3'-hydroxy-4'-methoxy-β-methyl-β-nitrostyrene inhibits tumorigenesis in colorectal cancer cells through ROS-mediated DNA damage and mitochondrial dysfunction.

Chun-Hao Tsai,Yi-Chen Lee,Stephen Chu-Sung Hu,Ya-Wen Chiu,Yu-Han Su,Yuan-Yin Chen,Shyng-Shiou F Yuan,Po-Chih Chang,Pei-Wen Hsieh,Amos C Hung

doi:10.18632/oncotarget.14996

Chun-Hao Tsai, Yi-Chen Lee + Show 8 more

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https://doi.org/10.18632/oncotarget.14996

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Abstract

The β-nitrostyrene family has been shown to suppress cell proliferation and induce apoptosis in types of various cancers. However, the mechanisms underlying the anticancer effects of β-nitrostyrenes in colorectal cancer remain poorly understood. In this study, we synthesized a β-nitrostyrene derivative, CYT-Rx20 (3’-hydroxy-4’-methoxy-β-methyl-β-nitrostyrene), and investigated its anticancer activities in human colorectal cancer cells both in vitro and in vivo. Our findings showed that treatment with CYT-Rx20 reduced cell viability and induced DNA damage in colorectal cancer cells. In addition, CYT-Rx20 induced cell cycle arrest of colorectal cancer cells at the G2/M phase and upregulated the protein expression of phospho-ERK, cyclin B1, phospho-cdc2 (Tyr15), aurora A, and aurora B, while it downregulated the expression of cdc25A and cdc25C. Furthermore, we found that CYT-Rx20 caused accumulation of intracellular reactive oxygen species (ROS) and reduction of mitochondrial membrane potential. The effects of CYT-Rx20 on cell viability, DNA damage, and mitochondrial membrane potential were reversed by pretreatment with the thiol antioxidant N-acetyl-L-cysteine (NAC), suggesting that ROS-mediated DNA damage and mitochondrial dysregulation play a critical role in these events. Finally, the nude mice xenograft study showed that CYT-Rx20 significantly reduced tumor growth of implanted colorectal cancer cells accompanied by elevated protein expression of aurora A, aurora B, γH2AX, phosphor-ERK, and MDA in the tumor tissues. Taken together, these results suggest that CYT-Rx20 may potentially be developed as a novel β-nitrostyrene-based anticancer agent for colorectal cancer.

Highlights

Colorectal cancer is one of the most common cancers worldwide with a five-year survival rate of less than 65% [1]
Five β-nitrostyrene derivatives (Figure 1A and Supplementary Figure 1A) were synthesized according to our previous report [13], and their cytotoxic effects on human colorectal cancer cells were analyzed by XTT assay (Supplementary Table 1)
Pretreatment with MEK/ ERK inhibitor U0126 blocked the CYT-Rx20-induced increases in aurora A and aurora B expression (Figure 4D). These results suggested that the anticancer effects of CYT-Rx20 on colorectal cancer cells were mediated through reactive oxygen species (ROS)-dependent DNA damage and mitochondrial dysfunction with the involvement of MEK/ERK signaling pathway

Summary

Introduction

Colorectal cancer is one of the most common cancers worldwide with a five-year survival rate of less than 65% [1]. Chemoresistance remains a major obstacle in the management of advanced colorectal cancer, and further development of effective and novel chemotherapeutic agents is required [6]. The β-nitrostyrene family and its derivatives have been found to exert various biological effects including antimicrobial, antiplatelet, anti-inflammatory, and anticancer activities [7,8,9,10,11,12,13]. 3,4-methylenedioxyβ-nitrostyrene inhibited β1 integrin and surface protein disulfide isomerase, resulting in suppression of breast cancer cell adhesion and migration [7]. A series of 2-aryl-3-nitro-2H-chromenes synthesized as hybrid analogs of β-nitrostyrene and flavanone caused cytotoxicity in breast cancer cells by induction of DNA damage and caspase-3 activity [12]

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