Inflammatory mammary carcinoma (IMC) is a rare disease with a poor prognosis and one affecting dogs. Inflammatory breast carcinoma (IBC) is a subtype of malignant breast cancer in humans with a high degree of malignancy and a similarly poor prognosis. Since the clinical symptoms and prognoses of both are similar, canine IMC has been considered as a model of human IBC. In this study, we newly established a stable IMC-derived cell line from a patient at the Yamaguchi University Animal Medical Center in Japan. The patient was a female toy poodle presenting with an inflamed mammary gland, which was diagnosed as IMC. The cell line was established from a tissue biopsy. Surface antigen marker (CD24 and CD44) expression was determined. Cystine/glutamate antiporter (xCT) expression was determined by Western blotting, flow cytometry and fluorescence immunostaining, and sulfasalazine was administered to ascertain if it suppressed xCT expression. Stem cell marker (Nanog, Sox2, Myc and Klf4) expression and aldehyde dehydrogenase (ALDH) activity were also investigated. The cultured cells showed xCT, and its suppression showed downregulation of stem cell markers and ALDH activity. Stable cell proliferation was verified. A new canine IMC-derived cell line was established. In the future, we aim to study the effect of xCT on the maintenance of cancer stem cell properties in canine tumours, and propose a new therapeutic method for the treatment of canine IMC by targeting xCT.

Hypoxia is a common pathological condition after spinal cord injury. Oestrogen-related receptor alpha (ERRα), as a key regulator of energy metabolism and mitochondrial functions, plays an important role in maintaining cell homeostasis. However, its role in hypoxic spinal microglia has not been fully elaborated. This study investigated the receptor’s activity when these cells are hypoxic and used as an in vitro model. In this study, microglia (BV2) were exposed to cobalt chloride as a hypoxic model, and the inverse agonist of ERRα, XCT790, and pyrido[1,2-α]-pyrimidin-4-one were used to regulate the expression of the receptor to explore the ERRα-related mechanisms involved in hypoxic spinal cord injury (SCI). ERRα promoted autophagy in BV2 cells and inhibited the activation of the p38 mitogen-activated protein kinase (MAPK) pathway and the expression of anti-inflammatory factors under hypoxic conditions. It also promoted the expression of fibronectin type III domain containing protein 5 (FNDC5). When a hypoxic SCI occurs, ERRα may maintain the homeostasis of spinal cord nerve cells by regulating autophagy and the p38MAPK/nuclear factor-kappa B cell and FNDC5/brain-derived neurotrophic factor signalling pathways, which are beneficial to the recovery of these cells.