Ongoing Clinical Trials and Future Research Scenarios of Circulating Tumor DNA for the Treatment of Metastatic Colorectal Cancer.

Liquid biopsy using circulating tumor DNA (ctDNA) has emerged as a minimally invasive, timely approach to provide molecular diagnosis and monitor tumor evolution in patients with cancer. Since the molecular landscape of metastatic colorectal cancer (mCRC) is substantially heterogeneous and dynamic over space and time, ctDNA holds significant advantages as a biomarker for this disease. Numerous studies have demonstrated that ctDNA broadly recapitulates the molecular profile of the primary tumor and metastases, and have mainly focused on the genotyping of RAS and BRAF, that is propaedeutic for anti-EGFR treatment selection. However, ctDNA soon broadened its scope towards the assessment of early tumor response, as well as the identification of drug resistance biomarkers to drive potential molecular actionability. In this review article, we provide an overview of the current state-of-the-art of this methodology and its applications, focusing on ongoing clinical trials that employ ctDNA to prospectively guide treatment in patients with mCRC.

Young-onset colorectal cancer: treatment-related nausea, vomiting and diarrhoea.

OBJECTIVES: Early-onset colorectal cancer (EO-CRC) incidence is increasing, raising a clinical challenge. Clinicians tend to treat EO-CRC patients with more intensive regimens despite the lack of survival benefits, based on an age-related bias. Limited evidence is available regarding treatment-related toxicities in this peculiar subset of patients. METHODS: We performed a literature search in MEDLINE/PubMed, EMBASE and Scopus, looking for reporting of nausea, vomiting and diarrhoea occurring in patients with EO-CRC, defined by age lower than 50 years old at initial diagnosis, while receiving anticancer treatment. RESULTS: 2318 records were screened and 9 full-text articles were considered eligible for inclusion for a total of 59 783 patients (of whom 8681 EO-CRC patients). We found nausea and vomiting occurring at higher incidence among EO-CRC compared with older patients, while no difference was reported as for diarrhoea. Peritoneal involvement, age younger than 40, female gender, suboptimal adherence to guidelines and oxaliplatin might represent potential risk factors for increased nausea and vomiting in patients with EO-CRC. CONCLUSION: EO-CRC patients experience more nausea and vomiting but equal or less diarrhoea compared with older patients. Adherence to clinical guidelines is recommended, and more data are warranted to assess if an enhanced antiemetic approach might be required, particularly in case of specific risk factors.

mef2ca and mef2cb Double Mutant Zebrafish Show Altered Craniofacial Phenotype and Motor Behaviour.

The transcription factor MEF2C is crucial in neuronal, cardiac, bone and cartilage molecular processes, as well as for craniofacial development. MEF2C was associated with the human disease MRD20, whose patients show abnormal neuronal and craniofacial development. Zebrafish mef2ca;mef2cb double mutants were analysed for abnormalities in craniofacial and behaviour development through phenotypic analysis. Quantitative PCR was performed to investigate the expression levels of neuronal marker genes in mutant larvae. The motor behaviour was analysed by the swimming activity of 6 dpf larvae. We found that mef2ca;mef2cb double mutants display several abnormal phenotypes during early development, including those already described in zebrafish carrying mutations in each paralog, but also (i) a severe craniofacial phenotype (comprising both cartilaginous and dermal bone structures), (ii) developmental arrest due to the disruption of cardiac oedema and (iii) clear alterations in behaviour. We demonstrate that the defects observed in zebrafish mef2ca;mef2cb double mutants are similar to those previously described in MEF2C-null mice and MRD20 patients, confirming the usefulness of these mutant lines as a model for studies concerning MRD20 disease, the identification of new therapeutic targets and screening for possible rescue strategies.

Histological validation of adipogenic differentiation potential of ASC on collagen-based 2D scaffolds.

Determination of the adipogenic potential and behavior of adipose-derived mesenchymal stem/stromal cells (ASCs) is particularly relevant for their potential clinical application in regenerative medicine, especially when regeneration is supported by biomaterials or scaffolds. Scaffolds need to be able to induce tissue repair and limit undesired adipogenic differentiation. Depending on the scaffold employed, determination of cell behavior may be hindered by material interference with staining, which will limit either cells identification or dye quantification. Collagen is a promising biomaterial in regenerative medicine, however, histological analysis of cells cultured on collagen-based scaffolds is challenging. Here we describe a new histological method based on iron hematoxylin combined with Oil red O (ORO) staining, for the determination of the adipogenic differentiation of ASCs cultivated on a collagen-based 2D scaffold. ASCs were seeded on collagen films or plastic, differentiated into adipocytes for 14 days, and then stained with either ORO or iron hematoxylin and ORO combined. The collagen films avidly absorbed the ORO dye; conventional staining and quantification by dye extraction failed to discriminate between differentiated and undifferentiated cells on the films. On the contrary, the iron hematoxylin-ORO combination provided a quantitative and more reliable determination of adipocytes based on single cell count. This method is particularly recommended for determining the adipogenic differentiation potential of ASCs and other cell types grown on highly absorptive materials that need to be validated for their potential use in bioengineering and regenerative medicine.

Distribution of different HBV DNA forms in plasma and peripheral blood mononuclear cells (PBMCs) of chronically infected patients with low or undetectable HBV plasma viremia.

Few studies have documented hepatitis B virus (HBV) DNA in peripheral blood mononuclear cells (PBMCs). We developed real-time PCR methods for differential amplification of covalently closed circular (cccDNA) and total HBV DNA (tDNA). The different distribution of cccDNA and tDNA in plasma and PBMCs was evaluated in 37 patients with low or undetectable viremia. Plasma tDNA measured by the Abbott reference system and the in-house assay correlated well (Spearman rho = 0.804; P<0.0001). tDNA was detected in four PBMC samples, all from patients with detectable plasma viremia (range 633-6,406 IU/ml), cccDNA was not detected in any sample. The reasons for apparently discrepant results need further investigation but possibly include the high diversification of HBV status and plasma viremia levels.

Actitud del donador vivo en pre y postrasplante de riñón / Attitude of the living donor in pre and post kidney transplants

El objetivo de esta investigación fue analizar las actitudes del donador vivo de riñón en las fases pre y posoperatorias, mediante estudio observacional, transversal y comparativo con medición antes y después, realizado en la Unidad de Trasplantes del Hospital de Especialidades del Centro Médico Nacional Siglo XXI. El universo de estudio se integró con 14 donadores inscritos en el protocolo de la unidad referida quienes aceptaron ser entrevistados en la fase pre y posoperatoria, durante cuatro meses. Asimismo fueron entrevistados 34 donadores más para identificar su actitud como posdonadores a fin de fortalecer los objetivos del estudio. Los resultados de este grupo se presentan por separado. Los criterios de inclusión fueron: paciente donador vivo de riñón, programado para nefrectomía con preparación psicológica preoperatoria previa; género femenino o masculino, de 18 a 65 años y en posoperatorio inmediatomediato. Se aplicó un cuestionario tipo escala de Likert con 34 preguntas para medir actitudes en 14 donadores ­períodos preoperatorio y posoperatorio inmediato­el mismo instrumento fue aplicado a 34 pacientes de posoperatorio mediato. La medición de actitudes se califican de 0-5 para cada reactivo positivo y negativo, con asociación de variables y proporciones. Los hallazgos revelaron que 71 % de las donaciones provino de hermano, padre o madre y 29% de esposo(a) y tío(a). La donación en 86% de los donadores provocó sentimientos de felicidad y realización; 7% sufrió depresión leve en el posoperatorio. Existe coincidencia en los hallazgos obtenidos en este grupo en relación con estudios semejantes en el sentido de que los donadores vivos de riñón experimentan cambios de actitud ambivalentes transitorios después del transplante.

The present investigation has as objective to know the attitude profile of the kidney alive donor in pre and posoperative phases. The study is observational, crossover and comparative with measurements before and after. The investigation is sponsored by the Transplant Unit from Centro Medico Nacional Siglo XXI. The study universe is integrated by the donors registered in the protocol made by the transplant unit. The conventional type sample is integrated by 14 donors who accepted an interview in pre and postoperatory phases during 1999. Thirty four donors also interviewed with the purpose to identify their attitudes post-donation. The results for this group are presented separately. Inclusion arterial allowed to interview all alive kidney donors programmed for nephrectomy who received psychological preoperatory preparation, either sex donors, no more that 65 and no less than 18 years of age in immediate, and mediatly postoperative. A Likert scale type questionnaire that contains 34 questions to monitor attitudes for 14 donors in immediate pre and posoperative period was applied and to 34 patients in their mediatly posoperative period. Attitude measurement was a 0-5 score for each positive and negative reactive, with variables and odds association. Findings so far reveal that donation is made in a 71% by a brother or sister, father or mother, 29% by spouses and aunts and uncles. Eighty six donors had happinness and accomplishment feelings against a 7% that occasionally gets depressed in the posoperatory. That generates ambivalent emotions and feelings.