bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Sym004: A Novel Synergistic Anti–Epidermal Growth Factor Receptor Antibody Mixture with Superior Anticancer Efficacy
Authors: Pedersen Mikkel Wandahl , Jacobsen Helle Jane , Koefoed Klaus , Hey Adam , Pyke Charles , Haurum John Sørensen , Kragh Michael
Published: March 2023

Abstract
Epidermal growth factor receptor (EGFR) is a validated therapeutic target in cancer and EGFR antagonists with greater effectiveness than existing clinical agents remain of interest. Here, we report a novel approach based on Sym004, a mixture of two anti-EGFR monoclonal antibodies directed against distinct nonoverlapping epitopes in EGFR extracellular domain III. Like anti-EGFR monoclonal antibodies in current clinical use, Sym004 inhibits cancer cell growth and survival by blocking ligand-binding receptor activation and phosphorylation and downstream receptor signaling. However, unlike the other antibodies, Sym004 induces rapid and efficient removal of the receptor from the cancer cell surface by triggering EGFR internalization and degradation. Compared with reference anti-EGFR monoclonal antibodies, Sym004 exhibited more pronounced growth inhibition in vitro and superior efficacy in vivo. Together, these findings illustrate a strategy to target EGFR more effectively than existing clinical antibodies. Cancer Res; 70(2); 588–97
Data from MicroRNA-21 in Pancreatic Cancer: Correlation with Clinical Outcome and Pharmacologic Aspects Underlying Its Role in the Modulation of Gemcitabine Activity
Authors: Giovannetti Elisa , Funel Niccola , Peters Godefridus J. , Del Chiaro Marco , Erozenci Leyla A. , Vasile Enrico , Leon Leticia G. , Pollina Luca E. , Groen Annemieke , Falcone Alfredo , Danesi Romano , Campani Daniela , Verheul Henk M. , Boggi Ugo
Published: March 2023

Abstract
MicroRNA-21 (miR-21) was reported to be overexpressed and contributes to invasion and gemcitabine resistance in pancreatic ductal adenocarcinoma (PDAC). The aim of this study was to evaluate whether miR-21 expression was associated with the overall survival (OS) of PDAC patients treated with gemcitabine and to provide mechanistic insights for new therapeutic targets. miR-21 expression was evaluated in cells (including 7 PDAC cell lines, 7 primary cultures, fibroblasts, and a normal pancreatic ductal cell line) and tissues (neoplastic specimens from 81 PDAC patients and normal ductal samples) isolated by laser microdissection. The role of miR-21 on the pharmacologic effects of gemcitabine was studied with a specific miR-21 precursor (pre-miR-21). Patients with high miR-21 expression had a significantly shorter OS both in the metastatic and in the adjuvant setting. Multivariate analysis confirmed the prognostic significance of miR-21. miR-21 expression in primary cultures correlated with expression in their respective tissues and with gemcitabine resistance. Pre-miR-21 transfection significantly decreased antiproliferative effects and apoptosis induction by gemcitabine, whereas matrix metalloproteinase (MMP)-2/MMP-9 and vascular endothelial growth factor expression were upregulated. Addition of inhibitors of phosphoinositide 3-kinase and mammalian target of rapamycin resulted in decrease of phospho-Akt and prevented pre-miR-21–induced resistance to the proapoptotic effects of gemcitabine. miR-21 expression correlated with outcome in PDAC patients treated with gemcitabine. Modulation of apoptosis, Akt phosphorylation, and expression of genes involved in invasive behavior may contribute to the role of miR-21 in gemcitabine chemoresistance and to the rational development of new targeted combinations. Cancer Res; 70(11); 4528–38. ©2010 AACR.
Data from The Phosphoinositide 3-Kinase Inhibitor PI-103 Downregulates Choline Kinase α Leading to Phosphocholine and Total Choline Decrease Detected by Magnetic Resonance Spectroscopy
Authors: Al-Saffar Nada M.S. , Jackson L. Elizabeth , Raynaud Florence I. , Clarke Paul A. , Ramírez de Molina Ana , Lacal Juan C. , Workman Paul , Leach Martin O.
Published: March 2023

Abstract
The phosphoinositide 3-kinase (PI3K) pathway is a major target for cancer drug development. PI-103 is an isoform-selective class I PI3K and mammalian target of rapamycin inhibitor. The aims of this work were as follows: first, to use magnetic resonance spectroscopy (MRS) to identify and develop a robust pharmacodynamic (PD) biomarker for target inhibition and potentially tumor response following PI3K inhibition; second, to evaluate mechanisms underlying the MRS-detected changes. Treatment of human PTEN null PC3 prostate and PIK3CA mutant HCT116 colon carcinoma cells with PI-103 resulted in a concentration- and time-dependent decrease in phosphocholine (PC) and total choline (tCho) levels (P < 0.05) detected by phosphorus (31P)- and proton (1H)-MRS. In contrast, the cytotoxic microtubule inhibitor docetaxel increased glycerophosphocholine and tCho levels in PC3 cells. PI-103–induced MRS changes were associated with alterations in the protein expression levels of regulatory enzymes involved in lipid metabolism, including choline kinase α (ChoKα), fatty acid synthase (FAS), and phosphorylated ATP-citrate lyase (pACL). However, a strong correlation (r2 = 0.9, P = 0.009) was found only between PC concentrations and ChoKα expression but not with FAS or pACL. This study identified inhibition of ChoKα as a major cause of the observed change in PC levels following PI-103 treatment. We also showed the capacity of 1H-MRS, a clinically well-established technique with higher sensitivity and wider applicability compared with 31P-MRS, to assess response to PI-103. Our results show that monitoring the effects of PI3K inhibitors by MRS may provide a noninvasive PD biomarker for PI3K inhibition and potentially of tumor response during early-stage clinical trials with PI3K inhibitors. Cancer Res; 70(13); 5507–17. ©2010 AACR.
Data from Development of a Lung Cancer Therapeutic Based on the Tumor Suppressor MicroRNA-34
Authors: Wiggins Jason F. , Ruffino Lynnsie , Kelnar Kevin , Omotola Michael , Patrawala Lubna , Brown David , Bader Andreas G.
Published: March 2023

Abstract
Tumor suppressor microRNAs (miRNA) provide a new opportunity to treat cancer. This approach, “miRNA replacement therapy,” is based on the concept that the reintroduction of miRNAs depleted in cancer cells reactivates cellular pathways that drive a therapeutic response. Here, we describe the development of a therapeutic formulation using chemically synthesized miR-34a and a lipid-based delivery vehicle that blocks tumor growth in mouse models of non–small-cell lung cancer. This formulation is effective when administered locally or systemically. The antioncogenic effects are accompanied by an accumulation of miR-34a in the tumor tissue and downregulation of direct miR-34a targets. Intravenous delivery of formulated miR-34a does not induce an elevation of cytokines or liver and kidney enzymes in serum, suggesting that the formulation is well tolerated and does not induce an immune response. The data provide proof of concept for the systemic delivery of a synthetic tumor suppressor mimic, obviating obstacles associated with viral-based miRNA delivery and facilitating a rapid route for miRNA replacement therapy into the clinic. Cancer Res; 70(14); 5923–30. ©2010 AACR.
Data from Genetically Engineered Salmonella typhimurium as an Imageable Therapeutic Probe for Cancer
Authors: Nguyen Vu H. , Kim Hyung-Seok , Ha Jung-Min , Hong Yeongjin , Choy Hyon E. , Min Jung-Joon
Published: March 2023

Abstract
Tumor-targeting bacteria have been studied in terms of their ability to visualize the infection pathway (through imaging probes) or to carry therapeutic molecules to tumors. To integrate these monitoring and therapeutic functions, we engineered attenuated Salmonella typhimurium defective in guanosine 5′-diphosphate-3′-diphosphate synthesis to carry cytotoxic proteins (cytolysin A) and express reporter genes. We successfully visualized the therapeutic process with these engineered bacteria in mice and found that they often mediated complete tumor (CT-26) eradication on cytotoxic gene induction. Furthermore, treatment with the engineered bacteria markedly suppressed metastatic tumor growth. Cancer Res; 70(1); 18–23
Data from Paradoxical Dependencies of Tumor Dormancy and Progression on Basic Cell Kinetics
Authors: Enderling Heiko , Anderson Alexander R.A. , Chaplain Mark A.J. , Beheshti Afshin , Hlatky Lynn , Hahnfeldt Philip
Published: March 2023

Abstract
Even after a tumor is established, it can early on enter a state of dormancy marked by balanced cell proliferation and cell death. Disturbances to this equilibrium may affect cancer risk, as they may cause the eventual lifetime clinical presentation of a tumor that might otherwise have remained asymptomatic. Previously, we showed that cell death, proliferation, and migration can play a role in shifting this dynamic, making the understanding of their combined influence on tumor development essential. We developed an individual cell-based computer model of the interaction of cancer stem cells and their nonstem progeny to study early tumor dynamics. Simulations of tumor growth show that three basic components of tumor growth—cell proliferation, migration, and death—combine in unexpected ways to control tumor progression and, thus, clinical cancer risk. We show that increased proliferation capacity in nonstem tumor cells and limited cell migration overall lead to space constraints that inhibit proliferation and tumor growth. By contrast, increasing the rate of cell death produces the expected tumor size reduction in the short term, but results ultimately in paradoxical accelerated long-term growth owing to the liberation of cancer stem cells and formation of self-metastases.[Cancer Res 2009;69(22):8814–21]
Data from Toll-like Receptors 3 and 7 Agonists Enhance Tumor Cell Lysis by Human γδ T Cells
Authors: Shojaei Hamed , Oberg Hans-Heinrich , Juricke Matthias , Marischen Lothar , Kunz Monika , Mundhenke Christoph , Gieseler Frank , Kabelitz Dieter , Wesch Daniela
Published: March 2023

Abstract
Toll-like receptor (TLR) agonists are considered adjuvants in clinical trials of cancer immunotherapy. Here, we investigated the modulation of γδ T cell–mediated tumor cell lysis by TLR ligands. γδ T-cell cytotoxicity and granzyme A/B production were enhanced after pretreatment of tumor cells with TLR3 [poly(I:C)] or TLR7 ligand (imiquimod). We examined TLR3- and TLR7-expressing pancreatic adenocarcinomas, squamous cell carcinomas of head and neck and lung carcinomas. Poly(I:C) treatment of pancreatic adenocarcinomas followed by coculture with γδ T cells resulted in an upregulation of CD54 on the tumor cells. The interaction of CD54 and the corresponding ligand CD11a/CD18 expressed on γδ T cells is responsible for triggering effector function in γδ T cells. Moreover, treatment with imiquimod downregulated MHC class I molecules on tumor cells possibly resulting in a reduced binding affinity for inhibitory receptor NKG2A expressed on γδ T cells. These results indicate that TLR3 or TLR7 ligand stimulation of tumor cells enhances the cytotoxic activity of expanded γδ T cells of cancer patients in vitro. [Cancer Res 2009;69(22):8710–7]
Data from Membrane Type 1-Matrix Metalloproteinase Cleaves Off the NH2-Terminal Portion of Heparin-Binding Epidermal Growth Factor and Converts It into a Heparin-Independent Growth Factor
Authors: Koshikawa Naohiko , Mizushima Hiroto , Minegishi Tomoko , Iwamoto Ryo , Mekada Eisuke , Seiki Motoharu
Published: March 2023

Abstract
Epidermal growth factor (EGF) receptors (ErbB) and EGF family members represent promising targets for cancer therapy. Heparin-binding EGF (HB-EGF) is a member of the EGF family and is an important target for therapy in some types of human cancers. Processing of HB-EGF by proprotein convertases, and successively, by ADAM family proteases, generates a soluble growth factor that requires heparin as a cofactor. Although heparin potentiates HB-EGF activity in vitro, it is not clear how the heparin-binding activity of HB-EGF is regulated. Here, we show that membrane type 1-matrix metalloproteinase (MT1-MMP; MMP14), a potent invasion-promoting protease, markedly enhances HB-EGF–dependent tumor formation in mice. MT1-MMP additionally cleaves HB-EGF and removes the NH2-terminal 20 amino acids that are important for binding heparin. Consequently, the processing of HB-EGF by MT1-MMP converts HB-EGF into a heparin-independent growth factor with enhanced mitogenic activity, and thereby, expression of both proteins costimulates tumor cell growth in vitro and in vivo. The ErbB family of receptors expressed in human gastric carcinoma cells play a role in mediating enhanced HB-EGF activity by MT1-MMP during invasive cell growth in collagen. Thus, we shed light on a new mechanism whereby HB-EGF activity is regulated that should be considered when designing HB-EGF–targeted cancer therapy. Cancer Res; 70(14); 6093–103. ©2010 AACR.
Data from Confirmation of Linkage to and Localization of Familial Colon Cancer Risk Haplotype on Chromosome 9q22
Authors: Gray-McGuire Courtney , Guda Kishore , Adrianto Indra , Lin Chee Paul , Natale Leanna , Potter John D. , Newcomb Polly , Poole Elizabeth M. , Ulrich Cornelia M. , Lindor Noralane , Goode Ellen L. , Fridley Brooke L. , Jenkins Robert , Le Marchand Loic , Casey Graham , Haile Robert , Hopper John , Jenkins Mark , Young Joanne , Buchanan Daniel , Gallinger Steve , Adams Mark , Lewis Susan , Willis Joseph , Elston Robert , Markowitz Sanford D. , Wiesner Georgia L.
Published: March 2023

Abstract
Genetic risk factors are important contributors to the development of colorectal cancer. Following the definition of a linkage signal at 9q22-31, we fine mapped this region in an independent collection of colon cancer families. We used a custom array of single-nucleotide polymorphisms (SNP) densely spaced across the candidate region, performing both single-SNP and moving-window association analyses to identify a colon neoplasia risk haplotype. Through this approach, we isolated the association effect to a five-SNP haplotype centered at 98.15 Mb on chromosome 9q. This haplotype is in strong linkage disequilibrium with the haplotype block containing HABP4 and may be a surrogate for the effect of this CD30 Ki-1 antigen. It is also in close proximity to GALNT12, also recently shown to be altered in colon tumors. We used a predictive modeling algorithm to show the contribution of this risk haplotype and surrounding candidate genes in distinguishing between colon cancer cases and healthy controls. The ability to replicate this finding, the strength of the haplotype association (odds ratio, 3.68), and the accuracy of our prediction model (∼60%) all strongly support the presence of a locus for familial colon cancer on chromosome 9q. Cancer Res; 70(13); 5409–18. ©2010 AACR.
Data from Activation-Induced Cytidine Deaminase Accelerates Clonal Evolution in BCR-ABL1–Driven B-Cell Lineage Acute Lymphoblastic Leukemia
Authors: Gruber Tanja Andrea , Chang Mi Sook , Sposto Richard , Müschen Markus
Published: March 2023

Abstract
Activation-induced cytidine deaminase (AID) is required for somatic hypermutation and immunoglobulin (Ig) class switch recombination in germinal center (GC) B cells. Occasionally, AID can target non-Ig genes and thereby promote GC B-cell lymphomagenesis. We recently showed that the oncogenic BCR-ABL1 kinase induces aberrant expression of AID in pre-B acute lymphoblastic leukemia (ALL) and lymphoid chronic myelogenous leukemia blast crisis. To elucidate the biological significance of aberrant AID expression, we studied loss of AID function in a murine model of BCR-ABL1 ALL. Mice transplanted with BCR-ABL1–transduced AID−/− bone marrow had prolonged survival compared with mice transplanted with leukemia cells generated from AID+/+ bone marrow. Consistent with a causative role of AID in genetic instability, AID−/− leukemia had a lower frequency of amplifications and deletions and a lower frequency of mutations in non-Ig genes, including Pax5 and Rhoh compared with AID+/+ leukemias. AID−/− and AID+/+ ALL cells showed a markedly distinct gene expression pattern, and AID−/− ALL cells failed to downregulate a number of tumor-suppressor genes including Rhoh, Cdkn1a (p21), and Blnk (SLP65). We conclude that AID accelerates clonal evolution in BCR-ABL1 ALL by enhancing genetic instability and aberrant somatic hypermutation, and by negative regulation of tumor-suppressor genes. Cancer Res; 70(19); 7411–20. ©2010 AACR.
Data from Essential Requirement for PP2A Inhibition by the Oncogenic Receptor c-KIT Suggests PP2A Reactivation as a Strategy to Treat c-KIT+ Cancers
Authors: Roberts Kathryn G. , Smith Amanda M. , McDougall Fiona , Carpenter Helen , Horan Martin , Neviani Paolo , Powell Jason A. , Thomas Daniel , Guthridge Mark A. , Perrotti Danilo , Sim Alistair T.R. , Ashman Leonie K. , Verrills Nicole M.
Published: March 2023

Abstract
Oncogenic mutations of the receptor tyrosine kinase c-KIT play an important role in the pathogenesis of gastrointestinal stromal tumors, systemic mastocytosis, and some acute myeloid leukemias (AML). Although juxtamembrane mutations commonly detected in gastrointestinal stromal tumor are sensitive to tyrosine kinase inhibitors, the kinase domain mutations frequently encountered in systemic mastocytosis and AML confer resistance and are largely unresponsive to targeted inhibition by the existing agent imatinib. In this study, we show that myeloid cells expressing activated c-KIT mutants that are imatinib sensitive (V560G) or imatinib resistant (D816V) can inhibit the tumor suppressor activity of protein phosphatase 2A (PP2A). This effect was associated with the reduced expression of PP2A structural (A) and regulatory subunits (B55α, B56α, B56γ, and B56δ). Overexpression of PP2A-Aα in D816V c-KIT cells induced apoptosis and inhibited proliferation. In addition, pharmacologic activation of PP2A by FTY720 reduced proliferation, inhibited clonogenic potential, and induced apoptosis of mutant c-KIT+ cells, while having no effect on wild-type c-KIT cells or empty vector controls. FTY720 treatment caused the dephosphorylation of the D816V c-KIT receptor and its downstream signaling targets pAkt, pSTAT5, and pERK1/2. Additionally, in vivo administration of FTY720 delayed the growth of V560G and D816V c-KIT tumors, inhibited splenic and bone marrow infiltration, and prolonged survival. Our findings show that PP2A inhibition is essential for c-KIT–mediated tumorigenesis, and that reactivating PP2A may offer an attractive strategy to treat drug-resistant c-KIT+ cancers. Cancer Res; 70(13); 5438–47. ©2010 AACR.
Data from Oncolysis of Prostate Cancers Induced by Vesicular Stomatitis Virus in PTEN Knockout Mice
Authors: Moussavi Maryam , Fazli Ladan , Tearle Howard , Guo Yubin , Cox Michael , Bell John , Ong Christopher , Jia William , Rennie Paul S.
Published: March 2023

Abstract
Vesicular stomatitis virus (VSV) is an oncolytic virus which selectively infects and kills cancer cells. The goal of the present study was to determine the safety and efficacy of VSV treatment of prostate tumors that arise in situ in immunocompetent, transgenic prostate-specific PTEN-null (PTEN−/−) mice. Interferon-sensitive VSV(AV3 strain), which expresses luciferase, was injected intraprostatically into tumor-bearing PTEN−/− and control mice and then monitored for tissue bioluminescence over 96 hours. Virus readily dispersed throughout the bodies of mice after only 3 hours; however, it persisted at high levels for >72 hours in PTEN−/− mice, but at relatively low levels and for only ∼48 hours in controls. Plaque assays provided a similar pattern, with much higher concentrations of replicating virus in prostates of PTEN−/− mice than in controls. Transient, low levels of virus were detected in the spleens of both groups. Apoptotic analyses by terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling staining revealed that VSV(AV3) is able to selectively infect and kill prostate cells in PTEN−/− mice, while sparing normal cells in control mice. The primary mechanism for cell kill is apparently apoptotic oncolysis as opposed to neutrophil invasion as has been reported using xenograft models. These results suggest that control of locally advanced human prostate cancer may be achievable through intraprostatic injection and amplification of a safe oncolytic virus, such as VSV(AV3). Cancer Res; 70(4); 1367–76
Data from Sphingosine-1-Phosphate Activates the AKT Pathway to Protect Small Intestines from Radiation-Induced Endothelial Apoptosis
Authors: Bonnaud Stéphanie , Niaudet Colin , Legoux François , Corre Isabelle , Delpon Gregory , Saulquin Xavier , Fuks Zvi , Gaugler Marie-Hélène , Kolesnick Richard , Paris François
Published: March 2023

Abstract
A previous in vitro study showed that sphingosine-1-phosphate (S1P), a ceramide antagonist, preserved endothelial cells in culture from radiation-induced apoptosis. We proposed to validate the role of S1P in tissue radioprotection by inhibiting acute gastrointestinal (GI) syndrome induced by endothelial cell apoptosis after high dose of radiation. Retro-orbital S1P was injected in mice exposed to 15 Gy, a dose-inducing GI syndrome within 10 days. Overall survival and apoptosis on intestines sections were studied. Intestinal cell type targeted by S1P and early molecular survival pathways were researched using irradiated in vitro cell models and in vivo mouse models. We showed that retro-orbital S1P injection before irradiation prevented GI syndrome by inhibiting endothelium collapse. We defined endothelium as a specific therapeutic target because only these cells and not intestinal epithelial cells, or B and T lymphocytes, were protected. Pharmacologic approaches using AKT inhibitor and pertussis toxin established that S1P affords endothelial cell protection in vitro and in vivo through a mechanism involving AKT and 7-pass transmembrane receptors coupled to Gi proteins. Our results provide strong pharmacologic and mechanistic proofs that S1P protects endothelial cells against acute radiation enteropathy. Cancer Res; 70(23); 9905–15. ©2010 AACR.
Data from Halogenated Benzimidazole Carboxamides Target Integrin α4β1 on T-Cell and B-Cell Lymphomas
Authors: Carpenter Richard D. , Natarajan Arutselvan , Lau Edmond Y. , Andrei Mirela , Solano Danielle M. , Lightstone Felice C. , DeNardo Sally J. , Lam Kit S. , Kurth Mark J.
Published: March 2023

Abstract
Integrin α4β1 is an attractive but poorly understood target for selective diagnosis and treatment of T-cell and B-cell lymphomas. This report focuses on the rapid microwave preparation, structure-activity relationships, and biological evaluation of medicinally pertinent benzimidazole heterocycles as integrin α4β1 antagonists. We documented tumor uptake of derivatives labeled with 125I in xenograft murine models of B-cell lymphoma. Molecular homology models of integrin α4β1 predicted that docked halobenzimidazole carboxamides have the halogen atom in a suitable orientation for halogen-hydrogen bonding. The high-affinity halogenated ligands identified offer attractive tools for medicinal and biological use, including fluoro and iodo derivatives with potential radiodiagnostic (18F) or radiotherapeutic (131I) applications, or chloro and bromo analogues that could provide structural insights into integrin-ligand interactions through photoaffinity, cross-linking/mass spectroscopy, and X-ray crystallographic studies. Cancer Res; 70(13); 5448–56. ©2010 AACR.
Data from Silencing of SPRY1 Triggers Complete Regression of Rhabdomyosarcoma Tumors Carrying a Mutated RAS Gene
Authors: Schaaf Gerben , Hamdi Mohamed , Zwijnenburg Danny , Lakeman Arjan , Geerts Dirk , Versteeg Rogier , Kool Marcel
Published: March 2023

Abstract
RAS oncogenes are among the most frequently mutated genes in human cancer, but effective strategies for therapeutic inhibition of the RAS pathway have been elusive. Sprouty1 (SPRY1) is an upstream antagonist of RAS that is activated by extracellular signal-related kinase (ERK), providing a negative feedback loop for RAS signaling, and other evidence suggests that SPRY1 may have a tumor suppressor function. Studies of RAS status in the human childhood tumor rhabdomyosarcoma (RMS) indicated mutations in approximately half of the tumors of the embryonal rhabdomyosarcoma subtype (ERMS) but not the alveolar subtype (ARMS). ERMS tumors also showed overexpression of SPRY1, which was indeed upregulated by mutant RAS. However, we found that, in the presence of mutant RAS, the function of SPRY1 was changed from an antagonist to an agonist of RAS signaling. Thus, SPRY1 supported formation of activated ERK and mitogen-activated protein/ERK kinase and was essential for ERMS cell proliferation and survival. Conversely, silencing of SPRY1 in ERMS cells (but not ARMS cells) abolished their tumorigenicity in mice. Moreover, silencing of SPRY1 caused regression of established ERMS tumors (but not ARMS tumors) formed in xenograft settings. Our findings argue that SPRY1 inhibition can offer a therapeutic strategy to treat childhood RMS and possibly other tumors carrying oncogenic RAS mutations. Cancer Res; 70(2); 762–71
Data from Diallyl Trisulfide Inhibits Phorbol Ester–Induced Tumor Promotion, Activation of AP-1, and Expression of COX-2 in Mouse Skin by Blocking JNK and Akt Signaling
Authors: Shrotriya Sangeeta , Kundu Joydeb Kumar , Na Hye-Kyung , Surh Young-Joon
Published: March 2023

Abstract
An inverse relationship exists between the consumption of garlic and the risk of certain cancers. The present study was aimed at investigating the effect of garlic constituent diallyl trisulfide (DATS) on 12-O-tetradecanoylphorbol-13-acetate (TPA)–induced cyclooxygenase-2 (COX-2) expression and tumor promotion in mouse skin and to explore the underlying molecular mechanisms. Pretreatment of mouse skin with different garlic-derived allyl sulfides showed DATS to be the most potent in suppressing TPA-induced COX-2 expression. DATS significantly attenuated the DNA binding of activator protein-1 (AP-1), one of the transcription factors that regulate COX-2 expression, in TPA-stimulated mouse skin. DATS also diminished TPA-induced expression of c-Jun and c-Fos, the principal components of AP-1, and blunted the activation of c-Jun NH2-terminal kinase (JNK) and Akt. Pharmacologic inhibition of JNK or Akt by SP600125 or LY294002, respectively, resulted in diminished AP-1 DNA binding, reduced levels of c-Jun and c-Fos, and inhibition of COX-2 expression in TPA-treated mouse skin. The JNK or Akt kinase assay, taking c-Jun fusion protein as a substrate, revealed that TPA induced JNK- or Akt-mediated c-Jun phosphorylation in mouse skin, which was significantly attenuated by DATS or respective pharmacologic inhibitors. Evaluation of antitumor-promoting effect of DATS on 7,12-dimethylbenz(a)anthracene–initiated and TPA-promoted mouse skin carcinogenesis showed that pretreatment with DATS significantly reduced the incidence and multiplicity of papillomas. Taken together, the inhibitory effects of DATS on TPA-induced AP-1 activation and COX-2 expression through modulation of JNK or Akt signaling may partly account for its antitumor-promoting effect on mouse skin carcinogenesis. Cancer Res; 70(5); 1932–40
Data from Aerobic Glycolysis Suppresses p53 Activity to Provide Selective Protection from Apoptosis upon Loss of Growth Signals or Inhibition of BCR-Abl
Authors: Mason Emily F. , Zhao Yuxing , Goraksha-Hicks Pankuri , Coloff Jonathan L. , Gannon Hugh , Jones Stephen N. , Rathmell Jeffrey C.
Published: March 2023

Abstract
Unlike the growth factor dependence of normal cells, cancer cells can maintain growth factor–independent glycolysis and survival through expression of oncogenic kinases, such as BCR-Abl. Although targeted kinase inhibition can promote cancer cell death, therapeutic resistance develops frequently, and further mechanistic understanding is needed. Cell metabolism may be central to this cell death pathway, as we have shown that growth factor deprivation leads to decreased glycolysis that promotes apoptosis via p53 activation and induction of the proapoptotic protein Puma. Here, we extend these findings to show that elevated glucose metabolism, characteristic of cancer cells, can suppress protein kinase Cδ (PKCδ)–dependent p53 activation to maintain cell survival after growth factor withdrawal. In contrast, DNA damage–induced p53 activation was PKCδ independent and was not metabolically sensitive. Both stresses required p53 Ser18 phosphorylation for maximal activity but led to unique patterns of p53 target gene expression, showing distinct activation and response pathways for p53 that were differentially regulated by metabolism. Consistent with oncogenic kinases acting to replace growth factors, treatment of BCR-Abl–expressing cells with the kinase inhibitor imatinib led to reduced metabolism and p53- and Puma-dependent cell death. Accordingly, maintenance of glucose uptake inhibited p53 activation and promoted imatinib resistance. Furthermore, inhibition of glycolysis enhanced imatinib sensitivity in BCR-Abl–expressing cells with wild-type p53 but had little effect on p53-null cells. These data show that distinct pathways regulate p53 after DNA damage and metabolic stress and that inhibiting glucose metabolism may enhance the efficacy of and overcome resistance to targeted molecular cancer therapies. Cancer Res; 70(20); 8066–76. ©2010 AACR.
Data from Frequent Attenuation of the WWOX Tumor Suppressor in Osteosarcoma Is Associated with Increased Tumorigenicity and Aberrant RUNX2 Expression
Authors: Kurek Kyle C. , Del Mare Sara , Salah Zaidoun , Abdeen Suhaib , Sadiq Hussain , Lee Suk-hee , Gaudio Eugenio , Zanesi Nicola , Jones Kevin B. , DeYoung Barry , Amir Gail , Gebhardt Mark , Warman Matthew , Stein Gary S. , Stein Janet L. , Lian Jane B. , Aqeilan Rami I.
Published: March 2023

Abstract
The WW domain-containing oxidoreductase (WWOX) is a tumor suppressor that is deleted or attenuated in most human tumors. Wwox-deficient mice develop osteosarcoma (OS), an aggressive bone tumor with poor prognosis that often metastasizes to lung. On the basis of these observations, we examined the status of WWOX in human OS specimens and cell lines. In human OS clinical samples, WWOX expression was absent or reduced in 58% of tumors examined (P < 0.0001). Compared with the primary tumors, WWOX levels frequently increased in tumors resected following chemotherapy. In contrast, tumor metastases to lung often exhibited reduced WWOX levels relative to the primary tumor. In human OS cell lines having reduced WWOX expression, ectopic expression of WWOX inhibited proliferation and attenuated invasion in vitro, and suppressed tumorigenicity in nude mice. Expression of WWOX was associated with reduced RUNX2 expression in OS cell lines, whereas RUNX2 levels were elevated in femurs of Wwox-deficient mice. Furthermore, WWOX reconstitution in HOS cells was associated with downregulation of RUNX2 levels and RUNX2 target genes, consistent with the ability of WWOX to suppress RUNX2 transactivation activity. In clinical samples, RUNX2 was expressed in the majority of primary tumors and undetectable in most tumors resected following chemotherapy, whereas most metastases were RUNX2 positive. Our results deepen the evidence of a tumor suppressor role for WWOX in OS, furthering its prognostic and therapeutic significance in this disease. Cancer Res; 70(13); 5577–86. ©2010 AACR.
Data from EGFR Promotes Lung Tumorigenesis by Activating miR-7 through a Ras/ERK/Myc Pathway That Targets the Ets2 Transcriptional Repressor ERF
Authors: Chou Yu-Ting , Lin Hua-Heng , Lien Yung-Chang , Wang Yuan-Hung , Hong Chun-Fu , Kao Yu-Rung , Lin Sheng-Chieh , Chang Ying-Che , Lin Shu-Yu , Chen Shu-Jen , Chen Hua-Chien , Yeh Shauh-Der , Wu Cheng-Wen
Published: March 2023

Abstract
MicroRNAs (miRNA) mediate distinct gene regulatory pathways triggered by epidermal growth factor receptor (EGFR) activation, which occurs commonly in lung cancers with poor prognosis. In this study, we report the discovery and mechanistic characterization of the miRNA miR-7 as an oncogenic “oncomiR” and its role as a key mediator of EGFR signaling in lung cancer cells. EGFR activation or ectopic expression of Ras as well as c-Myc stimulated miR-7 expression in an extracellular signal-regulated kinase (ERK)–dependent manner, suggesting that EGFR induces miR-7 expression through a Ras/ERK/Myc pathway. In support of this likelihood, c-Myc bound to the miR-7 promoter and enhanced its activity. Ectopic miR-7 promoted cell growth and tumor formation in lung cancer cells, significantly increasing the mortality of nude mice hosts, which were orthotopically implanted with lung cancers. Quantitative proteomic analysis revealed that miR-7 decreased levels of the Ets2 transcriptional repression factor ERF, the coding sequence of which was found to contain a miR-7 complementary sequence. Indeed, ectopic miR-7 inhibited production of ERF messages with a wild-type but not a silently mutated coding sequence, and ectopic miR-7 rescued growth arrest produced by wild-type but not mutated ERF. Together, these results identified that ERF is a direct target of miR-7 in lung cancer. Our findings suggest that miR-7 may act as an important modulator of EGFR-mediated oncogenesis, with potential applications as a novel prognostic biomarker and therapeutic target in lung cancer. Cancer Res; 70(21); 8822–31. ©2010 AACR.
Data from Different Tumor Microenvironments Contain Functionally Distinct Subsets of Macrophages Derived from Ly6C(high) Monocytes
Authors: Movahedi Kiavash , Laoui Damya , Gysemans Conny , Baeten Martijn , Stangé Geert , Van den Bossche Jan , Mack Matthias , Pipeleers Daniel , In't Veld Peter , De Baetselier Patrick , Van Ginderachter Jo A.
Published: March 2023

Abstract
Tumor-associated macrophages (TAM) form a major component of the tumor stroma. However, important concepts such as TAM heterogeneity and the nature of the monocytic TAM precursors remain speculative. Here, we show for the first time that mouse mammary tumors contained functionally distinct subsets of TAMs and provide markers for their identification. Furthermore, in search of the TAM progenitors, we show that the tumor-monocyte pool almost exclusively consisted of Ly6ChiCX3CR1low monocytes, which continuously seeded tumors and renewed all nonproliferating TAM subsets. Interestingly, gene and protein profiling indicated that distinct TAM populations differed at the molecular level and could be classified based on the classic (M1) versus alternative (M2) macrophage activation paradigm. Importantly, the more M2-like TAMs were enriched in hypoxic tumor areas, had a superior proangiogenic activity in vivo, and increased in numbers as tumors progressed. Finally, it was shown that the TAM subsets were poor antigen presenters, but could suppress T-cell activation, albeit by using different suppressive mechanisms. Together, our data help to unravel the complexities of the tumor-infiltrating myeloid cell compartment and provide a rationale for targeting specialized TAM subsets, thereby optimally “re-educating” the TAM compartment. Cancer Res; 70(14); 5728–39. ©2010 AACR.
Data from Cancer-Associated Fibroblasts Enhance the Gland-Forming Capability of Prostate Cancer Stem Cells
Authors: Liao Chun-Peng , Adisetiyo Helty , Liang Mengmeng , Roy-Burman Pradip
Published: March 2023

Abstract
Signals originating from cancer-associated fibroblasts (CAF) may positively regulate proliferation and tumorigenicity in prostate cancer. In this study, we investigated whether CAFs may regulate the biology of prostate cancer stem cells (CSC) by using a conditional Pten deletion mouse model of prostate adenocarcinoma to isolate both CAF cultures and CSC-enriched cell fractions from the tumors. CSCs that were isolated possessed self-renewal, spheroid-forming, and multipotential differentiation activities in tissue culture, segregating with a cell fraction exhibiting a signature expression phenotype, including SCA-1 (high), CD49f (high), CK5 (high), p63 (high), Survivin (high), RUNX2 (high), CD44 (low), CD133 (low), CK18 (low), and Androgen Receptor (low). CSC spheroid–forming efficiency was differentially influenced by the nature of fibroblasts in a coculture system: Compared with mouse urogenital sinus mesenchyme or normal prostate fibroblasts, CAFs enhanced spheroid formation, with the spheroids displaying generally larger sizes and more complex histology. Graft experiments showed that CSCs admixed with CAFs produced prostatic glandular structures with more numerous lesions, high proliferative index, and tumor-like histopathologies, compared with those formed in the presence of normal prostate fibroblasts. Together, our findings underscore a significant role of CAFs in CSC biology. Cancer Res; 70(18); 7294–303. ©2010 AACR.
Data from Discovery and Canine Preclinical Assessment of a Nontoxic Procaspase-3–Activating Compound
Authors: Peterson Quinn P. , Hsu Danny C. , Novotny Chris J. , West Diana C. , Kim Dewey , Schmit Joanna M. , Dirikolu Levent , Hergenrother Paul J. , Fan Timothy M.
Published: March 2023

Abstract
A critical event in the apoptotic cascade is the proteolytic activation of procaspases to active caspases. The caspase autoactivating compound PAC-1 induces cancer cell apoptosis and exhibits antitumor activity in murine xenograft models when administered orally as a lipid-based formulation or implanted s.c. as a cholesterol pellet. However, high doses of PAC-1 were found to induce neurotoxicity, prompting us to design and assess a novel PAC-1 derivative called S-PAC-1. Similar to PAC-1, S-PAC-1 activated procaspase-3 and induced cancer cell apoptosis. However, S-PAC-1 did not induce neurotoxicity in mice or dogs. Continuous i.v. infusion of S-PAC-1 in dogs led to a steady-state plasma concentration of ∼10 μmol/L for 24 to 72 hours. In a small efficacy trial of S-PAC-1, evaluation of six pet dogs with lymphoma revealed that S-PAC-1 was well tolerated and that the treatments induced partial tumor regression or stable disease in four of six subjects. Our results support this canine setting for further evaluation of small-molecule procaspase-3 activators, including S-PAC-1, a compound that is an excellent candidate for further clinical evaluation as a novel cancer chemotherapeutic. Cancer Res; 70(18); 7232–41. ©2010 AACR.
Data from Spi-1/PU.1 Oncogene Accelerates DNA Replication Fork Elongation and Promotes Genetic Instability in the Absence of DNA Breakage
Authors: Rimmelé Pauline , Komatsu Jun , Hupé Philippe , Roulin Christophe , Barillot Emmanuel , Dutreix Marie , Conseiller Emmanuel , Bensimon Aaron , Moreau-Gachelin Françoise , Guillouf Christel
Published: March 2023

Abstract
The multistage process of cancer formation is driven by the progressive acquisition of somatic mutations. Replication stress creates genomic instability in mammals. Using a well-defined multistep leukemia model driven by Spi-1/PU.1 overexpression in the mouse and Spi-1/PU.1–overexpressing human leukemic cells, we investigated the relationship between DNA replication and cancer progression. Here, using DNA molecular combing and flow cytometry methods, we show that Spi-1 increases the speed of replication by acting specifically on elongation rather than enhancing origin firing. This shortens the S-phase duration. Combining data from Spi-1 knockdown in murine cells with Spi-1 overexpression in human cells, we provide evidence that inappropriate Spi-1 expression is directly responsible for the replication alteration observed. Importantly, the acceleration of replication progression coincides with an increase in the frequency of genomic mutations without inducing DNA breakage. Thus, we propose that the hitherto unsuspected role for spi-1 oncogene in promoting replication elongation and genomic mutation promotes blastic progression during leukemic development. Cancer Res; 70(17); 6757–66. ©2010 AACR.
Data from Cocarcinogenic Effect of Capsaicin Involves Activation of EGFR Signaling but Not TRPV1
Authors: Hwang Mun Kyung , Bode Ann M. , Byun Sanguine , Song Nu Ry , Lee Hyong Joo , Lee Ki Won , Dong Zigang
Published: March 2023

Abstract
Epidemiologic and animal studies revealed that capsaicin can act as a carcinogen or cocarcinogen. However, the molecular mechanisms of the cancer-promoting effects of capsaicin are not clear. Here, we report that capsaicin has a cocarcinogenic effect on 12-O-tetradecanoylphorbol-13-acetate (TPA)–promoted skin carcinogenesis in vivo and is mediated through the epidermal growth factor receptor (EGFR), but not the transient receptor potential vanilloid subfamily member 1 (TRPV1). Topical application of capsaicin on the dorsal skin of 7,12-dimetylbenz(a)anthracene–initiated and TPA-promoted TRPV1 wild-type (WT) and TRPV1 knockout (KO) mice induced more and larger skin tumors in TRPV1/KO mice, suggesting a TRPV1-independent mechanism. Cyclooxygenase-2 (COX-2) was highly elevated by capsaicin treatment in tumors and murine embryonic fibroblasts from TRPV1/KO mice. Inhibitors of EGFR/MEK signaling suppressed TPA/capsaicin-induced COX-2 expression in TRPV1/KO cells, indicating that activation of EGFR and its downstream signaling is involved in COX-2 elevation. Capsaicin induced a further induction of TPA-increased COX-2 expression in EGFR/WT cells, but not in EGFR/KO cells. TPA/capsaicin cotreatment caused EGFR tyrosine phosphorylation and activated EGFR downstream signaling, including ERKs and Akt in EGFR/WT, but not EGFR/KO cells. Specific inhibition of EGFR and TRPV1 indicated that capsaicin-induced ERK activation in A431 cells was dependent on EGFR, but not TRPV1. Together, these findings suggest that capsaicin might act as a cocarcinogen in TPA-induced skin carcinogenesis through EGFR-dependent mechanisms. Cancer Res; 70(17); 6859–69. ©2010 AACR.
Data from Ionizing Radiation Activates the Nrf2 Antioxidant Response
Authors: McDonald J. Tyson , Kim Kwanghee , Norris Andrew J. , Vlashi Erina , Phillips Tiffany M. , Lagadec Chann , Della Donna Lorenza , Ratikan Josephine , Szelag Heather , Hlatky Lynn , McBride William H.
Published: March 2023

Abstract
The transcription factor NF-E2-related factor 2 (Nrf2) binds the antioxidant DNA response element (ARE) to activate important cellular cytoprotective defense systems. Recently several types of cancers have been shown to overexpress Nrf2, but its role in the cellular response to radiation therapy has yet to be fully determined. In this study, we report that single doses of ionizing radiation from 2 to 8 Gy activate ARE-dependent transcription in breast cancer cells in a dose-dependent manner, but only after a delay of five days. Clinically relevant daily dose fractions of radiation also increased ARE-dependent transcription, but again only after five days. Downstream activation of Nrf2-ARE-dependent gene and protein markers, such as heme oxygenase-1, occurred, whereas Nrf2-deficient fibroblasts were incapable of these responses. Compared with wild-type fibroblasts, Nrf2-deficient fibroblasts had relatively high basal levels of reactive oxygen species that increased greatly five days after radiation exposure. Further, in vitro clonogenic survival assays and in vivo sublethal whole body irradiation tests showed that Nrf2 deletion increased radiation sensitivity, whereas Nrf2-inducing drugs did not increase radioresistance. Our results indicate that the Nrf2-ARE pathway is important to maintain resistance to irradiation, but that it operates as a second-tier antioxidant adaptive response system activated by radiation only under specific circumstances, including those that may be highly relevant to tumor response during standard clinical dose-fractionated radiation therapy. Cancer Res; 70(21); 8886–95. ©2010 AACR.
Data from Global Downstream Pathway Analysis Reveals a Dependence of Oncogenic NF-E2–Related Factor 2 Mutation on the mTOR Growth Signaling Pathway
Authors: Shibata Tatsuhiro , Saito Shigeru , Kokubu Akiko , Suzuki Takafumi , Yamamoto Masayuki , Hirohashi Setsuo
Published: March 2023

Abstract
In multicellular organisms, adaptive responses to oxidative stress are regulated by NF-E2–related factor 2 (NRF2), a master transcription factor of antioxidant genes and phase II detoxifying enzymes. Aberrant activation of NRF2 by either loss-of-function mutations in the Keap1 gene or gain-of-function mutations in the Nrf2 gene occurs in a wide range of human cancers, but details of the biological consequences of NRF2 activation in the cancer cells remain unclear. Here, we report that mutant NRF2 induces epithelial cell proliferation, anchorage-independent growth, and tumorigenicity and metastasis in vivo. Genome-wide gene expression profiling revealed that mutant NRF2 affects diverse molecular pathways including the mammalian target of rapamycin (mTOR) pathway. Mutant NRF2 upregulates RagD, a small G-protein activator of the mTOR pathway, which was also overexpressed in primary lung cancer. Consistently, Nrf2-mutated lung cancer cells were sensitive to mTOR pathway inhibitors (rapamycin and NVP-BEZ235) in both in vitro and an in vivo xenograft model. The gene expression signature associated with mutant NRF2 was a marker of poor prognosis in patients with carcinoma of the head and neck region and lung. These results show that oncogenic Nrf2 mutation induces dependence on the mTOR pathway during carcinogenesis. Our findings offer a rationale to target NRF2 as an anticancer strategy, and they suggest NRF2 activation as a novel biomarker for personalized molecular therapies or prognostic assessment. Cancer Res; 70(22); 9095–105. ©2010 AACR.
Data from Danger Signaling Protein HMGB1 Induces a Distinct Form of Cell Death Accompanied by Formation of Giant Mitochondria
Authors: Gdynia Georg , Keith Martina , Kopitz Jürgen , Bergmann Marion , Fassl Anne , Weber Alexander N.R. , George Julie , Kees Tim , Zentgraf Hans-Walter , Wiestler Otmar D. , Schirmacher Peter , Roth Wilfried
Published: March 2023

Abstract
Cells dying by necrosis release the high-mobility group box 1 (HMGB1) protein, which has immunostimulatory effects. However, little is known about the direct actions of extracellular HMGB1 protein on cancer cells. Here, we show that recombinant human HMGB1 (rhHMGB1) exerts strong cytotoxic effects on malignant tumor cells. The rhHMGB1-induced cytotoxicity depends on the presence of mitochondria and leads to fast depletion of mitochondrial DNA, severe damage of the mitochondrial proteome by toxic malondialdehyde adducts, and formation of giant mitochondria. The formation of giant mitochondria is independent of direct nuclear signaling events, because giant mitochondria are also observed in cytoplasts lacking nuclei. Further, the reactive oxygen species scavenger N-acetylcysteine as well as c-Jun NH2-terminal kinase blockade inhibited the cytotoxic effect of rhHMGB1. Importantly, glioblastoma cells, but not normal astrocytes, were highly susceptible to rhHMGB1-induced cell death. Systemic treatment with rhHMGB1 results in significant growth inhibition of xenografted tumors in vivo. In summary, rhHMGB1 induces a distinct form of cell death in cancer cells, which differs from the known forms of apoptosis, autophagy, and senescence, possibly representing an important novel mechanism of specialized necrosis. Further, our findings suggest that rhHMGB1 may offer therapeutic applications in treatment of patients with malignant brain tumors. Cancer Res; 70(21); 8558–68. ©2010 AACR.