Shaath Hibah, Vishnubalaji Radhakrishnan, Elango Ramesh, Khattak Shahryar, Alajez Nehad M
College of Health & Life Sciences, Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), Doha, Qatar.
Cancer Research Center, Qatar Biomedical Research Institute (QBRI), Hamad Bin Khalifa University (HBKU), Qatar Foundation (QF), PO Box, 34110, Doha, Qatar.
Cell Death Discov. 2021 Jan 25;7(1):23. doi: 10.1038/s41420-020-00383-y.
Cumulative evidence suggests added benefit for neoadjuvant chemotherapy (NAC) in a subset of triple-negative breast cancer (TNBC) patients. Herein we identified the long noncoding RNA (lncRNA) transcriptional landscape associated with TNBC resistance to NAC, employing 1758 single cells from three extinction and three persistence TNBC patients. Using Iterative Clustering and Guide-gene Selection (ICGS) and uniform manifold approximation and projection (UMAP) dimensionality reduction analysis, we observed single cells derived from each patient to largely cluster together. Comparing the lncRNA transcriptome from single cells through the course of NAC treatment revealed minimal overlap based on lncRNA transcriptome, suggesting substantial effects of NAC on lncRNA transcription. The differential analysis revealed upregulation of 202 and downregulation of 19 lncRNAs in the persistence group, including upregulation of five different transcripts encoding for the MALAT1 lncRNA. CRISPR/Cas9-mediated MALAT1 promoter deletion in BT-549 TNBC model enhanced sensitivity to paclitaxel and doxorubicin, suggesting a role for MALAT1 in conferring resistance. Mechanistically, whole transcriptome analysis of MALAT1-KO cells revealed multiple affected mechanistic networks as well as oxidative phosphorylation canonical and angiogenesis functional category. Interestingly, lncRNA profiling of MALAT1-depleted TNBC also revealed a number of altered lncRNAs in response to MALAT1 deletion, suggesting a reciprocal relationship between MALAT1 and a number of lncRNAs, including NEAT1, USP3-AS1, and LINC-PINT, in TNBC. Elevated expression of MALAT1, USP3-AS1, and LINC-PINT correlated with worse clinical outcomes in BC patients. Our data revealed the lncRNA transactional portrait and highlighted a complex regulatory network orchestrated by MALAT1 in the context of TNBC resistance to NAC therapy.
越来越多的证据表明,新辅助化疗(NAC)对一部分三阴性乳腺癌(TNBC)患者有额外的益处。在此,我们使用来自三名病情缓解和三名病情持续的TNBC患者的1758个单细胞,确定了与TNBC对NAC耐药相关的长链非编码RNA(lncRNA)转录图谱。通过迭代聚类和引导基因选择(ICGS)以及均匀流形近似和投影(UMAP)降维分析,我们观察到来自每位患者的单细胞在很大程度上聚集在一起。比较NAC治疗过程中单细胞的lncRNA转录组发现,基于lncRNA转录组的重叠极少,这表明NAC对lncRNA转录有显著影响。差异分析显示,持续组中有202个lncRNA上调,19个lncRNA下调,其中包括编码MALAT1 lncRNA的五种不同转录本上调。在BT - 549 TNBC模型中,CRISPR/Cas9介导的MALAT1启动子缺失增强了对紫杉醇和阿霉素的敏感性,这表明MALAT1在赋予耐药性方面发挥了作用。从机制上讲,对MALAT1基因敲除细胞的全转录组分析揭示了多个受影响的机制网络以及氧化磷酸化经典和血管生成功能类别。有趣的是,对MALAT1缺失的TNBC进行lncRNA分析还发现,一些lncRNA因MALAT1缺失而发生改变,这表明在TNBC中,MALAT1与包括NEAT1、USP3 - AS1和LINC - PINT在内的一些lncRNA之间存在相互关系。MALAT1、USP3 - AS1和LINC - PINT的高表达与BC患者较差的临床结果相关。我们的数据揭示了lncRNA转录图谱,并突出了在TNBC对NAC治疗耐药的背景下,由MALAT1精心编排的复杂调控网络。