PO.TB03.01 · 肿瘤生物学
DNMTi与PARPi联合抑制三阴性乳腺癌中异常的Wnt/beta-catenin信号传导和tenascin-C通路、癌症干性及转移
DNMTi in combination with PARPi inhibits aberrant Wnt/beta-catenin signaling and tenasin-C pathways, cancer stemness and metastasis in triple negative breast cancer
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
与其他乳腺癌类型相比，三阴性乳腺癌（TNBC）转移率更高，预后和生存较差。聚ADP核糖聚合酶抑制剂（PARPi）用于治疗携带种系BRCA1/2突变的TNBC患者，诱导合成致死，但应答不持久。我们此前报道，PARPi与DNA甲基转移酶抑制剂（DNMTi）联合在TNBC中发挥协同细胞毒性，且不依赖于BRCA突变，但这些药物对与不良生存结局相关的转移和干性的影响尚不清楚。已知TNBC中异常的Wnt/beta-catenin信号传导可驱动癌症干性、转移以及对凋亡和化疗的耐药。在TNBC细胞系MDA MB 231中的全基因组转录组分析表明，联合使用DNMTi阿扎胞苷（AZA）和PARPi他拉唑帕利（TAL）下调了癌症干性和转移通路，且关键的前沿基因（leading-edge genes），包括参与Wnt/beta-catenin信号传导和tenascin-C（TNC，一种促进癌细胞迁移的多模块糖蛋白）的基因，均减少。使用划痕、transwell迁移和侵袭实验，在包括MDA MB 231和SUM159在内的多种TNBC细胞系以及患者来源类器官（N=3）中对该药物组合对细胞迁移的影响进行了功能验证。MDA MB 231经尾静脉和皮下注射的异种移植研究显示，该药物组合减少了肺转移。值得注意的是，干细胞实验，包括球体实验和干细胞标志物SOX2、ALDH1a1和CD44，在AZA和TAL治疗下也均降低。值得注意的是，我们首次在TNBC中证明Beta-catenin/TCF12通过结合TNC启动子区域转录调控TNC，且抑制或敲低WNT/Beta-catenin或TNC表达可降低细胞迁移、转移和干性，模拟了该药物组合在TNBC细胞中的效应。综上所述，我们的结果首次表明，PARPi和DNMTi联合治疗靶向WNT/Beta-catenin信号传导和TNC调控，从而驱动TNBC的侵袭性疾病、转移、干性和不良生存。
查看英文原文 English abstract
Triple-negative breast cancer (TNBC) has a higher rate of metastasis; a poor prognosis and survival compared with other breast cancer types. Poly-ADP ribose polymerase inhibitors (PARPis) are used to treat TNBC patients that harbor germline BRCA1/2 mutations, inducing synthetic lethality, but responses are not durable. We previously reported that PARPis in combination with DNA methyltransferase inhibitors (DNMTis) exert synergistic cytotoxicity in TNBC, independent of BRCA mutations, but the effects of these drugs on metastasis and stemness, which are associated with poor survival outcomes, are not known. Aberrant Wnt/beta-catenin signaling in TNBC is known to drive cancer stemness, metastasis, and resistance to apoptosis and chemotherapy. Genome-wide transcriptomic analysis in TNBC cell line MDA MB 231 demonstrated that combining DNMTis azacytidine (AZA) and PARPis talazoparib (TAL) down-regulated cancer stemness and metastases pathways, and key leading-edge genes including those involved in Wnt/beta-catenin signaling and tenasin-C (TNC), a multimodular glycoprotein that promotes the migration of cancer cells, were decreased. The effects of this drug combination on cell migration were functionally validated using scratch and transwell migration and invasion assays in multiple TNBC cell lines, including MDA MB231 and SUM159, and patient-derived organoids (N=3). Xenograft studies of MDA MB 231 by tail vein and SC injection showed decreased metastasis to the lung with this drug combination. Notably, stem cell assays, including spheroid assays and stem cell markers, SOX2, ALDH1a1 and CD44, were also decreased with AZA and TAL treatment. Notably, we show for the first time in TNBC that Beta-catenin/TCF12 transcriptionally regulates TNC by binding to its promoter region and that inhibition or KD of WNT/Beta catenin or TNC expression decreases the cell migration, metastasis and stemness, mimicking the effects of the drug combination in TNBC cells. Taken together, our results show for the first time that PARPi and DNMTi combination therapy targets WNT/Beta-catenin signaling and TNC regulation in driving aggressive disease, metastasis, stemness and poor survival in TNBC.
利益披露 Disclosure
L. Stojanovic, None..
Z. Gohari, None.