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Reusch U, Duell J, Ellwanger K, Herbrecht C, Knackmuss SH, Fucek I, Eser M, McAleese F, Molkenthin V, Gall FL, Topp M, Little M, Zhukovsky EA. A tetravalent bispecific TandAb (CD19/CD3), AFM11, efficiently recruits T cells for the potent lysis of CD19(+) tumor cells. MAbs 2016; 7:584-604. [PMID: 25875246 DOI: 10.1080/19420862.2015.1029216] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
To harness the potent tumor-killing capacity of T cells for the treatment of CD19(+) malignancies, we constructed AFM11, a humanized tetravalent bispecific CD19/CD3 tandem diabody (TandAb) consisting solely of Fv domains. The molecule exhibits good manufacturability and stability properties. AFM11 has 2 binding sites for CD3 and 2 for CD19, an antigen that is expressed from early B cell development through differentiation into plasma cells, and is an attractive alternative to CD20 as a target for the development of therapeutic antibodies to treat B cell malignancies. Comparison of the binding and cytotoxicity of AFM11 with those of a tandem scFv bispecific T cell engager (BiTE) molecule targeting the same antigens revealed that AFM11 elicited more potent in vitro B cell lysis. Though possessing high affinity to CD3, the TandAb mediates serial-killing of CD19(+) cells with little dependence of potency or efficacy upon effector:target ratio, unlike the BiTE. The advantage of the TandAb over the BiTE was most pronounced at lower effector:target ratios. AFM11 mediated strictly target-dependent T cell activation evidenced by CD25 and CD69 induction, proliferation, and cytokine release, notwithstanding bivalent CD3 engagement. In a NOD/scid xenograft model, AFM11 induced dose-dependent growth inhibition of Raji tumors in vivo, and radiolabeled TandAb exhibited excellent localization to tumor but not to normal tissue. After intravenous administration in mice, half-life ranged from 18.4 to 22.9 h. In a human ex vivo B-cell chronic lymphocytic leukemia study, AFM11 exhibited substantial cytotoxic activity in an autologous setting. Thus, AFM11 may represent a promising therapeutic for treatment of CD19(+) malignancies with an advantageous safety risk profile and anticipated dosing regimen.
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Key Words
- ALL
- AUCtot, total area under the curve
- B-ALL, B-precursor acute lymphoblastic leukemia
- BBB, blood-brain barrier
- BiTE, bispecific T cell engager
- CAR, chimeric antigen receptor
- CCS, cell culture supernatant
- CD, cluster of differentiation
- CD3
- CDR, complementarity determining region
- CHO, Chinese hamster ovary
- CL, clearance
- CLL, chronic lymphocytic leukemia
- CNS, central nervous system
- Cmax, maximal concentration
- DMSO, dimethyl sulfoxide
- E:T, effector:target
- EC50, half maximal effective concentration
- ECL, electrochemiluminescence
- F, fluorescence
- FACS, fluorescence-activated cell sorting
- FCS, fetal calf serum
- FR, framework region
- Fab, fragment antigen-binding
- Fc, fragment crystallizable
- FcRn, neonatal Fc receptor
- FcgR, Fc gamma receptor
- Fv, variable fragment
- HMF, high molecular weight forms
- HSA, human serum albumin
- His, histidine
- IFN, interferon
- IL, interleukin
- IgG, immunoglobulin G
- KD, dissociation constant
- LMF, low molecular weight forms
- MSD, MesoScale Discovery
- MWCO, molecular weight cut-off
- NHL, non-Hodgkin lymphoma
- NK, natural killer
- NOD/scid, nonobese diabetic/severe combined immunodeficiency
- Non-Hodgkin lymphoma
- ORR, overall response rate
- PBMC, peripheral blood mononuclear cell
- PBS, phosphate buffered saline
- PES, polyethersulfone
- PHA, phytohemagglutinin
- PI, propidium iodide
- SABC, standardized antibody binding capacity
- SD, standard deviation
- SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis
- SE-HPLC, size exclusion high-pressure liquid chromatography
- SEC, size exclusion chromatography
- SPR, surface plasmon resonance
- T cells
- TNF, tumor necrosis factor
- TandAb, tandem diabody
- VH, variable heavy
- VL, variable light
- Vss, volume of distribution at steady state
- WBA, whole body autoradiography
- bispecific antibodies
- ctrl., control
- i.v., intravenous
- ka, association rate constant
- kd, dissociation rate constant
- s.c., subcutaneous
- scFv, single-chain variable fragment
- t1/2, terminal elimination half-life
- w/o, without
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Shi Y, Tan SH, Ng S, Zhou J, Yang ND, Koo GB, McMahon KA, Parton RG, Hill MM, Del Pozo MA, Kim YS, Shen HM. Critical role of CAV1/caveolin-1 in cell stress responses in human breast cancer cells via modulation of lysosomal function and autophagy. Autophagy 2016; 11:769-84. [PMID: 25945613 DOI: 10.1080/15548627.2015.1034411] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
CAV1 (caveolin 1, caveolae protein, 22kDa) is well known as a principal scaffolding protein of caveolae, a specialized plasma membrane structure. Relatively, the caveolae-independent function of CAV1 is less studied. Autophagy is a process known to involve various membrane structures, including autophagosomes, lysosomes, and autolysosomes for degradation of intracellular proteins and organelles. Currently, the function of CAV1 in autophagy remains largely elusive. In this study, we demonstrate for the first time that CAV1 deficiency promotes both basal and inducible autophagy. Interestingly, the promoting effect was found mainly in the late stage of autophagy via enhancing lysosomal function and autophagosome-lysosome fusion. Notably, the regulatory function of CAV1 in lysosome and autophagy was found to be caveolae-independent, and acts through lipid rafts. Furthermore, the elevated autophagy level induced by CAV1 deficiency serves as a cell survival mechanism under starvation. Importantly, downregulation of CAV1 and enhanced autophagy level were observed in human breast cancer cells and tissues. Taken together, our data reveal a novel function of CAV1 and lipid rafts in breast cancer development via modulation of lysosomal function and autophagy.
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Key Words
- ATP6V0D1, ATPase H+ transporting lysosomal 38kDa, V0 subunit d1
- Baf, bafilomycin A1
- CAV1, caveolin 1
- CHO, water-soluble cholesterol
- CQ, choloroquine
- CTSL, cathepsin L
- CTxB, cholera toxin subunit B
- DRF, detergent-resistant fraction
- DSF, detergent-soluble fraction
- EGF, epidermal growth factor
- KO, knockout
- LAMP1, lysosomal-associated membrane protein 1
- MAP1LC3/LC3, microtubule-associated protein 1 light chain 3
- MBCD, methyl-β-cyclodextrin
- MEF, mouse embryonic fibroblasts
- MTOR, mechanistic target of rapamycin
- PBS, phosphate-buffered saline
- PI, propidium iodide
- PLA, proximity ligation assay
- PTRF, polymerase I and transcript release factor
- TFRC, transferrin receptor
- TSC, tuberous sclerosis complex
- WT, wild type.
- autophagy
- breast cancer
- caveolin 1
- lipid rafts
- lysosome
- tfLC3B, mRFP-GFP tandem fluorescent-tagged LC3B
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Brookes S, Gagrica S, Sanij E, Rowe J, Gregory FJ, Hara E, Peters G. Evidence for a CDK4-dependent checkpoint in a conditional model of cellular senescence. Cell Cycle 2016; 14:1164-73. [PMID: 25695870 PMCID: PMC4613988 DOI: 10.1080/15384101.2015.1010866] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Cellular senescence, the stable cell cycle arrest elicited by various forms of stress, is an important facet of tumor suppression. Although much is known about the key players in the implementation of senescence, including the pRb and p53 axes and the cyclin dependent kinase inhibitors p16INK4a and p21CIP1, many details remain unresolved. In studying conditional senescence in human fibroblasts that express a temperature sensitive SV40 large T-antigen (T-Ag), we uncovered an unexpected role for CDK4. At the permissive temperature, where pRb and p53 are functionally compromised by T-Ag, cyclin D-CDK4 complexes are disrupted by the high p16INK4a levels and reduced expression of p21CIP1. In cells arrested at the non-permissive temperature, p21CIP1 promotes reassembly of cyclin D-CDK4 yet pRb is in a hypo-phosphorylated state, consistent with cell cycle arrest. In exploring whether the reassembled cyclin D-CDK4-p21 complexes are functional, we found that shRNA-mediated knockdown or chemical inhibition of CDK4 prevented the increase in cell size associated with the senescent phenotype by allowing the cells to arrest in G1 rather than G2/M. The data point to a role for CDK4 kinase activity in a G2 checkpoint that contributes to senescence.
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Key Words
- BrdU, bromodeoxyuridine
- CDK, cyclin dependent kinase
- CDK4
- FACS, fluorescence actvated cell sorting
- HFs, human fibroblasts
- PI, propidium iodide
- SA-βgal, senescence-associated β-galactosidase activity
- SV40 T-antigen
- SV40, simian virus 40
- TERT, telomerase reverse transcriptase
- human fibroblasts
- p16INK4a
- p21CIP1
- p53
- pRb, retinoblastoma protein
- retinoblastoma protein
- senescence
- shRNA, short-hairpin RNA
- ts, temperature sensitive
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Jagot-Lacoussiere L, Faye A, Bruzzoni-Giovanelli H, Villoutreix BO, Rain JC, Poyet JL. DNA damage-induced nuclear translocation of Apaf-1 is mediated by nucleoporin Nup107. Cell Cycle 2016; 14:1242-51. [PMID: 25695197 DOI: 10.1080/15384101.2015.1014148] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Beside its central role in the mitochondria-dependent cell death pathway, the apoptotic protease activating factor 1 (Apaf-1) is involved in the DNA damage response through cell-cycle arrest induced by genotoxic stress. This non-apoptotic function requires a nuclear translocation of Apaf-1 during the G1-to-S transition. However, the mechanisms that trigger the nuclear accumulation of Apaf-1 upon DNA damage remain to be investigated. Here we show that the main 4 isoforms of Apaf-1 can undergo nuclear translocation and restore Apaf-1 deficient MEFs cell cycle arrest in the S phase following genotoxic stress through activation of Chk-1. Interestingly, DNA damage-dependent nuclear accumulation of Apaf-1 occurs independently of p53 and the retinoblastoma (pRb) pathway. We demonstrated that Apaf-1 associates with the nucleoporin Nup107 and this association is necessary for Apaf-1 nuclear import. The CED-4 domain of Apaf-1 directly binds to the central domain of Nup107 in an ATR-regulated, phosphorylation-dependent manner. Interestingly, expression of the Apaf-1-interacting domain of Nup107 interfered with Apaf-1 nuclear translocation upon genotoxic stress, resulting in a marked reduction of Chk-1 activation and cell cycle arrest. Thus, our results confirm the crucial role of Apaf-1 nuclear relocalization in mediating cell-cycle arrest induced by genotoxic stress and implicate Nup107 as a critical regulator of the DNA damage-induced intra-S phase checkpoint response.
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Tang B, Li Q, Zhao XH, Wang HG, Li N, Fang Y, Wang K, Jia YP, Zhu P, Gu J, Li JX, Jiao YJ, Tong WD, Wang M, Zou QM, Zhu FC, Mao XH. Shiga toxins induce autophagic cell death in intestinal epithelial cells via the endoplasmic reticulum stress pathway. Autophagy 2016; 11:344-54. [PMID: 25831014 DOI: 10.1080/15548627.2015.1023682] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Shiga toxins (Stxs) are a family of cytotoxic proteins that lead to the development of bloody diarrhea, hemolytic-uremic syndrome, and central nervous system complications caused by bacteria such as S. dysenteriae, E. coli O157:H7 and E. coli O104:H4. Increasing evidence indicates that macroautophagy (autophagy) is a key factor in the cell death induced by Stxs. However, the associated mechanisms are not yet clear. This study showed that Stx2 induces autophagic cell death in Caco-2 cells, a cultured line model of human enterocytes. Inhibition of autophagy using pharmacological inhibitors, such as 3-methyladenine and bafilomycin A1, or silencing of the autophagy genes ATG12 or BECN1 decreased the Stx2-induced death in Caco-2 cells. Furthermore, there were numerous instances of dilated endoplasmic reticulum (ER) in the Stx2-treated Caco-2 cells, and repression of ER stress due to the depletion of viable candidates of DDIT3 and NUPR1. These processes led to Stx2-induced autophagy and cell death. Finally, the data showed that the pseudokinase TRIB3-mediated DDIT3 expression and AKT1 dephosphorylation upon ER stress were triggered by Stx2. Thus, the data indicate that Stx2 causes autophagic cell death via the ER stress pathway in intestinal epithelial cells.
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Key Words
- 3-MA, 3-methyladenine
- AO, acridine orange
- ATF4, activating transcription factor 4
- ATG, autophagy-related
- BECN1, Beclin 1, autophagy-related
- Baf A1, bafilomycin A1
- CASP3, caspase 3, apoptosis-related cysteine peptidase
- DDIT3, DNA-damage-inducible transcript 3
- E. coli O157:H7
- EHEC O157, Escherichia coli O157:H7
- ER stress
- FACS, fluorescence activated cell sorting
- MAP1LC3B, microtubule-associated protein 1 light chain 3 beta
- MAPK, mitogen-activated protein kinase
- MDC, monodansylcadaverine
- NUPR1, nuclear protein, transcriptional regulator, 1
- PARP1, poly (ADP-ribose) polymerase 1
- PBS, phosphate-buffered saline
- PI, propidium iodide
- Shiga toxins
- Stxs, Shiga toxins
- TEM, transmission electron microscopy
- TRIB3, tribbles pseudokinase 3
- Thap, thapsigargin
- WT, wild type
- Z-VAD, Z-VAD-FMK
- autophagic cell death
- autophagy
- Δ, knockout
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31
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He J, Yu JJ, Xu Q, Wang L, Zheng JZ, Liu LZ, Jiang BH. Downregulation of ATG14 by EGR1-MIR152 sensitizes ovarian cancer cells to cisplatin-induced apoptosis by inhibiting cyto-protective autophagy. Autophagy 2016; 11:373-84. [PMID: 25650716 DOI: 10.1080/15548627.2015.1009781] [Citation(s) in RCA: 121] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Cisplatin is commonly used in ovarian cancer treatment by inducing apoptosis in cancer cells as a result of lethal DNA damage. However, the intrinsic and acquired resistance to cisplatin in cancer cells remains a big challenge for improving overall survival. The cyto-protective functions of autophagy in cancer cells have been suggested as a potential mechanism for chemoresistance. Here, we reported MIR152 as a new autophagy-regulating miRNA that plays a role in cisplatin-resistance. We showed that MIR152 expression was dramatically downregulated in the cisplatin-resistant cell lines A2780/CP70, SKOV3/DDP compared with their respective parental cells, and in ovarian cancer tissues associated with cisplatin-resistance. Overexpression of MIR152 sensitized cisplatin-resistant ovarian cancer cells by reducing cisplatin-induced autophagy, enhancing cisplatin-induced apoptosis and inhibition of cell proliferation. A mouse subcutaneous xenograft tumor model using A2780/CP70 cells with overexpressing MIR152 was established and displayed decreased tumor growth in response to cisplatin. We also identified that ATG14 is a functional target of MIR152 in regulating autophagy inhibition. Furthermore, we found that EGR1 (early growth response 1) regulated the MIR152 gene at the transcriptional level. Ectopic expression of EGR1 enhanced efficacy of chemotherapy in A2780/CP70 cells. More importantly, these findings were relevant to clinical cases. Both EGR1 and MIR152 expression levels were significantly lower in ovarian cancer tissues with high levels of ERCC1 (excision repair cross-complementation group 1), a marker for cisplatin-resistance. Collectively, these data provide insights into novel mechanisms for acquired cisplatin-resistance. Activation of EGR1 and MIR152 may be a useful therapeutic strategy to overcome cisplatin-resistance by preventing cyto-protective autophagy in ovarian cancer.
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Key Words
- ANXA5, annexin A5
- ATG14
- ATG14, autophagy-related 14
- CSF1, colony stimulating factor 1 (macrophage)
- EGR1
- EGR1, early growth response 1
- ERCC1
- ERCC1, excision repair cross-complementation group 1
- FOXO, forkhead box O
- GFP, green fluorescent protein
- MAPILC3/LC3, microtubule-associated protein 1 light chain 3
- MIR152
- MTOR, mechanistic target of rapamycin
- PI, propidium iodide
- RPS6KB1, ribosomal protein S6 kinase, 70kDa, polypeptide 1
- SQSTM1, sequestosome 1
- autophagy
- cisplatin-resistance
- ovarian cancer
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Jung JH, Liao JM, Zhang Q, Zeng S, Nguyen D, Hao Q, Zhou X, Cao B, Kim SH, Lu H. Inauhzin(c) inactivates c-Myc independently of p53. Cancer Biol Ther 2016; 16:412-9. [PMID: 25692307 DOI: 10.1080/15384047.2014.1002698] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Oncogene MYC is deregulated in many human cancers, especially in lymphoma. Previously, we showed that inauhzin (INZ) activates p53 and inhibits tumor growth. However, whether INZ could suppress cancer cell growth independently of p53 activity is still elusive. Here, we report that INZ(c), a second generation of INZ, suppresses c-Myc activity and thus inhibits growth of human lymphoma cells in a p53-independent manner. INZ(c) treatment decreased c-Myc expression at both mRNA and protein level, and suppressed c-Myc transcriptional activity in human Burkitt's lymphoma Raji cells with mutant p53. Also, we showed that overexpressing ectopic c-Myc rescues the inhibition of cell proliferation by INZ(c) in Raji cells, implicating c-Myc activity is targeted by INZ(c). Interestingly, the effect of INZ(c) on c-Myc expression was impaired by disrupting the targeting of c-Myc mRNA by miRNAs via knockdown of ribosomal protein (RP) L5, RPL11, or Ago2, a subunit of RISC complex, indicating that INZ(c) targets c-Myc via miRNA pathways. These results reveal a new mechanism that INZ
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Key Words
- Dox, doxorubicin
- FACS, Fluorescence-activated cell sorting
- GTP, guanosine triphosphate
- INZ, inauhzin
- Inauhzin
- MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide
- PBS, Phosphate Buffered Saline
- PI, propidium iodide
- RISC, RNA-induced silencing complex
- RP, ribosomal protein
- RPL11
- RPL5
- UTR, untranslated region
- c-Myc
- lymphoma
- microRNA
- q-RT-PCR, Real-time reverse transcription polymerase chain reaction
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Jiang LB, Cao L, Yin XF, Yasen M, Yishake M, Dong J, Li XL. Activation of autophagy via Ca(2+)-dependent AMPK/mTOR pathway in rat notochordal cells is a cellular adaptation under hyperosmotic stress. Cell Cycle 2015; 14:867-79. [PMID: 25590373 DOI: 10.1080/15384101.2015.1004946] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Nucleus pulposus (NP) cells experience hyperosmotic stress in spinal discs; however, how these cells can survive in the hostile microenvironment remains unclear. Autophagy has been suggested to maintain cellular homeostasis under different stresses by degrading the cytoplasmic proteins and organelles. Here, we explored whether autophagy is a cellular adaptation in rat notochordal cells under hyperosmotic stress. Hyperosmotic stress was found to activate autophagy in a dose- and time-dependent manner. SQSTM1/P62 expression was decreased as the autophagy level increased. Transient Ca(2+) influx from intracellular stores and extracellular space was stimulated by hyperosmotic stress. Activation of AMPK and inhibition of p70S6K were observed under hyperosmotic conditions. However, intercellular Ca(2+) chelation inhibited the increase of LC3-II and partly reversed the decrease of p70S6K. Hyperosmotic stress decreased cell viability and promoted apoptosis. Inhibition of autophagy led to SQSTM1/P62 accumulation, reduced cell viability, and accelerated apoptosis in notochordal cells under this condition. These evidences suggest that autophagy induction via the Ca(2+)-dependent AMPK/mTOR pathway might occur as an adaptation mechanism for notochordal cells under hyperosmotic stress. Thus, activating autophagy might be a promising approach to improve viability of notochordal cells in intervertebral discs.
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Key Words
- AMPK, AMP activated Protein Kinase
- Adaptation
- Apoptosis
- Autophagy
- BAPTA-AM, bis-(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid, tetra(acetoxymethyl) ester
- DAPI, 4′, 6-diamidino-2-phenylindole
- ECM, extracellular matrix
- EGTA, ethyleneglycol-bis (2-aminoethylether)-N,N,N′, N-tetraacetic acid
- FITC, fluorescein isothiocyanate
- Hyperosmotic stress
- IDD, Intervertebral disc degeneration
- JC-1, 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolyl-carbocyanine iodide
- MAPK, mitogen-activated protein kinase
- MDC, Monodansylcadaverine
- MMP, mitochondrial membrane potential
- MPT, mitochondrial permeability transition
- NP, nucleus pulposus
- Notochordal cells
- OD, optical density
- PI, propidium iodide
- PLC, phospholipase C
- SQSTM1, Sequestosome-1
- TRPV4, Transient receptor potential vanilloid 4
- fluo3-AM, fluo3 acetoximethylester
- mTOR, mammalian target of rapamycin
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Sharma K, Goehe RW, Di X, Hicks MA, Torti SV, Torti FM, Harada H, Gewirtz DA. A novel cytostatic form of autophagy in sensitization of non-small cell lung cancer cells to radiation by vitamin D and the vitamin D analog, EB 1089. Autophagy 2015; 10:2346-61. [PMID: 25629933 DOI: 10.4161/15548627.2014.993283] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The standard of care for unresectable lung cancer is chemoradiation. However, therapeutic options are limited and patients are rarely cured. We have previously shown that vitamin D and vitamin D analogs such as EB 1089 can enhance the response to radiation in breast cancer through the promotion of a cytotoxic form of autophagy. In A549 and H460 non-small cell lung cancer (NSCLC) cells, 1,25-D3 (the hormonally active form of vitamin D) and EB 1089 prolonged the growth arrest induced by radiation alone and suppressed proliferative recovery, which translated to a significant reduction in clonogenic survival. In H838 or H358 NSCLC cells, which lack VDR/vitamin D receptor or functional TP53, respectively, 1,25-D3 failed to modify the extent of radiation-induced growth arrest or suppress proliferative recovery post-irradiation. Sensitization to radiation in H1299 NSCLC cells was evident only when TP53 was induced in otherwise tp53-null H1299 NSCLC cells. Sensitization was not associated with increased DNA damage, decreased DNA repair or an increase in apoptosis, necrosis, or senescence. Instead sensitization appeared to be a consequence of the conversion of the cytoprotective autophagy induced by radiation alone to a novel cytostatic form of autophagy by the combination of 1,25-D3 or EB 1089 with radiation. While both pharmacological and genetic suppression of autophagy or inhibition of AMPK phosphorylation sensitized the NSCLC cells to radiation alone, inhibition of the cytostatic autophagy induced by the combination treatment reversed sensitization. Evidence for selectivity was provided by lack of radiosensitization in normal human bronchial cells and cardiomyocytes. Taken together, these studies have identified a unique cytostatic function of autophagy that appears to be mediated by VDR, TP53, and possibly AMPK in the promotion of an enhanced response to radiation by 1,25-D3 and EB 1089 in NSCLC.
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Key Words
- ACTB, actin, β
- AMPK, AMP activated protein kinase
- ANXA5, annexin A5
- ATG5, autophagy related 5
- AVO, acidic vesicular organelles
- BECN1, Beclin 1, autophagy-related
- Baf, bafilomycin A1
- FACS, fluorescence activating cell sorting
- GFP, green fluorescent protein; H2AFX/H2AX, H2A histone family, member X
- GLB, galactosidase
- MAP1LC3/LC3, microtubule-associated protein 1 light chain 3
- NSCLC
- NSCLC, non-small cell lung cancer
- PI, propidium iodide
- SQSTM1, sequestosome 1
- TP53, tumor protein p53
- VDR, vitamin D (1, 25-dihydroxyvitamin D3) receptor
- WT, wild-type; LC3 and LC3-II acronyms have been used to indicate the LC3B and LC3BII isoforms respectively
- autophagy
- cytoprotective
- cytostatic
- radiation
- β
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Premkumar DR, Jane EP, Pollack IF. Cucurbitacin-I inhibits Aurora kinase A, Aurora kinase B and survivin, induces defects in cell cycle progression and promotes ABT-737-induced cell death in a caspase-independent manner in malignant human glioma cells. Cancer Biol Ther 2015; 16:233-43. [PMID: 25482928 DOI: 10.4161/15384047.2014.987548] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Because STAT signaling is commonly activated in malignant gliomas as a result of constitutive EGFR activation, strategies for inhibiting the EGFR/JAK/STAT cascade are of significant interest. We, therefore, treated a panel of established glioma cell lines, including EGFR overexpressors, and primary cultures derived from patients diagnosed with glioblastoma with the JAK/STAT inhibitor cucurbitacin-I. Treatment with cucurbitacin-I depleted p-STAT3, p-STAT5, p-JAK1 and p-JAK2 levels, inhibited cell proliferation, and induced G2/M accumulation, DNA endoreduplication, and multipolar mitotic spindles. Longer exposure to cucurbitacin-I significantly reduced the number of viable cells and this decrease in viability was associated with cell death, as confirmed by an increase in the subG1 fraction. Our data also demonstrated that cucurbitacin-I strikingly downregulated Aurora kinase A, Aurora kinase B and survivin. We then searched for agents that exhibited a synergistic effect on cell death in combination with cucurbitacin-I. We found that cotreatment with cucurbitacin-I significantly increased Bcl(-)2/Bcl(-)xL family member antagonist ABT-737-induced cell death regardless of EGFR/PTEN/p53 status of malignant human glioma cell lines. Although >50% of the cucurbitacin-I plus ABT-737 treated cells were annexin V and propidium iodide positive, PARP cleavage or caspase activation was not observed. Pretreatment of z-VAD-fmk, a pan caspase inhibitor did not inhibit cell death, suggesting a caspase-independent mechanism of cell death. Genetic inhibition of Aurora kinase A or Aurora kinase B or survivin by RNA interference also sensitized glioma cells to ABT-737, suggesting a link between STAT activation and Aurora kinases in malignant gliomas.
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Key Words
- Aurora kinases
- BSA, bovine serum albumin
- DMSO, dimethyl sulfoxide
- EGFR, epidermal growth factor receptor
- FITC, fluorescein isothiocyanate
- Glioma
- MTS, 3-[4, 5-dimethylthiazol- 2yl]-5-[3-carboxymethoxyphenyl]-2-[4-sulfophenyl]-2H, tetrazolium
- NF-кB, nuclear factor кB
- PAGE, polyacrylamide gel electrophoresis
- PBS, phosphate-buffered saline
- PDGFR, platelet derived growth factor receptor
- PI, propidium iodide
- PI3K, Phosphatidylinositol 3-Kinase
- TBS, Tris-buffered saline
- TRAIL, tumor necrosis factor–related apoptosis inducing ligand
- caspase-independent cell death
- cell cycle arrest
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36
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Bakri NM, Ibrahim SF, Osman NA, Hasan N, Jaffar FHF, Rahman ZA, Osman K. Embryo apoptosis identification: Oocyte grade or cleavage stage? Saudi J Biol Sci 2015; 23:S50-5. [PMID: 26858565 PMCID: PMC4705312 DOI: 10.1016/j.sjbs.2015.10.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2015] [Revised: 10/29/2015] [Accepted: 10/29/2015] [Indexed: 11/25/2022] Open
Abstract
Apoptosis is a programed cell death that is vital for tissue homeostasis. However, embryo apoptosis had been known to be related to embryo fragmentation which should be avoided in in vitro fertilization (IVF). The purpose of this study was to evaluate the relationship of embryo apoptosis with the grade of immature oocytes and cleavage stage of in vitro produced (IVP) cattle embryos. This study consisted of 345 oocytes collected through ovary slicing. Immature oocytes were graded as A, B and C. This grading was based on cumulus cell thickness and compactness. All oocytes then underwent an in vitro maturation (IVM) procedure. An IVF was done 24 h after IVM culture. Prior to staining, stage of cleaved embryos was determined and classified as either 2, 4, 8 or >8-cell embryo stage. Apoptosis status of cleaved IVP embryos was determined by using annexin V-FITC staining technique at 48 and 72 h post insemination (hpi). Apoptosis status for each embryo was classified as either early or late. The result showed that there was no significant difference (p > 0.05) of apoptosis status among grade A, B and C embryos. All grades of oocytes showed embryo apoptosis where 1.5% late apoptosis for grade A, 4.5% and 10.4% of early and late apoptosis for grade B and grade C. Early apoptosis was not seen in grade A embryo. We also noted no significant difference (p > 0.05) of apoptosis status between 2, 4, 8 and >8-cell embryo stage. Early apoptosis was also not seen in >8-cell stage. Even though there were no differences in apoptosis expression between the three classes, the cleavage rate of grade A oocytes was significantly higher (p < 0.01) than grade B and grade C. In conclusion, the apoptosis expression in the embryo can occur regardless of the oocyte quality and the cleavage stage of the embryo produced.
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Key Words
- ART, assisted reproductive technologies
- Apoptosis
- BO, Brackett and Oliphant
- BSA, bovine serum albumin
- CC, cumulus cells
- CO2, carbon dioxide
- COC, cumulus–oocyte complex
- CR1aa, Charles Rosenkran’s 1 amino acid
- CaI, calcium ionophore
- Cleavage stage
- DNA, deoxyribonucleic acid
- DO, denuded oocyte
- EA, early apoptosis
- FBS, fetal bovine serum
- FITC, fluorescein isothiocyanate
- FSH, follicle stimulating hormone
- GSH, glutathione
- IVC, in vitro culture
- IVF, in vitro fertilization
- IVM, in vitro maturation
- IVP, in vitro produced
- LA, late apoptosis
- LH, luteinizing hormone
- Oocyte grading
- PBS, phosphate buffered saline
- PI, propidium iodide
- PS, phosphatidylserine
- TUNEL, terminal deoxynucleotidyl transfer-mediated dUTP nick end-labeling.
- hpi, hours post insemination
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Li C, Cui JF, Chen MB, Liu CY, Liu F, Zhang QD, Zou J, Lu PH. The preclinical evaluation of the dual mTORC1/2 inhibitor INK-128 as a potential anti-colorectal cancer agent. Cancer Biol Ther 2015; 16:34-42. [PMID: 25692620 PMCID: PMC4623257 DOI: 10.4161/15384047.2014.972274] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The colorectal cancer is the leading contributor of cancer-related mortality. Mammalian target of rapamycin (mTOR), existing in 2 complexes (mTORC1/2), is frequently dysregulated and constitutively activated in colorectal cancers. It represents an important drug target. Here we found that INK-128, the novel ATP-competitive kinase inhibitor of mTOR, blocked both mTORC1 and mTORC2 activation in colorectal cancer cells (both primary and transformed cells). The immunoprecipitation results showed that the assembly of mTORC1 (mTOR-Raptor association) and mTORC2 (mTOR-Rictor-Sin1 association) was also disrupted by INK-128. INK-128 inhibited colorectal cancer cell growth and survival, and induced both apoptotic and non-apoptotic cancer cell death. Further, INK-128 showed no effect on Erk/MAPK activation, while MEK/Erk inhibition by MEK-162 enhanced INK-128-induced cytotoxicity in colorectal cancer cells. Meanwhile, INK-128 downregulated Fascin1 (FSCN1)/E-Cadherin expressions and inhibited HT-29 cell in vitro migration. In vivo, daily INK-128 oral administration inhibited HT-29 xenograft growth in mice, which was further enhanced by MEK-162 administration. Finally, we found that INK-128 sensitized 5-fluorouracil-(5-FU)-mediated anti-HT-29 activity in vivo and in vitro. Thus, our preclinical studies strongly suggest that INK-128 might be investigated for colorectal cancer treatment in clinical trials.
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Key Words
- (S6K), p70S6K1
- (mTOR), mammalian target of rapamycin
- (mTORC1), mTOR complex 1
- (mTORC2), mTOR complex 2
- Co-IP, co-immunoprecipitation
- ECL, enhanced chemiluminescence
- FSCN10, Fascin1
- HRP, horseradish peroxidase
- INK-128
- PI, propidium iodide
- SD, standard deviation (SD)
- cell growth and migration
- colorectal cancer
- mTOR
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The antitumor effect of tanshinone IIA on anti-proliferation and decreasing VEGF/VEGFR2 expression on the human non-small cell lung cancer A549 cell line. Acta Pharm Sin B 2015; 5:554-63. [PMID: 26713270 PMCID: PMC4675810 DOI: 10.1016/j.apsb.2015.07.008] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 07/01/2015] [Accepted: 07/11/2015] [Indexed: 11/24/2022] Open
Abstract
The effects of tanshinone IIA on the proliferation of the human non-small cell lung cancer cell line A549 and its possible mechanism on the VEGF/VEGFR signal pathway were investigated. The exploration of the interaction between tanshinone IIA and its target proteins provides a feasible platform for studying the anticancer mechanism of active components of herbs. The CCK-8 assay was used to evaluate the proliferative activity of A549 cells treated with tanshinone IIA (2.5-80 μmol/L) for 24, 48 and 72 h, respectively. Flow cytometry was used for the detection of cell apoptosis and cell cycle perturbation. VEGF and VEGFR2 expression were studied by Western blotting. The binding mode of tanshinone IIA within the crystal structure of the VEGFR2 protein was evaluated with molecular docking analysis by use of the CDOCKER algorithm in Discovery Studio 2.1. The CCK-8 results showed that tanshinone IIA can significantly inhibit A549 cell proliferation in a dose- and time-dependent manner. Flow cytometry results showed that the apoptosis rate of tested group was higher than the vehicle control, and tanshinone IIA-treated cells accumulated at the S phase, which was higher than the vehicle control. Furthermore, the expression of VEGF and VEGFR2 was decreased in Western blot. Finally, molecular docking analysis revealed that tanshinone IIA could be stably docked into the kinase domain of VEGFR2 protein with its unique modes to form H-bonds with Cys917 and π-π stacking interactions with Val848. In conclusion, tanshinone IIA may suppress A549 proliferation, induce apoptosis and cell cycle arrest at the S phase. This drug may suppress angiogenesis by targeting the protein kinase domains of VEGF/VEGFR2.
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Key Words
- ADM, adriamycin
- CAM, chorioallantoic membrane
- CCK-8, cell counting kit-8
- DMSO, dimethylsulfoxide
- EPCs, endothelial progenitor cells
- FBS, fetal bovine serum
- FCM, flow cytometry
- HRP, horseradish peroxidase
- IC50, 50% inhibitory concentration
- MD, molecular dynamics
- Molecular docking
- NS, normal saline
- NSCLC, non-small cell lung cancer
- Non-small cell lung cancer
- PI, propidium iodide
- PKB/AKT, protein kinase B
- RMSD, root-mean-square deviation
- Tan IIA, tanshinone IIA
- Tanshinone IIA
- VEGF, vascular endothelial growth factor
- VEGF/VEGFR signal pathway
- mOS, median overall survival
- tRR, tumor response rate
- vdW, van der Waals force
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Yuan L, Liu ZH, Lin ZR, Xu LH, Zhong Q, Zeng MS. Recurrent FGFR3-TACC3 fusion gene in nasopharyngeal carcinoma. Cancer Biol Ther 2015; 15:1613-21. [PMID: 25535896 DOI: 10.4161/15384047.2014.961874] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Nasopharyngeal carcinoma (NPC) is one of the most common head and neck malignancies and exhibits regional differences in incidence. Because many fusion genes have been discovered in different types of tumors over the past few years, we aimed to investigate the existence of a fusion gene in primary NPC patients using RNA-seq. In this study, for the first time, we found that fibroblast growth factor receptor 3-transforming acidic coiled-coil-containing protein 3 (FGFR3-TACC3) fusion transcripts are recurrently detected in NPC. The presence of this fusion gene was also detected in head and neck cancer, esophageal squamous cell carcinoma (ESCC), and lung cancer. Furthermore, we found certain new isoforms of the FGFR3-TACC3 fusion transcripts, such as a gene fusion between exon 18 of FGFR3 and exon 6 or exon 14 of TACC3 and agene fusion between exon 19 of FGFR3 and exon 11 of TACC3. In addition, we showed that the FGFR3-TACC3 fusion gene promotes cell proliferation, colony formation, and transforming ability in vitro, whereas the FGFR3-TACC3 K508M mutant or treatment with the FGFR inhibitor PD173074 abrogates these effects, suggesting that FGFR3-TACC3 most likely exerts its effects through activation of FGFR kinase activity. This activation likely leads to the development of NPC. Additionally, FGFR3-TACC3 could trigger activation of the ERK and Akt signaling pathways, whereas FGFR3-TACC3 K508M mutant could not, suggesting that these 2 signaling pathways might be involved in the function of FGFR3-TACC3. Taken together, our data demonstrated the oncogenic role of FGFR3-TACC3 in vitro, indicating that FGFR3-TACC3 may be useful as a diagnostic marker and therapeutic target in cancers.
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Key Words
- CCND1, cyclin D1
- DMSO, dimethyl sulfoxide
- DTT, DL-dithiothreitol
- FBS, fetal bovine serum
- FGFR3, fibroblast growth factor receptor 3
- FGFR3-TACC3
- LTBR, lymphotoxin β receptor
- MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide
- NPC
- NPC, nasopharyngeal carcinoma
- PBS, phosphate-buffered saline
- PI, propidium iodide
- RT-PCR, reverse transcription-PCR
- SDS, sodium dodecyl sulfate
- TACC3, transforming acidic coiled-coil-containing protein 3
- fusion gene
- proliferation
- tumorigenesis
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Deegan S, Saveljeva S, Logue SE, Pakos-Zebrucka K, Gupta S, Vandenabeele P, Bertrand MJM, Samali A. Deficiency in the mitochondrial apoptotic pathway reveals the toxic potential of autophagy under ER stress conditions. Autophagy 2015; 10:1921-36. [PMID: 25470234 PMCID: PMC4502706 DOI: 10.4161/15548627.2014.981790] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Endoplasmic reticulum (ER) stress-induced cell death is normally associated with activation of the mitochondrial apoptotic pathway, which is characterized by CYCS (cytochrome c, somatic) release, apoptosome formation, and caspase activation, resulting in cell death. In this study, we demonstrate that under conditions of ER stress cells devoid of CASP9/caspase-9 or BAX and BAK1, and therefore defective in the mitochondrial apoptotic pathway, still undergo a delayed form of cell death associated with the activation of caspases, therefore revealing the existence of an alternative stress-induced caspase activation pathway. We identified CASP8/caspase-8 as the apical protease in this caspase cascade, and found that knockdown of either of the key autophagic genes, ATG5 or ATG7, impacted on CASP8 activation and cell death induction, highlighting the crucial role of autophagy in the activation of this novel ER stress-induced death pathway. In line with this, we identified a protein complex composed of ATG5, FADD, and pro-CASP8 whose assembly coincides with caspase activation and cell death induction. Together, our results reveal the toxic potential of autophagy in cells undergoing ER stress that are defective in the mitochondrial apoptotic pathway, and suggest a model in which the autophagosome functions as a platform facilitating pro-CASP8 activation. Chemoresistance, a common problem in the treatment of cancer, is frequently caused by the downregulation of key mitochondrial death effector proteins. Alternate stress-induced apoptotic pathways, such as the one described here, may become of particular relevance for tackling the problem of chemoresistance in cancer cells.
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Key Words
- ATG, autophagy related
- BAK1, BCL2-antagonist/killer 1
- BAX, BCL2-associated X protein
- BCL2, B-cell CLL/lymphoma 2
- DDIT3, DNA-damage-inducible transcript 3
- DISC, death inducing signaling complex
- DTT, dithiothreitol
- ER, endoplasmic reticulum
- FADD, Fas (TNFRSF6)-associated via death domain
- GAPDH, glyceraldehyde 3-phosphate dehydrogenase
- HSPA5, heat shock 70 kDa protein 5 (glucose-regulated protein, 78 kDa)
- MAP1LC3 (LC3), microtubule-associated protein 1 light chain 3
- MEFs, mouse embryonic fibroblasts
- MOMP, mitochondrial outer membrane permeabilization
- PARP, poly (ADP-ribose) polymerase
- PBS, phosphate-buffered saline
- PI, propidium iodide
- TNF, tumor necrosis factor
- TNFSF10, tumor necrosis factor (ligand) superfamily, member 10
- Tg, thapsigargin
- Tm, tunicamycin
- apoptosis
- autophagic cell death
- autophagy
- caspase
- endoplasmic reticulum stress
- unfolded protein response
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Pekkonen P, Järviluoma A, Zinovkina N, Cvrljevic A, Prakash S, Westermarck J, Evan GI, Cesarman E, Verschuren EW, Ojala PM. KSHV viral cyclin interferes with T-cell development and induces lymphoma through Cdk6 and Notch activation in vivo. Cell Cycle 2015; 13:3670-84. [PMID: 25483078 PMCID: PMC4613844 DOI: 10.4161/15384101.2014.964118] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Kaposi's sarcoma herpesvirus (KSHV)-encoded v-cyclin, a homolog of cellular cyclin D2, activates cellular CDK6, promotes G1-S transition of the cell cycle, induces DNA damage, apoptosis, autophagy and is reported to have oncogenic potential. Here we show that in vivo expression of v-cyclin in the B- and T-cell lymphocyte compartments results in a markedly low survival due to high penetrance of early-onset T-cell lymphoma and pancarditis. The v-cyclin transgenic mice have smaller pre-tumorigenic lymphoid organs, showing decreased cellularity, and increased proliferation and apoptosis. Furthermore, v-cyclin expression resulted in decreased amounts of CD3-expressing mature T-cells in the secondary lymphoid organs concurrent with alterations in the T-cell subpopulations of the thymus. This suggests that v-cyclin interferes with normal T-cell development. As the Notch pathway is recognized for its role in both T-cell development and lymphoma initiation, we addressed the role of Notch in the v-cyclin-induced alterations. Fittingly, we demonstrate induction of Notch3 and Hes1 in the pre-tumorigenic thymi and lymphomas of v-cyclin expressing mice, and show that lymphoma growth and viability are dependent on activated Notch signaling. Notch3 transcription and growth of the lymphomas was dependent on CDK6, as determined by silencing of CDK6 expression or chemical inhibition, respectively. Our work here reveals a viral cyclin-CDK6 complex as an upstream regulator of Notch receptor, suggesting that cyclins can play a role in the initiation of Notch-dependent lymphomagenesis.
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Goudarzi KM, Nistér M, Lindström MS. mTOR inhibitors blunt the p53 response to nucleolar stress by regulating RPL11 and MDM2 levels. Cancer Biol Ther 2015; 15:1499-514. [PMID: 25482947 DOI: 10.4161/15384047.2014.955743] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Mechanistic target of rapamycin (mTOR) is a master regulator of cell growth through its ability to stimulate ribosome biogenesis and mRNA translation. In contrast, the p53 tumor suppressor negatively controls cell growth and is activated by a wide range of insults to the cell. The mTOR and p53 signaling pathways are connected by a number of different mechanisms. Chemotherapeutics that inhibit ribosome biogenesis often induce nucleolar stress and activation of p53. Here we have investigated how the p53 response to nucleolar stress is affected by simultaneous mTOR inhibition in osteosarcoma and glioma cell lines. We found that inhibitors of the mTOR pathway including rapamycin, wortmannin, and caffeine blunted the p53 response to nucleolar stress induced by actinomycin D. Synthetic inhibitors of mTOR (temsirolimus, LY294.002 and PP242) also impaired actinomycin D triggered p53 stabilization and induction of p21. Ribosomal protein (RPL11) is known to be required for p53 protein stabilization following nucleolar stress. Treatment of cells with mTOR inhibitors may lead to reduced synthesis of RPL11 and thereby destabilize p53. We found that rapamycin mimicked the effect of RPL11 depletion in terms of blunting the p53 response to nucleolar stress. However, the extent to which the levels of p53 and RPL11 were reduced by rapamycin varied between cell lines. Additional mechanisms whereby rapamycin blunts the p53 response to nucleolar stress are likely to be involved. Indeed, rapamycin increased the levels of endogenous MDM2 despite inhibition of its phosphorylation at Ser-166. Our findings may have implications for the design of combinatorial cancer treatments with mTOR pathway inhibitors.
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Key Words
- 5-FU, 5-fluorouracil
- Act D, actinomycin D
- BrdU, bromodeoxyuridine
- CHX, cycloheximide
- DMSO, dimethylsulphoxide
- DOX, doxorubicin
- EGCG, epigallocatechin-3-gallate
- FACS, fluorescence-activated cell sorting
- MPA, mycophenolic acid
- MTT, (3-[4, 5-dimethylthiazol-2-yl]-2, 5 diphenyl tetrazolium bromide)
- PI, propidium iodide
- actinomycin D
- caffeine
- glioma
- mTOR
- mTOR, mechanistic target of rapamycin
- nutlin-3
- p21
- p53
- rapamycin
- ribosomal protein L11
- ribosome biogenesis
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Zhou L, Shang Y, Jin Z, Zhang W, Lv C, Zhao X, Liu Y, Li N, Liang J. UHRF1 promotes proliferation of gastric cancer via mediating tumor suppressor gene hypermethylation. Cancer Biol Ther 2015; 16:1241-51. [PMID: 26147747 DOI: 10.1080/15384047.2015.1056411] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Epigenetic changes play significant roles in cancer development. UHRF1, an epigenetic regulator, has been shown to be overexpressed and to coordinate tumor suppressor gene (TSG) silencing in several cancers. In a previous study, we found that UHRF1 promoted gastric cancer (GC) invasion and metastasis. However, the role and underlying mechanism of UHRF1 in GC carcinogenesis remain largely unknown. In the present study, we investigated UHRF1 expression and function in GC proliferation and explored its downstream regulatory mechanism. The results demonstrated that UHRF1 overexpression was an independent and significant predictor of GC prognosis. Downregulation of UHRF1 suppressed GC proliferation and growth in vitro and in vivo, and UHRF1 upregulation showed opposite effects. Furthermore, downregulation of UHRF1 reactivated 7 TSGs, including CDX2, CDKN2A, RUNX3, FOXO4, PPARG, BRCA1 and PML, via promoter demethylation. These results provide insight into the GC proliferation process, and suggest that targeting UHRF1 represents a new therapeutic approach to block GC development.
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Key Words
- BRCA, breast cancer
- CDH4, cadherin 4
- CDKN2A, cyclin-dependent kinase inhibitor 2A
- CDX2, caudal type homeobox 2
- DNA methylation
- DNMT, DNA methyltransferase
- FOXO, forkhead box O
- GAPDH, glyceraldehyde 3-phosphate dehydrogenase
- GC, gastric cancer
- GO, gene ontology
- MSP, methylation-specific PCR
- NC, negative control
- PBS, phosphate buffered saline
- PI, propidium iodide
- PLA, Chinese People's Liberation Army
- PML, promyelocytic leukemia
- PPARG,peroxisome proliferator-activated receptor gamma
- RB, retinoblastoma protein
- RUNX3, runt-related transcription factor 3
- TSG, tumor suppressor gene
- UHRF1
- UHRF1, ubiquitin-like containing PHD ring finger 1
- gastric cancer
- mRNA, messenger RNA
- proliferation
- qRT-PCR, quantitative reverse transcription–polymerase chain reaction
- shRNA, short hairpin RNA
- tumor suppressor gene
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Hattori T, Watanabe-Takahashi M, Ohoka N, Hamabata T, Furukawa K, Nishikawa K, Naito M. Proteasome inhibitors prevent cell death and prolong survival of mice challenged by Shiga toxin. FEBS Open Bio 2015; 5:605-14. [PMID: 26273560 PMCID: PMC4534485 DOI: 10.1016/j.fob.2015.06.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 06/05/2015] [Accepted: 06/08/2015] [Indexed: 11/23/2022] Open
Abstract
Shiga toxin (Stx) rapidly reduces the level of short-lived anti-apoptotic proteins. Stx induces activation of caspase 9 and apoptosis. Proteasome inhibitors prevent the reduction of anti-apoptotic proteins. Proteasome inhibitors suppress Stx-induced apoptosis. Bortezomib prolongs the survival of mice challenged with a lethal dose of Stx.
Shiga toxin (Stx) causes fatal systemic complications. Stx induces apoptosis, but the mechanism of which is unclear. We report that Stx induced rapid reduction of short-lived anti-apoptotic proteins followed by activation of caspase 9 and the progression of apoptosis. Proteasome inhibitors prevented the reduction of anti-apoptotic proteins, and inhibited caspase activation and apoptosis, suggesting that the reduction of anti-apoptotic proteins is a prerequisite for Stx-induced apoptosis. A clinically approved proteasome inhibitor, bortezomib, prolonged the survival of mice challenged by Stx. These results imply that proteasome inhibition may be a novel approach to prevent the fatal effects of Stx.
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Key Words
- Apoptosis
- Apoptosis inhibitory proteins
- BRZ, bortezomib
- CHX, cycloheximide
- ER, endoplasmic reticulum
- FLIP, FLICE (FADD-like IL-1β-converting enzyme)-inhibitory protein
- Mcl-1, myeloid cell leukemia 1
- PARP, Poly(ADP-ribose) polymerase
- PI, propidium iodide
- Proteasome
- Proteasome inhibitor
- STEC, Shiga toxin-producing Escherichia coli
- Shiga toxin
- Stx, Shiga toxin
- c-IAP1, cellular inhibitor of apoptosis protein 1
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Grimaldi A, Santini D, Zappavigna S, Lombardi A, Misso G, Boccellino M, Desiderio V, Vitiello PP, Di Lorenzo G, Zoccoli A, Pantano F, Caraglia M. Antagonistic effects of chloroquine on autophagy occurrence potentiate the anticancer effects of everolimus on renal cancer cells. Cancer Biol Ther 2015; 16:567-79. [PMID: 25866016 DOI: 10.1080/15384047.2015.1018494] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Renal cell carcinoma is an aggressive disease often asymptomatic and weakly chemo-radiosensitive. Currently, new biologic drugs are used among which everolimus, an mTOR inhibitor, that has been approved for second-line therapy. Since mTOR is involved in the control of autophagy, its antitumor capacity is often limited. In this view, chloroquine, a 4-alkylamino substituted quinoline family member, is an autophagy inhibitor that blocks the fusion of autophagosomes and lysosomes. In the present study, we evaluated the effects of everolimus alone or in combination with chloroquine on renal cancer cell viability and verified possible synergism. Our results demonstrate that renal cancer cells are differently sensitive to everolimus and chloroquine and the pharmacological combination everolimus/chloroquine was strongly synergistic inducing cell viability inhibition. In details, the pharmacological synergism occurs when chloroquine is administered before everolimus. In addition, we found a flow autophagic block and shift of death mechanisms to apoptosis. This event was associated with decrease of Beclin-1/Bcl(-)2 complex and parallel reduction of anti-apoptotic protein Bcl(-)2 in combined treatment. At last, we found that the enhancement of apoptosis induced by drug combination occurs through the intrinsic mitochondrial apoptotic pathway activation, while the extrinsic pathway is involved only partly following its activation by chloroquine. These results provide the basis for new therapeutic strategies for the treatment of renal cell carcinoma after appropriate clinical trial.
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Ajao C, Andersson MA, Teplova VV, Nagy S, Gahmberg CG, Andersson LC, Hautaniemi M, Kakasi B, Roivainen M, Salkinoja-Salonen M. Mitochondrial toxicity of triclosan on mammalian cells. Toxicol Rep 2015; 2:624-637. [PMID: 28962398 PMCID: PMC5598359 DOI: 10.1016/j.toxrep.2015.03.012] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 03/29/2015] [Accepted: 03/30/2015] [Indexed: 01/08/2023] Open
Abstract
Effects of triclosan (5-chloro-2'-(2,4-dichlorophenoxy)phenol) on mammalian cells were investigated using human peripheral blood mono nuclear cells (PBMC), keratinocytes (HaCaT), porcine spermatozoa and kidney tubular epithelial cells (PK-15), murine pancreatic islets (MIN-6) and neuroblastoma cells (MNA) as targets. We show that triclosan (1-10 μg ml-1) depolarised the mitochondria, upshifted the rate of glucose consumption in PMBC, HaCaT, PK-15 and MNA, and subsequently induced metabolic acidosis. Triclosan induced a regression of insulin producing pancreatic islets into tiny pycnotic cells and necrotic death. Short exposure to low concentrations of triclosan (30 min, ≤1 μg/ml) paralyzed the high amplitude tail beating and progressive motility of spermatozoa, within 30 min exposure, depolarized the spermatozoan mitochondria and hyperpolarised the acrosome region of the sperm head and the flagellar fibrous sheath (distal part of the flagellum). Experiments with isolated rat liver mitochondria showed that triclosan impaired oxidative phosphorylation, downshifted ATP synthesis, uncoupled respiration and provoked excessive oxygen uptake. These exposure concentrations are 100-1000 fold lower that those permitted in consumer goods. The mitochondriotoxic mechanism of triclosan differs from that of valinomycin, cereulide and the enniatins by not involving potassium ionophoric activity.
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Key Words
- Acidosis
- BCF, bioconcentration factor
- EC50, concentration that diminishes the respective vitality parameter by ≥50%
- Electric transmembrane potential
- Glycolysis
- HaCaT, a spontaneously immortalized (non-neoplastic) keratinocyte cell line
- JC-1, 5,5′,6,6′-tetrachloro-1,1′,3,3′-tetraethylbenzimidazolyl-carbocyanine iodide
- MIC, minimal inhibitory concentration
- MIN-6, a murine pancreatic beta cell line
- MNA, a murine neuroblastoma cells
- Oxidative phosphorylation
- PBMC, monocyte-enriched peripheral blood mononuclear cells
- PI, propidium iodide
- PK-15, a porcine kidney tubular epithelial cell line
- PN, pyridine nucleotides
- RLM, rat liver mitochondria
- Sperm motility
- TPP+, tetraphenylphosphonium
- Uncoupler
- ΔΨ, electric transmembrane potential
- ΔΨm, membrane potential of the mitochondrial membrane
- ΔΨp, membrane potential of the plasma membrane
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CRISPR-Cas system enables fast and simple genome editing of industrial Saccharomyces cerevisiae strains. Metab Eng Commun 2015; 2:13-22. [PMID: 34150504 PMCID: PMC8193243 DOI: 10.1016/j.meteno.2015.03.001] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 01/21/2015] [Accepted: 03/11/2015] [Indexed: 11/24/2022] Open
Abstract
There is a demand to develop 3rd generation biorefineries that integrate energy production with the production of higher value chemicals from renewable feedstocks. Here, robust and stress-tolerant industrial strains of Saccharomyces cerevisiae will be suitable production organisms. However, their genetic manipulation is challenging, as they are usually diploid or polyploid. Therefore, there is a need to develop more efficient genetic engineering tools. We applied a CRISPR–Cas9 system for genome editing of different industrial strains, and show simultaneous disruption of two alleles of a gene in several unrelated strains with the efficiency ranging between 65% and 78%. We also achieved simultaneous disruption and knock-in of a reporter gene, and demonstrate the applicability of the method by designing lactic acid-producing strains in a single transformation event, where insertion of a heterologous gene and disruption of two endogenous genes occurred simultaneously. Our study provides a foundation for efficient engineering of industrial yeast cell factories. We developed CRISPR–Cas9-based system for gene disruptions in industrial yeast. We showed high rate of disruption efficiency in unrelated industrial strains. Gene knock-in may be performed simultaneously with gene disruption. Use of the described Cas9-based system results in marker-free stable genetic modifications. The method was applied for single-step construction of lactic acid-producing strains.
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Key Words
- Biorefineries
- CRISPR–Cas9
- CRISPR–Cas9, clustered regularly interspaced short palindromic repeats–CRISPR-associated endonuclease 9
- Chemical production
- DSB, double strand break
- GOI, gene of interest
- Genome editing
- HDR, homology-directed repair
- HR, homologous recombination
- Industrial yeast
- NHEJ, non-homologous end joining
- PAM, protospacer adjacent motif
- PI, propidium iodide
- SNPs, single nucleotide polymorphisms
- TALENs, transcription activator-like effector nucleases
- USER, uracil-specific excision reaction
- ZFNs, zinc finger nucleases
- crRNA, CRISPR RNA
- gRNA, guide RNA
- tracrRNA, trans-activating RNA
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Tamura M, Kunihiro S, Hamashima Y, Yoshioka Y, Tone S, Kameda K. An improved superoxide-generating nanodevice for oxidative stress studies in cultured cells. ACTA ACUST UNITED AC 2015. [PMID: 28626696 PMCID: PMC5466258 DOI: 10.1016/j.btre.2015.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Our previously developed O2−-generating tool was unstable in culture medium. A new nanodevice, Device II, was prepared by cross-linking of the original device. The new nanodevice was much more stable in culture medium than the original device. Device II efficiently induced cell death mainly through apoptosis.
The effects of reactive oxygen species on cells have attracted great attention from both physiological and pathological aspects. Superoxide (O2−) is the primary reactive oxygen species formed in animals. We previously developed an O2−-generating nanodevice consisting of NADPH oxidase 2 (Nox2) and modulated activating factors. However, the device was subsequently found to be unstable in a standard culture medium. Here we improved the device in stability by cross-linking. This new nanodevice, Device II, had a half-life of 3 h at 37 °C in the medium. Device II induced cell death in 80% of HEK293 cells after 24 h of incubation. Superoxide dismutase alone did not diminish the effect of the device, but eliminated the effect when used together with catalase, confirming that the cell death was caused by H2O2 derived from O2−. Flow cytometric analyses revealed that Device II induced caspase-3 activation in HEK293 cells, suggesting that the cell death proceeded largely through apoptosis.
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Key Words
- Caspase-3
- EDC, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide
- MEM, Eagle’s minimal essential medium
- NV, DEVD-NucView488
- Nanodevice
- Nox, NADPH oxidase
- PBS, phosphate-buffered saline
- PI, propidium iodide
- PIPES, piperazine-N,N′-bis(ethanesulfonic acid)
- ROS, reactive oxygen species
- RacQ61L, Rac(Q61L, C189S)
- SOD, superoxide dismutase
- Superoxide
- cyt.b558, cytochrome b558
- p67N–p47N, p67phox(1-210)-p47phox(1-286)
- sulfo-NHSN, -hydroxysulfosuccinimide
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Mashiko S, Kitatani K, Toyoshima M, Ichimura A, Dan T, Usui T, Ishibashi M, Shigeta S, Nagase S, Miyata T, Yaegashi N. Inhibition of plasminogen activator inhibitor-1 is a potential therapeutic strategy in ovarian cancer. Cancer Biol Ther 2015; 16:253-60. [PMID: 25587663 PMCID: PMC4623014 DOI: 10.1080/15384047.2014.1001271] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 10/14/2014] [Accepted: 12/18/2014] [Indexed: 10/22/2022] Open
Abstract
Plasminogen activator inhibitor (PAI)-1 is predictive of poor outcome in several types of cancer. The present study investigated the biological role for PAI-1 in ovarian cancer and potential of targeted pharmacotherapeutics. In patients with ovarian cancer, PAI-1 mRNA expression in tumor tissues was positively correlated with poor prognosis. To determine the role of PAI-1 in cell proliferation in ovarian cancer, the effects of PAI-1 inhibition were examined in PAI-1-expressing ovarian cancer cells. PAI-1 knockdown by small interfering RNA resulted in significant suppression of cell growth accompanied with G2/M cell cycle arrest and intrinsic apoptosis. Similarly, treatment with the small molecule PAI-1 inhibitor TM5275 effectively blocked cell proliferation of ovarian cancer cells that highly express PAI-1. Together these results suggest that PAI-1 promotes cell growth in ovarian cancer. Interestingly, expression of PAI-1 was increased in ovarian clear cell carcinoma compared with that in serous tumors. Our results suggest that PAI-1 inhibition promotes cell cycle arrest and apoptosis in ovarian cancer and that PAI-1 inhibitors potentially represent a novel class of anti-tumor agents.
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Cicchini M, Chakrabarti R, Kongara S, Price S, Nahar R, Lozy F, Zhong H, Vazquez A, Kang Y, Karantza V. Autophagy regulator BECN1 suppresses mammary tumorigenesis driven by WNT1 activation and following parity. Autophagy 2014; 10:2036-52. [PMID: 25483966 PMCID: PMC4502817 DOI: 10.4161/auto.34398] [Citation(s) in RCA: 114] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Earlier studies reported allelic deletion of the essential autophagy regulator BECN1 in breast cancers implicating BECN1 loss, and likely defective autophagy, in tumorigenesis. Recent studies have questioned the tumor suppressive role of autophagy, as autophagy-related gene (Atg) defects generally suppress tumorigenesis in well-characterized mouse tumor models. We now report that, while it delays or does not alter mammary tumorigenesis driven by Palb2 loss or ERBB2 and PyMT overexpression, monoallelic Becn1 loss promotes mammary tumor development in 2 specific contexts, namely following parity and in association with wingless-type MMTV integration site family, member 1 (WNT1) activation. Our studies demonstrate that Becn1 heterozygosity, which results in immature mammary epithelial cell expansion and aberrant TNFRSF11A/TNR11/RANK (tumor necrosis factor receptor superfamily, member 11a, NFKB activator) signaling, promotes mammary tumorigenesis in multiparous FVB/N mice and in cooperation with the progenitor cell-transforming WNT1 oncogene. Similar to our Becn1(+/-);MMTV-Wnt1 mouse model, low BECN1 expression and an activated WNT pathway gene signature correlate with the triple-negative subtype, TNFRSF11A axis activation and poor prognosis in human breast cancers. Our results suggest that BECN1 may have nonautophagy-related roles in mammary development, provide insight in the seemingly paradoxical roles of BECN1 in tumorigenesis, and constitute the basis for further studies on the pathophysiology and treatment of clinically aggressive triple negative breast cancers (TNBCs).
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Key Words
- 8-O-dG, 8-oxo-7, 8-dihydroguanine
- ATG, autophagy-related
- BECN1, Beclin 1, autophagy-related
- BSA, bovine serum albumin
- Beclin 1
- CASP3, caspase 3
- CD24, cluster of differentiation 24
- DAPI, 4′, 6-diamidino-2-phenylindole
- DFS, disease-free survival
- DMEM, Dulbecco's modified Eagle's medium
- E, 17b-estradiol
- EGF, epidermal growth factor
- EGFP, enhanced green fluorescent protein
- EGFR/ERBB1, epidermal growth factor receptor
- EM, electron microscopy
- EMT, epithelial-to-mesenchymal transition
- ERBB2, v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2
- ESR1, estrogen receptor 1
- FACS, fluorescence activated cell sorting
- FGF2/bFGF, fibroblast growth factor 2 (basic)
- GSEA, gene set enrichment analysis
- H&E, hematoxylin &, eosin
- HR, hormone receptor
- IF, immunofluorescence
- IHC, immunohistochemistry
- IL, interleukin
- ITGB1/CD29, Integrin, beta 1 (fibronectin receptor beta polypeptide, antigen CD29 includes MDF2, MSK12)
- ITGB3/CD61, integrin, beta 3 (platelet glycoprotein IIIa, antigen CD61)
- KRT, keratin
- Keratin 6
- LIN−, lineage negative (CD31− CD45− LY76−)
- LY76/TER119, lymphocyte antigen 76
- MAP1LC3B/LC3B, microtubule-associated protein 1 light chain 3 beta
- MEC, mammary epithelial cell
- MEGM, mammary epithelial growth medium
- MGs, mammary glands
- MKI67, marker of proliferation Ki-67
- MMTV, mouse mammary tumor virus
- MaPC, mammary progenitor cell
- MaSC, mammary stem cell
- NFKB
- NFKB/NFkB, nuclear factor of kappa light polypeptide gene enhancer in B-cells
- PBS, phosphate-buffered saline
- PECAM1/CD31, platelet/endothelial cell adhesion molecule 1
- PGR, progesterone receptor
- PI, propidium iodide
- PTPRC/CD45, protein tyrosine phosphatase, receptor type, C
- RELA/P65, v-rel avian reticuloendotheliosis viral oncogene homolog a
- ROS, reactive oxygen species
- SD, standard deviation
- SNPs, single nucleotide polymorphisms
- SQSTM1/p62, sequestosome1
- TEBs, terminal end buds
- TNBC
- TNBCs, triple-negative breast cancers
- TNF, tumor necrosis factor
- TNF11
- TNFRSF11A
- TNFRSF11A/TNR11/RANK, tumor necrosis factor receptor superfamily, member 11a, NFKB activator
- TNFSF11
- TNFSF11/TNF11/RANKL, tumor necrosis factor (ligand) superfamily, member 11
- TNR11
- TP53 (TRP53 in mice), tumor protein p53 (transformation related protein 53 in mice)
- WNT1
- WNT1, wingless-Type MMTV integration site family, member 1
- basal-like breast cancer
- iMMECs, immortalized mouse mammary epithelial cells
- p-KRT8/p-K8, phosphorylated Keratin 8
- parity
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