bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Tyrosine Kinase Etk/BMX Is Up-regulated in Human Prostate Cancer and Its Overexpression Induces Prostate Intraepithelial Neoplasia in Mouse
Authors: Dai Bojie , Kim Oekyung , Xie Yingqiu , Guo Zhiyong , Xu Kexin , Wang Bin , Kong Xiangtian , Melamed Jonathan , Chen Hegang , Bieberich Charles J. , Borowsky Alexander D. , Kung Hsing-Jien , Wei Guo , Ostrowski Michael C. , Brodie Angela , Qiu Yun
Published: March 2023

Abstract
The nonreceptor tyrosine kinase Etk/BMX was originally identified from the human prostate xenograft CWR22. Here, we report that Etk is up-regulated in human prostate tumor specimens surveyed. Knocking down Etk expression by a specific small interfering RNA (siRNA) in prostate cancer cells attenuates cell proliferation, suggesting an essential role of Etk for prostate cancer cell survival and growth. Targeted expression of Etk in mouse prostate epithelium results in pathologic changes resembling human prostatic intraepithelial neoplasia, indicating that up-regulation of Etk may contribute to prostate cancer development. A marked increase of luminal epithelial cell proliferation was observed in the Etk transgenic prostate, which may be attributed in part to the elevated activity of Akt and signal transducers and activators of transcription 3 (STAT3). More interestingly, the expression level of acetyltransferase cyclic AMP–responsive element binding protein–binding protein (CBP) is also increased in the Etk transgenic prostate as well as in a prostate cancer cell line overexpressing Etk, concomitant with elevated histone 3 acetylation at lysine 18 (H3K18Ac). Down-modulation of Etk expression by a specific siRNA leads to a decrease of H3 acetylation in prostate cancer cell lines. Our data suggest that Etk may also modulate chromatin remodeling by regulating the activity of acetyltransferases, such as CBP. Given that Etk may exert its effects in prostate through modulation of multiple signaling pathways altered in human prostate cancer, the Etk transgenic mouse model may be a useful tool for studying the functions of Etk and identification of new molecular markers and drug targets relevant to human diseases. (Cancer Res 2006; 66(16): 8058-64)
Data from Topological and Functional Discovery in a Gene Coexpression Meta-Network of Gastric Cancer
Authors: Aggarwal Amit , Li Guo Dong , Hoshida Yujin , Tsan Yuen Siu , Chu Kent-Man , So Samuel , Boussioutas Alex , Chen Xin , Bowtell David , Aburatani Hiroyuki , Leung Suet Yi , Tan Patrick
Published: March 2023

Abstract
Gastric cancer is a leading cause of global cancer mortality, but comparatively little is known about the cellular pathways regulating different aspects of the gastric cancer phenotype. To achieve a better understanding of gastric cancer at the levels of systems topology, functional modules, and constituent genes, we assembled and systematically analyzed a consensus gene coexpression meta-network of gastric cancer incorporating >300 tissue samples from four independent patient populations (the “gastrome”). We find that the gastrome exhibits a hierarchical scale-free architecture, with an internal structure comprising multiple deeply embedded modules associated with diverse cellular functions. Individual modules display distinct subtopologies, with some (cellular proliferation) being integrated within the primary network, and others (ribosomal biosynthesis) being relatively isolated. One module associated with intestinal differentiation exhibited a remarkably high degree of autonomy, raising the possibility that its specific topological features may contribute towards the frequent occurrence of intestinal metaplasia in gastric cancer. At the single-gene level, we discovered a novel conserved interaction between the PLA2G2A prognostic marker and the EphB2 receptor, and used tissue microarrays to validate the PLA2G2A/EphB2 association. Finally, because EphB2 is a known target of the Wnt signaling pathway, we tested and provide evidence that the Wnt pathway may also similarly regulate PLA2G2A. Many of these findings were not discernible by studying the single patient populations in isolation. Thus, besides enhancing our knowledge of gastric cancer, our results show the broad utility of applying meta-analytic approaches to genome-wide data for the purposes of biological discovery. (Cancer Res 2006; 66(1): 232-41)
Data from Tip60 Protein Isoforms and Altered Function in Skin and Tumors that Overexpress Ornithine Decarboxylase
Authors: Hobbs Cheryl A. , Wei Gang , DeFeo Karen , Paul Barry , Hayes Candace S. , Gilmour Susan K.
Published: March 2023

Abstract
Elevated expression of ornithine decarboxylase (ODC) and increased synthesis of polyamines are hallmarks of epithelial tumorigenesis. The skin and tumors of K6/ODC and ODC/Ras transgenic mice, in which overexpression of ODC has been targeted to hair follicles, were found to exhibit intrinsically high histone acetyltransferase (HAT) activity. We identified Tip60 as a candidate enzyme for contributing significantly to this abnormally high HAT activity. Compared with normal littermate controls, the levels of Tip60 protein and an alternative splice variant Tip53 were found to be greater in K6/ODC mouse skin. Furthermore, skin tumors that spontaneously develop in ODC/Ras bigenic mice typically have substantially more Tip60 protein than adjacent non–tumor-bearing skin and exhibit a unique pattern of Tip60 size variants and chemically modified protein isoforms. Steady-state Tip60 and Tip53 mRNA levels were not affected in ODC-overexpressing skin and tumors, implying novel posttranscriptional regulation by polyamines. Given the diverse roles of Tip60, the overabundance of Tip60 protein is predicted to have biological consequences. Compared with normal littermate skin, we detected altered association of Tip60 with E2F1 and a subset of newly identified Tip60-interacting transcription factors in ODC transgenic mouse skin and tumors. E2F1 was shown to be bound in greater amounts to up-regulated target genes in ODC-overexpressing skin. Thus, up-regulation of Tip60 protein, influencing the expression of Tip60-regulated genes, could play a contributing role in polyamine-mediated tumor promotion. (Cancer Res 2006; 66(16): 8116-22)
Data from Ligand-Directed Surface Profiling of Human Cancer Cells with Combinatorial Peptide Libraries
Authors: Kolonin Mikhail G. , Bover Laura , Sun Jessica , Zurita Amado J. , Do Kim-Anh , Lahdenranta Johanna , Cardó-Vila Marina , Giordano Ricardo J. , Jaalouk Diana E. , Ozawa Michael G. , Moya Catherine A. , Souza Glauco R. , Staquicini Fernanda I. , Kunyiasu Akihiko , Scudiero Dominic A. , Holbeck Susan L. , Sausville Edward A. , Arap Wadih , Pasqualini Renata
Published: March 2023

Abstract
A collection of 60 cell lines derived from human tumors (NCI-60) has been widely explored as a tool for anticancer drug discovery. Here, we profiled the cell surface of the NCI-60 by high-throughput screening of a phage-displayed random peptide library and classified the cell lines according to the binding selectivity of 26,031 recovered tripeptide motifs. By analyzing selected cell-homing peptide motifs and their NCI-60 recognition patterns, we established that some of these motifs (a) are similar to domains of human proteins known as ligands for tumor cell receptors and (b) segregate among the NCI-60 in a pattern correlating with expression profiles of the corresponding receptors. We biochemically validated some of the motifs as mimic peptides of native ligands for the epidermal growth factor receptor. Our results indicate that ligand-directed profiling of tumor cell lines can select functional peptides from combinatorial libraries based on the expression of tumor cell surface molecules, which in turn could be exploited as “druggable” receptors in specific types of cancer. (Cancer Res 2006; 66(1): 34-40)
Data from The G691S RET Polymorphism Increases Glial Cell Line–Derived Neurotrophic Factor–Induced Pancreatic Cancer Cell Invasion by Amplifying Mitogen-Activated Protein Kinase Signaling
Authors: Sawai Hirozumi , Okada Yuji , Kazanjian Kevork , Kim Joseph , Hasan Sascha , Hines Oscar J. , Reber Howard A. , Hoon Dave S.B. , Eibl Guido
Published: March 2023

Abstract
Mutations of the RET proto-oncogene are responsible for several inherited human diseases and may function as genetic modifiers of the disease. However, the role of RET mutations in pancreatic cancer has not been studied. Expression of the glial cell line–derived neurotrophic factor (GDNF) receptors RET and GDNF family receptor α1 (GFRα1) in human pancreatic cancer cells was determined by Western blot, immunofluorescence, and flow cytometry. The effect of GDNF on cell proliferation and invasion was assessed. Small interfering RNA and antibodies were used to evaluate the involvement of RET. The G691S RET polymorphism was analyzed by sequencing and restriction analysis. The modifying effect of G691S RET on GDNF-induced invasion and mitogen-activated protein kinase (MAPK) signaling was evaluated. Transfection studies with wild-type and mutated RET determined the functional role of the G691S polymorphism. Pancreatic cancer specimens and matched tissues were analyzed for the presence of the G691S RET polymorphism. GDNF receptors were found on all cell lines. GDNF increased pancreatic cancer cell proliferation and invasion, which was mediated by RET. The effect of GDNF was more profound in cells with the G691S RET polymorphism (P < 0.01). G691S RET correlated with an enhanced activation of the downstream extracellular signal-regulated kinase pathway. Overexpression of G691S RET increased pancreatic cancer cell invasion. The G691S RET polymorphism was also detected in human pancreatic tumors and represented a somatic mutation in some patients. These findings indicate that the G691S RET single nucleotide polymorphism may directly correlate with the aggressive growth of pancreatic cancers and may function as a genetic modifier or even low-penetrance gene. (Cancer Res 2005; 65(24): 11536-44)
Data from Chemokine (C-C Motif) Ligand 2 Mediates the Prometastatic Effect of Dysadherin in Human Breast Cancer Cells
Authors: Nam Jeong-Seok , Kang Mi-Jin , Suchar Adam M. , Shimamura Takeshi , Kohn Ethan A. , Michalowska Aleksandra M. , Jordan V. Craig , Hirohashi Setsuo , Wakefield Lalage M.
Published: March 2023

Abstract
Dysadherin, a cancer-associated membrane glycoprotein, down-regulates E-cadherin and promotes cancer metastasis. This study examined the role of dysadherin in breast cancer progression. Expression of dysadherin was found to be highest in breast cancer cell lines and tumors that lacked the estrogen receptor (ER). Knockdown of dysadherin caused increased association of E-cadherin with the actin cytoskeleton in breast cancer cell lines that expressed E-cadherin. However, knockdown of dysadherin could still suppress cell invasiveness in cells that had no functional E-cadherin, suggesting the existence of a novel mechanism of action. Global gene expression analysis identified chemokine (C-C motif) ligand 2 (CCL2) as the transcript most affected by dysadherin knockdown in MDA-MB-231 cells, and dysadherin was shown to regulate CCL2 expression in part through activation of the nuclear factor-κB pathway. The ability of dysadherin to promote tumor cell invasion in vitro was dependent on the establishment of a CCL2 autocrine loop, and CCL2 secreted by dysadherin-positive tumor cells also promoted endothelial cell migration in a paracrine fashion. Finally, experimental suppression of CCL2 in MDA-MB-231 cells reduced their ability to metastasize in vivo. This study shows that dysadherin has prometastatic effects that are independent of E-cadherin expression and that CCL2 could play an important role in mediating the prometastatic effect of dysadherin in ER-negative breast cancer. (Cancer Res 2006; 66(14): 7176-84)
Data from Transgenic Mice Expressing the p75 CCAAT-Displacement Protein/Cut Homeobox Isoform Develop a Myeloproliferative Disease–Like Myeloid Leukemia
Authors: Cadieux Chantal , Fournier Sylvie , Peterson Alan C. , Bédard Christian , Bedell Barry J. , Nepveu Alain
Published: March 2023

Abstract
The p75 CCAAT-displacement protein/Cut homeobox (CDP/Cux) isoform was previously reported to be overexpressed in human breast cancers. To investigate its oncogenic potential, we engineered two transgenic mouse lines expressing p75 CDP/Cux under the control of the mouse mammary tumor virus-long terminal repeat. The FVB strain of mouse is generally used in the generation of mouse models for breast cancer. The transgene was introduced into the hprt locus of 129/Ola embryonic stem cells and, following germ line passage, was backcrossed onto the FVB and C57BL/6 mouse strains. Here, we describe the phenotype of p75 CDP/Cux transgenic virgin female mice of the first backcross generations. We report that after a long latency period, ∼33% of mice from two independent transgenic lines and from backcrosses into either the FVB or the C57BL/6 strains succumbed to a similar disease characterized by splenomegaly, hepatomegaly, and frequent infiltration of leukocytes into nonhematopoietic organs like the kidneys and lungs. Although an excess of B or T cells was observed in three diseased mice, in 17 other cases, histologic and flow cytometry analyses revealed the expansion of a population of neutrophils in the blood, spleen, and bone marrow. The increase in neutrophils correlated with signs of anemia and thrombocytopenia, whereas there was no indication of a reactive process. Therefore, p75 CDP/Cux transgenic mice displayed heightened susceptibility to a disease defined as a myeloproliferative disease–like myeloid leukemia. These results indicate that the overexpression of p75 CDP/Cux could alter homeostasis in the hematopoietic compartment. (Cancer Res 2006; 66(19): 9492-501)
Data from Optimizing Radiolabeled Engineered Anti-p185HER2 Antibody Fragments for In vivo Imaging
Authors: Olafsen Tove , Kenanova Vania E. , Sundaresan Gobalakrishnan , Anderson Anne-Line , Crow Desiree , Yazaki Paul J. , Li Lin , Press Michael F. , Gambhir Sanjiv S. , Williams Lawrence E. , Wong Jeffrey Y.C. , Raubitschek Andrew A. , Shively John E. , Wu Anna M.
Published: March 2023

Abstract
We have recently described the in vivo properties of an iodinated anti-p185HER2 engineered antibody fragment [minibody (scFv-CH3)2; 80 kDa], made from the internalizing 10H8 monoclonal antibody. Although the 10H8 minibody showed excellent binding to the target in vitro, only modest tumor uptake [5.6 ± 1.7% injected dose per gram (ID/g) of tissue] was achieved in nude mice bearing MCF7/HER2 breast cancer tumors. Here, in an attempt to improve targeting, the 10H8 minibody was conjugated to 1,4,7,10-tetraazacyclododecane-N, N′, N′′, N′′′-tetraacetic acid (DOTA), radiometal labeled, and evaluated in vivo. The tumor uptake of 111In-DOTA 10H8 minibody was 5.7 ± 0.1% ID/g, similar to the radioiodinated 10H8 minibody. However, in addition to the expected liver clearance, the kidneys had unexpectedly high activity (34.0 ± 4.0% ID/g). A minibody derived from a second anti-p185HER2 antibody (trastuzumab; hu4D5v8) was also made. Tumor uptakes, evaluated by quantitative microPET using 64Cu-DOTA hu4D5v8 minibody, were 4.2 ± 0.5% ID/g. Furthermore, in non-tumor-bearing mice, 111In-DOTA hu4D5v8 minibody exhibited similar elevated uptake in the kidneys (28.4 ± 6.5% ID/g). Immunohistochemical staining of kidneys from non-tumor-bearing mice showed strong specific staining of the proximal tubules, and Western blot analysis of kidney lysate confirmed the presence of cross-reactive antigen. To further improve tumor uptake and normal tissue distribution, a larger hu4D5v8 fragment [(scFv-CH2-CH3)2; 105 kDa] was made, engineered to exhibit rapid clearance kinetics. This fragment, when evaluated by microPET, exhibited improved tumor targeting (12.2 ± 2.4% ID/g) and reduced kidney uptake (13.1 ± 1.5% ID/g). Thus, by manipulating the size and format of anti-p185HER2 antibody fragments, the kidney activity was reduced and high or low expression of p185HER2 in xenografts could be distinguished by microPET imaging.
Data from Mutation Accumulation in the Intestine and Colon of Mice Deficient in Two Intracellular Glutathione Peroxidases
Authors: Lee Dong-Hyun , Esworthy R. Steven , Chu Christy , Pfeifer Gerd P. , Chu Fong-Fong
Published: March 2023

Abstract
Mice deficient in two glutathione peroxidases (GPX), Gpx1 and Gpx2, [Gpx1/2-double knockout (DKO) mice] are prone to ileocolitis on a mixed C57BL/6 and 129S1/SvJ (B6.129) genetic background. We reported previously that ∼25% of B6.129 Gpx1/2-DKO mice develop ileocolonic tumors by 6 to 9 months of age, when their non-DKO littermates [having at least one wild-type (WT) Gpx1 or Gpx2 allele] rarely have inflammation and none have tumors. Because genetic background affects tumor susceptibility, we have generated a B6 Gpx1/2-DKO colony and discovered that these mice have fewer inflammatory cells, milder ileocolitis, and low mortality, and only 2.5% of B6 mice developed tumors. The mutant frequency of a cII reporter gene was about 2- to 3-fold higher in 28-day-old Gpx1/2-DKO and 4-fold higher in 8-month-old Gpx1/2-DKO ileal mucosa than in controls in both genetic backgrounds. In contrast, mutant frequencies in the unaffected B6 liver were not significantly different between WT and Gpx1/2-DKO mice. The mutant frequency of 8-month-old B6.129 Gpx1/2-DKO ileum was 38.94 ± 15.5−5, which was not significantly higher than the age-matched B6 ileum, 25.54 ± 10.33−5. The mutation spectra analysis has shown that B6 Gpx1/2-DKO ileum had a 3-fold increase in small nucleotide deletions at mononucleotide repeats over control B6, which are a signature mutation associated with oxidative stress. Unexpectedly, B6 Gpx1/2-DKO mice had fewer C to T transitions at CpG dinucleotides than the WT B6 (18.0% versus 40.1%; P < 0.001). Our results suggest that inflammation drives gene mutations, which leads to neoplastic transformation of intestinal epithelium in the B6.129 Gpx1/2-DKO mice but rarely in the B6 Gpx1/2-DKO mice. (Cancer Res 2006; 66(20): 9845-51)
Data from Combined Depletion of Cell Cycle and Transcriptional Cyclin-Dependent Kinase Activities Induces Apoptosis in Cancer Cells
Authors: Cai Dongpo , Latham Vaughan M. , Zhang Xinxin , Shapiro Geoffrey I.
Published: March 2023

Abstract
Selective cyclin-dependent kinase (cdk) 2 inhibition is readily compensated. However, reduced cdk2 activity may have antiproliferative effects in concert with other family members. Here, inducible RNA interference was used to codeplete cdk2 and cdk1 from NCI-H1299 non–small cell lung cancer and U2OS osteosarcoma cells, and effects were compared with those mediated by depletion of either cdk alone. Depletion of cdk2 slowed G1 progression of NCI-H1299 cells and depletion of cdk1 slowed G2-M progression in both cell lines, with associated endoreduplication in U2OS cells. However, compared with the incomplete cell cycle blocks produced by individual depletion, combined depletion had substantial consequences, with G2-M arrest predominating in NCI-H1299 cells and apoptosis the primary outcome in U2OS cells. In U2OS cells, combined depletion affected RNA polymerase II expression and phosphorylation, causing decreased expression of the antiapoptotic proteins Mcl-1 and X-linked inhibitor of apoptosis (XIAP), effects usually mediated by inhibition of the transcriptional cdk9. These events do not occur after individual depletion of cdk2 and cdk1, suggesting that reduction of cdk2, cdk1, and RNA polymerase II activities all contribute to apoptosis in U2OS cells. The limited cell death induced by combined depletion in NCI-H1299 cells was significantly increased by codepletion of cdk9 or XIAP or by simultaneous treatment with the cdk9 inhibitor flavopiridol. These results show the potency of concomitant compromise of cell cycle and transcriptional cdk activities and may guide the selection of clinical drug candidates. (Cancer Res 2006; 66(18): 9270-80)
Data from Evidence for the Direct Binding of Phosphorylated p53 to Sites of DNA Breaks In vivo
Authors: Al Rashid Shahnaz T. , Dellaire Graham , Cuddihy Andrew , Jalali Farid , Vaid Mita , Coackley Carla , Folkard Melvyn , Xu Yang , Chen Benjamin P.C. , Chen David J. , Lilge Lothar , Prise Kevin M. , Bazett Jones David P. , Bristow Robert G.
Published: March 2023

Abstract
Despite a clear link between ataxia-telangiectasia mutated (ATM)–dependent phosphorylation of p53 and cell cycle checkpoint control, the intracellular biology and subcellular localization of p53 phosphoforms during the initial sensing of DNA damage is poorly understood. Using G0-G1 confluent primary human diploid fibroblast cultures, we show that endogenous p53, phosphorylated at Ser15 (p53Ser15), accumulates as discrete, dose-dependent and chromatin-bound foci within 30 minutes following induction of DNA breaks or DNA base damage. This biologically distinct subpool of p53Ser15 is ATM dependent and resistant to 26S-proteasomal degradation. p53Ser15 colocalizes and coimmunoprecipitates with γ-H2AX with kinetics similar to that of biochemical DNA double-strand break (DNA-dsb) rejoining. Subnuclear microbeam irradiation studies confirm p53Ser15 is recruited to sites of DNA damage containing γ-H2AX, ATMSer1981, and DNA-PKcsThr2609 in vivo. Furthermore, studies using isogenic human and murine cells, which express Ser15 or Ser18 phosphomutant proteins, respectively, show defective nuclear foci formation, decreased induction of p21WAF, decreased γ-H2AX association, and altered DNA-dsb kinetics following DNA damage. Our results suggest a unique biology for this p53 phosphoform in the initial steps of DNA damage signaling and implicates ATM-p53 chromatin-based interactions as mediators of cell cycle checkpoint control and DNA repair to prevent carcinogenesis.
Data from Expression Microarray Analysis and Oligo Array Comparative Genomic Hybridization of Acquired Gemcitabine Resistance in Mouse Colon Reveals Selection for Chromosomal Aberrations
Authors: van de Wiel Mark A. , Costa Jose L. , Smid Kees , Oudejans Cees B.M. , Bergman Andries M. , Meijer Gerrit A. , Peters Godefridus J. , Ylstra Bauke
Published: March 2023

Abstract
Gemcitabine is a commonly used therapy for many solid tumors. Acquired resistance to this nucleoside analogue, however, diminishes the long-term effectiveness in a majority of patients. To better define the molecular background of gemcitabine resistance, a mouse colon tumor was selected during successive rounds of transplantation with continued treatment of gemcitabine. Expression microarray analysis was applied to determine which genes are consistently and highly overexpressed or underexpressed in the resistant versus the nonresistant tumor. For the statistical interpretation of the microarray data, a parametric model was implemented, which returns model-based differential gene expression (log-) ratios and their uncertainties. This defined a set of 13 genes, putatively responsible for the gemcitabine resistance in solid tumors. One of these, RRM1, was previously identified as an important marker for gemcitabine resistance in human cell lines. Five of the 13 genes, including RRM1, are located within a 3 Mb region at chromosome 7E1 of which four are highly overexpressed, suggesting a chromosomal amplification. Therefore, chromosomal copy number changes were measured, using oligo array comparative genomic hybridization. A narrow and high amplification area was identified on 7E1 that encompassed all five genes. In addition, reduced RNA expression of two other genes at 8E1 encoding COX4I1 and RPL13 could be explained by a decrease in chromosomal copy number on chromosome 8. In conclusion, the array comparative genomic hybridization biologically validates our statistical approach and shows that gemcitabine is capable to select for chromosomally aberrant tumor cells, where changed gene expression levels lead to drug resistance.
Data from A Profile of Methyl-CpG Binding Domain Protein Occupancy of Hypermethylated Promoter CpG Islands of Tumor Suppressor Genes in Human Cancer
Authors: Lopez-Serra Lidia , Ballestar Esteban , Fraga Mario F. , Alaminos Miguel , Setien Fernando , Esteller Manel
Published: March 2023

Abstract
Methyl-CpG binding domain (MBD) proteins have been shown to couple DNA methylation to transcriptional repression. This biological property suggests a role for MBD proteins in the silencing of tumor suppressor genes that are hypermethylated at their promoter CpG islands in cancer cells. Despite the demonstration of the presence of MBDs in the methylated promoter of several genes, we still ignore how general and specific is this association. Here, we investigate the profile of MBD occupancy in a large panel of tumor suppressor gene promoters and cancer cell lines. Our study shows that most hypermethylated promoters are occupied by MBD proteins, whereas unmethylated promoters are generally devoid of MBDs, with the exception of MBD1. Treatment of cancer cells with the demethylating agent 5-aza-2′-deoxycytidine results in CpG island hypomethylation, MBD release, and gene reexpression, reinforcing the notion that association of MBDs with methylated promoters is methylation-dependent. Whereas several promoters are highly specific in recruiting a particular set of MBDs, other promoters seem to be less exclusive. Our results indicate that MBDs have a great affinity in vivo for binding hypermethylated promoter CpG islands of tumor suppressor genes, with a specific profile of MBD occupancy that it is gene and tumor type specific. (Cancer Res 2006; 66(17): 8342-6)
Data from Smad3 Deficiency Promotes Tumorigenesis in the Distal Colon of ApcMin/+ Mice
Authors: Sodir Nicole M. , Chen Xuan , Park Ryan , Nickel Andrea E. , Conti Peter S. , Moats Rex , Bading James R. , Shibata Darryl , Laird Peter W.
Published: March 2023

Abstract
Colorectal cancer, one of the most common human malignancies in the Western world, is often subdivided based on tumor location in either the distal or proximal colon. Several mouse models have been developed to study human colorectal cancer, but few display this clear distinction between the two colonic locations. By crossing ApcMin/+ and Smad3 mutant mice, we showed that combined activation of the Wnt pathway and attenuation of the transforming growth factor-β (TGF-β) pathway causes high multiplicity and rapid onset of invasive tumorigenesis almost exclusively in the distal colon, closely mimicking the familial adenomatous polyposis (FAP) disease and consisting with distinct colorectal cancer etiologies based on tumor location. Transcriptional profiling revealed higher expression of several TGF-β activators in the normal distal mucosa than in proximal mucosa, suggesting a stronger reliance on TGF-β-mediated growth control in the distal than in the proximal colon. ApcMin/+Smad3−/− mice provide an alternative model to ApcMin/+ mice to study FAP and distal sporadic colorectal cancer. This model will be useful in dissecting mechanistic and etiologic differences between proximal and distal colonic cancer, whereas the confinement of tumorigenesis to the distal colon offers unique advantages in monitoring tumor progression by in vivo imaging. (Cancer Res 2006; 66(17): 8430-8)
Data from Sensitization for γ-Irradiation–Induced Apoptosis by Second Mitochondria-Derived Activator of Caspase
Authors: Giagkousiklidis Stavros , Vogler Meike , Westhoff Mike-Andrew , Kasperczyk Hubert , Debatin Klaus-Michael , Fulda Simone
Published: March 2023

Abstract
Resistance to current treatment regimens, such as radiation therapy, remains a major concern in oncology and may be caused by defects in apoptosis programs. Because inhibitor of apoptosis proteins (IAPs), which are expressed at high levels in many tumors, block apoptosis at the core of the apoptotic machinery by inhibiting caspases, therapeutic modulation of IAPs could target a key control point in resistance. Here, we report for the first time that full-length or mature second mitochondria-derived activator of caspase (Smac), an inhibitor of IAPs, significantly enhanced γ-irradiation–induced apoptosis and reduced clonogenic survival in neuroblastoma, glioblastoma, or pancreatic carcinoma cells. Notably, Smac had no effect on DNA damage/DNA repair, activation of nuclear factor-κB, up-regulation of p53 and p21 proteins, or cell cycle arrest following γ-irradiation, indicating that Smac did not alter the initial damage and/or cellular stress response. Smac enhanced activation of caspase-2, caspase-3, caspase-8, and caspase-9, loss of mitochondrial membrane potential, and cytochrome c release on γ-irradiation. Inhibition of caspases also blocked γ-irradiation–induced mitochondrial perturbations, indicating that Smac facilitated caspase activation, which in turn triggered a mitochondrial amplification loop. Interestingly, mitochondrial perturbations were completely blocked by the broad-range caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone or the relatively selective caspase-2 inhibitor N-benzyloxycarbonyl-Val-Asp-Val-Ala-Asp-fluoromethylketone, whereas caspase-8 or caspase-3 inhibitors only inhibited the increased drop of mitochondrial membrane potential provided by Smac, suggesting that caspase-2 was acting upstream of mitochondria after γ-irradiation. In conclusion, our findings provide evidence that targeting IAPs (e.g., by Smac agonists) is a promising strategy to enhance radiosensitivity in human cancers.
Data from Targeting Tumor Angiogenesis with Adenovirus-Delivered Anti-Tie-2 Intrabody
Authors: Popkov Mikhail , Jendreyko Nina , McGavern Dorian B. , Rader Christoph , Barbas Carlos F.
Published: March 2023

Abstract
Inhibition of tumor angiogenesis is a promising approach for cancer therapy. As an endothelial cell–specific receptor kinase expressed almost exclusively on the surface of vascular endothelium, Tie-2 has an important role in tumor angiogenesis. To explore the therapeutic potential of blocking Tie-2 receptor-interaction pathway, an adenoviral vector was used to deliver a recombinant single-chain antibody fragment rabbit intrabody (pAd-2S03) capable of inhibition of both mouse and human Tie-2 surface expression. pAd-2S03 was given to mice with well-established primary tumors, either a human Kaposi's sarcoma (SLK) or a human colon carcinoma (SW1222). The intrabody significantly inhibited growth of both tumors (75% and 63%, respectively) when compared with pAd-GFP control-treated tumors (P < 0.01). Histopathologic analysis of cryosections taken from mice treated with pAd-2S03 revealed a marked decrease in vessel density, which was reduced by >87% in both tumor models when compared with control-treated tumors (P < 0.01). In contrast, human Tie-2-monospecific pAd-1S05 intrabody did not affect the growth of tumors, indicating that the antitumor effect of pAd-2S03 was due to the inhibition of tumor angiogenesis in these murine models. Our results show that the Tie-2 receptor pathway is essential for both SLK sarcoma and SW1222 colon carcinoma xenograft growth. The present study shows the potential utility of antiangiogenic agents that target the endothelium-specific receptor Tie-2 for down-regulation or genetic deletion.
Data from Oligomannurarate Sulfate, a Novel Heparanase Inhibitor Simultaneously Targeting Basic Fibroblast Growth Factor, Combats Tumor Angiogenesis and Metastasis
Authors: Zhao Huajun , Liu Haiying , Chen Yi , Xin Xianliang , Li Jing , Hou Yongtai , Zhang Zhonghua , Zhang Xiongwen , Xie Chengying , Geng Meiyu , Ding Jian
Published: March 2023

Abstract
Inhibitors of tumor angiogenesis and metastasis are increasingly emerging as promising agents for cancer therapy. Recently, heparanase inhibitors have offered a new avenue for such work because heparanase is thought to be critically involved in the metastatic and angiogenic potentials of tumor cells. Here, we report that oligomannurarate sulfate (JG3), a novel marine-derived oligosaccharide, acts as a heparanase inhibitor. Our results revealed that JG3 significantly inhibited tumor angiogenesis and metastasis, both in vitro and in vivo, by combating heparanase activity via binding to the KKDC and QPLK domains of the heparanase molecule. The JG3-heparanase interaction was competitively inhibited by low molecular weight heparin (4,000 Da) but not by other glycosaminoglycans. In addition, JG3 abolished heparanase-driven invasion, inhibited the release of heparan sulfate–sequestered basic fibroblast growth factor (bFGF) from the extracellular matrix, and repressed subsequent angiogenesis. Moreover, JG3 inactivated bFGF-induced bFGF receptor and extracellular signal–regulated kinase 1/2 phosphorylation and blocked bFGF-triggered angiogenic events by directly binding to bFGF. Thus, JG3 seems to inhibit both major heparanase activities by simultaneously acting as a substrate mimetic and as a competitive inhibitor of heparan sulfate. These findings suggest that JG3 should be considered as a promising candidate agent for cancer therapy. (Cancer Res 2006; 66(17): 8779-87)
Data from Association of Antigen-Processing Machinery and HLA Antigen Phenotype of Melanoma Cells with Survival in American Joint Committee on Cancer Stage III and IV Melanoma Patients
Authors: Anichini Andrea , Mortarini Roberta , Nonaka Daisuke , Molla Alessandra , Vegetti Claudia , Montaldi Elisabetta , Wang Xinhui , Ferrone Soldano
Published: March 2023

Abstract
Because changes in the expression level of antigen-processing machinery (APM) components and HLA class I and II antigens in melanoma cells are expected to affect their interactions with the immune system of the host, we assessed the clinical relevance of quantitative variations in the expression of these molecules in melanoma lesions. Short-term (<10 in vitro passages) melanoma cell lines isolated from 85 American Joint Committee on Cancer (AJCC) stage III and IV patients were stained with APM component and HLA class I antigen-specific and HLA class II antigen-specific monoclonal antibodies and analyzed by flow cytometry. The phenotype of all tumors was characterized by intertumor and intratumor heterogeneity in the expression of all the markers and by significant correlations in the level of expression of markers belonging to the HLA class I antigen-processing and presentation pathway. Hierarchical clustering of the mean fluorescence intensity data defined two main clusters of tumors. The corresponding groups of patients differed significantly in the overall survival but not in other relevant clinical variables, including AJCC stage and therapy received after surgery. Cox regression analysis showed that β2-microglobulin and HLA class II antigen expression were significantly associated with patients' survival. This evidence was corroborated by the immunohistochemical analysis for HLA class II antigen expression of melanoma lesions from an unrelated group of 52 AJCC stage III and IV patients. These results suggest that quantitative variations in APM component and HLA expression in melanoma lesions from AJCC stage III and IV patients may have an effect on the clinical course of the disease. (Cancer Res 2006; 66(12): 6405-11)
Data from Endothelin-1 Promotes Epithelial-to-Mesenchymal Transition in Human Ovarian Cancer Cells
Authors: Rosanò Laura , Spinella Francesca , Di Castro Valeriana , Nicotra Maria Rita , Dedhar Shoukat , de Herreros Antonio Garcia , Natali Pier Giorgio , Bagnato Anna
Published: March 2023

Abstract
Despite considerable efforts to improve early detection and advances in chemotherapy, metastatic relapses remain a major challenge in the management of ovarian cancer. The endothelin A receptor (ETAR)/endothelin-1 (ET-1) axis has been shown to have a significant role in ovarian carcinoma by promoting tumorigenesis. Here we show that the ET-1/ETAR autocrine pathway drives epithelial-to-mesenchymal transition (EMT) in ovarian tumor cells by inducing a fibroblastoid and invasive phenotype, down-regulation of E-cadherin, increased levels of β-catenin, Snail, and other mesenchymal markers, and suppression of E-cadherin promoter activity. Activation of ETAR by ET-1 triggers an integrin-linked kinase (ILK)–mediated signaling pathway leading to glycogen synthase kinase-3β (GSK-3β) inhibition, Snail and β-catenin stabilization, and regulation of transcriptional programs that control EMT. Transfection of dominant negative ILK or exposure to an ILK inhibitor suppresses the ET-1-induced phosphorylation of GSK-3β as well as Snail and β-catenin protein stability, activity, and invasiveness, indicating that ET-1/ETAR–induced EMT-promoting effects depend on ILK. ETAR blockade by specific antagonists or reduction by ETAR RNA interference reverses EMT and cell invasion by inhibiting autocrine signaling pathways. In ovarian carcinoma xenografts, ABT-627, a specific ETAR antagonist, suppresses EMT determinants and tumor growth. In human ovarian cancers, ETAR expression is associated with E-cadherin down-regulation, N-cadherin expression, and tumor grade. Collectively, these findings provide evidence of a critical role for the ET-1/ETAR axis during distinct steps of ovarian carcinoma progression and identify novel targets of therapeutic intervention. (Cancer Res 2005; 65(24): 11649-57)
Data from Genetic Bases of Estrogen-Induced Tumorigenesis in the Rat: Mapping of Loci Controlling Susceptibility to Mammary Cancer in a Brown Norway × ACI Intercross
Authors: Schaffer Beverly S. , Lachel Cynthia M. , Pennington Karen L. , Murrin Clare R. , Strecker Tracy E. , Tochacek Martin , Gould Karen A. , Meza Jane L. , McComb Rodney D. , Shull James D.
Published: March 2023

Abstract
Exposure to estrogens is associated with an increased risk of breast cancer. Our laboratory has shown that the ACI rat is uniquely susceptible to 17β-estradiol (E2)–induced mammary cancer. We previously mapped two loci, Emca1 and Emca2 (estrogen-induced mammary cancer), that act independently to determine susceptibility to E2-induced mammary cancer in crosses between the susceptible ACI rat strain and the genetically related, but resistant, Copenhagen (COP) rat strain. In this study, we evaluate susceptibility to E2-induced mammary cancer in a cross between the ACI strain and the unrelated Brown Norway (BN) rat strain. Whereas nearly 100% of the ACI rats developed mammary cancer when treated continuously with E2, BN rats did not develop palpable mammary cancer during the 196-day course of E2 treatment. Susceptibility to E2-induced mammary cancer segregated as a dominant or incompletely dominant trait in a cross between BN females and ACI males. In a population of 251 female (BN × ACI)F2 rats, we observed evidence for a total of five genetic determinants of susceptibility. Two loci, Emca4 and Emca5, were identified when mammary cancer status at sacrifice was evaluated as the phenotype, and three additional loci, Emca6, Emca7, and Emca8, were identified when mammary cancer number was evaluated as the phenotype. A total of three genetic interactions were identified. These data indicate that susceptibility to E2-induced mammary cancer in the BN × ACI cross behaves as a complex trait controlled by at least five loci and multiple gene-gene interactions. (Cancer Res 2006; 66(15): 7793-800)
Data from Development of Magnetic Resonance Imaging Contrast Material for In vivo Mapping of Tissue Transglutaminase Activity
Authors: Mazooz Galit , Mehlman Tevie , Lai Thung-Shen , Greenberg Charles S. , Dewhirst Mark W. , Neeman Michal
Published: March 2023

Abstract
Transglutaminases are a family of enzymes that play an important role in tissue remodeling by catalyzing covalent cross-links between proteins of the extracellular matrix. Elevated activity of transglutaminase was shown at the boundaries of invading tumors, in association with angiogenesis, in stabilization of atherosclerotic plaques, and in generation of blood clots. The aim of this work was to develop a low molecular weight substrate of transglutaminase that could serve for noninvasive magnetic resonance and optical mapping of transglutaminase-mediated cross-linking activity. A 2 kDa contrast material was generated which showed cross-linking by either tissue transglutaminase or factor XIII in the context of multicellular tumor spheroids or fibrin clots, respectively. Successful detection by nuclear magnetic resonance microscopy of transglutaminase-mediated cross-linking of the contrast material to MCF7 multicellular spheroids provides hope that this approach could potentially be developed for clinical demarcation of sites of transglutaminase activity.
Data from Synergy of p53 and Rb Deficiency in a Conditional Mouse Model for Metastatic Prostate Cancer
Authors: Zhou Zongxiang , Flesken-Nikitin Andrea , Corney David C. , Wang Wei , Goodrich David W. , Roy-Burman Pradip , Nikitin Alexander Yu.
Published: March 2023

Abstract
Pathways mediated by p53 and Rb are frequently altered in aggressive human cancers, including prostate carcinoma. To test directly the roles of p53 and Rb in prostate carcinogenesis, we have conditionally inactivated these genes in the prostate epithelium of the mouse. Inactivation of either p53 or Rb leads to prostatic intraepithelial neoplasia developing from the luminal epithelium by 600 days of age. In contrast, inactivation of both genes results in rapidly developing (median survival, 226 days) carcinomas showing both luminal epithelial and neuroendocrine differentiation. The resulting neoplasms are highly metastatic, resistant to androgen depletion from the early stage of development, and marked with multiple gene expression signatures commonly found in human prostate carcinomas. Interestingly, gains at 4qC3 and 4qD2.2 and loss at 14qA2-qD2 have been consistently found by comparative genomic hybridization. These loci contain such human cancer–related genes as Nfib, L-myc, and Nkx3.1, respectively. Our studies show a critical role for p53 and Rb deficiency in prostate carcinogenesis and identify likely secondary genetic alterations. The new genetically defined model should be particularly valuable for providing new molecular insights into the pathogenesis of human prostate cancer. (Cancer Res 2006; 66(16): 7889-98)
Data from Therapeutic Implications of a Human Neutralizing Antibody to the Macrophage-Stimulating Protein Receptor Tyrosine Kinase (RON), a c-MET Family Member
Authors: O'Toole Jennifer M. , Rabenau Karen E. , Burns Kerri , Lu Dan , Mangalampalli Venkat , Balderes Paul , Covino Nicole , Bassi Rajiv , Prewett Marie , Gottfredsen Kimberly J. , Thobe Megan N. , Cheng Yuan , Li Yiwen , Hicklin Daniel J. , Zhu Zhenping , Waltz Susan E. , Hayman Michael J. , Ludwig Dale L. , Pereira Daniel S.
Published: March 2023

Abstract
RON is a member of the c-MET receptor tyrosine kinase family. Like c-MET, RON is expressed by a variety of epithelial-derived tumors and cancer cell lines and it is thought to play a functional role in tumorigenesis. To date, antagonists of RON activity have not been tested in vivo to validate RON as a potential cancer target. In this report, we used an antibody phage display library to generate IMC-41A10, a human immunoglobulin G1 (IgG1) antibody that binds with high affinity (ED50 = 0.15 nmol/L) to RON and effectively blocks interaction with its ligand, macrophage-stimulating protein (MSP; IC50 = 2 nmol/L). We found IMC-41A10 to be a potent inhibitor of receptor and downstream signaling, cell migration, and tumorigenesis. It antagonized MSP-induced phosphorylation of RON, mitogen-activated protein kinase (MAPK), and AKT in several cancer cell lines. In HT-29 colon, NCI-H292 lung, and BXPC-3 pancreatic cancer xenograft tumor models, IMC-41A10 inhibited tumor growth by 50% to 60% as a single agent, and in BXPC-3 xenografts, it led to tumor regressions when combined with Erbitux. Western blot analyses of HT-29 and NCI-H292 xenograft tumors treated with IMC-41A10 revealed a decrease in MAPK phosphorylation compared with control IgG–treated tumors, suggesting that inhibition of MAPK activity may be required for the antitumor activity of IMC-41A10. To our knowledge, this is the first demonstration that a RON antagonist and specifically an inhibitory antibody of RON negatively affects tumorigenesis. Another major contribution of this report is an extensive analysis of RON expression in ∼100 cancer cell lines and ∼300 patient tumor samples representing 10 major cancer types. Taken together, our results highlight the potential therapeutic usefulness of RON activity inhibition in human cancers. (Cancer Res 2006; 66(18): 9162-70)
Data from BLM Helicase Facilitates Mus81 Endonuclease Activity in Human Cells
Authors: Zhang Ran , Sengupta Sagar , Yang Qin , Linke Steven P. , Yanaihara Nozomu , Bradsher John , Blais Veronique , McGowan Clare H. , Harris Curtis C.
Published: March 2023

Abstract
Bloom syndrome is a rare, autosomal recessive inherited disorder in humans. The product of the Bloom syndrome mutated gene, designated BLM, is a member of the RecQ helicase family. BLM has been proposed to function at the interface of replication and recombination, and to facilitate the repair of DNA damage. Here, we report in vivo physical interaction and colocalization of BLM and a DNA structure–specific endonuclease, Mus81, at sites of stalled replication forks outside the promyelocytic leukemia nuclear bodies during the S-phase arrest of the cell cycle. Amino acids 125 to 244 of Mus81 interact with the C-terminal region (amino acids 1,007-1,417) of BLM. Whereas Mus81 does not have any effect on the helicase activity of BLM, BLM can stimulate Mus81 endonuclease activity on the nicked Holliday junctions and 3′ flap. This stimulation is due to enhanced binding of Mus81 to the DNA substrates. These data suggest a new function of BLM in cooperating with Mus81 during processing and restoration of stalled replication forks.
Data from Prognostic Significance of Nuclear Factor-κB p105/p50 in Human Melanoma and Its Role in Cell Migration
Authors: Gao Kai , Dai Derek L. , Martinka Magdalena , Li Gang
Published: March 2023

Abstract
Transcriptional factor nuclear factor-κB (NF-κB) family has been shown to play an important role in tumor pathogenesis and serve as a potential target in cancer therapy. However, it is necessary to clarify the specific functions of NF-κB members, which would provide the basis for the selective blockade and reduction of therapeutic side effects resulting from unspecific inhibition of NF-κB members. In this study, we explored the role of NF-κB p105/p50 in melanoma pathogenesis in vitro and in vivo. We found that the expression of NF-κB p105/p50 significantly increased in dysplastic nevi, primary melanoma, and metastatic melanoma compared with normal nevi (P = 0.0004, χ2 test). Furthermore, NF-κB p105/p50 nuclear staining increased with melanoma progression and strong NF-κB p105/p50 nuclear staining was inversely correlated with disease-specific 5-year survival of patients with tumor thickness >2.0 mm (P = 0.014, log-rank test). Multivariate Cox regression analysis revealed that nuclear expression of NF-κB p105/p50 is an independent prognostic factor in this subgroup. Moreover, we found that up-regulation of NF-κB p50 enhanced melanoma cell migration, whereas small interfering RNA knockdown inhibited cell migration. In addition, overexpression of NF-κB p50 induced RhoA activity and Rock-mediated formation of stress fiber in melanoma cells. Taken together, our data indicate that NF-κB p105/p50 may be an important marker for human melanoma progression and prognosis as well as a potentially selective therapeutic target. (Cancer Res 2006; 66(17): 8382-8)