中文摘要
神经内分泌型前列腺癌多由前列腺癌腺癌长期激素治疗后继发而来,它是一种高度侵袭性的恶性肿瘤,对激素或化学治疗不敏感,预后差,病人多在发生后一年内死亡。这是部分前列腺癌复发和死亡的重要原因。但其发生机制和过程尚不清楚。我们在前期研究中建立了一种新型的前列腺腺癌异种移植动物模型,在雄性小鼠去势处理后可诱导不可逆转的横向转化为神经内分泌型前列腺癌。这为我们研究前列腺腺癌-神经内分泌癌横向分化机制提供了有力的研究工具。本课题拟通过全基因组和转录组测序的方法,系统分析比较该动物模型腺癌和神经内分泌癌的遗传和分子特征,在多个时间段动态观察腺癌向神经内分泌癌分化的系列变化,以阐明神经内分泌型前列腺癌的发生的动态过程。此外,我们还将针对该分化过程中的关键靶点,采用药物干预的方法,以阻断神经内分泌癌的形成。本研究通过阐明神经内分泌型前列腺癌的发生过程和分子机制,其预防和治疗提供临床前实验数据和理论依据。
英文摘要
Neuroendocrine prostate cancer (NEPC) most commonly evolved from prostatic adenocarcinoma after long-term hormone deprivation therapy. NEPC is a highly aggressive and lethal subtype of prostate cancer(PCa) with poor prognostics, death usually ensues within 1 year after NEPC formation. This is an important cause of recurrence and death of a large part of PCa patients, yet its mechanism and dynamic process remains largely unkown. In our pre-study we have established a novel prostatic adenocarcinoma xenograft model, by castration of male NOD-SCID mice, the adenocarinoma type of PCa irrevisbly trans-differentiated into pure NEPC. This provides us with a valuable tool to investigate the molecular mechanism underlying andenocarcinoma-NEPC trans-differentiation process. In this study, we will employ whole genome and transcription next generation sequencing methods to sysmeticly analysis and compare the genetic and molecular characteristics of adenocarcinoma and NEPC xenograft, and we will elucidate the dynamic course of trans-differentiation by observing kenetic changes during the process of adenocarcinoma-NEPC trans-differentiation at a serial of time points. We will also try to abrogate the formation of NEPC in this xenograft animal model by drug that targeting at the key molecules during the trans-differentiation process. This study will providing pre-clinical datas and theretical basis for the prevetion and therapy of NEPC by elucidating the dynamic process and molecular mechanism of the genesis of NEPC evloved from PCa after hormone deprivation therapy.
结题摘要
治疗后神经内分泌型前列腺癌(t-NEPC)由前列腺癌长期激素治疗引发,是前列腺癌患者肿瘤复发和死亡的重要原因,但其机制和过程不清。我们从转录因子介导的细胞重编程视角出发,利用生物信息学的方法初步构建了前列腺三种上皮细胞系(basal、 luminal 和NE) 的主转录因子组调控作用网络,解读了LTL331-LTL331R小鼠异种移植动物模型中前列腺癌从腺癌转变为t-NEPC的机制和动态过程。发现了t-NEPC相关的SOX2/AR-FOXA1/FOXM1/REST等4个核心转录因子表型及其相互关系,并解读了CCND1降低在NEPC中的肿瘤生物学意义。我们发现了t-NEPC形成过程中的TP63-基底细胞样中间态(TP63-TIS),该中间态具有前列腺基底干细胞特征,与炎症SASP和肿瘤免疫应答,hedgehog通路/WNT/NOTCH/SMAD/IRF1-STAT/NFKB等多个信号通路密切相关。我们还发现TP63-TIS中间态与前列腺癌细胞内胆固醇池耗竭表型同时出现,后者阻断了雄激素生物合成途径介导的CRPC-腺癌型的复发。TP63的表达降低和消失是t-NEPC最终出现的前提条件,TP63-TIS与受胆固醇调控活性的hedgehog通路分子SHH/GLI3/GLI2同步变化。在NEPC最终形成后hedgehog通路中SMO明显降低,是NEPC与小细胞肺癌的关键性区别之一,并使t-NEPC对hedgehog和BRD4抑制剂天然耐药。我们在TCGA的NEPC数据库中发现了两个与LTL-331动物模型TP63-TIS相关的基因变异:胆固醇生物合成途径相关基因的拷贝数缺失和表达下降;抗原递呈关键转录因子CIITA拷贝数缺失和表达降低,进一步证实了我们的分析结果在NEPC形成机制和过程具有普遍意义。
