Serum proteomics analysis of feline mammary carcinoma based on label-free and PRM techniques

Abstract

Background: Feline mammary carcinoma is the third most common cancer that affects female cats.

Objectives: The purpose of this study was to screen differential serum proteins in feline and clarify the relationship between them and the occurrence of feline mammary carcinoma.

Methods: Chinese pastoral cats were used as experimental animals. Six serum samples from cats with mammary carcinoma (group T) and six serum samples from healthy cats (group C) were selected. Differential protein analysis was performed using a Label-free technique, while parallel reaction monitoring (PRM) was performed to verify the screened differential proteins.

Results: A total of 82 differential proteins were detected between group T and group C, of which 55 proteins were down regulated and 27 proteins were up regulated. Apolipoprotein A-I, Apolipoprotein A-II (ApoA-II), Apolipoprotein B (ApoB), Apolipoprotein C-III (ApoC-III), coagulation factor V, coagulation factor X, C1q, albumen (ALB) were all associated with the occurrence of feline mammary carcinoma. Differential proteins were involved in a total of 40 signaling pathways, among which the metabolic pathways associated with feline mammary carcinoma were the complement and coagulation cascade and cholesterol metabolism. According to the Label-free results, ApoB, ApoC-III, ApoA-II, FN1, an uncharacterized protein, and ALB were selected for PRM target verification. The results were consistent with the trend of the label-free.

Conclusions: This experimen is the first to confirm ApoA-II and ApoB maybe new feline mammary carcinoma biomarkers and to analyze their mechanisms in the development of such carcinoma in feline.

Keywords: Feline mammary carcinoma; PRM; label-free; proteomics.

Fig. 1. Differential protein volcano map.

Fig. 2. Differential protein GO. The x-coordinate represents the cell components of GO Slim, the y-coordinate histogram is the number of proteins, and the red line is the enrichment degree of each cell component. (A) cellular component, (B) Molecular function, (C) Biological process.

GO, gene ontology.

Fig. 3. KEGG analysis. (A) Analysis of KEGG pathways for differentially expressed proteins. (B) The number of up-regulated and down-regulated proteins. The abscissa represents KEGG entries, the ordinate histogram is the number of proteins, and the red line is the enrichment of each KEGG entry.

KEGG, Kyoto Encyclopedia of Genes and Genomes.

Fig. 4. Screening of protein-protein interaction network for differentially expressed proteins.