Spatio-temporal tumor heterogeneity in metastatic CRC tumors: A mutational-based approach

It is well known that activating mutations in the KRAS and NRAS genes are associated with poor response to anti-EGFR therapies in patients with metastatic colorectal cancer (mCRC). Approximately half of the patients with wild-type (WT) KRAS colorectal carcinoma do not respond to these therapies. This could be because the treatment decision is determined by the mutational profile of the primary tumor, regardless of the presence of small tumor subclones harboring RAS mutations in lymph nodes or liver metastases. We analyzed the mutational profile of the KRAS, NRAS, BRAF and PI3KCA genes using low-density microarray technology in samples of 26 paired primary tumors, 16 lymph nodes and 34 liver metastases from 26 untreated mCRC patients (n=76 samples). The most frequent mutations found in primary tumors were KRAS (15%) and PI3KCA (15%), followed by NRAS (8%) and BRAF (4%). The distribution of the mutations in the 16 lymph node metastases analyzed was as follows: 4 (25%) in KRAS gene, 3 (19%) in NRAS gene and 1 mutation each in PI3KCA and BRAF genes (6%). As expected, the most prevalent mutation in liver metastasis was in the KRAS gene (35%), followed by PI3KCA (9%) and BRAF (6%). Of the 26 cases studied, 15 (58%) displayed an overall concordance in the mutation status detected in the lymph node metastases and liver metastases compared with primary tumor, suggesting no clonal evolution. In contrast, the mutation profiles differed in the primary tumor and lymph node/metastases samples of the remaining 11 patients (48%), suggesting a spatial and temporal clonal evolution. We confirm the presence of different mutational profiles among primary tumors, lymph node metastases and liver metastases. Our results suggest the need to perform mutational analysis in all available tumor samples of patients before deciding to commence anti-EGFR treatment.This work has been partially supported by grants from the Instituto de Salud Carlos III (ISCIII; Ministerio de Sanidad y Consumo, Madrid, Spain) (PI18/00282), the Gerencia Regional de Salud de Castilla y León, Valladolid, Spain (GRS1302/A/16), the RTICC of the ISCIII (RD12/0020/0035-FEDER, RD12/0036/0048-FEDER) and CIBERONC (CB16/12/00400 and CB16/12/00233), the Fundación Memoria de Don Samuel Solórzano Barruso (Salamanca, Spain) and the Fundación Eugenio Rodríguez Pascual, (Madrid, Spain). JM Sayagués and ME Sarasquete are supported by grants (CES11/004 and CP13/00080) from the ISCIII, Ministerio de Ciencia e Innovación, Madrid, Spain

Spatio-temporal tumor heterogeneity in metastatic CRC tumors: a mutational-based approach

[EN] It is well known that activating mutations in the KRAS and NRAS genes are associated with poor response to anti-EGFR therapies in patients with metastatic colorectal cancer (mCRC). Approximately half of the patients with wild-type (WT) KRAS colorectal carcinoma do not respond to these therapies. This could be because the treatment decision is determined by the mutational profile of the primary tumor, regardless of the presence of small tumor subclones harboring RAS mutations in lymph nodes or liver metastases. We analyzed the mutational profile of the KRAS, NRAS, BRAF and PI3KCA genes using low-density microarray technology in samples of 26 paired primary tumors, 16 lymph nodes and 34 liver metastases from 26 untreated mCRC patients (n=76 samples). The most frequent mutations found in primary tumors were KRAS (15%) and PI3KCA (15%), followed by NRAS (8%) and BRAF (4%). The distribution of the mutations in the 16 lymph node metastases analyzed was as follows: 4 (25%) in KRAS gene, 3 (19%) in NRAS gene and 1 mutation each in PI3KCA and BRAF genes (6%). As expected, the most prevalent mutation in liver metastasis was in the KRAS gene (35%), followed by PI3KCA (9%) and BRAF (6%). Of the 26 cases studied, 15 (58%) displayed an overall concordance in the mutation status detected in the lymph node metastases and liver metastases compared with primary tumor, suggesting no clonal evolution. In contrast, the mutation profiles differed in the primary tumor and lymph node/metastases samples of the remaining 11 patients (48%), suggesting a spatial and temporal clonal evolution. We confirm the presence of different mutational profiles among primary tumors, lymph node metastases and liver metastases. Our results suggest the need to perform mutational analysis in all available tumor samples of patients before deciding to commence anti-EGFR treatment

Combined assessment of the TNM stage and BRAF mutational status at diagnosis in sporadic colorectal cancer patients

The prognostic impact of KRAS mutations and other KRAS-related and nonrelated genes such as BRAF, NRAS and TP53, on sporadic colorectal cancer (sCRC) remain controversial and/or have not been fully established. Here we investigated the frequency of such mutations in primary sCRC tumors and their impact on patient progression-free survival (PFS) and overall survival (OS). Primary tumor tissues from 87 sCRC patients were analysed using a custom-built next generation sequencing (NGS) panel to assess the hotspot mutated regions of KRAS/NRAS (exons 2, 3 and 4), BRAF (exon 15) and TP53 (all exons). Overall, mutations in these genes were detected in 46/87 sCRC tumors analyzed (53%) with the following frequencies per gene: TP53, 33%; KRAS, 28%; BRAF, 7%; and NRAS, 1%. A significant association was found between KRAS mutations and right side colon tumor location (p=0.05), well-differentiated tumors (p=0.04) and absence of lymphovascular invasion (p=0.05). In turn, BRAF-mutated tumors frequently corresponded to poorlyor moderately-differentiated sCRC (p=0.02) and showed a higher frequency of peritoneal carcinomatosis (p=0.006) and microsatellite instability (p=0.007). From the prognostic point of view, the BRAF mutational status together with the TNM stage were the only variables that showed an independent adverse impact on patient outcome in the multivariate analyses for both PFS and OS. Based on these results a scoring system was built and patients were classified into three prognostic subgroups with different PFS rates at 2 years: 91% vs. 77% vs. 0%, respectively (p < 0.0001). Additional prospective studies in larger series of sCRC patients where mutations in genes other than those investigated here are required to validate the utility of the proposed predictive model.This work has been partially supported by grants from the Instituto de Salud Carlos III (ISCIII; Ministerio de Sanidad y Consumo, Madrid, Spain) (PI12/02053-FIS), Gerencia Regional de Salud de Castilla y León, Valladolid, Spain (GRS1302/A/16), Consejería de Sanidad (Junta de Castilla y León, Valladolid, Spain) (BIO/SA46/14, BIO/SA02/13), RTICC from the ISCIII (RD12/0020/0035-FEDER, RD12/0036/0048-FEDER) and CIBERONC (CB16/12/00400 and CB16/12/00233), Fundación Memoria de Don Samuel Solórzano Barruso, (Salamanca, Spain) and Fundación Eugenio Rodríguez Pascual, (Madrid, Spain). JM Sayagués and ME Sarasquete are supported by grants (CES11/004 and CP13/00080) from the ISCIII, Ministerio de Ciencia e Innovación, Madrid, Spain.Peer Reviewe

Prognostic impact of a novel gene expression profile classifier for the discrimination between metastatic and non-metastatic primary colorectal cancer tumors

Despite significant advances have been achieved in the genetic characterization of sporadic colorectal cancer (sCRC), the precise genetic events leading to the development of distant metastasis remain poorly understood. Thus, accurate prediction of metastatic disease in newly-diagnosed sCRC patients remains a challenge. Here, we evaluated the specific genes and molecular pathways associated with the invasive potential of colorectal tumor cells, through the assessment of the gene expression profile (GEP) of coding and non-coding genes in metastatic (MTX) vs. non-metastatic (non-MTX) primary sCRC tumors followed for >5 years. Overall, MTX tumors showed up-regulation of genes associated with tumor progression and metastatic potential while non-MTX cases displayed GEP associated with higher cell proliferation, activation of DNA repair and anti-tumoral immune/inflammatory responses. Based on only 19 genes a specific GEP that classifies sCRC tumors into two MTX-like and non-MTX-like molecular subgroups was defined which shows an independent prognostic impact on patient overall survival, particularly when it is combined with the lymph node status at diagnosis. In summary, we show an association between the global GEP of primary sCRC cells and their metastatic potential and defined a GEP-based classifier that provides the basis for further prognostic stratification of sCRC patients who are at risk of distant metastases.This work has been partially supported by grants from the Instituto de Salud Carlos III (ISCIII; Ministerio de Economía y Competitividad, Madrid, Spain) (PI12/02053-FIS and PI17/01779-FIS), Gerencia Regional de Salud de Castilla y León, Valladolid, Spain (GRS1302/A/16), Consejería de Sanidad (Junta de Castilla y Leon, Valladolid, Spain) (BIO/SA02/13), RTICC and CIBERONC from the ISCIII (RD12/0020/0035-FEDER, RD12/0036/0048-FEDER, CB16/12/00400), Fundación Memoria de Don Samuel Solórzano Barruso, (Salamanca, Spain) and Fundación Eugenio Rodríguez Pascual, (Madrid, Spain). ML Gutiérrez and JM Sayagués are supported by grants: PTA2014-09963-I and CES11/004 from the ISCIII.Peer Reviewe

Genomic characterization of liver metastases from colorectal cancer patients

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.This work has been partially supported by grants from the Instituto de Salud Carlos III (ISCIII; Ministerio de Sanidad y Consumo, Madrid, Spain) (PI12/02053-FIS), Gerencia Regional de Salud de Castilla y León, Valladolid, Spain (GRS1302/A/16), Consejería de Sanidad (Junta de Castilla y Leon, Valladolid, Spain) (BIO/SA02/13 and BIO/SA46/14), RTICC from the ISCIII (RD12/0020/0035-FEDER, RD12/0036/0048-FEDER), Fundación Memoria de Don Samuel Solórzano Barruso, (Salamanca, Spain) and Fundación Eugenio Rodríguez Pascual, (Madrid, Spain). JM Sayagués and ME Sarasquete are supported by grants (CES11/004 and CP13/00080; respectively) from the ISCIII, Ministerio de Ciencia e Innovación, Madrid, Spain.Peer Reviewe

Ciencias Sociales y Relaciones Internacionales : nuevas perspectivas desde América Latina

Esta obra es un modesto intento para situar la disciplina de las Relaciones Internacionales dentro de las Ciencias Sociales, pero con una visión desde América Latina. El conjunto de trabajos, que se solicitaron expresamente a autoras y autores, se agrupa en tres secciones: i) Epistemología e Investigación; ii) Enfoques teóricos y metodológicos y iii) Estudio de casos.This work is a modest attempt to place the discipline of International Relations within the Social Sciences, but with a view from Latin America. The set of works, which is expressly requested from authors, is grouped into three sections: i) Epistemology and Research; ii) Theoretical and methodological approaches and iii) Case studies.Universidad Nacional, Costa RicaIDESPOCLACSOEscuela de Relaciones Internacionale

Search for Higgs and ZZ Boson Decays to J/ψγJ/\psi\gamma and Υ(nS)γ\Upsilon(nS)\gamma with the ATLAS Detector

A search for the decays of the Higgs and $Z$ bosons to $J/\psi\gamma$ and $\Upsilon(nS)\gamma$ ($n=1,2,3$) is performed with $pp$ collision data samples corresponding to integrated luminosities of up to $20.3\mathrm{fb}^{-1}$ collected at $\sqrt{s}=8\mathrm{TeV}$ with the ATLAS detector at the CERN Large Hadron Collider. No significant excess of events is observed above expected backgrounds and 95% CL upper limits are placed on the branching fractions. In the $J/\psi\gamma$ final state the limits are $1.5\times10^{-3}$ and $2.6\times10^{-6}$ for the Higgs and $Z$ bosons, respectively, while in the $\Upsilon(1S,2S,3S)\,\gamma$ final states the limits are $(1.3,1.9,1.3)\times10^{-3}$ and $(3.4,6.5,5.4)\times10^{-6}$, respectively