Establishment of primary mixed cell cultures from spontaneous canine mammary tumors: Characterization of classic and new cancer-associated molecules

Abstract

There are many factors which make canine cancer like cancer in humans. The occurrence of spontaneous mammary tumors in pet dogs, tumor genetics, molecular targets and exposure to the same environmental risk factors are among these factors. Therefore, the study of canine cancer can provide useful information to the oncology field. This study aimed to establish and characterize a panel of primary mixed cell cultures obtained from spontaneous canine mammary tumors. Eight established cell cultures obtained from one normal mammary gland, one complex adenoma, one mixed adenoma, two complex carcinomas and two mixed carcinomas were analyzed. The gene expression levels of classic molecular cancer players such as fibroblast growth factor receptor (FGFR) 2, breast cancer (BRCA) 1, BRCA2 and estrogen receptor (ESR) 1 were evaluated. For the first time, three orphan nuclear receptors, estrogen-related receptors (ERRs) α, β and γ were studied in canine mammary cancer. The highest expression level of ERRα was observed in complex carcinoma-derived cell culture, while the highest levels of ERRβ and γ were observed in cells derived from a mixed carcinoma. Meanwhile, complex carcinomas presented the highest levels of expression of ESR1, BRCA1 and FGFR2 among all samples. BRCA2 was found exclusively in complex adenoma. The transcription factor GATA3 had its highest levels in mixed carcinoma samples and its lowest levels in complex adenoma. Proliferation assays were also performed to evaluate the mixed cell cultures response to ER ligands, genistein and DES, both in normoxia and hypoxic conditions. Our results demonstrate that morphological and functional studies of primary mixed cell cultures derived from spontaneous canine mammary tumors are possible and provide valuable tool for the study of various stages of mammary cancer development.

The Expression of Selected Factors Related to T Lymphocyte Activity in Canine Mammary Tumors

“…We found increased levels of GATA3 in benign canine mammary tumors compared to healthy tissue as well as malignant and metastatic tumors. Our results contradict a previous study that documented the highest GATA3 expression in canine mixed carcinoma, with the lowest level in a complex adenoma [57]. However, our results are consistent with a study performed on mice demonstrating that the loss of GATA3 expression is associated with mammary tumors with a high grade of malignancy [58].…”

Establishment and Characterization of Canine Mammary Gland Carcinoma Cell Lines With Vasculogenic Mimicry Ability in vitro and in vivo

“…Several cell lines are used as a preclinical model for understanding BC development and progression and for the investigation of the antitumor effects of new drugs (41)(42)(43)(44). Compared to human BC, there are fewer canine mammary gland tumor cell lines to study (37,(45)(46)(47). Mammary tumors of dogs are classified by the receptors expressed as luminal A, luminal B, triple-negative basal-like, triple-negative non-basallike, and overexpressing HER2, which are established in humans.…”