Faculty papers Kimmel Cancer Center Copyright (c) 2013 Thomas Jefferson University All rights reserved. http://jdc.jefferson.edu/kimmelccfp Recent documents in Faculty papers Kimmel Cancer Center en-us Fri, 22 Feb 2013 17:11:42 PST 3600 The Quest for the Perfect Prostate Biopsy Continues http://jdc.jefferson.edu/kimmelccfp/25 http://jdc.jefferson.edu/kimmelccfp/25 Mon, 18 Jun 2012 08:50:55 PDT Leonard G. Gomella The aryl hydrocarbon receptor binds to E2F1 and inhibits E2F1-induced apoptosis. http://jdc.jefferson.edu/kimmelccfp/24 http://jdc.jefferson.edu/kimmelccfp/24 Tue, 17 Apr 2012 11:43:00 PDT Cellular stress by DNA damage induces checkpoint kinase-2 (CHK2)-mediated phosphorylation and stabilization of the E2F1 transcription factor, leading to induction of apoptosis by activation of a subset of proapoptotic E2F1 target genes, including Apaf1 and p73. This report characterizes an interaction between the aryl hydrocarbon (Ah) receptor (AHR), a ligand-activated transcription factor, and E2F1 that results in the attenuation of E2F1-mediated apoptosis. In Ahr(-/-) fibroblasts stably transfected with a doxycycline-regulated AHR expression vector, inhibition of AHR expression causes a significant elevation of oxidative stress, gammaH2A.X histone phosphorylation, and E2F1-dependent apoptosis, which can be blocked by small interfering RNA-mediated knockdown of E2F1 expression. In contrast, ligand-dependent AHR activation protects these cells from etoposide-induced cell death. In cells expressing both proteins, AHR and E2F1 interact independently of the retinoblastoma protein (RB), because AHR and E2F1 coimmunoprecipitate from extracts of RB-negative cells. Additionally, chromatin immunoprecipitation assays indicate that AHR and E2F1 bind to the Apaf1 promoter at a region containing a consensus E2F1 binding site but no AHR binding sites. AHR activation represses Apaf1 and TAp73 mRNA induction by a constitutively active CHK2 expression vector. Furthermore, AHR overexpression blocks the transcriptional induction of Apaf1 and p73 and the accumulation of sub-G(0)/G(1) cells resulting from ectopic overexpression of E2F1. These results point to a proproliferative, antiapoptotic function of the Ah receptor that likely plays a role in tumor progression.

]]> Jennifer L Marlowe et al. Animals Apoptosis Apoptotic Protease-Activating Factor 1 Cell Cycle Cell Line, Tumor E2F1 Transcription Factor Fibroblasts Histones Humans Mice Models, Biological Oxidative Stress Promoter Regions, Genetic Receptors, Aryl Hydrocarbon A cyclin D1/microRNA 17/20 regulatory feedback loop in control of breast cancer cell proliferation. http://jdc.jefferson.edu/kimmelccfp/23 http://jdc.jefferson.edu/kimmelccfp/23 Tue, 10 Apr 2012 13:45:10 PDT Decreased expression of specific microRNAs (miRNAs) occurs in human tumors, which suggests a function for miRNAs in tumor suppression. Herein, levels of the miR-17-5p/miR-20a miRNA cluster were inversely correlated to cyclin D1 abundance in human breast tumors and cell lines. MiR-17/20 suppressed breast cancer cell proliferation and tumor colony formation by negatively regulating cyclin D1 translation via a conserved 3' untranslated region miRNA-binding site, thereby inhibiting serum-induced S phase entry. The cell cycle effect of miR-17/20 was abrogated by cyclin D1 siRNA and in cyclin D1-deficient breast cancer cells. Mammary epithelial cell-targeted cyclin D1 expression induced miR-17-5p and miR-20a expression in vivo, and cyclin D1 bound the miR-17/20 cluster promoter regulatory region. In summary, these studies identify a novel cyclin D1/miR-17/20 regulatory feedback loop through which cyclin D1 induces miR-17-5p/miR-20a. In turn, miR-17/20 limits the proliferative function of cyclin D1, thus linking expression of a specific miRNA cluster to the regulation of oncogenesis.

]]> Zuoren Yu et al. 3' Untranslated Regions Animals Base Sequence Binding Sites Breast Neoplasms Cell Line, Tumor Cell Proliferation Conserved Sequence Cyclin D1 Down-Regulation Feedback, Physiological G1 Phase Gene Expression Regulation, Neoplastic Humans Mice Mice, Inbred C57BL MicroRNAs Molecular Sequence Data Promoter Regions, Genetic Genetic Polymorphism in a VEGF-Independent Angiogenesis Gene ANGPT1 and Overall Survival of Colorectal Cancer Patients after Surgical Resection http://jdc.jefferson.edu/kimmelccfp/22 http://jdc.jefferson.edu/kimmelccfp/22 Tue, 10 Apr 2012 12:59:56 PDT

Background

The VEGF-independent angiogenic signaling plays an important role in the development of colorectal cancer (CRC). However, its implication in the clinical outcome of CRC has not been reported. This study aimed to investigate the association between genetic variations in several major VEGF-independent signaling pathway genes and the overall survival of CRC patients.

Methods

Seven single nucleotide polymorphisms (SNPs) in four important VEGF-independent angiogenic genes (ANGPT1, AMOT, DLL4 and ENG) were genotyped in a Chinese population with 408 CRC patients.

Results

One SNP, rs1954727 in ANGPT1, was significantly associated with CRC overall survival. Compared to patients with the homozygous wild-type genotype of rs1954727, those with heterozygous and homozygous variant genotypes exhibited a favorable overall survival with a hazard ratio (HR) of 0.89 (95% confidence interval [CI] 0.55–1.43, P = 0.623), and 0.32 (95% CI 0.15–0.71, P = 0.005), respectively (P trend = 0.008). In stratified analysis, this association remained significant in patients receiving chemotherapy (P trend = 0.012), but not in those without chemotherapy. We further evaluated the effects of chemotherapy on CRC survival that was stratified by rs1954727 genotypes. We found that chemotherapy resulted in a significantly better overall survival in the CRC patients (HR = 0.44, 95% CI 0.26–0.75, P = 0.002), which was especially prominent in those patients with the heterozygous genotype of rs1954727 (HR = 0.45, 95%CI 0.22–0.92, P = 0.028).

Conclusion

Our data suggest that rs1954727 in ANGPT1 gene might be a prognostic biomarker for the overall survival of CRC patients, especially in those receiving chemotherapy, a finding that warrants validation in larger independent populations.

]]> Jingyao Dai et al. MiR-128 Inhibits Tumor Growth and Angiogenesis by Targeting p70S6K1. http://jdc.jefferson.edu/kimmelccfp/21 http://jdc.jefferson.edu/kimmelccfp/21 Tue, 10 Apr 2012 12:43:10 PDT MicroRNAs are a class of small noncoding RNAs that function as critical gene regulators through targeting mRNAs for translational repression or degradation. In this study, we showed that miR-128 expression levels were decreased in glioma, and identified p70S6K1 as a novel direct target of miR-128. Overexpression of miR-128 suppressed p70S6K1 and its downstream signaling molecules such as HIF-1 and VEGF expression, and attenuated cell proliferation, tumor growth and angiogenesis. Forced expression of p70S6K1 can partly rescue the inhibitory effect of miR-128 in the cells. Taken together, these findings will shed light to the role and mechanism of miR-128 in regulating glioma tumor angiogenesis via miR-128/p70S6K1 axis, and miR-128 may serve as a potential therapeutic target in glioma in the future.

]]> Zhu-Mei Shi et al. Increase in muscle mitochondrial biogenesis does not prevent muscle loss but increased tumor size in a mouse model of acute cancer-induced cachexia. http://jdc.jefferson.edu/kimmelccfp/20 http://jdc.jefferson.edu/kimmelccfp/20 Mon, 09 Apr 2012 06:40:24 PDT Cancer-associated cachexia is a complex metabolic condition characterized by the progressive loss of body fat and deterioration of muscle mass. Although the cellular and molecular mechanisms of cachexia are incompletely understood, previous studies have suggested mitochondrial dysfunction in murine models of cancer cachexia. To better understand the metabolic shift in cancer-induced cachexia, we studied the effects of enhanced oxidative capacity on muscle wasting using transgenic mice over-expressing Peroxisome Proliferator-Activated Receptor gamma Co-activator-1α (PGC-1α) in skeletal muscle in a Lewis lung carcinoma-implanted model. Increased mitochondrial biogenesis was observed in the skeletal muscle of tumor-implanted mice. However, these increases did not prevent or reverse muscle wasting in mice harboring tumors. Moreover, tumor size was increased in muscle PGC-1α over-expressing mice. We found similar levels of circulating inflammatory cytokines in tumor-implanted animals, which was not affected by increased muscle expression of PGC-1α. Our data indicated that increased mitochondrial biogenesis in skeletal muscle is not sufficient to rescue tumor-associated, acute muscle loss, and could promote tumor growth, possibly through the release of myokines.

]]> Xiao Wang et al. Hyccin, the Molecule Mutated in the Leukodystrophy Hypomyelination and Congenital Cataract (HCC), Is a Neuronal Protein. http://jdc.jefferson.edu/kimmelccfp/19 http://jdc.jefferson.edu/kimmelccfp/19 Mon, 09 Apr 2012 06:31:54 PDT "Hypomyelination and Congenital Cataract", HCC (MIM #610532), is an autosomal recessive disorder characterized by congenital cataract and diffuse cerebral and peripheral hypomyelination. HCC is caused by deficiency of Hyccin, a protein whose biological role has not been clarified yet. Since the identification of the cell types expressing a protein of unknown function can contribute to define the physiological context in which the molecule is explicating its function, we analyzed the pattern of Hyccin expression in the central and peripheral nervous system (CNS and PNS). Using heterozygous mice expressing the b-galactosidase (LacZ) gene under control of the Hyccin gene regulatory elements, we show that the gene is primarily expressed in neuronal cells. Indeed, Hyccin-LacZ signal was identified in CA1 hippocampal pyramidal neurons, olfactory bulb, and cortical pyramidal neurons, while it did not colocalize with oligodendroglial or astrocytic markers. In the PNS, Hyccin was detectable only in axons isolated from newborn mice. In the brain, Hyccin transcript levels were higher in early postnatal development (postnatal days 2 and 10) and then declined in adult mice. In a model of active myelinogenesis, organotypic cultures of rat Schwann cells (SC)/Dorsal Root Ganglion (DRG) sensory neurons, Hyccin was detected along the neurites, while it was absent from SC. Intriguingly, the abundance of the molecule was upregulated at postnatal days 10 and 15, in the initial steps of myelinogenesis and then declined at 30 days when the process is complete. As Hyccin is primarily expressed in neurons and its mutation leads to hypomyelination in human patients, we suggest that the protein is involved in neuron-to-glia signalling to initiate or maintain myelination.

]]> Elisabetta Gazzerro et al. ChIP sequencing of cyclin D1 reveals a transcriptional role in chromosomal instability in mice. http://jdc.jefferson.edu/kimmelccfp/18 http://jdc.jefferson.edu/kimmelccfp/18 Wed, 28 Mar 2012 13:18:08 PDT Chromosomal instability (CIN) in tumors is characterized by chromosomal abnormalities and an altered gene expression signature; however, the mechanism of CIN is poorly understood. CCND1 (which encodes cyclin D1) is overexpressed in human malignancies and has been shown to play a direct role in transcriptional regulation. Here, we used genome-wide ChIP sequencing and found that the DNA-bound form of cyclin D1 occupied the regulatory region of genes governing chromosomal integrity and mitochondrial biogenesis. Adding cyclin D1 back to Ccnd1-/- mouse embryonic fibroblasts resulted in CIN gene regulatory region occupancy by the DNA-bound form of cyclin D1 and induction of CIN gene expression. Furthermore, increased chromosomal aberrations, aneuploidy, and centrosome abnormalities were observed in the cyclin D1-rescued cells by spectral karyotyping and immunofluorescence. To assess cyclin D1 effects in vivo, we generated transgenic mice with acute and continuous mammary gland-targeted cyclin D1 expression. These transgenic mice presented with increased tumor prevalence and signature CIN gene profiles. Additionally, interrogation of gene expression from 2,254 human breast tumors revealed that cyclin D1 expression correlated with CIN in luminal B breast cancer. These data suggest that cyclin D1 contributes to CIN and tumorigenesis by directly regulating a transcriptional program that governs chromosomal stability.

]]> Mathew C Casimiro et al. Physiologically based pharmacokinetics of molecular imaging nanoparticles for mRNA detection determined in tumor-bearing mice. http://jdc.jefferson.edu/kimmelccfp/17 http://jdc.jefferson.edu/kimmelccfp/17 Fri, 23 Mar 2012 12:17:08 PDT Disease detection and management might benefit from external imaging of disease gene mRNAs. Previously we designed molecular imaging nanoparticles (MINs) based on peptide nucleic acids complementary to cancer gene mRNAs. The MINs included contrast agents and analogs of insulin-like growth factor 1 (IGF-1). Analysis of MIN tumor uptake data showed stronger binding in tumors than in surrounding tissues. We hypothesized that MINs with an IGF-1 analog stay in circulation by binding to IGF-binding proteins. To test that hypothesis, we fit the tissue distribution results of several MINs in xenograft-bearing mice to a physiological pharmacokinetics model. Fitting experimental tissue distribution data to model-predicted mass transfer of MINs from blood into organs and tumors converged only when the parameter for MINs bound to circulating IGF-binding proteins was set to 10%-20% of the injected MIN dose. This result suggests that previous mouse imaging trials used more MINs than necessary. This prediction can be tested by a ramp of decreasing doses.

]]> Armin W Opitz et al. Animals Mice Nanoparticles Neoplasms, Experimental Pharmacokinetics RNA, Messenger Tissue Distribution Identification of Functionally Distinct TRAF Proinflammatory and PI3K/MEK Transforming Activities Emanating from the RET/PTC Fusion Oncoprotein http://jdc.jefferson.edu/kimmelccfp/16 http://jdc.jefferson.edu/kimmelccfp/16 Tue, 20 Mar 2012 11:15:20 PDT Thyroid carcinomas that harbor RET/PTC oncogenes are well differentiated, relatively benign neoplasms compared with those expressing oncogenic RAS or BRAF mutations despite signaling through shared transforming pathways. A distinction, however, is that RET/PTCs induce immunostimulatory programs, suggesting that, in the case of this tumor type, the additional pro-inflammatory pathway reduces aggressiveness. Here, we demonstrate that pro-inflammatory programs are selectively activated by TRAF2 and TRAF6 association with RET/PTC oncoproteins. Eliminating this mechanism reduces pro-inflammatory cytokine production without decreasing transformation efficiency. Conversely, ablating MEK/ERK or PI3K/AKT signaling eliminates transformation but not pro-inflammatory cytokine secretion. Functional uncoupling of the two pathways demonstrates that intrinsic pro-inflammatory pathways are not required for cellular transformation and suggests a need for further investigation into the role inflammation plays in thyroid tumor progression.

]]> Josephine H.F. Wixted et al. Implications of observation-fact modifiers to i2b2 ontologies http://jdc.jefferson.edu/kimmelccfp/15 http://jdc.jefferson.edu/kimmelccfp/15 Fri, 16 Mar 2012 10:38:49 PDT Biomedical translational research can be facilitated by integrating clinical and research data. In particular, study cohort identification and hypothesis generation is enabled by the mining of integrated clinical observations and research resources. The "informatics for integrating biology and the bedside, " or i2b2, framework is widely used for this biomedical data mining. The i2b2 "star schema" data model using entity-attribute-value (EA V) formatted concepts is a very efficient strategy for querying large amounts of data. However, until the most recent i2b2 release, the utility of the platform was somewhat constrained by the limitations on being able to express "facts about facts" - i.e., modify the observations about the patients. We have found that exploiting the new modifier functionality has significantly and favorably impacted the design of i2b2 ontologies, leading to easier and more meaningful query results. Copyright © 2011 IEEE.

]]> Jack W. London et al. The modifier of Min 2 (Mom2) locus: embryonic lethality of a mutation in the Atp5a1 gene suggests a novel mechanism of polyp suppression. http://jdc.jefferson.edu/kimmelccfp/14 http://jdc.jefferson.edu/kimmelccfp/14 Thu, 08 Mar 2012 08:53:22 PST Inactivation of the APC gene is considered the initiating event in human colorectal cancer. Modifier genes that influence the penetrance of mutations in tumor-suppressor genes hold great potential for preventing the development of cancer. The mechanism by which modifier genes alter adenoma incidence can be readily studied in mice that inherit mutations in the Apc gene. We identified a new modifier locus of ApcMin-induced intestinal tumorigenesis called Modifier of Min 2 (Mom2). The polyp-resistant Mom2R phenotype resulted from a spontaneous mutation and linkage analysis localized Mom2 to distal chromosome 18. To obtain recombinant chromosomes for use in refining the Mom2 interval, we generated congenic DBA.B6 ApcMin/+, Mom2R/+ mice. An intercross revealed that Mom2R encodes a recessive embryonic lethal mutation. We devised an exclusion strategy for mapping the Mom2 locus using embryonic lethality as a method of selection. Expression and sequence analyses of candidate genes identified a duplication of four nucleotides within exon 3 of the alpha subunit of the ATP synthase (Atp5a1) gene. Tumor analyses revealed a novel mechanism of polyp suppression by Mom2R in Min mice. Furthermore, we show that more adenomas progress to carcinomas in Min mice that carry the Mom2R mutation. The absence of loss of heterozygosity (LOH) at the Apc locus, combined with the tendency of adenomas to progress to carcinomas, indicates that the sequence of events leading to tumors in ApcMin/+ Mom2R/+ mice is consistent with the features of human tumor initiation and progression.

]]> Amy A Baran et al. Animals Chromosome Mapping Fetal Death Genetic Linkage Intestinal Polyposis Male Mice Mice, Inbred C57BL Mice, Inbred DBA Mitochondrial Proton-Translocating ATPases Mutation Phenotype Polyps Tumor Suppressor Proteins Disruption of c-Jun reduces cellular migration and invasion through inhibition of c-Src and hyperactivation of ROCK II kinase. http://jdc.jefferson.edu/kimmelccfp/13 http://jdc.jefferson.edu/kimmelccfp/13 Fri, 02 Mar 2012 13:21:57 PST The spread of metastatic tumors to different organs is associated with poor prognosis. The metastatic process requires migration and cellular invasion. The protooncogene c-jun encodes the founding member of the activator protein-1 family and is required for cellular proliferation and DNA synthesis in response to oncogenic signals and plays an essential role in chemical carcinogenesis. The role of c-Jun in cellular invasion remains to be defined. Genetic deletion of c-Jun in transgenic mice is embryonic lethal; therefore, transgenic mice encoding a c-Jun gene flanked by LoxP sites (c-jun(f/f)) were used. c-jun gene deletion reduced c-Src expression, hyperactivated ROCK II signaling, and reduced cellular polarity, migration, and invasiveness. c-Jun increased c-Src mRNA abundance and c-Src promoter activity involving an AP-1 site in the c-Src promoter. Transduction of c-jun(-/-) cells with either c-Jun or c-Src retroviral expression systems restored the defective cellular migration of c-jun(-/-) cells. As c-Src is a critical component of pathways regulating proliferation, survival, and metastasis, the induction of c-Src abundance, by c-Jun, provides a novel mechanism of cooperative signaling in cellular invasion.

]]> Xuanmao Jiao et al. 3T3 Cells Actins Animals Cell Movement Cells, Cultured Epithelial Cells Female Focal Adhesions Gene Deletion Genes, jun Genes, src Mammary Glands, Animal Mice Mice, Transgenic Neoplasm Invasiveness Paxillin Phosphorylation RNA, Messenger rho-Associated Kinases Whole-exome sequencing of DNA from peripheral blood mononuclear cells (PBMC) and EBV-transformed lymphocytes from the same donor. http://jdc.jefferson.edu/kimmelccfp/12 http://jdc.jefferson.edu/kimmelccfp/12 Thu, 23 Feb 2012 11:44:20 PST BACKGROUND: The creation of lymphoblastoid cell lines (LCLs) through Epstein-Barr virus (EBV) transformation of B-lymphocytes can result in a valuable biomaterial for cell biology research and a renewable source of DNA. While LCLs have been used extensively in cellular and genetic studies, the process of cell transformation and expansion during culturing may introduce genomic changes that may impact their use and the interpretation of subsequent genetic findings.

RESULTS: We performed whole exome sequencing on a tetrad family using DNA derived from peripheral blood mononuclear cells (PBMCs) and LCLs from each individual. We generated over 4.7 GB of mappable sequence to a 125X read coverage per sample. An average of 19,354 genetic variants were identified. Comparison of the two DNA sources from each individual showed an average concordance rate of 95.69%. By lowering the variant calling parameters, the concordance rate between the paired samples increased to 99.82%. Sanger sequencing of a subset of the remaining discordant variants did confirm the presence of de novo mutations arising in LCLs.

CONCLUSIONS: By varying software stringency parameters, we identified 99% concordance between DNA sequences derived from the two different sources from the same donors. These results suggest that LCLs are an appropriate representation of the genetic material of the donor and suggest that EBV transformation can result in low-level generation of de novo mutations. Therefore, use of PBMC or early passage EBV-transformed cells is recommended. These findings have broad-reaching implications, as there are thousands of LCLs in public biorepositories and individual laboratories.

]]> Eric R Londin et al. B-Lymphocytes Blood Donors Cell Line, Transformed Cell Transformation, Viral DNA Exome Herpesvirus 4, Human Humans Leukocytes, Mononuclear Sequence Analysis, DNA Enteric alpha defensins in norm and pathology. http://jdc.jefferson.edu/kimmelccfp/11 http://jdc.jefferson.edu/kimmelccfp/11 Thu, 23 Feb 2012 11:25:10 PST ABSTRACT: Microbes living in the mammalian gut exist in constant contact with immunity system that prevents infection and maintains homeostasis. Enteric alpha defensins play an important role in regulation of bacterial colonization of the gut, as well as in activation of pro- and anti-inflammatory responses of the adaptive immune system cells in lamina propria. This review summarizes currently available data on functions of mammalian enteric alpha defensins in the immune defense and changes in their secretion in intestinal inflammatory diseases and cancer.

]]> Nikolai A Lisitsyn et al. Prolactin-induced mouse mammary carcinomas model estrogen resistant luminal breast cancer. http://jdc.jefferson.edu/kimmelccfp/10 http://jdc.jefferson.edu/kimmelccfp/10 Fri, 17 Feb 2012 13:05:04 PST INTRODUCTION: Tumors that express estrogen receptor alpha (ERα+) comprise 75% of breast cancers in women. While treatments directed against this receptor have successfully lowered mortality rates, many primary tumors initially or later exhibit resistance. The paucity of murine models of this "luminal" tumor subtype has hindered studies of factors that promote their pathogenesis and modulate responsiveness to estrogen-directed therapeutics. Since epidemiologic studies closely link prolactin and the development of ERα+ tumors in women, we examined characteristics of the aggressive ERα+ and ERα- carcinomas which develop in response to mammary prolactin in a murine transgenic model (neu-related lipocalin- prolactin (NRL-PRL)). To evaluate their relationship to clinical tumors, we determined phenotypic relationships among these carcinomas, other murine models of breast cancer, and features of luminal tumors in women.

METHODS: We examined a panel of prolactin-induced tumors for characteristics relevant to clinical tumors: histotype, ERα/progesterone receptor (PR) expression and estrogen responsiveness, Activating Protein 1 (AP-1) components, and phosphorylation of signal transducer and activator of transcription 5 (Stat5), extracellular signal regulated kinase (ERK) 1/2 and AKT. We compared levels of transcripts in the ERα-associated "luminal" signature that defines this subtype of tumors in women and transcripts enriched in various mammary epithelial lineages to other well-studied genetically modified murine models of breast cancer. Finally, we used microarray analyses to compare prolactin-induced ERα+ and ERα- tumors, and examined responsiveness to estrogen and the anti-estrogen, Faslodex, in vivo.

RESULTS: Prolactin-induced carcinomas were markedly diverse with respect to histotype, ERα/PR expression, and activated signaling cascades. They constituted a heterogeneous, but distinct group of murine mammary tumors, with molecular features of the luminal subtype of human breast cancer. In contrast to morphologically normal and hyperplastic structures in NRL-PRL females, carcinomas were insensitive to ERα-mediated signals. These tumors were distinct from mouse mammary tumor virus (MMTV)-neu tumors, and contained elevated transcripts for factors associated with luminal/alveolar expansion and differentiation, suggesting that they arose from physiologic targets of prolactin. These features were shared by ERα+ and ERα- tumors, suggesting a common origin, although the former exhibited transcript profiles reflecting greater differentiation.

CONCLUSIONS: Our studies demonstrate that prolactin can promote diverse carcinomas in mice, many of which resemble luminal breast cancers, providing a novel experimental model to examine the pathogenesis, progression and treatment responsiveness of this tumor subtype.

]]> Lisa M Arendt et al. Biological rationale for the use of DNA methyltransferase inhibitors as new strategy for modulation of tumor response to chemotherapy and radiation. http://jdc.jefferson.edu/kimmelccfp/9 http://jdc.jefferson.edu/kimmelccfp/9 Tue, 14 Feb 2012 11:48:01 PST Epigenetic modifications play a key role in the patho-physiology of many tumors and the current use of agents targeting epigenetic changes has become a topic of intense interest in cancer research. DNA methyltransferase (DNMT) inhibitors represent a promising class of epigenetic modulators. Research performed yielded promising anti-tumorigenic activity for these agents in vitro and in vivo against a variety of hematologic and solid tumors. These epigenetic modulators cause cell cycle and growth arrest, differentiation and apoptosis. Rationale for combining these agents with cytotoxic therapy or radiation is straightforward since the use of DNMT inhibitor offers greatly improved access for cytotoxic agents or radiation for targeting DNA-protein complex. The positive results obtained with these combined approaches in preclinical cancer models demonstrate the potential impact DNMT inhibitors may have in treatments of different cancer types. Therefore, as the emerging interest in use of DNMT inhibitors as a potential chemo- or radiation sensitizers is constantly increasing, further clinical investigations are inevitable in order to finalize and confirm the consistency of current observations.The present article will provide a brief review of the biological significance and rationale for the clinical potential of DNMT inhibitors in combination with other chemotherapeutics or ionizing radiation. The molecular basis and mechanisms of action for these combined treatments will be discussed herein.

]]> Giovanni L Gravina et al. Animals DNA Modification Methylases Enzyme Inhibitors Epigenesis, Genetic Humans Neoplasms Radiation, Ionizing Lymph node ratio is an important and independent prognostic factor for patients with stage III melanoma http://jdc.jefferson.edu/kimmelccfp/8 http://jdc.jefferson.edu/kimmelccfp/8 Mon, 13 Feb 2012 11:52:38 PST

INTRODUCTION:

The incidence of melanoma is dramatically increasing worldwide. We hypothesized that the ratio of metastatic to examined lymph node ratio (LNR) would be the most important prognostic factor for stage III patients.

METHODS:

We retrospectively reviewed our institutional database of melanoma patients and identified 168 patients who underwent lymph node dissection (LND) for stage III disease between 1993 and 2007. Patients were divided into three groups based on LNR (≤10%, n = 93; 10-≤25%, n = 45; and >25%, n = 30). Univariate and multivariate analysis was performed using Cox proportional hazards model.

RESULTS:

The median survival time of the entire group of patients was 34 months. The median number of positive nodes was 2 (range = 1, 55), and the median number of examined nodes was 22 (range = 5-123). Tumor characteristics of the primary melanoma (such as thickness, ulceration, and primary site) were not significant predictors of survival in this analysis. By univariate analysis, LNR was an important prognostic factor. Patients with LNR 10-25% and >25% had decreased survival compared to those patients with LNR ≤10% (HR = hazard ratio = 2.0 and 3.1, respectively; P ≤ 0.005). The number of positive lymph nodes also impacted on survival (P = 0.001). In multivariate analysis, LNR of 10-25% and >25% predicted survival (HR = 2.5 and 4.0, respectively).

CONCLUSION:

LNR is an important prognostic factor in patients undergoing LND for stage III melanoma. It can be used to stratify patients being considered for adjuvant therapy trials and should be evaluated using a larger prospective database.

]]> Adam C. Berger et al. Assessment of Epidermal Growth Factor Receptor (EGFR) expression in human meningioma. http://jdc.jefferson.edu/kimmelccfp/7 http://jdc.jefferson.edu/kimmelccfp/7 Thu, 09 Feb 2012 11:15:56 PST PURPOSE: This study explores whether meningioma expresses epidermal growth factor receptor (EGFR) and determines if there is a correlation between the WHO grade of this tumor and the degree of EGFR expression.

METHODS: Following institutional review board approval, 113 meningioma specimens from 89 patients were chosen. Of these, 85 were used for final analysis. After a blinded review, immunohistochemical stains for EGFR were performed. Staining intensity (SI) was scored on a scale 0-3 (from no staining to strong staining). Staining percentage of immunoreactive cells (SP) was scored 1-5 (from the least to the maximum percent of the specimen staining). Immunohistochemical score (IHS) was calculated as the product of SI and SP.

RESULTS: Eighty-five samples of meningioma were classified in accordance with World Health Organization (WHO) criteria: benign 57/85 (67%), atypical 23/85 (27%), and malignant 5/85 (6%). The majority of samples demonstrated a moderate SI for EGFR. IHS for EGFR demonstrated a significant association between SI and histopathologic subtype. Also, there was a correlation between the SP and histopathologic subtype (p = 0.029). A significant association was determined when the benign and the atypical samples were compared to the malignant with respect to the SP (p = 0.009). While there was a range of the IHS for the benign and the atypical histologic subtypes, malignant tumors exhibited the lowest score and were statistically different from the benign and the atypical specimens (p < 0.001).

CONCLUSIONS: To our knowledge, this represents the largest series of meningioma samples analyzed for EGFR expression reported in the literature. EGFR expression is greatest in benign meningiomas and may serve a potential target for therapeutic intervention with selective EGFR inhibitors.

]]> A Gabriella Wernicke et al. Humans Immunoenzyme Techniques Meningeal Neoplasms Meningioma Neoplasm Staging Prognosis Receptor, Epidermal Growth Factor Tissue Array Analysis A meta-analysis of array-CGH studies implicates antiviral immunity pathways in the development of hepatocellular carcinoma. http://jdc.jefferson.edu/kimmelccfp/6 http://jdc.jefferson.edu/kimmelccfp/6 Wed, 08 Feb 2012 08:45:14 PST BACKGROUND: The development and progression of hepatocellular carcinoma (HCC) is significantly correlated to the accumulation of genomic alterations. Array-based comparative genomic hybridization (array CGH) has been applied to a wide range of tumors including HCCs for the genome-wide high resolution screening of DNA copy number changes. However, the relevant chromosomal variations that play a central role in the development of HCC still are not fully elucidated.

METHODS: In present study, in order to further characterize the copy number alterations (CNAs) important to HCC development, we conducted a meta-analysis of four published independent array-CGH datasets including total 159 samples.

RESULTS: Eighty five significant gains (frequency ≥ 25%) were mostly mapped to five broad chromosomal regions including 1q, 6p, 8q, 17q and 20p, as well as two narrow regions 5p15.33 and 9q34.2-34.3. Eighty eight significant losses (frequency ≥ 25%) were most frequently present in 4q, 6q, 8p, 9p, 13q, 14q, 16q, and 17p. Significant correlations existed between chromosomal aberrations either located on the same chromosome or the different chromosomes. HCCs with different etiologies largely exhibited surprisingly similar profiles of chromosomal aberrations with only a few exceptions. Furthermore, the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis indicated that the genes affected by these chromosomal aberrations were significantly enriched in 31 canonical pathways with the highest enrichment observed for antiviral immunity pathways.

CONCLUSIONS: Taken together, our findings provide novel and important clues for the implications of antiviral immunity-related gene pathways in the pathogenesis and progression of HCC.

]]> Xu Guo et al.