Vernolactone Promotes Apoptosis and Autophagy in Human Teratocarcinomal (NTERA-2) Cancer Stem-Like Cells

Nuwanka K Abeysinghe; Ira Thabrew; Sameera R Samarakoon; Meran K Ediriweera; Kamani H Tennekoon; Varuni P C Pathiranage; Anuka S Mendis

doi:10.1155/2019/6907893

Vernolactone Promotes Apoptosis and Autophagy in Human Teratocarcinomal (NTERA-2) Cancer Stem-Like Cells

Stem Cells Int. 2019 Dec 19:2019:6907893. doi: 10.1155/2019/6907893. eCollection 2019.

Authors

Nuwanka K Abeysinghe¹, Ira Thabrew¹, Sameera R Samarakoon¹, Meran K Ediriweera¹, Kamani H Tennekoon¹, Varuni P C Pathiranage¹, Anuka S Mendis¹

Affiliation

¹ Institute of Biochemistry, Molecular Biology and Biotechnology (IBMBB), University of Colombo, No. 90, Cumaratunga Munidasa Mawatha, Colombo 03, Sri Lanka.

Abstract

Vernonia zeylanica, is a shrub endemic to Sri Lanka. V. zeylanica has been used in Sri Lankan traditional medicine for the treatment of various diseases and conditions. The present study was designed to determine antiproliferative, apoptotic, autophagic, and antioxidant effects of vernolactone, isolated from V. zeylanica, in human embryonal carcinoma cells (NTERA-2, a cancer stem cell model). Antiproliferative effects of vernolactone in NTERA-2 cells and human peripheral blood mononuclear cells (control cells) were evaluated using the Sulforhodamine B (SRB) assay and WST-1 antiproliferative assays, respectively. The antiproliferative effect of vernolactone was further investigated using the colony formation assay. Effects of vernolactone on apoptosis were investigated by phase contrast light microscopic and fluorescence microscopic analysis, caspase 3/7 expression, and real-time PCR of apoptosis-associated genes p53 and Survivin. The effect of vernolactone on NTERA-2 cell migration was monitored using the wound healing assay. Effects of vernolactone on the expression of autophagy-related genes (LC3, Beclin 1, PI3K, Akt, and mTOR) were evaluated using real-time PCR. 2,2-Diphenyl-1-2,2-diphenyl-picrylhydrazyl (DPPH) radical scavenging assay, 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, and ferric reducing antioxidant power (FRAP) assays were also carried out to evaluate the antioxidant activity of vernolactone. Overall results confirm that vernolactone can exert antiproliferative effects, induce apoptosis and autophagy, and decrease NTERA-2 cell migration in a dose- and time-dependent manner with a very small antioxidant property.