Literature context: 75/p536_MDA-MB-231, RRID:CVCL_0062) cells. These cellular lines we
Extracellular nucleotides and nucleosides have emerged as important elements regulating tissue homeostasis. Acting through specific receptors, have the ability to control gene expression patterns to direct cellular fate. We observed that SKOV-3 cells express the ectonucleotidases: ectonucleotide pyrophosphatase 1 (ENPP1), ecto-5'-nucleotidase (NT5E), and liver alkaline phosphatase (ALPL). Strikingly, in pulse and chase experiments supplemented with ATP, SKOV-3 cells exhibited low catabolic efficiency in the conversion of ADP into AMP, but they were efficient in converting AMP into adenosine. Since these cells release ATP, we proposed that the conversion of ADP into AMP is a regulatory node associated with the migratory ability and the mesenchymal characteristics shown by SKOV-3 cells under basal conditions. The landscape of gene expression profiles of SKOV-3 cell cultures treated with apyrase or adenosine demonstrated similarities (e.g., decrease FGF16 transcript) and differences (e.g., the negative regulation of Wnt 2, and 10B by adenosine). Thus, in SKOV-3 we analyzed the migratory ability and the expression of epithelium to mesenchymal transition (EMT) markers in response to apyrase. Apyrase-treatment favored the epithelial-like phenotype, as revealed by the re-location of E-cadherin to the cell to cell junctions. Pharmacological approaches strongly suggested that the effect of Apyrase involved the accumulation of extracellular adenosine; this notion was strengthened when the incubation of the SKOV-3 cell with α,β-methylene ADP (CD73 inhibitor) or adenosine deaminase was sufficient to abolish the effect of apyrase on cell migration. Overall, adenosine signaling is a fine tune mechanism in the control of cell phenotype in cancer. J. Cell. Biochem. 118: 4468-4478, 2017. © 2017 Wiley Periodicals, Inc.
Literature context: -231 ATCC ATCC Cat# CRM-HTB-26; RRID:CVCL_0062 Cell line maintained in A. Risi
Chemotherapy-induced peripheral neuropathy (CIPN) arises from collateral damage to peripheral afferent sensory neurons by anticancer pharmacotherapy, leading to debilitating neuropathic pain. No effective treatment for CIPN exists, short of dose-reduction which worsens cancer prognosis. Here we report that stimulation of nicotinamide phosphoribosyltransferase (NAMPT) produced robust neuroprotection in an aggressive CIPN model utilizing the frontline anticancer drug, paclitaxel (PTX). Daily treatment of rats with the first-in-class NAMPT stimulator, P7C3-A20, prevented behavioral and histologic indicators of peripheral neuropathy, stimulated tissue NAD recovery, improved general health, and abolished attrition produced by a near maximum-tolerated dose of PTX. Inhibition of NAMPT blocked P7C3-A20-mediated neuroprotection, whereas supplementation with the NAMPT substrate, nicotinamide, potentiated a subthreshold dose of P7C3-A20 to full efficacy. Importantly, P7C3-A20 blocked PTX-induced allodynia in tumored mice without reducing antitumoral efficacy. These findings identify enhancement of NAMPT activity as a promising new therapeutic strategy to protect against anticancer drug-induced peripheral neurotoxicity.
Literature context: -26, RRID:CVCL_0062 Human: MDA-MB-436 ATCC Cat #HTB
Triple-negative breast cancer (TNBC) is an aggressive and heterogeneous carcinoma in which various tumor-suppressor genes are lost by mutation, deletion, or silencing. Here we report a tumor-suppressive mode of action for growth-differentiation factor 11 (GDF11) and an unusual mechanism of its inactivation in TNBC. GDF11 promotes an epithelial, anti-invasive phenotype in 3D triple-negative cultures and intraductal xenografts by sustaining expression of E-cadherin and inhibitor of differentiation 2 (ID2). Surprisingly, clinical TNBCs retain the GDF11 locus and expression of the protein itself. GDF11 bioactivity is instead lost because of deficiencies in its convertase, proprotein convertase subtilisin/kexin type 5 (PCSK5), causing inactive GDF11 precursor to accumulate intracellularly. PCSK5 reconstitution mobilizes the latent TNBC reservoir of GDF11 in vitro and suppresses triple-negative mammary cancer metastasis to the lung of syngeneic hosts. Intracellular GDF11 retention adds to the concept of tumor-suppressor inactivation and reveals a cell-biological vulnerability for TNBCs lacking therapeutically actionable mutations.
Literature context: TB-20Human: MDA-MB-231 cellsATCCHTB-26Experimental Models: Organisms/S
Targeted cancer therapies that use genetics are successful, but principles for selectively targeting tumor metabolism that is also dependent on the environment remain unknown. We now show that differences in rate-controlling enzymes during the Warburg effect (WE), the most prominent hallmark of cancer cell metabolism, can be used to predict a response to targeting glucose metabolism. We establish a natural product, koningic acid (KA), to be a selective inhibitor of GAPDH, an enzyme we characterize to have differential control properties over metabolism during the WE. With machine learning and integrated pharmacogenomics and metabolomics, we demonstrate that KA efficacy is not determined by the status of individual genes, but by the quantitative extent of the WE, leading to a therapeutic window in vivo. Thus, the basis of targeting the WE can be encoded by molecular principles that extend beyond the status of individual genes.
Literature context: HTB-26; RRID:CVCL_0062 Human: SK-OV-3 ATCC Cat#HTB-77;
A substantial fraction of eukaryotic transcripts are considered long non-coding RNAs (lncRNAs), which regulate various hallmarks of cancer. Here, we discovered that the lncRNA HOXB-AS3 encodes a conserved 53-aa peptide. The HOXB-AS3 peptide, not lncRNA, suppresses colon cancer (CRC) growth. Mechanistically, the HOXB-AS3 peptide competitively binds to the ariginine residues in RGG motif of hnRNP A1 and antagonizes the hnRNP A1-mediated regulation of pyruvate kinase M (PKM) splicing by blocking the binding of the ariginine residues in RGG motif of hnRNP A1 to the sequences flanking PKM exon 9, ensuring the formation of lower PKM2 and suppressing glucose metabolism reprogramming. CRC patients with low levels of HOXB-AS3 peptide have poorer prognoses. Our study indicates that the loss of HOXB-AS3 peptide is a critical oncogenic event in CRC metabolic reprogramming. Our findings uncover a complex regulatory mechanism of cancer metabolism reprogramming orchestrated by a peptide encoded by an lncRNA.
Literature context: D: RRID:CVCL_0062 MDA-MB-436 ATCC Cat#HTB-130; RR
To ensure the completion of DNA replication and maintenance of genome integrity, DNA repair factors protect stalled replication forks upon replication stress. Previous studies have identified a critical role for the tumor suppressors BRCA1 and BRCA2 in preventing the degradation of nascent DNA by the MRE11 nuclease after replication stress. Here we show that depletion of SMARCAL1, a SNF2-family DNA translocase that remodels stalled forks, restores replication fork stability and reduces the formation of replication stress-induced DNA breaks and chromosomal aberrations in BRCA1/2-deficient cells. In addition to SMARCAL1, other SNF2-family fork remodelers, including ZRANB3 and HLTF, cause nascent DNA degradation and genomic instability in BRCA1/2-deficient cells upon replication stress. Our observations indicate that nascent DNA degradation in BRCA1/2-deficient cells occurs as a consequence of MRE11-dependent nucleolytic processing of reversed forks generated by fork remodelers. These studies provide mechanistic insights into the processes that cause genome instability in BRCA1/2-deficient cells.
Literature context: rland), breast (MDA-MB-231, cn: CRM-HTB-26, ATCC), ovarian (HeLa, cn: CCL-
Group 2 innate lymphoid cells (ILC2s) are involved in human diseases, such as allergy, atopic dermatitis and nasal polyposis, but their function in human cancer remains unclear. Here we show that, in acute promyelocytic leukaemia (APL), ILC2s are increased and hyper-activated through the interaction of CRTH2 and NKp30 with elevated tumour-derived PGD2 and B7H6, respectively. ILC2s, in turn, activate monocytic myeloid-derived suppressor cells (M-MDSCs) via IL-13 secretion. Upon treating APL with all-trans retinoic acid and achieving complete remission, the levels of PGD2, NKp30, ILC2s, IL-13 and M-MDSCs are restored. Similarly, disruption of this tumour immunosuppressive axis by specifically blocking PGD2, IL-13 and NKp30 partially restores ILC2 and M-MDSC levels and results in increased survival. Thus, using APL as a model, we uncover a tolerogenic pathway that may represent a relevant immunosuppressive, therapeutic targetable, mechanism operating in various human tumour types, as supported by our observations in prostate cancer.Group 2 innate lymphoid cells (ILC2s) modulate inflammatory and allergic responses, but their function in cancer immunity is still unclear. Here the authors show that, in acute promyelocytic leukaemia, tumour-activated ILC2s secrete IL-13 to induce myeloid-derived suppressor cells and support tumour growth.
Literature context: RL-12532, RRID:CVCL_0062), and MCF7
Glutamate-ammonia ligase (GLUL) belongs to the glutamine synthetase family. It catalyzes the synthesis of glutamine from glutamate and ammonia in an ATP-dependent reaction. Here, we found higher expression of GLUL in the breast cancer patients was associated with larger tumor size and higher level of HER2 expression. In addition, GLUL was heterogeneously expressed in various breast cancer cells. The mRNA and protein expression levels of GLUL in SK-BR-3 cells were obviously higher than that in the other types of breast cancer cells. Results showed GLUL knockdown in SK-BR-3 cells could significantly decrease the proliferation ability. Furthermore, GLUL knockdown markedly inhibited the p38 MAPK and ERK1/ERK2 signaling pathways in SK-BR-3 cells. Thus, GLUL may represent a novel target for selectively inhibiting p38 MAPK and ERK1/ERK2 signaling pathways and the proliferation potential of breast cancer cells. J. Cell. Biochem. 118: 2018-2025, 2017. © 2016 Wiley Periodicals, Inc.
Literature context: ID:CVCL_0062; PC3: ATCC Cat# CRL-1435, RRID:
Many mammalian cancer cell lines depend on glutamine as a major tri-carboxylic acid (TCA) cycle anaplerotic substrate to support proliferation. However, some cell lines that depend on glutamine anaplerosis in culture rely less on glutamine catabolism to proliferate in vivo. We sought to understand the environmental differences that cause differential dependence on glutamine for anaplerosis. We find that cells cultured in adult bovine serum, which better reflects nutrients available to cells in vivo, exhibit decreased glutamine catabolism and reduced reliance on glutamine anaplerosis compared to cells cultured in standard tissue culture conditions. We find that levels of a single nutrient, cystine, accounts for the differential dependence on glutamine in these different environmental contexts. Further, we show that cystine levels dictate glutamine dependence via the cystine/glutamate antiporter xCT/SLC7A11. Thus, xCT/SLC7A11 expression, in conjunction with environmental cystine, is necessary and sufficient to increase glutamine catabolism, defining important determinants of glutamine anaplerosis and glutaminase dependence in cancer.
Literature context: 7 (RRID:CVCL_0031), MDA-MB-231 (RRID:CVCL_0062), human embryonic fibroblast WI
TAp63, a member of the p53 family, has been shown to regulate energy metabolism. Here, we report coiled coil domain-containing 3 (CCDC3) as a new TAp63 target. TAp63, but not ΔNp63, p53 or p73, upregulates CCDC3 expression by directly binding to its enhancer region. The CCDC3 expression is markedly reduced in TAp63-null mouse embryonic fibroblasts and brown adipose tissues and by tumor necrosis factor alpha that reduces p63 transcriptional activity, but induced by metformin, an anti-diabetic drug that activates p63. Also, the expression of CCDC3 is positively correlated with TAp63 levels, but conversely with ΔNp63 levels, during adipocyte differentiation. Interestingly, CCDC3, as a secreted protein, targets liver cancer cells and increases long chain polyunsaturated fatty acids, but decreases ceramide in the cells. CCDC3 alleviates glucose intolerance, insulin resistance and steatosis formation in transgenic CCDC3 mice on high-fat diet (HFD) by reducing the expression of hepatic PPARγ and its target gene CIDEA as well as other genes involved in de novo lipogenesis. Similar results are reproduced by hepatic expression of ectopic CCDC3 in mice on HFD. Altogether, these results demonstrate that CCDC3 modulates liver lipid metabolism by inhibiting liver de novo lipogenesis as a downstream player of the p63 network.
Literature context: e Identifiers: MDA-MB-231 cells RRID:CVCL_0062; Hs578T cells RRID:CVCL_0332; A
The urokinase receptor (uPAR) is a glycosylphosphatidylinositol (GPI)-anchored protein that promotes tissue remodeling, tumor cell adhesion, migration and invasion. uPAR mediates degradation of the extracellular matrix through protease recruitment and enhances cell adhesion, migration and signaling through vitronectin binding and interactions with integrins. Full-length uPAR is released from the cell surface, but the mechanism and significance of uPAR shedding remain obscure. Here we identify transmembrane glycerophosphodiesterase GDE3 as a GPI-specific phospholipase C that cleaves and releases uPAR with consequent loss of function, whereas its homologue GDE2 fails to attack uPAR. GDE3 overexpression depletes uPAR from distinct basolateral membrane domains in breast cancer cells, resulting in a less transformed phenotype, it slows tumor growth in a xenograft model and correlates with prolonged survival in patients. Our results establish GDE3 as a negative regulator of the uPAR signaling network and, furthermore, highlight GPI-anchor hydrolysis as a cell-intrinsic mechanism to alter cell behavior.
Literature context: Models: Cell LinesMDA-MB-231ATCCHTB-26AU565ATCCCRL-2351MDA-MB-468ATCCH
Aberrant signaling by the mammalian target of rapamycin (mTOR) contributes to the devastating features of cancer cells. Thus, mTOR is a critical therapeutic target and catalytic inhibitors are being investigated as anti-cancer drugs. Although mTOR inhibitors initially block cell proliferation, cell viability and migration in some cancer cells are quickly restored. Despite sustained inhibition of mTORC1/2 signaling, Akt, a kinase regulating cell survival and migration, regains phosphorylation at its regulatory sites. Mechanistically, mTORC1/2 inhibition promotes reorganization of integrin/focal adhesion kinase-mediated adhesomes, induction of IGFR/IR-dependent PI3K activation, and Akt phosphorylation via an integrin/FAK/IGFR-dependent process. This resistance mechanism contributes to xenograft tumor cell growth, which is prevented with mTOR plus IGFR inhibitors, supporting this combination as a therapeutic approach for cancers.
Literature context: 0Experimental Models: Cell LinesHuman: MDA-MB-231 cellsATCCHTB-26Human: MCF-7 cellsATCCHTB-22Huma
Extracellular cues that regulate cellular shape, motility, and navigation are generally classified as growth promoting (i.e., growth factors/chemoattractants and attractive guidance cues) or growth preventing (i.e., repellents and inhibitors). Yet, these designations are often based on complex assays and undefined signaling pathways and thus may misrepresent direct roles of specific cues. Here, we find that a recognized growth-promoting signaling pathway amplifies the F-actin disassembly and repulsive effects of a growth-preventing pathway. Focusing on Semaphorin/Plexin repulsion, we identified an interaction between the F-actin-disassembly enzyme Mical and the Abl tyrosine kinase. Biochemical assays revealed Abl phosphorylates Mical to directly amplify Mical Redox-mediated F-actin disassembly. Genetic assays revealed that Abl allows growth factors and Semaphorin/Plexin repellents to combinatorially increase Mical-mediated F-actin disassembly, cellular remodeling, and repulsive axon guidance. Similar roles for Mical in growth factor/Abl-related cancer cell behaviors further revealed contexts in which characterized positive effectors of growth/guidance stimulate such negative cellular effects as F-actin disassembly/repulsion.
Literature context: CCHTB-17Human: Hs578TATCCHTB-126Human: MDA-MB-231ATCCHTB-26Human: A549ATCCCCL-185Human: HEK
Mutations in cancer reprogram amino acid metabolism to drive tumor growth, but the molecular mechanisms are not well understood. Using an unbiased proteomic screen, we identified mTORC2 as a critical regulator of amino acid metabolism in cancer via phosphorylation of the cystine-glutamate antiporter xCT. mTORC2 phosphorylates serine 26 at the cytosolic N terminus of xCT, inhibiting its activity. Genetic inhibition of mTORC2, or pharmacologic inhibition of the mammalian target of rapamycin (mTOR) kinase, promotes glutamate secretion, cystine uptake, and incorporation into glutathione, linking growth factor receptor signaling with amino acid uptake and utilization. These results identify an unanticipated mechanism regulating amino acid metabolism in cancer, enabling tumor cells to adapt to changing environmental conditions.
Literature context: PMID:19122652OCI AML3DSMZACC 582MDA-MB-231ATCC Â®HTB-26â„¢MCF7ATCCÂ®HTB-22â„¢HT29ATCCÂ®HTB-38â„¢
Targeting of human cancer stem cells (CSCs) requires the identification of vulnerabilities unique to CSCs versus healthy resident stem cells (SCs). Unfortunately, dysregulated pathways that support transformed CSCs, such as Wnt/β-catenin signaling, are also critical regulators of healthy SCs. Using the ICG-001 and CWP family of small molecules, we reveal Sam68 as a previously unappreciated modulator of Wnt/β-catenin signaling within CSCs. Disruption of CBP-β-catenin interaction via ICG-001/CWP induces the formation of a Sam68-CBP complex in CSCs that alters Wnt signaling toward apoptosis and differentiation induction. Our study identifies Sam68 as a regulator of human CSC vulnerability.
Literature context: A-MB-231 (RRID:CVCL_0062), CAL-120
Activating mutations involving the PI3K pathway occur frequently in human cancers. However, PI3K inhibitors primarily induce cell cycle arrest, leaving a significant reservoir of tumor cells that may acquire or exhibit resistance. We searched for genes that are required for the survival of PI3K mutant cancer cells in the presence of PI3K inhibition by conducting a genome scale shRNA-based apoptosis screen in a PIK3CA mutant human breast cancer cell. We identified 5 genes (PIM2, ZAK, TACC1, ZFR, ZNF565) whose suppression induced cell death upon PI3K inhibition. We showed that small molecule inhibitors of the PIM2 and ZAK kinases synergize with PI3K inhibition. In addition, using a microscale implementable device to deliver either siRNAs or small molecule inhibitors in vivo, we showed that suppressing these 5 genes with PI3K inhibition induced tumor regression. These observations identify targets whose inhibition synergizes with PI3K inhibitors and nominate potential combination therapies involving PI3K inhibition.
Literature context: Cat# CRL-1687MDA-MB-231ATCCCat# HTB-26U251SigmaCat# 09063001Experiment
Autophagy is crucial for maintaining cell homeostasis. However, the precise mechanism underlying autophagy initiation remains to be defined. Here, we demonstrate that glutamine deprivation and hypoxia result in inhibition of mTOR-mediated acetyl-transferase ARD1 S228 phosphorylation, leading to ARD1-dependent phosphoglycerate kinase 1 (PGK1) K388 acetylation and subsequent PGK1-mediated Beclin1 S30 phosphorylation. This phosphorylation enhances ATG14L-associated class III phosphatidylinositol 3-kinase VPS34 activity by increasing the binding of phosphatidylinositol to VPS34. ARD1-dependent PGK1 acetylation and PGK1-mediated Beclin1 S30 phosphorylation are required for glutamine deprivation- and hypoxia-induced autophagy and brain tumorigenesis. Furthermore, PGK1 K388 acetylation levels correlate with Beclin1 S30 phosphorylation levels and poor prognosis in glioblastoma patients. Our study unearths an important mechanism underlying cellular-stress-induced autophagy initiation in which the protein kinase activity of the metabolic enzyme PGK1 plays an instrumental role and reveals the significance of the mutual regulation of autophagy and cell metabolism in maintaining cell homeostasis.
Literature context: o. 230132MDA-MB-231ATCCCat. No. HTB-26Experimental Models: Organisms/S
Design of small molecules that disrupt protein-protein interactions, including the interaction of RAS proteins and their effectors, may provide chemical probes and therapeutic agents. We describe here the synthesis and testing of potential small-molecule pan-RAS ligands, which were designed to interact with adjacent sites on the surface of oncogenic KRAS. One compound, termed 3144, was found to bind to RAS proteins using microscale thermophoresis, nuclear magnetic resonance spectroscopy, and isothermal titration calorimetry and to exhibit lethality in cells partially dependent on expression of RAS proteins. This compound was metabolically stable in liver microsomes and displayed anti-tumor activity in xenograft mouse cancer models. These findings suggest that pan-RAS inhibition may be an effective therapeutic strategy for some cancers and that structure-based design of small molecules targeting multiple adjacent sites to create multivalent inhibitors may be effective for some proteins.
Literature context: 31 (RRID:CVCL_0062), MDA-MB-4
Many lines of evidence have indicated that both genetic and non-genetic determinants can contribute to intra-tumor heterogeneity and influence cancer outcomes. Among the best described sub-population of cancer cells generated by non-genetic mechanisms are cells characterized by a CD44+/CD24- cell surface marker profile. Here, we report that human CD44+/CD24- cancer cells are genetically highly unstable because of intrinsic defects in their DNA-repair capabilities. In fact, in CD44+/CD24- cells, constitutive activation of the TGF-beta axis was both necessary and sufficient to reduce the expression of genes that are crucial in coordinating DNA damage repair mechanisms. Consequently, we observed that cancer cells that reside in a CD44+/CD24- state are characterized by increased accumulation of DNA copy number alterations, greater genetic diversity and improved adaptability to drug treatment. Together, these data suggest that the transition into a CD44+/CD24- cell state can promote intra-tumor genetic heterogeneity, spur tumor evolution and increase tumor fitness.