bluuebunny/crossref_metadata_2025 huggingface dataset:
Fatty Acid Synthase Gene Is Up-regulated by Hypoxia via Activation of Akt and Sterol Regulatory Element Binding Protein-1
Authors: Furuta Eiji , Pai Sudha K. , Zhan Rui , Bandyopadhyay Sucharita , Watabe Misako , Mo Yin-Yuan , Hirota Shigeru , Hosobe Sadahiro , Tsukada Taisei , Miura Kunio , Kamada Shuichi , Saito Ken , Iiizumi Megumi , Liu Wen , Ericsson Johan , Watabe Kounosuke
Published: February 2008

The fatty acid synthase (FAS) gene is significantly up-regulated in various types of cancers, and blocking the FAS expression results in apoptosis of tumor cells. Therefore, FAS is considered to be an attractive target for anticancer therapy. However, the molecular mechanism by which the FAS gene is up-regulated in tumor cells is poorly understood. We found that FAS was significantly up-regulated by hypoxia, which was also accompanied by reactive oxygen species (ROS) generation in human breast cancer cell lines. The FAS expression was also activated by H2O2, whereas N-acetyl-l-cystein, a ROS inhibitor, suppressed the expression. We also found that the hypoxia significantly up-regulated sterol regulatory–element binding protein (SREBP)-1, the major transcriptional regulator of the FAS gene, via phosphorylation of Akt followed by activation of hypoxia-inducible factor 1 (HIF1). Moreover, our results of reporter assay and chromatin immunoprecipitation analysis indicate that SREBP-1 strongly bound to the SREBP binding site/E-box sequence on the FAS promoter under hypoxia. In our xenograft mouse model, FAS was strongly expressed in the hypoxic regions of the tumor. In addition, our results of immunohistochemical analysis for human breast tumor specimens indicate that the expressions of both FAS and SREBP-1 were colocalized with hypoxic regions in the tumors. Furthermore, we found that hypoxia-induced chemoresistance to cyclophosphamide was partially blocked by a combination of FAS inhibitor and cyclophosphamide. Taken together, our results indicate that FAS gene is up-regulated by hypoxia via activation of the Akt and HIF1 followed by the induction of the SREBP-1 gene, and that hypoxia-induced chemoresistance is partly due to the up-regulation of FAS. [Cancer Res 2008;68(4):1003–11]
Targeting Tumor Antigens to Secreted Membrane VesiclesIn vivoInduces Efficient Antitumor Immune Responses
Authors: Zeelenberg Ingrid S. , Ostrowski Matias , Krumeich Sophie , Bobrie Angélique , Jancic Carolina , Boissonnas Alexandre , Delcayre Alain , Le Pecq Jean-Bernard , Combadière Béhazine , Amigorena Sebastian , Théry Clotilde
Published: February 2008

Expression of non-self antigens by tumors can induce activation of T cells in vivo, although this activation can lead to either immunity or tolerance. CD8+ T-cell activation can be direct (if the tumor expresses MHC class I molecules) or indirect (after the capture and cross-presentation of tumor antigens by dendritic cells). The modes of tumor antigen capture by dendritic cells in vivo remain unclear. Here we examine the immunogenicity of the same model antigen secreted by live tumors either in association with membrane vesicles (exosomes) or as a soluble protein. We have artificially addressed the antigen to secreted vesicles by coupling it to the factor VIII–like C1C2 domain of milk fat globule epidermal growth factor-factor VIII (MFG-E8)/lactadherin. We show that murine fibrosarcoma tumor cells that secrete vesicle-bound antigen grow slower than tumors that secrete soluble antigen in immunocompetent, but not in immunodeficient, host mice. This growth difference is due to the induction of a more potent antigen-specific antitumor immune response in vivo by the vesicle-bound than by the soluble antigen. Finally, in vivo secretion of the vesicle-bound antigen either by tumors or by vaccination with naked DNA protects against soluble antigen-secreting tumors. We conclude that the mode of secretion can determine the immunogenicity of tumor antigens and that manipulation of the mode of antigen secretion may be used to optimize antitumor vaccination protocols. [Cancer Res 2008;68(4):1228–35]
Cyclooxygenase-2 Inhibition Inhibits c-Met Kinase Activity and Wnt Activity in Colon Cancer
Authors: Tuynman Jurriaan B. , Vermeulen Louis , Boon Elles M. , Kemper Kristel , Zwinderman Aeilko H. , Peppelenbosch Maikel P. , Richel Dirk J.
Published: February 2008

Activity of receptor tyrosine kinases (RTK) in colorectal cancer (CRC) is associated with enhanced tumor growth and a poorer prognosis. In addition, cyclooxygenase-2 (COX-2) expression contributes to tumor growth and invasion. COX-2 inhibitors exhibit important anticarcinogenic potential against CRC, but the molecular mechanism underlying this effect and the relation with RTK signaling remain the subject of intense research effort. Therefore, the rapid effects of COX-2 inhibition in CRC on the complement of all cellular kinases were investigated using a kinase substrate peptide array, Western blotting, transfection, small interfering RNA assays, and CRC cell lines. The resulting alterations in the kinome profile revealed that celecoxib, a selective COX-2 inhibitor, impairs phosphorylation of substrates for the RTKs c-Met and insulin-like growth factor receptor, resulting in decreased downstream signaling. The decrease in c-Met activation is accompanied with an increase in glycogen synthase kinase 3β kinase activity together with a rapid increase in phosphorylation of β-catenin. In agreement, a significant reduction of β-catenin-T-cell factor–dependent transcription is observed both with celecoxib and selective inhibition of c-Met phosphorylation by small molecules. Hence, corepression of c-Met–related and β-catenin–related oncogenic signal transduction seems a major effector of celecoxib in CRC, which provides a rationale to use c-Met inhibitors and celecoxib analogous to target c-Met and Wnt signaling in a therapeutic setting for patients with CRC. [Cancer Res 2008;68(4):1213–20]
The SV40 Large T Antigen-p53 Complexes Bind and Activate the Insulin-like Growth Factor-I Promoter Stimulating Cell Growth
Authors: Bocchetta Maurizio , Eliasz Sandra , De Marco Melissa Arakelian , Rudzinski Jennifer , Zhang Lei , Carbone Michele
Published: February 2008

Inactivation of cellular p53 is a crucial step in carcinogenesis. Accordingly, p53 is inactivated in most human cancers by different mechanisms. In cells infected with DNA tumor viruses, p53 is bound to the viral tumor antigens (Tag). The current “dogma” views the Tag-p53 complexes as a way of sequestering and inactivating p53. Using primary human cells and SV40-transformed human cells, we show that in addition to inactivating p53 tumor suppressor activities, the Tag-p53 complex has growth stimulatory activities that are required for malignant cell growth. We found that in human cells, Tag-p53 complexes regulate transcription of the insulin-like growth factor I (IGF-I) gene by binding to the IGF-I promoter together with pRb and p300. Depletion of p53 leads to structural rearrangements of this multiprotein complex, resulting in IGF-I promoter transcriptional repression and growth arrest. Our data provide a novel mechanistic and biological interpretation of the p53-Tag complexes and of DNA tumor virus transformation in general. In the model we propose, p53 is not a passive inactive partner of Tag. Instead the p53-Tag complex promotes malignant cell growth through its ability to activate the IGF-I signaling pathway. [Cancer Res 2008;68(4):1022–9]
Silencing of DUOX NADPH Oxidases by Promoter Hypermethylation in Lung Cancer
Authors: Luxen Sylvia , Belinsky Steven A. , Knaus Ulla G.
Published: February 2008

The development of lung cancer is associated with aberrant promoter methylation and thus transcriptional silencing of many tumor suppressor genes or genes critical for cellular maintenance. Here we report that the NADPH oxidases DUOX1 and DUOX2, which are one of the main sources for reactive oxygen species production in the airway, are frequently silenced in human lung cancer. Screening of lung cancer cell lines revealed loss of DUOX1 and DUOX2 expression, which was restored after treatment with 5-aza 2′-deoxycytidine. Two genes, DUOXA1 and DUOXA2, which are transcriptionally and functionally linked to DUOX, also showed coordinated down-regulation in lung cancer cells and lung cancer specimen. Bisulfite sequencing and methylation-specific PCR revealed that CpG-rich promoter regions in both DUOX genes are hypermethylated. Epigenetic modification of at least one DUOX gene was detected in 50% of primary adenocarcinomas. Immunohistochemical analysis of airway sections derived from cancerous and matched healthy tissues confirmed down-regulation of Duox in the ciliated epithelial cells lining the respiratory tract. Reintroduction of functional Duox1 into lung cancer cell lines increased cell migration and wound repair without affecting cell growth. Our results suggest that an area on chromosome 15 that includes DUOX1, DUOX2, and their maturation factors is a frequent target for epigenetic silencing in lung cancer. [Cancer Res 2008;68(4):1037–45]
Mutational Analysis of Thirty-two Double-Strand DNA Break Repair Genes in Breast and Pancreatic Cancers
Authors: Wang Xianshu , Szabo Csilla , Qian Chiping , Amadio Peter G. , Thibodeau Stephen N. , Cerhan James R. , Petersen Gloria M. , Liu Wanguo , Couch Fergus J.
Published: February 2008

Inactivating mutations in several genes that encode components of the DNA repair machinery have been associated with an increased risk of breast cancer. To assess whether alterations in other DNA repair genes contribute to breast cancer and to further determine the relevance of these genes to pancreatic cancer, we performed mutational analysis of 32 DNA double-strand break repair genes in genomic DNA from 38 breast tumors, 48 pancreatic tumors, and 10 non-BRCA1/BRCA2 hereditary breast cancer patients. A total of 494 coding exons were screened by denatured high-performance liquid chromatography and direct DNA sequencing. Two inactivating mutations were identified in breast tumor samples, a germline single-nucleotide deletion in POLQ (c.3605delT) and a somatic nonsense change in PRKDC (c.2408C>A, p.Ser803X). Two germline-inactivating mutations in RAD50 (c.1875C>G, p.Tyr625X and IVS14+1G>A) were also detected in separate pancreatic tumor samples. In addition, 35 novel nonsynonymous amino acid substitutions, resulting from two in-frame deletions and 33 single nucleotide alterations, were identified. Seven of these were predicted to influence protein function. A separate analysis of the CLSPN c.3839C>T (rs35490896) variant that was observed more frequently in breast tumors than in pancreatic tumors or normal controls failed to detect a significant association with breast cancer risk in a Mayo Clinic breast cancer case-control study. In conclusion, this screen of DNA repair genes implicates PRKDC and POLQ as candidate tumor suppressor genes involved in breast cancer and suggests that inactivating mutations in RAD50 predispose to pancreatic cancer as well as breast cancer. [Cancer Res 2008;68(4):971–5]
FcγRIIIa Expression Is Not Increased on Natural Killer Cells Expressing the FcγRIIIa-158V Allotype
Authors: Congy-Jolivet Nicolas , Bolzec Armelle , Ternant David , Ohresser Marc , Watier Herve , Thibault Gilles
Published: February 2008

The presence of a valine (V) versus a phenylanaline (F) at position 158 of FcγRIIIa/CD16a improves the affinity for IgG and is associated with higher therapeutic response to rituximab. Increased CD16 expression on natural killer (NK) cells from donors with the VV or VF versus FF genotype has recently been reported. We indeed observed higher binding of the anti-CD16 monoclonal antibody (mAb) 3G8 on NK cells from V carriers (VV = VF > FF). However, the binding of two other anti-CD16 mAbs, LNK16 and DJ130c, decreased with the number of V allele (VV < VF < FF). CD16 transcript levels were independent on the genotype. Rituximab binding to NK cells from V carriers was higher than its binding to FF NK cells at low concentrations (10 and 100 μg/mL). However, the difference was nearly completely abolished at saturating concentrations (≥1,000 μg/mL). Finally, nearly 100% of CD16-expressing NK cells displayed a complete down-modulation of the receptor after optimal engagement by plate-bound 3G8, whatever the genotype. By contrast, the percentages of NK cells down-modulating CD16 after competitive engagement of the receptor by plate-bound rituximab increased with the number of V allele (FF, 18.2 ± 8.6%; VF, 32.0 ± 4.9%; and VV, 42.4 ± 9.9%). These results are in discrepancy with the expected increased competition that would result from an increased expression of CD16 on VV and VF NK cells. We conclude that increased binding and functional and clinical responses associated with the high-affinity FcγRIIIa-158V are unrelated to an increased expression of this allotype. [Cancer Res 2008;68(4):976–80]
Molecular Pathways Mediating Liver Metastasis in Patients with Uveal Melanoma
Authors: Bakalian Silvin , Marshall Jean-Claude , Logan Patrick , Faingold Dana , Maloney Shawn , Di Cesare Sebastian , Martins Claudia , Fernandes Bruno F. , Burnier Miguel N.
Published: February 2008

Uveal melanoma arises from melanocytes located in the uveal tract of the eye and is the most common primary intraocular tumor in adults. Metastatic liver disease is the overwhelming cause of death in uveal melanoma patients, with almost 50% of patients developing liver metastases up to 15 years after diagnosis. Most of these patients do not present with any evidence of overt metastasis at the time of initial diagnosis although it is assumed that they have undetectable micrometastases. Currently, there are no therapeutic modalities to prevent or efficiently treat the metastatic disease in uveal melanoma patients. Recent discoveries have shed light on the molecular pathways that may contribute to the progression of liver metastasis. The aim of this review is to describe new insights into the genetic and molecular pathways that may play a role in the development of liver metastases in uveal melanoma patients.
Targeting the Phosphoinositide 3-Kinase Isoform p110δ Impairs Growth and Survival in Neuroblastoma Cells
Authors: Boller Danielle , Schramm Alexander , Doepfner Kathrin T. , Shalaby Tarek , von Bueren André O. , Eggert Angelika , Grotzer Michael A. , Arcaro Alexandre
Published: February 2008

Purpose: The phosphoinositide 3-kinase (PI3K)/Akt pathway is frequently activated in human cancer and plays a crucial role in neuroblastoma biology. We were interested in gaining further insight into the potential of targeting PI3K/Akt signaling as a novel antiproliferative approach in neuroblastoma.

Experimental Design: The expression pattern and functions of class IA PI3K isoforms were investigated in tumor samples and cell lines. Effects on cell survival and downstream signaling were analyzed following down-regulation of p110α or p110δ in SH-SY5Y and LA-N-1 cells by means of RNA interference.

Results: Overexpression of the catalytic p110δ and regulatory p85α isoforms was detected in a panel of primary neuroblastoma samples and cell lines, compared with normal adrenal gland tissue. Although down-regulation of either p110α or p110δ led to impaired cell growth, reduced expression of p110δ also had a selective effect on the survival of SH-SY5Y cells. Decreased levels of p110δ were found to induce apoptosis and lead to lower expression levels of antiapoptotic Bcl-2 family proteins. SH-SY5Y cells with decreased p110δ levels also displayed reduced activation of ribosomal protein S6 kinase in response to stimulation with epidermal growth factor and insulin-like growth factor-I.

Conclusions: Together, our data reveal a novel function of p110δ in neuroblastoma growth and survival.
Irinophore C: A Liposome Formulation of Irinotecan with Substantially Improved Therapeutic Efficacy against a Panel of Human Xenograft Tumors
Authors: Ramsay Euan C. , Anantha Malathi , Zastre Jason , Meijs Marieke , Zonderhuis Jet , Strutt Dita , Webb Murray S. , Waterhouse Dawn , Bally Marcel B.
Published: February 2008

Purpose: To assess the pharmacokinetics, tumor drug accumulation, and therapeutic activity of Irinophore C, a novel liposomal formulation of irinotecan (CPT-11).

Experimental Design: The plasma lactone/carboxy levels of CPT-11 and SN-38 were determined in mice after a single i.v. dose of irinotecan (Camptosar), or Irinophore C, and the plasma t1/2, plasma area under the curve, plasma Cmax, and plasma clearance were calculated. Further, plasma and tumor drug levels were also measured in tumor-bearing mice following Irinophore C treatment. The efficacy of Irinophore C was compared with that of Camptosar in five s.c. human tumor xenografts using single-dose treatment (LS 180), a total of three doses administered at 4-day intervals (H460), or a total of three doses administered at 7-day intervals (Capan-1, PC-3, and HT-29).

Results: Compared with Camptosar, Irinophore C mediated an 8-fold increase in t1/2, a 100-fold increase in Cmax, a 1,000-fold increase in area under the curve, and a 1,000-fold decrease in clearance for the active lactone form of CPT-11. Further, the plasma and tumor SN-38 lactone levels were consistent for at least 48 h post-Irinophore C injection. Camptosar treatment (40 mg/kg) mediated a delay in the time required for tumors to increase to four times their pretreatment size compared with controls (T-C). T-Cs ranged from 2 days (LS 180 model) to 18 days (PC-3 model). Irinophore C (40 mg/kg) engendered T-Cs ranging from 14 days (LS 180 model) to 87 days (Capan-1 model).

Conclusion: Irinophore C improved CPT-11/SN-38 pharmacokinetics, promoted tumor drug accumulation, and increased therapeutic efficacy in a panel of five distinct human tumor xenografts.
Preclinical Toxicity, Toxicokinetics, and Antitumoral Efficacy Studies of DTS-201, a Tumor-Selective Peptidic Prodrug of Doxorubicin
Authors: Ravel Denis , Dubois Vincent , Quinonero Jérôme , Meyer-Losic Florence , Delord JeanPierre , Rochaix Philippe , Nicolazzi Céline , Ribes Fabien , Mazerolles Catherine , Assouly Elise , Vialatte Karine , Hor Inès , Kearsey Jonathan , Trouet André
Published: February 2008

Purpose: There is a clear clinical need for cytotoxic drugs with a lower systemic toxicity. DTS-201 (CPI-0004Na) is a peptidic prodrug of doxorubicin that shows an improved therapeutic index in experimental models. The purpose of the current study was to complete its preclinical characterization before initiation of phase I clinical trials.

Experimental Design: The preclinical development program consisted of a detailed assessment of the general and cardiac toxicity profiles of DTS-201 in mice, rats, and dogs, together with mass balance and antitumoral efficacy studies in rodents. Neprilysin and thimet oligopeptidase expression, two enzymatic activators of DTS-201, was also characterized in human breast and prostate tumor biopsies.

Results: The target organs of DTS-201 toxicity in rodents and dogs are typically those of doxorubicin, albeit at much higher doses. Importantly, chronic treatment with DTS-201 proved to be significantly less cardiotoxic than with doxorubicin at doses up to 8-fold higher in rats. The mass balance study showed that [14C] DTS-201 does not accumulate in the body after intravenous administration. The improved therapeutic index of DTS-201 compared with free doxorubicin was confirmed in three tumor xenograft models of prostate, breast, and lung cancer. Neprilysin and/or thimet oligopeptidase are expressed in all experimental human tumor types thus far tested as well as in a large majority of human breast and prostate tumor biopsies.

Conclusion: DTS-201 gave promising results in terms of general toxicity, cardiovascular tolerance, and in vivo efficacy in xenograft mouse models compared with free doxorubicin. Taken together, these results and the confirmation of the presence of activating enzymes in human tumor biopsies provide a strong rationale for a phase I clinical study in cancer patients.
Effects of Common Germ-Line Genetic Variation in Cell Cycle Genes on Ovarian Cancer Survival
Authors: Song Honglin , Hogdall Estrid , Ramus Susan J. , DiCioccio Richard A. , Hogdall Claus , Quaye Lydia , McGuire Valerie , Whittemore Alice S. , Shah Mitul , Greenberg David , Easton Douglas F. , Kjaer Susanne Kruger , Pharoah Paul D.P. , Gayther Simon A.
Published: February 2008

Purpose: Somatic alterations have been shown to correlate with ovarian cancer prognosis and survival, but less is known about the effects on survival of common inherited genetic variation. Of particular interest are genes involved in cell cycle pathways, which regulate cell division and could plausibly influence clinical characteristics of multiple tumors types.

Experimental Design: We examined associations between common germ-line genetic variation in 14 genes involved in cell cycle pathway (CCND1, CCND2, CCND3, CCNE1, CDKN1A, CDKN1B, CDKN2A, CDKN2B, CDKN2C, CDKN2D, CDK2, CDK4, CDK6, and RB1) and survival among women with invasive ovarian cancer participating in a multicenter case-control study from United Kingdom, Denmark, and United States. DNAs from up to 1,499 women were genotyped for 97 single-nucleotide polymorphisms that tagged the known common variants (minor allele frequency ≥0.05) in these genes. The genotypes of each polymorphism were tested for association with survival by Cox regression analysis.

Results: A nominally statistically significant association between genotype and ovarian cancer survival was observed for polymorphisms in CCND2 and CCNE1. The per-allele hazard ratios (95% confidence intervals) were 1.16 (1.03-1.31; P = 0.02) for rs3217933, 1.14 (1.02-1.27; P = 0.024) for rs3217901, and 0.85 (0.73-1.00; P = 0.043) for rs3217862 in CCND2 and 1.39 (1.04-1.85; P = 0.033) for rs3218038 in CCNE1. However, these were not significant after adjusting for multiple hypothesis tests.

Conclusion: It is unlikely that common variants in cell cycle pathways examined above associated with moderate effect in survival after diagnosis of ovarian cancer. Much larger studies will be needed to exclude common variants with small effects.
High-Resolution DNA Copy Number Profiling of Malignant Peripheral Nerve Sheath Tumors Using Targeted Microarray-Based Comparative Genomic Hybridization
Authors: Mantripragada Kiran K. , Spurlock Gillian , Kluwe Lan , Chuzhanova Nadia , Ferner Rosalie E. , Frayling Ian M. , Dumanski Jan P. , Guha Abhijit , Mautner Victor , Upadhyaya Meena
Published: February 2008

Purpose: Neurofibromatosis type 1 (NF1) is an autosomal dominant condition that predisposes to benign and malignant tumors. The lifetime risk of a malignant peripheral nerve sheath tumor (MPNST) in NF1 is ∼10%. These tumors have a poor survival rate and their molecular basis remains unclear. We report the first comprehensive investigation of DNA copy number across multitude of genes in NF1 tumors using high-resolution array comparative genomic hybridization (CGH), with the aim to identify molecular signatures that delineate malignant from benign NF1 tumors.

Experimental Design: We constructed an exon-level resolution microarray encompassing 57 selected genes and profiled DNA from 35 MPNSTs, 16 plexiform, and 8 dermal neurofibromas. Bioinformatic analysis was done on array CGH data to identify concurrent aberrations in malignant tumors.

Results: The array CGH profiles of MPNSTs and neurofibromas were markedly different. A number of MPNST-specific alterations were identified, including amplifications of ITGB4, PDGFRA, MET, TP73, and HGF plus deletions in NF1, HMMR/RHAMM, MMP13, L1CAM2, p16INK4A/CDKN2A, and TP53. Copy number changes of HMMR/RHAMM, MMP13, p16INK4A/CDKN2A, and ITGB4 were observed in 46%, 43%, 39%, and 32%, respectively of the malignant tumors, implicating these genes in MPNST pathogenesis. Concomitant amplifications of HGF, MET, and PDGFRA genes were also revealed in MPNSTs, suggesting the putative role of p70S6K pathway in NF1 tumor progression.

Conclusions: This study highlights the potential of array CGH in identifying novel diagnostic markers for MPNSTs.
Oncolytic Efficacy of Recombinant Vesicular Stomatitis Virus and Myxoma Virus in Experimental Models of Rhabdoid Tumors
Authors: Wu Yushui , Lun Xueqing , Zhou Hongyuan , Wang Limei , Sun Beichen , Bell John C. , Barrett John W. , McFadden Grant , Biegel Jaclyn A. , Senger Donna L. , Forsyth Peter A.
Published: February 2008

Purpose: Rhabdoid tumors are highly aggressive pediatric tumors that are usually refractory to available treatments. The purpose of this study was to evaluate the therapeutic potential of two oncolytic viruses, myxoma virus (MV) and an attenuated vesicular stomatitis virus (VSVΔM51), in experimental models of human rhabdoid tumor.

Experimental Design: Four human rhabdoid tumor cell lines were cultured in vitro and treated with live or inactivated control virus. Cytopathic effect, viral gene expression, infectious viral titers, and cell viability were examined at various time points after infection. To study viral oncolysis in vivo, human rhabdoid tumor cells were implanted s.c. in the hind flank or intracranially in CD-1 nude mice and treated with intratumoral (i.t.) or i.v. injections of live or UV-inactivated virus. Viral distribution and effects on tumor size and survival were assessed.

Results: All rhabdoid tumor cell lines tested in vitro were susceptible to productive lethal infections by MV and VSVΔM51. I.t. injection of live MV or VSVΔM51 dramatically reduced the size of s.c. rhabdoid tumor xenografts compared with control animals. I.v. administration of VSVΔM51 or i.t. injection of MV prolonged the median survival of mice with brain xenografts compared with controls (VSVΔM51: 25 days versus 21 days, log-rank test, P = 0.0036; MV: median survival not reached versus 21 days, log-rank test, P = 0.0007). Most of the MV-treated animals (4 of 6; 66.7%) were alive and apparently “cured” when the experiment was arbitrarily ended (>180 days).

Conclusions: These results suggest that VSVΔM51 and MV could be novel effective therapies against human rhabdoid tumor.
Proteomic Analysis of Laser-Captured Paraffin-Embedded Tissues: A Molecular Portrait of Head and Neck Cancer Progression
Authors: Patel Vyomesh , Hood Brian L. , Molinolo Alfredo A. , Lee Norman H. , Conrads Thomas P. , Braisted John C. , Krizman David B. , Veenstra Timothy D. , Gutkind J. Silvio
Published: February 2008

Purpose: Squamous cell carcinoma of the head and neck (HNSCC), the sixth most prevalent cancer among men worldwide, is associated with poor prognosis, which has improved only marginally over the past three decades. A proteomic analysis of HNSCC lesions may help identify novel molecular targets for the early detection, prevention, and treatment of HNSCC.

Experimental Design: Laser capture microdissection was combined with recently developed techniques for protein extraction from formalin-fixed paraffin-embedded (FFPE) tissues and a novel proteomics platform. Approximately 20,000 cells procured from FFPE tissue sections of normal oral epithelium and well, moderately, and poorly differentiated HNSCC were processed for mass spectrometry and bioinformatic analysis.

Results: A large number of proteins expressed in normal oral epithelium and HNSCC, including cytokeratins, intermediate filaments, differentiation markers, and proteins involved in stem cell maintenance, signal transduction, migration, cell cycle regulation, growth and angiogenesis, matrix degradation, and proteins with tumor suppressive and oncogenic potential, were readily detected. Of interest, the relative expression of many of these molecules followed a distinct pattern in normal squamous epithelia and well, moderately, and poorly differentiated HNSCC tumor tissues. Representative proteins were further validated using immunohistochemical studies in HNSCC tissue sections and tissue microarrays.

Conclusions: The ability to combine laser capture microdissection and in-depth proteomic analysis of FFPE tissues provided a wealth of information regarding the nature of the proteins expressed in normal squamous epithelium and during HNSCC progression, which may allow the development of novel biomarkers of diagnostic and prognostic value and the identification of novel targets for therapeutic intervention in HNSCC.
Thymidylate Synthase Expression in Gastroenteropancreatic and Pulmonary Neuroendocrine Tumors
Authors: Ceppi Paolo , Volante Marco , Ferrero Anna , Righi Luisella , Rapa Ida , Rosas Rosj , Berruti Alfredo , Dogliotti Luigi , Scagliotti Giorgio V. , Papotti Mauro
Published: February 2008

Purpose: The predictive role of the quantification of thymidylate synthase (TS) in tumors treated with antifolate drugs, such as 5-fluorouracil (5-FU), has been extensively reported in a variety of human tumors. Neuroendocrine tumors (NET) represent potential targets of antifolate agents, but no data on TS expression level in these tumors are currently available.

Experimental Design: A series of 116 NETs were collected, including 58 gastroenteropancreatic (GEP) and 58 lung NETs. In 24 well-differentiated GEP neuroendocrine carcinomas (WD-NEC), a 5-FU–based treatment was given. Total RNA was extracted from microdissected paraffin blocks. TS mRNA quantification was done by real-time PCR, whereas protein expression was evaluated by immunohistochemistry.

Results: By means of both quantification by real-time PCR and immunohistochemistry, a higher TS expression in pulmonary small cell lung cancer and large cell NEC compared with typical and atypical carcinoids was observed (P < 0.01). Similarly, in GEP tumors, a higher TS expression in poorly differentiated carcinomas than both WD-NEC and benign tumors (P < 0.01) was found. In patients with WD-NEC treated with 5-FU, high TS mRNA levels were associated with shorter time to progression (P = 0.002) and overall survival (P = 0.04). This negative prognostic role was confirmed in multivariate analysis adjusting for major prognostic variables (P = 0.01). No association between TS mRNA and survival was observed in WD-NEC patients not receiving 5-FU.

Conclusions: This study, for the first time, (a) reports the differential TS expression in the spectrum of NETs and (b) indicates TS as a possible predictive marker of treatment efficacy in WD-NEC patients treated with 5-FU.
Differential Wnt Pathway Gene Expression and E-Cadherin Truncation in Sporadic Colorectal Cancers with and without Microsatellite Instability
Authors: Ortega Paloma , Morán Alberto , de Juan Carmen , Frías Cristina , Hernández Susana , López-Asenjo Jose-Antonio , Sánchez-Pernaute Andrés , Torres Antonio , Iniesta Pilar , Benito Manuel
Published: February 2008

Purpose: Alterations in the Wnt pathway play a major role in colorectal cancer with high (MSI-H) or low microsatellite instability (MSS/MSI-L). However, the differential impact of the Wnt pathway components on these tumors is poorly understood. MMP-3 (stromelysin-1) promoter is a target of the mutator phenotype in sporadic colorectal cancer. Among MMP-3 targets, we investigated E-cadherin integrity status in both groups of tumors. Because beta-catenin is the main effector of the Wnt pathway, we have also investigated the differential cellular status of beta-catenin.

Experimental Design: Expression profiles of 114 genes related to the Wnt pathway were analyzed by oligo microarrays in 48 tumors classified by their MSI status. In addition, we analyzed 48 sporadic colorectal cancers for E-cadherin integrity status. We performed investigation of beta-catenin and cyclin D1 by immunohistochemistry using tissue arrays containing 96 tumors.

Results: Our data show that a group of genes that negatively regulate Wnt signaling are downregulated in MSS/MSI-L as compared with MSI-H colorectal tumors. E-cadherin truncation was significantly higher in MSS/MSI-L as compared with MSI-H tumors. Moreover, MSI-H tumors showed low or null beta-catenin nuclear presence, whereas the group of tumors classified as MSS or MSI-L displayed a high content of the nuclear beta-catenin location.

Conclusions: Our results suggest that the differential expression of genes that negatively regulate the Wnt pathway, as well as the status of E-cadherin and beta-catenin in MSI-H or MSS/MSI-L colorectal tumors, shed some light on the different clinical behavior showed by the two groups.
Epithelial Human Leukocyte Antigen-DR Expression Predicts Reduced Recurrence Rates and Prolonged Survival in Rectal Cancer Patients
Authors: de Bruin Elza C. , van de Velde Cornelis J.H. , van Krieken J. Han J.M. , Marijnen Corrie A.M. , Medema Jan Paul
Published: February 2008

Purpose: The development of local and distant recurrences is a major problem in the treatment of rectal cancer patients. In this study, we investigated whether epithelial human leukocyte antigen-DR (HLA-DR) expression allowed discrimination between high and low tumor recurrence rates, and analyzed the mechanism behind its expression.

Experimental Design: The role of IFNγ in HLA-DR expression was studied in rectal cancer cell lines and tumors by promoter-specific analyses of class II transactivator (CIITA). The predictive value of epithelial HLA-DR expression was investigated by immunohistochemical evaluation of 1,016 rectal tumors, obtained from a large prospective trial. Associations with recurrences and survival were determined by univariate and multivariate log-rank testing.

Results: HLA-DR was induced by IFNγ in rectal cancer cell lines. Activity of the IFNγ-inducible pIV-CIITA promoter correlated with epithelial HLA-DR expression in rectal tumors. Patients with HLA-DR–positive tumors developed less frequent local and distant recurrences [1.6% versus 9.1% (P = 0.0015) and 15.3% versus 29.9% (P < 0.0001), respectively, after 5 years of follow-up] and had better survival (78.6% versus 61.3%; P < 0.0001) than patients with HLA-DR–negative tumors. Epithelial HLA-DR was more often found in lower tumor-node-metastasis (TNM) stages. Next to TNM and circumferential resection margin, HLA-DR expression was independently associated with lower distant recurrence rates and prolonged survival.

Conclusions: Epithelial HLA-DR expression can be used as a marker to discriminate patients with high or low risk of developing recurrences. The possible involvement of IFNγ, the relationship with lower TNM stages, and the independent effect on recurrence development together suggest that the host immune response plays an important role in controlling tumor cells.
Identifying Breast Cancer Druggable Oncogenic Alterations: Lessons Learned and Future Targeted Options
Authors: Ocaña Alberto , Pandiella Atanasio
Published: February 2008

Although the introduction of novel therapies and drug combinations has improved the prognosis of metastatic breast cancer, this disease remains incurable. It is therefore important to develop additional novel therapeutic strategies and agents. Increased understanding of the biology and the molecular alterations present in breast cancer is facilitating the design of targeted therapies directed to oncogenic proteins. Here, we review the signaling pathways and proteins that participate in breast cancer proliferation and survival, with special emphasis in those that are druggable. We will also comment on how the knowledge on the basic pathogenetic processes is translated into drug development strategies that are reaching the breast cancer clinic.
Effect of Trans-2,3-Dimethoxycinnamoyl Azide on Enhancing Antitumor Activity of Romidepsin on Human Bladder Cancer
Authors: Fan Jinhai , Stanfield Jennifer , Guo Yi , Karam Jose A. , Frenkel Eugene , Sun Xiankai , Hsieh Jer-Tsong
Published: February 2008

Purpose: Romidepsin (FK228, depsipeptide, FR901228), a unique cyclic depsipeptide with a histone deacetylase inhibitor (HDACI) activity, is a potential cancer therapeutic agent and currently under clinical trials for several types of cancer. For bladder cancer, romidepsin seems to be a potent antitumor agent from our recent study. In this study, we further delineate a new agent that can enhance both HDACI and antitumor activity of romidepsin.

Experimental Design: We screened a chemical library to identify candidate(s) that could enhance romidepsin activity. Chemical synthesis and purification were carried out to produce pure compound to examine its biochemical and antitumor effect on bladder cancer cell lines both in vitro and in vivo.

Results: Tranilast, N-(acetoacetyl) anthranilic acid, was first identified as a lead compound from screening, and then, one of the analogues, 2,3-dimethoxycinnamoyl azide (DMCA), seems to be more potent than tranilast. Our data indicate that DMCA can potentiate the HDACI activity of romidepsin and other biological activities, such as cell cycle arrest and apoptosis; these effects were accompanied with the expression of various key cell cycle regulators in different bladder cancer cells. Consistently, DMCA can enhance the in vivo antitumor effect of romidepsin without causing any more weight loss than romidepsin alone.

Conclusion: DMCA is able to enhance the antitumor effect of romidepsin on bladder cancer from in vitro and in vivo.
Yeast-Derived β-Glucan Augments the Therapeutic Efficacy Mediated by Anti–Vascular Endothelial Growth Factor Monoclonal Antibody in Human Carcinoma Xenograft Models
Authors: Salvador Carolina , Li Bing , Hansen Richard , Cramer Daniel E. , Kong Maiying , Yan Jun
Published: February 2008

Purpose: Bevacizumab is a recombinant IgG1 humanized monoclonal antibody against vascular endothelial growth factor (VEGF). Its proposed mechanism of action is independent of immune effector functions. Many human carcinomas not only secrete VEGF but also express membrane-bound VEGF. In addition, VEGF receptors are expressed on tumor cells. It is hypothesized that bevacizumab could bind membrane-bound VEGF or VEGF-VEGF receptor complexes on tumors, thereby initiating potential immunologic consequences. We previously showed that yeast-derived β-glucan functions with antitumor antibodies that activate complement to recruit complement receptor 3–expressing leukocytes capable of mediating complement receptor 3–dependent cellular cytotoxicity of tumors opsonized with iC3b. In the current study, the therapeutic efficacy mediated by combining bevacizumab with yeast-derived β-glucan was studied in human carcinoma xenograft models.

Experimental Design: Human tumor cell lines were screened for membrane-bound VEGF expression both in vitro and in vivo. Complement activation mediated by bevacizumab was examined. Tumor cell lines positive or negative for membrane-bound VEGF expression were implanted in severe combined immunodeficient mice to establish xenograft models. Tumor-bearing mice were treated with different regimens. Tumor regression and long-term survival were recorded.

Results: Human ovarian carcinoma SKOV-3 cells expressed membrane-bound VEGF both in vitro and in vivo. Bevacizumab was bound to membrane-bound VEGF, activated complement, and synergized with β-glucan to elicit cellular cytotoxicity in vitro. In vivo study showed that β-glucan could significantly augment the therapeutic efficacy mediated by bevacizumab.

Conclusions: Yeast-derived β-glucan can synergize with anti-VEGF monoclonal antibody bevacizumab for the treatment of cancer with membrane-bound VEGF expression.
Suppression of Peutz-Jeghers Polyposis by Targeting Mammalian Target of Rapamycin Signaling
Authors: Wei Chongjuan , Amos Christopher I. , Zhang Nianxiang , Wang Xiaopei , Rashid Asif , Walker Cheryl L. , Behringer Richard R. , Frazier Marsha L.
Published: February 2008

Purpose: Peutz-Jeghers syndrome (PJS) is a unique disorder characterized by the development of hamartomas in the gastrointestinal tract as well as increased risks for variety of malignancies. Germ-line mutations of LKB1 cause PJS. We have generated Lkb1+/− mice, which model human PJS. Rapamycin and its analogues are promising preventive and therapeutic agents that specifically inhibit signaling from mammalian target of rapamycin (mTOR). Hyperactivation of mTOR signaling has been associated with PJS. The objective of the study is to investigate the efficacy of mTOR inhibition in suppressing Peutz-Jeghers polyposis in Lkb1+/− mice.

Experimental Design: We initiated a trial of rapamycin in Lkb1+/− mice at 9 months of age (after the onset of polyposis) at the dose of 2 mg/kg/d for a 2-month period. We assessed the efficacy of rapamycin by measuring polyp sizes and tumor burden. To examine the effect of rapamycin on mTOR signaling, phosphorylation levels of S6 were evaluated by immunostaining.

Results: We observed a significant decrease in mean tumor burden (Student's t test, P = 0.023) as well as total tumor burden in rapamycin-treated group compared with control group. Comparison of the polyp size observed in both rapamycin-treated and control groups showed that rapamycin efficiently decreased the tumor burden of large polyps (>8 mm). This inhibition of rapamycin was associated with a decrease in phosphorylated S6 levels in the polyps.

Conclusions: Rapamycin effectively suppresses Peutz-Jeghers polyposis in a mouse model, suggesting that rapamycin or its analogues may represent a new targeted therapy for the treatment of PJS.
Analysis of Integrin β4 Expression in Human Breast Cancer: Association with Basal-like Tumors and Prognostic Significance
Authors: Lu Shaolei , Simin Karl , Khan Ashraf , Mercurio Arthur M.
Published: February 2008

Purpose: The β4 integrin has been implicated in functions associated with the genesis and progression of carcinomas based on data obtained from cell lines and mouse models. Data on its expression and relevance to human carcinomas, however, are relatively scant. The aim of this study was to assess its expression and prognostic significance in human breast carcinomas.

Experimental Design: We integrated data on β4 expression from multiple gene profiling studies of breast tumors of known clinical outcome with immunohistochemical analysis of 105 breast carcinomas, and we identified genes whose expression correlates with that of β4.

Results: The expression of both β4 mRNA and protein is not homogeneous in breast cancer and it associates most significantly with the “basal-like” subtype of breast tumors (P = 0.008). No association between β4 and HER2 expression was evident from either gene profiling or immunohistochemical analysis. To gain insight into the relevance of β4 expression to human breast carcinomas, we generated a 65-gene “β4 signature” based on integration of four published gene profiling studies that included the top 0.1% of genes that correlated with β4, either positively or negatively. This β4 signature predicted decreased time to tumor recurrence and survival of patients when applied to four data sets including two independent ones.

Conclusions: These observations indicate that β4 expression in human breast cancer is restricted and associated with basal-like cancers, and they support the hypothesis that β4 may function in concert with a discrete set of proteins to facilitate the aggressive behavior of a subset of tumors.
Reduced hGC-1 Protein Expression Is Associated with Malignant Progression of Colon Carcinoma
Authors: Liu Wenli , Liu Yueqin , Zhu Jianqiong , Wright Elizabeth , Ding Ivan , Rodgers Griffin P.
Published: February 2008

Purpose: hGC-1 (human granulocyte colony–stimulating factor–stimulated clone 1) is a gastrointestinal protein that is a member of the olfactomedin glycoprotein family. Its biological function remains poorly understood. Aberrant expression of hGC-1 in some human carcinomas has been recently reported. The purpose of this study was to examine hGC-1 expression in colon carcinoma and explore the relationship between hGC-1 expression and the clinicopathologic features of patients with colon cancer.

Experimental Design: The expression of hGC-1 in colon adenocarcinoma tissues was examined by dot-blot analysis, in situ hybridization, and immunohistochemistry. The association of hGC-1 expression pattern with patient differentiation grade, tumor stage, metastasis, and survival were examined. To further investigate the involvement of hGC-1 in colon cancer progression, human colon carcinoma (HT-29) cells overexpressing hGC-1 were established and cell proliferation, adhesion, and migration were studied.

Results: Compared with normal colon mucosa, the up-regulation of hGC-1 was more frequently detected in more differentiated colon cancers, whereas down-regulation or no expression was associated with poorly differentiated colon cancers. Interestingly, hGC-1 down-regulation was also found in late tumor-node-metastasis stage, metastasis, and in patients with shorter survival. The morphology and cortical actin distribution of HT-29 cells were altered by hGC-1 overexpression. However, this did not change cell proliferation, but decreased cell adhesion and migration.

Conclusion: Our findings indicate that hGC-1 is involved in colon cancer adhesion and metastasis, and that hGC-1 may be a useful marker for tumor differentiation and progression of human colon carcinoma.
Phase I Trial of VNP40101M (Cloretazine) in Children with Recurrent Brain Tumors: A Pediatric Brain Tumor Consortium Study
Authors: Gururangan Sridharan , Turner Christopher D. , Stewart Clinton F. , O'Shaughnessy Melinda , Kocak Mehmet , Poussaint Tina Young , Phillips Peter C. , Goldman Stewart , Packer Roger , Pollack Ian F. , Blaney Susan M. , Karsten Verena , Gerson Stanton L. , Boyett James M. , Friedman Henry S. , Kun Larry E.
Published: February 2008

Purpose: VNP40101M (Cloretazine), a novel DNA alkylating agent, was evaluated in a phase I study in children with recurrent brain tumors.

Experimental Design: VNP40101M was given i.v. daily for 5 consecutive days every 6 weeks for up to eight cycles. Dose escalation was done independently in patients stratified based on intensity of prior therapy (moderately pretreated, stratum I; heavily pretreated, stratum II). Correlative studies included pharmacokinetics and measurement of O6-alkylguanine-DNA alkyl transferase levels in peripheral blood mononuclear cells before and after treatment.

Results: Forty-one eligible patients (stratum I, 19; stratum II, 22) were enrolled on this study. The dose-limiting toxicity in 35 evaluable patients was myelosuppression, which occurred in 4 of 16 patients in stratum I and 3 of 19 patients in stratum II. Pharmacokinetic studies showed a median terminal half-life of 30 min (range, 14-39.5). The maximum tolerated dose in stratum I and II were 45 and 30 mg/m2/d daily for 5 days every 6 weeks, respectively. Peripheral blood mononuclear cells alkylguanine alkyl transferase levels did not decrease significantly after VNP40101M treatment. Central imaging review confirmed that three patients had stable disease for a median of 45 weeks (range, 37-61+) after therapy.

Conclusions: The recommended dose of VNP40101M for phase II studies in children with brain tumors is 45 mg/m2/d in moderately pretreated and 30 mg/m2/d in heavily pretreated patients when administered for 5 consecutive days every 6 weeks.