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Vitamin K

November 2010

Vitamins K2, K3 and K5 exert in vivo antitumor effects on hepatocellular carcinoma by regulating the expression of G1 phase-related cell cycle molecules.

A number of studies have shown that various vitamins K, specifically vitamin K2, possessed antitumor activity on various types of rodent- and human-derived neoplastic cell lines. However, there are only a small number of reports demonstrating in vivo antitumor effects of vitamins K. Furthermore, the mechanism of antitumor effects of vitamins K still remains to be examined. In the present study, we examined the antitumor effects of vitamins K2, K3 and K5 on PLC/PRF/5 human hepatocellular carcinoma (HCC) cells in vivo. Furthermore, to examine the mechanism of antitumor actions of these vitamins K, mRNA expression levels of various G1 phase-related cell cycle molecules were evaluated by using a real-time reverse transcription-polymerase chain reaction (RT-PCR) method. HCC-bearing animals were produced by implanting PLC/PRF/5 cells subcutaneously into athymic nude mice, and drinking water containing vitamin K2, K3 or K5 was given to the animals. Treatments with vitamins K2, K3 and K5 were shown to markedly inhibit the growth of HCC tumors. To examine the mechanism of in vivo antitumor effects of vitamins K, total RNA was extracted from HCC tumors, and the expression of G1 phase-related cell cycle molecules was quantitatively examined. Real-time RT-PCR demonstrated that the expression of the cell cycle-driving molecule, cyclin-dependent kinase 4 (Cdk4), in HCC was significantly reduced by the treatments with vitamin K2, K3 and K5. Conversely, the expression of the cell cycle-suppressing molecules, Cdk inhibitor p16INK4a and retinoblastoma, in HCC was significantly enhanced by the treatments with vitamins K2, K3 and K5. These results indicate that vitamins K2, K3 and K5 exert antitumor effects on HCC by regulating the expression of G1 phase-related cell cycle molecules. These results also indicate that vitamins K2, K3 and K5 may be useful agents for the treatment of patients with HCC.

Int J Oncol. 2005 Aug;27(2):505-11

Effect of vitamin K2 on the recurrence in patients with hepatocellular carcinoma.

BACKGROUND/AIMS: Vitamin K2 (VK2) appears to have a potent inhibitory activity for cell growth including HCC cells. We investigated whether VK2 could reduce incidence of tumor recurrence after treatment of HCC. Forty-five patients with cured or possibly cured HCC were randomly selected, assigning patients to treatment (n=21) or control group (n=24) with randomization list. METHODOLOGY: For the treatment group, forty-five mg of Glakay was given orally every day after therapy for HCC. No patients complained of adverse effects. Abdominal ultrasonography and dynamic CT were performed at 3-month intervals. Recurrence was confirmed by abdominal angiography. RESULTS: Recurrence of HCC occurred in 7 cases (33.3%) for the treatment group and 12 cases (50.0%) for the control group during mean observation periods of 19.5 and 16.5 months, respectively. Administration of VK2 was not an independent variable for the recurrence on univariate analysis. Cumulative incidence of HCC recurrence did not differ between the two groups, and the cumulative survival rate tended to be high in treatment group (p =0.054). Cox regression analysis revealed that serum albumin concentration alone was an independent factor affecting the recurrence. CONCLUSIONS: These findings suggest that VK2 does not appear to prevent recurrence of HCC after curative treatment. Our study is preliminary and large-scale trials are needed to determine whether VK2 is of benefit to decrease the recurrence of HCC.

Hepatogastroenterology. 2007 Oct-Nov;54(79):2073-7

Preventive effects of vitamin K on recurrent disease in patients with hepatocellular carcinoma arising from hepatitis C viral infection.

BACKGROUND: Despite the progression of therapeutic approaches, a high frequency of recurrence is what determines the long-term prognosis of patients with hepatocellular carcinoma (HCC). In this study, the chemopreventive effects of vitamin K2 on the recurrence and survival of patients with HCC after curative therapy were evaluated. METHODS: Sixty patients who were diagnosed to be free of HCC after radiofrequency ablation therapy or surgery were randomly assigned to either the vitamin K2 group (n = 30 patients) or the control group (n = 30 patients). All patients were positive for the hepatitis C virus (HCV) antibody and hepatitis B surface antigen positive patients were excluded from this study. Patients in the vitamin K2 group received an oral dose of menatetrenone at 45 mg per day. Disease recurrence and the survival rates were analyzed in patients with HCC. RESULTS: The cumulative recurrence-free rates in the vitamin K2 group were 92.3% at 12 months, 48.6% at 24 months and 38.8% at 36 months; and those in the control group were 71.7%, 35.9% and 9.9%, respectively (P = 0.045). The cumulative survival rates in the vitamin K2 group were 100% at 12 months, 95.0% at 24 months and 77.5% at 36 months; and those in the control group were 95.8%, 90.2% and 66.4%, respectively (P = 0.70). CONCLUSIONS: Vitamin K2 may have a suppressive effect on the recurrence of HCC and a beneficial effect on tumor recurrence. However, there was no significant difference in the survival rates. The chemopreventive effects of vitamin K2 are not sufficient. The development of a further regimen such as combination therapy is required.

J Gastroenterol Hepatol. 2007 Apr;22(4):518-22

Combination of vitamin K2 and angiotensin-converting enzyme inhibitor ameliorates cumulative recurrence of hepatocellular carcinoma.

BACKGROUND/AIMS: No chemopreventive agent has been approved against hepatocellular carcinoma (HCC) yet. Since neovascularization plays a pivotal role in HCC, an angiostatic agent is considered as one of the promising approaches. The aim of this study was to elucidate the combined effect of the clinically used vitamin K(2) (VK) and angiotensin-converting enzyme inhibitor (ACE-I) on cumulative recurrence after curative treatment on a total of 87 patients, especially in consideration of neovascularization.METHODS: VK (menatetrenone; 45 mg/day) and/or ACE-I (perindopril; 4 mg/day) were administered for 36-48 months after curative therapy for HCC. The cumulative recurrence and several indices were analyzed. RESULTS: A 48-month follow-up revealed that the combination treatment with VK and ACE-I markedly inhibited the cumulative recurrence of HCC in association with suppression of the serum level of the vascular endothelial growth factor (VEGF); a central angiogenic factor. The serum level of lectin-reactive alpha-fetoprotein was also suppressed almost in parallel with VEGF. These beneficial effects were not observed with single treatment using VK or ACE-I. CONCLUSIONS: The combination treatment of VK and ACE-I may suppress the cumulative recurrence of HCC after the curative therapy, at least partly through suppression of the VEGF-mediated neovascularization.

J Hepatol. 2009 Aug;51(2):315-21

Combined treatment of vitamin K2 and angiotensin-converting enzyme inhibitor ameliorates hepatic dysplastic nodule in a patient with liver cirrhosis.

Although it is well known that the hepatocellular carcinoma (HCC) is an ominous complication in patients with liver cirrhosis, there has been no approved drug to prevent the development of HCC to date. We previously reported that the combined treatment of vitamin K2 (VK) and angiotensin-converting enzyme inhibitor (ACE-I) significantly suppressed the experimental hepatocarcinogenesis. A 66-year-old Japanese woman with hepatitis C virus (HCV)-related liver cirrhosis developed a dysplastic nodule in the liver detected by enhanced computed tomography along with elevation of the tumor markers, namely, alpha-fetoprotein (AFP) and lectin-reactive demarcation (AFP-L3), suggesting the presence of latent HCC. After oral administration of VK and ACE-I, the serum levels of both AFP and AFP-L3 gradually decreased without any marked alteration of the serum aminotransferase activity. After one-year treatment, not only the serum levels of AFP and AFP-L3 returned to the normal ranges, but also the dysplastic nodule disappeared. Since both VK and ACE-I are widely used without serious side effects, this combined regimen may become a new strategy for chemoprevention against HCC.

World J Gastroenterol. 2007 Jun 21;13(23):3259-61

Vitamin K, an example of triage theory: is micronutrient inadequacy linked to diseases of aging?

The triage theory posits that some functions of micronutrients (the approximately 40 essential vitamins, minerals, fatty acids, and amino acids) are restricted during shortage and that functions required for short-term survival take precedence over those that are less essential. Insidious changes accumulate as a consequence of restriction, which increases the risk of diseases of aging. For 16 known vitamin K-dependent (VKD) proteins, we evaluated the relative lethality of 11 known mouse knockout mutants to categorize essentiality. Results indicate that 5 VKD proteins that are required for coagulation had critical functions (knockouts were embryonic lethal), whereas the knockouts of 5 less critical VKD proteins [osteocalcin, matrix Gla protein (Mgp), growth arrest specific protein 6, transforming growth factor beta-inducible protein (Tgfbi or betaig-h3), and periostin] survived at least through weaning. The VKD gamma-carboxylation of the 5 essential VKD proteins in the liver and the 5 nonessential proteins in nonhepatic tissues sets up a dichotomy that takes advantage of the preferential distribution of dietary vitamin K1 to the liver to preserve coagulation function when vitamin K1 is limiting. Genetic loss of less critical VKD proteins, dietary vitamin K inadequacy, human polymorphisms or mutations, and vitamin K deficiency induced by chronic anticoagulant (warfarin/coumadin) therapy are all linked to age-associated conditions: bone fragility after estrogen loss (osteocalcin) and arterial calcification linked to cardiovascular disease (Mgp). There is increased spontaneous cancer in Tgfbi mouse knockouts, and knockdown of Tgfbi causes mitotic spindle abnormalities. A triage perspective reinforces recommendations of some experts that much of the population and warfarin/coumadin patients may not receive sufficient vitamin K for optimal function of VKD proteins that are important to maintain long-term health.

Am J Clin Nutr. 2009 Oct;90(4):889-907

The effect of menatetrenone, a vitamin K2 analog, on disease recurrence and survival in patients with hepatocellular carcinoma after curative treatment: a pilot study.

BACKGROUND: The high recurrence rate of hepatocellular carcinoma (HCC) determines the long-term prognosis for patients with HCC. In the current study, the authors tested the effects of menatetrenone, a vitamin K2 analog, on recurrent HCC and survival after curative treatment. METHODS: Sixty-one patients who were diagnosed as free of HCC after surgical resection or percutaneous local ablation were assigned randomly assigned to either a menatetrenone group (n = 32 patients) or a control group (n = 29 patients). Patients in the menatetrenone group received a daily oral dose of 45 mg of menatetrenone. Disease recurrence and survival rates were analyzed in patients with HCC. RESULTS: The cumulative recurrence rates in the menatetrenone group were 12.5% at 12 months, 39.0% at 24 months, and 64.3% at 36 months; and the corresponding recurrence rates in the control group were 55.2%, 83.2%, and 91.6%, respectively (P = 0.0002). Similar results were obtained even for patients who had low baseline levels of serum des-gamma-carboxy-prothrombin. Univariate and multivariate Cox proportional hazard analyses showed that the administration of menatetrenone was the only factor related to the recurrence rate of HCC. The cumulative survival rates for the patients who received menatetrenone were 100% at 12 months, 96.6% at 24 months, and 87.0% at 36 months; and the corresponding survival rates for patients in the control group were 96.4%, 80.9%, and 64.0%, respectively (P = 0.051). CONCLUSIONS: The current study findings suggested that menatetrenone may have a suppressive effect on recurrence of HCC and a beneficial effect on survival, although a larger, placebo-controlled trial will be required to prove these effects.

Cancer. 2006 Feb 15;106(4):867-72