Stucky Andres, Gao Li, Li Shengwen Calvin, Tu Lingli, Luo Jun, Huang Xi, Chen Xuelian, Li Xiaoqing, Park Tiffany H, Cai Jin, Kabeer Mustafa H, Plant Ashley S, Sun Lan, Zhang Xi, Zhong Jiang F
Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, CA, United States.
Medical Center of Hematology, Xinqiao Hospital, Army Medical University, Chongqing, China.
Front Cell Dev Biol. 2022 Mar 9;10:699144. doi: 10.3389/fcell.2022.699144. eCollection 2022.
The mechanism of tumorigenicity potentially evolved in mesenchymal stem cells (MSCs) remains elusive, resulting in inconsistent clinical application efficacy. We hypothesized that subclones in MSCs contribute to their tumorgenicity, and we approached MSC-subclones at the single-cell level. MSCs were cultured in an osteogenic differentiation medium and harvested on days 12, 19, and 25 for cell differentiation analysis using Alizarin Red and followed with the single-cell transcriptome. Single-cell RNA-seq analysis reveals a discrete cluster of MSCs during osteogenesis, including differentiation-resistant MSCs (DR-MSCs), differentiated osteoblasts (DO), and precursor osteoblasts (PO). The DR-MSCs population resembled cancer initiation cells and were subjected to further analysis of the yes associated protein 1 (YAP1) network. Verteporfin was also used for YAP1 inhibition in cancer cell lines to confirm the role of YAP1 in MSC--involved tumorigenicity. Clinical data from various cancer types were analyzed to reveal relationships among YAP1, OCT4, and CDH6 in MSC--involved tumorigenicity. The expression of cadherin 6 (CDH6), octamer-binding transcription factor 4 (OCT4), and YAP1 expression was significantly upregulated in DR-MSCs compared to PO and DO. YAP1 inhibition by Verteporfin accelerated the differentiation of MSCs and suppressed the expression of YAP1, CDH6, and OCT4. A survey of 56 clinical cohorts revealed a high degree of co-expression among CDH6, YAP1, and OCT4 in various solid tumors. YAP1 inhibition also down-regulated HeLa cell viability and gradually inhibited YAP1 nuclear localization while reducing the transcription of CDH6 and OCT4. We used single-cell sequencing to analyze undifferentiated MSCs and to discover a carcinogenic pathway in single-cell MSCs of differentiated resistance subclones.
间充质干细胞（MSC）中潜在的致瘤机制仍不清楚，导致临床应用疗效不一致。我们假设MSC中的亚克隆导致其致瘤性，并在单细胞水平研究了MSC亚克隆。将MSC在成骨分化培养基中培养，并在第12、19和25天收获，用于茜素红细胞分化分析，随后进行单细胞转录组分析。单细胞RNA测序分析揭示了成骨过程中MSC的一个离散簇，包括分化抗性MSC（DR-MSC）、分化的成骨细胞（DO）和前体成骨细胞（PO）。DR-MSC群体类似于癌症起始细胞，并对Yes相关蛋白1（YAP1）网络进行了进一步分析。维替泊芬也用于癌细胞系中YAP1的抑制，以证实YAP1在MSC相关致瘤性中的作用。分析了来自各种癌症类型的临床数据，以揭示YAP1、OCT4和CDH6在MSC相关致瘤性中的关系。与PO和DO相比，DR-MSC中钙黏蛋白6（CDH6）、八聚体结合转录因子4（OCT4）和YAP1的表达显著上调。维替泊芬抑制YAP1可加速MSC的分化，并抑制YAP1、CDH6和OCT4的表达。对56个临床队列的调查显示，各种实体瘤中CDH6、YAP1和OCT4之间存在高度共表达。YAP1抑制也下调了HeLa细胞活力，并逐渐抑制YAP1核定位，同时降低CDH6和OCT4的转录。我们使用单细胞测序分析未分化的MSC，并在分化抗性亚克隆的单细胞MSC中发现致癌途径。
