Faecal Proteomics and Functional Analysis of Equine Melanocytic Neoplasm in Grey Horses.

Narumon Phaonakrop,Amornthep Kingkaw,Paviga Limudomporn,Attawit Kovitvadhi,Sittiruk Roytrakul,Parichart Tesena,Wanwipa Vongsangnak

doi:10.3390/vetsci9020094

Abstract

Equine melanocytic neoplasm (EMN) is a common disease in older grey horses. The purpose of this study was to examine the potential proteins throughout EMN stages from faecal proteomic outlining using functional analysis. Faecal samples were collected from the rectum of 25 grey horses divided into three groups; normal group without EMN (n = 10), mild EMN (n = 6) and severe EMN (n = 9). Based on the results, 5910 annotated proteins out of 8509 total proteins were assessed from proteomic profiling. We observed differentially expressed proteins (DEPs) between the normal group and the EMN group, and 109 significant proteins were obtained, of which 28 and 81 were involved in metabolic and non-metabolic functions, respectively. We found 10 proteins that play a key role in lipid metabolism, affecting the tumour microenvironment and, consequently, melanoma progression. Interestingly, FOSL1 (FOS like 1, AP-1 transcription factor subunit) was considered as a potential highly expressed protein in a mild EMN group involved in melanocytes cell and related melanoma. Diacylglycerol kinase (DGKB), TGc domain-containing protein (Tgm2), structural maintenance of chromosomes 4 (SMC4) and mastermind-like transcriptional coactivator 2 (MAML2) were related to lipid metabolism, facilitating melanoma development in the severe-EMN group. In conclusion, these potential proteins can be used as candidate biomarkers for the monitoring of early EMN, the development of EMN, further prevention and treatment.

Highlights

66% of horses suffering from Equine melanocytic neoplasm (EMN) [5], contradicting the findings of MacGillivray et al [4], who reported that 14% of dermal melanomas become malignant tumours and may form metastases in vital visceral organs
Most
We discovered that the majority of proteins involved in lipid metabolism are expressed in both serum and faecal samples, which is consistent with other studies on lipid metabolic reprogramming in melanoma

Summary

Introduction

Equine melanocytic neoplasm (EMN) is a kind of skin tumour that mainly affects older grey horses [1,2]. EMN does not seem to be induced by ultraviolet radiation exposure [3]. The first stage of EMN is localised only in dermal typical sites and classified as benign, with slow growth [4]. In an unpredictable period, the growth rate increases and metastases occur in internal organs, which was observed around. 66% of horses suffering from EMN [5], contradicting the findings of MacGillivray et al [4], who reported that 14% of dermal melanomas become malignant tumours and may form metastases in vital visceral organs. The four melanocyte-related genes that mutate are nuclear receptor subfamily 4, group 66% of horses suffering from EMN [5], contradicting the findings of MacGillivray et al [4], who reported that 14% of dermal melanomas become malignant tumours and may form metastases in vital visceral organs. 4.0/).

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