Study on the effects of the different polar group of EPA-enriched phospholipids on the proliferation and apoptosis in 95D cells

Yao Guo,Yingying Tian,Yuanyuan Liu,Ziyi Yan,Qin Zhao,Changhu Xue,Jingfeng Wang

doi:10.1007/s42995-021-00097-9

Abstract

EPA-enriched phosphatidylcholine (EPA-PC) and EPA-enriched phosphatidylethanolamine (EPA-PE) are newly identified marine phospholipids. The polar group of phospholipids is known to influence EPA-phospholipid activity. However, the differences in anti-tumor effects between EPA-PC and EPA-PE have not been reported. In this study, we evaluated the effects of two forms of EPA on the proliferation and apoptosis in the lung-cancer cell line 95D as well as possible molecular mechanisms. Our results showed that EPA-PC effectively inhibited proliferative activity and promoted apoptosis of 95D cells in a dose-dependent manner, while EPA-PE had no effect on cell proliferation, although it slightly promoted apoptosis. Western blot results showed that EPA-PC and EPA-PE upregulated the expression of PPARγ, RXRα, and PTEN, and downregulated the PI3K/AKT signaling pathway. Furthermore, EPA-PC and EPA-PE induced the expression of the pro-apoptotic gene, Bax, and reduced the expression of the anti-apoptotic gene, Bcl-xl. Additionally, EPA-PC and EPA-PE promoted the release of cytochrome c and activated the apoptotic enzyme-cleaved caspase-3. These data suggest that the anti-tumor effect of EPA-phospholipids may be exerted via a PPARγ-related mechanism. EPA-PC was more efficacious as compared to EPA-PE, which might be due to the different polar groups of phospholipids.

Highlights

Cancer is the leading causing of death in over 91 countries
We compared the effects of two different Eicosapentaenoic acid (EPA)-binding forms, PC and PE, on the proliferation and apoptosis of 95D lung-cancer cells in vitro, and attempted to elucidate their mechanism of action
In vitro studies have shown that EPA can inhibit proliferation of various cancer cell lines, such as colon, breast, and human cervical carcinoma HeLa cells (Du et al 2015; Hossain et al 2009; Zheng et al 2017)

Summary

Introduction

Cancer is the leading causing of death in over 91 countries. Worldwide, in 2018, approximately 18.1 million people were newly diagnosed and 9.6 million died (Nasim et al 2018). Studies have shown that PPARγ agonists can inhibit the growth of a variety of cancer cells in vitro, and in combination with other chemotherapeutic drugs, can enhance the anti-tumor effect of the drugs. We compared the effects of different forms of EPA on the proliferation and apoptosis of 95D lung-cancer cells. We studied their molecular mechanisms in vitro to provide theoretical support for nutritional adjuvant therapy for cancer and for the high-value utilization of sea cucumbers

Results

Discussion

Materials and methods

Compliance with ethical standards