A novel role for NUAK1 in promoting ovarian cancer metastasis through regulation of fibronectin production in spheroids

Cancers

Karen Colwill¹  Brett Larsen¹  Anne-Claude Gingras¹  KyleE. Francis²  Robert Rottapel²  KevinR. Brown³  JamieLee Fritz⁴  TrevorG. Shepherd⁴  Adrian Buensuceso⁴  Olga Collins⁴  Parima Saxena⁴  Yudith Ramos Valdes⁴ 

[1] Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON M5G 1X5, Canada;Princess Margaret Cancer Centre, Toronto, ON M5G 2C1, Canada;Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada;The Mary & John Knight Translational Ovarian Cancer Research Unit, London Regional Cancer Program, London, ON N6A 4L6, Canada;

关键词: ovarian cancer;    spheroid;    LKB1;    NUAK1;    metastasis;    fibronectin;   

DOI  :  10.3390/cancers12051250

来源: DOAJ

【 摘 要 】

Epithelial ovarian cancer (EOC) has a unique mode of metastasis, where cells shed from the primary tumour, form aggregates called spheroids to evade anoikis, spread through the peritoneal cavity, and adhere to secondary sites. We previously showed that the master kinase Liver kinase B1 (LKB1) is required for EOC spheroid viability and metastasis. We have identified novel (nua) kinase 1 (NUAK1) as a top candidate LKB1 substrate in EOC cells and spheroids using a multiplex inhibitor beads-mass spectrometry approach. We confirmed that LKB1 maintains NUAK1 phosphorylation and promotes its stabilization. We next investigated NUAK1 function in EOC cells. Ectopic NUAK1-overexpressing EOC cell lines had increased adhesion, whereas the reverse was seen in OVCAR8-NUAK1KO cells. In fact, cells with NUAK1 loss generate spheroids with reduced integrity, leading to increased cell death after long-term culture. Following transcriptome analysis, we identified reduced enrichment for cell interaction gene expression pathways in OVCAR8-NUAK1KO spheroids. In fact, the FN1 gene, encoding fibronectin, exhibited a 745-fold decreased expression in NUAK1KO spheroids. Fibronectin expression was induced during native spheroid formation, yet this was completely lost in NUAK1KO spheroids. Co-incubation with soluble fibronectin restored the compact spheroid phenotype to OVCAR8-NUAK1KO cells. In a xenograft model of intraperitoneal metastasis, NUAK1 loss extended survival and reduced fibronectin expression in tumours. Thus, we have identified a new mechanism controlling EOC metastasis, through which LKB1-NUAK1 activity promotes spheroid formation and secondary tumours via fibronectin production.

【 授权许可】

Unknown