Betulinic acid arrests cell cycle at G2/M phase by up-regulating metallothionein 1G inhibiting proliferation of colon cancer cells
Sen Wang,
Yuqin Zhang,
Xiaxia Yang,
Kexin Wang,
Xiao Yang,
Baogui Zhang,
Bin Zhang,
Qingli Bie
Affiliations
Sen Wang
Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, China; Postdoctoral Mobile Station of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China
Yuqin Zhang
Blood Transfusion Department, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, China
Xiaxia Yang
Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, China
Kexin Wang
Department of Radiology, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, China
Xiao Yang
Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, China
Baogui Zhang
Gastrointestinal Surgery, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, China
Bin Zhang
Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, China; Institute of Forensic Medicine and Laboratory Medicine, Jining Medical University, Jining, Shandong, China
Qingli Bie
Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, Jining Medical University, Jining, Shandong, China; Postdoctoral Mobile Station of Shandong University of Traditional Chinese Medicine, Jinan, Shandong, China; Corresponding author. Department of Laboratory Medicine, Affiliated Hospital of Jining Medical University, 89 Guhuai Road, Jining 272000, China.
Betulinic acid (BA) is a pentacyclic triterpene found in many plant species and has a broad-spectrum anti-tumor effect in various cancers, including colon cancer (CRC). However, its anticancer mechanism in CRC is no clear. RNA sequencing and bioinformatics analysis showed BA up-regulated 378 genes and down-regulated 137 genes in HT29 cells, while 2303 up-regulated and 1041 down-regulated genes were found in SW480 cells. KEGG enrichment analysis showed BA significantly stimulated the expression of metallothionein 1 (MT1) family genes in both HT29 and SW480 cells. Metallothionein 1G (MT1G) was the gene with the highest upregulation of MT1 family genes induced by BA dose-dependently. High MT1G expression enhanced the sensitivity of CRC cells to BA, whereas, MT1G knockdown had the opposite effect in vitro and in vivo. GSEA and GSCA showed genes affected by BA treatment were involved in cell cycle and G2/M checkpoint in CRC. Flow cytometry further exhibited BA reduced the percentage of G0/G1 cells and increased the percentage of G2/M cells in a dose-dependent manner, which could be rescued by MT1G knockdown. Moreover, MT1G also counteracted the BA-induced changes in cell cycle-related proteins (CDK2 and CDK4) and p-Rb. In summary, we have revealed a new anti-tumor mechanism that BA altered the cell cycle progression of CRC cells by upregulating MT1G gene, thereby inhibiting the proliferation of CRC cells.
