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

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.

Neurotoxins Acting at Synaptic Sites: A Brief Review on Mechanisms and Clinical Applications

“…Several experiments demonstrated that crotoxin arrested the cell cycle at the G 2 /M phase [ 261 ]. Furthermore, recently it has been reported that crotoxin is also a potential regulator of the signaling cascade involved in epithelial–mesenchymal transition (EMT) [ 262 ]. Crotoxin may have a high affinity for EGFR [ 263 ], which suggests that crotoxin might modulate the EGFR signaling pathway to exert its anti-tumor activity in SPCA-1 cells [ 264 ].…”

Antiproliferative activity of snake venom-derived phospholipase classes against tumor cell lines: A systematic review.

“…Snake venoms comprise a vast biological library of toxins that can be used for various applications [28]. Among these molecules is crotoxin (CTX) which is characterized as a heterodimeric β-neurotoxin formed by the non-covalent association between two subunits, one of them the Crotoxin A or crotapotin acid and a base called crotoxin B or phospholipase A2 (PLA2) [19]. PLA2s consist of three α-helices, a highly conserved protein, the calcium-binding loop, two antiparallel β-strains, and a catalytically inactive flexible C-terminal loop.…”

Differential Migration and Proliferation Potential of the Hydrogel Aided 3D Tumoroid

“…[ 4–6 ] As an in vitro lung adenocarcinoma or non‐small cell lung cancer model, A549, a cell line has been frequently preferred by researchers. For developing in vitro A549 3D spheroid commonly used techniques are ultra‐low attachment [ 7 ] surface, [ 8,9 ] hanging drop assays, [ 10 ] 3D microprinted scaffold, [ 11 ] microfluidics, and hydrogel‐based scaffolds have been widely used. Most of the studies involve elucidating the cell proliferation, migration, invasion, and epithelial‐to‐mesenchymal transition (EMT) [ 10 ] after treating the cell with some molecular/chemical agents but very few studies have explored the difference in the native tumorigenic properties of A549 in context to the dimensionality when cultured in monolayer versus in 3D.…”

“…For developing in vitro A549 3D spheroid commonly used techniques are ultra‐low attachment [ 7 ] surface, [ 8,9 ] hanging drop assays, [ 10 ] 3D microprinted scaffold, [ 11 ] microfluidics, and hydrogel‐based scaffolds have been widely used. Most of the studies involve elucidating the cell proliferation, migration, invasion, and epithelial‐to‐mesenchymal transition (EMT) [ 10 ] after treating the cell with some molecular/chemical agents but very few studies have explored the difference in the native tumorigenic properties of A549 in context to the dimensionality when cultured in monolayer versus in 3D. Varied studies involving scaffold‐aided spheroid/tumoroid have variance in the reported proliferation and migration behavior of cells.…”