bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Metabolomic NMR Fingerprinting to Identify and Predict Survival of Patients with Metastatic Colorectal Cancer
Authors: Bertini Ivano , Cacciatore Stefano , Jensen Benny V. , Schou Jakob V. , Johansen Julia S. , Kruhøffer Mogens , Luchinat Claudio , Nielsen Dorte L. , Turano Paola
Published: March 2024

Abstract
Earlier detection of patients with metastatic colorectal cancer (mCRC) might improve their treatment and survival outcomes. In this study, we used proton nuclear magnetic resonance (1H-NMR) to profile the serum metabolome in patients with mCRC and determine whether a disease signature may exist that is strong enough to predict overall survival (OS). In 153 patients with mCRC and 139 healthy subjects from three Danish hospitals, we profiled two independent sets of serum samples in a prospective phase II study. In the training set, 1H-NMR metabolomic profiling could discriminate patients with mCRC from healthy subjects with a cross-validated accuracy of 100%. In the validation set, 96.7% of subjects were correctly classified. Patients from the training set with maximally divergent OS were chosen to construct an OS predictor. After validation, patients predicted to have short OS had significantly reduced survival (HR, 3.4; 95% confidence interval, 2.06–5.50; P = 1.33 × 10−6). A number of metabolites concurred with the 1H-NMR fingerprint of mCRC, offering insights into mCRC metabolic pathways. Our findings establish that 1H-NMR profiling of patient serum can provide a strong metabolomic signature of mCRC and that analysis of this signature may offer an independent tool to predict OS. Cancer Res; 72(1); 356–64. ©2011 AACR.
Data from 53BP1 Is a Haploinsufficient Tumor Suppressor and Protects Cells from Radiation Response in Glioma
Authors: Squatrito Massimo , Vanoli Fabio , Schultz Nikolaus , Jasin Maria , Holland Eric C.
Published: March 2024

Abstract
The DNA damage response (DDR) plays a crucial role in tumor development in different tissues. Here, we show that p53-binding protein 1 (53BP1), a key element of the DDR, is heterozygously lost in approximately 20% of human glioblastoma multiforme (GBM) specimens, primarily of the Proneural subtype, and low 53BP1 expression levels are associated with worse prognosis. We present evidence that 53BP1 behaves as haploinsufficient tumor suppressor in a mouse model of platelet-derived growth factor–induced gliomagenesis. We also show that very low level of 53BP1 as found in 53BP1 null gliomas or robust 53BP1 gene silencing in glioma cell lines (but not 53BP1 heterozygous tumors or partial gene knockdown) sensitizes glioma cells to ionizing radiation (IR), both in vitro and in vivo. We further show the 53BP1 gene silencing induces defects in the nonhomologous end-joining (NHEJ) DNA repair pathway. These deficiencies lead to a failure to fully repair the damaged DNA upon exposure of glioma cells to IR with a consequent prolonged cell-cycle arrest and increased apoptosis. Our data suggest that either 53BP1 or other NHEJ components may be critical molecules to be pharmacologically targeted in GBM in combination with standard therapies. Cancer Res; 72(20); 5250–60. ©2012 AACR.
Data from MEK Inhibition Leads to PI3K/AKT Activation by Relieving a Negative Feedback on ERBB Receptors
Authors: Turke Alexa B. , Song Youngchul , Costa Carlotta , Cook Rebecca , Arteaga Carlos L. , Asara John M. , Engelman Jeffrey A.
Published: March 2024

Abstract
The phosphoinositide 3-kinase (PI3K)/AKT and RAF/MEK/ERK signaling pathways are activated in a wide range of human cancers. In many cases, concomitant inhibition of both pathways is necessary to block proliferation and induce cell death and tumor shrinkage. Several feedback systems have been described in which inhibition of one intracellular pathway leads to activation of a parallel signaling pathway, thereby decreasing the effectiveness of single-agent targeted therapies. In this study, we describe a feedback mechanism in which MEK inhibition leads to activation of PI3K/AKT signaling in EGFR and HER2-driven cancers. We found that MEK inhibitor–induced activation of PI3K/AKT resulted from hyperactivation of ERBB3 as a result of the loss of an inhibitory threonine phosphorylation in the conserved juxtamembrane domains of EGFR and HER2. Mutation of this amino acid led to increased ERBB receptor activation and upregulation of the ERBB3/PI3K/AKT signaling pathway, which was no longer responsive to MEK inhibition. Taken together, these results elucidate an important, dominant feedback network regulating central oncogenic pathways in human cancer. Cancer Res; 72(13); 3228–37. ©2012 AACR.
Data from A Pharmacologic Inhibitor of the Protease Taspase1 Effectively Inhibits Breast and Brain Tumor Growth
Authors: Chen David Y. , Lee Yishan , Van Tine Brian A. , Searleman Adam C. , Westergard Todd D. , Liu Han , Tu Ho-Chou , Takeda Shugaku , Dong Yiyu , Piwnica-Worms David R. , Oh Kyoung J. , Korsmeyer Stanley J. , Hermone Ann , Gussio Richard , Shoemaker Robert H. , Cheng Emily H.-Y. , Hsieh James J.-D.
Published: March 2024

Abstract
The threonine endopeptidase Taspase1 has a critical role in cancer cell proliferation and apoptosis. In this study, we developed and evaluated small molecule inhibitors of Taspase1 as a new candidate class of therapeutic modalities. Genetic deletion of Taspase1 in the mouse produced no overt deficiencies, suggesting the possibility of a wide therapeutic index for use of Taspase1 inhibitors in cancers. We defined the peptidyl motifs recognized by Taspase1 and conducted a cell-based dual-fluorescent proteolytic screen of the National Cancer Institute diversity library to identify Taspase1 inhibitors (TASPIN). On the basis of secondary and tertiary screens the 4-[(4-arsonophenyl)methyl]phenyl] arsonic acid NSC48300 was determined to be the most specific active compound. Structure–activity relationship studies indicated a crucial role for the arsenic acid moiety in mediating Taspase1 inhibition. Additional fluorescence resonance energy transfer–based kinetic analysis characterized NSC48300 as a reversible, noncompetitive inhibitor of Taspase1 (Ki = 4.22 μmol/L). In the MMTV-neu mouse model of breast cancer and the U251 xenograft model of brain cancer, NSC48300 produced effective tumor growth inhibition. Our results offer an initial preclinical proof-of-concept to develop TASPINs for cancer therapy. Cancer Res; 72(3); 736–46. ©2011 AACR.
Data from Sphingosine-1-Phosphate Produced by Sphingosine Kinase 1 Promotes Breast Cancer Progression by Stimulating Angiogenesis and Lymphangiogenesis
Authors: Nagahashi Masayuki , Ramachandran Subramaniam , Kim Eugene Y. , Allegood Jeremy C. , Rashid Omar M. , Yamada Akimitsu , Zhao Renping , Milstien Sheldon , Zhou Huiping , Spiegel Sarah , Takabe Kazuaki
Published: March 2024

Abstract
Sphingosine-1-phosphate (S1P) is a pleiotropic bioactive lipid mediator that promotes breast cancer progression by diverse mechanisms that remain somewhat unclear. Here we report pharmacologic evidence of a critical role for sphingosine kinase 1 (SphK1) in producing S1P and mediating tumor-induced hemangiogenesis and lymphangiogenesis in a murine model of breast cancer metastasis. S1P levels increased both in the tumor and the circulation. In agreement, serum S1P levels were significantly elevated in stage IIIA human breast cancer patients, compared with age/ethnicity-matched healthy volunteers. However, treatment with the specific SphK1 inhibitor SK1-I suppressed S1P levels, reduced metastases to lymph nodes and lungs, and decreased overall tumor burden of our murine model. Both S1P and angiopoietin 2 (Ang2) stimulated hemangiogenesis and lymphangiogenesis in vitro, whereas SK1-I inhibited each process. We quantified both processes in vivo from the same specimen by combining directed in vivo angiogenesis assays with fluorescence-activated cell sorting, thereby confirming the results obtained in vitro. Notably, SK1-I decreased both processes not only at the primary tumor but also in lymph nodes, with peritumoral lymphatic vessel density reduced in SK1-I–treated animals. Taken together, our findings show that SphK1-produced S1P is a crucial mediator of breast cancer–induced hemangiogenesis and lymphangiogenesis. Our results implicate SphK1 along with S1P as therapeutic targets in breast cancer. Cancer Res; 72(3); 726–35. ©2012 AACR.
Data from Inhibition of Fatty Acid Synthase Attenuates CD44-Associated Signaling and Reduces Metastasis in Colorectal Cancer
Authors: Zaytseva Yekaterina Y. , Rychahou Piotr G. , Gulhati Pat , Elliott Victoria A. , Mustain William C. , O'Connor Kathleen , Morris Andrew J. , Sunkara Manjula , Weiss Heidi L. , Lee Eun Y. , Evers B. Mark
Published: March 2024

Abstract
Fatty acid synthase (FASN) and ATP-citrate lyase, key enzymes of de novo lipogenesis, are significantly upregulated and activated in many cancers and portend poor prognosis. Even though the role of lipogenesis in providing proliferative and survival advantages to cancer cells has been described, the impact of aberrant activation of lipogenic enzymes on cancer progression remains unknown. In this study, we found that elevated expression of FASN is associated with advanced stages of colorectal cancer (CRC) and liver metastasis, suggesting that it may play a role in progression of CRC to metastatic disease. Targeted inhibition of lipogenic enzymes abolished expression of CD44, a transmembrane protein associated with metastases in several cancers including CRC. In addition, inhibition of lipogenic enzymes and reduced expression of CD44 attenuated the activation of MET, Akt, FAK, and paxillin, which are known to regulate adhesion, migration, and invasion. These changes were consistent with an observed decrease in migration and adhesion of CRC cells in functional assays and with reorganization of actin cytoskeleton upon FASN inhibition. Despite the modest effect of FASN inhibition on tumor growth in xenografts, attenuation of lipogenesis completely abolished establishment of hepatic metastasis and formation of secondary metastasis. Together, our findings suggest that targeting de novo lipogenesis may be a potential treatment strategy for advanced CRC. Cancer Res; 72(6); 1504–17. ©2012 AACR.
Data from Myeloid Progenitor Cells in the Premetastatic Lung Promote Metastases by Inducing Mesenchymal to Epithelial Transition
Authors: Gao Dingcheng , Joshi Natasha , Choi Hyejin , Ryu Seongho , Hahn Mary , Catena Raul , Sadik Helen , Argani Pedram , Wagner Patrick , Vahdat Linda T. , Port Jeffrey L. , Stiles Brendon , Sukumar Saraswati , Altorki Nasser K. , Rafii Shahin , Mittal Vivek
Published: March 2024

Abstract
Tumors systemically initiate metastatic niches in distant target metastatic organs. These niches, composed of bone marrow–derived hematopoietic cells, provide permissive conditions for future metastases. However, the mechanisms by which these cells mediate outgrowth of metastatic tumor cells are not completely known. Using mouse models of spontaneous breast cancer, we show enhanced recruitment of bone marrow–derived CD11b+Gr1+ myeloid progenitor cells in the premetastatic lungs. Gene expression profiling revealed that the myeloid cells from metastatic lungs express versican, an extracellular matrix proteoglycan. Notably, versican in metastatic lungs was mainly contributed by the CD11b+Ly6Chigh monocytic fraction of the myeloid cells and not the tumor cells or other stromal cells. Versican knockdown in the bone marrow significantly impaired lung metastases in vivo, without impacting their recruitment to the lungs or altering the immune microenvironment. Versican stimulated mesenchymal to epithelial transition of metastatic tumor cells by attenuating phospho-Smad2 levels, which resulted in elevated cell proliferation and accelerated metastases. Analysis of clinical specimens showed elevated versican expression within the metastatic lung of patients with breast cancer. Together, our findings suggest that selectively targeting tumor-elicited myeloid cells or versican represents a potential therapeutic strategy for combating metastatic disease. Cancer Res; 72(6); 1384–94. ©2012 AACR.
Data from Expression and Function of Survivin in Canine Osteosarcoma
Authors: Shoeneman Jenette K. , Ehrhart E.J. , Eickhoff Jens C. , Charles J.B. , Powers Barbara E. , Thamm Douglas H.
Published: March 2024

Abstract
Osteosarcoma has a high mortality rate and remains in need of more effective therapeutic approaches. Survivin is an inhibitor of apoptosis family member protein that blocks apoptosis and drives proliferation in human cancer cells where it is commonly elevated. In this study, we illustrate the superiority of a canine osteosarcoma model as a translational tool for evaluating survivin-directed therapies, owing to the striking similarities in gross and microscopic appearance, biologic behavior, gene expression, and signaling pathway alterations. Elevated survivin expression in primary canine osteosarcoma tissue correlated with increased histologic grade and mitotic index and a decreased disease-free interval (DFI). Survivin attenuation in canine osteosarcoma cells inhibited cell-cycle progression, increased apoptosis, mitotic arrest, and chemosensitivity, and cooperated with chemotherapy to significantly improve in vivo tumor control. Our findings illustrate the utility of a canine system to more accurately model human osteosarcoma and strongly suggest that survivin-directed therapies might be highly effective in its treatment. Cancer Res; 72(1); 249–59. ©2011 AACR.
Data from miRNA-708 Control of CD44+ Prostate Cancer–Initiating Cells
Authors: Saini Sharanjot , Majid Shahana , Shahryari Varahram , Arora Sumit , Yamamura Soichiro , Chang Inik , Zaman Mohd Saif , Deng Guoren , Tanaka Yuichiro , Dahiya Rajvir
Published: March 2024

Abstract
Tumor recurrence in prostate cancer has been attributed to the presence of CD44-expressing tumor-initiating cells. In this study, we report that miR-708 is a key negative regulator of this CD44+ subpopulation of prostate cancer cells, with important implications for diagnosis and prognosis of this disease. miR-708 was underexpressed in CD44+ cells from prostate cancer xenografts. Reconstitution of miR-708 in prostate cancer cell lines or CD44+ prostate cancer cells led to decreased tumorigenicity in vitro. Intratumoral delivery of synthetic miR-708 oligonucleotides triggered regression of established tumors in a murine xenograft model of human prostate cancer. Conversely, miR-708 silencing in a purified CD44− population of prostate cancer cells promoted tumor growth. Functional studies validated CD44 to be a direct target of miR-708 and also identified the serine/threonine kinase AKT2 as an additional target. Clinically, low miR-708 expression was associated significantly with poor survival outcome, tumor progression, and recurrence in patients with prostate cancer. Together, our findings suggest that reduced miR-708 expression leads to prostate cancer initiation, progression, and development by regulating the expression of CD44 as well as AKT2. miR-708 therefore may represent a novel therapeutic target or diagnostic and prognostic biomarker in prostate cancer. Cancer Res; 72(14); 3618–30. ©2012 AACR.
Data from OTX2 Represses Myogenic and Neuronal Differentiation in Medulloblastoma Cells
Authors: Bai Ren-Yuan , Staedtke Verena , Lidov Hart G. , Eberhart Charles G. , Riggins Gregory J.
Published: March 2024

Abstract
The brain development transcription factor OTX2 is overexpressed and/or genomically amplified in most medulloblastomas, but the mechanistic basis for its contributions in this setting are not understood. In this study, we identified OTX2 as a transcriptional repressor and a gatekeeper of myogenic and neuronal differentiation in medulloblastoma cells. OTX2 binds to the MyoD1 core enhancer through its homeobox domain, and the remarkable repressor activity exhibited by the homeobox domain renders OTX2 transcriptionally repressive. RNA interference–mediated attenuation of OTX2 expression triggered myogenic and neuronal differentiation in vitro and prolonged the survival in an orthotopic medulloblastoma mouse model. Conversely, inducing myogenic conversion of medulloblastoma cells led to the loss of OTX2 expression. In medullomyoblastoma, a medulloblastoma subtype containing muscle elements, myogenic cells share cytogenetic signatures with the primitive tumor cells and OTX2 expression was lost in the differentiated myogenic cells. Thus, OTX2 functions via its homeobox domain as a suppressor of differentiation, and the loss of OTX2 expression is linked to the myogenesis in medullomyoblastoma. Together, our findings illustrate the origin of muscle cells in medullomyoblastomas and the oncogenic mechanism of OTX2 as a repressor of diverse differentiating potential. Cancer Res; 72(22); 5988–6001. ©2012 AACR.
Data from PRAS40 Is a Functionally Critical Target for EWS Repression in Ewing Sarcoma
Authors: Huang Lin , Nakai Yuji , Kuwahara Iku , Matsumoto Ken
Published: March 2024

Abstract
Ewing sarcoma family tumors (ESFT) are highly aggressive and highly metastatic tumors caused by a chromosomal fusion between the Ewing sarcoma protein (EWS) with the transcription factor FLI-1. However, expression of the EWS/FLI-1 chimeric oncogene by itself is insufficient for carcinogenesis, suggesting that additional events are required. Here, we report the identification of the Akt substrate PRAS40 as an EWS target gene. EWS negatively regulates PRAS40 expression by binding the 3′ untranslated region in PRAS40 mRNA. ESFT cell proliferation was suppressed by treatment with an Akt inhibitor, and ESFT cell proliferation and metastatic growth were suppressed by siRNA-mediated PRAS40 knockdown. Furthermore, PRAS40 knockdown was sufficient to reverse an increased cell proliferation elicited by EWS knockdown. In support of a pathologic role for PRAS40 elevation in EFST, we documented inverse protein levels of EWS and PRAS40 in ESFT cells. Together, our findings suggest that PRAS40 promotes the development of ESFT and might therefore represent a novel therapeutic target in this aggressive disease. Cancer Res; 72(5); 1260–9. ©2012 AACR.
Data from Antitumor Activity of BRAF Inhibitor Vemurafenib in Preclinical Models of BRAF-Mutant Colorectal Cancer
Authors: Yang Hong , Higgins Brian , Kolinsky Kenneth , Packman Kathryn , Bradley William D. , Lee Richard J. , Schostack Kathleen , Simcox Mary Ellen , Kopetz Scott , Heimbrook David , Lestini Brian , Bollag Gideon , Su Fei
Published: March 2024

Abstract
The protein kinase BRAF is a key component of the RAS–RAF signaling pathway which plays an important role in regulating cell proliferation, differentiation, and survival. Mutations in BRAF at codon 600 promote catalytic activity and are associated with 8% of all human (solid) tumors, including 8% to 10% of colorectal cancers (CRC). Here, we report the preclinical characterization of vemurafenib (RG7204; PLX4032; RO5185426), a first-in-class, specific small molecule inhibitor of BRAFV600E in BRAF-mutated CRC cell lines and tumor xenograft models. As a single agent, vemurafenib shows dose-dependent inhibition of ERK and MEK phosphorylation, thereby arresting cell proliferation in BRAFV600-expressing cell lines and inhibiting tumor growth in BRAFV600E bearing xenograft models. Because vemurafenib has shown limited single-agent clinical activity in BRAFV600E-mutant metastatic CRC, we therefore explored a range of combination therapies, with both standard agents and targeted inhibitors in preclinical xenograft models. In a BRAF-mutant CRC xenograft model with de novo resistance to vemurafenib (RKO), tumor growth inhibition by vemurafenib was enhanced by combining with an AKT inhibitor (MK-2206). The addition of vemurafenib to capecitabine and/or bevacizumab, cetuximab and/or irinotecan, or erlotinib resulted in increased antitumor activity and improved survival in xenograft models. Together, our findings suggest that the administration of vemurafenib in combination with standard-of-care or novel targeted therapies may lead to enhanced and sustained clinical antitumor efficacy in CRCs harboring the BRAFV600E mutation. Cancer Res; 72(3); 779–89. ©2011 AACR.
Data from Pharmacological Inhibition of LIM Kinase Stabilizes Microtubules and Inhibits Neoplastic Growth
Authors: Prudent Renaud , Vassal-Stermann Emilie , Nguyen Chi-Hung , Pillet Catherine , Martinez Anne , Prunier Chloé , Barette Caroline , Soleilhac Emmanuelle , Filhol Odile , Beghin Anne , Valdameri Glaucio , Honoré Stéphane , Aci-Sèche Samia , Grierson David , Antonipillai Juliana , Li Rong , Di Pietro Attilio , Dumontet Charles , Braguer Diane , Florent Jean-Claude , Knapp Stefan , Bernard Ora , Lafanechère Laurence
Published: March 2024

Abstract
The emergence of tumor resistance to conventional microtubule-targeting drugs restricts their clinical use. Using a cell-based assay that recognizes microtubule polymerization status to screen for chemicals that interact with regulators of microtubule dynamics, we identified Pyr1, a cell permeable inhibitor of LIM kinase, which is the enzyme that phosphorylates and inactivates the actin-depolymerizing factor cofilin. Pyr1 reversibly stabilized microtubules, blocked actin microfilament dynamics, inhibited cell motility in vitro and showed anticancer properties in vivo, in the absence of major side effects. Pyr1 inhibition of LIM kinase caused a microtubule-stabilizing effect, which was independent of any direct effects on the actin cytoskeleton. In addition, Pyr1 retained its activity in multidrug-resistant cancer cells that were resistant to conventional microtubule-targeting agents. Our findings suggest that LIM kinase functions as a signaling node that controls both actin and microtubule dynamics. LIM kinase may therefore represent a targetable enzyme for cancer treatment. Cancer Res; 72(17); 4429–39. ©2012 AACR.
Data from ROCK1 and ROCK2 Are Required for Non-Small Cell Lung Cancer Anchorage-Independent Growth and Invasion
Authors: Vigil Dominico , Kim Tai Young , Plachco Ana , Garton Andrew J. , Castaldo Linda , Pachter Jonathan A. , Dong Hanqing , Chen Xin , Tokar Brianna , Campbell Sharon L. , Der Channing J.
Published: March 2024

Abstract
Evidence is emerging that the closely related ROCK1 and ROCK2 serine/threonine kinases support the invasive and metastatic growth of a spectrum of human cancer types. Therefore, inhibitors of ROCK are under preclinical development. However, a key step in their development involves the identification of genetic biomarkers that will predict ROCK inhibitor antitumor activity. One identified mechanism for ROCK activation in cancer involves the loss of function of the DLC1 tumor suppressor gene, which encodes a GTPase activating protein (RhoGAP) for the RhoA and RhoC small GTPases. DLC-1 loss may lead to hyperactivation of RhoA/C and its downstream effectors, the ROCK kinases. We therefore determined whether loss of DLC-1 protein expression identifies non-small cell lung carcinoma (NSCLC) cell lines whose growth and invasion phenotypes are sensitive to ROCK inhibition. We identified and characterized a novel small molecule pharmacologic inhibitor of ROCK and additionally applied genetic approaches to impair ROCK1 and/or ROCK2 activity, and we determined that although NSCLC anchorage-dependent growth was ROCK-independent, both anchorage-independent growth and Matrigel invasion were ROCK-dependent. However, loss of DLC-1 expression did not correlate with ROCK activation or with OXA-06 sensitivity. Unexpectedly, suppression of ROCK1 or ROCK2 expression alone was sufficient to impair anchorage-independent growth, supporting their nonoverlapping roles in oncogenesis. Mechanistically, the block in anchorage-independent growth was associated with accumulation of cells in the G0–G1 phase of the cell cycle, but not increased anoikis. We conclude that ROCK may be a useful therapeutic target for NSCLC. Cancer Res; 72(20); 5338–47. ©2012 AACR.
Data from Raf Kinase Inhibitor RKIP Inhibits MDA-9/Syntenin-Mediated Metastasis in Melanoma
Authors: Das Swadesh K. , Bhutia Sujit K. , Sokhi Upneet K. , Azab Belal , Su Zhao-zhong , Boukerche Habib , Anwar Talha , Moen Erika L. , Chatterjee Devasis , Pellecchia Maurizio , Sarkar Devanand , Fisher Paul B.
Published: March 2024

Abstract
Melanoma differentiation associated gene-9 (MDA-9), also known as syntenin, functions as a positive regulator of melanoma progression and metastasis. In contrast, the Raf kinase inhibitor, RKIP, a negative modulator of RAF-stimulated MEKK activation, is strongly downregulated in metastatic melanoma cells. In this study, we explored a hypothesized inverse relationship between MDA-9 and RKIP in melanoma. Tumor array and cell line analyses confirmed an inverse relationship between expression of MDA-9 and RKIP during melanoma progression. We found that MDA-9 transcriptionally downregulated RKIP in support of a suggested cross-talk between these two proteins. Furthermore, MDA-9 and RKIP physically interacted in a manner that correlated with a suppression of FAK and c-Src phosphorylation, crucial steps necessary for MDA-9 to promote FAK/c-Src complex formation and initiate signaling cascades that drive the MDA-9–mediated metastatic phenotype. Finally, ectopic RKIP expression in melanoma cells overrode MDA-9–mediated signaling, inhibiting cell invasion, anchorage-independent growth, and in vivo dissemination of tumor cells. Taken together, these findings establish RKIP as an inhibitor of MDA-9–dependent melanoma metastasis, with potential implications for targeting this process therapeutically. Cancer Res; 72(23); 6217–26. ©2012 AACR.
Data from Tumor Suppressive MicroRNAs miR-34a/c Control Cancer Cell Expression of ULBP2, a Stress-Induced Ligand of the Natural Killer Cell Receptor NKG2D
Authors: Heinemann Anja , Zhao Fang , Pechlivanis Sonali , Eberle Jürgen , Steinle Alexander , Diederichs Sven , Schadendorf Dirk , Paschen Annette
Published: March 2024

Abstract
Malignant cells express ligands for the natural killer cell immunoreceptor NKG2D, which sensitizes to early recognition and elimination by cytotoxic lymphocytes and provides an innate barrier against tumor development. However, the mechanisms that control NKG2D ligand (NKG2DL) expression in tumor cells remain unknown. We recently identified the NKG2DL ULBP2 as strong prognostic marker in human malignant melanoma. Here, we provide evidence that the tumor-suppressive microRNAs (miRNA) miR-34a and miR-34c control ULBP2 expression. Reporter gene analyses revealed that both miRNAs directly targeted the 3′-untranslated region of ULBP2 mRNA and that levels of miR-34a inversely correlated with expression of ULBP2 surface molecules. Accordingly, treatment of cancer cells with miRNA inhibitors led to upregulation of ULBP2, whereas miR-34 mimics led to downregulation of ULBP2, diminishing tumor cell recognition by NK cells. Treatment with the small molecule inhibitor Nutlin-3a also decreased ULBP2 levels in a p53-dependent manner, which was due to a p53-mediated increase in cellular miR-34 levels. Taken together, our study shows that tumor-suppressive miR-34a and miR-34c act as ULBP2 repressors. These findings also implicate p53 in ULBP2 regulation, emphasizing the role of the specific NKG2DL in tumor immune surveillance. Cancer Res; 72(2); 460–71. ©2011 AACR.
Data from Dysfunction of Nucleus Accumbens-1 Activates Cellular Senescence and Inhibits Tumor Cell Proliferation and Oncogenesis
Authors: Zhang Yi , Cheng Yan , Ren Xingcong , Hori Tsukasa , Huber-Keener Kathryn J. , Zhang Li , Yap Kai Lee , Liu David , Shantz Lisa , Qin Zheng-Hong , Zhang Suping , Wang Jianrong , Wang Hong-Gang , Shih Ie-Ming , Yang Jin-Ming
Published: March 2024

Abstract
Nucleus accumbens-1 (NAC1), a nuclear factor belonging to the BTB/POZ gene family, has emerging roles in cancer. We report here that NAC1 acts as a negative regulator of cellular senescence in transformed and nontransformed cells, and dysfunction of NAC1 induces senescence and inhibits its oncogenic potential. We show that NAC1 deficiency markedly activates senescence and inhibits proliferation in tumor cells treated with sublethal doses of γ-irradiation. In mouse embryonic fibroblasts from NAC1 knockout mice, following infection with a Ras virus, NAC1−/− cells undergo significantly more senescence and are either nontransformed or less transformed in vitro and less tumorigenic in vivo when compared with NAC1+/+ cells. Furthermore, we show that the NAC1-caused senescence blunting is mediated by ΔNp63, which exerts its effect on senescence through p21, and that NAC1 activates transcription of ΔNp63 under stressful conditions. Our results not only reveal a previously unrecognized function of NAC1, the molecular pathway involved and its impact on pathogenesis of tumor initiation and development, but also identify a novel senescence regulator that may be exploited as a potential target for cancer prevention and treatment. Cancer Res; 72(16); 4262–75. ©2012 AACR.
Data from Autoregulatory Mechanisms of Phosphorylation of Checkpoint Kinase 1
Authors: Wang Jingna , Han Xiangzi , Zhang Youwei
Published: March 2024

Abstract
Checkpoint kinase 1 (Chk1), a serine/threonine protein kinase, is centrally involved in cell-cycle checkpoints and cellular response to DNA damage. Phosphorylation of Chk1 at 2 Ser/Gln (SQ) sites, Ser-317 and Ser-345, by the upstream kinase ATR is critical for checkpoint activation. However, the precise molecular mechanisms controlling Chk1 phosphorylation and subsequent checkpoint activation are not well understood. Here, we report unique autoregulatory mechanisms that control protein phosphorylation of human Chk1, as well as checkpoint activation and cell viability. Phosphorylation of Ser-317 is required, but not sufficient, for maximal phosphorylation at Ser-345. The N-terminal kinase domain of Chk1 prevents Chk1 phosphorylation at the C-terminus by ATR in the absence of DNA damage. Loss of the inhibitory effect imposed by the N-terminus causes constitutive phosphorylation of Chk1 by ATR under normal growth conditions, which in turn triggers artificial checkpoints that suppress the S-phase progression. Furthermore, two point mutations were identified that rendered Chk1 constitutively active, and expression of the constitutively active mutant form of Chk1 inhibited cancer cell proliferation. Our findings therefore reveal unique regulatory mechanisms of Chk1 phosphorylation and suggest that expression of constitutively active Chk1 may represent a novel strategy to suppress tumor growth. Cancer Res; 72(15); 3786–94. ©2012 AACR.
Data from Receptor Tyrosine Kinase Genes Amplified in Glioblastoma Exhibit a Mutual Exclusivity in Variable Proportions Reflective of Individual Tumor Heterogeneity
Authors: Little Suzanne E. , Popov Sergey , Jury Alexa , Bax Dorine A. , Doey Lawrence , Al-Sarraj Safa , Jurgensmeier Juliane M. , Jones Chris
Published: March 2024

Abstract
Intratumoral heterogeneity in human solid tumors represents a major barrier for the development of effective molecular treatment strategies, as treatment efficacies will reflect the molecular variegation in individual tumors. In glioblastoma, the generation of composite genomic profiles from bulk tumor samples has allowed one to map the genomic amplifications of putative genetic drivers and to prioritize therapeutic targeting strategies aimed at eradicating the tumor burden. Notably, amplification of multiple receptor tyrosine kinases (RTK) within a single tumor specimen obtained from patients is frequently observed. In this study, use of a detailed multicolor FISH mapping procedure in pathologic specimens revealed a mutual exclusivity of gene amplification in the majority of glioblastoma tumors examined. In particular, the two most commonly amplified RTK genes, EGFR and PDGFRA, were found to be present in variable proportions across the tumors, with one or the other gene predominating in certain areas of the same specimen. Our findings have profound implications for designing efficacious therapeutic regimens, as it remains unclear that how the cells with different gene amplification events contribute to disease propagation or the response to molecular targeted therapies. Cancer Res; 72(7); 1614–20. ©2012 AACR.
Data from Interleukin-17 Promotes Formation and Growth of Prostate Adenocarcinoma in Mouse Models
Authors: Zhang Qiuyang , Liu Sen , Ge Dongxia , Zhang Qingsong , Xue Yun , Xiong Zhenggang , Abdel-Mageed Asim B. , Myers Leann , Hill Steven M. , Rowan Brian G. , Sartor Oliver , Melamed Jonathan , Chen Zhenbang , You Zongbing
Published: March 2024

Abstract
The contributions of interleukin (IL)-17 to cancer remain unclear and somewhat controversial. We took a genetic approach to explore its role in prostate cancers by interbreeding IL-17 receptor C (IL-17RC)–deficient mice with mice that are conditionally mutant for PTEN, one established preclinical model for prostate cancer. Mice that were IL-17RC–deficient (IL-17RC−) displayed prostates that were smaller than mice that maintained IL-17RC expression (IL-17RC+). In addition, IL-17RC− mice developed a reduced number of invasive prostate adenocarcinomas with lower rates of cellular proliferation and higher apoptosis than IL-17RC+ mice. Moreover, the fibromuscular stroma surrounding prostatic glands was relatively thicker in IL-17RC− mice and was associated with decreased matrix metalloproteinase (Mmp)7 expression and increased Timp1, 2, and 4 expression, whereas administration of recombinant mouse IL-17 induced prostatic expression of Mmp7. Taken together, our results suggested that IL-17 promotes the formation and growth of prostate adenocarcinoma, and that an IL-17–MMP7 signaling axis is required for the transition of prostatic intraepithelial neoplasia to frank adenocarcinoma. Cancer Res; 72(10); 2589–99. ©2012 AACR.
Data from Concordant Release of Glycolysis Proteins into the Plasma Preceding a Diagnosis of ER+ Breast Cancer
Authors: Amon Lynn M. , Pitteri Sharon J. , Li Christopher I. , McIntosh Martin , Ladd Jon J. , Disis Mary , Porter Peggy , Wong Chee Hong , Zhang Qing , Lampe Paul , Prentice Ross L. , Hanash Samir M.
Published: March 2024

Abstract
Although the identification of peripheral blood biomarkers would enhance early detection strategies for breast cancer, the discovery of protein markers has been challenging. In this study, we sought to identify coordinated changes in plasma proteins associated with breast cancer based on large-scale quantitative mass spectrometry. We analyzed plasma samples collected up to 74 weeks before diagnosis from 420 estrogen receptor (ER)+ cases and matched controls enrolled in the Women's Health Initiative cohort. A gene set enrichment analysis was applied to 467 quantified proteins, linking their corresponding genes to particular biologic pathways. On the basis of differences in the concentration of individual proteins, glycolysis pathway proteins exhibited a statistically significant difference between cases and controls. In particular, the enrichment was observed among cases in which blood was drawn closer to diagnosis (effect size for the 0–38 weeks prediagnostic group, 1.91; P, 8.3E-05). Analysis of plasmas collected at the time of diagnosis from an independent set of cases and controls confirmed upregulated levels of glycolysis proteins among cases relative to controls. Together, our findings indicate that the concomitant release of glycolysis proteins into the plasma is a pathophysiologic event that precedes a diagnosis of ER+ breast cancer. Cancer Res; 72(8); 1935–42. ©2012 AACR.
Data from Mice Expressing Activated PI3K Rapidly Develop Advanced Colon Cancer
Authors: Leystra Alyssa A. , Deming Dustin A. , Zahm Christopher D. , Farhoud Mohammed , Olson Terrah J. Paul , Hadac Jamie N. , Nettekoven Laura A. , Albrecht Dawn M. , Clipson Linda , Sullivan Ruth , Washington Mary Kay , Torrealba Jose R. , Weichert Jamey P. , Halberg Richard B.
Published: March 2024

Abstract
Aberrations in the phosphoinositide 3-kinase (PI3K) signaling pathway play a key role in the pathogenesis of numerous cancers by altering cellular growth, metabolism, proliferation, and apoptosis. Mutations in the catalytic domain of PI3K that generate a dominantly active kinase are commonly found in human colorectal cancers and have been thought to drive tumor progression but not initiation. However, the effects of constitutively activated PI3K upon the intestinal mucosa have not been previously studied in animal models. Here, we show that the expression of a dominantly active form of the PI3K protein in the mouse intestine results in hyperplasia and advanced neoplasia. Mice expressing constitutively active PI3K in the epithelial cells of the distal small bowel and colon rapidly developed invasive adenocarcinomas in the colon that spread into the mesentery and adjacent organs. The histologic characteristics of these tumors were strikingly similar to invasive mucinous colon cancers in humans. Interestingly, these tumors formed without a benign polypoid intermediary, consistent with the lack of aberrant WNT signaling observed. Together, our findings indicate a noncanonical mechanism of colon tumor initiation that is mediated through activation of PI3K. This unique model has the potential to further our understanding of human disease and facilitate the development of therapeutics through pharmacologic screening and biomarker identification. Cancer Res; 72(12); 2931–6. ©2012 AACR.
Data from Inhibitory Roles of Signal Transducer and Activator of Transcription 3 in Antitumor Immunity during Carcinogen-Induced Lung Tumorigenesis
Authors: Ihara Shoichi , Kida Hiroshi , Arase Hisashi , Tripathi Lokesh P. , Chen Yi-An , Kimura Tetsuya , Yoshida Mitsuhiro , Kashiwa Yozo , Hirata Haruhiko , Fukamizu Reiko , Inoue Ruriko , Hasegawa Kana , Goya Sho , Takahashi Ryo , Minami Toshiyuki , Tsujino Kazuyuki , Suzuki Mayumi , Kohmo Satoshi , Inoue Koji , Nagatomo Izumi , Takeda Yoshito , Kijima Takashi , Mizuguchi Kenji , Tachibana Isao , Kumanogoh Atsushi
Published: March 2024

Abstract
Stat3 mediates a complex spectrum of cellular responses, including inflammation, cell proliferation, and apoptosis. Although evidence exists in support of a positive role for Stat3 in cancer, its role has remained somewhat controversial because of insufficient study of how its genetic deletion may affect carcinogenesis in various tissues. In this study, we show using epithelium-specific knockout mice (Stat3Δ/Δ) that Stat3 blunts rather than supports antitumor immunity in carcinogen-induced lung tumorigenesis. Although Stat3Δ/Δ mice did not show any lung defects in terms of proliferation, apoptosis, or angiogenesis, they exhibited reduced urethane-induced tumorigenesis and increased antitumor inflammation and natural killer (NK) cell immunity. Comparative microarray analysis revealed an increase in Stat3Δ/Δ tumors in proinflammatory chemokine production and a decrease in MHC class I antigen expression associated with NK cell recognition. Consistent with these findings, human non–small cell lung cancer (NSCLC) cells in which Stat3 was silenced displayed an enhancement of proinflammatory chemokine production, reduced expression of MHC class I antigen, and increased susceptibility to NK cell–mediated cytotoxicity. In addition, supernatants from Stat3-silenced NSCLC cells promoted monocyte migration. Collectively, our findings argue that Stat3 exerts an inhibitory effect on antitumor NK cell immunity in the setting of carcinogen-induced tumorigenesis. Cancer Res; 72(12); 2990–9. ©2012 AACR.
Data from Role of JNK in Mammary Gland Development and Breast Cancer
Authors: Cellurale Cristina , Girnius Nomeda , Jiang Feng , Cavanagh-Kyros Julie , Lu Shaolei , Garlick David S. , Mercurio Arthur M. , Davis Roger J.
Published: March 2024

Abstract
cJun NH2-terminal kinase (JNK) signaling has been implicated in the developmental morphogenesis of epithelial organs. In this study, we employed a compound deletion of the murine Jnk1 and Jnk2 genes in the mammary gland to evaluate the requirement for these ubiquitously expressed genes in breast development and tumorigenesis. JNK1/2 was not required for breast epithelial cell proliferation or motility. However, JNK1/2 deficiency caused increased branching morphogenesis and defects in the clearance of lumenal epithelial cells. In the setting of breast cancer development, JNK1/2 deficiency significantly increased tumor formation. Together, these findings established that JNK signaling is required for normal mammary gland development and that it has a suppressive role in mammary tumorigenesis. Cancer Res; 72(2); 472–81. ©2011 AACR.
Data from Cyclophosphamide Creates a Receptive Microenvironment for Prostate Cancer Skeletal Metastasis
Authors: Park Serk In , Liao Jinhui , Berry Janice E. , Li Xin , Koh Amy J. , Michalski Megan E. , Eber Matthew R. , Soki Fabiana N. , Sadler David , Sud Sudha , Tisdelle Sandra , Daignault Stephanie D. , Nemeth Jeffrey A. , Snyder Linda A. , Wronski Thomas J. , Pienta Kenneth J. , McCauley Laurie K.
Published: March 2024

Abstract
A number of cancers predominantly metastasize to bone, due to its complex microenvironment and multiple types of constitutive cells. Prostate cancer especially has been shown to localize preferentially to bones with higher marrow cellularity. Using an experimental prostate cancer metastasis model, we investigated the effects of cyclophosphamide, a bone marrow–suppressive chemotherapeutic drug, on the development and growth of metastatic tumors in bone. Priming the murine host with cyclophosphamide before intracardiac tumor cell inoculation was found to significantly promote tumor localization and subsequent growth in bone. Shortly after cyclophosphamide treatment, there was an abrupt expansion of myeloid lineage cells in the bone marrow and the peripheral blood, associated with increases in cytokines with myelogenic potential such as C-C chemokine ligand (CCL)2, interleukin (IL)-6, and VEGF-A. More importantly, neutralizing host-derived murine CCL2, but not IL-6, in the premetastatic murine host significantly reduced the prometastatic effects of cyclophosphamide. Together, our findings suggest that bone marrow perturbation by cytotoxic chemotherapy can contribute to bone metastasis via a transient increase in bone marrow myeloid cells and myelogenic cytokines. These changes can be reversed by inhibition of CCL2. Cancer Res; 72(10); 2522–32. ©2012 AACR.
Data from Numb Regulates Stability and Localization of the Mitotic Kinase PLK1 and Is Required for Transit through Mitosis
Authors: Schmit Travis L. , Nihal Minakshi , Ndiaye Mary , Setaluri Vijayasaradhi , Spiegelman Vladimir S. , Ahmad Nihal
Published: March 2024

Abstract
Numb functions in progenitor cell fate determination and early development, but it is also expressed in postdevelopmental tissues and cancers where its role is unclear. In this study, we report that a targeted knockdown of Numb expression causes a G2–M arrest and reduced cell growth in human melanoma cells. Co-immunoprecipitation and colocalization studies showed that Numb interacts with the serine/threonine polo-like kinase Plk1 and Numb cycles in a cell-cycle–dependent fashion along with this mitotic regulator. Interestingly, Numb expression was required for Plk1 protein stability and localization to the spindle poles during mitosis. Reduction in Numb expression resulted in mislocalization of Plk1 at both metaphase and anaphase, leading to disorganized γ-tubulin recruitment in centrosomes. Together, our findings present a novel function for Numb during symmetric cell division. We suggest that dysregulation of Numb expression results in mislocalized Plk1 and poor centrosomal γ-tubulin recruitment, potentially contributing to mitotic errors, aneuploidy, and cancer development. Cancer Res; 72(15); 3864–72. ©2012 AACR.
Data from Smurf2 Regulates the Senescence Response and Suppresses Tumorigenesis in Mice
Authors: Ramkumar Charusheila , Kong Yahui , Cui Hang , Hao Suyang , Jones Stephen N. , Gerstein Rachel M. , Zhang Hong
Published: March 2024

Abstract
The E3 ubiquitin ligase Smurf2 mediates ubiquitination and degradation of several protein targets involved in tumorigenesis and induces senescence in human cells. However, the functional role of Smurf2 in tumorigenesis has not been fully evaluated. In this study, we generated a mouse model of Smurf2 deficiency to characterize the function of this E3 ligase in tumorigenesis. Smurf2 deficiency attenuated p16 expression and impaired the senescence response of primary mouse embryonic fibroblasts. In support of a functional role in controlling cancer, Smurf2 deficiency increased the susceptibility of mice to spontaneous tumorigenesis, most notably B-cell lymphoma. At a premalignant stage of tumorigenesis, we documented a defective senescence response in the spleens of Smurf2-deficient mice, consistent with a mechanistic link between impaired senescence regulation and increased tumorigenesis. Taken together, our findings offer the genetic evidence of an important tumor suppressor function for Smurf2. Cancer Res; 72(11); 2714–9. ©2012 AACR.
Data from Fra-1 Promotes Breast Cancer Chemosensitivity by Driving Cancer Stem Cells from Dormancy
Authors: Lu Dan , Chen Si , Tan Xiaoyue , Li Na , Liu Chenghu , Li Zongjin , Liu Ze , Stupack Dwayne G. , Reisfeld Ralph A. , Xiang Rong
Published: March 2024

Abstract
Fra-1 is a member of the Fos transcription factor family that is highly expressed in multiple cancers, playing important roles in transformation, proliferation, and metastasis. In this study, we observed an inverse correlation between the expression of Fra-1 in human stage II breast cancer tissues and the corresponding level of clinical chemoresistance. Extending these findings in vitro, we found that knockdown of Fra-1 in breast tumor cells was sufficient to confer resistance to doxorubicin and cyclophosphamide, whereas enhanced Fra-1 expression could render these cells chemosensitive. The tumor cell side population, which is enriched for cancer stem cells, was found to be associated with chemoresistance. Increased side population fractions were detected among tumor cell lines subjected to Fra-1 knockdown. In contrast, enhanced expression of Fra-1 was correlated with a decreased side population fraction, and significantly, this finding was recapitulated in vivo, where tumors with enhanced expression of Fra-1 were found to have blunted growth. Tumor cells subjected to Fra-1 knockdown grew faster and were larger in size. Taken together, our findings suggest that Fra-1 may be an important prognostic marker for breast cancer therapy. Cancer Res; 72(14); 3451–6. ©2012 AACR.