Department of Obstetrics and Gynecology, University of Texas Health San Antonio, San Antonio, TX, 78229, USA.
Department of Gastroenterology, The Second Xiangya Hospital, Central South University, No.139 Middle Renmin Road, Changsha, 4100011, Hunan, People's Republic of China.
Breast Cancer Res Treat. 2021 Jan;185(2):343-357. doi: 10.1007/s10549-020-05963-1. Epub 2020 Oct 14.
Cancer stem cells (CSCs) are highly tumorigenic, spared by chemotherapy, sustain tumor growth, and are implicated in tumor recurrence after conventional therapies in triple negative breast cancer (TNBC). Lysine-specific histone demethylase 1A (KDM1A) is highly expressed in several human malignancies and CSCs including TNBC. However, the precise mechanistic role of KDM1A in CSC functions and therapeutic utility of KDM1A inhibitor for treating TNBC is poorly understood.
The effect of KDM1A inhibition on cell viability, apoptosis, and invasion were examined by Cell Titer Glo, Caspase 3/7 Glo, and matrigel invasion assays, respectively. Stemness and self-renewal of CSCs were examined using mammosphere formation and extreme limiting dilution assays. Mechanistic studies were conducted using RNA-sequencing, RT-qPCR, Western blotting and reporter gene assays. Mouse xenograft and patient derived xenograft models were used for preclinical evaluation of KDM1A inhibitor.
TCGA data sets indicated that KDM1A is highly expressed in TNBC. CSCs express high levels of KDM1A and inhibition of KDM1A reduced the CSCs enrichment in TNBC cells. KDM1A inhibition reduced cell viability, mammosphere formation, self-renewal and promoted apoptosis of CSCs. Mechanistic studies suggested that IL6-JAK-STAT3 and EMT pathways were downregulated in KDM1A knockdown and KDM1A inhibitor treated cells. Importantly, doxycycline inducible knockout of KDM1A reduced tumor progression in orthotopic xenograft models and KDM1A inhibitor NCD38 treatment significantly reduced tumor growth in patient derived xenograft (PDX) models.
Our results establish that KDM1A inhibition mitigates CSCs functions via inhibition of STAT3 and EMT signaling, and KDM1A inhibitor NCD38 may represent a novel class of drug for treating TNBC.
癌症干细胞（CSC）具有高度致瘤性，能够逃避化疗，维持肿瘤生长，并与三阴性乳腺癌（TNBC）常规治疗后的肿瘤复发有关。赖氨酸特异性组蛋白去甲基酶 1A（KDM1A）在几种人类恶性肿瘤和 CSC 中表达水平较高，包括 TNBC。然而，KDM1A 在 CSC 功能中的精确机制作用以及 KDM1A 抑制剂用于治疗 TNBC 的治疗效用仍知之甚少。
通过细胞活力测定试剂盒（Cell Titer Glo）、半胱天冬酶 3/7 活力测定试剂盒（Caspase 3/7 Glo）和基质胶侵袭测定分别检测 KDM1A 抑制对细胞活力、凋亡和侵袭的影响。使用乳腺球体形成和极限稀释分析检测 CSC 的干性和自我更新能力。通过 RNA 测序、实时定量 PCR、Western blot 和报告基因检测进行机制研究。使用小鼠异种移植和患者来源的异种移植模型进行 KDM1A 抑制剂的临床前评估。
TCGA 数据集表明 KDM1A 在 TNBC 中表达水平较高。CSC 表达高水平的 KDM1A，KDM1A 抑制降低了 TNBC 细胞中 CSC 的富集。KDM1A 抑制降低了细胞活力、乳腺球体形成、自我更新，并促进了 CSC 的凋亡。机制研究表明，在 KDM1A 敲低和 KDM1A 抑制剂处理的细胞中，IL6-JAK-STAT3 和 EMT 通路被下调。重要的是，强力霉素诱导的 KDM1A 敲除减少了原位异种移植模型中的肿瘤进展，而 KDM1A 抑制剂 NCD38 治疗显著减少了患者来源的异种移植（PDX）模型中的肿瘤生长。
我们的研究结果表明，KDM1A 抑制通过抑制 STAT3 和 EMT 信号来减轻 CSC 的功能，而 KDM1A 抑制剂 NCD38 可能代表治疗 TNBC 的一类新型药物。
