Development and molecular characterization of doxorubicin-resistant canine mammary gland tumour cells

Canine mammary gland tumour (CMT) commonly affects the female dog. The objective of this study was to develop a doxorubicin-resistant CMT cell line and determine its in vitro and in vivo characteristics, including mRNA and microRNA (miRNA) expression profiles. Doxorubicin-resistant CMT-Star cells were developed from CMT-Stylo cells. The cells were characterized, including tumorigenicity in NOD/SCID mouse models. MiRNA and mRNA expression of the two cell lines were profiled and clustered. ATP binding cassette subfamily B member 1 (ABCB1) and subfamily G member 2 (ABCG2) expressions were significantly increased in the CMT-Star cell line. CMT-Star cells also had altered expression of 785 genes and 14 miRNAs. Downregulating plasminogen (PLG) and plasminogen activator urokinase (PLAU) while upregulating transforming growth factor beta receptor 3 (TGFBR3), epidermal growth factor receptor 1 (EGFR1) and ABCB1 rendered CMT-Star cells less proliferative, less invasive and more resistant to chemotherapeutic drugs. The upregulated miRNAs in CMT-Star cells include miRNA-191, -29a, -107, -99b, -874, -93 and -210, while the downregulated miRNAs include miRNAs-106a, -92a, -92b, -155 and -15b. TGFβR, EGF receptor 1 and Wnt signalling are enriched in doxorubicin-resistant CMT-Star cells and could be potential therapeutic targets in dogs with doxorubicin-resistant CMT.

犬乳腺肿瘤（Canine Mammary Gland Tumour, CMT）是雌性犬高发的肿瘤性疾病。本研究旨在构建阿霉素耐药性犬乳腺肿瘤细胞系，并对其体外（in vitro）与体内（in vivo）生物学特性进行分析，涵盖信使RNA（mRNA）与微小RNA（microRNA, miRNA）的表达谱特征。研究人员以CMT-Stylo细胞为亲本株，成功构建了阿霉素耐药性CMT-Star细胞系。对该细胞系开展了全面的生物学特性鉴定，包括在NOD/SCID小鼠模型中的致瘤性评估。对两株细胞的miRNA与mRNA表达谱进行了检测与聚类分析。ATP结合盒亚家族B成员1（ABCB1）与ATP结合盒亚家族G成员2（ABCG2）在CMT-Star细胞系中的表达量显著上调。此外，CMT-Star细胞系中共计785个基因与14个miRNA的表达发生显著改变。纤溶酶原（PLG）与尿激酶型纤溶酶原激活物（PLAU）的表达下调，同时转化生长因子β受体3（TGFBR3）、表皮生长因子受体1（EGFR1）及ABCB1的表达上调，可使CMT-Star细胞的增殖能力、侵袭能力降低，并增强其对化疗药物的耐药性。CMT-Star细胞系中上调的miRNA包括miRNA-191、-29a、-107、-99b、-874、-93与-210，而下调的miRNA则包括miRNA-106a、-92a、-92b、-155与-15b。转化生长因子β受体（TGFβR）、表皮生长因子受体1及Wnt信号通路在阿霉素耐药的CMT-Star细胞中显著富集，可作为阿霉素耐药性犬乳腺肿瘤的潜在治疗靶点。