bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from p21CIP-1/WAF-1 Induction Is Required to Inhibit Prostate Cancer Growth Elicited by Deficient Expression of the Wnt Inhibitor Dickkopf-1
Authors: Hall Christopher L. , Zhang Honglai , Baile Shobun , Ljungman Mats , Kuhstoss Stuart , Keller Evan T.
Published: March 2023

Abstract
Osteoblastic bone metastases are the most common metastases produced by human prostate cancers (PCa). Deregulated activity of Wnt growth factors resulting from overexpression of the Wnt inhibitor Dickkopf-1 (DKK-1) is known to contribute to formation of the osteoblastic component of PCa skeletal bone metastases. In this study, we report that DKK-1 knockdown in osteolytic human PCa cells unexpectedly delays the development of both soft tissue and osseous lesions. PCa cells deficient in DKK-1 expression did not increase canonical Wnt signaling in target osteoblast cell lines; however, DKK-1 knockdown PCa cells exhibited increased expression of the CDK inhibitor p21CIP1/WAF1 and a 32% increase in G1 arrest compared with control cells. Ablating p21CIP1/WAF1 in PCa cells deficient in DKK-1 was sufficient to rescue tumor growth. Collectively, our findings demonstrate that DKK-1 overexpression supports tumor growth in part by restricting expression of p21CIP1/WAF1 through a mechanism independent of canonical Wnt signaling. Cancer Res; 70(23); 9916–26. ©2010 AACR.
Data from Quantitative Imaging of Lymphatic Function with Liposomal Indocyanine Green
Authors: Proulx Steven T. , Luciani Paola , Derzsi Stefanie , Rinderknecht Matthias , Mumprecht Viviane , Leroux Jean-Christophe , Detmar Michael
Published: March 2023

Abstract
Lymphatic vessels play a major role in cancer progression and in postsurgical lymphedema, and several new therapeutic approaches targeting lymphatics are currently being developed. Thus, there is a critical need for quantitative imaging methods to measure lymphatic flow. Indocyanine green (ICG) has been used for optical imaging of the lymphatic system, but it is unstable in solution and may rapidly enter venous capillaries after local injection. We developed a novel liposomal formulation of ICG (LP-ICG), resulting in vastly improved stability in solution and an increased fluorescence signal with a shift toward longer wavelength absorption and emission. When injected intradermally to mice, LP-ICG was specifically taken up by lymphatic vessels and allowed improved visualization of deep lymph nodes. In a genetic mouse model of lymphatic dysfunction, injection of LP-ICG showed no enhancement of draining lymph nodes and slower clearance from the injection site. In mice bearing B16 luciferase-expressing melanomas expressing vascular endothelial growth factor-C (VEGF-C), sequential near-IR imaging of intradermally injected LP-ICG enabled quantification of lymphatic flow. Increased flow through draining lymph nodes was observed in mice bearing VEGF-C–expressing tumors without metastases, whereas a decreased flow pattern was seen in mice with a higher lymph node tumor burden. This new method will likely facilitate quantitative studies of lymphatic function in preclinical investigations and may also have potential for imaging of lymphedema or improved sentinel lymph detection in cancer. Cancer Res; 70(18); 7053–62. ©2010 AACR.
Data from K-ras Mutation Targeted to Gastric Tissue Progenitor Cells Results in Chronic Inflammation, an Altered Microenvironment, and Progression to Intraepithelial Neoplasia
Authors: Okumura Tomoyuki , Ericksen Russell E. , Takaishi Shigeo , Wang Sophie S.W. , Dubeykovskiy Zinaida , Shibata Wataru , Betz Kelly S. , Muthupalani Sureshkuma , Rogers Arlin B. , Fox James G. , Rustgi Anil K. , Wang Timothy C.
Published: March 2023

Abstract
Chronic infectious diseases, such as Helicobacter pylori infection, can promote cancer in a large part through induction of chronic inflammation. Oncogenic K-ras mutation in epithelial cells activates inflammatory pathways, which could compensate for a lack of infectious stimulus. Gastric histopathology and putative progenitor markers [doublecortin and calcium/calmodulin-dependent protein kinase-like 1 (Dcamkl1) and keratin 19 (K19)] in K19-K-ras-V12 (K19-kras) transgenic mice were assessed at 3, 6, 12, and 18 months of age, in comparison with Helicobacter felis–infected wild-type littermates. Inflammation was evaluated by reverse transcription–PCR of proinflammatory cytokines, and K19-kras mice were transplanted with green fluorescent protein (GFP)–labeled bone marrow. Both H. felis infection and K-ras mutation induced upregulation of proinflammatory cytokines, expansion of Dcamkl1+ cells, and progression to oxyntic atrophy, metaplasia, hyperplasia, and high-grade dysplasia. K19-kras transgenic mice uniquely displayed mucous metaplasia as early as 3 months and progressed to high-grade dysplasia and invasive intramucosal carcinoma by 20 months. In bone marrow–transplanted K19-kras mice that progressed to dysplasia, a large proportion of stromal cells were GFP+ and bone marrow–derived, but only rare GFP+ epithelial cells were observed. GFP+ bone marrow–derived cells included leukocytes and CD45− stromal cells that expressed vimentin or α smooth muscle actin and were often found surrounding clusters of Dcamkl1+ cells at the base of gastric glands. In conclusion, the expression of mutant K-ras in K19+ gastric epithelial cells can induce chronic inflammation and promote the development of dysplasia. Cancer Res; 70(21); 8435–45. ©2010 AACR.
Data from Aberrant Silencing of Cancer-Related Genes by CpG Hypermethylation Occurs Independently of Their Spatial Organization in the Nucleus
Authors: Easwaran Hariharan P. , Van Neste Leander , Cope Leslie , Sen Subhojit , Mohammad Helai P. , Pageau Gayle J. , Lawrence Jeanne B. , Herman James G. , Schuebel Kornel E. , Baylin Stephen B.
Published: March 2023

Abstract
Aberrant promoter DNA-hypermethylation and repressive chromatin constitutes a frequent mechanism of gene inactivation in cancer. There is great interest in dissecting the mechanisms underlying this abnormal silencing. Studies have shown changes in the nuclear organization of chromatin in tumor cells as well as the association of aberrant methylation with long-range silencing of neighboring genes. Furthermore, certain tumors show a high incidence of promoter methylation termed as the CpG island methylator phenotype. Here, we have analyzed the role of nuclear chromatin architecture for genes in hypermethylated inactive versus nonmethylated active states and its relation with long-range silencing and CpG island methylator phenotype. Using combined immunostaining for active/repressive chromatin marks and fluorescence in situ hybridization in colorectal cancer cell lines, we show that aberrant silencing of these genes occurs without requirement for their being positioned at heterochromatic domains. Importantly, hypermethylation, even when associated with long-range epigenetic silencing of neighboring genes, occurs independent of their euchromatic or heterochromatic location. Together, these results indicate that, in cancer, extensive changes around promoter chromatin of individual genes or gene clusters could potentially occur locally without preference for nuclear position and/or causing repositioning. These findings have important implications for understanding relationships between nuclear organization and gene expression patterns in cancer. Cancer Res; 70(20); 8015–24. ©2010 AACR.
Data from Expression of Snail in Epidermal Keratinocytes Promotes Cutaneous Inflammation and Hyperplasia Conducive to Tumor Formation
Authors: Du Fei , Nakamura Yoshikazu , Tan Tuan-Lin , Lee Pedro , Lee Robert , Yu Benjamin , Jamora Colin
Published: March 2023

Abstract
Although metastasis is the most lethal consequence of tumor progression, comparatively little is known regarding the molecular machinery governing this process. In many carcinomas, there is a robust correlation between the expression of the transcription factor Snail and a poor prognosis, but the contribution of this protein to the metastatic process remains unresolved. Interestingly, the prolonged expression of Snail in epidermal keratinocytes is sufficient to recapitulate early features of metastasis. However, it does so without inducing a complete epithelial-mesenchymal transition (EMT), a developmental phenomenon mediated by Snail that is extensively invoked as the mechanism fueling tumorigenesis. Instead, we found that the local invasiveness of keratinocytes is the consequence of the recruitment and activity of macrophages. Moreover, keratinocyte proliferation is the product of an IL-17/IL-6/Stat3 signaling module initiated by activated resident γδT cells in the transgenic skin. Together, these phenotypes prime the transgenic skin for the formation and metastasis of tumors in response to chemically induced carcinogenesis. Thus, the contribution of Snail to the progression of carcinomas is largely through the creation of a hyperproliferative and inflammatory niche that facilitates tumor development and dissemination. Cancer Res; 70(24); 10080–9. ©2010 AACR.
Data from De novo Lipogenesis Protects Cancer Cells from Free Radicals and Chemotherapeutics by Promoting Membrane Lipid Saturation
Authors: Rysman Evelien , Brusselmans Koen , Scheys Katryn , Timmermans Leen , Derua Rita , Munck Sebastian , Van Veldhoven Paul P. , Waltregny David , Daniëls Veerle W. , Machiels Jelle , Vanderhoydonc Frank , Smans Karine , Waelkens Etienne , Verhoeven Guido , Swinnen Johannes V.
Published: March 2023

Abstract
Activation of de novo lipogenesis in cancer cells is increasingly recognized as a hallmark of aggressive cancers and has been implicated in the production of membranes for rapid cell proliferation. In the current report, we provide evidence that this activation has a more profound role. Using a mass spectrometry–based phospholipid analysis approach, we show that clinical tumor tissues that display the lipogenic phenotype show an increase in the degree of lipid saturation compared with nonlipogenic tumors. Reversal of the lipogenic switch in cancer cells by treatment with the lipogenesis inhibitor soraphen A or by targeting lipogenic enzymes with small interfering RNA leads to a marked decrease in saturated and mono-unsaturated phospholipid species and increases the relative degree of polyunsaturation. Because polyunsaturated acyl chains are more susceptible to peroxidation, inhibition of lipogenesis increases the levels of peroxidation end products and renders cells more susceptible to oxidative stress–induced cell death. As saturated lipids pack more densely, modulation of lipogenesis also alters lateral and transversal membrane dynamics as revealed by diffusion of membrane-targeted green fluorescent protein and by the uptake and response to doxorubicin. These data show that shifting lipid acquisition from lipid uptake toward de novo lipogenesis dramatically changes membrane properties and protects cells from both endogenous and exogenous insults. These findings provide important new insights into the role of de novo lipogenesis in cancer cells, and they provide a rationale for the use of lipogenesis inhibitors as antineoplastic agents and as chemotherapeutic sensitizers. Cancer Res; 70(20); 8117–26. ©2010 AACR.
Data from A Novel, Selective, and Efficacious Nanomolar Pyridopyrazinone Inhibitor of V600EBRAF
Authors: Whittaker Steven , Ménard Delphine , Kirk Ruth , Ogilvie Lesley , Hedley Douglas , Zambon Alfonso , Lopes Filipa , Preece Natasha , Manne Helen , Rana Sareena , Lambros Maryou , Reis-Filho Jorge S. , Marais Richard , Springer Caroline J.
Published: March 2023

Abstract
Oncogenic BRAF is a critical driver of proliferation and survival and is thus a validated therapeutic target in cancer. We have developed a potent inhibitor, termed 1t (CCT239065), of the mutant protein kinase, V600EBRAF. 1t inhibits signaling downstream of V600EBRAF in cancer cells, blocking DNA synthesis, and inhibiting proliferation. Importantly, we show that 1t is considerably more selective for mutated BRAF cancer cell lines compared with wild-type BRAF lines. The inhibitor is well tolerated in mice and exhibits excellent oral bioavailability (F = 71%). Suppression of V600EBRAF-mediated signaling in human tumor xenografts was observed following oral administration of a single dose of 1t. As expected, the growth rate in vivo of a wild-type BRAF human tumor xenograft model is unaffected by inhibitor 1t. In contrast, 1t elicits significant therapeutic responses in mutant BRAF–driven human melanoma xenografts. Cancer Res; 70(20); 8036–44. ©2010 AACR.
Data from CX-4945, an Orally Bioavailable Selective Inhibitor of Protein Kinase CK2, Inhibits Prosurvival and Angiogenic Signaling and Exhibits Antitumor Efficacy
Authors: Siddiqui-Jain Adam , Drygin Denis , Streiner Nicole , Chua Peter , Pierre Fabrice , O'Brien Sean E. , Bliesath Josh , Omori Mayuko , Huser Nanni , Ho Caroline , Proffitt Chris , Schwaebe Michael K. , Ryckman David M. , Rice William G. , Anderes Kenna
Published: March 2023

Abstract
Malignant transformation and maintenance of the malignant phenotype depends on oncogenic and non-oncogenic proteins that are essential to mediate oncogene signaling and to support the altered physiologic demands induced by transformation. Protein kinase CK2 supports key prosurvival signaling pathways and represents a prototypical non-oncogene. In this study, we describe CX-4945, a potent and selective orally bioavailable small molecule inhibitor of CK2. The antiproliferative activity of CX-4945 against cancer cells correlated with expression levels of the CK2α catalytic subunit. Attenuation of PI3K/Akt signaling by CX-4945 was evidenced by dephosphorylation of Akt on the CK2-specific S129 site and the canonical S473 and T308 regulatory sites. CX-4945 caused cell-cycle arrest and selectively induced apoptosis in cancer cells relative to normal cells. In models of angiogenesis, CX-4945 inhibited human umbilical vein endothelial cell migration, tube formation, and blocked CK2-dependent hypoxia-induced factor 1 alpha (HIF-1α) transcription in cancer cells. When administered orally in murine xenograft models, CX-4945 was well tolerated and demonstrated robust antitumor activity with concomitant reductions of the mechanism-based biomarker phospho-p21 (T145). The observed antiproliferative and anti-angiogenic responses to CX-4945 in tumor cells and endothelial cells collectively illustrate that this compound exerts its antitumor effects through inhibition of CK2-dependent signaling in multiple pathways. Finally, CX-4945 is the first orally bioavailable small molecule inhibitor of CK2 to advance into human clinical trials, thereby paving the way for an entirely new class of targeted treatment for cancer. Cancer Res; 70(24); 10288–98. ©2010 AACR.
Data from hPuf-A/KIAA0020 Modulates PARP-1 Cleavage upon Genotoxic Stress
Authors: Chang Hao-Yen , Fan Chi-Chen , Chu Po-Chen , Hong Bo-En , Lee Hyeon Jeong , Chang Mau-Sun
Published: March 2023

Abstract
Human hPuf-A/KIAA0020 was first identified as a new minor histocompatibility antigen in 2001. Its zebrafish orthologue contains six Pumilio-homology RNA-binding domains and has been shown to participate in the development of eyes and primordial germ cells, but the cellular function of hPuf-A remains unclear. In this report, we showed that hPuf-A predominantly localized in the nucleoli with minor punctate signals in the nucleoplasm. The nucleolar localization of hPuf-A would redistribute to the nucleoplasm after the treatment of RNA polymerase inhibitors (actinomycin D and 5,6-dichlorobenzimidazole riboside) and topoisomerase inhibitors [camptothecin (CPT) and etoposide]. Interestingly, knockdown of hPuf-A sensitized cells to CPT and UV treatment and cells constitutively overexpressing hPuf-A became more resistant to genotoxic exposure. Affinity gel pull-down coupled with mass spectrometric analysis identified PARP-1 as one of the hPuf-A interacting proteins. hPuf-A specifically interacts with the catalytic domain of PARP-1 and inhibits poly(ADP-ribosyl)ation of PARP-1 in vitro. Depletion of hPuf-A increased the cleaved PARP-1 and overexpression of hPuf-A lessened PARP-1 cleavage when cells were exposed to CPT and UV light. Collectively, hPuf-A may regulate cellular response to genotoxic stress by inhibiting PARP-1 activity and thus preventing PARP-1 degradation by caspase-3. Cancer Res; 71(3); 1126–34. ©2011 AACR.
Data from FOXQ1 Is Overexpressed in Colorectal Cancer and Enhances Tumorigenicity and Tumor Growth
Authors: Kaneda Hiroyasu , Arao Tokuzo , Tanaka Kaoru , Tamura Daisuke , Aomatsu Keiichi , Kudo Kanae , Sakai Kazuko , De Velasco Marco A. , Matsumoto Kazuko , Fujita Yoshihiko , Yamada Yasuhide , Tsurutani Junji , Okamoto Isamu , Nakagawa Kazuhiko , Nishio Kazuto
Published: March 2023

Abstract
Forkhead box Q1 (FOXQ1) is a member of the forkhead transcription factor family, and it has recently been proposed to participate in gastric acid secretion and mucin gene expression in mice. However, the role of FOXQ1 in humans and especially in cancer cells remains unknown. We found that FOXQ1 mRNA is overexpressed in clinical specimens of colorectal cancer (CRC; 28-fold/colonic mucosa). A microarray analysis revealed that the knockdown of FOXQ1 using small interfering RNA resulted in a decrease in p21CIP1/WAF1 expression, and a reporter assay and a chromatin immunoprecipitation assay showed that p21 was one of the target genes of FOXQ1. Stable FOXQ1-overexpressing cells (H1299/FOXQ1) exhibited elevated levels of p21 expression and inhibition of apoptosis induced by doxorubicin or camptothecin. Although cellular proliferation was decreased in H1299/FOXQ1 cells in vitro, H1299/FOXQ1 cells significantly increased tumorigenicity [enhanced green fluorescent protein (EGFP): 2/15, FOXQ1: 7/15] and enhanced tumor growth (437 ± 301 versus 1735 ± 769 mm3, P < 0.001) in vivo. Meanwhile, stable p21 knockdown of H1299/FOXQ1 cells increased tumor growth, suggesting that FOXQ1 promotes tumor growth independent of p21. Microarray analysis of H1299/EGFP and H1299/FOXQ1 revealed that FOXQ1 overexpression upregulated several genes that have positive roles for tumor growth, including VEGFA, WNT3A, RSPO2, and BCL11A. CD31 and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining of the tumor specimens showed that FOXQ1 overexpression mediated the angiogenic and antiapoptotic effect in vivo. In conclusion, FOXQ1 is overexpressed in CRC and enhances tumorigenicity and tumor growth presumably through its angiogenic and antiapoptotic effects. Our findings show that FOXQ1 is a new member of the cancer-related FOX family. Cancer Res; 70(5); 2053–63
Data from MicroRNA-519c Suppresses Hypoxia-Inducible Factor-1α Expression and Tumor Angiogenesis
Authors: Cha Shih-Ting , Chen Pai-Sheng , Johansson Gunnar , Chu Chia-Yu , Wang Ming-Yang , Jeng Yung-Ming , Yu Sung-Liang , Chen Jin-Shing , Chang King-Jen , Jee Shiou-Hwa , Tan Ching-Ting , Lin Ming-Tsan , Kuo Min-Liang
Published: March 2023

Abstract
Hypoxia-inducible factor-1α (HIF-1α) is widely considered to be one of the key regulators of tumor angiogenesis. The upstream regulation is complex and involves several growth factors, cytokines, and hypoxia. Herein, we have identified miR-519c as a hypoxia-independent regulator of HIF-1α, acting through direct binding to the HIF-1α 3′ untranslated region and leading to reduced tumor angiogenesis. Overexpression of miR-519c resulted in a significant decrease of HIF-1α protein levels and reduced the tube formation of human umbilical vein endothelial cells; similarly, antagomir inhibition of miR-519c increased the level of HIF-1α protein and enhanced angiogenic activity, suggesting an important role of miR-519c in HIF-1α–mediated angiogenesis. Consistent with the overexpression of miR-519c in cancer patients with better prognosis, mice injected with miR-519c–overexpressing cells exhibited dramatically reduced HIF-1α levels, followed by suppressed tumor angiogenesis, growth, and metastasis. In addition, we found that hepatocyte growth factor (HGF), a known HIF-1α inducer, reduced the miR-519c levels through an Akt-dependent pathway. This regulation was posttranscriptional and may be mediated by suppression of miR-519c maturation. Taken together, our findings provide the first evidence that miR-519c is a pivotal regulator of tumor angiogenesis and that microenvironmental HGF contributes to regulating miR-519c biogenesis in cancer cells. Cancer Res; 70(7); 2675–85
Data from Integrated Microfluidic and Imaging Platform for a Kinase Activity Radioassay to Analyze Minute Patient Cancer Samples
Authors: Fang Cong , Wang Yanju , Vu Nam T. , Lin Wei-Yu , Hsieh Yao-Te , Rubbi Liudmilla , Phelps Michael E. , Müschen Markus , Kim Yong-Mi , Chatziioannou Arion F. , Tseng Hsian-Rong , Graeber Thomas G.
Published: March 2023

Abstract
Oncogenic kinase activity and the resulting aberrant growth and survival signaling are a common driving force of cancer. Accordingly, many successful molecularly targeted anticancer therapeutics are directed at inhibiting kinase activity. To assess kinase activity in minute patient samples, we have developed an immunocapture-based in vitro kinase assay on an integrated polydimethylsiloxane microfluidics platform that can reproducibly measure kinase activity from as few as 3,000 cells. For this platform, we adopted the standard radiometric 32P-ATP–labeled phosphate transfer assay. Implementation on a microfluidic device required us to develop methods for repeated trapping and mixing of solid-phase affinity microbeads. We also developed a solid-state beta-particle camera imbedded directly below the microfluidic device for real-time quantitative detection of the signal from this and other microfluidic radiobioassays. We show that the resulting integrated device can measure ABL kinase activity from BCR-ABL–positive leukemia patient samples. The low sample input requirement of the device creates new potential for direct kinase activity experimentation and diagnostics on patient blood, bone marrow, and needle biopsy samples. Cancer Res; 70(21); 8299–308. ©2010 AACR.
Data from The Antidepressant Sertraline Inhibits Translation Initiation by Curtailing Mammalian Target of Rapamycin Signaling
Authors: Lin Chen-Ju , Robert Francis , Sukarieh Rami , Michnick Stephen , Pelletier Jerry
Published: March 2023

Abstract
Sertraline, a selective serotonin reuptake inhibitor, is a widely used antidepressant agent. Here, we show that sertraline also exhibits antiproliferative activity. Exposure to sertraline leads to a concentration-dependent decrease in protein synthesis. Moreover, polysome profile analysis of sertraline-treated cells shows a reduction in polysome content and a concomitant increase in 80S ribosomes. The inhibition in translation caused by sertraline is associated with decreased levels of the eukaryotic initiation factor (eIF) 4F complex, altered localization of eIF4E, and increased eIF2α phosphorylation. The latter event leads to increased REDD1 expression, which in turn impinges on the mammalian target of rapamycin (mTOR) pathway by affecting TSC1/2 signaling. Sertraline also independently targets the mTOR signaling pathway downstream of Rheb. In the Eμ-myc murine lymphoma model where carcinogenesis is driven by phosphatase and tensin homologue (PTEN) inactivation, sertraline is able to enhance chemosensitivity to doxorubicin. Our results indicate that sertraline exerts antiproliferative activity by targeting the mTOR signaling pathway in a REDD1-dependent manner. Cancer Res; 70(8); 3199–208. ©2010 AACR.
Data from A Framework to Select Clinically Relevant Cancer Cell Lines for Investigation by Establishing Their Molecular Similarity with Primary Human Cancers
Authors: Dancik Garrett M. , Ru Yuanbin , Owens Charles R. , Theodorescu Dan
Published: March 2023

Abstract
Experimental work on human cancer cell lines often does not translate to the clinic. We posit that this is because some cells undergo changes in vitro that no longer make them representative of human tumors. Here, we describe a novel alignment method named Spearman's rank correlation classification method (SRCCM) that measures similarity between cancer cell lines and human tumors via gene expression profiles, for the purpose of selecting lines that are biologically relevant. To show utility, we used SRCCM to assess similarity of 36 bladder cancer lines with 10 epithelial human tumor types (N = 1,630 samples) and with bladder tumors of different stages and grades (N = 144 samples). Although 34 of 36 lines aligned to bladder tumors rather than other histologies, only 16 of 28 had SRCCM assigned grades identical to that of their original source tumors. To evaluate the clinical relevance of this approach, we show that gene expression profiles of aligned cell lines stratify survival in an independent cohort of 87 bladder patients (HR = 3.41, log-rank P = 0.0077) whereas unaligned cell lines using original tumor grades did not. We repeated this process on 22 colorectal cell lines and found that gene expression profiles of 17 lines aligning to colorectal tumors and selected based on their similarity with 55 human tumors stratified survival in an independent cohort of 177 colorectal cancer patients (HR = 2.35, log-rank P = 0.0019). By selecting cell lines that reflect human tumors, our technique promises to improve the clinical translation of laboratory investigations in cancer. Cancer Res; 71(24); 7398–409. ©2011 AACR.
Data from Chronic Activation of Wild-Type Epidermal Growth Factor Receptor and Loss of Cdkn2a Cause Mouse Glioblastoma Formation
Authors: Acquaviva Jaime , Jun Hyun Jung , Lessard Julie , Ruiz Rolando , Zhu Haihao , Donovan Melissa , Woolfenden Steve , Boskovitz Abraham , Raval Ami , Bronson Roderick T. , Pfannl Rolf , Whittaker Charles A. , Housman David E. , Charest Al
Published: March 2023

Abstract
Glioblastoma multiforme (GBM) is characterized by overexpression of epidermal growth factor receptor (EGFR) and loss of the tumor suppressors Ink4a/Arf. Efforts at modeling GBM using wild-type EGFR in mice have proven unsuccessful. Here, we present a unique mouse model of wild-type EGFR-driven gliomagenesis. We used a combination of somatic conditional overexpression and ligand-mediated chronic activation of EGFR in cooperation with Ink4a/Arf loss in the central nervous system of adult mice to generate tumors with the histopathologic and molecular characteristics of human GBMs. Sustained, ligand-mediated activation of EGFR was necessary for gliomagenesis, functionally substantiating the clinical observation that EGFR-positive GBMs from patients express EGFR ligands. To gain a better understanding of the clinically disappointing EGFR-targeted therapies for GBM, we investigated the molecular responses to EGFR tyrosine kinase inhibitor (TKI) treatment in this model. Gefitinib treatment of primary GBM cells resulted in a robust apoptotic response, partially conveyed by mitogen-activated protein kinase (MAPK) signaling attenuation and accompanied by BIMEL expression. In human GBMs, loss-of-function mutations in the tumor suppressor PTEN are a common occurrence. Elimination of PTEN expression in GBM cells posttumor formation did not confer resistance to TKI treatment, showing that PTEN status in our model is not predictive. Together, these findings offer important mechanistic insights into the genetic determinants of EGFR gliomagenesis and sensitivity to TKIs and provide a robust discovery platform to better understand the molecular events that are associated with predictive markers of TKI therapy. Cancer Res; 71(23); 7198–206. ©2011 AACR.
Data from The IL-8–Regulated Chemokine Receptor CXCR7 Stimulates EGFR Signaling to Promote Prostate Cancer Growth
Authors: Singh Rajendra Kumar , Lokeshwar Bal L.
Published: March 2023

Abstract
The proinflammatory chemokine receptor CXCR7 that binds the ligands CXCL11 and CXCL12 (SDF-1a) is elevated in a variety of human cancers, but its functions are not understood as it does not elicit classical chemokine receptor signaling. Here we report that the procancerous cytokine IL-8 (interleukin-8) upregulates CXCR7 expression along with ligand-independent functions of CXCR7 that promote the growth and proliferation of human prostate cancer cells (CaP cells). In cell culture, ectopic expression or addition of IL-8 selectively increased expression of CXCR7 at the level of mRNA and protein production. Conversely, suppressing IL-8 signaling abolished the ability of IL-8 to upregulate CXCR7. RNAi-mediated knockdown of CXCR7 in CaP cells caused multiple antitumor effects, including decreased cell proliferation, cell-cycle arrest in G1 phase, and decreased expression of proteins involved in G1 to S phase progression. In contrast, addition of the CXCR7 ligand SDF-1a and CXCL11 to CaP cells did not affect cell proliferation. Over expression of CXCR7 in normal prostate cells increased their proliferation in a manner associated with increased levels of phospho-EGFR (epidermal growth factor receptor; pY1110) and phospho-ERK1/2. Notably, coimmunoprecipitation studies established a physical association of CXCR7 with EGFR, linking CXCR7-mediated cell proliferation to EGFR activation. Consistent with these findings, CXCR7-depleted CaP tumors grew more slowly than control tumors, expressing decreased tumor-associated expression of VEGF, cyclin D1, and p-EGFR. Together, these results reveal a novel mechanism of ligand-independent growth promotion by CXCR7 and its coregulation by the proinflammatory factor IL-8 in prostate cancer. Cancer Res; 71(9); 3268–77. ©2011 AACR.
Data from FOXO3a-Dependent Mechanism of E1A-Induced Chemosensitization
Authors: Su Jen-Liang , Cheng Xiaoyun , Yamaguchi Hirohito , Chang Yi-Wen , Hou Chao-Feng , Lee Dung-Fang , Ko How-Wen , Hua Kuo-Tai , Wang Ying-Nai , Hsiao Michael , Chen PoShen B. , Hsu Jung-Mao , Bast Robert C. , Hortobagyi Gabriel N. , Hung Mien-Chie
Published: March 2023

Abstract
Gene therapy trials in human breast, ovarian, and head and neck tumors indicate that adenovirus E1A can sensitize cancer cells to the cytotoxic effects of paclitaxel in vitro and in vivo. Resistance to paclitaxel has been reported to occur in cells expressing low levels of the Forkhead transcription factor FOXO3a. In this article, we report that FOXO3a is critical for E1A-mediated chemosensitization to paclitaxel. RNA interference–mediated knockdown of FOXO3a abolished E1A-induced sensitivity to paclitaxel. Mechanistic investigations indicated that E1A indirectly stabilized FOXO3a by acting at an intermediate step to inhibit a ubiquitin-dependent proteolysis pathway involving the E3 ligase βTrCP and the FOXO3a inhibitory kinase IKKβ. E1A derepressed this inhibitory pathway by stimulating expression of the protein phosphatase 2A (PP2A)/C protein phosphatases, which by binding to the TGF-β–activated kinase TAK1, inhibited its ability to activate IKKβ and, thereby, to suppress βTrCP-mediated degradation of FOXO3a. Thus, by stimulating PP2A/C expression, E1A triggers a signaling cascade that stabilizes FOXO3a and mediates chemosensitization. Our findings provide a leap forward in understanding paclitaxel chemosensitization by E1A, and offer a mechanistic rational to apply E1A gene therapy as an adjuvant for improving therapeutic outcomes in patients receiving paclitaxel treatment. Cancer Res; 71(21); 6878–87. ©2011 AACR.
Data from IMP-1 Displays Cross-Talk with K-Ras and Modulates Colon Cancer Cell Survival through the Novel Proapoptotic Protein CYFIP2
Authors: Mongroo Perry S. , Noubissi Felicite K. , Cuatrecasas Miriam , Kalabis Jiri , King Catrina E. , Johnstone Cameron N. , Bowser Mark J. , Castells Antoni , Spiegelman Vladimir S. , Rustgi Anil K.
Published: March 2023

Abstract
Insulin-like growth factor 2 mRNA-binding protein-1 (IMP-1) is an oncofetal protein that binds directly to and stabilizes oncogenic c-Myc and regulates, in turn, its posttranscriptional expression and translation. In contrast to normal adult tissue, IMP-1 is reexpressed and/or overexpressed in human cancers. We show that knockdown of c-Myc in human colon cancer cell lines increases the expression of mature let-7 miRNA family members and downregulates several of its mRNA targets: IMP-1, Cdc34, and K-Ras. We further show that loss of IMP-1 inhibits Cdc34, Lin-28B, and K-Ras, suppresses SW-480 cell proliferation and anchorage-independent growth, and promotes caspase- and lamin-mediated cell death. We also found that IMP-1 binds to the coding region and 3′UTR of K-Ras mRNA. RNA microarray profiling and validation by reverse transcription PCR reveals that the p53-inducible proapoptotic protein CYFIP2 is upregulated in IMP-1 knockdown SW480 cells, a novel finding. We also show that overexpression of IMP-1 increases c-Myc and K-Ras expression and LIM2405 cell proliferation. Furthermore, we show that loss of IMP-1 induces Caspase-3- and PARP-mediated apoptosis, and inhibits K-Ras expression in SW480 cells, which is rescued by CYFIP2 knockdown. Importantly, analysis of 228 patients with colon cancers reveals that IMP-1 is significantly upregulated in differentiated colon tumors (P ≤ 0.0001) and correlates with K-Ras expression (r = 0.35, P ≤ 0.0001) relative to adjacent normal mucosa. These findings indicate that IMP-1, interrelated with c-Myc, acts upstream of K-Ras to promote survival through a novel mechanism that may be important in colon cancer pathogenesis. Cancer Res; 71(6); 2172–82. ©2011 AACR.
Data from Distinct TRAIL Resistance Mechanisms Can Be Overcome by Proteasome Inhibition but not Generally by Synergizing Agents
Authors: Menke Christina , Bin Lianghua , Thorburn Jacqueline , Behbakht Kian , Ford Heide L. , Thorburn Andrew
Published: March 2023

Abstract
One impediment to the use of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor-targeted agents as antitumor drugs is the evolution of resistance, a common problem in cancer. On the contrary, many different kinds of drugs synergize with TRAIL in TRAIL-sensitive tumor cells, raising the question whether one can overcome resistance with the same drugs producing synergy. This is an important question, because recent clinical trials suggest that combination treatments with cytotoxic drugs and TRAIL receptor-targeted agents do not provide additional benefit compared with cytotoxic agents on their own. Such results might be expected if drug combinations that synergize in sensitive tumor cells but cannot overcome TRAIL resistance are used in patients whose tumors were not selected for retention of TRAIL sensitivity. We tested this idea by creating isogenic tumor cells with acquired TRAIL resistance or defined mechanisms of resistance that occur in human tumors and then comparing them to the TRAIL-sensitive parental cell line. Although diverse classes of anticancer drugs were all able to synergize with TRAIL in sensitive cells, most agents were unable to overcome resistance and there was no relationship between the amount of synergy seen with a particular agent and its ability to overcome acquired resistance. An important exception was proteasome inhibitors, which were, however, able to overcome diverse resistance mechanisms. Our findings suggest that one should select drugs for TRAIL receptor agonist combination therapy based not just on their ability to synergize, but rather on their ability to overcome resistance as well as synergize. Cancer Res; 71(5); 1883–92. ©2011 AACR.
Data from Inhibition of Neurotensin Receptor 1 Selectively Sensitizes Prostate Cancer to Ionizing Radiation
Authors: Valerie Nicholas C.K. , Casarez Eli V. , DaSilva John O. , Dunlap-Brown Marya E. , Parsons Sarah J. , Amorino George P. , Dziegielewski Jaroslaw
Published: March 2023

Abstract
Radiotherapy combined with androgen depletion is generally successful for treating locally advanced prostate cancer. However, radioresistance that contributes to recurrence remains a major therapeutic problem in many patients. In this study, we define the high-affinity neurotensin receptor 1 (NTR1) as a tractable new molecular target to radiosensitize prostate cancers. The selective NTR1 antagonist SR48692 sensitized prostate cancer cells in a dose- and time-dependent manner, increasing apoptotic cell death and decreasing clonogenic survival. The observed cancer selectivity for combinations of SR48692 and radiation reflected differential expression of NTR1, which is highly expressed in prostate cancer cells but not in normal prostate epithelial cells. Radiosensitization was not affected by androgen dependence or androgen receptor expression status. NTR1 inhibition in cancer cell–attenuated epidermal growth factor receptor activation and downstream signaling, whether induced by neurotensin or ionizing radiation, establish a molecular mechanism for sensitization. Most notably, SR48692 efficiently radiosensitized PC-3M orthotopic human tumor xenografts in mice, and significantly reduced tumor burden. Taken together, our findings offer preclinical proof of concept for targeting the NTR1 receptor as a strategy to improve efficacy and outcomes of prostate cancer treatments using radiotherapy. Cancer Res; 71(21); 6817–26. ©2011 AACR.
Data from Suppression of Glucosylceramide Synthase Restores p53-Dependent Apoptosis in Mutant p53 Cancer Cells
Authors: Liu Yong-Yu , Patwardhan Gauri A. , Bhinge Kaustubh , Gupta Vineet , Gu Xin , Jazwinski S. Michal
Published: March 2023

Abstract
Tumor suppressor p53 plays an essential role in protecting cells from malignant transformation by inducing cell-cycle arrest and apoptosis. Mutant p53 that is detected in more than 50% of cases of cancers loses its role in suppression of tumors but gains in oncogenic function. Strategies to convert mutant p53 into wild-type p53 have been suggested for cancer prevention and treatment, but they face a variety of challenges. Here, we report an alternative approach that involves suppression of glucosylceramide synthase (GCS), an enzyme that glycosylates ceramide and blunts its proapoptotic activity in cancer cells. Human ovarian cancer cells expressing mutant p53 displayed resistance to apoptosis induced by DNA damage. We found that GCS silencing sensitized these mutant p53 cells to doxorubicin but did not affect the sensitivity of cells with wild-type p53. GCS silencing increased the levels of phosphorylated p53 and p53-responsive genes, including p21Waf1/Cip1, Bax, and Puma, consistent with a redirection of the mutant p53 cells to apoptosis. Reactivated p53-dependent apoptosis was similarly verified in p53-mutant tumors where GCS was silenced. Inhibition of ceramide synthase with fumonisin B1 prevented p53 reactivation induced by GCS silencing, whereas addition of exogenous C6-ceramide reactivated p53 function in p53-mutant cells. Our findings indicate that restoring active ceramide to cells can resuscitate wild-type p53 function in p53-mutant cells, offering preclinical support for a novel type of mechanism-based therapy in the many human cancers harboring p53 mutations. Cancer Res; 71(6); 2276–85. ©2011 AACR.
Data from PAX3-FOXO1 Induces Cannabinoid Receptor 1 to Enhance Cell Invasion and Metastasis
Authors: Marshall Amy D. , Lagutina Irina , Grosveld Gerard C.
Published: March 2023

Abstract
Alveolar rhabdomyosarcoma (ARMS) is a muscle-derived childhood tumor characterized by production of oncogenic PAX3/7-FOXO1 chimeric transcription factors. While downstream targets of the PAX3-FOXO1 oncoprotein in ARMS have been defined, the functional relevance of these targets is unclear. Here, we show that upregulation of the cannabinoid receptor 1 (Cnr1/Cb1) by PAX3-FOXO1 in mouse primary myoblasts and ARMS cell lines, contributes to PAX3-FOXO1 phenotypes, both in vivo and in vitro. In primary myoblasts, Cnr1 was dispensable for PAX3-FOXO1 to mediate cell proliferation, differentiation, or transformation; however, Cnr1 function was essential to increase the invasive capacity conferred by PAX3-FOXO1 overexpression in these cells. Genetic or pharmacologic abrogation of Cnr1 inhibited the enhanced basement membrane invasion induced by PAX3-FOXO1. Cnr1 loss by either route also dramatically reduced lung metastasis formation. Taken together, our findings strongly implicate Cnr1 as a novel tractable target to inhibit ARMS invasion and metastasis. Cancer Res; 71(24); 7471–80. ©2011 AACR.
Data from Aberrant Expression of OX1 Receptors for Orexins in Colon Cancers and Liver Metastases: an Openable Gate to Apoptosis
Authors: Voisin Thierry , El Firar Aadil , Fasseu Magali , Rouyer-Fessard Christiane , Descatoire Véronique , Walker Francine , Paradis Valérie , Bedossa Pierre , Henin Dominique , Lehy Thérèse , Laburthe Marc
Published: March 2023

Abstract
Resistance to apoptosis is a recurrent theme in colon cancer. We have shown previously that the 7-transmembrane spanning receptor OX1R for orexins promotes robust apoptosis in the human colon cancer cell line HT29 through an entirely novel mechanism involving phosphorylation of tyrosine-based motifs in OX1R. Here, we investigated the status of OX1R in a large series of human colorectal tumors and hepatic metastases. All primary colorectal tumors regardless of their localization and Duke's stages and all hepatic metastases tested expressed OX1R mRNA and/or protein. In sharp contrast, adjacent normal colonocytes or hepatocytes as well as control normal tissues were negative. Next, we showed that nine human colon cancer cell lines established from primary tumors or metastases expressed OX1R mRNA and underwent important apoptosis on orexin-A challenge. Most interestingly, orexin-A also promoted robust apoptosis in cells that are resistant to the most commonly used drug in colon cancer chemotherapy, 5-fluorouracil. When human colon cancer cells were xenografted in nude mice, orexin-A administered at day 0 strongly slowed the tumor growth and even reversed the development of established tumors when administered 7 days after cell inoculation. Orexin-A also acts by promoting tumor apoptosis in vivo because caspase-3 is activated in tumors on orexin treatment of nude mice. These findings support that OX1R is an Achilles heel of colon cancers, even after metastasis or chemoresistance. They suggest that OX1R agonists might be novel candidates for colon cancer therapy. Cancer Res; 71(9); 3341–51. ©2011 AACR.
Data from p120RasGAP-Mediated Activation of c-Src Is Critical for Oncogenic Ras to Induce Tumor Invasion
Authors: Chan Po-Chao , Chen Hong-Chen
Published: March 2023

Abstract
Ras genes are the most common targets for somatic gain-of-function mutations in human cancers. In this study, we found a high incidence of correlation between Ras oncogenic mutations and c-Src activation in human cancer cells. We showed that oncogenic Ras induces c-Src activation mainly on the Golgi complex and endoplasmic reticulum. Moreover, we identified p120RasGAP as an effector for oncogenic Ras to activate c-Src. The recruitment of p120RasGAP to the Golgi complex by oncogenic Ras facilitated its interaction with c-Src, thereby leading to c-Src activation, and this p120RasGAP-mediated activation of c-Src was important for tumor invasion induced by oncogenic Ras. Collectively, our findings unveil a relationship between oncogenic Ras, p120RasGAP, and c-Src, suggesting a critical role for c-Src in cancers evoked by oncogenic mutations in Ras genes. Cancer Res; 72(9); 2405–15. ©2012 AACR.
Data from S100A7 Enhances Mammary Tumorigenesis through Upregulation of Inflammatory Pathways
Authors: Nasser Mohd W. , Qamri Zahida , Deol Yadwinder S. , Ravi Janani , Powell Catherine A. , Trikha Prashant , Schwendener Reto A. , Bai Xue-Feng , Shilo Konstantin , Zou Xianghong , Leone Gustavo , Wolf Ronald , Yuspa Stuart H. , Ganju Ramesh K.
Published: March 2023

Abstract
S100A7/psoriasin, a member of the epidermal differentiation complex, is widely overexpressed in invasive estrogen receptor (ER)α-negative breast cancers. However, it has not been established whether S100A7 contributes to breast cancer growth or metastasis. Here, we report the consequences of its expression on inflammatory pathways that impact breast cancer growth. Overexpression of human S100A7 or its murine homologue mS100a7a15 enhanced cell proliferation and upregulated various proinflammatory molecules in ERα-negative breast cancer cells. To examine in vivo effects, we generated mice with an inducible form of mS100a7a15 (MMTV-mS100a7a15 mice). Orthotopic implantation of MVT-1 breast tumor cells into the mammary glands of these mice enhanced tumor growth and metastasis. Compared with uninduced transgenic control mice, the mammary glands of mice where mS100a7a15 was induced exhibited increased ductal hyperplasia and expression of molecules involved in proliferation, signaling, tissue remodeling, and macrophage recruitment. Furthermore, tumors and lung tissues obtained from these mice showed further increases in prometastatic gene expression and recruitment of tumor-associated macrophages (TAM). Notably, in vivo depletion of TAM inhibited the effects of mS100a7a15 induction on tumor growth and angiogenesis. Furthermore, introduction of soluble hS100A7 or mS100a7a15 enhanced chemotaxis of macrophages via activation of RAGE receptors. In summary, our work used a powerful new model system to show that S100A7 enhances breast tumor growth and metastasis by activating proinflammatory and metastatic pathways. Cancer Res; 72(3); 604–15. ©2011 AACR.
Data from miRNA-130a Targets ATG2B and DICER1 to Inhibit Autophagy and Trigger Killing of Chronic Lymphocytic Leukemia Cells
Authors: Kovaleva Valentina , Mora Rodrigo , Park Yoon Jung , Plass Christoph , Chiramel Abhilash I. , Bartenschlager Ralf , Döhner Hartmut , Stilgenbauer Stephan , Pscherer Armin , Lichter Peter , Seiffert Martina
Published: March 2023

Abstract
Toxicity and relapses from the immunochemotherapy used to treat chronic lymphocytic leukemia (CLL) prompt continued interest in gentle but effective targeted treatment options for the mainly elderly population suffering from this disease. Here, we report the definition of critical CLL cell survival pathways that can be targeted by ectopic reexpression of the miRNA genes miR-130a and miR-143 which are widely downregulated in CLL. Notably, miR-130a inhibited autophagy by reducing autophagosome formation, an effect mediated by downregulation of the genes ATG2B and DICER1, the latter of which is a major component of the miRNA silencing machinery. In support of the concept of a fundamental connection between miRNA disregulation and altered autophagic flux in this cancer, we showed that RNA interference–mediated knockdown of DICER1 expression was sufficient to reduce autophagy in primary or established cultures of CLL cells. Together, our findings show that miR-130a modulates cell survival programs by regulating autophagic flux, and they define roles for miR-130a and Dicer1 in a regulatory feedback loop that mediates CLL cell survival. Cancer Res; 72(7); 1763–72. ©2012 AACR.
Data from Genetic Screening for Synthetic Lethal Partners of Polynucleotide Kinase/Phosphatase: Potential for Targeting SHP-1–Depleted Cancers
Authors: Mereniuk Todd R. , Maranchuk Robert A. , Schindler Anja , Penner-Chea Jonathan , Freschauf Gary K. , Hegazy Samar , Lai Raymond , Foley Edan , Weinfeld Michael
Published: March 2023

Abstract
A genetic screen using a library of 6,961 siRNAs led to the identification of SHP-1 (PTPN6), a tumor suppressor frequently mutated in malignant lymphomas, leukemias, and prostate cancer, as a potential synthetic lethal partner of the DNA repair protein polynucleotide kinase/phosphatase (PNKP). After confirming the partnership with SHP-1, we observed that codepletion of PNKP and SHP-1 induced apoptosis. A T-cell lymphoma cell line that is SHP-1 deficient (Karpas 299) was shown to be sensitive to a chemical inhibitor of PNKP, but resistance was restored by expression of wild-type SHP-1 in these cells. We determined that while SHP-1 depletion does not significantly impact DNA strand-break repair, it does amplify the level of reactive oxygen species (ROS) and elevate endogenous DNA damage. The ROS scavenger WR1065 afforded protection to SHP-1–depleted cells treated with the PNKP inhibitor. We propose that codisruption of SHP-1 and PNKP leads to an increase in DNA damage that escapes repair, resulting in the accumulation of cytotoxic double-strand breaks and induction of apoptosis. This supports an alternative paradigm for synthetic lethal partnerships that could be exploited therapeutically. Cancer Res; 72(22); 5934–44. ©2012 AACR.