Extracellular signal-regulated kinase phosphorylation due to menadione-induced arylation mediates growth inhibition of pancreas cancer cells

• Published in: Cancer chemotherapy and pharmacology 2008-07, Vol.62 (2), p.315-320
• Main Authors: Osada, Shinji, Sakashita, Fumio, Hosono, Yosiki, Nonaka, Kenichi, Tokuyama, Yasuharu, Tanaka, Hidenori, Sasaki, Yoshiyuki, Tomita, Hiroyuki, Komori, Shuji, Matsui, Satoshi, Takahashi, Takao
• Format: Article
• Language: English
• Subjects: Animals; Antineoplastic agents; Antioxidants - pharmacology; Biological and medical sciences; Cancer Research; Cell Line, Tumor; Cell Survival - drug effects; Dose-Response Relationship, Drug; Extracellular Signal-Regulated MAP Kinases - metabolism; Gastroenterology. Liver. Pancreas. Abdomen; Hydrogen Peroxide - pharmacology; Liver. Biliary tract. Portal circulation. Exocrine pancreas; Medical sciences; Medicine; Medicine & Public Health; Oncology; Original Article; Oxidative Stress - drug effects; Pancreatic Neoplasms - enzymology; Pancreatic Neoplasms - pathology; Pharmacology. Drug treatments; Pharmacology/Toxicology; Phosphorylation; Rats; Tumors; Vitamin K 3 - pharmacology
• ISSN: 0344-5704; 1432-0843
• DOI: 10.1007/s00280-007-0610-9

Background Cytotoxicity of Vitamin K3 (VK3) is indicated to have the same mechanism with oxidative stress (H 2 O 2 ). In the present study, we analyzed the differences and/or similarities in the cellular responses to oxidative stress and VK3 to clarify the mechanism of growth inhibition. Methods Cell viability was determined by a test method with 3-[4, 5-dimethyl-thiazol]-2, 5-dephenyl tetrazolium bromide (MTT). Expressions of cellular proteins were evaluated by Western blot analysis. Results The IC50 was calculated to be 47.3 ± 4.1 μM for VK3 and 2.2 ± 1.2 μM for H 2 O 2 . By Western blot analysis, VK3 or H 2 O 2 was shown to induce rapid phosphorylation of extracellular signal-regulated kinase (ERK), and c-Jun N-terminal kinases (JNKs). H 2 O 2 -induced phosphorylation of ERK and JNK was almost complete inhibited by more than 100-μM genistein. VK3-induced JNK phosphorylation was blocked by 100-μM genistein, but ERK phosphorylation was not inhibited completely even if 400-μM genistein was used. H 2 O 2 -induced inhibition of cell proliferation was completely blocked by 400-μM genistein, but the VK3 effect was reduced 72.8 ± 5.4% by the same concentration of genistein. H 2 O 2 -induced JNK phosphorylation and ERK phosphorylation were inhibited by staurosporine, protein kinase C (PKC) inhibitor. VK3-induced JNK phosphorylation was also blocked, but ERK phosphorylation was not affected. Staurosporine had no effect on VK3- or H 2 O 2 -induced growth inhibition. Treatment with a non-thiol antioxidant agent, catalase, completely abrogated H 2 O 2 -induced JNK and ERK phosphorylation, but a thiol antioxidant, l -cystein, had no effect on phosphorylation of them. The VK3-induced JNK phosphorylation was inhibited by catalase, but not l -cystein. But ERK phosphorylation was not inhibited by catalase and was abrogated completely by the thiol antioxidant. Catalase, but not l -cystein, blocked H 2 O 2 -induced growth inhibition, and l -cystein, but not catalase, blocked VK3-induced effects on cell proliferation completely. Conclusion VK3-induced ERK phosphorylation occurs by a different mechanism from oxidative stress, and it might have an important role to induce growth inhibition.