Search

The Barretos Cancer Hospital Animal Facility (BCHAF) is a unique facility in Brazil exclusively dedicated to working with animal models for cancer research. In this article, we briefly present our modern facility and the main experiments performed, focusing on mutant strains of mice (PTCH-knockout and ApcMin mice), xenograft models, and patient-derived xenografts (PDXs). Our results show the progress and challenges in establishing these models and the need for having an appropriate representation of our cancer population to better understand tumor biology and to identify cancer biomarkers, which could be putatively targeted, allowing for personalized therapy.

The use of droplet digital PCR (ddPCR) to identify and quantify low-abundance targets is a significant advantage for accurately detecting potentially oncogenic bacteria. Fusobacterium nucleatum (Fn) is implicated in colorectal cancer (CRC) tumorigenesis and is becoming an important prognostic biomarker. We evaluated the detection accuracy and clinical relevance of Fn DNA by ddPCR in a molecularly characterized, formalin-fixed, paraffin-embedded (FFPE) CRC cohort previously analyzed by qPCR for Fn levels. Following a ddPCR assay optimization and an analytical evaluation, Fn DNA were measured in 139 CRC FFPE cases. The measures of accuracy for Fn status compared to the prior results generated by qPCR and the association with clinicopathological and molecular patients’ features were also evaluated. The ddPCR-based Fn assay was sensitive and specific to positive controls. Fn DNA were detected in 20.1% of cases and further classified as Fn-high and Fn-low/negative, according to the median amount of Fn DNA that were detected in all cases and associated with the patient’s worst prognosis. There was a low agreement between the Fn status determined by ddPCR and qPCR (Cohen’s Kappa = 0.210). Our findings show that ddPCR can detect and quantify Fn in FFPE tumor tissues and highlights its clinical relevance in Fn detection in a routine CRC setting.