Unknown,Transcriptomics,Genomics,Proteomics

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Genetic alteration in recurrent melanoma - part 2

ABSTRACT: Studying a unique case of metastatic melanoma, we observed that cell lines derived from metachronous metastases arising over a decade retained a central core of genetic stability in spite of divergent phenotypes. In the present study we expanded our previous observations comparing these autologous cell lines of clonal derivation with heterologous ones and correlated array Comparative Genomic Hybridization with gene expression profiling to determine their relative contribution to the dynamics of disease progression. aCGH and gene expression profiling were performed on autologous cell lines and heterologous melanoma cell lines originated from other patients. A striking correlation existed between total extent of genetic imbalances, global transcriptional patterns and cellular phenotypes; they did not follow a strict temporal progression but stemmed independently at various time points from a central core of genetic stability best explained according to the cancer stem cell hypothesis; although their contribution was intertwined, genomic imbalances detectable by aCGH contributed only 25% of the transcriptional traits determining autologous tumors distinctiveness. Our study provides important insights about the dynamics of cancer progression and supports the development of targeted anti-cancer therapies against stable genetic factors determining the individuality of each patientâs disease that are maintained throughout the end stage of disease. Keywords: genetic modification design We report the analysis of gene expression profiling of melanoma cell lines obtained from metastsases of a long term survivor melanoma patient and other melanoma cell lines. RNA was amplified and hybridized to 17.5K cDNA arrays.

ORGANISM(S): Homo sapiens

SUBMITTER: Francesco Marincola

PROVIDER: E-GEOD-8778 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Conservation of genetic alterations in recurrent melanoma supports the melanoma stem cell hypothesis.

Sabatino Marianna M Zhao Yingdong Y Voiculescu Sonia S Monaco Alessandro A Robbins Paul P Karai Laszlo L Nickoloff Brian J BJ Maio Michele M Selleri Silvia S Marincola Francesco M FM Wang Ena E

Cancer research 20080101 1

It is generally accepted that human cancers derive from a mutated single cell. However, the genetic steps characterizing various stages of progression remain unclear. Studying a unique case of metastatic melanoma, we observed that cell lines derived from metachronous metastases arising over a decade retained a central core of genetic stability in spite of divergent phenotypes. In the present study, we expanded our previous observations comparing these autologous cell lines of clonal derivation w ...[more]

PMID: 18172304

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Project description:Abstract: Hematopoietic stem cells (HSCs) are used in transplantation therapy to reconstitute the hematopoietic system. Human cord blood (hCB) transplantation has emerged as an attractive alternative treatment option when traditional HSC sources are unavailable, however, the absolute number of hCB HSCs transplanted is significantly lower than bone marrow or mobilized peripheral blood stem cells (MPBSCs). We previously demonstrated that dimethyl-prostaglandin E2 (dmPGE2) increased HSCs in vertebrate models. Here, we describe preclinical analyses of the therapeutic potential of dmPGE2-treatment using human and non-human primate HSCs. dmPGE2 significantly increased total human hematopoietic colony formation in vitro and enhanced engraftment of unfractionated and CD34+ hCB following xenotransplantation. In non-human primate autologous transplantation, dmPGE2-treated CD34+ MPBSCs showed stable multilineage engraftment over one year post-infusion. Together, our analyses indicated that dmPGE2 mediates conserved responses in HSCs from human and non-human primates, and provided sufficient preclinical information to support proceeding to an FDA-approved phase 1 clinical trial. In order to identify the potential mechanism of action of dmPGE2 on gene expression and HSC function, and to possibly explain the muted response of rhesus CD34+ MPBSCs to dmPGE2 exposure, microarray gene expression analysis was conducted. Human and rhesus CD34+ MPBSCs were exposed to DMSO control or dmPGE2 at a dose of either 10 and 50 uM as described above, and processed for microarray analysis at 0, 2, 6, 12 and 24 hours post treatment. Four human donors contributed 8 to 10 samples each at varying time points and dosage for a total of 37 samples (2 samples were technical repeats). Six rhesus macaques contributed 3 to 9 samples each at varying time points and dosage for a total of 28 samples (4 samples were technical repeats). Pooled PBMC's from 6 donors aphereses were used as a reference sample.

Project description:Imiquimod is a Toll-like receptor (TLR)-7 agonist capable of inducing complete clearance of basal cell carcinoma (BCC) and other cutaneous malignancies. We hypothesized that the characterization of the early transcriptional events induced by imiquimod may provide insights about immunological events preceding acute tissue and/or tumor rejection. We report a paired analysis of adjacent punch biopsies obtained pre- and post-treatment from 36 patients with BCC subjected to local application of imiquimod (N = 22) or vehicle cream (N=14) in a blinded, randomized protocol. Four treatments were assessed (q12 applications for 2 or 4 days, or q24 hrs for 4 or 8 days). RNA was amplified and hybridized to 17.5K cDNA arrays. All treatment schedules similarly affected the transcriptional profile of BCC; however, the q12 X 4days regimen, associated with highest effectiveness, induced the most changes with 637 genes unequivocally stimulated by imiquimod. A minority of transcripts (98 genes) confirmed previous reports of interferon-Â involvement. The remaining 539 genes portrayed additional immunological functions predominantly involving the activation of cellular innate and adaptive immune-effector mechanisms. Importantly, these effector signatures recapitulate previous observations of tissue rejection in the context of cancer immunotherapy, acute allograft rejection and autoimmunity. This study based on a powerful and reproducible model of cancer eradication by innate immune mechanisms provides the first insight in humans of the early transcriptional events associated with immune rejection. This model is likely representative of constant immunological pathways through which innate and adaptive immune responses combine to induce tissue destruction. Keywords: compound treatment design We report a paired analysis of adjacent punch biopsies obtained pre- and post-treatment from 36 patients with BCC subjected to local application of imiquimod (N = 22) or vehicle cream (N=14) in a blinded, randomized protocol. Four treatments were assessed (q12 applications for 2 or 4 days, or q24 hrs for 4 or 8 days). RNA was amplified and hybridized to 17.5K cDNA arrays.

Project description:HGF has been reported to have both positive and negative effects on carcinogenesis. Here we show that the loss of c-Met signaling in hepatocytes enhanced rather than suppressed the early stages of chemical hepatocarcinogenesis. c-Met conditional knockout mice (c-metfl/fl, AlbCre+/-; MetLivKO) treated with N-nitrosodiethylamine (DEN) developed significantly more and bigger tumors and with a shorter latency as compared with control (wt/wt, AlbCre+/-; Cre-Ctrl) mice. Accelerated tumor development was associated with increased rate of cell proliferation and prolonged activation of epidermal growth factor receptor (EGFR) signaling. MetLivKO livers treated with DEN also displayed elevated lipid peroxidation, decreased ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG), and upregulation of superoxide dismutase 1 (Sod1) and heat shock protein 70 (Hsp70), all consistent with increased oxidative stress. Likewise, gene expression profiling performed at 3 and 5 months after DEN treatment revealed upregulation of genes associated with cell proliferation and stress responses in c-Met mutant livers. The negative effects of c-Met-deficiency were reversed by chronic oral administration of anti-oxidant N-acetylcysteine (NAC). NAC blocked the EGFR activation and reduced the DEN-initiated hepatocarcinogenesis to the levels of Cre-Ctrl mice. These results argue that intact HGF/c-Met signaling is essential for maintaining normal redox homeostasis in the liver and has tumor suppressor effect(s) during the early stages of DEN-induced hepatocarcinogenesis. Keywords: compound treatment design To address a role for c-Met in liver carcinogenesis, we employed a hepatocyte specific c-Met conditional knockout mouse model generated in our laboratory. Mice received a single intraperitoneal injection of 10 µg/g body weight of N-nitrosodiethylamine (DEN) (Sigma-Aldrich, Inc., St. Louis, MO, USA) at 14 days of age. Livers were examined at 3 and 5 months after DEN injection. Expression profiling was conducted on five animals from each genotype per time point. Total RNA pooled from five wild-type B6/129 strain mouse livers was used as universal hybridization reference. All experiments were performed in duplicates following a dye-swapping design. Arrays were scanned with a GenePix 4000A scanner (Axon Instruments Ltd., Burlingame, CA) in a way to achieve optimal signal intensity at both channels with less than 1% saturated spots. After excluding the invalid features, all arrays were normalized to the 50th percentile of the median signal intensity using the mAdb data analysis suite (http://nciarray.nci.nih.gov/). Unsupervised cluster analysis was performed with the Cluster and TreeView programs (http://rana.lbl.gov/EisenSoftware.htm). The BRB ArrayTools V3.3.0 software package (Biometric Research Branch, National Cancer Institute; http://linus.nci.nih.gov/BRB-ArrayTools.html) was used for the supervised comparison. Differentially expressed genes were selected using a univariate 2-sample t-test (P<0.001) with a random variance model (15). Functional classification of the significant genes was based on the Gene Ontology (GO) annotations (www.geneontology.org).

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Dataset Information

Genetic alteration in recurrent melanoma - part 2

Publications

Conservation of genetic alterations in recurrent melanoma supports the melanoma stem cell hypothesis.

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