Sirtuin1 (SIRT1) is involved in the anticancer effect of black raspberry anthocyanins in colorectal cancer

Abnormal acetylation modification is a common epigenetic change in tumorigenesis and is closely related to the progression of colorectal cancer (CRC). Our previous studies have suggested that black raspberry (BRB) anthocyanins have a significant chemopreventive effect against CRC. This study investigated whether protein acetylation plays an important role in BRB anthocyanins-mediated regulation of CRC progression.

We used the AOM-induced CRC mouse model and the CRC cell lines SW480 and Caco-2 to explore the potential role of acetylation of histone H4 and NF-κB signaling pathway-related proteins (non-histone proteins) in the antitumor process mediated by BRB anthocyanins. The expression of related proteins was detected by western blot. ROS level was detected by immunofluorescence.

BRB anthocyanins affected the acetylation level by down-regulating the expression of Sirtuin1 (SIRT1) and up-regulating the expression of MOF and EP300. The acetylation level of lysine sites on histone H4 (H4K5, H4K12 and H4K16) was increased. Furthermore, following BRB anthocyanins treatment, the expression of ac-p65 was significantly up-regulated and the NF-κB signal pathway was activated, which in turn up-regulated Bax expression and inhibited Bcl-2, cyclin-D1, c-myc and NLRP3 expression to promote CRC cell cycle arrest, apoptosis and relieve inflammation.

The findings suggested that protein acetylation could play a critical role in BRB anthocyanins-regulated CRC development.