bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Novel HSP90 Inhibitor NVP-HSP990 Targets Cell-Cycle Regulators to Ablate Olig2-Positive Glioma Tumor–Initiating Cells
Authors: Fu Jun , Koul Dimpy , Yao Jun , Wang Shuzhen , Yuan Ying , Colman Howard , Sulman Erik. P. , Lang Frederick. F. , Alfred Yung W.K.
Published: March 2024

Abstract
Genetic heterogeneity and signaling alterations diminish the effectiveness of single-agent therapies in glioblastoma multiforme (GBM). HSP90 is a molecular chaperone for several signaling proteins that are deregulated in glioma cells. Thus, HSP90 inhibition may offer an approach to coordinately correct multiple signaling pathways as a strategy for GBM therapy. In this study, we evaluated the effects of a novel HSP90 inhibitor, NVP-HSP990, in glioma tumor–initiating cell (GIC) populations, which are strongly implicated in the root pathobiology of GBM. In GIC cultures, NVP-HSP990 elicited a dose-dependent growth inhibition with IC50 values in the low nanomolar range. Two GIC subgroups with different responses were observed with an Olig2-expressing subset relatively more sensitive to treatment. We also showed that Olig2 is a functional marker associated with cell proliferation and response to NVP-HSP990, as NVP-HSP990 attenuated cell proliferation in Olig2-high GIC lines. In addition, NVP-HSP990 disrupted cell-cycle control mechanism by decreasing CDK2 and CDK4 and elevating apoptosis-related molecules. Mechanistic investigations revealed molecular interactions between CDK2/CDK4 and Olig2. Inhibition of CDK2/CDK4 activity disrupted Olig2–CDK2/CDK4 interactions and attenuated Olig2 protein stability. In vivo evaluation showed a relative prolongation of median survival in an intracranial model of GIC growth. Our results suggest that GBM characterized by high-expressing Olig2 GIC may exhibit greater sensitivity to NVP-HSP990 treatment, establishing a foundation for further investigation of the role of HSP90 signaling in GBM. Cancer Res; 73(10); 3062–74. ©2013 AACR.
Data from A Single-Nucleotide Substitution Mutator Phenotype Revealed by Exome Sequencing of Human Colon Adenomas
Authors: Nikolaev Sergey I. , Sotiriou Sotirios K. , Pateras Ioannis S. , Santoni Federico , Sougioultzis Stavros , Edgren Henrik , Almusa Henrikki , Robyr Daniel , Guipponi Michel , Saarela Janna , Gorgoulis Vassilis G. , Antonarakis Stylianos E. , Halazonetis Thanos D.
Published: March 2024

Abstract
Oncogene-induced DNA replication stress is thought to drive genomic instability in cancer. In particular, replication stress can explain the high prevalence of focal genomic deletions mapping within very large genes in human tumors. However, the origin of single-nucleotide substitutions (SNS) in nonfamilial cancers is strongly debated. Some argue that cancers have a mutator phenotype, whereas others argue that the normal DNA replication error rates are sufficient to explain the number of observed SNSs. Here, we sequenced the exomes of 24, mostly precancerous, colon polyps. Analysis of the sequences revealed mutations in the APC, CTNNB1, and BRAF genes as the presumptive cancer-initiating events and many passenger SNSs. We used the number of SNSs in the various lesions to calculate mutation rates for normal colon and adenomas and found that colon adenomas exhibit a mutator phenotype. Interestingly, the SNSs in the adenomas mapped more often than expected within very large genes, where focal deletions in response to DNA replication stress also map. We propose that single-stranded DNA generated in response to oncogene-induced replication stress compromises the repair of deaminated cytosines and other damaged bases, leading to the observed SNS mutator phenotype. Cancer Res; 72(23); 6279–89. ©2012 AACR.
Data from Genome-Wide Association Study of Genetic Predictors of Overall Survival for Non–Small Cell Lung Cancer in Never Smokers
Authors: Wu Xifeng , Wang Liang , Ye Yuanqing , Aakre Jeremiah A. , Pu Xia , Chang Gee-Chen , Yang Pan-Chyr , Roth Jack A. , Marks Randolph S. , Lippman Scott M. , Chang Joe Y. , Lu Charles , Deschamps Claude , Su Wu-Chou , Wang Wen-Chang , Huang Ming-Shyan , Chang David W. , Li Yan , Pankratz V. Shane , Minna John D. , Hong Waun Ki , Hildebrandt Michelle A.T. , Hsiung Chao Agnes , Yang Ping
Published: March 2024

Abstract
To identify the genetic factors that influence overall survival in never smokers who have non–small cell lung carcinoma (NSCLC), we conducted a consistency meta-analysis study using genome-wide association approaches for overall survival in 327 never smoker patients with NSCLC from The University of Texas MD Anderson Cancer Center (Houston, TX) and 293 cases from the Mayo Clinic (Rochester, MN). We then conducted a two-pronged validation of the top 25 variants that included additional validation in 1,256 patients with NSCLC from Taiwan and assessment of expression quantitative trait loci (eQTL) and differential expression of genes surrounding the top loci in 70 tumors and matched normal tissues. A total of 94 loci were significant for overall survival in both MD Anderson and Mayo studies in the consistency meta-analysis phase, with the top 25 variants reaching a P value of 10−6. Two variants of these 25 were also significant in the Taiwanese population: rs6901416 [HR, 1.44; 95% confidence interval (CI), 1.01–2.06] and rs10766739 (HR, 1.23; 95%CI, 1.00–1.51). These loci resulted in a reduction of median survival time of at least eight and five months in three populations, respectively. An additional six variants (rs4237904, rs7976914, rs4970833, rs954785, rs485411, and rs10906104) were validated through eQTL analysis that identified significant correlations with expression levels of six genes (LEMD3, TMBIM, ATXN7L2, SHE, ITIH2, and NUDT5, respectively) in normal lung tissue. These genes were also significantly differentially expressed between the tumor and normal lung tissue. These findings identify several novel, candidate prognostic markers for NSCLC in never smokers, with eQTL analysis suggesting a potential biologic mechanism for a subset of these observed associations. Cancer Res; 73(13); 4028–38. ©2013 AACR.
Data from Canonical Wnt Signaling Is Required for Pancreatic Carcinogenesis
Authors: Zhang Yaqing , Morris John P. , Yan Wei , Schofield Heather K. , Gurney Austin , Simeone Diane M. , Millar Sarah E. , Hoey Timothy , Hebrok Matthias , Pasca di Magliano Marina
Published: March 2024

Abstract
Wnt ligand expression and activation of the Wnt/β-catenin pathway have been associated with pancreatic ductal adenocarcinoma, but whether Wnt activity is required for the development of pancreatic cancer has remained unclear. Here, we report the results of three different approaches to inhibit the Wnt/β-catenin pathway in a established transgenic mouse model of pancreatic cancer. First, we found that β-catenin null cells were incapable of undergoing acinar to ductal metaplasia, a process associated with development of premalignant pancreatic intraepithelial neoplasia lesions. Second, we addressed the specific role of ligand-mediated Wnt signaling through inducible expression of Dkk1, an endogenous secreted inhibitor of the canonical Wnt pathway. Finally, we targeted the Wnt pathway with OMP-18R5, a therapeutic antibody that interacts with multiple Frizzled receptors. Together, these approaches showed that ligand-mediated activation of the Wnt/β-catenin pathway is required to initiate pancreatic cancer. Moreover, they establish that Wnt signaling is also critical for progression of pancreatic cancer, a finding with potential therapeutic implications. Cancer Res; 73(15); 4909–22. ©2013 AACR.
Data from Aldehyde Dehydrogenase in Combination with CD133 Defines Angiogenic Ovarian Cancer Stem Cells That Portend Poor Patient Survival
Authors: Silva Ines A. , Bai Shoumei , McLean Karen , Yang Kun , Griffith Kent , Thomas Dafydd , Ginestier Christophe , Johnston Carolyn , Kueck Angela , Reynolds R. Kevin , Wicha Max S. , Buckanovich Ronald J.
Published: March 2024

Abstract
Markers that reliably identify cancer stem cells (CSC) in ovarian cancer could assist prognosis and improve strategies for therapy. CD133 is a reported marker of ovarian CSC. Aldehyde dehydrogenase (ALDH) activity is a reported CSC marker in several solid tumors, but it has not been studied in ovarian CSC. Here we report that dual positivity of CD133 and ALDH defines a compelling marker set in ovarian CSC. All human ovarian tumors and cell lines displayed ALDH activity. ALDH+ cells isolated from ovarian cancer cell lines were chemoresistant and preferentially grew tumors, compared with ALDH− cells, validating ALDH as a marker of ovarian CSC in cell lines. Notably, as few as 1,000 ALDH+ cells isolated directly from CD133− human ovarian tumors were sufficient to generate tumors in immunocompromised mice, whereas 50,000 ALDH− cells were unable to initiate tumors. Using ALDH in combination with CD133 to analyze ovarian cancer cell lines, we observed even greater growth in the ALDH+CD133+ cells compared with ALDH+CD133− cells, suggesting a further enrichment of ovarian CSC in ALDH+CD133+ cells. Strikingly, as few as 11 ALDH+CD133+ cells isolated directly from human tumors were sufficient to initiate tumors in mice. Like other CSC, ovarian CSC exhibited increased angiogenic capacity compared with bulk tumor cells. Finally, the presence of ALDH+CD133+ cells in debulked primary tumor specimens correlated with reduced disease-free and overall survival in ovarian cancer patients. Taken together, our findings define ALDH and CD133 as a functionally significant set of markers to identify ovarian CSCs. Cancer Res; 71(11); 3991–4001. ©2011 AACR.
Data from The Proinflammatory Myeloid Cell Receptor TREM-1 Controls Kupffer Cell Activation and Development of Hepatocellular Carcinoma
Authors: Wu Juan , Li Jiaqi , Salcedo Rosalba , Mivechi Nahid F. , Trinchieri Giorgio , Horuzsko Anatolij
Published: March 2024

Abstract
Chronic inflammation drives liver cancer pathogenesis, invasion, and metastasis. Liver Kupffer cells have crucial roles in mediating the inflammatory processes that promote liver cancer, but the mechanistic basis for their contributions are not fully understood. Here we show that expression of the proinflammatory myeloid cell surface receptor TREM-1 expressed by Kupffer cells is a crucial factor in the development and progression of liver cancer. Deletion of the murine homolog Trem1 in mice attenuated hepatocellular carcinogenesis triggered by diethylnitrosamine (DEN). Trem1 deficiency attenuated Kupffer cell activation by downregulating transcription and protein expression of interleukin (IL)-6, IL-1β, TNF, CCL2, and CXCL10. In addition, Trem1 ablation diminished activation of the p38, extracellular regulated kinase 1/2, JNK, mitogen-activated protein kinase, and NF-κB signaling pathways in Kupffer cells, resulting in diminished liver injury after DEN exposure. Adoptive transfer of wild-type Kupffer cells to Trem1-deficient mice complemented these defects and reversed unresponsiveness to DEN-induced liver injury and malignant development. Together, our findings offer causal evidence that TREM-1 is a pivotal determinant of Kupffer cell activation in liver carcinogenesis, deepening mechanistic insights into how chronic inflammation underpins the development and progression of liver cancer. Cancer Res; 72(16); 3977–86. ©2012 AACR.
Data from 6-Bromoindirubin-3′-Oxime Inhibits JAK/STAT3 Signaling and Induces Apoptosis of Human Melanoma Cells
Authors: Liu Lucy , Nam Sangkil , Tian Yan , Yang Fan , Wu Jun , Wang Yan , Scuto Anna , Polychronopoulos Panos , Magiatis Prokopios , Skaltsounis Leandros , Jove Richard
Published: March 2024

Abstract
STAT3 is persistently activated and contributes to malignant progression in various cancers. Janus activated kinases (JAK) phosphorylate STAT3 in response to stimulation by cytokines or growth factors. The STAT3 signaling pathway has been validated as a promising target for development of anticancer therapeutics. Small-molecule inhibitors of JAK/STAT3 signaling represent potential molecular-targeted cancer therapeutic agents. In this study, we investigated the role of JAK/STAT3 signaling in 6-bromoindirubin-3′-oxime (6BIO)-mediated growth inhibition of human melanoma cells and assessed 6BIO as a potential anticancer drug candidate. We found that 6BIO is a pan-JAK inhibitor that induces apoptosis of human melanoma cells. 6BIO directly inhibited JAK-family kinase activity, both in vitro and in cancer cells. Apoptosis of human melanoma cells induced by 6BIO was associated with reduced phosphorylation of JAKs and STAT3 in both dose- and time-dependent manners. Consistent with inhibition of STAT3 signaling, expression of the antiapoptotic protein Mcl-1 was downregulated. In contrast to the decreased levels of phosphorylation of JAKs and STAT3, phosphorylation levels of the Akt and mitogen-activated protein kinase (MAPK) signaling proteins were not inhibited in cells treated with 6BIO. Importantly, 6BIO suppressed tumor growth in vivo with low toxicity in a mouse xenograft model of melanoma. Taken together, these results show that 6BIO is a novel pan-JAK inhibitor that can selectively inhibit STAT3 signaling and induces tumor cell apoptosis. Our findings support further development of 6BIO as a potential anticancer therapeutic agent that targets JAK/STAT3 signaling in tumor cells. Cancer Res; 71(11); 3972–9. ©2011 AACR.
Data from CDK Inhibitors Upregulate BH3-Only Proteins to Sensitize Human Myeloma Cells to BH3 Mimetic Therapies
Authors: Chen Shuang , Dai Yun , Pei Xin-Yan , Myers Jennifer , Wang Li , Kramer Lora B. , Garnett Mandy , Schwartz Daniella M. , Su Florence , Simmons Gary L. , Richey Justin D. , Larsen Dustin G. , Dent Paul , Orlowski Robert Z. , Grant Steven
Published: March 2024

Abstract
BH3 mimetic drugs induce cell death by antagonizing the activity of antiapoptotic Bcl-2 family proteins. Cyclin-dependent kinase (CDK) inhibitors that function as transcriptional repressors downregulate the Bcl-2 family member Mcl-1 and increase the activity of selective BH3 mimetics that fail to target this protein. In this study, we determined whether CDK inhibitors potentiate the activity of pan-BH3 mimetics directly neutralizing Mcl-1. Specifically, we evaluated interactions between the prototypical pan-CDK inhibitor flavopiridol and the pan-BH3 mimetic obatoclax in multiple myeloma (MM) cells in which Mcl-1 is critical for survival. Coadministration of flavopiridol and obatoclax synergistically triggered apoptosis in both drug-naïve and drug-resistant MM cells. Mechanistic investigations revealed that flavopiridol inhibited Mcl-1 transcription but increased transcription of Bim and its binding to Bcl-2/Bcl-xL. Obatoclax prevented Mcl-1 recovery and caused release of Bim from Bcl-2/Bcl-xL and Mcl-1, accompanied by activation of Bax/Bak. Whether administered singly or in combination with obatoclax, flavopiridol also induced upregulation of multiple BH3-only proteins, including BimEL, BimL, Noxa, and Bik/NBK. Notably, short hairpin RNA knockdown of Bim or Noxa abrogated lethality triggered by the flavopiridol/obatoclax combination in vitro and in vivo. Together, our findings show that CDK inhibition potentiates pan-BH3 mimetic activity through a cooperative mechanism involving upregulation of BH3-only proteins with coordinate downregulation of their antiapoptotic counterparts. These findings have immediate implications for the clinical trial design of BH3 mimetic-based therapies that are presently being studied intensively for the treatment of diverse hematopoietic malignancies, including lethal multiple myeloma. Cancer Res; 72(16); 4225–37. ©2012 AACR.
Data from E3 Ubiquitin Ligase RNF126 Promotes Cancer Cell Proliferation by Targeting the Tumor Suppressor p21 for Ubiquitin-Mediated Degradation
Authors: Zhi Xu , Zhao Dong , Wang Zehua , Zhou Zhongmei , Wang Chunyan , Chen Wenlin , Liu Rong , Chen Ceshi
Published: March 2024

Abstract
To identify novel oncogenic E3 ubiquitin ligases as anticancer targets, we screened an E3 ubiquitin ligase siRNA library containing siRNA pools against 555 individual E3s using the sulphorhodamine B assay in the MDA-MB-231 breast cancer cell line and the PC3 prostate cancer cell line. RNF126 was identified and validated as a candidate from this screening. Knockdown of RNF126 dramatically decreased cell viability in these cancer cell lines. Consistently, RNF126 knockdown delayed cell-cycle G1–S progression and decreased cell proliferation. Using protein array analysis we found that RNF126 silencing increased cell-cycle dependent kinase inhibitor p21cip protein levels in both MDA-MB-231 and PC3. Knockdown of RNF126 stabilized the p21 protein rather than increased p21 mRNA levels. We showed that RNF126 interacts with p21 and RNF126 overexpression increased p21 protein ubiquitination in an E3 ligase activity-dependent manner. RNF126 knockdown induced loss of cell viability in MDA-MB-231 and PC-3 can be partially rescued by depletion of p21. RNF126 stable knockdown in PC3 inhibited tumor growth in SCID mice. Finally, we found that RNF126 is highly expressed in a subset of breast cancer cell lines and negatively correlated with p21 expression levels. These findings suggest that RNF126 promotes cancer cell proliferation by targeting p21 for ubiquitin-mediated degradation. RNF126 could be a novel therapeutic target in breast and prostate cancers. Cancer Res; 73(1); 385–94. ©2012 AACR.
Data from Phosphorylation of Serine 68 of Twist1 by MAPKs Stabilizes Twist1 Protein and Promotes Breast Cancer Cell Invasiveness
Authors: Hong Jun , Zhou Jian , Fu Junjiang , He Tao , Qin Jun , Wang Li , Liao Lan , Xu Jianming
Published: March 2024

Abstract
Twist1, a basic helix–loop–helix transcription factor, promotes breast tumor cell epithelial–mesenchymal transition (EMT), invasiveness, and metastasis. However, the mechanisms responsible for regulating Twist1 stability are unknown in these cells. We identified the serine 68 (Ser 68) as a major phosphorylation site of Twist1 by mass spectrometry and with specific antibodies. This Ser 68 is phosphorylated by p38, c-Jun N-terminal kinases (JNK), and extracellular signal-regulated kinases1/2 in vitro, and its phosphorylation levels positively correlate with Twist1 protein levels in human embryonic kidney 293 and breast cancer cells. Prevention of Ser 68 phosphorylation by an alanine (A) mutation (Ser 68A) dramatically accelerates Twist1 ubiquitination and degradation. Furthermore, activation of mitogen-activated protein kinases (MAPK) by an active Ras protein or TGF-β treatment significantly increases Ser 68 phosphorylation and Twist1 protein levels without altering Twist1 mRNA expression, whereas blocking of MAPK activities by either specific inhibitors or dominant negative inhibitory mutants effectively reduces the levels of both induced and uninduced Ser 68 phosphorylation and Twist protein. Accordingly, the mammary epithelial cells expressing Twist1 exhibit much higher degrees of EMT and invasiveness on stimulation with TGF-β or the active Ras and paclitaxel resistance compared with the same cells expressing the Ser 68A-Twist1 mutant. Importantly, the levels of Ser 68 phosphorylation in the invasive human breast ductal carcinomas positively correlate with the levels of Twist1 protein and JNK activity and are significantly higher in progesterone receptor–negative and HER2-positive breast cancers. These findings suggest that activation of MAPKs by tyrosine kinase receptors and Ras signaling pathways may substantially promote breast tumor cell EMT and metastasis via phoshorylation and stabilization of Twist1. Cancer Res; 71(11); 3980–90. ©2011 AACR.
Data from Epithelial-to-Mesenchymal Transition Induced by TGF-β1 Is Mediated by Blimp-1–Dependent Repression of BMP-5
Authors: Romagnoli Mathilde , Belguise Karine , Yu Ziyang , Wang Xiaobo , Landesman-Bollag Esther , Seldin David C. , Chalbos Dany , Barillé-Nion Sophie , Jézéquel Pascal , Seldin Margaret L. , Sonenshein Gail E.
Published: March 2024

Abstract
Induction of epithelial-to-mesenchymal transition (EMT) by TGF-β1 requires Ras signaling. We recently identified the transcriptional repressor Blimp-1 (PRDM1) as a downstream effector of the NF-κB, RelB/Bcl-2/Ras-driven pathway that promotes breast cancer cell migration. As the RelB/Blimp-1 pathway similarly required Ras signaling activation, we tested whether Blimp-1 plays a role in TGF-β1–mediated EMT. Here, TGF-β1 treatment of untransformed NMuMG mammary epithelial and MDA-MB-231 breast cancer cells was shown to induce Blimp-1 expression, which promoted an EMT signature and cell migration. TGFB1 and BLIMP1 RNA levels were correlated in patient breast tumors. BLIMP1 gene transcription was activated by TGF-β1 via a c-Raf (RAF1) to AP-1 pathway. Blimp-1 induced expression of the EMT master regulator Snail (SNAI1) via repressing BMP-5, which inhibited Snail expression upon TGF-β1 treatment. Interestingly, a similar cascade was observed during postnatal mouse mammary gland development. RelB expression was detected early in pregnancy followed progressively by Blimp-1 and then Snail; whereas, BMP-5 levels were high in nulliparous and regressing glands. Finally, lower BMP5 RNA levels were detected in patient breast tumors versus normal tissues, and correlated with cancer recurrence. Thus, the Ras effector Blimp-1 plays an essential role in TGF-β1–induced EMT via repression of BMP-5 in breast cancer. Cancer Res; 72(23); 6268–78. ©2012 AACR.
Data from Reconsidering the Paradigm of Cancer Immunotherapy by Computationally Aided Real-time Personalization
Authors: Kogan Yuri , Halevi–Tobias Karin , Elishmereni Moran , Vuk-Pavlović Stanimir , Agur Zvia
Published: March 2024

Abstract
Although therapeutic vaccination often induces markers of tumor-specific immunity, therapeutic responses remain rare. An improved understanding of patient-specific dynamic interactions of immunity and tumor progression, combined with personalized application of immune therapeutics would increase the efficacy of immunotherapy. Here, we developed a method to predict and enhance the individual response to immunotherapy by using personalized mathematical models, constructed in the early phase of treatment. Our approach includes an iterative real-time in-treatment evaluation of patient-specific parameters from the accruing clinical data, construction of personalized models and their validation, model-based simulation of subsequent response to ongoing therapy, and suggestion of potentially more effective patient-specific modified treatment. Using a mathematical model of prostate cancer immunotherapy, we applied our model to data obtained in a clinical investigation of an allogeneic whole-cell therapeutic prostate cancer vaccine. Personalized models for the patients who responded to treatment were derived and validated by data collected before treatment and during its early phase. Simulations, based on personalized models, suggested that an increase in vaccine dose and administration frequency would stabilize the disease in most patients. Together, our findings suggest that application of our method could facilitate development of a new paradigm for studies of in-treatment personalization of the immune agent administration regimens (P-trials), with treatment modifications restricted to an approved range, resulting in more efficacious immunotherapies. Cancer Res; 72(9); 2218–27. ©2012 AACR.
Data from The V-ATPase-Inhibitor Archazolid Abrogates Tumor Metastasis via Inhibition of Endocytic Activation of the Rho-GTPase Rac1
Authors: Wiedmann Romina M. , von Schwarzenberg Karin , Palamidessi Andrea , Schreiner Laura , Kubisch Rebekka , Liebl Johanna , Schempp Christina , Trauner Dirk , Vereb Gyorgy , Zahler Stefan , Wagner Ernst , Müller Rolf , Scita Giorgio , Vollmar Angelika M.
Published: March 2024

Abstract
The abundance of the multimeric vacuolar ATP-dependent proton pump, V-ATPase, on the plasma membrane of tumor cells correlates with the invasiveness of the tumor cell, suggesting the involvement of V-ATPase in tumor metastasis. V-ATPase is hypothesized to create a proton efflux leading to an acidic pericellular microenvironment that promotes the activity of proinvasive proteases. An alternative, not yet explored possibility is that V-ATPase regulates the signaling machinery responsible for tumor cell migration. Here, we show that pharmacologic or genetic reduction of V-ATPase activity significantly reduces migration of invasive tumor cells in vitro. Importantly, the V-ATPase inhibitor archazolid abrogates tumor dissemination in a syngeneic mouse 4T1 breast tumor metastasis model. Pretreatment of cancer cells with archazolid impairs directional motility by preventing spatially restricted, leading edge localization of epidermal growth factor receptor (EGFR) as well as of phosphorylated Akt. Archazolid treatment or silencing of V-ATPase inhibited Rac1 activation, as well as Rac1-dependent dorsal and peripheral ruffles by inhibiting Rab5-mediated endocytotic/exocytotic trafficking of Rac1. The results indicate that archazolid effectively decreases metastatic dissemination of breast tumors by impairing the trafficking and spatially restricted activation of EGFR and Rho-GTPase Rac1, which are pivotal for directed movement of cells. Thus, our data reveals a novel mechanism underlying the role of V-ATPase in tumor dissemination. Cancer Res; 72(22); 5976–87. ©2012 AACR.
Data from Macrophage Delivery of an Oncolytic Virus Abolishes Tumor Regrowth and Metastasis after Chemotherapy or Irradiation
Authors: Muthana Munitta , Rodrigues Samuel , Chen Yung-Yi , Welford Abigail , Hughes Russell , Tazzyman Simon , Essand Magnus , Morrow Fiona , Lewis Claire E.
Published: March 2024

Abstract
Frontline anticancer therapies such as chemotherapy and irradiation often slow tumor growth, but tumor regrowth and spread to distant sites usually occurs after the conclusion of treatment. We recently showed that macrophages could be used to deliver large quantities of a hypoxia-regulated, prostate-specific oncolytic virus (OV) to prostate tumors. In the current study, we show that administration of such OV-armed macrophages 48 hours after chemotherapy (docetaxel) or tumor irradiation abolished the posttreatment regrowth of primary prostate tumors in mice and their spread to the lungs for up to 27 or 40 days, respectively. It also significantly increased the lifespan of tumor-bearing mice compared with those given docetaxel or irradiation alone. These new findings suggest that such a novel, macrophage-based virotherapy could be used to markedly increase the efficacy of chemotherapy and irradiation in patients with prostate cancer. Cancer Res; 73(2); 490–5. ©2012 AACR.
Data from Structure-Specific Endonucleases Xpf and Mus81 Play Overlapping but Essential Roles in DNA Repair by Homologous Recombination
Authors: Kikuchi Koji , Narita Takeo , Pham Van T. , Iijima Junko , Hirota Kouji , Keka Islam Shamima , Okawa Katsuya , Hori Tetsuya , Fukagawa Tatsuo , Essers Jeroen , Kanaar Roland , Whitby Matthew C. , Sugasawa Kaoru , Taniguchi Yoshihito , Kitagawa Katsumi , Takeda Shunichi
Published: March 2024

Abstract
DNA double-strand breaks (DSB) occur frequently during replication in sister chromatids and are dramatically increased when cells are exposed to chemotherapeutic agents including camptothecin. Such DSBs are efficiently repaired specifically by homologous recombination (HR) with the intact sister chromatid. HR, therefore, plays pivotal roles in cellular proliferation and cellular tolerance to camptothecin. Mammalian cells carry several structure-specific endonucleases, such as Xpf-Ercc1 and Mus81-Eme1, in which Xpf and Mus81 are the essential subunits for enzymatic activity. Here, we show the functional overlap between Xpf and Mus81 by conditionally inactivating Xpf in the chicken DT40 cell line, which has no Mus81 ortholog. Although mammalian cells deficient in either Xpf or Mus81 are viable, Xpf inactivation in DT40 cells was lethal, resulting in a marked increase in the number of spontaneous chromosome breaks. Similarly, inactivation of both Xpf and Mus81 in human HeLa cells and murine embryonic stem cells caused numerous spontaneous chromosome breaks. Furthermore, the phenotype of Xpf-deficient DT40 cells was reversed by ectopic expression of human Mus81-Eme1 or human Xpf-Ercc1 heterodimers. These observations indicate the functional overlap of Xpf-Ercc1 and Mus81-Eme1 in the maintenance of genomic DNA. Both Mus81-Eme1 and Xpf-Ercc1 contribute to the completion of HR, as evidenced by the data that the expression of Mus81-Eme1 or Xpf-Ercc1 diminished the number of camptothecin-induced chromosome breaks in Xpf-deficient DT40 cells, and to preventing early steps in HR by deleting XRCC3 suppressed the nonviability of Xpf-deficient DT40 cells. In summary, Xpf and Mus81 have a substantially overlapping function in completion of HR. Cancer Res; 73(14); 4362–71. ©2013 AACR.
Data from Notch1 Is Required for Kras-Induced Lung Adenocarcinoma and Controls Tumor Cell Survival via p53
Authors: Licciulli Silvia , Avila Jacqueline L. , Hanlon Linda , Troutman Scott , Cesaroni Matteo , Kota Smitha , Keith Brian , Simon M. Celeste , Puré Ellen , Radtke Fred , Capobianco Anthony J. , Kissil Joseph L.
Published: March 2024

Abstract
The Notch pathway has been implicated in a number of malignancies with different roles that are cell- and tissue-type dependent. Notch1 is a putative oncogene in non–small cell lung cancer (NSCLC) and activation of the pathway represents a negative prognostic factor. To establish the role of Notch1 in lung adenocarcinoma, we directly assessed its requirement in Kras-induced tumorigenesis in vivo using an autochthonous model of lung adenocarcinoma with concomitant expression of oncogenic Kras and deletion of Notch1. We found that Notch1 function is required for tumor initiation via suppression of p53-mediated apoptosis through the regulation of p53 stability. These findings implicate Notch1 as a critical effector in Kras-driven lung adenocarcinoma and as a regulator of p53 at a posttranslational level. Moreover, our study provides new insights to explain, at a molecular level, the correlation between Notch1 activity and poor prognosis in patients with NSCLC carrying wild-type p53. This information is critical for design and implementation of new therapeutic strategies in this cohort of patients representing 50% of NSCLC cases. Cancer Res; 73(19); 5974–84. ©2013 AACR.
Data from Loss of ARF Sensitizes Transgenic BRAFV600E Mice to UV-Induced Melanoma via Suppression of XPC
Authors: Luo Chi , Sheng Jinghao , Hu Miaofen G. , Haluska Frank G. , Cui Rutao , Xu Zhengping , Tsichlis Philip N. , Hu Guo-Fu , Hinds Philip W.
Published: March 2024

Abstract
Both genetic mutations and UV irradiation (UVR) can predispose individuals to melanoma. Although BRAFV600E is the most prevalent oncogene in melanoma, the BRAFV600E mutant is not sufficient to induce tumors in vivo. Mutation at the CDKN2A locus is another melanoma-predisposing event that can disrupt the function of both p16INK4a and ARF. Numerous studies have focused on the role of p16INK4a in melanoma, but the involvement of ARF, a well-known p53 activator, is still controversial. Using a transgenic BRAFV600E mouse model previously generated in our laboratory, we report that loss of ARF is able to enhance spontaneous melanoma formation and cause profound sensitivity to neonatal UVB exposure. Mechanistically, BRAFV600E and ARF deletion synergize to inhibit nucleotide excision repair by epigenetically repressing XPC and inhibiting the E2F4/DP1 complex. We suggest that the deletion of ARF promotes melanomagenesis not by abrogating p53 activation but by acting in concert with BRAFV600E to increase the load of DNA damage caused by UVR. Cancer Res; 73(14); 4337–48. ©2013 AACR.
Data from Histone Acetyltransferase PCAF Is Required for Hedgehog–Gli-Dependent Transcription and Cancer Cell Proliferation
Authors: Malatesta Martina , Steinhauer Cornelia , Mohammad Faizaan , Pandey Deo P. , Squatrito Massimo , Helin Kristian
Published: March 2024

Abstract
The Hedgehog (Hh) signaling pathway plays an important role in embryonic patterning and development of many tissues and organs as well as in maintaining and repairing mature tissues in adults. Uncontrolled activation of the Hh–Gli pathway has been implicated in developmental abnormalities as well as in several cancers, including brain tumors like medulloblastoma and glioblastoma. Inhibition of aberrant Hh–Gli signaling has, thus, emerged as an attractive approach for anticancer therapy; however, the mechanisms that mediate Hh–Gli signaling in vertebrates remain poorly understood. Here, we show that the histone acetyltransferase PCAF/KAT2B is an important factor of the Hh pathway. Specifically, we show that PCAF depletion impairs Hh activity and reduces expression of Hh target genes. Consequently, PCAF downregulation in medulloblastoma and glioblastoma cells leads to decreased proliferation and increased apoptosis. In addition, we found that PCAF interacts with GLI1, the downstream effector in the Hh–Gli pathway, and that PCAF or GLI1 loss reduces the levels of H3K9 acetylation on Hh target gene promoters. Finally, we observed that PCAF silencing reduces the tumor-forming potential of neural stem cells in vivo. In summary, our study identified the acetyltransferase PCAF as a positive cofactor of the Hh–Gli signaling pathway, leading us to propose PCAF as a candidate therapeutic target for the treatment of patients with medulloblastoma and glioblastoma. Cancer Res; 73(20); 6323–33. ©2013 AACR.
Data from A Novel Model for Evaluating Therapies Targeting Human Tumor Vasculature and Human Cancer Stem–like Cells
Authors: Burgos-Ojeda Daniela , McLean Karen , Bai Shoumei , Pulaski Heather , Gong Yusong , Silva Ines , Skorecki Karl , Tzukerman Maty , Buckanovich Ronald J.
Published: March 2024

Abstract
Human tumor vessels express tumor vascular markers (TVM), proteins that are not expressed in normal blood vessels. Antibodies targeting TVMs could act as potent therapeutics. Unfortunately, preclinical in vivo studies testing anti-human TVM therapies have been difficult to do due to a lack of in vivo models with confirmed expression of human TVMs. We therefore evaluated TVM expression in a human embryonic stem cell–derived teratoma (hESCT) tumor model previously shown to have human vessels. We now report that in the presence of tumor cells, hESCT tumor vessels express human TVMs. The addition of mouse embryonic fibroblasts and human tumor endothelial cells significantly increases the number of human tumor vessels. TVM induction is mostly tumor-type–specific with ovarian cancer cells inducing primarily ovarian TVMs, whereas breast cancer cells induce breast cancer specific TVMs. We show the use of this model to test an anti-human specific TVM immunotherapeutics; anti-human Thy1 TVM immunotherapy results in central tumor necrosis and a three-fold reduction in human tumor vascular density. Finally, we tested the ability of the hESCT model, with human tumor vascular niche, to enhance the engraftment rate of primary human ovarian cancer stem–like cells (CSC). ALDH+ CSC from patients (n = 6) engrafted in hESCT within 4 to 12 weeks whereas none engrafted in the flank. ALDH− ovarian cancer cells showed no engraftment in the hESCT or flank (n = 3). Thus, this model represents a useful tool to test anti-human TVM therapy and evaluate in vivo human CSC tumor biology. Cancer Res; 73(12); 3555–65. ©2013 AACR.
Data from PLA2R1 Mediates Tumor Suppression by Activating JAK2
Authors: Vindrieux David , Augert Arnaud , Girard Christophe A. , Gitenay Delphine , Lallet-Daher Helene , Wiel Clotilde , Le Calvé Benjamin , Gras Baptiste , Ferrand Mylène , Verbeke Stéphanie , de Launoit Yvan , Leroy Xavier , Puisieux Alain , Aubert Sébastien , Perrais Michael , Gelb Michael , Simonnet Hélène , Lambeau Gérard , Bernard David
Published: March 2024

Abstract
Little is known about the physiological role of the phospholipase A2 receptor (PLA2R1). PLA2R1 has been described as regulating the replicative senescence, a telomerase-dependent proliferation arrest. The downstream PLA2R1 signaling and its role in cancer are currently unknown. Senescence induction in response to activated oncogenes is a failsafe program of tumor suppression that must be bypassed for tumorigenesis. We now present evidence that PLA2R1 functions in vitro as a tumor suppressor, the depletion of which is sufficient to escape oncogene-induced senescence (OIS), thereby facilitating oncogenic cell transformation. Furthermore, mice that are genetically deficient in PLA2R1 display increased sensitivity to RAS-induced tumorigenesis by facilitating OIS escape, highlighting its physiological role as a tumor suppressor. Unexpectedly, PLA2R1 activated JAK2 and its effector signaling, with PLA2R1-mediated inhibition of cell transformation largely reverted in JAK2-depleted cells. This finding was unexpected as the JAK2 pathway has been associated mainly with protumoral functions and several inhibitors are currently in clinical trials. Taken together, our findings uncover an unanticipated tumor suppressive role for PLA2R1 that is mediated by targeting downstream JAK2 effector signaling. Cancer Res; 73(20); 6334–45. ©2013 AACR.
Data from Threshold Levels of ABL Tyrosine Kinase Inhibitors Retained in Chronic Myeloid Leukemia Cells Determine Their Commitment to Apoptosis
Authors: O'Hare Thomas , Eide Christopher A. , Agarwal Anupriya , Adrian Lauren T. , Zabriskie Matthew S. , MacKenzie Ryan J. , LaTocha Dorian H. , Johnson Kara J. , You Huihong , Luo Jenny , Riddle Steven M. , Marks Bryan D. , Vogel Kurt W. , Koop Dennis R. , Apgar John , Tyner Jeffrey W. , Deininger Michael W. , Druker Brian J.
Published: March 2024

Abstract
The imatinib paradigm in chronic myelogenous leukemia (CML) established continuous BCR-ABL inhibition as a design principle for ABL tyrosine kinase inhibitors (TKI). However, clinical responses seen in patients treated with the ABL TKI dasatinib despite its much shorter plasma half-life and the apparent rapid restoration of BCR-ABL signaling activity following once-daily dosing suggested acute, potent inhibition of kinase activity may be sufficient to irrevocably commit CML cells to apoptosis. To determine the specific requirements for ABL TKI-induced CML cell death for a panel of clinically important ABL TKIs (imatinib, nilotinib, dasatinib, ponatinib, and DCC-2036), we interrogated response of CML cell lines and primary CML cells following acute drug exposure using intracellular fluorescence-activated cell sorting and immunoblot analyses of BCR-ABL signaling, apoptosis measurements, liquid chromatography/tandem mass spectrometry of intracellular drug levels, and biochemical TKI dissociation studies. Importantly, significant intracellular TKI stores were detected following drug washout, levels of which tracked with onset of apoptosis and incomplete return of BCR-ABL signaling, particularly pSTAT5, to baseline. Among TKIs tested, ponatinib showed the most robust capacity for apoptotic commitment showing sustained suppression of BCR-ABL signaling even at low intracellular levels following extensive washout, consistent with high-affinity binding and slow dissociation from ABL kinase. Together, our findings suggest commitment of CML cells to apoptosis requires protracted incomplete restoration of BCR-ABL signaling mediated by intracellular retention of TKIs above a quantifiable threshold. These studies refine our understanding of apoptotic commitment in CML cells and highlight parameters important to design of therapeutic kinase inhibitors for CML and other malignancies. Cancer Res; 73(11); 3356–70. ©2013 AACR.
Data from Antitumor Efficacy of a Monoclonal Antibody That Inhibits the Activity of Cancer-Associated Carbonic Anhydrase XII
Authors: Gondi Gabor , Mysliwietz Josef , Hulikova Alzbeta , Jen Jian Ping , Swietach Pawel , Kremmer Elisabeth , Zeidler Reinhard
Published: March 2024

Abstract
Carbonic anhydrase XII (CA XII) is a membrane-tethered cell surface enzyme that is highly expressed on many human tumor cells. Carbonic anhydrase members in this class of exofacial molecules facilitate tumor metabolism by facilitating CO2 venting and intracellular pH regulation. Accordingly, inhibition of exofacial CAs has been proposed as a general therapeutic strategy to target cancer. The recent characterization of 6A10, the first CA XII-specific inhibitory monoclonal antibody, offered an opportunity to evaluate this strategy with regard to CA XII-mediated catalysis. Using functional assays, we showed that 6A10 inhibited exofacial CA activity in CA XII-expressing cancer cells. 6A10 reduced spheroid growth in vitro under culture conditions where CA XII was active (i.e., alkaline pH) and where its catalytic activity was likely rate-limiting (i.e., restricted extracellular HCO3− supply). These in vitro results argued that the antibody exerted its growth-retarding effect by acting on the catalytic process, rather than on antigen binding per se. Notably, when administered in a mouse xenograft model of human cancer, 6A10 exerted a significant delay on tumor outgrowth. These results corroborate the notion that exofacial CA is critical for cancer cell physiology and they establish the immunotherapeutic efficacy of targeting CA XII using an inhibitory antibody. Cancer Res; 73(21); 6494–503. ©2013 AACR.
Data from GPR116, an Adhesion G-Protein–Coupled Receptor, Promotes Breast Cancer Metastasis via the Gαq-p63RhoGEF-Rho GTPase Pathway
Authors: Tang Xiaolong , Jin Rongrong , Qu Guojun , Wang Xiu , Li Zhenxi , Yuan Zengjin , Zhao Chen , Siwko Stefan , Shi Tieliu , Wang Ping , Xiao Jianru , Liu Mingyao , Luo Jian
Published: March 2024

Abstract
Adhesion G-protein–coupled receptors (GPCR), which contain adhesion domains in their extracellular region, have been found to play important roles in cell adhesion, motility, embryonic development, and immune response. Because most adhesion molecules with adhesion domains have vital roles in cancer metastasis, we speculated that adhesion GPCRs are potentially involved in cancer metastasis. In this study, we identified GPR116 as a novel regulator of breast cancer metastasis through expression and functional screening of the adhesion GPCR family. We found that knockdown of GPR116 in highly metastatic (MDA-MB-231) breast cancer cells suppressed cell migration and invasion. Conversely, ectopic GPR116 expression in poorly metastatic (MCF-7 and Hs578T) cells promoted cell invasion. We further showed that knockdown of GPR116 inhibited breast cancer cell metastasis in two mammary tumor metastasis mouse models. Moreover, GPR116 modulated the formation of lamellipodia and actin stress fibers in cells in a RhoA- and Rac1-dependent manner. At a molecular level, GPR116 regulated cell motility and morphology through the Gαq-p63RhoGEF-RhoA/Rac1 pathway. The biologic significance of GPR116 in breast cancer is substantiated in human patient samples, where GPR116 expression is significantly correlated with breast tumor progression, recurrence, and poor prognosis. These findings show that GPR116 is crucial for the metastasis of breast cancer and support GPR116 as a potential prognostic marker and drug target against metastatic human breast cancer. Cancer Res; 73(20); 6206–18. ©2013 AACR.
Data from Chemopreventive Activity of Plant Flavonoid Isorhamnetin in Colorectal Cancer Is Mediated by Oncogenic Src and β-Catenin
Authors: Saud Shakir M. , Young Matthew R. , Jones-Hall Yava L. , Ileva Lilia , Evbuomwan Moses O. , Wise Jennifer , Colburn Nancy H. , Kim Young S. , Bobe Gerd
Published: March 2024

Abstract
Analysis of the Polyp Prevention Trial showed an association between an isorhamnetin-rich diet and a reduced risk of advanced adenoma recurrence; however, the mechanism behind the chemoprotective effects of isorhamnetin remains unclear. Here, we show that isorhamnetin prevents colorectal tumorigenesis of FVB/N mice treated with the chemical carcinogen azoxymethane and subsequently exposed to colonic irritant dextran sodium sulfate (DSS). Dietary isorhamnetin decreased mortality, tumor number, and tumor burden by 62%, 35%, and 59%, respectively. MRI, histopathology, and immunohistochemical analysis revealed that dietary isorhamnetin resolved the DSS-induced inflammatory response faster than the control diet. Isorhamnetin inhibited AOM/DSS–induced oncogenic c-Src activation and β-catenin nuclear translocation, while promoting the expression of C-terminal Src kinase (CSK), a negative regulator of Src family of tyrosine kinases. Similarly, in HT-29 colon cancer cells, isorhamnetin inhibited oncogenic Src activity and β-catenin nuclear translocation by inducing expression of csk, as verified by RNA interference knockdown of csk. Our observations suggest the chemoprotective effects of isorhamnetin in colon cancer are linked to its anti-inflammatory activities and its inhibition of oncogenic Src activity and consequential loss of nuclear β-catenin, activities that are dependent on CSK expression. Cancer Res; 73(17); 5473–84. ©2013 AACR.
Data from CIP4 Controls CCL19-Driven Cell Steering and Chemotaxis in Chronic Lymphocytic Leukemia
Authors: Malet-Engra Gema , Viaud Julien , Ysebaert Loïc , Farcé Manon , Lafouresse Fanny , Laurent Guy , Gaits-Iacovoni Frédérique , Scita Giorgio , Dupré Loïc
Published: March 2024

Abstract
Solid tumor dissemination relies on the reprogramming of molecular pathways controlling chemotaxis. Whether the motility of nonsolid tumors such as leukemia depends on the deregulated expression of molecules decoding chemotactic signals remains an open question. We identify here the membrane remodeling F-BAR adapter protein Cdc42-interacting protein 4 (CIP4) as a key regulator of chemotaxis in chronic lymphocytic leukemia (CLL). CIP4 is expressed at abnormally high levels in CLL cells, where it is required for CCL19-induced chemotaxis. Upon CCL19 stimulation of CLL cells, CIP4 associates with GTP-bound Cdc42 and is recruited to the rear of the lamellipodium and along microspikes radiating through the lamellipodium. Consistent with its cellular distribution, CIP4 removal impairs both the assembly of the polarized lamellipodium and directional migration along a diffusible CCL19 gradient. Furthermore, CIP4 depletion results in decreased activation of WASP, but increased activation of PAK1 and p38 mitogen-activated protein kinase (MAPK). Notably, p38 MAPK inhibition results in impaired lamellipodium assembly and loss of directional migration. This suggests that CIP4 modulates both the WASP and p38 MAPK pathways to promote lamellipodium assembly and chemotaxis. Overall, our study reveals a critical role of CIP4 in mediating chemotaxis of CLL cells by controlling the dynamics of microspike-containing protrusions and cell steering. Cancer Res; 73(11); 3412–24. ©2013 AACR.