Introduction New and more effective therapies for canine cancer patients are urgently required and this necessitates advanced experimental research. Dogs are good models for studies in comparative oncology; however, canine cancer cell biology research is currently limited by low availability of validated antibody reagents and techniques. This study characterises the expression of key components of the unfolded protein response (UPR) in a panel of haematopoietic canine cancer cell lines using commercially available antibodies, and validates the methods used to study this pathway. Material and Methods The CLBL-1 canine lymphoma cell line and the GL-1 canine leukaemia cell line sourced externally and two counterparts established in house (CNK-89 and CLB70) were used as models of different lymphoma and leukaemia canine cell lines for the study. The human U2OS cell line served as the control. Antibodies were selected for identifying UPR proteins according to known canine cell reactivity and canine–murine and canine–human homology. Endoplasmic reticulum stress was induced with thapsigargin and MG132 in the cell lines. Etoposide was used to induce DNA damage in the cells. The techniques used for this validation analysis were RNA sequencing to observe the expression of UPR components in canine cell lines, Western blot to observe changes of protein expression levels after inducing ER stress in the cells, and flow cytometry in order to study cell death. Results Substantial variations in both the basic expression and agonist-induced activation of the UPR pathway were observed in canine cancer cell lines, although the biological significance of these differences requires further investigation. Conclusion These findings will be a starting point for future studies on cancer biology in dogs. They will also contribute to developing novel anticancer therapies for canine patients and may provide new insights into human oncology.

中文翻译：

---

犬造血癌细胞系中未折叠蛋白反应途径的初步表征——这是未来开发肿瘤犬新疗法的必要步骤

简介 犬癌症患者迫切需要新的、更有效的疗法，这需要先进的实验研究。狗是比较肿瘤学研究的良好模型；然而，犬癌细胞生物学研究目前由于经过验证的抗体试剂和技术的可用性较低而受到限制。本研究使用市售抗体表征了一组造血犬癌细胞系中未折叠蛋白反应 (UPR) 关键成分的表达，并验证了用于研究该途径的方法。材料和方法使用外部来源的 CLBL-1 犬淋巴瘤细胞系和 GL-1 犬白血病细胞系以及内部建立的两个对应细胞系（CNK-89 和 CLB70）作为不同淋巴瘤和白血病犬细胞系的模型进行研究。人类 U2OS 细胞系作为对照。根据已知的犬细胞反应性和犬-鼠和犬-人同源性，选择抗体来鉴定 UPR 蛋白。在细胞系中用毒胡萝卜素和 MG132 诱导内质网应激。依托泊苷用于诱导细胞中的 DNA 损伤。用于该验证分析的技术是RNA测序以观察犬细胞系中UPR成分的表达，蛋白质印迹以观察在细胞中诱导ER应激后蛋白质表达水平的变化，以及流式细胞术以研究细胞死亡。结果在犬癌细胞系中观察到 UPR 通路的基本表达和激动剂诱导的激活均存在显着差异，尽管这些差异的生物学意义需要进一步研究。结论 这些发现将成为未来狗癌症生物学研究的起点。他们还将有助于为犬类患者开发新型抗癌疗法，并可能为人类肿瘤学提供新的见解。