Detection of single nucleotide polymorphisms (SNPs) in HER2, MUC1, ESR1, and BRCA1 genes associated with canine mammary cancer

Abstract

Worldwide, canine mammary cancer (CMC) is the most frequent type of neoplasia in female dogs, and it is three times more frequent in dogs than in humans. In Colombia, CMC is the second most frequent type of cancer, after skin neoplasia. Genetics is one of the most important factors in- volved in any type of cancer, and the genetic ba- sis of this disease is reflected through line breed- ing due to changes in allelic frequencies that are traceable using molecular markers. This study aimed to detect single nucleotide polymorphisms (SNPs) associated with CMC in blood samples collected from collected from healthy and CMC female dogs at Diego Villegas Toro Veterinary Hospital of Universidad de Caldas (Manizales, Colombia). We designed primers using Primer- BLAST and Primer3, and gene fragments from HER2, MUC1, ESR1, and BRCA1 were amplified to identify SNPs through genome mapping using the UCSC Genome Institute genome browser. We used the genome of Canis lupus familaris Boxer breed [GCF_000002285.3, (CanFam 3.1)] as a refer- ence to compare the gene fragments and SNPs. We associated SNPs with the CMC and control groups by testing odds ratios (OR) through Fish- er’s exact tests to determine an association or risk for CMC. We detected two SNPs for ESR1, three for MUC1, six for HER2, and one for BRCA1. MUC1 was the only gene to display an SNP in an exonic region that resulted in an amino acid substitution (Pro>Thr). No significant differences based on the OR were found, though the majority of SNPs, with the exception of four, were found in females with CMC. We report a novel molecu- lar marker for HER2 that amplifies exons 25–26 and introns 24–25, and highlight the importance of conducting further studies on MUC1 and elu- cidating the role of introns and splicing in candi- date genes associated with CMC.

Comparison of mucin-1 in human breast cancer and canine mammary gland tumor: a review study

“…In HBC, known mutations of MUC-1 gene occurs as somatic changes within tumor genome [ 32 ]. On one hand, Carvajal-Agudelo et al [ 33 ] found three single-nucleotide polymorphisms (SNPs) and two deletions (one in exon 7 and one in intron 6) in canine MUC-1. Furthermore, Carvajal-Agudelo et al [ 33 ] found no significant correlation between MUC-1 expression and tumor grade or tumor type among CMTs; they found no correlation between MUC-1 and CMT incidence [ 33 ].…”

“…On one hand, Carvajal-Agudelo et al [ 33 ] found three single-nucleotide polymorphisms (SNPs) and two deletions (one in exon 7 and one in intron 6) in canine MUC-1. Furthermore, Carvajal-Agudelo et al [ 33 ] found no significant correlation between MUC-1 expression and tumor grade or tumor type among CMTs; they found no correlation between MUC-1 and CMT incidence [ 33 ]. On the other hand, Manuali et al showed that in CMT, MUC-1 expression is positively related to tumor grade; high MUC-1 in serum is found in grade II and III [ 24 , 34 ].…”

“…MUC-1 involves in apoptotic response in cancer cells and HBC, playing as a carcinogen in it [ 33 ]. The MUC-1-C transmembrane subunit interacts with receptor tyrosine kinases (RTKs), such as ErB2 and epidermal growth factor receptor (EGFR), at the cell surface and contributes to the activation of PI3K- Akt and mitogen-activated protein kinase (MEK)-extracellular signal-regulated kinase (ERK) downstream intracellular signaling pathways [ 31 , 40 ].…”

Canine Mammary Tumors: Classification, Biomarkers, Traditional and Personalized Therapies

“…Over-expression of MUC-1 was found in many cancers and was related to increased tumor invasiveness and poor prognosis [ 39 , 40 ]. Gene mutations, such as two deletions (in intron 6 and exon 7) and three single-nucleotide polymorphisms, were found in canine MUC-1 [ 41 ]. In CMTs, MUC-1 expression was also associated with tumor invasion and the presence of metastases, which had prognostic significance [ 22 , 42 , 43 ].…”

Euthanasia and Pain in Canine Patients with Terminal and Chronic-Degenerative Diseases: Ethical and Legal Aspects

“…In these cases, there is an evident deterioration of the animal’s health due to the progress of the disease, and deciding to prolong the animal’s life could lead to dysthanasia (painful and agonic death) [ 41 , 60 ]. When considering patients with oncological diseases, prognostic indicators such as mitotic indices (e.g., argyrophilic nucleolar organizer regions, Ki-67, and proliferating cell nuclear antigen) [ 61 ], nucleotide polymorphisms in HER-2/neu, BRCA1, and P53 genes [ 62 ], and levels of E-cadherin expression [ 63 ] as markers of tumor grade and metastatic process in mast cell tumors, mammary cancer, and squamous cell carcinomas should be taken into account. In dogs with lymphoma, positive B-markers (CD20, CD21, CD79a, CD3, CD5, and PAX5) are used to diagnose and classify the tumors [ 64 , 65 ].…”