bluuebunny/crossref_metadata_2025 huggingface dataset:
Transactivation of the Epidermal Growth Factor Receptor by Formylpeptide Receptor Exacerbates the Malignant Behavior of Human Glioblastoma Cells
Authors: Huang Jian , Hu Jinyue , Bian Xiuwu , Chen Keqiang , Gong Wanghua , Dunlop Nancy M. , Howard O.M. Zack , Wang Ji Ming
Published: June 2007

The G protein-coupled formylpeptide receptor (FPR), which mediates leukocyte migration in response to bacterial and host-derived chemotactic peptides, promotes the chemotaxis, survival, and tumorigenesis of highly malignant human glioblastoma cells. Because glioblastoma cells may also express other receptors for growth signals, such as the epidermal growth factor (EGF) receptor (EGFR), we investigated the role of EGFR in the signaling cascade of FPR and how two receptors cross-talk to exacerbate tumor growth. We found that N-formyl-methionyl-leucyl-phenylalanine, an FPR agonist peptide, rapidly induced EGFR phosphorylation at tyrosine residue (Tyr) 992, but not residues 846, 1068, or 1173, in glioblastoma cells, whereas all these residues were phosphorylated after only EGF treatment. The FPR agonist-induced EGFR phosphorylation in tumor cells was dependent on the presence of FPR as well as Gαi proteins, and was controlled by Src tyrosine kinase. The transactivation of EGFR contributes to the biological function of FPR in glioblastoma cells because inhibition of EGFR phosphorylation significantly reduced FPR agonist-induced tumor cell chemotaxis and proliferation. Furthermore, depletion of both FPR and EGFR by short interference RNA abolished the tumorigenesis of the glioblastoma cells. Our study indicates that the glioblastoma-promoting activity of FPR is mediated in part by transactivation of EGFR and the cross-talk between two receptors exacerbates the malignant phenotype of tumor cells. Thus, targeting both receptors may yield antiglioblastoma agents superior to those targeting one of them. [Cancer Res 2007;67(12):5906–13]
In vitro Benzo[a]pyrene Diol Epoxide–Induced DNA Adducts and Risk of Squamous Cell Carcinoma of Head and Neck
Authors: Li Donghui , Wang Li-E , Chang Ping , El-Naggar Adel K. , Sturgis Erich M. , Wei Qingyi
Published: June 2007

In this large confirmatory study of 803 patients with squamous cell carcinoma of head and neck (SCCHN) and 839 controls frequency matched by age, sex, and ethnicity, we further examined potential predictors of benzo[a]pyrene diol epoxide (BPDE)-induced adduct levels and their associations with SCCHN risk. BPDE-DNA adduct levels were determined by the 32P-postlabeling method in peripheral lymphocytes after in vitro challenged by BPDE. We also genotyped for GSTM1 null, GSTT1 null, GSTP1 Ile105Val, and GSTP1 Ala114Val. Potential predictors of BPDE-DNA adducts were evaluated by stratification and multivariate linear regression analyses and the association between adduct levels and SCCHN risk by multivariate logistic regression analyses. We found that mean BPDE-DNA adduct levels (the relative adduct labeling × 107 ± SD) were significantly higher in cases (77.6 ± 111.8) than in controls (57.3 ± 98.3; P < 0.001). Using the median control value (29.22) as a cutoff, 63% of the cases were distributed above this level (adjusted odds ratio, 1.71; 95% confidence interval, 1.39–2.10). A significant dose-response relationship was observed between adduct quartiles and SCCHN risk (Ptrend < 0.001). Multivariate linear regression analysis revealed that ethnicity and smoking were significant predictors of BPDE-DNA adduct levels in controls. In conclusion, we confirmed the previously reported association between in vitro BPDE-induced DNA adduct levels and SCCHN risk, and the assay may help identify individuals at high risk of developing smoking-related cancers. [Cancer Res 2007;67(12):5628–34]
In vivo
19F Magnetic Resonance Spectroscopy and Chemical Shift Imaging of Tri-Fluoro-Nitroimidazole as a Potential Hypoxia Reporter in Solid Tumors
Authors: Procissi Daniel , Claus Filip , Burgman Paul , Koziorowski Jacek , Chapman J. Donald , Thakur Sunitha B. , Matei Cornelia , Ling C. Clifton , Koutcher Jason A.
Published: June 2007

Purpose: 2-Nitro-α-[(2,2,2-trifluoroethoxy)methyl]-imidazole-1-ethanol (TF-MISO) was investigated as a potential noninvasive marker of tissue oxygen levels in tumors using 19F magnetic resonance spectroscopy (MRS) and 19F chemical shift imaging.

Experimental Designs: In vitro data were obtained using high-performance liquid chromatography on tumor cells incubated under varying oxygen conditions to determine the oxygen-binding characteristics. In vivo data were obtained using a well-characterized hypoxic murine breast tumor (MCa), in addition to studies on a rat prostate tumor model (R3327-AT) implanted in nude mice. Detection of intratumor 19F signal from TF-MISO was done using MRS for up to 10 h following a 75 mg/kg i.v. injection. Localized distribution of the compound in the implanted MCa tumor has been imaged using slice-selective two-dimensional chemical shift imaging 6 h after injection.

Results: The in vitro results showed that TF-MISO preferentially accumulates in cells incubated under anoxic conditions. The in vivo 19F MR spectral features (line width and chemical shift) were recorded as a function of time after injection, and the results indicate that the fluorine atoms are indeed sensitive to changes in the local environment while still providing a detectable MR signal. Ex vivo spectra were collected and established the visibility of the 19F signal under conditions of maximum hypoxia. Late time point (>6 h) tumor tissue concentrations, as obtained from 19F MRS, suggest that TF-MISO is reduced and retained in hypoxic tumor. The feasibility of obtaining TF-MISO tumor distribution maps in a reasonable time frame was established.

Conclusions: Based on the results presented herein, it is suggested that TF-MISO has the potential to be a valid magnetic resonance hypoxia imaging reporter for both preclinical hypoxia studies and hypoxia-directed clinical therapy.
PIK3CA Mutations and PTEN Loss Correlate with Similar Prognostic Factors and Are Not Mutually Exclusive in Breast Cancer
Authors: Pérez-Tenorio Gizeh , Alkhori Liza , Olsson Birgit , Waltersson Marie Ahnström , Nordenskjöld Bo , Rutqvist Lars Erik , Skoog Lambert , Stål Olle
Published: June 2007

Purpose: The phosphatidylinositol 3′-kinase/Akt pathway is frequently altered in breast cancer. PTEN, a phosphatase that opposes the effect of phosphatidylinositol 3′-kinase, can be mutated or lost, whereas the PIK3CA gene is mutated. These have been proposed as alternative mechanisms, and their clinicalpathology significance is under discussion. In this study, we aimed to explore whether PIK3CA mutations and PTEN loss are mutually exclusive mechanisms, correlate with other known clinicopathologic markers, or have clinical implication in breast cancer.

Experimental Design: Exons 9 and 20 of the PIK3CA gene were analyzed in 270 breast tumors, and mutations were detected by single-stranded conformational analysis followed by sequencing. The expression of PTEN was evaluated by immunohistochemistry in 201 tumors.

Results: PIK3CA mutations were found in 24% of the tumors and associated with estrogen receptor+ status, small size, negative HER2 status, high Akt1, and high cyclin D1 protein expression. PTEN was negative in 37% of the cases and PTEN loss was associated with PIK3CA mutations (P = 0.0024). Tumors presenting PTEN loss or both alterations were often estrogen receptor+, small in size, and HER2−. PIK3CA mutations predicted for longer local recurrence-free survival. Moreover, PTEN loss by itself or combined with mutated PIK3CA tended to confer radiosensitivity. In addition, the patients with high S-phase fraction had longer recurrence-free survival if they carried mutations in the PIK3CA gene and/or had lost PTEN, whereas the same alterations were associated with shorter recurrence-free survival among patients with low S-phase fraction.

Conclusions: PIK3CA mutations and PTEN loss were not mutually exclusive events and associated with similar prognostic factors.
Matriptase-2 Inhibits Breast Tumor Growth and Invasion and Correlates with Favorable Prognosis for Breast Cancer Patients
Authors: Parr Christian , Sanders Andrew J. , Davies Gaynor , Martin Tracey , Lane Jane , Mason Malcolm D. , Mansel Robert E. , Jiang Wen G.
Published: June 2007

Purpose: The type II transmembrane serine proteases are cell surface proteolytic enzymes that mediate a diverse range of cellular functions, including tumor invasion and metastasis. Matriptase (matriptase-1) and matriptase-2 belong to the type II transmembrane serine protease family. Matriptase-1 is known to play a role in breast cancer progression, and elevated levels of matriptase-1 correlate with poor patient outcome. The role of matriptase-2 and its cellular function in cancer is unknown. This study aimed to provide new insights into the significance of matriptase-2 in cancer.

Experimental Design: Matriptase-2 expression levels were assessed in a cohort of human breast cancer specimens (normal, n = 34; cancer, n = 95), in association with patient clinical variables, using both quantitative and qualitative analysis of the matriptase-2 transcript along with immunohistochemical techniques. Matriptase-2 was also experimentally overexpressed in the MDA-MB-231 human breast cancer cell line. The effects of matriptase-2 overexpression were examined through a series of in vitro and in vivo studies.

Results: Here, we show that reduced matriptase-2 levels in breast cancer tissues correlate with an overall poor prognosis for the breast cancer patient. This study also reveals that matriptase-2 overexpression in breast cancer cells significantly suppressed tumorigenesis in CD1 athymic mice (P = 0.000003). Furthermore, we report that matriptase-2 overexpression dramatically reduced the invasive (P = 0.0001) and migratory properties (P = 0.01) of the breast cancer cells.

Conclusions: Matriptase-2 suppresses breast tumor development in vivo, displays prognostic value for breast cancer patients, inhibits both breast cancer cell invasion and motility in vitro, and may play a contrasting role to matriptase-1 in breast cancer.
A Randomized, Double-Blind, Phase II Study of Two Doses of Pemetrexed as First-Line Chemotherapy for Advanced Breast Cancer
Authors: Llombart-Cussac Antonio , Martin Miguel , Harbeck Nadia , Anghel Rodica M. , Eniu Alexandra E. , Verrill Mark W. , Neven Patrick , De Grève Jacques , Melemed Allen S. , Clark Romnee , Simms Lorinda , Kaiser Christopher J. , Ma Doreen
Published: June 2007

Purpose: Pemetrexed has shown varied response rates in advanced breast cancer. This randomized, double-blind, phase II study was conducted to assess the efficacy and safety of two doses of pemetrexed in a homogeneous population. A secondary objective was to identify molecular biomarkers correlating with response and toxicity.

Experimental Design: Patients with newly diagnosed metastatic breast cancer or locally recurrent breast cancer received 600 mg/m2 (P600 arm) or 900 mg/m2 (P900 arm) of pemetrexed on day 1 of a 21-day cycle. All patients received folic acid and vitamin B12 supplementation.

Results: The P600 (47 patients) and P900 (45 patients) arms had response rates of 17.0% (95% confidence interval, 7.7-30.8%) and 15.6% (95% confidence interval, 6.5-29.5%) with ∼50% stable disease per arm, median progression-free survival of 4.2 and 4.1 months, and median times to tumor progression of 4.2 and 4.6 months, respectively. Both arms exhibited minimal toxicity (grade 3/4 neutropenia <20%, leukopenia <9%, and other toxicities <5%). Tumor samples from 49 patients were assessed for the expression levels of 12 pemetrexed-related genes. Folylpolyglutamate synthetase and thymidine phosphorylase correlated with efficacy. Best response rates and median time to tumor progression for high versus low thymidine phosphorylase expression were 27.6% versus 6.3% (P = 0.023) and 5.4 versus 1.9 months (P = 0.076), and for folylpolyglutamate synthetase were 37.5% versus 10.0% (P = 0.115) and 8.6 versus 3.0 months (P = 0.019), respectively. γ-Glutamyl hydrolase expression correlated with grade 3/4 toxicities: 78.6% for high versus 27.3% for low γ-glutamyl hydrolase (P = 0.024).

Conclusion: The two pemetrexed doses yielded similar efficacy and safety profiles. Exploratory biomarker analysis identified efficacy and toxicity correlations and warrants further evaluation.
Dose-Escalating and Pharmacologic Study of Oxaliplatin in Adult Cancer Patients with Impaired Hepatic Function: A National Cancer Institute Organ Dysfunction Working Group Study
Authors: Synold Timothy W. , Takimoto Chris H. , Doroshow James H. , Gandara David , Mani Sridhar , Remick Scot C. , Mulkerin Daniel L. , Hamilton Anne , Sharma Sunil , Ramanathan Ramesh K. , Lenz Heinz Josef , Graham Martin , Longmate Jeffrey , Kaufman Bennett M. , Ivy Percy
Published: June 2007

Purpose: To determine the toxicities, pharmacokinetics, and maximally tolerated doses of oxaliplatin in patients with hepatic impairment and to develop formal guidelines for oxaliplatin dosing in this patient population.

Experimental Design: Sixty adult cancer patients with variable hepatic function received i.v. oxaliplatin ranging from 60 to 130 mg/m2 every 3 weeks. Patients were stratified by levels of total bilirubin, aspartate aminotransferase (AST), and alkaline phosphatase (AP) into five cohorts based on the degree of hepatic dysfunction: control group A [bilirubin, AST, and AP ≤ upper limit of normal (ULN)], mild dysfunction group B (bilirubin ≤ ULN, ULN < AST ≤ 2.5 × ULN, or ULN < AP ≤ 5 × ULN), moderate dysfunction group C (ULN < bilirubin ≤ 3.0 mg/dL, AST > 2.5 × ULN, or AP > 5 × ULN), severe dysfunction group D (bilirubin > 3.0 mg/dL, any AST, and any AP), and liver transplantation group E (any bilirubin, any AST, and any AP). Doses were escalated in cohorts of three patients, and urine and plasma ultrafiltrates were assayed for platinum concentrations.

Results: Dose escalation of single-agent oxaliplatin to 130 mg/m2 was well tolerated in all cohorts. Platinum clearance did not correlate with any liver function test. Two of 56 assessable patients with a diagnosis of laryngeal carcinoma and cervical adenocarcinoma experienced partial responses lasting 3 and 5.5 months.

Conclusions: Oxaliplatin at 130 mg/m2 every 3 weeks was well tolerated in all patients with impaired liver function. Dose reductions of single-agent oxaliplatin are not indicated in patients with hepatic dysfunction.
Neutrophils Promote Aerogenous Spread of Lung Adenocarcinoma with Bronchioloalveolar Carcinoma Features
Authors: Wislez Marie , Antoine Martine , Rabbe Nathalie , Gounant Valérie , Poulot Virginie , Lavolé Armelle , Fleury-Feith Jocelyne , Cadranel Jacques
Published: June 2007

Purpose: Adenocarcinoma with bronchioloalveolar carcinoma (BAC) features is a subtype of non–small cell lung cancers characterized by an intense inflammatory reaction composed of macrophages and neutrophils and by a distinct natural history with intrapulmonary spread leading to death due to respiratory failure. We hypothesized that neutrophils could promote aerogenous spread of lung adenocarcinoma with BAC features.

Experimental Design: We examined the effect of neutrophils on A549 cell line detachment in vitro and we quantified desquamation of tumor cells on tumor tissue (n = 25) and on matched bronchioloalveolar lavage (n = 17) in vivo in a series of patients with adenocarcinoma with BAC features.

Results: Neutrophils induced A549 detachment mediated by signals through cell-to-cell contact. Detached A549 cells were still viable and able to proliferate in vitro. Neutralization studies identified several membrane-bound molecules involved in detachment (i.e., intercellular adhesion molecule-1/lymphocyte function-associated antigen-1, tumor necrosis factor α/tumor necrosis factor α receptor inhibitor, interleukin-1α /interleukin-1α receptor, and neutrophil elastase). In tumor tissue, shedding was detected in all samples, with a median shedding score of 42% (range, 4-95%). Micropapillary clusters were detected in 23 of the 25 tumor tissue samples, with a median micropapillary score of 1.40 (range, 0-2.1), and tumor cells were detected in 7 of 17 lavages. The micropapillary score was associated with a high neutrophil count in bronchioloalveolar lavage (P = 0.051). The shedding cell percentage was a significant factor in shorter survival (P = 0.034, univariate Cox analysis).

Conclusions: Tumor shedding is induced by neutrophils. It is a significant factor of shorter survival and may be an important event in adenocarcinoma progression.
Inhibition of the T790M Gatekeeper Mutant of the Epidermal Growth Factor Receptor by EXEL-7647
Authors: Gendreau Steven B. , Ventura Richard , Keast Paul , Laird A. Douglas , Yakes F. Michael , Zhang Wentao , Bentzien Frauke , Cancilla Belinda , Lutman Jeffery , Chu Felix , Jackman Lisa , Shi Yongchang , Yu Peiwen , Wang Jing , Aftab Dana T. , Jaeger Christopher T. , Meyer Stephanie M. , De Costa Anushka , Engell Kelly , Chen Jason , Martini Jean-Francois , Joly Alison H.
Published: June 2007

Purpose: Agents inhibiting the epidermal growth factor receptor (EGFR) have shown clinical benefit in a subset of non–small cell lung cancer patients expressing amplified or mutationally activated EGFR. However, responsive patients can relapse as a result of selection for EGFR gene mutations that confer resistance to ATP competitive EGFR inhibitors, such as erlotinib and gefitinib. We describe here the activity of EXEL-7647 (XL647), a novel spectrum-selective kinase inhibitor with potent activity against the EGF and vascular endothelial growth factor receptor tyrosine kinase families, against both wild-type (WT) and mutant EGFR in vitro and in vivo.

Experimental Design: The activity of EGFR inhibitors against WT and mutant EGFRs and their effect on downstream signal transduction was examined in cellular assays and in vivo using A431 and MDA-MB-231 (WT EGFR) and H1975 (L858R and T790M mutant EGFR) xenograft tumors.

Results: EXEL-7647 shows potent and long-lived inhibition of the WT EGFR in vivo. In addition, EXEL-7647 inhibits cellular proliferation and EGFR pathway activation in the erlotinib-resistant H1975 cell line that harbors a double mutation (L858R and T790M) in the EGFR gene. In vivo efficacy studies show that EXEL-7647 substantially inhibited the growth of H1975 xenograft tumors and reduced both tumor EGFR signaling and tumor vessel density. Additionally, EXEL-7647, in contrast to erlotinib, substantially inhibited the growth and vascularization of MDA-MB-231 xenografts, a model which is more reliant on signaling through vascular endothelial growth factor receptors.

Conclusions: These studies provide a preclinical basis for clinical trials of XL647 in solid tumors and in patients bearing tumors that are resistant to existing EGFR-targeted therapies.
Bcl-2 and Bax Expression Predict Prostate Cancer Outcome in Men Treated with Androgen Deprivation and Radiotherapy on Radiation Therapy Oncology Group Protocol 92-02
Authors: Khor Li Yan , Moughan Jennifer , Al-Saleem Tahseen , Hammond Elizabeth H. , Venkatesan Varagur , Rosenthal Seth A. , Ritter Mark A. , Sandler Howard M. , Hanks Gerald E. , Shipley William U. , Pollack Alan
Published: June 2007

Purpose: Bcl-2 is antiapoptotic, and its overexpression has been associated with resistance to androgen deprivation and poor outcome in some patients treated with radiotherapy. Bax is proapoptotic, regulating Bcl-2 through heterodimer formation. In a prior study, Bcl-2 and Bax were not related to outcome in locally advanced patients treated with radiotherapy or short-term androgen deprivation + radiotherapy (STAD+RT) on another Radiation Therapy Oncology Group trial (86-10). A follow-up investigation was carried out here in more contemporary high-risk men treated on Radiation Therapy Oncology Group 92-02 with STAD+RT or long-term AD+RT (LTAD+RT).

Experimental Design: Adequate tissue was available to be analyzed immunohistochemically in 502 patients for Bcl-2 and 343 patients for Bax. Univariate and multivariate analyses by Cox proportional hazards models were applied to end points of failure.

Results: Bcl-2 was positive in 45.6% cases, and Bax expression altered in 53.9% cases. Abnormal Bcl-2 was not related to any of the failure end points tested. Altered Bax expression was significantly associated with any failure (P = 0.023) and marginally with biochemical failure (P = 0.085). The combination of negative Bcl-2/normal Bax expression seemed more robust, being significantly related to reduced biochemical failure (P = 0.036) and any failure (P = 0.046). The predictive value of negative Bcl-2/normal Bax was most pronounced in those who received STAD+RT, as opposed to LTAD+RT.

Conclusions: Normal Bax expression was associated with significantly more favorable outcome. The combination of negative Bcl-2 and normal Bax was more consistently significant, particularly when STAD+RT was the treatment administered. These data suggest that LTAD+RT should be used when either Bcl-2 or Bax is abnormally expressed.
Early Response Assessment Using 3′-Deoxy-3′-[18F]Fluorothymidine-Positron Emission Tomography in High-Grade Non-Hodgkin's Lymphoma
Authors: Herrmann Ken , Wieder Hinrich A. , Buck Andreas K. , Schöffel Marion , Krause Bernd-Joachim , Fend Falko , Schuster Tibor , Meyer zum Büschenfelde Christian , Wester Hans-Jürgen , Duyster Justus , Peschel Christian , Schwaiger Markus , Dechow Tobias
Published: June 2007

Purpose: To evaluate 3′-deoxy-3′-[18F]fluorothymidine-positron emission tomography (FLT-PET) for early monitoring response of high-grade non-Hodgkin's lymphoma to treatment with cyclophosphamide-adriamycin-vincristine-prednisone chemotherapy with or without rituximab immunotherapy (R-CHOP/CHOP).

Experimental Design: Twenty-two patients with histologically proven high-grade non-Hodgkin's lymphoma scheduled to undergo first line treatment with R-CHOP/CHOP were included. All patients received baseline imaging before therapy with FLT-PET. For noninvasive assessment of treatment response, FLT-PET was repeated at following time points: group 1 (n = 6), 1 and 6 weeks after R-CHOP/CHOP; group 2 (n = 16), 2 days after rituximab and 2 days after CHOP application. Emission images were acquired 45 min after injection of 300 to 370 MBq of FLT. FLT uptake was quantified by region-of-interest technique on a lesion basis. Maximum standardized uptake values (SUV) for FLT were calculated using circular region of interest (diameter, 1.5 cm).

Results: In all patients, morphologically proven lesions showed initially high FLT uptake (mean SUV, 8.1 ± 3.9). In group 1, mean FLT SUV decreased 7 days after R-CHOP/CHOP by 77% (P < 0.001), the reduction in FLT SUV from baseline was 85% after 40 days (P = 0.003). In group 2, FLT uptake in patients without dexamethasone pretreatment revealed no significant reduction after rituximab (P = 0.3) but significantly decreased 2 days after CHOP to 32% compared with the baseline value (P = 0.004).

Conclusions: Administration of R-CHOP/CHOP is associated with an early decrease in lymphoma FLT uptake. Interestingly, there was no reduction of FLT uptake after rituximab alone, indicating no early antiproliferative effect of immunotherapy. FLT-PET seems to be promising for early evaluation of drug effects in lymphoma.
αv Integrin-Targeted Immunoconjugates Regress Established Human Tumors in Xenograft Models
Authors: Chen Qiming , Millar Hillary J. , McCabe Francis L. , Manning Carol D. , Steeves Rita , Lai Kate , Kellogg Brenda , Lutz Robert J. , Trikha Mohit , Nakada Marian T. , Anderson G. Mark
Published: June 2007

Purpose: Targeted delivery of cytotoxic agents to solid tumors through cell surface antigens can potentially reduce systemic toxicity and increase the efficacy of the targeted compounds. The purpose of this study was to show the feasibility of treating solid tumors by targeting αv integrins with antibody-maytansinoid conjugates and to test the relative in vivo activities of several linker-maytansinoid chemistries.

Experimental Design: CNTO 364, CNTO 365, and CNTO 366 are targeted cytotoxic agents created by conjugating the CNTO 95 anti-αv integrin antibody with three distinct maytansinoid-linker structures. These structures were designed to have varying degrees of chemical substitution surrounding the disulfide bond linking the cytotoxic agent to the antibody. A model conjugate was shown to be specifically cytotoxic in vitro and highly active against established human tumor xenografts in immunocompromised rats. The in vivo antitumor activities of CNTO 364, CNTO 365, and CNTO 366 were compared in rat xenograft models.

Results: CNTO 365, with a linker chemistry of expected intermediate stability, was shown to be substantially more active than the other two conjugates with lesser or greater substitution around the disulfide linkage.

Conclusion: CNTO 95–maytansinoid immunoconjugates are potent antitumor agents against αv integrin–expressing human carcinomas. These studies show for the first time the feasibility of targeting αv integrins on solid tumors with tumor-activated prodrugs. The DM4 linker-maytansinoid configuration of CNTO 365 was substantially more active in the models tested here when compared with alternative configurations with greater or lesser chemical substitution surrounding the linker.
Ex vivoNicotine Stimulation Augments the Efficacy of Therapeutic Bone Marrow–Derived Dendritic Cell Vaccination
Authors: Gao Feng Guang , Wan Da Fang , Gu Jian Ren
Published: June 2007

Purpose: To explore the preventive and therapeutic antitumor effects of nicotine-treated immature dendritic cells (imDC).

Experimental Design: First, bone marrow–derived imDCs were stimulated with nicotine in vitro, and nicotinic acetylcholine receptor, costimulator molecules, chemokine receptor, and endocytosis ability of imDCs were detected by flow cytometry. Second, the DC-dependent antigen-specific T-cell proliferation, CTL priming, and interleukin-12 secretion were determined by flow cytometry, enzyme-linked immunospot assay, and ELISA, respectively. Finally, preventive and therapeutic antitumor effects of such imDCs were determined by i.p. transfer against tumor challenge or implantation in mice.

Results: Nicotine could up-regulate expression of nicotinic acetylcholine receptor, costimulatory molecules, such as CD80, CD86, and CD40, adhesion molecule CD11b, and chemokine receptor CCR7 and enhance endocytosis ability of imDCs. In addition, nicotine could promote imDC-dependent CTL priming and interleukin-12 secretion in vitro. Most importantly, systemic transfer of ex vivo nicotine-stimulated imDCs could reveal preventive and therapeutic effect on tumor development.

Conclusions: Ex vivo nicotine stimulation can significantly improve the efficacy of imDCs for adaptive therapy of cancer and nicotine-treated imDCs may be considered as a potential candidate for preventive and therapeutic tumor vaccination.
A Parallel Dose-Escalation Study of Weekly and Twice-Weekly Bortezomib in Combination with Gemcitabine and Cisplatin in the First-Line Treatment of Patients with Advanced Solid Tumors
Authors: Voortman Jens , Smit Egbert F. , Honeywell Richard , Kuenen Bart C. , Peters Godefridus J. , van de Velde Helgi , Giaccone Giuseppe
Published: June 2007

Purpose: To establish maximum tolerated dose (MTD) and tolerability of two schedules of bortezomib in combination with cisplatin and gemcitabine as first-line treatment of patients with advanced solid tumors.

Experimental Design: Patients were assigned to increasing doses of bortezomib days 1 and 8 (weekly schedule) or days 1, 4, 8, and 11 (twice-weekly schedule), in addition to gemcitabine 1,000 mg/m2 days 1 and 8 and cisplatin 70 mg/m2 day 1, every 21 days. Maximum of six cycles. Plasma pharmacokinetics of cisplatin and gemcitabine were determined at MTD.

Results: Thirty-four patients were enrolled of whom 27 had non–small cell lung cancer (NSCLC). Diarrhea, neutropenia, and thrombocytopenia were dose-limiting toxicities leading to an MTD of bortezomib 1.0 mg/m2 in the weekly schedule. Febrile neutropenia and thrombocytopenia with bleeding were dose-limiting toxicities in the twice-weekly schedule, leading to an MTD of bortezomib 1.0 mg/m2 as well. Most common ≥grade 3 treatment-related toxicities were thrombocytopenia and neutropenia. No grade ≥3 treatment-related sensory neuropathy was reported. Of 34 evaluable patients, 13 achieved partial responses, 17 stable disease, and 4 progressive disease. Response and survival of NSCLC patients treated with twice weekly or weekly bortezomib were similar. However, increased dose intensity of bortezomib led to increased gastrointestinal toxicity as well as myelosuppression. Pharmacokinetic profiles of cisplatin and gemcitabine were not significantly different in patients receiving either schedule.

Conclusions: Weekly bortezomib 1.0 mg/m2 plus gemcitabine 1,000 mg/m2 and cisplatin 70 mg/m2 is the recommended phase 2 schedule, constituting a safe combination, with activity in NSCLC.
Tumor-Specific Positron Emission Tomography Imaging in Patients: [18F] Fluorodeoxyglucose and Beyond
Authors: Mankoff David A. , Eary Janet F. , Link Jeanne M. , Muzi Mark , Rajendran Joseph G. , Spence Alexander M. , Krohn Kenneth A.
Published: June 2007

Biochemical and molecular imaging of cancer using positron emission tomography (PET) plays an increasing role in the care of cancer patients. Most clinical work to date uses the glucose analogue [18F]fluorodeoxyglucose (FDG) to detect accelerated and aberrant glycolysis present in most tumors. Although clinical FDG PET has been used largely to detect and localize cancer, more detailed studies have yielded biological insights and showed the utility of FDG as a prognostic marker and as a tool for therapeutic response evaluation. As cancer therapy becomes more targeted and individualized, it is likely that PET radiopharmaceuticals other than FDG, aimed at more specific aspects of cancer biology, will also play a role in guiding cancer therapy. Clinical trials designed to test and validate new PET agents will need to incorporate rigorous quantitative image analysis and adapt to the evolving use of imaging as a biomarker and will need to incorporate cancer outcomes, such as survival into study design.
Spatio-Temporal Control of Gene Expression and Cancer Treatment Using Magnetic Resonance Imaging–Guided Focused Ultrasound
Authors: Moonen Chrit T.W.
Published: June 2007

Local temperature elevation may be used for tumor ablation, gene expression, drug activation, and gene and/or drug delivery. High-intensity focused ultrasound (HIFU) is the only clinically viable technology that can be used to achieve a local temperature increase deep inside the human body in a noninvasive way. Magnetic resonance imaging (MRI) guidance of the procedure allows in situ target definition and identification of nearby healthy tissue to be spared. In addition, MRI can be used to provide continuous temperature mapping during HIFU for spatial and temporal control of the heating procedure and prediction of the final lesion based on the received thermal dose. The primary purpose of the development of MRI-guided HIFU was to achieve safe noninvasive tissue ablation. The technique has been tested extensively in preclinical studies and is now accepted in the clinic for ablation of uterine fibroids. MRI-guided HIFU for ablation shows conceptual similarities with radiation therapy. However, thermal damage generally shows threshold-like behavior, with necrosis above the critical thermal dose and full recovery below. MRI-guided HIFU is being clinically evaluated in the cancer field. The technology also shows great promise for a variety of advanced therapeutic methods, such as gene therapy. MR-guided HIFU, together with the use of a temperature-sensitive promoter, provides local, physical, and spatio-temporal control of transgene expression. Specially designed contrast agents, together with the combined use of MRI and ultrasound, may be used for local gene and drug delivery.
Prominent Microvascular Proliferation in Clinically Aggressive Neuroblastoma
Authors: Peddinti Radhika , Zeine Rana , Luca Dragos , Seshadri Roopa , Chlenski Alexandre , Cole Kristina , Pawel Bruce , Salwen Helen R. , Maris John M. , Cohn Susan L.
Published: June 2007

Purpose: Tumor vasculature is disorganized and glomeruloid microvascular proliferation (MVP) has been identified as a poor prognosticator in some adult cancers. To determine the clinical significance of MVP, including glomeruloid MVP in neuroblastoma, we initially examined vessel architecture in tumor sections from 51 children diagnosed at Children's Memorial Hospital (CMH) and subsequently evaluated 154 neuroblastoma tumors on a tissue microarray constructed at Children's Hospital of Philadelphia (CHOP).

Experimental Design: H&E sections were examined for the presence of structurally abnormal vessels and further characterized by immunostaining for CD31 and von Willebrand factor to highlight endothelial cells and α-smooth muscle actin for pericytes. Tumors with thickened walls containing a complete layer of hypertrophic endothelial cells plus additional layers of vascular mural cells were classified as MVP positive. Associations between MVP and established clinicopathologic features and outcome were assessed.

Results: In both series, MVP was significantly associated with Schwannian stroma-poor histology (CMH, P = 0.008; CHOP, P < 0.001) and decreased survival probability (CMH, P = 0.017; CHOP, P = 0.014). In the CHOP series, MVP was associated with high-risk group classification (P < 0.001), although this association was not seen in the smaller CMH cohort.

Conclusions: The association between MVP and poor outcome provides further support for the concept that angiogenesis plays an important role in determining the biological behavior of neuroblastoma tumors. Our results also indicate that angiogenesis is regulated differently in Schwannian stroma-rich versus stroma-poor neuroblastoma tumors. Further studies investigating the activity of angiogenic inhibitors in children with clinically aggressive stroma-poor neuroblastoma are warranted.
Imaging Tumor Vascular Heterogeneity and Angiogenesis using Dynamic Contrast-Enhanced Magnetic Resonance Imaging
Authors: Jackson Alan , O'Connor James P.B. , Parker Geoff J.M. , Jayson Gordon C.
Published: June 2007

This article reviews the application of dynamic contrast-enhanced magnetic resonance imaging in both clinical studies and early-phase trials of angiogenesis inhibitors. Emphasis is placed on how variation in image acquisition and analysis affects the meaning and use of derived variables. We then review the potential for future developments, with particular reference to the application of dynamic contrast-enhanced magnetic resonance imaging to evaluate the heterogeneity of tumor tissues.
Nuclear Imaging Probes: from Bench to Bedside
Authors: Wester Hans-Jürgen
Published: June 2007

The availability of specific imaging probes is the nuclear fuel for molecular imaging by positron emission tomography and single-photon emission computed tomography. These two radiotracer-based imaging modalities represent the prototype methods for noninvasive depiction and quantification of biochemical processes, allowing a functional characterization of tumor biology. A variety of powerful radiolabeled probes—tracers—are already established in the routine clinical management of human disease and others are currently subject to clinical assessment. Emerging from investigations of the genomic and proteomic signatures of cancer cells, an increasing number of promising targets are being identified, including receptors, enzymes, transporters, and antigens. Corresponding probes for these newly identified targets need to be developed and transferred into the clinical setting. Starting with a brief summary of the characteristics and prerequisites for a “good tracer,” an overview of tracer concepts, target selection, and development strategies is given. The influence of the imaging concepts on tracer development is also discussed.
Potential Applications for Circulating Tumor Cells Expressing the Insulin-Like Growth Factor-I Receptor
Authors: de Bono Johann S. , Attard Gerhardt , Adjei Alex , Pollak Michael N. , Fong Peter C. , Haluska Paul , Roberts Luisa , Melvin Carrie , Repollet Madeline , Chianese David , Connely Mark , Terstappen Leon W.M.M. , Gualberto Antonio
Published: June 2007

Purpose: To detect insulin-like growth factor-IR (IGF-IR) on circulating tumor cells (CTC) as a biomarker in the clinical development of a monoclonal human antibody, CP-751,871, targeting IGF-IR.

Experimental Design: An automated sample preparation and analysis system for enumerating CTCs (CellTracks) was adapted for detecting IGF-IR–positive CTCs with a diagnostic antibody targeting a different IGF-IR epitope to CP-751,871. This assay was used in three phase I trials of CP-751,871 as a single agent or with chemotherapy and was validated using cell lines and blood samples from healthy volunteers and patients with metastatic carcinoma.

Results: There was no interference between the analytic and therapeutic antibodies. Eighty patients were enrolled on phase I studies of CP-751,871, with 47 (59%) patients having CTCs detected during the study. Before treatment, 26 patients (33%) had CTCs, with 23 having detectable IGF-IR–positive CTCs. CP-751,871 alone, and CP-751,871 with cytotoxic chemotherapy, decreased CTCs and IGF-IR–positive CTCs; these increased toward the end of the 21-day cycle in some patients, falling again with retreatment. CTCs were commonest in advanced hormone refractory prostate cancer (11 of 20). Detectable IGF-IR expression on CTCs before treatment with CP-751,871 and docetaxel was associated with a higher frequency of prostate-specific antigen decline by >50% (6 of 10 versus 2 of 8 patients). A relationship was observed between sustained decreases in CTC counts and prostate-specific antigen declines by >50%.

Conclusions: IGF-IR expression is detectable by immunofluorescence on CTCs. These data support the further evaluation of CTCs in pharmacodynamic studies and patient selection, particularly in advanced prostate cancer.
An Open-Label, Two-Arm, Phase I Trial of Recombinant Human Interleukin-21 in Patients with Metastatic Melanoma
Authors: Davis Ian D. , Skrumsager Birte K. , Cebon Jonathan , Nicholaou Theo , Barlow John W. , Moller Niels Peter Hundahl , Skak Kresten , Lundsgaard Dorthe , Frederiksen Klaus Stensgaard , Thygesen Peter , McArthur Grant A.
Published: June 2007

Purpose: Human interleukin-21 (IL-21) is a pleiotropic class I cytokine that activates CD8+ T cells and natural killer cells. We report a phase 1 study of recombinant human IL-21 in patients with surgically incurable metastatic melanoma. The primary objective was to investigate safety and tolerability by determining dose-limiting toxicity (DLT). The secondary objectives were to identify a dose response for various biomarkers in the peripheral blood, estimate the minimum biologically effective dose, determine the pharmacokinetics of IL-21, determine if anti-IL-21 antibodies were induced during therapy, and measure effects on tumor size according to Response Evaluation Criteria in Solid Tumors.

Experimental Design: Open-label, two-arm, dose escalation trial of IL-21 administered by i.v. bolus injection at dose levels from 1 to 100 μg/kg using two parallel treatment regimens: thrice weekly for 6 weeks (3/wk) or three cycles of daily dosing for 5 days followed by 9 days of rest (5+9).

Results: Twenty-nine patients entered the study. IL-21 was generally well tolerated and no DLTs were observed at the 1, 3, and 10 μg/kg dose levels. In the 3/wk regimen, DLTs were increased in alanine aminotransferase, neutropenia, and lightheadedness with fever and rigors. DLTs in the 5+9 regimen were increased in aspartate aminotransferase and alanine aminotransferase, neutropenia, fatigue, and thrombocytopenia. The maximum tolerated dose was declared to be 30 μg/kg for both regimens. Effects on biomarkers were observed at all dose levels, including increased levels of soluble CD25 and up-regulation of perforin and granzyme B mRNA in CD8+ cells. One partial tumor response observed after treatment with IL-21 for 2 × 6 weeks (3/wk) became complete 3 months later.

Conclusions: IL-21 is biologically active at all dose levels administered and is generally well tolerated, and phase 2 studies have commenced using 30 μg/kg in the 5+9 regimen.
Flex-Hets differentially induce apoptosis in cancer over normal cells by directly targeting mitochondria
Authors: Liu Tongzu , Hannafon Bethany , Gill Lance , Kelly William , Benbrook Doris
Published: June 2007

Flex-Het drugs induce apoptosis in multiple types of cancer cells, with little effect on normal cells. This apoptosis occurs through the intrinsic mitochondrial pathway accompanied by generation of reactive oxygen species (ROS). The objective of this study was to determine if direct or indirect targeting of mitochondria is responsible for the differential sensitivities of cancer and normal cells to Flex-Hets. Mitochondrial effects and apoptosis were measured using JC-1 and Annexin V-FITC dyes with flow cytometry. Bcl-2, Bcl-xL, and Bax were measured by Western blot. Flex-Hets induced mitochondrial swelling and apoptosis in ovarian cancer cell lines but had minimal to no effects in a variety of normal cell cultures, including human ovarian surface epithelium. Effects on inner mitochondrial membrane (IMM) potential were variable and did not occur in normal cells. Two different antioxidants, administered at concentrations shown to quench intracellular and mitochondrial ROS, did not alter Flex-Het–induced mitochondrial swelling, loss of IMM potential, or apoptosis. Inhibition of protein synthesis with cycloheximide also did not prevent Flex-Het mitochondrial or apoptosis effects. Bcl-2 and Bcl-xL levels were decreased in an ovarian cancer cell line but increased in a normal culture, whereas Bax expression was unaffected by Flex-Hets treatment. In conclusion, ROS seems to be a consequence rather than a cause of mitochondrial swelling. The differential induction of apoptosis in cancer versus normal cells by Flex-Hets involves direct targeting of mitochondria associated with alterations in the balance of Bcl-2 proteins. This mechanism does not require IMM potential, ROS generation, or protein synthesis. [Mol Cancer Ther 2007;6(6):1814–22]
Depletion of major vault protein increases doxorubicin sensitivity and nuclear accumulation and disrupts its sequestration in lysosomes
Authors: Herlevsen Mikael , Oxford Gary , Owens Charles R. , Conaway Mark , Theodorescu Dan
Published: June 2007

The major vault protein (MVP) is the major constituent of the vault particle, the largest known ribonuclear protein complex. To date, vaults have no clear function, although their low expression levels in de novo chemosensitive and curable tumors, such as testicular cancer, make them attractive candidates as contributors to intrinsic drug resistance. Here, we show that MVP knockdown in human bladder cancer cells via small interfering RNA results in sensitization toward doxorubicin in two distinct exposure protocols. The drug was detected in the nucleus immediately following addition and was subsequently sequestered to lysosomes, predominantly located adjacent to the nucleus. MVP knockdown leads to increased sensitivity toward doxorubicin and an enhanced nuclear accumulation of the drug as well as a loss of its perinuclear sequestration. Not only doxorubicin subcellular distribution was perturbed by MVP knockdown but lysosomal markers, such as pH-sensitive LysoSensor, pinocytosed dextran conjugates after 24-h chase period, and the lysosomal specific antigen Lamp-1, also showed a markedly different staining compared with controls. Lysosomes appeared dispersed through the cytoplasm without a clear organization adjacent to the nucleus. Microtubules, however, appeared unperturbed in cells with reduced MVP expression. Based on these data, we hypothesize that MVP and, by extension, vault complexes are important for lysosomal function and may influence cellular drug resistance by virtue of this role. [Mol Cancer Ther 2007;6(6):1804–13]
Modifications enhance the apoptosis-inducing activity of FADD
Authors: Takashina Tomoki , Nakayama Manabu
Published: June 2007

The ability to enhance apoptosis-inducing activity in specific cells, despite the presence of cellular antiapoptotic proteins, would allow the removal of target cells from a cell population. Here, we show that modification of Fas-associated protein with death domain (FADD) by fusing the tandem death effector domains (DED) of FADD to the E protein of λ phage, a head coat protein with self-assembly activity, greatly increases the apoptosis-inducing activity of FADD in both adherent NIH3T3 and HEK293 cells. Induction of apoptosis in cell lines that stably express modified FADD (2DEDplusE) resulted in rapid blebbing, and most cells detached from the flask within 5 h. In contrast, following induction of apoptosis, it took over 24 h for the cells expressing unmodified FADD to exhibit these signs. The cells expressing the modified FADD underwent apoptosis through the typical apoptosis cascade via activation of caspase-3, and apoptosis was inhibited by a caspase inhibitor (i.e., z-VAD-fmk). Theoretically, as our adhesive stable cell lines undergo apoptosis rapidly and in synchrony following mifepristone- or tetracycline-controlled production of a single apoptosis protein without affecting any other cellular pathways, they provide excellent model systems in which to analyze the phenomenon of apoptosis in adhesive cell lines, in particular, blebbing and detachment. [Mol Cancer Ther 2007;6(6):1793–803]
Wnt3/RhoA/ROCK signaling pathway is involved in adhesion-mediated drug resistance of multiple myeloma in an autocrine mechanism
Authors: Kobune Masayoshi , Chiba Hiroki , Kato Junji , Kato Kazunori , Nakamura Kiminori , Kawano Yutaka , Takada Kohichi , Takimoto Rishu , Takayama Tetsuji , Hamada Hirofumi , Niitsu Yoshiro
Published: June 2007

Adhesion of myeloma cells to bone marrow stromal cells is now considered to play a critical role in chemoresistance. However, little is known about the molecular mechanism governing cell adhesion–mediated drug resistance (CAM-DR) of myeloma cells. In this study, we focused our interests on the implication of the Wnt signal in CAM-DR. We first screened the expression of Wnt family in myeloma cell lines and found that Wnt3 was overexpressed in all the myeloma cells examined. KMS-5 and ARH77, which highly expressed Wnt3 protein, tightly adhered to human bone marrow stromal cells, and accumulation of β-catenin and GTP-bounded RhoA was observed in these myeloma cell lines. Conversely, RPMI8226 and MM1S, which modestly expressed Wnt3 protein, rather weakly adhered to human bone marrow stromal. We then examined the relevance of Wnt3 expression to adhesive property to stromal cells and to CAM-DR of myeloma cells. KMS-5 and ARH-77 exhibited apparent CAM-DR against doxorubicin. This CAM-DR was significantly reduced by anti-integrin β1 antibody, anti-integrin α6 antibody and a Wnt-receptor competitor, secreted Frizzled-related protein-1, and Rho kinase inhibitor Y27632, but not by the specific inhibitor of canonical signaling (Dickkopf-1), indicating that Wnt-mediated CAM-DR that is dependent on integrin α6/β1 (VLA-6)–mediated attachment to stromal cells is induced by the Wnt/RhoA/Rho kinase pathway signal. This CAM-DR was also significantly reduced by Wnt3 small interfering RNA transfer to KMS-5. These results indicate that Wnt3 contributes to VLA-6–mediated CAM-DR via the Wnt/RhoA/ROCK pathway of myeloma cells in an autocrine manner. Thus, the Wnt3 signaling pathway could be a promising molecular target to overcome CAM-DR of myeloma cells. [Mol Cancer Ther 2007;6(6):1774–82]