bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Therapeutic Destruction of Insulin Receptor Substrates for Cancer Treatment
Authors: Reuveni Hadas , Flashner-Abramson Efrat , Steiner Lilach , Makedonski Kirill , Song Renduo , Shir Alexei , Herlyn Meenhard , Bar-Eli Menashe , Levitzki Alexander
Published: March 2024

Abstract
Insulin receptor substrates 1 and 2 (IRS1/2) mediate mitogenic and antiapoptotic signaling from insulin-like growth factor 1 receptor (IGF-IR), insulin receptor (IR), and other oncoproteins. IRS1 plays a central role in cancer cell proliferation, its expression is increased in many human malignancies, and its upregulation mediates resistance to anticancer drugs. IRS2 is associated with cancer cell motility and metastasis. Currently, there are no anticancer agents that target IRS1/2. We present new IGF-IR/IRS-targeted agents (NT compounds) that promote inhibitory Ser-phosphorylation and degradation of IRS1 and IRS2. Elimination of IRS1/2 results in long-term inhibition of IRS1/2-mediated signaling. The therapeutic significance of this inhibition in cancer cells was shown while unraveling a novel mechanism of resistance to B-RAFV600E/K inhibitors. We found that IRS1 is upregulated in PLX4032-resistant melanoma cells and in cell lines derived from patients whose tumors developed PLX4032 resistance. In both settings, NT compounds led to the elimination of IRS proteins and evoked cell death. Treatment with NT compounds in vivo significantly inhibited the growth of PLX4032-resistant tumors and displayed potent antitumor effects in ovarian and prostate cancers. Our findings offer preclinical proof-of-concept for IRS1/2 inhibitors as cancer therapeutics including PLX4032-resistant melanoma. By the elimination of IRS proteins, such agents should prevent acquisition of resistance to mutated-B-RAF inhibitors and possibly restore drug sensitivity in resistant tumors. Cancer Res; 73(14); 4383–94. ©2013 AACR.
Data from A Renewable Tissue Resource of Phenotypically Stable, Biologically and Ethnically Diverse, Patient-Derived Human Breast Cancer Xenograft Models
Authors: Zhang Xiaomei , Claerhout Sofie , Prat Aleix , Dobrolecki Lacey E. , Petrovic Ivana , Lai Qing , Landis Melissa D. , Wiechmann Lisa , Schiff Rachel , Giuliano Mario , Wong Helen , Fuqua Suzanne W. , Contreras Alejandro , Gutierrez Carolina , Huang Jian , Mao Sufeng , Pavlick Anne C. , Froehlich Amber M. , Wu Meng-Fen , Tsimelzon Anna , Hilsenbeck Susan G. , Chen Edward S. , Zuloaga Pavel , Shaw Chad A. , Rimawi Mothaffar F. , Perou Charles M. , Mills Gordon B. , Chang Jenny C. , Lewis Michael T.
Published: March 2024

Abstract
Breast cancer research is hampered by difficulties in obtaining and studying primary human breast tissue, and by the lack of in vivo preclinical models that reflect patient tumor biology accurately. To overcome these limitations, we propagated a cohort of human breast tumors grown in the epithelium-free mammary fat pad of severe combined immunodeficient (SCID)/Beige and nonobese diabetic (NOD)/SCID/IL-2γ-receptor null (NSG) mice under a series of transplant conditions. Both models yielded stably transplantable xenografts at comparably high rates (∼21% and ∼19%, respectively). Of the conditions tested, xenograft take rate was highest in the presence of a low-dose estradiol pellet. Overall, 32 stably transplantable xenograft lines were established, representing 25 unique patients. Most tumors yielding xenografts were “triple-negative” [estrogen receptor (ER)−progesterone receptor (PR)−HER2+; n = 19]. However, we established lines from 3 ER−PR−HER2+ tumors, one ER+PR−HER2−, one ER+PR+HER2−, and one “triple-positive” (ER+PR+HER2+) tumor. Serially passaged xenografts show biologic consistency with the tumor of origin, are phenotypically stable across multiple transplant generations at the histologic, transcriptomic, proteomic, and genomic levels, and show comparable treatment responses as those observed clinically. Xenografts representing 12 patients, including 2 ER+ lines, showed metastasis to the mouse lung. These models thus serve as a renewable, quality-controlled tissue resource for preclinical studies investigating treatment response and metastasis. Cancer Res; 73(15); 4885–97. ©2013 AACR.
Data from eIF4B Phosphorylation by Pim Kinases Plays a Critical Role in Cellular Transformation by Abl Oncogenes
Authors: Yang Jianling , Wang Jun , Chen Ke , Guo Guijie , Xi Ruijiao , Rothman Paul B. , Whitten Douglas , Zhang Lianfeng , Huang Shile , Chen Ji-Long
Published: March 2024

Abstract
Alterations in translation occur in cancer cells, but the precise pathogenic processes and mechanistic underpinnings are not well understood. In this study, we report that interactions between Pim family kinases and the translation initiation factor eIF4B are critical for Abl oncogenicity. Pim kinases, Pim-1 and Pim-2, both directly phosphorylated eIF4B on Ser406 and Ser422. Phosphorylation of eIF4B on Ser422 was highly sensitive to pharmacologic or RNA interference-mediated inhibition of Pim kinases. Expression and phosphorylation of eIF4B relied upon Abl kinase activity in both v-Abl- and Bcr-Abl–expressing leukemic cells based on their blockade by the Abl kinase inhibitor imatinib. Ectopic expression of phosphomimetic mutants of eIF4B conferred resistance to apoptosis by the Pim kinase inhibitor SMI-4a in Abl-transformed cells. In contrast, silencing eIF4B sensitized Abl-transformed cells to imatinib-induced apoptosis and also inhibited their growth as engrafted tumors in nude mice. Extending these observations, we found that primary bone marrow cells derived from eIF4B-knockdown transgenic mice were less susceptible to Abl transformation, relative to cells from wild-type mice. Taken together, our results identify eIF4B as a critical substrate of Pim kinases in mediating the activity of Abl oncogenes, and they highlight eIF4B as a candidate therapeutic target for treatment of Abl-induced cancers. Cancer Res; 73(15); 4898–908. ©2013 AACR.
Data from SOX10 Ablation Arrests Cell Cycle, Induces Senescence, and Suppresses Melanomagenesis
Authors: Cronin Julia C. , Watkins-Chow Dawn E. , Incao Art , Hasskamp Joanne H. , Schönewolf Nicola , Aoude Lauren G. , Hayward Nicholas K. , Bastian Boris C. , Dummer Reinhard , Loftus Stacie K. , Pavan William J.
Published: March 2024

Abstract
The transcription factor SOX10 is essential for survival and proper differentiation of neural crest cell lineages, where it plays an important role in the generation and maintenance of melanocytes. SOX10 is also highly expressed in melanoma tumors, but a role in disease progression has not been established. Here, we report that melanoma tumor cell lines require wild-type SOX10 expression for proliferation and SOX10 haploinsufficiency reduces melanoma initiation in the metabotropic glutamate receptor 1 (Grm1Tg) transgenic mouse model. Stable SOX10 knockdown in human melanoma cells arrested cell growth, altered cellular morphology, and induced senescence. Melanoma cells with stable loss of SOX10 were arrested in the G1 phase of the cell cycle, with reduced expression of the melanocyte determining factor microphthalmia-associated transcription factor, elevated expression of p21WAF1 and p27KIP2, hypophosphorylated RB, and reduced levels of its binding partner E2F1. As cell-cycle dysregulation is a core event in neoplastic transformation, the role for SOX10 in maintaining cell-cycle control in melanocytes suggests a rational new direction for targeted treatment or prevention of melanoma. Cancer Res; 73(18); 5709–18. ©2013 AACR.
Data from Comparative Expression Analysis Reveals Lineage Relationships between Human and Murine Gliomas and a Dominance of Glial Signatures during Tumor Propagation In Vitro
Authors: Henriquez Nico V. , Forshew Tim , Tatevossian Ruth , Ellis Matthew , Richard-Loendt Angela , Rogers Hazel , Jacques Thomas S. , Reitboeck Pablo Garcia , Pearce Kerra , Sheer Denise , Grundy Richard G. , Brandner Sebastian
Published: March 2024

Abstract
Brain tumors are thought to originate from stem/progenitor cell populations that acquire specific genetic mutations. Although current preclinical models have relevance to human pathogenesis, most do not recapitulate the histogenesis of the human disease. Recently, a large series of human gliomas and medulloblastomas were analyzed for genetic signatures of prognosis and therapeutic response. Using a mouse model system that generates three distinct types of intrinsic brain tumors, we correlated RNA and protein expression levels with human brain tumors. A combination of genetic mutations and cellular environment during tumor propagation defined the incidence and phenotype of intrinsic murine tumors. Importantly, in vitro passage of cancer stem cells uniformly promoted a glial expression profile in culture and in brain tumors. Gene expression profiling revealed that experimental gliomas corresponded to distinct subclasses of human glioblastoma, whereas experimental supratentorial primitive neuroectodermal tumors (sPNET) correspond to atypical teratoid/rhabdoid tumor (AT/RT), a rare childhood tumor. Cancer Res; 73(18); 5834–44. ©2013 AACR.
Data from Chromosomal Instability Selects Gene Copy-Number Variants Encoding Core Regulators of Proliferation in ER+ Breast Cancer
Authors: Endesfelder David , Burrell Rebecca A. , Kanu Nnennaya , McGranahan Nicholas , Howell Mike , Parker Peter J. , Downward Julian , Swanton Charles , Kschischo Maik
Published: March 2024

Abstract
Chromosomal instability (CIN) is associated with poor outcome in epithelial malignancies, including breast carcinomas. Evidence suggests that prognostic signatures in estrogen receptor–positive (ER+) breast cancer define tumors with CIN and high proliferative potential. Intriguingly, CIN induction in lower eukaryotic cells and human cells is context dependent, typically resulting in a proliferation disadvantage but conferring a fitness benefit under strong selection pressures. We hypothesized that CIN permits accelerated genomic evolution through the generation of diverse DNA copy-number events that may be selected during disease development. In support of this hypothesis, we found evidence for selection of gene amplification of core regulators of proliferation in CIN-associated cancer genomes. Stable DNA copy-number amplifications of the core regulators TPX2 and UBE2C were associated with expression of a gene module involved in proliferation. The module genes were enriched within prognostic signature gene sets for ER+ breast cancer, providing a logical connection between CIN and prognostic signature expression. Our results provide a framework to decipher the impact of intratumor heterogeneity on key cancer phenotypes, and they suggest that CIN provides a permissive landscape for selection of copy-number alterations that drive cancer proliferation. Cancer Res; 74(17); 4853–63. ©2014 AACR.
Data from A CD90+ Tumor-Initiating Cell Population with an Aggressive Signature and Metastatic Capacity in Esophageal Cancer
Authors: Tang Kwan Ho , Dai Yong Dong , Tong Man , Chan Yuen Piu , Kwan Pak Shing , Fu Li , Qin Yan Ru , Tsao Sai Wah , Lung Hong Lok , Lung Maria L. , Tong Daniel K. , Law Simon , Chan Kwok Wah , Ma Stephanie , Guan Xin Yuan
Published: March 2024

Abstract
Tumor-initiating cells (TIC), also known as cancer stem cells, are regarded widely as a specific subpopulation of cells needed for cancer initiation and progression. TICs have yet to be identified in esophageal tumors that have an increasing incidence in developed countries. Here, we report a CD90+ cell population found in esophageal squamous cell carcinoma (ESCC), which is endowed with stem cell–like properties and high tumorigenic and metastatic potential. mRNA profiling of these cells suggested pathways through which they drive tumor growth and metastasis, with deregulation of an Ets-1/MMP signaling pathway and epithelial–mesenchymal transition figuring prominently. These cells possessed higher self-renewal activity and were sufficient for tumor growth, differentiation, metastasis, and chemotherapeutic resistance. CD90+ TICs were isolated and characterized from ESCC clinical specimens as well as ESCC cell lines. In freshly resected clinical specimens, they represented a rare cell population, the levels of which correlated with strong family histories and lymph node metastasis. Our results prompt further study of this CD90+ population of esophageal TICs as potential therapeutic targets. Cancer Res; 73(7); 2322–32. ©2013 AACR.
Data from Transient Antiangiogenic Treatment Improves Delivery of Cytotoxic Compounds and Therapeutic Outcome in Lung Cancer
Authors: Chatterjee Sampurna , Wieczorek Caroline , Schöttle Jakob , Siobal Maike , Hinze Yvonne , Franz Thomas , Florin Alexandra , Adamczak Joanna , Heukamp Lukas C. , Neumaier Bernd , Ullrich Roland T.
Published: March 2024

Abstract
Extensive oncologic experience argues that the most efficacious applications of antiangiogenic agents rely upon a combination with cytotoxic drugs. Yet there remains a lack of clarity about how to optimize scheduling for such drug combinations. Prudent antiangiogenic therapy might transiently normalize blood vessels to improve tumor oxygenation and drug exposure. Using [15O]H2O positron emission tomography imaging in a preclinical mouse model of non–small cell lung cancer, we observed that short-term treatment with the vascular endothelial growth factor receptor/platelet-derived growth factor receptor inhibitor PTK787 licensed a transient window of improved tumor blood flow. The improvement observed was associated with a reduced leakiness from tumor vessels, consistent with induction of a vascular normalization process. Initiation of a cytotoxic treatment in this window of tumor vessel normalization resulted in increased efficacy, as illustrated by improved outcomes of erlotinib administration after initial PTK787 treatment. Notably, intermittent PTK787 treatment also facilitated long-term tumor regression. In summary, our findings offer strong evidence that short-term antiangiogenic therapy can promote a transient vessel normalization process that improves the delivery and efficacy of a targeted cytotoxic drug. Cancer Res; 74(10); 2816–24. ©2014 AACR.
Data from Endothelial Cell-Secreted EGF Induces Epithelial to Mesenchymal Transition and Endows Head and Neck Cancer Cells with Stem-like Phenotype
Authors: Zhang Zhaocheng , Dong Zhihong , Lauxen Isabel S. , Filho Manoel Sant'Ana , Nör Jacques E.
Published: March 2024

Abstract
Emerging evidence suggests that endothelial cell-secreted factors contribute to the pathobiology of squamous cell carcinoma (SCC) by enhancing invasive migration and resistance to anoikis. Here, we report that SCC cells within the perivascular niche have undergone epithelial to mesenchymal transition (EMT) in a primary human SCC of a patient that developed distant metastases. Endothelial cell–secreted EGF induced EMT of human SCC cells in vitro and also induced acquisition of a stem-like phenotype. In vivo, tumor xenografts vascularized with EGF-silenced endothelial cells exhibited a smaller fraction of cancer stem-like cells (ALDH+CD44+) and were less invasive than tumors vascularized with control endothelial cells. Collectively, these results demonstrated that endothelial cell-EGF induces EMT and acquisition of stem-like properties by head and neck tumor cells. On this basis, we suggest that vascular endothelial cells contribute to tumor dissemination by secreting factors that endow carcinoma cells with enhanced motility and stemness. Cancer Res; 74(10); 2869–81. ©2014 AACR.
Data from p53 Is Positively Regulated by miR-542-3p
Authors: Wang Yemin , Huang Jen-Wei , Castella Maria , Huntsman David George , Taniguchi Toshiyasu
Published: March 2024

Abstract
The tumor suppressor p53 and miRNAs are linked through a complex network. Several miRNAs modulate p53 expression, while p53 regulates the transcription and/or biogenesis of several other miRNAs. Here, we report the development of a cell-based assay used with a library of human miRNA mimics in a high-throughput screen for miRNAs that modulate p53 expression. Overexpression of miRNA (miR)-542-3p in cancer cells elevated p53 expression, stimulated the expression of p53 targets, and inhibited cell proliferation. Mechanistically, miR-542-3p increased p53 protein stability by weakening interactions between p53 and its negative regulator MDM2. Furthermore, miR-542-3p suppressed ribosome biogenesis by downregulating a subset of ribosomal proteins such as RPS23, leading to upregulation of RPL11 and stabilization of p53. The 3′untranslated region in the RPS23 transcript contained a miR-542-3p–binding site, suggesting that RPS23 is a direct target of miR-542-3p. Our results define miR-542-3p as an important new positive regulator of p53 with potential applications in cancer treatment. Cancer Res; 74(12); 3218–27. ©2014 AACR.
Data from MYC Regulation of CHK1 and CHK2 Promotes Radioresistance in a Stem Cell-like Population of Nasopharyngeal Carcinoma Cells
Authors: Wang Wen-Jun , Wu Si-Pei , Liu Jia-Bin , Shi Yong-Sheng , Huang Xue , Zhang Qian-Bing , Yao Kai-Tai
Published: March 2024

Abstract
Radiotherapy is the most successful nonsurgical treatment for nasopharyngeal carcinoma (NPC). Despite this, the prognosis remains poor. Although NPCs initially respond well to a full course of radiation, recurrence is frequent. The cancer stem cell (CSC) hypothesis provides a framework for explaining the discrepancy between the response of NPC to therapy and the poor survival rate. In this study, a stem cell-like subpopulation (PKH26+) was identified in NPC cell lines using a label-retention technique. PKH26+ cells were enriched for clonogenicity, sphere formation, side-population cells, and resistance to radiotherapy. Using genomic approaches, we show that the proto-oncogene c-MYC (MYC) regulates radiotolerance through transcriptional activation of CHK1 (CHEK1) and CHK2 (CHEK2) checkpoint kinases through direct binding to the CHK1 and CHK2 promoters. Overexpression of c-MYC in the PKH26+ subpopulation leads to increased expression of CHK1 and CHK2 and subsequent activation of the DNA-damage-checkpoint response, resulting in radioresistance. Furthermore, loss of CHK1 and CHK2 expression reverses radioresistance in PKH26+ (c-MYC high expression) cells in vitro and in vivo. This study elucidates the role of the c-MYC-CHK1/CHK2 axis in regulating DNA-damage-checkpoint responses and stem cell characteristics in the PKH26+ subpopulation. Furthermore, these data reveal a potential therapeutic application in reversal of radioresistance through inhibition of the c-MYC-CHK1/CHK2 pathway. Cancer Res; 73(3); 1219–31. ©2012 AACR.
Data from mTOR Inhibitors Block Kaposi Sarcoma Growth by Inhibiting Essential Autocrine Growth Factors and Tumor Angiogenesis
Authors: Roy Debasmita , Sin Sang-Hoon , Lucas Amy , Venkataramanan Raman , Wang Ling , Eason Anthony , Chavakula Veenadhari , Hilton Isaac B. , Tamburro Kristen M. , Damania Blossom , Dittmer Dirk P.
Published: March 2024

Abstract
Kaposi sarcoma originates from endothelial cells and it is one of the most overt angiogenic tumors. In Sub-Saharan Africa, where HIV and the Kaposi sarcoma–associated herpesvirus (KSHV) are endemic, Kaposi sarcoma is the most common cancer overall, but model systems for disease study are insufficient. Here, we report the development of a novel mouse model of Kaposi sarcoma, where KSHV is retained stably and tumors are elicited rapidly. Tumor growth was sensitive to specific allosteric inhibitors (rapamycin, CCI-779, and RAD001) of the pivotal cell growth regulator mTOR. Inhibition of tumor growth was durable up to 130 days and reversible. mTOR blockade reduced VEGF secretion and formation of tumor vasculature. Together, the results show that mTOR inhibitors exert a direct anti-Kaposi sarcoma effect by inhibiting angiogenesis and paracrine effectors, suggesting their application as a new treatment modality for Kaposi sarcoma and other cancers of endothelial origin. Cancer Res; 73(7); 2235–46. ©2012 AACR.
Data from Characterization of Torin2, an ATP-Competitive Inhibitor of mTOR, ATM, and ATR
Authors: Liu Qingsong , Xu Chunxiao , Kirubakaran Sivapriya , Zhang Xin , Hur Wooyoung , Liu Yan , Kwiatkowski Nicholas P. , Wang Jinhua , Westover Kenneth D. , Gao Peng , Ercan Dalia , Niepel Mario , Thoreen Carson C. , Kang Seong A. , Patricelli Matthew P. , Wang Yuchuan , Tupper Tanya , Altabef Abigail , Kawamura Hidemasa , Held Kathryn D. , Chou Danny M. , Elledge Stephen J. , Janne Pasi A. , Wong Kwok-Kin , Sabatini David M. , Gray Nathanael S.
Published: March 2024

Abstract
mTOR is a highly conserved serine/threonine protein kinase that serves as a central regulator of cell growth, survival, and autophagy. Deregulation of the PI3K/Akt/mTOR signaling pathway occurs commonly in cancer and numerous inhibitors targeting the ATP-binding site of these kinases are currently undergoing clinical evaluation. Here, we report the characterization of Torin2, a second-generation ATP-competitive inhibitor that is potent and selective for mTOR with a superior pharmacokinetic profile to previous inhibitors. Torin2 inhibited mTORC1-dependent T389 phosphorylation on S6K (RPS6KB1) with an EC50 of 250 pmol/L with approximately 800-fold selectivity for cellular mTOR versus phosphoinositide 3-kinase (PI3K). Torin2 also exhibited potent biochemical and cellular activity against phosphatidylinositol-3 kinase–like kinase (PIKK) family kinases including ATM (EC50, 28 nmol/L), ATR (EC50, 35 nmol/L), and DNA-PK (EC50, 118 nmol/L; PRKDC), the inhibition of which sensitized cells to Irradiation. Similar to the earlier generation compound Torin1 and in contrast to other reported mTOR inhibitors, Torin2 inhibited mTOR kinase and mTORC1 signaling activities in a sustained manner suggestive of a slow dissociation from the kinase. Cancer cell treatment with Torin2 for 24 hours resulted in a prolonged block in negative feedback and consequent T308 phosphorylation on Akt. These effects were associated with strong growth inhibition in vitro. Single-agent treatment with Torin2 in vivo did not yield significant efficacy against KRAS-driven lung tumors, but the combination of Torin2 with mitogen-activated protein/extracellular signal–regulated kinase (MEK) inhibitor AZD6244 yielded a significant growth inhibition. Taken together, our findings establish Torin2 as a strong candidate for clinical evaluation in a broad number of oncologic settings where mTOR signaling has a pathogenic role. Cancer Res; 73(8); 2574–86. ©2013 AACR.
Data from Automated Tracking of Nanoparticle-labeled Melanoma Cells Improves the Predictive Power of a Brain Metastasis Model
Authors: Sundstrøm Terje , Daphu Inderjit , Wendelbo Ingvild , Hodneland Erlend , Lundervold Arvid , Immervoll Heike , Skaftnesmo Kai Ove , Babic Michal , Jendelova Pavla , Sykova Eva , Lund-Johansen Morten , Bjerkvig Rolf , Thorsen Frits
Published: March 2024

Abstract
Biologic and therapeutic advances in melanoma brain metastasis are hampered by the paucity of reproducible and predictive animal models. In this work, we developed a robust model of brain metastasis that empowers quantitative tracking of cellular dissemination and tumor progression. Human melanoma cells labeled with superparamagnetic iron oxide nanoparticles (SPION) were injected into the left cardiac ventricle of mice and visualized by MRI. We showed that SPION exposure did not affect viability, growth, or migration in multiple cell lines across several in vitro assays. Moreover, labeling did not impose changes in cell-cycle distribution or apoptosis. In vivo, several SPION-positive cell lines displayed similar cerebral imaging and histologic features. MRI-based automated quantification of labeled cells in the brain showed a sigmoid association between metastasis frequency and doses of inoculated cells. Validation of this fully automated quantification showed a strong correlation with manual signal registration (r2 = 0.921, P < 0.001) and incidence of brain metastases (r2 = 0.708, P < 0.001). Metastasis formation resembled the pattern seen in humans and was unaffected by SPION labeling (histology; tumor count, P = 0.686; survival, P = 0.547). In summary, we present here a highly reproducible animal model that can improve the predictive value of mechanistic and therapeutic studies of melanoma brain metastasis. Cancer Res; 73(8); 2445–56. ©2013 AACR.
Data from Cholesterol Loading and Ultrastable Protein Interactions Determine the Level of Tumor Marker Required for Optimal Isolation of Cancer Cells
Authors: Jain Jayati , Veggiani Gianluca , Howarth Mark
Published: March 2024

Abstract
Cell isolation via antibody-targeted magnetic beads is a powerful tool for research and clinical applications, most recently for isolating circulating tumor cells (CTC). Nonetheless fundamental features of the cell–bead interface are still unknown. Here we apply a clinically relevant antibody against the cancer target HER2 (ErbB2) for magnetic cell isolation. We investigate how many target proteins per cell are sufficient for a cell to be isolated. To understand the importance of primary antibody affinity, we compared a series of point mutants with known affinities and show that even starting with subnanomolar affinity, improving antibody affinity improved cell isolation. To test the importance of the connection between the primary antibody and the magnetic bead, we compared bridging the antibody to the beads with Protein L, secondary antibody, or streptavidin: the high-stability streptavidin–biotin linkage improved sensitivity by an order of magnitude. Cytoskeletal polymerization did not have a major effect on cell isolation, but isolation was inhibited by cholesterol depletion and enhanced by cholesterol loading of cells. Analyzing a panel of human cancer cell lines spanning a wide range of expression showed that the standard approach could only isolate the highest expressing cells. However, our optimization of cholesterol level, primary antibody affinity, and antibody–bead linkage allowed efficient and specific isolation of cells expressing low levels of HER2 or epithelial cell adhesion molecule. These insights should guide future approaches to cell isolation, either magnetically or using other means, and extend the range of cellular antigens and biomarkers that can be targeted for CTC isolation in cancer research and diagnosis. Cancer Res; 73(7); 2310–21. ©2013 AACR.
Data from Sirtuin-1 Regulates Acinar-to-Ductal Metaplasia and Supports Cancer Cell Viability in Pancreatic Cancer
Authors: Wauters Elke , Sanchez-Arévalo Lobo Victor J. , Pinho Andreia V. , Mawson Amanda , Herranz Daniel , Wu Jianmin , Cowley Mark J. , Colvin Emily K. , Njicop Erna Ngwayi , Sutherland Rob L. , Liu Tao , Serrano Manuel , Bouwens Luc , Real Francisco X. , Biankin Andrew V. , Rooman Ilse
Published: March 2024

Abstract
The exocrine pancreas can undergo acinar-to-ductal metaplasia (ADM), as in the case of pancreatitis where precursor lesions of pancreatic ductal adenocarcinoma (PDAC) can arise. The NAD+-dependent protein deacetylase Sirtuin-1 (Sirt1) has been implicated in carcinogenesis with dual roles depending on its subcellular localization. In this study, we examined the expression and the role of Sirt1 in different stages of pancreatic carcinogenesis, i.e. ADM models and established PDAC. In addition, we analyzed the expression of KIAA1967, a key mediator of Sirt1 function, along with potential Sirt1 downstream targets. Sirt1 was co-expressed with KIAA1967 in the nuclei of normal pancreatic acinar cells. In ADM, Sirt1 underwent a transient nuclear-to-cytoplasmic shuttling. Experiments where during ADM, we enforced repression of Sirt1 shuttling, inhibition of Sirt1 activity or modulation of its expression, all underscore that the temporary decrease of nuclear and increase of cytoplasmic Sirt1 stimulate ADM. Our results further underscore that important transcriptional regulators of acinar differentiation, that is, Pancreatic transcription factor-1a and β-catenin can be deacetylated by Sirt1. Inhibition of Sirt1 is effective in suppression of ADM and in reducing cell viability in established PDAC tumors. KIAA1967 expression is differentially downregulated in PDAC and impacts on the sensitivity of PDAC cells to the Sirt1/2 inhibitor Tenovin-6. In PDAC, acetylation of β-catenin is not affected, unlike p53, a well-characterized Sirt1-regulated protein in tumor cells. Our results reveal that Sirt1 is an important regulator and potential therapeutic target in pancreatic carcinogenesis. Cancer Res; 73(7); 2357–67. ©2012 AACR.
Data from CD44-Positive Cancer Stem Cells Expressing Cellular Prion Protein Contribute to Metastatic Capacity in Colorectal Cancer
Authors: Du Lei , Rao Guanhua , Wang Hongyi , Li Baowei , Tian Weili , Cui Jiantao , He Leya , Laffin Brian , Tian Xiuyun , Hao Chunyi , Liu Hongmin , Sun Xin , Zhu Yushan , Tang Dean G. , Mehrpour Maryam , Lu Youyong , Chen Quan
Published: March 2024

Abstract
Cancer stem cells are implicated in tumor progression, metastasis, and recurrence, although the exact mechanisms remain poorly understood. Here, we show that the expression of cellular prion protein (PrPc, PRNP) is positively correlated with an increased risk of metastasis in colorectal cancer. PrPc defines a subpopulation of CD44-positive cancer stem cells that contributes to metastatic capacity. PrPc+CD44+ colorectal cancer stem cells displayed high liver metastatic capability, unlike PrPc−CD44+ stem cells, that was inhibited by RNAi-mediated attenuation of PrPc. Notably, administration of PrPc monoclonal antibodies significantly inhibited tumorigenicity and metastasis of colorectal cancer stem cells in mouse models of orthotopic metastasis. PrPc promoted epithelial to mesenchymal transition (EMT) via the ERK2 (MAPK1) pathway, thereby conferring high metastatic capacity. Our findings reveal the function of PrPc in regulating EMT in cancer stem cells, and they identify PrPc as candidate therapeutic target in metastatic colorectal cancer. Cancer Res; 73(8); 2682–94. ©2013 AACR.
Data from Tumor Endothelial Markers Define Novel Subsets of Cancer-Specific Circulating Endothelial Cells Associated with Antitumor Efficacy
Authors: Mehran Reza , Nilsson Monique , Khajavi Mehrdad , Du Zhiqiang , Cascone Tina , Wu Hua Kang , Cortes Andrea , Xu Li , Zurita Amado , Schier Robert , Riedel Bernhard , El-Zein Randa , Heymach John V.
Published: March 2024

Abstract
Circulating endothelial cells (CEC) are derived from multiple sources, including bone marrow (circulating endothelial progenitors; CEP), and established vasculature (mature CEC). Although CECs have shown promise as a biomarker for patients with cancer, their utility has been limited, in part, by the lack of specificity for tumor vasculature and the different nonmalignant causes that can impact CEC. Tumor endothelial markers (TEM) are antigens enriched in tumor versus nonmalignant endothelia. We hypothesized that TEMs may be detectable on CEC and that these circulating TEM+ endothelial cells (CTEC) may be a more specific marker for cancer and tumor response than standard CEC. We found that tumor-bearing mice had a relative increase in numbers of circulating CTEC, specifically with increased levels of TEM7 and TEM8 expression. Following treatment with various vascular-targeting agents, we observed a decrease in CTEC that correlated with the reductions in tumor growth. We extended these findings to human clinical samples and observed that CTECs were present in patients with esophageal cancer and non–small cell lung cancer (N = 40), and their levels decreased after surgical resection. These results demonstrate that CTECs are detectable in preclinical cancer models and patients with cancer. Furthermore, they suggest that CTECs offer a novel cancer-associated marker that may be useful as a blood-based surrogate for assessing the presence of tumor vasculature and antiangiogenic drug activity. Cancer Res; 74(10); 2731–41. ©2014 AACR.
Data from Oncolytic Vaccinia Virus Disrupts Tumor-Associated Vasculature in Humans
Authors: Breitbach Caroline J. , Arulanandam Rozanne , De Silva Naomi , Thorne Steve H. , Patt Richard , Daneshmand Manijeh , Moon Anne , Ilkow Carolina , Burke James , Hwang Tae-Ho , Heo Jeong , Cho Mong , Chen Hannah , Angarita Fernando A. , Addison Christina , McCart J. Andrea , Bell John C. , Kirn David H.
Published: March 2024

Abstract
Efforts to selectively target and disrupt established tumor vasculature have largely failed to date. We hypothesized that a vaccinia virus engineered to target cells with activation of the ras/MAPK signaling pathway (JX-594) could specifically infect and express transgenes (hGM-CSF, β-galactosidase) in tumor-associated vascular endothelial cells in humans. Efficient replication and transgene expression in normal human endothelial cells in vitro required either VEGF or FGF-2 stimulation. Intravenous infusion in mice resulted in virus replication in tumor-associated endothelial cells, disruption of tumor blood flow, and hypoxia within 48 hours; massive tumor necrosis ensued within 5 days. Normal vessels were not affected. In patients treated with intravenous JX-594 in a phase I clinical trial, we showed dose-dependent endothelial cell infection and transgene expression in tumor biopsies of diverse histologies. Finally, patients with advanced hepatocellular carcinoma, a hypervascular and VEGF-rich tumor type, were treated with JX-594 on phase II clinical trials. JX-594 treatment caused disruption of tumor perfusion as early as 5 days in both VEGF receptor inhibitor-naïve and -refractory patients. Toxicities to normal blood vessels or to wound healing were not evident clinically or on MRI scans. This platform technology opens up the possibility of multifunctional engineered vaccinia products that selectively target and infect tumor-associated endothelial cells, as well as cancer cells, resulting in transgene expression, vasculature disruption, and tumor destruction in humans systemically. Cancer Res; 73(4); 1265–75. ©2012 AACR.
Data from IFN-γ–Mediated Downregulation of LXA4 Is Necessary for the Maintenance of Nonresolving Inflammation and Papilloma Persistence
Authors: Wang Chunhui , Xiao Mingjie , Liu Xiaoman , Ni Chen , Liu Jianhong , Erben Ulrike , Qin Zhihai
Published: March 2024

Abstract
Nonresolving inflammation is a hallmark of many types of tumors and the molecular mechanisms maintaining this inflammation are still largely unknown. In a two-stage carcinogenesis model, we observed here that the lack of IFN-γ receptor or neutralization of IFN-γ accelerated spontaneous papilloma regression in mice. The impaired maintenance of local inflammation was associated with reduced IFN-γ and enhanced biosynthesis of proresolution lipid mediator lipoxin A4 (LXA4). Interestingly, blocking LXA4 eliminated the effect of anti-IFN-γ, whereas treatment of mice with a therapeutic dose of LXA4 accelerated papilloma regression in an IFN-γ–independent manner. These results link for the first time a cytokine-dependent maintenance of inflammation with a downregulated production of proresolution lipid mediators. Strategies promoting spontaneous resolution of chronic inflammation by blocking IFN-γ and/or increasing LXA4 may be useful for the treatment of inflammation-associated tumors. Cancer Res; 73(6); 1742–51. ©2012 AACR.
Data from HMMR Maintains the Stemness and Tumorigenicity of Glioblastoma Stem-like Cells
Authors: Tilghman Jessica , Wu Hao , Sang Yingying , Shi Xiaohai , Guerrero-Cazares Hugo , Quinones-Hinojosa Alfredo , Eberhart Charles G. , Laterra John , Ying Mingyao
Published: March 2024

Abstract
Glioblastoma (GBM) stem cells (GSC) are a subpopulation of tumor cells that display stem-like characteristics (stemness) and play unique roles in tumor propagation, therapeutic resistance, and tumor recurrence. Therapeutic targets in GSCs are a focus of increasing interest to improve GBM therapy. Here we report that the hyaluronan-mediated motility receptor (HMMR) is highly expressed in GBM tumors, where it supports the self-renewal and tumorigenic potential of GSCs. HMMR silencing impairs GSC self-renewal and inhibits the expression of GSC markers and regulators. Furthermore, HMMR silencing suppresses GSC-derived tumor growth and extends the survival of mice bearing GSC xenografts. Conversely, HMMR overexpression promotes GSC self-renewal and intracranial tumor propagation. In human GBM tumor specimens, HMMR expression is correlated positively with the expression of stemness-associated markers and regulators. Our findings identify HMMR as a candidate therapeutic target to GSCs as a GBM treatment strategy. Cancer Res; 74(11); 3168–79. ©2014 AACR.
Data from Dormant Cancer Cells Contribute to Residual Disease in a Model of Reversible Pancreatic Cancer
Authors: Lin Wan-chi , Rajbhandari Nirakar , Liu Chengbao , Sakamoto Kazuhito , Zhang Qian , Triplett Aleata A. , Batra Surinder K. , Opavsky Rene , Felsher Dean W. , DiMaio Dominick J. , Hollingsworth Michael A. , Morris John P. , Hebrok Matthias , Witkiewicz Agnieszka K. , Brody Jonathan R. , Rui Hallgeir , Wagner Kay-Uwe
Published: March 2024

Abstract
The initiation and progression of pancreatic ductal adenocarcinoma (PDAC) is governed by a series of genetic and epigenetic changes, but it is still unknown whether these alterations are required for the maintenance of primary and metastatic PDAC. We show here that the c-Myc oncogene is upregulated throughout the entire process of neoplastic progression in human PDAC and in genetically engineered mice that express mutant Kras. To experimentally address whether c-Myc is essential for the growth and survival of cancer cells, we developed a novel mouse model that allows a temporally and spatially controlled expression of this oncogene in pancreatic progenitors and derived lineages of the exocrine pancreas. Unlike previous reports, upregulation of c-Myc was sufficient to induce the formation of adenocarcinomas after a short latency without additional genetic manipulation of cell survival pathways. Deficiency in Cdkn2a increased the rate of metastasis but had no effect on tumor latency or c-Myc–mediated cancer maintenance. Despite a macroscopically complete regression of primary, metastatic, and transplantable tumors following the ablation of c-Myc, some cancer cells remained dormant. A significant number of these residual neoplastic cells expressed cancer stem cell markers, and re-expression of exogenous c-Myc in these cells led to rapid cancer recurrence. Collectively, the results of this study suggest that c-Myc plays a significant role in the progression and maintenance of PDAC, but besides targeting this oncogene or its downstream effectors, additional therapeutic strategies are necessary to eradicate residual cancer cells to prevent disease recurrence. Cancer Res; 73(6); 1821–30. ©2012 AACR.
Data from G-protein Inactivator RGS6 Mediates Myocardial Cell Apoptosis and Cardiomyopathy Caused By Doxorubicin
Authors: Yang Jianqi , Maity Biswanath , Huang Jie , Gao Zhan , Stewart Adele , Weiss Robert M. , Anderson Mark E. , Fisher Rory A.
Published: March 2024

Abstract
Clinical use of the widely used chemotherapeutic agent doxorubicin is limited by life-threatening cardiotoxicity. The mechanisms underlying doxorubicin-induced cardiomyopathy and heart failure remain unclear but are thought to involve p53-mediated myocardial cell apoptosis. The tripartite G-protein inactivating protein RGS6 has been implicated in reactive oxygen species (ROS) generation, ATM/p53 activation, and apoptosis in doxorubicin-treated cells. Thus, we hypothesized that RGS6, the expression of which is enriched in cardiac tissue, might also be responsible for the pathologic effects of doxorubicin treatment in heart. In this study, we show that RGS6 expression is induced strongly by doxorubicin in the ventricles of mice and isolated ventricular myocytes via a posttranscriptional mechanism. While doxorubicin-treated wild-type (WT) mice manifested severe left ventricular dysfunction, loss of heart and body mass, along with decreased survival 5 days after doxorubicin administration, mice lacking RGS6 were completely protected against these pathogenic responses. Activation of ATM/p53 apoptosis signaling by doxorubicin in ventricles of WT mice was also absent in their RGS6−/− counterparts. Doxorubicin-induced ROS generation was dramatically impaired in both the ventricles and ventricular myocytes isolated from RGS6−/− mice, and the apoptotic response to doxorubicin in ventricular myocytes required RGS6-dependent ROS production. These results identify RGS6 as an essential mediator of the pathogenic responses to doxorubicin in heart, and they argue that RGS6 inhibition offers a rational means to circumvent doxorubicin cardiotoxicity in human patients with cancer. Cancer Res; 73(6); 1662–7. ©2012 AACR.
Data from EGFR-Mediated Chromatin Condensation Protects KRAS-Mutant Cancer Cells against Ionizing Radiation
Authors: Wang Meng , Kern Ashley M. , Hülskötter Marieke , Greninger Patricia , Singh Anurag , Pan Yunfeng , Chowdhury Dipanjan , Krause Mechthild , Baumann Michael , Benes Cyril H. , Efstathiou Jason A. , Settleman Jeff , Willers Henning
Published: March 2024

Abstract
Therapeutics that target the epidermal growth factor receptor (EGFR) can enhance the cytotoxic effects of ionizing radiation (IR). However, predictive genomic biomarkers of this radiosensitization have remained elusive. By screening 40 non–small cell lung cancer cell (NSCLC) lines, we established a surprising positive correlation between the presence of a KRAS mutation and radiosensitization by the EGFR inhibitors erlotinib and cetuximab. EGFR signaling in KRAS-mutant NSCLC cells promotes chromatin condensation in vitro and in vivo, thereby restricting the number of DNA double-strand breaks (DSB) produced by a given dose of IR. Chromatin condensation in interphase cells is characterized by an unexpected mitosis-like colocalization of serine 10 phosphorylation and lysine 9 trimethylation on histone H3. Aurora B promotes this process in a manner that is codependent upon EGFR and protein kinase C α (PKCα). PKCα, in addition to MEK/ERK signaling, is required for the suppression of DSB-inducible premature senescence by EGFR. Blockade of autophagy results in a mutant KRAS-dependent senescence-to-apoptosis switch in cancer cells treated with IR and erlotinib. In conclusion, we identify EGFR as a molecular target to overcome a novel mechanism of radioresistance in KRAS-mutant tumor cells, which stands in contrast to the unresponsiveness of KRAS-mutant cancers to EGFR-directed agents in monotherapy. Our findings may reposition EGFR-targeted agents for combination with DSB-inducing therapies in KRAS-mutant NSCLC. Cancer Res; 74(10); 2825–34. ©2014 AACR.
Data from Real-time In Vivo Molecular Detection of Primary Tumors and Metastases with Ratiometric Activatable Cell-Penetrating Peptides
Authors: Savariar Elamprakash N. , Felsen Csilla N. , Nashi Nadia , Jiang Tao , Ellies Lesley G. , Steinbach Paul , Tsien Roger Y. , Nguyen Quyen T.
Published: March 2024

Abstract
Management of metastatic disease is integral to cancer treatment. Evaluation of metastases often requires surgical removal of all anatomically susceptible lymph nodes for ex vivo pathologic examination. We report a family of novel ratiometric activatable cell-penetrating peptides, which contain Cy5 as far red fluorescent donor and Cy7 as near-infrared fluorescent acceptor. Cy5 is quenched in favor of Cy7 re-emission until the intervening linker is cut by tumor-associated matrix metalloproteinases-2 and 9 (MMP2,9) or elastases. Such cleavage increases the Cy5:Cy7 emission ratio 40-fold and triggers tissue retention of the Cy5-containing fragment. This ratiometric increase provides an accelerated and quantifiable metric to identify primary tumors and metastases to liver and lymph nodes with increased sensitivity and specificity. This technique represents a significant advance over existing nonratiometric protease sensors and sentinel lymph node detection methods, which give no information about cancer invasion. Cancer Res; 73(2); 855–64. ©2012 AACR.
Data from Characterization of a Novel PERK Kinase Inhibitor with Antitumor and Antiangiogenic Activity
Authors: Atkins Charity , Liu Qi , Minthorn Elisabeth , Zhang Shu-Yun , Figueroa David J. , Moss Katherine , Stanley Thomas B. , Sanders Brent , Goetz Aaron , Gaul Nathan , Choudhry Anthony E. , Alsaid Hasan , Jucker Beat M. , Axten Jeffrey M. , Kumar Rakesh
Published: March 2024

Abstract
The unfolded protein response (UPR) is a signal transduction pathway that coordinates cellular adaptation to microenvironmental stresses that include hypoxia, nutrient deprivation, and change in redox status. These stress stimuli are common in many tumors and thus targeting components of the UPR signaling is an attractive therapeutic approach. We have identified a first-in-class, small molecule inhibitor of the eukaryotic initiation factor 2-alpha kinase 3 (EIF2AK3) or PERK, one of the three mediators of UPR signaling. GSK2656157 is an ATP-competitive inhibitor of PERK enzyme activity with an IC50 of 0.9 nmol/L. It is highly selective for PERK with IC50 values >100 nmol/L against a panel of 300 kinases. GSK2656157 inhibits PERK activity in cells with an IC50 in the range of 10–30 nmol/L as shown by inhibition of stress-induced PERK autophosphorylation, eIF2α substrate phosphorylation, together with corresponding decreases in ATF4 and CAAT/enhancer binding protein homologous protein (CHOP) in multiple cell lines. Oral administration of GSK2656157 to mice shows a dose- and time-dependent pharmacodynamic response in pancreas as measured by PERK autophosphorylation. Twice daily dosing of GSK2656157 results in dose-dependent inhibition of multiple human tumor xenografts growth in mice. Altered amino acid metabolism, decreased blood vessel density, and vascular perfusion are potential mechanisms for the observed antitumor effect. However, despite its antitumor activity, given the on-target pharmacologic effects of PERK inhibition on pancreatic function, development of any PERK inhibitor in human subjects would need to be cautiously pursued in cancer patients. Cancer Res; 73(6); 1993–2002. ©2012 AACR.
Data from MicroRNA-Related Genetic Variants Associated with Clinical Outcomes in Early-Stage Non–Small Cell Lung Cancer Patients
Authors: Pu Xia , Roth Jack A. , Hildebrandt Michelle A.T. , Ye Yuanqing , Wei Hua , Minna John D. , Lippman Scott M. , Wu Xifeng
Published: March 2024

Abstract
Given the density of single-nucleotide polymorphisms (SNP) in the human genome and the sensitivity of single-nucleotide changes in microRNA (miRNA) functionality and processing, we asked whether polymorphisms within miRNA processing pathways and binding sites may influence non–small cell lung cancer (NSCLC) patients' prognosis. We genotyped 240 miRNA-related SNPs in 535 patients with stage I and II NSCLCs to determine associations with overall recurrence and survival as well as effect in specific treatment subgroups. After correcting for multiple comparisons, the G allele of FZD4:rs713065 displayed a significant association with decreased risk of death in surgery-only patients [HR, 0.46; 95% confidence interval (CI), 0.32–0.65]. DROSHA:rs6886834 variant A allele (HR, 6.38; 95% CI, 2.49–16.31) remained significant for increased risk of recurrence in the overall and surgery-only populations, respectively. FAS:rs2234978 G allele remained significantly associated with survival in all patients (HR, 0.59; 95% CI, 0.44–0.77), whereas borderline significant in subgroups (surgery-only: HR, 0.59; 95% CI, 0.42–0.84; surgery plus chemo: HR, 0.19; 95% CI, 0.07–0.46). Luciferase assays showed that the FAS SNP created a miR-651 functional binding site. Survival tree analysis was conducted to classify patients into distinct risk subgroups based on their risk genotype combinations. These results indicate that miRNA-related polymorphisms may be associated with NSCLC patients' clinical outcomes through altered miRNA regulation of target genes. Cancer Res; 73(6); 1867–75. ©2013 AACR.