bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from RNAi-Mediated Silencing of Myc Transcription Inhibits Stem-like Cell Maintenance and Tumorigenicity in Prostate Cancer
Authors: Civenni Gianluca , Malek Anastasia , Albino Domenico , Garcia-Escudero Ramon , Napoli Sara , Di Marco Stefano , Pinton Sandra , Sarti Manuela , Carbone Giuseppina M. , Catapano Carlo V.
Published: March 2024

Abstract
Several studies link disease progression, recurrence, and treatment failures to the cancer stem-like cell (CSC) subpopulation within the heterogeneous tumor cell population. Myc is a transcription factor having a central function in stem cell biology and in human cancers. Hence, Myc represents an attractive target to develop CSC-specific therapies. Recent findings suggest that Myc transcription can be silenced using an RNA interference (RNAi)–based strategy that targets noncoding promoter-associated RNA (paRNA) overlapping the transcription start site. In this study, we investigated the effects of silencing Myc transcription on prostate CSC in cell culture and xenograft models of human prostate cancer. Treatment with an effective promoter-targeting siRNA reduced the fraction of CSCs, leading to reduced self-renewal, tumor-initiating, and metastatic capability. Combined analysis of stem-like cells and senescence markers indicated that Myc silencing triggered a phenotypic shift and senescence in the CSC subpopulation. Notably, systemic delivery of the promoter-targeting siRNA in the xenograft model produced a striking suppression in the development of prostate tumors. Our results support a pivotal role for Myc in CSC maintenance and show that Myc targeting via RNAi-based transcriptional silencing can trigger CSC senescence and loss of their tumor-initiating capability. More generally, our findings demonstrate the efficacy of RNAi-based transcriptional strategies and the potential to target regulatory noncoding paRNAs for therapeutic applications. Cancer Res; 73(22); 6816–27. ©2013 AACR.
Data from Telomere Length and Telomerase Activity Impact the UV Sensitivity Syndrome Xeroderma Pigmentosum C
Authors: Stout Gerdine J. , Blasco Maria A.
Published: March 2024

Abstract
Xeroderma pigmentosum (XP), a UV-sensitivity syndrome characterized by skin hyperpigmentation, premature aging, and increased skin cancer, is caused by defects in the nucleotide excision repair (NER) pathway. XP shares phenotypical characteristics with telomere-associated diseases like Dyskeratosis congenita and mouse models with dysfunctional telomeres, including mice deficient for telomerase (Terc−/− mice). Thus, we investigated a hypothesized role for telomerase and telomere dysfunction in the pathobiology of XP by comparing Xpc−/−-mutant mice and Xpc−/−G1-G3Terc−/− double-mutant mice and exposed them to UV radiation. Chronically UV-exposed Xpc−/− skin displayed shorter telomeres on an average compared with wild-type skin. Strikingly, this effect was reversed by an additional deficiency in the telomerase. Moreover, aberrantly long telomeres were observed in the double-mutant mice. Telomere lengthening in the absence of telomerase suggested activation of the alternative lengthening of telomeres (ALT) in the UV-exposed skin of the double mutants. Mechanistic investigations revealed an elevated susceptibility for UV-induced p53 patches, known to represent precursor lesions of carcinomas, in Xpc−/−G1-G3Terc−/− mice where a high number of UV-induced skin tumors occurred that were characterized by aggressive growth. Taken together, our results establish a role for xeroderma pigmentosum, complementation group C (XPC) in telomere stability, particularly upon UV exposure. In absence of telomerase, critically short telomeres in XP mutants seem to aggravate this pathology, associated with an increased tumor incidence, by activating the ALT pathway of telomere lengthening. Cancer Res; 73(6); 1844–54. ©2012 AACR.
Data from Dysregulation of Cholesterol Homeostasis in Human Prostate Cancer through Loss of ABCA1
Authors: Lee Byron H. , Taylor Margaret G. , Robinet Peggy , Smith Jonathan D. , Schweitzer Jessica , Sehayek Ephraim , Falzarano Sara M. , Magi-Galluzzi Cristina , Klein Eric A. , Ting Angela H.
Published: March 2024

Abstract
Recent epidemiologic data show that low serum cholesterol level as well as statin use is associated with a decreased risk of developing aggressive or advanced prostate cancer, suggesting a role for cholesterol in aggressive prostate cancer development. Intracellular cholesterol promotes prostate cancer progression as a substrate for de novo androgen synthesis and through regulation of AKT signaling. By conducting next-generation sequencing–based DNA methylome analysis, we have discovered marked hypermethylation at the promoter of the major cellular cholesterol efflux transporter, ABCA1, in LNCaP prostate cancer cells. ABCA1 promoter hypermethylation renders the promoter unresponsive to transactivation and leads to elevated cholesterol levels in LNCaP. ABCA1 promoter hypermethylation is enriched in intermediate- to high-grade prostate cancers and not detectable in benign prostate. Remarkably, ABCA1 downregulation is evident in all prostate cancers examined, and expression levels are inversely correlated with Gleason grade. Our results suggest that cancer-specific ABCA1 hypermethylation and loss of protein expression direct high intracellular cholesterol levels and hence contribute to an environment conducive to tumor progression. Cancer Res; 73(3); 1211–8. ©2012 AACR.
Data from CCR2 Deficiency Prevents Neuronal Dysfunction and Cognitive Impairments Induced by Cranial Irradiation
Authors: Belarbi Karim , Jopson Timothy , Arellano Carla , Fike John R. , Rosi Susanna
Published: March 2024

Abstract
Cranial irradiation can lead to long-lasting cognitive impairments in patients receiving radiotherapy for the treatment of malignant brain tumors. Recent studies have suggested inflammation as a major contributor to these deficits; we determined if the chemokine (C–C motif) receptor 2 (CCR2) was a mediator of cognitive impairments induced by irradiation. Two-month-old male Ccr2 knockout (−/−) and wild-type mice received 10 Gy cranial irradiation or sham-treatment. One month after irradiation, bromodeoxyuridine was injected intraperitoneally for seven consecutive days to label newly generated cells. At two months postirradiation, cognitive function was assessed by novel object recognition and Morris water maze. Our results show that CCR2 deficiency prevented hippocampus-dependent spatial learning and memory impairments induced by cranial irradiation. Hippocampal gene expression analysis showed that irradiation induced CCR2 ligands such as CCL8 and CCR2 deficiency reduced this induction. Irradiation reduced the number of adult-born neurons in both wild-type and Ccr2−/− mice, but the distribution pattern of the adult-born neurons through the granule cell layer was only altered in wild-type mice. Importantly, CCR2 deficiency normalized the fraction of pyramidal neurons expressing the plasticity-related immediate early gene Arc. These data offer new insight into the mechanism(s) of radiation-injury and suggest that CCR2 is a critical mediator of hippocampal neuronal dysfunction and hippocampal cognitive impairments after irradiation. Targeting CCR2 signaling could conceivably provide an effective approach to reduce or prevent the incidence and severity of this serious side effect of ionizing irradiation. Cancer Res; 73(3); 1201–10. ©2012 AACR.
Data from CLPTM1L Promotes Growth and Enhances Aneuploidy in Pancreatic Cancer Cells
Authors: Jia Jinping , Bosley Allen D. , Thompson Abbey , Hoskins Jason W. , Cheuk Adam , Collins Irene , Parikh Hemang , Xiao Zhen , Ylaya Kris , Dzyadyk Marta , Cozen Wendy , Hernandez Brenda Y. , Lynch Charles F. , Loncarek Jadranka , Altekruse Sean F. , Zhang Lizhi , Westlake Christopher J. , Factor Valentina M. , Thorgeirsson Snorri , Bamlet William R. , Hewitt Stephen M. , Petersen Gloria M. , Andresson Thorkell , Amundadottir Laufey T.
Published: March 2024

Abstract
Genome-wide association studies (GWAS) of 10 different cancers have identified pleiotropic cancer predisposition loci across a region of chromosome 5p15.33 that includes the TERT and CLPTM1L genes. Of these, susceptibility alleles for pancreatic cancer have mapped to the CLPTM1L gene, thus prompting an investigation of the function of CLPTM1L in the pancreas. Immunofluorescence analysis indicated that CLPTM1L localized to the endoplasmic reticulum where it is likely embedded in the membrane, in accord with multiple predicted transmembrane domains. Overexpression of CLPTM1L enhanced growth of pancreatic cancer cells in vitro (1.3–1.5–fold; PDAY7 < 0.003) and in vivo (3.46-fold; PDAY68 = 0.039), suggesting a role in tumor growth; this effect was abrogated by deletion of two hydrophilic domains. Affinity purification followed by mass spectrometry identified an interaction between CLPTM1L and non-muscle myosin II (NMM-II), a protein involved in maintaining cell shape, migration, and cytokinesis. The two proteins colocalized in the cytoplasm and, after treatment with a DNA-damaging agent, at the centrosomes. Overexpression of CLPTM1L and depletion of NMM-II induced aneuploidy, indicating that CLPTM1L may interfere with normal NMM-II function in regulating cytokinesis. Immunohistochemical analysis revealed enhanced staining of CLPTM1L in human pancreatic ductal adenocarcinoma (n = 378) as compared with normal pancreatic tissue samples (n = 17; P = 1.7 × 10−4). Our results suggest that CLPTM1L functions as a growth-promoting gene in the pancreas and that overexpression may lead to an abrogation of normal cytokinesis, indicating that it should be considered as a plausible candidate gene that could explain the effect of pancreatic cancer susceptibility alleles on chr5p15.33. Cancer Res; 74(10); 2785–95. ©2014 AACR.
Data from STC1 Expression By Cancer-Associated Fibroblasts Drives Metastasis of Colorectal Cancer
Authors: Peña Cristina , Céspedes María Virtudes , Lindh Maja Bradic , Kiflemariam Sara , Mezheyeuski Artur , Edqvist Per-Henrik , Hägglöf Christina , Birgisson Helgi , Bojmar Linda , Jirström Karin , Sandström Per , Olsson Eleonor , Veerla Srinivas , Gallardo Alberto , Sjöblom Tobias , Chang Andy C.-M. , Reddel Roger R. , Mangues Ramón , Augsten Martin , Östman Arne
Published: March 2024

Abstract
Platelet-derived growth factor (PDGF) receptor signaling is a major functional determinant of cancer-associated fibroblasts (CAF). Elevated expression of PDGF receptors on stromal CAFs is associated with metastasis and poor prognosis, but mechanism(s) that underlie these connections are not understood. Here, we report the identification of the secreted glycoprotein stanniocalcin-1 (STC1) as a mediator of metastasis by PDGF receptor function in the setting of colorectal cancer. PDGF-stimulated fibroblasts increased migration and invasion of cocultured colorectal cancer cells in an STC1-dependent manner. Analyses of human colorectal cancers revealed significant associations between stromal PDGF receptor and STC1 expression. In an orthotopic mouse model of colorectal cancer, tumors formed in the presence of STC1-deficient fibroblasts displayed reduced intravasation of tumor cells along with fewer and smaller distant metastases formed. Our results reveal a mechanistic basis for understanding the contribution of PDGF-activated CAFs to cancer metastasis. Cancer Res; 73(4); 1287–97. ©2012 AACR.
Data from Silencing of the miR-17∼92 Cluster Family Inhibits Medulloblastoma Progression
Authors: Murphy Brian L. , Obad Susanna , Bihannic Laure , Ayrault Olivier , Zindy Frederique , Kauppinen Sakari , Roussel Martine F.
Published: March 2024

Abstract
Medulloblastoma, originating in the cerebellum, is the most common malignant brain tumor in children. Medulloblastoma consists of four major groups where constitutive activation of the Sonic Hedgehog (SHH) signaling pathway is a hallmark of one group. Mouse and human SHH medulloblastomas exhibit increased expression of microRNAs encoded by the miR-17∼92 and miR-106b∼25 clusters compared with granule progenitors and postmitotic granule neurons. Here, we assessed the therapeutic potential of 8-mer seed-targeting locked nucleic acid (LNA)-modified anti-miR oligonucleotides, termed tiny LNAs, that inhibit microRNA seed families expressed by miR-17∼92 and miR-106b∼25 in two mouse models of SHH medulloblastomas. We found that tumor cells (medulloblastoma cells) passively took up 8-mer LNA-anti-miRs and specifically inhibited targeted microRNA seed-sharing family members. Inhibition of miR-17 and miR-19a seed families by anti-miR-17 and anti-miR-19, respectively, resulted in diminished tumor cell proliferation in vitro. Treatment of mice with systemic delivery of anti-miR-17 and anti-miR-19 reduced tumor growth in flank and brain allografts in vivo and prolonged the survival of mice with intracranial transplants, suggesting that inhibition of the miR-17∼92 cluster family by 8-mer LNA-anti-miRs might be considered for the treatment of SHH medulloblastomas. Cancer Res; 73(23); 7068–78. ©2013 AACR.
Data from API5 Confers Tumoral Immune Escape through FGF2-Dependent Cell Survival Pathway
Authors: Noh Kyung Hee , Kim Seok-Ho , Kim Jin Hee , Song Kwon-Ho , Lee Young-Ho , Kang Tae Heung , Han Hee Dong , Sood Anil K. , Ng Joanne , Kim Kwanghee , Sonn Chung Hee , Kumar Vinay , Yee Cassian , Lee Kyung-Mi , Kim Tae Woo
Published: March 2024

Abstract
Identifying immune escape mechanisms used by tumors may define strategies to sensitize them to immunotherapies to which they are otherwise resistant. In this study, we show that the antiapoptotic gene API5 acts as an immune escape gene in tumors by rendering them resistant to apoptosis triggered by tumor antigen-specific T cells. Its RNAi-mediated silencing in tumor cells expressing high levels of API5 restored antigen-specific immune sensitivity. Conversely, introducing API5 into API5low cells conferred immune resistance. Mechanistic investigations revealed that API5 mediated resistance by upregulating FGF2 signaling through a FGFR1/PKCδ/ERK effector pathway that triggered degradation of the proapoptotic molecule BIM. Blockade of FGF2, PKCδ, or ERK phenocopied the effect of API5 silencing in tumor cells expressing high levels of API5 to either murine or human antigen-specific T cells. Our results identify a novel mechanism of immune escape that can be inhibited to potentiate the efficacy of targeted active immunotherapies. Cancer Res; 74(13); 3556–66. ©2014 AACR.
Data from ATR Pathway Inhibition Is Synthetically Lethal in Cancer Cells with ERCC1 Deficiency
Authors: Mohni Kareem N. , Kavanaugh Gina M. , Cortez David
Published: March 2024

Abstract
The DNA damage response kinase ATR and its effector kinase CHEK1 are required for cancer cells to survive oncogene-induced replication stress. ATR inhibitors exhibit synthetic lethal interactions, with deficiencies in the DNA damage response enzymes ATM and XRCC1 and with overexpression of the cell cycle kinase cyclin E. Here, we report a systematic screen to identify synthetic lethal interactions with ATR pathway–targeted drugs, rationalized by their predicted therapeutic utility in the oncology clinic. We found that reduced function in the ATR pathway itself provided the strongest synthetic lethal interaction. In addition, we found that loss of the structure-specific endonuclease ERCC1-XPF (ERCC4) is synthetic lethal with ATR pathway inhibitors. ERCC1-deficient cells exhibited elevated levels of DNA damage, which was increased further by ATR inhibition. When treated with ATR or CHEK1 inhibitors, ERCC1-deficient cells were arrested in S-phase and failed to complete cell-cycle transit even after drug removal. Notably, triple-negative breast cancer cells and non–small cell lung cancer cells depleted of ERCC1 exhibited increased sensitivity to ATR pathway–targeted drugs. Overall, we concluded that ATR pathway–targeted drugs may offer particular utility in cancers with reduced ATR pathway function or reduced levels of ERCC4 activity. Cancer Res; 74(10); 2835–45. ©2014 AACR.
Data from Stalling the Engine of Resistance: Targeting Cancer Metabolism to Overcome Therapeutic Resistance
Authors: Butler Ethan B. , Zhao Yuhua , Muñoz-Pinedo Cristina , Lu Jianrong , Tan Ming
Published: March 2024

Abstract
Cancer cells are markedly different from normal cells with regards to how their metabolic pathways are used to fuel cellular growth and survival. Two basic metabolites that exemplify these differences through increased uptake and altered metabolic usage are glucose and glutamine. These molecules can be catabolized to manufacture many of the building blocks required for active cell growth and proliferation. The alterations in the metabolic pathways necessary to sustain this growth have been linked to therapeutic resistance, a trait that is correlated with poor patient outcomes. By targeting the metabolic pathways that import, catabolize, and synthesize essential cellular components, drug-resistant cancer cells can often be resensitized to anticancer treatments. The specificity and efficacy of agents directed at the unique aspects of cancer metabolism are expected to be high; and may, when in used in combination with more traditional therapeutics, present a pathway to surmount resistance within tumors that no longer respond to current forms of treatment. Cancer Res; 73(9); 2709–17. ©2013 AACR.
Data from Id-1 Is a Key Transcriptional Regulator of Glioblastoma Aggressiveness and a Novel Therapeutic Target
Authors: Soroceanu Liliana , Murase Ryuichi , Limbad Chandani , Singer Eric , Allison Juanita , Adrados Isabel , Kawamura Rumi , Pakdel Arash , Fukuyo Yayoi , Nguyen Daniel , Khan Sabeena , Arauz Robert , Yount Garret L. , Moore Dan H. , Desprez Pierre-Yves , McAllister Sean D.
Published: March 2024

Abstract
Glioblastoma is the most common form of primary adult brain tumors. A majority of glioblastomas grow invasively into distant brain tissue, leading to tumor recurrence, which is ultimately incurable. It is, therefore, essential to discover master regulators that control glioblastoma invasiveness and target them therapeutically. We show here that the transcriptional regulator Id-1 plays a critical role in modulating the invasiveness of glioblastoma cell lines and primary glioblastoma cells. Id-1 expression levels positively correlate with glioma cell invasiveness in culture and with histopathologic grades in patient biopsies. Id-1 knockdown dramatically reduces glioblastoma cell invasion that is accompanied by profound morphologic changes and robust reduction in expression levels of “mesenchymal” markers, as well as inhibition of self-renewal potential and downregulation of glioma stem cell markers. Importantly, genetic knockdown of Id-1 leads to a significant increase in survival in an orthotopic model of human glioblastoma. Furthermore, we show that a nontoxic compound, cannabidiol, significantly downregulates Id-1 gene expression and associated glioma cell invasiveness and self-renewal. In addition, cannabidiol significantly inhibits the invasion of glioblastoma cells through an organotypic brain slice and glioma progression in vivo. Our results suggest that Id-1 regulates multiple tumor-promoting pathways in glioblastoma and that drugs targeting Id-1 represent a novel and promising strategy for improving the therapy and outcome of patients with glioblastoma. Cancer Res; 73(5); 1559–69. ©2012 AACR.
Data from CDK4/6 and IGF1 Receptor Inhibitors Synergize to Suppress the Growth of p16INK4A-Deficient Pancreatic Cancers
Authors: Heilmann Andreas M. , Perera Rushika M. , Ecker Veronika , Nicolay Brandon N. , Bardeesy Nabeel , Benes Cyril H. , Dyson Nicholas J.
Published: March 2024

Abstract
Loss-of-function mutations in p16INK4A (CDKN2A) occur in approximately 80% of sporadic pancreatic ductal adenocarcinoma (PDAC), contributing to its early progression. Although this loss activates the cell-cycle–dependent kinases CDK4/6, which have been considered as drug targets for many years, p16INK4A-deficient PDAC cells are inherently resistant to CDK4/6 inhibitors. This study searched for targeted therapies that might synergize with CDK4/6 inhibition in this setting. We report that the IGF1R/IR inhibitor BMS-754807 cooperated with the CDK4/6 inhibitor PD-0332991 to strongly block proliferation of p16INK4A-deficient PDAC cells in vitro and in vivo. Sensitivity to this drug combination correlated with reduced activity of the master cell growth regulator mTORC1. Accordingly, replacing the IGF1R/IR inhibitor with the rapalog inhibitor temsirolimus broadened the sensitivity of PDAC cells to CDK4/6 inhibition. Our results establish targeted therapy combinations with robust cytostatic activity in p16INK4A-deficient PDAC cells and possible implications for improving treatment of a broad spectrum of human cancers characterized by p16INK4A loss. Cancer Res; 74(14); 3947–58. ©2014 AACR.
Data from Genetic Amplification of the NOTCH Modulator LNX2 Upregulates the WNT/β-Catenin Pathway in Colorectal Cancer
Authors: Camps Jordi , Pitt Jason J. , Emons Georg , Hummon Amanda B. , Case Chanelle M. , Grade Marian , Jones Tamara L. , Nguyen Quang T. , Ghadimi B. Michael , Beissbarth Tim , Difilippantonio Michael J. , Caplen Natasha J. , Ried Thomas
Published: March 2024

Abstract
Chromosomal copy number alterations (aneuploidy) define the genomic landscape of most cancer cells, but identification of the oncogenic drivers behind these imbalances remains an unfinished task. In this study, we conducted a systematic analysis of colorectal carcinomas that integrated genomic copy number changes and gene expression profiles. This analysis revealed 44 highly overexpressed genes mapping to localized amplicons on chromosome 13, gains of which occur often in colorectal cancers (CRC). RNA interference (RNAi)–mediated silencing identified eight candidates whose loss-of-function reduced cell viability 20% or more in CRC cell lines. The functional space of the genes NUPL1, LNX2, POLR1D, POMP, SLC7A1, DIS3, KLF5, and GPR180 was established by global expression profiling after RNAi exposure. One candidate, LNX2, not previously known as an oncogene, was involved in regulating NOTCH signaling. Silencing LNX2 reduced NOTCH levels but also downregulated the transcription factor TCF7L2 and markedly reduced WNT signaling. LNX2 overexpression and chromosome 13 amplification therefore constitutively activates the WNT pathway, offering evidence of an aberrant NOTCH–WNT axis in CRC. Cancer Res; 73(6); 2003–13. ©2012 AACR.
Data from Prooncogenic Factors miR-23b and miR-27b Are Regulated by Her2/Neu, EGF, and TNF-α in Breast Cancer
Authors: Jin Lianjin , Wessely Oliver , Marcusson Eric G. , Ivan Cristina , Calin George A. , Alahari Suresh K.
Published: March 2024

Abstract
miRNAs (miR) are a critical class of small (21–25 nucleotides) noncoding endogenous RNAs implicated in gene expression regulation. We identified miR-23b and miR-27b as miRNAs that are highly upregulated in human breast cancer. We found that engineered knockdown of miR-23b and miR-27b substantially repressed breast cancer growth. Nischarin (NISCH) expression was augmented by knockdown of miR-23b as well as miR-27b. Notably, these miRNAs and Nischarin were inversely expressed in human breast cancers, underscoring their biologic relevance. We showed the clinical relevance of the expression of these miRNAs and showed that high expression of miR-23b and miR-27b correlates with poor outcome in breast cancer. Moreover, intraperitoneally delivered anti-miR-27b restored Nischarin expression and decreased tumor burden in a mouse xenograft model of human mammary tumor. Also, we report for the first time that HER2/neu (ERBB2), EGF, and TNF-α promote miR-23b/27b expression through the AKT/NF-κB signaling cascade. Nischarin was found to regulate miR-27b/23b expression through a feedback loop mechanism by suppressing NF-κB phosphorylation. Because anti-miR-27b compounds that suppress miR-27b inhibit tumor growth, the anti-miR-27b seems to be a good candidate for the development of new antitumor therapies. Cancer Res; 73(9); 2884–96. ©2013 AACR.
Data from Erlotinib Prolongs Survival in Pancreatic Cancer by Blocking Gemcitabine-Induced MAPK Signals
Authors: Miyabayashi Koji , Ijichi Hideaki , Mohri Dai , Tada Motohisa , Yamamoto Keisuke , Asaoka Yoshinari , Ikenoue Tsuneo , Tateishi Keisuke , Nakai Yousuke , Isayama Hiroyuki , Morishita Yasuyuki , Omata Masao , Moses Harold L. , Koike Kazuhiko
Published: March 2024

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is one of the most deadly cancers worldwide. Although many regimens have been used for PDAC treatment, the combination of the EGF receptor (EGFR) inhibitor erlotinib with gemcitabine has been the only molecular-targeted drug tested so far that has been superior to gemcitabine alone. The mechanism underlying this effective combinational regimen remains unknown. Here, we show that the combination is superior to gemcitabine alone in blocking progression and prolonging survival in a murine model of PDAC (Kras activation with Tgfbr2 knockout). We found that gemcitabine induced mitogen-activated protein kinase signaling, which was dramatically inhibited by erlotinib even in the Kras-activated PDAC cells in the mouse model. Mechanistic investigations suggested that gemcitabine induces EGFR ligand expression and ERBB2 activation by increasing heterodimer formation with EGFR, thereby maintaining high levels of ERBB2 protein in PDAC cells. Overall, our findings suggest a significant role of ERBB in PDAC treatment. Cancer Res; 73(7); 2221–34. ©2013 AACR.
Data from Deficiency of Phospholipase A2 Group 7 Decreases Intestinal Polyposis and Colon Tumorigenesis in ApcMin/+ Mice
Authors: Xu Changxin , Reichert Ethan C. , Nakano Tomoyuki , Lohse Mariah , Gardner Alison A. , Revelo Mónica P. , Topham Matthew K. , Stafforini Diana M.
Published: March 2024

Abstract
Platelet-activating factor (PAF) is a naturally occurring phospholipid that mediates diverse effects such as physiological and pathological inflammation, immunosuppression, and cancer. Several lines of evidence support both positive and negative roles for PAF in carcinogenesis. PAF stimulates cell growth, oncogenic transformation, and metastasis, but can also limit proliferation and induce apoptosis. The biological context and microenvironment seem to define whether PAF has pro- or anticarcinogenic effects. To investigate the role of exacerbated PAF signaling in colon cancer, we conducted cell-based and in vivo studies using genetically engineered mice lacking expression of phospholipase A2 group 7 (PLA2G7), an enzyme that specifically metabolizes PAF and structurally related glycerophospholipids. Absence of Pla2g7 robustly decreased intestinal polyposis and colon tumor formation in ApcMin/+ mice, suggesting an antitumorigenic role for PAF in settings characterized by aberrant function of the tumor suppressor Adenomatous polyposis coli (Apc). In colonic epithelial cells, exposure to a PAF analog led to dephosphorylation of Akt at serine-473 and induction of apoptosis. The mechanism of this response involved formation of a complex between β-arrestin 1 and the Akt phosphatase PHLPP2, and activation of the intrinsic pathway of apoptosis. Our results suggest that strategies based on inhibiting PLA2G7 activity or increasing PAF-mediated signaling hold promise for the treatment of intestinal malignancies that harbor mutations in APC. Cancer Res; 73(9); 2806–16. ©2013 AACR.
Data from Targeting Mitochondrial Oxidative Metabolism in Melanoma Causes Metabolic Compensation through Glucose and Glutamine Utilization
Authors: Lim Ji-Hong , Luo Chi , Vazquez Francisca , Puigserver Pere
Published: March 2024

Abstract
Metabolic targets offer attractive opportunities for cancer therapy. However, their targeting may activate alternative metabolic pathways that can still support tumor growth. A subset of human melanomas relies on PGC1α-dependent mitochondrial oxidative metabolism to maintain growth and survival. Herein, we show that loss of viability caused by suppression of PGC1α in these melanomas is rescued by induction of glycolysis. Suppression of PGC1α elevates reactive oxygen species levels decreasing hypoxia-inducible factor-1α (HIF1α) hydroxylation that, in turn, increases its protein stability. HIF1α reprograms melanomas to become highly glycolytic and dependent on this pathway for survival. Dual suppression of PGC1α and HIF1α causes energetic deficits and loss of viability that are partially compensated by glutamine utilization. Notably, triple suppression of PGC1α, HIF1α, and glutamine utilization results in complete blockage of tumor growth. These results show that due to high metabolic and bioenergetic flexibility, complete treatment of melanomas will require combinatorial therapy that targets multiple metabolic components. Cancer Res; 74(13); 3535–45. ©2014 AACR.
Data from Bcl3 Selectively Promotes Metastasis of ERBB2-Driven Mammary Tumors
Authors: Wakefield Alison , Soukupova Jitka , Montagne Amelie , Ranger Jill , French Rhiannon , Muller William J. , Clarkson Richard W. E.
Published: March 2024

Abstract
Bcl3 is a putative proto-oncogene deregulated in hematopoietic and solid tumors. Studies in cell lines suggest that its oncogenic effects are mediated through the induction of proliferation and inhibition of cell death, yet its role in endogenous solid tumors has not been established. Here, we address the oncogenic effect of Bcl3 in vivo and describe how this Stat3-responsive oncogene promotes metastasis of ErbB2-positive mammary tumors without affecting primary tumor growth or normal mammary function. Deletion of the Bcl3 gene in ErbB2-positive (MMTV-Neu) mice resulted in a 75% reduction in metastatic tumor burden in the lungs with a 3.6-fold decrease in cell turnover index in these secondary lesions with no significant effect on primary mammary tumor growth, cyclin D1 levels, or caspase-3 activity. Direct inhibition of Bcl3 by siRNA in a transplantation model of an Erbb2-positive mammary tumor cell line confirmed the effect of Bcl3 in malignancy, suggesting that the effect of Bcl3 was intrinsic to the tumor cells. Bcl3 knockdown resulted in a 61% decrease in tumor cell motility and a concomitant increase in the cell migration inhibitors Nme1, Nme2, and Nme3, the GDP dissociation inhibitor Arhgdib, and the metalloprotease inhibitors Timp1 and Timp2. Independent knockdown of Nme1, Nme2, and Arhgdib partially rescued the Bcl3 motility phenotype. These results indicate for the first time a cell-autonomous disease-modifying role for Bcl3 in vivo, affecting metastatic disease progression rather than primary tumor growth. Cancer Res; 73(2); 745–55. ©2012 AACR.
Data from LOX-Mediated Collagen Crosslinking Is Responsible for Fibrosis-Enhanced Metastasis
Authors: Cox Thomas R. , Bird Demelza , Baker Ann-Marie , Barker Holly E. , Ho Melisa W-Y. , Lang Georgina , Erler Janine T.
Published: March 2024

Abstract
Tumor metastasis is a highly complex, dynamic, and inefficient process involving multiple steps, yet it accounts for more than 90% of cancer-related deaths. Although it has long been known that fibrotic signals enhance tumor progression and metastasis, the underlying molecular mechanisms are still unclear. Identifying events involved in creating environments that promote metastatic colonization and growth are critical for the development of effective cancer therapies. Here, we show a critical role for lysyl oxidase (LOX) in establishing a milieu within fibrosing tissues that is favorable to growth of metastastic tumor cells. We show that LOX-dependent collagen crosslinking is involved in creating a growth-permissive fibrotic microenvironment capable of supporting metastatic growth by enhancing tumor cell persistence and survival. We show that therapeutic targeting of LOX abrogates not only the extent to which fibrosis manifests, but also prevents fibrosis-enhanced metastatic colonization. Finally, we show that the LOX-mediated collagen crosslinking directly increases tumor cell proliferation, enhancing metastatic colonization and growth manifesting in vivo as increased metastasis. This is the first time that crosslinking of collagen I has been shown to enhance metastatic growth. These findings provide an important link between ECM homeostasis, fibrosis, and cancer with important clinical implications for both the treatment of fibrotic disease and cancer. Cancer Res; 73(6); 1721–32. ©2012 AACR.
Data from Mechanisms Promoting Escape from Mitotic Stress–Induced Tumor Cell Death
Authors: Sinnott Rebecca , Winters Leah , Larson Brittany , Mytsa Daniela , Taus Patrick , Cappell Kathryn M. , Whitehurst Angelique W.
Published: March 2024

Abstract
Non–small cell lung cancer (NSCLC) is notorious for its paltry responses to first-line therapeutic regimens. In contrast to acquired chemoresistance, little is known about the molecular underpinnings of the intrinsic resistance of chemo-naïve NSCLC. Here we report that intrinsic resistance to paclitaxel in NSCLC occurs at a cell-autonomous level because of the uncoupling of mitotic defects from apoptosis. To identify components that permit escape from mitotic stress–induced death, we used a genome-wide RNAi-based strategy, which combines a high-throughput toxicity screen with a live-cell imaging platform to measure mitotic fate. This strategy revealed that prolonging mitotic arrest with a small molecule inhibitor of the APC/cyclosome could sensitize otherwise paclitaxel-resistant NSCLC. We also defined novel roles for CASC1 and TRIM69 in supporting resistance to spindle poisons. CASC1, which is frequently co-amplified with KRAS in lung tumors, is essential for microtubule polymerization and satisfaction of the spindle assembly checkpoint. TRIM69, which associates with spindle poles and promotes centrosomal clustering, is essential for formation of a bipolar spindle. Notably, RNAi-mediated attenuation of CASC1 or TRIM69 was sufficient to inhibit tumor growth in vivo. On the basis of our results, we hypothesize that tumor evolution selects for a permissive mitotic checkpoint, which may promote survival despite chromosome segregation errors. Attacking this adaptation may restore the apoptotic consequences of mitotic damage to permit the therapeutic eradication of drug-resistant cancer cells. Cancer Res; 74(14); 3857–69. ©2014 AACR.
Data from CHD7 Expression Predicts Survival Outcomes in Patients with Resected Pancreatic Cancer
Authors: Colbert Lauren E. , Petrova Aleksandra V. , Fisher Sarah B. , Pantazides Brooke G. , Madden Matthew Z. , Hardy Claire W. , Warren Matthew D. , Pan Yunfeng , Nagaraju Ganji P. , Liu Elaine A. , Saka Burcu , Hall William A. , Shelton Joseph W. , Gandhi Khanjan , Pauly Rini , Kowalski Jeanne , Kooby David A. , El-Rayes Bassel F. , Staley Charles A. , Adsay N. Volkan , Curran Walter J. , Landry Jerome C. , Maithel Shishir K. , Yu David S.
Published: March 2024

Abstract
Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with poor outcomes with current therapies. Gemcitabine is the primary adjuvant drug used clinically, but its effectiveness is limited. In this study, our objective was to use a rationale-driven approach to identify novel biomarkers for outcome in patients with early-stage resected PDAC treated with adjuvant gemcitabine. Using a synthetic lethal screen in human PDAC cells, we identified 93 genes, including 55 genes linked to DNA damage responses (DDR), that demonstrated gemcitabine sensitization when silenced, including CHD7, which functions in chromatin remodeling. CHD7 depletion sensitized PDAC cells to gemcitabine and delayed their growth in tumor xenografts. Moreover, CHD7 silencing impaired ATR-dependent phosphorylation of CHK1 and increased DNA damage induced by gemcitabine. CHD7 was dysregulated, ranking above the 90th percentile in differential expression in a panel of PDAC clinical specimens, highlighting its potential as a biomarker. Immunohistochemical analysis of specimens from 59 patients with resected PDAC receiving adjuvant gemcitabine revealed that low CHD7 expression was associated with increased recurrence-free survival (RFS) and overall survival (OS), in univariate and multivariate analyses. Notably, CHD7 expression was not associated with RFS or OS for patients not receiving gemcitabine. Thus, low CHD7 expression was correlated selectively with gemcitabine sensitivity in this patient population. These results supported our rationale-driven strategy to exploit dysregulated DDR pathways in PDAC to identify genetic determinants of gemcitabine sensitivity, identifying CHD7 as a novel biomarker candidate to evaluate further for individualizing PDAC treatment. Cancer Res; 74(10); 2677–87. ©2014 AACR.
Data from Mislocalization of the Cell Polarity Protein Scribble Promotes Mammary Tumorigenesis and Is Associated with Basal Breast Cancer
Authors: Feigin Michael E. , Akshinthala S. Dipikaa , Araki Kiyomi , Rosenberg Avi Z. , Muthuswamy Lakshmi B. , Martin Bernard , Lehmann Brian D. , Berman Hal K. , Pietenpol Jennifer A. , Cardiff Robert D. , Muthuswamy Senthil K.
Published: March 2024

Abstract
Scribble (SCRIB) localizes to cell–cell junctions and regulates establishment of epithelial cell polarity. Loss of expression of SCRIB functions as a tumor suppressor in Drosophila and mammals; conversely, overexpression of SCRIB promotes epithelial differentiation in mammals. Here, we report that SCRIB is frequently amplified, mRNA overexpressed, and protein is mislocalized from cell–cell junctions in human breast cancers. High levels of SCRIB mRNA are associated with poor clinical prognosis, identifying an unexpected role for SCRIB in breast cancer. We find that transgenic mice expressing a SCRIB mutant [Pro 305 to Leu (P305L)] that fails to localize to cell–cell junctions, under the control of the mouse mammary tumor virus long terminal repeat promoter, develop multifocal hyperplasia that progresses to highly pleomorphic and poorly differentiated tumors with basal characteristics. SCRIB interacts with phosphatase and tensin homolog (PTEN) and the expression of P305L, but not wild-type SCRIB, promotes an increase in PTEN levels in the cytosol. Overexpression of P305L, but not wild-type SCRIB, activates the Akt/mTOR/S6K signaling pathway. Human breast tumors overexpressing SCRIB have high levels of S6K but do not harbor mutations in PTEN or PIK3CA, identifying SCRIB amplification as a mechanism of activating PI3K signaling in tumors without mutations in PIK3CA or PTEN. Thus, we demonstrate that high levels of mislocalized SCRIB functions as a neomorph to promote mammary tumorigenesis by affecting subcellular localization of PTEN and activating an Akt/mTOR/S6kinase signaling pathway. Cancer Res; 74(11); 3180–94. ©2014 AACR.
Data from HLA-Restricted CTL That Are Specific for the Immune Checkpoint Ligand PD-L1 Occur with High Frequency in Cancer Patients
Authors: Munir Shamaila , Andersen Gitte Holmen , Met Özcan , Donia Marco , Frøsig Thomas Mørch , Larsen Stine Kiaer , Klausen Tobias Wirenfeldt , Svane Inge Marie , Andersen Mads Hald
Published: March 2024

Abstract
PD-L1 (CD274) contributes to functional exhaustion of T cells and limits immune responses in patients with cancer. In this study, we report the identification of an human leukocyte antigen (HLA)-A2–restricted epitope from PD-L1, and we describe natural, cytolytic T-cell reactivity against PD-L1 in the peripheral blood of patients with cancer and healthy individuals. Notably, PD-L1–specific T cells were able not only to recognize and kill tumor cells but also PD-L1–expressing dendritic cells in a PD-L1–dependent manner, insofar as PD-L1 ablation rescued dendritic cells from killing. Furthermore, by incubating nonprofessional antigen-presenting cells with long peptides from PD-L1, we found that PD-L1 was rapidly internalized, processed, and cross-presented by HLA-A2 on the cell surface. Apparently, this cross-presentation was TAP-independent, as it was conducted not only by B cells but in addition by TAP-deficient T2-cells. This is intriguing, as soluble PD-L1 has been detected in the sera from patients with cancer. PD-L1–specific CTL may boost immunity by the killing of immunosuppressive tumor cells as well as regulatory cells. However, PD-L1–specific CTLs may as well suppress immunity by the elimination of normal immune cells especially PD-L1 expressing mature dendritic cells. Cancer Res; 73(6); 1764–76. ©2012 AACR.
Data from Chromosome Instability Modulated by BMI1–AURKA Signaling Drives Progression in Head and Neck Cancer
Authors: Chou Chun-Hung , Yang Neng-Kai , Liu Ting-Yun , Tai Shyh-Kuan , Hsu Dennis Shin-Shian , Chen Ya-Wei , Chen Yann-Jang , Chang Cheng-Chi , Tzeng Cheng-Hwai , Yang Muh-Hwa
Published: March 2024

Abstract
Chromosomal instability (CIN) is widely considered a hallmark of cancer, but its precise roles in cancer stem cells (CSC) and malignant progression remain uncertain. BMI1 is a member of the Polycomb group of chromatin-modifier proteins that is essential for stem cell self-renewal. In human cancers, BMI1 overexpression drives stem-like properties associated with induction of epithelial–mesenchymal transition (EMT) that promotes invasion, metastasis, and poor prognosis. Here, we report that BMI1 mediates its diverse effects through upregulation of the mitotic kinase Aurora A, which is encoded by the AURKA gene. Two mechanisms were found to be responsible for BMI1-induced AURKA expression. First, BMI1 activated the Akt pathway, thereby upregulating AURKA expression through activation of the β-catenin/TCF4 transcription factor complex. Second, BMI1 repressed miRNA let-7i through a Polycomb complex-dependent mechanism, thereby relieving AURKA expression from let-7i suppression. AURKA upregulation by BMI1 exerts several effects, including centrosomal amplification and aneuploidy, antiapoptosis, and cell-cycle progression through p53 degradation and EMT through stabilization of Snail. Inhibiting Aurora A kinase activity attenuated BMI1-induced tumor growth in vivo. In clinical specimens of head and neck cancer, we found that coamplification of BMI1 and AURKA correlated with poorer prognosis. Together, our results link CSCs, EMT, and CIN through the BMI1–AURKA axis and suggest therapeutic use from inhibiting Aurora A in head and neck cancers, which overexpress BMI1. Cancer Res; 73(2); 953–66. ©2012 AACR.
Data from Novel Mechanism of MDA-7/IL-24 Cancer-Specific Apoptosis through SARI Induction
Authors: Dash Rupesh , Bhoopathi Praveen , Das Swadesh K. , Sarkar Siddik , Emdad Luni , Dasgupta Santanu , Sarkar Devanand , Fisher Paul B.
Published: March 2024

Abstract
Subtraction hybridization combined with induction of cancer cell terminal differentiation in human melanoma cells identified melanoma differentiation–associated gene-7/interleukin-24 (mda-7/IL-24) and SARI (suppressor of AP-1, induced by IFN) that display potent antitumor activity. These genes are not constitutively expressed in cancer cells and forced expression of mda-7/IL-24 (Ad.mda-7) or SARI (Ad.SARI) promotes cancer-specific cell death. Ectopic expression of mda-7/IL-24 induces SARI mRNA and protein in a panel of different cancer cells, leading to cell death, without harming corresponding normal cells. Simultaneous inhibition of K-ras downstream extracellular signal-regulated kinase 1/2 signaling in pancreatic cancer cells reverses the translational block of MDA-7/IL-24 and induces SARI expression and cell death. Using SARI-antisense-based approaches, we demonstrate that SARI expression is necessary for mda-7/IL-24 antitumor effects. Secreted MDA-7/IL-24 protein induces antitumor “bystander” effects by promoting its own expression. Recombinant MDA-7/IL-24 (His-MDA-7) induces SARI expression, supporting the involvement of SARI in the MDA-7/IL-24-driven autocrine loop, culminating in antitumor effects. Moreover, His-MDA-7, after binding to its cognate receptors (IL-20R1/IL-20R2 or IL-22R/IL-20R2), induces intracellular signaling by phosphorylation of p38 MAPK, leading to transcription of a family of growth arrest and DNA damage inducible (GADD) genes, culminating in apoptosis. Inhibition of p38 MAPK fails to induce SARI following Ad.mda-7 infection. These findings reveal the significance of the mda-7/IL-24-SARI axis in cancer-specific killing and provide a potential strategy for treating both local and metastatic disease. Cancer Res; 74(2); 563–74. ©2013 AACR.
Data from Kinase Domain Activation of FGFR2 Yields High-Grade Lung Adenocarcinoma Sensitive to a Pan-FGFR Inhibitor in a Mouse Model of NSCLC
Authors: Tchaicha Jeremy H. , Akbay Esra A. , Altabef Abigail , Mikse Oliver R. , Kikuchi Eiki , Rhee Kevin , Liao Rachel G. , Bronson Roderick T. , Sholl Lynette M. , Meyerson Matthew , Hammerman Peter S. , Wong Kwok-Kin
Published: March 2024

Abstract
Somatic mutations in FGFR2 are present in 4% to 5% of patients diagnosed with non–small cell lung cancer (NSCLC). Amplification and mutations in FGFR genes have been identified in patients with NSCLCs, and clinical trials are testing the efficacy of anti-FGFR therapies. FGFR2 and other FGFR kinase family gene alterations have been found in both lung squamous cell carcinoma and lung adenocarcinoma, although mouse models of FGFR-driven lung cancers have not been reported. Here, we generated a genetically engineered mouse model (GEMM) of NSCLC driven by a kinase domain mutation in FGFR2. Combined with p53 ablation, primary grade 3/4 adenocarcinoma was induced in the lung epithelial compartment exhibiting locally invasive and pleiotropic tendencies largely made up of multinucleated cells. Tumors were acutely sensitive to pan-FGFR inhibition. This is the first FGFR2-driven lung cancer GEMM, which can be applied across different cancer indications in a preclinical setting. Cancer Res; 74(17); 4676–84. ©2014 AACR.
Data from Endothelin A Receptor/β-Arrestin Signaling to the Wnt Pathway Renders Ovarian Cancer Cells Resistant to Chemotherapy
Authors: Rosanò Laura , Cianfrocca Roberta , Tocci Piera , Spinella Francesca , Di Castro Valeriana , Caprara Valentina , Semprucci Elisa , Ferrandina Gabriella , Natali Pier Giorgio , Bagnato Anna
Published: March 2024

Abstract
The high mortality of epithelial ovarian cancer (EOC) is mainly caused by resistance to the available therapies. In EOC, the endothelin-1 (ET-1, EDN1)–endothelin A receptor (ETAR, EDNRA) signaling axis regulates the epithelial–mesenchymal transition (EMT) and a chemoresistant phenotype. However, there is a paucity of knowledge about how ET-1 mediates drug resistance. Here, we define a novel bypass mechanism through which ETAR/β-arrestin-1 (β-arr1, ARRB1) links Wnt signaling to acquire chemoresistant and EMT phenotype. We found that ETAR/β-arr1 activity promoted nuclear complex with β-catenin and p300, resulting in histone acetylation, chromatin reorganization, and enhanced transcription of genes, such as ET-1, enhancing the network that sustains chemoresistance. Silencing of β-arr1 or pharmacologic treatment with the dual ETAR/ETBR antagonist macitentan prevented core complex formation and restored drug sensitivity, impairing the signaling pathways involved in cell survival, EMT, and invasion. In vivo macitentan treatment reduced tumor growth, vascularization, intravasation, and metastatic progression. The combination of macitentan and cisplatinum resulted in the potentiation of the cytotoxic effect, indicating that macitentan can enhance sensitivity to chemotherapy. Investigations in clinical specimens of chemoresistant EOC tissues confirmed increased recruitment of β-arr1 and β-catenin to ET-1 gene promoter. In these tissues, high expression of ETAR significantly associated with poor clinical outcome and chemoresistance. Collectively, our findings reveal the existence of a novel mechanism by which ETAR/β-arr1 signaling is integrated with the Wnt/β-catenin pathway to sustain chemoresistance in EOC, and they offer a solid rationale for clinical evaluation of macitentan in combination with chemotherapy to overcome chemoresistance in this setting. Cancer Res; 74(24); 7453–64. ©2014 AACR.