title: ROBO1 deletion as a novel germline alteration in breast and colorectal cancer patients.
abstract: Despite one third of breast (BC) and colorectal cancer (CRC) cases having a hereditary component, only a small proportion can be explained by germline mutations. The aim of this study was to identify potential genomic alterations related to cancer predisposition. Copy number variations (CNVs) were interrogated in 113 unrelated cases fulfilling the criteria for hereditary BC/CRC and presenting non-pathogenic mutations in BRCA1, BRCA2, MLH1, MSH2, TP53, and CHEK2 genes. An identical germline deep intronic deletion of ROBO1 was identified in three index patients using two microarray platforms (Agilent 4x180K and Affymetrix CytoScan HD). The ROBO1 deletion was confirmed by quantitative PCR (qPCR). Six relatives were also evaluated by CytoScan HD Array. Genomic analysis confirmed a co-segregation of the ROBO1 deletion with the occurrence of cancer in two families. Direct sequencing revealed no pathogenic ROBO1 point mutations. Transcriptomic analysis (HTA 2.0, Affymetrix) in two breast carcinomas from a single patient revealed ROBO1 down-expression with no splicing events near the intronic deletion. Deeper in silico analysis showed several enhancer regions and a histone methylation mark in the deleted region. The ROBO1 deletion in a putative transcriptional regulatory region, its down-expression in tumor samples, and the results of the co-segregation analysis revealing the presence of the alteration in affected individuals suggest a pathogenic effect of the ROBO1 in cancer predisposition.
authors.affiliation: International Research Center (CIPE), A.C. Camargo Cancer Center, Rua Taguá 440, São Paulo, CEP: 01508-010, SP, Brazil.
authors.forename: Rolando A R
authors.initials: RA
authors.lastname: Villacis
authors.affiliation: International Research Center (CIPE), A.C. Camargo Cancer Center, Rua Taguá 440, São Paulo, CEP: 01508-010, SP, Brazil.
authors.forename: Francine B
authors.initials: FB
authors.lastname: Abreu
authors.affiliation: International Research Center (CIPE), A.C. Camargo Cancer Center, Rua Taguá 440, São Paulo, CEP: 01508-010, SP, Brazil.
authors.forename: Priscila M
authors.initials: PM
authors.lastname: Miranda
authors.affiliation: Department of Pathology, Faculty of Medicine, University of São Paulo State (UNESP), Botucatu, SP, Brazil.
authors.forename: Maria A C
authors.initials: MA
authors.lastname: Domingues
authors.affiliation: International Research Center (CIPE), A.C. Camargo Cancer Center, Rua Taguá 440, São Paulo, CEP: 01508-010, SP, Brazil.
authors.forename: Dirce M
authors.initials: DM
authors.lastname: Carraro
authors.affiliation: Oncology Center, Sírio-Libanês Hospital, São Paulo, SP, Brazil.
authors.forename: Erika M M
authors.initials: EM
authors.lastname: Santos
authors.affiliation: Department of Pathology, A.C. Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Victor P
authors.initials: VP
authors.lastname: Andrade
authors.affiliation: Oncology Center, Sírio-Libanês Hospital, São Paulo, SP, Brazil.
authors.forename: Benedito M
authors.initials: BM
authors.lastname: Rossi
authors.affiliation: Department of Oncogenetics, A.C. Camargo Cancer Center, São Paulo, SP, Brazil.
authors.forename: Maria I
authors.initials: MI
authors.lastname: Achatz
authors.affiliation: International Research Center (CIPE), A.C. Camargo Cancer Center, Rua Taguá 440, São Paulo, CEP: 01508-010, SP, Brazil. rogatto@fmb.unesp.br.|Department of Urology, Faculty of Medicine, University of São Paulo State (UNESP), CEP: 18618-970, Botucatu, SP, Brazil. rogatto@fmb.unesp.br.
authors.forename: Silvia R
authors.initials: SR
authors.lastname: Rogatto
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics*; D015179:Colorectal Neoplasms / Q000209:etiology / Q000235:genetics*; D056915:DNA Copy Number Variations; D005260:Female; D017353:Gene Deletion; D020869:Gene Expression Profiling; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics*; D011971:Receptors, Immunologic / Q000235:genetics*; D000097905:Roundabout Proteins
chemical_list: D009419:Nerve Tissue Proteins; D011971:Receptors, Immunologic; D000097905:Roundabout Proteins
keywords: Breast carcinoma; Colorectal cancer; Germline deletion; Hereditary cancer; ROBO1