Research Area, Instituto de Oncología Ángel H. Roffo (IOAHR), Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina.
Medical Biology Department, Groupe de Recherche en Signalisation Cellulaire (GRSC), Université du Quebec a Trois-Rivières, Trois-Rivières, QC, Canada.
J Mol Med (Berl). 2020 Nov;98(11):1615-1627. doi: 10.1007/s00109-020-01973-0. Epub 2020 Sep 16.
The expression of inducible nitric oxide (NO) synthase (iNOS) in human bladder cancer (BC) is a poor prognostic factor associated with invasion and tumor recurrence. Here, we evaluated the relevance of iNOS expression in BC progression and in cancer stem cell (CSC) maintenance in a murine BC model. Also, iNOS expression and CSC markers were analyzed in human BC samples. iNOS inhibitors (L-NAME or 1400W) or shRNA were used on murine BC model with different iNOS expressions and invasiveness grades: MB49 (iNOS+, non-muscle invasive (NMI)) and MB49-I (iNOS++, muscle invasive (MI)), in order to analyzed cell proliferation, tumor growth, angiogenesis, number of CSC, and pluripotential marker expression. iNOS, SOX2, Oct4, and Nanog expressions were also analyzed in human BC samples by qPCR and immunohistochemistry. iNOS inhibtion reduced parameters associated with tumor progression and reduced the number of CSC, wich resulted higher in MB49-I than in MB49, in concordance with the higher expression of SOX2, Oct4, and Nanog. The expression of SOX2 was notoriously diminished, when iNOS was inhibited only in the MI cell line. Similar results were observed in human samples, where MI tumors expressed higher levels of iNOS and pluripotential genes, in comparison to NMI tumors with a positive correlation between those and iNOS, suggesting that iNOS expression is associated with CSC. iNOS plays an important role in BC progression and CSC maintenance. Its inhibition could be a potential therapeutic target to eradicate CSC, responsible for tumor recurrences. KEY MESSAGES: • iNOS expression is involved in bladder tumor development, growth, and angiogenesis. • iNOS expression is involved in bladder cancer stem cell generation and maintenance, playing an important role regulating their self-renewal capacity, especially in muscle invasive murine bladder cancer cells. • iNOS expression is higher in human muscle invasive tumors, in association with a high expression of pluripotential genes, especially of SOX2.
诱导型一氧化氮合酶 (iNOS) 在人膀胱癌 (BC) 中的表达是与浸润和肿瘤复发相关的不良预后因素。在这里，我们在小鼠 BC 模型中评估了 iNOS 表达在 BC 进展和癌症干细胞 (CSC) 维持中的相关性。此外，还分析了人膀胱癌样本中的 iNOS 表达和 CSC 标志物。使用不同 iNOS 表达和侵袭程度的小鼠 BC 模型 (MB49 [iNOS+，非肌肉浸润 (NMI)] 和 MB49-I [iNOS++，肌肉浸润 (MI)]) 上使用了 iNOS 抑制剂 (L-NAME 或 1400W) 或 shRNA，以分析细胞增殖、肿瘤生长、血管生成、CSC 数量和多能性标志物表达。还通过 qPCR 和免疫组织化学分析了人膀胱癌样本中的 iNOS、SOX2、Oct4 和 Nanog 表达。iNOS 抑制降低了与肿瘤进展相关的参数，并减少了 CSC 的数量，在 MB49-I 中比在 MB49 中更高，与 SOX2、Oct4 和 Nanog 的更高表达一致。当仅在 MI 细胞系中抑制 iNOS 时，SOX2 的表达明显减少。在人样本中观察到了类似的结果，其中 MI 肿瘤与 NMI 肿瘤相比，iNOS 和多能基因表达水平更高，并且这些基因与 iNOS 之间存在正相关，这表明 iNOS 表达与 CSC 相关。iNOS 在 BC 进展和 CSC 维持中发挥重要作用。抑制 iNOS 可能是消除负责肿瘤复发的 CSC 的潜在治疗靶点。
