Amino-acid sequence conservation alignments were done using Jellyfish 3.3.1 software (Field Scientific, Lewisburg, PA, USA). in prostate tumorigenesis. Keywords:prostate cancer, genomic profiling, tumor suppressor, chromatin remodeling, cell invasion == Introduction == Prostate cancer is the most frequently diagnosed cancer and the second leading cause of cancer death among men in the United States (Jemalet al., 2010); approximately one in six men will be diagnosed within their lifetime. Prostate cancer exhibits a range of clinical behaviors, from indolent growth to highly aggressive and metastatic Hesperetin disease. Key unmet clinical needs include distinguishing indolent from aggressive cancer Hesperetin (to determine whether and how aggressively to treat), and identifying effective therapies for later-stage castration-recurrent prostate cancer (Damber and Aus, 2008). Defining the full range of molecular genetic alterations in prostate cancer should provide improved understanding and new targets for prevention and treatment. The molecular alterations underlying prostate cancer are partially understood (DeMarzoet al., 2003;Shen and Abate-Shen, 2010). Common events Hesperetin include deletion of tumor suppressors, includingCDKN1B(p27/KIP1),RB1,TP53,PTENand the prostate-specific homeobox transcription factorNKX3-1. Amplification of theMYConcogene is also frequent. In addition, oncogenic fusions driving ETS-family oncogenic transcription factors (ERG,ETV1,ETV4andETV5), most commonly asTMPRSS2-ERG, have been identified in approximately half of prostate cancers. Androgen receptor alterations, including amplification and rearrangement, can also occur in castration-recurrent prostate cancer. More recently, genomic profiling by comparative genomic hybridization (CGH) and single-nucleotide polymorphism arrays have provided comprehensive views of DNA copy number alterations in prostate cancer (Lapointeet al., 2004;Kimet al., 2007;Robbinset al., 2011), and have led to the nomination of new prostate cancer genes, for example,NCOA2(Tayloret al., 2010). Next-generation genome sequencing is also now beginning to reveal the full landscape of somatic rearrangements (Bergeret al., 2011). Here, we have carried out genomic profiling by array CGH of a large collection of primary prostate tumors. Among our findings, we identify focal recurrent deletions within 5q21 targeting the chromatin remodeler chromodomain helicase DNA-binding protein (CHD1), whose loss we characterize to be a driver of cancer cell invasiveness. == Results and discussion == To survey the landscape of DNA copy number alterations in prostate cancer, we profiled a collection of 86 primary prostate tumors (clinicopathological characteristics summarized inSupplementary Hesperetin Table S1) using Agilent 44K CGH arrays (Agilent, Santa Clara, CA, USA). Genomic Identification of Significant Targets in Cancer analysis (Beroukhimet Rabbit Polyclonal to ADA2L al., 2007) was applied to identify loci with significantly recurrent copy number alteration, which included 19 deletions and 7 amplifications (Figure 1). Deletions of known tumor suppressors included (ordered by chromosome)NKX3-1(8p21.2) (occurring in 38% of tumors),PTEN(10q23.31) (22%),CDKN1B(12p13.1) (20%),RB1(13q14.2) (40%) andTP53(17p13.1) (21%). Deletion of 21q22.2 (29%) also defined intrachromosomal rearrangements generatingTMPRSS2-ERG. Frequent gains included those on chromosomes 7 (12%) and 8 (9%), the latter spanningMYC(8q24.21), and 9 (10%). == Figure 1. == Landscape of copy number alterations in prostate cancer. Genomic Identification of Significant Targets in Cancer (GISTIC) plot identifies significant DNA copy number alterations (by consideration of both frequency and amplitude, and in comparison with randomly permuted data). Gains and losses are depicted in red and blue, respectively, and ordered by genome position. The significance threshold (false discovery rate, <0.25) is indicated, as are selected known cancer genes. Prostate tumors were obtained from radical prostatectomy cases performed at the Stanford University Hospital, with the Institutional Review Board approval and patient informed consent. Freshly-frozen specimens were cryostat sectioned and scalpel macrodissected to enrich tumor nuclei to >80%. Genomic DNA (and total RNA) were isolated using Qiagen Allprep DNA/RNA Mini Kits (Qiagen, Valencia, CA, USA). Tumor DNA and normal male reference DNA (pooled from eight donor leukocyte preparations) were respectively labeled with Cy5 and Cy3, as described (Kweiet al., 2008), then co-hybridized onto Agilent Human Genome CGH 44K arrays. Microarrays were scanned using an Agilent G2505C Microarray Scanner System, and normalized fluorescence ratios obtained using Feature Extraction 9.5.3 (Agilent). DNA gains and losses were called by Circular Binary Segmentation (Olshenet al., 2004) and significant alterations defined by GISTIC (Beroukhimet al., 2007). Array CGH data are accessible through the Gene Expression Omnibus (GSE29229). Among the most significant deletions not associated with a known tumor.