bluuebunny/crossref_metadata_2025 huggingface dataset:
Task-Specific Depression of the Soleus H-Reflex After Cocontraction Training of Antagonistic Ankle Muscles
Authors: Perez Monica A. , Lundbye-Jensen Jesper , Nielsen Jens B.
Published: October 2007

Ballet dancers have small soleus (SOL) H-reflex amplitudes, which may be related to frequent use of cocontraction of antagonistic ankle muscles. Indeed, SOL H-reflexes are depressed during cocontraction compared with plantarflexion at matched background EMG level. We investigated the effect of 30-min training of simultaneous activation of ankle dorsi- and plantarflexor muscles (cocontraction task) on the SOL H-reflex in 10 healthy volunteers. Measurements were taken during cocontraction. After training, there was a significant improvement in the ability of the subjects to perform a stable cocontraction. SOL H-reflex recruitment curves and H-max/M-max ratios were decreased after cocontraction training but not after 30 min of static dorsi or plantarflexion. The decreased H-reflex size correlated with improved motor performance. No changes in SOL and tibialis anterior (TA) EMG activity or EMG power were observed, suggesting that increased presynaptic inhibition of Ia afferents is a likely mechanism for H-reflex depression. In different sessions we measured SOL and TA motor-evoked potentials (MEPs) by using transcranial magnetic stimulation (TMS), TMS-elicited suppression of SOL EMG, and coherence between electroencephalographic (EEG) activity (Cz) and TA and SOL EMG. SOL and TA MEPs were depressed, whereas TMS-elicited suppression of SOL EMG and coherence were increased after training. Decreased excitability of corticospinal neurons due to increased intracortical inhibition seems a likely explanation of these observations. Our results indicate that the depression in H-reflex observed during a cocontraction task can be trained and that repeated performance of tasks involving cocontraction may lead to prolonged changes in reflex and corticospinal excitability.
The Rexinoid LG100268 Prevents the Development of Preinvasive and Invasive Estrogen Receptor–Negative Tumors in MMTV-erbB2 Mice
Authors: Li Yuxin , Zhang Yun , Hill Jamal , Shen Qiang , Kim Hee-Tae , Xu Xiaochun , Hilsenbeck Susan G. , Bissonnette Reid P. , Lamph William W. , Brown Powel H.
Published: October 2007

Purpose: To test whether a novel rexinoid, LG100268, prevents the development of preinvasive and invasive estrogen receptor–negative mammary tumorigenesis in MMTV-erbB2 mice.

Experimental Design: For invasive breast cancer prevention, MMTV-erbB2 mice were treated with daily gastric gavage of vehicle, LG100268 (10 mg/kg), or LG100268 (100 mg/kg) for long term starting at 3 months of age. For preinvasive lesion study, mice were treated with daily gastric gavage of vehicle or LG100268 (100 mg/kg) for 4 months.

Results: Long-term treatment with LG100268 significantly prevented invasive mammary tumor development. Median time (age) to tumor development was delayed from 217 days in vehicle group to 357 days in low-dose group. In high-dose group, only 2 of 20 mice developed tumors after 430 days of treatment. Short-term treatment of LG100268 significantly prevented the development of preinvasive mammary lesions including hyperplasia and ductal carcinoma in situ. The cancer prevention effect was associated with reduced expression of Ki67 and cyclin D1 in mammary glands by >80%.

Conclusion: Rexinoid LG100268 is an effective chemopreventive agent in preventing the development of both malignant and premalignant mammary lesions in MMTV-erbB2 mice.
The Double-Stranded RNA-Activated Protein Kinase Mediates Radiation Resistance in Mouse Embryo Fibroblasts through Nuclear Factor κB and Akt Activation
Authors: von Holzen Urs , Pataer Abujiang , Raju Uma , Bocangel Dora , Vorburger Stephan A. , Liu Yanna , Lu Xiaolin , Roth Jack A. , Aggarwal Bharat B. , Barber Glen N. , Keyomarsi Khandan , Hunt Kelly K. , Swisher Stephen G.
Published: October 2007

Purpose: Activation of the double-stranded RNA-activated protein kinase (PKR) leads to the induction of various pathways including the down-regulation of translation through phosphorylation of the eukaryotic translation initiation factor 2α (eIF-2α). There have been no reports to date about the role of PKR in radiation sensitivity.

Experimental Design: A clonogenic survival assay was used to investigate the sensitivity of PKR mouse embryo fibroblasts (MEF) to radiation therapy. 2-Aminopurine (2-AP), a chemical inhibitor of PKR, was used to inhibit PKR activation. Nuclear factor-κB (NF-κB) activation was assessed by electrophoretic mobility shift assay (EMSA). Expression of PKR and downstream targets was examined by Western blot analysis and immunofluorescence.

Results: Ionizing radiation leads to dose- and time-dependent increases in PKR expression and function that contributes to increased cellular radiation resistance as shown by clonogenic survival and terminal nucleotidyl transferase–mediated nick end labeling (TUNEL) apoptosis assays. Specific inhibition of PKR with the chemical inhibitor 2-AP restores radiation sensitivity. Plasmid transfection of the PKR wild-type (wt) gene into PKR−/− MEFs leads to increased radiation resistance. The protective effect of PKR to radiation may be mediated in part through NF-κB and Akt because both NF-κB and Akt are activated after ionizing radiation in PKR+/+ but not PKR−/− cells.

Conclusions: We suggest a novel role for PKR as a mediator of radiation resistance modulated in part through the protective effects of NF-κB and Akt activation. The modification of PKR activity may be a novel strategy in the future to overcome radiation resistance.
De novo Identification of MIZ-1 (ZBTB17) Encoding a MYC-Interacting Zinc-Finger Protein as a New Favorable Neuroblastoma Gene
Authors: Ikegaki Naohiko , Gotoh Takahiro , Kung Bing , Riceberg Justin S. , Kim David Y. , Zhao Huaqing , Rappaport Eric F. , Hicks Sakeenah L. , Seeger Robert C. , Tang Xao X.
Published: October 2007

Purpose: Neuroblastoma is a childhood cancer that exhibits either a favorable or an unfavorable phenotype. Favorable neuroblastoma genes (EPHB6, EFNB2, EFNB3, NTRK1, and CD44) are genes whose high-level expression predicts favorable neuroblastoma disease outcome. Accordingly, the forced expression of these genes or their reactivation by gene silencing inhibitors in unfavorable neuroblastoma cells results in suppression of tumor growth and metastases. This study was undertaken to design an experimental strategy to identify additional favorable neuroblastoma genes.

Experimental Design: Favorable neuroblastoma gene candidates were first identified by gene expression profiling analysis on IMR5 neuroblastoma cells treated with inhibitors of DNA methylation and histone deacetylase against the untreated control cells. Among the candidates, we focused on MIZ-1, which encodes a MYC-interacting zinc-finger protein, because it is known to enhance the expression of growth suppressive genes, such as CDKN1A.

Results: High-level MIZ-1 expression was associated with favorable disease outcome of neuroblastoma (P = 0.0048). Forced MIZ-1 expression suppressed in vitro growth of neuroblastoma cell lines. High MIZ-1 expression was correlated with the small-size neuroblastoma xenografts treated with gene silencing inhibitors or a glucocorticoid. In addition, forced MIZ-1 expression enhanced the expression of CD44 and EFNB2 in neuroblastoma cell lines in vitro. Furthermore, MIZ-1 expression was positively correlated with the expression of favorable neuroblastoma genes (EFNB2, EFNB3, EPHB6, and NTRK1) in the human neuroblastoma xenograft therapeutic models.

Conclusion: MIZ-1 is a new favorable neuroblastoma gene, which may directly or indirectly regulate the expression of other favorable neuroblastoma genes.
Telomere Shortening and Chromosomal Abnormalities in Intestinal Metaplasia of the Urinary Bladder
Authors: Morton Michael J. , Zhang Shaobo , Lopez-Beltran Antonio , MacLennan Gregory T. , Eble John N. , Montironi Rodolfo , Sung Ming-Tse , Tan Puay-Hoon , Zheng Suqin , Zhou Honghong , Cheng Liang
Published: October 2007

Purpose: Although intestinal metaplasia is often found in association with adenocarcinoma of the urinary bladder, it is unclear whether intestinal metaplasia of the bladder is a premalignant lesion. Telomere shortening has recently been implicated in epithelial carcinogenesis. We used quantitative fluorescent in situ hybridization (FISH) to measure telomere length and UroVysion FISH to detect cytogenetic abnormalities in urinary bladder specimens with intestinal metaplasia.

Experimental Design: Paraffin-embedded tissue blocks from 34 patients with intestinal metaplasia of the urinary bladder were evaluated. Twelve of the 34 patients had coexistent cystitis glandularis, and telomere length was measured in these lesions for comparison. Tissue sections were prepared and hybridized with a telomere-specific peptide nucleic acid probe. Quantitative FISH on interphase nuclei was used to assess telomere signal intensity. Additional sections were hybridized with centromeric probes for chromosomes 3, 7, and 17 and a locus-specific probe 9p21. Multicolor FISH was used to analyze for cytogenic abnormalities in the interphase nuclei of intestinal metaplasia.

Results: In all 34 cases, reduced average telomere signal intensity was observed in the nuclei of intestinal metaplasia cells compared with adjacent control nuclei to produce a mean relative intensity of 48.5% (P < 0.0001). When cystitis glandularis was present, significant differences in the telomere-specific signal intensity existed between cystitis glandularis and normal cells (P = 0.0005) and between cystitis glandularis and intestinal metaplasia cells (P = 0.0015). Three of the 34 cases showed chromosomal gains in the UroVysion FISH assay.

Conclusions: Our findings indicate that intestinal metaplasia in the urinary bladder is associated with significant telomere shortening relative to telomere length in adjacent normal urothelial cells. These lesions also occasionally showed cytogenetic abnormalities associated with telomere shortening. Our findings support the hypothesis that intestinal metaplasia of the urinary bladder is a precursor lesion to and could be a marker in the development of adenocarcinoma of the urinary bladder.
Antibody and CD8+ T Cell Responses against HER2/neu Required for Tumor Eradication after DNA Immunization with a Flt-3 Ligand Fusion Vaccine
Authors: Orlandi Francesca , Venanzi Franco M. , Concetti Antonio , Yamauchi Hanako , Tiwari Shakuntala , Norton Larry , Wolchok Jedd D. , Houghton Alan N. , Gregor Polly D.
Published: October 2007

Purpose: HER2/neu is frequently overexpressed in breast cancer. In a mouse model, vaccination with HER2/neu DNA elicits antibodies that confer partial protection against tumor challenge.

Experimental Design: To enhance antitumor immunity, we fused cDNA encoding Flt-3 ligand (FL) to the rat HER2/neu extracellular domain (neu), generating a chimeric FLneu molecule. FLneu and neu DNA vaccines were compared for immunogenicity and their ability to protect mice from tumor challenge.

Results: The neu vaccine generated a HER2/neu-specific antibody response. In contrast, vaccination with FLneu induced CD8+ T cells specific for HER2/neu but a negligible anti-HER2/neu antibody response. The switch from an antibody-mediated to T cell–mediated response was due to different intracellular localization of neu and FLneu. Although the neu protein was secreted, the FLneu protein was retained inside the cell, co-localizing with the endoplasmic reticulum, facilitating processing and presentation to T cells. The neu and FLneu vaccines individually conferred only weak tumor immunity. However, efficient tumor rejection was seen when neu and FLneu were combined, inducing both strong anti-HER2/neu-specific antibody and T cell responses. Adoptive transfer of both immune CD8+ T cells and immune sera from immunized mice was required to confer tumor immunity in naïve hosts.

Conclusions: These results show that active induction of both humoral and cellular immunity to HER2/neu is required for efficient tumor protection, and that neither response alone is sufficient.
Different Prognostic Roles of Mutations in the Helical and Kinase Domains of the PIK3CA Gene in Breast Carcinomas
Authors: Barbareschi Mattia , Buttitta Fiamma , Felicioni Lara , Cotrupi Sabrina , Barassi Fabio , Del Grammastro Maela , Ferro Antonella , Dalla Palma Paolo , Galligioni Enzo , Marchetti Antonio
Published: October 2007

Purpose: In breast cancer, the PIK3CA gene is frequently mutated at “hotspots” in exons 9 and 20, corresponding to the helical and kinase domains, respectively. We decided to investigate the association of PIK3CA mutations with pathologic features and clinical outcome in a large series of patients with breast cancer.

Experimental Design: Frozen samples from 163 consecutive patients were analyzed for PIK3CA mutations using PCR single-strand conformation polymorphism and sequence analyses.

Results: We identified 46 missense mutations, 24 (53%) in exon 9, and 21 (47%) in exon 20. Twelve (50%) of the 24 mutations in exon 9 were of the E542K type and 11 (46%) were of the E545K type. Twenty (95%) of the 21 mutations in exon 20 were H1047R substitutions. Mutations in exon 9 were more frequent in lobular carcinomas (42% of cases) than in ductal carcinoma (11% of cases; P = 0.002). At univariate survival analysis, PIK3CA exon 20 mutations were associated with prolonged overall and disease-free survival, whereas mutations in exon 9 were associated with significantly worse prognosis. At multivariate analysis, exon 9 PIK3CA mutations were the strongest independent factor to predict poor prognosis for disease-free survival (P = 0.0003) and overall survival (P = 0.001).

Conclusion: Our data show that exon 9 PIK3CA mutations are typical of infiltrating lobular carcinomas. In addition, they indicate that PIK3CA mutations in different exons are of different prognostic value: exon 9 mutations are independently associated with early recurrence and death, whereas exon 20 PIK3CA mutations are associated with optimal prognosis.
Efficacy and Safety of Single-Agent Pertuzumab, a Human Epidermal Receptor Dimerization Inhibitor, in Patients with Non–Small Cell Lung Cancer
Authors: Herbst Roy S. , Davies Angela M. , Natale Ronald B. , Dang Thao P. , Schiller Joan H. , Garland Linda L. , Miller Vincent A. , Mendelson David , Van den Abbeele Annick D. , Melenevsky Yulia , de Vries Daniel J. , Eberhard David A. , Lyons Benjamin , Lutzker Stuart G. , Johnson Bruce E.
Published: October 2007

Purpose: Pertuzumab, a first-in-class human epidermal receptor 2 (HER2) dimerization inhibitor, is a humanized monoclonal anti-HER2 antibody that binds HER2's dimerization domain and inhibits HER2 signaling. Based on supporting preclinical studies, we undertook a Phase II trial of pertuzumab in patients with recurrent non–small cell lung cancer (NSCLC).

Experimental Design: Patients with previously treated NSCLC accessible for core biopsy and naive to HER pathway inhibitors were treated with pertuzumab i.v. once every 3 weeks. Tumor assessments were done at 6 and 12 weeks and then every 3 months thereafter. The primary efficacy end point was overall response rate by Response Evaluation Criteria in Solid Tumors. Measurement of tumor glucose metabolism (SUVmax) by F-18-fluorodeoxyglucose positron emission tomography was used as an exploratory pharmacodynamic marker of drug activity.

Results: Of 43 patients treated with pertuzumab, no responses were seen; 18 of 43 (41.9%) and 9 of 43 (20.9%) patients had stable disease at 6 and 12 weeks, respectively. The median and 3-month progression-free survival rates (PFS) were 6.1 weeks (95% confidence interval, 5.3-11.3 weeks) and 28.4% (95% confidence interval, 14.4-44.2%), respectively. Of 22 patients who underwent F-18-fluorodeoxyglucose positron emission tomography, six (27.3%) had a metabolic response to pertuzumab as evidenced by decreased SUVmax. These patients had prolonged PFS (HR = 0.11, log-rank P value = 0.018) compared with the 16 patients who had no metabolic response. Four patients (9.3%) experienced a grade 3/grade 4 adverse event judged related to pertuzumab; none exhibited grade 3/grade 4 cardiac toxicity.

Conclusions: Pertuzumab is well tolerated as monotherapy. Pharmacodynamic activity correlated with prolonged PFS was detected in a moderate percentage of patients (27.3%). Further clinical development of pertuzumab should focus on rational combinations of pertuzumab with other drugs active in NSCLC.
Genome-Wide Allelotypes of Familial Pancreatic Adenocarcinomas and Familial and Sporadic Intraductal Papillary Mucinous Neoplasms
Authors: Abe Tadayoshi , Fukushima Noriyoshi , Brune Kieran , Boehm Corinne , Sato Norihiro , Matsubayashi Hiroyuki , Canto Marcia , Petersen Gloria M. , Hruban Ralph H. , Goggins Michael
Published: October 2007

Purpose: Most familial cancer susceptibility genes are tumor suppressor genes that are biallelically inactivated in familial neoplasms through somatic deletion of the wild-type allele. Identifying the genomic losses that occur in pancreatic neoplasms, particularly those that occur in familial and precursor neoplasms, may help localize the genes responsible for pancreatic cancer susceptibility.

Experimental Design: Normal and neoplastic tissue DNA was isolated from fresh-frozen surgically resected tissues from 20 patients with primary familial pancreatic adenocarcinoma (defined as having at least one first-degree relative with pancreatic cancer), 31 with sporadic intraductal papillary mucinous neoplasms (IPMN), and 7 with familial IPMNs using laser capture microdissection. Microdissected DNA was whole genome amplified using multiple strand displacement. Genome-wide allelotypes were determined using 391 microsatellite markers. The accuracy of microdissection and fidelity of the whole genome amplification were determined by comparing the genotypes of microdissected primary pancreatic cancers to the genotypes of xenografts derived from these cancers and by comparing the results of amplified to nonamplified specimens.

Results: The concordance of genotypes between LCM whole genome amplified primary pancreatic cancers and their corresponding pancreatic cancer xenograft DNAs was 98%. Among the 20 primary familial pancreatic adenocarcinomas, we found a high prevalence of loss of heterozygosity (LOH) with an average fractional allelic loss (FAL) of 49.9% of an aggregate of 2,378 informative markers. The level of FAL in the IPMNs (10%) was significantly lower than in the pancreatic adenocarcinomas. The most common locus of LOH in the IPMNs was at 19p (LOH at 24% of markers). The regions of frequent allelic loss observed in the familial pancreatic cancers were similar to those found in sporadic pancreatic cancers.

Conclusions: The allelic loss patterns of familial and sporadic pancreatic cancers and IPMNs provide clues as to the genomic locations of tumor suppressor genes inactivated in these neoplasms.
A Phase I and Pharmacologic Study of Belotecan in Combination with Cisplatin in Patients with Previously Untreated Extensive-Stage Disease Small Cell Lung Cancer
Authors: Lee Dae Ho , Kim Sang-We , Bae Kyun-Seop , Hong Jeong-Sook , Suh Cheolwon , Kang Yoon-Koo , Lee Jung-Shin
Published: October 2007

Purpose: Belotecan (Camtobell, CKD602) is a novel camptothecin derivative. This study was designed to determine the maximum tolerated dose (MTD), toxicity profile, and dose-limiting toxicity of belotecan in combination with cisplatin in patients with previously untreated extensive-stage disease small cell lung cancer (SCLC). Furthermore, pharmacokinetics and preliminary antitumor activity against SCLC were evaluated.

Experimental Design: Belotecan was administered i.v. as intermittent 30-min infusions on days 1 to 4, starting dose of 0.40 mg/m2/d with increment of 0.05 mg/m2/d. Intrapatient dose escalation was not allowed. Cisplatin (60 mg/m2) was given on day 1. The treatments were repeated every 3 weeks. Pharmacokinetics was determined during the first cycle using noncompartmental pharmacokinetic analysis.

Results: Seventeen chemotherapy-naive patients with extensive-stage disease SCLC were treated. The MTD of belotecan was 0.50 mg/m2/d with the dose-limiting toxicity of grade 4 neutropenia with fever. A partial response was seen in 13 of 17 patients (76.5%). The most common toxicity was neutropenia but nonhematologic toxicity was very favorable. Pharmacokinetic analysis revealed that, at the dose of 0.50 mg/m2/d, plasma clearance of belotecan was 5.78 ± 1.32 L/h and terminal half-life was 8.55 ± 2.12 h. Fraction of excreted amount in urine was 37.36 ± 5.55%. Pharmacokinetics of belotecan was not altered by administration of cisplatin compared with historical control.

Conclusions: The MTD and recommended dose of belotecan for phase II studies was 0.50 mg/m2/d on days 1 to 4 in combination with 60 mg/m2 cisplatin on day 1 every 3 weeks.
Synchronous Alterations of Wnt and Epidermal Growth Factor Receptor Signaling Pathways through Aberrant Methylation and Mutation in Non–Small Cell Lung Cancer
Authors: Suzuki Makoto , Shigematsu Hisayuki , Nakajima Takahiro , Kubo Rieko , Motohashi Shinichiro , Sekine Yasuo , Shibuya Kiyoshi , Iizasa Toshihiko , Hiroshima Kenzo , Nakatani Yukio , Gazdar Adi F. , Fujisawa Takehiko
Published: October 2007

Purpose: The Wnt and epidermal growth factor receptor (EGFR) signaling pathways play crucial roles in the pathogenesis of a variety of malignant tumors. Although the details of each cascade are understood, very little is known about their collective effects in non–small cell lung cancer (NSCLC).

Experimental Design: A total of 238 NSCLC samples were examined for methylation of Wnt antagonists [secreted frizzled-related protein (sFRP)-1, sFRP-2, sFRP-5, Wnt inhibitory factor-1, and Dickkopf-3] and for EGFR and KRAS mutations. Protein expression levels of β-catenin were assayed in 91 of the 238 NSCLCs.

Results: We found that (a) aberrant methylation of Wnt antagonists is common in NSCLCs; (b) methylation of sFRP-2 is more prevalent in females, nonsmokers, and adenocarcinoma cases; (c) Dickkopf-3 methylation is significantly associated with a poor prognosis in adenocarcinomas; (d) there is a positive correlation between activated EGFR mutation and nuclear accumulation of β-catenin; (e) KRAS mutation and aberrant methylation of Wnt antagonists are positively correlated; and (f) EGFR mutation is significantly associated with a good prognosis in tumors lacking methylated Wnt antagonist genes.

Conclusions: These results contribute to a better understanding of the cross-talk between the Wnt and EGFR signaling pathways and help foster development of chemotherapeutic treatments in NSCLCs.
DNA Replication Licensing Factors and Aurora Kinases are Linked to Aneuploidy and Clinical Outcome in Epithelial Ovarian Carcinoma
Authors: Kulkarni Anjana A. , Loddo Marco , Leo Elisabetta , Rashid Mohammed , Eward Kathryn L. , Fanshawe Thomas R. , Butcher Jessica , Frost Alison , Ledermann Jonathan A. , Williams Gareth H. , Stoeber Kai
Published: October 2007

Purpose: DNA replication licensing factors and Aurora kinases play critical roles in maintaining genomic integrity. We used multiparameter analyses of these cell cycle regulatory proteins to investigate their role in the progression of epithelial ovarian carcinoma (EOC).

Experimental Design: In a cohort of 143 patients, we linked the protein expression profiles of the proliferation marker Ki67, the replication licensing factors Mcm2 and geminin, and the Aurora A and B kinases to tumor DNA ploidy status and clinical outcome.

Results: Ki67, Mcm2, geminin, and Aurora A and B are significantly associated with tumor grade and ploidy status (P < 0.0001). Aurora A and its substrate H3S10ph are also significantly associated with Federation of International Obstetricians and Gynecologists tumor stage (P = 0.006 and P = 0.002, respectively). Aurora A and tumor ploidy status are predictive of disease-free survival in this cohort [hazard ratio (HR), 1.29; 95% confidence intervals (95% CI), 1.06-1.58, P = 0.01 and HR, 1.80 (1.05-3.08), P = 0.03, respectively], with Aurora A of particular prognostic importance in early stage disease [HR, 1.72 (1.19-2.48), P = 0.004 for disease-free survival and HR, 1.81 (1.14-2.87), P = 0.01 for overall survival].

Conclusions: Our data show that Ki67, Mcm2, geminin and Aurora A and B can be used as an adjunct to conventional prognostic indicators and as an aid to develop a tumor progression model for EOC. Dysregulation of Aurora A seems to be an early event in EOC with a key role in tumor progression. In view of present drug development programs for specific Aurora kinase inhibitors, our findings have important implications for the use of Aurora A as a biomarker and as a potential therapeutic target.
The Inhibitor of Apoptosis Proteins as Therapeutic Targets in Cancer
Authors: Vucic Domagoj , Fairbrother Wayne J.
Published: October 2007

Apoptosis is a cell suicide process with a major role in development and homeostasis in vertebrates and invertebrates. Inhibition of apoptosis enhances the survival of cancer cells and facilitates their escape from immune surveillance and cytotoxic therapies. Among the principal molecules contributing to this phenomenon are the inhibitor of apoptosis (IAP) proteins, a family of antiapoptotic regulators that block cell death in response to diverse stimuli through interactions with inducers and effectors of apoptosis. IAP proteins are expressed in the majority of human malignancies at elevated levels and play an active role in promoting tumor maintenance through the inhibition of cellular death and participation in signaling pathways associated with malignancies. Here, we discuss the role of IAP proteins in cancer and options for targeting IAP proteins for therapeutic intervention.
Novel Therapy with 2-Methoxyestradiol for the Treatment of Relapsed and Plateau Phase Multiple Myeloma
Authors: Rajkumar S. Vincent , Richardson Paul G. , Lacy Martha Q. , Dispenzieri Angela , Greipp Philip R. , Witzig Thomas E. , Schlossman Robert , Sidor Carolyn F. , Anderson Kenneth C. , Gertz Morie A.
Published: October 2007

Purpose: 2-Methoxyestradiol (2ME2) is an endogenous product of estradiol metabolism with antiangiogenic and antineoplastic properties. We report on the first phase II trial of 2ME2 in multiple myeloma.

Experimental Design: 2ME2 was administered orally at a dose of 1,000 mg daily. Sixty patients (31 men and 29 women) were treated. After 39 patients were accrued, the dose was increased to 800 mg twice daily for the remaining patients.

Results: Thirty-one patients had relapsed or refractory multiple myeloma, and 29 had plateau phase multiple myeloma. Median age was 60 years (range, 27-84 years). Therapy was well tolerated. Common adverse events included anemia (35%), fatigue (35%), nausea (25%), diarrhea (20%), hot flushes (20%), headache (17%), muscle cramps (15%), and upper respiratory tract infection (15%). Most adverse events were mild (grade 1-2); 12% experienced grade 3-4 adverse events. Median time to progression was 3.8 months, with 5.6 months for plateau phase disease and 2.3 months for relapsed multiple myeloma. Estimated progression-free survival rates for all patients at 1, 2, and 3 years were 24%, 17%, and 11%, respectively. Three patients, all with plateau phase disease, have been on study for over 4 years without progression at 50, 60, and 63 months, respectively. Minor response was noted in 2 patients.

Conclusions: Although no partial responses have been seen thus far, the minor responses and prolonged stable disease seen with 2ME2 therapy are promising. Plasma levels indicate that the dose of 2ME2 was inadequate. A new formulation with better bioavailability will be tested soon in multiple myeloma.
Pharmacogenomic Predictor Discovery in Phase II Clinical Trials for Breast Cancer
Authors: Pusztai Lajos , Anderson Keith , Hess Kenneth R.
Published: October 2007

Purpose: We examined if supervised analysis of gene expression data from phase II studies could identify HER-2 overexpression as a predictor of response to trastuzumab.

Experimental Design: Gene expression data from 132 newly diagnosed breast cancers were used to simulate 50,000 single-agent phase II trastuzumab studies. True HER-2 amplification was assessed by fluorescence in situ hybridization.

Results: Only 3.67% of the simulated studies yielded HER-2 as the top predictor, >96% of the individual “studies” picked a different gene as the most predictive of trastuzumab response. HER-2 was included in the top 10 gene list 9.73% of the time. When HER-2 was a priori defined as a potential predictor, 99.6% of the simulated studies confirmed overexpression among responders. Candidate marker testing may be more efficient than de novo predictor discovery in phase II trials. We describe a tandem, two-step phase II trial design for rapid marker assessment that combines two optimal two-stage phase II trials into a single study. In the first stage, unselected patients are treated, and if insufficient responses are seen, the trial remains open for marker-positive patients only and a second two-stage trial commences.

Conclusions: The probability of successful discovery of drug-specific pharmacogenomic response markers in a typical phase II study is small. The evaluation of predefined predictors using tandem two-step phase II design has the advantages of estimating response rates in both unselected and marker-selected patient populations and allows for simultaneous screening of multiple different predictors for the same drug and several distinct predictor-drug pairs in a single, parallel multiarm trial.
Phase 1 and Pharmacokinetic Study of Lexatumumab in Patients with Advanced Cancers
Authors: Plummer Ruth , Attard Gerhardt , Pacey Simon , Li Louise , Razak Albiruni , Perrett Rebecca , Barrett Mary , Judson Ian , Kaye Stan , Fox Norma Lynn , Halpern Wendy , Corey Alfred , Calvert Hilary , de Bono Johann
Published: October 2007

Purpose: To assess the safety and tolerability, pharmacokinetics, and early evidence of antitumor activity of escalating doses of lexatumumab (HGS-ETR2), a fully human agonistic monoclonal antibody which targets and activates the tumor necrosis factor–related apoptosis-inducing ligand receptor 2 (TRAIL-R2) in patients with advanced solid malignancies.

Experimental Design: In this phase 1, open label study, patients with advanced solid malignancies were treated with escalating doses of lexatumumab administered i.v. over 30 to 120 min every 21 days. A cohort of four patients, which could be expanded to six patients, was studied at each dose level. The dose-limiting toxicity (DLT) dose was defined as the dose at which the incidence of DLT in the first two cycles was ≥33%. The maximum tolerated dose was defined as the highest dose at which <33% of subjects experienced DLT. The pharmacokinetics and immunogenicity of lexatumumab were also characterized. Tumor specimens from historical or current biopsies, when available, were stained for TRAIL-R2 using immunohistochemistry techniques.

Results: Thirty-seven patients received 120 cycles of lexatumumab at doses ranging from 0.1 to 20 mg/kg every 21 days as of May 2006. The 20 mg/kg dose was identified as the DLT dose based on DLTs in three of seven patients treated with this dose; DLTs included asymptomatic elevations of serum amylase, transaminases, and bilirubin. The 10 mg/kg dose cohort was expanded to 12 patients and the 10 mg/kg dose was identified as the maximum tolerated dose. The mean (±SD) clearance and apparent terminal half-life values at the 10 mg/kg dose averaged 6.0 (2.9) mL/d/kg and 16.4 (10.9) days, respectively. Twelve patients had durable stable disease that lasted a median of 4.5 months, including three patients with sarcoma having prolonged stable disease (≥6.7 months). Immunohistochemistry for TRAIL-R2 showed specific staining in >10% of tumor cells for 16 of the 20 evaluable specimens submitted (80%).

Conclusions: Lexatumumab was safe and well tolerated at doses up to and including 10 mg/kg every 21 days. Lexatumumab was associated with sustained stable disease in several patients. Pharmacokinetics were linear over the dose range studied, and consistent with a two-compartment model with first-order elimination from the central compartment. Additional evaluation of this novel apoptosis-inducing agent, particularly in combination with chemotherapy agents, is warranted and ongoing.
High Promoter Methylation Levels of APC Predict Poor Prognosis in Sextant Biopsies from Prostate Cancer Patients
Authors: Henrique Rui , Ribeiro Franclim R. , Fonseca Daniel , Hoque Mohammad O. , Carvalho André L. , Costa Vera L. , Pinto Mafalda , Oliveira Jorge , Teixeira Manuel R. , Sidransky David , Jerónimo Carmen
Published: October 2007

Purpose: Prostate cancer is a highly prevalent malignancy and constitutes a major cause of cancer-related morbidity and mortality. Owing to the limitations of current clinical, serologic, and pathologic parameters in predicting disease progression, we sought to investigate the prognostic value of promoter methylation of a small panel of genes by quantitative methylation-specific PCR (QMSP) in prostate biopsies.

Experimental Design: Promoter methylation levels of APC, CCND2, GSTP1, RARB2, and RASSF1A were determined by QMSP in a prospective series of 83 prostate cancer patients submitted to sextant biopsy. Clinicopathologic data [age, serum prostate-specific antigen (PSA), stage, and Gleason score] and time to progression and/or death from prostate cancer were correlated with methylation findings. Log-rank test and Cox regression model were used to identify which epigenetic markers were independent predictors of prognosis.

Results: At a median follow-up time of 45 months, 15 (18%) patients died from prostate cancer, and 37 (45%) patients had recurrent disease. In univariate analysis, stage and hypermethylation of APC were significantly associated with worse disease–specific survival, whereas stage, Gleason score, high diagnostic serum PSA levels, and hypermethylation of APC, GSTP1, and RASSF1A were significantly associated with poor disease-free survival. However, in the final multivariate analysis, only clinical stage and high methylation of APC were significantly and independently associated with unfavorable prognosis, i.e., decreased disease-free and disease-specific survival.

Conclusions: High-level APC promoter methylation is an independent predictor of poor prognosis in prostate biopsy samples and might provide relevant prognostic information for patient management.
A Half-Log Increase in BCR-ABL RNA Predicts a Higher Risk of Relapse in Patients with Chronic Myeloid Leukemia with an Imatinib-Induced Complete Cytogenetic Response
Authors: Press Richard D. , Galderisi Chad , Yang Rui , Rempfer Carole , Willis Stephanie G. , Mauro Michael J. , Druker Brian J. , Deininger Michael W.N.
Published: October 2007

Purpose: Imatinib induces a complete cytogenetic response (CCR) in most chronic myeloid leukemia patients in chronic phase. Although CCR is usually durable, a minority of patients relapse. Biomarkers capable of predicting those CCR patients with a higher risk of relapse would improve therapeutic management.

Experimental Design: To assess whether changes in BCR-ABL RNA levels are a prognostic biomarker predictive of relapse, we regularly monitored transcript levels [every 3 months (median)] in 90 patients with CCR during 49 months (median) of imatinib therapy.

Results: Throughout follow-up, the 20 patients with eventual relapse had higher transcript levels than the durable responders. Major molecular response (MMR; >3-log reduction of BCR-ABL RNA) was attained by 76 patients (12 with subsequent relapse) and was a significant predictor of prolonged relapse-free survival (P = 0.0008). A minimal 0.5-log increase in transcripts (before relapse; experienced by 42 patients, 16 with subsequent relapse) conveyed a significantly shorter relapse-free survival (P = 0.0017). Loss of MMR (transcript increase to <2.5-log reduction, before relapse; experienced by 33 patients, 11 with subsequent relapse) was also predictive of shortened relapse-free survival (P = 0.0003). A complete molecular response (undetectable transcripts by nested PCR) was attained by 28 MMR patients (one with subsequent relapse) and conveyed a significantly prolonged relapse-free survival (P = 0.0052).

Conclusions: In chronic myeloid leukemia patients with an imatinib-induced CCR, a minimal half-log increase in BCR-ABL RNA (including loss of MMR) is a significant risk factor for future relapse. The achievement of a complete molecular response imparts longer progression-free survival than the achievement of an MMR.
Wwox and Ap2γ Expression Levels Predict Tamoxifen Response
Authors: Guler Gulnur , Iliopoulos Dimitrios , Guler Nilufer , Himmetoglu Cigdem , Hayran Mutlu , Huebner Kay
Published: October 2007

Purpose: Assessment of expression levels of Wwox, Wwox-interacting proteins Ap2α, Ap2γ, and ErbB4, the Ap2γ transcriptional target protein Her2, and the possible Ap2α transcriptional target PrkaRIα, in breast cancers, to determine their roles in tamoxifen resistance. The hypothesis was that sequestration of Wwox interactors in the cytoplasm might control tamoxifen response.

Experimental Design: Tissue sections from 51 tamoxifen-sensitive and 38 tamoxifen-resistant, estrogen receptor α–positive breast cancers were stained for the above proteins, as well as progesterone receptor (PR). The relation of tamoxifen resistance and other clinical features, with level of expression of these proteins, and pairwise correlations among various immunohistochemical markers were determined.

Results: Menopausal status, tumor, node, and stage, loss of PR, lost or reduced expression of Wwox, and high level of expression of PrkaRIα, Ap2γ, and Her2 were significantly correlated with tamoxifen resistance. In multivariate analysis, Wwox, PrkaRIα, Ap2γ, and ErbB4 were found to be independent markers of tamoxifen resistance. Reduced Wwox expression was better than PR in prediction of resistance, especially in high-risk patients, and nuclear Ap2γ expression was better than Her2, especially in low-risk patients.

Conclusion: The results illustrate the complex relationships among the marker proteins assessed in this in vivo study and suggest new markers for prediction of response to tamoxifen treatment as well as possible new targets for treatment of breast cancer. Wwox and Ap2γ emerge as new biomarkers that may be superior to PR and Her2 in predicting tamoxifen response.
High Levels of B-Cell Activating Factor in Patients with Active Chronic Graft-Versus-Host Disease
Authors: Sarantopoulos Stefanie , Stevenson Kristen E. , Kim Haesook T. , Bhuiya Nazmim S. , Cutler Corey S. , Soiffer Robert J. , Antin Joseph H. , Ritz Jerome
Published: October 2007

Purpose: Recent studies suggest that donor B cells as well as T cells contribute to immune pathology in patients with chronic graft-versus-host disease (GVHD). B-cell activating factor (BAFF) promotes survival and differentiation of activated B cells. Thus, we tested whether BAFF correlated with chronic GVHD disease activity and time of onset after allogeneic hematopoietic stem cell transplantation (HSCT).

Experimental Design: Patients who had undergone allogeneic HSCT between 1994 and 2005 for hematologic malignancies were studied. ELISA was used to measure plasma BAFF levels and flow cytometry was used to assess BAFF receptor expression on B cells in patients with or without chronic GVHD.

Results: In 104 patients, BAFF levels were significantly higher in patients with active chronic GVHD compared with those without disease (P = 0.02 and 0.0004, respectively). Treatment with high-dose prednisone (≥30 mg/d) was associated with reduced BAFF levels in patients with active chronic GVHD (P = 0.0005). Serial studies in 24 patients showed that BAFF levels were high in the first 3 months after HSCT but subsequently decreased in 13 patients who never developed chronic GVHD. In contrast, BAFF levels remained elevated in 11 patients who developed chronic GVHD. Six-month BAFF levels ≥10 ng/mL were strongly associated with subsequent development of chronic GVHD (P < 0.0001). Following transplant, plasma BAFF levels correlated inversely with BAFF receptor expression on B cells (P = 0.01), suggesting that soluble BAFF affected B cells through this receptor.

Conclusion: These results suggest that elevated BAFF levels contribute to B-cell activation in patients with active chronic GVHD.
A New Rexinoid, NRX194204, Prevents Carcinogenesis in Both the Lung and Mammary Gland
Authors: Liby Karen , Royce Darlene B. , Risingsong Renee , Williams Charlotte R. , Wood Matthew D. , Chandraratna Roshantha A. , Sporn Michael B.
Published: October 2007

Purpose: We evaluated the anti-inflammatory and growth-inhibitory properties of the novel rexinoid NRX194204 (4204) in vitro and then tested its ability to prevent and/or treat experimental lung and estrogen receptor (ER)–negative breast cancer in vivo.

Experimental Design: In cell culture studies, we measured the ability of 4204 to block the effects of lipopolysaccharide and induce apoptosis. For the lung cancer prevention studies, A/J mice were injected with the carcinogen vinyl carbamate and then fed 4204 (30-60 mg/kg diet) for 15 weeks, beginning 1 week after the administration of the carcinogen. For breast cancer prevention studies, mouse mammary tumor virus-neu mice were fed control diet or 4204 (20 mg/kg diet) for 50 weeks; for treatment, tumors at least 32 mm3 in size were allowed to form, and then mice were fed control diet or 4204 (60 mg/kg diet) for 4 weeks.

Results: Low nanomolar concentrations of 4204 blocked the ability of lipopolysaccharide and tumor necrosis factor-α to induce the release of nitric oxide and interleukin 6 and the degradation of IKBα in RAW264.7 macrophage-like cells. In the A/J mouse model of lung cancer, 4204 significantly (P < 0.05) reduced the number and size of tumors on the surface of the lungs and reduced the total tumor volume per slide by 64% to 81% compared with the control group. In mouse mammary tumor virus-neu mice, 4204 not only delayed the development of ER-negative mammary tumors in the prevention studies but also caused marked tumor regression (92%) or growth arrest (8%) in all of the mammary tumors when used therapeutically.

Conclusions: The combined anti-inflammatory and anticarcinogenic actions of 4204 suggest that it is a promising new rexinoid that should be considered for future clinical trials.
p53 Mutations in Deep Tissues Are More Strongly Associated with Recurrence than Mutation-Positive Mucosal Margins
Authors: Huang Xiaohong , Pateromichelakis Stelios , Hills Allison , Sherriff Martyn , Lyons Andrew , Langdon John , Odell Edward , Morgan Peter , Harrison John , Partridge Max
Published: October 2007

Purpose: Application of ultrasensitive diagnostics has shown that small numbers of p53 mutation-positive cells may signify the presence of residual tumor in histologically normal tissues after resection of squamous cell carcinomas arising in the head and neck area. To date, most studies in this area have focused on analysis of tissues at the mucosal aspect of the resection and highlighted the importance of molecular changes in the field with respect to the risk of recurrence.

Experimental Design: In the present investigation, we analyzed normal tissues from mucosal and deep surgical margins, referred to as “molecular margins,” for the presence of the signature p53 mutation identified for each tumor.

Results: The p53 mutation status of these carcinomas did not correlate with clinical or histopathologic variables, but these mutations provided an excellent target for ultrasensitive analysis of margin status. We found that 11 of 16 (68%) of cases with histologically tumor-free (including 9 without dysplasia), but with p53 mutation-positive molecular margins, developed recurrence. The probability of developing local recurrence was significantly higher for the group with p53 mutation-positive margins when compared with the group with clear margins (P = 0.048) and more strongly associated with p53 mutation-positive deep molecular margins than mutation-positive mucosal molecular margins or positivity at both sites (P = 0.009).

Conclusions: This shows that although persistent mucosal fields may contribute to recurrence, clonal p53 mutations in deep tissues are an important cause of treatment failure, and molecular margins from both sites should be analyzed in future prospective series.
Adenovirally Delivered Tumor Necrosis Factor-α Improves the Antiglioma Efficacy of Concomitant Radiation and Temozolomide Therapy
Authors: Yamini Bakhtiar , Yu Xiaohong , Pytel Peter , Galanopoulos Nicholas , Rawlani Vinay , Veerapong Jula , Bickenbach Kai , Weichselbaum Ralph R.
Published: October 2007

Purpose: Treatment of malignant glioma involves concomitant temozolomide and ionizing radiation (IR). Nevertheless, overall patient survival remains poor. This study was designed to evaluate if addition of Ad.Egr–tumor necrosis factor (TNF), a replication defective adenovector encoding a cDNA for TNF-α, to temozolomide and IR can improve overall antiglioma effect.

Experimental Design: The efficacy of combination treatment with Ad.Egr-TNF, IR, and temozolomide was assessed in two glioma xenograft models. Animal toxicity and brain histopathology after treatment were also examined. In addition, in an attempt to explain the antitumor interaction between these treatments, the activation status of the transcription factor nuclear factor-κB was examined.

Results: Triple therapy (Ad.Egr-TNF, IR, and temozolomide) leads to significantly increased survival in mice bearing glioma xenografts compared with dual treatment. Fifty percent of animals treated with the triple regimen survive for >130 days. Pathologic examination shows that triple therapy leads to a complete response with formation of a collagenous scar. No significant change in myelination pattern is noted after triple therapy, compared with any double treatment. Treatment of intracranial glioma bearing mice with Ad.Egr-TNF and IR leads to cachexia and poor feeding that does not improve, whereas triple therapy results in less toxicity, which improves over 21 days. Both Ad.Egr-TNF and IR activate nuclear factor-κB, and temozolomide inhibits this activity in an inhibitor of κBα (IκBα)–independent manner.

Conclusion: This work shows that the addition of adenoviral TNF-α gene delivery to temozolomide and IR significantly improves antiglioma efficacy and illustrates a potential new treatment regimen for use in patients with malignant glioma.