Functional analysis of CD44 variants and xCT in canine tumours

• Published in: Veterinary medicine and science Vol. 7; no. 2; pp. 577 - 585
• Main Authors: Tanabe, Atsushi, Kimura, Kento, Tazawa, Hana, Maruo, Takuya, Taguchi, Masayuki, Sahara, Hiroeki
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.03.2021; John Wiley and Sons Inc; Wiley
• Subjects: Antioxidants; Bone cancer; Breast cancer; canine; CD44; CD44 antigen; Cell growth; Cell surface; Gene expression; Glutathione; Melanoma; Metastasis; Original; Oxidative stress; Plasmids; Polymerase chain reaction; Protein transport; radiation; Reactive oxygen species; Reverse transcription; Skin cancer; Sulfasalazine; Tumors; Vectors (Biology); xCT; United States > US; Japan; Germany; xCT; canine; radiation; CD44; oxidative stress
• ISSN: 2053-1095; 2053-1095
• DOI: 10.1002/vms3.397

The cell surface glycoprotein CD44 has various types of splicing variants, which contribute to its multiple distinct cellular functions. Recently, it was reported that the CD44v8‐10 isoform interacts with the system Xc(‐) transporter‐related protein (xCT), and inhibits the accumulation of reactive oxygen species by promoting the synthesis of the antioxidant glutathione in human tumour cells. In this study, we investigated the expression and function of CD44 variants and xCT in canine tumours. From semi‐quantitative reverse transcription polymerase chain reaction analysis, the mRNA expression of the CD44v8‐10 isoform was observed in canine tumour tissues as well as human cases. The overexpression of CD44v8‐10 may promote the synthesis of glutathione and enhance the resistance to radiation of canine breast tumour cells. Furthermore, canine xCT mRNA expression was significantly upregulated in the canine breast tumour tissues as compared to the normal tissues surrounding the tumours. To investigate the function of canine xCT, we treated canine tumour cells with the xCT inhibitor sulfasalazine. Consequently, the sulfasalazine‐treated cells were more sensitive to oxidative stress than the non‐treated cells. Taken together, these results suggested that CD44v8‐10 and xCT play important roles in the therapy resistance of canine tumours as well as human tumours. CD44v8‐10 contributes H2O2‐ and radio‐resistance of canine breast tumour cells by promoting the production of GSH. A. The expression of CD44s or CD44v8‐10 molecules of these transfectants. B. The H2O2‐resistance of these transfectants. C. The cellular GSH content of CD44 transfectants. D. The radio‐resistance of CD44 transfectants.