Androgen-regulated microRNA-135a decreases prostate cancer cell migration and invasion through downregulating ROCK1 and ROCK2
Androgen-regulated microRNA-135a decreases prostate cancer cell migration and invasion through downregulating ROCK1 and ROCK2
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DOI：
10.1038/onc.2014.222
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发表时间：
2015-05-28
期刊：
影响因子：
8
通讯作者：
Allioli, N.
中科院分区：
文献类型：
--
作者：
Kroiss, A.;Vincent, S.;Allioli, N.
雄激素信号通过雄激素受体(AR)在前列腺癌(PCa)的发生和发展中起着至关重要的作用。识别雄激素/AR途径的新下游效应分子将有助于更好地了解这些机制，并可能揭示新的生物标志物和/或治疗药物以提高患者的存活率。我们通过高通量逆转录酶-定量聚合酶链式反应比较了1 nM R1881刺激和不刺激雄激素敏感的LNCaP细胞中的microRNA表达谱，发现miR-135a上调。在雄激素刺激后，我们发现AR通过与启动子区的雄激素反应元件结合直接激活miR-135a2基因的转录。我们的发现证实miR-135a是雄激素/AR信号通路中的一个新的效应器。通过对鸡胚和成年雄性小鼠的异种移植实验，我们发现miR-135a过表达降低了前列腺PC-3细胞的体内侵袭能力。通过体外伤口愈合迁移和侵袭实验，我们证明了这种作用是通过下调ROCK1和ROCK2的表达来实现的，我们将这两个基因描述为miR-135a直接靶基因。在人类前列腺癌手术标本中，我们观察到miR-135a在肿瘤中的表达低于配对的邻近正常组织，主要是在Gleason评分高(>；=8)的肿瘤中。此外，miR-135a在浸润性肿瘤中的表达较低，与前列腺局灶性肿瘤相比，表现为前列腺外侵犯。与正常腺体相比，我们还发现肿瘤组织中ROCK1蛋白的表达频率更高，这是通过半定量免疫组织化学分析确定的。因此，在肿瘤细胞中，miR-135a的低表达可能导致ROCK1蛋白的高表达，这可以解释肿瘤细胞的侵袭能力。MiR-135a表达水平与疾病侵袭性程度之间的关系提示miR-135a可作为PCa的预后指标。
Androgen signaling, via the androgen receptor (AR), is crucial in mediating prostate cancer (PCa) initiation and progression. Identifying new downstream effectors of the androgens/AR pathway will allow a better understanding of these mechanisms and could reveal novel biomarkers and/or therapeutic agents to improve the rate of patient survival. We compared the microRNA expression profiles in androgen-sensitive LNCaP cells stimulated or not with 1 nM R1881 by performing a high-throughput reverse transcriptase-quantitative PCR and found that miR-135a was upregulated. After androgen stimulation, we showed that AR directly activates the transcription of miR-135a2 gene by binding to an androgen response element in the promoter region. Our findings identify miR-135a as a novel effector in androgens/AR signaling. Using xenograft experiments in chick embryos and adult male mice, we showed that miR-135a overexpression decreases in vivo invasion abilities of prostate PC-3 cells. Through in vitro wound-healing migration and invasion assays, we demonstrated that this effect is mediated through downregulating ROCK1 and ROCK2 expression, two genes that we characterized as miR-135a direct target genes. In human surgical samples from prostatectomy, we observed that miR-135a expression was lower in tumoral compared with paired adjacent normal tissues, mainly in tumors classified with a high Gleason score (>= 8). Moreover, miR-135a expression is lower in invasive tumors, showing extraprostatic extension, as compared with intraprostatic localized tumors. In tumor relative to normal glands, we also showed a more frequently higher ROCK1 protein expression determined using a semi-quantitative immunohistochemistry analysis. Therefore, in tumor cells, the lower miR-135a expression could lead to a higher ROCK1 protein expression, which could explain their invasion abilities. The highlighted relationship between miR-135a expression level and the degree of disease aggressiveness suggests that miR-135a may be considered as a prognostic marker in human PCa.