Citation: Teixeira, S.A.; Luzzi, M.d.C.; Martin, A.C.B.M.; Duarte, T.T.; Leal, M.d.O.; Teixeira, G.R.; Reis, M.T.; Junior, C.R.A.; Santos, K.; Melendez, M.E.; et al. The Barretos Cancer Hospital Animal Facility: Implementation and Results of a Dedicated Platform for Preclinical Oncology Models. Vet. Sci. 2022, 9, 636. https://doi.org/10.3390/ vetsci9110636 Academic Editors: Katia Pinello, Renee Laufer Amorim, Carlos Eduardo Fonseca-Alves, Chiara Palmieri, Maria Lucia Zaidan Dagli and Fernando O. Mardones Received: 23 August 2022 Accepted: 17 October 2022 Published: 16 November 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). veterinary sciences Article The Barretos Cancer Hospital Animal Facility: Implementation and Results of a Dedicated Platform for Preclinical Oncology Models Silvia A. Teixeira 1, * , Mayara de Cassia Luzzi 1 , Ana Carolina Baptista Moreno Martin 1 , Terence Teixeira Duarte 1 ,Mônica de Oliveira Leal 1 , Gustavo Ramos Teixeira 2,3 , Monise Tadin Reis 2 , Carlos Roberto Almeida Junior 4 , Karina Santos 1,5 , Matias Eliseo Melendez 1,6 , Diego da Cunha Silveira Alves da Silva 5 , Priscila Neves Bernécule 1,3 , Higor Vinicius Lourenço Firmino 1,3 , Ana Laura Vieira Alves 1 , Denise Peixoto Guimarães 1,7 , João Vitor Borduqui 1,3 , Ana Carolina Laus 1 , Bruna Minniti Mançano 1,4 and Rui Manuel Reis 1,8,9 1 Molecular Oncology Research Center, Barretos Cancer Hospital, Barretos 14784-400, São Paulo, Brazil 2 Department of Pathology, Barretos Cancer Hospital, Barretos 14784-400, São Paulo, Brazil 3 Barretos School of Health Sciences, Dr. Paulo Prata—FACISB, Barretos 14785-002, São Paulo, Brazil 4 Department of Neurosurgery, Barretos Cancer Hospital, Barretos 14784-400, São Paulo, Brazil 5 Department of Radiology, Barretos Cancer Hospital, Barretos 14784-400, São Paulo, Brazil 6 Molecular Carcinogenesis Program, National Cancer Institute, Rio de Janeiro 20231-050, Brazil 7 Department of Endoscopy, Barretos Cancer Hospital, Barretos 14780-000, São Paulo, Brazil 8 Life and Health Sciences Research Institute (ICVS), School of Health Sciences, University of Minho, 4710-057 Braga, Portugal 9 ICVS/3B’s-PT Government Associate Laboratory, 4710-057 Braga/Guimarães, Portugal * Correspondence: steixeira.hcb@gmail.com or sateixeira@alumni.usp.br; Tel.: +55-17-3321-6600 (ext. 7352) Simple Summary: Preclinical models of Latin-American patients are scarce and urgently needed to properly translate our results, from bench to bedside, with a focus on personalized therapy. In addition, to discover more effective treatments for different cancer types we described here, an overview of the infrastructure of Barretos Cancer Hospital Animal Facility was designed to attend a multidisciplinary team and organized to perform pre-clinic in vivo models. This work describes the establishment of conventional mice models, using several commercial cancer cell lines, genetically modified mouse models that develop specific tumor types (colon cancer or brain tumor) and a platform of Brazilian patient-derived xenograft models (PDX) from patients diagnosed with cancer. These models have been used to understand cancer biology, tumor pathways and to enhance translational studies. Moreover, PDX models, which preserve cell interaction and cellular heterogeneity of parent tumors, have shown promise for identifying new biomarkers, testing panels of anticancer drug screening, and therapeutic strategies prior to clinical trials. We illustrated the establishment of a novel animal facility that fosters cancer research and preclinical studies in Brazil that will open novel avenues for studying tumor biology and tumor microenvironments to identify potential therapeutic targets, anti-cancer drugs, and personalized therapeutic approaches. Abstract: 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 Apc Min 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. Keywords: PTCH1-knockout; Apc Min ; xenografts; PDX; genetically engineered mouse models; personalized therapy; tumor biology Vet. Sci. 2022, 9, 636. https://doi.org/10.3390/vetsci9110636 https://www.mdpi.com/journal/vetsci