bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Sequential Activation of Snail1 and N-Myc Modulates Sonic Hedgehog–Induced Transformation of Neural Cells
Authors: Wanshura Leah E. Colvin , Galvin Katherine E. , Ye Hong , Fernandez-Zapico Martin E. , Wetmore Cynthia
Published: March 2024

Abstract
Activation of the Sonic hedgehog (Shh) pathway and increased expression of Gli1 play an important role in proliferation and transformation of granule cell progenitors (GCP) in the developing cerebellum. Medulloblastomas arising from cerebellar GCPs are frequently driven by Shh pathway–activating mutations; however, molecular mechanisms of Shh pathway dysregulation and transformation of neural progenitors remain poorly defined. We report that the transcription factor and oncogene Snail1 (Sna1) is directly induced by Shh pathway activity in GCPs, murine medulloblastomas, and human medulloblastoma cells. Enforced expression of Sna1 was sufficient to induce GCPs and medulloblastoma cell proliferation in the absence of Shh/Gli1 exposure. In addition, enforced expression of Sna1 increased transformation of medulloblastoma cells in vitro and in vivo. Analysis of potential Sna1 targets in neural cells revealed a novel Sna1 target, N-Myc, a transcription factor known to play a role in Shh-mediated GCP proliferation and medulloblastoma formation. We found that Sna1 directly induced transcription of N-Myc in human medulloblastoma cells and that depletion of N-Myc ablated the Sna1-induced proliferation and transformation. Taken together, these results provide further insight into the mechanism of Shh-induced transformation of neural progenitor cells and suggest that induction of Sna1 may serve to amplify the oncogenic potential of Shh pathway activation through N-Myc induction. Cancer Res; 71(15); 5336–45. ©2011 AACR.
Data from 2-Deoxyglucose Induces Noxa-Dependent Apoptosis in Alveolar Rhabdomyosarcoma
Authors: Ramírez-Peinado Silvia , Alcázar-Limones Fermín , Lagares-Tena Laura , El Mjiyad Nadia , Caro-Maldonado Alfredo , Tirado Oscar M. , Muñoz-Pinedo Cristina
Published: March 2024

Abstract
Alveolar and embryonal rhabdomyosarcomas are childhood tumors that do not respond well to current chemotherapies. Here, we report that the glycolytic inhibitor 2-deoxyglucose (2-DG) can efficiently promote cell death in alveolar, but not embryonal, rhabdomyosarcoma cell lines. Notably, 2-DG also induced cell differentiation accompanied by downregulation of PAX3/FOXO1a, the chromosome translocation–encoded fusion protein that is a central oncogenic driver in this disease. Cell death triggered by 2-DG was associated with its ability to activate Bax and Bak. Overexpression of the antiapoptotic Bcl-2 homologues Bcl-xL and Mcl-1 prevented apoptosis, indicating that cell death proceeds through the mitochondrial pathway. Mechanistic investigations indicated that Mcl-1 downregulation and Noxa upregulation were critical for 2-DG–induced apoptosis. In addition, 2-DG promoted eIF2α phosphorylation and inactivation of the mTOR pathway. Mcl-1 loss and cell death were prevented by downregulation of the endoplasmic reticulum (ER) stress–induced protein ATF4 and by incubating cells in the presence of mannose, which reverted 2-DG–induced ER stress but not ATP depletion. Thus, energetic stresses created by 2-DG were not the primary cause of cell death. Together, our findings suggest that glycolysis inhibitors such as 2-DG may be highly effective in treating alveolar rhabdomyosarcoma and that Noxa could offer a prognostic marker to monitor the efficacy of such agents. Cancer Res; 71(21); 6796–806. ©2011 AACR.
Data from Histone H3 Lysine 79 Methyltransferase Dot1 Is Required for Immortalization by MLL Oncogenes
Authors: Chang Ming-Jin , Wu Hongyu , Achille Nicholas J. , Reisenauer Mary Rose , Chou Chau-Wen , Zeleznik-Le Nancy J. , Hemenway Charles S. , Zhang Wenzheng
Published: March 2024

Abstract
Chimeric oncoproteins resulting from fusion of MLL to a wide variety of partnering proteins cause biologically distinctive and clinically aggressive acute leukemias. However, the mechanism of MLL-mediated leukemic transformation is not fully understood. Dot1, the only known histone H3 lysine 79 (H3K79) methyltransferase, has been shown to interact with multiple MLL fusion partners including AF9, ENL, AF10, and AF17. In this study, we utilize a conditional Dot1l deletion model to investigate the role of Dot1 in hematopoietic progenitor cell immortalization by MLL fusion proteins. Western blot and mass spectrometry show that Dot1-deficient cells are depleted of the global H3K79 methylation mark. We find that loss of Dot1 activity attenuates cell viability and colony formation potential of cells immortalized by MLL oncoproteins but not by the leukemic oncoprotein E2a-Pbx1. Although this effect is most pronounced for MLL-AF9, we find that Dot1 contributes to the viability of cells immortalized by other MLL oncoproteins that are not known to directly recruit Dot1. Cells immortalized by MLL fusions also show increased apoptosis, suggesting the involvement of Dot1 in survival pathways. In summary, our data point to a pivotal requirement for Dot1 in MLL fusion protein–mediated leukemogenesis and implicate Dot1 as a potential therapeutic target. Cancer Res; 70(24); 10234–42. ©2010 AACR.
Data from Telomerase-Dependent Oncolytic Adenovirus Sensitizes Human Cancer Cells to Ionizing Radiation via Inhibition of DNA Repair Machinery
Authors: Kuroda Shinji , Fujiwara Toshiya , Shirakawa Yasuhiro , Yamasaki Yasumoto , Yano Shuya , Uno Futoshi , Tazawa Hiroshi , Hashimoto Yuuri , Watanabe Yuichi , Noma Kazuhiro , Urata Yasuo , Kagawa Shunsuke , Fujiwara Toshiyoshi
Published: March 2024

Abstract
The inability to repair DNA double-strand breaks (DSB) leads to radiosensitization, such that ionizing radiation combined with molecular inhibition of cellular DSB processing may greatly affect treatment of human cancer. As a variety of viral products interact with the DNA repair machinery, oncolytic virotherapy may improve the therapeutic window of conventional radiotherapy. Here, we describe the mechanistic basis for synergy of irradiation and OBP-301 (Telomelysin), an attenuated type-5 adenovirus with oncolytic potency that contains the human telomerase reverse transcriptase promoter to regulate viral replication. OBP-301 infection led to E1B55kDa viral protein expression that degraded the complex formed by Mre11, Rad50, and NBS1, which senses DSBs. Subsequently, the phosphorylation of cellular ataxia-telangiectasia mutated protein was inhibited, disrupting the signaling pathway controlling DNA repair. Thus, tumor cells infected with OBP-301 could be rendered sensitive to ionizing radiation. Moreover, by using noninvasive whole-body imaging, we showed that intratumoral injection of OBP-301 followed by regional irradiation induces a substantial antitumor effect, resulting from tumor cell–specific radiosensitization, in an orthotopic human esophageal cancer xenograft model. These results illustrate the potential of combining oncolytic virotherapy and ionizing radiation as a promising strategy in the management of human cancer. Cancer Res; 70(22); 9339–48. ©2010 AACR.
Data from Inhibition of miR-193a Expression by Max and RXRα Activates K-Ras and PLAU to Mediate Distinct Aspects of Cellular Transformation
Authors: Iliopoulos Dimitrios , Rotem Asaf , Struhl Kevin
Published: March 2024

Abstract
MicroRNA profiling in isogenic models of cellular transformation involving either breast epithelial cells or fibroblasts reveals that expression of miR-193a is lower in transformed cells than in nontransformed cells. The transcription factors Max and RXRα bind directly to the miR-193a promoter and inhibit miR-193a expression during transformation. miR-193a inhibits cellular transformation by directly targeting the 3′ untranslated regions of PLAU and K-Ras. Interestingly, miR-193a controls anchorage-independent growth in soft agar through K-Ras, whereas it affects invasive growth through PLAU. miR-193a overexpression inhibits the tumorigenicity of developmentally diverse but not all cancer cell types, and it inhibits tumor growth in colon- and breast-derived xenografts. Finally, expression of miR-193a is inversely correlated with PLAU and K-Ras in human colon adenocarcinomas. Thus, a pathway in which Max and RXRα inhibit miR-193a expression, thereby activating the PLAU and K-Ras oncogenes is important for distinct aspects of cellular transformation, as well as tumor growth and colon (and perhaps other types of) cancer. Cancer Res; 71(15); 5144–53. ©2011 AACR.
Data from Human Solid Tumors Contain High Endothelial Venules: Association with T- and B-Lymphocyte Infiltration and Favorable Prognosis in Breast Cancer
Authors: Martinet Ludovic , Garrido Ignacio , Filleron Thomas , Le Guellec Sophie , Bellard Elisabeth , Fournie Jean-Jacques , Rochaix Philippe , Girard Jean-Philippe
Published: March 2024

Abstract
The mechanisms governing infiltration of lymphocytes into tumors remain poorly characterized, in spite of the critical impact of these cells on patient prognosis and therapeutic responses. High endothelial venules (HEV) are blood vessels found in lymphoid tissues, specialized in lymphocyte recruitment, but their implications in human cancer are unknown. In this article, we report the presence of MECA 79+ blood vessels displaying all the phenotypic characteristics of HEVs in most of the 319 human primary solid tumors, including melanomas, breast, ovarian, colon, and lung carcinomas, analyzed. Tumor HEVs were specifically located within lymphocyte-rich areas, and their density within the tumor stroma was a strong predictor of infiltration by CD3+ and CD8+ T cells as well as B cells. Large-scale flow cytometric and quantitative reverse transcriptase-PCR analyses in freshly operated breast tumors revealed that high densities of tumor HEVs correlated with increased naive, central memory and activated effector memory T-cell infiltration and upregulation of genes related to T-helper 1 adaptive immunity and T-cell cytotoxicity. Finally, in a retrospective cohort of 146 invasive breast cancer patients, we found that high densities of tumor HEVs independently conferred a lower risk of relapse and significantly correlated with longer metastasis-free, disease-free, and overall survival rates. Together, our findings suggest that tumor HEVs function as major gateways for lymphocyte infiltration into human tumors, and may represent attractive targets for cancer diagnosis and therapy. Cancer Res; 71(17); 5678–87. ©2011 AACR.
Data from Enhancement of Cancer Vaccine Therapy by Systemic Delivery of a Tumor-Targeting Salmonella-Based STAT3 shRNA Suppresses the Growth of Established Melanoma Tumors
Authors: Manuel Edwin R. , Blache Céline A. , Paquette Rebecca , Kaltcheva Teodora I. , Ishizaki Hidenobu , Ellenhorn Joshua D.I. , Hensel Michael , Metelitsa Leonid , Diamond Don J.
Published: March 2024

Abstract
Cancer vaccine therapies have only achieved limited success when focusing on effector immunity with the goal of eliciting robust tumor-specific T-cell responses. More recently, there is an emerging understanding that effective immunity can only be achieved by coordinate disruption of tumor-derived immunosuppression. Toward that goal, we have developed a potent Salmonella-based vaccine expressing codon-optimized survivin (CO-SVN), referred to as 3342Max. When used alone as a therapeutic vaccine, 3342Max can attenuate growth of aggressive murine melanomas overexpressing SVN. However, under more immunosuppressive conditions, such as those associated with larger tumor volumes, we found that the vaccine was ineffective. Vaccine efficacy could be rescued if tumor-bearing mice were treated initially with Salmonella encoding a short hairpin RNA (shRNA) targeting the tolerogenic molecule STAT3 (YS1646-shSTAT3). In vaccinated mice, silencing STAT3 increased the proliferation and granzyme B levels of intratumoral CD4+ and CD8+ T cells. The combined strategy also increased apoptosis in tumors of treated mice, enhancing tumor-specific killing of tumor targets. Interestingly, mice treated with YS1646-shSTAT3 or 3342Max alone were similarly unsuccessful in rejecting established tumors, whereas the combined regimen was highly potent. Our findings establish that a combined strategy of silencing immunosuppressive molecules followed by vaccination can act synergistically to attenuate tumor growth, and they offer a novel translational direction to improve tumor immunotherapy. Cancer Res; 71(12); 4183–91. ©2011 AACR.
Data from Tumor-Evoked Regulatory B Cells Promote Breast Cancer Metastasis by Converting Resting CD4+ T Cells to T-Regulatory Cells
Authors: Olkhanud Purevdorj B. , Damdinsuren Bazarragchaa , Bodogai Monica , Gress Ronald E. , Sen Ranjan , Wejksza Katarzyna , Malchinkhuu Enkhzol , Wersto Robert P. , Biragyn Arya
Published: March 2024

Abstract
Pulmonary metastasis of breast cancer requires recruitment and expansion of T-regulatory cells (Treg) that promote escape from host protective immune cells. However, it remains unclear precisely how tumors recruit Tregs to support metastatic growth. Here we report the mechanistic involvement of a unique and previously undescribed subset of regulatory B cells. These cells, designated tumor-evoked Bregs (tBreg), phenotypically resemble activated but poorly proliferative mature B2 cells (CD19+ CD25High CD69High) that express constitutively active Stat3 and B7-H1High CD81High CD86High CD62LLow IgMInt. Our studies with the mouse 4T1 model of breast cancer indicate that the primary role of tBregs in lung metastases is to induce TGF-β–dependent conversion of FoxP3+ Tregs from resting CD4+ T cells. In the absence of tBregs, 4T1 tumors cannot metastasize into the lungs efficiently due to poor Treg conversion. Our findings have important clinical implications, as they suggest that tBregs must be controlled to interrupt the initiation of a key cancer-induced immunosuppressive event that is critical to support cancer metastasis. Cancer Res; 71(10); 3505–15. ©2011 AACR.
Data from ARID1A, a Factor That Promotes Formation of SWI/SNF-Mediated Chromatin Remodeling, Is a Tumor Suppressor in Gynecologic Cancers
Authors: Guan Bin , Wang Tian-Li , Shih Ie-Ming
Published: March 2024

Abstract
ARID1A (BAF250A) promotes the formation of SWI/SNF chromatin remodeling complexes containing BRG1 or BRM. It has emerged as a candidate tumor suppressor based on its frequent mutations in ovarian clear cell and endometrioid cancers and in uterine endometrioid carcinomas. Here, we report that restoring wild-type ARID1A expression in ovarian cancer cells that harbor ARID1A mutations is sufficient to suppress cell proliferation and tumor growth in mice, whereas RNA interference–mediated silencing of ARID1A in nontransformed epithelial cells is sufficient to enhance cellular proliferation and tumorigenicity. Gene expression analysis identified several downstream targets of ARID1A including CDKN1A and SMAD3, which are well-known p53 target genes. In support of the likelihood that p53 mediates the effects of ARID1A on these genes, we showed that p53 was required and sufficient for their regulation by ARID1A. Furthermore, we showed that CDKN1A (encoding p21) acted in part to mediate growth suppression by ARID1A. Finally, we obtained evidence that the ARID1A/BRG1 complex interacted directly with p53 and that mutations in the ARID1A and TP53 genes were mutually exclusive in tumor specimens examined. Our results provide functional evidence in support of the hypothesis that ARID1A is a bona fide tumor suppressor that collaborates with p53 to regulate CDKN1A and SMAD3 transcription and tumor growth in gynecologic cancers. Cancer Res; 71(21); 6718–27. ©2011 AACR.
Data from Functional Parsing of Driver Mutations in the Colorectal Cancer Genome Reveals Numerous Suppressors of Anchorage-Independent Growth
Authors: Eskiocak Ugur , Kim Sang Bum , Ly Peter , Roig Andres I. , Biglione Sebastian , Komurov Kakajan , Cornelius Crystal , Wright Woodring E. , White Michael A. , Shay Jerry W.
Published: March 2024

Abstract
Landmark cancer genome resequencing efforts are leading to the identification of mutated genes in many types of cancer. The extreme diversity of mutations being detected presents significant challenges to subdivide causal from coincidental mutations to elucidate how disrupted regulatory networks drive cancer processes. Given that a common early perturbation in solid tumor initiation is bypass of matrix-dependent proliferation restraints, we sought to functionally interrogate colorectal cancer candidate genes (CAN-genes) to identify driver tumor suppressors. We have employed an isogenic human colonic epithelial cell (HCEC) model to identify suppressors of anchorage-independent growth by conducting a soft agar–based short hairpin RNA (shRNA) screen within the cohort of CAN-genes. Remarkably, depletion of 65 of the 151 CAN-genes tested collaborated with ectopic expression of K-RASV12 and/or TP53 knockdown to promote anchorage-independent proliferation of HCECs. In contrast, only 5 of 362 random shRNAs (1.4%) enhanced soft agar growth. We have identified additional members of an extensive gene network specifying matrix-dependent proliferation, by constructing an interaction map of these confirmed progression suppressors with approximately 700 mutated genes that were excluded from CAN-genes, and experimentally verifying soft agar growth enhancement in response to depletion of a subset of these genes. Collectively, this study revealed a profound diversity of nodes within a fundamental tumor suppressor network that are susceptible to perturbation leading to enhanced cell-autonomous anchorage-independent proliferative fitness. Tumor suppressor network fragility as a paradigm within this and other regulatory systems perturbed in cancer could, in large part, account for the heterogeneity of somatic mutations detected in tumors. Cancer Res; 71(13); 4359–65. ©2011 AACR.
Data from The Androgen Receptor Induces Integrin α6β1 to Promote Prostate Tumor Cell Survival via NF-κB and Bcl-xL Independently of PI3K Signaling
Authors: Lamb Laura E. , Zarif Jelani C. , Miranti Cindy K.
Published: March 2024

Abstract
Recent studies indicate that androgen receptor (AR) signaling is critical for prostate cancer cell survival, even in castration-resistant disease wherein AR continues to function independently of exogenous androgens. Integrin-mediated adhesion to the extracellular matrix is also important for prostate cell survival. AR-positive prostate cancer cells express primarily integrin α6β1 and adhere to a laminin-rich matrix. In this study, we show that active nuclear-localized AR protects prostate cancer cells from death induced by phosphoinositide 3-kinase (PI3K) inhibition when cells adhere to laminin. Resistance to PI3K inhibition is mediated directly by an AR-dependent increase in integrin α6β1 mRNA transcription and protein expression. Subsequent signaling by integrin α6β1 in AR-expressing cells increased NF-κB activation and Bcl-xL expression. Blocking AR, integrin α6, NF-κB, or Bcl-xL concurrent with inhibition of PI3K was sufficient and necessary to trigger death of laminin-adherent AR-expressing cells. Taken together, these results define a novel integrin-dependent survival pathway in prostate cancer cells that is regulated by AR, independent of and parallel to the PI3K pathway. Our findings suggest that combined targeting of both the AR/α6β1 and PI3K pathways may effectively trigger prostate cancer cell death, enhancing the potential therapeutic value of PI3K inhibitors being evaluated in this setting. Cancer Res; 71(7); 2739–49. ©2011 AACR.
Data from c-MYC Functions as a Molecular Switch to Alter the Response of Human Mammary Epithelial Cells to Oncostatin M
Authors: Kan Charlene E. , Cipriano Rocky , Jackson Mark W.
Published: March 2024

Abstract
Cytokines play an important role in creating an inflammatory microenvironment, which is now considered a hallmark of cancer. Although tumor cells can exploit cytokine signaling to promote growth, invasion, and metastasis, the response of normal and premalignant epithelial cells to cytokines present in a developing tumor microenvironment remains unclear. Oncostatin M (OSM), an IL-6 family cytokine responsible for STAT3 activation, has been implicated in cancer development, progression, invasion, and metastasis. Paradoxically, OSM can also suppress the growth of normal cells and certain tumor-derived cell lines. Using isogenic human mammary epithelial cells (HMEC) at different stages of neoplastic transformation, we found that OSM signaling suppressed c-MYC expression and engaged a p16- and p53-independent growth arrest that required STAT3 activity. Inhibition of STAT3 activation by expressing a dominant-negative STAT3 protein or a STAT3-shRNA prevented the OSM-mediated arrest. In addition, expression of c-MYC from a constitutive promoter also abrogated the STAT3-mediated arrest, and strikingly, cooperated with OSM to promote anchorage-independent growth (AIG), a property associated with malignant transformation. Cooperative transformation by c-MYC and OSM required PI3K and AKT signaling, showing the importance of multiple signaling pathways downstream of the OSM receptor in defining the cellular response to cytokines. These findings identify c-MYC as an important molecular switch that alters the cellular response to OSM-mediated signaling from tumor suppressive to tumor promoting. Cancer Res; 71(22); 6930–9. ©2011 AACR.
Data from ID4 Imparts Chemoresistance and Cancer Stemness to Glioma Cells by Derepressing miR-9*–Mediated Suppression of SOX2
Authors: Jeon Hye-Min , Sohn Young-Woo , Oh Se-Young , Kim Sung-Hak , Beck Samuel , Kim Soonhag , Kim Hyunggee
Published: March 2024

Abstract
Glioma stem cells (GSC) possess tumor-initiating potential and are relatively resistant to conventional chemotherapy and irradiation. Thus, they are considered to be major drivers for glioma initiation, progression, and recurrence. However, the precise mechanism governing acquisition of their drug resistance remains to be elucidated. Our previous study has shown that inhibitor of differentiation 4 (ID4) dedifferentiates Ink4a/Arf−/− mouse astrocytes and human glioma cells to glioma stem-like cells (induced GSCs or iGSCs). In this article, we report that ID4-driven iGSCs exhibit chemoresistant behavior to anticancer drugs through activation of ATP-binding cassette (ABC) transporters. We found that ID4 enhanced SOX2 protein expression by suppressing microRNA-9* (miR-9*), which can repress SOX2 by targeting its 3′-untranslated region. Consequently, ID4-mediated SOX2 induction enhanced ABCC3 and ABCC6 expression through direct transcriptional regulation, indicating that ID4 regulates the chemoresistance of iGSCs by promoting SOX2-mediated induction of ABC transporters. Furthermore, we found that short hairpin RNA-mediated knockdown of SOX2 in ID4-driven iGSCs resulted in loss of cancer stemness. Moreover, ectopic expression of SOX2 could dedifferentiate Ink4a/Arf−/− astrocytes and glioma cells to iGSCs, indicating a crucial role of SOX2 in genesis and maintenance of GSCs. Finally, we found that the significance of the ID4-miR-9*-SOX2-ABCC3/ABCC6 regulatory pathway is recapitulated in GSCs derived from patients with glioma. Together, our results reveal a novel regulatory mechanism by which ID4-driven suppression of miR-9* induces SOX2, which imparts stemness potential and chemoresistance to glioma cells and GSCs. Cancer Res; 71(9); 3410–21. ©2011 AACR.
Data from Epigenetic Silencing Mediated through Activated PI3K/AKT Signaling in Breast Cancer
Authors: Zuo Tao , Liu Ta-Ming , Lan Xun , Weng Yu-I , Shen Rulong , Gu Fei , Huang Yi-Wen , Liyanarachchi Sandya , Deatherage Daniel E. , Hsu Pei-Yin , Taslim Cenny , Ramaswamy Bhuvaneswari , Shapiro Charles L. , Lin Huey-Jen L. , Cheng Alfred S. L. , Jin Victor X. , Huang Tim H.-M.
Published: March 2024

Abstract
Trimethylation of histone 3 lysine 27 (H3K27me3) is a critical epigenetic mark for the maintenance of gene silencing. Additional accumulation of DNA methylation in target loci is thought to cooperatively support this epigenetic silencing during tumorigenesis. However, molecular mechanisms underlying the complex interplay between the two marks remain to be explored. Here we show that activation of PI3K/AKT signaling can be a trigger of this epigenetic processing at many downstream target genes. We also find that DNA methylation can be acquired at the same loci in cancer cells, thereby reinforcing permanent repression in those losing the H3K27me3 mark. Because of a link between PI3K/AKT signaling and epigenetic alterations, we conducted epigenetic therapies in conjunction with the signaling-targeted treatment. These combined treatments synergistically relieve gene silencing and suppress cancer cell growth in vitro and in xenografts. The new finding has important implications for improving targeted cancer therapies in the future. Cancer Res; 71(5); 1752–62. ©2011 AACR.
Data from Manganese Superoxide Dismutase Is a p53-Regulated Gene That Switches Cancers between Early and Advanced Stages
Authors: Dhar Sanjit K. , Tangpong Jitbanjong , Chaiswing Luksana , Oberley Terry D. , St. Clair Daret K.
Published: March 2024

Abstract
Manganese superoxide dismutase (MnSOD) plays a critical role in the survival of aerobic life, and its aberrant expression has been implicated in carcinogenesis and tumor resistance to therapy. However, despite extensive studies in MnSOD regulation and its role in cancer, when and how the alteration of MnSOD expression occurs during the process of tumor development in vivo are unknown. Here, we generated transgenic mice expressing a luciferase reporter gene under the control of human MnSOD promoter-enhancer elements and investigated the changes of MnSOD transcription using the 7,12-dimethylbenz(α)anthracene (DMBA)/12-O-tetradecanoylphorbol-l3-acetate (TPA) multistage skin carcinogenesis model. The results show that MnSOD expression was suppressed at a very early stage but increased at late stages of skin carcinogenesis. The suppression and subsequent restoration of MnSOD expression were mediated by two transcription-factors, Sp1 and p53. Exposure to DMBA and TPA activated p53 and decreased MnSOD expression via p53-mediated suppression of Sp1 binding to the MnSOD promoter in normal-appearing skin and benign papillomas. In squamous cell carcinomas, Sp1 binding increased because of the loss of functional p53. We used chromatin immunoprecipitation, electrophoretic mobility shift assay, and both knockdown and overexpression of Sp1 and p53 to verify their roles in the expression of MnSOD at each stage of cancer development. The results identify MnSOD as a p53-regulated gene that switches between early and advanced stages of cancer. These findings also provide strong support for the development of means to reactivate p53 for the prevention of tumor progression. Cancer Res; 71(21); 6684–95. ©2011 AACR.
Data from Glioblastoma Angiogenesis and Tumor Cell Invasiveness Are Differentially Regulated by β8 Integrin
Authors: Tchaicha Jeremy H. , Reyes Steve B. , Shin Jaekyung , Hossain Mohammad G. , Lang Frederick F. , McCarty Joseph H.
Published: March 2024

Abstract
Glioblastoma multiforme (GBM) is a highly invasive brain tumor that develops florid microvascular proliferation and hemorrhage. However, mechanisms that favor invasion versus angiogenesis in this setting remain largely uncharacterized. Here, we show that integrin β8 is an essential regulator of both GBM-induced angiogenesis and tumor cell invasiveness. Highly angiogenic and poorly invasive tumors expressed low levels of β8 integrin, whereas highly invasive tumors with limited neovascularization expressed high levels of β8 integrin. Manipulating β8 integrin protein levels altered the angiogenic and invasive growth properties of GBMs, in part, reflected by a diminished activation of latent TGFβs, which are extracellular matrix protein ligands for β8 integrin. Taken together, these results establish a role for β8 integrin in differential control of angiogenesis versus tumor cell invasion in GBM. Our findings suggest that inhibiting β8 integrin or TGFβ signaling may diminish tumor cell invasiveness during malignant progression and following antivascular therapies. Cancer Res; 71(20); 6371–81. ©2011 AACR.
Data from The Molecular Basis of Synergism between Carboplatin and ABT-737 Therapy Targeting Ovarian Carcinomas
Authors: Jain Harsh Vardhan , Meyer-Hermann Michael
Published: March 2024

Abstract
Resistance to standard chemotherapy (carboplatin + paclitaxel) is one of the leading causes of therapeutic failure in ovarian carcinomas. Emergence of chemoresistance has been shown to be mediated in part by members of the Bcl family of proteins including the antiapoptotic protein Bcl-xL, whose expression is correlated with shorter disease-free intervals in recurrent disease. ABT-737 is an example of one of the first small-molecule inhibitors of Bcl-2/Bcl-xL that has been shown to increase the sensitivity of ovarian cancer cells to carboplatin. To exploit the therapeutic potential of these two drugs and predict optimal doses and dose scheduling, it is essential to understand the molecular basis of their synergistic action. Here, we build and calibrate a mathematical model of ABT-737 and carboplatin action on an ovarian cancer cell line (IGROV-1). The model suggests that carboplatin treatment primes cells for ABT-737 therapy because of an increased dependence of cells with DNA damage on Bcl-xL for survival. Numerical simulations predict the existence of a threshold of Bcl-xL below which these cells are unable to recover. Furthermore, co- plus posttreatment of ABT-737 with carboplatin is predicted to be the best strategy to maximize synergism between these two drugs. A critical challenge in chemotherapy is to strike a balance between maximizing cell-kill while minimizing patient drug load. We show that the model can be used to compute minimal doses required for any desired fraction of cell kill. These results underscore the potential of the modeling work presented here as a valuable quantitative tool to aid in the translation of novel drugs such as ABT-737 from the experimental to clinical setting and highlight the need for close collaboration between modelers and experimental scientists. Cancer Res; 71(3); 705–15. ©2010 AACR.
Data from EGFR-AKT-Smad Signaling Promotes Formation of Glioma Stem-like Cells and Tumor Angiogenesis by ID3-Driven Cytokine Induction
Authors: Jin Xun , Yin Jinlong , Kim Sung-Hak , Sohn Young-Woo , Beck Samuel , Lim Young Chang , Nam Do-Hyun , Choi Yun-Jaie , Kim Hyunggee
Published: March 2024

Abstract
Aberrant activation of receptor tyrosine kinases (RTK) is causally linked to the pathobiological traits of glioblastoma and genesis of glioma stem-like cells (GSC), but the underlying mechanism is still unknown. Here, we show that epidermal growth factor receptor (EGFR) signaling regulates the proliferation, angiogenesis, and acquisition of GSC characteristics by inducing inhibitor of differentiation 3 (ID3) and ID3-regulated cytokines [GRO1 and interleukins (IL)-6 and 8] induction. We found that EGFR-mediated ID3 expression was regulated by Smad5, which was directly phosphorylated by AKT. Furthermore, ID3 alone imparted GSC features to primary astrocytes derived from Ink4a/Arf-deficient mouse, and EGFR–ID3–IL-6 signaling axis gave rise to tumor cell heterogeneity. Conversely, EGFR inhibitors suppressed EGFR-AKT-Smad5–driven induction of ID3, which led to a decrease in the tumorsphere forming ability of GSCs and U87MG cells that possess an active mutant EGFR, EGFRvIII, without obvious cytotoxic effects. However, these cells seemed to regain colonogenic ability after removal of the EGFR inhibitors. Together, the results delineate a novel integrative molecular mechanism in which the RTK-ID signaling pathway governs genesis and maintenance of GBM histopathologic features, such as GSCs-based tumor initiation, progression, and angiogenesis. Cancer Res; 71(22); 7125–34. ©2011 AACR.
Data from Coactivation of AKT and β-Catenin in Mice Rapidly Induces Formation of Lipogenic Liver Tumors
Authors: Stauffer Jimmy K. , Scarzello Anthony J. , Andersen Jesper B. , De Kluyver Rachel L. , Back Timothy C. , Weiss Jonathan M. , Thorgeirsson Snorri S. , Wiltrout Robert H.
Published: March 2024

Abstract
Obesity is a risk factor for development of certain cancers but the basis for this risk is unclear. In this study, we developed a novel mouse model that demonstrates directly how lipogenic phenotypes commonly associated with diet-induced metabolic syndromes can influence hepatic cancer development. Activated AKT and β-catenin (AKT/CAT) genes were hydrodynamically codelivered using the Sleeping Beauty transposon to initiate liver tumorigenesis. AKT/CAT and MET/CAT combination induced microscopic tumor foci by 4 weeks, whereas no tumorigenesis resulted from delivery of AKT, MET, or CAT alone. Primary AKT/CAT tumor cells were steatotic (fatty) hepatocellular adenomas which progressed to hepatocellular carcinomas (HCC) upon in vivo passage, whereas primary MET/CAT tumors emerged directly as frank HCC. Conversion of AKT/CAT tumor cells to frank HCC during passage was associated with induction of the human HCC marker α-fetoprotein and the stem cell marker CD133. Using hierarchical clustering and gene set enrichment analysis, we compared the primary murine AKT/CAT and MET/CAT tumors to a panel of 53 human HCCs and determined that these two mouse models could be stratified as distinct subtypes associated in humans with poor clinical prognosis. The chief molecular networks identified in primary and passaged AKT/CAT tumors were steatosis and lipid metabolic pathways, respectively. Our findings show how coactivation of the AKT and CAT pathways in hepatocytes can efficiently model development of a lipogenic tumor phenotype. Furthermore, we believe that our approach could speed the dissection of microenvironmental factors responsible for driving steatotic-neoplastic transformation to frank carcinoma, through genetic modification of existing immunodefined transgenic models. Cancer Res; 71(7); 2718–27. ©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 2024

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.
Data from Metformin Decreases the Dose of Chemotherapy for Prolonging Tumor Remission in Mouse Xenografts Involving Multiple Cancer Cell Types
Authors: Iliopoulos Dimitrios , Hirsch Heather A. , Struhl Kevin
Published: March 2024

Abstract
Metformin, the first-line drug for treating diabetes, selectively kills the chemotherapy resistant subpopulation of cancer stem cells (CSC) in genetically distinct types of breast cancer cell lines. In mouse xenografts, injection of metformin and the chemotherapeutic drug doxorubicin near the tumor is more effective than either drug alone in blocking tumor growth and preventing relapse. Here, we show that metformin is equally effective when given orally together with paclitaxel, carboplatin, and doxorubicin, indicating that metformin works together with a variety of standard chemotherapeutic agents. In addition, metformin has comparable effects on tumor regression and preventing relapse when combined with a four-fold reduced dose of doxorubicin that is not effective as a monotherapy. Finally, the combination of metformin and doxorubicin prevents relapse in xenografts generated with prostate and lung cancer cell lines. These observations provide further evidence for the CSC hypothesis for cancer relapse, an experimental rationale for using metformin as part of combinatorial therapy in a variety of clinical settings, and for reducing the chemotherapy dose in cancer patients. Cancer Res; 71(9); 3196–201. ©2011 AACR.
Data from ZNF668 Functions as a Tumor Suppressor by Regulating p53 Stability and Function in Breast Cancer
Authors: Hu Ruozhen , Peng Guang , Dai Hui , Breuer Eun-Kyoung , Stemke-Hale Katherine , Li Kaiyi , Gonzalez-Angulo Ana M. , Mills Gordon B. , Lin Shiaw-Yih
Published: March 2024

Abstract
Genome-wide sequencing studies in breast cancer have recently identified frequent mutations in the zinc finger protein 668 (ZNF668), the function of which is undefined. Here, we report that ZNF668 is a nucleolar protein that physically interacts with and regulates p53 and its negative regulator MDM2. Through MDM2 binding, ZNF668 regulated autoubiquitination of MDM2 and its ability to mediate p53 ubiquitination and degradation. ZNF668 deficiency also impaired DNA damage–induced stabilization of p53. RNA interference–mediated knockdown of ZNF668 was sufficient to transform normal mammary epithelial cells. ZNF668 effectively suppressed breast cancer cell proliferation in vitro and tumorigenicity in vivo. Taken together, our studies identify ZNF668 as a novel breast tumor suppressor gene that functions in regulating p53 stability. Cancer Res; 71(20); 6524–34. ©2011 AACR.
Data from Decreased Lymphangiogenesis and Lymph Node Metastasis by mTOR Inhibition in Head and Neck Cancer
Authors: Patel Vyomesh , Marsh Christina A. , Dorsam Robert T. , Mikelis Constantinos M. , Masedunskas Andrius , Amornphimoltham Panomwat , Nathan Cherie Ann , Singh Bhuvanesh , Weigert Roberto , Molinolo Alfredo A. , Gutkind J. Silvio
Published: March 2024

Abstract
Despite our improved understanding of cancer, the 5-year survival rate for head and neck squamous cell carcinomas (HNSCC) patients remains relatively unchanged at 50% for the past three decades. HNSCCs often metastasize to locoregional lymph nodes, and lymph node involvement represents one of the most important prognostic factors of poor clinical outcome. Among the multiple dysregulated molecular mechanism in HNSCCs, emerging basic, preclinical, and clinical findings support the importance of the mTOR signaling route in HNSCC progression. Indeed, we observed here that the activation of mTOR is a widespread event in clinical specimens of HNSCCs invading locoregional lymph nodes. We developed an orthotopic model of HNSCC consisting of the implantation of HNSCC cells into the tongues of immunocompromised mice. These orthotopic tumors spontaneously metastasize to the cervical lymph nodes, where the presence of HNSCC cells can be revealed by histologic and immunohistochemical evaluation. Both primary and metastatic experimental HNSCC lesions exhibited elevated mTOR activity. The ability to monitor and quantitate lymph node invasion in this model system enabled us to explore whether the blockade of mTOR could impact HNSCC metastasis. We found that inhibition of mTOR with rapamycin and the rapalog RAD001 diminished lymphangiogenesis in the primary tumors and prevented the dissemination of HNSCC cancer cells to the cervical lymph nodes, thereby prolonging animal survival. These findings may provide a rationale for the future clinical evaluation of mTOR inhibitors, including rapamycin and its analogues, as part of a molecular-targeted metastasis preventive strategy for the treatment of patients with HNSCC. Cancer Res; 71(22); 7103–12. ©2011 AACR.
Data from MAP Kinase-Interacting Kinase 1 Regulates SMAD2-Dependent TGF-β Signaling Pathway in Human Glioblastoma
Authors: Grzmil Michal , Morin Pier , Lino Maria Maddalena , Merlo Adrian , Frank Stephan , Wang Yuhua , Moncayo Gerald , Hemmings Brian A.
Published: March 2024

Abstract
Glioblastoma multiforme (GBM) is the most common aggressive brain cancer with a median survival of approximately 1 year. In a search for novel molecular targets that could be therapeutically developed, our kinome-focused microarray analysis identified the MAP (mitogen-activated protein) kinase-interacting kinase 1 (MNK1) as an attractive theranostic candidate. MNK1 overexpression was confirmed in both primary GBMs and glioma cell lines. Inhibition of MNK1 activity in GBM cells by the small molecule CGP57380 suppressed eIF4E phosphorylation, proliferation, and colony formation whereas concomitant treatment with CGP57380 and the mTOR inhibitor rapamycin accentuated growth inhibition and cell-cycle arrest. siRNA-mediated knockdown of MNK1 expression reduced proliferation of cells incubated with rapamycin. Conversely, overexpression of full-length MNK1 reduced rapamycin-induced growth inhibition. Analysis of polysomal profiles revealed inhibition of translation in CGP57380 and rapamycin-treated cells. Microarray analysis of total and polysomal RNA from MNK1-depleted GBM cells identified mRNAs involved in regulation of TGF-β pathway. Translation of SMAD2 mRNA as well as TGF-β–induced cell motility and vimentin expression was regulated by MNK1 signaling. Tissue microarray analysis revealed a positive correlation between the immunohistochemical staining of MNK1 and SMAD2. Taken together, our findings offer insights into how MNK1 pathways control translation of cancer-related mRNAs including SMAD2, a key component of the TGF-β signaling pathway. Furthermore, they suggest MNK1-controlled translational pathways in targeted strategies to more effectively treat GBM. Cancer Res; 71(6); 2392–402. ©2011 AACR.
Data from Loss of the Ceramide Transfer Protein Augments EGF Receptor Signaling in Breast Cancer
Authors: Heering Johanna , Weis Nicole , Holeiter Monika , Neugart Felix , Staebler Annette , Fehm Tanja N. , Bischoff Annabell , Schiller Jürgen , Duss Stephan , Schmid Simone , Korte Thomas , Herrmann Andreas , Olayioye Monilola A.
Published: March 2024

Abstract
Triple-negative breast cancers (TNBC) are especially refractory to treatment due to their negative hormone receptor and ErbB2/HER2 status. Therefore, the identification of cancer-associated deregulated signaling pathways is necessary to develop improved targeted therapies. Here, we show that expression of the ceramide transfer protein CERT is reduced in TNBCs. CERT transfers ceramide from the endoplasmic reticulum to the Golgi complex for conversion into sphingomyelin (SM). We provide evidence that by regulating cellular SM levels, CERT determines the signaling output of the EGF receptor (EGFR/ErbB1), which is upregulated in approximately 70% of TNBCs. CERT downregulation in breast cancer cells enhanced ErbB1 lateral mobility, ligand-induced autophosphorylation, internalization, and chemotaxis. Together, our findings provide a link between lipid metabolism at the Golgi with signaling at the plasma membrane, thereby implicating CERT loss in the progression of TNBCs. Cancer Res; 72(11); 2855–66. ©2012 AACR.
Data from Chk2 Phosphorylation of Survivin-ΔEx3 Contributes to a DNA Damage–Sensing Checkpoint in Cancer
Authors: Lopergolo Alessia , Tavecchio Michele , Lisanti Sofia , Ghosh Jagadish C. , Dohi Takehiko , Faversani Alice , Vaira Valentina , Bosari Silvano , Tanigawa Nobuhiko , Delia Domenico , Kossenkov Andrew V. , Showe Louise C. , Altieri Dario C.
Published: March 2024

Abstract
Survivin is an oncogene that functions in cancer cell cytoprotection and mitosis. Here we report that differential expression in cancer cells of a C-terminal splice variant of survivin, termed survivin-ΔEx3, is tightly associated with aggressive disease and markers of unfavorable prognosis. In contrast to other survivin variants, survivin-ΔEx3 localized exclusively to nuclei in tumor cells and was phosphorylated at multiple residues by the checkpoint kinase Chk2 during DNA damage. Mutagenesis of the Chk2 phosphorylation sites enhanced the stability of survivin-ΔEx3 in tumor cells, inhibited the expression of phosphorylated H2AX (γH2AX) in response to double-strand DNA breaks, and impaired growth after DNA damage. DNA damage induced Chk2 phosphorylation, stabilization of p53, induction of the cyclin-dependent kinase inhibitor p21, and homologous recombination–induced repair were not affected. In vivo, active Chk2 was detected at the earliest stages of the colorectal adenoma-to-carcinoma transition, persisted in advanced tumors, and correlated with increased survivin expression. Together, our findings suggest that Chk2-mediated phosphorylation of survivin-ΔEx3 contributes to a DNA damage–sensing checkpoint that may affect cancer cell sensitivity to genotoxic therapies. Cancer Res; 72(13); 3251–9. ©2012 AACR.
Data from Dynamic Mathematical Modeling of IL13-Induced Signaling in Hodgkin and Primary Mediastinal B-Cell Lymphoma Allows Prediction of Therapeutic Targets
Authors: Raia Valentina , Schilling Marcel , Böhm Martin , Hahn Bettina , Kowarsch Andreas , Raue Andreas , Sticht Carsten , Bohl Sebastian , Saile Maria , Möller Peter , Gretz Norbert , Timmer Jens , Theis Fabian , Lehmann Wolf-Dieter , Lichter Peter , Klingmüller Ursula
Published: March 2024

Abstract
Primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) share a frequent constitutive activation of JAK (Janus kinase)/STAT signaling pathway. Because of complex, nonlinear relations within the pathway, key dynamic properties remained to be identified to predict possible strategies for intervention. We report the development of dynamic pathway models based on quantitative data collected on signaling components of JAK/STAT pathway in two lymphoma-derived cell lines, MedB-1 and L1236, representative of PMBL and cHL, respectively. We show that the amounts of STAT5 and STAT6 are higher whereas those of SHP1 are lower in the two lymphoma cell lines than in normal B cells. Distinctively, L1236 cells harbor more JAK2 and less SHP1 molecules per cell than MedB-1 or control cells. In both lymphoma cell lines, we observe interleukin-13 (IL13)-induced activation of IL4 receptor α, JAK2, and STAT5, but not of STAT6. Genome-wide, 11 early and 16 sustained genes are upregulated by IL13 in both lymphoma cell lines. Specifically, the known STAT-inducible negative regulators CISH and SOCS3 are upregulated within 2 hours in MedB-1 but not in L1236 cells. On the basis of this detailed quantitative information, we established two mathematical models, MedB-1 and L1236 model, able to describe the respective experimental data. Most of the model parameters are identifiable and therefore the models are predictive. Sensitivity analysis of the model identifies six possible therapeutic targets able to reduce gene expression levels in L1236 cells and three in MedB-1. We experimentally confirm reduction in target gene expression in response to inhibition of STAT5 phosphorylation, thereby validating one of the predicted targets. Cancer Res; 71(3); 693–704. ©2010 AACR.