Furanodienone induces G0/G1 arrest and causes apoptosis via the ROS/MAPKs-mediated caspase-dependent pathway in human colorectal cancer cells: a study in vitro and in vivo

Furanodienone, a major bioactive constituents of sesquiterpene derived from Rhizoma Curcumae, has been proven to possess the potent anticancer efficacy on human breast cancer cells. Here, we investigated the cytotoxicity of furanodienone on human colorectal carcinoma cell lines in vitro and in vivo, as well as its underlying molecular mechanisms in the induction of apoptosis. In this study, we found that furanodienone significantly inhibited proliferation of RKO and HT-29 cells, induced mitochondrial dysfunction characterized by collapse of mitochondrial transmembrane potential and reduction of ATP level, and promoted the production of reactive oxygen species (ROS) that functions upstream of caspase-dependent apoptosis. The antioxidant N-acetyl cysteine, a ROS scavenger, abolished this apoptosis induced by furanodienone. In addition, furanodienone elevated the expression of p-p38, p-JNK, but decreased p-ERK, as a result of the produced ROS. The specific inhibitors U0126, SP600125 and SB202190 attenuated the expression of MAPKs, and regulated the expression of cleaved caspase-8, -9 and -3. Furthermore, the potential inhibitory effect of furanodienone on CRC cells was also corroborated in mouse xenograft model. In conclusion, the results demonstrated that furanodienone-triggered ROS plays a pivotal role in apoptosis as an upstream molecule-modulating activity of caspases in mitochondrial pathway via stimulating MAPKs signaling pathway. Our finding may provide a novel candidate for development of antitumor drugs targeting on colorectal cancer.