CPEΔN调控HDAC1/Snail/EZH2复合体组装促进肺腺癌转移分子机制研究

Recurrent metastasis is the leading cause of death in patients with lung cancers. Changes in the epigenetic modification of histone status may regulate the transcription and expression of tumor suppression and promotion genes and affect the progression of tumor recurrence and metastasis. CPEΔN, an isotype of carboxypeptidase E, is an early warning protein of lung cancer metastasis. Our previous results showed that CPEΔN could bind with Snail , histone methyltransferase (EZH2) and histone deacetylase (HDAC), forming into a complex that inhibited the transcription and expression of cell adhesion protein E-cadherin. We inferred that CPEΔN may alter the epigenetic modification status at the promoter region of E-cadherin, therefore, use of EZH2 or HDAC inhibitors that block the epigenetic modification of CPE△N may reverse the cancer-promoting effects of CPE△N. Our present study aims to explore the molecular pathways in which CPE△N is involved in the regulation of epigenetic modification using COIP、GST Pull down and ChIP techniques; moreover, we will also assess the efficacy and feasibility of the interventional treatments in CPEΔN/KrasG12D double knock-in mice . Completion of this project will contribute to explaining the underlying molecular mechanisms and may provide basic research data for the accurate treatment in patients with highly expressed CPE△N.

复发转移是肺癌死亡的首要原因。启动子区组蛋白表观修饰状态的改变可以调节抑癌或促癌基因的转录表达，调控肿瘤复发转移进程。羧肽酶E（Carboxypeptidase E)的异构体CPEΔN是肺腺癌转移的预警蛋白。前期研究证实，CPEΔN能够和HDAC1（去乙酰化酶1）、Snail及EZH2（甲基转移酶）形成复合体,抑制细胞粘附蛋白E-cadherin的转录和表达。我们推测CPEΔN可以改变E-cadherin启动子区的表观修饰状态，阻断CPE△N的表观修饰作用，可能逆转CPE△N的促癌效应。本研究拟采用COIP、GST Pull down，染色质免疫沉淀技术探明CPE△N参与转录调控的分子路径，并在CPEΔN/KrasG12D双基因敲入小鼠体内分析干预治疗的有效性和可行性。实施本项目有助于揭示CPE△N促进肺腺癌转移的分子机制，并为CPE△N高表达肺腺癌病例的精准诊疗提供基础研究数据。

复发转移是肺癌死亡的首要原因。启动子区组蛋白表观修饰状态的改变可以调节抑癌或促癌基因的转录表达，调控肿瘤复发转移进程。羧肽酶E的异构体CPEΔN是肺腺癌转移的预警蛋白。本研究我们采用COIP、GST Pull down，染色质免疫沉淀等技术证实CPE△N/Snail/HDAC1/HDAC3能够形成复合体并结合到CDH1基因启动子区，调节CDH1基因启动子区表观修饰，降低H3K9乙酰化，增加H3K9和H3K27三甲基化，最终抑制E-cadherin转录，促进肺癌癌症细胞的迁移和侵袭。并在195例肺腺癌患者中证实CPEΔN胞核表达与和肺腺癌进展呈正相关。晚期肺腺癌病例中CPEΔN的核表达较高，且CPEΔN核表达与E-cadherin的细胞膜表达呈负相关。本研究首次将CPEΔN 定位为转录调控因子，证实CPEΔN参与了上皮-间充质转换调控。我们的研究扩展了对 CPEΔN 基因功能的全面认知。为CPE△N促进肺腺癌转移提供了新的见解。