bluuebunny/crossref_metadata_2025 huggingface dataset:
The Anxiety and Depression of International Medical Students during COVID-19 Pandemic: A Cross-Sectional Study
Authors: Chen Xiaoqing , Sun Hong
Published: March 2024

The COVID-19 pandemic has inflicted physical harm and exacerbated a significant mental health crisis, warranting greater attention. This study investigated the prevalence of anxiety and depression among international medical students (IMSs) during the pandemic and explored its correlation with demographic factors. Participants completed a comprehensive questionnaire encompassing demographic details, the Zung self-rating anxiety scale, and the Zung self-rating depression scale. The findings revealed that 23.27% of IMSs reported anxiety, while 48.52% experienced symptoms of depression. Multivariate logistic regression analysis identified poor health conditions and limited access to the family as independent risk factors for anxiety. At the same time, depression was associated with both compromised health and notable financial burdens. This study provides crucial insights for policymakers, college administrators, and government authorities, urging proactive measures to support and manage the wellbeing of IMSs during pandemic situations.
Pancreatic Myeloid Sarcoma Causing Obstructive Jaundice: A Case Report and Literature Review
Authors: Lavette Laura E. , Niehaus Angela G. , Clark Clancy J. , Conway Jason D. , Mishra Girish , Jahann Darius A.
Published: March 2024

Myeloid sarcoma (MS) is an extramedullary manifestation of acute myeloid leukemia (AML) and commonly occurs in sites such as the lymph nodes, skin, soft tissues, and bone. It more rarely manifests in the pancreas, with less than 20 cases reported in the literature since 1987. Despite its rarity, MS should be considered in the differential diagnosis of a soft tissue mass causing obstructive jaundice, especially if the patient has a known hematologic disease. Isolated cases of pancreatic MS have been known to progress to AML; therefore, it is crucial to differentiate MS from more common diagnoses, such as pancreatic cancer or pancreatitis. This is a case of a 70-year-old male with symptomatic obstructive jaundice secondary to pancreatic MS, ultimately requiring endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) for diagnosis and management. Also included is a comprehensive review of previous case reports with similar clinical presentations, management, and treatment of pancreatic MS.
Different Dual-Task Paradigm Reduce Postural Control Ability and Dynamic Stability of Healthy Young Adults during Stair Descent
Authors: Yang Jiankang , Yan Shifang , Cao Chuanbao
Published: March 2024

Objective. This study aimed to compare the impacts of different dual-task paradigms on the postural control ability and dynamic stability of the youth during stair descent. Method. Twenty young adults without regular exercise habits were randomly recruited to perform stair descent tasks with three different paradigms: single-task, cognitive dual-task, and manual dual-task. Kinematic and dynamic data were collected using an 8 Vicon motion analysis system and a Kistler force plate to evaluate postural control ability and dynamic stability during stair descent. Results. The variation trends of lower limb joint moment were similar under the three task models. Compared with a single-task, both dual-task paradigms significantly reduced the mechanical parameters and dynamic stability during stair descent. Conclusion. The dual-task paradigm increases the risk of stair-related falls. Both cognitive and manual tasks have similar impacts on postural control ability and dynamic stability during stair walking. It is recommended that people avoid performing dual tasks during stair descent.
Data from Ikaros Modulates Cholesterol Uptake: A Link between Tumor Suppression and Differentiation
Authors: Loeper Siobhan , Asa Sylvia L. , Ezzat Shereen
Published: March 2024

Abstract
Ikaros is a transcription factor that directs lymphoid lineage commitment and pituitary neuroendocrine cell expansion and function. Here, we show that Ikaros regulates the low-density lipoprotein receptor (LDL-R) to alter metabolism in pituitary corticotroph cells. The DNA-binding Ikaros isoform Ik1 binds and enhances activity of the LDL-R promoter. Ik1 decreases methylation and increases acetylation of histone H3 (Lys9) at the LDL-R promoter. Confocal microscopy and quantitative fluorometry show enhanced LDL endocytosis in Ik1-transfected cells that exhibit abundant endoplasmic reticulum, large Golgi complexes, and prominent secretory granule formation, consistent with more robust cholesterol incorporation into functionally relevant membrane-rich organelles. Consistent with these data, LDL-R−/− mice, like Ik−/− mice, have decreased circulating levels of adrenocorticotropic hormone. These findings expand the repertoire of Ikaros actions to include regulation of the cholesterol uptake metabolic pathway with therapeutic implications for lipid-modifying drugs in Ikaros-associated cancers. [Cancer Res 2008;68(10):3715–23]
Data from The Extra-domain A of Fibronectin Is a Vascular Marker of Solid Tumors and Metastases
Authors: Rybak Jascha-N. , Roesli Christoph , Kaspar Manuela , Villa Alessandra , Neri Dario
Published: March 2024

Abstract
One of the most promising new avenues for the development of more selective and efficacious cancer therapies relies on the antibody-mediated targeted delivery of bioactive agents (e.g., cytokines) to the tumor environment. The identification of quantitative differences in the expression of accessible vascular proteins in metastatic lesions and host organs facilitate the development of antibody-based strategies, which should be highly efficient and selective, considering the fact that an over-exuberant neovasculature is a characteristic feature of aggressive cancers, and that tumor blood vessels are readily accessible for i.v. administered therapeutic agents. Metastasis is the main cause of death in cancer. The availability of metastasis-specific antigens accessible from the bloodstream will allow a selective delivery of therapeutic agents to metastatic lesions using antibodies as vehicles. Using a combination of vascular biotinylation of 129Sv mice bearing F9 liver metastases and mass spectrometry, we have identified 435 accessible proteins in metastasis and host organ specimens, of which 117 were exclusively detected in metastases. In particular, we found that the alternatively spliced extra-domain A (EDA) of fibronectin is strongly expressed in the neovasculature of liver metastases, while being undetectable in most normal organs. A human antibody to EDA was used to show EDA expression in the neovasculature of metastases and primary tumors of human cancer patients and to target mouse liver metastases and subcutaneous tumors in vivo. Human antibody fragments specific to the EDA domain of fibronectin promise to serve as general vehicles for the efficient and selective delivery of imaging agents or therapeutic molecules to metastatic sites. [Cancer Res 2007;67(22):10948–57]
Data from Cyclooxygenase-2 Transcription Is Regulated by Human Papillomavirus 16 E6 and E7 Oncoproteins: Evidence of a Corepressor/Coactivator Exchange
Authors: Subbaramaiah Kotha , Dannenberg Andrew J.
Published: March 2024

Abstract
Cyclooxygenase (COX-2) is overexpressed in human papillomavirus (HPV)-induced diseases, including cervical cancer. Although HPV E6 and E7 oncoproteins have been causally linked to cervical carcinogenesis, their effects on COX-2 gene expression are unknown. Increased levels of COX-2 mRNA, protein, and prostaglandin E2 synthesis were detected in HPV16 E6- and E7-expressing cervical cancer cells (CaSki and SiHa) compared with an uninfected cervical cancer cell line (C33A). HPV16 E6 and E7 oncoproteins induced COX-2 transcription by activating the epidermal growth factor receptor (EGFR)→Ras→mitogen-activated protein kinase pathway. Interestingly, HPV16 oncoproteins stimulated EGFR signaling, in part, by inducing the release of amphiregulin, an EGFR ligand. The inductive effects of HPV16 E6 and E7 were mediated by enhanced binding of activator protein-1 to the cyclic AMP (cAMP)-responsive element (−59/−53) of the COX-2 promoter. The potential contribution of coactivators and corepressors to HPV16 E6- and E7-mediated induction of COX-2 was also investigated. Chromatin immunoprecipitation assays indicated that E6 and E7 oncoproteins induced the recruitment of phosphorylated c-Jun, c-Fos, UbcH5, and cAMP-responsive element binding protein–binding protein/p300 to the COX-2 promoter. In contrast, E6 and E7 inhibited the binding of the histone deacetylase 3-nuclear receptor corepressor (NCoR) complex to the COX-2 promoter. Moreover, overexpression of NCoR blocked E6- and E7-mediated stimulation of the COX-2 promoter. Taken together, these results indicate that HPV16 E6 and E7 oncoproteins stimulated COX-2 transcription by inducing a corepressor/coactivator exchange. To our knowledge, this study also provides the first evidence that NCoR can function as a repressor of COX-2 gene expression. [Cancer Res 2007;67(8):3976–85]
Data from Tumor Suppression by IFN Regulatory Factor-1 Is Mediated by Transcriptional Down-regulation of Cyclin D1
Authors: Kröger Andrea , Stirnweiss Anja , Pulverer Julia Elisabeth , Klages Katjana , Grashoff Martina , Reimann Jörg , Hauser Hansjörg
Published: March 2024

Abstract
IFNs have been ascribed to mediate antitumor effects. IFN regulatory factor-1 (IRF-1) is a major target gene of IFNs. It inhibits cell proliferation and oncogenic transformation. Here, we show that 60% of all mRNAs deregulated by oncogenic transformation mediated by c-myc and H-ras are reverted to the expression levels of nontransformed cells by IRF-1. These include cell cycle–regulating genes. An indirect target is cyclin D1. Activation of IRF-1 decreased cyclin D1 expression and cyclin-dependent kinase 4 kinase activity concomitant with change in the levels of hyperphosphorylated retinoblastoma protein. These effects are mediated by inhibition of the mitogen-activated protein kinase kinase/extracellular signal-regulated kinase pathway and a transcriptional repression of cyclin D1. As shown by in vitro assays and tumor growth in nude mice, IRF-1–mediated effects on cell cycle progression were found to be overridden by ectopic expression of cyclin D1. Conversely, decrease of cyclin D1 by RNA interference experiments prevents transformation and tumor growth. The data show that cyclin D1 is a key target for IRF-1–mediated tumor-suppressive effects. [Cancer Res 2007;67(7):2972–81]
Data from Targeting the Nuclear Factor-κB Rescue Pathway Has Promising Future in Human Renal Cell Carcinoma Therapy
Authors: Sourbier Carole , Danilin Sabrina , Lindner Véronique , Steger Jacques , Rothhut Sylvie , Meyer Nicolas , Jacqmin Didier , Helwig Jean-Jacques , Lang Hervé , Massfelder Thierry
Published: March 2024

Abstract
Metastatic renal cell carcinoma (RCC) remains refractory to therapies. The nuclear factor-κB (NF-κB) transcription factor is involved in cell growth, cell motility, and vascularization. We evaluated whether targeting NF-κB could be of therapeutic and prognostic values in human RCC. The activation of the NF-κB pathway in human RCC cells and tumors was investigated by Western blot. In vitro, the effects of BAY 11-7085 and sulfasalazine, two NF-κB inhibitors, on tumor cell growth were investigated by cell counting, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analysis, terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling, and fluorescence-activated cell sorting. Their specificity toward NF-κB was analyzed by Western blot, confocal microscopy, NF-κB small interfering RNA, and NF-κB transcription assay. In vivo, the effects of BAY 11-7085 on the growth of human RCC tumors were investigated in nude mice. A tissue microarray (TMA) containing 241 cases of human RCC with 12 to 22 years of clinical follow-up and corresponding normal tissues was built up to assess prognostic significance of activated NF-κB. NF-κB is constitutively activated in cultured cells expressing or not the von Hippel-Lindau (VHL) tumor suppressor gene as a consequence of Akt kinase activation and in tumors. In vitro and in vivo NF-κB inhibition blocked tumor cell growth by inducing cell apoptosis. On the TMA, NF-κB activation was correlated with tumor dimension but was not found to be an independent prognostic factor for patient survival. This report provides strong evidence that the mechanisms responsible for the intrinsic resistance of RCC cells to apoptosis converge on NF-κB independently of VHL expression and that targeting this pathway has great anticancer potential. [Cancer Res 2007;67(24):11668–76]
Data from Syndecan-2 Affects the Basal and Chemotherapy-Induced Apoptosis in Osteosarcoma
Authors: Orosco Armelle , Fromigué Olivia , Bazille Céline , Entz-Werle Natacha , Levillain Pierre , Marie Pierre J. , Modrowski Dominique
Published: March 2024

Abstract
Syndecans are transmembrane heparan sulfate proteoglycans controlling cell adhesion, migration, and proliferation. We previously showed that syndecan-2 is involved in the control of apoptosis in cultured osteosarcoma cells. These data led us to the hypothesis that syndecan-2 may play a role in the apoptotic signaling in bone tumors. We immunohistochemically analyzed tissue sections from biopsies from 21 patients with well-characterized osteosarcoma. These tissues expressed low levels of syndecan-2 compared with osteoblasts and osteocytes in normal bone. Cultured human osteosarcoma cells also produced lower mRNA levels of syndecan-2 than normal osteoblastic cells. Moreover, the presence of syndecan-2 correlated with spontaneous apoptosis in osteosarcoma tissues as assessed by detection of DNA fragmentation in situ. Overexpression of syndecan-2 resulted in decreased number of migrating and invading U2OS osteosarcoma cells in Matrigel. In addition, overexpression of syndecan-2 sensitized human osteosarcoma cells to chemotherapy-induced apoptosis, increasing the response to methotrexate, doxorubicin, and cisplatin. Consistently, knockdown of the proteoglycan using stable transfection with a plasmid coding small interfering RNA resulted in inhibition of chemotherapy-induced apoptosis. Analysis of syndecan-2 expression both in biopsies and in corresponding postchemotherapy-resected tumors, as well as in cells treated with methotrexate or doxorubicin, showed that the cytotoxic action of chemotherapy can be associated with an increase in syndecan-2. These results provide support for a tumor-suppressor function for syndecan-2 and suggest that dysregulation of apoptosis may be related to abnormal syndecan-2 expression or induction in osteosarcoma. Moreover, our data identify syndecan-2 as a new factor mediating the antioncogenic effect of chemotherapeutic drugs. [Cancer Res 2007;67(8):3708–14]
Data from Metallothionein Expression Is Suppressed in Primary Human Hepatocellular Carcinomas and Is Mediated through Inactivation of CCAAT/Enhancer Binding Protein α by Phosphatidylinositol 3-Kinase Signaling Cascade
Authors: Datta Jharna , Majumder Sarmila , Kutay Huban , Motiwala Tasneem , Frankel Wendy , Costa Robert , Cha Hyuk C. , MacDougald Ormond A. , Jacob Samson T. , Ghoshal Kalpana
Published: March 2024

Abstract
Reactive oxygen species (ROS) resulting from chronic inflammation cause liver injury leading to transformation of regenerating hepatocytes. Metallothioneins (MT), induced at high levels by oxidative stress, are potent scavengers of ROS. Here, we report that the levels of MT-1 and MT-2A are drastically reduced in primary human hepatocellular carcinomas (HCCs) and in diethylnitrosamine-induced liver tumors in mice, which is primarily due to transcriptional repression. Expression of the transcription factor, MTF-1, essential for MT expression, and its target gene Zn-T1 that encodes the zinc transporter-1 was not significantly altered in HCCs. Inhibitors of both phosphatidylinositol 3-kinase (PI3K) and its downstream target AKT increased expression of MT genes in HCC cells but not in liver epithelial cells. Suppression of MT-1 and MT-2A by ectopic expression of the constitutively active PI3K or AKT and their up-regulation by dominant-negative PI3K or AKT mutant confirmed negative regulation of MT expression by PI3K/AKT signaling pathway. Further, treatment of cells with a specific inhibitor of glycogen synthase kinase-3 (GSK-3), a downstream effector of PI3K/AKT, inhibited MT expression specifically in HCC cells. Short interfering RNA–mediated depletion of CCAAT/enhancer binding protein α (C/EBPα), a target of GSK-3, impeded MT expression, which could not be reversed by PI3K inhibitors. DNA binding activity of C/EBPα and its phosphorylation at T222 and T226 by GSK-3 are required for MT expression. MTF-1 and C/EBPα act in concert to increase MT-2A expression, which probably explains the high level of MT expression in the liver. This study shows the role of PI3K/AKT signaling pathway and C/EBPα in regulation of MT expression in hepatocarcinogenesis. [Cancer Res 2007;67(6):2736–46]
Data from Aurora-A Kinase Regulates Breast Cancer–Associated Gene 1 Inhibition of Centrosome-Dependent Microtubule Nucleation
Authors: Sankaran Satish , Crone Donna E. , Palazzo Robert E. , Parvin Jeffrey D.
Published: March 2024

Abstract
Breast cancer–associated gene 1 (BRCA1) regulates the duplication and the function of centrosomes in breast cells. We have previously shown that BRCA1 ubiquitin ligase activity directly inhibits centrosome-dependent microtubule nucleation. However, there is a paradox because centrosome microtubule nucleation potential is highest during mitosis, a phase when BRCA1 is most abundant at the centrosome. In this study, we resolve this conundrum by testing whether centrosomes from cells in M phase are regulated differently by BRCA1 when compared with other phases of the cell cycle. We observed that BRCA1-dependent inhibition of centrosome microtubule nucleation was high in S phase but was significantly lower during M phase. The cell cycle–specific effects of BRCA1 on centrosome-dependent microtubule nucleation were detected in living cells and in cell-free experiments using centrosomes purified from cells at specific stages of the cell cycle. We show that Aurora-A kinase modulates the BRCA1 inhibition of centrosome function by decreasing the E3 ubiquitin ligase activity of BRCA1. In addition, dephosphorylation of BRCA1 by protein phosphatase 1α enhances the E3 ubiquitin ligase activity of BRCA1. These observations reveal that the inhibition of centrosome microtubule nucleation potential by the BRCA1 E3 ubiquitin ligase is controlled by Aurora-A kinase and protein phosphatase 1α–mediated phosphoregulation through the different phases of the cell cycle. [Cancer Res 2007;67(23):11186–94]
Data from Depletion of Peripheral Macrophages and Brain Microglia Increases Brain Tumor Titers of Oncolytic Viruses
Authors: Fulci Giulia , Dmitrieva Nina , Gianni Davide , Fontana Elisabeth J. , Pan Xiaogang , Lu Yanhui , Kaufman Claire S. , Kaur Balveen , Lawler Sean E. , Lee Robert J. , Marsh Clay B. , Brat Daniel J. , van Rooijen Nico , Rachamimov Anat Stemmer , Hochberg Fred H. , Weissleder Ralph , Martuza Robert L. , Chiocca E. Antonio
Published: March 2024

Abstract
Clinical trials have proven oncolytic virotherapy to be safe but not effective. We have shown that oncolytic viruses (OV) injected into intracranial gliomas established in rodents are rapidly cleared, and this is associated with up-regulation of markers (CD68 and CD163) of cells of monocytic lineage (monocytes/microglia/macrophages). However, it is unclear whether these cells directly impede intratumoral persistence of OV through phagocytosis and whether they infiltrate the tumor from the blood or the brain parenchyma. To investigate this, we depleted phagocytes with clodronate liposomes (CL) in vivo through systemic delivery and ex vivo in brain slice models with gliomas. Interestingly, systemic CL depleted over 80% of peripheral CD163+ macrophages in animal spleen and peripheral blood, thereby decreasing intratumoral infiltration of these cells, but CD68+ cells were unchanged. Intratumoral viral titers increased 5-fold. In contrast, ex vivo CL depleted only CD68+ cells from brain slices, and intratumoral viral titers increased 10-fold. These data indicate that phagocytosis by both peripheral CD163+ and brain-resident CD68+ cells infiltrating tumor directly affects viral clearance from tumor. Thus, improved therapeutic efficacy may require modulation of these innate immune cells. In support of this new therapeutic paradigm, we observed intratumoral up-regulation of CD68+ and CD163+ cells following treatment with OV in a patient with glioblastoma. [Cancer Res 2007;67(19):9398–406]
Data from Placental Growth Factor-1 Attenuates Vascular Endothelial Growth Factor-A–Dependent Tumor Angiogenesis during β Cell Carcinogenesis
Authors: Schomber Tibor , Kopfstein Lucie , Djonov Valentin , Albrecht Imke , Baeriswyl Vanessa , Strittmatter Karin , Christofori Gerhard
Published: March 2024

Abstract
Members of the vascular endothelial growth factor (VEGF) family are critical players in angiogenesis and lymphangiogenesis. Although VEGF-A has been shown to exert fundamental functions in physiologic and pathologic angiogenesis, the exact role of the VEGF family member placental growth factor (PlGF) in tumor angiogenesis has remained controversial. To gain insight into PlGF function during tumor angiogenesis, we have generated transgenic mouse lines expressing human PlGF-1 in the β cells of the pancreatic islets of Langerhans (Rip1PlGF-1). In single-transgenic Rip1PlGF-1 mice, intra-insular blood vessels are found highly dilated, whereas islet physiology is unaffected. Upon crossing of these mice with the Rip1Tag2 transgenic mouse model of pancreatic β cell carcinogenesis, tumors of double-transgenic Rip1Tag2;Rip1PlGF-1 mice display reduced growth due to attenuated tumor angiogenesis. The coexpression of transgenic PlGF-1 and endogenous VEGF-A in the β tumor cells of double-transgenic animals causes the formation of low-angiogenic hPlGF-1/mVEGF-A heterodimers at the expense of highly angiogenic mVEGF-A homodimers resulting in diminished tumor angiogenesis and reduced tumor infiltration by neutrophils, known to contribute to the angiogenic switch in Rip1Tag2 mice. The results indicate that the ratio between the expression levels of two members of the VEGF family of angiogenic factors, PlGF-1 and VEGF-A, determines the overall angiogenic activity and, thus, the extent of tumor angiogenesis and tumor growth. [Cancer Res 2007;67(22):10840–8]
Data from Elucidating the Function of Secreted Maspin: Inhibiting Cathepsin D–Mediated Matrix Degradation
Authors: Khalkhali-Ellis Zhila , Hendrix Mary J.C.
Published: March 2024

Abstract
Cellular interaction with the extracellular milieu plays a significant role in normal biological and pathologic processes. Excessive degradation of basement membrane matrix by proteolytic enzymes is a hallmark of tumor invasion and metastasis, and aspartyl proteinase cathepsin D is implicated as a major contributor to this process. Maspin, a non-inhibitory serpin, plays an important role in mammary gland development and remodeling. Expression of Maspin is decreased in primary tumors and lost in metastatic lesions. Maspin is mostly cytoplasmic and is partially secreted; however, the fate and function of secreted Maspin has remained mostly unexplored. We hypothesized that secreted Maspin is incorporated into the matrix deposited by normal mammary epithelial cells and thus could play a critical role in cathepsin D–mediated matrix degradation and remodeling of mammary tissue. In the absence of Maspin, as is the case with most cancer cells, matrix degradation proceeds unrestricted, thus facilitating the progression to metastasis. To test this, we employed an in vitro model where gels containing both types I and IV collagen were preconditioned with normal mammary epithelial cells to allow the incorporation of secreted Maspin. This conditioned matrix was used to examine cathepsin D–mediated collagen degradation by human breast cancer cell lines. Our results indicate that secretion of Maspin and its deposition into the extracellular milieu play an important role in matrix degradation. In this capacity, Maspin could potentially regulate mammary tissue remodeling occurring under normal and pathologic conditions. In addition, these findings could have a potential effect on future therapeutic intervention strategies for breast cancer. [Cancer Res 2007;67(8):3535–9]
Data from Frequently Methylated Tumor Suppressor Genes in Head and Neck Squamous Cell Carcinoma
Authors: Bennett Kristi L. , Karpenko Matthew , Lin Mau-ting , Claus Rainer , Arab Khelifa , Dyckhoff Gerhard , Plinkert Peter , Herpel Esther , Smiraglia Dominic , Plass Christoph
Published: March 2024

Abstract
Head and neck squamous cell carcinoma (HNSCC) is a very aggressive cancer. In advanced stages, the patient has poor chances of receiving effective treatment, and survival rates are low. To facilitate timely diagnosis and improve treatment, elucidation of early detection markers is crucial. DNA methylation markers are particularly advantageous because DNA methylation is an early event in tumorigenesis, and the epigenetic modification, 5-methylcytosine, is a stable mark. A genome-wide screen using Restriction Landmark Genomic Scanning found a set of genes that are most commonly methylated in head and neck cancers. Five candidate genes: septin 9 (SEPT9), sodium-coupled monocarboxylate transporter 1 (SLC5A8), functional smad-suppressing element on chromosome 18 (FUSSEL18), early B-cell factor 3 (EBF3), and iroquois homeobox 1 (IRX1) were methylated in 27% to 67% of the HNSCC patient samples tested. Furthermore, ∼50% of the methylated tumor samples shared methylation between two of the five genes (most commonly between EBF3 and IRX1), and 15% shared methylation between three of the five genes. Expression analysis revealed candidate gene down-regulation in 25% to 93% of the HNSCC samples, and 5-aza-2′-deoxycytidine treatment was able to restore expression in at least 2 of 5 HNSCC cell lines for all of the genes tested. Overexpression of the three most frequently down-regulated candidates, SLC5A8, IRX1, and EBF3, validated their tumor suppressor potential by growth curve analysis and colony formation assay. Interestingly, all of the candidates identified may be involved in the transforming growth factor β signaling pathway, which is often disrupted in HNSCC. [Cancer Res 2008;68(12):4494–99]
Data from Overexpression of N-Myc Rapidly Causes Acute Myeloid Leukemia in Mice
Authors: Kawagoe Hiroyuki , Kandilci Ayten , Kranenburg Tanya A. , Grosveld Gerard C.
Published: March 2024

Abstract
N-MYC encodes a basic helix-loop-helix/leucine zipper (bHLH/LZ) transcription factor that is frequently overexpressed in human neuroblastoma. N-MYC overexpression has also been reported in human acute myeloid leukemias (AML), which we show here is a frequent event. Myeloid cells in N-Myc–overexpressing mouse bone marrow hyperproliferate but those in c-MYC–overexpressing bone marrow do not. The NH2-terminal transactivation domain, nuclear localization signal, and bHLH/LZ domain of N-Myc are essential for this effect. Microarray analysis revealed 969 differentially expressed genes between N-Myc– and c-MYC–overexpressing myeloid cells. N-Myc–overexpressing cells showed decreased transforming growth factor β signaling and increased c-Jun-NH2-kinase signaling, both of which are associated with proliferation and leukemic transformation of myeloid cells. Mice transplanted with bone marrow expressing wild-type N-Myc developed clonal and transplantable AML after ∼1 month; those transplanted with bone marrow expressing mutant N-Myc did not. Twist, a known suppressor of the p19Arf/p53 pathway, was up-regulated in all tumors. These results show that N-Myc overexpression is highly oncogenic in mouse myeloid cells and suggest that N-MYC up-regulation contributes to human myeloid leukemogenesis. [Cancer Res 2007;67(22):10677–85]
Data from MicroRNA-21 Knockdown Disrupts Glioma Growth In vivo and Displays Synergistic Cytotoxicity with Neural Precursor Cell–Delivered S-TRAIL in Human Gliomas
Authors: Corsten Maarten F. , Miranda Rafael , Kasmieh Randa , Krichevsky Anna M. , Weissleder Ralph , Shah Khalid
Published: March 2024

Abstract
Despite the development of new glioma therapies that allow for tumor-targeted in situ delivery of cytotoxic drugs, tumor resistance to apoptosis remains a key impediment to effective treatment. Mounting evidence indicates that microRNAs (miRNA) might play a fundamental role in tumorigenesis, controlling cell proliferation and apoptosis. In gliomas, microRNA-21 (miR-21) levels have been reported to be elevated and their knockdown is associated with increased apoptotic activity. We hypothesized that suppression of miR-21 might sensitize gliomas for cytotoxic tumor therapy. With the use of locked nucleic acid (LNA)-antimiR-21 oligonucleotides, bimodal imaging vectors, and neural precursor cells (NPC) expressing a secretable variant of the cytotoxic agent tumor necrosis factor–related apoptosis inducing ligand (S-TRAIL), we show that the combined suppression of miR-21 and NPC-S-TRAIL leads to a synergistic increase in caspase activity and significantly decreased cell viability in human glioma cells in vitro. This phenomenon persists in vivo, as we observed complete eradication of LNA-antimiR-21–treated gliomas subjected to the presence of NPC-S-TRAIL in the murine brain. Our results reveal the efficacy of miR-21 antagonism in murine glioma models and implicate miR-21 as a target for therapeutic intervention. Furthermore, our findings provide the basis for developing combination therapies using miRNA modulation and cytotoxic tumor therapies. [Cancer Res 2007;67(19):8994–9000]
Data from Arsenic Trioxide Sensitizes Human Glioma Cells, but not Normal Astrocytes, to TRAIL-Induced Apoptosis via CCAAT/Enhancer-Binding Protein Homologous Protein–Dependent DR5 Up-regulation
Authors: Kim Eun Hee , Yoon Mi Jin , Kim Seung U. , Kwon Taeg Kyu , Sohn Seonghyang , Choi Kyeong Sook
Published: March 2024

Abstract
The current study shows that treatment of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL)–resistant glioma cells with a combination of TRAIL and subtoxic doses of arsenic trioxide (As2O3) induces rapid apoptosis. Whereas TRAIL-mediated proteolytic processing of procaspase-3 was partially blocked in glioma cells, treatment with As2O3 efficiently recovered TRAIL-induced activation of caspases. We also found that As2O3 treatment of glioma cells significantly up-regulated DR5, a death receptor of TRAIL. Furthermore, suppression of DR5 expression by small interfering RNA (siRNA) inhibited As2O3/TRAIL-induced apoptosis of U87MG glioma cells, suggesting that DR5 up-regulation is critical for As2O3-induced sensitization of glioma cells to TRAIL-mediated apoptosis. Our results also indicate that an increase in CCAAT/enhancer binding protein homologous protein (CHOP) protein levels precedes As2O3-induced DR5 up-regulation. The involvement of CHOP in this process was confirmed by siRNA-mediated CHOP suppression, which not only attenuated As2O3-induced DR5 up-regulation but also inhibited the As2O3-stimulated TRAIL-induced apoptosis. These results therefore suggest that the CHOP-mediated DR5 up-regulation, brought about by As2O3, stimulates the TRAIL-mediated signaling pathway. This in turn leads to complete proteolytic processing of caspase-3, which is partially primed by TRAIL in glioma cells. In contrast to human glioma cells, astrocytes were very resistant to the combined administration of As2O3 and TRAIL, demonstrating the safety of this treatment. In addition, As2O3-mediated up-regulation of CHOP and DR5, as well as partial proteolytic processing of procaspase-3 by TRAIL, was not induced in astrocytes. Taken together, the present results suggest that the combined treatment of glioma cells with As2O3 plus TRAIL may provide an effective and selective therapeutic strategy. [Cancer Res 2008;68(1):266–75]
Data from The Tyrosine Phosphatase Shp2 Interacts with NPM-ALK and Regulates Anaplastic Lymphoma Cell Growth and Migration
Authors: Voena Claudia , Conte Chiara , Ambrogio Chiara , Boeri Erba Elisabetta , Boccalatte Francesco , Mohammed Shabaz , Jensen Ole N. , Palestro Giorgio , Inghirami Giorgio , Chiarle Roberto
Published: March 2024

Abstract
Anaplastic large cell lymphomas (ALCL) are mainly characterized by the reciprocal translocation t(2;5)(p23;q35) that involves the anaplastic lymphoma kinase (ALK) gene and generates the fusion protein NPM-ALK with intrinsic tyrosine kinase activity. NPM-ALK triggers several signaling cascades, leading to increased cell growth, resistance to apoptosis, and changes in morphology and migration of transformed cells. To search for new NPM-ALK interacting molecules, we developed a mass spectrometry–based proteomic approach in HEK293 cells expressing an inducible NPM-ALK and identified the tyrosine phosphatase Shp2 as a candidate substrate. We found that NPM-ALK was able to bind Shp2 in coprecipitation experiments and to induce its phosphorylation in the tyrosine residues Y542 and Y580 both in HEK293 cells and ALCL cell lines. In primary lymphomas, antibodies against the phosphorylated tyrosine Y542 of Shp2 mainly stained ALK-positive cells. In ALCL cell lines, Shp2-constitutive phosphorylation was dependent on NPM-ALK, as it significantly decreased after short hairpin RNA (shRNA)–mediated NPM-ALK knock down. In addition, only the constitutively active NPM-ALK, but not the kinase dead NPM-ALKK210R, formed a complex with Shp2, Gab2, and growth factor receptor binding protein 2 (Grb2), where Grb2 bound to the phosphorylated Shp2 through its SH2 domain. Shp2 knock down by specific shRNA decreased the phosphorylation of extracellular signal-regulated kinase 1/2 and of the tyrosine residue Y416 in the activation loop of Src, resulting in impaired ALCL cell proliferation and growth disadvantage. Finally, migration of ALCL cells was reduced by Shp2 shRNA. These findings show a direct involvement of Shp2 in NPM-ALK lymphomagenesis, highlighting its critical role in lymphoma cell proliferation and migration. [Cancer Res 2007;67(9):4278–86]
Data from Identification of Candidate Molecular Markers Predicting Sensitivity in Solid Tumors to Dasatinib: Rationale for Patient Selection
Authors: Huang Fei , Reeves Karen , Han Xia , Fairchild Craig , Platero Suso , Wong Tai W. , Lee Francis , Shaw Peter , Clark Edwin
Published: March 2024

Abstract
Dasatinib is a multitargeted kinase inhibitor that was recently approved for the treatment of chronic myelogenous leukemia and Philadelphia chromosome–positive acute lymphoblastic leukemia with resistance or intolerance to prior therapy. It is also in clinical trials for treating patients with solid tumors. The identification of molecular markers predictive of response to dasatinib could assist in clinical development by selecting patients most likely to derive clinical benefit. Using baseline gene expression profiling of a panel of 23 breast cancer cell lines, we identified genomic signatures highly correlated with in vitro sensitivity to dasatinib. The ability of these signatures to predict dasatinib sensitivity was further confirmed and validated in independent test cell lines. A six-gene model was used to correctly predict dasatinib sensitivity in 11 out of 12 (92%) additional breast and 19 out of 23 (83%) lung cancer cell lines. Quantitative real-time PCR and immunohistochemical assays further confirmed the differential expression pattern of selected markers. Finally, these gene signatures were observed in a subset of primary breast, lung, and ovarian tumors suggesting potential utility in patient selection. The subset of breast cancer patients expressing the dasatinib-sensitive signature includes a distinct clinical and molecular subgroup: the so-called “triple negative” (i.e., estrogen receptor–negative, progesterone receptor–negative, and HER2-negative) or “basal” breast cancer subtype. This patient population has a poor prognosis and currently has few effective treatment options. Our results implicate that dasatinib may represent a valuable treatment option in this difficult-to-treat population. To test this hypothesis, clinical studies are now under way to determine the activity of dasatinib in these patients. [Cancer Res 2007;67(5):2226–38]
Data from Integrated Profiling of Basal and Luminal Breast Cancers
Authors: Adélaïde José , Finetti Pascal , Bekhouche Ismahane , Repellini Laetitia , Geneix Jeannine , Sircoulomb Fabrice , Charafe-Jauffret Emmanuelle , Cervera Nathalie , Desplans Jérôme , Parzy Daniel , Schoenmakers Eric , Viens Patrice , Jacquemier Jocelyne , Birnbaum Daniel , Bertucci François , Chaffanet Max
Published: March 2024

Abstract
Basal and luminal are two molecular subtypes of breast cancer with opposite histoclinical features. We report a combined, high-resolution analysis of genome copy number and gene expression in primary basal and luminal breast cancers. First, we identified and compared genomic alterations in 45 basal and 48 luminal tumors by using 244K oligonucleotide array comparative genomic hybridization (aCGH). We found various genome gains and losses and rare high-level gene amplifications that may provide therapeutic targets. We show that gain of 10p is a new alteration in basal breast cancer and that a subregion of the 8p12 amplification is specific of luminal tumors. Rare high-level amplifications contained BCL2L2, CCNE, EGFR, FGFR2, IGF1R, NOTCH2, and PIK3CA. Potential gene breaks involved ETV6 and FLT3. Second, we analyzed both aCGH and gene expression profiles for 42 basal and 32 luminal breast cancers. The results support the existence of specific oncogenic pathways in basal and luminal breast cancers, involving several potential oncogenes and tumor suppressor genes (TSG). In basal tumors, 73 candidate oncogenes were identified in chromosome regions 1q21-23, 10p14, and 12p13 and 28 candidate TSG in regions 4q32-34 and 5q11-23. In luminal breast cancers, 33 potential oncogenes were identified in 1q21-23, 8p12-q21, 11q13, and 16p12-13 and 61 candidate TSG in 16q12-13, 16q22-24, and 17p13. HORMAD1 (P = 6.5 × 10−5) and ZNF703 (P = 7 × 10−4) were the most significant basal and luminal potential oncogenes, respectively. Finally, among 10p candidate oncogenes associated with basal subtype, we validated CDC123/C10orf7 protein as a basal marker. [Cancer Res 2007;67(24):11565–75]
Data from Cortactin Is an Essential Regulator of Matrix Metalloproteinase Secretion and Extracellular Matrix Degradation in Invadopodia
Authors: Clark Emily S. , Whigham Amy S. , Yarbrough Wendell G. , Weaver Alissa M.
Published: March 2024

Abstract
Invadopodia are branched actin-rich structures associated with extracellular matrix (ECM) degradation that collectively form the invasive machinery of aggressive cancer cells. Cortactin is a prominent component and a specific marker of invadopodia. Amplification of cortactin is associated with poor prognosis in head and neck squamous cell carcinomas (HNSCC), possibly because of its activity in invadopodia. Although the role of cortactin in invadopodia has been attributed to signaling and actin assembly, it is incompletely understood. We made HNSCC cells deficient in cortactin by RNA interference knockdown methods. In these cortactin knockdown cells, invadopodia were reduced in number and lost their ability to degrade ECM. In the reverse experiment, overexpression of cortactin dramatically increased ECM degradation, far above and beyond the effect on formation of actin/Arp3–positive invadopodia puncta. Secretion of matrix metalloproteinases (MMP) MMP-2 and MMP-9, as well as plasma membrane delivery of MT1-MMP correlated closely with cortactin expression levels. MMP inhibitor treatment of control cells mimicked the cortactin knockdown phenotype, with abolished ECM degradation and fewer invadopodia, suggesting a positive feedback loop in which degradation products from MMP activity promote new invadopodia formation. Collectively, these data suggest that a major role of cortactin in invadopodia is to regulate the secretion of MMPs and point to a novel mechanism coupling dynamic actin assembly to the secretory machinery, producing enhanced ECM degradation and invasiveness. Furthermore, these data provide a possible explanation for the observed association between cortactin overexpression and enhanced invasiveness and poor prognosis in HNSCC patients. [Cancer Res 2007;67(9):4227–35]
Data from Cisplatin Depletes TREX2 and Causes Robertsonian Translocations as Seen in TREX2 Knockout Cells
Authors: Chen Ming-Jiu , Dumitrache Lavinia C. , Wangsa Danny , Ma Sheng-Mei , Padilla-Nash Hesed , Ried Thomas , Hasty Paul
Published: March 2024

Abstract
Cisplatin, an anticancer drug, forms DNA interstrand cross-links (ICL) that interfere with replication, whereas TREX2 is a 3′→5′ exonuclease that removes 3′ mismatched nucleotides and promotes cellular proliferation. Here, we show that TREX2 is depleted in human cells derived from cancer after exposure to cisplatin but not other genotoxins including another cross-linking agent, mitomycin C (MMC), indicating a potential role for TREX2 depletion in cisplatin-induced cytotoxicity. To better understand TREX2 cellular function, we deleted TREX2 in mouse embryonic stem (ES) cells by gene targeting and find these cells exhibit reduced proliferation and gross chromosomal rearrangements including Robertsonian translocations (RbT). Quite interestingly, ES cells exposed to cisplatin also exhibit RbTs. By contrast, RbTs are not observed for ES cells exposed to MMC, indicating that RbTs are not caused by ICLs but instead TREX2 depletion by either cisplatin exposure or mutation. Taken together, our results show that cisplatin depletes TREX2 and causes genomic instability that is similarly observed in TREX2-mutant cells. Thus, cisplatin has two potential cytotoxic activities: (a) the generation of ICLs and (b) the depletion of TREX2. [Cancer Res 2007;67(19):9077–83]
Data from A Novel Small Molecule Inhibitor of Signal Transducers and Activators of Transcription 3 Reverses Immune Tolerance in Malignant Glioma Patients
Authors: Hussain S. Farzana , Kong Ling-Yuan , Jordan Justin , Conrad Charles , Madden Timothy , Fokt Isabella , Priebe Waldemar , Heimberger Amy B.
Published: March 2024

Abstract
Overcoming the profound immunosuppression in patients with solid cancers has impeded efficacious immunotherapy. Signal transducers and activators of transcription 3 (STAT3) has recently emerged as a potential target for effective immunotherapy, and in this study, we describe a novel small molecule inhibitor of STAT3 that can penetrate the central nervous system (CNS) in mice and in physiologically relevant doses in vitro and reverse tolerance in immune cells isolated from glioblastoma multiforme (GBM) patients. Specifically, it induces the expression of costimulatory molecules on peripheral macrophages and tumor-infiltrating microglia, stimulates the production of the immune-stimulatory cytokines interleukin 2 (IL-2), IL-4, IL-12, and IL-15, and induces proliferation of effector T cells from GBM patients that are refractory to CD3 stimulation. We show that the functional enhancement of immune responses after STAT3 inhibition is accompanied by up-regulation of several key intracellular signaling molecules that critically regulate T-cell and monocyte activation. Specifically, the phosphorylation of Syk (Tyr352) in monocytes and ZAP-70 (Tyr319) in T cells are enhanced by the STAT-3 inhibitor in marked contrast to toll-like receptor and T-cell receptor agonists, respectively. This novel small molecule STAT3 inhibitor has tremendous potential for clinical applications with its penetration into the CNS, easy parental administration, direct tumor cytotoxicity, and potent immune adjuvant responses in immunosuppressed cancer patients. [Cancer Res 2007;67(20):9630–6]
Data from Stable Overexpression of Smad7 in Human Melanoma Cells Impairs Bone Metastasis
Authors: Javelaud Delphine , Mohammad Khalid S. , McKenna Christopher R. , Fournier Pierrick , Luciani Flavie , Niewolna Maryla , André Jocelyne , Delmas Véronique , Larue Lionel , Guise Theresa A. , Mauviel Alain
Published: March 2024

Abstract
Melanoma has a propensity to metastasize to bone, where it is exposed to high concentrations of transforming growth factor-β (TGF-β). Because TGF-β promotes bone metastases from other solid tumors, such as breast cancer, we tested the role of TGF-β in melanoma metastases to bone. 1205Lu melanoma cells, stably transfected to overexpress the natural TGF-β/Smad signaling inhibitor Smad7, were studied in an experimental model of bone metastasis whereby tumor cells are inoculated into the left cardiac ventricle of nude mice. All mice bearing parental and mock-transfected 1205Lu cells developed osteolytic bone metastases 5 weeks post-tumor inoculation. Mice bearing 1205Lu-Smad7 tumors had significantly less osteolysis on radiographs and longer survival compared with parental and mock-transfected 1205Lu mice. To determine if the reduced bone metastases observed in mice bearing 1205Lu-Smad7 clones was due to reduced expression of TGF-β target genes known to enhance metastases to bone from breast cancer cells, we analyzed gene expression of osteolytic factors, parathyroid hormone-related protein (PTHrP) and interleukin-11 (IL-11), the chemotactic receptor CXCR4, and osteopontin in 1205Lu cells. Quantitative reverse transcription-PCR analysis indicated that PTHrP, IL-11, CXCR4, and osteopontin mRNA steady-state levels were robustly increased in response to TGF-β and that Smad7 and the TβRI small-molecule inhibitor, SB431542, prevented such induction. In addition, 1205Lu-Smad7 bone metastases expressed significantly lower levels of IL-11, connective tissue growth factor, and PTHrP. These data suggest that TGF-β promotes osteolytic bone metastases due to melanoma by stimulating the expression of prometastatic factors via the Smad pathway. Blockade of TGF-β signaling may be an effective treatment for melanoma metastasis to bone. [Cancer Res 2007;67(5):2317–24]
Data from Jagged-1 and Notch3 Juxtacrine Loop Regulates Ovarian Tumor Growth and Adhesion
Authors: Choi Jung-Hye , Park Joon T. , Davidson Ben , Morin Patrice J. , Shih Ie-Ming , Wang Tian-Li
Published: March 2024

Abstract
Notch3 gene amplification and pathway activation have been reported in ovarian serous carcinoma. However, the primary Notch3 ligand that initiates signal transduction in ovarian cancer remains unclear. In this report, we identify Jagged-1 as the highest expressed Notch ligand in ovarian tumor cells as well as in peritoneal mesothelial cells that are in direct contact with disseminated ovarian cancer cells. Cell-cell adhesion and cellular proliferation were reduced in Notch3-expressing ovarian cancer cells that were cocultured with Jagged-1 knockdown mesothelial and tumor feeder cells. Interaction of Notch3-expressing ovarian cancer cells with Jagged-1–expressing feeder cells activated the promoter activity of candidate Notch3 target genes, and this activity was attenuated by Notch3 siRNA. Constitutive expression of the Notch3 intracellular domain significantly suppressed the Jagged-1 shRNA–mediated growth inhibitory effect. In Notch3-expressing ovarian cancer cells, Jagged-1–stimulating peptides enhanced cellular proliferation, which was suppressed by γ-secretase inhibitor and Notch3 siRNA. Taken together, our results show that Jagged-1 is the primary Notch3 ligand in ovarian carcinoma and Jagged-1/Notch3 interaction constitutes a juxtacrine loop promoting proliferation and dissemination of ovarian cancer cells within the intraperitoneal cavity. [Cancer Res 2008;68(14):5716–23]