Catalanotto Madison, Vaz Joel Markus, Abshire Camille, Youngblood Reneau, Chu Min, Levine Herbert, Jolly Mohit Kumar, Dragoi Ana-Maria
LSU Health Shreveport, School of Medicine, LA, USA.
School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA.
Transl Oncol. 2024 Jan;39:101837. doi: 10.1016/j.tranon.2023.101837. Epub 2023 Nov 18.
Epithelial-to-mesenchymal transition (EMT) is a developmental program that consists of the loss of epithelial features concomitant with the acquisition of mesenchymal features. Activation of EMT in cancer facilitates the acquisition of aggressive traits and cancer invasion. EMT plasticity (EMP), the dynamic transition between multiple hybrid states in which cancer cells display both epithelial and mesenchymal markers, confers survival advantages for cancer cells in constantly changing environments during metastasis.
RNAseq analysis was performed to assess genome-wide transcriptional changes in cancer cells depleted for histone regulators FLASH, NPAT, and SLBP. Quantitative PCR and Western blot were used for the detection of mRNA and protein levels. Computational analysis was performed on distinct sets of genes to determine the epithelial and mesenchymal score in cancer cells and to correlate FLASH expression with EMT markers in the CCLE collection.
We demonstrate that loss of FLASH in cancer cells gives rise to a hybrid E/M phenotype with high epithelial scores even in the presence of TGFβ, as determined by computational methods using expression of predetermined sets of epithelial and mesenchymal genes. Multiple genes involved in cell-cell junction formation are similarly specifically upregulated in FLASH-depleted cells, suggesting that FLASH acts as a repressor of the epithelial phenotype. Further, FLASH expression in cancer lines is inversely correlated with the epithelial score. Nonetheless, subsets of mesenchymal markers were distinctly up-regulated in FLASH, NPAT, or SLBP-depleted cells.
The ZEB1/SNAIL/E-cadherin phenotype described in FLASH-depleted cancer cells is driving a hybrid E/M phenotype in which epithelial and mesenchymal markers coexist.
上皮-间质转化（EMT）是一种发育程序，包括上皮特征的丧失以及间质特征的获得。癌症中EMT的激活促进了侵袭性特征的获得和癌症侵袭。EMT可塑性（EMP）是癌细胞在转移过程中处于不断变化的环境时，在多种混合状态（癌细胞同时表现出上皮和间质标志物）之间的动态转变，赋予癌细胞生存优势。
进行RNA测序分析以评估缺失组蛋白调节因子FLASH、NPAT和SLBP的癌细胞中的全基因组转录变化。使用定量PCR和蛋白质印迹法检测mRNA和蛋白质水平。对不同的基因集进行计算分析，以确定癌细胞中的上皮和间质评分，并将FLASH表达与CCLE数据集中的EMT标志物相关联。
我们证明，通过使用预定的上皮和间质基因集的表达进行计算方法确定，即使在存在TGFβ的情况下，癌细胞中FLASH的缺失也会导致具有高上皮评分的混合E/M表型。在缺失FLASH的细胞中，多个参与细胞间连接形成的基因同样特异性上调，这表明FLASH作为上皮表型的抑制因子发挥作用。此外，癌症细胞系中FLASH的表达与上皮评分呈负相关。尽管如此，间质标志物的子集在缺失FLASH、NPAT或SLBP的细胞中明显上调。
在缺失FLASH的癌细胞中描述的ZEB1/SNAIL/E-钙黏蛋白表型正在驱动一种上皮和间质标志物共存的混合E/M表型。
