PLK1-mediated phosphorylation of β-catenin enhances its stability and transcriptional activity for extracellular matrix remodeling in metastatic NSCLC

Abstract

Rationale: β-catenin is a component for cell adhesion and a transcriptional coactivator in epithelial-mesenchymal transition (EMT). Previously we found that catalytically active PLK1 drives EMT in non-small cell lung cancer (NSCLC), upregulating extracellular matrix factors including TSG6, laminin γ2, and CD44. To understand the underlying mechanism and clinical significance of PLK1 and β-catenin in NSCLC, their relationship and function in metastatic regulation were investigated. Methods: The clinical relevance between the survival rate of NSCLC patients and the expression of PLK1 and β-catenin was analyzed by a KM plot. Immunoprecipitation, kinase assay, LC-MS/MS spectrometry, and site-directed mutagenesis were performed to reveal their interaction and phosphorylation. A lentiviral doxycycline-inducible system, Transwell-based 3D culture, tail-vein injection model, confocal microscopy, and chromatin immunoprecipitation assays were used to elucidate the function of phosphorylated β-catenin in the EMT of NSCLC. Results: Clinical analysis revealed that the high expression of CTNNB1/PLK1 was inversely correlated with the survival rates of 1,292 NSCLC patients, especially in metastatic NSCLC. In TGF-β-induced or active PLK1-driven EMT, β-catenin, PLK1, TSG6, laminin γ2, and CD44 were concurrently upregulated. β-catenin is a binding partner of PLK1 in TGF-β-induced EMT and is phosphorylated at S311. Phosphomimetic β-catenin promotes cell motility, invasiveness of NSCLC cells, and metastasis in a tail-vein injection mouse model. Its upregulated stability by phosphorylation enhances transcriptional activity through nuclear translocation for the expression of laminin γ2, CD44, and c-Jun, therefore enhancing PLK1 expression by AP-1. Conclusions: Our findings provide evidence for the critical role of the PLK1/β-catenin/AP-1 axis in metastatic NSCLC, implying that β-catenin and PLK1 may serve as a molecular target and prognostic indicator of the therapeutic response in metastatic NSCLC patients.

Vitamin A Status Modulates Epithelial Mesenchymal Transition in the Lung: The Role of Furin

“…On the other hand, β-catenin mRNA levels did not change in VAD lungs, but its expression significantly increased after RA treatment (VAD + RA) ( Figure 1 A). β-catenin is a transcriptional coactivator known to be upregulated in TGF-β-induced EMT [ 36 ].…”

“…This process, in which differentiated epithelial cells acquire mesenchymal capabilities, is accompanied by ECM changes, rendering a migratory and invasive phenotype. In fact, EMT is an early-stage common factor in several respiratory pathologies associated with pulmonary fibrosis development and lung cancer [ 24 , 26 , 36 , 39 , 40 , 41 ]. In the present work, we have evaluated, in vivo and in vitro, the role of pulmonary vitamin A status on EMT markers and on furin expression, a protein proconvertase that regulates the levels of adhesion molecules and activates proteolytically matrix metalloproteinases, TGF-β factor, and other cytokines and receptors [ 29 , 31 ].…”

Phosphorylation-dependent deubiquitinase OTUD3 regulates YY1 stability and promotes colorectal cancer progression

“…Mass spectrometry identified PLK1 to be an interacting partner of OTUD3. In TGF-β-induced EMT, PLK1 binds and phosphorylates Ser-311 of β-catenin to facilitate non-small cell lung cancer metastasis [ 48 ]. PLK1 and AURKB mediated survivin phosphorylation promotes triple-negative breast cancer proliferation [ 49 ].…”

Identification of crucial anoikis-related genes as novel biomarkers and potential therapeutic targets for lung adenocarcinoma via bioinformatic analysis and experimental verification

“…Meanwhile, we performed the random forest algorithm to rank the importance of ARGs [11], and selected the top five important ARGs (PLK1, SLC2A1, ANGPTL4, CDKN3, PBK) (Figure 2C). Furthermore, four ARGs (PLK1, SLC2A1, ANGPTL4, CDKN3) were obtained by intersections of ARGs screened by the above two machine learning algorithms (Figure 2D), and these four genes have been found to play essential roles in LUAD development [12][13][14][15]. Moreover, we examined the protein expression levels of the four ARGs (PLK1, SLC2A1, ANGPTL4, CDKN3) in cancer tissues and para-cancer tissues from clinical LUAD patients.…”