menaquinone-6 and Carcinoma

The pregnane X receptor (PXR) is the key regulator of our defense mechanism against foreign substances such as drugs, dietary nutrients, or environmental pollutants. Because of increased health consciousness, the use of dietary supplements has gradually increased, and most of them can activate PXR. Therefore, an analysis of the interaction between drugs and nutrients is important because altered levels of drug-metabolizing enzymes or transporters can remarkably affect the efficiency of a co-administered drug. In the present study, we analyzed the effect of vitamin K-mediated PXR activation on drug metabolism-related gene expression in intestine-derived LS180 cells via gene expression studies and western blotting analyses. We demonstrated that menaquinone 4 (MK-4), along with other vitamin Ks, including vitamin K

Topics: ATP Binding Cassette Transporter, Subfamily B; Carcinoma; Cell Line, Tumor; Cytochrome P-450 CYP3A; Gene Expression; Humans; Intestinal Neoplasms; Nutritional Physiological Phenomena; Pregnane X Receptor; Rifampin; Vitamin K; Vitamin K 1; Vitamin K 2

Vitamin K2 (menaquinone-4: VK2) has been reported to show apoptosis and differentiation-inducing effects on leukemia cells. Furthermore, the clinical benefits of using VK2 have been demonstrated for the treatment of the patients with acute leukemia and myelodysplastic syndromes. In the present study, we examined the in vitro effects of VK2 on lung carcinoma cell lines LU-139 and LU-130 for small cell carcinomas, PC-14 and CCL-185 for adenocarcinomas, LC-AI and LC-1/sq for squamous cell carcinomas, and IA-LM for large cell carcinoma, respectively. Treatment with VK2 for 48 to 96 h resulted in cell growth suppression in a dose-dependent manner in all cell lines tested. IC50 (50% inhibitory concentration) for VK2 ranged from 7.5 to 75 micro M, and there was no relation between the efficacy of growth suppression by VK2 and tissue type of lung carcinoma cell lines. Morphologic features of the cells treated with VK2 were typical for apoptosis along with caspase-3 activation and becoming positive for APO2.7 monoclonal antibody, an antibody which specifically detects the cell undergoing apoptosis. In addition to the leukemia cell line, LU-139 cells accumulated into G0/G1 phase during 72-h exposure to VK2. Combined treatment of cisplatin plus VK2 resulted in enhanced cytocidal effect compared to the cells treated with either cisplatin or VK2 alone. Since VK2 is a safe medicine without prominent adverse effects including bone marrow suppression, our data strongly suggest the therapeutic possibility of using VK2 for the treatment of patients with lung carcinoma.

Topics: Antibodies, Monoclonal; Antineoplastic Agents; Apoptosis; Carcinoma; Caspase 3; Caspases; Cell Cycle; Cell Differentiation; Cell Line, Tumor; Cell Survival; Cisplatin; Dose-Response Relationship, Drug; Enzyme Activation; Flow Cytometry; G1 Phase; HL-60 Cells; Humans; Inhibitory Concentration 50; Lung Neoplasms; Resting Phase, Cell Cycle; Time Factors; Vitamin K 2