lncRNA-DRAT通过结合WDR5促进前列腺癌多西他赛耐药的机制研究

Currently there is no effective approach to treat Docetaxel resistant prostate cancer, thus Docetaxel resistant prostate cancer is the main reason of death in advanced prostate cancer patients. The activation of chemo-resistant and anti-apoptotic genes plays pivotal role in the Docetaxel resistance of prostate cancer, but the mechanism is not fully understood. Emerging evidence reveals that long non-coding RNAs (lncRNAs) may play an important regulatory role in cancer by acting as oncogenes or tumor suppressors. However, the roles of lncRNAs in prostate cancer remain elusive. Our previous study found that the expression of lncRNA-DRAT is increased in Docetaxel resistant prostate cancer tissues and cell line, associated with prostate cancer stage and Gleason Score, and leading to an enhanced cell viability under Docetaxel treatment. Furthermore, we identified that lncRNA-DRAT binds to WDR5 by RNA Pull-down and Mass Spectrometry. Therefore, we propose a new mechanism that lncRNA-DRAT activates the transcription of chemo-resistance associated genes by recruiting WDR5, thus promoting the Docetaxel resistance of prostate cancer. To gain the proof of lncRNA-DRAT regulating Docetaxel resistance of prostate cancer by WDR5, we will perform in vitro and vivo experiments, RNA Pull-down and next generation sequencing analysis. This study aims to elucidate the function and mechanism of lncRNA-DRAT in prostate cancer and how they modulate Docetaxel resistance by binding WDR5. We will evaluate the clinical significance of lncRNA-DRAT in prostate cancer, its significance as bio-marker of Docetaxel resistant prostate and target therapy.

多西他赛耐药的前列腺癌缺少有效治疗方案，容易进展，是患者死亡的重要原因，耐药和抗凋亡相关基因的激活是多西他赛耐药的重要原因。长链非编码RNA(lncRNA)在肿瘤细胞中起关键调控作用，但lncRNA在调控前列腺癌多西他赛耐药中的作用和机制尚不明确。我们预实验发现lncRNA-DRAT在多西他赛耐药前列腺癌组织和细胞株中高表达并促进前列腺癌细胞的化疗拮抗，与临床分期及Gleason评分相关。RNA pulldown证明它与WDR5结合。由此我们提出前列腺癌耐药的新机制：lncRNA-DRAT通过募集染色质修饰复合物WDR5/MLL1，激活一系列下游基因的表达，从而促进CRPC的耐药。本研究拟进一步采用体内外实验，免疫共沉淀和高通量测序等技术，获得lncRNA-DRAT通过WDR5调控前列腺癌细胞耐药的可靠证据，确定它在前列腺癌耐药和预后中的意义，为发现前列腺癌新的标记物和治疗靶点提供理论依据

前列腺癌是我国男性泌尿生殖系统发病率最高的恶性肿瘤。以多西他赛为基础的全身化疗是晚期前列腺癌的一线化疗方案，多西他赛耐药是前列腺癌治疗中的关键难题，但机制远未阐明。研究发现长链非编码RNA（lncRNA）能在转录、翻译等层面调控一系列基因表达，从而在肿瘤中发挥促癌或抑癌作用。课题组通过CRPC多西他赛耐药前列腺癌组织和细胞株筛选出一未报道过的lncRNA-DRAT，通过生物信息学研究发现其与细胞增殖、迁徙及耐药相关。经过细胞体内外实验、高通量测序、免疫共沉淀技术、分子原位杂交等技术，研究了lncRNA-DRAT在前列腺癌的生物学功能、调控机制以及临床意义。结果发现，lncRNA-DRAT促进了前列腺癌细胞的增殖、迁袭及耐药。沉默lncRNA-DRAT后，前列腺癌细胞增加对多西他赛的敏感性，降低了体内成瘤能力，耐药相关基因PLK1、ABCC1、Bcl2、Survivin和CCL2等基因表达显著下调，并通过与WDR5蛋白结合发挥调控作用。临床样本原位杂交验证发现，lncRNA-DRAT的表达与前列腺癌病理恶性程度呈正相关，生存分析发现其高表达与患者不良预后相关。.因此，通过lncRNA-DRAT的研究，有望揭示lncRNAs在CRPC多西他赛耐药中的作用及机制，寻找到在上游水平调控多个或多层面耐药基因的关键lncRNA，能够为预测CRPC化疗敏感性和提高化疗疗效提供理论基础，为CRPC的精准治疗提供新靶点和新思路。