Genomic characterization of liver metastases from colorectal cancer patients

// Jose Maria Sayagues 1 , Luis Antonio Corchete 2 , Maria Laura Gutierrez 1 , Maria Eugenia Sarasquete 2 , Maria del Mar Abad 3 , Oscar Bengoechea 3 , Encarna Ferminan 4 , Maria Fernanda Anduaga 5 , Sofia del Carmen 3 , Manuel Iglesias 5 , Carmen Esteban 5 , Maria Angoso 5 , Jose Antonio Alcazar 5 , Jacinto Garcia 5, * , Alberto Orfao 1, * , Luis Munoz-Bellvis 5, * 1 Cytometry Service-NUCLEUS, Department of Medicine, Cancer Research Center, IBMCC-CSIC/USAL and IBSAL, University of Salamanca, Salamanca, Spain 2 Cancer Research Center and Service of Hematology, University Hospital of Salamanca, Salamanca, Spain 3 Department of Pathology, University Hospital of Salamanca, Salamanca, Spain 4 Genomics Unit, Cancer Research Center, IBMCC-CSIC/USAL, Salamanca, Spain 5 Service of General and Gastrointestinal Surgery and IBSAL, University Hospital of Salamanca, Salamanca, Spain * These authors contributed equally to this work Correspondence to: Alberto Orfao, email: orfao@usal.es Keywords: GEP, colorectal cancer Received: April 06, 2016      Accepted: September 13, 2016      Published: September 20, 2016 ABSTRACT Metastatic dissemination is the most frequent cause of death of sporadic colorectal cancer (sCRC) patients. Genomic abnormalities which are potentially characteristic of such advanced stages of the disease are complex and so far, they have been poorly described and only partially understood. We evaluated the molecular heterogeneity of sCRC tumors based on simultaneous assessment of the overall GEP of both coding mRNA and non-coding RNA genes in primary sCRC tumor samples from 23 consecutive patients and their paired liver metastases. Liver metastases from the sCRC patients analyzed, systematically showed deregulated transcripts of those genes identified as also deregulated in their paired primary colorectal carcinomas. However, some transcripts were found to be specifically deregulated in liver metastases ( vs . non-tumoral colorectal tissues) while expressed at normal levels in their primary tumors, reflecting either an increased genomic instability of metastatic cells or theiradaption to the liver microenvironment. Newly deregulated metastatic transcripts included overexpression of APOA1, HRG, UGT2B4, RBP4 and ADH4 mRNAS and the miR-3180-3p, miR-3197, miR-3178, miR-4793 and miR-4440 miRNAs, together with decreased expression of the IGKV1-39, IGKC, IGKV1-27, FABP4 and MYLK mRNAS and the miR-363, miR-1, miR-143, miR-27b and miR-28-5p miRNAs. Canonical pathways found to be specifically deregulated in liver metastatic samples included multiple genes related with intercellular adhesion and the metastatic processes (e.g., IGF1R, PIK3CA, PTEN and EGFR), endocytosis (e.g., the PDGFRA, SMAD2, ERBB3, PML and FGFR2), and the cell cycle (e.g., SMAD2, CCND2, E2F5 and MYC). Our results also highlighted the activation of genes associated with the TGFβ signaling pathway, -e.g. RHOA, SMAD2, SMAD4, SMAD5, SMAD6, BMPR1A, SMAD7 and MYC-, which thereby emerge as candidate genes to play an important role in CRC tumor metastasis.