Saarland University Medical School; Department of Virology, Kirrbergerstrasse, Haus 47, 66421 Homburg/Saar, Germany.
Mol Cancer Res. 2014 Feb;12(2):250-63. doi: 10.1158/1541-7786.MCR-13-0230. Epub 2013 Dec 13.
MicroRNAs (miRNA) posttranscriptionally regulate gene expression and are important in tumorigenesis. Previous deep sequencing identified the miRNA profile of prostate carcinoma versus nonmalignant prostate tissue. Here, we generated miRNA expression profiles of prostate carcinoma by deep sequencing, with increasing tumor stage relative to corresponding nonmalignant and healthy prostate tissue, and detected clearly changed miRNA expression patterns. The miRNA profiles of the healthy and nonmalignant tissues were consistent with our previous findings, indicating a high fidelity of the method employed. In the tumors, quantitative real-time PCR (qRT-PCR) analysis of 40 paired samples of prostate carcinoma versus normal tissue revealed significant upregulation of miR-20a, miR-148a, miR-200b, and miR-375 and downregulation of miR-143 and miR-145. Hereby, miR-375 increased from normal to organ-confined tumors (pT2 pN0), slightly decreased in tumors with extracapsular growth (pT3 pN0), but was then expressed again at higher levels in lymph node metastasizing (pN1) tumors. The sequencing data for miR-375 were confirmed by Northern blotting and qRT-PCR. The regulation for other selected miRNAs could, however, not be confirmed by qRT-PCR in individual tumor stages. MiR-200b, in addition to miR-200c and miR-375 reduced the expression of SEC23A. Interestingly, miR-375, found by sequencing in pT2 upregulated by us and others in tumor versus normal tissue, and miR-15a, found by sequencing in pT2 and pT3 and in the metastasizing tumors, target the phosphatases PHLPP1 and PHLPP2, respectively. PHLPP1 and PHLPP2 dephosphorylate members of the AKT family of signal transducers, thereby inhibiting cell growth. Coexpression of miR-15a and miR-375 resulted in downregulation of PHLPP1/2 and strongly increased prostate carcinoma cell growth.
These genomic data reveal relevant miRNAs in prostate cancer that may have biomarker and therapeutic potential.
microRNAs（miRNA）在后转录水平上调控基因表达，在肿瘤发生中具有重要作用。先前的深度测序确定了前列腺癌与非恶性前列腺组织的 miRNA 图谱。在这里，我们通过深度测序生成了前列腺癌的 miRNA 表达谱，与相应的非恶性和健康前列腺组织相比，肿瘤阶段逐渐增加，并检测到明显改变的 miRNA 表达模式。健康和非恶性组织的 miRNA 图谱与我们之前的发现一致，表明所采用的方法具有很高的保真度。在肿瘤中，对 40 对前列腺癌与正常组织的样本进行定量实时 PCR（qRT-PCR）分析显示，miR-20a、miR-148a、miR-200b 和 miR-375 的表达明显上调，miR-143 和 miR-145 的表达下调。因此，miR-375 从正常组织到器官受限肿瘤（pT2 pN0）逐渐增加，在具有包膜外生长的肿瘤（pT3 pN0）中略有下降，但随后在淋巴结转移（pN1）肿瘤中再次表达较高水平。miR-375 的测序数据通过 Northern 印迹和 qRT-PCR 得到证实。然而，在个别肿瘤阶段，qRT-PCR 无法证实其他选定 miRNA 的调控。miR-200b 除了 miR-200c 和 miR-375 降低 SEC23A 的表达。有趣的是，通过测序在 pT2 中发现的 miR-375 被我们和其他人上调，以及在 pT2 和 pT3 以及转移肿瘤中通过测序发现的 miR-15a，分别靶向磷酸酶 PHLPP1 和 PHLPP2。PHLPP1 和 PHLPP2 去磷酸化 AKT 家族信号转导物的成员，从而抑制细胞生长。miR-15a 和 miR-375 的共表达导致 PHLPP1/2 的下调，并强烈增加前列腺癌细胞的生长。
这些基因组数据揭示了前列腺癌中具有潜在生物标志物和治疗潜力的相关 miRNA。
