bluuebunny/crossref_metadata_2025 huggingface dataset:
Opposing Effects of Toll-like Receptor (TLR3) Signaling in Tumors Can Be Therapeutically Uncoupled to Optimize the Anticancer Efficacy of TLR3 Ligands
Authors: Conforti Rosa , Ma Yuting , Morel Yannis , Paturel Carine , Terme Magali , Viaud Sophie , Ryffel Bernard , Ferrantini Maria , Uppaluri Ravindra , Schreiber Robert , Combadière Christophe , Chaput Nathalie , André Fabrice , Kroemer Guido , Zitvogel Laurence
Published: January 2010

Many cancer cells express Toll-like receptors (TLR) that offer possible therapeutic targets. Polyadenylic-polyuridylic acid [poly(A:U)] is an agonist of the Toll-like receptor TLR3 that displays anticancer properties. In this study, we illustrate how the immunostimulatory and immunosuppressive effects of this agent can be uncoupled to therapeutic advantage. We took advantage of two TLR3-expressing tumor models that produced large amounts of CCL5 (a CCR5 ligand) and CXCL10 (a CXCR3 ligand) in response to type I IFN and poly(A:U), both in vitro and in vivo. Conventional chemotherapy or in vivo injection of poly(A:U), alone or in combination, failed to reduce tumor growth unless an immunochemotherapeutic regimen of vaccination against tumor antigens was included. CCL5 blockade improved the efficacy of immunochemotherapy, whereas CXCR3 blockade abolished its beneficial effects. These findings show how poly(A:U) can elicit production of a range of chemokines by tumor cells that reinforce immunostimulatory or immunosuppressive effects. Optimizing the anticancer effects of TLR3 agonists may require manipulating these chemokines or their receptors. Cancer Res; 70(2); 490–500
Beyond Rapalog Therapy: Preclinical Pharmacology and Antitumor Activity of WYE-125132, an ATP-Competitive and Specific Inhibitor of mTORC1 and mTORC2
Authors: Yu Ker , Shi Celine , Toral-Barza Lourdes , Lucas Judy , Shor Boris , Kim Jae Eun , Zhang Wei-Guo , Mahoney Robert , Gaydos Christine , Tardio LuAnna , Kim Sung Kyoo , Conant Roger , Curran Kevin , Kaplan Joshua , Verheijen Jeroen , Ayral-Kaloustian Semiramis , Mansour Tarek S. , Abraham Robert T. , Zask Arie , Gibbons James J.
Published: January 2010

The mammalian target of rapamycin (mTOR) is a major component of the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway that is dysregulated in 50% of all human malignancies. Rapamycin and its analogues (rapalogs) partially inhibit mTOR through allosteric binding to mTOR complex 1 (mTORC1) but not mTOR complex 2 (mTORC2), an emerging player in cancer. Here, we report WYE-125132 (WYE-132), a highly potent, ATP-competitive, and specific mTOR kinase inhibitor (IC50: 0.19 ± 0.07 nmol/L; >5,000-fold selective versus PI3Ks). WYE-132 inhibited mTORC1 and mTORC2 in diverse cancer models in vitro and in vivo. Importantly, consistent with genetic ablation of mTORC2, WYE-132 targeted P-AKT(S473) and AKT function without significantly reducing the steady-state level of the PI3K/PDK1 activity biomarker P-AKT(T308), highlighting a prominent and direct regulation of AKT by mTORC2 in cancer cells. Compared with the rapalog temsirolimus/CCI-779, WYE-132 elicited a substantially stronger inhibition of cancer cell growth and survival, protein synthesis, cell size, bioenergetic metabolism, and adaptation to hypoxia. Oral administration of WYE-132 to tumor-bearing mice showed potent single-agent antitumor activity against MDA361 breast, U87MG glioma, A549 and H1975 lung, as well as A498 and 786-O renal tumors. An optimal dose of WYE-132 achieved a substantial regression of MDA361 and A549 large tumors and caused complete regression of A498 large tumors when coadministered with bevacizumab. Our results further validate mTOR as a critical driver for tumor growth, establish WYE-132 as a potent and profound anticancer agent, and provide a strong rationale for clinical development of specific mTOR kinase inhibitors as new cancer therapy. Cancer Res; 70(2); 621–31
Predicting Outcomes in Cervical Cancer: A Kinetic Model of Tumor Regression during Radiation Therapy
Authors: Huang Zhibin , Mayr Nina A. , Yuh William T.C. , Lo Simon S. , Montebello Joseph F. , Grecula John C. , Lu Lanchun , Li Kaile , Zhang Hualin , Gupta Nilendu , Wang Jian Z.
Published: January 2010

Applications of mathematical modeling can improve outcome predictions of cancer therapy. Here we present a kinetic model incorporating effects of radiosensitivity, tumor repopulation, and dead-cell resolving on the analysis of tumor volume regression data of 80 cervical cancer patients (stages 1B2-IVA) who underwent radiation therapy. Regression rates and derived model parameters correlated significantly with clinical outcome (P < 0.001; median follow-up: 6.2 years). The 6-year local tumor control rate was 87% versus 54% using radiosensitivity (2-Gy surviving fraction S2 < 0.70 vs. S2 ≥ 0.70) as a predictor (P = 0.001) and 89% vs. 57% using dead-cell resolving time (T1/2 < 22 days versus T1/2 ≥ 22 days, P < 0.001). The 6-year disease-specific survival was 73% versus 41% with S2 < 0.70 versus S2 ≥ 0.70 (P = 0.025), and 87% vs. 52% with T1/2 < 22 days versus T1/2 ≥ 22 days (P = 0.002). Our approach illustrates the promise of volume-based tumor response modeling to improve early outcome predictions that can be used to enable personalized adaptive therapy. Cancer Res; 70(2); 463–70
p38 Mitogen-Activated Protein Kinase–Driven MAPKAPK2 Regulates Invasion of Bladder Cancer by Modulation of MMP-2 and MMP-9 Activity
Authors: Kumar Binod , Koul Sweaty , Petersen Jane , Khandrika Lakshmipathi , Hwa Jeong S. , Meacham Randall B. , Wilson Shandra , Koul Hari K.
Published: January 2010

In transitional cell carcinoma, the most common form of bladder cancer, overexpression of the matrix metalloproteinases MMP-2 and MMP-9 offers prognostic value as markers of disease-specific survival. These molecules have been implicated in metastasis of bladder cancer, but the underlying mechanisms through which they are controlled are poorly defined. In this study, we investigated a role of p38 mitogen-activated protein kinase (MAPK) in this process, using bladder cancer cell lines HTB9 and HTB5 that were derived from different tumor stages. p38 MAPK modulated MMP-2/9 mRNA levels at the levels of transcript stability and MMP-2/9 activity along with invasive capacity. We defined a downstream effector of p38 MAPK, MAPK-activated protein kinase 2 (MAPKAPK2), that was associated with MMP-2/9 activation. Ectopic expression of wild-type or constitutively active forms of MAPKAPK2 increased MMP-2/9 activities and invasive capacity. Conversely, p38 MAPK inhibition blocked the MAPKAPK2-mediated increase in MMP-2/9 activities and the invasive capacity of the cancer cells. Our findings implicate p38 MAPK and MAPKAPK2 in mediating bladder cancer invasion via regulation of MMP-2 and MMP-9 at the level of mRNA stability. Cancer Res; 70(2); 832–41
Defective Mismatch Repair, Microsatellite Mutation Bias, and Variability in Clinical Cancer Phenotypes
Authors: Shah Sandeep N. , Hile Suzanne E. , Eckert Kristin A.
Published: January 2010

Microsatellite instability is associated with 10% to 15% of colorectal, endometrial, ovarian, and gastric cancers, and has long been used as a diagnostic tool for hereditary nonpolyposis colorectal carcinoma–related cancers. Tumor-specific length alterations within microsatellites are generally accepted to be a consequence of strand slippage events during DNA replication, which are uncorrected due to a defective postreplication mismatch repair (MMR) system. Mutations arising within microsatellites associated with critical target genes are believed to play a causative role in the evolution of MMR-defective tumors. In this review, we summarize current evidence of mutational biases within microsatellites arising as a consequence of intrinsic DNA sequence effects as well as variation in MMR efficiency. Microsatellite mutational biases are generally not considered during clinical testing; however, we suggest that such biases may be clinically significant as a factor contributing to phenotypic variation among microsatellite instability–positive tumors. Cancer Res; 70(2); 431–5
Discovery and Mechanistic Characterization of a Novel Selective Nuclear Androgen Receptor Exporter for the Treatment of Prostate Cancer
Authors: Narayanan Ramesh , Yepuru Muralimohan , Szafran Adam T. , Szwarc Maria , Bohl Casey E. , Young Natalie L. , Miller Duane D. , Mancini Michael A. , Dalton James T.
Published: January 2010

Despite the success of medical strategies to reduce androgen levels in the treatment of prostate cancer, this disease invariably relapses to a castrate-resistant state that is generally fatal. Although it had been thought that androgen-insensitive cancers no longer relied on the androgen receptor (AR) for growth and survival, it is now clear that this is not the case. Because relapses are known to occur by many mechanisms that keep the AR functionally active, strategies to block AR accumulation in the nucleus may be therapeutically useful. Here, we report the discovery of a selective nuclear androgen receptor exporter (SNARE) that functions to exclude AR from the nucleus. SNARE-1 binds wild-type and mutant ARs and efficiently inhibits their transactivation activity and ability to induce PSA gene expression. SNARE-1 inhibits the androgen-sensitive growth of LNCaP cells and tumor xenografts. Quantitative subcellular localization studies suggest that SNARE-1 inhibits nuclear translocation of AR, but also facilitates export of nuclear AR that has been translocated by an agonist. Mechanistic studies indicate that SNARE-1 rapidly phosphorylates p38 mitogen-activated protein kinase (MAPK) and Ser650 of the AR. Additionally, SNARE-1 was found to promote ubiquitination of AR in LNCaP cells. Lastly, SNARE-1 functions as a tissue-selective AR inhibitor, as it fails to phosphorylate p38 MAPK in U2OS bone cells that are stably transfected with AR. In summary, SNARE-1 inhibits AR function by a mechanism that is distinct from clinically available antiandrogens, such that it might inform novel methods to block AR function in androgen-independent prostate cancer. Cancer Res; 70(2); 842–51
Multivitamins, Folate, and Green Vegetables Protect against Gene Promoter Methylation in the Aerodigestive Tract of Smokers
Authors: Stidley Christine A. , Picchi Maria A. , Leng Shuguang , Willink Randy , Crowell Richard E. , Flores Kristina G. , Kang Huining , Byers Tim , Gilliland Frank D. , Belinsky Steven A.
Published: January 2010

One promising approach for early detection of lung cancer is by monitoring gene promoter hypermethylation events in sputum. Epidemiologic studies suggest that dietary fruits and vegetables and the micronutrients they contain may reduce risk of lung cancer. In this study, we evaluated whether diet and multivitamin use influenced the prevalence of gene promoter methylation in cells exfoliated from the aerodigestive tract of current and former smokers. Members (N = 1,101) of the Lovelace Smokers Cohort completed the Harvard Food Frequency Questionnaire and provided a sputum sample that was assessed for promoter methylation of eight genes commonly silenced in lung cancer and associated with risk for this disease. Methylation status was categorized as low (fewer than two genes methylated) or high (two or more genes methylated). Logistic regression models were used to identify associations between methylation status and 21 dietary variables hypothesized to affect the acquisition of gene methylation. Significant protection against methylation was observed for leafy green vegetables [odds ratio (OR) = 0.83 per 12 monthly servings; 95% confidence interval (95% CI), 0.74–0.93] and folate (OR, 0.84 per 750 μg/d; 95% CI, 0.72–0.99). Protection against gene methylation was also seen with current use of multivitamins (OR, 0.57; 95% CI, 0.40–0.83). This is the first cohort-based study to identify dietary factors associated with reduced promoter methylation in cells exfoliated from the airway epithelium of smokers. Novel interventions to prevent lung cancer should be developed based on the ability of diet and dietary supplements to affect reprogramming of the epigenome. Cancer Res; 70(2); 568–74
Phase I Study of Recombinant Human Interleukin-7 Administration in Subjects with Refractory Malignancy
Authors: Sportès Claude , Babb Rebecca R. , Krumlauf Michael C. , Hakim Frances T. , Steinberg Seth M. , Chow Catherine K. , Brown Margaret R. , Fleisher Thomas A. , Noel Pierre , Maric Irina , Stetler-Stevenson Maryalice , Engel Julie , Buffet Renaud , Morre Michel , Amato Robert J. , Pecora Andrew , Mackall Crystal L. , Gress Ronald E.
Published: January 2010

Purpose: Interleukin-7 (IL-7) has critical and nonredundant roles in T-cell development, hematopoiesis, and postdevelopmental immune functions as a prototypic homeostatic cytokine. Based on a large body of preclinical evidence, it may have multiple therapeutic applications in immunodeficiency states, either physiologic (immunosenescence), pathologic (HIV), or iatrogenic (postchemotherapy and posthematopoietic stem cell transplant), and may have roles in immune reconstitution or enhancement of immunotherapy. We report here on the toxicity and biological activity of recombinant human IL-7 (rhIL-7) in humans.

Design: Subjects with incurable malignancy received rhIL-7 subcutaneously every other day for 2 weeks in a phase I interpatient dose escalation study (3, 10, 30, and 60 μg/kg/dose). The objectives were safety and dose-limiting toxicity determination, identification of a range of biologically active doses, and characterization of biological and, possibly, antitumor effects.

Results: Mild to moderate constitutional symptoms, reversible spleen and lymph node enlargement, and marked increase in peripheral CD3+, CD4+, and CD8+ lymphocytes were seen in a dose-dependent and age-independent manner in all subjects receiving ≥10 μg/kg/dose, resulting in a rejuvenated circulating T-cell profile, resembling that seen earlier in life. In some subjects, rhIL-7 induced in the bone marrow a marked, transient polyclonal proliferation of pre-B cells showing a spectrum of maturation as well as an increase in circulating transitional B cells.

Conclusion: This study shows the potent biological activity of rhIL-7 in humans over a well-tolerated dose range and allows further exploration of its possible therapeutic applications. Clin Cancer Res; 16(2); 727–35
Activities of SYK and PLCγ2 Predict Apoptotic Response of CLL Cells to SRC Tyrosine Kinase Inhibitor Dasatinib
Authors: Song Zibo , Lu Pin , Furman Richard R. , Leonard John P. , Martin Peter , Tyrell Lauren , Lee Francis Y. , Knowles Daniel M. , Coleman Morton , Wang Y. Lynn
Published: January 2010

Purpose: B-cell receptor signaling plays an important role in the pathogenesis of chronic lymphocytic leukemia (CLL). However, blocking B-cell receptor signaling with dasatinib, an inhibitor of SRC kinase, produced variable results in preclinical and clinical studies. We aim to define the molecular mechanisms underlying the differential dasatinib sensitivity and to uncover more effective therapeutic targets in CLL.

Experimental Design: Fresh CLL B cells were treated with dasatinib, and cell viability was followed. The CLL cases were then divided into good and poor responders. The cellular response was correlated with the activities of B-cell receptor signaling molecules, as well as with molecular and cytogenetic prognostic factors.

Results: Among 50 CLL cases, dasatinib treatment reduced cell viability by 2% to 90%, with an average reduction of 47% on day 4 of culture. The drug induced CLL cell death through the intrinsic apoptotic pathway mediated by reactive oxygen species. Unexpectedly, phosphorylation of SRC family kinases was inhibited by dasatinib in good, as well as poor, responders. As opposed to SRC family kinases, activities of two downstream molecules, SYK and phospholipase Cγ2, correlate well with the apoptotic response of CLL cells to dasatinib.

Conclusions: Thus, SYK inhibition predicts cellular response to dasatinib. SYK, together with phospholipase Cγ2, may serve as potential biomarkers to predict dasatinib therapeutic response in patients. From the pathogenic perspective, our study suggests the existence of alternative mechanisms or pathways that activate SYK, independent of SRC kinase activities. The study further implicates that SYK might serve as a more effective therapeutic target in CLL treatment. Clin Cancer Res; 16(2); 587–99
A CYP3A4 Phenotype–Based Dosing Algorithm for Individualized Treatment of Irinotecan
Authors: van der Bol Jessica M. , Mathijssen Ron H.J. , Creemers Geert-Jan M. , Planting André S.Th. , Loos Walter J. , Wiemer Erik A.C. , Friberg Lena E. , Verweij Jaap , Sparreboom Alex , de Jong Floris A.
Published: January 2010

Purpose: Irinotecan, the prodrug of SN-38, is extensively metabolized by cytochrome P450-3A4 (CYP3A4). A randomized trial was done to assess the utility of an algorithm for individualized irinotecan dose calculation based on a priori CYP3A4 activity measurements by the midazolam clearance test.

Experimental Design: Patients were randomized to receive irinotecan at a conventional dose level of 350 mg/m2 (group A) or doses based on an equation consisting of midazolam clearance, γ-glutamyl-transferase, and height (group B). Pharmacokinetics and toxicities were obtained during the first treatment course.

Results: Demographics of 40 evaluable cancer patients were balanced between both groups, including UGT1A1*28 genotype and smoking status. The absolute dose of irinotecan ranged from 480 to 800 mg in group A and 380 to 1,060 mg in group B. The mean absolute dose and area under the curve of irinotecan and SN-38 were not significantly different in either group (P > 0.18). In group B, the interindividual variability in the area under the curve of irinotecan and SN-38 was reduced by 19% and 25%, respectively (P > 0.22). Compared with group A, the incidence of grades 3 to 4 neutropenia was >4-fold lower in group B (45 versus 10%; P = 0.013). The incidence of grades 3 to 4 diarrhea was equal in both groups (10%).

Conclusions: Incorporation of CYP3A4 phenotyping in dose calculation resulted in an improved predictability of the pharmacokinetic and toxicity profile of irinotecan, thereby lowering the incidence of severe neutropenia. In combination with UGT1A1*28 genotyping, CYP3A4 phenotype determination should be explored further as a strategy for the individualization of irinotecan treatment. Clin Cancer Res; 16(2); 736–42
ERBB2 Induces an Antiapoptotic Expression Pattern of Bcl-2 Family Members in Node-Negative Breast Cancer
Authors: Petry Ilka Brigitte , Fieber Esther , Schmidt Marcus , Gehrmann Mathias , Gebhard Susanne , Hermes Matthias , Schormann Wiebke , Selinski Silvia , Freis Evgenia , Schwender Holger , Brulport Marc , Ickstadt Katja , Rahnenführer Jörg , Maccoux Lindsey , West Jonathan , Kölbl Heinz , Schuler Martin , Hengstler Jan Georg
Published: January 2010

Purpose: Members of the Bcl-2 family act as master regulators of mitochondrial homeostasis and apoptosis. We analyzed whether ERBB2 influences the prognosis of breast cancer by influencing the proapoptotic versus antiapoptotic balance of Bcl-2 family members.

Experimental Design: ERBB2-regulated Bcl-2 family members were identified by inducible expression of ERBB2 in MCF-7 breast cancer cells and by correlation analysis with ERBB2 expression in breast carcinomas. The prognostic relevance of ERBB2-regulated and all additional Bcl-2 family members was determined in 782 patients with untreated node-negative breast cancer. The biological relevance of ERBB2-induced inhibition of apoptosis was validated in a murine tumor model allowing conditional ERBB2 expression.

Results: ERBB2 caused an antiapoptotic phenotype by upregulation of MCL-1, TEGT, BAG1, BNIP1, and BECN1 as well as downregulation of BAX, BMF, BNIPL, CLU, and BCL2L13. Upregulation of the antiapoptotic MCL-1 [P = 0.001, hazard ratio (HR) 1.5] and BNIP3 (P = 0.024; HR, 1.4) was associated with worse prognosis considering metastasis-free interval, whereas clusterin (P = 0.008; HR, 0.88) and the proapoptotic BCL2L13 (P = 0.019; HR, 0.45) were associated with better prognosis. This indicates that ERBB2 alters the expression of Bcl-2 family members in a way that leads to adverse prognosis. Analysis of apoptosis and tumor remission in a murine tumor model confirmed that the prototypic Bcl-2 family member Bcl-xL could partially substitute for ERBB2 to antagonize tumor remission.

Conclusions: Our results support the concept that ERBB2 influences the expression of Bcl-2 family members to induce an antiapoptotic phenotype. Antagonization of antiapoptotic Bcl-2 family members might improve breast cancer therapy, whereby MCL-1 and BNIP3 represent promising targets. Clin Cancer Res; 16(2); 451–60
DNA Microarrays Are Predictive of Cancer Prognosis: A Re-evaluation
Authors: Fan Xiaohui , Shi Leming , Fang Hong , Cheng Yiyu , Perkins Roger , Tong Weida
Published: January 2010

Purpose: The reliability of microarray-based cancer prognosis is questioned by Michiels et al. They reanalyzed seven studies published in the prominent journals as successful stories of microarray-based cancer prognosis and concluded that the originally reported assessments are overoptimistic. We set to investigate the reality of microarrays for predicting cancer prognosis by using the same data sets with commonly accepted data analysis approaches.

Experiment Design: Michiels et al.'s analysis protocol used a correlation-based feature selection method, split sample validation, and a nearest-centroid rule classifier. We examined their results through systematically replacing their analysis approaches with other commonly used methods as a parameter study. In addition, we applied a widely accepted permutation test in conjunction with 5-fold cross-validation to verify Michiels et al.'s findings.

Results: The stability of signature genes is likely obtained when a fold change–based feature selection method is applied. When cross-validation procedures are used to replace Michiels et al.'s split sample validation, only one of the seven studies yielded uninformative classifiers. The permutation test reveals that the confidence interval based on the split sample used in the Michiels et al.'s review is not a rigorous and robust approach to assess the validity of a classifier.

Conclusions: We concluded that the use of DNA microarrays for cancer prognosis can be demonstrated. We also stressed that caution should be exercised when a general conclusion is withdrawn based on a single statistical practice without alternative validation, which can leave a false impression and pessimistic perspective for emerging biomarker methodologies to advance cancer research. Clin Cancer Res; 16(2); 629–36
Phase II Trial of Ixabepilone Administered Daily for Five Days in Children and Young Adults with Refractory Solid Tumors: A Report from the Children's Oncology Group
Authors: Jacobs Shana , Fox Elizabeth , Krailo Mark , Hartley Gwen , Navid Fariba , Wexler Leonard , Blaney Susan M. , Goodwin Anne , Goodspeed Wendy , Balis Frank M. , Adamson Peter C. , Widemann Brigitte C.
Published: January 2010

Purpose: Ixabepilone is a microtubule-stabilizing agent with activity in adult solid tumors and in pediatric tumor xenograft models that are resistant to paclitaxel. The maximum tolerated dose on the daily-for-5-days i.v. schedule was 6 mg/m2/dose in adults and 8 mg/m2/dose in children, and the primary dose-limiting toxicity (DLT) was neutropenia. This study aimed to determine the response rate to ixabepilone in six solid tumor strata in children and young adults.

Experimental Design: We conducted a phase II trial of ixabepilone (8 mg/m2/dose for 5 days every 21 days) using a two-stage design in taxane-naïve children and young adults with treatment-refractory, measurable rhabdomyosarcoma, Ewing sarcoma family tumors, osteosarcoma, synovial sarcoma, or malignant peripheral nerve sheath tumor, neuroblastoma, and Wilms tumor.

Results: Sixty-one eligible patients (36 male) were enrolled. Median (range) age was 13 years (range, 3-36). Fifty-nine patients were fully evaluable for toxicity and response. DLTs, most commonly myelosuppression, occurred in 11 patients (15% incidence in 3-18 years old and 33% in 19-36 years old; P = 0.2) during cycle 1. The median (range) number of cycles was 2 (range, 1-38). No partial or complete responses (response evaluation criteria in solid tumors) were observed. Seven patients received ≥3 cycles, and two had prolonged stable disease (Wilms' tumor, 38 cycles; synovial sarcoma, 8 cycles).

Conclusions: Ixabepilone at 8 mg/m2/dose daily for 5 days was tolerable in children and adolescents, but did not show evidence of clinical activity in the childhood solid tumors studied. Clin Cancer Res; 16(2); 750–4
Angiopoietin-2 Promotes Disease Progression of Neuroendocrine Tumors
Authors: Detjen Katharina M. , Rieke Svenja , Deters Antje , Schulz Petra , Rexin Annett , Vollmer Sonja , Hauff Peter , Wiedenmann Bertram , Pavel Marianne , Scholz Arne
Published: January 2010

Purpose: Inhibition of angiogenesis represents a promising therapeutic strategy in neuroendocrine tumors. Angiopoietin-2 (Ang-2), a ligand of the endothelial tyrosine kinase Tie-2, is emerging as a key regulator of vascular remodeling during tumorangiogenesis. We therefore addressed the expression and biological significance of Ang-2 in human neuroendocrine tumors.

Experimental Design: Surgical specimens and serum from neuroendocrine tumor patients were used to determine Ang-2 expression by in situ hybridization or ELISA (circulating Ang-2). Ang-2 biological effects were evaluated following stable transfection into BON human pancreatic neuroendocrine tumor cells. BON clones were grown as orthotopic xenografts in nude mice to determine tumor growth and abdominal metastatic spread. Further analyses included microvessel density, lymphatic vessel density, and nodal invasion.

Results: Specimens from pancreatic neuroendocrine tumors and nontransformed pancreatic tissue revealed uniform expression of Ang-2 mRNA in endothelial cells. In contrast, epithelial expression of Ang-2 mRNA occurred exclusively in neuroendocrine tumors. Overexpression of Ang-2 in BON orthotopic xenografts did not affect primary tumor growth, although successful Ang-2 induction was confirmed from elevated serum levels. However, increased microvessel density and enhanced lymphatic metastasis were evident in Ang-2–expressing tumors, indicating a functional role of Ang-2 in experimental neuroendocrine tumors. Consistent with this notion, circulating Ang-2 was significantly elevated in neuroendocrine tumor patients compared with healthy controls. Circulating Ang-2 furthermore correlated with metastatic versus localized disease. The highest Ang-2 concentrations occurred in patients with liver metastasis, and concentrations ≥75th percentile predicted shorter survival (P = 0.0003).

Conclusion: Induction of Ang-2 in neuroendocrine tumors represents a clinically relevant pathomechanism of disease progression and constitutes an adverse prognostic marker. Clin Cancer Res; 16(2); 420–9.
Improved Potency and Selectivity of an Oncolytic E1ACR2 and E1B19K Deleted Adenoviral Mutant in Prostate and Pancreatic Cancers
Authors: Öberg Daniel , Yanover Eva , Adam Virginie , Sweeney Katrina , Costas Celina , Lemoine Nick R. , Halldén Gunnel
Published: January 2010

Purpose: Replication-selective oncolytic adenoviruses are a promising class of tumor-targeting agents with proven safety in hundreds of patients. However, clinical responses have been limited and viral mutants with higher potency are needed. Here, we report on the generation of a novel set of mutants with improved efficacy in prostate and pancreatic carcinoma models. Currently, no curative treatments are available for late-stage metastatic prostate or rapidly progressing pancreatic cancers.

Experimental Design: Adenovirus type 5 mutants were created with deletions in the E1ACR2 region for tumor selectivity and/or the E1B19K gene for attenuated replication in vivo; all constructs retain the E3 genes intact. Cell-killing efficacy, replication, and cytotoxicity in combination with chemotherapeutics were investigated in normal cells (PrEC and NHBE), seven carcinoma cell lines, and human (PC3 and DU145) and murine (TRAMPC, CMT-64, and CMT-93) tumor models in vivo.

Results: The double-deleted AdΔΔ (ΔE1ACR2 and ΔE1B19K) mutant had high cell-killing activity in prostate, pancreatic, and lung carcinomas. Replication was similar to wild-type in all tumor cells and was attenuated in normal cells to levels less than the single-deleted AdΔCR2 mutant. AdΔΔ combined with the chemotherapeutics docetaxel and mitoxantrone resulted in synergistically enhanced cell killing and greatly improved antitumor efficacy in prostate xenografts in vivo. In murine immunocompetent in vivo models efficacy was greater for mutants with the E3B genes intact even in the absence of viral replication, indicating attenuated macrophage-dependent clearance.

Conclusions: These data suggest that the novel oncolytic mutant AdΔΔ is a promising candidate for targeting of solid tumors specifically in combination with chemotherapeutics. Clin Cancer Res; 16(2); 541–53
Secretory Leukocyte Protease Inhibitor Antagonizes Paclitaxel in Ovarian Cancer Cells
Authors: Rasool Nabila , LaRochelle William , Zhong Haihong , Ara Gulshan , Cohen Joshua , Kohn Elise C.
Published: January 2010

Purpose: Ovarian cancer recurrence with the development of paclitaxel resistance is an obstacle to long-term survival. We showed that secretory leukocyte protease inhibitor (SLPI) is a survival factor for ovarian cancer. We hypothesize that SLPI may antagonize paclitaxel injury.

Experimental Design: Differential SLPI induction in response to paclitaxel and in response to stable forced expression of SLPI was shown in A2780-1A9 cells and their paclitaxel-resistant sublines, PTX10 and PTX22, and confirmed with HEY-A8 cells. SLPI-mediated survival was reduced by the MAP/extracellular signal-regulated kinase (ERK) kinase inhibitor, U0126, and a humanized neutralizing monoclonal anti-SLPI antibody, CR012. OVCAR3 xenographs tested the role of CR012 in vivo.

Results: SLPI expression was lower in A2780-1A9 ovarian cancer cells than in PTX10 and PTX22, and SLPI was induced by paclitaxel exposure. Stable SLPI expression yielded a proliferation advantage (P = 0.01); expression of and response to SLPI in OVCAR3 cells were abrogated by exposure to CR012. SLPI reduced the paclitaxel susceptibility of 1A9 and HEY-A8 cells (P ≤ 0.05), and SLPI expression did not increase the resistance of PTX10 and PTX22 cells. Both paclitaxel and SLPI overexpression induced ERK activation. Inhibition of MAP/ERK kinase with U0126 increased paclitaxel injury and overcame SLPI-mediated cell protection. It did not reinstate PTX10 sensitivity to paclitaxel, which was associated with AKT activation. Significant inhibition of OVCAR3 xenograft growth was observed with CR012 and paclitaxel, over single agents (P ≤ 0.001).

Conclusions: A two-pronged approach confirmed that SLPI overcomes paclitaxel in part through activation of ERK1/2. These results credential SLPI as a molecular target for ovarian cancer and suggest CR012 as a tool for proof of concept. Clin Cancer Res; 16(2); 600–9
Reduced DNA Repair Capacity for Removing Tobacco Carcinogen–Induced DNA Adducts Contributes to Risk of Head and Neck Cancer but not Tumor Characteristics
Authors: Wang Li-E , Hu Zhibin , Sturgis Erich M. , Spitz Margaret R. , Strom Sara S. , Amos Christopher I. , Guo Zhaozheng , Qiao Yawei , Gillenwater Ann Marie , Myers Jeffrey N. , Clayman Gary L. , Weber Randal S. , El-Naggar Adel K. , Mao Li , Lippman Scott M. , Hong Waun Ki , Wei Qingyi
Published: January 2010

Purpose: Although cigarette smoking and alcohol use are known risk factors for squamous cell carcinoma of head and neck (SCCHN), only a few exposed individuals develop this disease, suggesting an individual susceptibility. In this study, we investigated the associations between genetically determined DNA repair capacity (DRC) for removing tobacco-induced DNA adducts and risk of SCCHN and tumor characteristics.

Experimental Design: We measured DRC in cultured T lymphocytes using the host-cell reactivation assay in a hospital-based case-control study of 744 SCCHN patients and 753 age-, sex-, and ethnicity-matched cancer-free controls recruited from The University of Texas M.D. Anderson Cancer Center.

Results: Patients with SCCHN had significantly lower mean DRC (8.84% ± 2.68%) than controls (9.97% ± 2.61%; P < 0.0001), and the difference accounted for ∼2-fold increased risk of SCCHN [adjusted odds ratio (OR), 1.91; 95% confidence interval (CI), 1.52-2.40] after adjustment for other covariates. Compared with the highest DRC quartile of controls, this increased risk was dose dependent (second highest quartile: OR, 1.40; 95% CI, 0.99-1.98; third quartile: OR, 1.87; 95% CI, 1.34-2.62; and fourth quartile: OR, 2.76; 95% CI, 1.98-3.84, respectively; Ptrend < 0.0001). We also assessed the performance of DRC in risk prediction models by calculating the area of under the receiver operating characteristic curve. The addition of DRC to the model significantly improved the sensitivity of the expanded model. However, we did not find the association between DRC and tumor sites and stages.

Conclusion: DRC is an independent susceptibility biomarker for SCCHN risk but not a tumor marker. Clin Cancer Res; 16(2); 764–74
A Phase I Study of 7-t-Butyldimethylsilyl-10-Hydroxycamptothecin in Adult Patients with Refractory or Metastatic Solid Malignancies
Authors: Arnold Susanne M. , Rinehart John J. , Tsakalozou Eleftheria , Eckardt John R. , Fields Scott Z. , Shelton Brent J. , DeSimone Philip A. , Kee Bryan K. , Moscow Jeffrey A. , Leggas Markos
Published: January 2010

Purpose: 7-t-Butyldimethylsilyl-10-hydroxycamptothecin (AR-67) is a novel third generation camptothecin selected for development based on the blood stability of its pharmacologically active lactone form and its high potency in preclinical models. Here, we report the initial phase I experience with i.v. AR-67 in adults with refractory solid tumors.

Experimental Design and Methods: AR-67 was infused over 1 hour daily five times, every 21 days, using an accelerated titration trial design. Plasma was collected on the 1st and 4th day of cycle 1 to determine pharmacokinetic parameters.

Results: Twenty-six patients were treated at nine dosage levels (1.2-12.4 mg/m2/d). Dose-limiting toxicities were observed in five patients and consisted of grade 4 febrile neutropenia, grade 3 fatigue, and grade 4 thrombocytopenia. Common toxicities included leukopenia (23%), thrombocytopenia (15.4%), fatigue (15.4%), neutropenia (11.5%), and anemia (11.5%). No diarrhea was observed. The maximum tolerated dosage was 7.5 mg/m2/d. The lactone form was the predominant species in plasma (>87% of area under the plasma concentration-time curve) at all dosages. No drug accumulation was observed on day 4. Clearance was constant with increasing dosage and hematologic toxicities correlated with exposure (P < 0.001). A prolonged partial response was observed in one subject with non–small cell lung cancer. Stable disease was noted in patients with small cell lung cancer, non–small cell lung cancer, and duodenal cancer.

Conclusions: AR-67 is a novel, blood-stable camptothecin with a predictable toxicity profile and linear pharmacokinetics. The recommended phase II dosage is 7.5 mg/m2/d five times every 21 days. Clin Cancer Res; 16(2); 673–80
Accurate Classification of Non–Small Cell Lung Carcinoma Using a Novel MicroRNA-Based Approach
Authors: Bishop Justin A. , Benjamin Hila , Cholakh Hila , Chajut Ayelet , Clark Douglas P. , Westra William H.
Published: January 2010

Purpose: Advances in targeted lung cancer therapy now demand accurate classification of non–small cell lung cancer (NSCLC). MicroRNAs (miRNA) are recently discovered short, noncoding genes that play essential roles in tissue differentiation during normal development and tumorigenesis. For example, hsa-miR-205 is a miRNA that is highly expressed in lung squamous cell carcinomas (SqCC) but not in lung adenocarcinomas. The differential expression of miRNAs could be exploited to distinguish these tumor types.

Experimental Design: One hundred and two resected NSCLCs were classified as SqCC or adenocarcinoma based on their histologic features and immunohistochemical profiles. Corresponding preoperative biopsies/aspirates that had been originally diagnosed as poorly differentiated NSCLCs were available for 21 cases. A quantitative reverse transcription-PCR diagnostic assay that measures the expression level of hsa-miR-205 was used to classify the carcinomas as SqCC or adenocarcinoma based solely on expression levels. The two sets of diagnoses were compared.

Results: Using standard pathologic methods of classification (i.e., microscopy and immunohistochemistry), 52 resected lung carcinomas were classified as SqCCs and 50 as adenocarcinomas. There was 100% concordance between the diagnoses established by conventional and miRNA-based methods. MiRNA profiling also correctly classified 20 of the 21 preoperative biopsy specimens.

Conclusions: MiRNA profiling is a highly reliable strategy for classifying NSCLCs. Indeed, classification is consistently accurate even in small biopsies/aspirates of poorly differentiated tumors. Confirmation of its reliability across the full range of tumor grades and specimen types represents an important step toward broad application. Clin Cancer Res; 16(2); 610–9
The TRC8 Ubiquitin Ligase Is Sterol Regulated and Interacts with Lipid and Protein Biosynthetic Pathways
Authors: Lee Jason P. , Brauweiler Anne , Rudolph Michael , Hooper Joan E. , Drabkin Harry A. , Gemmill Robert M.
Published: January 2010

TRC8/RNF139 encodes an endoplasmic reticulum–resident E3 ubiquitin ligase that inhibits growth in a RING- and ubiquitylation-dependent manner. TRC8 also contains a predicted sterol-sensing domain. Here, we report that TRC8 protein levels are sterol responsive and that it binds and stimulates ubiquitylation of the endoplasmic reticulum anchor protein INSIG. Induction of TRC8 destabilized the precursor forms of the transcription factors SREBP-1 and SREBP-2. Loss of SREBP precursors was proteasome dependent, required a functional RING domain, occurred without generating processed nuclear forms, and suppressed SREBP target genes. TRC8 knockdown had opposite effects in sterol-deprived cells. In Drosophila, growth inhibition by DTrc8 was genetically suppressed by loss of specific Mprlp, Padlp N-terminal domain–containing proteins found in the COP9 signalosome and eIF3. DTrc8 genetically and physically interacted with two eIF3 subunits: eIF3f and eIF3h. Coimmunoprecipitation experiments confirmed these interactions in mammalian cells, and TRC8 overexpression suppressed polysome profiles. Moreover, high–molecular weight ubiquitylated proteins were observed in eIF3 immunoprecipitations from TRC8-overexpressing cells. Thus, TRC8 function may provide a regulatory link between the lipid and protein biosynthetic pathways. Mol Cancer Res; 8(1); 93–106
Cancer Chemopreventive Activity and Metabolism of Isoliquiritigenin, a Compound Found in Licorice
Authors: Cuendet Muriel , Guo Jian , Luo Yan , Chen Shaonong , Oteham Carol P. , Moon Richard C. , van Breemen Richard B. , Marler Laura E. , Pezzuto John M.
Published: January 2010

Isoliquiritigenin (2′,4′,4-trihydroxychalcone; ILG), a chalcone found in licorice root and many other plants, has shown potential chemopreventive activity through induction of phase II enzymes such as quinone reductase-1 in murine hepatoma cells. In this study, the in vivo metabolism of ILG was investigated in rats. In addition, ILG glucuronides and ILG-glutathione adducts were observed in human hepatocytes and in livers from rats treated with ILG. ILG glucuronides were detected in both plasma and rat liver tissues. In addition, in a full-term cancer chemoprevention study conducted with 7,12-dimethylbenz(a)anthracene–treated female Sprague-Dawley rats, dietary administration of ILG slightly increased tumor latency but had a negative effect on the incidence of mammary tumors starting at ∼65 days after 7,12-dimethylbenz(a)anthracene administration. Further, no significant induction of phase II enzymes was found in mammary glands, which is consistent with the low level of ILG observed in these tissues. However, ILG significantly induced quinone reductase-1 activity in the colon, and glutathione as well as glutathione S-transferase in the liver. Analysis of mRNA expression in tissues of rats treated with ILG supported these findings. These results suggest that ILG should be tested for chemopreventive efficacy in nonmammary models of cancer. Cancer Prev Res; 3(2); 221–32
Excised Porcine Cornea Integrity Evaluation in an in vitro Model of Iontophoretic Ocular Research
Authors: Gratieri T. , Gelfuso G.M. , Thomazini J.A. , Lopez R.F.V.
Published: January 2010

Background/Aims: It is a challenge to adapt traditional in vitro diffusion experiments to ocular tissue. Thus, the aim of this work was to present experimental evidence on the integrity of the porcine cornea, barrier function and maintenance of electrical properties for 6 h of experiment when the tissue is mounted on an inexpensive and easy-to-use in vitro model for ocular iontophoresis. Methods: A modified Franz diffusion cell containing two ports for the insertion of the electrodes and a receiving compartment that does not need gassing with carbogen was used in the studies. Corneal electron transmission microscopy images were obtained, and diffusion experiments with fluorescent markers were performed to examine the integrity of the barrier function. The preservation of the negatively charged corneal epithelium was verified by the determination of the electro-osmotic flow of a hydrophilic and non-ionized molecule. Results: The diffusion cell was able to maintain the temperature, homogenization, porcine epithelial corneal structure integrity, barrier function and electrical characteristics throughout the 6 h of permeation experiment, without requiring CO2 gassing when the receiving chamber was filled with 25 mM of HEPES buffer solution. Conclusion: The system described here is inexpensive, easy to handle and reliable as an in vitro model for iontophoretic ocular delivery studies.
Geographic Variation in One-Year Recurrent Ischemic Stroke Rates for Elderly Medicare Beneficiaries in the USA
Authors: Allen Norrina B. , Holford Theodore R. , Bracken Michael B. , Goldstein Larry B. , Howard George , Wang Yun , Lichtman Judith H.
Published: January 2010

Background: While geographic disparities in stroke mortality are well documented, there are no data describing geographic variation in recurrent stroke. Accordingly, we evaluated geographic variations in 1-year recurrent ischemic stroke rates in the USA with adjustment for patient characteristics. Methods: One-year recurrent stroke rates for ischemic stroke (International Classification of Diseases, 9th Revision codes 433, 434 and 436) following hospital discharge were calculated by county for all fee-for-service Medicare beneficiaries from 2000 to 2002. The rates were standardized and smoothed using a bayesian conditional autoregressive model that was risk-standardized for patients’ age, gender, race/ethnicity, prior hospitalizations, Deyo comorbidity score, acute myocardial infarction, congestive heart failure, diabetes, hypertension, dementia, cancer, chronic obstructive pulmonary disease and obesity. Results: The overall 1-year recurrent stroke rate was 9.4% among 895,916 ischemic stroke patients (mean age: 78 years; 56.6% women; 86.6% White, 9.7% Black and 1.2% Latino/Hispanic). The rates varied by geographic region and were highest in the South and in parts of the West and Midwest. Regional variation was present for all racial/ethnic subgroups and persisted after adjustment for individual patient characteristics. Conclusions: Almost 1 in 10 hospitalized ischemic stroke patients was readmitted for an ischemic stroke within 1 year. There was heterogeneity in recurrence patterns by geographic region. Further work is needed to understand the reasons for this regional variability.
Efficacy and Tolerability of Pegylated Interferon-α2a plus Ribavirin versus Pegylated Interferon-α2b plus Ribavirin in Treatment-Naive Chronic Hepatitis C Patients
Authors: Lee Seok , Kim In Hee , Kim Seong Hun , Kim Sang Wook , Lee Seung Ok , Lee Soo Teik , Kim Dae Ghon , Lee Chang Seop , Choi Chang Soo , Cho Eun Young , Kim Haak Cheoul
Published: January 2010

Objectives: The authors compared the efficacies and tolerabilities of pegylated interferon-α2a (PEG-IFN-α2a) + ribavirin and pegylated interferon-α2b (PEG-IFN-α2b) + ribavirin for the initial treatment of chronic hepatitis C. Methods: A total of 126 treatment-naive patients (29.4% genotype 1, 70.6% genotype non-1) were treated with PEG-IFN-α2a 180 µg/week (group A, n = 79) or PEG-IFN-α2b 1.5 µg/kg/week (group B, n = 47) with ribavirin (800 mg/day for genotype non-1 or 1,000–1,200 mg/day for genotype 1) for 24 (genotype non-1) or 48 weeks (genotype 1). Results: End-of-treatment virologic response, sustained virologic response, and biochemical response were not significantly different in groups A and B (84.8 vs. 89.4%, 70.9 vs. 72.3%, and 70.9 vs. 74.5%, respectively; p > 0.05). In patients with the HCV genotype 1 or non-1, treatment responses were not significantly different. Multivariate analysis showed that HCV genotype only was an independent factor that affected sustained virologic response (p = 0.048). The proportions of treatment discontinuations in groups A and B were similar (10.1 vs. 10.6%; p = 1.000). Conclusions: PEG-IFN-α2a or PEG-IFN-α2b + ribavirin combination therapies showed similar efficacies and tolerabilities as initial treatments for chronic hepatitis C.
Patient Reactions to Confidentiality, Liability, and Financial Aspects of Informed Consent in Cardiology Research
Authors: Fortune-Greeley Alice K. , Hardy N. Chantelle , Lin Li , Friedman Joëlle Y. , Lawlor Janice S. , Muhlbaier Lawrence H. , Hall Mark A. , Schulman Kevin A. , Sugarman Jeremy , Weinfurt Kevin P.
Published: January 2010

Background—

Although the informed consent process is supposed to help potential research participants make informed and voluntary decisions about participating in research, little is known about how participants react to language in the informed consent document and whether their reactions are related to their willingness to enroll in clinical trials. We examined the relationship between patients’ reactions to standard informed consent language and their willingness to participate in a hypothetical clinical trial.

Methods and Results—

We simulated the consent process for a hypothetical cardiology clinical trial with 470 patients in an outpatient cardiovascular medicine clinic at a large academic medical center. We analyzed the spontaneous comments and questions that participants made during the interviews about each section of the informed consent document. Few participants made positive comments. Participants made the most negative comments about the sections on risks, study purpose or protocol, and payment for injury. Having a negative reaction to any section was associated with a lower likelihood of participating in the clinical trial. Using a multivariable model, we found that negative reactions in the patient rights, financial disclosure, and confidentiality sections predicted willingness to participate (
P
<0.001).

Conclusions—

Recognizing elements of informed consent that elicit questions and concerns from potential research participants may help investigators design clinical research trials and model language in a way that reduces concerns or increases participant understanding, thereby enhancing informed consent for research.