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Showing papers on "Cancer cell published in 2011"


Journal ArticleDOI
14 Jul 2011-Nature
TL;DR: The mechanistic link between CCL2 expression and macrophage infiltration are correlated with poor prognosis and metastatic disease in human breast cancer and the origin of these macrophages is defined by showing that Gr1-positive inflammatory monocytes are preferentially recruited to pulmonary metastases but not to primary mammary tumours in mice.
Abstract: Macrophages, which are abundant in the tumour microenvironment, enhance malignancy. At metastatic sites, a distinct population of metastasis-associated macrophages promotes the extravasation, seeding and persistent growth of tumour cells. Here we define the origin of these macrophages by showing that Gr1-positive inflammatory monocytes are preferentially recruited to pulmonary metastases but not to primary mammary tumours in mice. This process also occurs for human inflammatory monocytes in pulmonary metastases of human breast cancer cells. The recruitment of these inflammatory monocytes, which express CCR2 (the receptor for chemokine CCL2), as well as the subsequent recruitment of metastasis-associated macrophages and their interaction with metastasizing tumour cells, is dependent on CCL2 synthesized by both the tumour and the stroma. Inhibition of CCL2-CCR2 signalling blocks the recruitment of inflammatory monocytes, inhibits metastasis in vivo and prolongs the survival of tumour-bearing mice. Depletion of tumour-cell-derived CCL2 also inhibits metastatic seeding. Inflammatory monocytes promote the extravasation of tumour cells in a process that requires monocyte-derived vascular endothelial growth factor. CCL2 expression and macrophage infiltration are correlated with poor prognosis and metastatic disease in human breast cancer. Our data provide the mechanistic link between these two clinical associations and indicate new therapeutic targets for treating metastatic breast cancer.

2,245 citations


Journal ArticleDOI
23 Nov 2011-Cell
TL;DR: The cell-matrix and cell-cell adhesion, protease, and cytokine systems that underlie tissue invasion by cancer cells are described and explained to explain how the reciprocal reprogramming of both the tumor cells and the surrounding tissue structures not only guides invasion, but also generates diverse modes of dissemination.

1,693 citations


Journal ArticleDOI
TL;DR: It is shown that primary human omental adipocytes promote homing, migration and invasion of ovarian cancer cells, and that adipokines including interleukin-8 (IL-8) mediate these activities, and adipocytes provide fatty acids for rapid tumor growth.
Abstract: Intra-abdominal tumors, such as ovarian cancer, have a clear predilection for metastasis to the omentum, an organ primarily composed of adipocytes. Currently, it is unclear why tumor cells preferentially home to and proliferate in the omentum, yet omental metastases typically represent the largest tumor in the abdominal cavities of women with ovarian cancer. We show here that primary human omental adipocytes promote homing, migration and invasion of ovarian cancer cells, and that adipokines including interleukin-8 (IL-8) mediate these activities. Adipocyte-ovarian cancer cell coculture led to the direct transfer of lipids from adipocytes to ovarian cancer cells and promoted in vitro and in vivo tumor growth. Furthermore, coculture induced lipolysis in adipocytes and β-oxidation in cancer cells, suggesting adipocytes act as an energy source for the cancer cells. A protein array identified upregulation of fatty acid-binding protein 4 (FABP4, also known as aP2) in omental metastases as compared to primary ovarian tumors, and FABP4 expression was detected in ovarian cancer cells at the adipocyte-tumor cell interface. FABP4 deficiency substantially impaired metastatic tumor growth in mice, indicating that FABP4 has a key role in ovarian cancer metastasis. These data indicate adipocytes provide fatty acids for rapid tumor growth, identifying lipid metabolism and transport as new targets for the treatment of cancers where adipocytes are a major component of the microenvironment.

1,665 citations


Journal ArticleDOI
TL;DR: The central role of pH sensors in cancer cell adaptations is highlighted and how dysregulated pH could be exploited to develop cancer-specific therapeutics is suggested.
Abstract: Although cancer is a diverse set of diseases, cancer cells share a number of adaptive hallmarks. Dysregulated pH is emerging as a hallmark of cancer because cancers show a 'reversed' pH gradient with a constitutively increased intracellular pH that is higher than the extracellular pH. This gradient enables cancer progression by promoting proliferation, the evasion of apoptosis, metabolic adaptation, migration and invasion. Several new advances, including an increased understanding of pH sensors, have provided insight into the molecular basis for pH-dependent cell behaviours that are relevant to cancer cell biology. We highlight the central role of pH sensors in cancer cell adaptations and suggest how dysregulated pH could be exploited to develop cancer-specific therapeutics.

1,630 citations


Journal ArticleDOI
19 Aug 2011-Cell
TL;DR: It is shown that subpopulations of cells purified for a given phenotypic state return towards equilibrium proportions over time, and this findings contribute to the understanding of cancer heterogeneity and reveal how stochasticity in single-cell behaviors promotes phenotypesic equilibrium in populations of cancer cells.

1,391 citations


Journal ArticleDOI
TL;DR: It is shown that platelet-tumor cell interactions are sufficient to prime tumor cells for subsequent metastasis and inhibit NF-κB signaling in cancer cells, resulting in their transition to an invasive mesenchymal-like phenotype and enhanced metastasis in vivo.

1,367 citations


Journal ArticleDOI
15 Mar 2011-Cancers
TL;DR: Understanding of the biochemical mechanisms triggered by cisplatin in tumor cells may lead to the design of more efficient platinum derivates (or other drugs) and might provide new therapeutic strategies and reduce side effects.
Abstract: Platinum complexes are clinically used as adjuvant therapy of cancers aiming to induce tumor cell death. Depending on cell type and concentration, cisplatin induces cytotoxicity, e.g., by interference with transcription and/or DNA replication mechanisms. Additionally, cisplatin damages tumors via induction of apoptosis, mediated by the activation of various signal transduction pathways, including calcium signaling, death receptor signaling, and the activation of mitochondrial pathways. Unfortunately, neither cytotoxicity nor apoptosis are exclusively induced in cancer cells, thus, cisplatin might also lead to diverse side-effects such as neuro- and/or renal-toxicity or bone marrow-suppression. Moreover, the binding of cisplatin to proteins and enzymes may modulate its biochemical mechanism of action. While a combination-chemotherapy with cisplatin is a cornerstone for the treatment of multiple cancers, the challenge is that cancer cells could become cisplatin-resistant. Numerous mechanisms of cisplatin resistance were described including changes in cellular uptake, drug efflux, increased detoxification, inhibition of apoptosis and increased DNA repair. To minimize cisplatin resistance, combinatorial therapies were developed and have proven more effective to defeat cancers. Thus, understanding of the biochemical mechanisms triggered by cisplatin in tumor cells may lead to the design of more efficient platinum derivates (or other drugs) and might provide new therapeutic strategies and reduce side effects.

1,333 citations


Journal ArticleDOI
TL;DR: Contributions of platelets to tumour cell survival and spread suggest platelets as a new avenue for therapy.
Abstract: Experimental evidence suggests that platelets contribute to metastasis through adhesive and haemostatic functions that promote cancer cell survival, immune evasion and interactions with vascular cells to assist organ colonization from the bloodstream. Extensive experimental evidence shows that platelets support tumour metastasis. The activation of platelets and the coagulation system have a crucial role in the progression of cancer. Within the circulatory system, platelets guard tumour cells from immune elimination and promote their arrest at the endothelium, supporting the establishment of secondary lesions. These contributions of platelets to tumour cell survival and spread suggest platelets as a new avenue for therapy.

1,309 citations


Journal ArticleDOI
18 Aug 2011-Nature
TL;DR: Results reveal that certain breast cancers are dependent upon increased serine pathway flux caused by PHGDH overexpression and demonstrate the utility of in vivo negative-selection RNAi screens for finding potential anticancer targets.
Abstract: Cancer cells adapt their metabolic processes to drive macromolecular biosynthesis for rapid cell growth and proliferation. RNA interference (RNAi)-based loss-of-function screening has proven powerful for the identification of new and interesting cancer targets, and recent studies have used this technology in vivo to identify novel tumour suppressor genes. Here we developed a method for identifying novel cancer targets via negative-selection RNAi screening using a human breast cancer xenograft model at an orthotopic site in the mouse. Using this method, we screened a set of metabolic genes associated with aggressive breast cancer and stemness to identify those required for in vivo tumorigenesis. Among the genes identified, phosphoglycerate dehydrogenase (PHGDH) is in a genomic region of recurrent copy number gain in breast cancer and PHGDH protein levels are elevated in 70% of oestrogen receptor (ER)-negative breast cancers. PHGDH catalyses the first step in the serine biosynthesis pathway, and breast cancer cells with high PHGDH expression have increased serine synthesis flux. Suppression of PHGDH in cell lines with elevated PHGDH expression, but not in those without, causes a strong decrease in cell proliferation and a reduction in serine synthesis. We find that PHGDH suppression does not affect intracellular serine levels, but causes a drop in the levels of α-ketoglutarate, another output of the pathway and a tricarboxylic acid (TCA) cycle intermediate. In cells with high PHGDH expression, the serine synthesis pathway contributes approximately 50% of the total anaplerotic flux of glutamine into the TCA cycle. These results reveal that certain breast cancers are dependent upon increased serine pathway flux caused by PHGDH overexpression and demonstrate the utility of in vivo negative-selection RNAi screens for finding potential anticancer targets.

1,248 citations


Journal ArticleDOI
TL;DR: The Keap1–Nrf2 regulatory pathway plays a central role in the protection of cells against oxidative and xenobiotic damage and discovery and development of selective Nrf2 inhibitors should make a critical contribution to improved cancer therapy.
Abstract: The Keap1–Nrf2 regulatory pathway plays a central role in the protection of cells against oxidative and xenobiotic damage. Under unstressed conditions, Nrf2 is constantly ubiquitinated by the Cul3–Keap1 ubiquitin E3 ligase complex and rapidly degraded in proteasomes. Upon exposure to electrophilic and oxidative stresses, reactive cysteine residues of Keap1 become modified, leading to a decline in the E3 ligase activity, stabilization of Nrf2 and robust induction of a battery of cytoprotective genes. Biochemical and structural analyses have revealed that the intact Keap1 homodimer forms a cherry-bob structure in which one molecule of Nrf2 associates with two molecules of Keap1 by using two binding sites within the Neh2 domain of Nrf2. This two-site binding appears critical for Nrf2 ubiquitination. In many human cancers, missense mutations in KEAP1 and NRF2 genes have been identified. These mutations disrupt the Keap1–Nrf2 complex activity involved in ubiquitination and degradation of Nrf2 and result in constitutive activation of Nrf2. Elevated expression of Nrf2 target genes confers advantages in terms of stress resistance and cell proliferation in normal and cancer cells. Discovery and development of selective Nrf2 inhibitors should make a critical contribution to improved cancer therapy.

1,232 citations


Journal ArticleDOI
TL;DR: Research into how changes in cell metabolism promote tumour growth has accelerated in recent years, and efforts to target metabolic dependencies of cancer cells as a selective anticancer strategy have refocused.
Abstract: Genetic events in cancer activate signalling pathways that alter cell metabolism. Clinical evidence has linked cell metabolism with cancer outcomes. Together, these observations have raised interest in targeting metabolic enzymes for cancer therapy, but they have also raised concerns that these therapies would have unacceptable effects on normal cells. However, some of the first cancer therapies that were developed target the specific metabolic needs of cancer cells and remain effective agents in the clinic today. Research into how changes in cell metabolism promote tumour growth has accelerated in recent years. This has refocused efforts to target metabolic dependencies of cancer cells as a selective anticancer strategy.

Journal ArticleDOI
TL;DR: Green tea catechin has great potential in cancer prevention because of its safety, low cost and bioavailability, and its mechanism of action at numerous points regulating cancer cell growth, survival, angiogenesis and metastasis.

Journal ArticleDOI
27 May 2011-Cell
TL;DR: In this article, the pyruvate kinase isoforms PKM1 and PKM2 are alternatively spliced products of the PKM 2 gene, and they are activated by hypoxia-inducible factor 1 (HIF-1).

Journal ArticleDOI
TL;DR: It is demonstrated that normal and CSC-like cells can arise de novo from more differentiated cell types and that hierarchical models of mammary stem cell biology should encompass bidirectional interconversions between stem and nonstem compartments.
Abstract: Current models of stem cell biology assume that normal and neoplastic stem cells reside at the apices of hierarchies and differentiate into nonstem progeny in a unidirectional manner. Here we identify a subpopulation of basal-like human mammary epithelial cells that departs from that assumption, spontaneously dedifferentiating into stem-like cells. Moreover, oncogenic transformation enhances the spontaneous conversion, so that nonstem cancer cells give rise to cancer stem cell (CSC)-like cells in vitro and in vivo. We further show that the differentiation state of normal cells-of-origin is a strong determinant of posttransformation behavior. These findings demonstrate that normal and CSC-like cells can arise de novo from more differentiated cell types and that hierarchical models of mammary stem cell biology should encompass bidirectional interconversions between stem and nonstem compartments. The observed plasticity may allow derivation of patient-specific adult stem cells without genetic manipulation and holds important implications for therapeutic strategies to eradicate cancer.

Journal ArticleDOI
TL;DR: The role of autophagy and its regulation in cancer cells continues to emerge, and studies aim to define optimal strategies to modulate Autophagy for therapeutic advantage.
Abstract: Autophagy is a homeostatic, catabolic degradation process whereby cellular proteins and organelles are engulfed into autophagosomes, digested in lysosomes and recycled to sustain cellular metabolism. Autophagy has dual roles in cancer, acting as both a tumor suppressor by preventing the accumulation of damaged proteins and organelles and as a mechanism of cell survival that can promote the growth of established tumors. Tumor cells activate autophagy in response to cellular stress including hypoxia and increased metabolic demands related to rapid cell proliferation. Autophagy-related stress tolerance can enable cell survival by maintaining energy production that can lead to tumor growth and therapeutic resistance, as shown in preclinical models where the inhibition of autophagy can restore chemosensitivity and enhance tumor cell death. These results established autophagy as a therapeutic target and have led to multiple early phase clinical trials in humans evaluating autophagy inhibition using hydroxychloroquine in combination with chemotherapy or targeted agents. Targeting autophagy in cancer provides new opportunities for drug development since more potent and specific inhibitors of autophagy are needed. The role of autophagy and its regulation in cancer cells continues to emerge and studies aim to define optimal strategies to modulate autophagy for therapeutic advantage.

01 Nov 2011
TL;DR: In this article, platelet-tumor cell interactions are sufficient to prime tumor cells for subsequent metastasis, resulting in an invasive mesenchymal-like phenotype and enhanced metastasis in vivo.
Abstract: SUMMARY Interactions of cancer cells with the primary tumor microenvironment are important determinants of cancer progression toward metastasis but it is unknown whether additional prometastatic signals are provided during the intravascular transit to the site of metastasis. Here, we show that platelet-tumor cell interactions are sufficient to prime tumor cells for subsequent metastasis. Platelet-derived TGFb and direct platelettumor cell contacts synergistically activate the TGFb/Smad and NF-kB pathways in cancer cells, resulting in their transition to an invasive mesenchymal-like phenotype and enhanced metastasis in vivo. Inhibition of NF-kB signaling in cancer cells or ablation of TGFb1 expression solely in platelets protects against lung metastasis in vivo. Thus, cancer cells rely on platelet-derived signals outside of the primary tumor for efficient metastasis.


Journal ArticleDOI
02 Dec 2011-Science
TL;DR: In this paper, the authors showed that acute increases in intracellular concentrations of reactive oxygen species (ROS) caused inhibition of the glycolytic enzyme pyruvate kinase M2 (PKM2) through oxidation of Cys358.
Abstract: Control of intracellular reactive oxygen species (ROS) concentrations is critical for cancer cell survival. We show that, in human lung cancer cells, acute increases in intracellular concentrations of ROS caused inhibition of the glycolytic enzyme pyruvate kinase M2 (PKM2) through oxidation of Cys358. This inhibition of PKM2 is required to divert glucose flux into the pentose phosphate pathway and thereby generate sufficient reducing potential for detoxification of ROS. Lung cancer cells in which endogenous PKM2 was replaced with the Cys358 to Ser358 oxidation-resistant mutant exhibited increased sensitivity to oxidative stress and impaired tumor formation in a xenograft model. Besides promoting metabolic changes required for proliferation, the regulatory properties of PKM2 may confer an additional advantage to cancer cells by allowing them to withstand oxidative stress.

Journal ArticleDOI
TL;DR: The toxicity of zinc oxide to bacteria was related to the generation of reactive oxygen species and to the induction of apoptosis, and these effects were differentially greater in human myeloblastic leukemia cells (HL60) than normal peripheral blood mononuclear cells.

Journal ArticleDOI
14 Jul 2011-Nature
TL;DR: The ability of a small molecule to induce apoptosis selectively in cells that have a cancer genotypes is demonstrated, by targeting a non-oncogene co-dependency acquired through the expression of the cancer genotype in response to transformation-induced oxidative stress.
Abstract: A chemical screen has identified a small molecule, piperlongumine (PL), as a compound that induces selective killing of cancer cells. Piperlongumine acts by increasing reactive oxygen species (ROS) levels in cancer cells. Although it is active against a number of tumour models in vivo irrespective of p53 status, it does not affect normal tissues, including rapidly proliferating non-tumour cells. This work suggests a novel strategy for eradicating cancer cells by targeting the ROS stress-response pathway, but further work will be needed to identify determinants of piperlongumine sensitivity in a wider range of cancers. Malignant transformation, driven by gain-of-function mutations in oncogenes and loss-of-function mutations in tumour suppressor genes, results in cell deregulation that is frequently associated with enhanced cellular stress (for example, oxidative, replicative, metabolic and proteotoxic stress, and DNA damage)1. Adaptation to this stress phenotype is required for cancer cells to survive, and consequently cancer cells may become dependent upon non-oncogenes that do not ordinarily perform such a vital function in normal cells. Thus, targeting these non-oncogene dependencies in the context of a transformed genotype may result in a synthetic lethal interaction and the selective death of cancer cells2. Here we used a cell-based small-molecule screening and quantitative proteomics approach that resulted in the unbiased identification of a small molecule that selectively kills cancer cells but not normal cells. Piperlongumine increases the level of reactive oxygen species (ROS) and apoptotic cell death in both cancer cells and normal cells engineered to have a cancer genotype, irrespective of p53 status, but it has little effect on either rapidly or slowly dividing primary normal cells. Significant antitumour effects are observed in piperlongumine-treated mouse xenograft tumour models, with no apparent toxicity in normal mice. Moreover, piperlongumine potently inhibits the growth of spontaneously formed malignant breast tumours and their associated metastases in mice. Our results demonstrate the ability of a small molecule to induce apoptosis selectively in cells that have a cancer genotype, by targeting a non-oncogene co-dependency acquired through the expression of the cancer genotype in response to transformation-induced oxidative stress3,4,5.

Journal ArticleDOI
TL;DR: The role that embryonic signaling pathways play in the function of CSCs, the development of new anti-CSC therapeutic agents, and the complexity of potential CSC signaling cross-talk are described in this Review.
Abstract: Tumor relapse and metastasis remain major obstacles for improving overall cancer survival, which may be due at least in part to the existence of cancer stem cells (CSCs). CSCs are characterized by tumorigenic properties and the ability to self-renew, form differentiated progeny, and develop resistance to therapy. CSCs use many of the same signaling pathways that are found in normal stem cells, such as Wnt, Notch, and Hedgehog (Hh). The origin of CSCs is not fully understood, but data suggest that they originate from normal stem or progenitor cells, or possibly other cancer cells. Therapeutic targeting of both CSCs and bulk tumor populations may provide a strategy to suppress tumor regrowth. Development of agents that target critical steps in the Wnt, Notch, and Hh pathways will be complicated by signaling cross-talk. The role that embryonic signaling pathways play in the function of CSCs, the development of new anti-CSC therapeutic agents, and the complexity of potential CSC signaling cross-talk are described in this Review.

Journal ArticleDOI
TL;DR: Homing of melanoma exosomes to sentinel lymph nodes imposes synchronized molecular signals that effect melanoma cell recruitment, extracellular matrix deposition, and vascular proliferation in the lymph nodes.
Abstract: Exosomes are naturally occurring biological nanovesicles utilized by tumors to communicate signals to local and remote cells and tissues. Melanoma exosomes can incite a proangiogenic signaling program capable of remodeling tissue matrices. In this study, we show exosome-mediated conditioning of lymph nodes and define microanatomic responses that license metastasis of melanoma cells. Homing of melanoma exosomes to sentinel lymph nodes imposes synchronized molecular signals that effect melanoma cell recruitment, extracellular matrix deposition, and vascular proliferation in the lymph nodes. Our findings highlight the pathophysiologic role and mechanisms of an exosome-mediated process of microanatomic niche preparation that facilitates lymphatic metastasis by cancer cells.

Journal ArticleDOI
TL;DR: In vitro and in vivo evidence is provided that invasive cancer cells dramatically impact surrounding adipocytes and peritumoral adipocytes exhibit a modified phenotype and specific biological features sufficient to be named cancer-associated adipocytes (CAA); and CAAs modify the cancer cell characteristics/phenotype leading to a more aggressive behavior.
Abstract: Early local tumor invasion in breast cancer results in a likely encounter between cancer cells and mature adipocytes, but the role of these fat cells in tumor progression remains unclear. We show that murine and human tumor cells cocultivated with mature adipocytes exhibit increased invasive capacities in vitro and in vivo, using an original two-dimensional coculture system. Likewise, adipocytes cultivated with cancer cells also exhibit an altered phenotype in terms of delipidation and decreased adipocyte markers associated with the occurrence of an activated state characterized by overexpression of proteases, including matrix metalloproteinase-11, and proinflammatory cytokines [interleukin (IL)-6, IL-1β]. In the case of IL-6, we show that it plays a key role in the acquired proinvasive effect by tumor cells. Equally important, we confirm the presence of these modified adipocytes in human breast tumors by immunohistochemistry and quantitative PCR. Interestingly, the tumors of larger size and/or with lymph nodes involvement exhibit the higher levels of IL-6 in tumor surrounding adipocytes. Collectively, all our data provide in vitro and in vivo evidence that (i) invasive cancer cells dramatically impact surrounding adipocytes; (ii) peritumoral adipocytes exhibit a modified phenotype and specific biological features sufficient to be named cancer-associated adipocytes (CAA); and (iii) CAAs modify the cancer cell characteristics/phenotype leading to a more aggressive behavior. Our results strongly support the innovative concept that adipocytes participate in a highly complex vicious cycle orchestrated by cancer cells to promote tumor progression that might be amplified in obese patients.

Journal ArticleDOI
TL;DR: Interestingly, mutations in the p53 gene were shown to occur at different phases of the multistep process of malignant transformation, thus contributing differentially to tumor initiation, promotion, aggressiveness, and metastasis.
Abstract: Inactivation of the p53 tumor suppressor is a frequent event in tumorigenesis. In most cases, the p53 gene is mutated, giving rise to a stable mutant protein whose accumulation is regarded as a hallmark of cancer cells. Mutant p53 proteins not only lose their tumor suppressive activities but often gain additional oncogenic functions that endow cells with growth and survival advantages. Interestingly, mutations in the p53 gene were shown to occur at different phases of the multistep process of malignant transformation, thus contributing differentially to tumor initiation, promotion, aggressiveness, and metastasis. Here, the authors review the different studies on the involvement of p53 inactivation at various stages of tumorigenesis and highlight the specific contribution of p53 mutations at each phase of cancer progression.

Journal ArticleDOI
TL;DR: A new type of molecular-targeted cancer therapy, photoimmunotherapy (PIT), that uses a target-specific photosensitizer based on a near-infrared (NIR) phthalocyanine dye, IR700, conjugated to monoclonal antibodies (mAbs) targeting epidermal growth factor receptors is developed.
Abstract: Makoto Mitsunaga et al. have developed a new form of molecular-targeted cancer therapy that provides an alternative to current photodynamic approaches where damage to surrounding healthy cells and tissues can be a problem. They use a target-specific photosensitizer based on a near-infrared phthalocyanine dye, which is conjugated to monoclonal antibodies targeting human epidermal growth factor receptors (HER1 and HER2). Selective treatment using this approach was shown in vivo in subcutaneous cancer xenografts in mice.

Journal ArticleDOI
TL;DR: The IL-6/JAK2/Stat3 pathway was preferentially active in CD44+CD24- breast cancer cells compared with other tumor cell types, and inhibition of JAK2 decreased their number and blocked growth of xenografts.
Abstract: Intratumor heterogeneity is a major clinical problem because tumor cell subtypes display variable sensitivity to therapeutics and may play different roles in progression. We previously characterized 2 cell populations in human breast tumors with distinct properties: CD44+CD24- cells that have stem cell-like characteristics, and CD44-CD24+ cells that resemble more differentiated breast cancer cells. Here we identified 15 genes required for cell growth or proliferation in CD44+CD24- human breast cancer cells in a large-scale loss-of-function screen and found that inhibition of several of these (IL6, PTGIS, HAS1, CXCL3, and PFKFB3) reduced Stat3 activation. We found that the IL-6/JAK2/Stat3 pathway was preferentially active in CD44+CD24- breast cancer cells compared with other tumor cell types, and inhibition of JAK2 decreased their number and blocked growth of xenografts. Our results highlight the differences between distinct breast cancer cell types and identify targets such as JAK2 and Stat3 that may lead to more specific and effective breast cancer therapies.

Journal ArticleDOI
20 Jan 2011-Nature
TL;DR: This issue is examined in childhood acute lymphoblastic leukaemia in which the ETV6–RUNX1 gene fusion is an early or initiating genetic lesion followed by a modest number of recurrent or ‘driver’ copy number alterations.
Abstract: Little is known of the genetic architecture of cancer at the subclonal and single-cell level or in the cells responsible for cancer clone maintenance and propagation Here we have examined this issue in childhood acute lymphoblastic leukaemia in which the ETV6–RUNX1 gene fusion is an early or initiating genetic lesion followed by a modest number of recurrent or ‘driver’ copy number alterations By multiplexing fluorescence in situ hybridization probes for these mutations, up to eight genetic abnormalities can be detected in single cells, a genetic signature of subclones identified and a composite picture of subclonal architecture and putative ancestral trees assembled Subclones in acute lymphoblastic leukaemia have variegated genetics and complex, nonlinear or branching evolutionary histories Copy number alterations are independently and reiteratively acquired in subclones of individual patients, and in no preferential order Clonal architecture is dynamic and is subject to change in the lead-up to a diagnosis and in relapse Leukaemia propagating cells, assayed by serial transplantation in NOD/SCID IL2Rγnull mice, are also genetically variegated, mirroring subclonal patterns, and vary in competitive regenerative capacity in vivo These data have implications for cancer genomics and for the targeted therapy of cancer Genome-wide analysis of cancer cells in individual patients has revealed extensive genetic heterogeneity Two groups have now mapped genetic homogeneity in patients with acute lymphoblastic leukaemia (ALL) Mel Greaves and colleagues obtained mutational profiles of large numbers of single cells from 60 individuals with ETV6–RUNX1-positive ALL, while John Dick and colleagues profile BCR-ABL1-positive ALL Both groups deduce the evolutionary path by which different subclones emerge during disease progression Leukaemia-propagating cells that transplant the disease mirror the genetic variegation of the bulk tumours, providing insight into the heterogeneity of these functional subpopulations at the genetic level This work has implications for therapeutic approaches targeting the tumours and specifically leukaemia-propagating cells Analysing single cells from human B-cell acute lymphoblastic leukaemias, this study maps the genetic heterogeneity of cells within a given tumour sample, the evolutionary path by which different subclones have emerged, and ongoing dynamic changes associated with relapse Leukaemia-propagating cells that transplant the disease mirror the genetic variegation of the bulk tumours, providing insights into the heterogeneity of these functional subpopulations at the genetic level This has implications for therapeutic approaches targeting the tumours and specifically leukaemia-propagating cells

Journal ArticleDOI
TL;DR: The most frequent target organs of metastasis are bone, brain, liver and the lung, and how tumor‐stromal interactions influence metastasis in each of these organs is discussed.
Abstract: The fact that certain tumors exhibit a predilection for metastasis to specific organs has been recognized for well over a century now. An extensive body of clinical data and experimental research has confirmed Stephen Paget's original "seed and soil" hypothesis that proposed the organ-preference patterns of tumor metastasis are the product of favorable interactions between metastatic tumor cells (the "seed") and their organ microenvironment (the "soil"). Indeed, many of the first-line therapeutic regimens, currently in use for the treatment of human cancer are designed to target cancer cells (such as chemotherapy) and also to modulate the tumor microenvironment (such as antiangiogenic therapy). While some types of tumors are capable of forming metastases in virtually every organ in the body, the most frequent target organs of metastasis are bone, brain, liver and the lung. In this review, we discuss how tumor-stromal interactions influence metastasis in each of these organs.

Journal ArticleDOI
TL;DR: It is shown that FoxA1 is a key determinant that can influence differential interactions between ER and chromatin and that CTCF was an upstream negative regulator of FOXA1-chromatin interactions.
Abstract: Estrogen receptor-α (ER) is the key feature of most breast cancers and binding of ER to the genome correlates with expression of the Forkhead protein FOXA1 (also called HNF3α). Here we show that FOXA1 is a key determinant that can influence differential interactions between ER and chromatin. Almost all ER-chromatin interactions and gene expression changes depended on the presence of FOXA1 and FOXA1 influenced genome-wide chromatin accessibility. Furthermore, we found that CTCF was an upstream negative regulator of FOXA1-chromatin interactions. In estrogen-responsive breast cancer cells, the dependency on FOXA1 for tamoxifen-ER activity was absolute; in tamoxifen-resistant cells, ER binding was independent of ligand but depended on FOXA1. Expression of FOXA1 in non-breast cancer cells can alter ER binding and function. As such, FOXA1 is a major determinant of estrogen-ER activity and endocrine response in breast cancer cells.

Journal ArticleDOI
TL;DR: It is shown that the mitochondrial NAD-dependent deacetylase SIRT3 is a crucial regulator of the Warburg effect, and it is found that Sirt3 overexpression represses glycolysis and proliferation in breast cancer cells, providing a metabolic mechanism for tumor suppression.