bluuebunny/crossref_metadata_2025 huggingface dataset:
Protein Phosphatase-2A Is a Target of Epigallocatechin-3-Gallate and Modulates p53-Bak Apoptotic Pathway
Authors: Qin Jichao , Chen He-Ge , Yan Qin , Deng Mi , Liu Jinping , Doerge Stephan , Ma Weiya , Dong Zigang , Wan-Cheng Li David
Published: June 2008

(-)-Epigallocatechin-3-gallate (EGCG) is a well-known chemoprevention factor. Recent studies have revealed that EGCG triggers cancer cells undergoing apoptosis through p53-dependent pathway. How EGCG activates p53-dependent apoptosis is not fully understood. In the present study using JB6 cell as a model system, we have shown that EGCG can negatively regulate protein serine/threonine phosphatase-2A (PP-2A) to positively regulate p53-dependent apoptosis. First, EGCG at physiologic levels down-regulates PP-2A at the protein and enzyme activity levels. Second, EGCG induces apoptosis of JB6 cells, which is associated with hyperphosphorylation of p53 and up-regulation of the proapoptotic gene, Bak. DNA sequence analysis, gel mobility shifting, chromatin immunoprecipitation, and reporter gene activity assays revealed that p53 directly controls Bak in JB6 cells. Knockdown of p53 and Bak expression with RNAi substantially inhibits EGCG-induced apoptosis. Third, PP-2A directly interacts with p53 and dephosphorylates p53 at Ser-15 in vitro and in vivo. Fourth, overexpression of the catalytic subunit for PP-2A down-regulates p53 phosphorylation at Ser15, attenuates expression of the downstream proapoptotic gene, Bak, and antagonizes EGCG-induced apoptosis. Inhibition of PP-2A activity enhances p53 phosphorylation at Ser-15 and up-regulates Bak expression to promote EGCG-induced apoptosis. Finally, in the p53−/− H1299 and p53+/+ H1080 cells, EGCG down-regulates PP-2A similarly but induces differential apoptosis. In summary, our results show that (a) PP-2A directly dephosphorylates p53 at Ser-15; (b) P53 directly controls Bak expression; and (c) EGCG negatively regulates PP-2A. Together, our results show that EGCG-mediated negative regulation of PP-2A is an important molecular event for the activation of p53-dependent apoptosis during its chemoprevention. [Cancer Res 2008;68(11):4150–62]
A Phase 1 Study of Mapatumumab (Fully Human Monoclonal Antibody to TRAIL-R1) in Patients with Advanced Solid Malignancies
Authors: Hotte Sébastien J. , Hirte Hal W. , Chen Eric X. , Siu Lillian L. , Le Lyly H. , Corey Alfred , Iacobucci Anne , MacLean Martha , Lo Larry , Fox Norma Lynn , Oza Amit M.
Published: June 2008

Purpose: Mapatumumab (TRM-1, HGS-ETR1) is a fully human agonistic monoclonal antibody that targets and activates tumor necrosis factor–related apoptosis-inducing ligand (TRAIL) receptor 1 (death receptor 4). Mapatumumab functions like the natural receptor ligand, TRAIL, a tumor necrosis factor superfamily member that is an important mediator of apoptosis in cancer cell lines. Promising preclinical activity with mapatumumab has been observed.

Experimental Design: This phase I, open-label, dose-escalation study assessed the tolerability and toxicity profile of ≥2 doses of mapatumumab administered i.v. in patients with advanced solid tumors. Patients received mapatumumab every 28 days until progression or dose-limiting toxicity.

Results: There were escalation levels from 0.01 to 20.0 mg/kg. Forty-one patients, 27 female, with a median age of 55 years (range, 23-81) were entered into the study and received 143 courses. The most common diagnoses were colorectal (10 patients) and ovarian cancer (9 patients). Patients received a median of two cycles (range, 1-33). Mapatumumab was well tolerated. Adverse events considered at least possibly related to mapatumumab that occurred most frequently included fatigue (36.2%), hypotension (34.1%), nausea (29.3%), and pyrexia (12.2%). The majority of adverse events were grade 1 or 2. The maximum tolerated dose was not reached. Linear pharmacokinetics was observed for doses up to 0.3 mg/kg and for the 20 mg/kg level, whereas exposure at 3 and 10 mg/kg increased less than proportionally. No objective responses were observed, but 12 patients had stable disease for 1.9 to 29.4 months.

Conclusions: Mapatumumab is well tolerated and further evaluation of this TRAIL-R1 targeting agent is warranted.
Protein Expression of Platelet-Derived Growth Factor Receptor Correlates with Malignant Histology and PTEN with Survival in Childhood Gliomas
Authors: Thorarinsdottir Halldora K. , Santi Mariarita , McCarter Robert , Rushing Elisabeth J. , Cornelison Robert , Jales Alessandra , MacDonald Tobey J.
Published: June 2008

Purpose: We previously showed that overexpression of epidermal growth factor receptor (EGFR) is associated with malignant grade in childhood glioma. The objective of this study was to determine whether protein expression of EGFR or platelet-derived growth factor receptor (PDGFR) and their active signaling pathways are related to malignant histology, progression of disease, and worse survival.

Experimental Design: Tissue microarrays were prepared from untreated tumors from 85 new glioma patients [22 high-grade gliomas (HGG) and 63 low-grade gliomas (LGG)] diagnosed at this institution from 1989 to 2004. Immunohistochemistry was used to assess total expression of EGFR, PDGFRβ, and PTEN and expression of phosphorylated EGFR, phosphorylated PDGFRα (p-PDGFRα), phosphorylated AKT, phosphorylated mitogen-activated protein kinase, and phosphorylated mammalian target of rapamycin. These results were correlated with clinicopathologic data, including extent of initial tumor resection, evidence of dissemination, tumor grade, proliferation index, and survival, as well as with Affymetrix gene expression profiles previously obtained from a subset of these tumors.

Results: High expression of p-PDGFRα, EGFR, PDGFRβ, and phosphorylated EGFR was seen in 85.7%, 80.0%, 78.9%, and 47.4% of HGG and 40.0%, 87.1%, 41.7%, and 30.6% of LGG, respectively. However, high expression of p-PDGFRα and PDGFRβ was the only significant association with malignant histology (P = 0.031 and 0.005, respectively); only the loss of PTEN expression was associated with worse overall survival. None of these targets, either alone or in combination, was significantly associated with progression-free survival in either LGG or HGG.

Conclusions: High PDGFR protein expression is significantly associated with malignant histology in pediatric gliomas, but it does not represent an independent prognostic factor. Deficient PTEN expression is associated with worse overall survival in HGG.
Continuing Reassessment of the Risks of Erythropoiesis-Stimulating Agents in Patients with Cancer
Authors: Juneja Vinni , Keegan Patricia , Gootenberg Joseph E. , Rothmann Mark D. , Shen Yuan Li , Lee Kyung Y. , Weiss Karen D. , Pazdur Richard
Published: June 2008

Purpose: Erythropoiesis-stimulating agents (ESA) are approved for the treatment of anemia in patients with nonmyeloid malignancies whose anemia is due to the effect of concomitantly administered chemotherapy. Since the 1993 approval of epoetin alfa in patients with cancer, the risk of thrombovascular events, decreased survival, and poorer tumor control have been increasingly recognized. The risks of ESAs in patients with cancer and the design of trials to assess these risks have been the topic of discussion at two Oncologic Drugs Advisory Committees in 2004 and 2007.

Experimental Design: Evaluation of randomized clinical trials comparing use of ESAs to transfusion support alone in patients with active cancer.

Results: Six studies (Breast Cancer Erythropoeitin Survival Trial, Evaluation of NeoRecormon on outcome in Head And Neck Cancer in Europe, Danish Head and Neck Cancer, Lymphoid Malignancy, CAN-20, and Anemia of Cancer) investigating ESAs in oncology patients showed decreased survival, decreased duration of locoregional tumor control, and/or increased risk of thrombovascular events. In these six studies, ESA dosing was targeted to achieve and maintain hemoglobin values in excess of current recommendations, and in three of the six studies, ESAs were administered to patients not receiving chemotherapy.

Conclusions: ESAs increase the risk of thrombovascular events and result in decreased survival and poorer tumor control when administered to achieve hemoglobin levels of ≥12 g/dL in patients with nonmyeloid malignancies. No completed or ongoing randomized, controlled trial has addressed safety issues of ESAs in patients with chemotherapy-associated anemia using currently approved dosing regimens in an epidermal tumor type. Additional studies are needed to better characterize these risks.
A Paclitaxel-Hyaluronan Bioconjugate Targeting Ovarian Cancer Affords a Potent In vivo Therapeutic Activity
Authors: Banzato Alessandra , Bobisse Sara , Rondina Maria , Renier Davide , Bettella Fabio , Esposito Giovanni , Quintieri Luigi , Meléndez-Alafort Laura , Mazzi Ulderico , Zanovello Paola , Rosato Antonio
Published: June 2008

Purpose: This study was designed to evaluate the pharmacologic and biological properties of a paclitaxel-hyaluronan bioconjugate (ONCOFID-P) against IGROV-1 and OVCAR-3 human ovarian cancer xenografts following i.p. administration.

Experimental Design: In vitro tumor sensitivity to ONCOFID-P was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, whereas bioconjugate interaction with cells was studied cytofluorimetrically and by confocal microscopy. In vivo toxicity was assessed by a single-dose maximum-tolerated dose, peripheral blood cell count determination and by histologic analysis. Biodistribution of the compound was evaluated with a small animal–dedicated scintigraphy gamma camera following injection of 99mTc-labeled ONCOFID-P. Pharmacokinetic analysis was also carried out. Female severe combined immunodeficiency mice implanted with ovarian cancer cells underwent treatment with ONCOFID-P or free paclitaxel starting from day 7 or 14 after tumor injection, and survivals were compared.

Results: ONCOFID-P interacted with CD44, entered cells through a receptor-mediated mechanism, and exerted a concentration-dependent inhibitory effect against tumor cell growth. After i.p. administration, the bioconjugate distributed quite uniformly within the peritoneal cavity, was well-tolerated, and was not associated with local histologic toxicity. Pharmacokinetic studies revealed that blood levels of bioconjugate-derived paclitaxel were much higher and persisted longer than those obtained with the unconjugated free drug. Intraperitoneal treatment of tumor-bearing mice with the bioconjugate revealed that ONCOFID-P exerted a relevant increase in therapeutic activity compared with free drug.

Conclusions: ONCOFID-P significantly improved results obtained with conventional paclitaxel, in terms of in vivo tolerability and therapeutic efficacy; these data strongly support its development for locoregional treatment of ovarian cancer.
Nonviral Nanoscale-Based Delivery of Antisense Oligonucleotides Targeted to Hypoxia-Inducible Factor 1α Enhances the Efficacy of Chemotherapy in Drug-Resistant Tumor
Authors: Wang Yang , Saad Maha , Pakunlu Refika I. , Khandare Jayant J. , Garbuzenko Olga B. , Vetcher Alexandre A. , Soldatenkov Viatcheslav A. , Pozharov Vitaly P. , Minko Tamara
Published: June 2008

Purpose: To enhance the efficacy of cancer treatment, we propose a complex approach: simultaneous delivery to the tumor of a chemotherapeutic agent and a suppressor of hypoxia-inducible factor 1α (HIF1A).

Experimental Design: The novel complex liposomal drug delivery system was developed and evaluated in vitro and in vivo on nude mice bearing xenografts of multidrug-resistant human ovarian carcinoma. The proposed novel complex drug delivery system consists of liposomes as a nanocarrier, a traditional anticancer drug (doxorubicin) as a cell death inducer, and antisense oligonucleotides targeted to HIF1A mRNA as a suppressor of cellular resistance and angiogenesis.

Results: The system effectively delivers active ingredients into tumor cells, multiplies the cell death signal initiated by doxorubicin, and inhibits cellular defensive mechanisms and angiogenesis by down-regulating BCL2, HSP90, and vascular endothelial growth factor proteins. This, in turn, activates caspases, promotes apoptosis, necrosis, and tumor shrinkage. The proposed novel complex multipronged approach enhances the efficiency of chemotherapy.

Conclusions: The proposed combination therapy prevents the development of resistance in cancer cells, and thus, increases the efficacy of chemotherapy to an extent that cannot be achieved by individual components applied separately. It could form the foundation for a novel type of cancer therapy based on simultaneous delivery of an anticancer drug and a suppressor of HIF1A.
TMPRSS2:ERG Fusion Identifies a Subgroup of Prostate Cancers with a Favorable Prognosis
Authors: Saramäki Outi R. , Harjula Anna E. , Martikainen Paula M. , Vessella Robert L. , Tammela Teuvo L.J. , Visakorpi Tapio
Published: June 2008

Purpose: Our aim was to assess the frequency of ERG overexpression and TMPRSS2:ERG rearrangement in prostate cancer and their association with clinicopathologic variables and outcome.

Experimental Design: The presence of the TMPRSS2:ERG rearrangement was studied by reverse transcription-PCR and fluorescence in situ hybridization in 19 prostate cancer xenografts and 7 prostate cancer cell lines. The expression of ERG was studied in the xenografts and cell lines and in 49 freshly frozen clinical prostate samples by quantitative reverse transcription-PCR. The frequency of the TMPRSS2:ERG fusion in clinical prostate cancer (n = 253) on tissue microarrays was assessed by three-color fluorescence in situ hybridization.

Results: Seven of 19 (37%) of the xenografts overexpressed ERG and had TMPRSS2:ERG rearrangement. Two xenografts, representing small cell carcinomas, also contained the fusion but did not express ERG. In clinical tumor specimens, the overexpression of ERG was associated with the rearrangement (P = 0.0019). Fifty of 150 (33%) of the prostatectomy specimens and 28 of 76 (37%) of the hormone-refractory prostate cancers on the tissue microarrays carried the TMPRSS2:ERG rearrangement. It was associated with longer progression-free survival in patients treated by prostatectomy (P = 0.019), and according to multivariate analysis, it was an independent predictor of favorable outcome (relative risk, 0.54; 95% confidence interval, 0.30-0.98). The fusion was not associated with Gleason score, pT stage, diagnostic prostate-specific antigen, or cell proliferation activity in prostatectomy specimens nor with the AR gene amplification in hormone-refractory tumors.

Conclusions: The TMPRSS2:ERG rearrangement can be found in about one third of prostate cancers. A subgroup of prostate cancer patients with a good prognosis may be identified by the rearrangement.
Astrocyte Elevated Gene-1 is a Novel Prognostic Marker for Breast Cancer Progression and Overall Patient Survival
Authors: Li Jun , Zhang Nu , Song Li-Bing , Liao Wen-Ting , Jiang Li-Li , Gong Li-Yun , Wu Jueheng , Yuan Jie , Zhang Hui-Zhong , Zeng Mu-Sheng , Li Mengfeng
Published: June 2008

Purpose: The present study was aimed at clarifying the expression of astrocyte elevated gene-1 (AEG-1), one of the target genes of oncogenic Ha-ras, in breast cancer and its correlation with clinicopathologic features, including the survival of patients with breast cancer.

Experimental Design: The expression of AEG-1 in normal breast epithelial cells, breast cancer cell lines, and in four cases of paired primary breast tumor and normal breast tissue was examined using reverse transcription-PCR and Western blot. Real-time reverse transcription-PCR was applied to determine the mRNA level of AEG-1 in the four paired tissues, each from the same subject. Furthermore, AEG-1 protein expression was analyzed in 225 clinicopathologically characterized breast cancer cases using immunohistochemistry. Statistical analyses were applied to test for the prognostic and diagnostic associations.

Results: Western blot and reverse transcription-PCR showed that the expression level of AEG-1 was markedly higher in breast cancer cell lines than that in the normal breast epithelial cells at both mRNA and protein levels. AEG-1 expression levels were significantly up-regulated by up to 35-fold in primary breast tumors in comparison to the paired normal breast tissue from the same patient. Immunohistochemical analysis revealed high expression of AEG-1 in 100 of 225 (44.4%) paraffin-embedded archival breast cancer biopsies. Statistical analysis showed a significant correlation of AEG-1 expression with the clinical staging of the patients with breast cancer (P = 0.001), as well as with the tumor classification (P = 0.004), node classification (P = 0.026), and metastasis classification (P = 0.001). Patients with higher AEG-1 expression had shorter overall survival time, whereas patients with lower AEG-1 expression had better survival. Multivariate analysis suggested that AEG-1 expression might be an independent prognostic indicator for the survival of patients with breast cancer.

Conclusions: Our results suggest that AEG-1 protein is a valuable marker of breast cancer progression. High AEG-1 expression is associated with poor overall survival in patients with breast cancer.
Effect of SLCO1B3 Haplotype on Testosterone Transport and Clinical Outcome in Caucasian Patients with Androgen-Independent Prostatic Cancer
Authors: Hamada Akinobu , Sissung Tristan , Price Douglas K. , Danesi Romano , Chau Cindy H. , Sharifi Nima , Venzon David , Maeda Kenji , Nagao Keisuke , Sparreboom Alex , Mitsuya Hiroaki , Dahut William L. , Figg William D.
Published: June 2008

Purpose: The organic anion transporter OATP1B3, encoded by SLCO1B3, is involved in the transport of steroid hormones. However, its role in testosterone uptake and clinical outcome of prostatic cancer is unknown. This study examined (a) the SLCO1B3 genotype in cancer cells as well as the uptake of testosterone by cells transfected with genetic variants of SLCO1B3; (b) the expression of OATP1B3 in normal prostate, benign prostatic hyperplasia, and prostatic cancer; and (c) the role of SLCO1B3 haplotype on clinical outcome of Caucasian patients with androgen-independent prostatic cancer.

Experimental Design: SLCO1B3 genotype was assessed in the NCI-60 panel of tumor cells by sequencing, whereas testosterone transport was analyzed in Cos-7 cells transfected with WT, 334G, and 699A SLCO1B3 variants. OATP1B3 expression in prostatic tissues was examined by fluorescence microscopy, and the relationship between SLCO1B3 haplotypes and survival was examined in patients.

Results: Cells transfected with wild-type (334T/699G) SLCO1B3, or with a vector containing either the 334G or 699A variants, actively transported testosterone, whereas its uptake was impaired in cells transfected with a gene carrying both 334G and 699A single nucleotide polymorphisms. Prostatic cancer overexpresses OATP1B3 compared with normal or benign hyperplastic tissue; patients with SLCO1B3 334GG/699AA haplotype showed longer median survival (8.5 versus 6.4 years; P = 0.020) and improved survival probability at 10 years (42% versus 23%; P < 0.023) than patients carrying TT/AA and TG/GA haplotypes.

Conclusions: The common SLCO1B3 GG/AA haplotype is associated with impaired testosterone transport and improved survival in patients with prostatic cancer.
Combination Strategy Targeting the Hypoxia Inducible Factor-1α with Mammalian Target of Rapamycin and Histone Deacetylase Inhibitors
Authors: Verheul Henk M.W. , Salumbides Brenda , Van Erp Karen , Hammers Hans , Qian David Z. , Sanni Tolib , Atadja Peter , Pili Roberto
Published: June 2008

Purpose: The hypoxia-inducible factor-1α (HIF-α) is a key regulator of tumor angiogenesis. Mammalian target of rapamycin (mTOR) and histone deacetylase (HDAC) inhibitors suppress tumor-induced angiogenesis by reducing tumor HIF-1α protein expression. Thus, we hypothesized that combination treatment of rapamycin and the HDAC inhibitor LBH589 has greater antiangiogenic and antitumor activity compared with single agents.

Experimental Design: To evaluate the effect of LBH589 and rapamycin on HIF-1α in human prostate PC3, renal C2 carcinoma cell lines, and endothelial cells (human umbilical vein endothelial cells), we did Western blot analysis. To determine the antitumor activity of LBH589 and rapamycin, cell proliferation assays and xenograft experiments were conducted.

Results: Western blotting showed that combination treatment of human umbilical vein endothelial cells, C2 and PC3, significantly reduced HIF-1α protein expression compared with single agents. Treatment with rapamycin resulted in inhibition of the downstream signals of the mTOR pathway and increased phosphorylation of Akt in C2 cells, whereas the constitutively activated Akt in PC3 cells was not modulated. LBH589 decreased both constitutively expressed and rapamycin-induced phosphorylated Akt levels in PC3 and C2 cell lines. In clonogenic assays, the combination treatment had a greater inhibitory effect in PC3 cells (93 ± 1.4%) compared with single agents (66 ± 9% rapamycin and 43 ± 4% LBH589). Combination of rapamycin and LBH589 significantly inhibited PC3 and C2 in vivo tumor growth and angiogenesis as measured by tumor weight and microvessel density.

Conclusions: Combination treatment of mTOR and HDAC inhibitors represents a rational therapeutic strategy targeting HIF-1α that warrants clinical testing.
HLA Class I Antigen Processing Machinery Component Expression and Intratumoral T-Cell Infiltrate as Independent Prognostic Markers in Ovarian Carcinoma
Authors: Han Liz Y. , Fletcher Mavis S. , Urbauer Diana L. , Mueller Peter , Landen Charles N. , Kamat Aparna A. , Lin Yvonne G. , Merritt William M. , Spannuth Whitney A. , Deavers Michael T. , De Geest Koen , Gershenson David M. , Lutgendorf Susan K. , Ferrone Soldano , Sood Anil K.
Published: June 2008

Purpose: Defects in the antigen processing machinery (APM) may provide tumor cells with a mechanism to escape immune recognition. The purpose of this study is to determine the clinical significance of APM component down-regulation and tumor-infiltrating T cells in ovarian carcinoma.

Experimental Design: After institutional review board approval, tumor samples from 150 patients with invasive epithelial ovarian cancers were examined for TAP1, TAP2, tapasin, HLA class I heavy chain (HLA-HC), β2 microglobulin, and T-cell (CD3+ and CD8+) tumor infiltration using immunohistochemistry.

Results: The majority of tumors had either heterogeneous or positive expression of TAP1, TAP2, HLA-HC, and β2 microglobulin (66.7%, 73.3%, 70.7%, and 63.3%, respectively), except tapasin for which 58% of the tumors lacked expression. Furthermore, 67% and 88% of the lesions possessed intratumoral and peritumoral CD3+ or CD8+ cells, respectively. The majority of APM component expression examined was significantly associated with both intratumoral and peritumoral T-cell infiltration (P < 0.05). The expression of APM components and the presence of intratumoral T-cell infiltrates were significantly associated with improved survival (all P ≤ 0.01); however, peritumoral T-cell infiltrates did not significantly affect survival (P = 0.33). APM component down-regulation (P < 0.001), lack of intratumoral T-cell infiltrates (P = 0.03), and suboptimal cytoreduction (P < 0.001) were independent prognostic markers for death from ovarian carcinoma.

Conclusion: The negative effect of APM component down-regulation by itself and in combination with absent intratumoral T-cell infiltration on the survival of patients with ovarian carcinoma implies a role for immune escape in addition to immunosurveillance in the clinical course of disease.
Oral Administration of Gemcitabine in Patients with Refractory Tumors: A Clinical and Pharmacologic Study
Authors: Veltkamp Stephan A. , Jansen Robert S. , Callies Sophie , Pluim Dick , Visseren-Grul Carla M. , Rosing Hilde , Kloeker-Rhoades Susanne , Andre Valerie A.M. , Beijnen Jos H. , Slapak Christopher A. , Schellens Jan H.M.
Published: June 2008

Purpose: To determine the toxicity, tolerability, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of oral gemcitabine (2′,2′-difluorodeoxycytidine; dFdC) in patients with cancer.

Experimental Design: Patients with advanced or metastatic cancer refractory to standard therapy were eligible. Gemcitabine was administered p.o. starting at 1 mg once daily using dose escalation with three patients per dose level. Patients received one of two dosing schemes: (a) once daily dosing for 14 days of a 21-day cycle or (b) every other day dosing for 21 days of a 28-day cycle. Pharmacokinetics were assessed by measuring concentrations of dFdC and 2′,2′-difluorodeoxyuridine (dFdU) in plasma and gemcitabine triphosphate in peripheral blood mononuclear cells, and pharmacodynamics by measuring the effect on T-cell proliferation.

Results: Thirty patients entered the study. Oral gemcitabine was generally well-tolerated. The maximum tolerated dose was not reached. Mainly moderate gastrointestinal toxicities occurred except for one patient who died after experiencing grade 4 hepatic failure during cycle two. One patient with a leiomyosarcoma had stable disease during 2 years and 7 months. Systemic exposure to dFdC was low with an estimated bioavailability of 10%. dFdC was highly converted to dFdU, probably via first pass metabolism and dFdU had a long terminal half-life (∼89 h). Concentrations of dFdCTP in peripheral blood mononuclear cells were low, but high levels of gemcitabine triphosphate, the phosphorylated metabolite of dFdU, were detected.

Conclusions: Systemic exposure to oral gemcitabine was low due to extensive first-pass metabolism to dFdU. Moderate toxicity combined with hints of activity warrant further investigation of the concept of prolonged exposure to gemcitabine.
Aneuploidy Predicts Outcome in Patients with Endometrial Carcinoma and Is Related to Lack of CDH13 Hypermethylation
Authors: Suehiro Yutaka , Okada Toshiyuki , Okada Takae , Anno Keiko , Okayama Naoko , Ueno Koji , Hiura Mikako , Nakamura Mikiko , Kondo Tomoko , Oga Atsunori , Kawauchi Shigeto , Hirabayashi Kei , Numa Fumitaka , Ito Takehisa , Saito Toshiaki , Sasaki Kohsuke , Hinoda Yuji
Published: June 2008

Purpose: Many investigators have reported that aneuploidy detected by flow cytometry is a useful prognostic marker in patients with endometrial cancer. Laser scanning cytometry (LSC) is a technology similar to flow cytometry but is more feasible for clinical laboratory use. We evaluated the usefulness of DNA ploidy detected by LSC as a prognostic marker in patients with endometrial cancer and investigated genetic and epigenetic factors related to aneuploidy.

Experimental Design: Endometrial cancer specimens from 106 patients were evaluated. The methylation status of CDH13, Rassf1, SFRP1, SFRP2, SFRP4, SFRP5, p16, hMLH1, MGMT, APC, ATM, and WIF1 and mutations in the p53 and CDC4 genes were investigated. LSC was carried out to determine DNA ploidy. Fluorescence in situ hybridization was done with chromosome-specific centromeric probes to assess chromosomal instability.

Results: Univariate and multivariate analyses revealed that p53 mutation and lack of CDH13 hypermethylation associated positively with aneuploidy. Univariate analysis showed that aneuploidy, chromosomal instability, and lack of CDH13 hypermethylation as well as surgical stage were significantly predictive of death from endometrial cancer. Furthermore, multivariate analysis revealed that stage in combination with either DNA aneuploidy or lack of CDH13 hypermethylation was an independent prognostic factor.

Conclusion: These results suggest that analysis of DNA ploidy and methylation status of CDH13 may help predict clinical outcome in patients with endometrial cancer. Prospective randomized trials are needed to confirm the validity of an individualized approach, including determination of tumor ploidy and methylation status of CDH13, to management of endometrial cancer patients.
Activity of the Bcl-2 Family Inhibitor ABT-263 in a Panel of Small Cell Lung Cancer Xenograft Models
Authors: Shoemaker Alex R. , Mitten Michael J. , Adickes Jessica , Ackler Scott , Refici Marion , Ferguson Debra , Oleksijew Anatol , O'Connor Jacqueline M. , Wang Baole , Frost David J. , Bauch Joy , Marsh Kennan , Tahir Steven K. , Yang Xiufen , Tse Christin , Fesik Stephen W. , Rosenberg Saul H. , Elmore Steven W.
Published: June 2008

Purpose: The purpose of this study was to characterize the activity of the Bcl-2 protein family inhibitor ABT-263 in a panel of small cell lung cancer (SCLC) xenograft models.

Experimental Design: A panel of 11 SCLC xenograft models was established to evaluate the efficacy of ABT-263. Single agent activity was examined on a continuous dosing schedule in each of these models. The H146 model was used to further evaluate dose and schedule, comparison to standard cytotoxic agents, and induction of apoptosis.

Results: ABT-263 exhibited a range of antitumor activity, leading to complete tumor regression in several models. Significant regressions of tumors as large as 1 cc were also observed. The efficacy of ABT-263 was also quite durable; in several cases, minimal tumor regrowth was noted several weeks after the cessation of treatment. Antitumor effects were equal or superior to that of several clinically approved cytotoxic agents. Regression of large established tumors was observed through several cycles of therapy and efficacy was retained in a Pgp-1 overexpressing line. Significant efficacy was observed on several dose and therapeutic schedules and was associated with significant induction of apoptosis.

Conclusions: ABT-263 is a potent, orally bioavailable inhibitor of Bcl-2 family proteins that has recently entered clinical trials. The efficacy data reported here suggest that SCLC is a promising area of clinical investigation with this agent.
Preoperative Plasma Endoglin Levels Predict Biochemical Progression After Radical Prostatectomy
Authors: Svatek Robert S. , Karam Jose A. , Roehrborn Claus G. , Karakiewicz Pierre I. , Slawin Kevin M. , Shariat Shahrokh F.
Published: June 2008

Purpose: Endoglin (CD105) is a transmembrane glycoprotein expressed by human vascular endothelial cells thought to play a pivotal role in endothelial cell proliferation. The aim of this study was to evaluate the association of preoperative plasma endoglin levels with established clinical and pathologic features of prostate cancer and disease progression after radical prostatectomy.

Experimental Design: Preoperative plasma endoglin levels were measured in 425 patients who underwent radical prostatectomy for clinically localized prostate cancer using a commercially available ELISA assay. Multivariate logistic regression was used to test the association of plasma endoglin levels with biochemical progression after radical prostatectomy.

Results: Median follow-up for patients alive at the time of analysis was 36.8 months (interquartile range, 44.1). Of 425 patients, 77 patients (18.1%) experienced biochemical progression after radical prostatectomy. Preoperative plasma endoglin levels were significantly elevated in patients with higher preoperative total serum prostate-specific antigen (P < 0.001) and adverse pathologic features. Preoperative plasma endoglin was an independent predictor of biochemical progression after surgery after adjusting for the effects of standard preoperative and postoperative features (P < 0.001 and P = 0.026, respectively).

Conclusions: Preoperative plasma endoglin levels are associated with established features of advanced prostate cancer. More importantly, higher preoperative plasma endoglin levels are independent predictors of an increased risk of biochemical progression in patients treated with radical prostatectomy and bilateral pelvic lymphadenectomy.
Impact of a Single Nucleotide Polymorphism in the MDM2 Gene on Neuroblastoma Development and Aggressiveness: Results of a Pilot Study on 239 Patients
Authors: Cattelani Sara , Defferrari Raffaella , Marsilio Sonia , Bussolari Rita , Candini Olivia , Corradini Francesca , Ferrari-Amorotti Giovanna , Guerzoni Clara , Pecorari Luisa , Menin Chiara , Bertorelle Roberta , Altavista Pierluigi , McDowell Heather P. , Boldrini Renata , Dominici Carlo , Tonini Gian Paolo , Raschellà Giuseppe , Calabretta Bruno
Published: June 2008

Purpose: MDM2 is a key negative regulator of p53 activity, and a single nucleotide polymorphism (SNP309, T>G change; rs 2279744) in its promoter increases the affinity for the transcription factor SP1, enhancing MDM2 expression. We carried out a pilot study to investigate the effect of this polymorphism on development and behavior of neuroblastoma, an extracranial pediatric tumor with unfrequent genetic inactivation of p53.

Experimental Design: We genotyped the MDM2-SNP309 alleles of tumor DNA from 239 neuroblastoma patients and peripheral blood DNA from 237 controls. In 40 of 239 neuroblastomas, the MDM2-SNP309 alleles were also genotyped in peripheral blood DNA. Data were analyzed by two-sided Fisher's exact test, log-rank test, and Kaplan-Meier statistics. Where appropriate, data are reported with 95% confidence intervals (CI).

Results: The frequency of both the T/G and G/G genotypes or the G/G or T/G genotype only was higher in neuroblastoma DNA samples than in controls: 60.3% (95% CI, 54.1-66.5) versus 47.3% (95% CI, 40.9-53.6), 30.4% (95% CI, 22.4-37.8) versus 15.0% (95% CI, 9.2-20.7), and 52.0% (95% CI, 45.0-59.9) versus 41.9% (95% CI, 35.3-48.5), respectively; Two-Sided Fisher's Exact Test P values were 0.006, 0.003, and 0.048, respectively; Odds ratios were 1.69 (95% CI, 1.18-2.43), 2.45 (95% CI, 1.37-4.39) and 1.51 (95% CI, 1.02-2.22), respectively. A significant association (P = 0.016) between heterozygous (T/G)/homozygous (G/G) genotypes at SNP309 and advanced clinical stages was also shown. Homozygous/heterozygous SNP309 variant carriers had a shorter 5-year overall survival than patients with the wild-type allele (P = 0.046; log-rank test). A shorter overall survival in patients with heterozygous/homozygous SNP309 was also observed in the subgroups with age at diagnosis >1 year and adrenal primary tumor (P = 0.024 and P = 0.014, respectively).

Conclusions: Data from this pilot study suggest that the MDM2 G/G and T/G-SNP309 alleles are markers of increased predisposition to tumor development and disease aggressiveness in neuroblastoma. However, additional studies with larger patient cohorts are required for a definitive assessment of the clinical relevance of these data.
Direct and Natural Killer Cell-Mediated Antitumor Effects of Low-Dose Bortezomib in Hepatocellular Carcinoma
Authors: Armeanu Sorin , Krusch Matthias , Baltz Katrin M. , Weiss Thomas S. , Smirnow Irina , Steinle Alexander , Lauer Ulrich M. , Bitzer Michael , Salih Helmut R.
Published: June 2008

Purpose: Hepatocellular carcinoma (HCC) displays particular resistance to conventional cytostatic agents. Alternative treatment strategies focus on novel substances exhibiting antineoplastic and/or immunomodulatory activity enhancing for example natural killer (NK) cell antitumor reactivity. However, tumor-associated ligands engaging activating NK cell receptors are largely unknown. Exceptions are NKG2D ligands (NKG2DL) of the MHC class I-related chain and UL16-binding protein families, which potently stimulate NK cell responses. We studied the consequences of proteasome inhibition with regard to direct and NK cell–mediated effects against HCC.

Experimental Design: Primary human hepatocytes (PHH) from different donors, hepatoma cell lines, and NK cells were exposed to Bortezomib. Growth and viability of the different cells, and immunomodulatory effects including alterations of NKG2DL expression on hepatoma cells, specific induction of NK cell cytotoxicity and IFN-γ production were investigated.

Results: Bortezomib treatment inhibited hepatoma cell growth with IC50 values between 2.4 and 7.7 nmol/L. These low doses increased MICA/B mRNA levels, resulting in an increase of total and cell surface protein expression in hepatoma cells, thus stimulating cytotoxicity and IFN-γ production of cocultured NK cells. Importantly, although NK cell IFN-γ production was concentration-dependently reduced, low-dose Bortezomib neither induced NKG2DL expression or cell death in PHH nor altered NK cell cytotoxicity.

Conclusions: Low-dose Bortezomib mediates a specific dual antitumor effect in HCC by inhibiting tumor cell proliferation and priming hepatoma cells for NK cell antitumor reactivity. Our data suggest that patients with HCC may benefit from Bortezomib treatment combined with immunotherapeutic approaches such as adoptive NK cell transfer taking advantage of enhanced NKG2D-mediated antitumor immunity.
Combining Nanoliposomal Ceramide with Sorafenib Synergistically Inhibits Melanoma and Breast Cancer Cell Survival to Decrease Tumor Development
Authors: Tran Melissa A. , Smith Charles D. , Kester Mark , Robertson Gavin P.
Published: June 2008

Purpose: Deregulation of phosphatidylinositol 3-kinase/Akt and Ras/Raf/mitogen-activated protein kinase/extracellular signal-regulated kinase kinase/extracellular signal-regulated kinase pathways occurs in melanoma and breast cancer, deregulating normal cellular apoptosis and proliferation. Therapeutic cocktails simultaneously targeting these pathways could promote synergistically acting tumor inhibition. However, agents with manageable toxicity and mechanistic basis for synergy need identification. The purpose of this study is to evaluate the preclinical therapeutic efficacy and associated toxicity of combining sorafenib with nanoliposomal ceramide.

Experimental Design: Effects of sorafenib and nanoliposomal ceramide as single and combinatorial agents were examined on cultured cells using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt assays and CalcuSyn software used to assess synergistic or additive inhibition. Western blotting measured cooperative effects on signaling pathways. Rates of proliferation, apoptosis, and angiogenesis were measured in size- and time-matched tumors to identify mechanistic basis for inhibition. Toxicity was evaluated measuring animal weight, blood toxicity parameters, and changes in liver histology.

Results: Sorafenib and nanoliposomal ceramide synergistically inhibited cultured cells by cooperatively targeting mitogen-activated protein kinase and phosphatidylinositol 3-kinase signaling. A 1- to 2-fold increase in cellular apoptosis and 3- to 4-fold decrease in cellular proliferation were observed following combination treatment compared with single agents, which caused synergistically acting inhibition. In vivo, an ∼30% increase in tumor inhibition compared with sorafenib treatment alone and an ∼58% reduction in tumor size compared with nanoliposomal ceramide monotherapy occurred by doubling apoptosis rates with negligible systemic toxicity.

Conclusions: This study shows that nanoliposomal ceramide enhances effectiveness of sorafenib causing synergistic inhibition. Thus, a foundation is established for clinical trials evaluating the efficacy of combining sorafenib with nanoliposomal ceramide for treatment of cancers.
Modulation of Gemcitabine (2′,2′-Difluoro-2′-Deoxycytidine) Pharmacokinetics, Metabolism, and Bioavailability in Mice by 3,4,5,6-Tetrahydrouridine
Authors: Beumer Jan H. , Eiseman Julie L. , Parise Robert A. , Joseph Erin , Covey Joseph M. , Egorin Merrill J.
Published: June 2008

Purpose: In vivo, 2′,2′-difluoro-2′-deoxycytidine (dFdC) is rapidly inactivated by gut and liver cytidine deaminase (CD) to 2′,2′-difluoro-2′-deoxyuridine (dFdU). Consequently, dFdC has poor oral bioavailability and is administered i.v., with associated costs and limitations in administration schedules. 3,4,5,6-Tetrahydrouridine (THU) is a potent CD inhibitor with a 20% oral bioavailability. We investigated the ability of THU to decrease elimination and first-pass effect by CD, thereby enabling oral dosing of dFdC.

Experimental Design: A liquid chromatography-tandem mass spectrometry assay was developed for plasma dFdC and dFdU. Mice were dosed with 100 mg/kg dFdC i.v. or orally with or without 100 mg/kg THU i.v. or orally. At specified times between 5 and 1,440 min, mice (n = 3) were euthanized. dFdC, dFdU, and THU concentrations were quantitated in plasma and urine.

Results: THU i.v. and orally produced concentrations >4 μg/mL for 3 and 2 h, respectively, whereas concentrations of >1 μg/mL have been associated with near-complete inhibition of CD in vitro. THU i.v. decreased plasma dFdU concentrations but had no effect on dFdC plasma area under the plasma concentration versus time curve after i.v. dFdC dosing. Both THU i.v. and orally substantially increased oral bioavailability of dFdC. Absorption of dFdC orally was 59%, but only 10% passed liver and gut CD and eventually reached the systemic circulation. Coadministration of THU orally increased dFdC oral bioavailability from 10% to 40%.

Conclusions: Coadministration of THU enables oral dosing of dFdC and warrants clinical testing. Oral dFdC treatment would be easier and cheaper, potentially prolong dFdC exposure, and enable exploration of administration schedules considered impractical by the i.v. route.
A Phase I and Pharmacokinetic Study of Weekly Oxaliplatin Followed by Paclitaxel in Patients with Solid Tumors
Authors: Bekaii-Saab Tanios S. , Liu Jing , Chan Kenneth K. , Balcerzak Stanley P. , Ivy Percy S. , Grever Michael R. , Kraut Eric H.
Published: June 2008

Purpose: Oxaliplatin and paclitaxel are widely used in treating solid tumors. We designed a phase I study with the purpose of determining the maximal tolerated dose and pharmacokinetic properties of weekly oxaliplatin followed by paclitaxel based on evidence suggesting that weekly administration of both drugs allows equivalent dose intensity with less neurotoxicity.

Experimental Design: Twenty-three patients with advanced solid tumors were treated. Starting doses were 35 mg/m2 oxaliplatin followed by 45 mg/m2 paclitaxel weekly for 4 weeks every 6 weeks. Dose was escalated as follows: 45 mg/m2 oxaliplatin and 45 mg/m2 paclitaxel, 60 mg/m2 oxaliplatin and 45 mg/m2 paclitaxel, and 60 mg/m2 oxaliplatin and 60 mg/m2 paclitaxel. Pharmacokinetic studies were evaluated during the first course of therapy for oxaliplatin using population kinetics approach.

Results: A total of 49 courses were administered. The dose-limiting toxicity was peripheral neuropathy with oxaliplatin and paclitaxel both at 60 mg/m2. There were three partial responses. There was evidence of pharmacokinetic interaction with a significant amount of total platinum (46.2-49.5%/24 h) eliminated in the urine in this group of patients, consistent with published data from others. The total body clearance values of plasma platinum and ultrafiltrable platinum were higher in this combination compared with corresponding values from our previous study with oxaliplatin only (P < 0.001).

Conclusions: The recommended phase II dose of this combination is 60 mg/m2 oxaliplatin followed by 45 mg/m2 paclitaxel. Evidence of antitumor activity and acceptable toxicity with this combination and schedule warrants further investigation. We have obtained more definitive pharmacokinetic properties of oxaliplatin and confirmed its drug interaction with paclitaxel in the current sequence.
Hypertension and Rarefaction during Treatment with Telatinib, a Small Molecule Angiogenesis Inhibitor
Authors: Steeghs Neeltje , Gelderblom Hans , Roodt Jos op 't , Christensen Olaf , Rajagopalan Prabhu , Hovens Marcel , Putter Hein , Rabelink Ton J. , de Koning Eelco
Published: June 2008

Purpose: Hypertension is a commonly reported side effect in antiangiogenic therapy. We investigated the hypothesis that telatinib, a small molecule angiogenesis inhibitor, impairs vascular function, induces rarefaction, and causes hypertension.

Experimental Design: A side-study was done in a phase I trial of telatinib, a small molecule tyrosine kinase inhibitor of vascular endothelial growth factor receptors 2 and 3, platelet-derived growth factor receptor, and c-KIT in patients with advanced solid tumors. Measurements of blood pressure, flow-mediated dilation, nitroglycerin-mediated dilation, aortic pulse wave velocity, skin blood flux with laser Doppler flow, and capillary density with sidestream dark field imaging were done at baseline and after 5 weeks of treatment. Blood pressure and proteinuria were measured weekly.

Results: Mean systolic and diastolic blood pressure values increased significantly at +6.6 mm Hg (P = 0.009) and +4.7 mm Hg (P = 0.016), respectively. Mean flow-mediated dilation and mean nitroglycerin-mediated dilation values significantly decreased by −2.1% (P = 0.003) and −5.1% (P = 0.001), respectively. After 5 weeks of treatment, mean pulse wave velocity significantly increased by 1.2 m/s (P = 0.001). A statistically significant reduction of mean skin blood flux of 532.8% arbitrary units was seen (P = 0.015). Capillary density statistically significantly decreased from 20.8 to 16.7 capillary loops (P = 0.015). Proteinuria developed or increased in six patients during telatinib treatment.

Conclusion: The increase in blood pressure observed in the treatment with telatinib, an angiogenesis inhibitor, may be caused by functional or structural rarefaction.
Development of Clinical Trials in a Cooperative Group Setting: The Eastern Cooperative Oncology Group
Authors: Dilts David M. , Sandler Alan , Cheng Steven , Crites Joshua , Ferranti Lori , Wu Amy , Gray Robert , MacDonald Jean , Marinucci Donna , Comis Robert
Published: June 2008

Purpose: We examine the processes and document the calendar time required to activate phase II and III clinical trials by an oncology group: the Eastern Cooperative Oncology Group (ECOG).

Methods: Setup steps were documented by (a) interviewing ECOG headquarters and statistical center staff, and committee chairs, (b) reviewing standard operating procedure manuals, and (c) inspecting study records, documents, and e-mails to identify additional steps. Calendar time was collected for each major process for each study in this set.

Results: Twenty-eight phase III studies were activated by ECOG during the January 2000 to July 2006 study period. We examined a sample from 16 of those studies in detail. More than 481 distinct processes were required for study activation: 420 working steps, 61 major decision points, 26 processing loops, and 13 stopping points. Median calendar days to activate a trial in the phase III subset was 783 days (range, 285-1,542 days) from executive approval and 808 days (range, 435-1,604 days) from initial conception of the study. Data were collected for all phase II and phase III trials activated and completed during this time period (n = 52) for which development time represented 43.9% and 54.1% of the total trial time, respectively.

Conclusion: The steps required to develop and activate a clinical trial may require as much or more time than the actual completion of a trial. The data shows that to improve the activation process, research should to be directed toward streamlining both internal and external groups and processes.