Colorectal Cancer
Copyright ©2007 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Dec 28, 2007; 13(48): 6512-6517
Published online Dec 28, 2007. doi: 10.3748/wjg.v13.i48.6512
New anti-proliferative agent, MK615, from Japanese apricot “Prunus mume” induces striking autophagy in colon cancer cells in vitro
Shozo Mori, Tokihiko Sawada, Toshie Okada, Tatsushi Ohsawa, Masakazu Adachi, Kubota Keiichi
Shozo Mori, Tokihiko Sawada, Toshie Okada, Kubota Keiichi, Second Department of Surgery, Dokkyo University School of Medicine, Kitakobayashi 880, Mibu, Shimotsuga, Tochigi 321-0293, Japan
Tatsushi Ohsawa, Masakazu Adachi, Japan Apricot Co., Ltd., Midori-cho 1-11-7, Takasaki, Gunma 370-0073, Japan
Correspondence to: Tokihiko Sawada, MD, PhD, Second Department of Surgery, Dokkyo University School of Medicine, Kitakobayashi 880, Mibu, Shimotsuga, Tochigi 321-0293, Japan. tsawada@dokkyomed.ac.jp
Telephone: +81-282-861111 Fax: +81-282-866317
Received: April 9, 2007
Revised: August 27, 2007
Accepted: August 30, 2007
Published online: December 28, 2007
Abstract

AIM: To investigate the anti-neoplastic effects of MK615, an extract from the Japanese apricot (Prunus mume), against colon cancer cells.

METHODS: Three colon cancer cell lines, SW480, COLO, and WiDr, were cultured with MK615. Growth inhibition was evaluated by cell proliferation assay and killing activity was determined by lactate dehydrogenase assay. Induction of apoptosis was evaluated by annexin V flow cytometry. Morphological changes were studied by light and electron microscopy, and immunofluorescence staining with Atg8.

RESULTS: MK615 inhibited growth and lysed SW480, COLO and WiDr cells in a dose-dependent manner. Annexin V flow cytometry showed that MK615 induced apoptosis after 6 h incubation, at which point the occurrence of apoptotic cells was 68.0%, 65.7% and 64.7% for SW480, COLO, and WiDr cells, respectively. Light and electron microscopy, and immunofluorescence staining with Atg8 revealed that MK615 induced massive cytoplasmic vacuoles (autophagosomes) in all three cell lines.

CONCLUSION: MK615 has an anti-neoplastic effect against colon cancer cells. The effect may be exerted by induction of apoptosis and autophagy.

Keywords: Colon cancer; Japanese apricot; Prunus mume; Autophagy; Apoptosis; MK615