Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, and Department of Laboratory Medicine and Pathobiology, University of Toronto, Canada.
Histol Histopathol. 2012 Oct;27(10):1263-70. doi: 10.14670/HH-27.1263.
In the multiple steps in cancer progression, microRNAs (miRNAs) play significant roles in each stage. Reports of considerable differences in expression levels of miRNAs between normal and malignant tissues are understandable considering miRNAs are key regulators of gene expression. Dysregulation of miRNA expression levels in neoplasia occurs because many miRNAs are located in "fragile sites", which are frequently deleted in cancer. miRNAs are often down regulated in cancerous tissues and target oncogenic proteins are classified as tumour suppressor miRNAs, such as let-7. While, miRNAs that are frequently over-expression in neoplastic tissues compared to normal tissues and regulate tumour suppressor proteins are categorized as "oncomiRs". In this review, we summarize information about microRNAs involved in the emerging field of cancer stem cells, and microRNAs involved in breast cancer, an area of our expertise. The application of miRNAs to cancer therapeutics and diagnostics is emerging as an important field of gene therapy. The diverse nature of miRNAs in cancer is continually being elucidated to lead to the enigmatic treatment options for neoplastic disease.
在癌症进展的多个步骤中，microRNAs（miRNAs）在每个阶段都发挥着重要作用。考虑到 miRNAs 是基因表达的关键调节剂，miRNAs 在正常组织和恶性组织之间的表达水平存在显著差异的报道是可以理解的。miRNA 表达水平的失调发生在癌发生中，因为许多 miRNAs 位于“脆性位点”，这些位点在癌症中经常缺失。miRNAs 在癌组织中常常下调，靶向致癌蛋白被归类为肿瘤抑制 miRNA，如 let-7。相比之下，与正常组织相比，在肿瘤组织中经常过度表达并调节肿瘤抑制蛋白的 miRNAs 被归类为“oncomiRs”。在这篇综述中，我们总结了参与癌症干细胞这一新兴领域以及乳腺癌（我们专业领域）的 microRNAs 的信息。miRNAs 在癌症治疗和诊断中的应用正在成为基因治疗的一个重要领域。miRNAs 在癌症中的多样性不断被阐明，为肿瘤疾病的治疗选择带来了神秘性。
