bluuebunny/crossref_metadata_2025 huggingface dataset:
Aspirin, Nonsteroidal Anti-inflammatory Drugs, and the Risks of Cancers of the Esophagus
Authors: Sadeghi Shahram , Bain Christopher J. , Pandeya Nirmala , Webb Penelope M. , Green Adèle C. , Whiteman David C. ,   for the Australian Cancer Study
Published: May 2008

Background: Frequent consumption of aspirin and nonsteroidal anti-inflammatory drugs (NSAID) has been associated with reduced occurrence of cancers of the esophagus, although potential modifying effects of other causal factors remain relatively unexplored.

Methods: We compared nationwide samples of Australian patients with adenocarcinomas of the esophagus (EAC; n = 367) or esophagogastric junction (EGJAC; n = 426) or esophageal squamous cell carcinoma (ESCC; n = 309) with control participants sampled from a population register (n = 1,580). Intakes of aspirin, other NSAIDs, and acetaminophen (paracetamol) were assessed from self-reports. We calculated odds ratios (OR) and 95% confidence intervals (95% CI) using multivariable logistic regression.

Results: Compared with never-users of aspirin, those who used aspirin at least weekly had significantly lower risks of EAC (OR, 0.48; 95% CI, 0.32-0.72), EGJAC (OR, 0.71; 95% CI, 0.49-1.01), and ESCC (OR, 0.63; 95% CI, 0.40-0.98). At least weekly use of other NSAIDs was also associated with reduced risks of EAC (OR, 0.74; 95% CI, 0.51-1.08), EGJAC (OR, 0.53; 95% CI, 0.37-0.77), and ESCC (OR, 0.46; 95% CI, 0.30-0.73). No association was observed between frequent use of acetaminophen and esophageal cancer. Risk reductions for EAC among users of aspirin and NSAIDs were greater among those who experienced at least weekly symptoms of reflux (OR, 0.26; 95% CI, 0.12-0.55 and OR, 0.41; 95% CI, 0.21-0.77, respectively) than those who did not experience reflux (OR, 0.96; 95% CI, 0.46-2.00 and OR, 0.78; 95% CI, 0.35-1.72, respectively). Recent use of NSAIDs in the past 5 years was associated with greater risk reductions.

Conclusions: Frequent use of aspirin and NSAIDs is associated with reduced occurrence of esophageal cancers, particularly among those with frequent symptoms of gastroesophageal reflux. (Cancer Epidemiol Biomarkers Prev 2008;17(5):1169–9)
High Levels of Carcinogenic Polycyclic Aromatic Hydrocarbons in Mate Drinks
Authors: Kamangar Farin , Schantz Michele M. , Abnet Christian C. , Fagundes Renato B. , Dawsey Sanford M.
Published: May 2008

Background: Drinking mate has been associated with cancers of the esophagus, oropharynx, larynx, lung, kidney, and bladder. We conducted this study to determine whether drinking mate could lead to substantial exposure to polycyclic aromatic hydrocarbons (PAH), including known carcinogens, such as benzo[a]pyrene.

Methods: The concentrations of 21 individual PAHs were measured in dry leaves of eight commercial brands of yerba mate and in infusions made with hot (80°C) or cold (5°C) water. Measurements were done using gas chromatography/mass spectrometry, with deuterated PAHs as the surrogates. Infusions were made by adding water to the leaves, removing the resulting infusion after 5 min, and then adding more water to the remaining leaves. This process was repeated 12 times for each infusion temperature.

Results: The total concentrations of the 21 PAHs in different brands of yerba mate ranged from 536 to 2,906 ng/g dry leaves. Benzo[a]pyrene concentrations ranged from 8.03 to 53.3 ng/g dry leaves. For the mate infusions prepared using hot water and brand 1, 37% (1,092 of 2,906 ng) of the total measured PAHs and 50% (25.1 of 50 ng) of the benzo[a]pyrene content were released into the 12 infusions. Similar results were obtained for other hot and cold infusions.

Conclusion: Very high concentrations of carcinogenic PAHs were found in yerba mate leaves and in hot and cold mate infusions. Our results support the hypothesis that the carcinogenicity of mate may be related to its PAH content. (Cancer Epidemiol Biomarkers Prev 2008;17(5):1262–8)
Helicobacter pylori Infection and Development of Pancreatic Cancer
Authors: de Martel Catherine , Llosa Augusto E. , Friedmana Gary D. , Vogelman Joseph H. , Orentreich Norman , Stolzenberg-Solomon Rachael Z. , Parsonnet Julie
Published: May 2008

Background: Infection with Helicobacter pylori is an established risk factor for gastric cancer. Results from two studies suggest that it may also be a risk factor for pancreatic cancer.

Methods: We conducted a nested case control study among 128,992 adult subscribers to the Kaiser Permanente Medical Care Program who had been enrolled in a multiphasic health checkup from 1964 to 1969. Serum collected during the checkup was maintained frozen, and subjects were followed for cancer. Cases consisted of 104 randomly selected subjects among 507 who developed pancreatic cancer in the cohort. Controls consisted of 262 pancreatic cancer–free subjects from a pool of 730 controls previously tested for studies conducted on this cohort. Controls were individually matched to cases on age, gender, race, site, and date of multiphasic health checkup. Control sera were compared with cases for antibodies to H. pylori and the CagA protein. The effects of smoking, alcohol consumption, obesity, and years of education were also investigated.

Results: Neither H. pylori [odds ratio (OR), 0.85; 95% confidence interval (95% CI), 0.49-1.48] nor its CagA protein (OR, 0.96; 95% CI, 0.48-1.92) was associated with subsequent development of pancreatic cancer. Smoking (OR, 2.09; 95% CI, 1.17-3.74) and greater number of years of education (OR, 2.13; 95% CI, 1.23-3.69) were risk factors for pancreatic cancer, whereas alcohol consumption and obesity were not.

Conclusion: Our results suggest that H. pylori infection is not associated with development of pancreatic cancer. (Cancer Epidemiol Biomarkers Prev 2008;17(5):1188–94)
Prognostic Role of Detection Method and Its Relationship with Tumor Biomarkers in Breast Cancer: The University of Texas M. D. Anderson Cancer Center Experience
Authors: Dong Wenli , Berry Donald A. , Bevers Therese B. , Kau Shu-Wan , Hsu Limin , Theriault Richard L. , Shen Yu
Published: May 2008

Purpose: To assess the effect of tumor detection method (screening versus symptom-based diagnosis) in predicting breast cancer survival and investigate how biological features of breast cancer are related to the tumor detection method.

Patients and Methods: The study population consisted of 5,481 women diagnosed with primary invasive breast cancer between 1997 and 2005 and received their treatment at The University of Texas M. D. Anderson Cancer Center.

Results: Patients with symptom-detected tumors had an increased risk of recurrence or death [relative risk (RR), 1.34; P = 0.006] and breast cancer–specific death (RR, 1.31; P = 0.117) than patients with screen-detected tumors after adjusting for tumor characteristics and treatments received. This relationship was especially evident among estrogen receptor (ER)–negative tumors (RR, 1.60 for breast cancer recurrence for ER-negative tumors; RR, 1.18 for ER-positive tumors). ER status and Ki-67 expression were statistically significantly associated with symptom detection rate after adjusting for patients' age, tumor stage, tumor size, and nuclear grade [odds ratio (OR) of ER negative versus ER positive, 1.35; P < 0.001; OR of Ki-67 10-30% versus <10%, 1.40; P = 0.005; OR of Ki-67 >30% versus <10%, 2.11; P < 0.001].

Conclusion: The method of detection was a statistically significant independent predictor of breast cancer recurrence. Information on the method of tumor detection should be collected to improve the prediction of prognosis of breast cancer patients. (Cancer Epidemiol Biomarkers Prev 2008;17(5):1096–103)
N-[N-[(S)-1,3-Dicarboxypropyl]Carbamoyl]-4-[18F]Fluorobenzyl-l-Cysteine, [18F]DCFBC: A New Imaging Probe for Prostate Cancer
Authors: Mease Ronnie C. , Dusich Crystal L. , Foss Catherine A. , Ravert Hayden T. , Dannals Robert F. , Seidel Jurgen , Prideaux Andrew , Fox James J. , Sgouros George , Kozikowski Alan P. , Pomper Martin G.
Published: May 2008

Purpose: Previously, we showed successful imaging of xenografts that express the prostate-specific membrane antigen (PSMA) using small-animal positron emission tomography (PET) and the radiolabeled PSMA inhibitor N-[N-[(S)-1,3-dicarboxypropyl]carbamoyl]-S-[11C]methyl-l-cysteine. Herein, we extend that work by preparing and testing a PSMA inhibitor of the same class labeled with fluorine-18.

Experimental Design: N-[N-[(S)-1,3-Dicarboxypropyl]carbamoyl]-4-[18F]fluorobenzyl-l-cysteine ([18F]DCFBC) was prepared by reacting 4-[18F]fluorobenzyl bromide with the precursor (S)-2-[3-[(R)-1-carboxy-2-mercaptoethyl]ureido]-pentanedioic acid in ammonia-saturated methanol at 60°C for 10 min followed by purification using C-18 reverse-phase semipreparative high-performance liquid chromatography. Severe combined immunodeficient mice bearing a s.c. PSMA+ PC-3 PIP tumor behind one shoulder and a PSMA− PC-3 FLU tumor behind the other shoulder were injected via the tail vein with either 1.85 MBq (50 μCi) of [18F]DCFBC for ex vivo biodistribution or 7.4 MBq (200 μCi) for imaging. For biodistribution, mice were sacrificed at 5, 15, 30, 60, and 120 min. Tumor, blood, and major organs were harvested and weighed, and radioactivity was counted. Imaging was done on the GE eXplore Vista small-animal PET scanner by collecting 12 consecutive 10-min frames.

Results: Radiochemical yield for [18F]DCFBC averaged 16 ± 6% (n = 8) from 4-[18F]fluorobenzyl bromide. Specific radioactivities ranged from 13 to 133 GBq/μmol (350-3,600 Ci/mmol) with an average of 52 GBq/μmol (1,392 Ci/mmol; n = 6). Biodistribution and imaging studies showed high uptake of [18F]DCFBC in the PIP tumors with little to no uptake in FLU tumors. High radiopharmaceutical uptake was also seen in kidneys and bladder; however, washout of radioactivity from these organs was faster than from the PIP tumors. The maximum PIP tumor uptake was 8.16 ± 2.55% injected dose per gram, achieved at 60 min after injection, which decreased to 4.69 ± 0.89 at 120 min. The PIP tumor to muscle ratio was 20 at 120 min after injection. Based on the mouse biodistribution, the dose-limiting organ is the kidneys (human estimated absorbed dose: 0.05 mGy/MBq; 0.2 rad/mCi).

Conclusion: [18F]DCFBC localizes to PSMA+-expressing tumors in mice, permitting imaging by small-animal PET. This new radiopharmaceutical is an attractive candidate for further studies of PET imaging of prostate cancer.
Mechanisms of Chemoresistance to Alkylating Agents in Malignant Glioma
Authors: Sarkaria Jann N. , Kitange Gaspar J. , James C. David , Plummer Ruth , Calvert Hilary , Weller Michael , Wick Wolfgang
Published: May 2008

Intrinsic or acquired chemoresistance to alkylating agents is a major cause of treatment failure in patients with malignant brain tumors. Alkylating agents, the mainstay of treatment for brain tumors, damage the DNA and induce apoptosis, but the cytotoxic activity of these agents is dependent on DNA repair pathways. For example, O6-methylguanine DNA adducts can cause double-strand breaks, but this is dependent on a functional mismatch repair pathway. Thus, tumor cell lines deficient in mismatch repair are resistant to alkylating agents. Perhaps the most important mechanism of resistance to alkylating agents is the DNA repair enzyme O6-methylguanine methyltransferase, which can eliminate the cytotoxic O6-methylguanine DNA adduct before it causes harm. Another mechanism of resistance to alkylating agents is the base excision repair (BER) pathway. Consequently, efforts are ongoing to develop effective inhibitors of BER. Poly(ADP-ribose)polymerase plays a pivotal role in BER and is an important therapeutic target. Developing effective strategies to overcome chemoresistance requires the identification of reliable preclinical models that recapitulate human disease and which can be used to facilitate drug development. This article describes the diverse mechanisms of chemoresistance operating in malignant glioma and efforts to develop reliable preclinical models and novel pharmacologic approaches to overcome resistance to alkylating agents.
Vascular Endothelial Growth Factor Expression in Ovarian Cancer: A Model for Targeted Use of Novel Therapies?
Authors: Duncan Timothy J. , Al-Attar Ahmad , Rolland Phil , Scott Ian V. , Deen Suha , Liu David T.Y. , Spendlove Ian , Durrant Lindy G.
Published: May 2008

Purpose: Angiogenesis has a vital role in tumor growth and metastasis, and vascular endothelial growth factor (VEGF) represents a potent cytokine in this process. However, the influence of VEGF in ovarian cancer remains controversial. Interest has focused on the use of antiangiogenic drugs in ovarian cancer. This study aims to establish the pattern of expression and effect on prognosis of VEGF in a large population of ovarian cancer patients and to potentially identify a cohort in whom antiangiogenic therapy is appropriate.

Experimental Design: Using a tissue microarray of 339 primary ovarian cancers, the expression of VEGF was assessed immunohistochemically. Coupled to a comprehensive database of clinicopathologic variables, its effect on these factors and survival was studied.

Results: Tumors expressing high levels of VEGF had significantly poorer survival (P = 0.04). Factors shown to predict prognosis independently of each other were age, International Federation of Gynecologists and Obstetricians stage, and the absence of macroscopic disease after surgery. VEGF was independently predictive of prognosis on multivariate analysis (P = 0.02). There was no correlation between VEGF and any clinicopathologic variable. High expression of VEGF was seen in only 7% of the tumors, suggesting that the role of antiangiogenic drugs may be limited to a small subset of patients.

Conclusion: High VEGF expression occurs in a small proportion of ovarian cancers, and this independently predicts poor prognosis. The small percentage of tumors with high levels of VEGF activity suggests that the role of bevacizumab may potentially be limited to a few patients; these patients could be targeted by molecular profiling.
Bcl-B Expression in Human Epithelial and Nonepithelial Malignancies
Authors: Krajewska Maryla , Kitada Shinichi , Winter Jane N. , Variakojis Daina , Lichtenstein Alan , Zhai Dayong , Cuddy Michael , Huang Xianshu , Luciano Frederic , Baker Cheryl H. , Kim Hoguen , Shin Eunah , Kennedy Susan , Olson Allen H. , Badzio Andrzej , Jassem Jacek , Meinhold-Heerlein Ivo , Duffy Michael J. , Schimmer Aaron D. , Tsao Ming , Brown Ewan , Sawyers Anne , Andreeff Michael , Mercola Dan , Krajewski Stan , Reed John C.
Published: May 2008

Purpose: Apoptosis plays an important role in neoplastic processes. Bcl-B is an antiapoptotic Bcl-2 family member, which is known to change its phenotype upon binding to Nur77/TR3. The expression pattern of this protein in human malignancies has not been reported.

Experimental Design: We investigated Bcl-B expression in normal human tissues and several types of human epithelial and nonepithelial malignancy by immunohistochemistry, correlating results with tumor stage, histologic grade, and patient survival.

Results: Bcl-B protein was strongly expressed in all normal plasma cells but found in only 18% of multiple myelomas (n = 133). Bcl-B immunostaining was also present in normal germinal center centroblasts and centrocytes and in approximately half of diffuse large B-cell lymphoma (n = 48) specimens, whereas follicular lymphomas (n = 57) did not contain Bcl-B. In breast (n = 119), prostate (n = 66), gastric (n = 180), and colorectal (n = 106) adenocarcinomas, as well as in non–small cell lung cancers (n = 82), tumor-specific overexpression of Bcl-B was observed. Bcl-B expression was associated with variables of poor prognosis, such as high tumor grade in breast cancer (P = 0.009), microsatellite stability (P = 0.0002), and left-sided anatomic location (P = 0.02) of colorectal cancers, as well as with greater incidence of death from prostate cancer (P = 0.005) and shorter survival of patients with small cell lung cancer (P = 0.009). Conversely, although overexpressed in many gastric cancers, Bcl-B tended to correlate with better outcome (P = 0.01) and more differentiated tumor histology (P < 0.0001).

Conclusions: Tumor-specific alterations in Bcl-B expression may define subsets of nonepithelial and epithelial neoplasms with distinct clinical behaviors.
Critical Role of Notch Signaling in Osteosarcoma Invasion and Metastasis
Authors: Zhang Pingyu , Yang Yanwen , Zweidler-McKay Patrick A. , Hughes Dennis P.M.
Published: May 2008

Purpose: Notch signaling is an important mediator of growth and survival in several cancer types, with Notch pathway genes functioning as oncogenes or tumor suppressors in different cancers. However, the role of Notch in osteosarcoma is unknown.

Experimental Design: We assessed the expression of Notch pathway genes in human osteosarcoma cell lines and patient samples. We then used pharmacologic and retroviral manipulation of the Notch pathway and studied the effect on osteosarcoma cell proliferation, survival, anchorage-independent growth, invasion, and metastasis in vitro and in vivo.

Results: Notch pathway genes, including Notch ligand DLL1, Notch1 and Notch2, and the Notch target gene HES1, were expressed in osteosarcoma cells, and expression of HES1 was associated with invasive and metastatic potential. Blockade of Notch pathway signaling with a small molecule inhibitor of γ secretase eliminated invasion in Matrigel without affecting cell proliferation, survival, or anchorage-independent growth. Manipulation of Notch and HES1 signaling showed a crucial role for HES1 in osteosarcoma invasiveness and metastasis in vivo.

Conclusion: These studies identify a new invasion and metastasis-regulating pathway in osteosarcoma and define a novel function for the Notch pathway: regulation of metastasis. Because the Notch pathway can be inhibited pharmacologically, these findings point toward possible new treatments to reduce invasion and metastasis in osteosarcoma.
Histone Deacetylase Inhibition and Blockade of the Glycolytic Pathway Synergistically Induce Glioblastoma Cell Death
Authors: Egler Vivian , Korur Serdar , Failly Mike , Boulay Jean-Louis , Imber Roland , Lino Maria M. , Merlo Adrian
Published: May 2008

Purpose: High-grade gliomas are difficult to treat due to their location behind the blood-brain barrier and to inherent radioresistance and chemoresistance.

Experimental Design: Because tumorigenesis is considered a multistep process of accumulating mutations affecting distinct signaling pathways, combinations of compounds, which inhibit nonoverlapping pathways, are being explored to improve treatment of gliomas. Histone deacetylase inhibitors (HDI) have proven antitumor activity by blocking cell proliferation, promoting differentiation, and inducing tumor cell apoptosis.

Results: In this report, we show that the HDIs trichostatin A, sodium butyrate, and low nanomolar doses of LAQ824 combined with the glycolysis inhibitor 2-deoxy-d-glucose induce strong apoptosis in cancer cell lines of brain, breast, and cervix in a p53-independent manner. HDIs up-regulate p21, which is blocked by concomitant administration of 2-deoxy-d-glucose.

Conclusions: We propose simultaneous blockade of histone deacetylation and glycolysis as a novel therapeutic strategy for several major cancers.
Homeostatic Proliferation Plus Regulatory T-Cell Depletion Promotes Potent Rejection of B16 Melanoma
Authors: Kline Justin , Brown Ian E. , Zha Yuan-Yuan , Blank Christian , Strickler John , Wouters Harald , Zhang Long , Gajewski Thomas F.
Published: May 2008

Purpose: To investigate the antitumor efficacy of T-cell anergy reversal through homeostatic proliferation and regulatory T-cell (Treg) depletion in a clinically relevant murine adoptive immunotherapy model.

Experimental Design: B16 melanoma cells were engineered to express the model SIYRYYGL (SIY) antigen to enable immune monitoring. Tumor-specific T cells expanded in tumor-challenged wild-type hosts but became hyporesponsive. To examine whether lymphopenia-induced homeostatic proliferation could reverse tumor-induced T-cell anergy, total splenic T cells were transferred into lymphopenic RAG2−/− mice or control P14/RAG2−/− mice. Tumor growth was measured, and SIY-specific immune responses were monitored using ELISPOT and SIY/Kb tetramers. To determine whether Treg depletion could synergize with homeostatic proliferation, RAG2−/− mice received total or CD25-depleted T cells, followed or preceded by B16.SIY challenge. This approach was further investigated in wild-type mice lymphodepleted with sublethal total body irradiation.

Results: Adoptive transfer of total splenic T cells into RAG2−/− mice moderately affected the growth rate of B16.SIY. As Treg expansion occurred in tumor-bearing mice, CD25+ T cells were depleted from total T cells before adoptive transfer. Interestingly, transfer of CD25-depleted T cells into RAG2−/− mice resulted in potent rejection of B16 melanoma in both prophylactic and short-term preimplanted tumor settings and was associated with maintained T-cell effector function. Using a clinically applicable approach, wild-type mice were lymphodepleted using sublethal total body irradiation, which similarly supported tumor rejection upon transfer of CD25-depleted T cells.

Conclusions: Our results indicate that combined CD25 depletion and homeostatic proliferation support a potent antitumor immune response—an approach with potential for clinical translation.
Phase II Trial of Tipifarnib as Maintenance Therapy in First Complete Remission in Adults with Acute Myelogenous Leukemia and Poor-Risk Features
Authors: Karp Judith E. , Smith B. Douglas , Gojo Ivana , Lancet Jeffrey E. , Greer Jacqueline , Klein Maureen , Morris Larry , Levis Mark J. , Gore Steven D. , Wright John J. , Garrett-Mayer Elizabeth
Published: May 2008

Purpose: Acute myelogenous leukemia (AML) does not have a high cure rate, particularly in patients with poor-risk features. Such patients might benefit from additional therapy in complete remission (CR). Tipifarnib is an oral farnesyltransferase inhibitor with activity in AML. We conducted a phase II trial of maintenance tipifarnib monotherapy for 48 adults with poor-risk AML in first CR.

Experimental Design: Tipifarnib 400 mg twice daily for 14 of 21 days was initiated after recovery from consolidation chemotherapy, for a maximum of 16 cycles (48 weeks).

Results: Twenty (42%) patients completed 16 cycles, 24 (50%) were removed from study for relapse, and 4 (8%) discontinued drug prematurely for intolerance. Nonhematologic toxicities were rare, but tipifarnib dose was reduced in 58% for myelosuppression. Median disease-free survival (DFS) was 13.5 months (range, 3.5-59+ months), with 30% having DFS >2 years. Comparison of CR durations for 25 patients who received two-cycle timed sequential therapy followed by tipifarnib maintenance with 23 historically similar patients who did not receive tipifarnib showed that tipifarnib was associated with DFS prolongation for patients with secondary AML and adverse cytogenetics.

Conclusions: This study suggests that some patients with poor-risk AML, including patients with secondary AML and adverse cytogenetics, may benefit from tipifarnib maintenance therapy. Future studies are warranted to examine alternative tipifarnib dosing and continuation beyond 16 cycles.
Inhibition of Vascular Endothelial Growth Factor-A Signaling Induces Hypertension: Examining the Effect of Cediranib (Recentin; AZD2171) Treatment on Blood Pressure in Rat and the Use of Concomitant Antihypertensive Therapy
Authors: Curwen Jon O. , Musgrove Helen L. , Kendrew Jane , Richmond Graham H.P. , Ogilvie Donald J. , Wedge Stephen R.
Published: May 2008

Purpose: Inhibition of vascular endothelial growth factor-A (VEGF) signaling is a key therapeutic approach in oncology given the role of VEGF in angiogenesis and vascular permeability in solid tumors. Clinical trials examining VEGF signaling inhibitors commonly report hypertension. We examined the effect of cediranib, a highly potent VEGF signaling inhibitor, on the blood pressure of rats and the ability of standard antihypertensive agents to modulate the consequences of VEGF signaling inhibition.

Experimental Design: The ability of cediranib to induce hypertensive changes and the effect of giving antihypertensive therapy were investigated in conscious, unrestrained telemetered rats. Two antihypertensive agents were studied: captopril, an angiotensin-converting enzyme inhibitor, and nifedipine, a dihydropyridine calcium channel blocker. The antitumor activity of cediranib, alone and in combination with nifedipine, was also evaluated in a LoVo human colorectal tumor xenograft model in nude rats. All treatments were given orally.

Results: Administration of 0.1 to 1.5 mg/kg/d of cediranib for 4 consecutive days induced a relatively mild hypertensive effect, elevating diastolic blood pressure by 10 to 14 mmHg. Dosing 3 mg/kg/d cediranib for 4 days induced a marked hypertension of 35 to 50 mmHg. Captopril (30 mg/kg, qd) was effective at lowering a 10 mmHg increase in blood pressure but not a 35 to 50 mmHg increase. However, the latter was rapidly reversed by administration of nifedipine (10 mg/kg, bd). Coadministration of nifedipine did not negatively affect the antitumor activity of cediranib (1.5 mg/kg/d).

Conclusions: Hypertension is a direct consequence of inhibiting VEGF signaling but can be controlled with appropriately selected, standard antihypertensive medication.
Novel Glioblastoma Markers with Diagnostic and Prognostic Value Identified through Transcriptome Analysis
Authors: Reddy Sreekanth P. , Britto Ramona , Vinnakota Katyayni , Aparna Hebbar , Sreepathi Hari Kishore , Thota Balaram , Kumari Arpana , Shilpa B.M. , Vrinda M. , Umesh Srikantha , Samuel Cini , Shetty Mitesh , Tandon Ashwani , Pandey Paritosh , Hegde Sridevi , Hegde A.S. , Balasubramaniam Anandh , Chandramouli B.A. , Santosh Vani , Kondaiah Paturu , Somasundaram Kumaravel , Rao M.R. Satyanarayana
Published: May 2008

Purpose: Current methods of classification of astrocytoma based on histopathologic methods are often subjective and less accurate. Although patients with glioblastoma have grave prognosis, significant variability in patient outcome is observed. Therefore, the aim of this study was to identify glioblastoma diagnostic and prognostic markers through microarray analysis.

Experimental Design: We carried out transcriptome analysis of 25 diffusely infiltrating astrocytoma samples [WHO grade II—diffuse astrocytoma, grade III—anaplastic astrocytoma, and grade IV—glioblastoma (GBM)] using cDNA microarrays containing 18,981 genes. Several of the markers identified were also validated by real-time reverse transcription quantitative PCR and immunohistochemical analysis on an independent set of tumor samples (n = 100). Survival analysis was carried out for two markers on another independent set of retrospective cases (n = 51).

Results: We identified several differentially regulated grade-specific genes. Independent validation by real-time reverse transcription quantitative PCR analysis found growth arrest and DNA-damage–inducible α (GADD45α) and follistatin-like 1 (FSTL1) to be up-regulated in most GBMs (both primary and secondary), whereas superoxide dismutase 2 and adipocyte enhancer binding protein 1 were up-regulated in the majority of primary GBM. Further, identification of the grade-specific expression of GADD45α and FSTL1 by immunohistochemical staining reinforced our findings. Analysis of retrospective GBM cases with known survival data revealed that cytoplasmic overexpression of GADD45α conferred better survival while the coexpression of FSTL1 with p53 was associated with poor survival.

Conclusions: Our study reveals that GADD45α and FSTLI are GBM-specific whereas superoxide dismutase 2 and adipocyte enhancer binding protein 1 are primary GBM-specific diagnostic markers. Whereas GADD45α overexpression confers a favorable prognosis, FSTL1 overexpression is a hallmark of poor prognosis in GBM patients.
Modulation of Drug Resistance in Ovarian Adenocarcinoma by Enhancing Intracellular Ceramide Using Tamoxifen-Loaded Biodegradable Polymeric Nanoparticles
Authors: Devalapally Harikrishna , Duan Zhenfeng , Seiden Michael V. , Amiji Mansoor M.
Published: May 2008

Purpose: To modulate intracellular ceramide levels and lower the apoptotic threshold in multidrug-resistant ovarian adenocarcinoma, we have examined the efficacy and preliminary safety of tamoxifen coadministration with paclitaxel in biodegradable poly(ethylene oxide)–modified poly(epsilon-caprolactone) (PEO-PCL) nanoparticles.

Experimental Design: In vitro cytotoxicity and proapoptotic activity of paclitaxel and tamoxifen, either as single agent or in combination, was examined in wild-type (SKOV3) and MDR-1–positive (SKOV3TR) human ovarian adenocarcinoma cells. Subcutaneous SKOV3 and SKOV3TR xenografts were established in female nu/nu mice, and this model was used to evaluate the antitumor efficacy and preliminary safety. Paclitaxel (20 mg/kg) and tamoxifen (70 mg/kg) were administered i.v. either as a single agent or in combination in aqueous solution and in PEO-PCL nanoparticles.

Results: In vitro cytotoxicity results showed that administration of paclitaxel and tamoxifen in combination lowered the IC50 of paclitaxel by 10-fold in SKOV3 cells and by >3-fold in SKOV3TR cells. The combination paclitaxel/tamoxifen co-therapy showed even more pronounced effect when administered in nanoparticle formulations. Upon i.v. administration of paclitaxel/tamoxifen combination in PEO-PCL nanoparticle formulations, significant enhancement in antitumor efficacy was observed. Furthermore, the combination paclitaxel/tamoxifen therapy did not induce any acute toxicity as measured by body weight changes, blood cell counts, and hepatotoxicity.

Conclusions: The results of this study show that combination of paclitaxel and tamoxifen in biodegradable PEO-PCL nanoparticles can serve as an effective clinically translatable strategy to overcome multidrug resistance in ovarian cancer.
Pretreatment with Cisplatin Enhances E7-Specific CD8+ T-Cell–Mediated Antitumor Immunity Induced by DNA Vaccination
Authors: Tseng Chih-Wen , Hung Chien-Fu , Alvarez Ronald D. , Trimble Cornelia , Huh Warner K. , Kim Daejin , Chuang Chi-Mu , Lin Cheng-Tao , Tsai Ya-Chea , He Liangmei , Monie Archana , Wu T-C.
Published: May 2008

Purpose: Because the combination of multiple modalities for cancer treatment is more likely to generate more potent therapeutic effects for the control of cancer, we have explored the combination of chemotherapy using cisplatin, which is routinely used in chemotherapy for advanced cervical cancer, with immunotherapy using DNA vaccines encoding calreticulin (CRT) linked to human papillomavirus type 16 E7 antigen (CRT/E7) in a preclinical model.

Experimental Design: We characterized the combination of cisplatin with CRT/E7 DNA vaccine using different regimen for its potential ability to generate E7-specific CD8+ T-cell immune responses as well as antitumor effects against E7-expressing tumors.

Results: Our results indicate that treatment of tumor-bearing mice with chemoimmunotherapy combining cisplatin followed by CRT/E7 DNA generated the highest E7-specific CD8+ T-cell immune response and produced the greatest antitumor effects and long-term survival as well as significant levels of E7-specific tumor-infiltrating lymphocytes compared with all the other treatment regimens. Furthermore, we found that treatment with cisplatin leads to the cell-mediated lysis of E7-expressing tumor cells in vitro and increased number of E7-specific CD8+ T-cell precursors in tumor-bearing mice. In addition, we observed that E7-specific CD8+ T cells migrate to and proliferate in the location of TC-1 tumors in mice treated with cisplatin.

Conclusions: Thus, our data suggest that chemoimmunotherapy using cisplatin followed by CRT/E7 DNA vaccine is an effective treatment against E7-expressing tumors and may potentially be translated into the clinical arena.
Pilot Study of Vaccination with Recombinant CEA-MUC-1-TRICOM Poxviral-Based Vaccines in Patients with Metastatic Carcinoma
Authors: Gulley James L. , Arlen Philip M. , Tsang Kwong-Yok , Yokokawa Junko , Palena Claudia , Poole Diane J. , Remondo Cinzia , Cereda Vittore , Jones Jacquin L. , Pazdur Mary P. , Higgins Jack P. , Hodge James W. , Steinberg Seth M. , Kotz Herbert , Dahut William L. , Schlom Jeffrey
Published: May 2008

Purpose: Poxviral vectors have a proven safety record and can be used to incorporate multiple transgenes. Prior clinical trials with poxviral vaccines have shown that immunologic tolerance to self-antigens can be broken. Carcinoembryonic antigen (CEA) and MUC-1 are overexpressed in a substantial proportion of common solid carcinomas. The primary end point of this study was vaccine safety, with immunologic and clinical responses as secondary end points.

Experimental Design: We report here a pilot study of 25 patients treated with a poxviral vaccine regimen consisting of the genes for CEA and MUC-1, along with a triad of costimulatory molecules (TRICOM; composed of B7.1, intercellular adhesion molecule 1, and lymphocyte function–associated antigen 3) engineered into vaccinia (PANVAC-V) as a prime vaccination and into fowlpox (PANVAC-F) as a booster vaccination.

Results: The vaccine was well tolerated. Apart from injection-site reaction, no grade ≥2 toxicity was seen in more than 2% of the cycles. Immune responses to MUC-1 and/or CEA were seen following vaccination in 9 of 16 patients tested. A patient with clear cell ovarian cancer and symptomatic ascites had a durable (18-month) clinical response radiographically and biochemically, and one breast cancer patient had a confirmed decrease of >20% in the size of large liver metastasis.

Conclusions: This vaccine strategy seems to be safe, is associated with both CD8 and CD4 immune responses, and has shown evidence of clinical activity. Further trials with this agent, either alone or in combination with immunopotentiating and other therapeutic agents, are warranted.
Inhibition of DNA binding of the NF-Y transcription factor by the pyrrolobenzodiazepine-polyamide conjugate GWL-78
Authors: Kotecha Minal , Kluza Jerome , Wells Geoff , O'Hare C. Caroline , Forni Claudia , Mantovani Roberto , Howard Philip W. , Morris Peter , Thurston David E. , Hartley John A. , Hochhauser Daniel
Published: May 2008

Many genes involved in cell cycle control have promoters that bind the heterotrimeric transcription factor NF-Y. Several minor-groove binding drugs have been shown to block interactions of transcription factors with cognate DNA-binding sequences. We showed previously that noncovalent minor-groove binding agents block interactions of NF-Y with the promoter of topoisomerase IIα (topo IIα). In this study, we investigated the ability of GWL-78, a pyrrolobenzodiazepine-poly(N-methylpyrrole) conjugate, to inhibit the binding of NF-Y to DNA. Electrophoretic mobility shift assays showed that GWL-78 could displace NF-Y bound to several CCAAT motifs within promoters of genes involved in cell cycle progression. DNase I footprinting of the topo IIα promoter confirmed binding of GWL-78 to AT-rich sequences corresponding to the preferred binding site of NF-Y. Incubation with GWL-78 resulted in displacement of NF-Y binding to DNA. Chromatin immunoprecipitation assays on the topo IIα promoter showed that GWL-78 was able to enter the nucleus and interact with specific DNA sequences. Treatment of NIH3T3 cells with GWL-78 resulted in a block of cell cycle progression, which did not involve activation of p53. Thus, agents such as GWL-78 may be useful in modulating transcription and blocking cellular proliferation. [Mol Cancer Ther 2008;7(5):1319–28]
Reprogramming epigenetic silencing: artificial transcription factors synergize with chromatin remodeling drugs to reactivate the tumor suppressor mammary serine protease inhibitor
Authors: Beltran Adriana S. , Sun Xueguang , Lizardi Paul M. , Blancafort Pilar
Published: May 2008

Mammary serine protease inhibitor (maspin) is an important tumor suppressor gene whose expression is associated not only with tumor growth inhibition but also with decreased angiogenesis and metastasis. Maspin expression is down-regulated in metastatic tumors by epigenetic mechanisms, including aberrant promoter hypermethylation. We have constructed artificial transcription factors (ATFs) as novel therapeutic effectors able to bind 18-bp sites in the maspin promoter and reactivate maspin expression in cell lines that harbor an epigenetically silenced promoter. In this article, we have investigated the influence of epigenetic modifications on ATF-mediated regulation of maspin by challenging MDA-MB-231 breast cancer cells, comprising a methylated maspin promoter, with different doses of ATFs and chromatin remodeling drugs: the methyltransferase inhibitor 5-aza-2′-deoxycytidine and the histone deacetylase inhibitor suberoylanilide hydroxamic acid. We found that the ATFs synergized with both inhibitors in reactivating endogenous maspin expression. The strongest synergy was observed with the triple treatment ATF-126 + 5-aza-2′-deoxycytidine + suberoylanilide hydroxamic acid, in which the tumor suppressor was reactivated by 600-fold. Furthermore, this combination inhibited tumor cell proliferation by 95%. Our data suggest that ATFs enhance the efficiency of chromatin remodeling drugs in reactivating silenced tumor suppressors. Our results document the power of a novel therapeutic approach that combines both epigenetic and genetic (sequence-specific ATFs) strategies to reactivate specifically silenced regions of the genome and reprogram cellular phenotypes. [Mol Cancer Ther 2008;7(5):1080–90]
Integrin-targeted imaging and therapy with RGD4C-TNF fusion protein
Authors: Wang Hui , Chen Kai , Cai Weibo , Li Zibo , He Lina , Kashefi Amir , Chen Xiaoyuan
Published: May 2008

This study used integrin αvβ3 as a target for tumor-specific delivery of tumor necrosis factor-α (TNF). The fusion protein RGD4C-TNF bound specifically to αvβ3 as evidenced by cell receptor binding assay and noninvasive micro-positron emission tomography imaging. 64Cu-DOTA-RGD4C-TNF had significantly higher activity accumulation in integrin-positive tumors (U87MG and MDA-MB-435) but not in integrin-negative tumors (C6) compared with 64Cu-DOTA-TNF. The magnitude of tumor uptake of 64Cu-DOTA-RGD4C-TNF correlated well with the αvβ3 level (U87MG > MDA-MB-435 > C6). Tumor accumulation of 64Cu-DOTA-RGD4C-TNF could be effectively blocked by c(RGDyK) peptide in αvβ3-positive tumor models, suggesting αvβ3 specificity of RGD4C-TNF fusion protein in vivo. Furthermore, although the fusion of RGD4C moiety to TNF had little effect on the bioactivity and cytotoxicity of RGD4C-TNF compared with TNF in cell culture, RGD4C-TNF was significantly more potent than TNF in inhibiting orthotopic MDA-MB-435 tumor growth. Ex vivo tissue staining confirmed specific cytotoxicity of RGD4C-TNF against integrin-positive tumor cells and tumor vasculature. [Mol Cancer Ther 2008;7(5):1044–53]
p27Kip1 expression inhibits glioblastoma growth, invasion, and tumor-induced neoangiogenesis
Authors: Schiappacassi Monica , Lovat Francesca , Canzonieri Vincenzo , Belletti Barbara , Berton Stefania , Di Stefano Domenica , Vecchione Andrea , Colombatti Alfonso , Baldassarre Gustavo
Published: May 2008

The tumor suppressor gene CDKN1B encodes for a 27-kDa cyclin-dependent kinase inhibitory protein, p27Kip1, which together with its well-established role in the inhibition of cell proliferation, displays additional activities in the control of gene transcription and cell motility. p27Kip1 thus represents a good candidate for a gene therapy approach, especially in those cancers refractory to the conventional therapies, like human glioblastoma. Here, we show that overexpression of p27Kip1 in glioblastoma cell lines induced cell cycle arrest and inhibition of cell motility through extracellular matrix substrates. The use of adenoviral vectors in the treatment of glioblastoma in vivo showed that p27Kip1 was able to block not only cancer cell growth but also local invasion and tumor-induced neoangiogenesis. The latter effect was due to the ability of p27 to impair both endothelial cell growth and motility, thus preventing proper vessel formation in the tumor. The block of neoangiogenesis depended on cytoplasmic p27Kip1 antimigratory activity and was linked to its ability to bind to and inhibit the microtubule-destabilizing protein stathmin. Our work provides the first evidence that a successful p27Kip1-based gene therapy is linked to tumor microenvironment modification, thus opening new perspectives to the use of gene therapy approaches for the treatment of refractory cancers. [Mol Cancer Ther 2008;7(5):1164–75]
An experimental and theoretical evaluation of the influence of pretargeting antibody on the tumor accumulation of effector
Authors: Liu Guozheng , Dou Shuping , Rusckowski Mary , Hnatowich Donald J.
Published: May 2008

In treating tumors by pretargeting, the antitumor antibody and the cytotoxic effector (e.g., toxins and radioactivity) are separately administered. Therefore, pretargeting is more complicated with many variables. We are conducting studies to understand the influence of each variable using a novel recognition pair of mutually complementary phosphorodiamidate morpholino oligomers (MORF/cMORF). Earlier we developed a semi-empirical model capable of accurately predicting the behavior of a radiolabeled cMORF effector with variations in dosages and timing. We have now extended the model to predict the effector behavior, in particular, its maximum percent tumor accumulation (MPTA) in mice pretargeted with three different MORF-conjugated antibodies (MN14, B72.3, and CC49). The MN14 and the CC49 target different antigens in the same tumor, whereas the CC49 and the B72.3 target the same antigen but with very different tumor accumulation. By comparing the pretargeting results of these three antibodies with our prediction, we confirmed that the MPTA of the radiolabeled cMORF effector in the LS174T tumor is independent of the antibodies. In conclusion, the MPTA cannot be improved through the use of different pretargeting antibodies, although different antibodies may improve the maximum absolute tumor accumulation, the heterogeneity, and/or the tumor-to-normal tissue ratios of the effector. This conclusion will apply equally well to effectors carrying a fluorescent probe, an anticancer agent, or a radioactive imaging agent. [Mol Cancer Ther 2008;7(5):1025–32]
Ethnic disparities in Americans of European descent versus Americans of African descent related to polymorphic ERCC1, ERCC2, XRCC1, and PARP1
Authors: Gao Rui , Price Douglas K. , Sissung Tristan , Reed Eddie , Figg William D.
Published: May 2008

Nucleotide excision repair (NER) and base excision repair (BER) pathways are DNA repair pathways that are important in carcinogenesis and in response to DNA-damaging chemotherapy. ERCC1 and ERCC2 are important molecular markers for NER; XRCC1 and PARP1 are important molecular markers for BER. Functional polymorphisms have been described that are associated with altered expression levels of these genes and with altered DNA repair capability. We assayed genomic DNA from 156 Americans of European descent and 164 Americans of African descent for the allelic frequencies of specific polymorphisms of ERCC1 N118N (500C>T), ERCC1 C8092A, ERCC2 K751Q (2282A>C), XRCC1 R399Q (1301G>A), XRCC1 R194W (685C>T), and PARP1 V762A (2446T>C). Differences were observed between Americans of European descent and Americans of African descent in the allelic frequencies of the ERCC1 N118N polymorphism (P < 0.000001). Differences were also observed between these two ethnic groups for ERCC2 K751Q (P = < 0.006675), XRCC1 R399Q (P < 0.000001), and PARP1 V762A (P = 0.000001). The ERCC1 N118N polymorphic variant that is seen most commonly in Americans of European descent is associated with a measurable reduction in NER function. ERCC1-mediated reduction in NER functionality affects the repair of cisplatin-DNA lesions. [Mol Cancer Ther 2008;7(5):1246–50]
LS104, a non-ATP-competitive small-molecule inhibitor of JAK2, is potently inducing apoptosis in JAK2V617F-positive cells
Authors: Lipka Daniel B. , Hoffmann Linda S. , Heidel Florian , Markova Boyka , Blum Marie-Christine , Breitenbuecher Frank , Kasper Stefan , Kindler Thomas , Levine Ross L. , Huber Christoph , Fischer Thomas
Published: May 2008

The activating JAK2V617F mutation has been described in the majority of patients with BCR-ABL-negative myeloproliferative disorders (MPD). In this report, we characterize the small-molecule LS104 as a novel non-ATP-competitive JAK2 inhibitor: Treatment of JAK2V617F-positive cells with LS104 resulted in dose-dependent induction of apoptosis and inhibition of JAK2 autophosphorylation and of downstream targets. Activation of these targets by JAK2 was confirmed in experiments using small interfering RNA. LS104 inhibited JAK2 kinase activity in vitro. This effect was not reversible using elevated ATP concentrations, whereas variation of the kinase substrate peptide led to modulation of the IC50 value for LS104. In line with these data, combination treatment using LS104 plus an ATP-competitive JAK2 inhibitor (JAK inhibitor I) led to synergistically increased apoptosis in JAK2V617F-positive cells. Furthermore, LS104 strongly inhibited cytokine-independent growth of endogenous erythroid colonies isolated from patients with JAK2V617F-positive MPD in vitro, whereas there was no significant effect on growth of myeloid colonies obtained from normal controls. Based on these data, we have recently started a phase I clinical trial of LS104 for patients with JAK2V617F-positive MPDs. To the best of our knowledge, this is the first report on a non-ATP-competitive kinase inhibitor being tested in a clinical trial. [Mol Cancer Ther 2008;7(5):1176–84]
Comparison of antitumor effects of multitargeted tyrosine kinase inhibitors in acute myelogenous leukemia
Authors: Hu Shuiying , Niu Hongmei , Minkin Patton , Orwick Shelley , Shimada Akira , Inaba Hiroto , Dahl Gary V.H. , Rubnitz Jeffrey , Baker Sharyn D.
Published: May 2008

We compared the antitumor activities of the multitargeted tyrosine kinase inhibitors imatinib, sorafenib, and sunitinib to determine which inhibitor is best suited to be used for the treatment of acute myelogenous leukemia (AML). In nine human AML cell lines, sorafenib and sunitinib were more potent inhibitors of cellular proliferation than imatinib (IC50, 0.27 to >40, 0.002-9.1, and 0.007-13 μmol/L for imatinib, sorafenib, and sunitinib, respectively). Sorafenib and sunitinib were potent inhibitors of cells with fms-like tyrosine kinase 3 internal tandem duplication (IC50, 2 and 7 nmol/L) and c-KIT N822K mutations (IC50, 23 and 40 nmol/L). In four cell lines (MV4-11, Kasumi-1, KG-1, and U937) that spanned a range of drug sensitivities, sorafenib and sunitinib had similar activity in apoptosis and cell cycle assays, except that sunitinib did not promote apoptosis in U937 cells. Both drugs inhibited mitogen-activated protein kinase signaling but had no effect on AKT signaling in most of the cell lines tested. Sorafenib was substantially more bound than sunitinib in human plasma (unbound fraction, 0.59% versus 8.4%) and cell culture medium (unbound fraction, 1.3% versus 39%), indicating that sorafenib was more potent than sunitinib and that unbound sorafenib concentrations with activity against most AML cell lines are achievable in vivo. There was more intracellular accumulation of sorafenib than of sunitinib and imatinib in AML cells. Between 1 and 10 μmol/L, sorafenib inhibited the proliferation of six of nine primary AML blast samples by ≥50%. Our results highlight the pharmacologic features of sorafenib that may provide it an advantage in the treatment of AML. [Mol Cancer Ther 2008;7(5):1110–20]