bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from A Novel Role of Dipeptidyl Peptidase 9 in Epidermal Growth Factor Signaling
Authors: Yao Tsun-Wen , Kim Woo-Shin , Yu Denise MT. , Sharbeen George , McCaughan Geoffrey W. , Choi Kang-Yell , Xia Pu , Gorrell Mark D.
Published: March 2024

Abstract
Dipeptidyl peptidase IV (DPP4), DPP8, DPP9, and fibroblast activation protein (FAP), the four proteases of the DPP4 gene family, have unique peptidase and extra-enzymatic activities that have been implicated in various diseases including cancers. We report here a novel role of DPP9 in regulating cell survival and proliferation through modulating molecular signaling cascades. Akt (protein kinase B) activation was significantly inhibited by human DPP9 overexpression in human hepatoma cells (HepG2 and Huh7) and human embryonic kidney cells (HEK293T), whereas extracellular signal-regulated kinases (ERK1/2) activity was unaffected, revealing a pathway-specific effect. Interestingly, the inhibitory effect of DPP9 on Akt pathway activation was growth factor dependent. DPP9 overexpression caused apoptosis and significantly less epidermal growth factor (EGF)-mediated Akt activation in HepG2 cells. However, such inhibitory effect was not observed in cells stimulated with other growth factors, including connective tissue growth factor, hepatic growth factor, insulin or platelet-derived growth factor-BB. The effect of DPP9 on Akt did not occur when DPP9 enzyme activity was ablated by either mutagenesis or inhibition. The phosphatidylinositol 3-kinase (PI3K)/Akt pathway is a major downstream effector of Ras. We found that DPP9 and DPP8, but not DPP4 or FAP, associate with H-Ras, a key signal molecule of the EGF receptor signaling pathway. These findings suggest an important signaling role of DPP9 in the regulation of survival and proliferation pathways. Mol Cancer Res; 9(7); 948–59. ©2011 AACR.
Data from Transcription Factor Egr-1 Is Essential for Maximal Matrix Metalloproteinase-9 Transcription by Tumor Necrosis Factor α
Authors: Shin Soon Young , Kim Ji Ho , Baker Andrew , Lim Yoongho , Lee Young Han
Published: March 2024

Abstract
Matrix metalloproteinase-9 (MMP-9) is involved in a wide range of normal and pathologic conditions, including inflammation, tissue repair, tumor invasion, and metastasis. Tumor necrosis factor α (TNFα) is a major proinflammatory cytokine that plays crucial roles in tumor progression, including tumor invasion and metastasis in the tumor microenvironment. Egr-1 is a member of the zinc-finger transcription factor family induced by diverse stimuli, including TNFα. However, the role of Egr-1 in MMP-9 expression was previously unknown. This study shows that Egr-1 directly binds to the MMP-9 promoter and plays an essential role for TNFα induction of MMP-9 transcription. Furthermore, Egr-1 together with NF-κB can synergistically activate both basal and TNFα-induced MMP-9 promoter activities in the presence of p300. We found that Egr-1 mediates extracellular signal–regulated kinase and c-jun NH2-terminal kinase mitogen-activated protein kinase–dependent MMP-9 transcription on TNFα stimulation. The requirement for Egr-1 in MMP-9 expression is further supported by the fact that HeLa cells expressing Egr-1 siRNA and Egr-1–null mouse embryonic fibroblasts were refractory to TNFα-induced MMP-9 expression. This report establishes that Egr-1 is essential for MMP-9 transcription in response to TNFα within the tumor microenvironment. Mol Cancer Res; 8(4); 507–19. ©2010 AACR.
Data from Clusterin Is a Critical Downstream Mediator of Stress-Induced YB-1 Transactivation in Prostate Cancer
Authors: Shiota Masaki , Zoubeidi Amina , Kumano Masafumi , Beraldi Eliana , Naito Seiji , Nelson Colleen C. , Sorensen Poul H.B. , Gleave Martin E.
Published: March 2024

Abstract
Clusterin is a stress-activated, cytoprotective chaperone that confers broad-spectrum treatment resistance in cancer. However, the molecular mechanisms mediating CLU transcription following anticancer treatment stress remain incompletely defined. We report that Y-box binding protein-1 (YB-1) directly binds to CLU promoter regions to transcriptionally regulate clusterin expression. In response to endoplasmic reticulum stress inducers, including paclitaxel, YB-1 is translocated to the nucleus to transactivate clusterin. Furthermore, higher levels of activated YB-1 and clusterin are seen in taxane-resistant, compared with parental, prostate cancer cells. Knockdown of either YB-1 or clusterin sensitized prostate cancer cells to paclitaxel, whereas their overexpression increased resistance to taxane. Clusterin overexpression rescued cells from increased paclitaxel-induced apoptosis following YB-1 knockdown; in contrast, however, YB-1 overexpression did not rescue cells from increased paclitaxel-induced apoptosis following clusterin knockdown. Collectively, these data indicate that YB-1 transactivation of clusterin in response to stress is a critical mediator of paclitaxel resistance in prostate cancer. Mol Cancer Res; 9(12); 1755–66. ©2011 AACR.
Data from z-Leucinyl-Leucinyl-Norleucinal Induces Apoptosis of Human Glioblastoma Tumor–Initiating Cells by Proteasome Inhibition and Mitotic Arrest Response
Authors: Monticone Massimiliano , Biollo Emanuela , Fabiano Andrea , Fabbi Marina , Daga Antonio , Romeo Francesco , Maffei Massimo , Melotti Alice , Giaretti Walter , Corte Giorgio , Castagnola Patrizio
Published: March 2024

Abstract
γ-secretase inhibitors have been proposed as drugs able to kill cancer cells by targeting the NOTCH pathway. Here, we investigated two of such inhibitors, the Benzyloxicarbonyl-Leu-Leu-Nle-CHO (LLNle) and the N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT), to assess whether they were effective in killing human glioblastoma tumor–initiating cells (GBM TIC) in vitro. We found that only LLNle was able at the micromolar range to induce the death of GBM TICs by apoptosis. To determine the cellular processes that were activated in GBM TICs by treatment with LLNle, we analyzed the amount of the NOTCH intracellular domain and the gene expression profiles following treatment with LLNle, DAPT, and DMSO (vehicle). We found that LLNIe, beside inhibiting the generation of the NOTCH intracellular domain, also induces proteasome inhibition, proteolytic stress, and mitotic arrest in these cells by repressing genes required for DNA synthesis and mitotic progression and by activating genes acting as mitotic inhibitors. DNA content flow cytometry clearly showed that cells treated with LLNle undergo arrest in the G2-M phases of the cell cycle. We also found that DAPT and L-685,458, another selective Notch inhibitor, were unable to kill GBM TICs, whereas lactacystin, a pure proteasome inhibitor, was effective although at a much less extent than LLNle. These data show that LLNle kills GBM TIC cells by inhibiting the proteasome activity. We suggest that LLNle, being able to target two relevant pathways for GBM TIC survival, may have a potential therapeutic value that deserves further investigation in animal models. (Mol Cancer Res 2009;7(11):1822–34)
Data from c-MYC Oncoprotein Dictates Transcriptional Profiles of ATP-Binding Cassette Transporter Genes in Chronic Myelogenous Leukemia CD34+ Hematopoietic Progenitor Cells
Authors: Porro Antonio , Iraci Nunzio , Soverini Simona , Diolaiti Daniel , Gherardi Samuele , Terragna Carolina , Durante Sandra , Valli Emanuele , Kalebic Thea , Bernardoni Roberto , Perrod Chiara , Haber Michelle , Norris Murray D. , Baccarani Michele , Martinelli Giovanni , Perini Giovanni
Published: March 2024

Abstract
Resistance to chemotherapeutic agents remains one of the major impediments to a successful treatment of chronic myeloid leukemia (CML). Misregulation of the activity of a specific group of ATP-binding cassette transporters (ABC) is responsible for reducing the intracellular concentration of drugs in leukemic cells. Moreover, a consistent body of evidence also suggests that ABC transporters play a role in cancer progression beyond the efflux of cytotoxic drugs. Despite a large number of studies that investigated the function of the ABC transporters, little is known about the transcriptional regulation of the ABC genes. Here, we present data showing that the oncoprotein c-MYC is a direct transcriptional regulator of a large set of ABC transporters in CML. Furthermore, molecular analysis carried out in CD34+ hematopoietic cell precursors of 21 CML patients reveals that the overexpression of ABC transporters driven by c-MYC is a peculiar characteristic of the CD34+ population in CML and was not found either in the population of mononuclear cells from which they had been purified nor in CD34+ cells isolated from healthy donors. Finally, we describe how the methylation state of CpG islands may regulate the access of c-MYC to ABCG2 gene promoter, a well-studied gene associated with multidrug resistance in CML, hence, affecting its expression. Taken together, our findings support a model in which c-MYC–driven transcriptional events, combined with epigenetic mechanisms, direct and regulate the expression of ABC genes with possible implications in tumor malignancy and drug efflux in CML. Mol Cancer Res; 9(8); 1054–66. ©2011 AACR.
Data from Cytokine Induction of Tumor Necrosis Factor Receptor 2 Is Mediated by STAT3 in Colon Cancer Cells
Authors: Hamilton Kathryn E. , Simmons James G. , Ding Shengli , Van Landeghem Laurianne , Lund P. Kay
Published: March 2024

Abstract
The IL-6/STAT3 and TNFα/NFκB pathways are emerging as critical mediators of inflammation-associated colon cancer. TNF receptor (TNFR) 2 expression is increased in inflammatory bowel diseases, the azoxymethane/dextran sodium sulfate (AOM/DSS) model of colitis-associated cancer, and by combined interleukin (IL) 6 and TNFα. The molecular mechanisms that regulate TNFR2 remain undefined. This study used colon cancer cell lines to test the hypothesis that IL-6 and TNFα induce TNFR2 via STAT3 and/or NFκB. Basal and IL-6 + TNFα–induced TNFR2 were decreased by pharmacologic STAT3 inhibition. NFκB inhibition had little effect on IL-6 + TNFα–induced TNFR2, but did inhibit induction of endogenous IL-6 and TNFR2 in cells treated with TNFα alone. Chromatin immunoprecipitation (ChIP) revealed cooperative effects of IL-6 + TNFα to induce STAT3 binding to a −1,578 STAT response element in the TNFR2 promoter but no effect on NFκB binding to consensus sites. Constitutively active STAT3 was sufficient to induce TNFR2 expression. Overexpression of SOCS3, a cytokine-inducible STAT3 inhibitor, which reduces tumorigenesis in preclinical models of colitis-associated cancer, decreased cytokine-induced TNFR2 expression and STAT3 binding to the −1,578 STAT response element. SOCS3 overexpression also decreased proliferation of colon cancer cells and dramatically decreased anchorage-independent growth of colon cancer cells, even cells overexpressing TNFR2. Collectively, these studies show that IL-6- and TNFα-induced TNFR2 expression in colon cancer cells is mediated primarily by STAT3 and provide evidence that TNFR2 may contribute to the tumor-promoting roles of STAT3. Mol Cancer Res; 9(12); 1718–31. ©2011 AACR.
Data from A Lipid-Modified Estrogen Derivative that Treats Breast Cancer Independent of Estrogen Receptor Expression through Simultaneous Induction of Autophagy and Apoptosis
Authors: Sinha Sutapa , Roy Sayantani , Reddy Bathula Surendar , Pal Krishnendu , Sudhakar Godeshala , Iyer Seethalakshmi , Dutta Shamit , Wang Enfeng , Vohra Pawan Kumar , Roy Karnati Rammohan , Reddanna Pallu , Mukhopadhyay Debabrata , Banerjee Rajkumar
Published: March 2024

Abstract
It is a challenge to develop a universal single drug that can treat breast cancer at single- or multiple-stage complications, yet remains nontoxic to normal cells. The challenge is even greater when breast cancer–specific, estrogen-based drugs are being developed that cannot act against multistaged breast cancer complications owing to the cells differential estrogen receptor (ER) expression status and their possession of drug-resistant and metastatic phenotypes. We report here the development of a first cationic lipid-conjugated estrogenic derivative (ESC8) that kills breast cancer cells independent of their ER expression status. This ESC8 molecule apparently is nontoxic to normal breast epithelial cells, as well as to other noncancer cells. ESC8 induces apoptosis through an intrinsic pathway in ER-negative MDA-MB-231 cells. In addition, ESC8 treatment induces autophagy in these cells by interfering with the mTOR activity. This is the first example of an estrogen structure–based molecule that coinduces apoptosis and autophagy in breast cancer cells. Further in vivo study confirms the role of this molecule in tumor regression. Together, our results open new perspective of breast cancer chemotherapy through a single agent, which could provide the therapeutic benefit across all stages of breast cancer. Mol Cancer Res; 9(3); 364–74. ©2011 AACR.
Data from Role of CXCL13-CXCR5 Crosstalk Between Malignant Neuroblastoma Cells and Schwannian Stromal Cells in Neuroblastic Tumors
Authors: Del Grosso Federica , Coco Simona , Scaruffi Paola , Stigliani Sara , Valdora Francesca , Benelli Roberto , Salvi Sandra , Boccardo Simona , Truini Mauro , Croce Michela , Ferrini Silvano , Longo Luca , Tonini Gian Paolo
Published: March 2024

Abstract
Neuroblastoma is a stroma-poor (SP) aggressive pediatric cancer belonging to neuroblastic tumors, also including ganglioneuroblastoma and ganglioneuroma, two stroma-rich (SR) less aggressive tumors. Our previous gene-expression profiling analysis showed a different CXCL13 mRNA expression between SP and SR tumors. Therefore, we studied 13 SP and 13 SR tumors by reverse transcription quantitative real-time PCR (RT-qPCR) and we found that CXCR5b was more expressed in SP than in SR and CXCL13 was predominantly expressed in SR tumors. Then, we isolated neuroblastic and Schwannian stromal cells by laser capture microdissection and we found that malignant neuroblasts express CXCR5b mRNA, whereas Schwannian stromal cells express CXCL13. Immunohistochemistry confirmed that stroma expresses CXCL13 but not CXCR5. To better understand the role of CXCL13 and CXCR5 in neuroblastic tumors we studied 11 neuroblastoma cell lines and we detected a heterogeneous expression of CXCL13 and CXCR5b. Interestingly, we found that only CXCR5b splice variant was expressed in both tumors and neuroblastoma lines, whereas CXCR5a was never detected. Moreover, we found that neuroblastoma cells expressing CXCR5 receptor migrate toward a source of recombinant CXCL13. Lastly, neuroblastoma cells induced to glial cell differentiation expressed CXCL13 mRNA and protein. The chemokine released in the culture medium was able to stimulate chemotaxis of LA1–5S neuroblastoma cells. Collectively, our data suggest that CXCL13 produced by stromal cells may contribute to the generation of an environment in which the malignant neuroblasts are retained, thus limiting the possible development of metastases in patients with SR tumor. Mol Cancer Res; 9(7); 815–23. ©2011 AACR.
Data from Inhibition of DNA-Dependent Protein Kinase Induces Accelerated Senescence in Irradiated Human Cancer Cells
Authors: Azad Arun , Jackson Susan , Cullinane Carleen , Natoli Anthony , Neilsen Paul M. , Callen David F. , Maira Sauveur-Michel , Hackl Wolfgang , McArthur Grant A. , Solomon Benjamin
Published: March 2024

Abstract
DNA-dependent protein kinase (DNA-PK) plays a pivotal role in the repair of DNA double-strand breaks (DSB) and is centrally involved in regulating cellular radiosensitivity. Here, we identify DNA-PK as a key therapeutic target for augmenting accelerated senescence in irradiated human cancer cells. We find that BEZ235, a novel inhibitor of DNA-PK and phosphoinositide 3-kinase (PI3K)/mTOR, abrogates radiation-induced DSB repair resulting in cellular radiosensitization and growth delay of irradiated tumor xenografts. Importantly, radiation enhancement by BEZ235 coincides with a prominent p53-dependent accelerated senescence phenotype characterized by positive β-galactosidase staining, G2–M cell-cycle arrest, enlarged and flattened cellular morphology, and increased p21 expression and senescence-associated cytokine secretion. Because this senescence response to BEZ235 is accompanied by unrepaired DNA DSBs, we examined whether selective targeting of DNA-PK also induces accelerated senescence in irradiated cells. Significantly, we show that specific pharmacologic inhibition of DNA-PK, but not PI3K or mTORC1, delays DSB repair leading to accelerated senescence after radiation. We additionally show that PRKDC knockdown using siRNA promotes a striking accelerated senescence phenotype in irradiated cells comparable with that of BEZ235. Thus, in the context of radiation treatment, our data indicate that inhibition of DNA-PK is sufficient for the induction of accelerated senescence. These results validate DNA-PK as an important therapeutic target in irradiated cancer cells and establish accelerated senescence as a novel mechanism of radiosensitization induced by DNA-PK blockade. Mol Cancer Res; 9(12); 1696–707. ©2011 AACR.
Data from The a3 Isoform Vacuolar Type H+-ATPase Promotes Distant Metastasis in the Mouse B16 Melanoma Cells
Authors: Nishisho Toshihiko , Hata Kenji , Nakanishi Masako , Morita Yoshihiro , Sun-Wada Ge-Hong , Wada Yoh , Yasui Natsuo , Yoneda Toshiyuki
Published: March 2024

Abstract
Accumulating evidence indicates that the acidic microenvironments critically influence malignant behaviors of cancer including invasiveness, metastasis, and chemoresistance. Because the vacuolar-type H+-ATPase (V-ATPase) has been shown to cause extracellular acidification by pumping protons, we studied the role of V-ATPase in distant metastasis. Real-time PCR analysis revealed that the high-metastatic B16-F10 melanoma cells strongly expressed the a3 isoform V-ATPase compared to the low-metastatic B16 parental cells. Consistent with this, B16-F10 cells created acidic environments in lung metastases by acridine orange staining and strong a3 V-ATPase expression in bone metastases by immunohistochemistry. Immunocytochemical analysis showed B16-F10 cells expressed a3 V-ATPase not only in cytoplasm but also plasma membrane, whereas B16 parental cells exhibited its expression only in cytoplasm. Of note, knockdown of a3 V-ATPase suppressed invasiveness and migration with reduced MMP-2 and MMP-9 expression in B16-F10 cells and significantly decreased lung and bone metastases, despite that tumor growth was not altered. Importantly, administration of a specific V-ATPase a3 inhibitor FR167356 reduced bone metastasis of B16-F10 cells. These results suggest that a3 V-ATPase promotes distant metastasis of B16-F10 cells by creating acidic environments via proton secretion. Our results also suggest that inhibition of the development of cancer-associated acidic environments by suppressing a3 V-ATPase could be a novel therapeutic approach for the treatment of cancer metastasis. Mol Cancer Res; 9(7); 845–55. ©2011 AACR.
Data from A Sensitized RNA Interference Screen Identifies a Novel Role for the PI3K p110γ Isoform in Medulloblastoma Cell Proliferation and Chemoresistance
Authors: Guerreiro Ana S. , Fattet Sarah , Kulesza Dorota W. , Atamer Abdullah , Elsing Alexandra N. , Shalaby Tarek , Jackson Shaun P. , Schoenwaelder Simone M. , Grotzer Michael A. , Delattre Olivier , Arcaro Alexandre
Published: March 2024

Abstract
Medulloblastoma is the most common malignant brain tumor in children and is associated with a poor outcome. We were interested in gaining further insight into the potential of targeting the human kinome as a novel approach to sensitize medulloblastoma to chemotherapeutic agents. A library of small interfering RNA (siRNA) was used to downregulate the known human protein and lipid kinases in medulloblastoma cell lines. The analysis of cell proliferation, in the presence or absence of a low dose of cisplatin after siRNA transfection, identified new protein and lipid kinases involved in medulloblastoma chemoresistance. PLK1 (polo-like kinase 1) was identified as a kinase involved in proliferation in medulloblastoma cell lines. Moreover, a set of 6 genes comprising ATR, LYK5, MPP2, PIK3CG, PIK4CA, and WNK4 were identified as contributing to both cell proliferation and resistance to cisplatin treatment in medulloblastoma cells. An analysis of the expression of the 6 target genes in primary medulloblastoma tumor samples and cell lines revealed overexpression of LYK5 and PIK3CG. The results of the siRNA screen were validated by target inhibition with specific pharmacological inhibitors. A pharmacological inhibitor of p110γ (encoded by PIK3CG) impaired cell proliferation in medulloblastoma cell lines and sensitized the cells to cisplatin treatment. Together, our data show that the p110γ phosphoinositide 3-kinase isoform is a novel target for combinatorial therapies in medulloblastoma. Mol Cancer Res; 9(7); 925–35. ©2011 AACR.
Data from Endogenous γ-H2AX-ATM-Chk2 Checkpoint Activation in Bloom's Syndrome Helicase–Deficient Cells Is Related to DNA Replication Arrested Forks
Authors: Rao V. Ashutosh , Conti Chiara , Guirouilh-Barbat Josee , Nakamura Asako , Miao Ze-Hong , Davies Sally L. , Saccá Barbara , Hickson Ian D. , Bensimon Aaron , Pommier Yves
Published: March 2024

Abstract
The Bloom syndrome helicase (BLM) is critical for genomic stability. A defect in BLM activity results in the cancer-predisposing Bloom syndrome (BS). Here, we report that BLM-deficient cell lines and primary fibroblasts display an endogenously activated DNA double-strand break checkpoint response with prominent levels of phosphorylated histone H2AX (γ-H2AX), Chk2 (pT68Chk2), and ATM (pS1981ATM) colocalizing in nuclear foci. Interestingly, the mitotic fraction of γ-H2AX foci did not seem to be higher in BLM-deficient cells, indicating that these lesions form transiently during interphase. Pulse labeling with iododeoxyuridine and immunofluorescence microscopy showed the colocalization of γ-H2AX, ATM, and Chk2 together with replication foci. Those foci costained for Rad51, indicating homologous recombination at these replication sites. We therefore analyzed replication in BS cells using a single molecule approach on combed DNA fibers. In addition to a higher frequency of replication fork barriers, BS cells displayed a reduced average fork velocity and global reduction of interorigin distances indicative of an elevated frequency of origin firing. Because BS is one of the most penetrant cancer-predisposing hereditary diseases, it is likely that the lack of BLM engages the cells in a situation similar to precancerous tissues with replication stress. To our knowledge, this is the first report of high ATM-Chk2 kinase activation and its linkage to replication defects in a BS model. (Mol Cancer Res 2007;5(7):713–24)
Data from The Fibroblast Growth Factor–Inducible 14 Receptor Is Highly Expressed in HER2-Positive Breast Tumors and Regulates Breast Cancer Cell Invasive Capacity
Authors: Willis Amanda L. , Tran Nhan L. , Chatigny Julie M. , Charlton Nichole , Vu Hong , Brown Sharron A.N. , Black Michael A. , McDonough Wendy S. , Fortin Shannon P. , Niska Joshua R. , Winkles Jeffrey A. , Cunliffe Heather E.
Published: March 2024

Abstract
Genomic characterization is beginning to define a molecular taxonomy for breast cancer; however, the molecular basis of invasion and metastasis remains poorly understood. We report a pivotal role for the fibroblast growth factor–inducible 14 (Fn14) receptor in this process. We examined whether Fn14 and its ligand tumor necrosis factor–like weak inducer of apoptosis (TWEAK) were expressed in breast tumors and whether deregulation of Fn14 levels affected malignant behavior of breast cancer cell lines. Analysis of TWEAK and Fn14 in publicly available gene expression data indicated that high Fn14 expression levels significantly correlated with several poor prognostic indicators (P < 0.05). Fn14 expression was highest in the HER2-positive/estrogen receptor–negative (HER2+/ER−) intrinsic subtype (P = 0.0008). An association between Fn14 and HER2 expression in breast tumors was confirmed by immunohistochemistry. Fn14 levels were elevated in invasive, ER− breast cancer cell lines. Overexpression of Fn14 in weakly invasive MCF7 and T47D cells resulted in a marked induction of invasion and activation of nuclear factor-κB (NF-κB) signaling. Ectopic expression of Fn14tCT, a Fn14 deletion mutant that cannot activate NF-κB signaling, was not able to induce invasion. Moreover, ectopic expression of Fn14tCT in highly invasive MDA-MB-231 cells reduced their invasive capability. RNA interference–mediated inhibition of Fn14 expression in both MDA-MB-231 and MDA-MB-436 cells reduced invasion. Expression profiling of the Fn14-depleted cells revealed deregulation of NF-κB activity. Our findings support a role for Fn14-mediated NF-κB pathway activation in breast tumor invasion and metastasis. (Mol Cancer Res 2008;6(5):725–34)
Data from Oligodendrocyte Lineage Transcription Factor 2 Inhibits the Motility of a Human Glial Tumor Cell Line by Activating RhoA
Authors: Tabu Kouichi , Ohba Yusuke , Suzuki Tadaki , Makino Yoshinori , Kimura Taichi , Ohnishi Akiko , Sakai Mieko , Watanabe Takuya , Tanaka Shinya , Sawa Hirofumi
Published: March 2024

Abstract
The basic helix-loop-helix transcription factor, oligodendrocyte lineage transcription factor 2 (OLIG2), is specifically expressed in the developing and mature central nervous system and plays an important role in oligodendrogenesis from neural progenitors. It is also expressed in various types of glial tumors, but rarely in glioblastoma. Although we previously showed that OLIG2 expression inhibits glioma cell growth, its role in tumorigenesis remains incompletely understood. Here, we investigated the effect of OLIG2 expression on the migration of the human glioblastoma cell line U12-1. In these cells, OLIG2 expression is controlled by the Tet-off system. Induction of OLIG2 expression inhibited both the migration and invasiveness of U12-1 cells. OLIG2 expression also increased the activity of the GTPase RhoA as well as inducing the cells to form stress fibers and focal adhesions. Experiments using short interfering RNA against p27Kip1 revealed that up-regulation of the p27Kip1 protein was not essential for RhoA activation, rather it contributed independently to the decreased motility of OLIG2-expressing U12-1 cells. Alternatively, semiquantitative reverse transcription-PCR analysis revealed that mRNA expression of RhoGAP8, which regulates cell migration, was decreased by OLIG2 expression. Furthermore, expression of C3 transferase, which inhibits Rho via ADP ribosylation, attenuated the OLIG2-induced inhibition of cell motility. Imaging by fluorescence resonance energy transfer revealed that in U12-1 cells lacking OLIG2, the active form of RhoA was localized to protrusions of the cell membrane. In contrast, in OLIG2-expressing cells, it lined almost the entire plasma membrane. Thus, OLIG2 suppresses the motile phenotype of glioblastoma cells by activating RhoA. (Mol Cancer Res 2007;5(10):1099–109)
Data from Comprehensive Molecular Profiling of Desmoplastic Small Round Cell Tumor
Authors: Slotkin Emily K. , Bowman Anita S. , Levine Max F. , Dela Cruz Filemon , Coutinho Diego F. , Sanchez Glorymar I. , Rosales Nestor , Modak Shakeel , Tap William D. , Gounder Mrinal M. , Thornton Katherine A. , Bouvier Nancy , You Daoqi , Gundem Gunes , Gerstle Justin T. , Heaton Todd E. , LaQuaglia Michael P. , Wexler Leonard H. , Meyers Paul A. , Kung Andrew L. , Papaemmanuil Elli , Zehir Ahmet , Ladanyi Marc , Shukla Neerav
Published: March 2024

Abstract
Desmoplastic small round cell tumor (DSRCT) is characterized by the EWSR1–WT1 t(11;22) (p13:q12) translocation. Few additional putative drivers have been identified, and research has suffered from a lack of model systems. Next-generation sequencing (NGS) data from 68 matched tumor-normal samples, whole-genome sequencing data from 10 samples, transcriptomic and affymetrix array data, and a bank of DSRCT patient-derived xenograft (PDX) are presented. EWSR1–WT1 fusions were noted to be simple, balanced events. Recurrent mutations were uncommon, but were noted in TERT (3%), ARID1A (6%), HRAS (5%), and TP53 (3%), and recurrent loss of heterozygosity (LOH) at 11p, 11q, and 16q was identified in 18%, 22%, and 34% of samples, respectively. Comparison of tumor-normal matched versus unmatched analysis suggests overcalling of somatic mutations in prior publications of DSRCT NGS data. Alterations in fibroblast growth factor receptor 4 (FGFR4) were identified in 5 of 68 (7%) of tumor samples, whereas differential overexpression of FGFR4 was confirmed orthogonally using 2 platforms. PDX models harbored the pathognomic EWSR1–WT1 fusion and were highly representative of corresponding tumors. Our analyses confirm DSRCT as a genomically quiet cancer defined by the balanced translocation, t(11;22)(p13:q12), characterized by a paucity of secondary mutations but a significant number of copy number alterations. Against this genomically quiet background, recurrent activating alterations of FGFR4 stood out, and suggest that this receptor tyrosine kinase, also noted to be highly expressed in DSRCT, should be further investigated. Future studies of DSRCT biology and preclinical therapeutic strategies should benefit from the PDX models characterized in this study.
Implications:
These data describe the general quiescence of the desmoplastic small round cell tumor (DSRCT) genome, present the first available bank of DSRCT model systems, and nominate FGFR4 as a key receptor tyrosine kinase in DSRCT, based on high expression, recurrent amplification, and recurrent activating mutations.
Data from In Situ Analysis of N-Linked Glycans as Potential Biomarkers of Clinical Course in Human Prostate Cancer
Authors: Conroy Lindsey R. , Stanback Alexandra E. , Young Lyndsay E.A. , Clarke Harrison A. , Austin Grant L. , Liu Jinze , Allison Derek B. , Sun Ramon C.
Published: March 2024

Abstract
Prostate cancer is the most common cancer in men worldwide. Despite its prevalence, there is a critical knowledge gap in understanding factors driving disparities in survival among different cohorts of patients with prostate cancer. Identifying molecular features separating disparate populations is an important first step in prostate cancer research that could lead to fundamental hypotheses in prostate biology, predictive biomarker discovery, and personalized therapy. N-linked glycosylation is a cotranslational event during protein folding that modulates a myriad of cellular processes. Recently, aberrant N-linked glycosylation has been reported in prostate cancers. However, the full clinical implications of dysregulated glycosylation in prostate cancer has yet to be explored. Herein, we performed direct on-tissue analysis of N-linked glycans using matrix-assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) from tissue microarrays of over 100 patient tumors with over 10 years of follow-up metadata. We successfully identified a panel of N-glycans that are unique between benign and prostate tumor tissue. Specifically, high-mannose as well as tri-and tetra-antennary N-glycans were more abundant in tumor tissue and increase proportionally with tumor grade. Further, we expanded our analyses to examine the N-glycan profiles of Black and Appalachian patients and have identified unique glycan signatures that correlate with recurrence in each population. Our study highlights the potential applications of MALDI-MSI for digital pathology and biomarker discovery for prostate cancer.
Implications:
MALDI-MSI identifies N-glycan perturbations in prostate tumors compared with benign tissue. This method can be utilized to predict prostate cancer recurrence and study prostate cancer disparities.
Data from The Heme-Regulated Inhibitor Pathway Modulates Susceptibility of Poor Prognosis B-Lineage Acute Leukemia to BH3-Mimetics
Authors: Smith Kaitlyn H. , Budhraja Amit , Lynch John , Roberts Kathryn , Panetta John C. , Connelly Jon P. , Turnis Meghan E. , Pruett-Miller Shondra M. , Schuetz John D. , Mullighan Charles G. , Opferman Joseph T.
Published: March 2024

Abstract
Antiapoptotic MCL1 is one of the most frequently amplified genes in human cancers and elevated expression confers resistance to many therapeutics including the BH3-mimetic agents ABT-199 and ABT-263. The antimalarial, dihydroartemisinin (DHA) translationally represses MCL-1 and synergizes with BH3-mimetics. To explore how DHA represses MCL-1, a genome-wide CRISPR screen identified that loss of genes in the heme synthesis pathway renders mouse BCR-ABL+ B-ALL cells resistant to DHA-induced death. Mechanistically, DHA disrupts the interaction between heme and the eIF2α kinase heme-regulated inhibitor (HRI) triggering the integrated stress response. Genetic ablation of Eif2ak1, which encodes HRI, blocks MCL-1 repression in response to DHA treatment and represses the synergistic killing of DHA and BH3-mimetics compared with wild-type leukemia. Furthermore, BTdCPU, a small-molecule activator of HRI, similarly triggers MCL-1 repression and synergizes with BH3-mimetics in mouse and human leukemia including both Ph+ and Ph-like B-ALL. Finally, combinatorial treatment of leukemia bearing mice with both BTdCPU and a BH3-mimetic extended survival and repressed MCL-1 in vivo. These findings reveal for the first time that the HRI-dependent cellular heme-sensing pathway can modulate apoptosis in leukemic cells by repressing MCL-1 and increasing their responsiveness to BH3-mimetics. This signaling pathway could represent a generalizable mechanism for repressing MCL-1 expression in malignant cells and sensitizing them to available therapeutics.
Implications:
The HRI-dependent cellular heme-sensing pathway can modulate apoptotic sensitivity in leukemic cells by repressing antiapoptotic MCL-1 and increasing their responsiveness to BH3-mimetics.
Data from Oncogenic KrasG12D Activation in the Nonhematopoietic Bone Marrow Microenvironment Causes Myelodysplastic Syndrome in Mice
Authors: Osswald Lena , Hamarsheh Shaima'a , Uhl Franziska Maria , Andrieux Geoffroy , Klein Claudius , Dierks Christine , Duquesne Sandra , Braun Lukas M. , Schmitt-Graeff Annette , Duyster Justus , Boerries Melanie , Brummer Tilman , Zeiser Robert
Published: March 2024

Abstract
The bone marrow microenvironment (BMME) is key player in regulation and maintenance of hematopoiesis. Oncogenic RAS mutations, causing constitutive activation of multiple tumor-promoting pathways, are frequently found in human cancer. So far in hematologic malignancies, RAS mutations have only been reported to occur in hematopoietic cells. In this study, we investigated the effect of oncogenic Kras expression in the BMME in a chimeric mouse model. We observed that an activating mutation of Kras in the nonhematopoietic system leads to a phenotype resembling myelodysplastic syndrome (MDS) characterized by peripheral cytopenia, marked dysplasia within the myeloid lineage as well as impaired proliferation and differentiation capacity of hematopoietic stem and progenitor cells. The phenotypic changes could be reverted when the BM was re-isolated and transferred into healthy recipients, indicating that the KrasG12D-activation in the nonhematopoietic BMME was essential for the MDS phenotype. Gene expression analysis of sorted nonhematopoietic BM niche cells from KrasG12D mice revealed upregulation of multiple inflammation-related genes including IL1-superfamily members (Il1α, Il1β, Il1f9) and the NLPR3 inflammasome. Thus, pro-inflammatory IL1-signaling in the BMME may contribute to MDS development. Our findings show that a single genetic change in the nonhematopoietic BMME can cause an MDS phenotype. Oncogenic Kras activation leads to pro-inflammatory signaling in the BMME which impairs HSPCs function.
Implications:
These findings may help to identify new therapeutic targets for MDS.
Data from Extracellular Matrix–Bound FGF2 Mediates Estrogen Receptor Signaling and Therapeutic Response in Breast Cancer
Authors: DiGiacomo Josh W. , Godet Inês , Trautmann-Rodriguez Michael , Gilkes Daniele M.
Published: March 2024

Abstract
The extracellular matrix (ECM) is often unaccounted for in studies that consider the stromal contribution to cancer cell signaling and response to treatment. To investigate the influence of a fibrotic microenvironment, we use fibroblast-derived ECM scaffolds as a cell culture platform. We uncover that estrogen receptor–positive (ER+) breast cancer cells cultured within ECM-scaffolds have an increase in ER signaling that occurs via an MAPK-dependent, but estrogen-independent manner. The ECM acts as a reservoir by binding, enriching, and presenting growth factors to adjacent epithelial cells. We identified FGF2 as a specific ECM-bound factor that drives ER signaling. ER+ cells cultured on ECM matrices have reduced sensitivity to ER-targeted therapies. The sensitivity to ER-targeted therapy can be restored by inhibiting FGF2–FGFR1 binding. ECM–FGF2 complexes promote Cyclin D1 induction that prevents G1 arrest even in the presence of antiestrogens. This work demonstrates that the ECM can drive ER signaling and resistance to endocrine therapy, and suggests that patients with ER+ breast cancer that have high mammographic breast density may benefit from existing FGFR-targeted therapies.
Implications:
This work uncovers how the ECM may mediate signaling between growth factors and ER+ breast cancer cells to promote estrogen-independent ER signaling and resistance to endocrine therapy.
Data from IQGAP3, a YAP Target, Is Required for Proper Cell-Cycle Progression and Genome Stability
Authors: Leone Marina , Cazorla-Vázquez Salvador , Ferrazzi Fulvia , Wiederstein Janica L. , Gründl Marco , Weinstock Grit , Vergarajauregui Silvia , Eckstein Markus , Krüger Marcus , Gaubatz Stefan , Engel Felix B.
Published: March 2024

Abstract
Controlling cell proliferation is critical for organism development, tissue homeostasis, disease, and regeneration. IQGAP3 has been shown to be required for proper cell proliferation and migration, and is associated to a number of cancers. Moreover, its expression is inversely correlated with the overall survival rate in the majority of cancers. Here, we show that IQGAP3 expression is elevated in cervical cancer and that in these cancers IQGAP3 high expression is correlated with an increased lethality. Furthermore, we demonstrate that IQGAP3 is a target of YAP, a regulator of cell cycle gene expression. IQGAP3 knockdown resulted in an increased percentage of HeLa cells in S phase, delayed progression through mitosis, and caused multipolar spindle formation and consequentially aneuploidy. Protein–protein interaction studies revealed that IQGAP3 interacts with MMS19, which is known in Drosophila to permit, by competitive binding to Xpd, Cdk7 to be fully active as a Cdk-activating kinase (CAK). Notably, IQGAP3 knockdown caused decreased MMS19 protein levels and XPD knockdown partially rescued the reduced proliferation rate upon IQGAP3 knockdown. This suggests that IQGAP3 modulates the cell cycle via the MMS19/XPD/CAK axis. Thus, in addition to governing proliferation and migration, IQGAP3 is a critical regulator of mitotic progression and genome stability.
Implications:
Our data indicate that, while IQGAP3 inhibition might be initially effective in decreasing cancer cell proliferation, this approach harbors the risk to promote aneuploidy and, therefore, the formation of more aggressive cancers.
Data from HER2 Isoforms Uniquely Program Intratumor Heterogeneity and Predetermine Breast Cancer Trajectories During the Occult Tumorigenic Phase
Authors: Ginzel Joshua D. , Acharya Chaitanya R. , Lubkov Veronica , Mori Hidetoshi , Boone Peter G. , Rochelle Lauren K. , Roberts Wendy L. , Everitt Jeffrey I. , Hartman Zachary C. , Crosby Erika J. , Barak Lawrence S. , Caron Marc G. , Chen Jane Q. , Hubbard Neil E. , Cardiff Robert D. , Borowsky Alexander D. , Lyerly H. Kim , Snyder Joshua C.
Published: March 2024

Abstract
HER2-positive breast cancers are among the most heterogeneous breast cancer subtypes. The early amplification of HER2 and its known oncogenic isoforms provide a plausible mechanism in which distinct programs of tumor heterogeneity could be traced to the initial oncogenic event. Here a Cancer rainbow mouse simultaneously expressing fluorescently barcoded wildtype (WTHER2), exon-16 null (d16HER2), and N-terminally truncated (p95HER2) HER2 isoforms is used to trace tumorigenesis from initiation to invasion. Tumorigenesis was visualized using whole-gland fluorescent lineage tracing and single-cell molecular pathology. We demonstrate that within weeks of expression, morphologic aberrations were already present and unique to each HER2 isoform. Although WTHER2 cells were abundant throughout the mammary ducts, detectable lesions were exceptionally rare. In contrast, d16HER2 and p95HER2 induced rapid tumor development. d16HER2 incited homogenous and proliferative luminal-like lesions which infrequently progressed to invasive phenotypes whereas p95HER2 lesions were heterogenous and invasive at the smallest detectable stage. Distinct cancer trajectories were observed for d16HER2 and p95HER2 tumors as evidenced by oncogene-dependent changes in epithelial specification and the tumor microenvironment. These data provide direct experimental evidence that intratumor heterogeneity programs begin very early and well in advance of screen or clinically detectable breast cancer.
Implications:
Although all HER2 breast cancers are treated equally, we show a mechanism by which clinically undetected HER2 isoforms program heterogenous cancer phenotypes through biased epithelial specification and adaptations within the tumor microenvironment.
Data from Merkel Cell Polyomavirus Small T Antigen Activates Noncanonical NF-κB Signaling to Promote Tumorigenesis
Authors: Zhao Jiawei , Jia Yuemeng , Shen Shunli , Kim Jiwoong , Wang Xun , Lee Eunice , Brownell Isaac , Cho-Vega Jeong Hee , Lewis Cheryl , Homsi Jade , Sharma Rohit R. , Wang Richard C.
Published: March 2024

Abstract
Multiple human polyomaviruses (HPyV) can infect the skin, but only Merkel cell polyomavirus (MCPyV) has been implicated in the development of a cancer, Merkel cell carcinoma (MCC). While expression of HPyV6, HPyV7, and MCPyV small T antigens (sT), all induced a senescence-associated secretory phenotype (SASP), MCPyV sT uniquely activated noncanonical NF-κB (ncNF-κB), instead of canonical NF-κB signaling, to evade p53-mediated cellular senescence. Through its large T stabilization domain, MCPyV sT activated ncNF-κB signaling both by inducing H3K4 trimethylation-mediated increases of NFKB2 and RELB transcription and also by promoting NFKB2 stabilization and activation through FBXW7 inhibition. Noncanonical NF-κB signaling was required for SASP cytokine secretion, which promoted the proliferation of MCPyV sT–expressing cells through autocrine signaling. Virus-positive MCC cell lines and tumors showed ncNF-κB pathway activation and SASP gene expression, and the inhibition of ncNF-κB signaling prevented VP-MCC cell growth in vitro and in xenografts. We identify MCPyV sT–induced ncNF-κB signaling as an essential tumorigenic pathway in MCC.
Implications:
This work is the first to identify the activation of ncNF-κB signaling by any polyomavirus and its critical role in MCC tumorigenesis.
Data from AraC-FdUMP[10] Is a Next-Generation Fluoropyrimidine with Potent Antitumor Activity in PDAC and Synergy with PARG Inhibition
Authors: Haber Alex O. , Jain Aditi , Mani Chinnadurai , Nevler Avinoam , Agostini Lebaron C. , Golan Talia , Palle Komaraiah , Yeo Charles J. , Gmeiner William H. , Brody Jonathan R.
Published: March 2024

Abstract
AraC-FdUMP[10] (CF10) is a second-generation polymeric fluoropyrimidine that targets both thymidylate synthase (TS), the target of 5-fluorouracil (5-FU), and DNA topoisomerase 1 (Top1), the target of irinotecan, two drugs that are key components of FOLFIRNOX, a standard-of-care regimen for pancreatic ductal adenocarcinoma (PDAC). We demonstrated that F10 and CF10 are potent inhibitors of PDAC cell survival (in multiple cell lines including patient-derived lines) with IC50s in the nanomolar range and are nearly 1,000-fold more potent than 5-FU. The increased potency of CF10 relative to 5-FU correlated with enhanced TS inhibition and strong Top1 cleavage complex formation. Furthermore, CF10 displayed single-agent activity in PDAC murine xenografts without inducing weight loss. Through a focused drug synergy screen, we identified that combining CF10 with targeting the DNA repair enzyme, poly (ADP-ribose) glycohydrolase, induces substantial DNA damage and apoptosis. This work moves CF10 closer to a clinical trial for the treatment of PDAC.
Implications:
CF10 is a promising polymeric fluoropyrimidine with dual mechanisms of action (i.e., TS and Top1 inhibition) for the treatment of PDAC and synergizes with targeting of DNA repair.
Data from Loss of Aryl Hydrocarbon Receptor Promotes Colon Tumorigenesis in ApcS580/+; KrasG12D/+ Mice
Authors: Han Huajun , Davidson Laurie A. , Hensel Martha , Yoon Grace , Landrock Kerstin , Allred Clinton , Jayaraman Arul , Ivanov Ivan , Safe Stephen H. , Chapkin Robert S.
Published: March 2024

Abstract
The mutational genetic landscape of colorectal cancer has been extensively characterized; however, the ability of “cooperation response genes” to modulate the function of cancer “driver” genes remains largely unknown. In this study, we investigate the role of aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, in modulating oncogenic cues in the colon. We show that intestinal epithelial cell–targeted AhR knockout (KO) promotes the expansion and clonogenic capacity of colonic stem/progenitor cells harboring ApcS580/+; KrasG12D/+ mutations by upregulating Wnt signaling. The loss of AhR in the gut epithelium increased cell proliferation, reduced mouse survival rate, and promoted cecum and colon tumorigenesis in mice. Mechanistically, the antagonism of Wnt signaling induced by Lgr5 haploinsufficiency attenuated the effects of AhR KO on cecum and colon tumorigenesis.
Implications:
Our findings reveal that AhR signaling plays a protective role in genetically induced colon tumorigenesis at least by suppressing Wnt signaling and provides rationale for the AhR as a therapeutic target for cancer prevention and treatment.