bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from The Aryl Hydrocarbon Receptor Functions as a Tumor Suppressor of Liver Carcinogenesis
Authors: Fan Yunxia , Boivin Gregory P. , Knudsen Erik S. , Nebert Daniel W. , Xia Ying , Puga Alvaro
Published: March 2023

Abstract
The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor that mediates the biological and toxic effects of its xenobiotic ligands. Previous cell culture studies have shown that, in addition to controlling the xenobiotic detoxification response, AHR activation leads to G0-G1 arrest, diminished capacity for DNA replication, and inhibition of cell proliferation. In fact, recent work from our own and from other laboratories suggests that AHR may function as a tumor suppressor gene that becomes silenced during the process of tumor formation. To test this hypothesis and determine whether the mouse Ahr gene acts as a tumor suppressor gene in vivo, we have examined the role of Ahr ablation in liver tumorigenesis induced by the genotoxic chemical diethylnitrosamine (DEN), a hepatic carcinogen that is not an AHR ligand. In mice given a single i.p. injection of DEN, AHR antagonized liver tumor formation and growth by regulating cell proliferation, inflammatory cytokine expression, and DNA damage, parameters which were significantly elevated in the livers of control and, more so, of DEN-exposed Ahr−/− mice. Ahr−/− hepatocytes also showed significantly higher numbers of 4N cells, increased expression of proliferative markers, and repression of tumor suppressor genes. These data support the concept that in its basal state in the absence of a xenobiotic ligand, the Ahr gene functions as a tumor suppressor gene, and that its silencing may be associated with cancer progression. Cancer Res; 70(1); 212–220
Data from Heterogeneity of Regional Redox Status and Relation of the Redox Status to Oxygenation in a Tumor Model, Evaluated Using Electron Paramagnetic Resonance Imaging
Authors: Takeshita Keizo , Kawaguchi Kumiko , Fujii-Aikawa Kaori , Ueno Megumi , Okazaki Shoko , Ono Mitsuhiro , Krishna Murali C. , Kuppusamy Periannan , Ozawa Toshihiko , Ikota Nobuo
Published: March 2023

Abstract
It is widely accepted that redox status, along with the partial pressure of oxygen (pO2), determines the efficacy of some therapeutic methods applied to treat tumors, including radiation. Redox status, evaluated by the reduction of a nitroxyl probe, was reportedly heterogeneous in a mouse tumor model. However, neither variation of heterogeneity of the redox status among mice nor the relation of the redox status to pO2 in tumors has been characterized sufficiently. In this study, the regional reduction status in a mouse radiation-induced fibrosarcoma tumor model was evaluated using sequential three-dimensional electron paramagnetic resonance (EPR) imaging after i.v. injection of a tissue-permeable nitroxyl probe, HM-PROXYL. The regional decay of HM-PROXYL signal obeyed first-order kinetics, and the amplitude of the reduction rate and extent of its heterogeneity in a tumor varied among six mice. The tissue pO2 was measured using EPR oximetry with lithium phthalocyanine (LiPc) microcrystals implanted within the tumor. The location of LiPc was determined with EPR imaging. A sequential image was obtained following the injection of HM-PROXYL, even after LiPc implantation, by choosing an HM-PROXYL signal peak which does not overlap with the signal of LiPc. The relationship between pO2 and the reduction rate at the region of pO2 measurement was found to be low (r = 0.357) in 13 tumor-bearing mice, indicating that the extent of oxygenation does not necessarily affect the redox status under air-breathing conditions. The results strongly indicate the necessity of measurements of both redox status and oxygenation in every tumor to characterize tumor physiology. Cancer Res; 70(10); 4133–40. ©2010 AACR.
Data from Hepatocyte Nuclear Factor 4α Suppresses the Development of Hepatocellular Carcinoma
Authors: Ning Bei-Fang , Ding Jin , Yin Chuan , Zhong Wei , Wu Kun , Zeng Xin , Yang Wen , Chen Yue-Xiang , Zhang Jun-Ping , Zhang Xin , Wang Hong-Yang , Xie Wei-Fen
Published: March 2023

Abstract
Hepatocyte nuclear factor 4α (HNF4α) is a transcription factor that plays a key role in hepatocyte differentiation and the maintenance of hepatic function, but its role in hepatocarcinogenesis has yet to be examined. Here, we report evidence of a suppressor role for HNF4α in liver cancer. HNF4α expression was progressively decreased in the diethylinitrosamine-induced rat model of liver carcinogenesis. In human liver tissues, HNF4α expression was decreased in cirrhotic tissue and further decreased in hepatocarcinoma relative to healthy tissue. Notably, an inverse correlation existed with epithelial-mesenchymal transition (EMT). Enforced expression of HNF4α attenuated hepatocyte EMT during hepatocarcinogenesis, alleviated hepatic fibrosis, and blocked hepatocellular carcinoma (HCC) occurrence. In parallel, stem cell marker gene expression was inhibited along with cancer stem/progenitor cell generation. Further, enforced expression of HNF4α inhibited activation of β-catenin, which is closely associated with EMT and hepatocarcinogenesis. Taken together, our results suggest that the inhibitory effect of HNF4α on HCC development might be attributed to suppression of hepatocyte EMT and cancer stem cell generation through an inhibition of β-catenin signaling pathways. More generally, our findings broaden knowledge on the biological significance of HNF4α in HCC development, and they imply novel strategies for HCC prevention through the manipulation of differentiation-determining transcription factors in various types of carcinomas. Cancer Res; 70(19); 7640–51. ©2010 AACR.
Data from Regulation of Insulin-like Growth Factor–Mammalian Target of Rapamycin Signaling by MicroRNA in Childhood Adrenocortical Tumors
Authors: Doghman Mabrouka , Wakil Abeer El , Cardinaud Bruno , Thomas Emilie , Wang Jinling , Zhao Wei , Peralta-Del Valle Maria Helena C. , Figueiredo Bonald C. , Zambetti Gerard P. , Lalli Enzo
Published: March 2023

Abstract
MicroRNAs (miRNAs) act at the posttranscriptional level to control gene expression in virtually every biological process, including oncogenesis. Here, we report the identification of a set of miRNAs that are differentially regulated in childhood adrenocortical tumors (ACT), including miR-99a and miR-100. Functional analysis of these miRNAs in ACT cell lines showed that they coordinately regulate expression of the insulin-like growth factor–mammalian target of rapamycin (mTOR)–raptor signaling pathway through binding sites in their 3′-untranslated regions. In these cells, the active Ser2448-phosphorylated form of mTOR is present only in mitotic cells in association with the mitotic spindle and midbody in the G2-M phases of the cell cycle. Pharmacologic inhibition of mTOR signaling by everolimus greatly reduces tumor cell growth in vitro and in vivo. Our results reveal a novel mechanism of regulation of mTOR signaling by miRNAs, and they lay the groundwork for clinical evaluation of drugs inhibiting the mTOR pathway for treatment of adrenocortical cancer. Cancer Res; 70(11); 4666–75. ©2010 AACR.
Data from Prostate Cancer Radiosensitization through Poly(ADP-Ribose) Polymerase-1 Hyperactivation
Authors: Dong Ying , Bey Erik A. , Li Long-Shan , Kabbani Wareef , Yan Jingsheng , Xie Xian-Jin , Hsieh Jer-Tsong , Gao Jinming , Boothman David A.
Published: March 2023

Abstract
The clinical experimental agent, β-lapachone (β-lap; Arq 501), can act as a potent radiosensitizer in vitro through an unknown mechanism. In this study, we analyzed the mechanism to determine whether β-lap may warrant clinical evaluation as a radiosensitizer. β-Lap killed prostate cancer cells by NAD(P)H:quinone oxidoreductase 1 (NQO1) metabolic bioactivation, triggering a massive induction of reactive oxygen species, irreversible DNA single-strand breaks (SSB), poly(ADP-ribose) polymerase-1 (PARP-1) hyperactivation, NAD+/ATP depletion, and μ-calpain–induced programmed necrosis. In combination with ionizing radiation (IR), β-lap radiosensitized NQO1+ prostate cancer cells under conditions where nontoxic doses of either agent alone achieved threshold levels of SSBs required for hyperactivation of PARP-1. Combination therapy significantly elevated SSB level, γ-H2AX foci formation, and poly(ADP-ribosylation) of PARP-1, which were associated with ATP loss and induction of μ-calpain–induced programmed cell death. Radiosensitization by β-lap was blocked by the NQO1 inhibitor dicoumarol or the PARP-1 inhibitor DPQ. In a mouse xenograft model of prostate cancer, β-lap synergized with IR to promote antitumor efficacy. NQO1 levels were elevated in ∼60% of human prostate tumors evaluated relative to adjacent normal tissue, where β-lap might be efficacious alone or in combination with radiation. Our findings offer a rationale for the clinical utilization of β-lap (Arq 501) as a radiosensitizer in prostate cancers that overexpress NQO1, offering a potentially synergistic targeting strategy to exploit PARP-1 hyperactivation. Cancer Res; 70(20); 8088–96. ©2010 AACR.
Data from The Mitotic Kinase Aurora-A Induces Mammary Cell Migration and Breast Cancer Metastasis by Activating the Cofilin-F-actin Pathway
Authors: Wang Li-hui , Xiang Jin , Yan Min , Zhang Yan , Zhao Yan , Yue Cai-feng , Xu Jie , Zheng Fei-meng , Chen Jin-na , Kang Zhuang , Chen Tong-sheng , Xing Da , Liu Quentin
Published: March 2023

Abstract
The mitotic kinase Aurora-A (Aur-A) is required to form the bipolar spindle and ensure accurate chromosome segregation before cell division. Aur-A dysregulation represents an oncogenic event that promotes tumor formation. Here, we report that Aur-A promotes breast cancer metastasis. Aur-A overexpression enhanced mammary cell migration by dephosphorylation and activation of cofilin, which facilitates actin reorganization and polymerization. Cofilin knockdown impaired Aur-A–driven cell migration and protrusion of the cell membrane. Conversely, overexpression of activated cofilin abrogated the effects of Aur-A knockdown on cell migration. Moreover, Aur-A overexpession increased the expression of the cofilin phosphatase Slingshot-1 (SSH1), contributing to cofilin activation and cell migration. We found that phosphatidylinositol 3-kinase (PI3K) inhibition blocked Aur-A–induced cofilin dephosphorylation, actin reorganization, and cell migration, suggesting crosstalk with PI3K signaling and a potential benefit of PI3K inhibition in tumors with deregulated Aur-A. Additionally, we found an association between Aur-A overexpression and cofilin activity in breast cancer tissues. Our findings indicate that activation of the cofilin-F-actin pathway contributes to tumor cell migration and metastasis enhanced by Aur-A, revealing a novel function for mitotic Aur-A kinase in tumor progression. Cancer Res; 70(22); 9118–28. ©2010 AACR.
Data from The Oncoprotein c-Ski Functions as a Direct Antagonist of the Transforming Growth Factor-β Type I Receptor
Authors: Ferrand Nathalie , Atfi Azeddine , Prunier Céline
Published: March 2023

Abstract
The oncoprotein c-Ski has been implicated in the negative regulation of transforming growth factor-β (TGF-β) signaling owing to its ability to repress Smad transcriptional activity via recruitment of a transcriptional corepressor complex containing histone deacetylases. However, c-Ski has also been shown to localize to the cytoplasm, raising the interesting possibility that it might disable TGF-β signaling through alternative mechanisms. Here, we provide evidence that c-Ski can restrict TGF-β signaling by interacting directly with the activated TGF-β type I receptor (TβRI). We explored the physiologic relevance of the c-Ski/TβRI interaction and found that it can culminate in a constitutive association of TβRI with a nonfunctional R-Smad/Smad4 complex. Based on these findings, we hypothesize that the interaction between c-Ski and TβRI might interfere with nuclear translocation of the R-Smad/Smad4 complex, thereby attenuating TGF-β signaling. Such a mechanism may play a crucial role in tumor progression, because many tumors that express high levels of c-Ski also display impaired nuclear accumulation of Smads. Cancer Res; 70(21); 8457–66. ©2010 AACR.
Data from HGF/c-Met Acts as an Alternative Angiogenic Pathway in Sunitinib-Resistant Tumors
Authors: Shojaei Farbod , Lee Joseph H. , Simmons Brett H. , Wong Anthony , Esparza Carlos O. , Plumlee Pamela A. , Feng Junli , Stewart Albert E. , Hu-Lowe Dana D. , Christensen James G.
Published: March 2023

Abstract
Molecular and cellular mechanisms underlying resistance/low responsiveness to antiangiogenic compounds are under extensive investigations. Both populations of tumor and stroma (nontumor compartment) seem to contribute in inherent/acquired resistance to antiangiogenic therapy. Here, investigating in vivo efficacy of sunitinib in experimental models resulted in the identification of tumors that were resistant/sensitive to the therapy. Analysis of tumor protein lysates indicated a greater concentration of hepatocyte growth factor (HGF) in resistant tumors than in sensitive ones. In addition, using flow cytometry, c-Met expression was found to be significantly higher in endothelial cells than in tumor cells, suggesting that HGF might target the vascular endothelial cells in resistant tumors. Combination of sunitinib and a selective c-Met inhibitor significantly inhibited tumor growth compared with sunitinib or c-Met inhibitor alone in resistant tumors. Histology and in vitro analyses suggested that combination treatment mainly targeted the vasculature in the resistant tumors. Conversely, systemic injection of HGF in the sensitive tumor models conferred resistance to sunitinib through maintenance of tumor angiogenesis. In conclusion, our study indicates a role for HGF/c-Met pathway in development of resistance to antiangiogenic therapy and suggests a potential strategy to circumvent resistance to vascular endothelial growth factor receptor tyrosine kinase inhibitor in the clinic. Cancer Res; 70(24); 10090–100. ©2010 AACR.
Data from Cell Signaling by Urokinase-type Plasminogen Activator Receptor Induces Stem Cell–like Properties in Breast Cancer Cells
Authors: Jo Minji , Eastman Boryana M. , Webb Drue L. , Stoletov Konstantin , Klemke Richard , Gonias Steven L.
Published: March 2023

Abstract
Signaling by urokinase-type plasminogen activator receptor (uPAR) can cause epithelial-mesenchymal transition (EMT) in cultured breast cancer cells. In this report, we show that uPAR signaling can also induce cancer stem cell (CSC)–like properties. Ectopic overexpression of uPAR in human MDA-MB-468 breast cancer cells promoted the emergence of a CD24−/CD44+ phenotype, characteristic of CSCs, while increasing the cell surface abundance of integrin subunits β1/CD29 and α6/CD49f that represent putative mammary gland stem cell biomarkers. uPAR overexpression increased mammosphere formation in vitro and tumor formation in an immunocompromized severe combined immunodeficient (SCID) mouse model of orthotopic breast cancer. Hypoxic conditions that are known to induce EMT in MDA-MB-468 cells also increased cell surface β1/CD29, mimicking the effects of uPAR overexpression. Antagonizing uPAR effector signaling pathways reversed the increase in cell surface integrin expression. Whereas uPAR overexpression did not induce EMT in MCF-7 breast cancer cells, CSC-like properties were nevertheless still induced along with an increase in tumor initiation and growth in the orthotopic setting in SCID mice. Notably, in MCF-7 cell mammospheres, which display a well-defined acinus-like structure with polarized expression of E-cadherin and β1-integrin, cell collapse into the central cavity was decreased by uPAR overexpression, suggesting that uPAR signaling may stabilize epithelial morphology. In summary, our findings show that uPAR signaling can induce CSC-like properties in breast cancer cells, either concomitantly with or separately from EMT. Cancer Res; 70(21); 8948–58. ©2010 AACR.
Data from Phosphorescent Light–Emitting Iridium Complexes Serve as a Hypoxia-Sensing Probe for Tumor Imaging in Living Animals
Authors: Zhang Shaojuan , Hosaka Masahiro , Yoshihara Toshitada , Negishi Kazuya , Iida Yasuhiko , Tobita Seiji , Takeuchi Toshiyuki
Published: March 2023

Abstract
Iridium complex is a promising organic light–emitting diode material for next generation video displays that emits phosphorescence quenched by oxygen. We used this oxygen-quenching feature for imaging tumor hypoxia. Red light–emitting Ir(btp)2(acac) (BTP) presented hypoxia-dependent light emission in culture cell lines, whose intensity was in parallel with hypoxia-inducible factor-1α images. BTP was further applied to imaging five nude mouse transplanted with tumors. All tumors presented a bright BTP-emitting image even 5 minutes after injection. The minimal image recognition size was ∼2 mm in diameter. By morphologic examination and phosphorescence lifetime measurement, BTP appeared to localize to the tumor cells. Because BTP is easily modifiable, we synthesized BTP analogues with a longer excitation/emission wavelength. One of them, BTPHSA, depicted clear imaging from tumors transplanted 6 to 7 mm deep from the skin surface. We suggest that iridium complex materials have a vast potential for imaging hypoxic lesions such as tumor tissues. Cancer Res; 70(11); 4490–8. ©2010 AACR.
Data from Inhibition of ALK, PI3K/MEK, and HSP90 in Murine Lung Adenocarcinoma Induced by EML4-ALK Fusion Oncogene
Authors: Chen Zhao , Sasaki Takaaki , Tan Xiaohong , Carretero Julian , Shimamura Takeshi , Li Danan , Xu Chunxiao , Wang Yuchuan , Adelmant Guillaume O. , Capelletti Marzia , Lee Hyun Joo , Rodig Scott J. , Borgman Christa , Park Seung-il , Kim Hyeong Ryul , Padera Robert , Marto Jarrod A. , Gray Nathanael S. , Kung Andrew L. , Shapiro Geoffrey I. , Jänne Pasi A. , Wong Kwok-Kin
Published: March 2023

Abstract
Genetic rearrangements of the anaplastic lymphoma kinase (ALK) kinase occur in 3% to 13% of non–small cell lung cancer patients and rarely coexist with KRASor EGFR mutations. To evaluate potential treatment strategies for lung cancers driven by an activated EML4-ALK chimeric oncogene, we generated a genetically engineered mouse model that phenocopies the human disease where this rearranged gene arises. In this model, the ALK kinase inhibitor TAE684 produced greater tumor regression and improved overall survival compared with carboplatin and paclitaxel, representing clinical standard of care. 18F-FDG-PET-CT scans revealed almost complete inhibition of tumor metabolic activity within 24 hours of TAE684 exposure. In contrast, combined inhibition of the PI3K/AKT and MEK/ERK1/2 pathways did not result in significant tumor regression. We identified EML4-ALK in complex with multiple cellular chaperones including HSP90. In support of a functional reliance, treatment with geldanamycin-based HSP90 inhibitors resulted in rapid degradation of EML4-ALK in vitro and substantial, albeit transient, tumor regression in vivo. Taken together, our findings define a murine model that offers a reliable platform for the preclinical comparison of combinatorial treatment approaches for lung cancer characterized by ALK rearrangement.Cancer Res; 70(23); 9827–36. ©2010 AACR.
Data from Insulin-Mediated Acceleration of Breast Cancer Development and Progression in a Nonobese Model of Type 2 Diabetes
Authors: Novosyadlyy Ruslan , Lann Danielle E. , Vijayakumar Archana , Rowzee Anne , Lazzarino Deborah A. , Fierz Yvonne , Carboni Joan M. , Gottardis Marco M. , Pennisi Patricia A. , Molinolo Alfredo A. , Kurshan Naamit , Mejia Wilson , Santopietro Stefania , Yakar Shoshana , Wood Teresa L. , LeRoith Derek
Published: March 2023

Abstract
Epidemiologic studies suggest that type 2 diabetes (T2D) increases breast cancer risk and mortality, but there is limited experimental evidence supporting this association. Moreover, there has not been any definition of a pathophysiological pathway that diabetes may use to promote tumorigenesis. In the present study, we used the MKR mouse model of T2D to investigate molecular mechanisms that link T2D to breast cancer development and progression. MKR mice harbor a transgene encoding a dominant-negative, kinase-dead human insulin-like growth factor-I receptor (IGF-IR) that is expressed exclusively in skeletal muscle, where it acts to inactivate endogenous insulin receptor (IR) and IGF-IR. Although lean female MKR mice are insulin resistant and glucose intolerant, displaying accelerated mammary gland development and enhanced phosphorylation of IR/IGF-IR and Akt in mammary tissue, in the context of three different mouse models of breast cancer, these metabolic abnormalities were found to accelerate the development of hyperplastic precancerous lesions. Normal or malignant mammary tissue isolated from these mice exhibited increased phosphorylation of IR/IGF-IR and Akt, whereas extracellular signal-regulated kinase 1/2 phosphorylation was largely unaffected. Tumor-promoting effects of T2D in the models were reversed by pharmacological blockade of IR/IGF-IR signaling by the small-molecule tyrosine kinase inhibitor BMS-536924. Our findings offer compelling experimental evidence that T2D accelerates mammary gland development and carcinogenesis,and that the IR and/or the IGF-IR are major mediators of these effects. Cancer Res; 70(2); 741–51
Data from Functional Roles of Multiple Feedback Loops in Extracellular Signal-Regulated Kinase and Wnt Signaling Pathways That Regulate Epithelial-Mesenchymal Transition
Authors: Shin Sung-Young , Rath Oliver , Zebisch Armin , Choo Sang-Mok , Kolch Walter , Cho Kwang-Hyun
Published: March 2023

Abstract
Epithelial-mesenchymal transition (EMT) is a key event in the generation of invasive tumor cells. A hallmark of EMT is the repression of E-cadherin expression, which is regulated by various signal transduction pathways including extracellular signal-regulated kinase (ERK) and Wnt. These pathways are highly interconnected via multiple coupled feedback loops (CFL). As the function of such coupled feedback regulations is difficult to analyze experimentally, we used a systems biology approach where computational models were designed to predict biological effects that result from the complex interplay of CFLs. Using epidermal growth factor (EGF) and Wnt as input and E-cadherin transcriptional regulation as output, we established an ordinary differential equation model of the ERK and Wnt signaling network containing six feedback links and used extensive computer simulations to analyze the effects of these feedback links in isolation and different combinations. The results show that the feedbacks can generate a rich dynamic behavior leading to various dose-response patterns and have a decisive role in determining network responses to EGF and Wnt. In particular, we made two important findings: first, that coupled positive feedback loops composed of phosphorylation of Raf kinase inhibitor RKIP by ERK and transcriptional repression of RKIP by Snail have an essential role in causing a switch-like behavior of E-cadherin expression; and second, that RKIP expression inhibits EMT progression by preventing E-cadherin suppression. Taken together, our findings provide us with a system-level understanding of how RKIP can regulate EMT progression and may explain why RKIP is downregulated in so many metastatic cancer cells. Cancer Res; 70(17); 6715–24. ©2010 AACR.
Data from A Functional Polymorphism in the NAD(P)H Oxidase Subunit CYBA Is Related to Gene Expression, Enzyme Activity, and Outcome in Non–Hodgkin Lymphoma
Authors: Hoffmann Marion , Schirmer Markus A. , Tzvetkov Mladen V. , Kreuz Markus , Ziepert Marita , Wojnowski Leszek , Kube Dieter , Pfreundschuh Michael , Trümper Lorenz , Loeffler Markus , Brockmöller Jürgen
Published: March 2023

Abstract
NAD(P)H oxidase is a major endogenous source of reactive oxygen species (ROS). ROS may not only be involved in carcinogenesis but also in efficacy of chemotherapeutic agents like doxorubicin. By a comprehensive genotyping approach covering 48 genetic polymorphisms (single-nucleotide polymorphisms) in five subunits of phagocytic NAD(P)H oxidase, we asked whether they affect gene expression, enzymatic activity, and outcome of CHO(E)P chemotherapy. A highly consistent effect was observed for the CYBA 640A>G variant. In peripheral blood granulocytes of 125 healthy volunteers, the G allele of 640A>G was associated with lower NAD(P)H oxidase activity (P = 0.006). Moreover, the G allele was associated with lower mRNA and protein expression (both P = 0.02). Of clinical importance, the outcome of patients suffering from non-Hodgkin lymphoma and treated with CHO(E)P regimen was dependent on the CYBA 640A>G polymorphism. In an exploratory study (n = 401), carriers of 640GG had an event-free survival (EFS) risk ratio of 1.95 [95% confidence interval (95% CI), 1.31–2.90; P = 0.001] compared with 640AA. In a confirmatory set (n = 477), the risk ratios were 1.53 (1.04–2.25, P = 0.03). The complete set of 878 patients showed a relative risk of 1.72 (1.30–2.26) and 1.59 (1.14–2.21) for EFS and overall survival, respectively. Further molecular-biological experiments showed lower expression and reduced stability of transcripts with the G allele in lymphoblastoid cell lines. Transfection of allele-specific plasmids into HEK293 cells elicited lower activity for the G allele in a luciferase reporter gene construct. Thus, CYBA 640A>G was shown to be a functional polymorphism with possible consequences for patients receiving CHO(E)P chemotherapy and might have further implications for other ROS-mediated modalities. Cancer Res; 70(6); 2328–38
Data from p66Shc Is Indispensable for Phenethyl Isothiocyanate–Induced Apoptosis in Human Prostate Cancer Cells
Authors: Xiao Dong , Singh Shivendra V.
Published: March 2023

Abstract
Naturally occurring phenethyl isothiocyanate (PEITC) selectively inhibits growth of cancer cells by causing apoptosis, but the mechanism of cell death induction is not fully understood. We now show, for the first time, that growth factor adapter protein p66Shc is indispensable for PEITC-induced apoptosis. Mouse embryonic fibroblasts derived from p66Shc knockout mice were significantly more resistant to PEITC-mediated growth inhibition, cytoplasmic histone-associated apoptotic DNA fragmentation, and caspase-3 activation compared with wild-type fibroblasts. The PEITC treatment resulted in induction as well as increased Ser36 phosphorylation of p66Shc in PC-3 and LNCaP human prostate cancer cells. Knockdown of p66Shc protein conferred significant protection against PEITC-mediated cytoplasmic histone-associated DNA fragmentation as well as production of reactive oxygen species in both PC-3 and LNCaP cells. The PEITC-treated PC-3 and LNCaP cells exhibited increased binding of p66Shc with prolyl isomerase Pin1, a protein implicated in translocation of p66Shc to mitochondria. Consistent with these results, treatment of PC-3 cells with PEITC resulted in translocation of p66Shc to the mitochondria as judged by immunoblotting using cytosolic and mitochondrial fractions and immunofluorescence microscopy. Growth suppression and apoptosis induction in tumor xenografts in vivo by oral administration of PEITC to the PC-3 tumor-bearing male athymic mice were accompanied by statistically significant increase in the level of Ser36-phosphorylated p66Shc. Collectively, these results provide novel insight into the critical role of p66Shc in regulation of PEITC-induced apoptotic cell death in human prostate cancer cells. Cancer Res; 70(8); 3150–8. ©2010 AACR.
Data from Mouse Mammary Tumor Virus–like Sequences in Human Breast Cancer
Authors: Lawson James S. , Glenn Wendy K. , Salmons Brian , Ye Yulan , Heng Benjamin , Moody Patrick , Johal Harpreet , Rawlinson William D. , Delprado Warick , Lutze-Mann Louise , Whitaker Noel J.
Published: March 2023

Abstract
Mouse mammary tumor virus (MMTV) sequences have been reported to be present in some human breast cancers, but it is unclear whether they have any causal role. In mice, MMTV promotes tumor formation indirectly by insertional mutagenesis of Wnt oncogenes that lead to their activation. In this study, we investigated the status of Wnt-1 in human breast cancers harboring MMTV-like sequences encoding viral envelope (env) genes. We confirmed the detection of env sequences in the nucleus of human breast cancer specimens that are similar in appearance to mouse mammary tumors expressing MMTV env sequences. MMTV env sequences in human breast cancers were also nearly indistinguishable from env sequences in mouse MMTV isolates. Further, Wnt-1 expression was higher in specimens of env-positive ductal carcinoma in situ and invasive ductal carcinoma, relative to env-negative specimens. Our findings extend the evidence that MMTV sequences found in naturally occurring mouse mammary tumors can be found in some human breast cancers, prompting further evaluation of causal roles in these settings. Cancer Res; 70(9); 3576–85. ©2010 AACR.
Data from Protein Tyrosine Phosphatase Receptor Type γ Is a Functional Tumor Suppressor Gene Specifically Downregulated in Chronic Myeloid Leukemia
Authors: Della Peruta Marco , Martinelli Giovanni , Moratti Elisabetta , Pintani Davide , Vezzalini Marzia , Mafficini Andrea , Grafone Tiziana , Iacobucci Ilaria , Soverini Simona , Murineddu Marco , Vinante Fabrizio , Tecchio Cristina , Piras Giovanna , Gabbas Attilio , Monne Maria , Sorio Claudio
Published: March 2023

Abstract
Chronic myelogenous leukemia (CML) is the most common myeloproliferative disease. Protein tyrosine phosphatase receptor type γ (PTPRG) is a tumor suppressor gene and a myeloid cell marker expressed by CD34+ cells. Downregulation of PTPRG increases colony formation in the PTPRG-positive megakaryocytic cell lines MEG-01 and LAMA-84 but has no effect in the PTPRG-negative cell lines K562 and KYO-1. Its overexpression has an oncosuppressive effect in all these cell lines and is associated with myeloid differentiation and inhibition of BCR/ABL-dependent signaling. The intracellular domain of PTPRG directly interacts with BCR/ABL and CRKL, but not with signal transducers and activators of transcription 5. PTPRG is downregulated at the mRNA and protein levels in leukocytes of CML patients in both peripheral blood and bone marrow, including CD34+ cells, and is reexpressed following molecular remission of disease. Reexpression was associated with a loss of methylation of a CpG island of PTPRG promoter occurring in 55% of the patients analyzed. In K562 cell line, the DNA hypomethylating agent 5-aza-2′-deoxycytidine induced PTPRG expression and caused an inhibition of colony formation, partially reverted by downregulation of PTPRG expression. These findings establish, for the first time, PTPRG as a tumor suppressor gene involved in the pathogenesis of CML, suggesting its use as a potential diagnostic and therapeutic target. Cancer Res; 70(21); 8896–906. ©2010 AACR.
Data from Androgen-Induced TMPRSS2:ERG Fusion in Nonmalignant Prostate Epithelial Cells
Authors: Bastus Nuria Coll , Boyd Lara K. , Mao Xueying , Stankiewicz Elzbieta , Kudahetti Sakunthala C. , Oliver R. Tim D. , Berney Daniel M. , Lu Yong-Jie
Published: March 2023

Abstract
Fusion genes play important roles in tumorigenesis. The identification of the high-frequency TMPRSS2 fusion with ERG and other ETS family genes in prostate cancer highlights the importance of fusion genes in solid tumor development and progression. However, the mechanisms leading to these fusions are unclear. We investigated whether androgen, through stimulating its receptor, could promote spatial genome reorganization and contribute to the generation of the TMPRSS2:ERG fusion. We show that treatment with androgen can induce the TMPRSS2:ERG fusion in both malignant and nonmalignant prostate epithelial cells. Although the fusion could be detected in malignant cells following 24-hour treatment, prolonged exposure to androgen was required to detect the fusion transcript in nonmalignant cells. We associated the fusion incidence with genetic factors, including androgen-induced gene proximity, androgen receptor exon1 CAG repeat length and expression of the PIWIL1 gene. This study demonstrates that fusions can be induced prior to malignant transformation and generation of the fusion is associated with both gene proximity and loss of the ability to prevent double-strand breaks. Cancer Res; 70(23); 9544–8. ©2010 AACR.
Data from Concomitant Tumor and Minor Histocompatibility Antigen–Specific Immunity Initiate Rejection and Maintain Remission from Established Spontaneous Solid Tumors
Authors: Hess Michelini Rodrigo , Freschi Massimo , Manzo Teresa , Jachetti Elena , Degl'Innocenti Elena , Grioni Matteo , Basso Veronica , Bonini Chiara , Simpson Elizabeth , Mondino Anna , Bellone Matteo
Published: March 2023

Abstract
Nonmyeloablative hematopoietic cell transplantation can cure patients with hematologic malignancies but has reported limited success against solid tumors. This is possibly because of profound peripheral tolerance mechanisms and/or suboptimal tumor recognition by effector T lymphocytes. We report that in mice developing spontaneous prostate cancer, nonmyeloablative minor histocompatibility mismatched hematopoietic stem cell transplantation, and donor lymphocyte infusion of unmanipulated lymphocytes combined with posttransplant tumor-specific vaccination circumvents tumor-specific tolerance, allowing acute tumor rejection and the establishment of protective immunosurveillance. Although donor-derived tumor-specific T cells readily differentiated into effector cells and infiltrated the tumor soon after infusion, they were alone insufficient for tumor eradication, which instead required the concomitance of minor histocompatibiltiy antigen–specific CD8+ T-cell responses. The establishment of protective immunosurveillance was best induced by posttransplant tumor-specific vaccination. Hence, these results provide the proof of principle that tumor-specific T-cell responses have to be harnessed together with minor histocompatibility responses and sustained by posttransplant tumor-specific vaccination to improve the efficacy of allotransplantion for the cure of solid tumors. Cancer Res; 70(9); 3505–14. ©2010 AACR.
Data from NF-κB, and not MYCN, Regulates MHC Class I and Endoplasmic Reticulum Aminopeptidases in Human Neuroblastoma Cells
Authors: Forloni Matteo , Albini Sonia , Limongi Maria Zaira , Cifaldi Loredana , Boldrini Renata , Nicotra Maria Rita , Giannini Giuseppe , Natali Pier Giorgio , Giacomini Patrizio , Fruci Doriana
Published: March 2023

Abstract
Neuroblastoma (NB) is the most common solid extracranial cancer of childhood. Amplification and overexpression of the MYCN oncogene characterize the most aggressive forms and are believed to severely downregulate MHC class I molecules by transcriptional inhibition of the p50 NF-κB subunit. In this study, we found that in human NB cell lines, high MYCN expression is not responsible for low MHC class I expression because neither transfection-mediated overexpression nor small interfering RNA suppression of MYCN affects MHC class I and p50 levels. Furthermore, we identified NF-κB as the immediate upstream regulator of MHC class I because the p65 NF-κB subunit binds MHC class I promoter in chromatin immunoprecipitation experiments, and MHC class I expression is enhanced by p65 transfection and reduced by (a) the chemical NF-κB inhibitor sulfasalazine, (b) a dominant-negative IKBα gene, and (c) p65 silencing. Moreover, we showed that the endoplasmic reticulum aminopeptidases ERAP1 and ERAP2, which generate MHC class I binding peptides, are regulated by NF-κB, contain functional NF-κB–binding elements in their promoters, and mimic MHC class I molecules in the expression pattern. Consistent with these findings, nuclear p65 was detected in NB cells that express MHC class I molecules in human NB specimens. Thus, the coordinated downregulation of MHC class I, ERAP1, and ERAP2 in aggressive NB cells is attributable to a low transcriptional availability of NF-κB, possibly due to an unknown suppressor other than MYCN. Cancer Res; 70(3); 916–24
Data from Loss of PTEN Expression by Blocking Nuclear Translocation of EGR1 in Gefitinib-Resistant Lung Cancer Cells Harboring Epidermal Growth Factor Receptor–Activating Mutations
Authors: Yamamoto Chizuko , Basaki Yuji , Kawahara Akihiko , Nakashima Kazutaka , Kage Masayoshi , Izumi Hiroto , Kohno Kimitoshi , Uramoto Hidetaka , Yasumoto Kosei , Kuwano Michihiko , Ono Mayumi
Published: March 2023

Abstract
Gefitinib (Iressa) and erlotinib (Tarceva), which target the epidermal growth factor receptor (EGFR), are approved for treatment of patients with advanced non–small cell lung cancer (NSCLC). Patients whose tumors harbor mutations in the EGFR gene, including delE746-A750 in exon 19 and L858R in exon 21, may benefit in particular from gefitinib treatment. However, acquired resistance to gefitinib has been a serious clinical problem, and further optimization is needed for application of EGFR-targeted drugs in lung cancer patients. In this study, we established gefitinib-resistant NSCLC cells from PC-9 cell line, which harbors the delE746-A750 mutation, by exposing the cell line to gefitinib for over 7 months. Gefitinib-resistant PC-9/GEFs cell lines showed a marked downregulation of PTEN expression and increased Akt phosphorylation. In revertant, gefitinib-sensitive clones (PC-9/Rev) derived from PC-9/GEF1-1 and PC-9/GEF2-1, PTEN expression, as well as sensitivity to gefitinib and erlotinib, was restored. Knockdown of PTEN expression using small interfering RNA specific for PTEN in PC-9 cells resulted in drug resistance to gefitinib and erlotinib. Nuclear translocation of the EGR1 transcription factor, which regulates PTEN expression, was shown to be suppressed in resistant clones and restored in their revertant clones. Reduced PTEN expression was also seen in tumor samples from a patient with gefitinib-refractory NSCLC. This study thus strongly suggests that loss of PTEN expression contributes to gefitinib and erlotinib resistance in NSCLC. Our findings reinforce the therapeutic importance of PTEN expression in the treatment of NSCLC with EGFR-targeted drugs. Cancer Res; 70(21); 8715–25. ©2010 AACR.
Data from Acquired Resistance of Non–Small Cell Lung Cancer Cells to MET Kinase Inhibition Is Mediated by a Switch to Epidermal Growth Factor Receptor Dependency
Authors: McDermott Ultan , Pusapati Raju V. , Christensen James G. , Gray Nathanael S. , Settleman Jeff
Published: March 2023

Abstract
Cancer cells harboring MET amplification display striking sensitivity to selective small molecule inhibitors of MET kinase, prompting their clinical evaluation. Similar to the experience with traditional therapeutics, most patients responding to treatment with such molecular targeted therapeutics ultimately relapse with drug-resistant disease. In this study we modeled acquired resistance to experimental MET kinase inhibitor PF2341066 in MET-amplified non–small cell lung carcinoma (NSCLC) cell lines to identify drug resistance mechanisms that may arise in clinic. We found that activation of the epidermal growth factor receptor (EGFR) pathway emerges as a resistance mechanism in MET-amplified cells after prolonged exposure to PF2341066. Whereas combined inhibition of MET and EGFR kinases in MET-dependent NSCLC cells did not enhance their initial sensitivity to PF2341066, this combination dramatically suppressed the eventual emergence of drug-resistant clones after prolonged drug exposure. Conversely, activation of the EGFR pathway increased the yield of PF2341066-resistant clones, confirming the significance of this pathway in conferring resistance. Our findings support an intimate relationship between the EGFR and MET signaling pathways in NSCLC, and they suggest that combination treatment with MET and EGFR kinase inhibitors may be beneficial in MET-amplified NSCLC by reducing selection for drug resistant clones. Cancer Res; 70(4); 1625–34
Data from Polo-like Kinase 1 (Plk1) as a Novel Drug Target in Chronic Myeloid Leukemia: Overriding Imatinib Resistance with the Plk1 Inhibitor BI 2536
Authors: Gleixner Karoline V. , Ferenc Veronika , Peter Barbara , Gruze Alexander , Meyer Renata A. , Hadzijusufovic Emir , Cerny-Reiterer Sabine , Mayerhofer Matthias , Pickl Winfried F. , Sillaber Christian , Valent Peter
Published: March 2023

Abstract
In most patients with chronic myeloid leukemia (CML), the disease can be kept under control using the BCR/ABL kinase inhibitor imatinib. Nevertheless, resistance or intolerance to imatinib and other BCR/ABL inhibitors may occur during therapy. Therefore, CML research is focusing on novel targets and targeted drugs. Polo-like kinase 1 (Plk1) is a serine/threonine kinase that plays an essential role in mitosis. In this study, we examined the expression of Plk1 in CML cells and its potential role as a therapeutic target. Plk1 was found to be expressed in phosphorylated form in the CML cell line K562 as well as in primary CML cells in all patients tested. Inhibition of BCR/ABL by imatinib or nilotinib (AMN107) led to decreased expression of the Plk1 protein in CML cells, suggesting that BCR/ABL promotes Plk1 generation. Silencing of Plk1 in CML cells by a small interfering RNA approach was followed by cell cycle arrest and apoptosis. Furthermore, the Plk1-targeting drug BI 2536 was found to inhibit proliferation of imatinib-sensitive and imatinib-resistant CML cells, including leukemic cells, carrying the T315 mutation of BCR/ABL with reasonable IC50 values (1–50 nmol/L). The growth-inhibitory effects of BI 2536 on CML cells were found to be associated with cell cycle arrest and apoptosis. Moreover, BI 2536 was found to synergize with imatinib and nilotinib in producing growth inhibition in CML cells. In conclusion, Plk1 is expressed in CML cells and may represent a novel, interesting target in imatinib-sensitive and imatinib-resistant CML. Cancer Res; 70(4); 1513–23
Data from Selective Visualization of Cyclooxygenase-2 in Inflammation and Cancer by Targeted Fluorescent Imaging Agents
Authors: Uddin Md. Jashim , Crews Brenda C. , Blobaum Anna L. , Kingsley Philip J. , Gorden D. Lee , McIntyre J. Oliver , Matrisian Lynn M. , Subbaramaiah Kotha , Dannenberg Andrew J. , Piston David W. , Marnett Lawrence J.
Published: March 2023

Abstract
Effective diagnosis of inflammation and cancer by molecular imaging is challenging because of interference from nonselective accumulation of the contrast agents in normal tissues. Here, we report a series of novel fluorescence imaging agents that efficiently target cyclooxygenase-2 (COX-2), which is normally absent from cells, but is found at high levels in inflammatory lesions and in many premalignant and malignant tumors. After either i.p. or i.v. injection, these reagents become highly enriched in inflamed or tumor tissue compared with normal tissue and this accumulation provides sufficient signal for in vivo fluorescence imaging. Further, we show that only the intact parent compound is found in the region of interest. COX-2–specific delivery was unambiguously confirmed using animals bearing targeted deletions of COX-2 and by blocking the COX-2 active site with high-affinity inhibitors in both in vitro and in vivo models. Because of their high specificity, contrast, and detectability, these fluorocoxibs are ideal candidates for detection of inflammatory lesions or early-stage COX-2–expressing human cancers, such as those in the esophagus, oropharynx, and colon. Cancer Res; 70(9); 3618–27. ©2010 AACR.
Data from Systematic Analysis of MicroRNAs Targeting the Androgen Receptor in Prostate Cancer Cells
Authors: Östling Päivi , Leivonen Suvi-Katri , Aakula Anna , Kohonen Pekka , Mäkelä Rami , Hagman Zandra , Edsjö Anders , Kangaspeska Sara , Edgren Henrik , Nicorici Daniel , Bjartell Anders , Ceder Yvonne , Perälä Merja , Kallioniemi Olli
Published: March 2023

Abstract
Androgen receptor (AR) is expressed in all stages of prostate cancer progression, including in castration-resistant tumors. Eliminating AR function continues to represent a focus of therapeutic investigation, but AR regulatory mechanisms remain poorly understood. To systematically characterize mechanisms involving microRNAs (miRNAs), we conducted a gain-of function screen of 1129 miRNA molecules in a panel of human prostate cancer cell lines and quantified changes in AR protein content using protein lysate microarrays. In this way, we defined 71 unique miRNAs that influenced the level of AR in human prostate cancer cells. RNA sequencing data revealed that the 3′UTR of AR (and other genes) is much longer than currently used in miRNA target prediction programs. Our own analyses predicted that most of the miRNA regulation of AR would target an extended 6 kb 3′UTR. 3′UTR-binding assays validated 13 miRNAs that are able to regulate this long AR 3′UTR (miR-135b, miR-185, miR-297, miR-299-3p, miR-34a, miR-34c, miR-371–3p, miR-421, miR-449a, miR-449b, miR-634, miR-654–5p, and miR-9). Fifteen AR downregulating miRNAs decreased androgen-induced proliferation of prostate cancer cells. In particular, analysis of clinical prostate cancers confirmed a negative correlation of miR-34a and miR-34c expression with AR levels. Our findings establish that miRNAs interacting with the long 3′UTR of the AR gene are important regulators of AR protein levels, with implications for developing new therapeutic strategies to inhibit AR function and androgen-dependent cell growth. Cancer Res; 71(5); 1956–67. ©2011 AACR.
Data from MTGR1 Is Required for Tumorigenesis in the Murine AOM/DSS Colitis-Associated Carcinoma Model
Authors: Barrett Caitlyn W. , Fingleton Barbara , Williams Amanda , Ning Wei , Fischer Melissa A. , Washington Mary K. , Chaturvedi Rupesh , Wilson Keith T. , Hiebert Scott W. , Williams Christopher S.
Published: March 2023

Abstract
Myeloid Translocation Gene, Related-1 (MTGR1) CBFA2T2 is a member of the Myeloid Translocation Gene (MTG) family of transcriptional corepressors. The remaining two family members, MTG8 (RUNX1T1) and MTG16 (CBFA2T3) are identified as targets of chromosomal translocations in acute myeloid leukemia (AML). Mtgr1−/− mice have defects in intestinal lineage allocation and wound healing. Moreover, these mice show signs of impaired intestinal stem cell function. Based on these phenotypes, we hypothesized that MTGR1 may influence tumorigenesis arising in an inflammatory background. We report that Mtgr1−/− mice were protected from tumorigenesis when injected with azoxymethane (AOM) and then subjected to repeated cycles of dextran sodium sulfate (DSS). Tumor cell proliferation was comparable, but Mtgr1−/− tumors had significantly higher apoptosis rates. These phenotypes were dependent on epithelial injury, the resultant inflammation, or a combination of both as there was no difference in aberrant crypt foci (ACF) or tumor burden when animals were treated with AOM as the sole agent. Gene expression analysis indicated that Mtgr1−/− tumors had significant upregulation of inflammatory networks, and immunohistochemistry (IHC) for immune cell subsets revealed a marked multilineage increase in infiltrates, consisting predominately of CD3+ and natural killer T (NKT) cells as well as macrophages. Transplantation of wild type (WT) bone marrow into Mtgr1−/− mice, and the reciprocal transplant, did not alter the phenotype, ruling out an MTGR1 hematopoietic cell-autonomous mechanism. Our findings indicate that MTGR1 is required for efficient inflammatory carcinogenesis in this model, and implicate its dysfunction in colitis-associated carcinoma. This represents the first report functionally linking MTGR1 to intestinal tumorigenesis. Cancer Res; 71(4); 1302–12. ©2011 AACR.