bluuebunny/crossref_metadata_2025 huggingface dataset:
Data from A Pivotal Role for Heat Shock Protein 90 in Ewing Sarcoma Resistance to Anti-Insulin-like Growth Factor 1 Receptor Treatment: In vitro and In vivo Study
Authors: Martins Ana Sofia , Ordoñez José Luis , García-Sánchez Alfredo , Herrero David , Sevillano Victoria , Osuna Daniel , Mackintosh Carlos , Caballero Gemma , Otero Ana Pastora , Poremba Christopher , Madoz-Gúrpide Juan , de Alava Enrique
Published: March 2024

Abstract
Ewing Sarcoma (ES) shows several deregulated autocrine loops mediating cell survival and proliferation. Therefore, their blockade is a promising therapeutic approach. We previously reported the in vitro effect of insulin-like growth factor 1 receptor (IGF1R)/KIT pathway blockade on ES cell lines, and we now extend our observations to changes induced by this treatment in interacting proteins/networks. A proteomic analysis revealed that Heat Shock Protein (HSP)90 was differentially expressed between ES cell lines sensitive and resistant to specific IGF1R/KIT inhibitors. We therefore inhibited HSP90 with 17-allylamino-17-demethoxygeldanamycin (17-AAG) and siRNA, and observed that ES cell line growth and survival were reduced, especially in the resistant cell lines. Conversely, HSP90 induced–expression conferred resistance to anti-IGF1R/KIT treatment in the sensitive cell lines. 17-AAG treatment induced HSP90 client protein degradation, including AKT, KIT, or IGF1R, by inhibiting their physical interaction with HSP90. Xenograft models developed with A673 ES cell line confirmed that HSP90 inhibition, alone or combined with IGF1R inhibition, significantly reduced tumor growth and expression of client proteins. Remarkably, using two independent clinical sample sets, we have found that nearly half of IGF1R-positive tumors also show HSP90 overexpression. This delineates a subset of patients that could benefit from combination of anti-HSP90 agents when considering IGF1R-targeting therapies. Importantly, sensitivity to drugs such as ADW/IMA depends not only on the levels of expression and basal activation of IGF1R/KIT, but also, and for the first time reported in ES, on the development of the stress response mechanism. Accordingly, HSP90 expression could be a predictive factor of response to IGF1R-targeting therapies. [Cancer Res 2008;68(15):6260–70]
Data from Clinical and Biological Significance of Tissue Transglutaminase in Ovarian Carcinoma
Authors: Hwang Jee Young , Mangala Lingegowda S. , Fok Jansina Y. , Lin Yvonne G. , Merritt William M. , Spannuth Whitney A. , Nick Alpa M. , Fiterman Derek J. , Vivas-Mejia Pablo E. , Deavers Michael T. , Coleman Robert L. , Lopez-Berestein Gabriel , Mehta Kapil , Sood Anil K.
Published: March 2024

Abstract
Tissue type transglutaminase (TG2) is a unique multifunctional protein that plays a role in many steps in the cancer metastatic cascade. Here, we examined the clinical (n = 93 epithelial ovarian cancers) and biological (in vitro adhesion, invasion, and survival and in vivo therapeutic targeting) significance of TG2 in ovarian cancer. The overexpression of TG2 was associated with significantly worse overall patient survival in both univariate and multivariate analyses. Transfection of TG2 into SKOV3ip1 cells promoted attachment and spreading on fibronectin-coated surfaces and increased the in vitro invasive potential of these cells. Conversely, TG2 silencing with small interfering RNA (siRNA) of HeyA8 cells significantly decreased the invasive potential of the cells and also increased docetaxel-induced cell death. In vivo therapy experiments using chemotherapy-sensitive (HeyA8) and chemotherapy-resistant (HeyA8-MDR and RMG2) models showed significant antitumor activity both with TG2 siRNA-1,2-dioleoyl-sn-glycero-3-phosphatidylcholine alone and in combination with docetaxel chemotherapy. This antitumor activity was related to decreased proliferation and angiogenesis and increased tumor cell apoptosis in vivo. Taken together, these findings indicate that TG2 overexpression is an adverse prognostic factor in ovarian carcinoma and TG2 targeting may be an attractive therapeutic approach. [Cancer Res 2008;68(14):5849–58]
Data from A New Pharmacologic Action of CCI-779 Involves FKBP12-Independent Inhibition of mTOR Kinase Activity and Profound Repression of Global Protein Synthesis
Authors: Shor Boris , Zhang Wei-Guo , Toral-Barza Lourdes , Lucas Jessica , Abraham Robert T. , Gibbons James J. , Yu Ker
Published: March 2024

Abstract
The mammalian target of rapamycin (mTOR) inhibitor CCI-779 (temsirolimus) is a recently Food and Drug Administration–approved anticancer drug with efficacy in certain solid tumors and hematologic malignancies. In cell culture studies, CCI-779 at the commonly used nanomolar concentrations generally confers a modest and selective antiproliferative activity. Here, we report that, at clinically relevant low micromolar concentrations, CCI-779 completely suppressed proliferation of a broad panel of tumor cells. This “high-dose” drug effect did not require FKBP12 and correlated with an FKBP12-independent suppression of mTOR signaling. An FKBP12-rapamycin binding domain (FRB) binding–deficient rapamycin analogue failed to elicit both the nanomolar and micromolar inhibitions of growth and mTOR signaling, implicating FRB binding in both actions. Biochemical assays indicated that CCI-779 and rapamycin directly inhibited mTOR kinase activity with IC50 values of 1.76 ± 0.15 and 1.74 ± 0.34 μmol/L, respectively. Interestingly, a CCI-779–resistant mTOR mutant (mTOR-SI) displayed an 11-fold resistance to the micromolar CCI-779 in vitro (IC50, 20 ± 3.4 μmol/L) and conferred a partial protection in cells exposed to micromolar CCI-779. Treatment of cancer cells with micromolar but not nanomolar concentrations of CCI-779 caused a marked decline in global protein synthesis and disassembly of polyribosomes. The profound inhibition of protein synthesis was accompanied by rapid increase in the phosphorylation of translation elongation factor eEF2 and the translation initiation factor eIF2α. These findings suggest that high-dose CCI-779 inhibits mTOR signaling through an FKBP12-independent mechanism that leads to profound translational repression. This distinctive high-dose drug effect could be directly related to the antitumor activities of CCI-779 and other rapalogues in human cancer patients. [Cancer Res 2008;68(8):2934–43]
Data from Effect of Low-Fat Diet on Development of Prostate Cancer and Akt Phosphorylation in the Hi-Myc Transgenic Mouse Model
Authors: Kobayashi Naoko , Barnard R. James , Said Jonathan , Hong-Gonzalez Jenny , Corman Dan M. , Ku Melvin , Doan Ngan Bao , Gui Dorina , Elashoff David , Cohen Pinchas , Aronson William J.
Published: March 2024

Abstract
This study evaluated the effect of dietary fat on prostate cancer development by using the Hi-Myc mouse transgenic prostate cancer model. Hi-Myc mice develop murine prostatic intraepithelial neoplasia (mPIN) as early as 2 to 4 weeks and invasive adenocarcinoma between 6 and 9 months due to the overexpression of human c-Myc in the mouse prostate. Three-week-old male Hi-Myc mice were placed on high-fat (HF; 42% Kcal) or low-fat (LF; 12% Kcal) diets, and equal caloric intake was maintained until euthanasia at 7 months. The number of mice that developed invasive adenocarcinoma at 7 months was 27% less in the LF diet group (12/28) compared with the HF diet group (23/33, P < 0.05). Epithelial cells in mPIN lesions in the LF group had a significantly lower proliferative index compared with epithelial cells in the HF group (21.7% versus 28.9%, P < 0.05). During the mPIN phase of carcinogenesis (4 months), the LF group had higher serum insulin-like growth factor (IGF) binding protein-1 levels (21.0 ± 8.9 ng/mL versus 3.2 ± 0.8 ng/mL, P < 0.05) relative to the HF group. Akt (Ser473) phosphorylation, Akt kinase activity, and phosphorylation of downstream targets of Akt in prostates were significantly reduced in the LF diet group compared with the HF group. We conclude that dietary fat reduction delays transition from mPIN to invasive cancer in this Myc-driven transgenic mouse model, possibly through suppression of the IGF-Akt pathway and decreased proliferation of mPIN epithelial cells. [Cancer Res 2008;68(8):3066–73]
Data from The Differential Role of L1 in Ovarian Carcinoma and Normal Ovarian Surface Epithelium
Authors: Zecchini Silvia , Bianchi Marco , Colombo Nicoletta , Fasani Roberta , Goisis Giovanni , Casadio Chiara , Viale Giuseppe , Liu Jinsong , Herlyn Meenhard , Godwin Andrew K. , Nuciforo Paolo G. , Cavallaro Ugo
Published: March 2024

Abstract
Epithelial ovarian carcinoma (EOC) arises from the ovarian surface epithelium (OSE), a monolayer of poorly differentiated epithelial cells that lines the ovary. The molecular mechanisms underlying EOC invasion into the surrounding stroma and dissemination to the peritoneum and to retroperitoneal lymph nodes are still unclear. Here, we analyzed the expression and the functional role of the cell adhesion molecule L1 during EOC development. In patient-derived samples, L1 was expressed both in OSE and in a subset of EOC, in the latter being mostly restricted to the invasive areas of the tumors. The expression of L1 correlated significantly with poor outcome and with unfavorable clinicopathologic features of the disease. The peculiar expression pattern of L1 in normal OSE and invasive EOC raised the possibility that this adhesion molecule serves a different function in nontransformed versus neoplastic ovarian epithelial cells. Indeed, we showed that in OSE cells L1 supports cell-cell adhesion and enhances apoptosis, whereas it has no effect on cell proliferation and invasion. In contrast, L1 inhibits cell-cell adhesion and apoptosis in ovarian carcinoma cells, where it promotes malignancy-related properties, such as cell proliferation, Erk1/2-dependent and phosphoinositide 3-kinase–dependent invasion, and transendothelial migration. Interestingly, a crosstalk with the fibroblast growth factor receptor signaling is implicated in the promalignant function of L1 in tumor cells. Our findings point to L1 as an EOC biomarker correlating with poor prognosis, and highlight a switch in L1 function associated to the neoplastic transformation of ovarian epithelial cells, thus implicating L1 as a potential therapeutic target. [Cancer Res 2008;68(4):1110–8]
Data from Neutrophil Gelatinase–Associated Lipocalin: A Novel Suppressor of Invasion and Angiogenesis in Pancreatic Cancer
Authors: Tong Zhimin , Kunnumakkara Ajaikumar B. , Wang Huamin , Matsuo Yoichi , Diagaradjane Parmeswaran , Harikumar Kuzhuvelil B. , Ramachandran Vijaya , Sung Bokyung , Chakraborty Arup , Bresalier Robert S. , Logsdon Craig , Aggarwal Bharat B. , Krishnan Sunil , Guha Sushovan
Published: March 2024

Abstract
Neutrophil gelatinase–associated lipocalin (NGAL) is a 25-kDa secreted acute phase protein, which is also up-regulated in multiple cancers, including breast, lung, and pancreas. Recently, NGAL has been proposed as an early biomarker in pancreatic cancer (PaCa). However, its biological role in PaCa is unknown. In this study, we examined in vitro and in vivo the functional role of NGAL in PaCa. Well- to moderately differentiated PaCa cells (AsPC-1, BxPC-3, and Capan-2) expressed high levels of NGAL but moderately to poorly differentiated PaCa cells (PANC-1 and MIAPaCa-2) expressed undetectable NGAL levels. Immunohistochemistry of untreated tissue microarray showed specific NGAL staining in resected PaCa specimens (P = 0.0167). Stable NGAL overexpression (MIAPaCa-2 and PANC-1) significantly blocked PaCa cell adhesion and invasion in vitro and vice versa with stable PaCa clones (BxPC-3 and AsPC-1). Moreover, NGAL overexpression reduced focal adhesion kinase (FAK) tyrosine-397 phosphorylation in PaCa cells. Furthermore, NGAL overexpression potently decreased angiogenesis in vitro partly through reduced vascular endothelial growth factor (VEGF) production and vice versa. Stable NGAL overexpression or underexpression had no effect on PaCa cell survival, viability, and response to chemotherapeutic drugs. Finally, MIAPaCa-2 cells overexpressing NGAL reduced tumor volume (P = 0.012), local and distant metastasis (P = 0.002), and angiogenesis (P = 0.05) with no effect on K-67 proliferation index (P > 0.1) in an orthotopic nude mouse PaCa model. Collectively, our results suggest that NGAL reduces adhesion/invasion partly by suppressing FAK activation and inhibits angiogenesis partly by blocking VEGF production in PaCa cells. Thus, NGAL is a potential suppressor of invasion and angiogenesis in advanced PaCa. [Cancer Res 2008;68(15):6100–8]
Data from Defining the Cooperative Genetic Changes That Temporally Drive Alveolar Rhabdomyosarcoma
Authors: Naini Sarasija , Etheridge Katherine T. , Adam Stacey J. , Qualman Stephen J. , Bentley Rex C. , Counter Christopher M. , Linardic Corinne M.
Published: March 2024

Abstract
Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood and adolescence. Despite advances in therapy, patients with a histologic variant of RMS known as alveolar (aRMS) have a 5-year survival rate of <30%. aRMS tissues exhibit a number of genetic changes, including loss-of-function of the p53 and Rb tumor suppressor pathways, amplification of MYCN, stabilization of telomeres, and most characteristically, reciprocal translocation of loci involving the PAX and FKHR genes, generating the PAX7-FKHR or PAX3-FKHR fusion proteins. We previously showed that PAX3-FKHR expression in primary human myoblasts, cells that can give rise to RMS, cooperated with loss of p16INK4A to promote extended proliferation. To better understand the genetic events required for aRMS formation, we then stepwise converted these cells to their transformed counterpart. PAX3-FKHR, the catalytic unit of telomerase hTERT, and MycN, in cooperation with down-regulation of p16INK4A/p14ARF expression, were necessary and sufficient to convert normal human myoblasts into tumorigenic cells that gave rise to aRMS tumors. However, the order of expression of these transgenes was critical, as only those cells expressing PAX3-FKHR early could form tumors. We therefore suggest that the translocation of PAX3 to FKHR drives proliferation of myoblasts, and a selection for loss of p16INK4A/p14ARF. These early steps, coupled with MycN amplification and telomere stabilization, then drive the cells to a fully tumorigenic state. [Cancer Res 2008;68(23):9583–8]
Data from Overcoming Glutathione S-Transferase P1–Related Cisplatin Resistance in Osteosarcoma
Authors: Pasello Michela , Michelacci Francesca , Scionti Isabella , Hattinger Claudia Maria , Zuntini Monia , Caccuri Anna Maria , Scotlandi Katia , Picci Piero , Serra Massimo
Published: March 2024

Abstract
Cisplatin (cis-diamminedichloroplatinum, CDDP) is one of the most used drugs for osteosarcoma chemotherapy. By using a series of CDDP-resistant variants, which were established from the U-2OS and Saos-2 human osteosarcoma cell lines, we found that CDDP resistance was mainly associated with the increase of both the intracellular level and enzymatic activity of glutathione S-transferase P1 (GSTP1). On the basis of these findings, we evaluated the clinical effect of GSTP1 in a series of 34 high-grade osteosarcoma patients and we found that the increased expression of GSTP1 gene was associated with a significantly higher relapse rate and a worse clinical outcome. These indications prompted us to assess the in vitro effectiveness of 6-(7-nitro-2,1,3-benzoxadiazol-4-ylthio)hexanol (NBDHEX), a promising new anticancer agent that is a highly efficient inhibitor of GSTP1. NBDHEX was tested on a panel of 10 human osteosarcoma cell lines and 20 variants of the U-2OS or Saos-2 cell lines that were resistant to CDDP, doxorubicin, or methotrexate. NBDHEX proved to be very active on the vast majority of these cell lines, including those with higher GSTP1 levels and enzymatic activity. Drug combination studies showed that NBDHEX can be used in association with CDDP and provided useful information about the best modality of their combined administration. In conclusion, our findings show that GSTP1 has a relevant effect for both CDDP resistance and clinical outcome of high-grade osteosarcoma and that targeting GSTP1 with NBDHEX may be considered a promising new therapeutic possibility for osteosarcoma patients who fail to respond to conventional chemotherapy. [Cancer Res 2008;68(16):6661–8]
Data from FGFR2-Amplified Gastric Cancer Cell Lines Require FGFR2 and Erbb3 Signaling for Growth and Survival
Authors: Kunii Kaiko , Davis Lenora , Gorenstein Julie , Hatch Harold , Yashiro Masakazu , Di Bacco Alessandra , Elbi Cem , Lutterbach Bart
Published: March 2024

Abstract
We have identified a critical role for amplified FGFR2 in gastric cancer cell proliferation and survival. In a panel of gastric cancer cell lines, fibroblast growth factor receptor 2 (FGFR2) was overexpressed and tyrosine phosphorylated selectively in FGFR2-amplified cell lines KatoIII, Snu16, and OCUM-2M. FGFR2 kinase inhibition by a specific small-molecule inhibitor resulted in selective and potent growth inhibition in FGFR2-amplified cell lines, resulting in growth arrest in KatoIII cells and prominent induction of apoptosis in both Snu16 and OCUM-2M cells. FGFR2-amplified cell lines also contained elevated phosphotyrosine in EGFR, Her2, and Erbb3, but the elevated phosphorylation in EGFR could not be inhibited by gefitinib or erlotinib. We show that the elevated EGFR, Her2, and Erbb3 phosphotyrosine is dependent on FGFR2, revealing EGFR family kinases to be downstream targets of amplified FGFR2. Moreover, shRNA to Erbb3 resulted in a loss of proliferation, confirming a functional role for the activated EGFR signaling pathway. These results reveal that both the FGFR2 and EGFR family signaling pathways are activated in FGFR2-amplified gastric cancer cell lines to drive cell proliferation and survival. Inhibitors of FGFR2 or Erbb3 signaling may have therapeutic efficacy in the subset of gastric cancers containing FGFR2 amplification. [Cancer Res 2008;68(7):2340–8]
Data from PIK3CA Mutations and Copy Number Gains in Human Lung Cancers
Authors: Yamamoto Hiromasa , Shigematsu Hisayuki , Nomura Masaharu , Lockwood William W. , Sato Mitsuo , Okumura Naoki , Soh Junichi , Suzuki Makoto , Wistuba Ignacio I. , Fong Kwun M. , Lee Huei , Toyooka Shinichi , Date Hiroshi , Lam Wan L. , Minna John D. , Gazdar Adi F.
Published: March 2024

Abstract
We investigated the frequency and function of mutations and increased copy number of the PIK3CA gene in lung cancers. PIK3CA mutations are one of the most common gene changes present in human cancers. We analyzed the mutational status of exons 9 and 20 and gene copy number of PIK3CA using 86 non–small cell lung cancer (NSCLC) cell lines, 43 small cell lung cancer (SCLC) cell lines, 3 extrapulmonary small cell cancer (ExPuSC) cell lines, and 691 resected NSCLC tumors and studied the relationship between PIK3CA alterations and mutational status of epidermal growth factor receptor (EGFR) signaling pathway genes (EGFR, KRAS, HER2, and BRAF). We also determined PIK3CA expression and activity and correlated the findings with effects on cell growth. We identified mutations in 4.7% of NSCLC cell lines and 1.6% of tumors of all major histologic types. Mutations in cell lines of small cell origin were limited to two ExPuSC cell lines. PIK3CA copy number gains were more frequent in squamous cell carcinoma (33.1%) than in adenocarcinoma (6.2%) or SCLC lines (4.7%). Mutational status of PIK3CA was not mutually exclusive to EGFR or KRAS. PIK3CA alterations were associated with increased phosphatidylinositol 3-kinase activity and phosphorylated Akt expression. RNA interference–mediated knockdown of PIK3CA inhibited colony formation of cell lines with PIK3CA mutations or gains but was not effective in PIK3CA wild-type cells. PIK3CA mutations or gains are present in a subset of lung cancers and are of functional importance. [Cancer Res 2008;68(17):6913–21]
Data from Improved Cellular Pharmacokinetics and Pharmacodynamics Underlie the Wide Anticancer Activity of Sagopilone
Authors: Hoffmann Jens , Vitale Ilio , Buchmann Bernd , Galluzzi Lorenzo , Schwede Wolfgang , Senovilla Laura , Skuballa Werner , Vivet Sonia , Lichtner Rosemarie B. , Vicencio José M. , Panaretakis Theocharis , Siemeister Gerhard , Lage Hermann , Nanty Lisa , Hammer Stefanie , Mittelstaedt Kevin , Winsel Sebastian , Eschenbrenner Julia , Castedo Maria , Demarche Carine , Klar Ulrich , Kroemer Guido
Published: March 2024

Abstract
Sagopilone (ZK-EPO) is the first fully synthetic epothilone undergoing clinical trials for the treatment of human tumors. Here, we investigate the cellular pathways by which sagopilone blocks tumor cell proliferation and compare the intracellular pharmacokinetics and the in vivo pharmacodynamics of sagopilone with other microtubule-stabilizing (or tubulin-polymerizing) agents. Cellular uptake and fractionation/localization studies revealed that sagopilone enters cells more efficiently, associates more tightly with the cytoskeleton, and polymerizes tubulin more potently than paclitaxel. Moreover, in contrast to paclitaxel and other epothilones [such as the natural product epothilone B (patupilone) or its partially synthetic analogue ixabepilone], sagopilone is not a substrate of the P-glycoprotein efflux pumps. Microtubule stabilization by sagopilone caused mitotic arrest, followed by transient multinucleation and activation of the mitochondrial apoptotic pathway. Profiling of the proapoptotic signal transduction pathway induced by sagopilone with a panel of small interfering RNAs revealed that sagopilone acts similarly to paclitaxel. In HCT 116 colon carcinoma cells, sagopilone-induced apoptosis was partly antagonized by the knockdown of proapoptotic members of the Bcl-2 family, including Bax, Bak, and Puma, whereas knockdown of Bcl-2, Bcl-XL, or Chk1 sensitized cells to sagopilone-induced cell death. Related to its improved subcellular pharmacokinetics, however, sagopilone is more cytotoxic than other epothilones in a large panel of human cancer cell lines in vitro and in vivo. In particular, sagopilone is highly effective in reducing the growth of paclitaxel-resistant cancer cells. These results underline the processes behind the therapeutic efficacy of sagopilone, which is now evaluated in a broad phase II program. [Cancer Res 2008;68(13):5301–8]
Data from PIK3CA Cooperates with Other Phosphatidylinositol 3′-Kinase Pathway Mutations to Effect Oncogenic Transformation
Authors: Oda Katsutoshi , Okada Jennifer , Timmerman Luika , Rodriguez-Viciana Pablo , Stokoe David , Shoji Keiko , Taketani Yuji , Kuramoto Hiroyuki , Knight Zachary A. , Shokat Kevan M. , McCormick Frank
Published: March 2024

Abstract
Mutations in genes functioning in different pathways frequently occur together in the same cancer, whereas mutations in the same pathway tend to be mutually exclusive. However, the majority of colon, breast, and endometrial cancers that possess mutations in PIK3CA, the catalytic subunit p110α of phosphatidylinositol 3′-kinase (PI3K), also possess mutations or alterations in genes upstream of PI3K such as Ras, ERBB2/ERBB3, or PTEN. PIK3CA mutations occur almost exclusively in invasive tumors, whereas upstream mutations occur as frequently in early-stage and late-stage tumors, suggesting that PIK3CA mutation is a late-stage event that may augment earlier activation of the PI3K pathway. Consistent with this, we find that levels of p-AKT (Ser473) induced by mutant Ras or knockdown of PTEN were dramatically increased by addition of mutant PIK3CA. Soft agar assays revealed that anchorage-independent growth induced by mutant Ras was greatly increased in the presence of mutant PIK3CA. In breast, colon, and endometrial cancers in which the PI3K pathway is activated by a combination of mutant PIK3CA and alterations in Ras, ERBB2/3, or PTEN, signaling to downstream elements such as Akt was mediated exclusively by the p110α isoform, rather than a combination of different PI3K isoforms. Our data therefore suggest that in tumors with co-occurring mutations in multiple components of the PI3K pathway, selective inhibition of the α isoform of p110 is an attractive therapeutic strategy, especially for late-stage tumors. [Cancer Res 2008;68(19):8127–36]
Data from An Epigenetic Genome-Wide Screen Identifies SPINT2 as a Novel Tumor Suppressor Gene in Pediatric Medulloblastoma
Authors: Kongkham Paul N. , Northcott Paul A. , Ra Young Shin , Nakahara Yukiko , Mainprize Todd G. , Croul Sidney E. , Smith Christian A. , Taylor Michael D. , Rutka James T.
Published: March 2024

Abstract
Medulloblastoma (MB) is a malignant cerebellar tumor that occurs primarily in children. The hepatocyte growth factor (HGF)/MET pathway has an established role in both normal cerebellar development as well as the development and progression of human brain tumors, including MB. To identify novel tumor suppressor genes involved in MB pathogenesis, we performed an epigenome-wide screen in MB cell lines, using 5-aza-2′deoxycytidine to identify genes aberrantly silenced by promoter hypermethylation. Using this technique, we identified an inhibitor of HGF/MET signaling, serine protease inhibitor kunitz-type 2 (SPINT2/HAI-2), as a putative tumor suppressor silenced by promoter methylation in MB. In addition, based on single nucleotide polymorphism array analysis in primary MB samples, we identified hemizygous deletions targeting the SPINT2 locus in addition to gains on chromosome 7 encompassing the HGF and MET loci. SPINT2 gene expression was down-regulated and MET expression was up-regulated in 73.2% and 45.5% of tumors, respectively, by quantitative real-time PCR. SPINT2 promoter methylation was detected in 34.3% of primary MBs examined by methylation-specific PCR. SPINT2 reexpression in MB cell lines reduced proliferative capacity, anchorage independent growth, cell motility in vitro, and increased overall survival times in vivo in a xenograft model (P < 0.0001). Taken together, these data support the role of SPINT2 as a putative tumor suppressor gene in MB, and further implicate dysregulation of the HGF/MET signaling pathway in the pathogenesis of MB. [Cancer Res 2008;68(23):9945–53]
Data from Baicalein Overcomes Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand Resistance via Two Different Cell-Specific Pathways in Cancer Cells but not in Normal Cells
Authors: Taniguchi Hiroya , Yoshida Tatsushi , Horinaka Mano , Yasuda Takashi , Goda Ahmed E. , Konishi Masako , Wakada Miki , Kataoka Keisho , Yoshikawa Toshikazu , Sakai Toshiyuki
Published: March 2024

Abstract
Tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) is one of the most promising candidates for new cancer therapeutics. A current problem is that some cancers still remain resistant to TRAIL. We show for the first time that a naturally occurring flavonoid, baicalein, overcomes TRAIL resistance in cancer cells. The combination of baicalein and TRAIL effectively induced apoptosis in TRAIL-resistant colon cancer SW480 cells. Baicalein up-regulated the expression of death receptor 5 (DR5) among TRAIL receptors at the mRNA and protein levels. Suppression of this up-regulation with small interfering RNA (siRNA) efficiently reduced the apoptosis induced by TRAIL and baicalein, suggesting that the sensitization was mediated through DR5 induction. Moreover, baicalein also overcame TRAIL resistance with DR5 up-regulation in prostate cancer PC3 cells. Of note, the combination of TRAIL and baicalein hardly induced apoptosis in normal human cells, such as blood cells and hepatocytes. Baicalein increased DR5 promoter activity, and this enhanced activity was diminished by mutation of a CCAAT/enhancer-binding protein homologous protein (CHOP)–binding site in SW480 cells. In SW480 cells, CHOP siRNA blocked both functions of baicalein. CHOP expression was induced by baicalein in SW480 cells; however, in PC3 cells, baicalein scarcely induced CHOP and mutation of the CHOP-binding site did not abrogate the DR5 promoter activation by baicalein. Interestingly, baicalein induced reactive oxygen species (ROS) and a ROS scavenger prevented DR5 expression and TRAIL sensitization in PC3 but not SW480 cells. These results indicate that, using two different pathways, baicalein exposes cancer surveillance of TRAIL and overcomes TRAIL resistance in cancer cells. [Cancer Res 2008;68(21):8918–27]
Data from CREB3L2-PPARγ Fusion Mutation Identifies a Thyroid Signaling Pathway Regulated by Intramembrane Proteolysis
Authors: Lui Weng-Onn , Zeng Lingchun , Rehrmann Victoria , Deshpande Seema , Tretiakova Maria , Kaplan Edwin L. , Leibiger Ingo , Leibiger Barbara , Enberg Ulla , Höög Anders , Larsson Catharina , Kroll Todd G.
Published: March 2024

Abstract
The discovery of gene fusion mutations, particularly in leukemia, has consistently identified new cancer pathways and led to molecular diagnostic assays and molecular-targeted chemotherapies for cancer patients. Here, we report our discovery of a novel CREB3L2-PPARγ fusion mutation in thyroid carcinoma with t(3;7)(p25;q34), showing that a family of somatic PPARγ fusion mutations exist in thyroid cancer. The CREB3L2-PPARγ fusion encodes a CREB3L2-PPARγ fusion protein that is composed of the transactivation domain of CREB3L2 and all functional domains of PPARγ1. CREB3L2-PPARγ was detected in <3% of thyroid follicular carcinomas. Engineered overexpression of CREB3L2-PPARγ induced proliferation by 40% to 45% in primary human thyroid cells, consistent with a dominant oncogenic mechanism. Wild-type CREB3L2 was expressed in the thyroid as a bZIP transcription factor with a transmembrane domain that has flanking S1P and S2P proteolytic cleavage sites. Native CREB3L2 was cleaved to nuclear CREB3L2 by regulated intramembrane proteolysis in normal thyroid cells that expressed the S1P and S2P proteases. Nuclear CREB3L2 stimulated transcription 8-fold from the EVX1 cyclic AMP (cAMP) response element in the absence of cAMP, whereas CREB3L2-PPARγ inhibited transcription 6-fold from EVX1 in the same experiments. CREB3L2-PPARγ also inhibited 4-fold the expression of thyroglobulin, a native cAMP-responsive gene, in primary thyroid cells treated with thyroid-stimulating hormone. Our findings identify a novel CREB3L2-PPARγ gene fusion mutation in thyroid carcinoma and reveal a thyroid signaling pathway that is regulated by intramembrane proteolysis and disrupted in cancer. [Cancer Res 2008;68(17):7156–64]
Data from Conditional Deletion of Insulin-like Growth Factor-I Receptor in Prostate Epithelium
Authors: Sutherland Brent W. , Knoblaugh Sue E. , Kaplan-Lefko Paula J. , Wang Fen , Holzenberger Martin , Greenberg Norman M.
Published: March 2024

Abstract
Insulin-like growth factor-I (IGF-I) is a polypeptide hormone that can influence growth, differentiation, and survival of cells expressing the cognate type 1 receptor (IGF-IR). To better understand cell autonomous IGF-IR signaling in the epithelial compartment of the prostate gland, we generated a conditional (Cre/loxP) prostate-specific IGF-IR knockout mouse model. In contrast to epidemiologic studies that established a correlation between elevated serum IGF-I and the risk of developing prostate cancer, we show that abrogation of IGF-IR expression in the dorsal and lateral prostate could activate extracellular signal-regulated kinase 1/2 signaling and cause cell autonomous proliferation and hyperplasia. Moreover, persistent loss of IGF-IR expression in dorsal and ventral lobes induced p53-regulated apoptosis and cellular senescence rescue programs, predicting that titration of IGF-IR signaling might facilitate growth of tumors with compromised p53 activity. Therefore, we crossed the mice carrying the prostate-specific IGF-IR knockout alleles into the transgenic adenocarcinoma of the mouse prostate model that is driven, in part, by T antigen–mediated functional inactivation of p53. Consistent with our prediction, prostate epithelial–specific deletion of IGF-IR accelerated the emergence of aggressive prostate cancer when p53 activity was compromised. Collectively, these data support a critical role for IGF-IR signaling in prostate tumorigenesis and identify an important IGF-IR–dependent growth control mechanism. [Cancer Res 2008;68(9):3495–504]
Data from Apoptotic Activity and Mechanism of 2-Cyano-3,12-Dioxoolean-1,9-Dien-28-Oic-Acid and Related Synthetic Triterpenoids in Prostate Cancer
Authors: Hyer Marc L. , Shi Ranxin , Krajewska Maryla , Meyer Colin , Lebedeva Irina V. , Fisher Paul B. , Reed John C.
Published: March 2024

Abstract
Synthetic triterpenoids 2-cyano-3, 12-dioxooleana-1, 9-(11)-dien-28-oic acid (CDDO) and CDDO-Me (CDDO-methyl ester) have entered clinical trials for cancer. We determined that CDDO analogues at submicromolar concentrations induce apoptosis of cultured prostate cancer cell lines, LNCaP, ALVA31, Du145, PC3, and PPC1, with lethal dose 50% ∼1 μmol/L for CDDO-Me and an imidazole analogue (CDDO-Im). These compounds induced apoptosis of prostate cancer cells as characterized by cleavage of caspase-3, caspase-7, caspase-8, caspase-9, caspase-10, BID, and poly(ADP)ribose polymerase and by dependence on caspase activity. Moreover, triterpenoid-induced cell death was abolished by caspase-8–targeting small interfering (si) RNA. To explore the mechanism(s) involved in caspase-8 activation, we examined cell surface expression of death receptor (DR)4 and DR5 after triterpenoid treatment. Cell surface DR4 and DR5 expression was significantly up-regulated by CDDO or CDDO-Im but not by CDDO-Me. DR4 and DR5 knockdown with siRNA significantly inhibited apoptosis induced by CDDO and CDDO-Im but had no effect on CDDO-Me–induced killing, suggesting that CDDO and CDDO-Im induce apoptosis by a different mechanism than CDDO-Me. In addition to activating the caspase-8–dependent extrinsic apoptosis pathway, we observed that Bcl-XL overexpression inhibited triterpenoid-mediated killing of prostate cancer cell line Du145, suggesting that the intrinsic pathway (via mitochondria) also participates in triterpenoid-mediated killing. In vivo antitumor activity of CDDO-Me was shown using a Du145 tumor xenograft model in nude rats. Altogether, these findings suggest CDDO and related synthetic triterpenoids should be further evaluated as potential novel therapeutics for hormone refractory prostate cancers. [Cancer Res 2008;68(8):2927–33]
Data from Amyloid Precursor Protein Is a Primary Androgen Target Gene That Promotes Prostate Cancer Growth
Authors: Takayama Ken-ichi , Tsutsumi Shuichi , Suzuki Takashi , Horie-Inoue Kuniko , Ikeda Kazuhiro , Kaneshiro Kiyofumi , Fujimura Tetsuya , Kumagai Jinpei , Urano Tomohiko , Sakaki Yoshiyuki , Shirahige Katsuhiko , Sasano Hironobu , Takahashi Satoru , Kitamura Tadaichi , Ouchi Yasuyoshi , Aburatani Hiroyuki , Inoue Satoshi
Published: March 2024

Abstract
Androgen receptor (AR) is a critical transcription factor that regulates various target genes and contributes to the pathophysiology of prostate cancer hormone dependently. Here, we identify amyloid precursor protein (APP) as a primary androgen target through chromatin immunoprecipitation (ChIP) combined with genome tiling array analysis (ChIP-chip). ChIP-treated DNA were obtained from prostate cancer LNCaP cells with R1881 or vehicle treatment using AR or acetylated histone H3 antibodies. Ligand-dependent AR binding was further enriched by PCR subtraction. Using chromosome 21/22 arrays, we identified APP as one of the androgen-regulated genes with adjacent functional AR binding sites. APP expression is androgen-inducible in LNCaP cells and APP immunoreactivity was correlated with poor prognosis in patients with prostate cancer. Gain-of-function and loss-of-function studies revealed that APP promotes the tumor growth of prostate cancer. The present study reveals a novel APP-mediated pathway responsible for the androgen-dependent growth of prostate cancer. Our findings will indicate that APP could be a potential molecular target for the diagnosis and treatment of prostate cancer. [Cancer Res 2009;69(1):137–42]
Data from Loss of Cannabinoid Receptor 1 Accelerates Intestinal Tumor Growth
Authors: Wang Dingzhi , Wang Haibin , Ning Wei , Backlund Michael G. , Dey Sudhansu K. , DuBois Raymond N.
Published: March 2024

Abstract
Although endocannabinoid signaling is important for certain aspects of gastrointestinal homeostasis, the role of the cannabinoid receptors (CB) in colorectal cancer has not been defined. Here we show that CB1 expression was silenced in human colorectal cancer due to methylation of the CB1 promoter. Our genetic and pharmacologic studies reveal that loss or inhibition of CB1 accelerated intestinal adenoma growth in ApcMin/+ mice whereas activation of CB1 attenuated intestinal tumor growth by inducing cell death via down-regulation of the antiapoptotic factor survivin. This down-regulation of survivin by CB1 is mediated by a cyclic AMP–dependent protein kinase A signaling pathway. These results indicate that the endogenous cannabinoid system may represent a potential therapeutic target for prevention or treatment of colorectal cancer. [Cancer Res 2008;68(15):6468–76]
Data from Activation of Apoptosis by 1-Hydroxy-5,7-Dimethoxy-2-Naphthalene-Carboxaldehyde, a Novel Compound from Aegle marmelos
Authors: Subramaniam Dharmalingam , Giridharan Periyasamy , Murmu Nabendu , Shankaranarayanan Nallakandy P. , May Randal , Houchen Courtney W. , Ramanujam Rama P. , Balakrishnan Arun , Vishwakarma Ram A. , Anant Shrikant
Published: March 2024

Abstract
We have identified a natural compound that activates apoptosis of epithelial cancer cells through activation of tumor necrosis factor-α (TNF-α), TNF receptor (TNFR)-associated death domain (TRADD), and caspases. The molecule 1-hydroxy-5,7-dimethoxy-2-naphthalene-carboxaldehyde (HDNC, marmelin) was isolated and characterized from ethyl acetate fraction of extracts of Aegle marmelos. HDNC treatment inhibited the growth of HCT-116 colon cancer tumor xenografts in vivo. Immunostaining for CD31 showed that there was a significant reduction in microvessels in the HDNC-treated animals, coupled with decreased cyclooxygenase-2, interleukin-8, and vascular endothelial growth factor mRNA. Using hexoseaminidase assay, we determined that HDNC inhibits proliferation of HCT-116 colon and HEp-2 alveolar epithelial carcinoma cells. Furthermore, the cancer cells showed increased levels of activated caspase-3 and induced G1 cell cycle arrest, which was suppressed by caspase-3 inhibitors. HDNC induced TNF-α, TNFR1, and TRADD mRNA and protein expression. Moreover, caspase-8 and Bid activation, and cytochrome c release, were observed, suggesting the existence of a cross-talk between death receptor and the mitochondrial pathways. HDNC inhibited AKT and extracellular signal-regulated kinase phosphorylation both in cells in culture and in tumor xenografts. In addition, electrophoretic mobility shift assay and luciferase reporter assays showed that HDNC significantly suppressed TNF-α–mediated activation and translocation of nuclear factor-κB (NF-κB). This was further confirmed by Western blot analysis of nuclear extracts wherein levels of RelA, the p65 component of NF-κB, were significantly less in cells treated with HDNC. Together, the data suggest that the novel compound HDNC (marmelin) is a potent anticancer agent that induces apoptosis during G1 phase of the cell cycle and could be a potential chemotherapeutic candidate. [Cancer Res 2008;68(20):8573–81]
Data from Drug Delivery with Carbon Nanotubes for In vivo Cancer Treatment
Authors: Liu Zhuang , Chen Kai , Davis Corrine , Sherlock Sarah , Cao Qizhen , Chen Xiaoyuan , Dai Hongjie
Published: March 2024

Abstract
Chemically functionalized single-walled carbon nanotubes (SWNT) have shown promise in tumor-targeted accumulation in mice and exhibit biocompatibility, excretion, and little toxicity. Here, we show in vivo SWNT drug delivery for tumor suppression in mice. We conjugate paclitaxel (PTX), a widely used cancer chemotherapy drug, to branched polyethylene glycol chains on SWNTs via a cleavable ester bond to obtain a water-soluble SWNT-PTX conjugate. SWNT-PTX affords higher efficacy in suppressing tumor growth than clinical Taxol in a murine 4T1 breast cancer model, owing to prolonged blood circulation and 10-fold higher tumor PTX uptake by SWNT delivery likely through enhanced permeability and retention. Drug molecules carried into the reticuloendothelial system are released from SWNTs and excreted via biliary pathway without causing obvious toxic effects to normal organs. Thus, nanotube drug delivery is promising for high treatment efficacy and minimum side effects for future cancer therapy with low drug doses. [Cancer Res 2008;68(16):6652–60]
Data from Aberrant Activation of Androgen Receptor in a New Neuropeptide-Autocrine Model of Androgen-Insensitive Prostate Cancer
Authors: Yang Joy C. , Ok Joon-ha , Busby J. Erik , Borowsky Alexander D. , Kung Hsing-Jien , Evans Christopher P.
Published: March 2024

Abstract
Treatment of advanced prostate cancer with androgen deprivation therapy inevitably renders the tumors castration-resistant and incurable. Under these conditions, neuroendocrine differentiation of prostate cancer (CaP) cells is often detected and neuropeptides released by these cells may facilitate the development of androgen independence. Exemplified by gastrin-releasing peptide (GRP), these neuropeptides transmit their signals through G protein–coupled receptors, which are often overexpressed in prostate cancer, and aberrantly activate androgen receptor (AR) in the absence of androgen. We developed an autocrine neuropeptide model by overexpressing GRP in LNCaP cells and the resultant cell line, LNCaP-GRP, exhibited androgen-independent growth with enhanced motility in vitro. When orthotopically implanted in castrated nude mice, LNCaP-GRP produced aggressive tumors, which express GRP, prostate-specific antigen, and nuclear-localized AR. Chromatin immunoprecipitation studies of LNCaP-GRP clones suggest that GRP activates and recruits AR to the cognate promoter in the absence of androgen. A Src family kinase (SFK) inhibitor, AZD0530, inhibits androgen-independent growth and migration of the GRP-expressing cell lines, and blocks the nuclear translocation of AR, indicating the involvement of SFK in the aberrant activation of AR and demonstrating the potential use of SFK inhibitor in the treatment of castration-resistant CaP. In vivo studies have shown that AZD0530 profoundly inhibits tumor metastasis in severe combined immunodeficient mice implanted with GRP-autocrine LNCaP cells. This xenograft model shows autocrine, neuropeptide- and Src kinase–mediated progression of androgen-independent CaP postcastration, and is potentially useful for testing novel therapeutic agents. [Cancer Res 2009;69(1):151–60]
Data from Pten Deficiency in Melanocytes Results in Resistance to Hair Graying and Susceptibility to Carcinogen-Induced Melanomagenesis
Authors: Inoue-Narita Tae , Hamada Koichi , Sasaki Takehiko , Hatakeyama Sachiko , Fujita Sachiko , Kawahara Kohichi , Sasaki Masato , Kishimoto Hiroyuki , Eguchi Satoshi , Kojima Itaru , Beermann Friedrich , Kimura Tetsunori , Osawa Masatake , Itami Satoshi , Mak Tak Wah , Nakano Toru , Manabe Motomu , Suzuki Akira
Published: March 2024

Abstract
Phosphate and tensin homologue deleted on chromosome 10 (PTEN) is a tumor suppressor gene inactivated in numerous sporadic cancers, including melanomas. To analyze Pten functions in melanocytes, we used the Cre-loxP system to delete Pten specifically in murine pigment-producing cells and generated DctCrePtenflox/flox mice. Half of DctCrePtenflox/flox mice died shortly after birth with enlargements of the cerebral cortex and hippocampus. Melanocytes were increased in the dermis of perinatal DctCrePtenflox/flox mice. When the mutants were subjected to repeated depilations, melanocyte stem cells in the bulge of the hair follicle resisted exhaustion and the mice were protected against hair graying. Although spontaneous melanomas did not form in DctCrePtenflox/flox mice, large nevi and melanomas developed after carcinogen exposure. DctCrePtenflox/flox melanocytes were increased in size and exhibited heightened activation of Akt and extracellular signal–regulated kinases, increased expression of Bcl-2, and decreased expression of p27Kip1. Our results show that Pten is important for the maintenance of melanocyte stem cells and the suppression of melanomagenesis. [Cancer Res 2008;68(14):5760–8]
Data from 250K Single Nucleotide Polymorphism Array Karyotyping Identifies Acquired Uniparental Disomy and Homozygous Mutations, Including Novel Missense Substitutions of c-Cbl, in Myeloid Malignancies
Authors: Dunbar Andrew J. , Gondek Lukasz P. , O'Keefe Christine L. , Makishima Hideki , Rataul Manjot S. , Szpurka Hadrian , Sekeres Mikkael A. , Wang Xiao Fei , McDevitt Michael A. , Maciejewski Jaroslaw P.
Published: March 2024

Abstract
Two types of acquired loss of heterozygosity are possible in cancer: deletions and copy-neutral uniparental disomy (UPD). Conventionally, copy number losses are identified using metaphase cytogenetics, whereas detection of UPD is accomplished by microsatellite and copy number analysis and as such, is not often used clinically. Recently, introduction of single nucleotide polymorphism (SNP) microarrays has allowed for the systematic and sensitive detection of UPD in hematologic malignancies and other cancers. In this study, we have applied 250K SNP array technology to detect previously cryptic chromosomal changes, particularly UPD, in a cohort of 301 patients with myelodysplastic syndromes (MDS), overlap MDS/myeloproliferative disorders (MPD), MPD, and acute myeloid leukemia. We show that UPD is a common chromosomal defect in myeloid malignancies, particularly in chronic myelomonocytic leukemia (CMML; 48%) and MDS/MPD-unclassifiable (38%). Furthermore, we show that mapping minimally overlapping segmental UPD regions can help target the search for both known and unknown pathogenic mutations, including newly identified missense mutations in the proto-oncogene c-Cbl in 7 of 12 patients with UPD11q. Acquired mutations of c-Cbl E3 ubiquitin ligase may explain the pathogenesis of a clonal process in a subset of MDS/MPD, including CMML. [Cancer Res 2008;68(24):10349–57]
Data from Functional Interaction between BubR1 and Securin in an Anaphase-Promoting Complex/CyclosomeCdc20–Independent Manner
Authors: Kim Hyun-Soo , Jeon Yoon-Kyung , Ha Geun-Hyoung , Park Hye-Young , Kim Yu-Jin , Shin Hyun-Jin , Lee Chang Geun , Chung Doo-Hyun , Lee Chang-Woo
Published: March 2024

Abstract
Activation of the mitotic checkpoint requires the precise timing and spatial organization of mitotic regulatory events, and ensures accurate chromosome segregation. Mitotic checkpoint proteins such as BubR1 and Mad2 bind to Cdc20, and inhibit anaphase-promoting complex/cyclosomeCdc20–mediated securin degradation and the onset of anaphase. BubR1 mediates the proper attachment of microtubules to kinetochores, and links the regulation of chromosome-spindle attachment to mitotic checkpoint signaling. Therefore, disruption of BubR1 activity results in a loss of the checkpoint control, chromosome instability, and/or early onset of malignancy. In this study, we show that BubR1 directly interacts with securin in vitro and in vivo. In addition, the BubR1 interaction contributes to the stability of securin, and there is a significant positive correlation between BubR1 and securin expressions in human cancer. Importantly, BubR1 competes with Cdc20 for binding to securin, and thereby the interaction between BubR1 and securin is greatly increased by the depletion of Cdc20. Our findings may identify a novel regulation of BubR1 that can generate an additional anaphase-inhibitory signal through the Cdc20-independent interaction of BubR1 with securin. [Cancer Res 2009;69(1):27–36]