bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Osteoblast-Derived Factors Induce an Expression Signature that Identifies Prostate Cancer Metastasis and Hormonal Progression
Authors: Wang Gang , Haile Simon , Comuzzi Barbara , Tien Amy H. , Wang Jun , Yong Theresa M.K. , Jelescu-Bodos Anca E. , Blaszczyk Natalie , Vessella Robert L. , Masri Bassam A. , Sadar Marianne D.
Published: March 2023

Abstract
Identification of gene expression signatures associated with metastases provides a tool to discern mechanisms and potential therapeutic targets and may lead toward a molecular classification system in pathology. Prostate cancer (CaP) frequently metastasizes to the bone to form osteoblastic lesions. Correlative clinical data and in vitro evidence have led to the hypothesis that osteoblast-derived factors promote hormonal progression of CaP cells. Here, the gene expression signature of CaP exposed to osteoblast-derived factors was identified. This signature included known androgen-regulated genes, oncogenes, tumor suppressors, and genes whose products are involved in apoptosis and cell cycle. A comparative functional genomic approach involved the application of this responsive gene expression signature to clinical samples of human CaP, melanomas, and oral cancers. Cluster analysis revealed that this gene expression signature had specificity for CaP and could resolve clinical specimens according to stage (benign, localized, and metastatic) and androgen sensitivity with an accuracy of 100% and 80%, respectively. Together, these results suggest that factors derived from osteoblasts induce a more advanced phenotype of CaP and promotes hormonal progression. [Cancer Res 2009;69(8):3433–42]
Data from Synergistic Activity of the Src Family Kinase Inhibitor Dasatinib and Oxaliplatin in Colon Carcinoma Cells Is Mediated by Oxidative Stress
Authors: Kopetz Scott , Lesslie Donald P. , Dallas Nikolas A. , Park Serk I. , Johnson Marjorie , Parikh Nila U. , Kim Michael P. , Abbruzzese James L. , Ellis Lee M. , Chandra Joya , Gallick Gary E.
Published: March 2023

Abstract
Chemotherapeutic regimens for the treatment of colorectal cancer generally include oxaliplatin, although inherent and acquired resistance is common. One potential mediator of oxaliplatin sensitivity is the nonreceptor protein tyrosine kinase, Src, the activity of which correlates with disease stage and patient survival. Therefore, we investigated the effects of Src inhibition using the tyrosine kinase inhibitor dasatinib on oxaliplatin sensitivity. We show that oxaliplatin acutely activates Src and that combination treatment with dasatinib is synergistic in a cell-line dependent manner, with the level of Src activation correlating with extent of synergy in a panel of six cell lines. Intracellular reactive oxygen species (ROS) are generated after oxaliplatin treatment, and ROS potently activates Src. Pretreatment with antioxidants inhibits oxaliplatin-induced Src activation. In oxaliplatin-resistant cell lines, Src activity is constitutively increased. In a mouse model of colorectal liver metastases, treatment with oxaliplatin also results in chronic Src activation. The combination of dasatinib and oxaliplatin results in significantly smaller tumors compared with single-agent treatment, corresponding with reduced proliferation and angiogenesis. Therefore, we conclude that oxaliplatin activates Src through a ROS-dependent mechanism. Src inhibition increases oxaliplatin activity both in vitro and in vivo. These results suggest that Src inhibitors combined with oxaliplatin may have efficacy in metastatic colon cancer and may provide the first indication of a molecular phenotype that might be susceptible to such combinations. [Cancer Res 2009;69(9):3842–9]
Data from Computationally Guided Photothermal Tumor Therapy Using Long-Circulating Gold Nanorod Antennas
Authors: von Maltzahn Geoffrey , Park Ji-Ho , Agrawal Amit , Bandaru Nanda Kishor , Das Sarit K. , Sailor Michael J. , Bhatia Sangeeta N.
Published: March 2023

Abstract
Plasmonic nanomaterials have the opportunity to considerably improve the specificity of cancer ablation by i.v. homing to tumors and acting as antennas for accepting externally applied energy. Here, we describe an integrated approach to improved plasmonic therapy composed of multimodal nanomaterial optimization and computational irradiation protocol development. We synthesized polyethylene glycol (PEG)–protected gold nanorods (NR) that exhibit superior spectral bandwidth, photothermal heat generation per gram of gold, and circulation half-life in vivo (t1/2, ∼17 hours) compared with the prototypical tunable plasmonic particles, gold nanoshells, as well as ∼2-fold higher X-ray absorption than a clinical iodine contrast agent. After intratumoral or i.v. administration, we fuse PEG-NR biodistribution data derived via noninvasive X-ray computed tomography or ex vivo spectrometry, respectively, with four-dimensional computational heat transport modeling to predict photothermal heating during irradiation. In computationally driven pilot therapeutic studies, we show that a single i.v. injection of PEG-NRs enabled destruction of all irradiated human xenograft tumors in mice. These studies highlight the potential of integrating computational therapy design with nanotherapeutic development for ultraselective tumor ablation. [Cancer Res 2009;69(9):3892–900]
Data from Structure-Function Approach Identifies a COOH-Terminal Domain That Mediates Heparanase Signaling
Authors: Fux Liat , Feibish Nir , Cohen-Kaplan Victoria , Gingis-Velitski Svetlana , Feld Sari , Geffen Chen , Vlodavsky Israel , Ilan Neta
Published: March 2023

Abstract
Heparanase is an endo-β-d-glucuronidase capable of cleaving heparan sulfate, activity that is strongly implicated in cellular invasion associated with tumor metastasis, angiogenesis, and inflammation. In addition, heparanase was noted to exert biological functions apparently independent of its enzymatic activity, enhancing the phosphorylation of selected protein kinases and inducing gene transcription. A predicted three-dimensional structure of constitutively active heparanase clearly delineates a TIM-barrel fold previously anticipated for the enzyme. Interestingly, the model also revealed the existence of a COOH-terminal domain (C-domain) that apparently is not an integral part of the TIM-barrel fold. We provide evidence that the C-domain is critical for heparanase enzymatic activity and secretion. Moreover, the C-domain was found to mediate nonenzymatic functions of heparanase, facilitating Akt phosphorylation, cell proliferation, and tumor xenograft progression. These findings support the notion that heparanase exerts enzymatic activity-independent functions, and identify, for the first time, a protein domain responsible for heparanase-mediated signaling. Inhibitors directed against the C-domain, combined with inhibitors of heparanase enzymatic activity, are expected to neutralize heparanase functions and to profoundly affect tumor growth, angiogenesis, and metastasis. [Cancer Res 2009;69(5):1758–67]
Data from Wnt/β-Catenin Signaling Regulates Cytokine-Induced Human Inducible Nitric Oxide Synthase Expression by Inhibiting Nuclear Factor-κB Activation in Cancer Cells
Authors: Du Qiang , Zhang Xinglu , Cardinal Jon , Cao Zongxian , Guo Zhong , Shao Lifang , Geller David A.
Published: March 2023

Abstract
The human inducible nitric oxide synthase (hiNOS) gene is regulated by nuclear factor κB (NF-κB) and has recently been shown to be a target of the Wnt/β-catenin pathway. In this study, we tested the hypothesis that Wnt/β-catenin signaling might regulate cytokine- or tumor necrosis factor α (TNFα)–induced hiNOS expression through interaction with NF-κB. A cytokine mixture of TNFα + interleukin (IL)-1β + IFNγ induced a 2- to 3-fold increase in hiNOS promoter activity in HCT116 and DLD1 colon cells, but produced a 2-fold decrease in SW480 colon cancer cells. A similar differential activity was seen in liver cancer cells (HepG2, Huh7, and Hep3B). Overexpression of β-catenin produced a dose-dependent decrease in NF-κB reporter activity and decreased cytokine mixture–induced hiNOS promoter activity. Gel shift for TNFα-induced hiNOS NF-κB activation showed decreased p50 binding and decreased NF-κB reporter activity in the β-catenin–mutant HAβ18 cells. Conversely, enhanced p50 binding and increased NF-κB reporter activity were seen in HAβ85 cells, which lack β-catenin signaling. Coimmunoprecipitation confirmed that β-catenin complexed with both p65 and p50 NF-κB proteins. NF-κB–dependent Traf1 protein expression also inversely correlated with the level of β-catenin. Furthermore, SW480 cells stably transformed with wild-type adenomatous polyposis coli showed decreased β-catenin protein and increased TNFα-induced p65 NF-κB binding as well as iNOS and Traf1 expression. Finally, β-catenin inversely correlated with iNOS and Fas expression in vivo in hepatocellular carcinoma tumor samples. Our in vitro and in vivo data show that β-catenin signaling inversely correlates with cytokine-induced hiNOS and other NF-κB–dependent gene expression. These findings underscore the complex role of Wnt/β-catenin, NF-κB, and iNOS signaling in the pathophysiology of inflammation-associated carcinogenesis. [Cancer Res 2009;69(9):3764–71]
Data from CD47 Regulates Bone Mass and Tumor Metastasis to Bone
Authors: Uluçkan Özge , Becker Stephanie N. , Deng Hongju , Zou Wei , Prior Julie L. , Piwnica-Worms David , Frazier William A. , Weilbaecher Katherine N.
Published: March 2023

Abstract
CD47, also called integrin-associated protein, plays a critical role in the innate immune response and is an atypical member of the immunoglobulin superfamily that interacts with and activates β3 integrins. β3 integrin−/− mice have defective platelet and osteoclast function and are protected from bone metastasis. The role of CD47 in skeletal homeostasis and bone metastasis has not been described. CD47−/− mice had increased bone mass and defective osteoclast function in vivo. Although the number of functional osteoclasts formed by differentiating CD47−/− bone marrow macrophages was decreased, high doses of RANKL rescued differentiation and function of CD47−/− osteoclasts ex vivo and rescued the osteoclast defect in CD47−/− mice. Inhibition of nitric oxide (NO) synthase, which is expressed at higher levels in CD47−/− osteoclasts, also rescued the osteoclast defect in CD47−/− cells. We then examined the consequences of this osteoclast defect in bone metastasis. In a model of tumor metastasis to bone, bone tumor burden was decreased in the CD47−/− mice compared with wild-type (WT) controls, with no decrease in s.c. tumor growth in CD47−/− mice. There was decreased tumor-associated bone destruction in the CD47−/− mice compared with WT controls, consistent with a defect in osteoclast function that was not rescued by the presence of tumor. Our data show that CD47 regulates osteoclastogenesis, in part, via regulation of NO production, and its disruption leads to a decrease in tumor bone metastasis. CD47 is a novel therapeutic target to strengthen bone mass and diminish metastatic tumor growth in bone. [Cancer Res 2009;69(7):3196–204]
Data from Combined Integrin Phosphoproteomic Analyses and Small Interfering RNA–Based Functional Screening Identify Key Regulators for Cancer Cell Adhesion and Migration
Authors: Chen Yanling , Lu Bingwen , Yang Qingkai , Fearns Colleen , Yates John R. , Lee Jiing-Dwan
Published: March 2023

Abstract
Integrins interact with extracellular matrix (ECM) and deliver intracellular signaling for cell proliferation, survival, and motility. During tumor metastasis, integrin-mediated cell adhesion to and migration on the ECM proteins are required for cancer cell survival and adaptation to the new microenvironment. Using stable isotope labeling by amino acids in cell culture–mass spectrometry, we profiled the phosphoproteomic changes induced by the interactions of cell integrins with type I collagen, the most common ECM substratum. Integrin-ECM interactions modulate phosphorylation of 517 serine, threonine, or tyrosine residues in 513 peptides, corresponding to 357 proteins. Among these proteins, 33 key signaling mediators with kinase or phosphatase activity were subjected to small interfering RNA–based functional screening. Three integrin-regulated kinases, DBF4, PAK2, and GRK6, were identified for their critical role in cell adhesion and migration possibly through their regulation of actin cytoskeleton arrangement. Altogether, we not only depict an integrin-modulated phosphorylation network during cell-ECM protein interactions but also reveal novel regulators for cell adhesion and migration. [Cancer Res 2009;69(8):3713–20]
Data from The Cell Fate Determination Factor Dachshund Inhibits Androgen Receptor Signaling and Prostate Cancer Cellular Growth
Authors: Wu Kongming , Katiyar Sanjay , Witkiewicz Agnes , Li Anping , McCue Peter , Song Liang-Nian , Tian Lifeng , Jin Ming , Pestell Richard G.
Published: March 2023

Abstract
Initially isolated as the dominant suppressor of the mutant epidermal growth factor receptor (ellipse), the Dachshund gene plays a key role in metazoan development regulating the Retinal Determination Gene Network. Herein, the DACH1 gene was expressed in normal prostate epithelial cells with reduced expression in human prostate cancer. DACH1 inhibited prostate cancer cellular DNA synthesis, growth in colony forming assays, and blocked contact-independent growth in soft agar assays. DACH1 inhibited androgen receptor (AR) activity, requiring a conserved DS Domain (Dachshund domain conserved with Ski/Sno) that bound NCoR/HDAC and was recruited to an androgen-responsive gene promoter. DACH1 inhibited ligand-dependent activity of AR mutations identified in patients with androgen-insensitive prostate cancer. The DS domain was sufficient for repression of the AR wild-type but failed to repress an AR acetylation site point mutant. These studies show a role for the Retinal Determination Gene Network in regulating cellular growth and signaling in prostate cancer. [Cancer Res 2009;69(8):3347–55]
Data from Histone Deacetylases Are Required for Androgen Receptor Function in Hormone-Sensitive and Castrate-Resistant Prostate Cancer
Authors: Welsbie Derek S. , Xu Jin , Chen Yu , Borsu Laetitia , Scher Howard I. , Rosen Neal , Sawyers Charles L.
Published: March 2023

Abstract
Transcriptional activity of the androgen receptor (AR) is crucial for growth and survival of prostate cancer even upon development of resistance to androgen ablation and antiandrogen therapies. Therefore, novel therapies that can suppress AR transcriptional activity when conventional hormone therapies fail are needed. Here, we show that histone deacetylase (HDAC) inhibitors, including SAHA (vorinostat) and LBH589, which are currently being tested in clinic, could be such a therapy. HDAC inhibitors block the AR-mediated transcriptional activation of many genes, including the TMPRSS2 gene involved in fusion with ETS family members in a majority of prostate cancers. Genetic knockdown of either HDAC1 or HDAC3 can also suppress expression of AR-regulated genes, recapitulating the effect of HDAC inhibitor treatment. Whereas HDAC inhibitor treatment can lower androgen receptor protein levels in prostate cancer cells, we show that independent of AR protein levels, HDAC inhibitors block AR activity through inhibiting the assembly of coactivator/RNA polymerase II complex after AR binds to the enhancers of target genes. Failed complex assembly is associated with a phase shift in the cyclical wave of AR recruitment that typically occurs in response to ligand treatment. HDAC inhibitors retain the ability to block AR activity in castration-resistant prostate cancer models and, therefore, merit clinical investigation in this setting. The HDAC-regulated AR target genes defined here can serve as biomarkers to ensure sufficient levels of HDAC inhibition. [Cancer Res 2009;69(3):958–66]
Data from TMPRSS2-ERG Gene Fusion Is Not Associated with Outcome in Patients Treated by Prostatectomy
Authors: Gopalan Anuradha , Leversha Margaret A. , Satagopan Jaya M. , Zhou Qin , Al-Ahmadie Hikmat A. , Fine Samson W. , Eastham James A. , Scardino Peter T. , Scher Howard I. , Tickoo Satish K. , Reuter Victor E. , Gerald William L.
Published: March 2023

Abstract
A significant number of prostate cancers have been shown to have recurrent chromosomal rearrangements resulting in the fusion of the androgen-regulated TMPRSS2 promoter to a member of the ETS transcription factor family, most commonly ERG. This results in ERG overexpression, which may have a direct causal role in prostate tumorigenesis or progression. However, the clinical significance of the rearrangement is unclear, and in particular, relationship to outcome has been inconsistent in recent reports. We analyzed TMPRSS2-ERG gene rearrangement status by fluorescence in situ hybridization in 521 cases of clinically localized surgically treated prostate cancer with 95 months of median follow-up and also in 40 unmatched metastases. Forty-two percent of primary tumors and 40% of metastases had rearrangements. Eleven percent had copy number increase (CNI) of the TMPRRS2-ERG region. Rearrangement alone was associated with lower grade, but not with stage, biochemical recurrence, metastases, or death. CNI with and without rearrangement was associated with high grade and advanced stage. Further, a subgroup of cancers with CNI and rearrangement by deletion, with two or more copies of the deleted locus, tended to be more clinically aggressive. DNA index assessment revealed that the majority of tumors with CNI of TMPRSS2-ERG had generalized aneuploidy/tetraploidy in contrast to tumors without TMPRSS2-ERG CNI, which were predominantly diploid. We therefore conclude that translocation of TMPRSS2-ERG is not associated with outcome, and the aggressive clinical features associated with CNI of chromosome 21 reflect generalized aneuploidy and are not due to CNI specifically of rearranged TMPRSS2-ERG. [Cancer Res 2009;69(4):1400–6]
Data from A Destructive Cascade Mediated by CCL2 Facilitates Prostate Cancer Growth in Bone
Authors: Li Xin , Loberg Robert , Liao Jinhui , Ying Chi , Snyder Linda A. , Pienta Kenneth J. , McCauley Laurie K.
Published: March 2023

Abstract
Monocyte chemoattractant protein 1 (CCL2) is a recently identified prominent regulator of prostate cancer growth and metastasis. The purpose of this study was to investigate the mechanistic role of CCL2 in prostate cancer growth in bone. The present study found that CCL2 was up-regulated in osteoblasts (3-fold by PC-3 and 2-fold by VCaP conditioned medium) and endothelial cells (2-fold by PC-3 and VCaP conditioned medium). Parathyroid hormone-related protein (PTHrP) treatment of osteoblastic cells up-regulated CCL2 and was blocked by a PTHrP antagonist, suggesting that prostate cancer–derived PTHrP plays an important role in elevation of osteoblast-derived CCL2. CCL2 indirectly increased blood vessel formation in endothelial cells through vascular endothelial growth factor-A, which was up-regulated 2-fold with administration of CCL2 in prostate cancer cells. In vivo, anti-CCL2 treatment suppressed tumor growth in bone. The decreased tumor burden was associated with decreased bone resorption (serum TRAP5b levels were decreased by 50–60% in anti–CCL2-treated animals from VCaP or PC-3 cell osseous lesions) and microvessel density was decreased by 70% in anti–CCL2-treated animals with bone lesions from VCaP cells. These data suggest that a destructive cascade is driven by tumor cell–derived, PTHrP-mediated induction of CCL2, which facilitates tumor growth via enhanced osteoclastic and endothelial cell activity in bone marrow. Taken together, CCL2 mediates the interaction between tumor-derived factors and host-derived chemokines acting in cooperation to promote skeletal metastasis. [Cancer Res 2009;69(4):1685–92]
Data from A Novel Experimental Heme Oxygenase-1–Targeted Therapy for Hormone-Refractory Prostate Cancer
Authors: Alaoui-Jamali Moulay A. , Bismar Tarek A. , Gupta Ajay , Szarek Walter A. , Su Jie , Song Wei , Xu Yingjie , Xu Bin , Liu Guoan , Vlahakis Jason Z. , Roman Gheorghe , Jiao Jinsong , Schipper Hyman M.
Published: March 2023

Abstract
Heme oxygenase-1 (HO-1), a member of the heat shock protein family, plays a key role as a sensor and regulator of oxidative stress. Herein, we identify HO-1 as a biomarker and potential therapeutic target for advanced prostate cancer (PCA). Immunohistochemical analysis of prostate tissue using a progression tissue microarray from patients with localized PCA and across several stages of disease progression revealed a significant elevation of HO-1 expression in cancer epithelial cells, but not in surrounding stromal cells, from hormone-refractory PCA (HRPCA) compared with hormone-responsive PCA and benign tissue. Silencing the ho-1 gene in HRPCA cells decreased the HO-1 activity, oxidative stress, and activation of the mitogen-activated protein kinase–extracellular signal-regulated kinase/p38 kinase. This coincided with reduced cell proliferation, cell survival, and cell invasion in vitro, as well as inhibition of prostate tumor growth and lymph node and lung metastases in vivo. The effect of ho-1 silencing on these oncogenic features was mimicked by exposure of cells to a novel selective small-molecule HO-1 inhibitor referred to as OB-24. OB-24 selectively inhibited HO-1 activity in PCA cells, which correlated with a reduction of protein carbonylation and reactive oxygen species formation. Moreover, OB-24 significantly inhibited cell proliferation in vitro and tumor growth and lymph node/lung metastases in vivo. A potent synergistic activity was observed when OB-24 was combined with Taxol. Together, these results establish HO-1 as a potential therapeutic target for advanced PCA. [Cancer Res 2009;69(20):8017–24]
Data from The Receptor Interacting Protein 1 Inhibits p53 Induction through NF-κB Activation and Confers a Worse Prognosis in Glioblastoma
Authors: Park Seongmi , Hatanpaa Kimmo J. , Xie Yang , Mickey Bruce E. , Madden Christopher J. , Raisanen Jack M. , Ramnarain Deepti B. , Xiao Guanghua , Saha Debabrata , Boothman David A. , Zhao Dawen , Bachoo Robert M. , Pieper Russell O. , Habib Amyn A.
Published: March 2023

Abstract
Nuclear factor-κB (NF-κB) activation may play an important role in the pathogenesis of cancer and also in resistance to treatment. Inactivation of the p53 tumor suppressor is a key component of the multistep evolution of most cancers. Links between the NF-κB and p53 pathways are under intense investigation. In this study, we show that the receptor interacting protein 1 (RIP1), a central component of the NF-κB signaling network, negatively regulates p53 tumor suppressor signaling. Loss of RIP1 from cells results in augmented induction of p53 in response to DNA damage, whereas increased RIP1 level leads to a complete shutdown of DNA damage–induced p53 induction by enhancing levels of cellular mdm2. The key signal generated by RIP1 to up-regulate mdm2 and inhibit p53 is activation of NF-κB. The clinical implication of this finding is shown in glioblastoma, the most common primary malignant brain tumor in adults. We show that RIP1 is commonly overexpressed in glioblastoma, but not in grades II and III glioma, and increased expression of RIP1 confers a worse prognosis in glioblastoma. Importantly, RIP1 levels correlate strongly with mdm2 levels in glioblastoma. Our results show a key interaction between the NF-κB and p53 pathways that may have implications for the targeted treatment of glioblastoma. [Cancer Res 2009;69(7):2809–16]
Data from EGFRvIII Antibody–Conjugated Iron Oxide Nanoparticles for Magnetic Resonance Imaging–Guided Convection-Enhanced Delivery and Targeted Therapy of Glioblastoma
Authors: Hadjipanayis Costas G. , Machaidze Revaz , Kaluzova Milota , Wang Liya , Schuette Albert J. , Chen Hongwei , Wu Xinying , Mao Hui
Published: March 2023

Abstract
The magnetic nanoparticle has emerged as a potential multifunctional clinical tool that can provide cancer cell detection by magnetic resonance imaging (MRI) contrast enhancement as well as targeted cancer cell therapy. A major barrier in the use of nanotechnology for brain tumor applications is the difficulty in delivering nanoparticles to intracranial tumors. Iron oxide nanoparticles (IONP; 10 nm in core size) conjugated to a purified antibody that selectively binds to the epidermal growth factor receptor (EGFR) deletion mutant (EGFRvIII) present on human glioblastoma multiforme (GBM) cells were used for therapeutic targeting and MRI contrast enhancement of experimental glioblastoma, both in vitro and in vivo, after convection-enhanced delivery (CED). A significant decrease in glioblastoma cell survival was observed after nanoparticle treatment and no toxicity was observed with treatment of human astrocytes (P < 0.001). Lower EGFR phosphorylation was found in glioblastoma cells after EGFRvIIIAb-IONP treatment. Apoptosis was determined to be the mode of cell death after treatment of GBM cells and glioblastoma stem cell–containing neurospheres with EGFRvIIIAb-IONPs. MRI-guided CED of EGFRvIIIAb-IONPs allowed for the initial distribution of magnetic nanoparticles within or adjacent to intracranial human xenograft tumors and continued dispersion days later. A significant increase in animal survival was found after CED of magnetic nanoparticles (P < 0.01) in mice implanted with highly tumorigenic glioblastoma xenografts (U87ΔEGFRvIII). IONPs conjugated to an antibody specific to the EGFRvIII deletion mutant constitutively expressed by human glioblastoma tumors can provide selective MRI contrast enhancement of tumor cells and targeted therapy of infiltrative glioblastoma cells after CED. Cancer Res; 70(15); 6303–12. ©2010 AACR.
Data from PIK3CA Mutation Uncouples Tumor Growth and Cyclin D1 Regulation from MEK/ERK and Mutant KRAS Signaling
Authors: Halilovic Ensar , She Qing-Bai , Ye Qing , Pagliarini Raymond , Sellers William R. , Solit David B. , Rosen Neal
Published: March 2023

Abstract
Mutational activation of KRAS is a common event in human tumors. Identification of the key signaling pathways downstream of mutant KRAS is essential for our understanding of how to pharmacologically target these cancers in patients. We show that PD0325901, a small-molecule MEK inhibitor, decreases MEK/ERK pathway signaling and destabilizes cyclin D1, resulting in significant anticancer activity in a subset of KRAS mutant tumors in vitro and in vivo. Mutational activation of PIK3CA, which commonly co-occurs with KRAS mutation, provides resistance to MEK inhibition through reactivation of AKT signaling. Genetic ablation of the mutant PIK3CA allele in MEK inhibitor–resistant cells restores MEK pathway sensitivity, and re-expression of mutant PIK3CA reinstates the resistance, highlighting the importance of this mutation in resistance to therapy in human cancers. In KRAS mutant tumors, PIK3CA mutation restores cyclin D1 expression and G1-S cell cycle progression so that they are no longer dependent on KRAS and MEK/ERK signaling. Furthermore, the growth of KRAS mutant tumors with coexistent PIK3CA mutations in vivo is profoundly inhibited with combined pharmacologic inhibition of MEK and AKT. These data suggest that tumors with both KRAS and phosphoinositide 3-kinase mutations are unlikely to respond to the inhibition of the MEK pathway alone but will require effective inhibition of both MEK and phosphoinositide 3-kinase/AKT pathway signaling. Cancer Res; 70(17); 6804–14. ©2010 AACR.
Data from A Useful Approach to Identify Novel Small-Molecule Inhibitors of Wnt-Dependent Transcription
Authors: Ewan Kenneth , Pająk Bożena , Stubbs Mark , Todd Helen , Barbeau Olivier , Quevedo Camilo , Botfield Hannah , Young Rodrigo , Ruddle Ruth , Samuel Lee , Battersby Alysia , Raynaud Florence , Allen Nicholas , Wilson Stephen , Latinkic Branko , Workman Paul , McDonald Edward , Blagg Julian , Aherne Wynne , Dale Trevor
Published: March 2023

Abstract
The Wnt signaling pathway is frequently deregulated in cancer due to mutations in genes encoding APC, β-catenin, and axin. To identify small-molecule inhibitors of Wnt signaling as potential therapeutics, a diverse chemical library was screened using a transcription factor reporter cell line in which the activity of the pathway was induced at the level of Disheveled protein. A series of deconvolution studies was used to focus on three compound series that selectively killed cancer cell lines with constitutive Wnt signaling. Activities of the compounds included the ability to induce degradation of β-catenin that had been stabilized by a glycogen synthase kinase-3 (GSK-3) inhibitor. This screen illustrates a practical approach to identify small-molecule inhibitors of Wnt signaling that can seed the development of agents suitable to treat patients with Wnt-dependent tumors. Cancer Res; 70(14); 5963–73. ©2010 AACR.
Data from A Functional Receptor for B-Cell–Activating Factor Is Expressed on Human Acute Lymphoblastic Leukemias
Authors: Parameswaran Reshmi , Müschen Markus , Kim Yong-mi , Groffen John , Heisterkamp Nora
Published: March 2023

Abstract
B-lineage acute lymphoblastic leukemia (ALL) arises by transformation of a progenitor (pre-B) cell. Cure rates in adults remain low and treatment is complicated by support provided by the microenvironment to the leukemic cells, indicating an urgent need to better understand the factors that promote their survival. B-cell–activating factor (BAFF) and its receptor BAFF-R are important for survival and growth of mature normal and malignant B cells but are not expressed on pre-B cells. Unexpectedly, all cells in the primary Philadelphia chromosome (Ph)–positive and Ph-negative ALL samples tested were positive for high BAFF-R cell surface expression. BAFF-R was fully competent to bind BAFF, and stimulation of the receptor activated both the classic and the noncanonical NF-κB pathways. Recombinant BAFF supported survival of the ALL cells in the absence of stroma, and it significantly attenuated the rate of apoptosis caused by exposure to nilotinib, a drug used therapeutically to treat Ph-positive ALLs. Surprisingly, BAFF mRNA and protein were also expressed in the same cells but BAFF was not shed into the medium. Our report is the first showing universal expression of BAFF-R by pre-B ALL cells and opens the possibility of blocking its function as an adjuvant therapeutic strategy. Cancer Res; 70(11); 4346–56. ©2010 AACR.
Data from Perifosine Inhibits Mammalian Target of Rapamycin Signaling through Facilitating Degradation of Major Components in the mTOR Axis and Induces Autophagy
Authors: Fu Lei , Kim Young-Ae , Wang Xuerong , Wu Xiaoyun , Yue Ping , Lonial Sagar , Khuri Fadlo R. , Sun Shi-Yong
Published: March 2023

Abstract
Perifosine is an alkylphospholipid exhibiting antitumor activity as shown in both preclinical studies and clinical trials. This activity is partly associated with its ability to inhibit Akt activity. It has been shown that the mammalian target of rapamycin (mTOR) axis plays a critical role in regulation of cell proliferation and survival primarily through functioning both downstream and upstream of Akt. The current study reveals a novel mechanism by which perifosine inhibits Akt and the mTOR axis. In addition to inhibition of Akt, perifosine inhibited the assembly of both mTOR/raptor and mTOR/rictor complexes. Strikingly, perifosine reduced the levels of Akt and other major components including mTOR, raptor, rictor, 70-kDa ribosomal S6 kinase, and 4E-binding protein 1 in the mTOR axis by promoting their degradation through a GSK3/FBW7-dependent mechanism. These results thus suggest that perifosine inhibits the mTOR axis through a different mechanism from inhibition of mTOR signaling by classic mTOR inhibitors such as rapamycin. Moreover, perifosine substantially increased the levels of type II light chain 3, a hallmark of autophagy, in addition to increasing poly(ADP-ribose) polymerase cleavage, suggesting that perifosine induces both apoptosis and autophagy. The combination of perifosine with a lysosomal inhibitor enhanced apoptosis and inhibited the growth of xenografts in nude mice, suggesting that perifosine-induced autophagy protects cells from undergoing apoptosis. Collectively, we conclude that perifosine inhibits mTOR signaling and induces autophagy, highlighting a novel mechanism accounting for the anticancer activity of perifosine and a potential strategy to enhance the anticancer efficacy of perifosine by preventing autophagy. [Cancer Res 2009;69(23):8967–76]
Data from Inhibition of Histone Deacetylase in Cancer Cells Slows Down Replication Forks, Activates Dormant Origins, and Induces DNA Damage
Authors: Conti Chiara , Leo Elisabetta , Eichler Gabriel S. , Sordet Olivier , Martin Melvenia M. , Fan Angela , Aladjem Mirit I. , Pommier Yves
Published: March 2023

Abstract
Protein acetylation is a reversible process regulated by histone deacetylases (HDAC) that is often altered in human cancers. Suberoylanilide hydroxamic acid (SAHA) is the first HDAC inhibitor to be approved for clinical use as an anticancer agent. Given that histone acetylation is a key determinant of chromatin structure, we investigated how SAHA may affect DNA replication and integrity to gain deeper insights into the basis for its anticancer activity. Nuclear replication factories were visualized with confocal immunofluorescence microscopy and single-replicon analyses were conducted by genome-wide molecular combing after pulse labeling with two thymidine analogues. We found that pharmacologic concentrations of SAHA induce replication-mediated DNA damage with activation of histone γH2AX. Single DNA molecule analyses indicated slowdown in replication speed along with activation of dormant replication origins in response to SAHA. Similar results were obtained using siRNA-mediated depletion of HDAC3 expression, implicating this HDAC member as a likely target in the SAHA response. Activation of dormant origins was confirmed by molecular analyses of the β-globin locus control region. Our findings demonstrate that SAHA produces profound alterations in DNA replication that cause DNA damage, establishing a critical link between robust chromatin acetylation and DNA replication in human cancer cells. Cancer Res; 70(11); 4470–80. ©2010 AACR.
Data from Exchange Protein Directly Activated by Cyclic AMP Increases Melanoma Cell Migration by a Ca2+-Dependent Mechanism
Authors: Baljinnyam Erdene , De Lorenzo Mariana S. , Xie Lai-Hua , Iwatsubo Mizuka , Chen Suzie , Goydos James S. , Nowycky Martha C. , Iwatsubo Kousaku
Published: March 2023

Abstract
Melanoma has a poor prognosis due to its strong metastatic ability. Although Ca2+ plays a major role in cell migration, little is known about the role of Ca2+ in melanoma cell migration. We recently found that the exchange protein directly activated by cyclic AMP (Epac) increases melanoma cell migration via a heparan sulfate–related mechanism. In addition to this mechanism, we also found that Epac regulates melanoma cell migration by a Ca2+-dependent mechanism. An Epac agonist increased Ca2+ in several different melanoma cell lines but not in melanocytes. Ablation of Epac1 with short hairpin RNA inhibited the Epac agonist–induced Ca2+ elevation, suggesting the critical role of Epac1 in Ca2+ homeostasis in melanoma cells. Epac-induced Ca2+ elevation was negated by the inhibition of phospholipase C (PLC) and inositol triphosphate (IP3) receptor. Furthermore, Epac-induced cell migration was reduced by the inhibition of PLC or IP3 receptor. These data suggest that Epac activates Ca2+ release from the endoplasmic reticulum via the PLC/IP3 receptor pathway, and this Ca2+ elevation is involved in Epac-induced cell migration. Actin assembly was increased by Epac-induced Ca2+, suggesting the involvement of actin in Epac-induced cell migration. In human melanoma specimens, mRNA expression of Epac1 was higher in metastatic melanoma than in primary melanoma, suggesting a role for Epac1 in melanoma metastasis. In conclusion, our findings reveal that Epac is a potential target for the suppression of melanoma cell migration, and, thus, the development of metastasis. Cancer Res; 70(13); 5607–17. ©2010 AACR.
Data from Tgfbr1 Haploinsufficiency Inhibits the Development of Murine Mutant Kras-Induced Pancreatic Precancer
Authors: Adrian Kevin , Strouch Matthew J. , Zeng Qinghua , Barron Morgan R. , Cheon Eric C. , Honasoge Akilesh , Xu Yanfei , Phukan Sharbani , Sadim Maureen , Bentrem David J. , Pasche Boris , Grippo Paul J.
Published: March 2023

Abstract
To dissect the role of constitutively altered Tgfbr1 signaling in pancreatic cancer development, we crossed Elastase-KrasG12D (EL-Kras) mice with Tgfbr1 haploinsufficient mice to generate EL-Kras/Tgfbr1+/− mice. Mice were euthanized at 6 to 9 months to compare the incidence, frequency, and size of precancerous lesions in the pancreas. Only 50% of all EL-Kras/Tgfbr1+/− mice developed preinvasive lesions compared with 100% of EL-Kras (wild-type Tgfbr1) mice. The frequency of precancerous lesions was 4-fold lower in haploinsufficient than in control mice. Paradoxically, the precancerous lesions of EL-Kras/Tgfbr1+/− mice were considerably larger than those in EL-Kras mice. Yet, the mitotic index of precancerous cells and the observable levels of fibrosis, lipoatrophy, and lymphocytic infiltration were reduced in EL-Kras/Tgfbr1+/− mice. We conclude that Tgfbr1 signaling promotes the development of precancerous lesions in mice. These findings suggest that individuals with constitutively decreased TGFBR1 expression may have a decreased risk of pancreatic cancer. [Cancer Res 2009;69(24):9169–74]
Data from Molecular Imaging of CXCR4 Receptor Expression in Human Cancer Xenografts with [64Cu]AMD3100 Positron Emission Tomography
Authors: Nimmagadda Sridhar , Pullambhatla Mrudula , Stone Kristie , Green Gilbert , Bhujwalla Zaver M. , Pomper Martin G.
Published: March 2023

Abstract
The chemokine receptor CXCR4 and its cognate ligand CXCL12 are pivotal for establishing metastases from many tumor types. Thus, CXCR4 may offer a cell surface target for molecular imaging of metastases, assisting diagnosis, staging, and therapeutic monitoring. Furthermore, noninvasive detection of CXCR4 status of a primary tumor may provide an index of the metastatic potential of the lesion. Here, we report the development and evaluation of [64Cu]AMD3100, a positron-emitting analogue of the stem cell mobilizing agent plerixafor to image CXCR4 in human tumor xenografts preselected for graded expression of this receptor. This imaging method was evaluated in lung metastases derived from human MDA-MB-231 breast cancer cells. Ex vivo biodistribution studies, performed to validate the in vivo imaging data, confirmed the ability of [64Cu]AMD3100 to image CXCR4 expression. Our findings show the feasibility of imaging CXCR4 by positron emission tomography using a clinically approved agent as a molecular scaffold. Cancer Res; 70(10); 3935–44. ©2010 AACR.
Data from EZH2 Is Essential for Glioblastoma Cancer Stem Cell Maintenance
Authors: Suvà Mario-Luca , Riggi Nicolò , Janiszewska Michalina , Radovanovic Ivan , Provero Paolo , Stehle Jean-Christophe , Baumer Karine , Le Bitoux Marie-Aude , Marino Denis , Cironi Luisa , Marquez Victor E. , Clément Virginie , Stamenkovic Ivan
Published: March 2023

Abstract
Overexpression of the polycomb group protein enhancer of zeste homologue 2 (EZH2) occurs in diverse malignancies, including prostate cancer, breast cancer, and glioblastoma multiforme (GBM). Based on its ability to modulate transcription of key genes implicated in cell cycle control, DNA repair, and cell differentiation, EZH2 is believed to play a crucial role in tissue-specific stem cell maintenance and tumor development. Here, we show that targeted pharmacologic disruption of EZH2 by the S-adenosylhomocysteine hydrolase inhibitor 3-deazaneplanocin A (DZNep), or its specific downregulation by short hairpin RNA (shRNA), strongly impairs GBM cancer stem cell (CSC) self-renewal in vitro and tumor-initiating capacity in vivo. Using genome-wide expression analysis of DZNep-treated GBM CSCs, we found the expression of c-myc, recently reported to be essential for GBM CSCs, to be strongly repressed upon EZH2 depletion. Specific shRNA-mediated downregulation of EZH2 in combination with chromatin immunoprecipitation experiments revealed that c-myc is a direct target of EZH2 in GBM CSCs. Taken together, our observations provide evidence that direct transcriptional regulation of c-myc by EZH2 may constitute a novel mechanism underlying GBM CSC maintenance and suggest that EZH2 may be a valuable new therapeutic target for GBM management. [Cancer Res 2009;69(24):9211–8]
Data from Colorectal Cancer Incidence Trends in the United States and United Kingdom: Evidence of Right- to Left-Sided Biological Gradients with Implications for Screening
Authors: Meza Rafael , Jeon Jihyoun , Renehan Andrew G. , Luebeck E. Georg
Published: March 2023

Abstract
Several lines of evidence support the premise that screening colonoscopy reduces colorectal cancer (CRC) incidence, but there may be differential benefits for right- and left-sided tumors. To better understand the biological basis of this differential effect, we derived biomathematical models of CRC incidence trends in U.S. and U.K. populations, representing relatively high- and low-prevalence screening, respectively. Using the Surveillance Epidemiology and End Results (SEER) and the Office for National Statistics (ONS) registries (both 1973–2006), we derived stochastic multistage clonal expansion (MSCE) models for right-sided (proximal colon) and left-sided (distal colon and rectal) tumors. The MSCE concept is based on the initiation-promotion-progression paradigm of carcinogenesis and provides a quantitative description of natural tumor development from the initiation of an adenoma (via biallelic tumor suppressor gene inactivation) to the clinical detection of CRC. From 1,228,036 (SEER: 340,582; ONS: 887,454) cases, parameter estimates for models adjusted for calendar-year and birth-cohort effects showed that adenoma initiation rates were higher for right-sided tumors, whereas, paradoxically, adenoma growth rates were higher for left-sided tumors. The net effect was a higher cancer risk in the right colon only after age 70 years. Consistent with this finding, simulations of adenoma development predicted that the relative prevalence for right- versus left-sided tumors increases with increasing age, a differential effect most striking in women. Using a realistic biomathematical description of CRC development for two nationally representative registries, we show age- and sex-dependent biological gradients for right- and left-sided colorectal tumors. These findings argue for an age-, sex-, and site-directed approach to CRC screening. Cancer Res; 70(13); 5419–29. ©2010 AACR.
Data from Extracellular Signal-Regulated Kinase Positively Regulates the Oncogenic Activity of MCT-1 in Diffuse Large B-Cell Lymphoma
Authors: Dai Bojie , Zhao X. Frank , Hagner Patrick , Shapiro Paul , Mazan-Mamczarz Krystyna , Zhao Shuchun , Natkunam Yasodha , Gartenhaus Ronald B.
Published: March 2023

Abstract
The MCT-1 oncogene was originally identified from lymphoma cell lines. Herein we establish that MCT-1 is highly expressed in 85% of human diffuse large B-cell lymphomas (DLBCL) and that knocking down MCT-1 by a specific short hairpin RNA in DLBCL cells induces apoptosis, supporting a critical role for MCT-1 in DLBCL cell survival. However, the mechanism underlying MCT-1 regulation is largely unknown. We find that MCT-1 is phosphorylated and up-regulated by extracellular signal-regulated kinase (ERK). Furthermore, by using a small inhibitory molecule targeting ERK, we interrupted MCT-1 phosphorylation and stability. Significantly, cells with distinct levels of MCT-1 protein displayed differential sensitivity to ERK inhibitor–induced apoptosis. Treatment with the ERK inhibitor showed marked in vivo antitumor activity in a human DLBCL xenograft model. Our findings establish a functional molecular interaction between MCT-1 and the MEK/ERK signaling pathway and suggest that the activation of MCT-1 function by its upstream kinase ERK plays an important role in lymphomagenesis. [Cancer Res 2009;69(19):7835–43]
Data from Epigenetic Repression of microRNA-129-2 Leads to Overexpression of SOX4 Oncogene in Endometrial Cancer
Authors: Huang Yi-Wen , Liu Joseph C. , Deatherage Daniel E. , Luo Jingqin , Mutch David G. , Goodfellow Paul J. , Miller David S. , Huang Tim H-M.
Published: March 2023

Abstract
Genetic amplification, mutation, and translocation are known to play a causal role in the upregulation of an oncogene in cancer cells. Here, we report an emerging role of microRNA, the epigenetic deregulation of which may also lead to this oncogenic activation. SOX4, an oncogene belonging to the SRY-related high mobility group box family, was found to be overexpressed (P < 0.005) in endometrial tumors (n = 74) compared with uninvolved controls (n = 20). This gene is computationally predicted to be the target of a microRNA, miR-129-2. When compared with the matched endometria, the expression of miR-129-2 was lost in 27 of 31 primary endometrial tumors that also showed a concomitant gain of SOX4 expression (P < 0.001). This inverse relationship is associated with hypermethylation of the miR-129-2 CpG island, which was observed in endometrial cancer cell lines (n = 6) and 68% of 117 endometrioid endometrial tumors analyzed. Reactivation of miR-129-2 in cancer cells by pharmacologic induction of histone acetylation and DNA demethylation resulted in decreased SOX4 expression. In addition, restoration of miR-129-2 by cell transfection led to decreased SOX4 expression and reduced proliferation of cancer cells. Further analysis found a significant correlation of hypermethylated miR-129-2 with microsatellite instability and MLH1 methylation status (P < 0.001) and poor overall survival (P < 0.039) in patients. Therefore, these results imply that the aberrant expression of SOX4 is, in part, caused by epigenetic repression of miR-129-2 in endometrial cancer. Unlike the notion that promoter hypomethylation may upregulate an oncogene, we present a new paradigm in which hypermethylation-mediated silencing of a microRNA derepresses its oncogenic target in cancer cells. [Cancer Res 2009;69(23):9038–46]
Data from Suppression of Integrin α3β1 in Breast Cancer Cells Reduces Cyclooxygenase-2 Gene Expression and Inhibits Tumorigenesis, Invasion, and Cross-Talk to Endothelial Cells
Authors: Mitchell Kara , Svenson Kimberly B. , Longmate Whitney M. , Gkirtzimanaki Katerina , Sadej Rafal , Wang Xianhui , Zhao Jihe , Eliopoulos Aristides G. , Berditchevski Fedor , DiPersio C. Michael
Published: March 2023

Abstract
Integrin receptors for cell adhesion to extracellular matrix have important roles in promoting tumor growth and progression. Integrin α3β1 is highly expressed in breast cancer cells in which it is thought to promote invasion and metastasis; however, its roles in regulating malignant tumor cell behavior remain unclear. In the current study, we used short-hairpin RNA (shRNA) to show that suppression of α3β1 in a human breast cancer cell line, MDA-MB-231, leads to decreased tumorigenicity, reduced invasiveness, and decreased production of factors that stimulate endothelial cell migration. Real-time PCR revealed that suppression of α3β1 caused a dramatic reduction in expression of the cyclooxygenase-2 (COX-2) gene, which is frequently overexpressed in breast cancers and has been exploited as a therapeutic target. Decreased COX-2 was accompanied by reduced prostaglandin E2 (PGE2), a major prostanoid produced downstream of COX-2 and an important effector of COX-2 signaling. shRNA-mediated suppression of COX-2 showed that it has a role in tumor cell invasion and cross-talk to endothelial cells. Furthermore, treatment with PGE2 restored these functions in α3β1-deficient MDA-MB-231 cells. These findings identify a role for α3β1 in regulating two properties of tumor cells that facilitate cancer progression: invasiveness and ability to stimulate endothelial cells. They also reveal a novel role for COX-2 as a downstream effector of α3β1 in tumor cells, thereby identifying α3β1 as a potential therapeutic target to inhibit breast cancer. Cancer Res; 70(15); 6359–67. ©2010 AACR.