bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from MK-5108, a Highly Selective Aurora-A Kinase Inhibitor, Shows Antitumor Activity Alone and in Combination with Docetaxel
Authors: Shimomura Toshiyasu , Hasako Shinichi , Nakatsuru Yoko , Mita Takashi , Ichikawa Koji , Kodera Tsutomu , Sakai Takumi , Nambu Tadahiro , Miyamoto Mayu , Takahashi Ikuko , Miki Satomi , Kawanishi Nobuhiko , Ohkubo Mitsuru , Kotani Hidehito , Iwasawa Yoshikazu
Published: April 2023

Abstract
Aurora-A kinase is a one of the key regulators during mitosis progression. Aurora-A kinase is a potential target for anticancer therapies because overexpression of Aurora-A, which is frequently observed in some human cancers, results in aberrant mitosis leading to chromosomal instability and possibly tumorigenesis. MK-5108 is a novel small molecule with potent inhibitory activity against Aurora-A kinase. Although most of the Aurora-kinase inhibitors target both Aurora-A and Aurora-B, MK-5108 specifically inhibited Aurora-A kinase in a panel of protein kinase assays. Inhibition of Aurora-A by MK-5108 in cultured cells induced cell cycle arrest at the G2-M phase in flow cytometry analysis. The effect was confirmed by the accumulation of cells with expression of phosphorylated Histone H3 and inhibition of Aurora-A autophosphorylation by immunostaining assays. MK-5108 also induced phosphorylated Histone H3 in skin and xenograft tumor tissues in a nude rat xenograft model. MK-5108 inhibited growth of human tumor cell lines in culture and in different xenograft models. Furthermore, the combination of MK-5108 and docetaxel showed enhanced antitumor activities compared with control and docetaxel alone–treated animals without exacerbating the adverse effects of docetaxel. MK-5108 is currently tested in clinical trials and offers a new therapeutic approach to combat human cancers as a single agent or in combination with existing taxane therapies. Mol Cancer Ther; 9(1); 157–66
Data from Targeting homologous recombination using imatinib results in enhanced tumor cell chemosensitivity and radiosensitivity
Authors: Choudhury Ananya , Zhao Helen , Jalali Farid , AL Rashid Shahnaz , Ran Jane , Supiot Stephane , Kiltie Anne E. , Bristow Robert G.
Published: April 2023

Abstract
RAD51 is a key protein in the homologous recombination (HR) pathway of DNA double-strand break repair, and HR represents a novel target for cancer therapy. Because imatinib (Gleevec) has been reported to reduce RAD51 protein levels, we tested the clonogenic survival for RT112, H1299, PANC1, and PC3 tumor cell lines of varying p53 status and normal GM05757 normal fibroblasts after exposure to single agent imatinib (0–20 μmol/L; 0–72 hours). We also combined imatinib with DNA damaging agents that are toxic to RAD51-deficient cells, including ionizing radiation, gemcitabine, and mitomycin C. We observed decreased nuclear expression and chromatin binding of RAD51 protein following imatinib treatment. Imatinib also resulted in decreased error-free HR as determined by a flow cytometry–based integrated direct repeat-green fusion protein reporter system; this correlated to reduced RAD51 expression. Clonogenic survival experiments revealed increased cell kill for imatinib-treated cells in combination with ionizing radiation, gemcitabine, and mitomycin C, due in part to mitotic catastrophe. In experiments using imatinib and gemcitabine, tumor cell lines were sensitized to a greater extent than normal fibroblasts. This preservation of the therapeutic ratio was confirmed in vivo using PC3 xenograft growth delay and intestinal crypt cell clonogenic assays. HR inhibition may be an additional mechanism of action for the chemosensitization and radiosensitization of solid tumors with imatinib with preservation of the therapeutic ratio. [Mol Cancer Ther 2009;8(1):203–13]
Data from Chemokine CXC receptor 4–mediated glioma tumor tracking by bone marrow–derived neural progenitor/stem cells
Authors: Xu Qijin , Yuan Xiangpeng , Xu Minlin , McLafferty Fred , Hu Jinwei , Lee Bong Seop , Liu Gentao , Zeng Zhaohui , Black Keith L. , Yu John S.
Published: April 2023

Abstract
Malignant gliomas manifest frequent tumor recurrence after surgical resection and/or other treatment because of their nature of invasiveness and dissemination. The recognized brain tumor-tracking property of neural progenitor/stem cells opened the possibility of targeting malignant brain tumors using neural progenitor/stem cells. We and others have previously shown that fetal neural progenitor/stem cells can be used to deliver therapeutic molecules to brain tumors. Our recent work has further shown that gene delivery by bone marrow–derived neural progenitor/stem cells achieves therapeutic effects in a glioma model. In this study, we isolate and characterize bone marrow–derived neural progenitor/stem cells, which also express the chemokine receptor chemokine CXC receptor 4 (CXCR4). We show that CXCR4 is required for their chemotaxis and extracellular matrix invasion against a gradient of glioma soluble factors. Furthermore, β-galactosidase-labeled bone marrow–derived neural progenitor/stem cells implanted in the contralateral side of the brain were shown to track gliomas as early as day 1 and increased through days 3 and 7. Intracranial glioma tracking by bone marrow–derived neural progenitor/stem cells is significantly inhibited by preincubation of bone marrow–derived neural progenitor/stem cells with a blocking anti–CXCR4 antibody, suggesting a CXCR4–dependent tracking mechanism. Glioma tracking bone marrow–derived neural progenitor/stem cells were found to express progenitor/stem cell markers, as well as CXCR4. Although bromodeoxyuridine incorporation assays and proliferating antigen staining indicated that tumor tracking bone marrow–derived neural progenitor/stem cells were mostly nonproliferating, these cells survive in the local tumor environment with little apoptosis. Elucidating the molecular mechanism of brain tumor tracking by adult source stem cells may provide basis for the development of future targeted therapy for malignant brain tumors. [Mol Cancer Ther 2009;8(9):2746–53]
Data from Garcinol Potentiates TRAIL-Induced Apoptosis through Modulation of Death Receptors and Antiapoptotic Proteins
Authors: Prasad Sahdeo , Ravindran Jayaraj , Sung Bokyung , Pandey Manoj K. , Aggarwal Bharat B.
Published: April 2023

Abstract
Whether garcinol, the active component of Garcinia indica, can modulate the sensitivity of cancer cells to TRAIL, a cytokine currently in phase II clinical trial, was investigated. We found that garcinol potentiated TRAIL-induced apoptosis of cancer cells as indicated by intracellular esterase activity, DNA strand breaks, accumulation of the membrane phospholipid phosphatidylserine, mitochondrial activity, and activation of caspase-8, -9, and -3. We found that garcinol, independent of the cell type, induced both of the TRAIL receptors, death receptor 4 (DR4) and DR5. Garcinol neither induced the receptors on normal cells nor sensitized them to TRAIL. Deletion of DR5 or DR4 by small interfering RNA significantly reduced the apoptosis induced by TRAIL and garcinol. In addition, garcinol downregulated various cell survival proteins including survivin, bcl-2, XIAP, and cFLIP, and induced bid cleavage, bax, and cytochrome c release. Induction of death receptors by garcinol was found to be independent of modulation of CCAAT/enhancer-binding protein-homologous protein, p53, bax, extracellular signal-regulated kinase, or c-Jun-NH2-kinase. The effect of garcinol was mediated through the generation of reactive oxygen species, in as much as induction of both death receptors, modulation of antiapoptotic and proapoptotic proteins, and potentiation of TRAIL-induced apoptosis were abolished by N-acetyl cysteine and glutathione. Interestingly, garcinol also converted TRAIL-resistant cells into TRAIL-sensitive cells. Overall, our results indicate that garcinol can potentiate TRAIL-induced apoptosis through upregulation of death receptors and downregulation of antiapoptotic proteins. Mol Cancer Ther; 9(4); 856–68. ©2010 AACR.
Data from Na,K-ATPase Subunits as Markers for Epithelial-Mesenchymal Transition in Cancer and Fibrosis
Authors: Rajasekaran Sigrid A. , Huynh Thu P. , Wolle Daniel G. , Espineda Cromwell E. , Inge Landon J. , Skay Anna , Lassman Charles , Nicholas Susanne B. , Harper Jeffrey F. , Reeves Anna E. , Ahmed Mansoor M. , Leatherman James M. , Mullin James M. , Rajasekaran Ayyappan K.
Published: April 2023

Abstract
Epithelial-to-mesenchymal transition (EMT) is an important developmental process, participates in tissue repair, and occurs during pathologic processes of tumor invasiveness, metastasis, and tissue fibrosis. The molecular mechanisms leading to EMT are poorly understood. Although it is well documented that transforming growth factor (TGF)-β plays a central role in the induction of EMT, the targets of TGF-β signaling are poorly defined. We have shown earlier that Na,K-ATPase β1-subunit levels are highly reduced in poorly differentiated kidney carcinoma cells in culture and in patients' tumor samples. In this study, we provide evidence that Na,K-ATPase is a new target of TGF-β1–mediated EMT in renal epithelial cells, a model system used in studies of both cancer progression and fibrosis. We show that following treatment with TGF-β1, the surface expression of the β1-subunit of Na,K-ATPase is reduced, before well-characterized EMT markers, and is associated with the acquisition of a mesenchymal phenotype. RNAi-mediated knockdown confirmed the specific involvement of the Na,K-ATPase β1-subunit in the loss of the epithelial phenotype and exogenous overexpression of the Na,K-ATPase β1-subunit attenuated TGF-β1–mediated EMT. We further show that both Na,K-ATPase α- and β-subunit levels are highly reduced in renal fibrotic tissues. These findings reveal for the first time that Na,K-ATPase is a target of TGF-β1–mediated EMT and is associated with the progression of EMT in cancer and fibrosis. Mol Cancer Ther; 9(6); 1515–24. ©2010 AACR.
Data from Identification of genes and molecular pathways involved in the progression of premalignant oral epithelia
Authors: Banerjee Abhijit G. , Bhattacharyya Indraneel , Vishwanatha Jamboor K.
Published: April 2023

Abstract
An early interventional effort in oral premalignancy requires novel molecular targets and diagnostic biomarkers to delay or reverse incidences of malignant progression. Microarray-based transcriptional profiling in disease states provides global insight into the causal biomolecular processes and novel pathways involved. In this study, we investigated transcript profiles in precancerous oral lesions to identify nearly 1,700 genes as significantly overexpressed or underexpressed and a primarily affected metabolic pathway that may be responsible for irreversible transition to progressive stages of oral cancer. For the first time, we show a convergence of several genes and pathways known for their oncogenic capabilities, in progression of premalignant oral epithelial tissues. This study consequently provides a molecular basis for persistent proinflammatory conditions in oral premalignant tissues. We found that lipocalin-type prostaglandin D2 synthase (PTGDS), a key enzyme in the arachidonic acid metabolism pathway, as repressed in premalignant stages. We show the protective role of these enzyme-derived metabolites in inhibiting cell proliferation using an in vitro oral cancer progression model. We have also confirmed the overexpression of two invasion-related biomarkers, psoriasin (PSOR1) and versican (CSPG2), in oral premalignant and malignant archival tissues. Our results clearly indicate that pharmacologic intervention with anti-inflammatory prostaglandin D2–like analogues may help prevent or delay oral epithelial carcinogenesis because of metabolic restoration of a negative feedback regulatory loop through its several cognate receptors or target molecules. Further studies directed toward a multitude of possible protective mechanisms of this lipocalin-type enzyme or its products in oral cancer progression are warranted.
Data from Triptolide is an inhibitor of RNA polymerase I and II–dependent transcription leading predominantly to down-regulation of short-lived mRNA
Authors: Vispé Stéphane , DeVries Luc , Créancier Laurent , Besse Jérome , Bréand Sophie , Hobson David J. , Svejstrup Jesper Q. , Annereau Jean-Philippe , Cussac Didier , Dumontet Charles , Guilbaud Nicolas , Barret Jean-Marc , Bailly Christian
Published: April 2023

Abstract
Triptolide, a natural product extracted from the Chinese plant Tripterygium wilfordii, possesses antitumor properties. Despite numerous reports showing the proapoptotic capacity and the inhibition of NF-κB–mediated transcription by triptolide, the identity of its cellular target is still unknown. To clarify its mechanism of action, we further investigated the effect of triptolide on RNA synthesis in the human non–small cell lung cancer cell line A549. Triptolide inhibited both total RNA and mRNA de novo synthesis, with the primary action being on the latter pool. We used 44K human pan-genomic DNA microarrays and identified the genes primarily affected by a short treatment with triptolide. Among the modulated genes, up to 98% are down-regulated, encompassing a large array of oncogenes including transcription factors and cell cycle regulators. We next observed that triptolide induced a rapid depletion of RPB1, the RNA polymerase II main subunit that is considered a hallmark of a transcription elongation blockage. However, we also show that triptolide does not directly interact with the RNA polymerase II complex nor does it damage DNA. We thus conclude that triptolide is an original pharmacologic inhibitor of RNA polymerase activity, affecting indirectly the transcription machinery, leading to a rapid depletion of short-lived mRNA, including transcription factors, cell cycle regulators such as CDC25A, and the oncogenes MYC and Src. Overall, the data shed light on the effect of triptolide on transcription, along with its novel potential applications in cancers, including acute myeloid leukemia, which is in part driven by the aforementioned oncogenic factors. [Mol Cancer Ther 2009;8(10):2780–90]
Data from BNC105: A Novel Tubulin Polymerization Inhibitor That Selectively Disrupts Tumor Vasculature and Displays Single-Agent Antitumor Efficacy
Authors: Kremmidiotis Gabriel , Leske Annabell F. , Lavranos Tina C. , Beaumont Donna , Gasic Jelena , Hall Allison , O'Callaghan Michael , Matthews Clayton A. , Flynn Bernard
Published: April 2023

Abstract
Vascular disruption agents (VDA) cause occlusion of tumor vasculature, resulting in hypoxia-driven tumor cell necrosis. Tumor vascular disruption is a therapeutic strategy of great potential; however, VDAs currently under development display a narrow therapeutic margin, with cardiovascular toxicity posing a dose-limiting obstacle. Discovery of new VDAs, which display a wider therapeutic margin, may allow attainment of improved clinical outcomes. To identify such compounds, we used an in vitro selectivity screening approach that exploits the fact that tumor endothelial cells are in a constant state of activation and angiogenesis and do not undergo senescence. Our effort yielded the compound BNC105. This compound acts as a tubulin polymerization inhibitor and displays 80-fold higher potency against endothelial cells that are actively proliferating or are engaged in the formation of in vitro capillaries compared with nonproliferating endothelial cells or endothelium found in stable capillaries. This selectivity was not observed with CA4, a VDA currently under evaluation in phase III clinical trials. BNC105 is more potent and offers a wider therapeutic window. CA4 produces 90% vascular disruption at its no observed adverse event level (NOAEL), whereas BNC105 causes 95% vascular disruption at 1/8th of its NOAEL. Tissue distribution analysis of BNC105 in tumor-bearing mice showed that while the drug is cleared from all tissues 24 hours after administration, it is still present at high concentrations within the solid tumor mass. Furthermore, BNC105 treatment causes tumor regressions with complete tumor clearance in 20% of treated animals. Mol Cancer Ther; 9(6); 1562–73. ©2010 AACR.
Data from MEK/ERK inhibitor U0126 affects in vitro and in vivo growth of embryonal rhabdomyosarcoma
Authors: Marampon Francesco , Bossi Gianluca , Ciccarelli Carmela , Di Rocco Agnese , Sacchi Ada , Pestell Richard G. , Zani Bianca M.
Published: April 2023

Abstract
We reported previously that the disruption of c-Myc through mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) inhibition blocks the expression of the transformed phenotype in the embryonal rhabdomyosarcoma (ERMS) cell line (RD), thereby inducing myogenic differentiation in vitro. In this article, we investigate whether MEK/ERK inhibition, by the MEK/ERK inhibitor U0126, affects c-Myc protein level and growth of RMS tumor in an in vivo xenograft model. U0126 significantly reduced RMS tumor growth in RD cell line-xenotransplanted mice. Immunobiochemical and immunohistochemical analysis showed (a) phospho-active ERK levels were reduced by U0126 therapy and unaltered in normal tissues, (b) phospho-Myc and c-Myc was reduced commensurate with phospho-ERK inhibition, and (c) reduction in Ki-67 and endothelial (CD31) marker expression. These results indicate that MEK/ERK inhibition affects growth and angiogenic signals in tumor. The RD-M1 cultured xenograft tumor-derived cell line and the ERMS cell line TE671 responded to U0126 by arresting growth, down-regulating c-Myc, and initiating myogenesis. All these results suggest a tight correlation of MEK/ERK inhibition with c-Myc down-regulation and arrest of tumor growth. Thus, MEK inhibitors may be investigated for a signal transduction-based targeting of the c-Myc as a therapeutic strategy in ERMS. [Mol Cancer Ther 2009;8(3):543–51]
Data from Induction of programmed cell death in ErbB2/HER2-expressing cancer cells by targeted delivery of apoptosis-inducing factor
Authors: Mahmud Hayat , Dälken Benjamin , Wels Winfried S.
Published: April 2023

Abstract
Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein with NADH oxidase activity that has a vital function in healthy cells but is also an important mediator of caspase-independent programmed cell death in stressed and damaged cells. Here, we generated a truncated AIF derivative (AIFΔ100) that lacks the mitochondrial import signal of the protein. Bacterially expressed AIFΔ100 was functionally active and induced cell death on microinjection into Vero cells accompanied by clear signs of apoptosis. For specific targeting to tumor cells, AIFΔ100 was genetically fused to the scFv(FRP5) antibody fragment that recognizes the ErbB2 (HER2) receptor tyrosine kinase frequently overexpressed in many human cancers. Recombinant scFv(FRP5)-AIFΔ100 (5-AIFΔ100) protein and a similar scFv(FRP5)-ETA252-366-AIFΔ100 (5-E-AIFΔ100) molecule harboring in addition the nontoxic translocation domain of Pseudomonas exotoxin A as an endosome escape function displayed binding to ErbB2-expressing cells followed by protein internalization and accumulation in intracellular vesicles. In the presence of the endosomolytic reagent chloroquine 5-E-AIFΔ100 but not the similar 5-AIFΔ100 protein displayed potent cell killing activity, which was strictly dependent on the expression of ErbB2 on the target cell surface. Our results show that recombinant AIF specifically targeted to human cancer cells and delivered into the cytosol has potent cell killing activity, suggesting this molecule as an effector function suitable for the development of humanized immunotoxin-like molecules. [Mol Cancer Ther 2009;8(6):1526–35]
Data from Curcumin Enhances the Effect of Cisplatin in Suppression of Head and Neck Squamous Cell Carcinoma via Inhibition of IKKβ Protein of the NFκB Pathway
Authors: Duarte Victor M. , Han Eugene , Veena Mysore S. , Salvado Amanda , Suh Jeffrey D. , Liang Li-Jung , Faull Kym F. , Srivatsan Eri S. , Wang Marilene B.
Published: April 2023

Abstract
Previous experiments have shown that curcumin or cisplatin treatment suppresses growth of head and neck squamous cell carcinoma (HNSCC). To study the potential cooperative effect of both agents, two HNSCC cell lines were treated with curcumin or cisplatin alone or in combination. In vivo studies consisted of intravenous tail vein injection of liposomal curcumin, with intraperitoneal cisplatin, into nude mice growing xenograft HNSCC tumors. Introduction of curcumin and suboptimal concentrations of cisplatin showed a significant suppressive effect compared with treatment with either agent alone. Reduced expression of cyclin D1, IκBα, phospho-IκBα, and IKKβ occurred in cisplatin- and curcumin-treated cell lines. Confocal microscopy showed expression of IKKβ in the nucleus of the cell lines. Chromatin immunoprecipitation assay on DNA isolated from IKKβ immunoprecipitated samples showed PCR amplification of interleukin-8 promoter sequences, a binding site of NFκB, indicating an interaction between IKKβ and NFκB. Curcumin inhibited IKKβ in the cytoplasm and nucleus, leading to reduced NFκB activity, with no effect on phospho-AKT. In vivo studies showed significant growth inhibition of xenograft tumors treated with a combination of liposomal curcumin and cisplatin. The suppressive effect of curcumin was mediated through inhibition of cytoplasmic and nuclear IKKβ, resulting in inhibition of NFκB activity. Cisplatin treatment led to cellular senescence, indicating an effect mediated by p53 activation. The mechanisms of the two agents through different growth signaling pathways suggest potential for the clinical use of subtherapeutic doses of cisplatin in combination with curcumin, which will allow effective suppression of tumor growth while minimizing the toxic side effects of cisplatin. Mol Cancer Ther; 9(10); 2665–75. ©2010 AACR.
Data from Mitogen-activated protein kinase kinase 1/2 inhibitors and 17-allylamino-17-demethoxygeldanamycin synergize to kill human gastrointestinal tumor cells in vitro via suppression of c-FLIP-s levels and activation of CD95
Authors: Park Margaret A. , Zhang Guo , Mitchell Clint , Rahmani Mohamed , Hamed Hossein , Hagan Michael P. , Yacoub Adly , Curiel David T. , Fisher Paul B. , Grant Steven , Dent Paul
Published: April 2023

Abstract
Prior studies have noted that inhibitors of mitogen-activated protein kinase (MAPK) kinase 1/2 (MEK1/2) enhanced geldanamycin lethality in malignant hematopoietic cells by promoting mitochondrial dysfunction. The present studies focused on defining the mechanism(s) by which these agents altered survival in carcinoma cells. MEK1/2 inhibitors [PD184352; AZD6244 (ARRY-142886)] interacted in a synergistic manner with geldanamycins [17-allylamino-17-demethoxygeldanamycin (17AAG) and 17-dimethylaminoethylamino-17-demethoxy-geldanamycin] to kill hepatoma and pancreatic carcinoma cells that correlated with inactivation of extracellular signal-regulated kinase 1/2 and AKT and with activation of p38 MAPK; p38 MAPK activation was reactive oxygen species dependent. Treatment of cells with MEK1/2 inhibitors and 17AAG reduced expression of c-FLIP-s that was mechanistically connected to loss of MEK1/2 and AKT function; inhibition of caspase-8 or overexpression of c-FLIP-s abolished cell killing by MEK1/2 inhibitors and 17AAG. Treatment of cells with MEK1/2 inhibitors and 17AAG caused a p38 MAPK-dependent plasma membrane clustering of CD95 without altering the levels or cleavage of FAS ligand. In parallel, treatment of cells with MEK1/2 inhibitors and 17AAG caused a p38 MAPK-dependent association of caspase-8 with CD95. Inhibition of p38 MAPK or knockdown of BID, FAS-associated death domain, or CD95 expression suppressed MEK1/2 inhibitor and 17AAG lethality. Similar correlative data were obtained using a xenograft flank tumor model system. Our data show that treatment of tumor cells with MEK1/2 inhibitors and 17AAG induces activation of the extrinsic pathway and that suppression of c-FLIP-s expression is crucial in transduction of the apoptotic signal from CD95 to promote cell death. [Mol Cancer Ther 2008;7(9):2633–48]
Data from Modulation of cell cycle and gene expression in pancreatic tumor cell lines by methionine deprivation (methionine stress): implications to the therapy of pancreatic adenocarcinoma
Authors: Kokkinakis Demetrius M. , Liu XiaoYan , Neuner Russell D.
Published: April 2023

Abstract
The effect of methionine deprivation (methionine stress) on the proliferation, survival, resistance to chemotherapy, and regulation of gene and protein expression in pancreatic tumor lines is examined. Methionine stress prevents successful mitosis and promotes cell cycle arrest and accumulation of cells with multiple micronuclei with decondensed chromatin. Inhibition of mitosis correlates with CDK1 down-regulation and/or inhibition of its function by Tyr15 phosphorylation or Thr161 dephosphorylation. Inhibition of cell cycle progression correlates with loss of hyperphosphorylated Rb and up-regulation of p21 via p53 and/or transforming growth factor-β (TGF-β) activation depending on p53 status. Although methionine stress–induced toxicity is not solely dependent on p53, the gain in p21 and loss in CDK1 transcription are more enhanced in wild-type p53 tumors. Up-regulation of SMAD7, a TGF-β signaling inhibitor, suggests that SMAD7 does not restrict the TGF-β-mediated induction of p21, although it may prevent up-regulation of p27. cDNA oligoarray analysis indicated a pleiotropic response to methionine stress. Cell cycle and mitotic arrest is in agreement with up-regulation of NF2, ETS2, CLU, GADD45α, GADD45β, and GADD45γ and down-regulation of AURKB, TOP2A, CCNA, CCNB, PRC1, BUB1, NuSAP, IFI16, and BRCA1. Down-regulation of AREG, AGTR1, M-CSF, and EGF, IGF, and VEGF receptors and up-regulation of GNA11 and IGFBP4 signify loss of growth factor support. PIN1, FEN1, and cABL up-regulation and LMNB1, AREG, RhoB, CCNG, TYMS, F3, and MGMT down-regulation suggest that methionine stress sensitizes the tumor cells to DNA-alkylating drugs, 5-fluorouracil, and radiation. Increased sensitivity of pancreatic tumor cell lines to temozolomide is shown under methionine stress conditions and is attributed in part to diminished O6-methylguanine-DNA methyltransferase and possibly to inhibition of the cell cycle progression.
Data from Gene Expression Signatures as a Guide to Treatment Strategies for In-Transit Metastatic Melanoma
Authors: Augustine Christina K. , Jung Sin-Ho , Sohn Insuk , Yoo Jin Soo , Yoshimoto Yasunori , Olson John A. , Friedman Henry S. , Ali-Osman Francis , Tyler Douglas S.
Published: April 2023

Abstract
In-transit metastatic melanoma, which typically presents as multifocal lesions, provides a unique setting to evaluate the utility of gene signatures for defining optimal regional therapeutic strategies and assessing the efficacy of treatment. The goal of this study was to determine whether a single multifocal lesion is representative of residual tumor burden in terms of gene expression signatures predictive of response to therapy. Using microarray-based gene expression profiling, we examined 55 in-transit melanoma lesions across 29 patients with multifocal disease. Principal component analysis, unsupervised hierarchical clustering, one-way ANOVA, binary regression analysis, and gene signatures predictive of oncogenic pathway activation were used to compare patterns of gene expression across all multifocal lesions from a patient. Patterns of gene expression were highly similar (P < 0.006; average r = 0.979) across pretreatment lesions from a single patient compared with the significantly different patterns observed across patients (P < 0.05). The findings presented in this study show that individual melanoma tumor nodules in patients with multifocal disease harbor similar patterns of gene expression and a single lesion can be used to predict response to chemotherapy, evaluate the activation status of oncogenic signaling pathways, and characterize other aspects of the biology of an individual patient's disease. These results will facilitate the use of gene expression profiling in melanoma regional therapy clinical trials to not only select optimal regional chemotherapeutic agents but to also allow for a more rational identification of candidates for specific targeted therapies and evaluation of their therapeutic efficacy. Mol Cancer Ther; 9(4); 779–90. ©2010 AACR.
Data from Gossypol Induces Apoptosis by Activating p53 in Prostate Cancer Cells and Prostate Tumor–Initiating Cells
Authors: Volate Suresh R. , Kawasaki Brian T. , Hurt Elaine M. , Milner John A. , Kim Young S. , White Jeffrey , Farrar William L.
Published: April 2023

Abstract
Prostate cancer continues to represent a burgeoning medical problem in the United States. Recent studies suggest that gossypol, a bioactive phytochemical produced by cotton plants, is a promising agent against prostate cancer. The current studies were undertaken to examine the chemotherapeutic efficacy of gossypol on human prostate cancer cell lines and prostate tumor–initiating cells. Gossypol reduced the viability of three prostate cancer cell lines (LAPC4, PC3, and DU145) with an IC50 between 3 and 5 μmol/L. Additionally, gossypol was effective at inhibiting prostate tumor–initiating cell-driven tumor growth in a nonobese diabetic/severe combined immunodeficient xenograft model. Our integrated molecular profiling approach encompassing proteomics, activated transcription factors, and genomics suggests that the decrease in viability was associated with increased DNA damage and the induction of apoptosis. Exposure of DU145 cells to gossypol (1–10 μmol/L) resulted in the activation of 13 proteins and 7 transcription factors, and the expression of 17 genes involved in the mitochondrial pathway of apoptosis. These studies show for the first time that gossypol treatment induces DNA damage and activates p53. Collectively, these data support the use of gossypol as a novel agent for prostate cancer. Mol Cancer Ther; 9(2); 461–70
Data from Organic Cation Transporters Modulate the Uptake and Cytotoxicity of Picoplatin, a Third-Generation Platinum Analogue
Authors: More Swati S. , Li Shuanglian , Yee Sook Wah , Chen Ligong , Xu Zhidong , Jablons David M. , Giacomini Kathleen M.
Published: April 2023

Abstract
Picoplatin, a third-generation platinum agent, is efficacious against lung cancers that are otherwise resistant or become refractory during platinum treatment. This effort was aimed at the determination of the influence of organic cation transporters 1, 2, and 3 (OCT1, OCT2, and OCT3) and their genetic variants on cellular uptake of picoplatin and on the individual components of the ensuing cytotoxicity such as DNA adduct formation. The effect of OCT1 on picoplatin pharmacokinetics and antitumor efficacy was determined using OCT knockout mice and HEK293 xenografts stably expressing OCT1. The uptake and DNA adduct formation of picoplatin were found to be significantly enhanced by the expression of the OCTs. Expression of OCT1 and OCT2, but not OCT3, significantly enhanced picoplatin cytotoxicity, which was reduced in the presence of an OCT inhibitor. Common reduced functional variants of OCT1 and OCT2 led to reduction in uptake and DNA adduct formation of picoplatin in comparison with the reference OCT1 and OCT2. Pharmacokinetic parameters of picoplatin in Oct1−/− and Oct1+/+ mice were not significantly different, suggesting that the transporters do not influence the disposition of the drug. In contrast, the volume of OCT1-expressing xenografts in mice was significantly reduced by picoplatin treatment, suggesting that OCT1 may enhance the antitumor efficacy of picoplatin. These studies provide a basis for follow-up clinical studies that would seek to examine the relationship between the anticancer efficacy of picoplatin and expression levels of OCTs and their genetic variants in tumors. Mol Cancer Ther; 9(4); 1058–69. ©2010 AACR.
Data from A Synergistic Interaction between Lapatinib and Chemotherapy Agents in a Panel of Cell Lines Is Due to the Inhibition of the Efflux Pump BCRP
Authors: Perry Jackie , Ghazaly Essam , Kitromilidou Christiana , McGrowder Eva H. , Joel Simon , Powles Thomas
Published: April 2023

Abstract
Lapatinib is a specific HER1 and 2 targeted tyrosine kinase inhibitor now widely used in combination with chemotherapy in the clinical setting. In this work, we investigated the interactions between lapatinib and specific chemotherapy agents (cisplatin, SN-38, topotecan) in a panel of cell lines [breast (n = 2), lung (n = 2), testis (n = 4)]. A high-sensitivity cell proliferation/cytotoxicity ATP assay and flow cytometry were used to determine cell viability, apoptosis, and the effect of the drugs on cell-cycle distribution. CalcuSyn analysis was employed to formally identify synergistic interactions between drugs. Intracellular concentrations of SN-38 were measured using a novel high-performance liquid chromatography (HPLC) technique. Flow cytometry and HPLC techniques were used to identify the effect of lapatinib on drug influx and efflux pumps, using specific substrates and inhibitors of these pumps. Results showed significant synergy between SN-38, and lapatinib in the majority of cell lines (combination index < 0.75), associated with increased apoptosis. This synergy was not universal but, when observed (Susa S/R, H1975, H358, and MDA-MB-231 cell lines), was related to SN-38 intracellular accumulation (2.2- to 4.8-fold increase, P < 0.05 for each), attributable to the inhibition of the breast cancer–related protein (BCRP) efflux pump by lapatinib. Flow cytometry analysis showed that lapatinib (10 μmol/L) inhibited the efflux of mitoxantrone, a specific substrate of the BCRP pump, in a manner similar to fumitremorgin C, a known BCRP inhibitor, confirming lapatinib as a BCRP inhibitor. This work shows that lapatinib has a direct inhibitory effect on BCRP accounting for the synergistic findings. The synergy is cell line dependent and related to the activity of specific efflux pumps. Mol Cancer Ther; 9(12); 3322–9. ©2010 AACR.
Data from Aflibercept Exerts Antivascular Effects and Enhances Levels of Anthracycline Chemotherapy In vivo in Human Acute Myeloid Leukemia Models
Authors: Lal Deepika , Park Jennifer A. , Demock Kellie , Marinaro Joseph , Perez Amanda M. , Lin Mei-Hui , Tian Lili , Mashtare Terry J. , Murphy Michael , Prey Joshua , Wetzler Meir , Fetterly Gerald J. , Wang Eunice S.
Published: April 2023

Abstract
We examined whether potent vascular endothelial growth factor (VEGF) blockade mediated by aflibercept, a decoy VEGF receptor (VEGFR) 1/2 moiety with stronger affinity for VEGF than bevacizumab, resulted in antileukemia effects and enhanced the efficacy of systemic chemotherapy. The efficacy of aflibercept alone and in combination with doxorubicin was evaluated in human VEGF-expressing acute myeloid leukemia (AML) cell lines and primary cells xenotransplanted into immunodeficient mice. Aflibercept reduced primary VEGF/VEGFR-positive AML colony formation growth in vitro and inhibited AML xenograft growth up to 93% in association with antiangiogenic and antiproliferative effects, hypoxia, and VEGF sequestration in multiple models. High VEGF-A expression by AML cells promoted in vivo xenograft growth and aflibercept sensitivity. Aflibercept therapy slowed disease progression in two systemic human AML xenograft models and reduced peripheral leukemia disease in a primary relapsed AML model in NOD/SCID/IL2Rγnull mice. Combination aflibercept and doxorubicin enhanced antitumor effects in local xenograft models. Sequential aflibercept followed by doxorubicin resulted in progressive anthracycline accumulation in marrow and extramedullary AML sites and resulted in 2-fold higher drug levels 24 hours after administration. In contrast, tissues (tumor, plasma, marrow) treated with chemotherapy only showed progressive drug clearance over time. Combination aflibercept and doxorubicin also resulted in vascular narrowing, decreased vessel number, and perivascular apoptosis. These data suggest that inefficient drug delivery by leukemia-associated vasculature may mediate chemoresistance and support further clinical evaluation of combination aflibercept and anthracycline therapy in refractory/relapsed AML patients. Mol Cancer Ther; 9(10); 2737–51. ©2010 AACR.
Data from Potent and Selective Inhibition of Polycythemia by the Quinoxaline JAK2 Inhibitor NVP-BSK805
Authors: Baffert Fabienne , Régnier Catherine H. , De Pover Alain , Pissot-Soldermann Carole , Tavares Gisele A. , Blasco Francesca , Brueggen Josef , Chène Patrick , Drueckes Peter , Erdmann Dirk , Furet Pascal , Gerspacher Marc , Lang Marc , Ledieu David , Nolan Lynda , Ruetz Stephan , Trappe Joerg , Vangrevelinghe Eric , Wartmann Markus , Wyder Lorenza , Hofmann Francesco , Radimerski Thomas
Published: April 2023

Abstract
The recent discovery of an acquired activating point mutation in JAK2, substituting valine at amino acid position 617 for phenylalanine, has greatly improved our understanding of the molecular mechanism underlying chronic myeloproliferative neoplasms. Strikingly, the JAK2V617F mutation is found in nearly all patients suffering from polycythemia vera and in roughly every second patient suffering from essential thrombocythemia and primary myelofibrosis. Thus, JAK2 represents a promising target for the treatment of myeloproliferative neoplasms and considerable efforts are ongoing to discover and develop inhibitors of the kinase. Here, we report potent inhibition of JAK2V617F and JAK2 wild-type enzymes by a novel substituted quinoxaline, NVP-BSK805, which acts in an ATP-competitive manner. Within the JAK family, NVP-BSK805 displays more than 20-fold selectivity towards JAK2 in vitro, as well as excellent selectivity in broader kinase profiling. The compound blunts constitutive STAT5 phosphorylation in JAK2V617F-bearing cells, with concomitant suppression of cell proliferation and induction of apoptosis. In vivo, NVP-BSK805 exhibited good oral bioavailability and a long half-life. The inhibitor was efficacious in suppressing leukemic cell spreading and splenomegaly in a Ba/F3 JAK2V617F cell-driven mouse mechanistic model. Furthermore, NVP-BSK805 potently suppressed recombinant human erythropoietin-induced polycythemia and extramedullary erythropoiesis in mice and rats. Mol Cancer Ther; 9(7); 1945–55. ©2010 AACR.
Data from Nanaomycin A Selectively Inhibits DNMT3B and Reactivates Silenced Tumor Suppressor Genes in Human Cancer Cells
Authors: Kuck Dirk , Caulfield Thomas , Lyko Frank , Medina-Franco Jose L.
Published: April 2023

Abstract
Enzymes involved in the epigenetic regulation of the genome represent promising starting points for therapeutic intervention by small molecules, and DNA methyltransferases (DNMT) are emerging targets for the development of a new class of cancer therapeutics. In this work, we present nanaomycin A, initially identified by a virtual screening for inhibitors against DNMT1, as a compound inducing antiproliferative effects in three different tumor cell lines originating from different tissues. Nanaomycin A treatment reduced the global methylation levels in all three cell lines and reactivated transcription of the RASSF1A tumor suppressor gene. In biochemical assays, nanaomycin A revealed selectivity toward DNMT3B. To the best of our knowledge, this is the first DNMT3B-selective inhibitor identified to induce genomic demethylation. Our study thus establishes the possibility of selectively inhibiting individual DNMT enzymes. Mol Cancer Ther; 9(11); 3015–23. ©2010 AACR.
Data from Poly(ADP-ribose) polymerase inhibitor ABT-888 potentiates the cytotoxic activity of temozolomide in leukemia cells: influence of mismatch repair status and O6-methylguanine-DNA methyltransferase activity
Authors: Horton Terzah M. , Jenkins Gaye , Pati Debananda , Zhang Linna , Dolan M. Eileen , Ribes-Zamora Albert , Bertuch Alison A. , Blaney Susan M. , Delaney Shannon L. , Hegde Madhuri , Berg Stacey L.
Published: April 2023

Abstract
The poly(ADP-ribose) polymerase (PARP) inhibitor ABT-888 potentiates the antitumor activity of temozolomide (TMZ). TMZ resistance results from increased O6-methylguanine-DNA methyltransferase (MGMT) activity and from mismatch repair (MMR) system mutations. We evaluated the relative importance of MGMT activity, MMR deficiency, nonhomologous end joining (NHEJ), and PARP activity in ABT-888 potentiation of TMZ. MMR-proficient and MMR-deficient leukemia cells with varying MGMT activity, as well as primary leukemia samples, were used to determine TMZ IC50 alone and with ABT-888. ABT-888 effectively inhibited PARP activity and enhanced TMZ growth inhibition in most leukemia cells. ABT-888 potentiation was most effective in MMR-deficient cells with low MGMT activity [potentiation factor (PF) = 21]. ABT-888 also potentiated TMZ activity in MMR-deficient cells with elevated MGMT activity. Unexpectedly, ABT-888 also enhanced TMZ activity in MMR-proficient cells (PF = 3–7). ABT-888 potentiation was unrelated to NHEJ activity. ABT-888 potentiated TMZ (PF = 2–5) in two of four acute myeloid leukemia patient samples but showed little potentiation in primary acute lymphoblastic leukemia. In conclusion, although ABT-888 potentiation of TMZ was most pronounced in MMR-deficient cells with low MGMT activity, neither MMR proficiency nor MGMT overexpression completely abrogated ABT-888 potentiation of TMZ. [Mol Cancer Ther 2009;8(8):2232–42]
Data from Cytotoxicity of the matrix metalloproteinase–activated anthrax lethal toxin is dependent on gelatinase expression and B-RAF status in human melanoma cells
Authors: Alfano Randall W. , Leppla Stephen H. , Liu Shihui , Bugge Thomas H. , Herlyn Meenhard , Smalley Keiran S. , Bromberg-White Jennifer L. , Duesbery Nicholas S. , Frankel Arthur E.
Published: April 2023

Abstract
Anthrax lethal toxin (LeTx) shows potent mitogen-activated protein kinase pathway inhibition and apoptosis in melanoma cells that harbor the activating V600E B-RAF mutation. LeTx is composed of two proteins, protective antigen and lethal factor. Uptake of the toxin into cells is dependent on proteolytic activation of protective antigen by the ubiquitously expressed furin or furin-like proteases. To circumvent nonspecific LeTx activation, a substrate preferably cleaved by gelatinases was substituted for the furin LeTx activation site. Here, we have shown that the toxicity of this matrix metalloproteinase (MMP)–activated LeTx is dependent on host cell surface MMP-2 and MMP-9 activity as well as the presence of the activating V600E B-RAF mutation, making this toxin dual specific. This additional layer of tumor cell specificity would potentially decrease systemic toxicity from the reduction of nonspecific toxin activation while retaining antitumor efficacy in patients with V600E B-RAF melanomas. Moreover, our results indicate that cell surface-associated gelatinase expression can be used to predict sensitivity among V600E B-RAF melanomas. This finding will aid in the better selection of patients that will potentially respond to MMP-activated LeTx therapy. [Mol Cancer Ther 2008;7(5):1218–26]
Data from ATM Deficiency Sensitizes Mantle Cell Lymphoma Cells to Poly(ADP-Ribose) Polymerase-1 Inhibitors
Authors: Williamson Chris T. , Muzik Huong , Turhan Ali G. , Zamò Alberto , O'Connor Mark J. , Bebb D. Gwyn , Lees-Miller Susan P.
Published: April 2023

Abstract
Poly(ADP-ribose) polymerase-1 (PARP-1) inhibition is toxic to cells with mutations in the breast and ovarian cancer susceptibility genes BRCA1 or BRCA2, a concept termed synthetic lethality. However, whether this approach is applicable to other human cancers with defects in other DNA repair genes has yet to be determined. The ataxia telangiectasia mutated (ATM) gene is altered in several human cancers including mantle cell lymphoma (MCL). Here, we characterize a panel of MCL cell lines for ATM status and function and investigate the potential for synthetic lethality in MCL in the presence of small-molecule inhibitors of PARP-1. We show that Granta-519 and UPN2 cells have low levels of ATM protein, are defective in DNA damage-induced ATM-dependent signaling, are radiation sensitive, and have cell cycle checkpoint defects: all characteristics of defective ATM function. Significantly, Granta-519 and UPN2 cells were more sensitive to PARP-1 inhibition than were the ATM-proficient MCL cell lines examined. Furthermore, the PARP-1 inhibitor olaparib (known previously as AZD2281/KU-0059436) significantly decreased tumor growth and increased overall survival in mice bearing s.c. xenografts of ATM-deficient Granta-519 cells while producing only a modest effect on overall survival of mice bearing xenografts of the ATM-proficient cell line, Z138. Thus, PARP inhibitors have therapeutic potential in the treatment of MCL, and the concept of synthetic lethality extends to human cancers with ATM alterations. Mol Cancer Ther; 9(2); 347–57
Data from The Aurora kinase inhibitor SNS-314 shows broad therapeutic potential with chemotherapeutics and synergy with microtubule-targeted agents in a colon carcinoma model
Authors: VanderPorten Erica C. , Taverna Pietro , Hogan Jennifer N. , Ballinger Marcus D. , Flanagan W. Michael , Fucini Raymond V.
Published: April 2023

Abstract
Aurora kinases play key roles in regulating centrosome maturation, mitotic spindle formation, and cytokinesis during cell division, and are considered promising drug targets due to their frequent overexpression in a variety of human cancers. SNS-314 is a selective and potent pan Aurora inhibitor currently in a dose escalation phase 1 clinical trial for the treatment of patients with advanced solid tumors. Here, we report the antiproliferative effects of SNS-314 in combination with common chemotherapeutics in cell culture and xenograft models. The HCT116 colorectal carcinoma cell line, with intact or depleted p53 protein levels, was treated with SNS-314 and a cytotoxic chemotherapeutic from a panel comprised of gemcitabine, 5-fluorouracil (5-FU), carboplatin, daunomycin, SN-38 (the active metabolite of irinotecan), docetaxel, and vincristine. Combinations were administered under either concurrent or sequential schedules. SNS-314 has predominantly additive effects when administered concurrently with commonly used anticancer agents. Sequential administration of SNS-314 with chemotherapeutic compounds showed additive antiproliferative effects with carboplatin, gemcitabine, 5-FU, daunomycin, and SN-38, and synergy was observed in combination with gemcitabine, docetaxel, or vincristine. The most profound antiproliferative effects were observed with sequential administration of SNS-314 followed by docetaxel or vincristine. In vivo, SNS-314 potentiated the antitumor activity of docetaxel in xenografts. Both the in vitro synergies observed between SNS-314 and agents that target the mitotic spindle and the potentiation seen with docetaxel in vivo are consistent with a mechanism of action in which Aurora inhibition bypasses the mitotic spindle assembly checkpoint and prevents cytokinesis, augmenting subsequent spindle toxin–mediated mitotic catastrophe and cell death. [Mol Cancer Ther 2009;8(4):930–9]