bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Paracrine Effect of NRG1 and HGF Drives Resistance to MEK Inhibitors in Metastatic Uveal Melanoma
Authors: Cheng Hanyin , Terai Mizue , Kageyama Ken , Ozaki Shinji , McCue Peter A. , Sato Takami , Aplin Andrew E.
Published: March 2024

Abstract
Uveal melanoma patients with metastatic disease usually die within one year, emphasizing an urgent need to develop new treatment strategies for this cancer. MEK inhibitors improve survival in cutaneous melanoma patients but show only modest efficacy in metastatic uveal melanoma patients. In this study, we screened for growth factors that elicited resistance in newly characterized metastatic uveal melanoma cell lines to clinical-grade MEK inhibitors, trametinib and selumetinib. We show that neuregulin 1 (NRG1) and hepatocyte growth factor (HGF) provide resistance to MEK inhibition. Mechanistically, trametinib enhances the responsiveness to NRG1 and sustained HGF-mediated activation of AKT. Individually targeting ERBB3 and cMET, the receptors for NRG1 and HGF, respectively, overcome resistance to trametinib provided by these growth factors and by conditioned medium from fibroblasts that produce NRG1 and HGF. Inhibition of AKT also effectively reverses the protective effect of NRG1 and HGF in trametinib-treated cells. Uveal melanoma xenografts growing in the liver in vivo and a subset of liver metastases of uveal melanoma patients express activated forms of ERBB2 (the coreceptor for ERBB3) and cMET. Together, these results provide preclinical evidence for the use of MEK inhibitors in combination with clinical-grade anti-ERBB3 or anti-cMET monoclonal antibodies in metastatic uveal melanoma. Cancer Res; 75(13); 2737–48. ©2015 AACR.
Data from The PKC/NF-κB Signaling Pathway Induces APOBEC3B Expression in Multiple Human Cancers
Authors: Leonard Brandon , McCann Jennifer L. , Starrett Gabriel J. , Kosyakovsky Leah , Luengas Elizabeth M. , Molan Amy M. , Burns Michael B. , McDougle Rebecca M. , Parker Peter J. , Brown William L. , Harris Reuben S.
Published: March 2024

Abstract
Overexpression of the antiviral DNA cytosine deaminase APOBEC3B has been linked to somatic mutagenesis in many cancers. Human papillomavirus infection accounts for APOBEC3B upregulation in cervical and head/neck cancers, but the mechanisms underlying nonviral malignancies are unclear. In this study, we investigated the signal transduction pathways responsible for APOBEC3B upregulation. Activation of protein kinase C (PKC) by the diacylglycerol mimic phorbol-myristic acid resulted in specific and dose-responsive increases in APOBEC3B expression and activity, which could then be strongly suppressed by PKC or NF-κB inhibition. PKC activation caused the recruitment of RELB, but not RELA, to the APOBEC3B promoter, implicating noncanonical NF-κB signaling. Notably, PKC was required for APOBEC3B upregulation in cancer cell lines derived from multiple tumor types. By revealing how APOBEC3B is upregulated in many cancers, our findings suggest that PKC and NF-κB inhibitors may be repositioned to suppress cancer mutagenesis, dampen tumor evolution, and decrease the probability of adverse outcomes, such as drug resistance and metastasis. Cancer Res; 75(21); 4538–47. ©2015 AACR.
Data from ITPR1 Protects Renal Cancer Cells against Natural Killer Cells by Inducing Autophagy
Authors: Messai Yosra , Noman Muhammad Zaeem , Hasmim Meriem , Janji Bassam , Tittarelli Andrés , Boutet Marie , Baud Véronique , Viry Elodie , Billot Katy , Nanbakhsh Arash , Ben Safta Thouraya , Richon Catherine , Ferlicot Sophie , Donnadieu Emmanuel , Couve Sophie , Gardie Betty , Orlanducci Florence , Albiges Laurence , Thiery Jerome , Olive Daniel , Escudier Bernard , Chouaib Salem
Published: March 2024

Abstract
Clear cell renal cell carcinomas (RCC) frequently display inactivation of von Hippel-Lindau (VHL) gene leading to increased level of hypoxia-inducible factors (HIF). In this study, we investigated the potential role of HIF2α in regulating RCC susceptibility to natural killer (NK) cell–mediated killing. We demonstrated that the RCC cell line 786-0 with mutated VHL was resistant to NK-mediated lysis as compared with the VHL-corrected cell line (WT7). This resistance was found to require HIF2α stabilization. On the basis of global gene expression profiling and chromatin immunoprecipitation assay, we found ITPR1 (inositol 1,4,5-trisphosphate receptor, type 1) as a direct novel target of HIF2α and that targeting ITPR1 significantly increased susceptibility of 786-0 cells to NK-mediated lysis. Mechanistically, HIF2α in 786-0 cells lead to overexpression of ITPR1, which subsequently regulated the NK-mediated killing through the activation of autophagy in target cells by NK-derived signal. Interestingly, both ITPR1 and Beclin-1 silencing in 786-0 cells inhibited NK-induced autophagy and subsequently increased granzyme B activity in target cells. Finally, in vivo ITPR1 targeting significantly enhanced the NK-mediated tumor regression. Our data provide insight into the link between HIF2α, the ITPR1-related pathway, and natural immunity and strongly suggest a role for the HIF2α/ITPR1 axis in regulating RCC cell survival. Cancer Res; 74(23); 6820–32. ©2014 AACR.
Data from Interleukin-6 Stimulates Defective Angiogenesis
Authors: Gopinathan Ganga , Milagre Carla , Pearce Oliver M.T. , Reynolds Louise E. , Hodivala-Dilke Kairbaan , Leinster David A. , Zhong Haihong , Hollingsworth Robert E. , Thompson Richard , Whiteford James R. , Balkwill Frances
Published: March 2024

Abstract
The cytokine IL6 has a number of tumor-promoting activities in human and experimental cancers, but its potential as an angiogenic agent has not been fully investigated. Here, we show that IL6 can directly induce vessel sprouting in the ex vivo aortic ring model, as well as endothelial cell proliferation and migration, with similar potency to VEGF. However, IL6-stimulated aortic ring vessel sprouts had defective pericyte coverage compared with VEGF-stimulated vessels. The mechanism of IL6 action on pericytes involved stimulation of the Notch ligand Jagged1 as well as angiopoietin2 (Ang2). When peritoneal xenografts of ovarian cancer were treated with an anti-IL6 antibody, pericyte coverage of vessels was restored. In addition, in human ovarian cancer biopsies, there was an association between levels of IL6 mRNA, Jagged1, and Ang2. Our findings have implications for the use of cancer therapies that target VEGF or IL6 and for understanding abnormal angiogenesis in cancers, chronic inflammatory disease, and stroke. Cancer Res; 75(15); 3098–107. ©2015 AACR.
Data from Curcumin Promotes Autophagic Survival of a Subset of Colon Cancer Stem Cells, Which Are Ablated by DCLK1-siRNA
Authors: Kantara Carla , O'Connell Malaney , Sarkar Shubhashish , Moya Stephanie , Ullrich Robert , Singh Pomila
Published: March 2024

Abstract
Curcumin is known to induce apoptosis of cancer cells by different mechanisms, but its effects on cancer stem cells (CSC) have been less investigated. Here, we report that curcumin promotes the survival of DCLK1-positive colon CSCs, potentially confounding application of its anticancer properties. At optimal concentrations, curcumin greatly reduced expression levels of stem cell markers (DCLK1/CD44/ALDHA1/Lgr5/Nanog) in three-dimensional spheroid cultures and tumor xenografts derived from colon cancer cells. However, curcumin unexpectedly induced proliferation and autophagic survival of a subset of DCLK1-positive CSCs. Spheroid cultures were disintegrated by curcumin in vitro but regrew within 30 to 40 days of treatment, suggesting a survival benefit from autophagy, permitting long-term persistence of colorectal cancer. Notably, RNA interference–mediated silencing of DCLK1 triggered apoptotic cell death of colon cancer cells in vitro and in vivo, and abolished colorectal cancer survival in response to curcumin; combination of DCLK1-siRNA and curcumin dramatically reversed CSC phenotype, contributing to attenuation of the growth of spheroid cultures and tumor xenografts. Taken together, our findings confirm a role of DCLK1 in colon CSCs and highlight DCLK1 as a target to enhance antitumor properties of curcumin. Cancer Res; 74(9); 2487–98. ©2014 AACR.
Data from Selective Inhibition of Parallel DNA Damage Response Pathways Optimizes Radiosensitization of Glioblastoma Stem-like Cells
Authors: Ahmed Shafiq U. , Carruthers Ross , Gilmour Lesley , Yildirim Salih , Watts Colin , Chalmers Anthony J.
Published: March 2024

Abstract
Glioblastoma is the most common form of primary brain tumor in adults and is essentially incurable. Despite aggressive treatment regimens centered on radiotherapy, tumor recurrence is inevitable and is thought to be driven by glioblastoma stem-like cells (GSC) that are highly radioresistant. DNA damage response pathways are key determinants of radiosensitivity but the extent to which these overlapping and parallel signaling components contribute to GSC radioresistance is unclear. Using a panel of primary patient-derived glioblastoma cell lines, we confirmed by clonogenic survival assays that GSCs were significantly more radioresistant than paired tumor bulk populations. DNA damage response targets ATM, ATR, CHK1, and PARP1 were upregulated in GSCs, and CHK1 was preferentially activated following irradiation. Consequently, GSCs exhibit rapid G2–M cell-cycle checkpoint activation and enhanced DNA repair. Inhibition of CHK1 or ATR successfully abrogated G2–M checkpoint function, leading to increased mitotic catastrophe and a modest increase in radiation sensitivity. Inhibition of ATM had dual effects on cell-cycle checkpoint regulation and DNA repair that were associated with greater radiosensitizing effects on GSCs than inhibition of CHK1, ATR, or PARP alone. Combined inhibition of PARP and ATR resulted in a profound radiosensitization of GSCs, which was of greater magnitude than in bulk populations and also exceeded the effect of ATM inhibition. These data demonstrate that multiple, parallel DNA damage signaling pathways contribute to GSC radioresistance and that combined inhibition of cell-cycle checkpoint and DNA repair targets provides the most effective means to overcome radioresistance of GSC. Cancer Res; 75(20); 4416–28. ©2015 AACR.
Data from NF-κB: Regulation by Methylation
Authors: Lu Tao , Stark George R.
Published: March 2024

Abstract
In normal cells exposed to stress, the central transcription factor NF-κB is activated only transiently, to modulate the activation of downstream immune responses. However, in most cancers, NF-κB is abnormally activated constitutively, contributing thus to oncogenesis and tumor progression. Therefore, downregulating NF-κB activity is an important goal of cancer treatment. In order to control NF-κB activity therapeutically, it is helpful to understand the molecular mechanisms that normally govern its activation and how dysregulated NF-κB activity may aid the development of disease. Recent evidence from our laboratories and others indicates that, in addition to various posttranslational modifications of NF-κB that have been observed previously, including phosphorylation, ubiquitination, and acetylation, NF-κB can be methylated reversibly on lysine or arginine residues by histone-modifying enzymes, including lysine and arginine methyl transferases and demethylases. Furthermore, these methylations are required to activate many downstream genes. Interestingly, amplifications and mutations of several such enzymes have been linked to cancer. We propose that some of these mutations may alter the methylation not only of histones but also of NF-κB, making them attractive therapeutic targets. Cancer Res; 75(18); 3692–5. ©2015 AACR.
Data from Defects in the Fanconi Anemia Pathway and Chromatid Cohesion in Head and Neck Cancer
Authors: Stoepker Chantal , Ameziane Najim , van der Lelij Petra , Kooi Irsan E. , Oostra Anneke B. , Rooimans Martin A. , van Mil Saskia E. , Brink Arjen , Dietrich Ralf , Balk Jesper A. , Ylstra Bauke , Joenje Hans , Feller Stephan M. , Brakenhoff Ruud H.
Published: March 2024

Abstract
Failure to repair DNA damage or defective sister chromatid cohesion, a process essential for correct chromosome segregation, can be causative of chromosomal instability (CIN), which is a hallmark of many types of cancers. We investigated how frequent this occurs in head and neck squamous cell carcinoma (HNSCC) and whether specific mechanisms or genes could be linked to these phenotypes. The genomic instability syndrome Fanconi anemia is caused by mutations in any of at least 16 genes regulating DNA interstrand crosslink (ICL) repair. Since patients with Fanconi anemia have a high risk to develop HNSCC, we investigated whether and to which extent Fanconi anemia pathway inactivation underlies CIN in HNSCC of non–Fanconi anemia individuals. We observed ICL-induced chromosomal breakage in 9 of 17 (53%) HNSCC cell lines derived from patients without Fanconi anemia. In addition, defective sister chromatid cohesion was observed in five HNSCC cell lines. Inactivation of FANCM was responsible for chromosomal breakage in one cell line, whereas in two other cell lines, somatic mutations in PDS5A or STAG2 resulted in inadequate sister chromatid cohesion. In addition, FANCF methylation was found in one cell line by screening an additional panel of 39 HNSCC cell lines. Our data demonstrate that CIN in terms of ICL-induced chromosomal breakage and defective chromatid cohesion is frequently observed in HNSCC. Inactivation of known Fanconi anemia and chromatid cohesion genes does explain CIN in the minority of cases. These findings point to phenotypes that may be highly relevant in treatment response of HNSCC. Cancer Res; 75(17); 3543–53. ©2015 AACR.
Data from NHANES 2009–2012 Findings: Association of Sexual Behaviors with Higher Prevalence of Oral Oncogenic Human Papillomavirus Infections in U.S. Men
Authors: Chaturvedi Anil K. , Graubard Barry I. , Broutian Tatevik , Pickard Robert K.L. , Tong Zhen-yue , Xiao Weihong , Kahle Lisa , Gillison Maura L.
Published: March 2024

Abstract
The incidence of human papillomavirus (HPV)–positive oropharyngeal cancers is higher and increasing more rapidly among men than women in the United States for unknown reasons. We compared the epidemiology of oral oncogenic HPV infection between men and women ages 14 to 69 years (N = 9,480) within the U.S. National Health and Nutritional Examination Surveys (NHANES) 2009–2012. HPV presence was detected in oral DNA by PCR. Analyses were stratified by gender and used NHANES sample weights. Oral oncogenic HPV prevalence was higher among men than women (6.6% vs. 1.5%, P < 0.001), corresponding to 7.07 million men versus 1.54 million women with prevalent infection at any point in time during 2009–2012. Prevalence increased significantly with age, current smoking, and lifetime number of sexual partners for both genders (adjusted Ptrend < 0.02). However, men had more partners than women (mean = 18 vs. 7, P < 0.001). Although oncogenic HPV prevalence was similar for men and women with 0 to 1 lifetime partners, the male–female difference in prevalence significantly increased with number of lifetime partners (adjusted prevalence differences for none, 1, 2–5, 6–10, 11–20, and 20+ partners = 1.0%, 0.5%, 3.0%, 5.7%, 4.6%, and 9.3%, respectively). Importantly, the per-sexual partner increase in prevalence was significantly stronger among men than among women (adjusted synergy index = 3.3; 95% confidence interval, 1.1–9.7), and this increase plateaued at 25 lifetime partners among men versus10 partners among women. Our data suggest that the higher burden of oral oncogenic HPV infections and HPV-positive oropharyngeal cancers among men than women arises in part from higher number of lifetime sexual partners and stronger associations with sexual behaviors among men. Cancer Res; 75(12); 2468–77. ©2015 AACR.
Data from Oncogenic Transformation Can Orchestrate Immune Evasion and Inflammation in Human Mesenchymal Stem Cells Independently of Extrinsic Immune-Selective Pressure
Authors: Miranda Alex , Funes Juan M. , Sánchez Nilda , Limia Celia M. , Mesa Mónica , Quezada Sergio A. , Pérez Rolando , de León Joel
Published: March 2024

Abstract
Immune escape is a hallmark of cancer, but whether it relies upon extrinsic immune-selective pressure or is inherently orchestrated by oncogenic pathways is unresolved. To address this question, we took advantage of an in vitro model of sequentially transformed human mesenchymal stem cells (hMSC). Neoplastic transformation in this model increased the natural immune-evasive properties of hMSC, both by reducing their immunogenicity and by increasing their capacity to inhibit mitogen-driven T-cell proliferation. We also found that IFNγ signaling was globally affected in transformed hMSC. As a consequence, the natural inhibitory effect of hMSC on T-cell proliferation switched from an inducible mechanism depending on IFNγ signaling and mediated by indoleamine 2,3-dioxygenase to a constitutive mechanism that relied upon IL1β involving both secreted and membrane-expressed molecules. After transformation, increased IL1β expression both sustained the immunosuppressive properties of hMSC and increased their tumorigenicity. Thus, in this model system, IL1β acted as intrinsic inflammatory mediator that exerted an autocrine influence on tumor growth by coordinately linking immune escape and tumorigenicity. Collectively, our findings show how oncogenes directly orchestrate inflammation and immune escape to drive the multistep process of cancer progression, independently of any need for immunoediting in the tumor microenvironment. Cancer Res; 75(15); 3032–42. ©2015 AACR.
Data from Mitochondrial DNA Copy Number in Peripheral Blood Cells and Risk of Developing Breast Cancer
Authors: Lemnrau Alina , Brook Mark N. , Fletcher Olivia , Coulson Penny , Tomczyk Katarzyna , Jones Michael , Ashworth Alan , Swerdlow Anthony , Orr Nick , Garcia-Closas Montserrat
Published: March 2024

Abstract
Increased mitochondrial DNA (mtDNA) copy number in peripheral blood cells (PBC) has been associated with the risk of developing several tumor types. Here we evaluate sources of variation of this biomarker and its association with breast cancer risk in a prospective cohort study. mtDNA copy number was measured using quantitative real-time PCR on PBC DNA samples from participants in the UK-based Breakthrough Generations Study. Temporal and assay variation was evaluated in a serial study of 91 women, with two blood samples collected approximately 6-years apart. Then, associations with breast cancer risk factors and risk were evaluated in 1,108 cases and 1,099 controls using a nested case–control design. In the serial study, mtDNA copy number showed low assay variation but large temporal variation [assay intraclass correlation coefficient (ICC), 79.3%–87.9%; temporal ICC, 38.3%). Higher mtDNA copy number was significantly associated with younger age at blood collection, being premenopausal, having an older age at menopause, and never taking HRT, both in cases and controls. Based on measurements in a single blood sample taken on average 6 years before diagnosis, higher mtDNA copy number was associated with increased breast cancer risk [OR (95% CI) for highest versus lowest quartile, 1.37 (1.02–1.83); P trend = 0.007]. In conclusion, mtDNA copy number is associated with breast cancer risk and represents a promising biomarker for risk assessment. The relatively large temporal variation should be taken into account in future analyses. Cancer Res; 75(14); 2844–50. ©2015 AACR.
Data from A Polymer-Based Antibody–Vinca Drug Conjugate Platform: Characterization and Preclinical Efficacy
Authors: Yurkovetskiy Alexander V. , Yin Mao , Bodyak Natalya , Stevenson Cheri A. , Thomas Joshua D. , Hammond Charles E. , Qin LiuLiang , Zhu Bangmin , Gumerov Dmitry R. , Ter-Ovanesyan Elena , Uttard Alex , Lowinger Timothy B.
Published: March 2024

Abstract
Antibody–drug conjugates (ADC) are an emerging drug class that uses antibodies to improve cytotoxic drug targeting for cancer treatment. ADCs in current clinical trials achieve a compromise between potency and physicochemical/pharmacokinetic properties by conjugating potent cytotoxins directly to an antibody at a 4:1 or less stoichiometric ratio. Herein, we report a novel, polyacetal polymer-based platform for creating ADC that use poly-1-hydroxymethylethylene hydroxymethyl-formal (PHF), also known as Fleximer. The high hydrophilicity and polyvalency properties of the Fleximer polymer can be used to produce ADC with high drug loading without compromising physicochemical and pharmacokinetic properties. Using trastuzumab and a vinca drug derivative to demonstrate the utility of this platform, a novel Fleximer-based ADC was prepared and characterized in vivo. The ADC prepared had a vinca-antibody ratio of 20:1. It exhibited a high antigen-binding affinity, an excellent pharmacokinetic profile and antigen-dependent efficacy, and tumor accumulation in multiple tumor xenograft models. Our findings illustrate the robust utility of the Fleximer platform as a highly differentiated alternative to the conjugation platforms used to create ADC currently in clinical development. Cancer Res; 75(16); 3365–72. ©2015 AACR.
Data from Grapefruit-Derived Nanovectors Use an Activated Leukocyte Trafficking Pathway to Deliver Therapeutic Agents to Inflammatory Tumor Sites
Authors: Wang Qilong , Ren Yi , Mu Jingyao , Egilmez Nejat K. , Zhuang Xiaoyin , Deng Zhongbin , Zhang Lifeng , Yan Jun , Miller Donald , Zhang Huang-Ge
Published: March 2024

Abstract
Inflammation is a hallmark of cancer. Activated immune cells are intrinsically capable of homing to inflammatory sites. Using three inflammatory-driven disease mouse models, we show that grapefruit-derived nanovectors (GNV) coated with inflammatory-related receptor enriched membranes of activated leukocytes (IGNVs) are enhanced for homing to inflammatory tumor tissues. Blocking LFA-1 or CXCR1 and CXCR2 on the IGNVs significantly inhibits IGNV homing to the inflammatory tissue. The therapeutic potential of IGNVs was further demonstrated by enhancing the chemotherapeutic effect as shown by inhibition of tumor growth in two tumor models and inhibiting the inflammatory effects of dextran sulfate sodium-induced mouse colitis. The fact that IGNVs are capable of homing to inflammatory tissue and that chemokines are overexpressed in diseased human tissue provides the rationale for using IGNVs to more directly deliver therapeutic agents to inflammatory tumor sites and the rationale for the use of IGNVs as treatment for certain cancers in personalized medicine. Cancer Res; 75(12); 2520–9. ©2015 AACR.
Data from Preclinical Characterization of Novel Chordoma Cell Systems and Their Targeting by Pharmocological Inhibitors of the CDK4/6 Cell-Cycle Pathway
Authors: von Witzleben Adrian , Goerttler Lukas T. , Marienfeld Ralf , Barth Holger , Lechel André , Mellert Kevin , Böhm Michael , Kornmann Marko , Mayer-Steinacker Regine , von Baer Alexandra , Schultheiss Markus , Flanagan Adrienne M. , Möller Peter , Brüderlein Silke , Barth Thomas F.E.
Published: March 2024

Abstract
Chordomas are tumors that arise at vertebral bodies and the base of the skull. Although rare in incidence, they are deadly owing to slow growth and a lack of effective therapeutic options. In this study, we addressed the need for chordoma cell systems that can be used to identify therapeutic targets and empower testing of candidate pharmacologic drugs. Eight human chordoma cell lines that we established exhibited cytology, genomics, mRNA, and protein profiles that were characteristic of primary chordomas. Candidate responder profiles were identified through an immunohistochemical analysis of a chordoma tissue bank of 43 patients. Genomic, mRNA, and protein expression analyses confirmed that the new cell systems were highly representative of chordoma tissues. Notably, all cells exhibited a loss of CDKN2A and p16, resulting in universal activation of the CDK4/6 and Rb pathways. Therefore, we investigated the CDK4/6 pathway and responses to the CDK4/6–specific inhibitor palbociclib. In the newly validated system, palbociclib treatment efficiently inhibited tumor cell growth in vitro and a drug responder versus nonresponder molecular signature was defined on the basis of immunohistochemical expression of CDK4/6/pRb (S780). Overall, our work offers a valuable new tool for chordoma studies including the development of novel biomarkers and molecular targeting strategies. Cancer Res; 75(18); 3823–31. ©2015 AACR.
Data from Secalonic Acid-D Represses HIF1α/VEGF-Mediated Angiogenesis by Regulating the Akt/mTOR/p70S6K Signaling Cascade
Authors: Guru Santosh Kumar , Pathania Anup Singh , Kumar Suresh , Ramesh Deshidi , Kumar Manjeet , Rana Satiander , Kumar Ajay , Malik Fayaz , Sharma P.R. , Chandan B.K. , Jaglan Sundeep , Sharma J.P. , Shah Bhahwal Ali , Tasduq Sheikh Abdullah , Lattoo Surrinder K. , Faruk Abdul , Saxena A.K. , Vishwakarma R.A. , Bhushan Shashi
Published: March 2024

Abstract
Tumor angiogenesis is a validated target for therapeutic intervention, but agents that are more disease selective are needed. Here, we report the isolation of secalonic acid-D (SAD), a mycotoxin from a novel source that exhibits potent antiangiogenic antitumor activity. SAD inhibited multiple HIF1α/VEGF-arbitrated angiogenesis dynamics as scored in human umbilical vascular endothelial cells and human MCF-7 breast tumor xenografts. Similarly, SAD suppressed VEGF-induced microvessel sprouting from rat aortic ring and blood vessel formation in the Matrigel plug assay in C57/BL6J mice. Under normoxic or hypoxic conditions, SAD inhibited cell survival through the Akt/mTOR/p70S6K pathway, with attendant effects on key proangiogenesis factors, including HIF1α, VEGFR, and MMP-2/MMP-9. These effects were reversed by cotreatment with the Akt inhibitors perifosine and GSK69069 or by the addition of neutralizing VEGF antibodies. The apoptotic properties of SAD were determined to be both extrinsic and intrinsic in nature, whereas the cell-cycle inhibitory effects were mediated by altering the level of key G1–S transition-phase proteins. In experimental mouse models of breast cancer, SAD dosing produced no apparent toxicities (either orally or intraperitoneal) at levels that yielded antitumor effects. Taken together, our findings offered a preclinical validation and mechanistic definition of the antiangiogenic activity of a novel mycotoxin, with potential application as a cancer-selective therapeutic agent. Cancer Res; 75(14); 2886–96. ©2015 AACR.
Data from Development of Resistance to EGFR-Targeted Therapy in Malignant Glioma Can Occur through EGFR-Dependent and -Independent Mechanisms
Authors: Klingler Stefan , Guo Baofeng , Yao Jun , Yan Haiyan , Zhang Ling , Vaseva Angelina V. , Chen Sida , Canoll Peter , Horner James W. , Wang Y. Alan , Paik Ji-Hye , Ying Haoqiang , Zheng Hongwu
Published: March 2024

Abstract
Epidermal growth factor receptor (EGFR) is highly amplified, mutated, and overexpressed in human malignant gliomas. Despite its prevalence and growth-promoting functions, therapeutic strategies to inhibit EGFR kinase activity have not been translated into profound beneficial effects in glioma clinical trials. To determine the roles of oncogenic EGFR signaling in gliomagenesis and tumor maintenance, we generated a novel glioma mouse model driven by inducible expression of a mutant EGFR (EGFR*). Using combined genetic and pharmacologic interventions, we revealed that EGFR*-driven gliomas were insensitive to EGFR tyrosine kinase inhibitors, although they could efficiently inhibit EGFR* autophosphorylation in vitro and in vivo. This is in contrast with the genetic suppression of EGFR* induction that led to significant tumor regression and prolonged animal survival. However, despite their initial response to genetic EGFR* extinction, all tumors would relapse and propagate independent of EGFR*. We further showed that EGFR*-independent tumor cells existed prior to treatment and were responsible for relapse following genetic EGFR* suppression. And, the addition of a PI3K/mTOR inhibitor could significantly delay relapse and prolong animal survival. Our findings shed mechanistic insight into EGFR drug resistance in glioma and provide a platform to test therapies targeting aberrant EGFR signaling in this setting. Cancer Res; 75(10); 2109–19. ©2015 AACR.
Data from TGFβ Is a Master Regulator of Radiation Therapy-Induced Antitumor Immunity
Authors: Vanpouille-Box Claire , Diamond Julie M. , Pilones Karsten A. , Zavadil Jiri , Babb James S. , Formenti Silvia C. , Barcellos-Hoff Mary Helen , Demaria Sandra
Published: March 2024

Abstract
T cells directed to endogenous tumor antigens are powerful mediators of tumor regression. Recent immunotherapy advances have identified effective interventions to unleash tumor-specific T-cell activity in patients who naturally develop them. Eliciting T-cell responses to a patient's individual tumor remains a major challenge. Radiation therapy can induce immune responses to model antigens expressed by tumors, but it remains unclear whether it can effectively prime T cells specific for endogenous antigens expressed by poorly immunogenic tumors. We hypothesized that TGFβ activity is a major obstacle hindering the ability of radiation to generate an in situ tumor vaccine. Here, we show that antibody-mediated TGFβ neutralization during radiation therapy effectively generates CD8+ T-cell responses to multiple endogenous tumor antigens in poorly immunogenic mouse carcinomas. Generated T cells were effective at causing regression of irradiated tumors and nonirradiated lung metastases or synchronous tumors (abscopal effect). Gene signatures associated with IFNγ and immune-mediated rejection were detected in tumors treated with radiation therapy and TGFβ blockade in combination but not as single agents. Upregulation of programmed death (PD) ligand-1 and -2 in neoplastic and myeloid cells and PD-1 on intratumoral T cells limited tumor rejection, resulting in rapid recurrence. Addition of anti–PD-1 antibodies extended survival achieved with radiation and TGFβ blockade. Thus, TGFβ is a fundamental regulator of radiation therapy's ability to generate an in situ tumor vaccine. The combination of local radiation therapy with TGFβ neutralization offers a novel individualized strategy for vaccinating patients against their tumors. Cancer Res; 75(11); 2232–42. ©2015 AACR.
Data from B-Raf Inhibitors Induce Epithelial Differentiation in BRAF-Mutant Colorectal Cancer Cells
Authors: Herr Ricarda , Köhler Martin , Andrlová Hana , Weinberg Florian , Möller Yvonne , Halbach Sebastian , Lutz Lisa , Mastroianni Justin , Klose Martin , Bittermann Nicola , Kowar Silke , Zeiser Robert , Olayioye Monilola A. , Lassmann Silke , Busch Hauke , Boerries Melanie , Brummer Tilman
Published: March 2024

Abstract
BRAF mutations are associated with aggressive, less-differentiated and therapy-resistant colorectal carcinoma. However, the underlying mechanisms for these correlations remain unknown. To understand how oncogenic B-Raf contributes to carcinogenesis, in particular to aspects other than cellular proliferation and survival, we generated three isogenic human colorectal carcinoma cell line models in which we can dynamically modulate the expression of the B-RafV600E oncoprotein. Doxycyclin-inducible knockdown of endogenous B-RafV600E decreases cellular motility and invasion in conventional and three-dimensional (3D) culture, whereas it promotes cell–cell contacts and induces various hallmarks of differentiated epithelia. Importantly, all these effects are recapitulated by B-Raf (PLX4720, vemurafenib, and dabrafenib) or MEK inhibitors (trametinib). Surprisingly, loss of B-RafV600E in HT29 xenografts does not only stall tumor growth, but also induces glandular structures with marked expression of CDX2, a tumor-suppressor and master transcription factor of intestinal differentiation. By performing the first transcriptome profiles of PLX4720-treated 3D cultures of HT29 and Colo-205 cells, we identify several upregulated genes linked to epithelial differentiation and effector functions, such as claudin-1, a Cdx-2 target gene encoding a critical tight junction component. Thereby, we provide a mechanism for the clinically observed correlation between mutant BRAF and the loss of Cdx-2 and claudin-1. PLX4720 also suppressed several metastasis-associated transcripts that have not been implicated as targets, effectors or potential biomarkers of oncogenic B-Raf signaling so far. Together, we identify a novel facet of clinically applied B-Raf or MEK inhibitors by showing that they promote cellular adhesion and differentiation of colorectal carcinoma cells. Cancer Res; 75(1); 216–29. ©2014 AACR.
Data from Breast Cancer Cell–Derived GM-CSF Licenses Regulatory Th2 Induction by Plasmacytoid Predendritic Cells in Aggressive Disease Subtypes
Authors: Ghirelli Cristina , Reyal Fabien , Jeanmougin Marine , Zollinger Raphaël , Sirven Philémon , Michea Paula , Caux Christophe , Bendriss-Vermare Nathalie , Donnadieu Marie-Hélène , Caly Martial , Fourchotte Virginie , Vincent-Salomon Anne , Sigal-Zafrani Brigitte , Sastre-Garau Xavier , Soumelis Vassili
Published: March 2024

Abstract
Reciprocal interactions between tumor cells and their microenvironment vitally impact tumor progression. In this study, we show that GM-CSF produced by primary breast tumor cells induced the activation of plasmacytoid predendritic cells (pDC), a cell type critical to anti-viral immunity. pDC that expressed the GM-CSF receptor were increased in breast tumors compared with noninvolved adjacent breast tissue. Tumor-activated pDC acquired naïve CD4+ T-cell stimulatory capacity and promoted a regulatory Th2 response. Finally, the concomitant increase of GM-CSF and pDC was significantly associated with relatively more aggressive breast cancer subtypes. Our results characterize the first tumor-derived factor that can activate pDC to promote a regulatory Th2 response, with implications for therapeutic targeting of a tumor-immune axis of growing recognition in its significance to cancer. Cancer Res; 75(14); 2775–87. ©2015 AACR.
Data from Tumor Endothelial Cells with Distinct Patterns of TGFβ-Driven Endothelial-to-Mesenchymal Transition
Authors: Xiao Lin , Kim Dae Joong , Davis Clayton L. , McCann James V. , Dunleavey James M. , Vanderlinden Alissa K. , Xu Nuo , Pattenden Samantha G. , Frye Stephen V. , Xu Xia , Onaitis Mark , Monaghan-Benson Elizabeth , Burridge Keith , Dudley Andrew C.
Published: March 2024

Abstract
Endothelial-to-mesenchymal transition (EndMT) occurs during development and underlies the pathophysiology of multiple diseases. In tumors, unscheduled EndMT generates cancer-associated myofibroblasts that fuel inflammation and fibrosis, and may contribute to vascular dysfunction that promotes tumor progression. We report that freshly isolated subpopulations of tumor-specific endothelial cells (TEC) from a spontaneous mammary tumor model undergo distinct forms of EndMT in response to TGFβ stimulation. Although some TECs strikingly upregulate α smooth muscle actin (SMA), a principal marker of EndMT and activated myofibroblasts, counterpart normal mammary gland endothelial cells (NEC) showed little change in SMA expression after TGFβ treatment. Compared with NECs, SMA+ TECs were 40% less motile in wound-healing assays and formed more stable vascular-like networks in vitro when challenged with TGFβ. Lineage tracing using ZsGreenCdh5-Cre reporter mice confirmed that only a fraction of vessels in breast tumors contain SMA+ TECs, suggesting that not all endothelial cells (EC) respond identically to TGFβ in vivo. Indeed, examination of 84 TGFβ-regulated target genes revealed entirely different genetic signatures in TGFβ-stimulated NEC and TEC cultures. Finally, we found that basic FGF (bFGF) exerts potent inhibitory effects on many TGFβ-regulated genes but operates in tandem with TGFβ to upregulate others. ECs challenged with TGFβ secrete bFGF, which blocks SMA expression in secondary cultures, suggesting a cell-autonomous or lateral-inhibitory mechanism for impeding mesenchymal differentiation. Together, our results suggest that TGFβ-driven EndMT produces a spectrum of EC phenotypes with different functions that could underlie the plasticity and heterogeneity of the tumor vasculature. Cancer Res; 75(7); 1244–54. ©2015 AACR.
Data from MyD88-Dependent Signaling Decreases the Antitumor Efficacy of Epidermal Growth Factor Receptor Inhibition in Head and Neck Cancer Cells
Authors: Koch Adam T. , Love-Homan Laurie , Espinosa-Cotton Madelyn , Stanam Aditya , Simons Andrean L.
Published: March 2024

Abstract
EGFR is upregulated in the majority of head and neck squamous cell carcinomas (HNSCC). However, many patients with HNSCC respond poorly to the EGFR inhibitors (EGFRI) cetuximab and erlotinib, despite tumor expression of EGFR. Gene expression analysis of erlotinib-treated HNSCC cells revealed an upregulation of genes involved in MyD88-dependent signaling compared with their respective vehicle-treated cell lines. We therefore investigated whether MyD88-dependent signaling may reduce the antitumor efficacy of EGFRIs in HNSCC. Erlotinib significantly upregulated IL6 secretion in HNSCC cell lines, which our laboratory previously reported to result in reduced drug efficacy. Suppression of MyD88 expression blocked erlotinib-induced IL6 secretion in vitro and increased the antitumor activity of erlotinib in vivo. There was little evidence of Toll-like receptor or IL18 receptor involvement in erlotinib-induced IL6 secretion. However, suppression of IL1R signaling significantly reduced erlotinib-induced IL6 production. A time-dependent increase of IL1α but not IL1β was observed in response to erlotinib treatment, and IL1α blockade significantly increased the antitumor activity of erlotinib and cetuximab in vivo. A pan-caspase inhibitor reduced erlotinib-induced IL1α secretion, suggesting that IL1α was released because of cell death. Human HNSCC tumors showed higher IL1α mRNA levels compared with matched normal tissue, and IL1α was found to be negatively correlated with survival in patients with HNSCC. Overall, the IL1α/IL1R/MYD88/IL6 pathway may be responsible for the reduced antitumor efficacy of erlotinib and other EGFRIs, and blockade of IL1 signaling may improve the efficacy of EGFRIs in the treatment of HNSCC. Cancer Res; 75(8); 1657–67. ©2015 AACR.
Data from Lung Tumor Suppressor GPRC5A Binds EGFR and Restrains Its Effector Signaling
Authors: Zhong Shuangshuang , Yin Huijing , Liao Yueling , Yao Feng , Li Qi , Zhang Jie , Jiao Huike , Zhao Yongxu , Xu Dongliang , Liu Shuli , Song Hongyong , Gao Yong , Liu Jingyi , Ma Lina , Pang Zhi , Yang Ruixu , Ding Chengyi , Sun Beibei , Lin Xiaofeng , Ye Xiaofeng , Guo Wenzheng , Han Baohui , Zhou Binhua P. , Chin Y. Eugene , Deng Jiong
Published: March 2024

Abstract
GPRC5A is a G-protein–coupled receptor expressed in lung tissue but repressed in most human lung cancers. Studies in Gprc5a−/− mice have established its role as a tumor-suppressor function in this setting, but the basis for its role has been obscure. Here, we report that GPRC5A functions as a negative modulator of EGFR signaling. Mouse tracheal epithelial cells (MTEC) from Gprc5a−/− mice exhibited a relative increase in EGFR and downstream STAT3 signaling, whereas GPRC5A expression inhibited EGFR and STAT3 signaling. GPRC5A physically interacted with EGFR through its transmembrane domain, which was required for its EGFR inhibitory activity. Gprc5a−/− MTEC were much more susceptible to EGFR inhibitors than wild-type MTEC, suggesting their dependence on EGFR signaling for proliferation and survival. Dysregulated EGFR and STAT3 were identified in the normal epithelia of small and terminal bronchioles as well as tumors of Gprc5a−/− mouse lungs. Moreover, in these lungs EGFR inhibitor treatment inhibited EGFR and STAT3 activation along with cell proliferation. Finally, overexpression of ectopic GPRC5A in human non–small cell lung carcinoma cells inhibited both EGF-induced and constitutively activated EGFR signaling. Taken together, our results show how GPRC5A deficiency leads to dysregulated EGFR and STAT3 signaling and lung tumorigenesis. Cancer Res; 75(9); 1801–14. ©2015 AACR.
Data from Elevated Expression of the C-Type Lectin CD93 in the Glioblastoma Vasculature Regulates Cytoskeletal Rearrangements That Enhance Vessel Function and Reduce Host Survival
Authors: Langenkamp Elise , Zhang Lei , Lugano Roberta , Huang Hua , Elhassan Tamador Elsir Abu , Georganaki Maria , Bazzar Wesam , Lööf Johan , Trendelenburg George , Essand Magnus , Pontén Fredrik , Smits Anja , Dimberg Anna
Published: March 2024

Abstract
Glioblastoma is an aggressive brain tumor characterized by an abnormal blood vasculature that is hyperpermeable. Here, we report a novel role for CD93 in regulating angiogenesis in this setting by modulating cell–cell and cell–matrix adhesion of endothelial cells. Tissue microarray analysis demonstrated that vascular expression of CD93 was correlated with poor survival in a clinical cohort of patients with high-grade astrocytic glioma. Similarly, intracranial growth in the GL261 mouse model of glioma was delayed significantly in CD93−/− hosts, resulting in improved survival compared with wild-type mice. This effect was associated with increased vascular permeability and decreased vascular perfusion of tumors, indicating reduced vessel functionality in the absence of CD93. RNAi-mediated attenuation of CD93 in endothelial cells diminished VEGF-induced tube formation in a three-dimensional collagen gel. CD93 was required for efficient endothelial cell migration and proper cell polarization in vitro. Further, in endothelial cells where CD93 was attenuated, decreased cell spreading led to a severe reduction in cell adhesion, a lack of proper cell contacts, a loss of VE-cadherin, and aberrant actin stress fiber formation. Our results identify CD93 as a key regulator of glioma angiogenesis and vascular function, acting via cytoskeletal rearrangements required for cell–cell and cell–matrix adhesion. Cancer Res; 75(21); 4504–16. ©2015 AACR.
Data from A Urokinase Receptor–Bim Signaling Axis Emerges during EGFR Inhibitor Resistance in Mutant EGFR Glioblastoma
Authors: Wykosky Jill , Hu Jingjing , Gomez German G. , Taylor Tiffany , Villa Genaro R. , Pizzo Donald , VandenBerg Scott R. , Thorne Amy Haseley , Chen Clark C. , Mischel Paul S. , Gonias Steven L. , Cavenee Webster K. , Furnari Frank B.
Published: March 2024

Abstract
EGFR is the most common genetically altered oncogene in glioblastoma (GBM), but small-molecule EGFR tyrosine kinase inhibitors (TKI) have failed to yield durable clinical benefit. Here, we show that in two novel model systems of acquired resistance to EGFR TKIs, elevated expression of urokinase plasminogen activator (uPA) drives signaling through the MAPK pathway, which results in suppression of the proapoptotic BCL2-family member protein BIM (BCL2L11). In patient-derived GBM cells and genetic GBM models, uPA is shown to suppress BIM levels through ERK1/2 phosphorylation, which can be reversed by siRNA-mediated knockdown of uPA. TKI-resistant GBMs are resensitized to EGFR TKIs by pharmacologic inhibition of MEK or a BH3 mimetic drug to replace BIM function. A link between the uPA–uPAR–ERK1/2 pathway and BIM has not been previously demonstrated in GBM, and involvement of this signaling axis in resistance provides rationale for a new strategy to target EGFR TKI-resistant GBM. Cancer Res; 75(2); 394–404. ©2014 AACR.
Data from Aberrant Expression of proPTPRN2 in Cancer Cells Confers Resistance to Apoptosis
Authors: Sorokin Alexey V. , Nair Binoj C. , Wei Yongkun , Aziz Kathryn E. , Evdokimova Valentina , Hung Mien-Chie , Chen Junjie
Published: March 2024

Abstract
The protein tyrosine phosphatase receptor PTPRN2 is expressed predominantly in endocrine and neuronal cells, where it functions in exocytosis. We found that its immature isoform proPTPRN2 is overexpressed in various cancers, including breast cancer. High proPTPRN2 expression was associated strongly with lymph node–positive breast cancer and poor clinical outcome. Loss of proPTPRN2 in breast cancer cells promoted apoptosis and blocked tumor formation in mice, whereas enforced expression of proPTPRN2 in nontransformed human mammary epithelial cells exerted a converse effect. Mechanistic investigations suggested that ProPTPRN2 elicited these effects through direct interaction with TRAF2, a hub scaffold protein for multiple kinase cascades, including ones that activate NF-κB. Overall, our results suggest PTPRN2 as a novel candidate biomarker and therapeutic target in breast cancer. Cancer Res; 75(9); 1846–58. ©2015 AACR.
Data from Proteasomal Inhibition by Ixazomib Induces CHK1 and MYC-Dependent Cell Death in T-cell and Hodgkin Lymphoma
Authors: Ravi Dashnamoorthy , Beheshti Afshin , Abermil Nasséra , Passero Frank , Sharma Jaya , Coyle Michael , Kritharis Athena , Kandela Irawati , Hlatky Lynn , Sitkovsky Michail V. , Mazar Andrew , Gartenhaus Ronald B. , Evens Andrew M.
Published: March 2024

Abstract
Proteasome-regulated NF-κB has been shown to be important for cell survival in T-cell lymphoma and Hodgkin lymphoma models. Several new small-molecule proteasome inhibitors are under various stages of active preclinical and clinical development. We completed a comprehensive preclinical examination of the efficacy and associated biologic effects of a second-generation proteasome inhibitor, ixazomib, in T-cell lymphoma and Hodgkin lymphoma cells and in vivo SCID mouse models. We demonstrated that ixazomib induced potent cell death in all cell lines at clinically achievable concentrations. In addition, it significantly inhibited tumor growth and improved survival in T-cell lymphoma and Hodgkin lymphoma human lymphoma xenograft models. Through global transcriptome analyses, proteasomal inhibition showed conserved overlap in downregulation of cell cycle, chromatin modification, and DNA repair processes in ixazomib-sensitive lymphoma cells. The predicted activity for tumor suppressors and oncogenes, the impact on “hallmarks of cancer,” and the analysis of key significant genes from global transcriptome analysis for ixazomib strongly favored tumor inhibition via downregulation of MYC and CHK1, its target genes. Furthermore, in ixazomib-treated lymphoma cells, we identified that CHK1 was involved in the regulation of MYC expression through chromatin modification involving histone H3 acetylation via chromatin immunoprecipitation. Finally, using pharmacologic and RNA silencing of CHK1 or the associated MYC-related mechanism, we demonstrated synergistic cell death in combination with antiproteasome therapy. Altogether, ixazomib significantly downregulates MYC and induces potent cell death in T-cell lymphoma and Hodgkin lymphoma, and we identified that combinatorial therapy with anti-CHK1 treatment represents a rational and novel therapeutic approach. Cancer Res; 76(11); 3319–31. ©2016 AACR.