scholarly journals The EMT activator ZEB1 accelerates endosomal trafficking to establish a polarity axis in lung adenocarcinoma cells

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Priyam Banerjee ◽  
Guan-Yu Xiao ◽  
Xiaochao Tan ◽  
Veronica J. Zheng ◽  
Lei Shi ◽  
...  

AbstractEpithelial-to-mesenchymal transition (EMT) is a transcriptionally governed process by which cancer cells establish a front-rear polarity axis that facilitates motility and invasion. Dynamic assembly of focal adhesions and other actin-based cytoskeletal structures on the leading edge of motile cells requires precise spatial and temporal control of protein trafficking. Yet, the way in which EMT-activating transcriptional programs interface with vesicular trafficking networks that effect cell polarity change remains unclear. Here, by utilizing multiple approaches to assess vesicular transport dynamics through endocytic recycling and retrograde trafficking pathways in lung adenocarcinoma cells at distinct positions on the EMT spectrum, we find that the EMT-activating transcription factor ZEB1 accelerates endocytosis and intracellular trafficking of plasma membrane-bound proteins. ZEB1 drives turnover of the MET receptor tyrosine kinase by hastening receptor endocytosis and transport to the lysosomal compartment for degradation. ZEB1 relieves a plus-end-directed microtubule-dependent kinesin motor protein (KIF13A) and a clathrin-associated adaptor protein complex subunit (AP1S2) from microRNA-dependent silencing, thereby accelerating cargo transport through the endocytic recycling and retrograde vesicular pathways, respectively. Depletion of KIF13A or AP1S2 mitigates ZEB1-dependent focal adhesion dynamics, front-rear axis polarization, and cancer cell motility. Thus, ZEB1-dependent transcriptional networks govern vesicular trafficking dynamics to effect cell polarity change.

Author(s):  
Weili Min ◽  
Liangzhang Sun ◽  
Burong Li ◽  
Xiao Gao ◽  
Shuqun Zhang ◽  
...  

EMT confers increased metastatic potential and the resistance to chemotherapies to cancer cells. However, the precise mechanisms of EMT-related chemotherapy resistance remain unclear. c-Src-mediated Caspase-8 phosphorylation essential for EMT in lung adenocarcinoma cell lines preferentially occurs in cells with the mesenchymal phenotype, resulting in chemoresistance to cisplatin plus paclitaxel inpatients with resectable lung adenocarcinoma and a significantly worse 5-year PFS. Cisplatin killed lung adenocarcinoma cells regardless of Caspase-8. Paclitaxel-triggered necroptosis in lung adenocarcinoma cells was dependent on the phosphorylation or deficiency of Caspase-8, during which FADD interacted with RIPK1 to activateRIPK1/RIPK3/MLKL signaling axis. Accompanied with c-Src-mediated Caspase-8 phosphorylation to trigger EMT, a novel lncRNA named lncCRLA was markedly upregulated and inhibited RIPK1-induced necroptosis by impairing RIPK1-RIPK3 interaction via binding to the intermediate domain of RIPK1. Dasatinib mitigated c-Src-mediated phosphorylation of Caspase-8-induced EMT and enhanced necroptosis in mesenchymal-like lung adenocarcinoma cells treated with paclitaxel, while c-FLIP knockdown predominantly sensitized the mesenchymal-like lung adenocarcinoma cells to paclitaxel+dasatinib. c-Src-Caspase-8 interaction initiates EMT and chemoresistance viaCaspase-8 phosphorylation and lncCRLA expression, to which the dasatinib/paclitaxel liposome+siFLIP regimen was lethal.


2017 ◽  
Vol 44 (4) ◽  
pp. 1337-1351 ◽  
Author(s):  
Xia Wang ◽  
Long Li ◽  
Ruijuan Guan ◽  
Danian Zhu ◽  
Nana Song ◽  
...  

Background/Aims: Extracellular ATP performs multiple important functions via activation of P2 receptors on the cell surface. P2Y receptors play critical roles in ATP evoked response in human lung adenocarcinoma cells (A549 cells). Emodin is an anthraquinone derivative originally isolated from Chinese rhubarb, possesses anticancer properties. In this study we examined the inhibiting effects of emodin on proliferation, migration and epithelial-mesenchymal transition (EMT) by suppressing P2Y receptors-dependent Ca2+ increase and nuclear factor-κB (NF-KB) signaling in A549 cells. Methods: A549 cells were pretreated with emodin before stimulation with ATP for the indicated time. Then, intracellular Ca2+ concentration ([Ca2+]i) was measured by Fluo-8/AM staining. Cell proliferation and cell cycle progression were tested by CCK8 assay and flow cytometry In addition, wound healing and western blot were performed to determine cell migration and related protein levels (Bcl-2, Bax, claudin-1, NF-κB). Results: Emodin blunted ATP/UTP-induced increase of [Ca2+]i and cell proliferation concentration-dependently Meanwhile, it decreased ATP-induced cells accumulation in the S phase. Furthermore, emodin altered protein abundance of Bcl-2, Bax and claudin-1 and attenuated EMT caused by ATP. Such ATP-induced cellular reactions were also inhibited by a nonselective P2Y receptors antagonist, suramin, in a similar way to emodin. Besides, emodin could inhibit activation of NF-κB, thus suppressed ATP-induced proliferation, migration and EMT. Conclusion: Our results demonstrated that emodin inhibits ATP-induced proliferation, migration, EMT by suppressing P2Y receptors-mediated [Ca2+]i increase and NF-κB signaling in A549 cells.


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