bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from Computationally Guided Photothermal Tumor Therapy Using Long-Circulating Gold Nanorod Antennas
Authors: von Maltzahn Geoffrey , Park Ji-Ho , Agrawal Amit , Bandaru Nanda Kishor , Das Sarit K. , Sailor Michael J. , Bhatia Sangeeta N.
Published: March 2024

Abstract
Plasmonic nanomaterials have the opportunity to considerably improve the specificity of cancer ablation by i.v. homing to tumors and acting as antennas for accepting externally applied energy. Here, we describe an integrated approach to improved plasmonic therapy composed of multimodal nanomaterial optimization and computational irradiation protocol development. We synthesized polyethylene glycol (PEG)–protected gold nanorods (NR) that exhibit superior spectral bandwidth, photothermal heat generation per gram of gold, and circulation half-life in vivo (t1/2, ∼17 hours) compared with the prototypical tunable plasmonic particles, gold nanoshells, as well as ∼2-fold higher X-ray absorption than a clinical iodine contrast agent. After intratumoral or i.v. administration, we fuse PEG-NR biodistribution data derived via noninvasive X-ray computed tomography or ex vivo spectrometry, respectively, with four-dimensional computational heat transport modeling to predict photothermal heating during irradiation. In computationally driven pilot therapeutic studies, we show that a single i.v. injection of PEG-NRs enabled destruction of all irradiated human xenograft tumors in mice. These studies highlight the potential of integrating computational therapy design with nanotherapeutic development for ultraselective tumor ablation. [Cancer Res 2009;69(9):3892–900]
Data from MET Kinase Inhibitor SGX523 Synergizes with Epidermal Growth Factor Receptor Inhibitor Erlotinib in a Hepatocyte Growth Factor–Dependent Fashion to Suppress Carcinoma Growth
Authors: Zhang Yu-Wen , Staal Ben , Essenburg Curt , Su Yanli , Kang Liang , West Rich , Kaufman Dafna , DeKoning Tom , Eagleson Bryn , Buchanan Sean G. , Vande Woude George F.
Published: March 2024

Abstract
The hepatocyte growth factor (HGF)-MET pathway supports several hallmark cancer traits, and it is frequently activated in a broad spectrum of human cancers (http://www.vai.org/met/). With the development of many cancer drugs targeting this pathway, there is a need for relevant in vivo model systems for preclinical evaluation of drug efficacy. Here, we show that production of the human HGF ligand in transgenic severe combined immunodeficient mice (hHGFtg-SCID mice) enhances the growth of many MET-expressing human carcinoma xenografts, including those derived from lung, breast, kidney, colon, stomach, and pancreas. In this model, the MET-specific small-molecule kinase inhibitor SGX523 partially inhibits the HGF-dependent growth of lung, breast, and pancreatic tumors. However, much greater growth suppression is achieved by combinatorial inhibition with the epidermal growth factor receptor (EGFR) kinase inhibitor erlotinib. Together, these results validate the hHGFtg-SCID mouse model for in vivo determination of MET sensitivity to drug inhibition. Our findings also indicate that simultaneously targeting the MET and EGFR pathways can provide synergistic inhibitory effects for the treatment of cancers in which both pathways are activated. Cancer Res; 70(17); 6880–90. ©2010 AACR.
Data from Intrinsic Gene Expression Profiles of Gliomas Are a Better Predictor of Survival than Histology
Authors: Gravendeel Lonneke A.M. , Kouwenhoven Mathilde C.M. , Gevaert Olivier , de Rooi Johan J. , Stubbs Andrew P. , Duijm J. Elza , Daemen Anneleen , Bleeker Fonnet E. , Bralten Linda B.C. , Kloosterhof Nanne K. , De Moor Bart , Eilers Paul H.C. , van der Spek Peter J. , Kros Johan M. , Sillevis Smitt Peter A.E. , van den Bent Martin J. , French Pim J.
Published: March 2024

Abstract
Gliomas are the most common primary brain tumors with heterogeneous morphology and variable prognosis. Treatment decisions in patients rely mainly on histologic classification and clinical parameters. However, differences between histologic subclasses and grades are subtle, and classifying gliomas is subject to a large interobserver variability. To improve current classification standards, we have performed gene expression profiling on a large cohort of glioma samples of all histologic subtypes and grades. We identified seven distinct molecular subgroups that correlate with survival. These include two favorable prognostic subgroups (median survival, >4.7 years), two with intermediate prognosis (median survival, 1–4 years), two with poor prognosis (median survival, <1 year), and one control group. The intrinsic molecular subtypes of glioma are different from histologic subgroups and correlate better to patient survival. The prognostic value of molecular subgroups was validated on five independent sample cohorts (The Cancer Genome Atlas, Repository for Molecular Brain Neoplasia Data, GSE12907, GSE4271, and Li and colleagues). The power of intrinsic subtyping is shown by its ability to identify a subset of prognostically favorable tumors within an external data set that contains only histologically confirmed glioblastomas (GBM). Specific genetic changes (epidermal growth factor receptor amplification, IDH1 mutation, and 1p/19q loss of heterozygosity) segregate in distinct molecular subgroups. We identified a subgroup with molecular features associated with secondary GBM, suggesting that different genetic changes drive gene expression profiles. Finally, we assessed response to treatment in molecular subgroups. Our data provide compelling evidence that expression profiling is a more accurate and objective method to classify gliomas than histologic classification. Molecular classification therefore may aid diagnosis and can guide clinical decision making. [Cancer Res 2009;69(23):9065–72]
Data from CUB Domain–Containing Protein 1, a Prognostic Factor for Human Pancreatic Cancers, Promotes Cell Migration and Extracellular Matrix Degradation
Authors: Miyazawa Yuri , Uekita Takamasa , Hiraoka Nobuyoshi , Fujii Satoko , Kosuge Tomoo , Kanai Yae , Nojima Yoshihisa , Sakai Ryuichi
Published: March 2024

Abstract
CUB domain–containing protein 1 (CDCP1) is a membrane protein that is highly expressed in several solid cancers. We reported previously that CDCP1 regulates anoikis resistance as well as cancer cell migration and invasion, although the underlying mechanisms have not been elucidated. In this study, we found that expression of CDCP1 in pancreatic cancer tissue was significantly correlated with overall survival and that CDCP1 expression in pancreatic cancer cell lines was relatively high among solid tumor cell lines. Reduction of CDCP1 expression in these cells suppressed extracellular matrix (ECM) degradation by inhibiting matrix metalloproteinase-9 secretion. Using the Y734F mutant of CDCP1, which lacks the tyrosine phosphorylation site, we showed that CDCP1 regulates cell migration, invasion, and ECM degradation in a tyrosine phosphorylation–dependent manner and that these CDCP1-associated characteristics were inhibited by blocking the association of CDCP1 and protein kinase Cδ (PKCδ). CDCP1 modulates the enzymatic activity of PKCδ through the tyrosine phosphorylation of PKCδ by recruiting PKCδ to Src family kinases. Cortactin, which was detected as a CDCP1-dependent binding partner of PKCδ, played a significant role in migration and invasion but not in ECM degradation of pancreatic cells. These results suggest that CDCP1 expression might play a crucial role in poor outcome of pancreatic cancer through promotion of invasion and metastasis and that molecules blocking the expression, phosphorylation, or the PKCδ-binding site of CDCP1 are potential therapeutic candidates. Cancer Res; 70(12); 5136–46. ©2010 AACR.
Data from Altered Dynamics of Intestinal Cell Maturation in Apc1638N/+ Mice
Authors: Wang Donghai , Pezo Rossanna C. , Corner Georgia , Sison Cristina , Lesser Martin L. , Shenoy Shailesh M. , Mariadason John M. , Singer Robert H. , Augenlicht Leonard H.
Published: March 2024

Abstract
Novel imaging of active transcription sites in interphase nuclei of intestinal epithelial cells in situ showed that key genes associated with Wnt and Notch signaling were dynamically regulated as the cells underwent normal maturation during their migration along the mouse crypt-villus axis (CVA). However, oscillating patterns of activation of these genes were displaced along this axis in the histologically normal intestinal mucosa of Apc1638N/+ mice before tumor development. Gene expression profiling then showed that the normal reprogramming of cells along the CVA was dampened in the Apc1638N/+ mice, with an overrepresentation of c-myc target genes among those loci affected in the mutant mice. Moreover, in the Apc1638N/+ mice, there was a perturbed pattern of expression of lineage-specific markers along the CVA consistent with transcription site repression of the Math1 gene, and genes encoding enzymes of every step of the tricarboxylic acid cycle were downregulated in the crypt of Apc1638N/+ mice compared with WT, but not in the villus. These changes may alter energy metabolism and generate a pseudohypoxic state, suggested by elevated expression of Hif1α and its target genes. Thus, although intestinal tumors develop in Apc1638N/+ mice on focal loss or inactivation of the WT allele, our results show that in the Apc1638N/+ mouse, inheritance of only a single WT Apc allele perturbs the dynamic and complex reprogramming underlying normal cell maturation, which links epithelial function and homeostasis with architectural organization of the intestine. Cancer Res; 70(13); 5348–57. ©2010 AACR.
Data from Glioblastoma-Specific Protein Interaction Network Identifies PP1A and CSK21 as Connecting Molecules between Cell Cycle–Associated Genes
Authors: Ladha Jayashree , Donakonda Sainitin , Agrawal Shipra , Thota Balaram , Srividya Mallavarapu R. , Sridevi Sambandam , Arivazhagan Arimappamagan , Thennarasu Kandavel , Balasubramaniam Anandh , Chandramouli Bangalore A. , Hegde Alangar Sattiyaranjandas , Kondaiah Paturu , Somasundaram Kumaravel , Santosh Vani , Rao Satyanarayana M.R.
Published: March 2024

Abstract
Glioblastoma (GBM; grade IV astrocytoma) is a very aggressive form of brain cancer with a poor survival and few qualified predictive markers. This study integrates experimentally validated genes that showed specific upregulation in GBM along with their protein-protein interaction information. A system level analysis was used to construct GBM-specific network. Computation of topological parameters of networks showed scale-free pattern and hierarchical organization. From the large network involving 1,447 proteins, we synthesized subnetworks and annotated them with highly enriched biological processes. A careful dissection of the functional modules, important nodes, and their connections identified two novel intermediary molecules CSK21 and protein phosphatase 1 α (PP1A) connecting the two subnetworks CDC2-PTEN-TOP2A-CAV1-P53 and CDC2-CAV1-RB-P53-PTEN, respectively. Real-time quantitative reverse transcription-PCR analysis revealed CSK21 to be moderately upregulated and PP1A to be overexpressed by 20-fold in GBM tumor samples. Immunohistochemical staining revealed nuclear expression of PP1A only in GBM samples. Thus, CSK21 and PP1A, whose functions are intimately associated with cell cycle regulation, might play key role in gliomagenesis. Cancer Res; 70(16); 6437–47. ©2010 AACR.
Data from Distinct Genomic Alterations in Prostate Cancers in Chinese and Western Populations Suggest Alternative Pathways of Prostate Carcinogenesis
Authors: Mao Xueying , Yu Yongwei , Boyd Lara K. , Ren Guoping , Lin Dongmei , Chaplin Tracy , Kudahetti Sakunthala C. , Stankiewicz Elzbieta , Xue Liyan , Beltran Luis , Gupta Manu , Oliver R. Tim D. , Lemoine Nick R. , Berney Daniel M. , Young Bryan D. , Lu Yong-Jie
Published: March 2024

Abstract
Prostate cancer is significantly more common in Western men than in Asian men, but the basis for this difference remains unknown. Because genomic studies of Asian prostate cancer are very limited, we used a genome-wide approach to reveal the genomic alterations in Chinese prostate cancers. We found a significant reduction in the frequency of certain somatic genomic changes that are commonly found in Western prostate cancers, including the 21q22.2-22.3 deletion, which involves the TMPRSS2:ERG fusion gene, and 10q deletion, which causes PTEN inactivation. Array results were confirmed by PCR-based molecular copy-number counting in selected samples. The different frequencies of these genomic changes were further evaluated by fluorescent in situ hybridization and immunohistochemistry analyses of tissue microarray samples. These alterations might be key genetic changes underlying the regional/ethnic difference in clinical incidence and might be induced by specific environmental and/or genetic risk factors that Western men are exposed to. Our findings suggest that tumors arise in Western and Chinese populations by alternative pathogenetic mechanisms. Cancer Res; 70(13); 5207–12. ©2010 AACR.
Data from C-Propeptides of Procollagens Iα1 and II that Differentially Accumulate in Enchondromas versus Chondrosarcomas Regulate Tumor Cell Survival and Migration
Authors: Vincourt Jean-Baptiste , Etienne Stéphanie , Cottet Justine , Delaunay Camille , Malanda Bantsimba , Lionneton Frédéric , Sirveaux François , Netter Patrick , Plénat François , Mainard Didier , Vignaud Jean-Michel , Magdalou Jacques
Published: March 2024

Abstract
Chondrogenic tumors that exhibit benign or malignant behaviors synthesize variable amounts of cartilage-like extracellular matrix. To define the regulators of these phenotypes, we performed a proteomic comparison of multiple human chondrogenic tumors, which revealed differential accumulation of the C-propeptides of procollagens Iα1 and II (PC1CP and PC2CP) in malignant versus benign tumors, respectively. Expression patterns of PC1CP correlated with levels of tumor vascularization, whereas expression patterns of PC2CP suggested its susceptibility to immobilization within the extracellular matrix. Prompted by these observations, we investigated the functions of recombinant PC1CP and PC2CP in the extracellular matrix in soluble or immobilized states. Each induced β1 integrin–mediated chondrocyte adhesion by distinct domains and efficacies, suggesting that they initiated distinct signaling pathways. Indeed, immobilized PC2CP, but not PC1CP, induced apoptosis of primary chondrocytes and EAhy926 endothelial cells. In contrast, soluble PC1CP, but not PC2CP, induced the migration of EAhy926 cells and increased vascular endothelial growth factor (VEGF) and CXCR4 expression in chondrocytes. Soluble PC2CP also increased VEGF expression, but along with a more pronounced effect on CXCR4 and matrix metalloproteinase 13 expression. Our findings suggest that PC1CP favors angiogenesis and tumor progression, but that PC2CP acts in a more complex manner, exerting antitumor and antiangiogenic properties through apoptosis induction when immobilized, but progression and metastasis when soluble. In summary, the relative levels of PC1CP and PC2CP and their interactions within the extracellular matrix contribute to tumor progression, angiogenesis, and metastasis in chondrogenic tumors. Cancer Res; 70(11); 4739–48. ©2010 AACR.
Data from Regulation of Vascular Endothelial Growth Factor Receptors by Rb and E2F1: Role of Acetylation
Authors: Pillai Smitha , Kovacs Michelle , Chellappan Srikumar
Published: March 2024

Abstract
E2F transcription factors regulate a variety of cellular processes, but their role in angiogenesis is not clear. We find that many genes involved in angiogenesis such as FLT-1, KDR, and angiopoietin 2 have potential E2F1 binding sites in their promoter. Chromatin immunoprecipitation (ChIP) assays showed that E2F1 can associate with these promoters and the recruitment of E2F1 was enhanced upon vascular endothelial growth factor (VEGF) stimulation with concomitant dissociation of Rb, leading to the transcriptional activation of these promoters. Transient transfection experiments showed that these promoters were induced by E2F1 and repressed by Rb, whereas depletion of E2F1 decreased their expression. The increased binding of E2F1 to these promoters upon VEGF stimulation correlated with the acetylation of histones and E2F1; this required VEGF receptor function, as seen in ChIP-re-ChIP experiments. This suggests the existence of a positive feedback loop regulating E2F1 acetylation and VEGF receptor expression. Acetylation associated with VEGF signaling seems to be predominantly mediated by P300/CBP-associated factor, and the depletion of histone acetyl transferases disrupted the formation of angiogenic tubules. These results suggest a novel role for E2F1 and acetylation in the angiogenic process. Cancer Res; 70(12); 4931–40. ©2010 AACR.
Data from Identification of Susceptibility Loci in a Mouse Model of KRASG12D-Driven Pancreatic Cancer
Authors: Jorgenson Tonia C. , Williams Bret R. , Wendland Allyson , Bilger Andrea , Sandgren Eric P. , Drinkwater Norman R.
Published: March 2024

Abstract
Genetic background affects susceptibility to pancreatic ductal adenocarcinoma in the Ela-KRASG12D mouse model. In this model, KRAS oncogene expression is driven by an elastase promoter in acinar cells of the pancreas on an FVB/NTac (FVB) background [FVB-Tg(Ela-KRASG12D)] with the transgene carried on the Y chromosome. Through linkage analysis of crosses between the C57BL/6J (B6), BALB/cJ (BALB), and DBA/2J (D2) inbred strains of mice and resistant FVB-Tg(Ela-KRASG12D), we have identified six susceptibility loci that affect mean preinvasive lesion multiplicity. Markers on chromosome 2 segregated with high tumor multiplicity in all three strains; these loci were designated Prsq1-3 (pancreatic ras susceptibility quantitative trait loci 1-3; combined F2 and N2 LODW, 6.0, 4.1, and 2.7, respectively). Susceptibility loci on chromosome 4, designated Prsq4 and Prsq5, were identified in crosses between FVB transgenic mice and B6 or BALB mice (combined F2 and N2 LODW, 3.6 and 2.9, respectively). A marker on chromosome 12 segregated with tumor multiplicity in a BALB × FVB-Tg(Ela-KRASG12D) cross and was designated Prsq6 (LODW, ∼2.5). B6-Chr YFVB-Tg(Ela-KRASG12D) and BALB-Chr YFVB-Tg(Ela-KRASG12D) consomics, which carry the KRAS transgene on the FVB Y chromosome on an otherwise inbred B6 or BALB background, developed ∼4-fold (B6) and ∼10-fold (BALB) more lesions than FVB-Tg(Ela-KRASG12D) mice. By 12 months of age, 10% of BALB-Chr YFVB-Tg(Ela-KRASG12D) mice developed invasive carcinomas. Our findings provide evidence that regions of chromosomes 2, 4, and 12 influence the development and progression of pancreatic neoplasms initiated by an oncogenic allele of KRAS in mice. Cancer Res; 70(21); 8398–406. ©2010 AACR.
Data from MicroRNA Mediates DNA Demethylation Events Triggered by Retinoic Acid during Neuroblastoma Cell Differentiation
Authors: Das Sudipto , Foley Niamh , Bryan Kenneth , Watters Karen M. , Bray Isabella , Murphy Derek M. , Buckley Patrick G. , Stallings Raymond L.
Published: March 2024

Abstract
Neuroblastoma is an often fatal pediatric cancer arising from precursor cells of the sympathetic nervous system. 13-Cis retinoic acid is included in the treatment regimen for patients with high-risk disease, and a similar derivative, all-trans-retinoic acid (ATRA), causes neuroblastoma cell lines to undergo differentiation. The molecular signaling pathways involved with ATRA-induced differentiation are complex, and the role that DNA methylation changes might play are unknown. The purpose of this study was to evaluate the genome-wide effects of ATRA on DNA methylation using methylated DNA immunoprecipitation applied to microarrays representing all known promoter and CpG islands. Four hundred and two gene promoters became demethylated, whereas 88 were hypermethylated post-ATRA. mRNA expression microarrays revealed that 82 of the demethylated genes were overexpressed by >2-fold, whereas 13 of the hypermethylated genes were underexpressed. Gene ontology analysis indicated that demethylated and re-expressed genes were enriched for signal transduction pathways, including NOS1, which is required for neural cell differentiation. As a potential mechanism for the DNA methylation changes, we show the downregulation of methyltransferases, DNMT1 and DNMT3B, along with the upregulation of endogenous microRNAs targeting them. Ectopic overexpression of miR-152, targeting DNMT1, also negatively affected cell invasiveness and anchorage-independent growth, contributing in part to the differentiated phenotype. We conclude that functionally important, miRNA-mediated DNA demethylation changes contribute to the process of ATRA-induced differentiation resulting in the activation of NOS1, a critical determinant of neural cell differentiation. Our findings illustrate the plasticity and dynamic nature of the epigenome during cancer cell differentiation. Cancer Res; 70(20); 7874–81. ©2010 AACR.
Data from Voluntary Running Prevents Progressive Memory Decline and Increases Adult Hippocampal Neurogenesis and Growth Factor Expression after Whole-Brain Irradiation
Authors: Wong-Goodrich Sarah J.E. , Pfau Madeline L. , Flores Catherine T. , Fraser Jennifer A. , Williams Christina L. , Jones Lee W.
Published: March 2024

Abstract
Whole-brain irradiation (WBI) therapy produces progressive learning and memory deficits in patients with primary or secondary brain tumors. Exercise enhances memory and adult hippocampal neurogenesis in the intact brain, so we hypothesized that exercise may be an effective treatment to alleviate consequences of WBI. Previous studies using animal models to address this issue have yielded mixed results and have not examined potential molecular mechanisms. We investigated the short- and long-term effects of WBI on spatial learning and memory retention and determined whether voluntary running after WBI aids recovery of brain and cognitive function. Forty adult female C57Bl/6 mice given a single dose of 5 Gy or sham WBI were trained 2.5 weeks and up to 4 months after WBI in a Barnes maze. Half of the mice received daily voluntary wheel access starting 1 month after sham or WBI. Daily running following WBI prevented the marked decline in spatial memory retention observed months after irradiation. Bromodeoxyuridine (BrdUrd) immunolabeling and enzyme-linked immunosorbent assay indicated that this behavioral rescue was accompanied by a partial restoration of newborn BrdUrd+/NeuN+ neurons in the dentate gyrus and increased hippocampal expression of brain-derived vascular endothelial growth factor and insulin-like growth factor-1, and occurred despite irradiation-induced elevations in hippocampal proinflammatory cytokines. WBI in adult mice produced a progressive memory decline consistent with what has been reported in cancer patients receiving WBI therapy. Our findings show that running can abrogate this memory decline and aid recovery of adult hippocampal plasticity, thus highlighting exercise as a potential therapeutic intervention. Cancer Res; 70(22); 9329–38. ©2010 AACR.
Data from H3K9 Histone Methyltransferase G9a Promotes Lung Cancer Invasion and Metastasis by Silencing the Cell Adhesion Molecule Ep-CAM
Authors: Chen Min-Wei , Hua Kuo-Tai , Kao Hsin-Jung , Chi Chia-Chun , Wei Lin-Hung , Johansson Gunnar , Shiah Shine-Gwo , Chen Pai-Sheng , Jeng Yung-Ming , Cheng Tsu-Yao , Lai Tsung-Ching , Chang Jeng-Shou , Jan Yi-Hua , Chien Ming-Hsien , Yang Chih-Jen , Huang Ming-Shyan , Hsiao Michael , Kuo Min-Liang
Published: March 2024

Abstract
G9a is a mammalian histone methyltransferase that contributes to the epigenetic silencing of tumor suppressor genes. Emerging evidence suggests that G9a is required to maintain the malignant phenotype, but the role of G9a function in mediating tumor metastasis has not been explored. Here, we show that G9a is expressed in aggressive lung cancer cells, and its elevated expression correlates with poor prognosis. RNAi-mediated knockdown of G9a in highly invasive lung cancer cells inhibited cell migration and invasion in vitro and metastasis in vivo. Conversely, ectopic G9a expression in weakly invasive lung cancer cells increased motility and metastasis. Mechanistic investigations suggested that repression of the cell adhesion molecule Ep-CAM mediated the effects of G9a. First, RNAi-mediated knockdown of Ep-CAM partially relieved metastasis suppression imposed by G9a suppression. Second, an inverse correlation between G9a and Ep-CAM expression existed in primary lung cancer. Third, Ep-CAM repression was associated with promoter methylation and an enrichment for dimethylated histone H3K9. G9a knockdown reduced the levels of H3K9 dimethylation and decreased the recruitment of the transcriptional cofactors HP1, DNMT1, and HDAC1 to the Ep-CAM promoter. Our findings establish a functional contribution of G9a overexpression with concomitant dysregulation of epigenetic pathways in lung cancer progression. Cancer Res; 70(20); 7830–40. ©2010 AACR.
Data from Multivalent DR5 Peptides Activate the TRAIL Death Pathway and Exert Tumoricidal Activity
Authors: Pavet Valeria , Beyrath Julien , Pardin Christophe , Morizot Alexandre , Lechner Marie-Charlotte , Briand Jean-Paul , Wendland Miriam , Maison Wolfgang , Fournel Sylvie , Micheau Olivier , Guichard Gilles , Gronemeyer Hinrich
Published: March 2024

Abstract
Ongoing clinical trials are exploring anticancer approaches based on signaling by TRAIL, a ligand for the cell death receptors DR4 and DR5. In this study, we report on the selective apoptotic effects of multivalent DR5 binding peptides (TRAILmim/DR5) on cancer cells in vitro and in vivo. Surface plasmon resonance revealed up to several thousand-fold increased affinities of TRAILmim/DR5-receptor complexes on generation of divalent and trivalent molecules, the latter of which was achieved with a conformationally restricted adamantane core. Notably, only multivalent molecules triggered a substantial DR5-dependent apoptotic response in vitro. In tumor models derived from human embryonic kidney cells or primary foreskin fibroblasts, TRAILmim/DR5 peptides exerted a cancer cell–selective action that could synergize with resveratrol in a manner independent of p53. In a xenograft model of human colon cancer, a divalent TRAILmim/DR5 peptide inhibited tumor growth. Our results offer a proof-of-principle for the development of synthetic small molecules to trigger the TRAIL apoptosis pathway for cancer therapy. Cancer Res; 70(3); 1101–10
Data from Cancer Exosomes Trigger Fibroblast to Myofibroblast Differentiation
Authors: Webber Jason , Steadman Robert , Mason Malcolm D. , Tabi Zsuzsanna , Clayton Aled
Published: March 2024

Abstract
There is a growing interest in the cell–cell communication roles in cancer mediated by secreted vesicles termed exosomes. In this study, we examined whether exosomes produced by cancer cells could transmit information to normal stromal fibroblasts and trigger a cellular response. We found that some cancer-derived exosomes could trigger elevated α-smooth muscle actin expression and other changes consistent with the process of fibroblast differentiation into myofibroblasts. We show that TGF-β is expressed at the exosome surface in association with the transmembrane proteoglycan betaglycan. Although existing in a latent state, this complex was fully functional in eliciting SMAD-dependent signaling. Inhibiting either signaling or betaglycan expression attenuated differentiation. While the kinetics and overall magnitude of the response were similar to that achieved with soluble TGF-β, we identified important qualitative differences unique to the exosomal route of TGF-β delivery, as exemplified by a significant elevation in fibroblast FGF2 production. This hitherto unknown trigger for instigating cellular differentiation in a distinctive manner has major implications for mechanisms underlying cancer-recruited stroma, fibrotic diseases, and wound-healing responses. Cancer Res; 70(23); 9621–30. ©2010 AACR.
Data from Activation of Murine Double Minute 2 by Akt in Mammary Epithelium Delays Mammary Involution and Accelerates Mammary Tumorigenesis
Authors: Cheng Xiaoyun , Xia Weiya , Yang Jer-Yen , Hsu Jennifer L. , Lang Jing-Yu , Chou Chao-Kai , Du Yi , Sun Hui-Lung , Wyszomierski Shannon L. , Mills Gordon B. , Muller William J. , Yu Dihua , Hung Mien-Chie
Published: March 2024

Abstract
Amplification or overexpression of murine double minute 2 (MDM2) promotes a variety of human tumors by degrading tumor suppressor proteins such as p53. Phosphorylation of MDM2 on Ser166 and Ser186 by the survival kinase Akt inhibits p53-mediated apoptosis. However, it is unclear whether this pathway contributes to normal or malignant pathophysiology in vivo. To address these questions, we generated transgenic mice expressing the Akt-phosphorylated form of MDM2 (MDM2DDS166D/S186D) in the mammary epithelium. Activation of MDM2 delayed mammary gland involution and accelerated tumor progression in mouse mammary tumor virus/neu transgenic mice by inhibiting apoptosis in a manner associated with decreased p53 expression. Our findings offer in vivo evidence that activation of MDM2 by Akt contributes to mammary development and tumorigenesis. Cancer Res; 70(19); 7684–9. ©2010 AACR.
Data from Inhibition of Autophagy Enhances Anticancer Effects of Atorvastatin in Digestive Malignancies
Authors: Yang Pei-Ming , Liu Yuan-Ling , Lin Yi-Chu , Shun Chia-Tung , Wu Ming-Shiang , Chen Ching-Chow
Published: March 2024

Abstract
Preclinical and clinical studies have shown that statins, the 3-hydroxy-3-methylglutaryl–CoA reductase inhibitors with cholesterol-lowering properties, exhibited anticancer effects. However, the underlying mechanisms remain ill defined. In this study, we showed that atorvastatin could inhibit the growth of hepatocellular carcinoma (HCC) and colorectal carcinoma (CRC) cells via induction of apoptosis. Atorvastatin also induced autophagy that is a physiologic process involved in the turnover of intracellular organelles. Atorvastatin-induced autophagy was found to be inhibited by AMP-activated protein kinase (AMPK) small interfering RNA. Examination of HCC patients showed the positive correlation between AMPK activity and autophagic marker (beclin-1). Atorvastatin-induced AMPK activation could induce p21 expression, which was also positively correlated with beclin-1 expression in CRC patients. AMPK/p21 signaling caused endoplasmic reticulum (ER) stress response leading to the induction of autophagy. Inhibition of autophagy by an autophagic inhibitor bafilomycin A1 or genetic knockout of autophagy-related gene 5 enhanced atorvastatin-induced cytotoxicity and apoptosis. In summary, activation of AMPK by atorvastatin enhances p21 expression and ER stress response, leading to autophagy, which promotes survival of cancer cells. Combinations of atorvastatin with bafilomycin A1 provide a novel and promising strategy to improve the treatment of digestive malignancies. Cancer Res; 70(19); 7699–709. ©2010 AACR.
Data from MET and KRAS Gene Amplification Mediates Acquired Resistance to MET Tyrosine Kinase Inhibitors
Authors: Cepero Virna , Sierra J. Rafael , Corso Simona , Ghiso Elena , Casorzo Laura , Perera Tim , Comoglio Paolo Maria , Giordano Silvia
Published: March 2024

Abstract
The establishment of the role of MET in human cancer has led to the development of small-molecule inhibitors, many of which are currently in clinical trials. Thus far, nothing is known about their therapeutic efficacy and the possible emergence of resistance to treatment, a problem that has been often observed with other receptor tyrosine kinase (RTK) inhibitors. To predict mechanisms of acquired resistance, we generated resistant cells by treating MET-addicted cells with increasing concentrations of the MET small-molecule inhibitors PHA-665752 or JNJ38877605. Resistant cells displayed MET gene amplification, leading to increased expression and constitutive phosphorylation of MET, followed by subsequent amplification and overexpression of wild-type (wt) KRAS. Cells harboring KRAS amplification progressively lost their MET dependence and acquired KRAS dependence. Our results suggest that MET and KRAS amplification is a general mechanism of resistance to specific MET inhibitors given that similar results were observed with two small inhibitors and in different cell lines of different histotypes. To our knowledge, this is the first report showing that overexpression of wt KRAS can overcome the inhibitory effect of a RTK inhibitor. In view of the fact that cellular models of resistance to inhibitors targeting other tyrosine kinases have predicted and corroborated clinical findings, our results provide insights into strategies for preventing and/or overcoming drug resistance. Cancer Res; 70(19); 7580–90. ©2010 AACR.
Data from Alternative Splicing of Caspase 9 Is Modulated by the Phosphoinositide 3-Kinase/Akt Pathway via Phosphorylation of SRp30a
Authors: Shultz Jacqueline C. , Goehe Rachel W. , Wijesinghe D. Shanaka , Murudkar Charuta , Hawkins Amy J. , Shay Jerry W. , Minna John D. , Chalfant Charles E.
Published: March 2024

Abstract
Increasing evidence points to the functional importance of alternative splice variations in cancer pathophysiology. Two splice variants are derived from the CASP9 gene via the inclusion (Casp9a) or exclusion (Casp9b) of a four-exon cassette. Here we show that alternative splicing of Casp9 is dysregulated in non–small cell lung cancers (NSCLC) regardless of their pathologic classification. Based on these findings we hypothesized that survival pathways activated by oncogenic mutation regulated this mechanism. In contrast to K-RasV12 expression, epidermal growth factor receptor (EGFR) overexpression or mutation dramatically lowered the Casp9a/9b splice isoform ratio. Moreover, Casp9b downregulation blocked the ability of EGFR mutations to induce anchorage-independent growth. Furthermore, Casp9b expression blocked inhibition of clonogenic colony formation by erlotinib. Interrogation of oncogenic signaling pathways showed that inhibition of phosphoinositide 3-kinase or Akt dramatically increased the Casp9a/9b ratio in NSCLC cells. Finally, Akt was found to mediate exclusion of the exon 3,4,5,6 cassette of Casp9 via the phosphorylation state of the RNA splicing factor SRp30a via serines 199, 201, 227, and 234. Taken together, our findings show that oncogenic factors activating the phosphoinositide 3-kinase/Akt pathway can regulate alternative splicing of Casp9 via a coordinated mechanism involving the phosphorylation of SRp30a. Cancer Res; 70(22); 9185–96. ©2010 AACR.
Data from Overexpression of the Protein Tyrosine Phosphatase PRL-2 Correlates with Breast Tumor Formation and Progression
Authors: Hardy Serge , Wong Nau Nau , Muller William J. , Park Morag , Tremblay Michel L.
Published: March 2024

Abstract
The PRL-1, PRL-2, and PRL-3 phosphatases are prenylated protein tyrosine phosphatases with oncogenic activity that are proposed to drive tumor metastasis. We found that PRL-2 mRNA is elevated in primary breast tumors relative to matched normal tissue, and also dramatically elevated in metastatic lymph nodes compared with primary tumors. PRL-2 knockdown in metastatic MDA-MB-231 breast cancer cells decreased anchorage-independent growth and cell migration, suggesting that the malignant phenotype of these cells is mediated at least in part through PRL-2 signaling. In different mouse mammary tumor–derived cell lines overexpressing PRL-2, we confirmed its role in anchorage-independent growth and cell migration. Furthermore, injection of PRL-2–overexpressing cells into the mouse mammary fat pad promoted extracellular signal-regulated kinase 1/2 activation and tumor formation. MMTV–PRL-2 transgenic mice engineered to overexpress the enzyme in mammary tissue did not exhibit spontaneous tumorigenesis, but they exhibited an accelerated development of mammary tumors initiated by introduction of an MMTV-ErbB2 transgene. Together, our results argue that PRL-2 plays a role in breast cancer progression. Cancer Res; 70(21); 8959–67. ©2010 AACR.
Data from Ligand-Independent Toll-like Receptor Signals Generated by Ectopic Overexpression of MyD88 Generate Local and Systemic Antitumor Immunity
Authors: Hartman Zachary C. , Osada Takuya , Glass Oliver , Yang Xiao Y. , Lei Gang-jun , Lyerly H. Kim , Clay Timothy M.
Published: March 2024

Abstract
Although critical for initiating and regulating immune responses, the therapeutic use of individual cytokines as anticancer immunotherapeutic agents has achieved only modest clinical success. Consequently, many current strategies have focused on the use of specific immunotherapeutic agonists that engage individual receptors of innate immune networks, such as the Toll-like receptor (TLR) system, each resulting in specific patterns of gene expression, cytokine production, and inflammatory outcome. However, these immunotherapeutics are constrained by variable cellular TLR expression and responsiveness to particular TLR agonists, as well as the specific cellular context of different tumors. We hypothesized that overexpression of MyD88, a pivotal regulator of multiple TLR signaling pathways, could circumvent these constraints and mimic coordinated TLR signaling across all cell types in a ligand-independent fashion. To explore this hypothesis, we generated an adenoviral vector expressing MyD88 and show that Ad-MyD88 infection elicits extensive Th1-specific transcriptional and secreted cytokine signatures in all murine and human cell types tested in vitro and in vivo. Importantly, in vivo intratumoral injection of Ad-MyD88 into established tumor masses enhanced adaptive immune responses and inhibited local tumor immunosuppression, resulting in significantly inhibited local and systemic growth of multiple tumor types. Finally, Ad-MyD88 infection of primary human dendritic cells, tumor-associated fibroblasts, and colorectal carcinoma cells elicited significant Th1-type cytokine responses, resulting in enhanced tumor cell lysis and expansion of human tumor antigen–specific T cells. Thus, Ad-MyD88 initiated robust antitumor activity in established murine tumor microenvironments and in human contexts, suggesting its potential effectiveness as a clinical immunotherapeutic strategy. Cancer Res; 70(18); 7209–20. ©2010 AACR.
Data from Lung Metastasis Fails in MMTV-PyMT Oncomice Lacking S100A4 Due to a T-Cell Deficiency in Primary Tumors
Authors: Grum-Schwensen Birgitte , Klingelhöfer Jörg , Grigorian Mariam , Almholt Kasper , Nielsen Boye Schnack , Lukanidin Eugene , Ambartsumian Noona
Published: March 2024

Abstract
Interactions between tumor and stroma cells are essential for the progression of cancer from its initial growth at a primary site to its metastasis to distant organs. The metastasis-stimulating protein S100A4 exerts its function as a stroma cell–derived factor. Genetic depletion of S100A4 significantly reduced the metastatic burden in lungs of PyMT-induced mammary tumors. In S100A4+/+ PyMT mice, massive leukocyte infiltration at the site of the growing tumor at the stage of malignant transition was associated with increased concentration of extracellular S100A4 in the tumor microenvironment. In contrast, in S100A4−/− PyMT tumors, a significant suppression of T-cell infiltration was documented at the transition period. In vitro, the S100A4 protein mediated the attraction of T cells. Moreover, S100A4+/+, but not S100A4−/−, fibroblasts stimulated the invasion of T lymphocytes into fibroblast monolayers. In vivo, the presence of S100A4+/+, but not S100A4−/−, fibroblasts significantly stimulated the attraction of T lymphocytes to the site of the growing tumor. Increased levels of T cells were also observed in the premetastatic lungs of tumor-bearing mice primed to metastasize by S100A4+/+ fibroblasts. Treatment of T cells with the S100A4 protein stimulated production of cytokines, particularly granulocyte colony-stimulating factor and eotaxin-2. The same cytokines were detected in the fluid of S100A4+/+ PyMT tumors at the transition period. We suggest that release of S100A4 in the primary tumor stimulates infiltration of T cells and activates secretion of cytokines, thus triggering sequential events that fuel tumor cells to metastasize. Similar processes could occur in the premetastatic lungs, facilitating generation of inflammatory milieu favorable for metastasis formation. Cancer Res; 70(3); 936–47
Data from A Small Interfering RNA Screen of Genes Involved in DNA Repair Identifies Tumor-Specific Radiosensitization by POLQ Knockdown
Authors: Higgins Geoff S. , Prevo Remko , Lee Yin-Fai , Helleday Thomas , Muschel Ruth J. , Taylor Steve , Yoshimura Michio , Hickson Ian D. , Bernhard Eric J. , McKenna W. Gillies
Published: March 2024

Abstract
The effectiveness of radiotherapy treatment could be significantly improved if tumor cells could be rendered more sensitive to ionizing radiation (IR) without altering the sensitivity of normal tissues. However, many of the key therapeutically exploitable mechanisms that determine intrinsic tumor radiosensitivity are largely unknown. We have conducted a small interfering RNA (siRNA) screen of 200 genes involved in DNA damage repair aimed at identifying genes whose knockdown increased tumor radiosensitivity. Parallel siRNA screens were conducted in irradiated and unirradiated tumor cells (SQ20B) and irradiated normal tissue cells (MRC5). Using γH2AX foci at 24 hours after IR, we identified several genes, such as BRCA2, Lig IV, and XRCC5, whose knockdown is known to cause increased cell radiosensitivity, thereby validating the primary screening end point. In addition, we identified POLQ (DNA polymerase θ) as a potential tumor-specific target. Subsequent investigations showed that POLQ knockdown resulted in radiosensitization of a panel of tumor cell lines from different primary sites while having little or no effect on normal tissue cell lines. These findings raise the possibility that POLQ inhibition might be used clinically to cause tumor-specific radiosensitization. Cancer Res; 70(7); 2984–93
Data from Quantitative In vivo Imaging of the Effects of Inhibiting Integrin Signaling via Src and FAK on Cancer Cell Movement: Effects on E-cadherin Dynamics
Authors: Canel Marta , Serrels Alan , Miller Derek , Timpson Paul , Serrels Bryan , Frame Margaret C. , Brunton Valerie G.
Published: March 2024

Abstract
Most cancer-related deaths are due to the development of metastatic disease, and several new molecularly targeted agents in clinical development have the potential to prevent disease progression. However, it remains difficult to assess the efficacy of antimetastatic agents in the clinical setting, and an increased understanding of how such agents work at different stages of the metastatic cascade is important in guiding their clinical use. We used optical window chambers combined with photobleaching, photoactivation, and photoswitching to quantitatively measure (a) tumor cell movement and proliferation by tracking small groups of cells in the context of the whole tumor, and (b) E-cadherin molecular dynamics in vivo following perturbation of integrin signaling by inhibiting focal adhesion kinase (FAK) and Src. We show that inhibition of Src and FAK suppresses E-cadherin–dependent collective cell movement in a complex three-dimensional tumor environment, and modulates cell-cell adhesion strength and endocytosis in vitro. This shows a novel role for integrin signaling in the regulation of E-cadherin internalization, which is linked to regulation of collective cancer cell movement. This work highlights the power of fluorescent, direct, in vivo imaging approaches in the preclinical evaluation of chemotherapeutic agents, and shows that inhibition of the Src/FAK signaling axis may provide a strategy to prevent tumor cell spread by deregulating E-cadherin–mediated cell-cell adhesions. Cancer Res; 70(22); 9413–22. ©2010 AACR.
Data from The Proteasome Inhibitor Bortezomib Sensitizes Melanoma Cells toward Adoptive CTL Attack
Authors: Seeger Jens Michael , Schmidt Patrick , Brinkmann Kerstin , Hombach Andreas A. , Coutelle Oliver , Zigrino Paola , Wagner-Stippich Diana , Mauch Cornelia , Abken Hinrich , Krönke Martin , Kashkar Hamid
Published: March 2024

Abstract
Adoptive transfer of tumor-specific cytolytic T lymphocytes (CTL) results in target cell lysis by activating the intrinsic apoptotic cell death program. Not surprisingly, deregulation of the apoptotic machinery is one of the central mechanisms by which tumor cells escape immune destruction despite specific CTL recognition. Here we show that treatment with the proteasome inhibitor bortezomib sensitizes previously resistant tumor cells for cytolytic T-cell attack. Human T cells were redirected toward melanoma cells by engineered expression of an immunoreceptor with binding specificity for high molecular weight–melanoma-associated antigen. Established melanoma cell lines as well as primary melanoma cells from tumor biopsies, which are notoriously resistant toward T-cell lysis, became sensitive upon bortezomib treatment. Detailed analysis of the underlying molecular mechanism revealed that bortezomib treatment induced mitochondrial accumulation of NOXA, which potentiated the release of mitochondrial second mitochondria-derived activator of caspase (SMAC) in response to CTL effector functions, including caspase-8 and granzyme B. Our data indicate that proteasome inhibition increases the sensitivity of tumor cells toward cytolytic T-cell attack by NOXA-mediated enhancement of mitochondrial SMAC release. Cancer Res; 70(5); 1825–34
Data from Genetic Screen Identifies Insulin-like Growth Factor Binding Protein 5 as a Modulator of Tamoxifen Resistance in Breast Cancer
Authors: Ahn Bo Young , Elwi Adam N. , Lee Byoungchun , Trinh Diane L.N. , Klimowicz Alexander C. , Yau Annie , Chan Jennifer A. , Magliocco Anthony , Kim Sung-Woo
Published: March 2024

Abstract
Tamoxifen resistance is one of the overarching challenges in the treatment of patients with estrogen receptor (ER)–positive breast cancer. Through a genome-wide RNA interference screen to discover genes responsible for tamoxifen resistance in vitro, we identified insulin-like growth factor binding protein 5 (IGFBP5) as a determinant of drug sensitivity. Specific knockdown of IGFBP5 by retroviral infection with short hairpin RNA–expressing cassette in MCF7 human breast cancer cells (pRS-shIGFBP5) conferred tamoxifen resistance in vitro due to concomitant loss of ERα expression and signaling. IGFBP5 expression was also reduced in MCF7 cells selected for tamoxifen resistance in culture (TAMR). Both tamoxifen-resistant MCF7-TAMR and MCF7-pRS-shIGFBP5 cells could be resensitized to drug by treatment with exogenous recombinant IGFBP5 (rIGFBP5) protein. Treatment with rIGFBP5 protein in mouse tumor xenografts reversed the in vivo tamoxifen resistance of MCF7-pRS-shIGFBP5 cell–derived tumors by reducing tumor cell proliferation. IGFBP5 immunohistochemical staining in a cohort of 153 breast cancer patients showed that low IGFBP5 expression was associated with shorter overall survival after tamoxifen therapy. Thus, IGFBP5 warrants investigation as an agent to reverse tamoxifen resistance. Cancer Res; 70(8); 3013–9. ©2010 AACR.