Noninvasive bioluminescence imaging of the dynamics of sanguinarine induced apoptosis via activation of reactive oxygen species

Yan Wang,Wei Liu,Yunpeng Dai,Beilei Zhang,Yaru Shi,Qi Zeng,Fu Wang

doi:10.18632/oncotarget.7971

Abstract

Most chemotherapeutic drugs exert their anti-tumor effects primarily by triggering a final pathway leading to apoptosis. Noninvasive imaging of apoptotic events in preclinical models would greatly facilitate the development of apoptosis-inducing compounds and evaluation of their therapeutic efficacy. Here we employed a cyclic firefly luciferase (cFluc) reporter to screen potential pro-apoptotic compounds from a number of natural agents. We demonstrated that sanguinarine (SANG) could induce apoptosis in a dose- and time-dependent manner in UM-SCC-22B head and neck cancer cells. Moreover, SANG-induced apoptosis was associated with the generation of reactive oxygen species (ROS) and activation of c-Jun-N-terminal kinase (JNK) and nuclear factor-kappaB (NF-κB) signal pathways. After intravenous administration with SANG in 22B-cFluc xenograft models, a dramatic increase of luminescence signal can be detected as early as 48 h post-treatment, as revealed by longitudinal bioluminescence imaging in vivo. Remarkable apoptotic cells reflected from ex vivo TUNEL staining confirmed the imaging results. Importantly, SANG treatment caused distinct tumor growth retardation in mice compared with the vehicle-treated group. Taken together, our results showed that SANG is a candidate anti-tumor drug and noninvasive imaging of apoptosis using cFluc reporter could provide a valuable tool for drug development and therapeutic efficacy evaluation.

Highlights

Apoptosis, or programmed cell death, is central to regulate normal cell growth and development in all multicellular organism [1, 2]
Our results showed that SANG is a candidate anti-tumor drug and noninvasive imaging of apoptosis using cyclic firefly luciferase (cFluc) reporter could provide a valuable tool for drug development and therapeutic efficacy evaluation
We showed that sanguinarine (SANG), a benzophenanthridine alkaloid derived from the root of Sanguinaria Canadensis, could stimulate apoptosis via activating the production of reactive oxygen species (ROS) in head and neck tumor cells and animal models

Summary

Introduction

Programmed cell death, is central to regulate normal cell growth and development in all multicellular organism [1, 2]. A number of natural agents have been shown to exert their anti-tumor effects via a variety of apoptosis-inducing mechanisms in cancer cells [7,8,9]. V [10, 11] or TdT-mediated dUTP nick end labeling (TUNEL) [12] assays, have been widely employed to detect apoptosis progress by taking advantage of the characteristic biochemical changes occurring in apoptosis These methods usually require lysing or fixing of cells. To overcome these limitations, noninvasively real-time monitoring apoptosis in living organisms would be a great advance for better understanding of apoptotic process, www.impactjournals.com/oncotarget rapid screening of apoptosis-related drugs and early evaluation of drug therapeutic efficiency [18]

Methods

Results

Conclusion