Crotoxin Modulates Events Involved in Epithelial-Mesenchymal Transition in 3D Spheroid Model.

Ellen Emi Kato,Sandra Coccuzzo Sampaio

doi:10.3390/toxins13110830

Ellen Emi Kato, Sandra Coccuzzo Sampaio

Open Access

https://doi.org/10.3390/toxins13110830

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Journal: Toxins	Publication Date: Nov 22, 2021
Citations: 5	License type: CC BY 4.0

Affiliation: Instituto Butantan, Universidade de São Paulo

Abstract

Epithelial–mesenchymal transition (EMT) occurs in the early stages of embryonic development and plays a significant role in the migration and the differentiation of cells into various types of tissues of an organism. However, tumor cells, with altered form and function, use the EMT process to migrate and invade other tissues in the body. Several experimental (in vivo and in vitro) and clinical trial studies have shown the antitumor activity of crotoxin (CTX), a heterodimeric phospholipase A2 present in the Crotalus durissus terrificus venom. In this study, we show that CTX modulates the microenvironment of tumor cells. We have also evaluated the effect of CTX on the EMT process in the spheroid model. The invasion of type I collagen gels by heterospheroids (mix of MRC-5 and A549 cells constitutively prepared with 12.5 nM CTX), expression of EMT markers, and secretion of MMPs were analyzed. Western blotting analysis shows that CTX inhibits the expression of the mesenchymal markers, N-cadherin, α-SMA, and αv. This study provides evidence of CTX as a key modulator of the EMT process, and its antitumor action can be explored further for novel drug designing against metastatic cancer.

Highlights

Events of metastasis begin with epithelial–mesenchymal transition (EMT), whereby epithelial cells lose their inherent characteristics, including apicobasal polarity, and acquire invasive and infiltrating mesenchymal properties [1,2,3,4]
Cancer-associated fibroblasts (CAFs) are among the predominant cells within solid tumors and secrete several soluble growth factors, including transforming growth factor-β1 (TGF-β1), interleukin-6 (IL-6), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), stromal cell-derived factor-1 (SDF-1), and hepatocyte growth factor (HGF)
We found that TGF-β1 and tumor-conditioned medium (CM) induced higher α-smooth muscle actin (α-SMA) expression in untreated than in CTX-treated MRC-5 cells (Figure 1A,B)

Summary

Introduction

Events of metastasis begin with epithelial–mesenchymal transition (EMT), whereby epithelial cells lose their inherent characteristics, including apicobasal polarity, and acquire invasive and infiltrating mesenchymal properties [1,2,3,4]. The expression of N-cadherin is switched on along with upregulation of other mesenchymal markers, including vimentin, fibronectin, and metalloproteases [5,6,7,8,9]. CAFs are among the predominant cells within solid tumors and secrete several soluble growth factors, including transforming growth factor-β1 (TGF-β1), interleukin-6 (IL-6), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), stromal cell-derived factor-1 (SDF-1), and hepatocyte growth factor (HGF). Some of these growth mediators can induce EMT in carcinoma cells [10,11,12]

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