Mammary tumours (MT) are one of the most prevalent malignancies in female dogs and women. Currently, molecular analyzes have shown that each tumour type presents its own genetic signature. In this context, liquid biopsy allows a comprehensive genetic characterisation of the tumour, enabling early diagnosis and personalised treatment of patients. In women, deleterious mutations inherited in BRCA2 gene are associated with an increased risk of breast cancer, resistance to therapies and worse prognosis. In female dogs, there are many divergent data on the involvement of BRCA2 gene with mammary carcinogenesis and what its pathogenic potential is. Therefore, the objective was to identify BRCA2 gene variants in 20 plasma DNA samples, from 10 newly diagnosed dogs with mammary cancer (RD), five control (CTR) and five mastectomized patients. Eleven single nucleotide polymorphisms (SNPs) were detected, most of them in the exon 11 and two indels (deletion/insertion) in the BRCA2 gene. However, there was no statistically significant difference in the SNPs/indels detected between the groups. In addition, only one SNP (p.T1425P) and one deletion (p.L2307del) were considered deleterious using in silico computational models. Interestingly, most common variants were present in the plasma of all groups, except for the Ile2614Thr, Ile2614Val, Thr1425Pro and p.L2307del variants. Thus, we observed that SNPs are common in the BRCA2 gene of female dogs with MT, with a similar condition identified in women with breast cancer. Liquid biopsy approach in dogs with MT is useful for genetic and therapeutic proposals.

Background: Trafficking of regulatory T cells (Tregs) modulate inflammatory response after kidney transplantation. There is scarce information on whether circulating and intragraft Tregs are similarly affected by immunosuppressive drugs (ISD) and by the type of deceased kidney donor.Objectives: 1-to study the simultaneous gene and protein expression of the FOXP3 (forkhead-winged helix transcription factor) in the peripheral blood (PB) and within renal allografts; 2-to correlate FOXP3 expression with the immunosuppressive drugs (ISD) used and kidney donor type. Methods: FOXP3 gene and protein expression were assessed by real-time PCR and immunohistochemical analysis in the peripheral blood (PB) and kidney biopsies (Bx) of patients receiving Tacrolimus (Tac; n=21) or Everolimus (Eve; n=19) at the 3rd month post-Tx. FOXP3 expression was correlated with donor type (standard -SCD or extended criteria -ECD donors), ISD, acute rejection (AR), delayed graft function (DGF), and serum creatinine (sCr) at one year. Results: Eve-treated patients had a longer DGF duration (p=0.04) and a lower frequency of de novo post-Tx diabetes (p=0.03) compared with the Tac group. FOXP3 expression in the PB and Bx was greater in Eve than in Tac-treated patients. Immunohistochemistry did not show differences in the FOXP3 expression for both types of ISD. Recipients of SCD and ECD had similar gene and protein expression inside allografts and in the renal tissue regardless of the ISD. However, in the PB, ECD recipients treated with Eve (ECD/Eve) had higher FOXP3 expression than ECD/Tac (p=0.04) and SCD/Eve (p= 0.01). In the blood Eve and ECD kidney (OR= 5.6; p= 0.04 and OR= 8.7; p= 0,015, respectively) were independently associated with FOXP3 expression while in the Bx only Eve was associate with increased gene expression (OR=5.1; p= 0.03). Conclusion: FOXP3 gene and protein expression does occur differently in the blood and inside allografts from recipients of ECD kidneys treated with mTOR inhibitors. We suggest caution when interpreting studies comparing outcomes based on the measurement of the FOXP3 gene expression in different tissues and compartments and kidney donor types.

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