Integrative analysis of genomic amplification-dependent expression and loss-of-function screen identifies ASAP1 as a driver gene in triple-negative breast cancer progression
ONCOGENE
Authors: He, Jichao; McLaughlin, Ronan P.; van der Beek, Lambert; Canisius, Sander; Wessels, Lodewyk; Smid, Marcel; Martens, John W. M.; Foekens, John A.; Zhang, Yinghui; van de Water, Bob
Abstract
The genetically heterogeneous triple-negative breast cancer (TNBC) continues to be an intractable disease, due to lack of effective targeted therapies. Gene amplification is a major event in tumorigenesis. Genes with amplification-dependent expression are being explored as therapeutic targets for cancer treatment. In this study, we have applied Analytical Multi-scale Identification of Recurring Events analysis and transcript quantification in the TNBC genome across 222 TNBC tumors and identified 138 candidate genes with positive correlation in copy number gain (CNG) and gene expression. siRNA-based loss-of-function screen of the candidate genes has validated EGFR, MYC, ASAP1, IRF2BP2, and CCT5 genes as drivers promoting proliferation in different TNBC cells. MYC, ASAP1, IRF2BP2, and CCT5 display frequent CNG and concurrent expression over 2173 breast cancer tumors (cBioPortal dataset). More frequently are MYC and ASAP1 amplified in TNBC tumors (>30%, n = 320). In particular, high expression of ASAP1, the ADP-ribosylation factor GTPase-activating protein, is significantly related to poor metastatic relapse-free survival of TNBC patients (n = 257, bc-GenExMiner). Furthermore, we have revealed that silencing of ASAP1 modulates numerous cytokine and apoptosis signaling components, such as IL1B, TRAF1, AIFM2, and MAP3K11 that are clinically relevant to survival outcomes of TNBC patients. ASAP1 has been reported to promote invasion and metastasis in various cancer cells. Our findings that ASAP1 is an amplification-dependent TNBC driver gene promoting TNBC cell proliferation, functioning upstream apoptosis components, and correlating to clinical outcomes of TNBC patients, support ASAP1 as a potential actionable target for TNBC treatment.
Analysis of a 62 kb DNA sequence of chromosome X reveals 36 open reading frames and a gene cluster with a counterpart on chromosome XI
YEAST
Authors: Huang, ME; Manus, V; Chuat, JC; Galibert, F
Abstract
We have sequenced a 61,989 bp stretch located between genes RAD7 and FIP1 of Saccharomyces cerevisiae chromosome X. This stretch contains 36 open reading frames (ORFs) of at least 100 codons. Fourteen of these correspond to sequences previously published as HIT1, CDC8, YAP17, CBF1, NAT1, RPA12, CCT5, TOR1, RFC2, PEM2, CDC11, MIR1, STE18 and GRR1. The proteins deduced from four ORFs (YJR059w, YJR065c, YJR075w, YJR078w) have significant similarity to proteins of known function from yeast or other organisms, including S. cerevisiae serine/threonine-specific protein kinase, Schizosaccharomyces pombe Act2 protein, S. cerevisiae mannosyltransferase OCH1 protein and mouse indoleamine 2,3-dioxygenase, respectively. Four of the remaining 18 ORFs have similarity to proteins with unknown function, six are weakly similar to other known sequences, while another eight exhibit no similarity to any known sequence. In addition, three tRNA genes have been recognized. Three genes clustered within 22 kb (YJR059w, YJR061w and TOR1) have counterparts arranged within 15 kb on the left arm of chromosome XI. The sequence has been deposited in the Genome Sequence Data Base under Accession Number L47993.