YWHAE affects proliferation, migration and apoptosis of colorectal cancer by regulating extracellular vesicles secretion and Wnt/β-catenin signaling pathway.

BACKGROUND: Colorectal cancer (CRC) has higher rates of metastasis, recurrence, and poor clinical prognosis. The 14-3-3ε (YWHAE) protein is closely related to the occurrence and development of CRC. Here, we aimed to explore the effects of YWHAE on the proliferation, migration, and apoptosis of CRC cells, and elucidate its mechanism. METHODS: Western blot and reverse transcription quantitative polymerase chain reaction (RT-qPCR) were used to detect YWHAE protein and messenger RNA (mRNA) expression levels in CRC cell lines. Cell viability was detected by Cell Counting Kit-8 (CCK-8) method. The cell proliferation activity was detected by 5-ethynyl-2'-deoxyuridine (EdU) assay. The effect of cell migration was detected by scratch healing test. The number of cell migration was detected by Transwell assay. The apoptosis of cells in each group was detected by flow cytometry. The effect of altered YWHAE expression on extracellular vesicles (EVs) secretion was detected by nanoparticle tracking analysis (NTA) and western blot. RESULTS: In this study, the results of reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot showed that YWHAE was highly expressed in CRC cells and tissues. Moreover, we constructed expression silenced cells and overexpression cells. Consistently, CCK-8, EdU assay, scratch healing test and Transwell assay showed that the silenced expression of YWHAE inhibited migration, and proliferation, while flow cytometry analysis promoted the apoptosis in YWHAE silenced cells. Mechanically, the expression levels of Wingless-related integration site (Wnt)/β-catenin and related genes (E-cadherin, cyclin D, c-myc, vimentin, P-120 catenin) in the silenced group signaling pathway were partially decreased. The results of NTA and western blot suggested that the ability of expression silenced cells to secrete EVs was weakened. In addition, the expression level of β-catenin in EVs from silenced cells was significantly decreased, which inhibited the proliferation activity of tumor microenvironment (TME) cells. Nevertheless, the data of overexpression group showed the opposite trend. CONCLUSIONS: Altogether, these results demonstrate that silencing YWHAE expression can inhibit the proliferation and migration of CRC cells and promote cell apoptosis, which may be related to the inhibition of Wnt/β-catenin signaling and EVs secretion.