Targeting the NF-κB signaling pathway in Notch1-induced T-cell leukemia (original) (raw)
TLX1 and NOTCH coregulate transcription in T cell acute lymphoblastic leukemia cells
Molecular Cancer, 2010
Background: The homeobox gene TLX1 (for T-cell leukemia homeobox 1, previously known as HOX11) is inappropriately expressed in a major subgroup of T cell acute lymphoblastic leukemia (T-ALL) where it is strongly associated with activating NOTCH1 mutations. Despite the recognition that these genetic lesions cooperate in leukemogenesis, there have been no mechanistic studies addressing how TLX1 and NOTCH1 functionally interact to promote the leukemic phenotype.
Leukemia, 2014
Notch signaling deregulation is linked to the onset of several tumors including T-cell acute lymphoblastic leukemia (T-ALL). Deregulated microRNA (miRNA) expression is also associated with several cancers, including leukemias. However, the transcriptional regulators of miRNAs, as well as the relationships between Notch signaling and miRNA deregulation, are poorly understood. To identify miRNAs regulated by Notch pathway, we performed microarray-based miRNA profiling of several Notch-expressing T-ALL models. Among seven miRNAs, consistently regulated by overexpressing or silencing Notch3, we focused our attention on miR-223, whose putative promoter analysis revealed a conserved RBPjk binding site, which was nested to an NF-kB consensus. Luciferase and chromatin immunoprecipitation assays on the promoter region of miR-223 show that both Notch and NF-kB are novel coregulatory signals of miR-223 expression, being able to activate cooperatively the transcriptional activity of miR-223 promoter. Notably, the Notch-mediated activation of miR-223 represses the tumor suppressor FBXW7 in T-ALL cell lines. Moreover, we observed the inverse correlation of miR-223 and FBXW7 expression in a panel of T-ALL patient-derived xenografts. Finally, we show that miR-223 inhibition prevents T-ALL resistance to g-secretase inhibitor (GSI) treatment, suggesting that miR-223 could be involved in GSI sensitivity and its inhibition may be exploited in target therapy protocols.
Cancers, 2010
Two main NF-B signaling pathways, canonical and noncanonical, performing distinct functions in organisms have been characterized. Identification of mutations in genes encoding components of these NF-B signaling pathways in lymphoid malignancies confirmed their key role in leukemogenesis. T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive malignancy of thymocytes that despite significant therapeutic advances can still be fatal. Although mutations in NF-B genes have not been reported in T-ALL, NF-B constitutive activation in human T-ALL and in acute T-cell leukemia mouse models has been observed. Although these studies revealed activation of members of both canonical and noncanonical NF-B pathways in acute T-cell leukemia, only inhibition of canonical NF-B signaling was shown to impair leukemic T cell growth. Besides playing an important pro-oncogenic role in leukemic T cells, NF-B signaling also appears to modulate T-cell leukemogenesis through its action in microenvironmental stromal cells. This article reviews recent data on the role of these transcription factors in T-ALL and pinpoints further research crucial to determine the value of NF-B inhibition as a means to treat T-ALL.
Leukemia & Lymphoma, 2013
Chronic lymphocytic leukemia (CLL) is a clinically and biologically heterogeneous disease where the majority of patients have an indolent disease course, while others may experience a far more aggressive disease, treatment failure and poor overall survival. During the last two decades, there has been an intense search to fi nd novel biomarkers that can predict prognosis as well as guide treatment decisions. Two of the most reliable molecular prognostic markers, both of which are off ered in routine diagnostics, are the immunoglobulin heavy chain variable ( IGHV ) gene mutational status and fl uorescence in situ hybridization (FISH) detection of prognostically relevant genomic aberrations (e.g. 11q ؊ , 13q ؊ , ؉ 12 and 17p ؊ ). In addition to these markers, a myriad of additional biomarkers have been postulated as potential prognosticators in CLL, on the protein (e.g. CD38, ZAP70, TCL1), the RNA (e.g. LPL , CLLU1 , micro-RNAs) and the genomic (e.g. TP53 , NOTCH1 , SF3B1 and BIRC3 mutations) level. Eff orts are now being made to test these novel markers in larger patient cohorts as well as in prospective trials, with the ultimate goal to combine the " best " markers in a " CLL prognostic index " applicable for the individual patient. Although it is clear that these studies have signifi cantly improved our knowledge regarding both prognostication and the biology of the disease, there is still an immediate need for recognizing biomarkers that can predict therapy response, and eff orts should now focus on addressing this pertinent issue. In the present article, we review the extensive literature in the fi eld of prognostic markers in CLL, focus on the most clinically relevant markers and discuss future directions regarding biomarkers in CLL.
A role for PKR in hematologic malignancies
Journal of Cellular Physiology, 2010
The double-stranded RNA-dependent kinase PKR has been described for many years as strictly a pro-apoptotic kinase. Recent data suggest that the main purpose of this kinase is damage control and repair following stress and, if all else fails, apoptosis. Aberrant activation of PKR has been reported in numerous neurodegenerative diseases and cancer. Although a subset of myelodysplastic syndromes (MDS) and chronic lymphocytic leukemia contain low levels of PKR expression and activity, elevated PKR activity and/or expression have been detected in a wide range of hematologic malignancies, from bone marrow failure disorders to acute leukemia. With the recent findings that cancers containing elevated PKR activity are highly sensitive to PKR inhibition, we explore the role of PKR in hematologic malignancies, signal transduction pathways affected by PKR, and how PKR may contribute to leukemic transformation.
Regulation of lymphocyte progenitor survival by the proapoptotic activities of Bim and Bid
Proceedings of the National Academy of Sciences, 2008
On their entry into the thymus, developing lymphocyte progenitors depend on signaling from the pre-T cell receptor (pre-TCR), which orchestrates differentiation, cell proliferation, and survival. The exact mechanism of pre-TCR-mediated suppression of T cell death remains unclear and controversial. Here, we identify Bim and Bid, 2 members of the BH3-only group of the BCL2 family, as important regulators of pre-T cell death. Both factors are highly expressed in proapoptotic thymocytes and their expression is suppressed on signaling through the pre-TCR. Their expression is directly regulated by the transcription factors FoxO3a and p53. Bid expression and p53 activity are related to the ongoing rearrangement of the TCR loci and induced DNA damage responses. Bim expression and FoxO3a nuclear translocation are directly controlled by the pre-TCR by means of its downstream kinase Akt/PKB. Interestingly, deletion of either gene on a pre-TCR ؊/؊ background rescues survival, but fails to induce further progenitor differentiation uncoupling the 2 processes.
Glia, 2008
Radial glia are neural stem cells that exist only transiently during CNS development where they serve as scaffolds for neuronal migration. Their instability makes them difficult to study and therefore we have isolated stabilized radial glial clones from E14.5 cortical progenitors (e.g. L2.3) after expression of v-myc. Activated Notch1 intracellular region (actNotch1) promotes radial glia in the embryonic mouse forebrain and when it was introduced into E14.5 cortical progenitors or radial glial clone L2.3, the cells exhibited enhanced radial morphology and increased expression of the radial glial marker BLBP. A representative clone of L2.3 cells expressing actNotch1 called NL2.3-4 migrated more extensively than L2.3 cells in culture and in white matter of adult rat spinal cord. Microarray and RT-PCR comparisons of mRNAs expressed in these closely related clones showed extensive similarities but differed significantly for certain mRNAs including several cell adhesion molecules. Cell adhesion assays demonstrated significantly enhanced adhesion to laminin of NL2.3-4 by comparison to L2.3 cells. The laminin binding protein nidogen was the most highly induced adhesion molecule in NL2.3-4, and immunological analyses indicated that radial glia synthesize and secrete nidogen. Adhesion of NL2.3-4 cells to laminin was inhibited by anti-nidogen antibodies and required the nidogen binding region in laminin, indicating that nidogen promotes cell adhesion to laminin. The combined results indicate that persistent expression of activated Notch1 maintains the phenotype of radial glial cells, inhibits their differentiation, and promotes their adhesion and migration on a laminin/nidogen complex.
The implications of cancer stem cells for cancer therapy
International journal of molecular sciences, 2012
Surgery, radiotherapy and chemotherapy are universally recognized as the most effective anti-cancer therapies. Despite significant advances directed towards elucidating molecular mechanisms and developing clinical trials, cancer still remains a major public health issue. Recent studies have showed that cancer stem cells (CSCs), a small subpopulation of tumor cells, can generate bulk populations of nontumorigenic cancer cell progeny through the self-renewal and differentiation processes. As CSCs are proposed to persist in tumors as a distinct population and cause relapse and metastasis by giving rise to new tumors, development of CSC-targeted therapeutic strategies holds new hope for improving survival and quality of life in patients with cancer. Therapeutic innovations will emerge from a better understanding of the biology and environment of CSCs, which, however, are largely unexplored. This review summarizes the characteristics, evidences and development of CSCs, as well as implica...
Differential requirements for Wnt and Notch signaling in hematopoietic versus thymic niches
Annals of the New York Academy of Sciences, 2012
are Wnt and Notch signaling. These signals also play important but controversial roles in the HSC niche. Here, we review the differences and similarities between the thymic and hematopoietic niches, with particular focus on Wnt and Notch signals, as well as the latest insights into regulation of these developmentally important pathways.
Nature Communications, 2016
Activation of NOTCH signalling is associated with advanced prostate cancer and treatment resistance in prostate cancer patients. However, the mechanism that drives NOTCH activation in prostate cancer remains still elusive. Moreover, preclinical evidence of the therapeutic efficacy of NOTCH inhibitors in prostate cancer is lacking. Here, we provide evidence that PTEN loss in prostate tumours upregulates the expression of ADAM17, thereby activating NOTCH signalling. Using prostate conditional inactivation of both Pten and Notch1 along with preclinical trials carried out in Pten-null prostate conditional mouse models, we demonstrate that Pten-deficient prostate tumours are addicted to the NOTCH signalling. Importantly, we find that pharmacological inhibition of g-secretase promotes growth arrest in both Pten-null and Pten/Trp53-null prostate tumours by triggering cellular senescence. Altogether, our findings describe a novel pro-tumorigenic network that links PTEN loss to ADAM17 and NOTCH signalling, thus providing the rational for the use of g-secretase inhibitors in advanced prostate cancer patients.
Chemotactic Cues for NOTCH1-Dependent Leukemia
Frontiers in immunology, 2018
The NOTCH signaling pathway is a conserved signaling cascade that regulates many aspects of development and homeostasis in multiple organ systems. Aberrant activity of this signaling pathway is linked to the initiation and progression of several hematological malignancies, exemplified by T-cell acute lymphoblastic leukemia (T-ALL). Interestingly, frequent non-mutational activation of NOTCH1 signaling has recently been demonstrated in B-cell chronic lymphocytic leukemia (B-CLL), significantly extending the pathogenic significance of this pathway in B-CLL. Leukemia patients often present with high-blood cell counts, diffuse disease with infiltration of the bone marrow, secondary lymphoid organs, and diffusion to the central nervous system (CNS). Chemokines are chemotactic cytokines that regulate migration of cells between tissues and the positioning and interactions of cells within tissue. Homeostatic chemokines and their receptors have been implicated in regulating organ-specific inf...
Aberrant Signaling Pathways in T-Cell Acute Lymphoblastic Leukemia
International Journal of Molecular Sciences
T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive disease caused by the malignant transformation of immature progenitors primed towards T-cell development. Clinically, TALL patients present with diffuse infiltration of the bone marrow by immature T-cell blasts high blood cell counts, mediastinal involvement, and diffusion to the central nervous system. In the past decade, the genomic landscape of TALL has been the target of intense research. The identification of specific genomic alterations has contributed to identify strong oncogenic drivers and signaling pathways regulating leukemia growth. Notwithstanding, TALL patients are still treated with high-dose multiagent chemotherapy, potentially exposing these patients to considerable acute and long-term side effects. This review summarizes recent advances in our understanding of the signaling pathways relevant for the pathogenesis of TALL and the opportunities offered for targeted therapy.
Notch Signaling in Skeletal Development, Homeostasis and Pathogenesis
Biomolecules
Skeletal development is a complex process which requires the tight regulation of gene activation and suppression in response to local signaling pathways. Among these pathways, Notch signaling is implicated in governing cell fate determination, proliferation, differentiation and apoptosis of skeletal cells-osteoblasts, osteoclasts, osteocytes and chondrocytes. Moreover, human genetic mutations in Notch components emphasize the critical roles of Notch signaling in skeletal development and homeostasis. In this review, we focus on the physiological roles of Notch signaling in skeletogenesis, postnatal bone and cartilage homeostasis and fracture repair. We also discuss the pathological gain- and loss-of-function of Notch signaling in bone and cartilage, resulting in osteosarcoma and age-related degenerative diseases, such as osteoporosis and osteoarthritis. Understanding the physiological and pathological function of Notch signaling in skeletal tissues using animal models and human genet...
Leukemia, 2009
We explored the impact of mutations in the NOTCH1, FBW7 and PTEN genes on prognosis and downstream signaling in a well-defined cohort of 47 pediatric T-cell acute lymphoblastic leukemia (T-ALL) patients. In TALL lymphoblasts, we identified high frequency mutations in NOTCH1 (n=16), FBW7 (n=5) and PTEN (n=26). NOTCH1 mutations resulted in 1.3-3.3-fold increased transactivation of a HES1 reporter construct over wild-type NOTCH1; mutant FBW7 resulted in further augmentation of reporter gene activity. NOTCH1 and FBW7 mutations were accompanied by increased median transcripts for NOTCH1 target genes (HES1, DELTEX1, cMYC). However, none of these mutations were associated with treatment outcome. Elevated HES1, DELTEX1 and cMYC transcripts were associated with significant increases in transcript levels of several chemotherapy relevant genes, including MDR1, ABCC5, reduced folate carrier, asparagine synthetase, thiopurine methyltranserase, Bcl-2 and dihydrofolate reductase. PTEN transcripts positively correlated with HES1 and cMYC transcript levels. Our results suggest that (1) multiple factors should be considered with attempting to identify molecular-based prognostic factors for pediatric TALL , and (2) depending on the NOTCH1 signaling status, modifications in the types or dosing of standard chemotherapy drugs for TALL , or combinations of agents capable of targeting NOTCH1, AKT and/or mTOR with standard chemotherapy agents may be warranted.
AKT and 14-3-3 Regulate Notch4 Nuclear Localization
Scientific Reports, 2015
Members of the Notch family of transmembrane receptors, Notch1-4 in mammals, are involved in the regulation of cell fate decisions and cell proliferation in various organisms. The Notch4 isoform, which is specific to mammals, was originally identified as a viral oncogene in mice, Int3, able to initiate mammary tumors. In humans, Notch4 expression appears to be associated with breast cancer stem cells and endocrine resistance. Following ligand binding, the Notch4 receptor undergoes cleavage at the membrane and the Notch4-intracellular domain (ICD), translocates to the nucleus and regulates gene transcription. Little is known on the mechanisms regulating Notch4-ICD and its nuclear localization. Here, we describe the identification of four distinct AKT phosphorylation sites in human Notch4-ICD and demonstrate that AKT binds Notch4-ICD and phosphorylates all four sites in vitro and in vivo. The phosphorylation in cells is regulated by growth factors and is sensitive to phosphatidyl inositol-3 kinase (PI3K) inhibitors. This phosphorylation generates binding sites to the 14-3-3 regulatory proteins, which are involved in the regulation of nucleocytoplasmic shuttling of target proteins, restricting phosphorylated Notch4-ICD to the cytoplasm. Our findings provide a novel mechanism for Notch4-ICD regulation, suggesting a negative regulatory role for the PI3K-AKT pathway in Notch4 nuclear signaling. T he evolutionarily conserved Notch family of transmembrane receptors are involved in the regulation of cell fate decisions and cell proliferation via their activity as transcriptional regulators 1. Canonical Notch signaling is mediated by the transcription factor CSL (CBF-1, Suppressor of Hairless, Lag-1), also known as RBP-Jk. Mammals express four Notch genes, Notch1-4, with distinct functions and regulation, though there is some functional redundancy 2,3. Notch4, which is specific to mammals, was initially identified as a truncated oncogenic form in mice, Int3, able of initiating mammary tumors 4,5. The oncogenic activity of Notch4-ICD in transgenic mice has been shown to be independent of CSL, and thus presumably requires a yet to be identified non-canonical signaling pathway 6. In humans, Notch4 overexpression is associated with breast cancer stem cells and with endocrine resistance in estrogen-receptor a (ERa)-positive breast cancer 7,8. In normal development, Notch4 expression appears to be restricted to endothelial cells 9-11 , where it regulates vascularization during development, as well as endothelial cell function and response to inflammation 11-14. It has also a role in tumor angiogenesis and blood vessel perfusion 15,16. Activation of Notch receptors is initiated by the binding of transmembrane ligands on adjoining cells, such as Delta and Serrate/Jagged families to the Notch receptor, leading to its sequential cleavage and the release of the intracellular domain, designated Notch-ICD 17. This fragment translocates to the nucleus and participates in the formation of specific transcriptional complexes 1,18,19. Much of what is known about Notch signaling derives from studies of Notch1 and Notch2, the most conserved paralogs. Non-canonical, non-nuclear signaling has been described for Notch1 in T-cells. Specifically, Notch1 has been reported to signal through AKT via mTORC2 and to NF-kB via the IKK signalosome and nuclear IKKa 20-23. Notch-ICD is a relatively short-lived protein and undergoes rapid degradation through an ubiquitin-mediated pathway. The pathways that regulate the stability of Notch-ICDs other than Notch1 as well as the protein complexes they form are still poorly defined. Specifically, the regulation of Notch4-ICD by phosphorylation or other post-translational modifications or by interaction with adapter proteins, which are key regulators of many other transcription modulators, is largely unknown 24. A recent
Notch and NF-κB: Coach and Players of Regulatory T-Cell Response in Cancer
Frontiers in Immunology
The Notch signaling pathway plays multiple roles in driving T-cell fate decisions, proliferation, and aberrant growth. NF-κB is a cell-context key player interconnected with Notch signaling either in physiological or in pathological conditions. This review focuses on how the multilayered crosstalk between different Notches and NF-κB subunits may converge on Foxp3 gene regulation and orchestrate CD4 + regulatory T (Treg) cell function, particularly in a tumor microenvironment. Notably, Treg cells may play a pivotal role in the inhibition of antitumor immune responses, possibly promoting tumor growth. A future challenge is represented by further dissection of both Notch and NF-κB pathways and consequences of their intersection in tumor-associated Treg biology. This may shed light on the molecular mechanisms regulating Treg cell expansion and migration to peripheral lymphoid organs thought to facilitate tumor development and still to be explored. In so doing, new opportunities for combined and/or more selective therapeutic approaches to improve anticancer immunity may be found.
Drugs, 2013
Over the past 50 years, numerous advances in treatment have produced dramatic increases in the cure rates of pediatric leukemias. Despite this progress, the majority of children with relapsed leukemia are not expected to survive. With current chemotherapy regimens, approximately 15 % of children with acute lymphoblastic leukemia and 45 % of children with acute myeloid leukemia will have refractory disease or experience a relapse. Advances in the treatment of pediatric relapsed leukemia have not mirrored the successes of upfront therapy, and newer treatments are desperately needed in order to improve survival in these challenging patients. Recent improvements in our knowledge of cancer biology have revealed an extensive number of targets that have the potential to be exploited for anticancer therapy. These advances have led to the development of a number of new treatments that are now being explored in children with relapsed or refractory leukemia. Novel agents seek to exploit the same molecular aberrations that contribute to leukemia development and resistance to therapy. Newer classes of drugs, including monoclonal antibodies, tyrosine kinase inhibitors and epigenetic modifiers are transforming the treatment of patients who are not cured with conventional therapies. As the side effects of many new agents are distinct from those seen with conventional chemotherapy, these treatments are often explored in combination with each other or combined with conventional treatment regimens. This review discusses the biological rationale for the most promising new agents and the results of recent studies conducted in pediatric patients with relapsed leukemia.
Notch1 upregulates LPS-induced macrophage activation by increasing NF-κB activity
European Journal of Immunology, 2009
Macrophages present different Notch receptors and ligands on their surface. Following macrophage activation by LPS or other TLR ligands, Notch1 expression is upregulated. We report here that Notch signaling increases both basal and LPS-induced NF-jB activation, favoring the expression of genes implicated in the inflammatory response, such as the cytokines TNF-a and IL-6, or enzymes, such as iNOS. Delta4 seems to be the most effective ligand to induce Notch activation and increasing NF-jB transcriptional activity in macrophages. We show that Notch1 signaling promotes NF-jB translocation to the nucleus and DNA binding by increasing both phosphorylation of the IjB kinase a/b complex and the expression of some NF-jB family members. Treatment of macrophages with the c-secretase inhibitor DAPT, which prevents the cleavage and activation of Notch receptors, inhibits all these processes, diminishing NF-jB activity following LPS stimulation. Additionally, we show that the active intracellular Notch fragment can directly interact with TNF-a and iNOS promoters. Our results suggest that Notch signaling results in an amplification of the macrophage-dependent inflammatory response by enhancing NF-jB signaling.
RelB-Dependent Stromal Cells Promote T-Cell Leukemogenesis
PLoS ONE, 2008
Background: The Rel/NF-kB transcription factors are often activated in solid or hematological malignancies. In most cases, NF-kB activation is found in malignant cells and results from activation of the canonical NF-kB pathway, leading to RelA and/or c-Rel activation. Recently, NF-kB activity in inflammatory cells infiltrating solid tumors has been shown to contribute to solid tumor initiation and progression. Noncanonical NF-kB activation, which leads to RelB activation, has also been reported in breast carcinoma, prostate cancer, and lymphoid leukemia. Methodology/Principal Findings: Here we report a novel role for RelB in stromal cells that promote T-cell leukemogenesis. RelB deficiency delayed leukemia onset in the TEL-JAK2 transgenic mouse model of human T acute lymphoblastic leukemia. Bone marrow chimeric mouse experiments showed that RelB is not required in the hematopoietic compartment. In contrast, RelB plays a role in radio-resistant stromal cells to accelerate leukemia onset and increase disease severity. Conclusions/Significance: The present results are the first to uncover a role for RelB in the crosstalk between nonhematopoietic stromal cells and leukemic cells. Thus, besides its previously reported role intrinsic to specific cancer cells, the noncanonical NF-kB pathway may also play a pro-oncogenic role in cancer microenvironmental cells.
Vital roles of mTOR complex 2 in Notch-driven thymocyte differentiation and leukemia
Journal of Experimental Medicine, 2012
Notch plays critical roles in both cell fate decisions and tumorigenesis. Notch receptor engagement initiates signaling cascades that include a phosphatidylinositol 3-kinase/target of rapamycin (TOR) pathway. Mammalian TOR (mTOR) participates in two distinct biochemical complexes, mTORC1 and mTORC2, and the relationship between mTORC2 and physiological outcomes dependent on Notch signaling is unknown. In this study, we report contributions of mTORC2 to thymic T-cell acute lymphoblastic leukemia (T-ALL) driven by Notch. Conditional deletion of Rictor, an essential component of mTORC2, impaired Notch-driven proliferation and differentiation of pre-T cells. Furthermore, NF-κB activity depended on the integrity of mTORC2 in thymocytes. Active Akt restored NF-κB activation, a normal rate of proliferation, and differentiation of Rictor-deficient pre-T cells. Strikingly, mTORC2 depletion lowered CCR7 expression in thymocytes and leukemic cells, accompanied by decreased tissue invasion and ...
Review on the molecular signaling pathways involved in controlling cancer stem cells and treatment
The Journal of Qazvin University of Medical Sciences
In recent years, knowledge of the biology of stem cell has been very effective and the precise and proper regulation of stem cell function are important for their bio-activity. Several main signaling pathways have roles in regulating them including Wnt/β-catenin, and Hedgehog which mediate different stem cell properties including self-renewal, survival, proliferation, and differentiation. Also, molecular structures such as microRNAs act as tumor inhibitors or oncogenes and will change the direction of the messenger. The purpose of this review is to find and introduce different signaling pathways involved in controlling cancer stem cells with cancer treatment goals. The search was conducted using several databases including Google Scholar, PubMed, Scopus, Science Direct and totally 93 papers were selected. It seems that very important signaling pathways have been disturbed in cancers and excessive or abnormal signaling through these pathways can contribute to the survival of stem cells. Many of these pathways are not direct, but as an interconnected network of signaling could feed each other. Better therapeutic goals can be achieved with understanding signaling pathways involved in cancer stem cells and drug resistance.
Role of Notch Receptors in Hematologic Malignancies
Cells
Notch receptors are single-pass transmembrane proteins that play a critical role in cell fate decisions and have been implicated in the regulation of many developmental processes. The human Notch family comprises of four receptors (Notch 1 to 4) and five ligands. Their signaling can regulate extremely basic cellular processes such as differentiation, proliferation and death. Notch is also involved in hematopoiesis and angiogenesis, and increasing evidence suggests that these genes are involved and frequently deregulated in several human malignancies, contributing to cell autonomous activities that may be either oncogenic or tumor suppressive. It was recently proposed that Notch signaling could play an active role in promoting and sustaining a broad spectrum of lymphoid malignancies as well as mutations in Notch family members that are present in several disorders of T- and B-cells, which could be responsible for altering the related signaling. Therefore, different Notch pathway mole...
NK-like homeodomain proteins activate NOTCH3-signaling in leukemic T-cells
BMC Cancer, 2009
Background: Homeodomain proteins control fundamental cellular processes in development and in cancer if deregulated. Three members of the NK-like subfamily of homeobox genes (NKLs), TLX1, TLX3 and NKX2-5, are implicated in T-cell acute lymphoblastic leukemia (T-ALL). They are activated by particular chromosomal aberrations. However, their precise function in leukemogenesis is still unclear. Here we screened further NKLs in 24 TALL cell lines and identified the common expression of MSX2. The subsequent aim of this study was to analyze the role of MSX2 in T-cell differentiation which may be disturbed by oncogenic NKLs. Methods: Specific gene activity was examined by quantitative real-time PCR, and globally by expression profiling. Proteins were analyzed by western blot, immuno-cytology and immunoprecipitation. For overexpression studies cell lines were transduced by lentiviruses. Results: Quantification of MSX2 mRNA in primary hematopoietic cells demonstrated higher levels in CD34+ stem cells as compared to peripheral blood cells and mature CD3+ T-cells. Furthermore, analysis of MSX2 expression levels in T-cell lines after treatment with core thymic factors confirmed their involvement in regulation. These results indicated that MSX2 represents an hematopoietic NKL family member which is downregulated during T-cell development and may functionally substituted by oncogenic NKLs. For functional analysis JURKAT cells were lentivirally transduced, overexpressing either MSX2 or oncogenic TLX1 and NKX2-5, respectively. These cells displayed transcriptional activation of NOTCH3-signaling, including NOTCH3 and HEY1 as analyzed by gene expression profiling and quantitative RT-PCR, and consistently attenuated sensitivity to gamma-secretase inhibitor as analyzed by MTT-assays. Furthermore, in addition to MSX2, both TLX1 and NKX2-5 proteins interacted with NOTCH-pathway repressors, SPEN/
Frontiers in Pharmacology, 2019
Notch and its ligands on adjacent cells are key mediators of cellular communication during developmental choice in embryonic and adult tissues. This communication is frequently altered in the pathological interaction between cancer cells and healthy cells of the microenvironment due to the aberrant expression of tumor derived Notch receptors or ligands, that results in homotypic or heterotypic Notch signaling activation in tumor cells or surrounding stromal cells. A deadly consequence of this pathological communication is pharmacological resistance that results in patient's relapse. We will provide a survey of the role of Notch signaling in the bone marrow (BM), a microenvironment with a very high capacity to support several types of cancer, including primary cancers such as osteosarcoma or multiple myeloma and bone metastases from carcinomas. Moreover, in the BM niche several hematological malignancies maintain a reservoir of cancer stem cells, characterized by higher intrinsic drug resistance. Cell-cell communication in BM-tumor interaction triggers signaling pathways by direct contact and paracrine communication through soluble growth factors or extracellular vesicles, which can deliver specific molecules such as mRNAs, miRNAs, proteins, metabolites, etc. enabling tumor cells to reprogram the healthy cells of the microenvironment inducing them to support tumor growth. In this review we will explore how the dysregulated Notch activity contributes to tumor-mediated reprogramming of the BM niche and drug resistance, strengthening the rationale of a Notch-directed therapy to re-establish apoptosis competence in cancer.
Biomedicines, 2020
Increasing lines of evidence suggest that chronic inflammation mediates most chronic diseases, including cancer. The transcription factor, NF-κB, has been shown to be a major regulator of inflammation and metastasis in tumor cells. Therefore, compounds or any natural agents that can inhibit NF-κB activation have the potential to prevent and treat cancer. However, the mechanism by which Calebin A, a component of turmeric, regulates inflammation and disrupts the interaction between HCT116 colorectal cancer (CRC) cells and multicellular tumor microenvironment (TME) is still poorly understood. The 3D-alginate HCT116 cell cultures in TME were treated with Calebin A, BMS-345541, and dithiothreitol (DTT) and examined for invasiveness, proliferation, and apoptosis. The mechanism of TME-induced malignancy of cancer cells was confirmed by phase contrast, Western blotting, immunofluorescence, and DNA-binding assay. We found through DNA binding assay, that Calebin A inhibited TME-induced NF-κB ...
Drug Resistance in Non-Small Cell Lung Cancer: A Potential for NOTCH Targeting?
Frontiers in Oncology, 2018
Drug resistance is a major cause for therapeutic failure in non-small cell lung cancer (NSCLC) leading to tumor recurrence and disease progression. Cell intrinsic mechanisms of resistance include changes in the expression of drug transporters, activation of pro-survival, and anti-apoptotic pathways, as well as non-intrinsic influences of the tumor microenvironment. It has become evident that tumors are composed of a heterogeneous population of cells with different genetic, epigenetic, and phenotypic characteristics that result in diverse responses to therapy, and underlies the emergence of resistant clones. This tumor heterogeneity is driven by subpopulations of tumor cells termed cancer stem cells (CSCs) that have tumor-initiating capabilities, are highly self-renewing, and retain the ability for multi-lineage differentiation. CSCs have been identified in NSCLC and have been associated with chemo-and radiotherapy resistance. Stem cell pathways are frequently deregulated in cancer and are implicated in recurrence after treatment. Here, we focus on the NOTCH signaling pathway, which has a role in stem cell maintenance in non-squamous non-small lung cancer, and we critically assess the potential for targeting the NOTCH pathway to overcome resistance to chemotherapeutic and targeted agents using both preclinical and clinical evidence.
Metalloprotease-Disintegrin ADAM12 Expression Is Regulated by Notch Signaling via MicroRNA-29
Journal of Biological Chemistry, 2011
Metalloprotease-disintegrin ADAM12 is overexpressed and frequently mutated in breast cancer. We report here that ADAM12 expression in cultured mammalian cells is up-regulated by Notch signals. Expression of a constitutively active form of Notch1 in murine fibroblasts, myoblasts, or mammary epithelial cells or activation of the endogenous Notch signaling by co-culture with ligand-expressing cells increases ADAM12 protein and mRNA levels. Up-regulation of ADAM12 expression by Notch requires new transcription, is activated in a CSL-dependent manner, and is abolished upon inhibition of IB kinase. Expression of a constitutively active Notch1 in NIH3T3 cells increases the stability of Adam12 mRNA. We further show that the microRNA-29 family, which has a predicted conserved site in the 3-untranslated region of mouse Adam12, plays a critical role in mediating the stimulatory effect of Notch on ADAM12 expression. In human cells, Notch up-regulates the expression of the long form, but not the short form, of ADAM12 containing a divergent 3-untranslated mRNA region. These studies uncover a novel paradigm in Notch signaling and establish Adam12 as a Notch-related gene.
Clinical Cancer Research, 2009
Purpose: Constitutive nuclear factor-κB (NF-κB) activation has been implicated in the pathogenesis of chronic lymphocytic leukemia (CLL). Our purpose was to characterize the molecular mechanisms underlying for the selective IκB kinase inhibitor BMS-345541 in CLL cells together with the analysis of its combination with several antineoplasic drugs. Experimental Design: Primary cells from 34 CLL patients were incubated with different doses of BMS-345541. NF-κB DNA-binding activity was analyzed by ELISA-based kits and the characterization of the apoptotic pathway was done by flow cytometry, immunoblotting, quantitative reverse transcription-PCR, and immunofluorescence techniques. Results: BMS-345541 selectively induced apoptosis in CLL cells in the low micromolar range irrespective of p53 status. Noteworthy, the high ZAP-70 group was significantly more sensitive to BMS-345541 than the low ZAP-70 group, in correlation with high levels of p65 phosphorylation and DNA-binding activity. Foll...
Arteriosclerosis, thrombosis, and vascular biology, 2018
Endothelial upregulation of adhesion molecules serves to recruit leukocytes to inflammatory sites and appears to be promoted by NOTCH1; however, current models based on interactions between active NOTCH1 and NF-κB components cannot explain the transcriptional selectivity exerted by NOTCH1 in this context. Observing that Cre/Lox-induced conditional mutations of endothelial Notch modulated inflammation in murine contact hypersensitivity, we found that IL (interleukin)-1β stimulation induced rapid recruitment of RELA (v-rel avian reticuloendotheliosis viral oncogene homolog A) to genomic sites occupied by NOTCH1-RBPJ (recombination signal-binding protein for immunoglobulin kappa J region) and that NOTCH1 knockdown reduced histone H3K27 acetylation at a subset of NF-κB-directed inflammatory enhancers. Our findings reveal that NOTCH1 signaling supports the expression of a subset of inflammatory genes at the enhancer level and demonstrate how key signaling pathways converge on chromatin t...
Off the beaten pathway: the complex cross talk between Notch and NF-κB
Laboratory Investigation, 2007
The canonical Notch pathway that has been well characterized over the past 25 years is relatively simple compared to the plethora of recently published data suggesting non-canonical signaling mechanisms and cross talk with other pathways. The manner in which other pathways cross talk with Notch signaling appears to be extraordinarily complex and, not surprisingly, context-dependent. While the physiological relevance of many of these interactions remains to be established, there is little doubt that Notch signaling is integrated with numerous other pathways in ways that appear increasingly complex. Among the most intricate cross talks described for Notch is its interaction with the NF-kB pathway, another major cell fate regulatory network involved in development, immunity, and cancer. Numerous reports over the last 11 years have described multiple cross talk mechanisms between Notch and NF-kB in diverse experimental models. This article will provide a brief overview of the published evidence for Notch-NF-kB cross talk, focusing on vertebrate systems.
Medical oncology (Northwood, London, England), 2016
Breast cancer has a high incidence in the world and is becoming a leading cause of death in female patients due to its high metastatic ability. High expression of Notch-1 and its ligand Jagged-1 correlates with poor prognosis in breast cancer. Our previous work has shown that Notch-1 signaling pathway upregulates NF-κB transcriptional activity and induces the adhesion, migration and invasion of human breast cancer cell line MDA-MB-231. However, the role of Notch-1 in NF-κB activation is still poorly understood. Here, we aim to understand the exact mechanism that Notch-1 regulates NF-κB activity. In MDA-MB-231 cells where Notch-1 is constitutively activated, the phosphorylation of p85 and AKT (Tyr308/Ser473) is upregulated, indicating PI3K/AKT pathway is activated. Notch-1 activation caused the increase of PP2A phosphorylation at Tyr307, indicating Notch-1 inhibits PP2A activity. NF-κB transcriptional activity was evaluated by dual-luciferase reporter assay, and the results showed th...
FEBS Letters, 2019
Low Temperature Plasma (LTP) generates reactive oxygen and nitrogen species, causing cell death, similarly to radiation. Radiation resistance results in tumour recurrence, however mechanisms of LTP resistance are unknown. LTP was applied to patient-derived prostate epithelial cells and gene expression assessed. A typical global oxidative response (AP-1 and Nrf2 signalling) was induced, whereas Notch signalling was activated exclusively in progenitor cells. Notch inhibition induced expression of prostatic acid phosphatase (PAP), a marker of prostate epithelial cell differentiation, whilst reducing colony forming ability and preventing tumour formation. Therefore, if LTP is to be progressed as a novel treatment for prostate cancer, combination treatments should be considered in the context of cellular heterogeneity and existence of cell type-specific resistance mechanisms.
The opposing roles of NOTCH signalling in head and neck cancer: a mini review
Oral Diseases, 2015
NOTCH signalling can exert oncogenic or tumour suppressive effects in both solid and haematological malignancies. Similar to T-cell acute lymphoblastic leukaemia (T-ALL), early studies suggested a pro-tumorigenic role of NOTCH in head and neck squamous cell carcinoma (HNSCC), mainly based on the increased expression levels of the genes within the pathway. Recently, data from exome sequencing analyses unexpectedly pointed to a tumour suppressor role for NOTCH in HNSCC by identifying loss-of-function mutations in the NOTCH1 gene in a significant proportion of patients. These data have questioned the accepted role of NOTCH in HNSCC and the possible rationale of targeting NOTCH in this disease. This review summarises the current information on NOTCH signalling in HNSCC and discusses how this pathway can apparently exert opposing effects within the same disease.
Genes
Acute lymphoblastic leukemia (ALL) is the most common childhood cancer. Although its prognosis continually improves with time, a significant proportion of patients still relapse from the disease because of the leukemia’s resistance to therapy. Methotrexate (MTX), a folic-acid antagonist, is a chemotherapy agent commonly used against ALL and as an immune-system suppressant for rheumatoid arthritis that presents multiple and complex mechanisms of action and resistance. Previous studies have shown that MTX modulates the nuclear factor kappa B (NF-κB) pathway, an important family of transcription factors involved in inflammation, immunity, cell survival, and proliferation which are frequently hyperactivated in ALL. Using a gene set enrichment analysis of publicly available gene expression data from 161 newly diagnosed pediatric ALL patients, we found the Tumor necrosis factor α (TNF-α) signaling pathway via NF-κB to be the most enriched Cancer Hallmark in MTX-poor-responder patients. A ...
Serum deprivation initiates adaptation and survival to oxidative stress in prostate cancer cells
Scientific Reports, 2020
Inadequate nutrient intake leads to oxidative stress disrupting homeostasis, activating signaling, and altering metabolism. Oxidative stress serves as a hallmark in developing prostate lesions, and an aggressive cancer phenotype activating mechanisms allowing cancer cells to adapt and survive. It is unclear how adaptation and survival are facilitated; however, literature across several organisms demonstrates that a reversible cellular growth arrest and the transcription factor, nuclear factor-kappaB (NF-κB), contribute to cancer cell survival and therapeutic resistance under oxidative stress. We examined adaptability and survival to oxidative stress following nutrient deprivation in three prostate cancer models displaying varying degrees of tumorigenicity. We observed that reducing serum (starved) induced reactive oxygen species which provided an early oxidative stress environment and allowed cells to confer adaptability to increased oxidative stress (H2O2). Measurement of cell viab...
LDB1 Enforces Stability on Direct and Indirect Oncoprotein Partners in Leukemia
Molecular and Cellular Biology, 2020
The LMO2/LDB1 macromolecular complex is critical in hematopoietic stem and progenitor cell specification and in the development of acute leukemia. This complex is comprised of core subunits of LMO2 and LDB1 as well as s ingle- s tranded DNA- b inding p rotein (SSBP) cofactors and DNA-binding b asic h elix- l oop- h elix (bHLH) and GATA transcription factors. We analyzed the steady-state abundance and kinetic stability of LMO2 and its partners via Halo protein tagging in conjunction with variant proteins deficient in binding their respective direct protein partners.
2019
SummaryMultisubunit protein complexes operate in many cellular functions. The LDB1/LMO2 macromolecular complex has been posited to be critical in hematopoietic stem and progenitor cell specification and in the development of acute leukemia. This complex is comprised of core subunits of LMO2 and LDB1 as well as bHLH and GATA transcription factors. We analyzed the steady state abundance and kinetic stability of LMO2 and its partners via HALO protein tagging in conjunction with variant proteins deficient in binding their respective direct protein partners. We discovered a hierarchy of protein stability, with half lives in descending order: LDB1>SSBP>LMO2>TAL1. Importantly, LDB1 conferred enhanced stability upon each and every subunit component and nucleated the formation of the multisubunit protein complex. Our studies provide significant insights into LDB1/LMO2 macromolecular protein complex assembly and stability, which has implications for understanding its role in blood ce...