PCYT2 inhibits epithelial-to-mesenchymal transition in colorectal cancer by elevating YAP1 phosphorylation

Metabolic reprogramming is a common feature in tumor progression and metastasis. Like proteins, lipids can transduce signals through lipid-protein interactions. During tumor initiation and metastasis, dysregulation of the Hippo pathway plays a critical role. Specifically, the inhibition of YAP1 phosphorylation leads to the relocation of YAP1 to the nucleus to activate transcription of genes involved in metastasis. Although recent studies reveal the involvement of phosphatidylethanolamine (PE) synthesis enzyme phosphoethanolamine cytidylyltransferase 2 (PCYT2) in tumor chemoresistance, the impact of PCYT2 on tumor metastasis remains elusive. Here, we showed that PCYT2 was significantly downregulated in metastatic colorectal cancer (CRC) and acted as a tumor metastasis suppressor. Mechanistically, PCYT2 increased the interaction between PEBP1 and YAP1-phosphatase PPP2R1A, thus disrupting PPP2R1A-YAP1 association. As a result, phosphorylated-YAP1 levels were increased, leading to YAP1 degradation through the ubiquitin protease pathway. YAP1 reduction in the nucleus repressed the transcription of ZEB1 and Snail2, eventually resulting in metastasis suppression. Our work provides insight into the role of PE synthesis in regulating metastasis and presents PCYT2 as a potential therapeutic target for CRC. Overall design: In order to find downstream genes related to PCYT2 in colorectal cancer, we knocked down PCYT2 in SW480 and performed RNA-seq. The experiment was designed into 3 groups, namely shNT, shPcyt2-1, shPcyt2-2, with 2 replicates in each group.