Division of Applied Molecular Oncology, Ontario Cancer Institute, University of Toronto, Toronto, Ontario, Canada.
Clin Cancer Res. 2010 Feb 15;16(4):1129-39. doi: 10.1158/1078-0432.CCR-09-2166. Epub 2010 Feb 9.
The objective of this study is to investigate the significance of microRNAs (miRNA) in patients with locally advanced head and neck squamous cell carcinoma (HNSCC).
A global miRNA profiling was done on 51 formalin-fixed archival HNSCC samples using quantitative reverse transcription-PCR approach, correlated with patients' clinical parameters. Functional characterization of HNSCC-associated miRNAs was conducted on three HNSCC cell lines. Cell viability and proliferation were investigated using MTS and clonogenic assays, respectively; cell cycle analyses were assessed using flow cytometry.
Thirty-eight of the 117 (33%) consistently detected miRNAs were significantly differentially expressed between malignant versus normal tissues. Concordant with previous reports, overexpression of miR-21, miR-155, let-7i, and miR-142-3p and underexpression of miR-125b and miR-375 were detected. Upregulation of miR-423, miR-106b, miR-20a, and miR-16 as well as downregulation of miR-10a were newly observed. Exogenous overexpression of miR-375 in HNSCC cell lines reduced proliferation and clonogenicity and increased cells in sub-G(1). Similar cellular effects were observed in knockdown studies of the miR-106b-25 cluster but with accumulation of cells in G(1) arrest. No major difference was detected in miRNA profiles among laryngeal, oropharyngeal, or hypopharyngeal cancers. miR-451 was found to be the only significantly overexpressed miRNA by 4.7-fold between nonrelapsed and relapsed patients.
We have identified a group of aberrantly expressed miRNAs in HNSCC and showed that underexpression of miR-375 and overexpression of miR-106b-25 cluster might play oncogenic roles in this disease. Further detailed examinations of miRNAs will provide opportunities to dissect the complex molecular abnormalities driving HNSCC progression.
本研究旨在探讨微小 RNA（miRNA）在局部晚期头颈部鳞状细胞癌（HNSCC）患者中的意义。
采用定量逆转录-PCR 方法对 51 例福尔马林固定存档的 HNSCC 样本进行了全局 miRNA 谱分析，并与患者的临床参数相关联。在三个 HNSCC 细胞系中对 HNSCC 相关 miRNA 进行了功能特征分析。使用 MTS 和集落形成测定法分别研究细胞活力和增殖；通过流式细胞术评估细胞周期分析。
在恶性与正常组织之间，117 个 miRNA 中有 38 个（33%）的表达存在显著差异。与先前的报道一致，miR-21、miR-155、let-7i 和 miR-142-3p 的过表达以及 miR-125b 和 miR-375 的低表达被检测到。miR-423、miR-106b、miR-20a 和 miR-16 的上调以及 miR-10a 的下调是新观察到的。在 HNSCC 细胞系中外源性过表达 miR-375 可降低增殖和集落形成能力，并使更多的细胞处于 sub-G1 期。在 miR-106b-25 簇的敲低研究中观察到类似的细胞效应，但细胞在 G1 期停滞中积累。在喉癌、口咽癌或下咽癌之间未检测到 miRNA 谱的主要差异。miR-451 是唯一在非复发和复发患者之间表达上调 4.7 倍的 miRNA。
我们已经确定了一组在 HNSCC 中异常表达的 miRNA，并表明 miR-375 的低表达和 miR-106b-25 簇的高表达可能在该疾病中发挥致癌作用。对 miRNA 的进一步详细检查将为剖析驱动 HNSCC 进展的复杂分子异常提供机会。
