bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Oncosome Formation in Prostate Cancer: Association with a Region of Frequent Chromosomal Deletion in Metastatic Disease
Authors: Di Vizio Dolores , Kim Jayoung , Hager Martin H. , Morello Matteo , Yang Wei , Lafargue Christopher J. , True Lawrence D. , Rubin Mark A. , Adam Rosalyn M. , Beroukhim Rameen , Demichelis Francesca , Freeman Michael R.
Published: March 2024

Abstract
Oncosomes have recently been described as membrane-derived microvesicles secreted by cancer cells, which transfer oncogenic signals and protein complexes across cell boundaries. Here, we show the rapid formation and secretion of oncosomes from DU145 and LNCaP human prostate cancer cells. Oncosome formation was stimulated by epidermal growth factor receptor activation and also by overexpression of membrane-targeted Akt1. Microvesicles shed from prostate cancer cells contained numerous signal transduction proteins and were capable of activating rapid phospho-tyrosine and Akt pathway signaling, and stimulating proliferation and migration, in recipient tumor cells. They also induced a stromal reaction in recipient normal cells. Knockdown of the actin nucleating protein Diaphanous Related Formin 3 (DRF3/Dia2) by RNA interference enhanced rates of oncosome formation, indicating that these structures resemble, and may be identical to, nonapoptotic membrane blebs, a feature of the amoeboid form of cell motility. Analysis of primary and metastatic human prostate tumors using 100K single nucleotide polymorphism arrays revealed a significantly higher frequency of deletion of the locus encoding DRF3 (DIAPH3) in metastatic tumors (P = 0.001) in comparison with organ-confined tumors. Fluorescence in situ hybridization confirmed increased chromosomal loss of DIAPH3 in metastatic tumors in a different cohort of patients (P = 0.006). These data suggest that microvesicles shed from prostate cancer cells can alter the tumor microenvironment in a manner that may promote disease progression. They also show that DRF3 is a physiologically relevant protein that seems to regulate this process. [Cancer Res 2009;69(13):5601–9]
Data from Microcephalin Regulates BRCA2 and Rad51-Associated DNA Double-Strand Break Repair
Authors: Wu Xianglin , Mondal Gourish , Wang Xianshu , Wu Jianmin , Yang Lin , Pankratz Vernon S. , Rowley Matthew , Couch Fergus J.
Published: March 2024

Abstract
Microcephalin (MCPH1) is a BRCA1 COOH terminal (BRCT) domain containing protein involved in the cellular response to DNA damage that has been implicated in autosomal recessive primary microcephaly. MCPH1 is recruited to sites of DNA double-strand breaks by phosphorylated histone H2AX (γH2AX), but the mechanism by which MCPH1 contributes to the repair process remains to be determined. Here, we show that MCPH1 binds to BRCA2 and regulates the localization of BRCA2 and Rad51 at sites of DNA damage. The interaction occurs through the NH2 terminus of BRCA2 and the COOH terminal BRCT domains of MCPH1. Disruption of the interaction between MCPH1 and BRCA2 has no effect on the ability of BRCA2 to form a complex with Rad51 but is associated with substantially reduced levels of both BRCA2 and Rad51 at sites of DNA double-strand breaks. Uncoupling of MCPH1 from BRCA2 also interferes with Rad51-dependent and BRCA2-dependent homologous recombination repair activity. These results suggest that the role of MCPH1 in the DNA damage response is in part associated with the ability to localize BRCA2 to sites of DNA double-stand breaks. [Cancer Res 2009;69(13):5531–6]
Data from Epidermal Growth Factor Receptor Variant III–Induced Glioma Invasion Is Mediated through Myristoylated Alanine-Rich Protein Kinase C Substrate Overexpression
Authors: Micallef Johann , Taccone Michael , Mukherjee Joydeep , Croul Sidney , Busby Jennifer , Moran Michael F. , Guha Abhijit
Published: March 2024

Abstract
Glioblastoma multiforme (GBM) is the most common and most malignant adult brain tumor. A characteristic of GBM is their highly invasive nature, making complete surgical resection impossible. The most common gain-of-function alteration in GBM is amplification, overexpression, and mutations of the epidermal growth factor receptor (EGFR). The constitutively activated mutant EGFR variant III (EGFRvIII), found in ∼20% of GBM, confers proliferative and invasive advantage. The signaling cascades downstream of aberrant EGFR activation contributing to the invasive phenotype are not completely understood. Here, we show myristoylated alanine-rich protein kinase C substrate (MARCKS), previously implicated in cell adhesion and motility, contributes to EGFR-mediated invasion of human GBM cells. EGFRvIII-expressing or EGF-stimulated human GBM cells increased expression, phosphorylation, and cytosolic translocation of MARCKS in a protein kinase C-α–dependent manner. Down-regulation of MARCKS expression with small interfering RNA in GBM cells expressing EGFRvIII led to decreased cell adhesion, spreading, and invasion. Elucidation of mechanisms that promote EGFRvIII-mediated tumorigenesis in GBM, such as MARCKS, provides additional understanding and potential biological targets against this currently terminal human cancer. [Cancer Res 2009;69(19):7548–56]
Data from Human Papillomavirus 16 E7 Oncoprotein Attenuates DNA Damage Checkpoint Control by Increasing the Proteolytic Turnover of Claspin
Authors: Spardy Nicole , Covella Kathryn , Cha Elliot , Hoskins Elizabeth E. , Wells Susanne I. , Duensing Anette , Duensing Stefan
Published: March 2024

Abstract
The human papillomavirus (HPV) 16 E7 oncoprotein has been reported previously to stimulate DNA damage and to activate host cell DNA damage checkpoints. How HPV-16 E7 maintains proliferation despite activated DNA damage checkpoints is incompletely understood. Here, we provide evidence that cells expressing the HPV-16 E7 oncoprotein can enter mitosis in the presence of DNA damage. We show that this activity of HPV-16 E7 involves attenuation of DNA damage checkpoint control by accelerating the proteolytic turnover of claspin. Claspin mediates the activation of CHK1 by ATR in response to replication stress, and its degradation plays a critical role in DNA damage checkpoint recovery. Expression of a nondegradable mutant of claspin was shown to inhibit mitotic entry in HPV-16 E7–expressing cells. Multiple components of the SCFβ-TrCP–based claspin degradation machinery were found deregulated in the presence of HPV-16 E7, including cullin 1, β-TrCP, Aurora A, and Polo-like kinase-1 (PLK1). In contrast, no difference in the expression level of the claspin deubiquitinating enzyme USP7 was detected. Levels of Aurora A and PLK1 as well as phosphorylated PLK1 at threonine 210, a prerequisite for DNA damage checkpoint recovery, remained detectable following replication stress in HPV-16 E7–expressing cells but not in control cells. In summary, our results suggest that the HPV-16 E7 oncoprotein alleviates DNA damage checkpoint responses and promotes mitotic entry by accelerating claspin degradation through a mechanism that involves deregulation of components of the SCFβ-TrCP–based claspin degradation machinery. [Cancer Res 2009;69(17):7022–9]
Data from Integrin α2 Mediates Selective Metastasis to the Liver
Authors: Yoshimura Kiyoshi , Meckel Kristen F. , Laird Lindsay S. , Chia Christina Y. , Park Jang-June , Olino Kelly L. , Tsunedomi Ryouichi , Harada Toshio , Iizuka Norio , Hazama Shoichi , Kato Yukihiko , Keller Jesse W. , Thompson John M. , Chang Fumin , Romer Lewis H. , Jain Ajay , Iacobuzio-Donahue Christine , Oka Masaaki , Pardoll Drew M. , Schulick Richard D.
Published: March 2024

Abstract
Cancers display distinct patterns of organ-specific metastasis. Comparative analysis of a broad array of cell membrane molecules on a liver-metastasizing subline of B16 melanoma versus the parental B16-F0 revealed unique up-regulation of integrin α2. The direct role of integrin α2 in hepatic metastasis was shown by comparison of high versus low-expressing populations, antibody blockade, and ectopic expression. Integrin α2–mediated binding to collagen type IV (highly exposed in the liver sinusoids) and collagen type IV–dependent activation of focal adhesion kinase are both known to be important in the metastatic process. Analysis of primary colorectal cancers as well as coexisting liver and lung metastases from individual patients suggests that integrin α2 expression contributes to liver metastasis in human colorectal cancer. These findings define integrin α2 as a molecule conferring selective potential for formation of hepatic metastasis, as well as a possible target to prevent their formation. [Cancer Res 2009;69(18):7320–8]
Data from Identification of Nuclear Export Inhibitors with Potent Anticancer Activity In vivo
Authors: Mutka Sarah C. , Yang Wen Qing , Dong Steven D. , Ward Shannon L. , Craig Darren A. , Timmermans Pieter B.M.W.M. , Murli Sumati
Published: March 2024

Abstract
The export protein CRM1 is required for the nuclear export of a wide variety of cancer-related “cargo” proteins including p53, c-Abl, and FOXO-3A. Leptomycin B (LMB) is a highly specific inhibitor of CRM1 with significant in vitro potency but limited in vivo efficacy due to toxicity. We now report a series of semisynthetic LMB derivatives showing substantially improved therapeutic windows. Exposure of cancer cells to these compounds leads to a rapid and prolonged block of nuclear export and apoptosis. In contrast to what is observed in cancer cells, these agents induce cell cycle arrest, but not apoptosis, in normal lung fibroblasts. These new nuclear export inhibitors (NEI) maintain the high potency of LMB, are up to 16-fold better tolerated than LMB in vivo, and show significant efficacy in multiple mouse xenograft models. These NEIs show the potential of CRM1 inhibitors as novel and potent anticancer agents. [Cancer Res 2009;69(2):510–7]
Data from The CHRNA5-CHRNA3-CHRNB4 Nicotinic Receptor Subunit Gene Cluster Affects Risk for Nicotine Dependence in African-Americans and in European-Americans
Authors: Saccone Nancy L. , Wang Jen C. , Breslau Naomi , Johnson Eric O. , Hatsukami Dorothy , Saccone Scott F. , Grucza Richard A. , Sun Lingwei , Duan Weimin , Budde John , Culverhouse Robert C. , Fox Louis , Hinrichs Anthony L. , Steinbach Joseph Henry , Wu Meng , Rice John P. , Goate Alison M. , Bierut Laura J.
Published: March 2024

Abstract
Genetic association studies have shown the importance of variants in the CHRNA5-CHRNA3-CHRNB4 cholinergic nicotinic receptor subunit gene cluster on chromosome 15q24-25.1 for the risk of nicotine dependence, smoking, and lung cancer in populations of European descent. We have carried out a detailed study of this region using dense genotyping in both European-Americans and African-Americans. We genotyped 75 known single nucleotide polymorphisms (SNPs) and one sequencing-discovered SNP in an African-American sample (N = 710) and in a European-American sample (N = 2,062). Cases were nicotine-dependent and controls were nondependent smokers. The nonsynonymous CHRNA5 SNP rs16969968 is the most significant SNP associated with nicotine dependence in the full sample of 2,772 subjects [P = 4.49 × 10−8; odds ratio (OR), 1.42; 95% confidence interval (CI), 1.25–1.61] as well as in African-Americans only (P = 0.015; OR, 2.04; 1.15–3.62) and in European-Americans only (P = 4.14 × 10−7; OR, 1.40; 1.23–1.59). Other SNPs that have been shown to affect the mRNA levels of CHRNA5 in European-Americans are associated with nicotine dependence in African-Americans but not in European-Americans. The CHRNA3 SNP rs578776, which has a low correlation with rs16969968, is associated with nicotine dependence in European-Americans but not in African-Americans. Less common SNPs (frequency ≤ 5%) are also associated with nicotine dependence. In summary, multiple variants in this gene cluster contribute to nicotine dependence risk, and some are also associated with functional effects on CHRNA5. The nonsynonymous SNP rs16969968, a known risk variant in populations of European-descent, is also significantly associated with risk in African-Americans. Additional SNPs contribute to risk in distinct ways in these two populations. [Cancer Res 2009;69(17):6848–56]
Data from PUMA Suppresses Intestinal Tumorigenesis in Mice
Authors: Qiu Wei , Carson-Walter Eleanor B. , Kuan Shih Fan , Zhang Lin , Yu Jian
Published: March 2024

Abstract
Defective apoptosis contributes to tumorigenesis, although the critical molecular targets remain to be fully characterized. PUMA, a BH3-only protein essential for p53-dependent apoptosis, has been shown to suppress lymphomagenesis. In this study, we investigated the role of PUMA in intestinal tumorigenesis using two animal models. In the azoxymethane (AOM)/dextran sulfate sodium salt model, PUMA deficiency increased the multiplicity and size of colon tumors but reduced the frequency of β-catenin hotspot mutations. The absence of PUMA led to a significantly elevated incidence of precursor lesions induced by AOM. AOM was found to induce p53-dependent PUMA expression and PUMA-dependent apoptosis in the colonic crypts and stem cell compartment. Furthermore, PUMA deficiency significantly enhanced the formation of spontaneous macroadenomas and microadenomas in the distal small intestine and colon of APCMin/+ mice. These results show an essential role of PUMA-mediated apoptosis in suppressing intestinal tumorigenesis in mice. [Cancer Res 2009;69(12):4999–5006]
Data from MicroRNA Classifiers for Predicting Prognosis of Squamous Cell Lung Cancer
Authors: Raponi Mitch , Dossey Lesley , Jatkoe Tim , Wu Xiaoying , Chen Guoan , Fan Hongtao , Beer David G.
Published: March 2024

Abstract
Non–small cell lung cancer (NSCLC), which is comprised mainly of adenocarcinoma and squamous cell carcinoma (SCC), is the cause of 80% of all lung cancer deaths in the United States. NSCLC is also associated with a high rate of relapse after clinical treatment and, therefore, requires robust prognostic markers to better manage therapy options. The aim of this study was to identify microRNA (miRNA) expression profiles in SCC of the lung that would better predict prognosis. Total RNA from 61 SCC samples and 10 matched normal lung samples was processed for small RNA species and profiled on MirVana miRNA Bioarrays (version 2, Ambion). We identified 15 miRNAs that were differentially expressed between normal lung and SCC, including members of the miR-17-92 cluster and its paralogues. We also identified miRNAs, including miR-155 and let-7, which had previously been shown to have prognostic value in adenocarcinoma. Based on cross-fold validation analyses, miR-146b alone was found to have the strongest prediction accuracy for stratifying prognostic groups at ∼78%. The miRNA signatures were superior in predicting overall survival than a previously described 50-gene prognostic signature. Whereas there was no overlap between the mRNAs targeted by the prognostic miRNAs and the 50-gene expression signature, there was a significant overlap in the corresponding biological pathways, including fibroblast growth factor and interleukin-6 signaling. Our data indicate that miRNAs may have greater clinical utility in predicting the prognosis of patients with squamous cell lung carcinomas than mRNA-based signatures. [Cancer Res 2009;69(14):5776–83]
Data from Overexpression of Protease-Activated Receptor-1 Contributes to Melanoma Metastasis via Regulation of Connexin 43
Authors: Villares Gabriel J. , Dobroff Andrey S. , Wang Hua , Zigler Maya , Melnikova Vladislava O. , Huang Li , Bar-Eli Menashe
Published: March 2024

Abstract
Protease-activated receptor-1 (PAR-1) is a key player in melanoma metastasis with higher expression seen in metastatic melanoma cell lines and tissue specimens. cDNA microarray and Western blot analyses reveal that the gap junctional intracellular communication molecule connexin 43 (Cx-43), known to be involved in tumor cell diapedesis and attachment to endothelial cells, is significantly decreased after PAR-1 silencing in metastatic melanoma cell lines. Furthermore, Cx-43 promoter activity was significantly inhibited in PAR-1–silenced cells, suggesting that PAR-1 regulates Cx-43 at the transcriptional level. Chromatin immunoprecipitation studies showed a reduction in the binding of SP-1 and AP-1 transcription factors to the promoter of Cx-43. Both transcription factors have been shown previously to be required for maximal Cx-43 promoter activity. These results were corroborated by mutating the AP-1 and SP-1 binding sites resulting in decreased Cx-43 promoter activity in PAR-1–positive cells. Moreover, as Cx-43 has been shown to facilitate arrest of circulating tumor cells at the vascular endothelium, melanoma cell attachment to endothelial cells was significantly decreased in PAR-1–silenced cells, with this effect being abrogated after PAR-1 rescue. Herein, we report that up-regulation of PAR-1 expression, seen in melanoma progression, mediates high levels of Cx-43 expression. As both SP-1 and AP-1 transcription factors act as positive regulators of Cx-43, our data provide a novel mechanism for the regulation of Cx-43 expression by PAR-1. Indeed, Cx-43 expression was restored following PAR-1 rescue in PAR-1–silenced cells. Taken together, our data support the tumor promoting function of Cx-43 in melanoma. [Cancer Res 2009;69(16):6730–7]
Data from 3-Phosphoinositide–Dependent Kinase 1 Potentiates Upstream Lesions on the Phosphatidylinositol 3-Kinase Pathway in Breast Carcinoma
Authors: Maurer Matthew , Su Tao , Saal Lao H. , Koujak Susan , Hopkins Benjamin D. , Barkley Christina R. , Wu Jiaping , Nandula Subhadra , Dutta Bhaskar , Xie Yuli , Chin Y. Rebecca , Kim Da-In , Ferris Jennifer S. , Gruvberger-Saal Sofia K. , Laakso Mervi , Wang Xiaomei , Memeo Lorenzo , Rojtman Albert , Matos Tulio , Yu Jennifer S. , Cordon-Cardo Carlos , Isola Jorma , Terry Mary Beth , Toker Alex , Mills Gordon B. , Zhao Jean J. , Murty Vundavalli V.V.S. , Hibshoosh Hanina , Parsons Ramon
Published: March 2024

Abstract
Lesions of ERBB2, PTEN, and PIK3CA activate the phosphatidylinositol 3-kinase (PI3K) pathway during cancer development by increasing levels of phosphatidylinositol-3,4,5-triphosphate (PIP3). 3-Phosphoinositide-dependent kinase 1 (PDK1) is the first node of the PI3K signal output and is required for activation of AKT. PIP3 recruits PDK1 and AKT to the cell membrane through interactions with their pleckstrin homology domains, allowing PDK1 to activate AKT by phosphorylating it at residue threonine-308. We show that total PDK1 protein and mRNA were overexpressed in a majority of human breast cancers and that 21% of tumors had five or more copies of the gene encoding PDK1, PDPK1. We found that increased PDPK1 copy number was associated with upstream pathway lesions (ERBB2 amplification, PTEN loss, or PIK3CA mutation), as well as patient survival. Examination of an independent set of breast cancers and tumor cell lines derived from multiple forms of human cancers also found increased PDK1 protein levels associated with such upstream pathway lesions. In human mammary cells, PDK1 enhanced the ability of upstream lesions to signal to AKT, stimulate cell growth and migration, and rendered cells more resistant to PDK1 and PI3K inhibition. After orthotopic transplantation, PDK1 overexpression was not oncogenic but dramatically enhanced the ability of ERBB2 to form tumors. Our studies argue that PDK1 overexpression and increased PDPK1 copy number are common occurrences in cancer that potentiate the oncogenic effect of upstream lesions on the PI3K pathway. Therefore, we conclude that alteration of PDK1 is a critical component of oncogenic PI3K signaling in breast cancer. [Cancer Res 2009;69(15):6299–306]
Data from TWIST-1 Is Overexpressed in Neoplastic Choroid Plexus Epithelial Cells and Promotes Proliferation and Invasion
Authors: Hasselblatt Martin , Mertsch Sonja , Koos Björn , Riesmeier Barbara , Stegemann Heike , Jeibmann Astrid , Tomm Manuel , Schmitz Nicole , Wrede Brigitte , Wolff Johannes E. , Zheng Wei , Paulus Werner
Published: March 2024

Abstract
The pathogenesis of choroid plexus papillomas, intraventricular papillary neoplasms most often occurring sporadically in children and young adults, remains poorly understood. To identify pathways operative in the development of choroid plexus papillomas, gene expression profiles obtained from laser-microdissected human choroid plexus papilloma cells (n = 7) were compared with that of normal choroid plexus epithelial cells laser microdissected from autopsy tissue (n = 8). On DNA microarray data analysis, 53 probe sets were differentially expressed in choroid plexus papilloma tumor cells (>7-fold). Up-regulation of TWIST1, WIF1, TRPM3, BCLAF1, and AJAP1, as well as down-regulation of IL6ST was confirmed using quantitative reverse transcription-PCR. Knockdown of Twist1 gene expression in the rat choroid plexus epithelial cell line Z310 significantly reduced proliferation as assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and cell invasion in a Matrigel assay, whereas cell migration was not affected. Screening for expressional changes of cancer-related genes upon Twist1 knockdown revealed up-regulation of Cdkn1a, Cflar, and Serpinb2 and down-regulation of Figf. To conclude, using gene expression profiling, several genes differentially expressed in human choroid plexus papillomas could be identified. Among those, TWIST1 is highly expressed in choroid plexus papillomas and promotes proliferation and invasion. [Cancer Res 2009;69(6):2219–23]
Data from Repression of NHE1 Expression by PPARγ Activation Is a Potential New Approach for Specific Inhibition of the Growth of Tumor Cells In vitro and In vivo
Authors: Kumar Alan Prem , Quake Ai Li , Chang Michelle Ker Xing , Zhou Ting , Lim Kelly Swee Ying , Singh Rajeev , Hewitt Robert Edwin , Salto-Tellez Manuel , Pervaiz Shazib , Clément Marie-Véronique
Published: March 2024

Abstract
Ligand-induced activation of peroxisome proliferator-activated receptor γ (PPARγ) inhibits proliferation in cancer cells in vitro and in vivo; however, the downstream targets remain undefined. We report the identification of a peroxisome proliferator response element in the promoter region of the Na+/H+ transporter gene NHE1, the overexpression of which has been associated with carcinogenesis. Exposure of breast cancer cells expressing high levels of PPARγ to its natural and synthetic agonists resulted in downregulation of NHE1 transcription as well as protein expression. Furthermore, the inhibitory effect of activated PPARγ on tumor colony-forming ability was abrogated on overexpression of NHE1, whereas small interfering RNA–mediated gene silencing of NHE1 significantly increased the sensitivity of cancer cells to growth-inhibitory stimuli. Finally, histopathologic analysis of breast cancer biopsies obtained from patients with type II diabetes treated with the synthetic agonist rosiglitazone showed significant repression of NHE1 in the tumor tissue. These data provide evidence for tumor-selective downregulation of NHE1 by activated PPARγ in vitro and in pathologic specimens from breast cancer patients and could have potential implications for the judicious use of low doses of PPARγ ligands in combination chemotherapy regimens for an effective therapeutic response. [Cancer Res 2009;69(22):8636–44]
Data from Copy Number Alterations that Predict Metastatic Capability of Human Breast Cancer
Authors: Zhang Yi , Martens John W.M. , Yu Jack X. , Jiang John , Sieuwerts Anieta M. , Smid Marcel , Klijn Jan G.M. , Wang Yixin , Foekens John A.
Published: March 2024

Abstract
We have analyzed the DNA copy numbers for over 100,000 single-nucleotide polymorphism loci across the human genome in genomic DNA from 313 lymph node–negative primary breast tumors for which genome-wide gene expression data were also available. Combining these two data sets allowed us to identify the genomic loci and their mapped genes, having high correlation with distant metastasis. An estimation of the likely response based on published predictive signatures was performed in the identified prognostic subgroups defined by gene expression and DNA copy number data. In the training set of 200 patients, we constructed an 81-gene prognostic copy number signature (CNS) that identified a subgroup of patients with increased probability of distant metastasis in the independent validation set of 113 patients [hazard ratio (HR), 2.8; 95% confidence interval (95% CI), 1.4–5.6] and in an external data set of 116 patients (HR, 3.7; 95% CI, 1.3–10.6). These high-risk patients constituted a subset of the high-risk patients predicted by our previously established 76-gene gene expression signature (GES). This very poor prognostic group identified by CNS and GES was putatively more resistant to preoperative paclitaxel and 5-fluorouracil-doxorubicin-cyclophosphamide combination chemotherapy (P = 0.0048), particularly against the doxorubicin compound, while potentially benefiting from etoposide. Our study shows the feasibility of using copy number alterations to predict patient prognostic outcome. When combined with gene expression–based signatures for prognosis, the CNS refines risk classification and can help identify those breast cancer patients who have a significantly worse outlook in prognosis and a potential differential response to chemotherapeutic drugs. [Cancer Res 2009;69(9):3795–801]
Data from MicroRNA-101, Down-regulated in Hepatocellular Carcinoma, Promotes Apoptosis and Suppresses Tumorigenicity
Authors: Su Hang , Yang Jian-Rong , Xu Teng , Huang Jun , Xu Li , Yuan Yunfei , Zhuang Shi-Mei
Published: March 2024

Abstract
Although aberrant microRNA (miRNA) expressions have been observed in different types of cancer, their pathophysiologic role and their relevance to tumorigenesis are still largely unknown. In this study, we first evaluated the expression of 308 miRNAs in human hepatocellular carcinoma (HCC) and normal hepatic tissues and identified 29 differentially expressed miRNAs in HCC tissues. miR-101, a significantly down-regulated miRNA, was further studied in greater detail because the signal pathway(s) regulated by miR-101 and the role of miR-101 in tumorigenesis have not yet been elucidated. Interestingly, decreased expression of miR-101 was found in all six hepatoma cell lines examined and in as high as 94.1% of HCC tissues, compared with their nontumor counterparts. Furthermore, ectopic expression of miR-101 dramatically suppressed the ability of hepatoma cells to form colonies in vitro and to develop tumors in nude mice. We also found that miR-101 could sensitize hepatoma cell lines to both serum starvation– and chemotherapeutic drug–induced apoptosis. Further investigation revealed that miR-101 significantly repressed the expression of luciferase carrying the 3′-untranslated region of Mcl-1 and reduced the endogenous protein level of Mcl-1, whereas the miR-101 inhibitor obviously up-regulated Mcl-1 expression and inhibited cell apoptosis. Moreover, silencing of Mcl-1 phenocopied the effect of miR-101 and forced expression of Mcl-1 could reverse the proapoptotic effect of miR-101. These results indicate that miR-101 may exert its proapoptotic function via targeting Mcl-1. Taken together, our data suggest an important role of miR-101 in the molecular etiology of cancer and implicate the potential application of miR-101 in cancer therapy. [Cancer Res 2009;69(3):1135–42]
Data from Critical Role of Smad2 in Tumor Suppression and Transforming Growth Factor-β–Induced Apoptosis of Prostate Epithelial Cells
Authors: Yang Jiayi , Wahdan-Alaswad Reema , Danielpour David
Published: March 2024

Abstract
Transforming growth factor-β (TGF-β) functions as a tumor suppressor of the prostate through mechanisms that remain unresolved. Although TGF-β receptors directly activate both Smads 2 and 3, to date, Smad3 has been shown to be the essential mediator of most Smad-dependent TGF-β responses, including control of gene expression, cell growth, apoptosis, and tumor suppression. Using a robust lentiviral short hairpin RNA system to silence Smads 2 and/or 3 in the NRP-152 nontumorigenic rat prostate basal epithelial cell line, we provide the first evidence for Smad2 as a critical mediator of TGF-β–induced apoptosis and gene expression. Parallel analyses revealed that Smad3 is the major mediator of TGF-β–induced transcriptional and apoptotic responses in the NRP-154 rat prostate carcinoma cell line. Remarkably, silencing Smad2 alone caused malignant transformation of NRP-152 cells, as assayed by s.c. tumor growth in athymic mice, whereas silencing Smad3 alone did not induce tumors. Nevertheless, tumors induced by silencing both Smads 2 and 3 were larger than those from silencing Smad2 alone. Given previous reports that NRP-152 cells have a stem cell phenotype, we speculate a critical role for Smad2 as a tumor suppressor in the basal epithelial or stem cell compartment of the prostate. [Cancer Res 2009;69(6):2185–90]
Data from Thrombin Induces Tumor Cell Cycle Activation and Spontaneous Growth by Down-regulation of p27Kip1, in Association with the Up-regulation of Skp2 and MiR-222
Authors: Hu Liang , Ibrahim Sherif , Liu Cynthia , Skaar Jeffrey , Pagano Michele , Karpatkin Simon
Published: March 2024

Abstract
The effect of thrombin on tumor cell cycle activation and spontaneous growth was examined in synchronized serum-starved tumor cell lines and a model of spontaneous prostate cancer development in TRAMP mice. BrdUrd incorporation and propidium iodide staining of prostate LNCaP cells arrested in G0 and treated with thrombin or serum revealed a 48- and 29-fold increase in S phase cells, respectively, at 8 hours. Similar results were obtained with TRAMP cells and a glioblastoma cell line, T98G. Cell cycle kinases and inhibitors in synchronized tumor cells revealed high levels of p27Kip1 and low levels of Skp2 and cyclins D1 and A. Addition of thrombin, TFLLRN, or serum down-regulated p27Kip1 with concomitant induction of Skp2, Cyclin D1, and Cyclin A with similar kinetics. LNCaP p27Kip1-transfected cells or Skp2 knockdown cells were refractory to thrombin-induced cell cycle activation. MicroRNA 222, an inhibitor of p27Kip1, was robustly up-regulated by thrombin. The in vitro observations were tested in vivo with transgenic TRAMP mice. Repetitive thrombin injection enhanced prostate tumor volume 6- to 8-fold (P < 0.04). Repetitive hirudin, a specific potent antithrombin, decreased tumor volume 13- to 24-fold (P < 0.04). Thus, thrombin stimulates tumor cell growth in vivo by down-regulation of p27Kip1. [Cancer Res 2009;69(8):3374–81]
Data from Association of a Germ-Line Copy Number Variation at 2p24.3 and Risk for Aggressive Prostate Cancer
Authors: Liu Wennuan , Sun Jishan , Li Ge , Zhu Yi , Zhang Scott , Kim Seong-Tae , Sun Jielin , Wiklund Fredrik , Wiley Kathleen , Isaacs Sarah D. , Stattin Pär , Xu Jianfeng , Duggan David , Carpten John D. , Isaacs William B. , Grönberg Henrik , Zheng S. Lilly , Chang Bao-Li
Published: March 2024

Abstract
We searched for deletions in the germ-line genome among 498 aggressive prostate cancer cases and 494 controls from a population-based study in Sweden [CAncer of the Prostate in Sweden (CAPS)] using Affymetrix SNP arrays. By comparing allele intensities of ∼500,000 SNP probes across the genome, a germ-line deletion at 2p24.3 was observed to be significantly more common in cases (12.63%) than in controls (8.28%); P = 0.028. To confirm the association, we genotyped this germ-line copy number variation (CNV) in additional subjects from CAPS and from Johns Hopkins Hospital (JHH). Overall, among 4,314 cases and 2,176 controls examined, the CNV was significantly associated with prostate cancer risk [odds ratio (OR), 1.25; 95% confidence interval (95% CI), 1.06–1.48; P = 0.009]. More importantly, the association was stronger for aggressive prostate cancer (OR, 1.31; 95% CI, 1.08–1.58; P = 0.006) than for nonaggressive prostate cancer (OR, 1.19; 95% CI, 0.98–1.45; P = 0.08). The biological effect of this germ-line CNV is unknown because no known gene resides in the deletion. Results from this study represent the first novel germ-line CNV that was identified from a genome-wide search and was significantly, but moderately, associated with prostate cancer risk. Additional confirmation of this association and functional studies are warranted. [Cancer Res 2009;69(6):2176–9]
Data from Mitochondrial Dysfunction and Reactive Oxygen Species Imbalance Promote Breast Cancer Cell Motility through a CXCL14-Mediated Mechanism
Authors: Pelicano Helene , Lu Weiqin , Zhou Yan , Zhang Wan , Chen Zhao , Hu Yumin , Huang Peng
Published: March 2024

Abstract
Although mitochondrial dysfunction and reactive oxygen species (ROS) stress have long been observed in cancer cells, their role in promoting malignant cell behavior remains unclear. Here, we show that perturbation of the mitochondrial respiratory chain in breast cancer cells leads to a generation of subclones of cells with increased ROS, active proliferation, high cellular motility, and invasive behaviors in vitro and in vivo. Gene expression analysis using microarrays revealed that all subclones overexpressed CXCL14, a novel chemokine with undefined function. We further show that CXCL14 expression is up-regulated by ROS through the activator protein-1 signaling pathway and promotes cell motility through elevation of cytosolic Ca2+ by binding to the inositol 1,4,5-trisphosphate receptor on the endoplasmic reticulum. Abrogation of CXCL14 expression using a decoy approach suppressed cell motility and invasion. Our data suggest that mitochondrial dysfunction and ROS stress promote cancer cell motility through a novel pathway mediated by CXCL14. [Cancer Res 2009;69(6):2375–83]
Data from B-MYB Is Required for Recovery from the DNA Damage–Induced G2 Checkpoint in p53 Mutant Cells
Authors: Mannefeld Mirijam , Klassen Elena , Gaubatz Stefan
Published: March 2024

Abstract
In response to DNA damage, several signaling pathways that arrest the cell cycle in G1 and G2 are activated. The down-regulation of mitotic genes contributes to the stable maintenance of the G2 arrest. The human LINC or DREAM complex, together with the B-MYB transcription factor, plays an essential role in the expression of G2-M genes. Here, we show that DNA damage results in the p53-dependent binding of p130 and E2F4 to LINC and the dissociation of B-MYB from LINC. We find that B-MYB fails to dissociate from LINC in p53 mutant cells, that this contributes to increased G2-M gene expression in response to DNA damage in these cells, and, importantly, that B-MYB is required for recovery from the G2 DNA damage checkpoint in p53-negative cells. Reanalysis of microarray expression data sets revealed that high levels of B-MYB correlate with a p53 mutant status and an advanced tumor stage in primary human breast cancer. Taken together, these data suggest that B-MYB/LINC plays an important role in the DNA damage response downstream of p53. [Cancer Res 2009;69(9):4073–80]
Data from Gene Expression Profiles in Peripheral Blood Mononuclear Cells Can Distinguish Patients with Non–Small Cell Lung Cancer from Patients with Nonmalignant Lung Disease
Authors: Showe Michael K. , Vachani Anil , Kossenkov Andrew V. , Yousef Malik , Nichols Calen , Nikonova Elena V. , Chang Celia , Kucharczuk John , Tran Bao , Wakeam Elliot , Yie Ting An , Speicher David , Rom William N. , Albelda Steven , Showe Louise C.
Published: March 2024

Abstract
Early diagnosis of lung cancer followed by surgery presently is the most effective treatment for non–small cell lung cancer (NSCLC). An accurate, minimally invasive test that could detect early disease would permit timely intervention and potentially reduce mortality. Recent studies have shown that the peripheral blood can carry information related to the presence of disease, including prognostic information and information on therapeutic response. We have analyzed gene expression in peripheral blood mononuclear cell samples including 137 patients with NSCLC tumors and 91 patient controls with nonmalignant lung conditions, including histologically diagnosed benign nodules. Subjects were primarily smokers and former smokers. We have identified a 29-gene signature that separates these two patient classes with 86% accuracy (91% sensitivity, 80% specificity). Accuracy in an independent validation set, including samples from a new location, was 78% (sensitivity of 76% and specificity of 82%). An analysis of this NSCLC gene signature in 18 NSCLCs taken presurgery, with matched samples from 2 to 5 months postsurgery, showed that in 78% of cases, the signature was reduced postsurgery and disappeared entirely in 33%. Our results show the feasibility of using peripheral blood gene expression signatures to identify early-stage NSCLC in at-risk populations. [Cancer Res 2009;69(24):9202–10]
Data from Breast Cancer Cell Lines Contain Functional Cancer Stem Cells with Metastatic Capacity and a Distinct Molecular Signature
Authors: Charafe-Jauffret Emmanuelle , Ginestier Christophe , Iovino Flora , Wicinski Julien , Cervera Nathalie , Finetti Pascal , Hur Min-Hee , Diebel Mark E. , Monville Florence , Dutcher Julie , Brown Marty , Viens Patrice , Xerri Luc , Bertucci François , Stassi Giorgio , Dontu Gabriela , Birnbaum Daniel , Wicha Max S.
Published: March 2024

Abstract
Tumors may be initiated and maintained by a cellular subcomponent that displays stem cell properties. We have used the expression of aldehyde dehydrogenase as assessed by the ALDEFLUOR assay to isolate and characterize cancer stem cell (CSC) populations in 33 cell lines derived from normal and malignant mammary tissue. Twenty-three of the 33 cell lines contained an ALDEFLUOR-positive population that displayed stem cell properties in vitro and in NOD/SCID xenografts. Gene expression profiling identified a 413-gene CSC profile that included genes known to play a role in stem cell function, as well as genes such as CXCR1/IL-8RA not previously known to play such a role. Recombinant interleukin-8 (IL-8) increased mammosphere formation and the ALDEFLUOR-positive population in breast cancer cell lines. Finally, we show that ALDEFLUOR-positive cells are responsible for mediating metastasis. These studies confirm the hierarchical organization of immortalized cell lines, establish techniques that can facilitate the characterization of regulatory pathways of CSCs, and identify potential stem cell markers and therapeutic targets. [Cancer Res 2009;69(4):1302–13]
Data from Noninvasive De novo Imaging of Human Embryonic Stem Cell–Derived Teratoma Formation
Authors: Cao Feng , Li Zibo , Lee Andrew , Liu Zhaofei , Chen Kai , Wang Hui , Cai Weibo , Chen Xiaoyuan , Wu Joseph C.
Published: March 2024

Abstract
Teratoma formation can be a serious drawback after the therapeutic transplantation of human embryonic stem (hES) cells. Therefore, noninvasive imaging of teratomas could be a valuable tool for monitoring patients undergoing hES cell treatment. Here, we investigated the angiogenic process within teratomas derived from hES cells and now report the first example of using 64Cu-labeled RGD tetramer (64Cu-DOTA-RGD4) for positron emission tomography imaging of teratoma formation by targeting αvβ3 integrin. H9 hES cells (2 × 106), stably expressing firefly luciferase, and enhanced green fluorescence protein (Fluc-eGFP) were injected into adult nude mice (n = 12) s.c. Eight weeks after transplantation, these hES cell grafts evolved into teratomas as confirmed by longitudinal bioluminescence imaging. Under micropositron emission tomography imaging, 2-deoxy-2-[18F]fluoro-D-glucose and 3′-deoxy-3′-[18F]-fluorothymidine both failed to detect hES cell–derived teratomas (0.8 ± 0.5 versus 1.1 ± 0.4 %ID/g, respectively; P = not significant versus background signals). By contrast, 64Cu-DOTA-RGD4 revealed specific and prominent uptake in vascularized teratoma and significantly lower uptake in control tumors (human ovarian carcinoma 2008 cell line), which had low intergrin expression (10.1 ± 3.4 versus 1.4 ± 1.2 %ID/g; P < 0.01). Immunofluorescence staining of CD31 and β3 integrin also supported our in vivo imaging results (P < 0.05). Moreover, we found that the cells dissociated from teratomas showed higher αvβ3 integrin expression than the 2008 cells. In conclusion, by targeting αvβ3 integrin, we successfully showed the ability of 64Cu-DOTA-RGD4 to noninvasively visualize teratoma formation in vivo for the first time. [Cancer Res 2009;69(7):2709–13]
Data from GD3, an Overexpressed Tumor-Derived Ganglioside, Mediates the Apoptosis of Activated but not Resting T Cells
Authors: Sa Gaurisankar , Das Tanya , Moon Christina , Hilston Cynthia M. , Rayman Patricia A. , Rini Brian I. , Tannenbaum Charles S. , Finke James H.
Published: March 2024

Abstract
We previously elucidated an important role for gangliosides in renal cell carcinoma–mediated T lymphocyte apoptosis, although the mechanism by which they mediated lymphocyte death remained unclear. Here, we show that when added in purified form, GD3 is internalized by activated T cells, initiating a series of proapoptotic events, including the induction of reactive oxygen species (ROS), an enhancement of p53 and Bax accumulation, an increase in mitochondrial permeability, cytochrome c release, and the activation of caspase-9. GD3-induced apoptosis of activated T cells was dose dependent and inhibitable by pretreating the lymphocytes with N-acetylcysteine, cyclosporin A, or bongkrekic acid, emphasizing the essential role of ROS and mitochondrial permeability to the process. Ganglioside-induced T-cell killing was associated with the caspase-dependent degradation of nuclear factor-κB–inducible, antiapoptotic proteins, including RelA; this suggests that their loss is initiated only after the cascade is activated and that their disappearance amplifies but not triggers GD3 susceptibility. Resting T cells did not internalize appreciable levels of GD3 and did not undergo any of the proapoptotic changes that characterize activated T lymphocytes exposed to the ganglioside. RelA overexpression endows Jurkat cells with resistance to GD3-mediated apoptosis, verifying the role of the intact transcription factor in mediating protection from the ganglioside. [Cancer Res 2009;69(7):3095–104]
Data from The Human Cytomegalovirus–Encoded Chemokine Receptor US28 Promotes Angiogenesis and Tumor Formation via Cyclooxygenase-2
Authors: Maussang David , Langemeijer Ellen , Fitzsimons Carlos P. , Stigter-van Walsum Marijke , Dijkman Remco , Borg Martin K. , Slinger Erik , Schreiber Andreas , Michel Detlef , Tensen Cornelis P. , van Dongen Guus A.M.S. , Leurs Rob , Smit Martine J.
Published: March 2024

Abstract
The human cytomegalovirus (HCMV), potentially associated with the development of malignancies, encodes the constitutively active chemokine receptor US28. Previously, we have shown that US28 expression induces an oncogenic phenotype both in vitro and in vivo. Microarray analysis revealed differential expression of genes involved in oncogenic signaling in US28-expressing NIH-3T3 cells. In particular, the expression of cyclooxygenase-2 (COX-2), a key mediator of inflammatory diseases and major determinant in several forms of cancer, was highly up-regulated. US28 induced increases in COX-2 expression via activation of nuclear factor-κB, driving the production of vascular endothelial growth factor. Also, in HCMV-infected cells, US28 contributed to the viral induction of COX-2. Finally, the involvement of COX-2 in US28-mediated tumor formation was evaluated using the COX-2 selective inhibitor Celecoxib. Targeting COX-2 in vivo with Celecoxib led to a marked delay in the onset of tumor formation in nude mice injected with US28-transfected NIH-3T3 cells and a reduction of subsequent growth by repressing the US28-induced angiogenic activity. Hence, the development of HCMV-related proliferative diseases may partially be ascribed to the ability of US28 to activate COX-2. [Cancer Res 2009;69(7):2861–9]
Data from Role for Krüppel-Like Factor 4 in Determining the Outcome of p53 Response to DNA Damage
Authors: Zhou Qibing , Hong Yuan , Zhan Qimin , Shen Yan , Liu Zhihua
Published: March 2024

Abstract
Cells are incessantly exposed to many sources of genotoxic stress. A critical unresolved issue is how the resulting activation of the p53 tumor suppressor can lead to either cell cycle arrest or apoptosis depending on the extent of DNA damage. The present study shows that the level of Krüppel-like factor 4 (KLF4) expression is inversely correlated with the extent of DNA damage. KLF4 is activated by p53 following cytostatic, mild DNA damage, whereas it is strongly repressed via enhanced turnover of mRNA on severe DNA damage that irreversibly drives cells to apoptosis. Blocking the repression of KLF4 on severe DNA damage suppresses p53-mediated apoptosis, whereas ablation of the KLF4 induction on mild DNA damage shifts the p53 response from cell cycle arrest to cell death. Our results suggest that coordinate regulation of KLF4 expression depending on the extent of DNA damage may be an important mechanism that dictates the life and death decisions of p53. [Cancer Res 2009;69(21):8284–92]
Data from Retinoblastoma Family Proteins Have Distinct Functions in Pulmonary Epithelial Cells In vivo Critical for Suppressing Cell Growth and Tumorigenesis
Authors: Simpson David S. , Mason-Richie Nicole A. , Gettler Caitlin A. , Wikenheiser-Brokamp Kathryn A.
Published: March 2024

Abstract
Lung cancer is the leading cause of cancer deaths, accounting for more deaths than breast, colon, and prostate cancer combined. The retinoblastoma (Rb)/p16 tumor suppressive pathway is deregulated in most cancers. Loss of p16 occurs more frequently than Rb loss, suggesting that p16 suppresses cancer by regulating Rb as well as the related proteins p107 and p130. However, direct evidence demonstrating that p130 or p107 cooperate with Rb to suppress epithelial cancers associated with p16 loss is currently lacking. Moreover, the roles of p130 and p107 in lung cancer are not clear. In the present studies, Rb ablation was targeted to the lung epithelium in wild-type, p107, or p130 null mice to determine unique and overlapping Rb family functions critical in tumor suppression. Rb ablation during development resulted in marked epithelial abnormalities despite p107 upregulation. In contrast, p130 and p107 were not required during development but had distinct functions in the Rb-deficient epithelium: p107 was required to suppress proliferation, whereas a novel proapoptotic function was identified for p130. Adult Rb-ablated lungs lacked the epithelial phenotype seen at birth and showed compensatory p107 upregulation and p16 induction in epithelial cell lineages that share phenotypic characteristics with human non–small cell lung cancers (NSCLC) that frequently show p16 loss. Importantly, Rb/p107-deficient, but not Rb/p130-deficient, lungs developed tumors resembling NSCLC. Taken together, these studies identify distinct Rb family functions critical in controlling epithelial cell growth, and provide direct evidence that p107 cooperates with Rb to protect against a common adult cancer. [Cancer Res 2009;69(22):8733–41]