bluuebunny/crossref_metadata_2025 huggingface dataset:
Curcumin, a Dietary Component, Has Anticancer, Chemosensitization, and Radiosensitization Effects by Down-regulating the MDM2 Oncogene through the PI3K/mTOR/ETS2 Pathway
Authors: Li Mao , Zhang Zhuo , Hill Donald L. , Wang Hui , Zhang Ruiwen
Published: March 2007

The oncoprotein MDM2, a major ubiquitin E3 ligase of tumor suppressor p53, has been suggested as a novel target for human cancer therapy based on its p53-dependent and p53-independent activities. We have identified curcumin, which has previously been shown to have anticancer activity, as an inhibitor of MDM2 expression. Curcumin down-regulates MDM2, independent of p53. In a human prostate cancer cell lines PC3 (p53null), curcumin reduced MDM2 protein and mRNA in a dose- and time-dependent manner, and enhanced the expression of the tumor suppressor p21Waf1/CIP1. The inhibitory effects occur at the transcriptional level and seem to involve the phosphatidylinositol 3-kinase/mammalian target of rapamycin/erythroblastosis virus transcription factor 2 pathway. Curcumin induced apoptosis and inhibited proliferation of PC3 cells in culture, but both MDM2 overexpression and knockdown reduced these effects. Curcumin also inhibited the growth of these cells and enhanced the cytotoxic effects of gemcitabine. When it was administered to tumor-bearing nude mice, curcumin inhibited growth of PC3 xenografts and enhanced the antitumor effects of gemcitabine and radiation. In these tumors, curcumin reduced the expression of MDM2. Down-regulation of the MDM2 oncogene by curcumin is a novel mechanism of action that may be essential for its chemopreventive and chemotherapeutic effects. Our observations help to elucidate the process by which mitogens up-regulate MDM2, independent of p53, and identify a mechanism by which curcumin functions as an anticancer agent. [Cancer Res 2007;67(5):1988–96]
PARC and CUL7 Form Atypical Cullin RING Ligase Complexes
Authors: Skaar Jeffrey R. , Florens Laurence , Tsutsumi Takeya , Arai Takehiro , Tron Adriana , Swanson Selene K. , Washburn Michael P. , DeCaprio James A.
Published: March 2007

CUL7 and the p53-associated, PARkin-like cytoplasmic protein (PARC) were previously reported to form homodimers and heterodimers, the first demonstration of cullin dimerization. Although a CUL7-based SKP1/CUL1/F-box (SCF)–like complex has been observed, little is known about the existence of a PARC-based SCF-like complex and how PARC interacts with CUL7-based complexes. To further characterize PARC-containing complexes, we examined the ability of PARC to form an SCF-like complex. PARC binds RBX1 and is covalently modified by NEDD8, defining PARC as a true cullin. However, PARC fails to bind SKP1 or F-box proteins, including the CUL7-associated FBXW8. To examine the assembly of PARC- and CUL7-containing complexes, tandem affinity purification followed by multidimensional protein identification technology were used. Multidimensional protein identification technology analysis revealed that the CUL7 interaction with FBXW8 was mutually exclusive of CUL7 binding to PARC or p53. Notably, although heterodimers of CUL7 and PARC bind p53, p53 is not required for the dimerization of CUL7 and PARC. The observed physical separation of FBXW8 and PARC is supported functionally by the generation of Parc−/−, Fbxw8−/− mice, which do not show exacerbation of the Fbxw8−/− phenotype. Finally, all of the PARC and CUL7 subcomplexes examined exhibit E3 ubiquitin ligase activity in vitro. Together, these findings indicate that the intricate assembly of PARC- and CUL7-containing complexes is highly regulated, and multiple subcomplexes may exhibit ubiquitin ligase activity. [Cancer Res 2007;67(5):2006–14]
Blockade of Hedgehog Signaling Inhibits Pancreatic Cancer Invasion and Metastases: A New Paradigm for Combination Therapy in Solid Cancers
Authors: Feldmann Georg , Dhara Surajit , Fendrich Volker , Bedja Djahida , Beaty Robert , Mullendore Michael , Karikari Collins , Alvarez Hector , Iacobuzio-Donahue Christine , Jimeno Antonio , Gabrielson Kathleen L. , Matsui William , Maitra Anirban
Published: March 2007

In the context of pancreatic cancer, metastasis remains the most critical determinant of resectability, and hence survival. The objective of this study was to determine whether Hedgehog (Hh) signaling plays a role in pancreatic cancer invasion and metastasis because this is likely to have profound clinical implications. In pancreatic cancer cell lines, Hh inhibition with cyclopamine resulted in down-regulation of snail and up-regulation of E-cadherin, consistent with inhibition of epithelial-to-mesenchymal transition, and was mirrored by a striking reduction of in vitro invasive capacity (P < 0.0001). Conversely, Gli1 overexpression in immortalized human pancreatic ductal epithelial cells led to a markedly invasive phenotype (P < 0.0001) and near total down-regulation of E-cadherin. In an orthotopic xenograft model, cyclopamine profoundly inhibited metastatic spread; only one of seven cyclopamine-treated mice developed pulmonary micrometastases versus seven of seven mice with multiple macrometastases in control animals. Combination of gemcitabine and cyclopamine completely abrogated metastases while also significantly reducing the size of “primary” tumors. Gli1 levels were up-regulated in tissue samples of metastatic human pancreatic cancer samples compared with matched primary tumors. Aldehyde dehydrogenase (ALDH) overexpression is characteristic for both hematopoietic progenitors and leukemic stem cells; cyclopamine preferentially reduced “ALDH-high” cells by ∼3-fold (P = 0.048). We confirm pharmacologic Hh pathway inhibition as a valid therapeutic strategy for pancreatic cancer and show for the first time its particular efficacy against metastatic spread. By targeting specific cellular subpopulations likely involved in tumor initiation at metastatic sites, Hh inhibitors may provide a new paradigm for therapy of disseminated malignancies, particularly when used in combination with conventional antimetabolites that reduce “bulk” tumor size. [Cancer Res 2007;67(5):2187–96]
Tumor Cells Expressing Anti-CD137 scFv Induce a Tumor-Destructive Environment
Authors: Yang Yi , Yang Shilin , Ye Zhengmao , Jaffar Jade , Zhou Yifeng , Cutter Erin , Lieber Andre , Hellström Ingegerd , Hellström Karl Erik
Published: March 2007

For immunotherapy to become more effective, there is a need to maximize the antitumor response at the tumor site as well as to eliminate tumor cell variants that lack a given tumor antigen or the ability to present it. We have previously shown that wild-type (WT) cells from the K1735 melanoma (K1735-WT) are rejected following vaccination with cells (K1735-1D8) transfected to express scFv from the anti-CD137 monoclonal antibody 1D8, and that CD4+ T cells and natural killer (NK) cells are needed for this rejection. We now show that tumors harvested 4 to 10 days after mice had been transplanted with K1735-1D8 cells or a mixture of K1735-1D8 and K1735-WT cells contained more NK cells and that they had an increased percentage of CD4+ T lymphocytes producing IFNγ or tumor necrosis factor-α. We further show that the percentage of NK cells was higher in B16-1D8 melanomas expressing anti-CD137 scFv than in the WT tumors and that the percentage of FoxP3+ cells was lower. Admixture of 10% K1735-1D8 cells prevented the progressive growth of transplanted K1735-WT cells in syngeneic mice and also of cells from the antigenically different sarcoma Ag104. Inhibition of WT tumor cells by tumor cells transfected to express anti-CD137 scFv was shown also with the TC1 carcinoma and B16 melanoma. Furthermore, injection of an adenovirus vector, Ad-1D8, which encodes anti-CD137 scFv into established B16 melanomas, significantly prolonged the survival of tumor-bearing mice and could induce regression. Our data suggest that targeting of anti-CD137 scFv to tumors should be explored for therapy for some human cancers. [Cancer Res 2007;67(5):2339–44]
Cyclooxygenase-2 Inhibits UVB-Induced Apoptosis in Mouse Skin by Activating the Prostaglandin E2 Receptors, EP2 and EP4
Authors: Chun Kyung-Soo , Akunda Jacqueline K. , Langenbach Robert
Published: March 2007

Cyclooxygenase-2 (COX-2) is induced by UVB light and reduces UVB-induced epidermal apoptosis; however, the mechanism is unclear. Therefore, wild-type (WT) and COX-2−/− mice were acutely treated with UVB (5 kJ/m2), and apoptotic signaling pathways were compared. Following exposure, apoptosis was 2.5-fold higher in COX-2−/− compared with WT mice. Because prostaglandin E2 (PGE2) is the major UV-induced prostaglandin and manifests its activity via four receptors, EP1 to EP4, possible differences in EP signaling were investigated in WT and COX-2−/− mice. Following UVB exposure, protein levels of EP1, EP2, and EP4 were elevated in WT mice, but EP2 and EP4 levels were 50% lower in COX-2−/− mice. Activated cyclic AMP-dependent protein kinase (PKA) and Akt are downstream in EP2 and EP4 signaling, and their levels were reduced in UVB-exposed COX-2−/− mice. Furthermore, p-Bad (Ser136 and Ser155), antiapoptotic products of activated Akt and PKA, respectively, were significantly reduced in UVB-exposed COX-2−/− mice. To further study the roles of EP2 and EP4, UVB-exposed CD-1 mice were topically treated with indomethacin to block endogenous PGE2 production, and PGE2, the EP2 agonist (butaprost) or EP4 agonist (PGE1 alcohol), was applied. Indomethacin reduced PKA and Akt activation by ∼60%, but PGE2 and the agonists restored their activities. Furthermore, both agonists decreased apoptosis in COX-2−/− mice by 50%. The data suggest that COX-2–generated PGE2 has antiapoptotic roles in UVB-exposed mouse skin that involves EP2- and EP4-mediated signaling. [Cancer Res 2007;67(5):2015–21]
Phenethyl Isothiocyanate Inhibits Angiogenesis In vitro and Ex vivo
Authors: Xiao Dong , Singh Shivendra V.
Published: March 2007

Previous studies, including those from our laboratory, have revealed that phenethyl isothiocyanate (PEITC), a constituent of many edible cruciferous vegetables, not only affords significant protection against chemically induced cancer in animal models but also inhibits growth of cancer cells in culture and in vivo by causing cell cycle arrest and apoptosis induction. We now report a novel response to PEITC involving inhibition of angiogenesis in vitro and ex vivo at pharmacologically achievable concentrations. The PEITC treatment caused a decrease in survival of human umbilical vein endothelial cells (HUVEC) in a concentration- and time-dependent manner. The capillary-like tube structure formation (in vitro neovascularization) and migration (invasion potential) by HUVEC was also inhibited significantly in the presence of PEITC at pharmacologically relevant concentrations (<1 μmol/L). The PEITC-mediated inhibition of angiogenic features of HUVEC in vitro was associated with suppression of vascular endothelial growth factor (VEGF) secretion, down-regulation of VEGF receptor 2 protein levels, and inactivation of prosurvival serine-threonine kinase Akt. The PEITC treatment reduced migration by PC-3 human prostate cancer cells, which correlated with inactivation of Akt and suppression of VEGF, epidermal growth factor (EGF), and granulocyte colony-stimulating factor (G-CSF) secretion. The PEITC-mediated inhibition of PC-3 cell migration was statistically significantly attenuated by ectopic expression of constitutively active Akt. Most importantly, PEITC treatment inhibited ex vivo angiogenesis as revealed by chicken egg chorioallantoic membrane assay. In conclusion, the present study suggests that inhibition of angiogenesis may be an important mechanism in cancer chemoprevention by PEITC. [Cancer Res 2007;67(5):2239–46]
K-Ras Promotes Growth Transformation and Invasion of Immortalized Human Pancreatic Cells by Raf and Phosphatidylinositol 3-Kinase Signaling
Authors: Campbell Paul M. , Groehler Angela L. , Lee Kwang M. , Ouellette Michel M. , Khazak Vladimir , Der Channing J.
Published: March 2007

Mutational activation of the K-Ras oncogene is well established as a key genetic step in the development and growth of pancreatic adenocarcinomas. However, the mechanism by which aberrant Ras signaling promotes uncontrolled pancreatic tumor cell growth remains to be fully elucidated. The recent use of primary human cells to study Ras-mediated oncogenesis provides important model cell systems to dissect this mechanism. We have used a model of telomerase-immortalized human pancreatic duct-derived cells (E6/E7/st) to study mechanisms of Ras growth transformation. First, we found that human papillomavirus E6 and E7 oncogenes, which block the function of the p53 and Rb tumor suppressors, respectively, and SV40 small t antigen were required to allow mutant K-Ras(12D) growth transformation. Second, K-Ras(12D) caused growth transformation in vitro, including enhanced growth rate and loss of density dependency for growth, anchorage independence, and invasion through reconstituted basement membrane proteins, and tumorigenic transformation in vivo. Third, we determined that the Raf, phosphatidylinositol 3-kinase (PI3K), and Ral guanine nucleotide exchange factor effector pathways were activated, although extracellular signal-regulated kinase (ERK) activity was not up-regulated persistently. Finally, pharmacologic inhibition of Raf/mitogen-activated protein kinase/ERK and PI3K signaling impaired K-Ras–induced anchorage-independent growth and invasion. In summary, our studies established, characterized, and validated E6/E7/st cells for the study of Ras-induced oncogenesis. [Cancer Res 2007;67(5):2098–106]
MG-132 Sensitizes TRAIL-Resistant Prostate Cancer Cells by Activating c-Fos/c-Jun Heterodimers and Repressing c-FLIP(L)
Authors: Li Wenhua , Zhang Xiaoping , Olumi Aria F.
Published: March 2007

Tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) is a promising anticancer agent because it induces apoptosis in cancer cells but not in normal cells. Unfortunately, some cancer cells develop resistance to TRAIL-induced apoptosis. Therefore, it is clinically relevant to determine the molecular mechanisms that differentiate between TRAIL-sensitive and TRAIL-resistant tumors. Previously, we have shown that the antiapoptotic molecule cellular-FLICE-inhibitory protein long isoform [c-FLIP(L)] is necessary and sufficient to maintain resistance to TRAIL-induced apoptosis. We have found that c-FLIP(L) is transcriptionally regulated by the activator protein-1 (AP-1) family member protein c-Fos. Here, we report that MG-132, a small-molecule inhibitor of the proteasome, sensitizes TRAIL-resistant prostate cancer cells by inducing c-Fos and repressing c-FLIP(L). c-Fos, which is activated by MG-132, negatively regulates c-FLIP(L) by direct binding to the putative promoter region of the c-FLIP(L) gene. In addition to activating c-Fos, MG-132 activates another AP-1 family member, c-Jun. We show that c-Fos heterodimerizes with c-Jun to repress transcription of c-FLIP(L). Therefore, MG-132 sensitizes TRAIL-resistant prostate cancer cells by activating the AP-1 family members c-Fos and c-Jun, which, in turn, repress the antiapoptotic molecule c-FLIP(L). [Cancer Res 2007;67(5):2247–55]
High Levels of Heat Shock Protein Hsp72 in Cancer Cells Suppress Default Senescence Pathways
Authors: Yaglom Julia A. , Gabai Vladimir L. , Sherman Michael Y.
Published: March 2007

The major heat shock protein Hsp72 is constitutively expressed in many tumor cell lines and biopsies, and its expression correlates with poor prognosis in several types of cancer. Hsp72 was suggested to play an important role in neoplastic transformation and tumor development. We addressed the role of Hsp72 in cancer cells by investigating the consequences of specific depletion of Hsp72 using small interfering RNA. Down-regulation of Hsp72 in certain cancer lines triggered cell senescence associated with activation and stabilization of p53 and induction of the cell cycle inhibitor p21. Effects of Hsp72 depletion on senescence and p53 did not result from a proteotoxic stress, DNA instability, or activation of ataxia-telangiectasia-mutated (ATM) and ATM- and Rad3-related pathways. Instead, depletion of Hsp72 reduced stability and activity of the p53 inhibitor Hdm2. In addition, Hsp72 depletion triggered a p53-independent senescence program through inhibitory phosphorylation and down-regulation of the cell cycle kinase Cdc2. Therefore, Hsp72 provides a selective advantage to cancer cells by suppressing default senescence via p53-dependent and p53-independent pathways. [Cancer Res 2007;67(5):2373–81]
New Soft Alkylating Agents with Enhanced Cytotoxicity against Cancer Cells Resistant to Chemotherapeutics and Hypoxia
Authors: Patenaude Alexandre , Deschesnes Réna G. , Rousseau Jean L.C. , Petitclerc Éric , Lacroix Jacques , Côté Marie-France , C.-Gaudreault René
Published: March 2007

Chloroethylureas (CEU) are soft alkylating agents that covalently bind to β-tubulin (βTAC) and affect microtubule polymerization dynamics. Herein, we report the identification of a CEU subset and its corresponding oxazolines, which induce cell growth inhibition, apoptosis, and microtubule disruption without alkylating β-tubulin (N-βTAC). Both βTAC and N-βTAC trigger the collapse of mitochondrial potential (ΔΨm) and modulate reactive oxygen species levels, following activation of intrinsic caspase-8 and caspase-9. Experiments using human fibrosarcoma HT1080 respiratory-deficient cells (ρ0) and uncoupler of the mitochondrial respiratory chain (MRC) showed that βTAC and N-βTAC impaired the MRC. ρ0 cells displayed an increased sensitivity toward N-βTAC as compared with ρ+ cells but, in contrast, were resistant to βTAC or classic chemotherapeutics, such as paclitaxel. Oxazoline-195 (OXA-195), an N-βTAC derivative, triggered massive swelling of isolated mitochondria. This effect was insensitive to cyclosporin A and to Bcl-2 addition. In contrast, adenine nucleotide translocator (ANT) antagonists, bongkrekic acid or atractyloside, diminished swelling induced by OXA-195. The antiproliferative activities of the N-βTACs CEU-025 and OXA-152 were markedly decreased in the presence of atractyloside. Conversely, pretreatment with cyclosporin A enhanced growth inhibition induced by βTAC and N-βTAC. One of the proteins alkylated by N-βTAC was identified as the voltage-dependent anion channel isoform-1, an ANT partner. Our results suggest that βTAC and N-βTAC, despite their common ability to affect the microtubule network, trigger different cytotoxic mechanisms in cancer cells. The role of mitochondria in these mechanisms and the potential of N-βTAC as a new therapeutic approach for targeting hypoxia-resistant cells are discussed. [Cancer Res 2007;67(5):2306–16]
Stable Overexpression of Smad7 in Human Melanoma Cells Impairs Bone Metastasis
Authors: Javelaud Delphine , Mohammad Khalid S. , McKenna Christopher R. , Fournier Pierrick , Luciani Flavie , Niewolna Maryla , André Jocelyne , Delmas Véronique , Larue Lionel , Guise Theresa A. , Mauviel Alain
Published: March 2007

Melanoma has a propensity to metastasize to bone, where it is exposed to high concentrations of transforming growth factor-β (TGF-β). Because TGF-β promotes bone metastases from other solid tumors, such as breast cancer, we tested the role of TGF-β in melanoma metastases to bone. 1205Lu melanoma cells, stably transfected to overexpress the natural TGF-β/Smad signaling inhibitor Smad7, were studied in an experimental model of bone metastasis whereby tumor cells are inoculated into the left cardiac ventricle of nude mice. All mice bearing parental and mock-transfected 1205Lu cells developed osteolytic bone metastases 5 weeks post-tumor inoculation. Mice bearing 1205Lu-Smad7 tumors had significantly less osteolysis on radiographs and longer survival compared with parental and mock-transfected 1205Lu mice. To determine if the reduced bone metastases observed in mice bearing 1205Lu-Smad7 clones was due to reduced expression of TGF-β target genes known to enhance metastases to bone from breast cancer cells, we analyzed gene expression of osteolytic factors, parathyroid hormone-related protein (PTHrP) and interleukin-11 (IL-11), the chemotactic receptor CXCR4, and osteopontin in 1205Lu cells. Quantitative reverse transcription-PCR analysis indicated that PTHrP, IL-11, CXCR4, and osteopontin mRNA steady-state levels were robustly increased in response to TGF-β and that Smad7 and the TβRI small-molecule inhibitor, SB431542, prevented such induction. In addition, 1205Lu-Smad7 bone metastases expressed significantly lower levels of IL-11, connective tissue growth factor, and PTHrP. These data suggest that TGF-β promotes osteolytic bone metastases due to melanoma by stimulating the expression of prometastatic factors via the Smad pathway. Blockade of TGF-β signaling may be an effective treatment for melanoma metastasis to bone. [Cancer Res 2007;67(5):2317–24]
Histone Deacetylase Inhibitors Synergize p300 Autoacetylation that Regulates Its Transactivation Activity and Complex Formation
Authors: Stiehl Daniel P. , Fath Donna M. , Liang Dongming , Jiang Yubao , Sang Nianli
Published: March 2007

p300/cyclic AMP–responsive element binding protein–binding protein (CBP) are general coactivators for multiple transcription factors involved in various cellular processes. Several highly conserved domains of p300/CBP serve as interacting sites for transcription factors and regulatory proteins. Particularly, the intrinsic histone acetyltransferase (HAT) activity and transactivation domains (TAD) play essential roles for their coactivating function. Autoacetylation of p300/CBP is commonly observed in cell-free HAT assays and has been implicated in the regulation of their HAT activity. Here, we show that six lysine-rich regions in several highly conserved functional domains of p300 are targeted by p300HAT for acetylation in cell-free systems. We show that p300 is susceptible to acetylation in cultured tumor cells and that its acetylation status is affected by histone deacetylase inhibitor trichostatin A. We further show that either treatment with deacetylase inhibitors or coexpression of Gal4-p300HAT, which alone has no transactivation activity, stimulates the activity of the COOH-terminal TAD of p300 (p300C-TAD). We have defined the minimal p300C-TAD and show that it is sufficient to respond to deacetylase inhibitors and is a substrate for p300HAT. Finally, we show that acetylated p300 possesses enhanced ability to interact with p53. Taken together, our data suggest that acetylation regulates p300C-TAD and that acetylation of p300/CBP may contribute to the dynamic regulation of their complex formation with various interacting partners. [Cancer Res 2007;67(5):2256–64]
Epidermal Growth Factor Receptor Mutants from Human Lung Cancers Exhibit Enhanced Catalytic Activity and Increased Sensitivity to Gefitinib
Authors: Mulloy Roseann , Ferrand Audrey , Kim Youngjoo , Sordella Raffaella , Bell Daphne W. , Haber Daniel A. , Anderson Karen S. , Settleman Jeffrey
Published: March 2007

Somatic mutations within the epidermal growth factor receptor (EGFR) kinase domain are detected in 10% to 30% of human non–small cell lung cancers and are correlated with striking clinical responses in a subset of patients treated with EGFR kinase inhibitors, such as gefitinib and erlotinib. Cell-based studies suggest that these mutant EGFRs promote increased autophosphorylating activity on a subset of EGFR COOH-terminal tyrosines and the consequent engagement of a subset of downstream effectors. Because EGFR function is regulated at multiple levels in vivo, and it is therefore difficult to assess the direct consequences of these mutations on EGFR enzyme function, we measured EGFR catalytic activity in in vitro kinase assays using purified recombinant proteins corresponding to the cytoplasmic domain of wild-type and two frequently detected EGFR mutants (DelL747-P753insS and L858R). Both mutants exhibit substantially increased autophosphorylating activity relative to wild-type EGFR, and they exhibit distinct reaction kinetics. In addition, the mutant kinases are more sensitive to kinase inhibition by gefitinib, which seems to reflect their increased drug affinity. These findings suggest that the altered signaling properties and drug sensitivity of these EGFR mutants that have been observed in vivo largely result from differences in the catalytic properties of the kinase. In addition, we find that the T790M secondary “drug resistance mutation” of EGFR, which frequently arises in relapsed patients that initially responded to treatment, confers enhanced kinase activity to primary activating EGFR alleles and may, therefore, be oncogenic in some contexts. [Cancer Res 2007;67(5):2325–30]
Overexpression of Hedgehog Signaling Molecules and Its Involvement in the Proliferation of Endometrial Carcinoma Cells
Authors: Feng Yu-Zhen , Shiozawa Tanri , Miyamoto Tsutomu , Kashima Hiroyasu , Kurai Miyuki , Suzuki Akihisa , Ying-Song Jiang , Konishi Ikuo
Published: March 2007

Purpose: Research has revealed abnormal activation of the hedgehog pathway in human malignancies. The present study was undertaken to examine the expression and functional involvement of the hedgehog pathway in endometrial tissues.

Experimental Design: The expression of sonic hedgehog (Shh), patched (Ptch), Smoothened (Smo), and Gli1 was examined in various endometrial tissues and endometrial carcinoma cell lines. The effect of hedgehog signaling on the proliferation of endometrial carcinoma cell lines was also examined.

Results: The expression of Shh, Ptch, Smo, and Gli1 was very weak in normal endometrium, but was increased in endometrial hyperplasia and carcinoma stepwisely with significant differences. There was no marked difference in the expression of these molecules in carcinomas according to stages and histologic grades. Treatment with cyclopamine, a specific inhibitor of the hedgehog pathway, for endometrial carcinoma Ishikawa and HHUA cells suppressed growth by 56% and 67%, respectively, compared with the control. The addition of recombinant Shh peptide to HHUA cells enhanced their proliferation by 41%. The silencing of Gli1 using small interfering RNA (siGli1) resulted in the growth suppression and down-regulation of Ptch expression. In addition, the cyclopamine/siGli1-induced growth suppression was associated with the down-regulation of cyclins D1 and A and N-myc. No somatic mutations for ptch and smo genes were detected in the endometrial carcinoma cases examined.

Conclusions: The abnormal activation of this pathway is involved in the proliferation of endometrial carcinoma cells possibly in an auto-/paracrine fashion, suggesting the possibility of the hedgehog pathway being a novel candidate for molecular targeting.
Long-term Idiotype Vaccination Combined with Interleukin-12 (IL-12), or IL-12 and Granulocyte Macrophage Colony-Stimulating Factor, in Early-Stage Multiple Myeloma Patients
Authors: Hansson Lotta , Abdalla Amir Osman , Moshfegh Ali , Choudhury Aniruddha , Rabbani Hodjattallah , Nilsson Bo , Osterborg Anders , Mellstedt Håkan
Published: March 2007

Purpose and Experimental Design: Twenty-eight patients with immunoglobulin G myeloma stages I to II were immunized i.d. over 110 weeks with autologous M protein combined with interleukin-12 (IL-12; n = 15) or with IL-12 and granulocyte macrophage colony-stimulating factor (GM-CSF; n = 13). Idiotype-specific T-cell responses were assessed by [3H]thymidine incorporation, enzyme-linked immunospot assay, and delayed-type hypersensitivity reaction.

Results: Based on these three assays, idiotype-specific immune responses were noted in 5 of 15 (33%) patients in the IL-12 group and in 11 of 13 (85%) patients in the GM-CSF/IL-12 group (P < 0.01). Immune response was seen only in patients with M-component concentration of <50 g/L. Three of 16 (19%) responders showed a gradually increasing idiotype-specific T-cell response, whereas 11 of 16 (69%) patients showed initial response, which then disappeared rapidly; the latter pattern was frequently associated with subsequent progressive disease. Immune nonresponse was associated with an increase in the numbers of CD4+/CD25+ cells (regulatory T cells), which was absent in responding patients. Median time to progression for immune responders (n = 16) was 108 weeks compared with 26 weeks for nonresponders (n = 12; P = 0.03).

Conclusions: These results indicate that idiotype immunization of myeloma patients with GM-CSF and IL-12 may induce specific T-cell response more frequently than with IL-12 alone and that immune response may correlate with time to progression and nonresponse with increased numbers of regulatory T cells.
Combined Inhibitory Effects of Green Tea Polyphenols and Selective Cyclooxygenase-2 Inhibitors on the Growth of Human Prostate Cancer Cells Both In vitro and In vivo
Authors: Adhami Vaqar Mustafa , Malik Arshi , Zaman Najia , Sarfaraz Sami , Siddiqui Imtiaz Ahmad , Syed Deeba Nadeem , Afaq Farrukh , Pasha Farrukh Sierre , Saleem Mohammad , Mukhtar Hasan
Published: March 2007

Purpose: Cyclooxygenase-2 (COX-2) inhibitors hold promise for cancer chemoprevention; however, recent toxicity concerns suggest that new strategies are needed. One approach to overcome this limitation is to use lower doses of COX-2 inhibitors in combination with other established agents with complementary mechanisms. In this study, the effect of (−)epigallocatechin-3-gallate (EGCG), a promising chemopreventive agent from green tea, was tested alone and in combination with specific COX-2 inhibitors on the growth of human prostate cancer cells both in vitro and in vivo.

Experimental Design: Human prostate cancer cells LNCaP, PC-3, and CWR22Rν1 were treated with EGCG and NS398 alone and in combination, and their effect on growth and apoptosis was evaluated. In vivo, athymic nude mice implanted with androgen-sensitive CWR22Rν1 cells were given green tea polyphenols (0.1% in drinking water) and celecoxib (5 mg/kg, i.p., daily, 5 days per week), alone and in combination, and their effect on tumor growth was evaluated.

Results: Combination of EGCG (10-40 μmol/L) and NS-398 (10 μmol/L) resulted in enhanced (a) cell growth inhibition; (b) apoptosis induction; (c) expression of Bax, pro-caspase-6, and pro-caspase-9, and poly(ADP)ribose polymerase cleavage; (d) inhibition of peroxisome proliferator activated receptor γ; and (e) inhibition of nuclear factor-κB compared with the additive effects of the two agents alone, suggesting a possible synergism. In vivo, combination treatment with green tea polyphenols and celecoxib resulted in enhanced (a) tumor growth inhibition, (b) lowering of prostate-specific antigen levels, (c) lowering of insulin-like growth factor-I levels, and (d) circulating levels of serum insulin-like growth factor binding protein-3 compared with results of single-agent treatment.

Conclusions: These data suggest synergistic and/or additive effects of combinatorial chemopreventive agents and underscore the need for rational design of human clinical trials.
Approval Summary: Sunitinib for the Treatment of Imatinib Refractory or Intolerant Gastrointestinal Stromal Tumors and Advanced Renal Cell Carcinoma
Authors: Goodman Vicki L. , Rock Edwin P. , Dagher Ramzi , Ramchandani Roshni P. , Abraham Sophia , Gobburu Jogarao V.S. , Booth Brian P. , Verbois S. Leigh , Morse David E. , Liang Cheng Yi , Chidambaram Nallaperumal , Jiang Janet X. , Tang Shenghui , Mahjoob Kooros , Justice Robert , Pazdur Richard
Published: March 2007

Purpose: To describe the Food and Drug Administration (FDA) review and approval of sunitinib malate (Sutent). Sunitinib received regular approval for the treatment of gastrointestinal stromal tumor (GIST) after disease progression or intolerance to imatinib mesylate (Gleevec). Additionally, sunitinib received accelerated approval for the treatment of advanced renal cell carcinoma.

Experimental Design: For the GIST indication, FDA reviewed data from a randomized, placebo-controlled trial with supportive evidence from a single-arm study. For the advanced renal cell carcinoma indication, FDA reviewed data from two single-arm studies of patients with cytokine-refractory metastatic renal cell carcinoma.

Results: In patients with imatinib refractory or intolerant GIST, time-to-tumor progression of sunitinib-treated patients was superior to that of placebo-treated patients. Median time-to-tumor progression of sunitinib-treated patients was 27.3 weeks, compared with 6.4 weeks for placebo-treated patients (P < 0.0001). Partial responses were observed in 6.8% of sunitinib-treated patients. In patients with metastatic renal cell carcinoma, partial responses were observed in 25.5% (95% confidence interval, 17.5, 34.9) and 36.5% (95% confidence interval, 24.7, 49.6) of patients treated with sunitinib. Median response durations were 27.1 and 54 weeks. The most common adverse events attributed to sunitinib included diarrhea, mucositis, skin abnormalities, and altered taste. Reductions in left ventricular ejection fraction and severe hypertension were also more common in sunitinib-treated patients.

Conclusions: On January 26, 2006, the FDA approved sunitinib for the treatment of patients with imatinib refractory or intolerant GIST. Accelerated approval was granted for the treatment of advanced renal cell carcinoma.
Consonant Profile of Arabic-Speaking School-Age Children in Jordan
Authors: Hamdan Jihad M. , Amayreh Mousa M.
Published: March 2007

The paper provides a detailed consonant profile of 100 Jordanian children at the onset of formal schooling. The data were elicited through a modified version of Amayreh’s (1994) articulation test. The findings showed that all consonants of Jordanian Spoken Arabic were acquired. The six consonants that were not acquired in Standard Arabic have dialectal forms. The accuracy rates of these consonants were discussed in the light of frequency of occurrence of consonants and diglossia. The study recommended an earlier targeting of consonants that have dialectal variants. It also suggested that knowledge of the diglossic nature of Arabic is important for literacy development as well as for diagnosis and treatment of articulation problems.
Veränderungsmessung der Fähigkeit zur lautsprachlichen Analogiebildung schallempfindungsgestörter Kinder
Authors: Reeh Marcus , Kiese-Himmel Christiane
Published: March 2007

Objective: The aim of this study was to assess the lexical outcomes in auditory closure of children with aided residual hearing. Patients and Methods: A total of 37 children (from 4;7 to 8;2 years old) with bilateral (n = 23) or unilateral (n = 14) sensorineural hearing loss (average at frequencies of 0.5, 1, 2, 4 kHz >20 to >90 dB in the better ear) of unknown onset (n = 31) were recruited out of the 1994 implemented Göttinger Hör-Sprachregister (Gö HSR). Mean age at diagnosis: 72.0 months (SD 9.8; min. 48; max. 88), mean age at hearing aid implementation: 73.0 months (SD 9.4). All children demonstrated an average nonverbal intelligence, and none suffered from major comorbidities. The subtest ‘Auditory Closure’ of the standardized (compared to normally developing hearing children) German version of the Illinois Test of Psycholinguistic Abilities was carried out at 3 time points (t1–t3). Mean time interval t1–t3: 20.3 months (SD 4.7). The test raw scores were converted to T scores (mean = 50, SD = 10). The first psychometric examination took place after the ascertainment of the hearing loss (t1). Two follow-ups (t2, t3) were performed at 6- to 9-month time intervals. Results: On average, the study group exhibited age-appropriate performances at t1 and significantly improved over time. The average performance of bilaterally impaired children increased most notably (t1–t3; p = 0.008). Subgrouped by age at diagnosis ≤73 months (cut-off for split-half comparison), the performances at t3 were statistically significantly different from those of t1 (t1–t3; p = 0.002). A multiple regression analysis demonstrated the effect of the ability of auditory closure at t1 (p < 0.001) and of nonverbal intelligence (p = 0.002) on the outcome measure at t3. Conclusion: Auditory closure is less determined by degree of hearing loss than by the size of the individual vocabulary and the nonverbal intelligence potential.
The Impact of Obsessive-Compulsive Personality Disorder on the Suicidal Risk of Patients with Mood Disorders
Authors: Raja Michele , Azzoni Antonella
Published: March 2007

Background: The association of mood disorders with personality disorder is frequent and relevant in terms of clinical and therapeutic aspects. Personality disorders may modify the phenomenology of axis I psychiatric disorders, generating atypical clinical features, uncommon behavior or unusual patient attitudes. Sampling and Methods: The paper describes the atypical symptoms of 7 patients affected by mood disorder associated with obsessive-compulsive personality disorder (OCPD) who made a near-lethal suicide attempt and were admitted to a psychiatric intensive care unit. Results and Conclusions: The presence of OCPD associated with mood disorders may increase the risk of misdiagnosis, render some life events more stressful than usual for patients and increase the severity of the suicide attempt.
Safety and Efficacy of Oral Escitalopram as Continuation Treatment of Intravenous Citalopram in Patients with Major Depressive Disorder
Authors: Schmitt Laurent , Tonnoir Brigitte , Arbus Christophe
Published: March 2007

The objective of this open-label, multicentre study was to evaluate the safety and efficacy of treatment with escitalopram (10 or 20 mg/day) for 6 weeks following a switch from intravenous citalopram treatment (20 or 40 mg/day) in patients presenting with a major depressive episode. A total of 173 patients were included, 147 (85%) of whom completed the study. The mean Montgomery-Åsberg Depression Rating Scale (MADRS) total score at inclusion (last citalopram dose) was 31.6 ± 9.9. The MADRS score decreased to 23.4 ± 10.5 after 3 days of oral treatment with escitalopram and was 12.7 ± 9.3 at the end of the study. The scores on the Clinical Global Impression (CGI) and Patient Global Evaluation scales also improved: at the end of the study, the response rates were 67% on the MADRS (defined as ≧50% decrease from MADRS baseline score) and 68% on the CGI-I (defined as CGI-I ≤2). More than half of the patients were in remission (MADRS score ≤12). Overall, the switch from intravenous citalopram to escitalopram was well tolerated. In all, 57 patients (33%) reported at least 1 adverse event, and 7 patients (4%) were withdrawn due to an adverse event. The most frequently reported adverse events were probably linked to residual depressive symptoms (anxiety: 9%; insomnia: 5%). In conclusion, escitalopram was well tolerated as a continuation treatment after switching from intravenous citalopram and reduced depressive symptoms in patients with a moderate to severe major depressive episode.
The Relationship between Protein C, Protein S and Cytokines in Acute Ischemic Stroke
Authors: Akyol Ali , Ozkul Ayca , Yenisey Cigdem , Kiylioglu Nefati
Published: March 2007

Objective: The role of inflammation in the pathogenesis of acute ischemic stroke is well known, but its association with the clinical picture is as yet unclear. Material and Methods: In our study, we measured the serum levels of the proinflammatory cytokines interleukin-1β (IL-1β), tumor necrosis factor α (TNFα) and interleukin-6 (IL-6) within the first 50 h of stroke in 60 acute stroke patients, and examined the association with the natural anticoagulants protein C and free protein S. We compared the results with a control group that consisted of 30 volunteers. We also correlated their levels with the clinical outcomes by using the Canadian Neurological Scale (CNS). Results: Neither stroke patients nor the control group had any elevations in IL-1β serum levels. However, the levels of serum IL-6 were significantly higher in stroke patients (13.7 ± 19.46 vs. 4.3 ± 15.88, p = 0.002). In addition, the protein S levels of patients were lower than those of the controls (84.36 ± 27.97 vs. 95.9 ± 25.64, p = 0.007). Although IL-6 showed negative correlation with protein S (r = –0.504, p = 0.000), the other studied cytokines TNFα and IL-1β did not correlate with these natural anticoagulants. Another negative correlation was found between IL-6 and CNS scores (r = –0.451, p = 0.000). In addition, both protein C and protein S positively correlated with CNS (r = 0.263, p = 0.042; r = 0.381, p = 0.003). There was also a positive correlation between protein C and protein S (r = 0.408, p = 0.001). Conclusions: Our results suggest that TNFα and IL1β serum levels are not elevated in the acute phase of stroke and have no correlation with the natural anticoagulants protein C and protein S. However, a decrease in free protein S may be related to elevated IL-6 levels. In addition, increased levels of IL-6 and reduced levels of protein C and protein S may play a role in acute ischemic stroke severity.
Assessment of Unstable Atherosclerosis in Mice
Authors: Jackson Christopher L. , Bennett Martin R. , Biessen Erik A.L. , Johnson Jason L. , Krams Rob
Published: March 2007

There is an urgent need for representative animal models where prospective examination of the events leading up to plaque rupture and the rupture process itself can be performed. Recently, reports have begun to emerge that apolipoprotein E and low density lipoprotein receptor knockout mice may spontaneously develop unstable atherosclerosis, with plaques in certain parts of the arterial tree showing features suggestive of plaque rupture. Here we discuss the problems inherent in applying definitions of plaque rupture as seen in human arteries to mice; the anatomic locations in mice where unstable plaques do and do not occur; methods of inducing plaque instability in mice; and how to assess plaque stability in mice. These considerations lead us to a number of general recommendations.
AMP-Activated Protein Kinase in the Heart
Authors: Arad Michael , Seidman Christine E. , Seidman J.G.
Published: March 2007

AMP-activated protein kinase (AMPK) is a heterotrimeric enzyme that is expressed in most mammalian tissues including cardiac muscle. Among the multiple biological processes influenced by AMPK, regulation of fuel supply and energy-generating pathways in response to the metabolic needs of the organism is fundamental and likely accounts for the remarkable evolutionary conservation of this enzyme complex. By regulating the activity of acetyl–coenzyme A carboxylase, AMPK affects levels of malonyl–coenzyme A, a key energy regulator in the cell. AMPK is generally quiescent under normal conditions but is activated in response to hormonal signals and stresses sufficient to produce an increase in AMP/ATP ratio, such as hypoglycemia, strenuous exercise, anoxia, and ischemia. Once active, muscle AMPK enhances uptake and oxidative metabolism of fatty acids as well as increases glucose transport and glycolysis. Data from AMPK deficiency models suggest that AMPK activity might influence the pathophysiology and therapy of diabetes and increase heart tolerance to ischemia. Effects that are not as well understood include AMPK regulation of transcription. Different AMPK isoforms are found in distinct locations within the cell and have distinct functions in different tissues. A principal mode of AMPK activation is phosphorylation by upstream kinases (eg, LKB1). These kinases have a fundamental role in cell-cycle regulation and protein synthesis, suggesting involvement in a number of human disorders including cardiac hypertrophy, apoptosis, cancer, and atherosclerosis. The physiological role played by AMPK during health and disease is far from being clearly defined. Naturally occurring mutations affecting the nucleotide-sensing modules in the regulatory γ subunit of AMPK lead to enzyme dysregulation and inappropriate activation under resting conditions. Glycogen accumulation ensues, leading to human disease manifesting as cardiac hypertrophy, accessory atrioventricular connections, and degeneration of the physiological conduction system. Whether AMPK is a key participant or bystander in other disease states and whether its selective manipulation may significantly benefit these conditions remain important questions.
Tetralogy of Fallot and Alterations in Vascular Endothelial Growth Factor-A Signaling and Notch Signaling in Mouse Embryos Solely Expressing the VEGF120 Isoform
Authors: van den Akker Nynke M.S. , Molin Daniël G.M. , Peters Patricia P.W.M. , Maas Saskia , Wisse Lambertus J. , van Brempt Ronald , van Munsteren Conny J. , Bartelings Margot M. , Poelmann Robert E. , Carmeliet Peter , Gittenberger-de Groot Adriana C.
Published: March 2007

The importance of vascular endothelial growth factor-A (VEGF) and subsequent Notch signaling in cardiac outflow tract development is generally recognized. Although genetic heterogeneity and mutations of these genes in both humans and mouse models relate to a high susceptibility to develop outflow tract malformations such as tetralogy of Fallot and peripheral pulmonary stenosis, no etiology has been proposed so far. Using immunohistochemistry, in situ hybridization, and quantitative RT-PCR on embryonic hearts, we have shown spatiotemporal increase and abnormal patterning of
Vegf
/VEGF/(phosphorylated) VEGFR-2, (cleaved) Notch1, and Jagged2 in the outflow tract of
Vegf120/120
mouse embryos. This coincides with hyperplasia of specifically the outflow tract cushions and a high degree of subpulmonary myocardial apoptosis that, in later stages, manifest as pulmonary stenosis and ventricular septal defects. We postulate that increase of VEGF and Notch signaling during right ventricular outflow tract development can lead to abnormal development of both cushion and myocardial structures. Defective right ventricular outflow tract development as presented provides new insight in the etiology of tetralogy of Fallot.
High-Sensitivity C-Reactive Protein and Soluble CD40 Ligand as Indices of Inflammation and Platelet Activation in 880 Patients With Nonvalvular Atrial Fibrillation
Authors: Lip Gregory Y.H. , Patel Jeetesh V. , Hughes Elizabeth , Hart Robert G.
Published: March 2007

Background and Purpose—

There is now considerable evidence that atrial fibrillation is associated with an inflammatory state. We tested the hypothesis that plasma levels of C-reactive protein (CRP; an index of inflammation) and soluble CD40 ligand (an index of platelet activation, with links to inflammation) could be related to 3 established stroke risk stratification schema (SPAF, CHADS
2
, and NICE), recognized stroke risk factors or other cardiovascular disease, and prognosis.

Methods—

We studied 880 subjects with atrial fibrillation recruited from subjects receiving aspirin 325 mg/d (alone or combined with fixed inefficacious doses of warfarin) from the Stroke Prevention in Atrial Fibrillation (SPAF) III clinical trial. CRP and soluble CD40 ligand were measured by enzyme-linked immunosorbent assay.

Results—

With respect to the SPAF III stroke risk stratification criteria, those with moderate to high risk had the highest levels of CRP (Kruskal Wallis test,
P
<0.001), but those with the highest risk had the lowest levels of soluble CD40 ligand (
P
=0.01). Similarly, CRP levels increased in a positive fashion with increasing stroke risk with respect to the CHADS
2
and NICE risk stratification criteria, whereas soluble CD40 ligand levels were negatively associated with stroke risk. CRP levels were higher among those patients with raised body mass index, diabetes, hypertension, ischemic heart disease, peripheral vascular disease, and recent heart failure, but not those with thromboembolism. Patients were followed-up for a mean time of 453 (standard deviation, 229) days, and all-cause mortality (log rank test,
P
=0.001), and vascular events (
P
=0.05), but not stroke, were more common in patients with high CRP levels. Soluble CD40 ligand levels were not related to stroke, vascular events, or all-cause mortality.

Conclusion—

Among atrial fibrillation patients, CRP was positively correlated to stroke risk and related to stroke risk factors and prognosis (mortality, vascular events). Soluble CD40 ligand levels were lowest in those at moderate to high risk of stroke and not related to prognosis. The use of CRP in risk stratification for atrial fibrillation merits further study.