J Cancer 2020; 11(13):3725-3735. doi:10.7150/jca.40983

Research Paper

Brevilin A induces ROS-dependent apoptosis and suppresses STAT3 activation by direct binding in human lung cancer cells

Muhammad Khan1, Amara Maryam1, Muhammad Zubair Saleem2, Hafiz Abdullah Shakir1, Javed Iqbal Qazi1, Yongming Li3✉, Tonghui Ma3✉

1. Department of Zoology, University of the Punjab, Quaid-e-Azam Campus, Lahore-54590, Pakistan.
2. College of Basic Medical Sciences, Dalian Medical University, Dalian-116044, P.R. China
3. School of Medicine and Holistic Integrative Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, P.R. China

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Citation:
Khan M, Maryam A, Saleem MZ, Shakir HA, Qazi JI, Li Y, Ma T. Brevilin A induces ROS-dependent apoptosis and suppresses STAT3 activation by direct binding in human lung cancer cells. J Cancer 2020; 11(13):3725-3735. doi:10.7150/jca.40983. Available from https://www.jcancer.org/v11p3725.htm

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Abstract

Sesquiterpene lactones have been shown to be promising leads for anticancer drug development. Brevilin A (BLN-A), a sesquiterpene lactone compound of Centipeda minima has been shown to exhibit anticancer effects against various cancer cells. However, the anticancer mechanism and cellular targets of BLN-A remain elusive. Here in this study, BLN-A inhibits proliferation and induces cell morphological changes in A549 and NCI-H1650 non-small cell lung cancer cells in a dose-dependent manner. Moreover, BLN-A increased ROS generation and bax/bcl-2 ratio while decreased intracellular glutathione (GSH), and mitochondrial membrane potential which resulted in induction of apoptosis as evident by annexin-V/FITC staining, caspase-3 activation and PARP cleavage. Supplementation of cells with NAC (ROS Scavenger) effectively protected the cells from BLN-A-induced apoptosis. Finally, BLN-A inhibited constitutive as well as IL-6- and EGF-induced STAT3 activation at Tyr705. Using molecular docking and SPR analyses, we found that BLN-A directly binds with STAT3 and thereby inhibits its activation. Knocking down of STAT3 by stable transfection with shRNA suppressed growth and augmented cytotoxicity of BLN-A, indicating the key role of STAT3 in BLN-A-mediated apoptosis. Cumulative findings suggest that BLN-A is a promising lead structure for developing it into a potent STAT3 inhibitor and therapeutic agent against NSCLC as well.

Keywords: Brevilin A, NSCLC, ROS, STAT3, SPR, apoptosis