犬口腔恶性黑色素瘤(COMM)是口腔中最常见的肿瘤,其特征是局部侵袭性和高转移潜能。缺氧代表实体瘤微环境促进癌症进展和耐药性的关键特征。缺氧诱导因子-1α(HIF-1α)及其下游效应子,血管内皮生长因子A(VEGF-A),葡萄糖转运蛋白亚型1(GLUT1),C-X-C趋化因子受体4型(CXCR4),和碳酸酐酶IX(CAIX),是对低氧可用性的自适应响应的主要调节器。使用免疫组织化学在36个COMs中评估了这些标志物的预后价值。此外,在1个原代COMM细胞系中评估了氯化钴介导的缺氧的影响。在细胞核中观察到HIF-1α表达,这种定位与蛋白质水平的HIF-1α调节基因的存在或表达增强有关。多因素分析显示,在给予硫酸软骨素蛋白聚糖-4(CSPG4)DNA疫苗的狗中,表达HIF-1α的COMs,VEGF-A,与这些标志物阴性的肿瘤相比,CXCR4与较短的无病间隔(DFI)相关(P=0.03),提示缺氧可影响免疫治疗反应。西方印迹显示,在化学诱导的缺氧下,COMM细胞积累HIF-1α和较少量的CAIX。免疫荧光证实了缺氧引发的HIF-1α诱导和稳定,显示它的核易位。这些发现加强了COMM中低氧微环境在肿瘤进展和患者预后中的作用。正如以前在几种人类和犬类癌症中建立的那样。此外,缺氧标志物可能代表有希望的预后标志物,强调它们在COMs治疗策略中的使用机会。
Canine oral malignant melanoma (COMM) is the most common neoplasm in the oral cavity characterized by local invasiveness and high metastatic potential. Hypoxia represents a crucial feature of the solid tumor microenvironment promoting cancer progression and drug resistance. Hypoxia-inducible factor-1α (HIF-1α) and its downstream effectors, vascular endothelial growth factor A (VEGF-A), glucose transporter isoform 1 (GLUT1), C-X-C chemokine receptor type 4 (CXCR4), and carbonic anhydrase IX (CAIX), are the main regulators of the adaptive response to low oxygen availability. The prognostic value of these markers was evaluated in 36 COMMs using immunohistochemistry. In addition, the effects of cobalt chloride-mediated hypoxia were evaluated in 1 primary COMM cell line. HIF-1α expression was observed in the nucleus, and this localization correlated with the presence or enhanced expression of HIF-1α-regulated genes at the protein level. Multivariate analysis revealed that in dogs given chondroitin sulfate proteoglycan-4 (CSPG4) DNA vaccine, COMMs expressing HIF-1α, VEGF-A, and CXCR4 were associated with shorter disease-free intervals (DFI) compared with tumors that were negative for these markers (P = .03), suggesting hypoxia can influence immunotherapy response. Western blotting showed that, under chemically induced hypoxia, COMM cells accumulate HIF-1α and smaller amounts of CAIX. HIF-1α induction and stabilization triggered by hypoxia was corroborated by immunofluorescence, showing its nuclear translocation. These findings reinforce the role of an hypoxic microenvironment in tumor progression and patient outcome in COMM, as previously established in several human and canine cancers. In addition, hypoxic markers may represent promising prognostic markers, highlighting opportunities for their use in therapeutic strategies for COMMs.