Lysophosphatidylcholine acyltransferase 1 is involved in the regulation of exosome secretion and uptake in colorectal cancer cells

Haizheng Liu,Shaofei Chang

doi:10.32604/biocell.2022.015340

Abstract

Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is a phospholipid acyltransferase that promotes phospholipid synthesis and plasma membrane reconstruction. Exosomes play an important role in tumor metastasis. The release and uptake of exosomes are key steps of their functions and depend on plasma membrane fusion and plasma membrane receptors, respectively. The purpose of this study was to explore whether LPCAT1-induced plasma membrane remodeling would change the secretion and uptake behavior of exosomes in tumor cells. We first confirmed the abnormally high expression of LPCAT1 in colorectal cancer cells by quantitative real-time PCR (qPCR) and Western blot analysis. Then, SW620 cells were used as exosome source cells, and SW480 cells were used as exosome receiver cells. Exosomes from SW620 cells could effectively promote the migration of SW480 cells. When LPCAT1 expression was reduced via siRNA knockdown in the source cells, the secretion of exosomes was downregulated, thus weakening the pro-migratory effects of exosomes on target cells. Conversely, when LPCAT1 was knocked down in target cells, the uptake of exosomes in target cells also decreased sharply. These results undoubtedly revealed that LPCAT1 is functionally associated with the release and internalization of exosomes in colorectal cancer cells and could affect the paracrine effects of exosomes, preliminarily extending the classical metabolic function of LPCAT1 to exosome-related pathways.

Highlights

Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is an important enzyme involved in complex lipid metabolism
We explored the relationship between LPCAT1 and exosome release and uptake, as well as the autocrine or paracrine effects of exosomes on colorectal cancer cells
LPCAT1 level affects the exosome secretion We compared the amounts of exosomes secreted by CCD18-Co and colon cancer cell lines (SW620, SW480, and HCT116) under the same conditions by collecting exosomes from identical volumes of culture supernatant at the corresponding time points

Summary

Introduction

Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is an important enzyme involved in complex lipid metabolism. It is widely found in plants and animals and has (MVBs) and the cell membrane, exosomes can be released into the extracellular matrix. Tumor cell exosomes usually have autocrine and paracrine effects, which are involved in the release and uptake of exosomes (Joo et al, 2020; Mills et al, 2019; Oliveira et al, 2020). The release of exosomes depends on plasma membrane fusion, while the uptake of exosomes by most cells depends on specific receptors in the plasma membrane (McKelvey et al, 2015; Salunkhe et al, 2020)

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