163069 20251009133841.0 doi 10.3390/ani15172632 sideral 145530 ART-2025-145530 eng Reséndiz-Pozos, Raúl A. Histopathological and Immunohistochemical Study of Neoplastic Cell Heterogeneity in Early and Advanced Ovine Pulmonary Adenocarcinoma 2025 Access copy available to the general public Unrestricted Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring lung neoplasia in sheep caused by jaagsiekte sheep retrovirus (JSRV). JSRV infects alveolar type II pneumocytes (ATII) and club cells (CC), and the expression of viral oncoproteins induces a lung adenocarcinoma. The gross pathology of OPA exhibits differences in the anatomical patterns known as classical and atypical forms. Thirty natural OPA tumors, divided equally into early OPA tumors (Group A, GA), atypical tumors (Group B, GB), and classical tumors (Group C, GC), were obtained from adult sheep (2–9 years old). Tumor heterogeneity was studied comparing the histopathology (growth patterns, local invasion, mitotic figures, myxoid nodules), together with immunohistochemistry (IHC) using markers of JSRV-ENV, epithelial cells (ATII cells, CC, ki67), progenitor-stem epithelial cells (K5, p63, CD44), and the anterior grade protein 2 (AGR2). Papillary pattern was predominant in all groups. Lepidic pattern was also relevant in GA, and acinar pattern was relevant in GB. Low proliferation indexes and local invasion were observed in all groups. Myxoid nodules were few. IHC showed that all samples were positive for JSRV-ENV. Cell markers demonstrated that GA was different when compared to GB and GC, showing significantly the highest levels of CC, K5, and p63 positive tumor cells. There were no significant differences between GB and GC. The heterogeneity analysis of OPA tumors revealed that in early tumors, repair is important but is not reflected in classical or atypical different anatomical OPA forms. info:eu-repo/grantAgreement/ES/DGA/A15-23R info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion González-Saínz, Jose María Universidad de Zaragoza (orcid)0000-0002-4655-9171 Ortín, Aurora Universidad de Zaragoza (orcid)0000-0002-0313-5926 Asin, Javier Climent, María Universidad de Zaragoza (orcid)0000-0002-0606-0763 Borderías, Luis Universidad de Zaragoza (orcid)0000-0003-3296-9644 Heras, Marcelo de las Universidad de Zaragoza (orcid)0000-0003-3792-287X 1001 025 Universidad de Zaragoza Dpto. Anatom.,Embri.Genét.Ani. Área Anatom.Anatom.Patológ.Com 1009 773 Universidad de Zaragoza Dpto. Patología Animal Área Sanidad Animal 1007 610 Universidad de Zaragoza Dpto. Medicina, Psiqu. y Derm. Area Medicina 1009 617 Universidad de Zaragoza Dpto. Patología Animal Área Medicina y Cirugía Animal 15, 17 (2025), 2632 [17 pp.] Animals (Basel) Animals 2076-2615 2164276 http://zaguan.unizar.es/record/163069/files/texto_completo.pdf Versión publicada 2738958 http://zaguan.unizar.es/record/163069/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:163069 articulos driver 2025-10-09-13:25:56 ARTICLE