Isolation And Identification Of Canine Inflammatory Mammary Cancer Cell Line

Background: Spontaneous canine mammary tumors have epidemiological and biological features similar to those of human breast cancer.With a higher incidence and more rapid disease progression,canine mammary tumors have been an ideal model for human breast cancer research.Although some stable and long-lived cell lines have been established in the global study of canine mammary tumors,the number of canine inflammatory mammary cancer cell lines is very small.The histomorphology of canine mammary tumor cells is complex and no well-established canine mammary tumor cell lines have been clinically established,which hinders further research on canine mammary tumors.Purpose: Through case collection of clinical canine mammary tumors and primary culture of malignant tumor cells,a new canine mammary tumor cell line was established to further understand its biological characteristics and to use this cell line for animal modeling.To provide a basis for the diagnosis and treatment modalities of canine mammary tumors in the clinical setting,in order to enrich their personalized treatment,reduce the mortality and recurrence rates of affected dogs,and may also provide a reference for the accurate diagnosis,treatment and prognosis of human breast tumors.Methods: Stable passaged canine mammary tumor cells were obtained by primary cell culture,and their biological characteristics were characterized by morphological observation,chromosome analysis,growth curve plotting and proliferation doubling time calculation,cell colony formation,immunohistochemistry(IHC),cellular immunofluorescence(IF),and the establishment of a tumorigenic model in nude mice.Results: A total of 23 canine mammary tumor samples were collected for primary culture,and a cell line was successfully screened for stable in vitro transmission for more than 50 generations and was able to become tumorigenic in mice,which was diagnosed as canine inflammatory mammary carcinoma(IMC)based on the clinical symptoms and histopathological findings of the primary tumor.The IHC results showed that this breast tumor was negative for estrogen receptor(ER),weakly positive for progesterone receptor(PR)and human epidermal growth factor receptor 2(HER-2),and strongly positive for Ki-67,consistent with the receptor expression profile of a Luminal B breast tumor.The IMC-118 cell line was able to become tumorigenic in immunodeficient mice,and the immunophenotype of xenograft tumors was consistent with the primary tumor.Conclusion: In this study,a canine inflammatory mammary cancer cell line was successfully cultured and characterized.It was able to become tumour-forming in immunodeficient mice,which can be used for subsequent biological studies related to inflammatory mammary cancer.