长链非编码RNA-PCGEM1调控miR-145影响前列腺癌侵袭迁移的分子机制研究

Prostate cancer is one of the most common malignancies of the urinary system in the male. Occurrence of prostate cancer is related to the molecular signaling network in regulation of multiple genes at different levels. Our previous studies have demonstrated that abnormally high expression levels of long noncoding RNA (lncRNA)-PCGEM1 negatively regulated miR-145 in LNCaP prostate cancer cells, and thus promoted invasion and migration of prostate cancer cells. However, the molecular mechanisms of the regulation remains to be further explored. Bioinformatics predicted STAT1 binding sites in the promoter region of PCGEM1. The gene of SENP1 protein is a target gene that is regulated by miR-145. The transcription factor STAT1 could bind to the promoter region of PCGEM1 which has been confirmed by Co-Immunoprecipitation. Therefor, we believe that the transcription factor, STAT1, may activate the high expression of lncRNA-PCGEM1. Besides, via competitively 'spongeing' miR-145, lncRNA-PCGEM1 may relieve its inhibition of the translation of SENP1 protein. Finally, the high expression of SENP1 may promote the invasion and metastasis of prostate cancer. Based on this hypothesis, we are planning to explore the effects of these regulatory networks, with constructed STAT1/ PCGEM1/ miR-145/ SENP1, on prostate cancer cell invasion and migration. By using RNA interference and over expression technology, we hope to provide with a new intervention therapeutic strategy for prostate cancer.

前列腺癌是男性最常见的泌尿系统恶性肿瘤之一，其发生与多基因、多层次的分子信号网络调控有关。申请者在前期研究中发现前列腺癌LNCaP细胞中lncRNA-PCGEM1的高表达与miR-145呈负性调控，并促进前列腺癌的侵袭迁移。但是，其分子机制需进一步探讨。生物信息学预测提示SENP1蛋白基因为miR-145调控的靶基因，免疫共沉淀技术已证实转录因子STAT1能结合到PCGEM1启动子区域。因此，我们有理由认为：STAT1激活了lncRNA-PCGEM1的高表达，lncRNA-PCGEM1通过竞争性吸附miR-145，解除其对蛋白SENP1的翻译抑制，最终SENP1的高表达促进前列腺癌的侵袭迁移。针对这一假说，申请者运用RNA 干扰技术，过表达技术，探讨STAT1/ PCGEM1/ miR-145/ SENP1构成的调控网络对前列腺癌胞侵袭迁移的影响，为前列腺癌的靶向治疗提供新的干预策略。

主要背景：前列腺癌（ Prostatic Cancer，PCa）是发生在前列腺上皮的恶性肿瘤，其发生与遗传因素有关，发病率随年龄增长而升高.目前对前列腺癌的发生、发展机制尚不十分清楚。miRNA（microRNA，微小RNA）与PCa的发生和发展密切相关，约50％得到注解的miRNAs在基因组上定位于与肿瘤相关的脆性位点，类似于抑癌基因和癌基因的功能。miR-145在神经母细胞瘤、骨肉瘤、宫颈癌、前列腺癌等肿瘤中也发挥抑癌作用，但是其调控机制需进一步阐明。.研究内容:（1）观察STAT1/ PCGEM1，miR-145/ SENP1在前列腺癌组织及细胞株中的表达水平；（2）观察STAT1与PCGEM1上游启动子区域的结合作用及PCGEM1/ miR-145、miR-145/ SENP1的直接相互作用(3)观察STAT1/PCGEM1/miR-145/ SENP1调控网络对前列腺癌细胞侵袭迁移的影响.重要研究结果：.（1）STAT1/PCGEM1/SENP1在前列腺癌组织及细胞株中的表达水平是增高的.（2）STAT1能结合PCGEM1上游启动子区域.（3）PCGEM1/miR-145、miR-145/SENP1存在直接相互作用.（4）过表达miR-145-5p显著抑制LNCaP细胞增殖、克隆形成、侵袭与迁移、前列腺癌移植瘤的生长，并促进LNCap细胞早期凋亡。.（5）.CDX2通过抑制mir-145-5p的表达，从而解除mir-145-5p抑制SENP1的翻译作用，并影响前列腺癌细胞侵袭与迁移.（6）过表达 miR-145促进hsa_circRNA_101981, hsa_circRNA_008068 和 hsa_circRNA_40655的表达,但是抑制 hsa_circRNA_101996 和 hsa_circRNA_091420的表达在LNCaP细胞里..科学意义：.为前列腺癌的治疗提供一种新的靶标，为揭示前列腺癌潜在的发生与发展潜在的分子机制提供一定理论依据。