Colorectal Cancer
Copyright ©The Author(s) 2003. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 15, 2003; 9(3): 485-490
Published online Mar 15, 2003. doi: 10.3748/wjg.v9.i3.485
Photodynamic inhibitory effects of three perylenequinones on human colorectal carcinoma cell line and primate embryonic stem cell line
Lan Ma, Tai Hong, Cong Li, Yu Zhang, Ze-Hua Wang, Wei-Zhi Ji
Lan Ma, Tai Hong, Graduate School of the Chinese Academy of Sciences, Beijing 100871, China
Lan Ma, Yu Zhang, Ze-Hua Wang, Monoclonal Antibody Biotechnology Center, Yunnan University, Kunming 650091, Yunnan Province, China
Tai Hong, The First People's Hospital of Yunnan Province, Kunming 650032, Yunnan Province, China
Cong Li, Chemistry, Yunnan University, Kunming 650091, Yunnan Province, China
Lan Ma, Tai Hong, Wei-Zhi Ji, Kunming Institute of Zoology, Chinese Academy of Science, Kunming 650223, Yunnan Province, China
Author contributions: All authors contributed equally to the work.
Supported by National Natural Science Foundation of China, No. 980174, Natural Scientific Foundation of Yunnan Province, No. C0106M
Correspondence to: Wei-Zhi Ji, Kunming Institute of Zoology, Chinese Academy of Science, Kunming 650223, Yunnan, China. wji@mail.kiz.ac.cn
Telephone: +86-871-5139413 Fax: +86-871-5139413
Received: July 4, 2002
Revised: July 13, 2002
Accepted: July 27, 2002
Published online: March 15, 2003
Abstract

AIM: To investigate the photodynamic inhibitory effects of Elsinochrome A (EA), Hypocrellin A (HA) and Hypocrellin B (HB) on human colorectal carcinoma Hce-8693 cells and rhesus monkey embryonic stem R366.4 cells, via inducing apoptosis.

METHODS: EA, HA and HB were extracted from metabolites of Hypomyces (Fr) Tul.Sp. R366.4 cells or Hce-8693 cells were cultured with different concentrations of EA, HA or HB respectively, irradiated and incubated with fresh medium for 2 h. Cell cycle analysis was performed by flow cytometry (FCM). Data were expressed as means ± SD and analysis of variance and Student’t-test for individual comparisons.

RESULTS: The photodynamic bioactivity of EA was first reported in this study. After irradiation for 5 min, 6 min, 10 min or 20 min, photoactivated EA at lower concentrations, which were 10-7 Mol/L, 10- 6 Mol/L, 10 - 5 Mol/L respectively, had no cytotoxic effects on R366.4 ES cells. Whereas, all of the three perylenequinones could induce apoptosis with a dose-dependent manner when Hce-8693 cells were incubated with photoactivated EA, HA and HB respectively. When Hce-8693 cells were incubated with EA at 10-6 Mol/L and irradiated 5 min, 6 min, 10 min and 20 min respectively, the rates of EA-induced apoptosis were 0, 0, 13.4% and 40.5%. While the rates of HA-induced apoptosis were 29.5%, 32.0%, 40.2% and 22.6%. And the rates of HB-induced apoptosis were 0, 0, 0 and 13.7% respectively. Meanwhile, after 10-5 Mol/L treatment, the rates of EA-induced apoptosis were 32.7%, 19.3%, 26.4% and 52.7%, the rates of HA-induced apoptosis were 47.2%, 39.1%, 45.2% and 56.6%, and the rates of HB-induced apoptosis were 0, 0, 20.0% and 13.9% respectively.

CONCLUSION: EA, HA and HB have significant anti-cancer activity. The order of photodynamic inhibitory effects on tumor cells would be approximately HA > EA > HB. The molecular mechanisms of apoptosis may not be induced by reactive oxygen species and are worth further investigation.

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