bluuebunny/crossref_metadata_2025 huggingface dataset:
Profiling Cytochrome P450 Expression in Ovarian Cancer: Identification of Prognostic Markers
Authors: Downie Diane , McFadyen Morag C.E. , Rooney Patrick H. , Cruickshank Margaret E. , Parkin David E. , Miller Iain D. , Telfer Colin , Melvin William T. , Murray Graeme I.
Published: March 2006

Purpose: The cytochromes P450 are a multigene family of enzymes with a central role in the oxidative metabolism of a wide range of xenobiotics, including anticancer drugs and biologically active endogenous compounds. The purpose of this study was to define the cytochrome P450 profile of ovarian cancer and identify novel therapeutic targets and establish the prognostic significance of expression of individual cytochrome P450s in this type of cancer.

Experimental Design: Immunohistochemistry for a panel of 23 cytochrome P450s and cytochrome P450 reductase was done on an ovarian cancer tissue microarray consisting of 99 primary epithelial ovarian cancers, 22 peritoneal metastasis, and 13 normal ovarian samples. The intensity of immunoreactivity in each sample was established by light microscopy.

Results: In primary ovarian cancer, several P450s (CYP1B1, CYP2A/2B, CYP2F1, CYP2R1, CYP2U1, CYP3A5, CYP3A7, CYP3A43, CYP4Z1, CYP26A1, and CYP51) were present at a significantly higher level of intensity compared with normal ovary. P450 expression was also detected in ovarian cancer metastasis and CYP2S1 and P450 reductase both showed significantly increased expression in metastasis compared with primary ovarian cancer. The presence of low/negative CYP2A/2B (log rank = 7.06, P = 0.008) or positive CYP4Z1 (log rank = 6.19, P = 0.01) immunoreactivity in primary ovarian cancer were each associated with poor prognosis. Both CYP2A/2B and CYP4Z1 were also independent markers of prognosis.

Conclusions: The expression profile of individual P450s has been established in ovarian cancer. Several P450s show increased expression in ovarian cancer and this provides the basis for developing P450-based therapeutics in ovarian cancer. Expression of CYP2A/2B or CYP4Z1 in primary ovarian cancer were independent markers of prognosis.
Serum Free Light Chain Analysis and Urine Immunofixation Electrophoresis in Patients with Multiple Myeloma
Authors: Nowrousian Mohammad R. , Brandhorst Dieter , Sammet Christiane , Kellert Michaela , Daniels Rainer , Schuett Philipp , Poser Miriam , Mueller Siemke , Ebeling Peter , Welt Anja , Bradwell Arthur R. , Buttkereit Ulrike , Opalka Bertram , Flasshove Michael , Moritz Thomas , Seeber Siegfried
Published: March 2006

Purpose: Retrospective studies have shown that immunoassays measuring free light chains (FLC) in serum are useful for diagnosis and monitoring of multiple myeloma. This study prospectively evaluates the use of FLC assays and, for the first time, investigates the relationship between serum FLC concentrations and the presence and detectability of Bence Jones (BJ) proteins in the urine.

Patients and Methods: Three hundred seventy-eight paired samples of serum and urine were tested from 82 patients during the course of their disease. The sensitivities of serum FLC analysis and urine immunofixation electrophoresis (IFE) in detecting monoclonal FLC were compared. Serum FLC concentrations required for producing BJ proteins detected by IFE were determined.

Results: Abnormal FLC were present in 54% of serum samples compared with 25% by urine tests. In abnormal serum samples for κ or λ, the sensitivity of IFE to detect the respective BJ proteins in urine were 51% and 35% and the median serum FLC concentrations required to produce detectable BJ proteins were 113 and 278 mg/L. Renal excretions of monoclonal FLC increased with serum concentrations, but excretions significantly decreased at high serum concentrations combined with renal dysfunction.

Conclusion: Serum FLC assays are significantly more sensitive for detecting monoclonal FLC than urine IFE analysis. They also have the advantage of FLC quantification and are more reliable for monitoring disease course and response to treatment.
Optimizing Photodynamic Therapy:In vivoPharmacokinetics of Liposomalmeta-(Tetrahydroxyphenyl)Chlorin in Feline Squamous Cell Carcinoma
Authors: Buchholz Julia , Kaser-Hotz Barbara , Khan Tania , Rohrer Bley Carla , Melzer Katja , Schwendener Reto A. , Roos Malgorzata , Walt Heinrich
Published: March 2006

Purpose: The aim of the present study was to optimize and simplify photodynamic therapy using a new liposomal formulation of the photosensitizer meta-(tetrahydroxyphenyl)chlorin [m-THPC (Foscan); liposomal m-THPC (Fospeg)] and to reduce systemic reactions to the photosensitizer.

Experimental Design: To examine the pharmacokinetics of liposomal m-THPC, we determined tissue and plasma variables in feline patients with spontaneous squamous cell carcinoma. In vivo fluorescence intensity measurements of tumor and skin were done with a fiber spectrophotometer after i.v. injection of m-THPC or liposomal m-THPC in 10 cats. Blood samples, drawn at several time points after photosensitizer administration, were analyzed by high-performance liquid chromatography.

Results: None of the liposomal m-THPC–treated cats showed side effects during or after drug injection. Fluorescence intensities, fluorescence ratios (tumor fluorescence divided by skin fluorescence), and bioavailability in the tumor were 2 to 4 times higher with liposomal m-THPC compared with m-THPC. Liposomal m-THPC concentration in the tumor increased constantly to reach a maximum at 4 hours after injection. Plasma concentration and bioavailability were ∼3 times higher with liposomal m-THPC compared with m-THPC measured at the time points of highest plasma concentration. The distribution half-life was shorter with liposomal m-THPC, resulting in maximal tumor accumulation up to 5.5 times earlier. Maximal tumor accumulation and maximal fluorescence ratio with liposomal m-THPC occurred at the same time point, indicating maximal selectivity. In both groups, all cats responded to therapy.

Conclusions: Liposomal m-THPC was well tolerated by all cats and seems to have superior pharmacokinetic properties compared with m-THPC. The efficacy of the drug warrants further study.
p53 Codon 72 Polymorphism Predicts the Pathologic Response to Neoadjuvant Chemotherapy in Patients with Breast Cancer
Authors: Xu Ye , Yao Lihua , Ouyang Tao , Li Jinfeng , Wang Tianfeng , Fan Zhaoqing , Lin Benyao , Lu Youyong , Xie Yuntao
Published: March 2006

Purpose: Recent studies have highlighted that the p53 codon 72 polymorphism plays a crucial role in modulating wild-type p53 apoptotic capacity, and as such may influence the response to chemotherapy. Thus, the purpose of this study was to investigate whether the p53 codon 72 polymorphism might influence pathologic response to neoadjuvant chemotherapy in primary breast cancer.

Experimental Design: One hundred and ten operable breast cancer patients received anthracycline-based neoadjuvant chemotherapy and p53 codon 72 polymorphism status was analyzed by PCR-RFLP.

Results: The distribution of initial clinical stage, tumor size, estrogen receptor or progesterone receptor status, menopausal status, or erbB2 expression was not significantly different among the polymorphic variants. However, we found that only 13% (3 of 23) of patients with the Pro/Pro variant had a good pathologic response, defined as a complete pathologic response or minimal residual disease. In comparison, 40% (22 of 55) or 37.5% (12 of 32) of patients with the Pro/Arg or Arg/Arg variant had a good pathologic response (P = 0.019). Moreover, patients with the Pro/Pro variant were more likely to have a positive axillary lymph node status than those with the Pro/Arg or Arg/Arg variant (P = 0.007). Furthermore, in multivariate analysis, p53 codon 72 polymorphism was found to be a strong predictor of pathologic response (odds ratio 6.7, 95% confidence interval, 1.4-31.2; P = 0.016).

Conclusion: Our study indicates that breast cancer patients with the Pro/Pro variant may be less sensitive to anthracycline-based treatment than those with the Pro/Arg or Arg/Arg variant and suggests that analysis of p53 codon 72 polymorphism may provide a simple predictive marker for selecting the right breast cancer patients to anthracycline-based neoadjuvant chemotherapy in clinical setting.
Effect of CommonCYP3A4andCYP3A5Variants on the Pharmacokinetics of the CytochromeP450 3A Phenotyping Probe Midazolam in Cancer Patients
Authors: Lepper Erin R. , Baker Sharyn D. , Permenter Matt , Ries Nicole , van Schaik Ron H.N. , Schenk Paul W. , Price Douglas K. , Ahn Danielle , Smith Nicola F. , Cusatis George , Ingersoll Roxann G. , Bates Susan E. , Mathijssen Ron H.J. , Verweij Jaap , Figg William D. , Sparreboom Alex
Published: March 2006

Purpose: To evaluate the effect of naturally occurring variants in genes encoding the cytochrome P450 (CYP) isoforms CYP3A4 and CYP3A5 in patients with cancer receiving midazolam as a phenotyping probe.

Experimental Design: Five variants in CYP3A4 and CYP3A5 were evaluated in 58 patients (21 women and 37 men) receiving a short i.v. bolus of midazolam (dose, 0.0145 or 0.025 mg/kg). Midazolam concentrations in plasma were determined using liquid chromatography-mass spectrometry, and pharmacokinetic variables were calculated using noncompartmental analysis. Genomic DNA was characterized for the variants by PCR-RFLP, and all genotypes were confirmed by direct nucleotide sequencing.

Results: The mean clearance of midazolam was 24.4 ± 9.12 L/h, and phenotypic CYP3A activity varied about 4-fold in this population (range, 10.8-44.3 L/h). There were six carriers of the CYP3A4*1B allele (allele frequency, 0.061). No variant alleles for CYP3A4*17, CYP3A4*18A, or CYP3A5*6 were identified. Forty-eight of the 58 patients were homozygous variant for CYP3A5*3C, eight were heterozygous, and two were homozygous wild type (allele frequency, 0.897). No associations were noted between any of the studied genotypes and the phenotypic measures (P ≥ 0.16). Likewise, a common variant in exon 26 in the gene encoding P-glycoprotein [i.e., ABCB1 (MDR1) 3435C>T] that was previously reported to be linked to CYP3A4 mRNA levels was unrelated to any of the studied phenotypic measures (P ≥ 0.49).

Conclusions. The studied genetic variants in CYP3A4 and CYP3A5 are unlikely to have an important functional significance to phenotypic CYP3A activity in patients with cancer.
The Phenotypic Plasticity of Myeloma Plasma Cells as Expressed by Dedifferentiation into an Immature, Resilient, and Apoptosis-Resistant Phenotype
Authors: Yaccoby Shmuel
Published: March 2006

Purpose: We previously showed the ability of osteoclasts to support myeloma plasma cell survival and proliferation in vivo and ex vivo. The aim of the current study was to investigate osteoclast-induced phenotypic changes associated with long-term survival of myeloma cells in coculture.

Experimental Design: CD138-selected myeloma plasma cells from 16 patients were cocultured with human osteoclasts for up to 20 weeks.

Results: Precultured cells were typically CD45low/intermediate CD38high CD138high, CD19−CD34−. After >6 weeks, the phenotype of cocultured myeloma cells consistently shifted to cells expressing CD45intermediate/high CD19low CD34low. Expression of CD38 and CD138 were reduced to subpopulations with CD38intermediate and CD138low levels. Morphologically, cocultured plasma cells became plasmablastic. Blocking interleukin-6 activity did not affect the immature phenotype of myeloma cells. The effect of dexamethasone on myeloma cells cultured alone or in cocultures at baseline and after 6 weeks of coculture was determined. When baseline myeloma cells were cultured alone, dexamethasone significantly increased the percentage of apoptotic cells over the spontaneous rate. Conversely, myeloma cells recovered from cocultures had high survival rates and were resistant to dexamethasone-induced apoptosis. Long-term coculture of normal CD34-expressing hematopoietic stem cells (HSC) resulted in loss of CD34 expression, suggesting a common mechanism for osteoclast-induced myeloma and HSC plasticity.

Conclusions: This study indicates that myeloma cells have plasticity expressed by their ability to reprogram, dedifferentiate, and acquire autonomous survival properties.
Differential Expression of CXCR4 Is Associated with the Metastatic Potential of Human Non–Small Cell Lung Cancer Cells
Authors: Su Liping , Zhang Jinping , Xu Huanbin , Wang Ying , Chu Yiwei , Liu Ruizi , Xiong Sidong
Published: March 2006

Purpose: To evaluate the relation between CXCR4 expression and the presence of metastatic disease in human non–small cell lung cancer (NSCLC) patients and investigate whether modulation of CXCR4 expression could serve as a potential pathway in preventing metastasis of NSCLC.

Experimental Design: CXCR4 expression in 36 patients with NSCLC and 10 normal lung tissues was detected by real-time PCR and immunohistochemistry. CXCR4 expression in two human NSCLC clones (95C and 95D) with different metastatic potential was determined by real-time PCR and flow cytometry. 95C and 95D cells were transfected with the plasmid DNA containing CXCR4 coding gene or CXCR4 antisense nucleotide fragment, respectively, and the effects on in vitro cell migration, invasion, and adhesion and in vivo metastasis were measured.

Results: Up-regulated expression of CXCR4 was detected in 34 tumors, which were further divided into 17 high expression cancers and 17 low expression cancers by their staining intensities. High CXCR4 tumors (13 of 17) were more prone to clinical metastasis in comparison with low expression tumors. CXCR4 was differentially expressed in 95C and 95D cells with low or high metastatic potential, and the surface expression of CXCR4 were 50% up-regulated or down-regulated following the stable transfection. The metastatic potential of NSCLC in vitro, such as migration, invasion, and adhesion, were significantly enhanced or impaired. In addition, neutralizing the interactions of stromal cell–derived factor-1/CXCR4 in vitro with CXCR4-specific antibodies inhibited the CXCR4-dependent migration, invasion, and adhesion. Furthermore, s.c. inoculation of lung cancer cells with low expression of CXCR4 in nude mice showed 0- to 2-fold decrease in lung metastatic foci than that with high expression of CXCR4.

Conclusions: Differential expression of CXCR4 is associated with the metastatic potential of human NSCLC, raising the possibility that blockade of CXCR4/stromal cell–derived factor-1 interaction may lead the way to design novel therapeutic tools for the treatment of metastatic NSCLC patients.
Gemcitabine Radiosensitization after High-Dose Samarium for Osteoblastic Osteosarcoma
Authors: Anderson Peter M. , Wiseman Gregory A. , Erlandson Linda , Rodriguez Vilmarie , Trotz Barbara , Dubansky Stephen A. , Albritton Karen
Published: March 2006

Osteoblastic metastases and osteosarcoma can avidly concentrate bone-seeking radiopharmaceuticals. We sought to increase effectiveness of high-dose 153Samarium ethylenediaminetetramethylenephosphonate (153Sm-EDTMP, Quadramet) on osteosarcomas using a radiosensitizer, gemcitabine. Fourteen patients with osteoblastic lesions were treated with 30 mCi/kg 153Sm-EDTMP. Gemcitabine was administered 1 day after samarium infusion. Residual total body radioactivity was within the safe range of <3.6 mCi on day +14 (1.1 ± 0.4 mCi; range, 0.67-1.8 mCi). All patients received autologous stem cell reinfusion 2 weeks after 153Sm to correct expected grade 4 hematopoietic toxicity. Peripheral blood progenitor cells were infused in 11 patients; three patients had marrow infused. Blood count recovery was uneventful after peripheral blood progenitor cells in 11 of 11 patients. Toxicity from a single infusion of gemcitabine (1,500 mg/m2) in combination with 153Sm-EDTMP was minimal (pancytopenia). However, toxicity from a daily gemcitabine regimen (250 mg/m2/d × 4-5 days) was excessive (grade 3 mucositis) in one of two patients. There were no reported episodes of hemorrhagic cystitis (hematuria) or nephrotoxicity. At the 6- to 8-week follow-up, there were six partial remissions, two mixed responses, and six patients with progressive disease. In the 12 patients followed >1 year, there have been no durable responses. Thus, although high-dose 153Sm-EDTMP + gemcitabine has moderate palliative activity (improved pain; radiologic responses) in this poor-risk population, additional measures of local and systemic control are required for durable control of relapsed osteosarcoma with osteoblastic lesions. The strategy of radioactive drug binding to a target followed by a radiosensitizer may provide synergy and improved response rate.
Overexpression of the Cytokine Osteopontin Identifies Aggressive Laryngeal Squamous Cell Carcinomas and Enhances Carcinoma Cell Proliferation and Invasiveness
Authors: Celetti Angela , Testa Domenico , Staibano Stefania , Merolla Francesco , Guarino Valentina , Castellone Maria Domenica , Iovine Renata , Mansueto Gelsomina , Somma Pasquale , De Rosa Gaetano , Galli Vieri , Melillo Rosa Marina , Santoro Massimo
Published: March 2006

Purpose: Osteopontin is a secreted cytokine that binds to the cell surface CD44v6 receptor. We studied osteopontin and CD44v6 expression in laryngeal squamous cell carcinomas and correlated osteopontin expression levels with clinicopathologic tumor features.

Experimental Design: We used immunohistochemistry, immunoblotting, and reverse transcription-PCR to study osteopontin expression in 58 laryngeal squamous cell carcinomas. Cultured squamous carcinoma cells were treated with exogenous osteopontin or with RNA interference to knockdown osteopontin expression.

Results: Osteopontin expression was higher in all the invasive carcinomas than in patient-matched normal mucosa. Its expression levels were significantly correlated with tumor stage and grade and with the presence of lymph node and distant metastases. Osteopontin positivity was negatively correlated with overall survival (P = 0.03). Osteopontin expression was paralleled by intense cell surface reactivity for CD44v6. Treatment of squamous carcinoma cells with recombinant osteopontin sharply increased proliferation and Matrigel invasion in comparison with the untreated cells parallel to activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase kinase/mitogen-activated protein kinase signaling cascade. Osteopontin knockdown by RNA interference, anti-CD44 antibodies, and mitogen-activated protein kinase/extracellular signal-regulated kinase kinase inhibition prevented these effects.

Conclusions: These results identify osteopontin as a marker and a potential therapeutic target in cases of aggressive laryngeal squamous cell carcinomas.
Possible Prediction of Chemoradiosensitivity of Esophageal Cancer by Serum Protein Profiling
Authors: Hayashida Yasuharu , Honda Kazufumi , Osaka Yoshiaki , Hara Tomohiko , Umaki Tomoko , Tsuchida Akihiko , Aoki Tatsuya , Hirohashi Setsuo , Yamada Tesshi
Published: March 2006

Purpose: Establishment of a reliable method of predicting the efficacy of chemotherapy and radiotherapy is necessary to provide the most suitable treatment for each cancer patient. We investigated whether proteomic profiles of serum samples obtained from untreated patients were capable of being used to predict the efficacy of combined preoperative chemoradiotherapy against esophageal cancer.

Experimental Design: Proteomic spectra were obtained from a training set of 27 serum samples (15 pathologically diagnosed responders to preoperative chemoradiotherapy and 12 nonresponders) by surface-enhanced laser desorption and ionization coupled with hybrid quadrupole time-of-flight mass spectrometry. A proteomic pattern prediction model was constructed from the training set by machine learning algorithms, and it was then tested with an independent validation set consisting of serum samples from 15 esophageal cancer patients in a blinded manner.

Results: We selected a set of four mass peaks, at 7,420, 9,112, 17,123, and 12,867 m/z, from a total of 859 protein peaks, as perfectly distinguishing responders from nonresponders in the training set with a support vector machine algorithm. This set of peaks (i.e., the classifier) correctly diagnosed chemoradiosensitivity in 93.3% (14 of 15) of the cases in the validation set.

Conclusions: Recent mass spectrometric approaches have revealed that serum contains a large volume of information that reflects the microenvironment of diseased organs. Although a multi-institutional large-scale study will be necessary to confirm each component of the classifier, there is a subtle but definite difference in serum proteomic profile between responders and nonresponders to chemoradiotherapy.
Transcription RepressorSlugPromotes Carcinoma Invasion and Predicts Outcome of Patients with Lung Adenocarcinoma
Authors: Shih Jin-Yuan , Tsai Meng-Feng , Chang Tzu-Hua , Chang Yih-Leong , Yuan Ang , Yu Chong-Jen , Lin Shin-Bey , Liou Geou-Yarh , Lee Meng-Larn , Chen Jeremy J.W. , Hong Tse-Ming , Yang Shuenn-Chen , Su Jen-Liang , Lee Yung-Chie , Yang Pan-Chyr
Published: March 2006

Purpose: In a previous genome-wide gene expression profiling analysis using an invasion cancer cell lines model, we have identified Slug as selectively overexpressed in the highly invasive cancer cells. Here, we investigated the clinical significance of Slug in lung adenocarcinoma and the role of Slug in the process of cancer cell invasion and metastasis.

Experimental Design: Real-time quantitative reverse transcription-PCR was used to investigate Slug mRNA in surgically resected lung adenocarcinoma of 54 patients and its correlation with survival. We overexpressed Slug in a lung adenocarcinoma cell line with very low Slug levels and investigated the in vitro and in vivo effects of Slug expression.

Results: High expression of Slug mRNA in lung cancer tissue was significantly associated with postoperative relapse (P = 0.03) and shorter patient survival (P < 0.001). The overexpression of Slug enhanced xenograft tumor growth and increased microvessel counts in angiogenesis assay. Both inducible and constitutive overexpression of Slug suppressed the expression of E-cadherin and increased the in vitro invasive ability. Zymography revealed increased matrix metalloproteinase-2 activity in Slug overexpressed cells. ELISA, reverse transcription-PCR, and immunohistochemistry confirmed the increase of matrix metalloproteinase-2 proteins and mRNA in Slug overexpressed cells and xenograft tumors.

Conclusions: Slug expression can predict the clinical outcome of lung adenocarcinoma patients. Slug is a novel invasion-promoting gene in lung adenocarcinoma.
Phase I and Pharmacologic Study of PKI166, an Epidermal Growth Factor Receptor Tyrosine Kinase Inhibitor, in Patients with Advanced Solid Malignancies
Authors: Hoekstra Ronald , Dumez Herlinde , Eskens Ferry A.L.M. , van der Gaast Ate , Planting Andre S.T. , de Heus Gerda , Sizer Kurt C. , Ravera Christina , Vaidyanathan Sujata , Bucana Corazon , Fidler Isaiah J. , van Oosterom Allan T. , Verweij Jaap
Published: March 2006

Purpose: This phase I study was conducted to assess the tolerability, pharmacokinetics, and antitumor activity of the oral, selective epidermal growth factor receptor tyrosine kinase inhibitor PKI166 in patients with advanced solid malignancies.

Experimental Design: PKI166 was first given once daily continuously and in the second part of the study once daily for 2 weeks every 4 weeks to establish the maximum tolerated dose (MTD). Ten additional patients were studied at MTD to acquire additional safety information and characterize the effect of food intake on PKI166 pharmacokinetics. Pharmacokinetics of PKI166 were characterized after single and multiple doses at all dose levels.

Results: Fifty-four patients received a total of one hundred sixteen 28-day cycles of PKI166. Dose-limiting transaminase elevations were observed in two of seven and two of eight patients using 50 and 100 mg PKI166 continuously. In the second part with PKI166 once daily for 2 weeks every 4 weeks, MTD was set at 750 mg. Dose-limiting toxicity consisted of diarrhea, skin rash, and transaminase elevations. Pharmacokinetic analysis revealed fast absorption, a linear dose-response relationship without drug accumulation after multiple doses. At MTD, no significant influence of food intake on PKI166 pharmacokinetics was observed. Stable disease for more than two cycles was observed in 11 patients.

Conclusions: PKI166 given once daily for 2 weeks every 4 weeks is well tolerated with linear pharmacokinetics, compatible with once daily dosing, and without significant effect of food intake on absorption. The recommended dose for further studies is 750 mg once daily for 2 weeks every 4 weeks.
Estrogen Receptor α–Negative Breast Cancer Tissues Express Significant Levels of Estrogen-Independent Transcription Factors, ERβ1 and ERβ5: Potential Molecular Targets for Chemoprevention
Authors: Poola Indira , Fuqua Suzanne A.W. , De Witty Robert L. , Abraham Jessy , Marshallack Josephine J. , Liu Aiyi
Published: March 2006

We have investigated the expression of two estrogen receptor β (ERβ) isoforms, ERβ1 and ERβ5, which activate gene transcription independent of estrogen or growth factors, in ERα-negative breast cancer tissues. We report here, for the first time, that ERα-negative tissues express significant levels of ERβ1 and ERβ5, and their expression levels are not different from levels in ERα positive tumors. However, significant differences exist between the two racial groups, African American and Caucasian, in that the patients from the former group express higher levels of ERβ1 and ERβ5 but not ERα. These two transcription factors could be potential molecular targets for designing chemopreventive drugs to treat ERα-negative breast cancers.
In vivo Evaluation of Ixabepilone (BMS247550), A Novel Epothilone B Derivative, against Pediatric Cancer Models
Authors: Peterson Jennifer K. , Tucker Chandra , Favours Edward , Cheshire Pamela J. , Creech Jeremy , Billups Catherine A. , Smykla Richard , Lee Francis Y.F. , Houghton Peter J.
Published: March 2006

Purpose: Vinca alkaloids, agents that cause depolymerization of microtubules, are highly active in treatment of many pediatric cancers. In contrast, taxanes, agents that stabilize microtubules, are far less effective against the same cancer types. The purpose of the current study was to evaluate the antitumor activity of ixabepilone, an epothilone B derivative representing a new class of microtubule-stabilizing antimitotic agent in a wide variety of pediatric solid tumor models.

Experimental Design: Ixabepilone was administered i.v. every 4 days for three doses to scid mice bearing s.c. human rhabdomyosarcoma (three lines), neuroblastoma (four), Wilms' tumors (six), osteosarcoma (four), or brain tumors (seven). Tumor diameters were measured weekly, and tumor growth or regressions were determined. Pharmacokinetic studies were done following a single administration of drug at the maximum tolerated dose (MTD) level (10 mg/kg).

Results: At the MTD (10 mg/kg), ixabepilone induced objective responses (all tumors in a group achieved ≥50% volume regression) in three of three rhabdomyosarcoma lines, three of five neuroblastomas, six of seven Wilms' tumor models, two of six osteosarcoma, and four of eight brain tumor models. However, the dose-response curve was steep with only 2 of 19 tumors models regressing (≥50%) at 4.4 mg/kg. In comparison, paclitaxel administered at the MTD on the same schedule failed to induce objective regressions of three tumor lines that were highly sensitive to treatment with ixabepilone. Pharmacokinetics following single i.v. administration of ixabepilone at its MTD (10 mg/kg) were biexponential with Cmax of 12.5 μmol/L, elimination half-life of 19.2 hours, and total area under the curve of 5.8 μmol/L-h. The achieved drug exposure of ixabepilone at this efficacious MTD dose level in mice is similar to those achieved in patients given the recommended phase II dose of 40 mg/m2 by either 1- or 3-hour infusion every 3 weeks, a regimen that has shown significant anticancer activity in phase II clinical trials in adult patients.

Conclusions: Administered at doses ranging from 66% to 100% of its MTD in mice, the epothilone B derivative ixabepilone shows broad spectrum activity against a panel of pediatric tumor xenograft models. Pharmacokinetic analysis indicates that the systemic ixabepilone exposure achieved in mice at its MTD is similar to that achieved in patients at the recommended phase II dose of 40 mg/m2 administered every 3 weeks. Importantly, the present results showed a clear distinction in sensitivity of pediatric solid tumors to this epothilone derivative compared with paclitaxel.
Motexafin-Gadolinium Taken UpIn vitroby at Least 90% of Glioblastoma Cell Nuclei
Authors: De Stasio Gelsomina , Rajesh Deepika , Ford Judith M. , Daniels Matthew J. , Erhardt Robert J. , Frazer Bradley H. , Tyliszczak Tolek , Gilles Mary K. , Conhaim Robert L. , Howard Steven P. , Fowler John F. , Estève François , Mehta Minesh P.
Published: March 2006

Purpose: We present preclinical data showing the in vitro intranuclear uptake of motexafin gadolinium by glioblastoma multiforme cells, which could serve as a prelude to the future development of radiosensitizing techniques, such as gadolinium synchrotron stereotactic radiotherapy (GdSSR), a new putative treatment for glioblastoma multiforme.

Experimental Design: In this approach, administration of a tumor-seeking Gd-containing compound would be followed by stereotactic external beam radiotherapy with 51-keV photons from a synchrotron source. At least two criteria must be satisfied before this therapy can be established: Gd must accumulate in cancer cells and spare the normal tissue; Gd must be present in almost all the cancer cell nuclei. We address the in vitro intranuclear uptake of motexafin gadolinium in this article. We analyzed the Gd distribution with subcellular resolution in four human glioblastoma cell lines, using three independent methods: two novel synchrotron spectromicroscopic techniques and one confocal microscopy. We present in vitro evidence that the majority of the cell nuclei take up motexafin gadolinium, a drug that is known to selectively reach glioblastoma multiforme.

Results: With all three methods, we found Gd in at least 90% of the cell nuclei. The results are highly reproducible across different cell lines. The present data provide evidence for further studies, with the goal of developing GdSSR, a process that will require further in vivo animal and future clinical studies.
Herceptin Sensitizes ErbB2–Overexpressing Cells to Apoptosis by Reducing Antiapoptotic Mcl-1 Expression
Authors: Henson Elizabeth S. , Hu Xiaojie , Gibson Spencer B.
Published: March 2006

Purpose: Monoclonal antibodies, such as herceptin and trastuzumab, against the epidermal growth factor receptor ErbB2 (also known as HER2/neu) are an effective therapy for breast cancer patients with overexpression of ErbB2. Herceptin, in combination with standard chemotherapy, such as taxol or etoposide, gives a synergistically apoptotic response in breast tumors.

Experimental Design: The mechanism underlying this synergy between chemotherapy and herceptin treatment is not well understood. Herein, we have determined that addition of herceptin, sensitized breast cancer cell lines MDA-MB-231 and MCF-7 to etoposide- or taxol-induced apoptosis.

Results: This treatment resulted in reduced expression of ErbB2 and the antiapoptotic Bcl-2 family member Mcl-1 in MDA-MB-231 cells. Using antisense oligonucleotides against Mcl-1, MDA-MB-231 cells were rendered sensitive to etoposide-induced apoptosis similar to herceptin, but combined treatment of antisense against Mcl-1 and herceptin failed to give a significant increase in apoptosis. In 29 human breast tumors immunostained for ErbB2 and Mcl-1, we found that when ErbB2 was overexpressed, there was a corresponding increase in Mcl-1 expression.

Discussion: Using murine fibroblasts that express human ErbB2, but no other ErbB family member (NE2), these cells showed resistance to both taxol- and etoposide-induced apoptosis compared with parental cells. In addition, NE2 cells preferentially express the antiapoptotic Bcl-2 family member Mcl-1 compared with parental cells, and treatment with herceptin reduces Mcl-1 expression. Taken together, these results suggest that herceptin sensitizes ErbB2-overexpressing cells to apoptosis by reducing antiapoptotic Mcl-1 protein levels.
Molecular Pathogenesis of Ovarian Borderline Tumors: New Insights and Old Challenges
Authors: Shih Ie-Ming , Kurman Robert J.
Published: March 2006

Ovarian borderline (low malignant potential) tumors are a puzzling group of neoplasms that do not fall neatly into benign or malignant categories. Their behavior is enigmatic, their pathogenesis unclear, and their clinical management controversial, especially for serous borderline tumors (SBT), the most common type of ovarian borderline tumor. Clarifying the nature of borderline tumors and their relationship to invasive carcinoma has puzzled investigators since the category was created over 30 years ago. Much of the confusion and controversy concerning these tumors is due to a lack of understanding of their pathogenesis and an absence of a model for the development of ovarian carcinoma. This review summarizes recent molecular studies of ovarian borderline tumors with special emphasis on the role of SBT in tumor progression and its relationship to ovarian serous carcinoma.
Dasatinib (BMS-354825) Tyrosine Kinase Inhibitor Suppresses Invasion and Induces Cell Cycle Arrest and Apoptosis of Head and Neck Squamous Cell Carcinoma and Non–Small Cell Lung Cancer Cells
Authors: Johnson Faye M. , Saigal Babita , Talpaz Moshe , Donato Nicholas J.
Published: March 2006

Purpose: Epithelial tumors, including non–small cell lung cancer (NSCLC) and head and neck squamous cell carcinoma (HNSCC), present clinical challenges. One potential target for systemic therapy is Src family nonreceptor tyrosine kinases, which are overexpressed in these tumors and induce pleiotropic effects, including increased proliferation, enhanced survival, stimulation of angiogenesis, and changes in motility. Dasatinib (BMS-354825), an ATP-competitive, small molecule tyrosine kinase inhibitor, suppresses the activity of these kinases at subnanomolar concentrations. Therefore, we tested the antitumor effects of this inhibitor in vitro to determine whether in vivo analyses were warranted.

Experimental Design: The antitumor effects of dasatinib on HNSCC and NSCLC cells were evaluated using assays to measure cell cycle progression, apoptosis, migration, and invasion. Western blotting was used to monitor its effects on cell signaling.

Results: Dasatinib inhibited migration and invasion in all cell lines and induced cell cycle arrest (blocking the G1-S transition) and apoptosis in some lines. The effects on migration and invasion correlated with the inhibition of Src and downstream mediators of adhesion [e.g., focal adhesion kinase (FAK), p130, and paxillin], and the cell cycle effects and apoptosis correlated with the induction of p27 and the dephosphorylation of Rb. Dasatinib also induced morphologic changes that were consistent with an upstream role for Src in regulating focal adhesion complexes.

Conclusions: This study showed that Src inhibition in HNSCC and NSCLC has antitumor effects in vitro. This suggests that dasatinib would have therapeutic activity against these tumors. Clinical studies in these tumor types are warranted.
Cyclooxygenase-2 Is an Independent Prognostic Factor in Gastric Cancer and Its Expression Is Regulated by the Messenger RNA Stability Factor HuR
Authors: Mrena Johanna , Wiksten Jan-Patrik , Thiel Alexandra , Kokkola Arto , Pohjola Leena , Lundin Johan , Nordling Stig , Ristimäki Ari , Haglund Caj
Published: March 2006

Purpose: Cyclooxygenase-2 (COX-2) promotes carcinogenesis and its expression associates with clinicopathologic characteristics in gastric cancer. HuR is an mRNA binding protein that controls the stability of certain transcripts including COX-2. We evaluated the prognostic significance of COX-2 and HuR expressions in gastric cancer and whether there exists a link between HuR and COX-2 expressions.

Experimental Design: The study included 342 consecutive patients with histologically confirmed gastric adenocarcinoma, of whom 321 patients had tissue specimens available for COX-2 and 316 for HuR immunohistochemistry. Specimens were stained by COX-2– and HuR-specific monoclonal antibodies and scored by two independent observers. Correlation to clinical data and survival was assessed. TMK-1 gastric adenocarcinoma cells were treated with small interfering RNA against HuR and expressions of HuR and COX-2 were detected by immunofluorescence and Western blot analysis.

Results: Patients with low COX-2 expression had a cumulative 5-year survival of 53% and those with high COX-2 expression had 16% (P < 0.0001). In multivariate analysis, COX-2 was an independent prognostic factor (P = 0.003). Cytoplasmic HuR expression was associated with high COX-2 expression (P < 0.0001) and with reduced survival (P = 0.004) whereas nuclear positivity for HuR was not. When TMK-1 cells were treated with HuR small interfering RNA, expressions of HuR and COX-2 were reduced.

Conclusions: High COX-2 is an independent prognostic factor in gastric cancer. Cytoplasmic expression of HuR associates with high COX-2 expression and with reduced survival, and tissue culture experiments show that HuR can regulate expression of COX-2 in gastric cancer cells.
Monocyte Chemoattractant Protein-1 Transfection Induces Angiogenesis and Tumorigenesis of Gastric Carcinoma in Nude Mice via Macrophage Recruitment
Authors: Kuroda Tsuyoshi , Kitadai Yasuhiko , Tanaka Shinji , Yang Xiaoqin , Mukaida Naofumi , Yoshihara Masaharu , Chayama Kazuaki
Published: March 2006

Purpose: Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that has various roles in tumor development and progression. We previously reported that expression of MCP-1 is associated with macrophage infiltration and tumor vessel density in human gastric carcinomas. The present study was undertaken to obtain direct evidence that MCP-1 participates in recruitment of macrophages and induction of angiogenesis.

Experimental Design: We did transfection experiments to analyze the role of MCP-1 in tumorigenicity and angiogenesis in gastric carcinoma in nude mice. The human MCP-1 gene cloned into the BCMGS-Neo expression vector was transfected into the human gastric carcinoma TMK-1 cell line. We examined tumor volumes with the ectopic s.c. xenograft model and tumorigenicity with the orthotopic gastric xenograft model. We determined intratumor microvessel counts and tumor-infiltrating macrophage counts by immunohistochemical staining.

Results: There was no difference in in vitro proliferation between MCP-1-transfected TMK-1 cells and mock-transfected (control) cells; however, MCP-1 transfectants induced tumor growth in ectopic xenografts and increased tumorigenicity and induced lymph node metastases and ascites in orthotopic xenografts. In both ectopic and orthotopic xenograft models, strong infiltration of macrophages was observed within and around the tumors after implantation of MCP-1 transfectants whereas fewer macrophages were seen after inoculation of control cells. The microvessel density was significantly higher in tumors produced by MCP-1 transfectants than in control tumors.

Conclusions: MCP-1 produced by gastric carcinoma cells may regulate angiogenesis via macrophage recruitment. MCP-1 may be a potential target for antiangiogenic therapy for gastric carcinoma.
More Efficient Induction of HLA-A*0201-Restricted and Carcinoembryonic Antigen (CEA)–Specific CTL Response by Immunization with Exosomes Prepared from Heat-Stressed CEA-Positive Tumor Cells
Authors: Dai Shengming , Wan Tao , Wang Baomei , Zhou Xiangyang , Xiu Fangming , Chen Taoyong , Wu Yanfeng , Cao Xuetao
Published: March 2006

Purpose: Tumor-derived exosomes are proposed as a new type of cancer vaccine. Heat shock proteins are potent Th1 adjuvant, and heat stress can induce heat shock protein and MHC-I expression in tumor cells, leading to the increased immunogenicity of tumor cells. To improve the immunogenicity of exosomes as cancer vaccine, we prepared exosomes from heat-stressed carcinoembryonic antigen (CEA)–positive tumor cells (CEA+/HS-Exo) and tested the efficacy of these exosomes in the induction of CEA-specific antitumor immunity.

Experimental Design: First, we identified the composition of CEA+/HS-Exo and observed their effects on human dendritic cell maturation. Then, we evaluated their ability to induce a CEA-specific immune response in vivo in HLA-A2.1/Kb transgenic mice and CEA-specific CTL response in vitro in HLA-A*0201+ healthy donors and HLA-A*0201+CEA+ cancer patients.

Results: CEA+/HS-Exo contained CEA and more heat shock protein 70 and MHC-I and significantly induced dendritic cell maturation. Immunization of HLA-A2.1/Kb transgenic mice with CEA+/HS-Exo was more efficient in priming a CEA-specific CTL, and the CTL showed antitumor effect when adoptively transferred to SW480-bearing nude mice. Moreover, in vitro incubation of lymphocytes from HLA-A*0201+ healthy donors and HLA-A*0201+CEA+ cancer patients with CEA+/HS-Exo-pulsed autologous dendritic cells induces HLA-A*0201-restricted and CEA-specific CTL response.

Conclusions: Our results show that CEA+/HS-Exo has superior immunogenicity than CEA+/Exo in inducing CEA-specific CTL response and suggest that exosomes derived from heat-stressed tumor cells may be used as efficient vaccine for cancer immunotherapy.
Enhancement of Sensitivity to Tumor Necrosis Factor α in Non–Small Cell Lung Cancer Cells with Acquired Resistance to Gefitinib
Authors: Ando Koichi , Ohmori Tohru , Inoue Fumiko , Kadofuku Tsuyoki , Hosaka Takamichi , Ishida Hiroo , Shirai Takao , Okuda Kentaro , Hirose Takashi , Horichi Naoya , Nishio Kazuto , Saijo Nagahiro , Adachi Mitsuru , Kuroki Toshio
Published: March 2006

Tumor cells that have acquired resistance to gefitinib through continuous drug administration may complicate future treatment. To investigate the mechanisms of acquired resistance, we established PC-9/ZD2001, a non-small-cell lung cancer cell line resistant to gefitinib, by continuous exposure of the parental cell line PC-9 to gefitinib. After 6 months of culture in gefitinib-free conditions, PC-9/ZD2001 cells reacquired sensitivity to gefitinib and were established as a revertant cell line, PC-9/ZD2001R. PC-9/ZD2001 cells showed collateral sensitivity to several anticancer drugs (vinorelbine, paclitaxel, camptothecin, and 5-fluorouracil) and to tumor necrosis factor α (TNF-α). Compared with PC-9 cells, PC-9/ZD2001 cells were 67-fold more sensitive to TNF-α and PC-9/ZD2001R cells were 1.3-fold more sensitive. Therefore, collateral sensitivity to TNF-α was correlated with gefitinib resistance. PC-9/ZD2001 cells expressed a lower level of epidermal growth factor receptor (EGFR) than did PC-9 cells; this down-regulation was partially reversed in PC-9/ZD2001R cells. TNF-α-induced autophosphorylation of EGFR (cross-talk signaling) was detected in all three cell lines. However, TNF-α-induced Akt phosphorylation and IκB degradation were observed much less often in PC-9/ZD2001 cells than in PC-9 cells or PC-9/ZD2001R cells. Expression of the inhibitor of apoptosis proteins c-IAP1 and c-IAP2 was induced by TNF-α in PC-9 and PC-9/ZD2001R cells but not in PC-9/ZD2001 cells. This weak effect of EGFR on Akt pathway might contribute to the TNF-α sensitivity of PC-9/ZD2001 cells. These results suggest that therapy with TNF-α would be effective in some cases of non-small-cell lung cancer that have acquired resistance to gefitinib.
Pilot Trial of Unlabeled and Indium-111–Labeled Anti–Prostate-Specific Membrane Antigen Antibody J591 for Castrate Metastatic Prostate Cancer
Authors: Morris Michael J. , Divgi Chaitanya R. , Pandit-Taskar Neeta , Batraki Maria , Warren Nyasha , Nacca Angelo , Smith-Jones Peter , Schwartz Lawrence , Kelly W. Kevin , Slovin Susan , Solit David , Halpern Jennifer , Delacruz Anthony , Curley Tracy , Finn Ronald , O'Donoghue Joseph A. , Livingston Philip , Larson Steven , Scher Howard I.
Published: March 2006

Background: Prostate-specific membrane antigen (PSMA) is a transmembrane glycoprotein primarily expressed on benign and malignant prostatic epithelial cells. J591 is an IgG1 monoclonal antibody that targets the external domain of the PSMA. The relationship among dose, safety, pharmacokinetics, and antibody-dependent cellular cytotoxicity (ADCC) activation for unlabeled J591 has not been explored.

Patients and Methods: Patients with progressive metastatic prostate cancer despite androgen deprivation were eligible. Each patient received 10, 25, 50, and 100 mg of J591. Two milligrams of antibody, conjugated with the chelate 1,4,7,10-tetraazacyclododecane-N, N′,N″,N‴-tetraacetic acid, were labeled with 5 mCi indium-111 (111In) as a tracer. One group of patients received unlabeled J591 before the labeled antibody; the other received both together. Toxicities, pharmacokinetic properties, biodistribution, ADCC induction, immunogenicity, and clinical antitumor effects were assessed.

Results: Fourteen patients were treated (seven in each group). Treatment was well tolerated. Biodistribution of 111In-labeled J591 was comparable in both groups. The mean T1/2 was .96, 1.9, 2.75, and 3.47 days for the 10, 25, 50, and 100 mg doses, respectively. Selective targeting of 111In-labeled J591 to tumor was seen. Hepatic saturation occurred by the 25-mg dose. ADCC activity was proportional to dose. One patient showed a >50% prostate-specific antigen decline.

Conclusions: J591 is well tolerated in repetitive dose-escalating administrations. The rate of serum clearance decreases with increasing antibody mass. ADCC activation is proportional to antibody mass. The optimal dose is 25 mg for radioimmunotherapy and 100 mg for immunotherapy. Phase II studies using J591 as a radioconjugate are under way.
Prediction of Lymph Node Metastasis in Patients with Endometrioid Endometrial Cancer Using Expression Microarray
Authors: Bidus Michael A. , Risinger John I. , Chandramouli Gadisetti V.R. , Dainty Lou A. , Litzi Tracy J. , Berchuck Andrew , Barrett J. Carl , Maxwell G. Larry
Published: March 2006

Purpose: To characterize the gene expression profiles of endometrioid endometrial cancers associated with lymph node metastasis in an effort to identify genes associated with metastatic spread.

Experimental Design: Tumors from 41 patients with endometrioid endometrial cancer grossly confined to the uterine cavity were evaluated. Positive lymph nodes were noted in 12 of 41 patients. RNA was analyzed for gene expression using the Affymetrix HG133A and HG133B GeneChip set, representing 45,000 array features covering >28,000 UniGene clusters. Data analysis was done using multidimensional scaling, binary comparison, and hierarchical clustering. Gene expression for several differentially expressed genes was examined using quantitative PCR.

Results: Gene expression data was obtained from 30,964 genes that were detected in at least 5% of the cases. Supervised analysis of node-positive versus node-negative cases indicated that 450 genes were significantly differentially expressed between the two classes at P < 0.005, 81 of which were differentially expressed by at least 2-fold at P < 0.005. Overexpressed genes included two cell cycle checkpoint genes, CDC2 and MAD2L1, which have previously been described in association with lymph node metastasis in other cancer types. The ZIC2 zinc finger gene was overexpressed in endometrial cancers with positive nodes versus those with negative nodes.

Conclusion: Gene expression profiling of the primary tumors in patients with endometrioid endometrial cancers seems promising for identifying genes associated with lymph node metastasis. Future studies should address whether the status of nodal metastasis can be determined from the expression profiles of preoperative tissue specimens.