatments.
Abstract: Background: The type 1 insulin-like growth factor receptor (IGF1R) plays a critical role in transformation, invasion and apoptosis protection, and is an attractive cancer treatment target. Objective: To review IGF1R antibodies and kinase inhibitors that are in preclinical and clinical development, and to discuss questions that will influence the success of this approach in clinical practice. Methods: This review is drawn from published literature, meeting abstracts and online resources. Results/conclusion: IGF1R blockade is generally well tolerated although it can induce hyperglycaemia. Single-agent activity has been documented in Ewing's sarcoma but not thus far in common solid tumours. Key issues include identification of factors that influence sensitivity to IGF1R blockade, and how most effectively to combine IGF1R inhibitors with other treatments.
TL;DR: FGFR-mediated signals in cooperation with those transmitted by epidermal growth factor receptor are involved in growth and survival of human NSCLC cells and should be considered as targets for combined therapeutic approaches.
Abstract: Fibroblast growth factors (FGF) and their high-affinity receptors (FGFR) represent an extensive cellular growth and survival system. Aim of this study was to evaluate the contribution of FGF/FGFR-mediated signals to the malignant growth of non-small cell lung cancer (NSCLC) and to assess their potential as targets for therapeutic interventions. Multiple FGFR mRNA splice variants were coexpressed in NSCLC cells (n = 16) with predominance of FGFR1. Accordingly, both expression of a dominant-negative FGFR1 (dnFGFR1) IIIc-green fluorescent protein fusion protein and application of FGFR small-molecule inhibitors (SU5402 and PD166866) significantly reduced growth, survival, clonogenicity, and migratory potential of the majority of NSCLC cell lines. Moreover, dnFGFR1 expression completely blocked or at least significantly attenuated s.c. tumor formation of NSCLC cells in severe combined immunodeficient mice. Xenograft tumors expressing dnFGFR1 exhibited significantly reduced size and mitosis rate, enhanced cell death, and decreased tissue invasion. When FGFR inhibitors were combined with chemotherapy, antagonistic to synergistic in vitro anticancer activities were obtained depending on the application schedule. In contrast, simultaneous blockage of FGFR- and epidermal growth factor receptor-mediated signals exerted synergistic effects. In summary, FGFR-mediated signals in cooperation with those transmitted by epidermal growth factor receptor are involved in growth and survival of human NSCLC cells and should be considered as targets for combined therapeutic approaches.
TL;DR: The current status of the various growth factor receptor-based treatment strategies is summarized and in view of the multitude of novel targeted approaches, the rationale for combination therapies for advanced HCC treatment will also be taken into account.
Abstract: Growth factors and their corresponding receptors are commonly overexpressed and/or dysregulated in many cancers including hepatocellular cancer (HCC). Clinical trials indicate that growth factor receptors and their related signalling pathways play important roles in HCC cancer etiology and progression, thus providing rational targets for innovative cancer therapies. A number of strategies including monoclonal antibodies, tyrosine kinase inhibitors (“small molecule inhibitors”) and antisense oligonucleotides have already been evaluated for their potency to inhibit the activity and downstream signalling cascades of these receptors in HCC. First clinical trials have also shown that multi-kinase inhibition is an effective novel treatment strategy in HCC. In this respect sorafenib, an inhibitor of Raf-, VEGF- and PDGF-signalling, is the first multi-kinase inhibitor that has been approved by the FDA for the treatment of advanced HCC. Moreover, the serine-threonine kinase of mammalian target of rapamycin (mTOR) upon which the signalling of several growth factor receptors converge plays a central role in cancer cell proliferation. mTOR inhibition of HCC is currently also being studied in preclinical trials. As HCCs represent hypervascularized neoplasms, inhibition of tumour vessel formation via interfering with the VEGF/VEGFR system is another promising approach in HCC treatment. This review will summarize the current status of the various growth factor receptor-based treatment strategies and in view of the multitude of novel targeted approaches, the rationale for combination therapies for advanced HCC treatment will also be taken into account.
TL;DR: Sarcomas are good candidates for the design of a clinical study targeting insulin-like growth factor-I receptor, and an attention to schedule with chemotherapy agents and new drugs, measurement of relevant indicators of response and better molecular understanding of the metabolic functions of insulin- like growth factors receptor and its functional relationship with insulin receptor are necessary to proceed safely with theDesign of anti-insulin-likegrowth factor strategies.
Abstract: PURPOSE OF REVIEW The present review examines the rationale for targeting insulin-like growth factor-I receptor in sarcoma therapy and highlights some key issues that need to be addressed as clinical trials targeting insulin-like growth factor-I receptor proceed. RECENT FINDINGS Preclinical evidence supports proof of principle for targeting insulin-like growth factor-I receptor signaling in sarcomas. The insulin-like growth factor system is activated by or associated with most of the fusion oncoproteins that genetically characterize a group of sarcomas, but alterations in this pathway appear as a common feature. Correlation of cancer risk with insulin-like growth factor-I receptor signaling expression and polymorphisms has also been described. Blockade of insulin-like growth factor-I receptor functions results in an inhibition of tumor growth and metastasis, both when the targeted drugs were used as single agents and in combined therapies. Antibodies against insulin-like growth factor-I receptor and small kinase inhibitors represent, at this point, the most probable clinical options. SUMMARY Sarcomas are good candidates for the design of a clinical study targeting insulin-like growth factor-I receptor. An attention to schedule with chemotherapy agents and new drugs, measurement of relevant indicators of response and better molecular understanding of the metabolic functions of insulin-like growth factor-I receptor and its functional relationship with insulin receptor are necessary to proceed safely with the design of anti-insulin-like growth factor strategies.
TL;DR: It is established that EGFR can be activated with functional consequences by HGF as a result of EGFR ligand expression, expanding the understanding of receptor tyrosine kinase signaling networks and may have considerable consequences for oncogenic mechanisms and cancer therapeutics.
Abstract: The mechanisms and biological implications of coordinated receptor tyrosine kinase coactivation remain poorly appreciated. Epidermal growth factor receptor (EGFR) and c-Met are frequently coexpressed in cancers, including those associated with hepatocyte growth factor (HGF) overexpression, such as malignant astrocytoma. In a previous analysis of the HGF-induced transcriptome, we found that two EGFR agonists, transforming growth factor-alpha and heparin-binding epidermal growth factor-like growth factor (HB-EGF), are prominently up-regulated by HGF in human glioma cells. We now report that stimulating human glioblastoma cells with recombinant HGF induces biologically relevant EGFR activation. EGFR phosphorylation at Tyr(845) and Tyr(1068) increased 6 to 24 h after cell stimulation with HGF and temporally coincided with the induction of transforming growth factor-alpha (~5-fold) and HB-EGF (~23-fold) expression. Tyr(845) and Tyr(1068) phosphorylation, in response to HGF, was inhibited by cycloheximide and actinomycin D, consistent with a requirement for DNA transcription and RNA translation. Specifically, blocking HB-EGF binding to EGFR with the antagonist CRM197 inhibited HGF-induced EGFR phosphorylation by 60% to 80% and inhibited HGF-induced S-G(2)-M transition. CRM197 also inhibited HGF-induced anchorage-dependent cell proliferation but had no effect on HGF-mediated cytoprotection. These findings establish that EGFR can be activated with functional consequences by HGF as a result of EGFR ligand expression. This transcription-dependent cross-talk between the HGF receptor c-Met and EGFR expands our understanding of receptor tyrosine kinase signaling networks and may have considerable consequences for oncogenic mechanisms and cancer therapeutics.
TL;DR: It is reported that MUC1* acts as a growth factor receptor on undifferentiated human embryonic stem cells (hESCs) and this primal growth mechanism could be utilized to propagate large numbers of pluripotent stem cells for therapeutic interventions.
Abstract: The MUC1 protein is aberrantly expressed on an estimated 75% of all human solid tumor cancers. We recently reported that a transmembrane cleavage product, MUC1*, is the predominant form of the protein on cancer cells [1]. Further, our evidence indicated that MUC1* functions as a growth factor receptor on tumor cells, while the full-length protein appeared to have no growth promoting activity. Here, we report that MUC1* acts as a growth factor receptor on undifferentiated human embryonic stem cells (hESCs). Cleavage of the full-length ectodomain to form MUC1*, a membrane receptor, appears to make binding to its ligand, NM23, possible. Unexpectedly, we found that newly differentiated cells no longer express the cleaved form, MUC1*, or its ligand, NM23. Newly differentiated stem cells exclusively present full-length MUC1. Antibody-induced dimerization of the MUC1* receptor on hESCs stimulated cell growth to a far greater degree than currently used methods that require the addition of exogenous basic fibroblast growth factor (bFGF) as well as factors secreted by fibroblast “feeder cells”. Further, MUC1* mediated growth was shown to be independent of growth stimulated by bFGF or the milieu of factors secreted by feeder cells. Stimulating the MUC1* receptor with either the cognate antibody or its ligand NM23 enabled hESC growth in a feeder cell-free system and produced pluripotent colonies that resisted spontaneous differentiation. These findings suggest that this primal growth mechanism could be utilized to propagate large numbers of pluripotent stem cells for therapeutic interventions.
TL;DR: A novel molecular mechanism by which ADP-ribosylation factor 1 regulates breast cancer cell growth and invasion during cancer progression is uncovered.
TL;DR: Evidence is provided that S 100A11 plays a dual role in growth regulation of epithelial cells and production and secretion of S100A11 are markedly enhanced in human squamous cancer cells.
Abstract: We previously revealed a novel signal pathway involving S100A11 for inhibition of the growth of normal human keratinocytes (NHK) caused by high Ca++ or transforming growth factor β. Exposure to eit...
TL;DR: In this article, the authors have shown that increased tumor vascularity is associated with poor overall survival (P=0.047) and is independent of the international prognostic index, while high expression of vascular endothelial growth factor receptor-1 by lymphoma cells was associated with improved overall survival.
TL;DR: The type I insulin-like growth factor receptor (IGF-IR) plays multiple roles in several cancers and increased circulating levels of IGF-I are associated with increased risk of breast, colon, and prostate cancers as mentioned in this paper.
Abstract: The type I insulin-like growth factor receptor (IGF-IR) plays multiple roles in several cancers and increased circulating levels of insulin-like growth factor-I (IGF-I) are associated with increased risk of breast, colon, and prostate cancers. Because IGF-II and insulin signal via the insulin receptor (IR) to stimulate the growth of cancer cells, inhibition of IR might be necessary to totally disrupt the action of IGFs and their receptors. This review describes the well-recognized roles of IGF-IR in driving the malignant phenotype, examines the evidence that perhaps IR should also be targeted to inhibit the effects of the IGF ligands and insulin in cancer, describes the strategies to disrupt IGF signaling in cancer, and highlights some key issues that need to be considered as clinical trials targeting IGF-IR proceed.