bluuebunny/crossref_metadata_2025 huggingface dataset:
Is the Olfactory Bulb Computationally Similar to the Retina?
Authors: Ghatpande Ambarish S.
Published: November 2008

The computational role of the olfactory bulb remains a mystery after 60 yr of physiological research. Recently, Fantana and colleagues proposed a new model of bulb function based on sparse inhibitory connections between glomeruli, the functional units of the bulb, rather than the existing lateral inhibition model. I present a summary of their model here and its implications along with comparison to recent work in the very similar Drosophila olfactory system.
ADAMTS-1 Metalloproteinase Promotes Tumor Development through the Induction of a Stromal Reaction In vivo
Authors: Rocks Natacha , Paulissen Geneviève , Quesada-Calvo Florence , Munaut Carine , Gonzalez Maria-Luz Alvarez , Gueders Maud , Hacha Jonathan , Gilles Christine , Foidart Jean-Michel , Noel Agnès , Cataldo Didier D.
Published: November 2008

ADAMTS-1 (a disintegrin and metalloproteinase with thrombospondin motifs), the first described member of the ADAMTS family, is differentially expressed in various tumors. However, its exact role in tumor development and progression is still unclear. The aim of this study was to investigate the effects of ADAMTS-1 transfection in a bronchial epithelial tumor cell line (BZR) and its potential to modulate tumor development. ADAMTS-1 overexpression did not affect in vitro cell properties such as (a) proliferation in two-dimensional culture, (b) proliferation in three-dimensional culture, (c) anchorage-independent growth in soft agar, (d) cell migration and invasion in modified Boyden chamber assay, (e) angiogenesis in the aortic ring assay, and (f) cell apoptosis. In contrast, ADAMTS-1 stable transfection in BZR cells accelerated the in vivo tumor growth after s.c. injection into severe combined immunodeficient mice. It also promoted a stromal reaction characterized by myofibroblast infiltration and excessive matrix deposition. These features are, however, not observed in tumors derived from cells overexpressing a catalytically inactive mutant of ADAMTS-1. Conditioned media from ADAMTS-1–overexpressing cells display a potent chemotactic activity toward fibroblasts. ADAMTS-1 overexpression in tumors was associated with increased production of matrix metalloproteinase-13, fibronectin, transforming growth factor β (TGF-β), and interleukin-1β (IL-1β). Neutralizing antibodies against TGF-β and IL-1β blocked the chemotactic effect of medium conditioned by ADAMTS-1–expressing cells on fibroblasts, showing the contribution of these factors in ADAMTS-1–induced stromal reaction. In conclusion, we propose a new paradigm for catalytically active ADAMTS-1 contribution to tumor development, which consists of the recruitment of fibroblasts involved in tumor growth and tumor-associated stroma remodeling. [Cancer Res 2008;68(22):9541–50]
Erlotinib Attenuates Homologous Recombinational Repair of Chromosomal Breaks in Human Breast Cancer Cells
Authors: Li Liping , Wang Hong , Yang Eddy S. , Arteaga Carlos L. , Xia Fen
Published: November 2008

The epidermal growth factor receptor (EGFR) family has been implicated in several cancers, including breast, and its members have become the target of novel cancer therapies. In this report, we show a novel link between erlotinib, a potent EGFR inhibitor, DNA damage, and homology-directed recombinational repair (HDR) in human breast cancer cells. Erlotinib suppresses HDR. This is not secondary to erlotinib-mediated changes in cell cycle and is associated with increased γ-H2AX foci, which is an in situ marker of chromosomal double-strand breaks. Both Rad51 and BRCA1 are essential components of the HDR machinery. Consistent with decreased HDR in erlotinib-treated cells, erlotinib also attenuates DNA damage-induced Rad51 foci and results in cytoplasmic retention of BRCA1. As BRCA1 is a shuttling protein and its nuclear function of promoting HDR is controlled by its subcellular localization, we further show that targeted translocation of BRCA1 to the cytoplasm enhances erlotinib sensitivity. These findings suggest a novel mechanism of action of erlotinib through its effects on the BRCA1/HDR pathway. Furthermore, BRCA1/HDR status may be an innovative avenue to enhance the sensitivity of cancer cells to erlotinib. [Cancer Res 2008;68(22):9141–6]
Phosphatidylinositol 3-Kinase Hyperactivation Results in Lapatinib Resistance that Is Reversed by the mTOR/Phosphatidylinositol 3-Kinase Inhibitor NVP-BEZ235
Authors: Eichhorn Pieter J.A. , Gili Magüi , Scaltriti Maurizio , Serra Violeta , Guzman Marta , Nijkamp Wouter , Beijersbergen Roderick L. , Valero Vanesa , Seoane Joan , Bernards René , Baselga José
Published: November 2008

Small molecule inhibitors of HER2 are clinically active in women with advanced HER2-positive breast cancer who have progressed on trastuzumab treatment. However, the effectiveness of this class of agents is limited by either primary resistance or acquired resistance. Using an unbiased genetic approach, we performed a genome wide loss-of-function short hairpin RNA screen to identify novel modulators of resistance to lapatinib, a recently approved anti-HER2 tyrosine kinase inhibitor. Here, we have identified the tumor suppressor PTEN as a modulator of lapatinib sensitivity in vitro and in vivo. In addition, we show that two dominant activating mutations in PIK3CA (E545K and H1047R), which are prevalent in breast cancer, also confer resistance to lapatinib. Furthermore, we show that phosphatidylinositol 3-kinase (PI3K)–induced lapatinib resistance can be abrogated through the use of NVP-BEZ235, a dual inhibitor of PI3K/mTOR. Our data show that deregulation of the PI3K pathway, either through loss-of-function mutations in PTEN or dominant activating mutations in PIK3CA, leads to lapatinib resistance, which can be effectively reversed by NVP-BEZ235. [Cancer Res 2008;68(22):9221–30]
p53-Inducible Ribonucleotide Reductase (p53R2/RRM2B) Is a DNA Hypomethylation–Independent Decitabine Gene Target That Correlates with Clinical Response in Myelodysplastic Syndrome/Acute Myelogenous Leukemia
Authors: Link Petra A. , Baer Maria R. , James Smitha R. , Jones David A. , Karpf Adam R.
Published: November 2008

While the therapeutic activity of the deoxycytidine analogue decitabine is thought to reflect its ability to reactivate methylation-silenced genes, this agent is also known to trigger p53-dependent DNA damage responses. Here, we report that p53-inducible ribonucleotide reductase (p53R2/RRM2B) is a robust transcriptional target of decitabine. In cancer cells, decitabine treatment induces p53R2 mRNA expression, protein expression, and promoter activity in a p53-dependent manner. The mechanism of p53R2 gene induction by decitabine does not seem to be promoter DNA hypomethylation, as the p53R2 5′ CpG island is hypomethylated before treatment. Small interfering RNA (siRNA) targeting of DNA methyltransferase 1 (DNMT1) in wild-type p53 cells leads to genomic DNA hypomethylation but does not induce p53R2, suggesting that DNMT/DNA adduct formation is the molecular trigger for p53R2 induction. Consistent with this idea, only nucleoside-based DNMT inhibitors that form covalent DNA adducts induce p53R2 expression. siRNA targeting of p53R2 reduces the extent of cell cycle arrest following decitabine treatment, supporting a functional role for p53R2 in decitabine-mediated cellular responses. To determine the clinical relevance of p53R2 induction, we measured p53R2 expression in bone marrow samples from 15 myelodysplastic syndrome/acute myelogenous leukemia (MDS/AML) patients undergoing decitabine therapy. p53R2 mRNA and protein were induced in 7 of 13 (54%) and 6 of 9 (67%) patients analyzed, respectively, despite a lack of methylation changes in the p53R2 promoter. Most notably, there was a significant association (P = 0.0047) between p53R2 mRNA induction and clinical response in MDS/AML. These data establish p53R2 as a novel hypomethylation-independent decitabine gene target associated with clinical response. [Cancer Res 2008;68(22):9358–66]
Smokers with theCHRNALung Cancer–Associated Variants Are Exposed to Higher Levels of Nicotine Equivalents and a Carcinogenic Tobacco-Specific Nitrosamine
Authors: Le Marchand Loïc , Derby Kiersten S. , Murphy Sharon E. , Hecht Stephen S. , Hatsukami Dorothy , Carmella Steven G. , Tiirikainen Maarit , Wang Hansong
Published: November 2008

A locus at 15q24/15q25.1, which includes the nicotinic acetylcholine receptor A subunits 3 and 5 (CHRNA3 and CHRNA5) genes, has recently been associated with lung cancer risk, self-reported number of cigarettes smoked per day, and a nicotine dependence scale. It is not clear whether the association with lung cancer is direct or mediated through differences in smoking behavior. We used urinary biomarkers to test whether two linked lung cancer risk variants in CHRNA3 (rs1051730) and CHRNA5 (rs16969968) are associated with intensity of smoking and exposure to a tobacco-specific carcinogenic nitrosamine per cigarette dose. We studied 819 smokers and found that carriers of these variants extract a greater amount of nicotine (P = 0.003) and are exposed to a higher internal dose of 4-(methylnitrosamino)-I-(3-pyridyl)-1-butanone (P = 0.03) per cigarette than noncarriers. Thus, smokers who carry the CHRNA3 and CHRNA5 variants are expected to be at increased risk for lung cancer compared with smokers who do not carry these alleles even if they smoked the same number of cigarettes. Number of cigarettes per day, even if it could be accurately assessed, is not an adequate measure of smoking dose. [Cancer Res 2008;68(22):9137–40]
Regulated Expression of a Tumor-Associated Antigen Reveals Multiple Levels of T-Cell Tolerance in a Mouse Model of Lung Cancer
Authors: Cheung Ann F. , DuPage Michel J.P. , Dong H. Katie , Chen Jianzhu , Jacks Tyler
Published: November 2008

Maximizing the potential of cancer immunotherapy requires model systems that closely recapitulate human disease to study T-cell responses to tumor antigens and to test immunotherapeutic strategies. We have created a new system that is compatible with Cre-LoxP–regulatable mouse cancer models in which the SIY antigen is specifically overexpressed in tumors, mimicking clinically relevant TAAs. To show the utility of this system, we have characterized SIY-reactive T cells in the context of lung adenocarcinoma, revealing multiple levels of antigen-specific T-cell tolerance that serve to limit an effective antitumor response. Thymic deletion reduced the number of SIY-reactive T cells present in the animals. When potentially self-reactive T cells in the periphery were activated, they were efficiently eliminated. Inhibition of apoptosis resulted in more persistent self-reactive T cells, but these cells became anergic to antigen stimulation. Finally, in the presence of tumors overexpressing SIY, SIY-specific T cells required a higher level of costimulation to achieve functional activation. This system represents a valuable tool in which to explore sources contributing to T-cell tolerance of cancer and to test therapies aimed at overcoming this tolerance. [Cancer Res 2008;68(22):9459–68]
SM-164: A Novel, Bivalent Smac Mimetic That Induces Apoptosis and Tumor Regression by Concurrent Removal of the Blockade of cIAP-1/2 and XIAP
Authors: Lu Jianfeng , Bai Longchuan , Sun Haiying , Nikolovska-Coleska Zaneta , McEachern Donna , Qiu Su , Miller Rebecca S. , Yi Han , Shangary Sanjeev , Sun Yi , Meagher Jennifer L. , Stuckey Jeanne A. , Wang Shaomeng
Published: November 2008

Small-molecule Smac mimetics are being developed as a novel class of anticancer drugs. Recent studies have shown that Smac mimetics target cellular inhibitor of apoptosis protein (cIAP)-1/2 for degradation and induce tumor necrosis factor-α (TNFα)–dependent apoptosis in tumor cells. In this study, we have investigated the mechanism of action and therapeutic potential of two different types of novel Smac mimetics, monovalent SM-122 and bivalent SM-164. Our data showed that removal of cIAP-1/2 by Smac mimetics or small interfering RNA is not sufficient for robust TNFα-dependent apoptosis induction, and X-linked inhibitor of apoptosis protein (XIAP) plays a critical role in inhibiting apoptosis induction. Although SM-164 is modestly more effective than SM-122 in induction of cIAP-1/2 degradation, SM-164 is 1,000 times more potent than SM-122 as an inducer of apoptosis in tumor cells, which is attributed to its much higher potency in binding to and antagonizing XIAP. SM-164 induces rapid cIAP-1 degradation and strong apoptosis in the MDA-MB-231 xenograft tumor tissues and achieves tumor regression, but has no toxicity in normal mouse tissues. Our study provides further insights into the mechanism of action for Smac mimetics and regulation of apoptosis by inhibitor of apoptosis proteins. Furthermore, our data provide evidence that SM-164 is a promising new anticancer drug for further evaluation and development. [Cancer Res 2008;68(22):9384–93]
MUC4, a Multifunctional Transmembrane Glycoprotein, Induces Oncogenic Transformation of NIH3T3 Mouse Fibroblast Cells
Authors: Bafna Sangeeta , Singh Ajay P. , Moniaux Nicolas , Eudy James D. , Meza Jane L. , Batra Surinder K.
Published: November 2008

Numerous studies have established the association of MUC4 with the progression of cancer and metastasis. An aberrant expression of MUC4 is reported in precancerous lesions, indicating its early involvement in the disease process; however, its precise role in cellular transformation has not been explored. MUC4 contains many unique domains and is proposed to affect cell signaling pathways and behavior of the tumor cells. In the present study, to decipher the oncogenic potential of MUC4, we stably expressed the MUC4 mucin in NIH3T3 mouse fibroblast cells. Stable ectopic expression of MUC4 resulted in increased growth, colony formation, and motility of NIH3T3 cells in vitro and tumor formation in nude mice when cells were injected s.c. Microarray analysis showed increased expression of several growth-associated and mitochondrial energy production–associated genes in MUC4-expressing NIH3T3 cells. In addition, expression of MUC4 in NIH3T3 cells resulted in enhanced levels of oncoprotein ErbB2 and its phosphorylated form (pY1248-ErbB2). In conclusion, our studies provide the first evidence that MUC4 alone induces cellular transformation and indicates a novel role of MUC4 in cancer biology. [Cancer Res 2008;68(22):9231–8]
Monoclonal Antibody CC188 Binds a Carbohydrate Epitope Expressed on the Surface of Both Colorectal Cancer Stem Cells and their Differentiated Progeny
Authors: Xu Mai , Yuan Yuan , Xia Yang , Achilefu Samuel
Published: November 2008

Purpose: Recently, cancer stem cells (CSC), undifferentiated cancer progenitor cells, have been successfully isolated from colorectal tumors. Targeting both CSCs and differentiated, rapidly proliferating tumor cells with therapeutic drugs provides a focused strategy to treat cancer. In this study, we isolated the monoclonal antibody (mAb) CC188 and characterized the epitope recognized by mAb CC188, which is useful for developing biological reagents that target CSCs.

Experimental Design: We used a hybridoma technique to generate mAbs and an immunomagnetic method to isolate colon CSCs. We characterized mAb CC188 binding epitope and examined the epitope distribution in normal and tumor tissues, particularly in CSCs using tissue arrays and immunofluorescence staining method. We also evaluated the effect of mAb CC188 on invasiveness of NSY tumor cells.

Results: mAb CC188 was generated and 98.9% (187 of 189 cases) of colon cancer were positively stained by mAb CC188. “+”, “++,” and “+++” staining were 25.9%, 28.6%, and 43.4%, respectively. The mAb CC188 binding epitope was identified as a carbohydrate, which was expressed on the surface of colon CSCs (CD133+), differentiated colon cancer cells (CD133−), and cells from various types of epithelial tumors. In contrast, the expression of the carbohydrate epitope was low in normal prostate muscle and pancreatic acinar cells, as well as in some normal epithelial cells of the breast duct, cervix, and skin. A functional study indicated that mAb CC188 suppressed the invasiveness of NSY tumor cells.

Conclusion: mAb CC188 selectively targets a carbohydrate epitope expressed on cancer cells, providing a viable method for specific tumor imaging and targeted therapy.
Predictive Value of Plasma Hepatocyte Growth Factor/Scatter Factor Levels in Patients with Clinically Localized Prostate Cancer
Authors: Gupta Amit , Karakiewicz Pierre I. , Roehrborn Claus G. , Lotan Yair , Zlotta Alexandre R. , Shariat Shahrokh F.
Published: November 2008

Purpose: Hepatocyte growth factor/scatter factor (HGF/SF) is a multifunctional cytokine that is involved in cancer growth, motility, invasion, and angiogenesis. We assessed whether preoperative plasma levels of HGF can enhance the accuracy of standard models for predicting pathologic features and clinical outcomes.

Experimental Design: The study comprised 421 consecutive patients treated with radical prostatectomy and bilateral lymphadenectomy for clinically localized prostatic adenocarcinoma. HGF/SF was measured using a commercially available immunoassay. Multivariate logistic regression was used to assess the relationship between plasma HGF/SF and pathologic features. Multivariate Cox regression was used to predict disease recurrence. One thousand bootstrap replicates were created for internal validation and predictive accuracies were estimated for each model.

Results: Plasma HGF/SF levels were significantly elevated in patients with lymph node and/or seminal vesicle invasion (P < 0.0001 and P = 0.007, respectively). Preoperative plasma HGF/SF level was an independent predictor of lymph node invasion [odds ratio (OR) for every 100 pg/mL increase in HGF/SF, 1.82; 95% confidence interval (95% CI), 1.33-2.49] and seminal vesicle invasion (OR, 1.18; 95% CI, 1.06-1.3). Addition of HGF/SF increased the accuracy of a base model that included standard preoperative variables for prediction of lymph node invasion by 6.7% (predictive accuracy, 98.4%). HGF/SF also independently predicted disease recurrence after surgery (hazard ratio, 1.07; 95% CI, 1.0-1.15).

Conclusions: Preoperative plasma level of HGF/SF is an independent predictor of prostate cancer metastasis to lymph nodes and disease recurrence after surgery. Use of HGF may help in therapeutic decision-making and enrollment into clinical trials.
The Use of Genetic Markers to Identify Lung Cancer in Fine Needle Aspiration Samples
Authors: Gill Rajbir K. , Vazquez Madeline F. , Kramer Arin , Hames Megan , Zhang Lijuan , Heselmeyer-Haddad Kerstin , Ried Thomas , Shilo Konstantin , Henschke Claudia , Yankelevitz David , Jen Jin
Published: November 2008

Purpose: We seek to establish a genetic test to identify lung cancer using cells obtained through computed tomography–guided fine needle aspiration (FNA).

Experimental Design: We selected regions of frequent copy number gains in chromosomes 1q32, 3q26, 5p15, and 8q24 in non–small cell lung cancer and tested their ability to determine the neoplastic state of cells obtained by FNA using fluorescent in situ hybridization. Two sets of samples were included. The pilot set included six paraffin-embedded, noncancerous lung tissues and 33 formalin-fixed FNA specimens. These 39 samples were used to establish the optimal fixation and single scoring criteria for the samples. The test set included 40 FNA samples. The results of the genetic test were compared with the cytology, pathology, and clinical follow-up for each case to assess the sensitivity and specificity of the genetic test.

Results: Nontumor lung tissues had ≤4 signals per nucleus for all tested markers, whereas tumor samples had ≥5 signals per nucleus in five or more cells for at least one marker. Among the 40 testing cases, 36 of 40 (90%) FNA samples were analyzable. Genetic analysis identified 15 cases as tumor and 21 cases as nontumor. Clinical and pathologic diagnoses confirmed the genetic test in 15 of 16 lung cancer cases regardless of tumor subtype, stage, or size and in 20 of 20 cases diagnosed as benign lung diseases.

Conclusions: A set of only four genetic markers can distinguish the neoplastic state of lung lesion using small samples obtained through computed tomography–guided FNA.
Acquired Resistance to Epidermal Growth Factor Receptor Kinase Inhibitors Associated with a Novel T854A Mutation in a Patient with EGFR-Mutant Lung Adenocarcinoma
Authors: Bean James , Riely Gregory J. , Balak Marissa , Marks Jenifer L. , Ladanyi Marc , Miller Vincent A. , Pao William
Published: November 2008

Purpose: Somatic mutations in the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene are associated with sensitivity of lung adenocarcinomas to the EGFR tyrosine kinase inhibitors, gefitinib and erlotinib. Acquired drug resistance is frequently associated with a secondary somatic mutation that leads to the substitution of methionine for threonine at position 790 (T790M). We aimed to identify additional second-site alterations associated with acquired resistance.

Experimental Design: Tumor samples were obtained from 48 patients with acquired resistance. Tumor cell DNA was analyzed for EGFR kinase domain mutations. Molecular analyses were then done to characterize the biological properties of a novel mutant EGFR allele.

Results: A previously unreported mutation in exon 21 of EGFR, which leads to substitution of alanine for threonine at position 854 (T854A), was identified in one patient with a drug-sensitive EGFR L858R–mutant lung adenocarcinoma after long-term treatment with tyrosine kinase inhibitors. The T854A mutation was not detected in a pretreatment tumor sample. The crystal structure analyses of EGFR suggest that the T854 side chain is within contact distance of gefitinib and erlotinib. Surrogate kinase assays show that the EGFR T854A mutation abrogates the inhibition of tyrosine phosphorylation by erlotinib. Such resistance seems to be overcome by a new irreversible dual EGFR/HER2 inhibitor, BIBW 2992.

Conclusions: The T854A mutation is the second reported second-site acquired resistance mutation that is within contact distance of gefitinib and erlotinib. These data suggest that acquired resistance to ATP-mimetic EGFR kinase inhibitors may often be associated with amino acid substitutions that alter drug contact residues in the EGFR ATP-binding pocket.
Microtubule Active Agents: Beyond the Taxane Frontier
Authors: Morris Patrick G. , Fornier Monica N.
Published: November 2008

Microtubules are essential to cell transport, signaling, and mitosis. An increasing range of anticancer drugs interferes with the normal formation and function of microtubules. Vinca alkaloids act as microtubule destabilizers and the taxanes act as microtubule stabilizers. Taxanes are widely used cytotoxic agents that are active in a range of solid tumor malignancies and are routinely used in a variety of settings. Significant limitations with the taxanes exist, including acquired and intrinsic tumor resistance through the expression of multidrug resistance proteins such as P-glycoprotein, risk of hypersensitivity reactions, dose-limiting hematopoietic toxicity, and cumulative neurotoxicity. Hence, there is a need to develop novel agents that act on the microtubules. Epothilones are macrolide antibiotics that bind near the taxane-binding site on microtubules and have been extensively studied in recent and ongoing clinical trials. A variety of other agents that act on the microtubules at different sites with a variety of structures are at varying stages of development.
Prognostic Relevance of Occult Nodal Micrometastases and Circulating Tumor Cells in Colorectal Cancer in a Prospective Multicenter Trial
Authors: Koyanagi Kazuo , Bilchik Anton J. , Saha Sukamal , Turner Roderick R. , Wiese David , McCarter Martin , Shen Perry , Deacon Linda , Elashoff David , Hoon Dave S.B.
Published: November 2008

Purpose: Nodal micrometastasis and circulating tumor cells detected by multimarker quantitative real-time reverse transcription-PCR (qRT-PCR) may have prognostic importance in patients with colorectal cancer.

Experimental Design: Paraffin-embedded sentinel lymph nodes from 67 patients and blood from 34 of these patients were evaluated in a prospective multicenter trial of sentinel lymph node mapping in colorectal cancer. Sentinel lymph nodes were examined by H&E staining and cytokeratin immunohistochemistry. Sentinel lymph nodes and blood were examined by a four-marker qRT-PCR assay (c-MET, melanoma antigen gene-A3 family, β1→4-N-acetylgalactosaminyltransferase, and cytokeratin-20); qRT-PCR results were correlated with disease stage and outcome.

Results: In H&E-negative sentinel lymph node patients that recurred, cytokeratin immunohistochemistry and qRT-PCR detected metastasis in 30% and 60% of patients, respectively. Disease-free survival differed significantly by multimarker qRT-PCR upstaged sentinel lymph node (P = 0.014). qRT-PCR analysis of blood for circulating tumor cells correlated with overall survival (P = 0.040).

Conclusion: Molecular assessment for micrometastasis in sentinel lymph node and blood specimens may help identify patients at high risk for recurrent colorectal cancer, who could benefit from adjuvant therapy.
[18F]Fluorothymidine Positron Emission Tomography before and 7 Days after Gefitinib Treatment Predicts Response in Patients with Advanced Adenocarcinoma of the Lung
Authors: Sohn Hee-Jung , Yang You-Jung , Ryu Jin-Sook , Oh Seung Jun , Im Ki Chun , Moon Dae Hyuk , Lee Dae Ho , Suh Cheolwon , Lee Jung-Shin , Kim Sang-We
Published: November 2008

Purpose: To evaluate the usefulness of 3′-deoxy-3′-[18F]fluorothymidine (FLT)-positron emission tomography (PET) for predicting response and patient outcome of gefitinib therapy in patients with adenocarcinoma of the lung.

Experimental Design: Nonsmokers with advanced or recurrent adenocarcinoma of the lung were eligible. FLT-PET images of the thorax were obtained before and 7 days after the start of gefitinib (250 mg/d) therapy, the maximum standardized uptake values (SUVmax) of primary tumors were measured, and the percent changes in SUVmax were calculated. After 6 weeks of therapy, the responses were assessed by computed tomography of the chest.

Results: Among 31 patients who were enrolled, we analyzed 28 patients for whom we had complete data. Chest computed tomography revealed partial response in 14 (50%), stable disease in 4 (14%), and progressive disease in 10 (36%) after 6 weeks of treatment. Pretreatment SUVmax of the tumors did not differ between responders and nonresponders. At 7 days after the initiation of therapy, the percent changes in SUVmax were significantly different (−36.0 ± 15.4% versus 10.1 ± 19.5%; P < 0.001). Decrease of >10.9% in SUVmax was used as the criterion for predicting response. The positive and negative predictive values were both 92.9%. The time to progression was significantly longer in FLT-PET responders than nonresponders (median, 7.9 versus 1.2 months; P = 0.0041).

Conclusion: FLT-PET can predict response to gefitinib 7 days after treatment in nonsmokers with advanced adenocarcinoma of the lung. The change in tumor SUVmax obtained by FLT-PET seems to be a promising predictive variable.
Clinical and Pharmacologic Study of the Novel Prodrug Delimotecan (MEN 4901/T-0128) in Patients with Solid Tumors
Authors: Veltkamp Stephan A. , Witteveen Els O. , Capriati Angela , Crea Attilio , Animati Fabio , Voogel-Fuchs Marja , van den Heuvel Ingeborg J.G.M. , Beijnen Jos H. , Voest Emile E. , Schellens Jan H.M.
Published: November 2008

Purpose: To investigate i.v. administration of delimotecan (MEN 4901/T-0128), a carboxymethyldextran polymer prodrug of the active camptothecin derivative T-2513, and to assess the maximum tolerated dose, safety profile, clinical pharmacology, and antitumor activity of delimotecan and metabolites.

Experimental Design: Patients with solid tumors refractory to standard therapy received i.v. delimotecan as 3-hour infusion once every 6 weeks. The starting dose was 150 mg/m2, followed by an accelerated dose escalation with at least one patient per dose level. The pharmacokinetics of delimotecan, T-2513, and its metabolites, SN-38, SN-38G, T-1335, T-0055, and T-3921, were assessed in plasma and urine, and their pharmacodynamics were determined by measuring the effect of the treatment on hematologic and nonhematologic toxicity.

Results: Twenty-two patients received 35 courses. Dose-limiting toxicities were observed at 5,400 mg/m2 (n = 1), 3,600 mg/m2 (n = 1), and 2,400 mg/m2 (n = 2). The dose level of 1,800 mg/m2 was determined as maximum tolerated dose. Two partial responses were observed in patients with anal cancer (1800 mg/m2) and head and neck cancer (2400 mg/m2). Delimotecan had a long terminal half-life of 109 h, and relatively high exposures to T-2513 and SN-38 were obtained. The percentage decrease in WBC and absolute neutrophil count significantly correlated with the dose of delimotecan.

Conclusions: Based on its preliminary antitumor activity, safety profile, and pharmacokinetic profile, we recommend to evaluate delimotecan given as 3-hour infusion once every 6 weeks at a dose level of 1,800 mg/m2 in a phase II study.
Integrin αvβ3-Targeted Radioimmunotherapy of Glioblastoma Multiforme
Authors: Veeravagu Anand , Liu Zhaofei , Niu Gang , Chen Kai , Jia Bing , Cai Weibo , Jin Cunjing , Hsu Andrew R. , Connolly Andrew J. , Tse Victor , Wang Fan , Chen Xiaoyuan
Published: November 2008

Purpose: Abegrin is a monoclonal antibody to human integrin αVβ3, a cell adhesion molecule highly expressed on actively angiogenic endothelium and glioblastoma multiforme tumor cells. The purpose of this study was to evaluate the efficacy of a novel 90Y-Abegrin radioimmunotherapeutic agent in murine xenograft glioblastoma models with noninvasive in vivo molecular imaging modalities.

Experimental Design: A s.c. U87MG human glioblastoma xenograft model was used to determine maximum tolerated dose (MTD), biodistribution, dose response, and efficacy of 90Y-Abegrin. Antitumor efficacy was also characterized in an orthotopic U87MG and in a HT-29 colorectal cancer model, a low integrin-expressing carcinoma. Small-animal positron emission tomography imaging was used to correlate histologic findings of treatment efficacy.

Results: MTD and dose response analysis revealed 200 μCi per mouse as appropriate treatment dose with hepatic clearance and no organ toxicity. 90Y-Abegrin–treated U87MG tumor mice showed partial regression of tumor volume, with increased tumor volumes in 90Y-IgG, Abegrin, and saline groups. 18F-FDG imaging revealed a reduction of cell proliferation and metabolic activity whereas 18F-FLT reflected decreased DNA synthesis in the 90Y-Abegrin group. Ki67 analysis showed reduced proliferative index and quantitative terminal deoxynucleotidyl transferase dUTP nick-end labeling–positive analysis revealed increased DNA fragmentation and apoptosis in 90Y-Abegrin animals. CD31 and 4′,6-diamidino-2-phenylindole staining showed increased vascular fragmentation and dysmorphic vessel structure in 90Y-Abegrin animals only. Orthotopic U87MG tumors treated with 90Y-Abegrin displayed reduced tumor volume. HT-29 tumors showed no significant difference among the various groups.

Conclusion: Radioimmunotherapy with 90Y-labeled Abegrin may prove promising in the treatment of highly vascular, invasive, and heterogeneous malignant brain tumors.
Human Telomerase Reverse Transcriptase Activated by E6 Oncoprotein Is Required for Human Papillomavirus-16/18-Infected Lung Tumorigenesis
Authors: Cheng Ya-Wen , Wu Tzu-Chin , Chen Chih-Yi , Chou Ming-Chih , Ko Jiunn-Liang , Lee Huei
Published: November 2008

Purpose: Our recent report indicates that human papillomavirus (HPV)-16/18 E6 oncoprotein is expressed in lung tumors and is related to p53 inactivation. We further explored whether human telomerase reverse transcriptase (hTERT) transcription is up-regulated by E6 and contributes to lung tumor development.

Experimental Design: Immunohistochemistry detected HPV-16 E6 oncoprotein in 135 lung tumors, and hTERT mRNA was evaluated by real-time reverse transcription-PCR and in situ hybridization, respectively. A small RNA interference (RNAi), Western blotting, and chromatin immunoprecipitation analysis were used to clarify whether hTERT transcription was regulated by c-Myc and Sp1. The telomerase activity and oncogenic potential of TL-1 with or without E6- or hTERT-RNAi was determined by real-time quantitative telomeric repeat amplification protocol analysis and soft-agar assay, respectively.

Results: hTERT mRNA levels in E6-positive tumors, which were prevalent in females, nonsmokers, and adenocarcinomas, were significantly higher than in E6-negative tumors. In addition, hTERT mRNA levels in early tumors (stage I) were greater than levels in advanced tumors (stages II and III). Chromatin immunoprecipitation assay showed that Sp1 cooperated with c-Myc to activate hTERT transcription in TL-1 cells, which was similar to the SiHa cells. The telomerase activity of the TL-1 cells decreased concomitantly with the transfection of various doses of E6- or hTERT-RNAi. A soft-agar assay showed that the oncogenic potential of TL-1 cells was significantly reduced after being transfected with E6-RNAi. Moreover, a colony of TL-1 cells could not form after transfection with hTERT-RNAi.

Conclusion: Transcriptional activation of hTERT by E6 oncoprotein is required for HPV-16/18-infected lung tumorigenesis.
Prognostic Significance of Epithelial-Mesenchymal and Mesenchymal-Epithelial Transition Protein Expression in Non–Small Cell Lung Cancer
Authors: Soltermann Alex , Tischler Verena , Arbogast Stefanie , Braun Julia , Probst-Hensch Nicole , Weder Walter , Moch Holger , Kristiansen Glen
Published: November 2008

Purpose: In carcinomas, invasive tumor growth is accompanied by desmoplastic stroma reaction and facilitated by epithelial-mesenchymal transition (EMT) of cancer cells. We investigated the prognostic significance of the EMT indicator proteins periostin and vimentin in comparison with versican, a putative indicator of the opposite mechanism mesenchymal-epithelial transition (MET), and to the desmoplasia proteins collagen and elastin in non-small cell lung cancer (NSCLC).

Experimental Design: Tumor of 533 patients with surgically resected NSCLC was used for analysis of stromal and epithelial protein expression by immunohistochemistry (EMT-MET proteins) and Elastica van Gieson histochemical staining (collagen and elastin). A semiquantitative sum scoring system was done on three tissue microarrays.

Results: Of the 533 patients, 48% had squamous cell carcinoma, 47% adenocarcinoma, and 5% adenosquamous carcinoma. High expression of periostin in either stroma or tumor epithelia, independently scored by two pathologists, correlated with male gender, higher stage, higher pT category, and larger tumor size, and in only stroma with tumor relapse. High expression of versican in either stroma or epithelia as well as of stromal collagen had fewer but concordant associations with advanced tumor and periostin, respectively. High expression of elastin was oppositely associated with less advanced disease. Associations of high vimentin were inconsistent (all P values <0.05). High stromal periostin was found to be a prognostic factor for decreased progression-free survival on univariate analysis (P = 0.007).

Conclusions: Because up-regulation is frequently observed in the stromal and epithelial tumor compartment, EMT-MET indicator proteins may be integrated in progression models of NSCLC.
Relapse-Free Survival in Breast Cancer Patients Is Associated with a Gene Expression Signature Characteristic for Inflammatory Breast Cancer
Authors: Van Laere Steven , Beissbarth Tim , Van der Auwera Ilse , Van den Eynden Gert , Trinh Xuan Bich , Elst Hilde , Van Hummelen Paul , van Dam Peter , Van Marck Eric , Vermeulen Peter , Dirix Luc
Published: November 2008

Purpose: We hypothesize that a gene expression profile characteristic for inflammatory breast cancer (IBC), an aggressive form of breast cancer associated with rapid cancer dissemination and poor survival, might be related to tumor aggressiveness in non-IBC (nIBC).

Experimental Design: RNA from 17 IBC samples and 40 nIBC samples was hybridized onto Affymetrix chips. A gene signature predictive of IBC was identified and applied onto 1,157 nIBC samples with survival data of 881 nIBC samples. Samples were classified as IBC-like or nIBC-like. The IBC signature classification was compared with the classifications according to other prognostically relevant gene signatures and clinicopathologic variables. In addition, relapse-free survival (RFS) was compared by the Kaplan-Meyer method.

Results: Classification according to the IBC signature is significantly (P < 0.05) associated with the cell-of-origin subtypes, the wound healing response, the invasive gene signature, the genomic grade index, the fibroblastic neoplasm signature, and the 70-gene prognostic signature. Significant associations (P < 0.01) were found between the IBC signature and tumor grade, estrogen receptor status, ErbB2 status, and patient age at diagnosis. Patients with an IBC-like phenotype show a significantly shorter RFS interval (P < 0.05). Oncomine analysis identified cell motility as an important concept linked with the IBC signature.

Conclusions: We show that nIBC carcinomas having an IBC-like phenotype have a reduced RFS interval. This suggests that IBC and nIBC show comparable phenotypic traits, for example augmented cell motility, with respect to aggressive tumor cell behavior. This observation lends credit to the use of IBC to study aggressive tumor cell behavior.
Opposing Roles of c-Jun NH2-Terminal Kinase and p38 Mitogen-Activated Protein Kinase in the Cellular Response to Ionizing Radiation in Human Cervical Cancer Cells
Authors: Kim Min-Jung , Choi Soon-Young , Park In-Chul , Hwang Sang-Gu , Kim Changil , Choi Young-Hyun , Kim Haekwon , Lee Kee-Ho , Lee Su-Jae
Published: November 2008

Exposure of cells to ionizing radiation induces activation of multiple signaling pathways that play critical roles in determining cell fate. However, the molecular basis for cell death or survival signaling in response to radiation is unclear at present. Here, we show opposing roles of the c-jun NH2-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK) pathways in the mitochondrial cell death in response to ionizing radiation in human cervical cancer cells. Ionizing radiation triggered Bax and Bak activation, Bcl-2 down-regulation, and subsequent mitochondrial cell death. Inhibition of JNK completely suppressed radiation-induced Bax and Bak activation and Bcl-2 down-regulation. Dominant-negative forms of stress-activated protein kinase/extracellular signal-regulated kinase kinase 1 (SEK-1)/mitogen-activated protein kinase kinase-4 (MKK-4) inhibited JNK activation. Radiation also induced phosphoinositide 3-kinase (PI3K) activation. Interestingly, inhibition of PI3K effectively attenuated radiation-induced mitochondrial cell death and increased clonogenic survival. Inhibition of PI3K also suppressed SEK-1/MKK-4 and JNK activation, Bax and Bak activation, and Bcl-2 down-regulation. In contrast, inhibition of p38 MAPK led to enhanced Bax and Bak activation and mitochondrial cell death. RacN17, a dominant-negative form of Rac1, inhibited p38 MAPK activation and increased Bax and Bak activation. Exposure of cells to radiation also induced selective activation of c-Src among Src family kinases. Inhibition of c-Src by pretreatment with Src family kinase inhibitor PP2 or small interfering RNA targeting of c-Src attenuated radiation-induced p38 MAPK and Rac1 activation and enhanced Bax and Bak activation and cell death. Our results support the notion that the PI3K-SEK-1/MKK-4-JNK pathway is required for the mitochondrial cell death in response to radiation, whereas the c-Src-Rac1-p38 MAPK pathway plays a cytoprotective role against mitochondrial cell death. (Mol Cancer Res 2008;6(11):1718–31)
Mesothelin-Induced Pancreatic Cancer Cell Proliferation Involves Alteration of Cyclin E via Activation of Signal Transducer and Activator of Transcription Protein 3
Authors: Bharadwaj Uddalak , Li Min , Chen Changyi , Yao Qizhi
Published: November 2008

Mesothelin (MSLN) is a cell surface glycoprotein that is overexpressed in human pancreatic cancer. Although its value as a tumor marker for diagnosis and prognosis and as a preferred target of immunointervention has been evaluated, there is little information on the growth advantage of MSLN on tumor cells. In this study, we examined the effect of MSLN on pancreatic cancer cell proliferation, cell cycle progression, expression of cell cycle regulatory proteins, and signal transduction pathways in two pancreatic cancer cell lines, MIA-MSLN (overexpressing MSLN in MIA PaCa-2 cells) and BxPC-siMSLN (silencing MSLN in BxPC-3 cells). Increased cyclin E and cyclin-dependent kinase 2 expression found in MIA-MSLN cells correlated with significantly increased cell proliferation and faster cell cycle progression compared with control cells. BxPC-siMSLN cells showed slower proliferation and slower entry into the S phase than control cells. Signal transducer and activator of transcription protein 3 (Stat3) was constitutively activated in MIA-MSLN cells, but not in control cells. Inhibition of Stat3 activation in MIA-MSLN cells by the Janus-activated kinase–selective inhibitor tyrphostin AG490 was followed by a marked decrease in proliferation of the cells. Small interfering RNA against Stat3 significantly reduced the MIA-MSLN cell cycle progression with a concomitant decrease in cyclin E expression. Our data indicate that overexpression of MSLN in pancreatic cancer cells leads to constitutive activation of the transcription factor Stat3, which results in enhanced expression of cyclin E and cyclin E/cyclin-dependent kinase 2 complex formation as well as increased G1-S transition. (Mol Cancer Res 2008;6(11):1755–65)
Pancreatobiliary Reflux Resulting in Pancreatic Ascites and Choleperitoneum after Gallbladder Perforation
Authors: Rapetti Rachele , Scaglia Elena , Fangazio Stefano , Burlone Michela Emma , Leutner Monica , Pirisi Mario
Published: November 2008

A 65-year-old man with chronic hepatitis C and no history of alcohol abuse was admitted to our liver unit for the recent development of massive ascites and presumed hepatorenal syndrome. In the preceding two weeks, he had received medical treatment for acute pancreatitis and cholecystitis. Abdominal paracentesis demonstrated a cloudy, orange peritoneal fluid, with total protein concentration 3.6 g/dl, serum-ascites albumin gradient 1.0 g/dl, and ratios of ascites-serum bilirubin and amylase approximately 8:1. Diagnostic imaging demonstrated no pancreatic pseudocysts. Ten days later, at laparotomy, acalculous perforation of the gallbladder was identified. After cholecystectomy, amylase concentration in the ascitic fluid dropped within a few days to 40% of serum values; ascites disappeared within a few weeks. We conclude that in the presence of a perforated gallbladder, pancreatobiliary reflux was responsible for this unusual combination of choleperitoneum and pancreatic ascites, which we propose to call pancreatobiliary ascites.
Clinicopathologic Features and Predictors for Survival of Mucinous and Nonmucinous Appendiceal Adenocarcinoma
Authors: Hsu Jun-Te , Chen Han-Ming , Liao Chien-Hung , Yeh Chun-Nan , Yeh Ta-Sen , Hwang Tsann-Long , Jan Yi-Yin , Chen Miin-Fu
Published: November 2008

Background/Aims: We report a study in patients with mucinous and nonmucinous appendiceal adenocarcinoma treated surgically whose records were examined to elucidate their clinicopathologic features and prognostic factors for survival. Methods: The medical records of 34 patients with mucinous and nonmucinous appendiceal adenocarcinoma (1991–2005) were retrospectively reviewed. Results: There was no significant difference between mucinous and nonmucinous tumors in patient demographics, clinicopathologic features, type of operation and outcome. Nonmucinous tumors had a higher incidence of leukocytosis than mucinous ones. The overall 5-year survival rate for 34 patients with appendiceal adenocarcinoma was 35.8%. In the univariate analysis, predictors of survival were the type of operation, resectability, carcinomatosis and tumor stage. Tumor stage significantly influenced patient survival in the multivariate analysis. Conclusion: Mucinous appendiceal adenocarcinoma had clinicopathologic characteristics and a prognosis similar to nonmucinous, except that there was more leukocytosis in nonmucinous tumors. Tumor stage is an independent predictor for survival among patients with appendiceal adenocarcinoma.
Clinicopathologic Features and Long-Term Outcomes of Chinese Patients with Hepatocellular Carcinoma in Non-Cirrhotic Liver
Authors: Xu Li , Huang Liang , Li Bin-kui , Zhang Ya-qi , Li Jin-qing , Yuan Yun-fei
Published: November 2008

Background/Aims: Most hepatocellular carcinomas (HCC) are associated with cirrhosis. The clinicopathologic characteristics and outcomes of HCC present in non-cirrhotic livers are not well known in Chinese patients. This study was performed to explore the features of these patients and their outcomes after hepatectomy. Methods: 96 patients with histologically confirmed HCC in non-cirrhotic liver who underwent partial hepatectomy between 1995 and 2001 in our cancer center were reviewed. A retrospective analysis of the clinicopathologic features was performed, and survival of patients was analyzed by the Kaplan-Meier method and Cox regression model. Results: Operative mortality and morbidity were none and 8.3% (8/96), respectively. Postoperative overall survival (OS) rates at 1, 3, 5 and 10 years were 84.4, 62.5, 47.9 and 38.2%, respectively, with a median OS of 57 months. Disease-free survival (DFS) rates at 1, 3, and 5 years were 56.3, 39.6, and 33.3%, respectively, with a median DFS of 18 months. TNM stage was an independent prognostic factor for both OS and DFS of non-cirrhotic HCC. Operative blood loss was an independent prognostic factor for OS and DFS of patients who received curative resection. Conclusion: Curative partial hepatectomy was an effective and safe treatment for non-cirrhotic HCC. Aggressive local therapies were recommended for patients with intrahepatic recurrence.
Use of Phototherapy for Neonatal Hyperbilirubinemia Affects Cytokine Production and Lymphocyte Subsets
Authors: Kurt Abdullah , Aygun A. Denizmen , Kurt A. Nese Citak , Godekmerdan Ahmet , Akarsu Saadet , Yilmaz Erdal
Published: November 2008

Background: Most studies regarding the influence of ultraviolet radiation on levels of inflammatory cytokines were conducted mainly in cultures of human keratinocytes or in laboratory animals. Few studies were also performed in human subjects. Objectives: To investigate the influence of the use of phototherapy on the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8 such as cytokines expressed from keratinocytes and on the expression of some lymphocyte subsets in the prevention or treatment of neonatal hyperbilirubinemia. Methods: The study group included 21 term newborns with hyperbilirubinemia and the control group included 16 healthy term newborns. Blood samples were obtained from hyperbilirubinemic newborns before and at 72 h of exposure to phototherapy and from controls at the examination time. The levels of TNF-α, IL-1β, IL-6, IL-8 and lymphocyte subsets were measured in the samples using appropriate methods. Results: Serum TNF-α, IL-1β, IL-6, and IL-8 levels are similar in study and control groups. At 72 h of exposure to phototherapy serum TNF-α, IL-1β and IL-8 levels are significantly increased, while the serum IL-6 level at the same time is not significantly changed. Lymphocytes, lymphocyte subsets and white blood cell levels are similar in the study and control groups. Only, the percentage of CD3+ lymphocyte subset is significantly lower in newborns at 72 h of exposure to phototherapy. All other lymphocyte subsets are decreased by the exposure to phototherapy, and this change was not statistically significant. Conclusions: The results demonstrate that in addition to the well-known positive effect of phototherapy on the neonatal serum bilirubin level, this treatment can affect the function of the immune system in newborns via alterations in cytokine production.