bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Transcriptional Control of the ERBB2 Amplicon by ERRα and PGC-1β Promotes Mammary Gland Tumorigenesis
Authors: Deblois Geneviève , Chahrour Ghada , Perry Marie-Claude , Sylvain-Drolet Guillaume , Muller William J , Giguère Vincent
Published: March 2024

Abstract
Overexpression of ERBB2 and its neighboring genes on chromosome 17 occurs in approximately 25% of breast tumors and is associated with poor prognosis. While amplification of the 17q12-21 chromosomal region often correlates with an increase in the transcriptional rates of the locus, the molecular mechanisms and the factors involved in the coordinated expression of genes residing within the ERBB2 amplicon remain largely unknown. Here we demonstrate that estrogen-related receptor α (ERRα, NR3B1) and its coregulator PGC-1β are key effectors in this process. Using a mouse model of ERBB2-initiated mammary tumorigenesis, we first show that ablation of ERRα significantly delays ERBB2-induced tumor development and lowers the levels of amplicon transcripts. Chromosome 17q-wide binding site location analyses in human breast cancer cells show preferential recruitment of ERRα to DNA segments associated with the ERBB2 amplicon. Furthermore, ERRα directs the co-recruitment of the coactivator PGC-1β to segments in the 17q12 region and the recruitment of RNA polymerase II to the promoters of the ERBB2 and coamplified genes. ERRα and PGC-1β also participate in the de-repression of ERBB2 expression through competitive genomic cross-talk with estrogen receptor α (ERα) and, as a consequence, influence tamoxifen sensitivity in breast cancer cells. Taken together, our results suggest that ERRα and PGC-1β are key players in the etiology of malignant breast cancer by coordinating the transcriptional regulation of genes located in the 17q12 region, a process that also involves interference with the repressive function of ERα on ERBB2 expression. Cancer Res; 70(24); 10277–87. ©2010 AACR.
Data from Dissecting the Oncogenic and Tumorigenic Potential of Differentiated Human Induced Pluripotent Stem Cells and Human Embryonic Stem Cells
Authors: Ghosh Zhumur , Huang Mei , Hu Shijun , Wilson Kitchener D. , Dey Devaveena , Wu Joseph C.
Published: March 2024

Abstract
Pluripotent stem cells, both human embryonic stem cells (hESC) and human-induced pluripotent stem cells (hiPSC), can give rise to multiple cell types and hence have tremendous potential for regenerative therapies. However, the tumorigenic potential of these cells remains a great concern, as reflected in the formation of teratomas by transplanted pluripotent cells. In clinical practice, most pluripotent cells will be differentiated into useful therapeutic cell types such as neuronal, cardiac, or endothelial cells prior to human transplantation, drastically reducing their tumorigenic potential. Our work investigated the extent to which these differentiated stem cell derivatives are truly devoid of oncogenic potential. In this study, we analyzed the gene expression patterns from three sets of hiPSC- and hESC-derivatives and the corresponding primary cells, and compared their transcriptomes with those of five different types of cancer. Our analysis revealed a significant gene expression overlap of the hiPSC- and hESC-derivatives with cancer, whereas the corresponding primary cells showed minimum overlap. Real-time quantitative PCR analysis of a set of cancer-related genes (selected on the basis of rigorous functional and pathway analyses) confirmed our results. Overall, our findings suggested that pluripotent stem cell derivatives may still bear oncogenic properties even after differentiation, and additional stringent functional assays to purify these cells should be done before they can be used for regenerative therapy. Cancer Res; 71(14); 5030–9. ©2011 AACR.
Data from Imatinib Sensitivity in BCR-ABL1–Positive Chronic Myeloid Leukemia Cells Is Regulated by the Remaining Normal ABL1 Allele
Authors: Virgili Anna , Koptyra Mateusz , Dasgupta Yashodhara , Glodkowska-Mrowka Eliza , Stoklosa Tomasz , Nacheva Elisabeth P. , Skorski Tomasz
Published: March 2024

Abstract
Chronic myeloid leukemia in chronic phase (CML-CP) cells that harbor oncogenic BCR-ABL1 and normal ABL1 allele often become resistant to the ABL1 kinase inhibitor imatinib. Here, we report that loss of the remaining normal ABL1 allele in these tumors, which results from cryptic interstitial deletion in 9q34 in patients who did not achieve a complete cytogenetic remission (CCyR) during treatment, engenders a novel unexpected mechanism of imatinib resistance. BCR-ABL1–positive Abl1−/− leukemia cells were refractory to imatinib as indicated by persistent BCR-ABL1–mediated tyrosine phosphorylation, lack of BCR-ABL1 protein degradation, increased cell survival, and clonogenic activity. Expression of ABL1 kinase, but not a kinase-dead mutant, restored the antileukemic effects of imatinib in ABL1-negative chronic myelogenous leukemia (CML) cells and in BCR-ABL1–positive Abl1−/− murine leukemia cells. The intracellular concentration of imatinib and expression of its transporters were not affected, although proteins involved in BCR-ABL1 degradation were downregulated in Abl1−/− cells. Furthermore, 12 genes associated with imatinib resistance were favorably deregulated in Abl1−/− leukemia. Taken together, our results indicate that loss of the normal ABL1 kinase may serve as a key prognostic factor that exerts major impact on CML treatment outcomes. Cancer Res; 71(16); 5381–6. ©2011 AACR.
Data from Perinatal or Adult Nf1 Inactivation Using Tamoxifen-Inducible PlpCre Each Cause Neurofibroma Formation
Authors: Mayes Debra A. , Rizvi Tilat A. , Cancelas Jose A. , Kolasinski Nathan T. , Ciraolo Georgianne M. , Stemmer-Rachamimov Anat O. , Ratner Nancy
Published: March 2024

Abstract
Plexiform neurofibromas are peripheral nerve sheath tumors initiated by biallelic mutation of the NF1 tumor suppressor gene in the Schwann cell lineage. To understand whether neurofibroma formation is possible after birth, we induced Nf1 loss of function with an inducible proteolipid protein Cre allele. Perinatal loss of Nf1 resulted in the development of small plexiform neurofibromas late in life, whereas loss in adulthood caused large plexiform neurofibromas and morbidity beginning 4 months after onset of Nf1 loss. A conditional EGFP reporter allele identified cells showing recombination, including peripheral ganglia satellite cells, peripheral nerve S100β+ myelinating Schwann cells, and peripheral nerve p75+ cells. Neurofibromas contained cells with Remak bundle disruption but no recombination within GFAP+ nonmyelinating Schwann cells. Extramedullary lympho-hematopoietic expansion was also observed in PlpCre;Nf1fl/fl mice. These tumors contained EGFP+/Sca-1+ stromal cells among EGFP-negative lympho-hematopoietic cells indicating a noncell autonomous effect and unveiling a role of Nf1-deleted microenvironment on lympho-hematopoietic proliferation in vivo. Together these findings define a tumor suppressor role for Nf1 in the adult and narrow the range of potential neurofibroma-initiating cell populations. Cancer Res; 71(13); 4675–85. ©2011 AACR.
Data from Invasive Prostate Carcinoma Driven by c-Src and Androgen Receptor Synergy
Authors: Cai Houjian , Babic Ivan , Wei Xiao , Huang Jiaoti , Witte Owen N.
Published: March 2024

Abstract
Cellular Src (c-Src) integrates a large number of signal transduction pathways regulating cell division, migration, and other aspects of cell physiology. Mutations of Src kinase have not been described in human prostate cancer, but evidence for increased levels of expression accompanying cancer progression has been reported. We analyzed overexpression of c-Src in naïve mouse prostate epithelium and observed no change in tubule formation frequency or histologic structure. However, when enhanced c-Src expression is coupled with enhanced expression of androgen receptor (AR), it results in a strong activation of Src kinase activity accompanied by activation of the MAPK pathway, and enhanced AR activity. Similar to the pathology induced by constitutively active c-Src(Y529F), the tubules progress to frank carcinoma with invasion and display markers of epithelial-to-mesenchymal transition. These combined results suggest that nonmutated Src kinase may play a more important role in the genesis and progression of prostate cancer than previously appreciated and that epigenetic changes that enhance the level of AR may select for enhanced expression of c-Src with accompanying activation and a strong drive to malignant progression. Cancer Res; 71(3); 862–72. ©2010 AACR.
Data from Maximal T Cell–Mediated Antitumor Responses Rely upon CCR5 Expression in Both CD4+ and CD8+ T Cells
Authors: González-Martín Alicia , Gómez Lucio , Lustgarten Joseph , Mira Emilia , Mañes Santos
Published: March 2024

Abstract
Immune responses against cancer rely upon leukocyte trafficking patterns that are coordinated by chemokines. CCR5, the receptor for chemotactic chemokines MIP1alpha, MIP1beta, and RANTES (CCL3, CCL4, CCL5), exerts major regulatory effects on CD4+- and CD8+ T cell-mediated immunity. Although CCR5 and its ligands participate in the response to various pathogens, its relevance to tumoral immune control has been debated. Here, we report that CCR5 has a specific, ligand-dependent role in optimizing antitumor responses. In adoptive transfer studies, efficient tumor rejection required CCR5 expression by both CD4+ and CD8+ T cells. CCR5 activation in CD4+ cells resulted in CD40L upregulation, leading to full maturation of antigen-presenting cells and enhanced CD8+ T-cell crosspriming and tumor infiltration. CCR5 reduced chemical-induced fibrosarcoma incidence and growth, but did not affect the onset or progression of spontaneous breast cancers in tolerogenic Tg(MMTV-neu) mice. However, CCR5 was required for TLR9-mediated reactivation of antineu responses in these mice. Our results indicate that CCR5 boosts T-cell responses to tumors by modulating helper-dependent CD8+ T-cell activation. Cancer Res; 71(16); 5455–66. ©2011 AACR.
Data from MicroRNA miR-302 Inhibits the Tumorigenecity of Human Pluripotent Stem Cells by Coordinate Suppression of the CDK2 and CDK4/6 Cell Cycle Pathways
Authors: Lin Shi-Lung , Chang Donald C. , Ying Shao-Yao , Leu Davey , Wu David T.S.
Published: March 2024

Abstract
miR-302 is the major microRNA found in human embryonic stem cells and induced pluripotent stem cells, but its function has been unclear. In mice, there is evidence that miR-302 may silence p21Cip1 (CDKN1A) to promote cell proliferation, whereas studies in human reprogrammed pluripotent stem cells suggested that elevated miR-302 expression inhibited cell cycle transit. Here, we clarify this difference, reporting that in human cells, miR-302 simultaneously suppressed both the cyclin E-CDK2 and cyclin D-CDK4/6 pathways to block >70% of the G1-S cell cycle transition. Concurrent silencing of BMI-1, a cancer stem cell marker targeted by miR-302, further promoted tumor suppressor functions of p16Ink4a and p14/p19Arf directed against CDK4/6–mediated cell proliferation. Among all G1 phase checkpoint regulators, human p21Cip1 was found not to be a valid target of miR-302. Overall, our findings indicate that miR-302 inhibits human pluripotent stem cell tumorigenicity by enhancing multiple G1 phase arrest pathways rather than by silencing p21Cip1. Cancer Res; 70(22); 9473–82. ©2010 AACR.
Data from Telomerase Inhibition Potentiates the Effects of Genotoxic Agents in Breast and Colorectal Cancer Cells in a Cell Cycle–Specific Manner
Authors: Tamakawa Raina A. , Fleisig Helen B. , Wong Judy M.Y.
Published: March 2024

Abstract
Previous studies have shown that telomerase facilitates DNA-damage repair and cell survival following stress. It is not clear how telomerase promotes DNA repair, or whether short-term telomerase inhibition, combined with genotoxic stress, can be exploited for cancer therapy. Here, we show that transient inhibition of telomerase activity by the specific inhibitor, GRN163L, increases the cytotoxicity of some, but not all, DNA-damaging agents. Such synergistic inhibition of growth requires the use of DNA-damaging agents that are toxic in the S/G2 phase of the cell cycle. Notably, inhibition of Ataxia Telangiectasia Mutated (ATM) kinase, together with telomerase inhibition, synergistically increases the cytotoxicity induced by the G2-specific topoisomerase II inhibitor etoposide. By varying the timing of telomerase inhibition, relative to the timing of DNA damage, it is apparent that the prosurvival functions of telomerase occur at early stages of DNA damage recognition and repair. Our results suggest that the protective role of telomerase in cell cycle–restricted DNA damage repair could be exploited for combined anticancer chemotherapy. Cancer Res; 70(21); 8684–94. ©2010 AACR.
Data from The Dual EGFR/HER2 Inhibitor Lapatinib Synergistically Enhances the Antitumor Activity of the Histone Deacetylase Inhibitor Panobinostat in Colorectal Cancer Models
Authors: LaBonte Melissa J. , Wilson Peter M. , Fazzone Will , Russell Jared , Louie Stan G. , El-Khoueiry Anthony , Lenz Heinz-Josef , Ladner Robert D.
Published: March 2024

Abstract
As key molecules that drive progression and chemoresistance in gastrointestinal cancers, epidermal growth factor receptor (EGFR) and HER2 have become efficacious drug targets in this setting. Lapatinib is an EGFR/HER2 kinase inhibitor suppressing signaling through the RAS/RAF/MEK (MAP/ERK kinase)/MAPK (mitogen-activated protein kinase) and PI3K (phosphoinositide 3-kinase)/AKT pathways. Histone deacetylase inhibitors (HDACi) are a novel class of agents that induce cell cycle arrest and apoptosis following the acetylation of histone and nonhistone proteins modulating gene expression and disrupting HSP90 function inducing the degradation of EGFR-pathway client proteins. This study sought to evaluate the therapeutic potential of combining lapatinib with the HDACi panobinostat in colorectal cancer (CRC) cell lines with varying EGFR/HER2 expression and KRAS/BRAF/PIK3CA mutations. Lapatinib and panobinostat exerted concentration-dependent antiproliferative effects in vitro (panobinostat range 7.2–30 nmol/L; lapatinib range 7.6–25.8 μmol/L). Combined lapatinib and panobinostat treatment interacted synergistically to inhibit the proliferation and colony formation in all CRC cell lines tested. Combination treatment resulted in rapid induction of apoptosis that coincided with increased DNA double-strand breaks, caspase-8 activation, and PARP cleavage. This was paralleled by decreased signaling through both the PI3K and MAPK pathways and increased downregulation of transcriptional targets including NF-κB1, IRAK1, and CCND1. Panobinostat treatment induced downregulation of EGFR, HER2, and HER3 mRNA and protein through transcriptional and posttranslational mechanisms. In the LoVo KRAS mutant CRC xenograft model, the combination showed greater antitumor activity than either agent alone, with no apparent increase in toxicity. Our results offer preclinical rationale warranting further clinical investigation combining HDACi with EGFR and HER2-targeted therapies for CRC treatment. Cancer Res; 71(10); 3635–48. ©2011 AACR.
Data from Profound Coordinated Alterations of Intratumoral NK Cell Phenotype and Function in Lung Carcinoma
Authors: Platonova Sophia , Cherfils-Vicini Julien , Damotte Diane , Crozet Lucile , Vieillard Vincent , Validire Pierre , André Pascale , Dieu-Nosjean Marie-Caroline , Alifano Marco , Régnard Jean-François , Fridman Wolf-Herman , Sautès-Fridman Catherine , Cremer Isabelle
Published: March 2024

Abstract
Both the innate and adaptive immune systems contribute to tumor immunosurveillance in mice and humans; however, there is a paucity of direct evidence of a role for natural killer (NK) cells in this important process. In this study, we investigated the intratumoral phenotypic profile and functions of NK cells in primary human tumor specimens of non–small cell lung carcinoma (NSCLC). We used in situ methods to quantify and localize NK cells using the NKp46 marker and we characterized their phenotype in blood, tumoral, and nontumoral samples of NSCLC patients. Intratumoral NK cells displayed a profound and coordinated alteration of their phenotype, with a drastic reduction of NK cell receptor expression specifically detected in the tumoral region. According to their altered phenotype, intratumoral NK cells exhibited profound defects in the ability to activate degranulation and IFN-γ production. We found that the presence of NK cells did not impact the clinical outcome of patients with NSCLC. Finally, we showed that tumor cells heterogeneously express ligands for both activating and inhibitory NK receptors. Taken together, our results suggest that the NSCLC tumor microenvironment locally impairs NK cells, rendering them less tumorcidal and thereby supportive to cancer progression. Cancer Res; 71(16); 5412–22. ©2011 AACR.
Data from Preconditioned Endothelial Progenitor Cells Reduce Formation of Melanoma Metastases through SPARC-Driven Cell–Cell Interactions and Endocytosis
Authors: Defresne Florence , Bouzin Caroline , Grandjean Marie , Dieu Marc , Raes Martine , Hatzopoulos Antonis K. , Kupatt Christian , Feron Olivier
Published: March 2024

Abstract
Tumor progression is associated with the release of signaling substances from the primary tumor into the bloodstream. Tumor-derived cytokines are known to promote the mobilization and the recruitment of cells from the bone marrow, including endothelial progenitor cells (EPC). Here, we examined whether such paracrine influence could also influence the capacity of EPC to interfere with circulating metastatic cells. We therefore consecutively injected EPC prestimulated by tumor-conditioned medium (EPC-CM) and luciferase-expressing B16 melanoma cells to mice. A net decrease in metastases spreading (vs. nonstimulated EPC) led us to carry out a 2-dimensional difference gel electrophoresis (2D-DIGE) proteomic study to identify possible mediators of EPC-driven protection. Among 33 proteins exhibiting significant changes in expression, secreted protein, acidic and rich in cysteine (SPARC) presented the highest induction after EPC exposure to CM. We then showed that contrary to control EPC, SPARC-silenced EPC were not able to reduce the extent of metastases when injected with B16 melanoma cells. Using adhesion tests and the hanging drop assay, we further documented that cell–cell interactions between EPC-CM and melanoma cells were promoted in a SPARC-dependent manner. This interaction led to the engulfment of melanoma cells by EPC-CM, a process prevented by SPARC silencing and mimicked by recombinant SPARC. Finally, we showed that contrary to melanoma cells, the prometastatic human breast cancer cell line MDA-MB231-D3H2 reduced SPARC expression in human EPC and stimulated metastases spreading. Our findings unravel the influence of tumor cells on EPC phenotypes through a SPARC-driven accentuation of macrophagic capacity associated with limitations to metastatic spread. Cancer Res; 71(14); 4748–57. ©2011 AACR.
Data from Conditional Deletion of the Focal Adhesion Kinase FAK Alters Remodeling of the Blood–Brain Barrier in Glioma
Authors: Lee Jisook , Borboa Alexandra K. , Chun Hyun Bae , Baird Andrew , Eliceiri Brian P.
Published: March 2024

Abstract
Gliomas generally infiltrate the surrounding normal brain parenchyma, a process associated with increased vascular permeability (VP) and dysregulation of the blood–brain barrier (BBB). However, the molecular mechanisms underlying glioma-induced VP in the brain remain poorly understood. Using a conditional, endothelium-specific deletion of the focal adhesion kinase (FAK) in the mouse (FAK CKO), we show that FAK is critical for destabilization of the tumor endothelium in tumor-bearing mice, with mutant mice exhibiting a relatively normalized vasculature compared with wild-type mice (FAK WT). Tumor vessels in the FAK CKO mice displayed reduced VP compared with FAK WT mice, resulting in reduced tumor growth. Additionally, FAK CKO mice displayed partial restoration of cell–cell junction proteins in the tumor vessels and astrocyte–endothelium interactions in tumors, revealing an additional role of astrocytes in mediating tumor-induced VP. Together, these results provide genetic evidence that FAK is a mediator of tumor-induced VP in the brain. Our findings may help understand how therapeutics might be used to regulate specific cell-type interactions to restore BBB structure/function in cancer and perhaps other pathologic conditions. Cancer Res; 70(24); 10131–40. ©2010 AACR.
Data from Common and Overlapping Oncogenic Pathways Contribute to the Evolution of Acute Myeloid Leukemias
Authors: Kvinlaug Brynn T. , Chan Wai-In , Bullinger Lars , Ramaswami Mukundhan , Sears Christopher , Foster Donna , Lazic Stanley E. , Okabe Rachel , Benner Axel , Lee Benjamin H. , De Silva Inusha , Valk Peter J.M. , Delwel Ruud , Armstrong Scott A. , Döhner Hartmut , Gilliland D. Gary , Huntly Brian J.P.
Published: March 2024

Abstract
Fusion oncogenes in acute myeloid leukemia (AML) promote self-renewal from committed progenitors, thereby linking transformation and self-renewal pathways. Like most cancers, AML is a genetically and biologically heterogeneous disease, but it is unclear whether transformation results from common or overlapping genetic programs acting downstream of multiple mutations or by the engagement of unique genetic programs acting cooperatively downstream of individual mutations. This distinction is important, because the involvement of common programs would imply the existence of common molecular targets to treat AML, no matter which oncogenes are involved. Here we show that the ability to promote self-renewal is a generalized property of leukemia-associated oncogenes. Disparate oncogenes initiated overlapping transformation and self-renewal gene expression programs, the common elements of which were defined in established leukemic stem cells from an animal model as well as from a large cohort of patients with differing AML subtypes, where they strongly predicted pathobiological character. Notably, individual genes commonly activated in these programs could partially phenocopy the self-renewal function of leukemia-associated oncogenes in committed murine progenitors. Furthermore, they could generate AML following expression in murine bone marrow. In summary, our findings reveal the operation of common programs of self-renewal and transformation downstream of leukemia-associated oncogenes, suggesting that mechanistically common therapeutic approaches to AML are likely to be possible, regardless of the identity of the driver oncogene involved. Cancer Res; 71(12); 4117–29. ©2011 AACR.
Data from Combination Therapy with Vidaza and Entinostat Suppresses Tumor Growth and Reprograms the Epigenome in an Orthotopic Lung Cancer Model
Authors: Belinsky Steven A. , Grimes Marcie J. , Picchi Maria A. , Mitchell Hugh D. , Stidley Chris A. , Tesfaigzi Yohannes , Channell Meghan M. , Liu Yanbin , Casero Robert A. , Baylin Stephen B. , Reed Mathew D. , Tellez Carmen S. , March Thomas H.
Published: March 2024

Abstract
Epigenetic therapy for solid tumors could benefit from an in vivo model that defines tumor characteristics of responsiveness and resistance to facilitate patient selection. Here we report that combining the histone deacetylase inhibitor entinostat with the demethylating agent vidaza profoundly affected growth of K-ras/p53 mutant lung adenocarcinomas engrafted orthotopically in immunocompromised nude rats by targeting and ablating pleomorphic cells that occupied up to 75% of the tumor masses. A similar reduction in tumor burden was seen with epigenetic therapy in K-ras or EGFR mutant tumors growing orthotopically. Increased expression of proapoptotic genes and the cyclin-dependent kinase inhibitor p21 was seen. Hundreds of genes were demethylated highlighted by the reexpression of polycomb-regulated genes coding for transcription factor binding proteins and the p16 gene, a key regulator of the cell cycle. Highly significant gene expression changes were seen in key regulatory pathways involved in cell cycle, DNA damage, apoptosis, and tissue remodeling. These findings show the promise for epigenetic therapy in cancer management and provide an orthotopic lung cancer model that can assess therapeutic efficacy and reprogramming of the epigenome in tumors harboring different genetic and epigenetic profiles to guide use of these drugs. Cancer Res; 71(2); 454–62. ©2011 AACR.
Data from Effects of Carbon Ion Beam on Putative Colon Cancer Stem Cells and Its Comparison with X-rays
Authors: Cui Xing , Oonishi Kazuhiko , Tsujii Hirohiko , Yasuda Takeshi , Matsumoto Yoshitaka , Furusawa Yoshiya , Akashi Makoto , Kamada Tadashi , Okayasu Ryuichi
Published: March 2024

Abstract
Although carbon ion therapy facilities are expensive, the biological effects of carbon ion beam treatment may be better against cancer (and cancer stem cells) than the effects of a photon beam. To investigate whether a carbon ion beam may have a biological advantage over X-rays by targeting cancer stem–like cells, human colon cancer cells were used in vitro and in vivo. The in vitro relative biological effectiveness (RBE) values of a carbon ion beam relative to X-rays at the D10 values were from 1.63 to 1.74. Cancer stem–like CD133+, CD44+/ESA+ cells had a greater ability for colony and spheroid formation, as well as in vivo tumorigenicity compared with the CD133−, CD44−/ESA− cells. FACS (fluorescence-activated cell sorting) data showed that cancer stem–like cells were more highly enriched after irradiation with X-rays than carbon ion at doses that produced the same level of biological efficacy. A colony assay for cancer stem–like cells showed that RBE values calculated by the D10 levels were from 2.05 to 2.28 for the carbon ion beam relative to X-rays. The in vivo xenotransplant assay showed an RBE of 3.05 to 3.25, calculated from the slope of the dose–response curve for tumor growth suppression. Carbon ion irradiation with 15 Gy induced more severe xenograft tumor cell cavitation and fibrosis without significant enhancement of cells with putative cancer stem cell markers, CD133, ESA, and CD44, compared with 30 Gy X-rays, and marker positive cells were significantly decreased following 30 Gy carbon ion irradiation. Taken together, carbon ion beam therapy may have an advantage over photon beam therapy by improved targeting of putative colon cancer stem–like cells. Cancer Res; 71(10); 3676–87. ©2011 AACR.
Data from FUS/TLS Is a Novel Mediator of Androgen-Dependent Cell-Cycle Progression and Prostate Cancer Growth
Authors: Brooke Greg N. , Culley Rachel L. , Dart D. Alwyn , Mann David J. , Gaughan Luke , McCracken Stuart R. , Robson Craig N. , Spencer-Dene Bradley , Gamble Simon C. , Powell Sue M. , Wait Robin , Waxman Jonathan , Walker Marjorie M. , Bevan Charlotte L.
Published: March 2024

Abstract
Progression of prostate cancer is highly dependent upon the androgen receptor pathway, such that knowledge of androgen-regulated proteins is vital to understand and combat this disease. Using a proteomic screen, we found the RNA-binding protein FUS/TLS (Fused in Ewing's Sarcoma/Translocated in Liposarcoma) to be downregulated in response to androgen. FUS has recently been shown to be recruited by noncoding RNAs to the regulatory regions of target genes such as cyclin D1, in which it represses transcription by disrupting complex formation. Here we show that FUS has some characteristics of a putative tumor suppressor, as its overexpression promoted growth inhibition and apoptosis of prostate cancer cells, whereas its knockdown increased cell proliferation. This effect was reproducible in vivo, such that increasing FUS levels in tumor xenografts led to dramatic tumor regression. Furthermore, FUS promoted conditions that favored cell-cycle arrest by reducing the levels of proliferative factors such as cyclin D1 and Cdk6 and by increasing levels of the antiproliferative Cdk inhibitor p27. Immunohistochemical analysis revealed that FUS expression is inversely correlated with Gleason grade, demonstrating that patients with high levels of FUS survived longer and were less likely to have bone metastases, suggesting that loss of FUS expression may contribute to cancer progression. Taken together, our results address the question of how androgens regulate cell-cycle progression, by demonstrating that FUS is a key link between androgen receptor signaling and cell-cycle progression in prostate cancer. Cancer Res; 71(3); 914–24. ©2010 AACR.
Data from Protein Kinase C δ Is a Downstream Effector of Oncogenic K-ras in Lung Tumors
Authors: Symonds Jennifer M. , Ohm Angela M. , Carter Cristan J. , Heasley Lynn E. , Boyle Theresa A. , Franklin Wilbur A. , Reyland Mary E.
Published: March 2024

Abstract
Oncogenic activation of K-ras occurs commonly in non–small cell lung cancer (NSCLC), but strategies to therapeutically target this pathway have been challenging to develop. Information about downstream effectors of K-ras remains incomplete, and tractable targets are yet to be defined. In this study, we investigated the role of protein kinase C δ (PKCδ) in K-ras–dependent lung tumorigenesis by using a mouse carcinogen model and human NSCLC cells. The incidence of urethane-induced lung tumors was decreased by 69% in PKCδ-deficient knockout (δKO) mice compared with wild-type (δWT) mice. δKO tumors are smaller and showed reduced proliferation. DNA sequencing indicated that all δWT tumors had activating mutations in KRAS, whereas only 69% of δKO tumors did, suggesting that PKCδ acts as a tumor promoter downstream of oncogenic K-ras while acting as a tumor suppressor in other oncogenic contexts. Similar results were obtained in a panel of NSCLC cell lines with oncogenic K-ras but which differ in their dependence on K-ras for survival. RNA interference–mediated attenuation of PKCδ inhibited anchorage-independent growth, invasion, migration, and tumorigenesis in K-ras–dependent cells. These effects were associated with suppression of mitogen-activated protein kinase pathway activation. In contrast, PKCδ attenuation enhanced anchorage-independent growth, invasion, and migration in NSCLC cells that were either K-ras–independent or that had WT KRAS. Unexpectedly, our studies indicate that the function of PKCδ in tumor cells depends on a specific oncogenic context, as loss of PKCδ in NSCLC cells suppressed transformed growth only in cells dependent on oncogenic K-ras for proliferation and survival. Cancer Res; 71(6); 2087–97. ©2011 AACR.
Data from Repression of Vascular Endothelial Growth Factor Expression by the Runt-Related Transcription Factor 1 in Acute Myeloid Leukemia
Authors: ter Elst Arja , Ma Bin , Scherpen Frank J.G. , de Jonge Hendrik J.M. , Douwes Jenny , Wierenga Albertus T.J. , Schuringa Jan Jacob , Kamps Willem A. , de Bont Eveline S.J.M.
Published: March 2024

Abstract
VEGFA is considered one of the most important regulators of tumor-associated angiogenesis in cancer. In acute myeloid leukemia (AML) VEGFA is an independent prognostic factor for reduced overall and relapse-free survival. Transcriptional activation of the VEGFA promoter, a core mechanism for VEGFA regulation, has not been fully elucidated. We found a significant (P < 0.0001) inverse correlation between expression of VEGFA and AML1/RUNX1 in a large set of gene expression array data. Strikingly, highest VEGFA levels were demonstrated in AML blasts containing a t(8;21) translocation, which involves the AML1/RUNX1 protein (AML1/ETO). Overexpression of AML1/RUNX1 led to downregulation of VEGFA expression, whereas blocking of AML1/RUNX1 with siRNAs resulted in increased VEGFA expression. Cotransfection of AML1/RUNX1 and VEGFA promoter luciferase promoter constructs resulted in a decrease in VEGFA promoter activity. ChIP analysis shows a direct binding of AML1/RUNX1 to the promoter of VEGFA on three AML1/RUNX1 binding sites. Silencing of AML1/ETO caused a decrease in VEGFA mRNA expression and a decrease in secreted VEGFA protein levels in AML1/ETO-positive Kasumi-1 cells. Taken together, these data pinpoint to a model whereby in normal cells AML1/RUNX1 acts as a repressor for VEGFA, while in AML cells VEGFA expression is upregulated due to AML1/RUNX1 aberrations, for example, AML1/ETO. In conclusion, these observations give insight in the regulation of VEGFA at the mRNA level in AML. Cancer Res; 71(7); 2761–71. ©2011 AACR.
Data from Notch Signaling in CD66+ Cells Drives the Progression of Human Cervical Cancers
Authors: Bajaj Jeevisha , Maliekal Tessy Thomas , Vivien Eric , Pattabiraman Chitra , Srivastava Sweta , Krishnamurthy H. , Giri V. , Subramanyam Deepa , Krishna Sudhir
Published: March 2024

Abstract
Human epithelial tumor progression and metastasis involve cellular invasion, dissemination in the vasculature, and regrowth at metastatic sites. Notch signaling has been implicated in metastatic progression but its roles have yet to be fully understood. Here we report the important role of Notch signaling in maintaining cells expressing the carcinoembryonic antigen cell adhesion molecule CEACAM (CD66), a known mediator of metastasis. CD66 and Notch1 were studied in clinical specimens and explants of human cervical cancer, including specimens grown in a pathophysiologically relevant murine model. Gene expression profiling of CD66+ cells from primary tumors showed enhanced features of Notch signaling, metastasis, and stemness. Significant differences were also seen in invasion, colony formation, and tumor forming efficiency between CD66+ and CD66− cancer cells. Notably, CD66+ cells showed a marked sensitivity to a Notch small molecule inhibitor. In support of studies in established cell lines, we documented the emergence of a tumorigenic CD66+ cell subset within a metastatic lesion-derived cervical-cancer cell line. Similar to primary cancers, CD66 expression in the cell line was blocked by chemical and genetic inhibitors of ligand-dependent nuclear Notch signaling. Collectively, our work on the oncogenic properties of CD66+ cells in epithelial cancers provides insights into the nature of tumor progression and offers a mechanistic rationale to inhibit the Notch signaling pathway as a generalized therapeutic strategy to treat metastatic cancers. Cancer Res; 71(14); 4888–97. ©2011 AACR.
Data from BCR/ABL Stimulates WRN to Promote Survival and Genomic Instability
Authors: Slupianek Artur , Poplawski Tomasz , Jozwiakowski Stanislaw K. , Cramer Kimberly , Pytel Dariusz , Stoczynska Ewelina , Nowicki Michal O. , Blasiak Janusz , Skorski Tomasz
Published: March 2024

Abstract
BCR/ABL-transformed chronic myeloid leukemia (CML) cells accumulate numerous DNA double-strand breaks (DSB) induced by reactive oxygen species (ROS) and genotoxic agents. To repair these lesions BCR/ABL stimulate unfaithful DSB repair pathways, homologous recombination repair (HRR), nonhomologous end-joining (NHEJ), and single-strand annealing (SSA). Here, we show that BCR/ABL enhances the expression and increase nuclear localization of WRN (mutated in Werner syndrome), which is required for processing DSB ends during the repair. Other fusion tyrosine kinases (FTK), such as TEL/ABL, TEL/JAK2, TEL/PDGFβR, and NPM/ALK also elevate WRN. BCR/ABL induces WRN mRNA and protein expression in part by c-MYC-mediated activation of transcription and Bcl-xL–dependent inhibition of caspase-dependent cleavage, respectively. WRN is in complex with BCR/ABL resulting in WRN tyrosine phosphorylation and stimulation of its helicase and exonuclease activities. Activated WRN protects BCR/ABL-positive cells from the lethal effect of oxidative and genotoxic stresses, which causes DSBs. In addition, WRN promotes unfaithful recombination-dependent repair mechanisms HRR and SSA, and enhances the loss of DNA bases during NHEJ in leukemia cells. In summary, we postulate that BCR/ABL-mediated stimulation of WRN modulates the efficiency and fidelity of major DSB repair mechanisms to protect leukemia cells from apoptosis and to facilitate genomic instability. Cancer Res; 71(3); 842–51. ©2010 AACR.
Data from Intratumoral De Novo Steroid Synthesis Activates Androgen Receptor in Castration-Resistant Prostate Cancer and Is Upregulated by Treatment with CYP17A1 Inhibitors
Authors: Cai Changmeng , Chen Sen , Ng Patrick , Bubley Glenn J. , Nelson Peter S. , Mostaghel Elahe A. , Marck Brett , Matsumoto Alvin M. , Simon Nicholas I. , Wang Hongyun , Chen Shaoyong , Balk Steven P.
Published: March 2024

Abstract
Relapse of castration-resistant prostate cancer (CRPC) that occurs after androgen deprivation therapy of primary prostate cancer can be mediated by reactivation of the androgen receptor (AR). One important mechanism mediating this AR reactivation is intratumoral conversion of the weak adrenal androgens DHEA and androstenedione into the AR ligands testosterone and dihydrotestosterone. DHEA and androstenedione are synthesized by the adrenals through the sequential actions of the cytochrome P450 enzymes CYP11A1 and CYP17A1, so that CYP17A1 inhibitors such as abiraterone are effective therapies for CRPC. However, the significance of intratumoral CYP17A1 and de novo androgen synthesis from cholesterol in CRPC, and the mechanisms contributing to CYP17A1 inhibitor resistance/relapse, remain to be determined. We report that AR activity in castration-resistant VCaP tumor xenografts can be restored through CYP17A1-dependent de novo androgen synthesis, and that abiraterone treatment of these xenografts imposes selective pressure for increased intratumoral expression of CYP17A1, thereby generating a mechanism for development of resistance to CYP17A1 inhibitors. Supporting the clinical relevance of this mechanism, we found that intratumoral expression of CYP17A1 was markedly increased in tumor biopsies from CRPC patients after CYP17A1 inhibitor therapy. We further show that CRPC cells expressing a progesterone responsive T877A mutant AR are not CYP17A1 dependent, but that AR activity in these cells is still steroid dependent and mediated by upstream CYP11A1-dependent intraturmoral pregnenolone/progesterone synthesis. Together, our results indicate that CRPCs resistant to CYP17A1 inhibition may remain steroid dependent and therefore responsive to therapies that can further suppress de novo intratumoral steroid synthesis. Cancer Res; 71(20); 6503–13. ©2011 AACR.
Data from Appearance of the Novel Activating F1174S ALK Mutation in Neuroblastoma Correlates with Aggressive Tumor Progression and Unresponsiveness to Therapy
Authors: Martinsson Tommy , Eriksson Therese , Abrahamsson Jonas , Caren Helena , Hansson Magnus , Kogner Per , Kamaraj Sattu , Schönherr Christina , Weinmar Joel , Ruuth Kristina , Palmer Ruth H. , Hallberg Bengt
Published: March 2024

Abstract
Mutations in the kinase domain of the ALK kinase have emerged recently as important players in the genetics of the childhood tumor neuroblastoma. Here, we report the appearance of a novel ALK mutation in neuroblastoma, correlating with aggressive tumor behavior. Analyses of genomic DNA from biopsy samples initially showed ALK sequence to be wild type. However, during disease progression, mutation of amino acid F1174 to a serine within the ALK kinase domain was observed, which correlated with aggressive neuroblastoma progression in the patient. We show that mutation of F1174 to serine generates a potent gain-of-function mutant, as observed in 2 independent systems. First, PC12 cell lines expressing ALKF1174S display ligand-independent activation of ALK and further downstream signaling activation. Second, analysis of ALKF1174S in Drosophila models confirms that the mutation mediates a strong, rough eye phenotype upon expression in the developing eye. Thus, we report a novel ALKF1174S mutation that displays ligand-independent activity in vivo, correlating with rapid and treatment-resistant tumor growth. The study also shows that initial screening in the first tumor biopsy of a patient may not be sufficient and that further molecular analysis, in particular in tumor progression and/or tumor relapse, is warranted for better understanding of the treatment of neuroblastoma patients. Cancer Res; 71(1); 98–105. ©2011 AACR.
Data from Paxillin Predicts Survival and Relapse in Non–Small Cell Lung Cancer by MicroRNA-218 Targeting
Authors: Wu De-Wei , Cheng Ya-Wen , Wang John , Chen Chih-Yi , Lee Huei
Published: March 2024

Abstract
Paxillin (PXN) gene mutations are associated with lung adenocarcinoma progression and PXN is known to be a target gene of microRNA-218 (miR-218). On this basis, we hypothesized that PXN overexpression via miR-218 suppression may promote tumor progression and metastasis and that PXN may predict survival and relapse in non–small cell lung cancer (NSCLC). Expression of miR-218 and PXN in 124 surgically resected lung tumors were evaluated by real-time PCR and immunohistochemical analysis. The prognostic value of miR-218 and PXN expression on overall survival (OS) and relapse-free survival (RFS) was analyzed by the Kaplan–Meier test and Cox regression analysis. miR-218 expression in lung tumors was negatively associated with PXN expression. Multivariate analyses showed that PXN and miR-218 might independently predict OS and RFS, respectively, in NSCLC. Moreover, patients with low miR-218 combined with PXN-positive had the worst OS and RFS among the 4 combinations. In a cell model, PXN was negatively regulated by miR-218 and cell proliferation, invasion, and soft agar colony formation were enhanced by PXN overexpression induced by miR-218 suppression. Taken together, our findings suggest that PXN overexpression induced by miR-218 suppression is an independent predictor of survival and relapse in NSCLC, highlighting PXN as a potential therapeutic target to improve clinical outcomes in this disease. Cancer Res; 70(24); 10392–401. ©2010 AACR.
Data from Double-Negative Feedback Loop between Reprogramming Factor LIN28 and microRNA let-7 Regulates Aldehyde Dehydrogenase 1–Positive Cancer Stem Cells
Authors: Yang Xiaojun , Lin Xiaojuan , Zhong Xiaomin , Kaur Sippy , Li Ning , Liang Shun , Lassus Heini , Wang Liping , Katsaros Dionyssios , Montone Kathleen , Zhao Xia , Zhang Youcheng , Bützow Ralf , Coukos George , Zhang Lin
Published: March 2024

Abstract
A relatively rare aldehyde dehydrogenase 1 (ALDH1)–positive “stem cell–like” subpopulation of tumor cells has the unique ability to initiate and perpetuate tumor growth; moreover, it is highly resistant to chemotherapy and significantly associated with poor clinical outcomes. The development of more effective therapies for cancer requires targeting of this cell population. Using cDNA microarray analysis, we identified that the expression of the Caenorhabditis elegans lin-28 homologue (LIN28) was positively correlated with the percentage of ALDH1+ tumor cells; this was further validated in an independent set of tissue arrays (n = 197). Both loss-of-function and gain-of-function studies showed that LIN28 plays a critical role in the maintenance of ALDH1+ tumor cells. In addition, we found that there is a double-negative feedback loop between LIN28 and let-7 in tumor cells, and that let-7 negatively regulates ALDH1+ tumor cells. Finally, we report that a LIN28/let-7 loop modulates self-renewal and differentiation of mammary gland epithelial progenitor cells. Our data provide evidence that cancer stem cells may arise through a “reprogramming-like” mechanism. A rebalancing of the LIN28/let-7 regulatory loop could be a novel therapeutic strategy to target ALDH1+ cancer stem cells. Cancer Res; 70(22); 9463–72. ©2010 AACR.
Data from STAT3 Plays a Critical Role in KRAS-Induced Pancreatic Tumorigenesis
Authors: Corcoran Ryan B. , Contino Gianmarco , Deshpande Vikram , Tzatsos Alexandros , Conrad Claudius , Benes Cyril H. , Levy David E. , Settleman Jeffrey , Engelman Jeffrey A. , Bardeesy Nabeel
Published: March 2024

Abstract
The STAT3 transcription factor is an important regulator of stem cell self-renewal, cancer cell survival, and inflammation. In the pancreas, STAT3 is dispensable for normal development, whereas the majority of pancreatic ductal adenocarcinomas (PDAC) show constitutive activation of STAT3, suggesting its potential as a therapeutic target in this cancer. Here, we sought to define the mechanisms of STAT3 activation and its functional importance in PDAC pathogenesis. Large-scale screening of cancer cell lines with a JAK2 inhibitor that blocks STAT3 function revealed a more than 30-fold range in sensitivity in PDAC, and showed a close correlation of sensitivity with levels of tyrosine-phosphorylated STAT3 and of the gp130 receptor, an upstream signaling component. Correspondingly, upregulation of the IL6/LIF-gp130 pathway accounted for the strong STAT3 activation in PDAC subsets. To define functions of STAT3 in vivo, we developed mouse models that test the impact of conditional inactivation of STAT3 in KRAS-driven PDAC. We showed that STAT3 is required for the development of the earliest premalignant pancreatic lesions, acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia (PanIN). Moreover, acute STAT3 inactivation blocked PDAC initiation in a second in vivo model. Our results show that STAT3 has critical roles throughout the course of PDAC pathogenesis, supporting the development of therapeutic approaches targeting this pathway. Moreover, our work suggests that gp130 and phospho-STAT3 expression may be effective biomarkers for predicting response to JAK2 inhibitors. Cancer Res; 71(14); 5020–9. ©2011 AACR.
Data from Microvesicles Released from Human Renal Cancer Stem Cells Stimulate Angiogenesis and Formation of Lung Premetastatic Niche
Authors: Grange Cristina , Tapparo Marta , Collino Federica , Vitillo Loriana , Damasco Christian , Deregibus Maria Chiara , Tetta Ciro , Bussolati Benedetta , Camussi Giovanni
Published: March 2024

Abstract
Recent studies suggest that tumor-derived microvesicles (MV) act as a vehicle for exchange of genetic information between tumor and stromal cells, engendering a favorable microenvironment for cancer development. Within the tumor mass, all cell types may contribute to MV shedding, but specific contributions to tumor progression have yet to be established. Here we report that a subset of tumor-initiating cells expressing the mesenchymal stem cell marker CD105 in human renal cell carcinoma releases MVs that trigger angiogenesis and promote the formation of a premetastatic niche. MVs derived only from CD105-positive cancer stem cells conferred an activated angiogenic phenotype to normal human endothelial cells, stimulating their growth and vessel formation after in vivo implantation in immunocompromised severe combined immunodeficient (SCID) mice. Furthermore, treating SCID mice with MVs shed from CD105-positive cells greatly enhanced lung metastases induced by i.v. injection of renal carcinoma cells. Molecular characterization of CD105-positive MVs defines a set of proangiogenic mRNAs and microRNAs implicated in tumor progression and metastases. Our results define a specific source of cancer stem cell–derived MVs that contribute to triggering the angiogenic switch and coordinating metastatic diffusion during tumor progression. Cancer Res; 71(15); 5346–56. ©2011 AACR.