Beclin 1, LC3 and P62 Expression in Equine Sarcoids

• Published in: Animals (Basel) Vol. 12; no. 1; p. 20
• Main Authors: Martano, Manuela, Altamura, Gennaro, Power, Karen, Liguori, Pierluigi, Restucci, Brunella, Borzacchiello, Giuseppe, Maiolino, Paola
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 23.12.2021; MDPI
• Subjects: Antibodies; Autophagy; BPV; Cancer; Cattle; Cell proliferation; Collagen; equine sarcoids; Fibroblasts; Horses; Hypoxia; Immunohistochemistry; Impairment; Infections; Laboratories; Membranes; Microenvironments; Papillomaviridae; Proteins; Skin; Statistical analysis; Survival; Tumors; Viruses; Wound healing; United States > US; Italy; equine sarcoids; BPV; autophagy
• ISSN: 2076-2615; 2076-2615
• DOI: 10.3390/ani12010020

It is well known that δ-bovine papillomaviruses (BPV-1, BPV-2 and BPV-13) are one of the major causative agents of equine sarcoids, the most common equine skin tumors. Different viruses, including papillomaviruses, evolved ingenious strategies to modulate autophagy, a complex process involved in degradation and recycling of old and damaged material. The aim of this study was to evaluate, by immunohistochemistry (IHC) and Western blot (WB) analysis, the expression of the main related autophagy proteins (Beclin 1, protein light chain 3 (LC3) and P62), in 35 BPV1/2 positive equine sarcoids and 5 BPV negative normal skin samples. Sarcoid samples showed from strong-to-moderate cytoplasmic immunostaining, respectively, for Beclin 1 and P62 in >60% of neoplastic fibroblasts, while LC3 immunostaining was weak to moderate in ≤60% of neoplastic fibroblasts. Western blot analysis confirmed the specificity of the antibodies and revealed no activation of autophagic flux despite Beclin 1 overexpression in sarcoid samples. Results could suggest the activation of the initial phase of autophagy in equine sarcoids, and its impairment during the following steps. The impairment of autophagy could lead to a selection of a quiescent population of fibroblasts, which survive longer in a hypoxic microenvironment and produced more and/or altered collagen.