bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism of Increased Lipolysis in Cancer Cachexia
Authors: Agustsson Thorhallur , Rydén Mikael , Hoffstedt Johan , van Harmelen Vanessa , Dicker Andrea , Laurencikiene Jurga , Isaksson Bengt , Permert Johan , Arner Peter
Published: June 2007

Loss of fat mass is a key feature of cancer cachexia and has been attributed to increased adipocyte lipolysis. The mechanism behind this alteration is unknown and was presently investigated. We studied mature s.c. fat cells and differentiated preadipocytes from 26 cancer patients with and without cachexia. Hormone-induced lipolysis and expression of lipolysis-regulating genes were determined together with body composition and in vivo lipolytic activity (fasting plasma glycerol or fatty acids related to body fat). Body fat was reduced by 40% and in vivo lipolytic activity was 2-fold increased in cachexia (P = 0.001). In mature adipocytes, the lipolytic effects of catecholamines and natriuretic peptide were 2- to 3-fold increased in cachexia (P < 0.001). This was completely counteracted by inhibiting the rate-limiting lipolysis enzyme hormone-sensitive lipase (HSL). In cachexia, the expression levels of HSL mRNA and protein were increased by 50% and 100%, respectively (P = 0.005–0.03), which strongly correlated with in vitro lipolytic stimulation (r = 0.7–0.9). The antilipolytic effect of insulin in mature fat cells and the stimulated lipolytic effect in differentiated preadipocytes were unaltered in cachexia. Patients who lost weight due to other factors than cancer cachexia had no change in adipocyte lipolysis. In conclusion, adipocyte lipolysis is increased in cancer cachexia not due to nonepigenic factors or to weight loss per se, but most probably because of enhanced expression and function of adipocyte HSL. The selective inhibition of this enzyme may prevent fat loss in cancer patients. [Cancer Res 2007;67(11):5531–7]
Platelet-Derived Growth Factor Receptor β–Mediated Phosphorylation of MUC1 Enhances Invasiveness in Pancreatic Adenocarcinoma Cells
Authors: Singh Pankaj K. , Wen Yunfei , Swanson Benjamin J. , Shanmugam Kandavel , Kazlauskas Andrius , Cerny Ronald L. , Gendler Sandra J. , Hollingsworth Michael A.
Published: June 2007

MUC1 is a heterodimeric transmembrane glycoprotein that is overexpressed and aberrantly glycosylated in ductal adenocarcinomas. Differential phosphorylation of the MUC1 cytoplasmic tail (MUC1CT) has been associated with signaling events that influence the proliferation and metastasis of cancer cells. We identified a novel tyrosine phosphorylation site (HGRYVPP) in the MUC1CT by mass spectrometric analysis of MUC1 from human pancreatic adenocarcinoma cell lines. Analyses in vitro and in vivo showed that platelet-derived growth factor receptor β (PDGFRβ) catalyzed phosphorylation of this site and of tyrosine in the RDTYHPM site. Stimulation of S2-013.MUC1F cells with PDGF-BB increased nuclear colocalization of MUC1CT and β-catenin. PDGF-BB stimulation had no significant effect on cell proliferation rate; however, it enhanced invasion in vitro through Matrigel and in vivo tumor growth and metastases. Invasive properties of the cells were significantly altered on expression of phosphorylation-abrogating or phosphorylation-mimicking mutations at these sites. We propose that interactions of MUC1 and PDGFRβ induce signal transduction events that influence the metastatic properties of pancreatic adenocarcinoma. [Cancer Res 2007;67(11):5201–10]
Adenovirus Tumor Targeting and Hepatic Untargeting by a Coxsackie/Adenovirus Receptor Ectodomain Anti–Carcinoembryonic Antigen Bispecific Adapter
Authors: Li Hua-Jung , Everts Maaike , Pereboeva Larisa , Komarova Svetlana , Idan Anat , Curiel David T. , Herschman Harvey R.
Published: June 2007

Adenovirus vectors have a number of advantages for gene therapy. However, because of their lack of tumor tropism and their preference for liver infection following systemic administration, they cannot be used for systemic attack on metastatic disease. Many epithelial tumors (e.g., colon, lung, and breast) express carcinoembryonic antigen (CEA). To block the natural hepatic tropism of adenovirus and to “retarget” the virus to CEA-expressing tumors, we used a bispecific adapter protein (sCAR-MFE), which fuses the ectodomain of the coxsackie/adenovirus receptor (sCAR) with a single-chain anti-CEA antibody (MFE-23). sCAR-MFE untargets adenovirus-directed luciferase transgene expression in the liver by >90% following systemic vector administration. Moreover, sCAR-MFE can “retarget” adenovirus to CEA-positive epithelial tumor cells in cell culture, in s.c. tumor grafts, and in hepatic tumor grafts. The sCAR-MFE bispecific adapter should, therefore, be a powerful agent to retarget adenovirus vectors to epithelial tumor metastases. [Cancer Res 2007;67(11):5354–61]
Kallikrein 4 Is a Proliferative Factor that Is Overexpressed in Prostate Cancer
Authors: Klokk Tove Irene , Kilander Anette , Xi Zhijun , Wæhre Håkon , Risberg Bjørn , Danielsen Håvard E. , Saatcioglu Fahri
Published: June 2007

Kallikrein 4 (KLK4) is a member of the human tissue KLK family. Whereas all other KLKs are secreted proteins with extracellular functions, KLK4 is primarily localized to the nucleus, indicating that it has a different function compared with other members of the KLK family. In addition, KLK4 expression is highly enriched in the prostate and is regulated by androgens. Here, we studied the possible functional role of KLK4 in prostate cancer cells and examined its expression at the protein level in prostate cancer specimens. Consistent with its mRNA expression, KLK4 protein is significantly overexpressed in malignant prostate compared with normal prostate. KLK4 expression is predominantly in the nucleus of basal cells in the prostate epithelium in keeping with its distribution in prostate cancer cells in vitro. Furthermore, adenovirus-mediated expression of KLK4 dramatically induces proliferation of prostate cancer cells, at least in part through significant alterations in cell cycle regulatory gene expression. Consistent with these data, small interfering RNA–mediated knockdown of endogenous KLK4 in LNCaP prostate cancer cells inhibits cell growth. These data identify KLK4 as the first member of the KLK family that is a proliferative factor with effects on gene expression and indicate that it may have an important role in prostate cancer development and progression. [Cancer Res 2007;67(11):5221–30]
Arsenic Induced Mitochondrial DNA Damage and Altered Mitochondrial Oxidative Function: Implications for Genotoxic Mechanisms in Mammalian Cells
Authors: Partridge Michael A. , Huang Sarah X.L. , Hernandez-Rosa Evelyn , Davidson Mercy M. , Hei Tom K.
Published: June 2007

Arsenic is a well-established human carcinogen that is chronically consumed in drinking water by millions of people worldwide. Recent evidence has suggested that arsenic is a genotoxic carcinogen. Furthermore, we have shown that mitochondria mediate the mutagenic effects of arsenic in mammalian cells, as arsenic did not induce nuclear mutations in mitochondrial DNA (mtDNA)–depleted cells. Using the human-hamster hybrid AL cells, we show here that arsenic alters mitochondrial function by decreasing cytochrome c oxidase function and oxygen consumption but increasing citrate synthase function. These alterations correlated with depletion in mtDNA copy number and increase in large heteroplasmic mtDNA deletions. In addition, mtDNA isolated periodically from cultures treated continuously with arsenic did not consistently display the same deletion pattern, indicating that the mitochondrial genome was subjected to repeated and continuous damage. These data support the theory that the mitochondria, and particularly mtDNA, are important targets of the mutagenic effects of arsenic in mammalian cells. [Cancer Res 2007;67(11):5239–47]
Localization of Human TACC3 to Mitotic Spindles Is Mediated by Phosphorylation on Ser558 by Aurora A: A Novel Pharmacodynamic Method for Measuring Aurora A Activity
Authors: LeRoy Patrick J. , Hunter John J. , Hoar Kara M. , Burke Krissy E. , Shinde Vaishali , Ruan Jason , Bowman Douglas , Galvin Katherine , Ecsedy Jeffrey A.
Published: June 2007

Aurora A is a serine/threonine protein kinase essential for normal mitotic progression. Aberrant increased expression of Aurora A, which occurs frequently in human cancers, results in abnormal mitoses leading to chromosome instability and possibly tumorigenesis. Consequently, Aurora A has received considerable attention as a potential target for anticancer therapeutic intervention. Aurora A coordinates several essential mitotic activities through phosphorylation of a variety of proteins, including TACC3, which modulates microtubule stabilization of the mitotic spindle. Recent studies identified a conserved serine in Xenopus (Ser626) and Drosophila (Ser863) TACC3 orthologues that is phosphorylated by Aurora A. We show that this conserved serine on human TACC3 (Ser558) is also phosphorylated by Aurora A. Moreover, phosphorylation of TACC3 by Aurora A in human cells is essential for its proper localization to centrosomes and proximal mitotic spindles. Inhibition of Aurora A with the selective small molecule inhibitor MLN8054 in cultured human tumor cells resulted in mislocalization of TACC3 away from mitotic spindles in a concentration-dependent manner. Furthermore, oral administration of MLN8054 to nude mice bearing HCT-116 human tumor xenografts caused a dose-dependent mislocalization of TACC3 away from spindle poles that correlated with tumor growth inhibition. As TACC3 localization to mitotic spindles depends on Aurora A–mediated phosphorylation, quantifying TACC3 mislocalization represents a novel pharmacodynamic approach for measuring Aurora A activity in cancer patients treated with inhibitors of Aurora A kinase. [Cancer Res 2007;67(11):5362–70]
BCR-ABL Activity Is Critical for the Immunogenicity of Chronic Myelogenous Leukemia Cells
Authors: Brauer Katharina M. , Werth Daniela , von Schwarzenberg Karin , Bringmann Anita , Kanz Lothar , Grünebach Frank , Brossart Peter
Published: June 2007

Chronic myelogenous leukemia (CML) is a myeloproliferative disorder caused by excessive granulopoiesis due to the formation of the constitutively active tyrosine kinase BCR-ABL. An effective drug against CML is imatinib mesylate, a tyrosine kinase inhibitor acting on Abl kinases, c-KIT, and platelet-derived growth factor receptor. Recently, a study revealed that patients treated with imatinib showed impaired CTL responses compared with patients treated with IFN-α, which might be due to a treatment-induced reduction in immunogenicity of CML cells or immunosuppressive effects. In our study, we found that inhibition of BCR-ABL leads to a down-regulation of immunogenic antigens on the CML cells in response to imatinib treatment, which results in the inhibition of CML-directed immune responses. By treating CML cells with imatinib, we could show that the resulting inhibition of BCR-ABL leads to a decreased expression of tumor antigens, including survivin, adipophilin, hTERT, WT-1, Bcl-xL, and Bcl-2 in correlation to a decreased development of CML-specific CTLs. In contrast, this reduction in immunogenicity was not observed when a CML cell line resistant to the inhibitory effects of imatinib was used, but could be confirmed by transfection with specific small interfering RNA against BCR-ABL or imatinib treatment of primary CML cells. [Cancer Res 2007;67(11):5489–97]
Recognition of Prostate and Melanoma Tumor Cells by Six-Transmembrane Epithelial Antigen of Prostate–Specific Helper T Lymphocytes in a Human Leukocyte Antigen Class II–Restricted Manner
Authors: Kobayashi Hiroya , Nagato Toshihiro , Sato Keisuke , Aoki Naoko , Kimura Shoji , Murakami Masamoto , Iizuka Hajime , Azumi Makoto , Kakizaki Hidehiro , Tateno Masatoshi , Celis Esteban
Published: June 2007

The six-transmembrane epithelial antigen of prostate (STEAP) protein is an attractive candidate for T cell–based immunotherapy because it is overexpressed in prostate cancer and various other tumor types. Several peptide epitopes capable of stimulating CTLs that killed STEAP-expressing tumor cells have been described. Our goal was the identification of helper T lymphocyte (HTL) epitopes of STEAP for the optimization of T cell–based immunotherapies against STEAP-expressing malignancies. Candidate HTL epitopes for STEAP were predicted using in silico algorithms for HLA class II–binding peptides and were tested for their ability to elicit HTL responses by in vitro peptide vaccination of CD4 T lymphocytes from healthy individuals and prostate cancer patients. Two peptides (STEAP102–116 and STEAP192–206) were effective in stimulating in vitro antitumor HTL responses in both normal individuals and prostate cancer patients. Notably, both STEAP HTL peptides behaved as promiscuous T-cell epitopes because they stimulated T cells in the context of more than one MHC class II allele. These newly described STEAP HTL epitopes could be of value for the design and optimization of T cell–based immunotherapy against STEAP-expressing tumors. [Cancer Res 2007;67(11):5498–504]
NRH:Quinone Oxidoreductase 2 and NAD(P)H:Quinone Oxidoreductase 1 Protect Tumor Suppressor p53 against 20S Proteasomal Degradation Leading to Stabilization and Activation of p53
Authors: Gong Xing , Kole Labanyamoy , Iskander Karim , Jaiswal Anil K.
Published: June 2007

Tumor suppressor p53 is either lost or mutated in several types of cancer. MDM2 interaction with p53 results in ubiquitination and 26S proteasomal degradation of p53. Chronic DNA damage leads to inactivation of MDM2, stabilization of p53, and apoptotic cell death. Here, we present a novel MDM2/ubiquitination-independent mechanism of stabilization and transient activation of p53. The present studies show that 20S proteasomes degrade p53. The 20S degradation of p53 was observed in ubiquitin-efficient and -deficient cells, indicating that this pathway of degradation did not require ubiquitination of p53. The cytosolic quinone oxidoreductases [NRH:quinone oxidoreductase 2 (NQO2) and NAD(P)H:quinone oxidoreductase 1 (NQO1)] interacted with p53 and protected p53 against 20S proteasomal degradation. Further studies revealed that acute exposure to radiation or chemical leads to induction of NQO1 and NQO2 that stabilizes and transiently activates p53 and downstream genes. These results suggest that stress-induced NQO1 and NQO2 transiently stabilize p53, which leads to protection against adverse effects of stressors. [Cancer Res 2007;67(11):5380–8]
Extracellular Signal-Regulated Kinase Is a Target of Cyclooxygenase-1-Peroxisome Proliferator-Activated Receptor-δ Signaling in Epithelial Ovarian Cancer
Authors: Daikoku Takiko , Tranguch Susanne , Chakrabarty Anindita , Wang Dingzhi , Khabele Dineo , Orsulic Sandra , Morrow Jason D. , DuBois Raymond N. , Dey Sudhansu K.
Published: June 2007

The underlying causes of epithelial ovarian cancer (EOC) are unclear, and treatment options for patients with advanced disease are limited. There is evidence that the use of nonsteroidal anti-inflammatory drugs is associated with decreased risk of developing EOC. Nonsteroidal anti-inflammatory drugs inhibit cyclooxygenase (COX)-1 and COX-2, which catalyze prostaglandin biosynthesis. We previously showed that mouse and human EOCs have increased levels of COX-1, but not COX-2, and a COX-1–selective inhibitor, SC-560, attenuates prostaglandin production and tumor growth. However, the downstream targets of COX-1 signaling in EOC are not yet known. To address this question, we evaluated peroxisome proliferator-activated receptor δ (PPARδ) expression and function in EOC. We found that EOC cells express high levels of PPARδ, and neutralizing PPARδ function reduces tumor growth in vivo. More interestingly, aspirin, a nonsteroidal anti-inflammatory drug that preferentially inhibits COX-1, compromises PPARδ function and cell growth by inhibiting extracellular signal-regulated kinases 1/2, members of the mitogen-activated protein kinase family. Our study, for the first time, shows that whereas PPARδ can be a target of COX-1, extracellular signal-regulated kinase is a potential target of PPARδ. The ability of aspirin to inhibit EOC growth in vivo is an exciting finding because of its low cost, lack of cardiovascular side effects, and availability. [Cancer Res 2007;67(11):5285–92]
The Antitumor Agent Imexon Activates Antioxidant Gene Expression: Evidence for an Oxidative Stress Response
Authors: Baker Amanda F. , Landowski Terry , Dorr Robert , Tate Wendy R. , Gard Jaime M.C. , Tavenner Breonna E. , Dragovich Tomislov , Coon Amy , Powis Garth
Published: June 2007

Purpose: The aim of this study was to identify biomarkers that may be predictive for the clinical activity of the redox-active antitumor agent imexon.

Experimental Design: cDNA microarray and quantitative real-time PCR were used to identify global changes in gene expression in peripheral blood mononuclear cells (PBMC) collected from patients treated with imexon during a phase I trial. Electrophoretic mobility shift assays and Western blot analysis were done using the RPMI8226 myeloma cell line grown in vitro and PBMCs treated ex vivo to investigate the molecular mechanism responsible for these gene changes.

Results: Both cDNA microarray and quantitative real-time PCR showed the up-regulation of many antioxidant genes, including thioredoxin reductase-1, glutaredoxin-2, and peroxiredoxin-3 in PBMCs collected from patients treated with imexon. Studies in PBMCs treated ex vivo and RPMI8226 myeloma cells showed that imexon increased binding to the activator protein-1 consensus sequence measured by electrophoretic mobility shift assay. Supershift analysis showed that the majority of the activator protein-1 DNA binding activity was c-Jun, with minor contribution of Jun-D. Nuclear translocation of the nuclear factor (erythroid-derived 1)-like 2 transcription factor and its binding to the antioxidant response element was also increased after imexon treatment, which correlated with an increase in the message levels for nuclear factor (erythroid-derived 1)-like 2/antioxidant response element–regulated antioxidant genes.

Conclusions: Together, these results show that a predominant biological effect of imexon is a change in redox state that can be detected in surrogate normal tissues as increased redox-sensitive transcription factor binding and increased antioxidant gene expression.
Fluorodeoxyglucose Uptake of Primary Non-Small Cell Lung Cancer at Positron Emission Tomography: New Contrary Data on Prognostic Role
Authors: Vesselle Hubert , Freeman Joseph D. , Wiens Linda , Stern Joshua , Nguyen Huang Q. , Hawes Stephen E. , Bastian Philip , Salskov Alexander , Vallières Eric , Wood Douglas E.
Published: June 2007

Purpose: This prospective study evaluated the prognostic significance of 18F-fluorodeoxyglucose (18F-FDG) uptake in primary non-small cell lung cancer (NSCLC) at positron emission tomography, in a carefully staged population, while correcting for partial volume effects.

Experimental Design: Two hundred eight potentially resectable NSCLC patients were referred for FDG positron emission tomography staging after thoracic computed tomography. Each tumor stage was confirmed surgically, or for some stage IV tumors by additional imaging. The tumor maximum pixel-standardized uptake value (maxSUV) and the maxSUV partial volume corrected for lesion size (PVCmaxSUV) were compared with overall survival and disease-free survival using Cox proportional hazards regression.

Results: Stage distribution: stage I, 36%; stage II, 15%; stage III, 30%; stage IV, 19%. Patients were followed for a median of 33.6 months, with 90 deaths from NSCLC (median survival for all stages, 43.3 months). With respect to overall survival, the most significant cutoff value for both maxSUV and PVCmaxSUV was 7. MaxSUV ≥7 was significantly associated with an increased risk of death from NSCLC in univariable analysis, whereas PVCmaxSUV ≥7 was only marginally associated. However, in multivariable analyses, neither maxSUV ≥7 nor PVCmaxSUV ≥7 provided significant additional prognostic information over stage, tumor size, and age. In the 103 patients who underwent surgical resection only, surgical stage, but not maxSUV or PVCmaxSUV, was univariably associated with survival or recurrence. SUV definitions based on lean body mass, body surface area, and plasma glucose correction yielded identical results.

Conclusions: As expected, tumor stage is prognostic in NSCLC. However, tumor FDG uptake does not provide additional prognostic information. This prospective study contradicts prior reports.
A Comparison of the Pharmacokinetics and Pharmacodynamics of Docetaxel between African-American and Caucasian Cancer Patients: CALGB 9871
Authors: Lewis Lionel D. , Miller Antonius A. , Rosner Gary L. , Dowell Jonathan E. , Valdivieso Manuel , Relling Mary V. , Egorin Merrill J. , Bies Robert R. , Hollis Donna R. , Levine Ellis G. , Otterson Gregory A. , Millard Frederick , Ratain Mark J. ,   for the Cancer and Leukemia Group B
Published: June 2007

Purpose: Increased clearance of drugs, such as oral cyclosporine, that are CYP3A and/or ABCB1 (P-gp/MDR1) substrates was reported in African-American compared with Caucasian patients. We hypothesized that the pharmacokinetics and pharmacodynamics of docetaxel, an i.v. administered cytotoxic and substrate for CYP3A4, CYP3A5, and ABCB1, would differ between African-American and Caucasian patients.

Experimental Design: We investigated population pharmacokinetics and pharmacodynamics and the pharmacogenetics of CYP3A4, CYP3A5, and ABCB1 in African-American and Caucasian cancer patients who received docetaxel 75 or 100 mg/m2 as a 1-h i.v. infusion. Plasma docetaxel concentrations were measured by high-performance liquid chromatography. Clinical toxicity and absolute neutrophil count (ANC) were monitored on days 8, 15, and 22 postadministration of docetaxel. Using a limited sampling strategy and nonlinear mixed-effects modeling, each patient's docetaxel clearance was estimated. Genotyping for known polymorphisms in CYP3A4, CYP3A5, and ABCB1 was done.

Results: We enrolled 109 patients: 40 African-Americans (26 males; 14 females), with a median age of 61 years (range, 29-73), and 69 Caucasians (43 males; 26 females), with a median age of 63 years (range, 38-81). There was no difference in the geometric mean docetaxel clearance between African-American patients [40.3 L/h; 95% confidence interval (95% CI), 19.3-84.1] and Caucasian patients (41.8 L/h; 95% CI, 22.0-79.7; P = 0.6). We observed no difference between African-American and Caucasian patients in the percentage decrease in ANC nor were docetaxel pharmacokinetic parameters related to the genotypes studied.

Conclusions: Docetaxel clearance and its associated myelosuppression were similar in African-American and Caucasian cancer patients.
A Phase I, Randomized, Open-Label, Parallel-Cohort, Dose-Finding Study of Elacridar (GF120918) and Oral Topotecan in Cancer Patients
Authors: Kuppens Isa E.L.M. , Witteveen Els O. , Jewell Roxanne C. , Radema Sandra A. , Paul Elaine M. , Mangum Steve G. , Beijnen Jos H. , Voest Emile E. , Schellens Jan H.M.
Published: June 2007

Purpose: Breast cancer resistance protein (ABCG2) substantially limits the oral bioavailability of topotecan. Coadministration with elacridar, an inhibitor of breast cancer resistance protein–mediated drug transport, increases the bioavailability of topotecan. The aim of this study was to establish the lowest effective dose of elacridar to obtain maximum oral bioavailability of topotecan and to determine the optimal schedule of coadministration of oral topotecan and elacridar. In the second part of this study, dose-limiting toxicities and maximum tolerated dose of oral topotecan coadministered with elacridar, at a daily times five regimen administered every 21 days, were established.

Experimental Design: In part I, 20 patients were randomized to receive 100, 300, 500, 700, or 1,000 mg of elacridar on days 1 and 8 1 h before or simultaneously with 2.0 mg oral topotecan, which was also randomized. On day 15, all patients were treated with 1.5 mg/m2 i.v. topotecan. In part II of the study, patients were treated daily with oral topotecan and with the lowest effective dose of elacridar following from part I. The maximum tolerated dose and dose-limiting toxicity were determined in cohorts of three patients. Blood samples were taken on days 1, 8, and 15 of part I and on day 1 of cycles 1 and 2 of part II.

Results: Complete apparent oral bioavailability of topotecan (102 ± 7%) for all treatment arms with elacridar in both schedules was seen in part I. In the topotecan dose escalation part, two dose-limiting toxicities were seen at the 2.5 mg topotecan dose level.

Conclusion: The recommended schedule is 2.0 mg oral topotecan plus 100 mg elacridar administered concomitantly daily times five every 21 days.
Sorafenib Inhibits Imatinib-Resistant KIT and Platelet-Derived Growth Factor Receptor β Gatekeeper Mutants
Authors: Guida Teresa , Anaganti Suresh , Provitera Livia , Gedrich Richard , Sullivan Elizabeth , Wilhelm Scott M. , Santoro Massimo , Carlomagno Francesca
Published: June 2007

Purpose: Targeting of KIT and platelet-derived growth factor receptor (PDGFR) tyrosine kinases by imatinib is an effective anticancer strategy. However, mutations of the gatekeeper residue (T670 in KIT and T681 in PDGFRβ) render the two kinases resistant to imatinib. The aim of this study was to evaluate whether sorafenib (BAY 43-9006), a multitargeted ATP-competitive inhibitor of KIT and PDGFR, was active against imatinib-resistant KIT and PDGFRβ kinases.

Experimental Design: We used in vitro kinase assays and immunoblot with phosphospecific antibodies to determine the activity of sorafenib on KIT and PDGFRβ kinases. We also exploited reporter luciferase assays to measure the effects of sorafenib on KIT and PDGFRβ downstream signaling events. The activity of sorafenib on interleukin-3–independent proliferation of Ba/F3 cells expressing oncogenic KIT or its imatinib-resistant T670I mutant was also tested.

Results: Sorafenib efficiently inhibited gatekeeper mutants of KIT and PDGFRβ (IC50 for KIT T670I, 60 nmol/L; IC50 for PDGFRβ T681I, 110 nmol/L). Instead, it was less active against activation loop mutants of the two receptors (IC50 for KIT D816V, 3.8 μmol/L; IC50 for PDGFRβ D850V, 1.17 μmol/L) that are also imatinib-resistant. Sorafenib blocked receptor autophosphorylation and signaling of KIT and PDGFRβ gatekeeper mutants in intact cells as well as activation of AP1-responsive and cyclin D1 gene promoters, respectively. Finally, the compound inhibited KIT-dependent proliferation of Ba/F3 cells expressing the oncogenic KIT mutant carrying the T670I mutation.

Conclusions: Sorafenib might be a promising anticancer agent for patients carrying KIT and PDGFRβ gatekeeper mutations.
Overexpression of Clostridium perfringens Enterotoxin Receptors Claudin-3 and Claudin-4 in Uterine Carcinosarcomas
Authors: Santin Alessandro D. , Bellone Stefania , Siegel Eric R. , McKenney Jesse K. , Thomas Maria , Roman Juan J. , Burnett Alexander , Tognon Germana , Bandiera Elisabetta , Pecorelli Sergio
Published: June 2007

Purpose: To evaluate the expression levels of claudin-3 and claudin-4, the low- and high-affinity receptors, respectively, for the cytotoxic Clostridium perfringens enterotoxin (CPE) in uterine carcinosarcomas and explore the potential for targeting these receptors in the treatment of this aggressive uterine tumor.

Experimental Design: We analyzed claudin-3 and claudin-4 receptor expression at mRNA and protein levels in flash frozen and formalin-fixed, paraffin-embedded carcinosarcoma specimens. Recombinant CPE was used as a novel therapy against chemotherapy-resistant carcinosarcoma cell lines in vitro. The therapeutic effect of sublethal doses of CPE was studied in severe combined immunodeficient mouse xenografts harboring large s.c. carcinosarcomas.

Results: All flash-frozen carcinosarcoma biopsies (12 of 12) and short-term carcinosarcoma cell lines evaluated overexpressed claudin-3 and claudin-4 by quantitative reverse transcription-PCR. Membranous immunoreactivity for claudin-4 protein expression was documented in 80% (20 of 25) of primary tumors and 100% (6 of 6) of the metastatic carcinosarcomas, whereas negligible staining was found in normal endometrial cells. Regardless of their resistance to chemotherapeutic agents, all short-term carcinosarcoma cell lines tested died within 1 h of exposure to 3.3 μg/mL of CPE in vitro. Intratumoral injections of well-tolerated doses of CPE in large s.c. carcinosarcoma xenografts led to large areas of tumor cell necrosis and tumor disappearance in all treated animals.

Conclusions: Claudin-3 and claudin-4 receptors are highly overexpressed in carcinosarcoma. These proteins may offer promising targets for the use of CPE as a novel type-specific therapy against this biologically aggressive variant of endometrial cancer.
Body Composition as an Independent Determinant of 5-Fluorouracil–Based Chemotherapy Toxicity
Authors: Prado Carla M.M. , Baracos Vickie E. , McCargar Linda J. , Mourtzakis Marina , Mulder Karen E. , Reiman Tony , Butts Charles A. , Scarfe Andrew G. , Sawyer Michael B.
Published: June 2007

Purpose: Evidence suggests that lean body mass (LBM) may be useful to normalize doses of chemotherapy. Data from a prospective study were used to determine if the highest doses of 5-fluorouracil (5-FU) per kilogram LBM would be associated with dose-limiting toxicity in stage II/III colon cancer patients treated with 5-FU and leucovorin.

Experimental Design: Toxicity after cycle 1 was graded according to National Cancer Institute Common Toxicity Criteria, version 2.0. Muscle tissue was measured by computerized tomography. An extrapolation to the LBM compartment of the whole body was employed.

Results: Mean values of 5-FU/LBM of the entire population were different in terms of presence or absence of toxicity (P = 0.036). A cut point of 20 mg 5-FU/kg LBM seemed to be a threshold for developing toxicity (P = 0.005). This observation was pertinent to women (odds ratio, 16.73; P = 0.021). Women in this study had a relatively low proportion of LBM relative to their body surface area.

Conclusion: Our study shows that low LBM is a significant predictor of toxicity in female patients administered 5-FU using the convention of dosing per unit of body surface area. We conclude that variation in toxicity between females and males may be partially explained by this feature of body composition.
Curcumin Inhibits Tumor Growth and Angiogenesis in Ovarian Carcinoma by Targeting the Nuclear Factor-κB Pathway
Authors: Lin Yvonne G. , Kunnumakkara Ajaikumar B. , Nair Asha , Merritt William M. , Han Liz Y. , Armaiz-Pena Guillermo N. , Kamat Aparna A. , Spannuth Whitney A. , Gershenson David M. , Lutgendorf Susan K. , Aggarwal Bharat B. , Sood Anil K.
Published: June 2007

Purpose: Curcumin, a component of turmeric, has been shown to suppress inflammation and angiogenesis largely by inhibiting the transcription factor nuclear factor-κB (NF-κB). This study evaluates the effects of curcumin on ovarian cancer growth using an orthotopic murine model of ovarian cancer.

Experimental Design: In vitro and in vivo experiments of curcumin with and without docetaxel were done using human ovarian cancer cell lines SKOV3ip1, HeyA8, and HeyA8-MDR in athymic mice. NF-κB modulation was ascertained using electrophoretic mobility shift assay. Evaluation of angiogenic cytokines, cellular proliferation (proliferating cell nuclear antigen), angiogenesis (CD31), and apoptosis (terminal deoxynucleotidyl transferase–mediated dUTP nick end labeling) was done using immunohistochemical analyses.

Results: Curcumin inhibited inducible NF-κB activation and suppressed proliferation in vitro. In vivo dose-finding experiments revealed that 500 mg/kg orally was the optimal dose needed to suppress NF-κB and signal transducers and activators of transcription 3 activation and decrease angiogenic cytokine expression. In the SKOV3ip1 and HeyA8 in vivo models, curcumin alone resulted in 49% (P = 0.08) and 55% (P = 0.01) reductions in mean tumor growth compared with controls, whereas when combined with docetaxel elicited 96% (P < 0.001) and 77% reductions in mean tumor growth compared with controls. In mice with multidrug-resistant HeyA8-MDR tumors, treatment with curcumin alone and combined with docetaxel resulted in significant 47% and 58% reductions in tumor growth, respectively (P = 0.05). In SKOV3ip1 and HeyA8 tumors, curcumin alone and with docetaxel decreased both proliferation (P < 0.001) and microvessel density (P < 0.001) and increased tumor cell apoptosis (P < 0.05).

Conclusions: Based on significant efficacy in preclinical models, curcumin-based therapies may be attractive in patients with ovarian carcinoma.
Functional Up-regulation of Human Leukocyte Antigen Class I Antigens Expression by 5-aza-2′-deoxycytidine in Cutaneous Melanoma: Immunotherapeutic Implications
Authors: Fonsatti Ester , Nicolay Hugues J.M. , Sigalotti Luca , Calabrò Luana , Pezzani Laura , Colizzi Francesca , Altomonte Maresa , Guidoboni Massimo , Marincola Francesco M. , Maio Michele
Published: June 2007

Purpose: To investigate the potential of the DNA hypomethylating agent 5-aza-2′-deoxycytidine (5-aza-CdR) to improve the effectiveness of immunotherapeutic approaches against melanocyte differentiation antigens.

Experimental Design: The effect of 5-aza-CdR on the constitutive expression of gp100 was investigated in 11 human melanoma cell lines by real-time reverse transcription-PCR and indirect immunofluorescence (IIF) analyses. 5-aza-CdR–mediated changes in the levels of expression of human leukocyte antigen (HLA) class I antigens and HLA-A2 allospecificity, intercellular adhesion molecule-1 (ICAM-1), and leukocyte-function–associated antigen-3 were investigated by IIF analysis on melanoma cells under study. The recognition of gp100-positive Mel 275 melanoma cells, treated or not with 5-aza-CdR, by HLA-A2–restricted gp100(209–217)-specific CTL was investigated by 51Cr-release assays, IFN-γ release and IFN-γ ELISPOT assays.

Results: The constitutive expression of gp100 was not affected by 5-aza-CdR on all melanoma cells investigated. Compared with untreated cells, the exposure of Mel 275 melanoma cells to 5-aza-CdR significantly (P < 0.05) up-regulated their expression of HLA class I antigens and of ICAM-1. These phenotypic changes significantly (P < 0.05) increased the lysis of 5-aza-CdR–treated Mel 275 melanoma cells by gp100-specific CTL and increased their IFN-γ release. 5-aza-CdR treatment of Mel 275 cells also induced a higher number of gp100-specific CTL to secrete IFN-γ.

Conclusions: Treatment with 5-aza-CdR improves the recognition of melanoma cells by gp100-specific CTL through the up-regulation of HLA class I antigens expression; ICAM-1 also contributes to this phenomenon. These findings highlight a broader range of therapeutic implications of 5-aza-CdR when used in association with active or adoptive immunotherapeutic approaches against a variety of melanoma-associated antigens.
A Novel Approach for Treatment of Unresectable Pancreatic Cancer: Design of Radioactive Stents and Trial Studies on Normal Pigs
Authors: Liu Yan , Liu Jun-lou , Cai Zhen-zhai , Lu Zheng , Dong Yuan-hang , Li Zhao-shen , Gong Yan-fang , Man Xiao-hua
Published: June 2007

Purpose: Patients diagnosed with pancreatic cancer typically have a poor prognosis. The aims of these studies were to design radioactive stents and to evaluate the feasibility and safety of the stents in animals.

Experimental Design: To combine the effects of stents and brachytherapy, plastic stents with inserted iodine-125 seeds were designed and tested in 18 normal pigs. The pigs were divided into five groups on the basis of radiation dose. The estimated radiation dose at a 5-mm radial distance from the axis of the seeds was 50 Gy in group A, 100 Gy in group B, 150 Gy in group C, and 200 Gy in group D, with four pigs in each group. In the control group (n = 2), the same plastic stents with non-radioactive seeds were implanted in the pancreatic duct.

Results: The procedures were successfully done on 14 of 18 (78%) pigs, whereas pancreatic duct perforation occurred in four pigs (22%). The thickened wall of the dilated pancreatic duct was clearly observed in the control group. However, the normal morphologic structure of the pancreatic duct wall disappeared in the experimental groups. Histopathologic examination revealed that the stents were surrounded with necrotic tissues and lateral fibrous tissues. During the follow-up period, the width of outside fibrous tissues gradually increased.

Conclusions: These results indicate that the radioactive stents are safe in all dose groups, and it is feasible to design a special radioactive stent for each patient according to the size, shape, and position of the pancreatic tumor.
Bortezomib Sensitizes Primary Human Astrocytoma Cells of WHO Grades I to IV for Tumor Necrosis Factor–Related Apoptosis-Inducing Ligand–Induced Apoptosis
Authors: Koschny Ronald , Holland Heidrun , Sykora Jaromir , Haas Tobias L. , Sprick Martin R. , Ganten Tom M. , Krupp Wolfgang , Bauer Manfred , Ahnert Peter , Meixensberger Jürgen , Walczak Henning
Published: June 2007

Purpose: Malignant gliomas are the most aggressive human brain tumors without any curative treatment. The antitumor effect of tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) in gliomas has thus far only been thoroughly established in tumor cell lines. In the present study, we investigated the therapeutic potential of TRAIL in primary human glioma cells.

Experimental Design: We isolated primary tumor cells from 13 astrocytoma and oligoastrocytoma patients of all four WHO grades of malignancy and compared the levels of TRAIL-induced apoptosis induction, long-term tumor cell survival, caspase, and caspase target cleavage.

Results: We established a stable culture model for isolated primary human glioma cells. In contrast to cell lines, isolated primary tumor cells from all investigated glioma patients were highly TRAIL resistant. Regardless of the tumor heterogeneity, cotreatment with the proteasome inhibitor bortezomib efficiently sensitized all primary glioma samples for TRAIL-induced apoptosis and tremendously reduced their clonogenic survival. Due to the pleiotropic effect of bortezomibenhanced TRAIL DISC formation upon TRAIL triggering, down-regulation of cFLIPL and activation of the intrinsic apoptosis pathway seem to cooperatively contribute to the antitumor effect of bortezomib/TRAIL cotreatment.

Conclusion: TRAIL sensitivity of tumor cell lines is not a reliable predictor for the behavior of primary tumor cells. The widespread TRAIL resistance in primary glioma cells described here questions the therapeutic clinical benefit of TRAIL as a monotherapeutic agent. Overcoming TRAIL resistance by bortezomib cotreatment might, however, provide a powerful therapeutic option for glioma patients.
A Phase I Biodistribution and Pharmacokinetic Trial of Humanized Monoclonal Antibody Hu3s193 in Patients with Advanced Epithelial Cancers that Express the Lewis-Y Antigen
Authors: Scott Andrew M. , Tebbutt Niall , Lee Fook-Thean , Cavicchiolo Tina , Liu Zhanqi , Gill Sanjeev , Poon Aurora M.T. , Hopkins Wendie , Smyth Fiona E. , Murone Carmel , MacGregor Duncan , Papenfuss Anthony T. , Chappell Bridget , Saunder Timothy H. , Brechbiel Martin W. , Davis Ian D. , Murphy Roger , Chong Geoffrey , Hoffman Eric W. , Old Lloyd J.
Published: June 2007

Purpose: We report a first-in-man trial of a humanized antibody (hu3S193) against the Ley antigen.

Experimental Design: Patients with advanced Ley-positive cancers received four infusions of hu3S193 at weekly intervals, with four dose levels (5, 10, 20, and 40 mg/m2). The first infusion of hu3S193 was trace labeled with Indium-111, and biodistribution, pharmacokinetics, tumor uptake, and immune response were evaluated in all patients.

Results: A total of 15 patients (7 male/8 female; age range, 42-76 years; 6 breast, 8 colorectal cancer, and 1 non–small-cell lung cancer) were entered into the study. Transient grade 1 to 2 nausea and vomiting was observed following infusion of hu3S193 at the 40mg/m2 dose level only. There was one episode of dose-limiting toxicity with self-limiting Common Toxicity Criteria grade 3 elevated alkaline phosphatase observed in one patient with extensive liver metastases. The biodistribution of 111In-hu3S193 showed no evidence of any consistent normal tissue uptake, and 111In-hu3S193 uptake was observed in cutaneous, lymph node, and hepatic metastases. Hu3S193 displayed a long serum half-life (T1/2β = 189.63 ± 62.17 h). Clinical responses consisted of 4 patients with stable disease and 11 patients with progressive disease, although one patient experienced a 89% decrease in a lymph node mass, and one patient experienced inflammatory symptoms in cutaneous metastases, suggestive of a biological effect of hu3S193. No immune responses (human anti-human antibody) to hu3S193 were observed.

Conclusion: Hu3S193 is well tolerated and selectively targets tumors, and the long half-life and biological function in vivo of this antibody makes it an attractive potential therapy for patients with Ley-expressing cancers.
The peroxisome proliferator-activated receptor-γ agonist troglitazone inhibits transforming growth factor-β–mediated glioma cell migration and brain invasion
Authors: Coras Roland , Hölsken Annett , Seufert Sebastian , Hauke Jan , Eyüpoglu Ilker Y. , Reichel Martin , Tränkle Christian , Siebzehnrübl Florian A. , Buslei Rolf , Blümcke Ingmar , Hahnen Eric
Published: June 2007

Gliomas are the most common primary tumors of the central nervous system, with glioblastomas as the most malignant entity. Rapid proliferation and diffuse brain invasion of these tumors are likely to determine the unfavorable prognosis. Considering its promigratory properties, the transforming growth factor-β (TGF-β) signaling pathway has become a major therapeutic target. Analyses of resected glioma tissues revealed an intriguing correlation between tumor grade and the expression of TGF-β1-3 as well as their receptors I and II. Here, we analyzed the effects of peroxisome proliferator-activated receptor γ (PPAR-γ) agonists on glioma proliferation, migration, and brain invasion. Using an organotypic glioma invasion model, we show that micromolar doses of the PPAR-γ activator troglitazone blocked glioma progression without neurotoxic damage to the organotypic neuronal environment observed. This intriguing antiglioma property of troglitazone seems to be only partially based on its moderate cytostatic effects. We identified troglitazone as a potent inhibitor of glioma cell migration and brain invasion, which occurred in a PPAR-γ–independent manner. The antimigratory property of troglitazone was in concordance with the transcriptional repression of TGF-β1-3 and their receptors I and II and associated with reduced TGF-β release. Due to its capacity to counteract TGF-β release and glioma cell motility and invasiveness already at low micromolar doses, troglitazone represents a promising drug for adjuvant therapy of glioma and other highly migratory tumor entities. [Mol Cancer Ther 2007;6(6):1745–54]
A novel treatment strategy targeting Aurora kinases in acute myelogenous leukemia
Authors: Ikezoe Takayuki , Yang Jing , Nishioka Chie , Tasaka Taizo , Taniguchi Ayuko , Kuwayama Yoshio , Komatsu Naoki , Bandobashi Kentaro , Togitani Kazuto , Koeffler H. Phillip , Taguchi Hirokuni
Published: June 2007

The Aurora kinases play an important role in chromosome alignment, segregation, and cytokinesis during mitosis. Aberrant expression of these kinases occurs in solid tumors and is associated with aneuploidy and carcinogenesis. We found in this study that Aurora kinase A and B were aberrantly expressed in a variety of types of human leukemia cell lines (n = 15, e.g., PALL-1, PALL-2, HL-60, NB4, MV4-11, etc.), as well as freshly isolated leukemia cells from individuals with acute myelogenous leukemia (n = 44) compared with bone marrow mononuclear cells from healthy volunteers (n = 11), as measured by real-time PCR. ZM447439 is a novel selective Aurora kinase inhibitor. The compound induced growth inhibition, caused accumulation of cells with 4N/8N DNA content, and mediated apoptosis of human leukemia cells as measured by thymidine uptake, cell cycle analysis, and annexin V staining, respectively. Especially profound growth inhibition occurred with the PALL-1 and PALL-2 cells, which possess wild-type p53 gene. In contrast, ZM447439 did not inhibit clonogenic growth of myeloid committed stem cells harvested from healthy normal volunteers. Taken together, inhibition of Aurora kinases may be a promising treatment strategy for individuals with leukemia. [Mol Cancer Ther 2007;6(6):1851–7]
Detection of myeloma in skeleton of mice by whole-body optical fluorescence imaging
Authors: Oyajobi Babatunde O. , Muñoz Steve , Kakonen Rami , Williams Paul J. , Gupta Anjana , Wideman Christi L. , Story Beryl , Grubbs Barry , Armstrong Allison , Dougall William C. , Garrett I. Ross , Mundy Gregory R.
Published: June 2007

Development of new therapies for myeloma has been hindered by the lack of suitable preclinical animal models of the disease in which widespread tumor foci in the skeleton can be detected reliably. Traditional means of detecting skeletal tumor infiltration such as histopathology are cumbersome and labor-intensive and do not allow temporal monitoring of tumor progression or regression in response to therapy. To resolve this problem, we modified the Radl 5TGM1 model of myeloma bone disease such that fluorescent myeloma tumors can be optically imaged in situ. Here, we show that murine myeloma 5TGM1 tumor cells, engineered to express enhanced green fluorescent protein (eGFP; 5TGM1-eGFP cells), can be imaged in a temporal fashion using a fluorescence illuminator and a charge-coupled device camera in skeletons of live C57BL/KaLwRij mice. High-resolution, whole-body images of tumor-bearing mice revealed that myeloma cells homed almost exclusively to the skeleton, with multiple focal tumor foci in the axial skeleton, consistent with myeloma tumor distribution in humans. Finally, the tested antitumor treatment effect of Velcade (bortezomib), a proteasome inhibitor used clinically in myeloma, was readily detected by GFP imaging, suggesting the power of the technique in combination with the Radl 5TGM1-eGFP model for rapid preclinical assessment and sensitive monitoring of novel and potential therapeutics. Whole-body GFP imaging is practical, convenient, inexpensive, and rapid, and these advantages should enable a high throughput when evaluating in vivo efficacy of new potential antimyeloma therapeutics and assessing response to treatment. [Mol Cancer Ther 2007;6(6):1701–8]