Henrici Alexander, Montalbano Roberta, Neureiter Daniel, Krause Michael, Stiewe Thorsten, Slater Emily Prentice, Quint Karl, Ocker Matthias, Di Fazio Pietro
Institute for Surgical Research, Philipps University of Marburg, Marburg, Germany.
Department of Visceral, Thoracic and Vascular Surgery, Philipps University of Marburg, Marburg, Germany.
Mol Carcinog. 2015 Aug;54(8):585-97. doi: 10.1002/mc.22122. Epub 2013 Dec 23.
Deacetylase inhibitors (DACi) are a new class of drugs with a broad spectrum of mechanisms that favor their application in cancer therapy. Currently, the exact mechanisms and cellular effects of DACi have not been fully elucidated. In addition to their effects on histone acetylation, DACi can interfere with gene expression via miRNA pathways. Treatment with panobinostat (LBH589), a novel potent DACi, led to the highly aberrant modulation of several miRNAs in hepatocellular carcinoma (HCC) cell lines as shown by miRNA array analysis. Among them, hsa-miR-19a, hsa-miR-19b1 and the corresponding precursors were down-regulated by panobinostat in TP53(-/-) Hep3B and TP53(+/+) HepG2 cell lines; hsa-miR30a-5p mature form only was suppressed in both HCC cell lines, as confirmed by further RT-qPCR analysis. In HCC cell lines, panobinostat caused the upregulation of the predicted miRNA targets APAF1 and Beclin1 protein levels. Transfection with oligonucleotides mimicking these miRNAs led to an increase in the viability rate of both cell lines as analyzed by impedance-based real-time cell analysis. In addition, transfecting miRNA mimicking oligonucleotides resulted in the decrease of APAF1, Beclin1 and PAK6 at the protein level, proving the regulating influence of the investigated miRNAs on gene final products. The overexpression of the above mentioned oncomiRs in Hep3B and HepG2 cell lines leads to cell proliferation and downregulation of cell death associated proteins. In our model, panobinostat exerts its anti-cancer effect by suppressing these miRNAs and restoring the expression of their corresponding tumor suppressor targets.
去乙酰化酶抑制剂（DACi）是一类新型药物，其作用机制广泛，有利于应用于癌症治疗。目前，DACi的确切机制和细胞效应尚未完全阐明。除了对组蛋白乙酰化的影响外，DACi还可通过微小RNA（miRNA）途径干扰基因表达。如miRNA阵列分析所示，新型强效DACi帕比司他（LBH589）处理导致肝癌（HCC）细胞系中几种miRNA高度异常调节。其中，hsa-miR-19a、hsa-miR-19b1及其相应前体在TP53（-/-）Hep3B和TP53（+/+）HepG2细胞系中被帕比司他下调；进一步的逆转录定量聚合酶链反应（RT-qPCR）分析证实，仅hsa-miR30a-5p成熟形式在两种HCC细胞系中均受到抑制。在HCC细胞系中，帕比司他导致预测的miRNA靶标APAF1和Beclin1蛋白水平上调。用模拟这些miRNA的寡核苷酸转染导致两种细胞系的存活率增加，这通过基于阻抗的实时细胞分析进行分析。此外，转染miRNA模拟寡核苷酸导致APAF1、Beclin1和PAK6蛋白水平降低，证明了所研究的miRNA对基因终产物的调节作用。上述致癌miRNA在Hep3B和HepG2细胞系中的过表达导致细胞增殖以及细胞死亡相关蛋白的下调。在我们的模型中，帕比司他通过抑制这些miRNA并恢复其相应肿瘤抑制靶标的表达来发挥其抗癌作用。
