SKLB316, a novel small-molecule inhibitor of cell-cycle progression, induces G2/M phase arrest and apoptosis in vitro and inhibits tumor growth in vivo.

Abstract

Benzothiazole derivatives have received considerable attentions for their potencies in cancer therapy. In the present study, we reported that SKLB316, a novel synthesized benzothiazole derivative, exhibits activities to inhibit colorectal and pancreatic cancer in vitro and in vivo by inducing G2/M cell cycle arrest and apoptosis. In vitro, it exhibited significant anti-proliferative activities against human cancer cells derived from different histotypes including the colorectal cancer cell line HCT116 and pancreatic cancer cell line CFPAC-1. We chose these cell lines to study the possible anti-tumor mechanism because they are sensitive to SKLB316 treatment. Flow cytometry assays showed that SKLB316 could induce G2/M cell cycle arrest. Mechanistically, SKLB316 could decrease the activities of cdc2/cyclin B1 complex, including decreasing the synthesis of cyclin B1, cdc2 and cdc25c, while accumulating the levels of phosphorylated cdc2 (Tyr15) and checkpoint kinase 2. SKLB316 could also decrease the level of cyclin E and A2. Moreover, SKLB316 could induce cancer cell apoptosis, which was associated with activation of caspase 9, downregulation of Bcl-2 and upregulation of Bax. SKLB316 could also decrease the mitochondrial membrane potential and induce the generation of reactive oxygen species in cells. The results implied that SKLB316 may induce apoptosis via the mitochondria-mediated apoptotic pathway. Moreover, SKLB316 could suppress the growth of established colorectal and pancreatic cancer tumors in nude mice without causing obvious side effects. TUNEL assays confirmed that SKLB316 could also induce tumor cell apoptosis in vivo. Taken together, these findings demonstrate the potential value of SKLB316 as a novel anti-tumor drug candidate.

• Authors: Yong Xia, Qian Lei, Yongxia Zhu, Tinghong Ye, Ningyu Wang, Guobo Li, Xuanhong Shi, Yantong Liu, Bin Shao, Tao Yin, Lifeng Zhao, Wenshuang Wu, Xuejiao Song, Ying Xiong, Yuquan Wei, Luoting Yu
• Journal: Cancer letters (Cancer Lett) Vol. 355 Issue 2 Pg. 297-309 (Dec 28 2014) ISSN: 1872-7980 [Electronic] Ireland
• PMID: 25301449 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Chemical References

• Antineoplastic Agents
• Benzothiazoles
• Cyclins
• Reactive Oxygen Species
• bcl-2-Associated X Protein
• Checkpoint Kinase 2
• CDC2 Protein Kinase
• CDC25C protein, human
• cdc25 Phosphatases
• Caspase 9

Topics

• Animals
• Antineoplastic Agents (pharmacology)
• Apoptosis (drug effects)
• Benzothiazoles (pharmacology)
• CDC2 Protein Kinase (genetics, metabolism)
• Caspase 9 (metabolism)
• Cell Proliferation (drug effects)
• Checkpoint Kinase 2 (metabolism)
• Colorectal Neoplasms (drug therapy, metabolism, pathology)
• Cyclins (metabolism)
• Female
• G2 Phase Cell Cycle Checkpoints (drug effects)
• HCT116 Cells
• Humans
• Membrane Potential, Mitochondrial (drug effects)
• Mice
• Mice, Nude
• Pancreatic Neoplasms (drug therapy, metabolism, pathology)
• Phosphorylation (drug effects)
• Reactive Oxygen Species (metabolism)
• Xenograft Model Antitumor Assays
• bcl-2-Associated X Protein (genetics, metabolism)
• cdc25 Phosphatases (metabolism)