Differences in expression profiling and biomarkers between histological colorectal carcinomas subsets from the serrated pathway.

Histological subtypes of colorectal carcinomas (CRCs) arising from the serrated route, such as serrated adenocarcinoma (SAC) and CRC showing histological and molecular features of microsatellite instability (hmMSI-H), share common features (female gender, right-sided location, mucinous histology and altered CpG methylation) but dramatically differ in terms of prognosis, development of immune response and treatment options. Despite this, to date no expression profiling comparison has been carried out for finding out functions and molecules responsible for such differences. METHODS AND RESULTS: Molecular signatures of SAC and hmMSI-H were obtained by transcriptomic array; qPCR and immunohistochemistry (IHC) were used to validate differentially expressed genes. An over-representation of innate immunity functions (granulomonocytic recruitment, chemokine production, TLR signaling, antigen processing and presentation) were obtained from this comparison and ICAM1 was more expressed in hmMSI-H whereas two genes (CRCP and CXCL14) were more expressed in SAC. These array results were subsequently validated by qPCR, and CXCL14 and ICAM1 by IHC. Information retrieved from public databanks confirmed our findings. CONCLUSIONS: Our findings highlight specific functions and genes which provide a better understanding of the role of the immune response in the serrated pathological route and may be of help in identifying actionable molecules. This article is protected by copyright. All rights reserved.pre-print664 K

Study of IDO1 gene expression in histological variants of colorectal carcinoma.

pre-print477 K

Methylome profiling reveals functions and genes which are differentially methylated in serrated compared to conventional colorectal carcinoma.

Background: Serrated adenocarcinoma (SAC) is a recently recognized colorectal cancer (CRC) subtype accounting for 7.5–8.7 % of CRCs. It has been shown that SAC has a worse prognosis and different histological and molecular features compared to conventional carcinoma (CC) but, to date, there is no study analysing its methylome profile. Results: The methylation status of 450,000 CpG sites using the Infinium Human Methylation 450 BeadChip array was investigated in 103 colorectal specimens, including 39 SACs and 34 matched CCs, from Spanish and Finnish patients. Microarray data showed a higher representation of morphogenesis-, neurogenesis-, cytoskeleton- and vesicle transport-related functions and also significant differential methylation of 15 genes, including the iodothyronine deiodinase DIO3 and the forkhead family transcription factor FOXD2 genes which were validated at the CpG, mRNA and protein level using pyrosequencing, methylation-specific PCR, quantitative polymerase chain reaction (qPCR) and immunohistochemistry. A quantification study of the methylation status of CpG sequences in FOXD2 demonstrated a novel region controlling gene expression. Moreover, differences in these markers were also evident when comparing SAC with CRC showing molecular and histological features of high-level microsatellite instability. Conclusions: This methylome study demonstrates distinct epigenetic regulation patterns in SAC which are consistent to previous expression profile studies and that DIO3 and FOXD2 might be molecular targets for a specific histologyoriented treatment of CRC.post-print2306 K

Micropartículas de PLLA y CHT como andamiaje para la regeneración del cartílago articular : modelo animal.

The avascular nature of cartilaginous tissue has historically lead to bad prognosis in osteochondral injuries. One of the possible treatment options of these injuries is the use of scaffolds, being superior to other options that obtain a fibrous cartilage as a result. We have elaborated PLLA and CHT microspheres as a scaffold for the treatment of osteochondral injuries carried out in albine New Zealand rabbits. They were distributed into groups with different proportions of microspheres, having also a control group with untreated injuries. Native cartilage of the contralateral knees was also analysed. Samples were evaluated in order to establish the quality of the cartilage obtained (using de macroscopic ICRS, microscopic ICRS II scales and a histomorphometric study).The groups with microspheres obtained a regeneration cartilage with hyaline characteristics, a good cell distribution and regular surface. The control group resulted in a cartilage with worse organization and an irregular surface

ctDNA analysis reveals different molecular patterns upon disease progression in patients treated with osimertinib

Background: Several clinical trials have demonstrated the efficacy and safety of osimertinib in advanced nonsmall-cell lung cancer (NSCLC). However, there is significant unexplained variability in treatment outcome. Methods: Observational prospective cohort of 22 pre-treated patients with stage IV NSCLC harboring the epidermal growth factor receptor (EGFR) p.T790M resistance mutation and who were treated with osimertinib. Three hundred and twenty-six serial plasma samples were collected and analyzed by digital PCR (dPCR) and next-generation sequencing (NGS). Results: The median progression-free survival (PFS), since the start of osimertinib, was 8.9 [interquartile range (IQR): 4.6–18.0] months. The median treatment durations of sequential gefitinib + osimertinib, afatinib + osimertinib and erlotinib + osimertinib treatments were 30.1, 24.6 and 21.1 months, respectively. The p.T790M mutation was detected in 19 (86%) pre-treatment blood samples. Undetectable levels of the original EGFR-sensitizing mutation after 3 months of treatment were associated with superior PFS (HR: 0.2, 95% CI: 0.05–0.7). Likewise, re-emergence of the original EGFR mutation, alone or together with the p.T790M mutation was significantly associated with shorter PFS (HR: 8.8, 95% CI: 1.1–70.7 and HR: 5.9, 95% CI: 1.2–27.9, respectively). Blood-based monitoring revealed three molecular patterns upon progression to osimertinib: sensitizing+/T790M+/C797S+, sensitizing+/T790M+/C797S–, and sensitizing+/T790M–/ C797S–. Median time to progression in patients showing the triplet pattern (sensitizing+/T790M+/C797S+) was 12.27 months compared with 4.87 months in patients in whom only the original EGFR sensitizing was detected, and 2.17 months in patients showing the duplet pattern (sensitizing+/T790M+). Finally, we found that mutations in exon 545 of the PIK3CA gene were the most frequent alteration detected upon disease progression in patients without acquired EGFR-resistance mutations. Conclusions: Different molecular patterns identified by plasma genotyping may be of prognostic significance, suggesting that the use of liquid biopsy is a valuable approach for tumor monitoring.post-print468 K

Relaciones genotipo-fenotipo en líneas celulares de melanoma humano / María del Carmen Turpín Sevilla; director, José Carlos García-Borrón Martínez.

Tesis-Universidad de Murcia.Consulte la tesis en: BCA. GENERAL. ARCHIVO UNIVERSITARIO. TM 3924

Study of IDO1 gene expression in histological variants of colorectal carcinoma.

Conventional carcinomas (CCs) which represent most colorectal carcinomas (CRCs) have no alteration in microsatellite instability (MSI) and are classified as microsatellite stable tumors (MSS) while tumors with high-grade of microsatellite instability (MSI-H) has been associated with proximal-located sporadic CRC showing MLH1 promoter methylation and BRAF mutation. MSI-H tumors present more lymphocytic infiltrate than CCs. MSI-H tumors are considered as one end-point of the so-called serrated polyp pathway. In contrast, another CRC from this pathway, the serrated adenocarcinoma (SAC), which is more frequently KRAS mutated, usually microsatellite stable (MSS) and has no lymphocytic infiltrate, is associated with a bad prognosis. Patients with MSI-H tumors have been reported to get some benefits from immunotherapy treatments while CC and SACs patients do not obtain any benefits. These differences are believed to be due to the differences in the microsatellite instability (MSS or MSI tumors). The aim of this study is to determine the IDO gene expression in the different subtypes of colorectal carcinomas.pre-print133 K

Opiniones de profesores y alumnos sobre un programa integral online en medicina durante el confinamiento por COVID-19.

Introducción La crisis por COVID-19 supuso en marzo del 2020 el cierre de las universidades del país, con interrupción total de actividad presencial. Para afrontar el último cuatrimestre 2019/20 en confinamiento, nuestra Facultad de Medicina elaboró y aplicó un programa docente íntegramente online con un enfoque «autorregulativo» (enfocado en el aprendizaje autónomo del alumno). Este estudio presenta las opiniones de profesores y alumnos. Métodos Las características educativas del Programa online ante COVID-19 (POLAC), para primero y segundo cursos, estructuración, organización de la intervención y resultados académicos, han sido descritos en otro trabajo. Este estudio mediante encuestas online, explora opiniones de profesores y alumnos tras su desarrollo. Dos investigadores codificaron temática e independientemente las respuestas abiertas obtenidas, clasificándolas en categorías. Resultados Respondieron los ocho profesores implicados y un número variable por asignatura de alumnos, recibiéndose 234 cuestionarios (17%). Los alumnos destacan de positivo la optimización de recursos docentes utilizados, la utilidad de las herramientas online, especialmente autoevaluaciones y sistema de gestión de dudas. El desarrollo de las prácticas y aspectos propios de la presencialidad se destacaron como negativos. La dedicación de los profesores recibió comentarios, tanto positivos como negativos. Los profesores resaltaron la potenciación de la autonomía del alumno, la utilidad de las herramientas online y la necesidad adicional de presencialidad. Conclusión Globalmente, los comentarios positivos y negativos están en línea con las fortalezas y debilidades tanto de la enseñanza online como de enfoques docentes «autorregulativos». Se precisan estudios de diseños más robustos para comprobar el alcance real de estos resultados.post-print333 K

Global methylome scores correlate with histological subtypes of colorectal carcinoma and show different associations with common clinical and molecular features

Abstract Background: The typical methylation patterns associated with cancer are hypermethylation at gene promoters and global genome hypomethylation. Aberrant CpG island hypermethylation at promoter regions and global genome hypomethylation have not been associated with histological colorectal carcinomas (CRC) subsets. Using Illumina’s 450 k Infinium Human Methylation beadchip, the methylome of 82 CRCs were analyzed, comprising different histological subtypes: 40 serrated adenocarcinomas (SAC), 32 conventional carcinomas (CC) and 10 CRCs showing histological and molecular features of microsatellite instability (hmMSI-H), and, additionally, 35 normal adjacent mucosae. Scores reflecting the overall methylation at 250 bp, 1 kb and 2 kb from the transcription starting site (TSS) were studied. Results: SAC has an intermediate methylation pattern between CC and hmMSI-H for the three genome locations. In addition, the shift from promoter hypermethylation to genomic hypomethylation occurs at a small sequence between 250 bp and 1 Kb from the gene TSS, and an asymmetric distribution of methylation was observed between both sides of the CpG islands (N vs. S shores). Conclusion: These findings show that different histological subtypes of CRC have a particular global methylation pattern depending on sequence distance to TSS and highlight the so far underestimated importance of CpGs aberrantly hypomethylated in the clinical phenotype of CRCs