Induction of apoptosis in hepatocellular carcinoma Smmc-7721 cells by vitamin K(2) is associated with p53 and independent of the intrinsic apoptotic pathway. Mol Cell Biochem. 2010;342:125-131. [PMID: 20449638 DOI: 10.1007/s11010-010-0476-8]

Vitamin K: Calcium Metabolism Modulator for Menopausal Women

Vitamin K (VitK) exists in multiple forms, with Vitamin K1 (VitK1) and Vitamin K2 (VitK2) being the most prominent. VitK1 primarily regulates clotting factors in the liver, whereas VitK2 plays a crucial role in activating extrahepatic proteins involved in various physiological processes. VitK plays a pivotal role in various physiological functions, including vascular health, bone metabolism, neuroprotection, hepatoprotection, immune response modulation, dental health, and glucose control. Particularly, activation of the matrix Gla protein and osteocalcin through VitK2 inhibits vascular calcification (VC) and promotes bone mineralization. This review provides an overview of the physiological functions of VitK2, underscoring its role in calcium metabolism modulation and its diverse effects on health. Additionally, this article provides a comprehensive overview of the beneficial functions of VitK, and discusses the significance of adequate dietary intake and oral supplementation of VitK. Particularly, emphasizing on the need for VitK2 supplementation owing to its relatively limited availability in Western diets. VitK2 supplementation effectively counters VC, enhances bone density, and offers neuroprotective, hepatoprotective, and anti-inflammatory benefits. Thus, the supplementation of VitK2, alongside dietary intake, is essential for preventive healthcare, particularly in the prevention of osteoporosis and vascular diseases. Incorporating adequate VitK2 intake highlights its significance in promoting overall well-being. Illustrated summary of the role of VitK in menopausal women.

Research progress on the anticancer effects of vitamin K2

Despite the availability of multiple therapeutic methods for patients with cancer, the long-term prognosis is not satisfactory in a number of different cancer types. Vitamin K2 (VK2), which exerts anticancer effects on a number of cancer cell lines, is considered to be a prospective novel agent for the treatment of cancer. The present review aims to summarize the results of studies in which VK2 was administered either to patients with cancer or animals inoculated with cancerous cells, particularly investigating the inhibitory effects of VK2 on cancerous cells, primarily involving cell-cycle arrest, cell differentiation, apoptosis, autophagy and invasion. The present review summarizes evidence stating that treatment with VK2 could positively inhibit the growth of cancer cells, making it a potentially useful approach for the prevention and clinical treatment of cancer. Additionally, the combination treatment of VK2 and established chemotherapeutics may achieve better results, with fewer side effects. Therefore, more attention should be paid to the effects of micronutrients on tumors.

Clinical Impact of Vitamin K Dosing on Sorafenib Treatment for Hepatocellular Carcinoma

Background: Some researchers have suggested that vitamin K enhances the antitumor effect of sorafenib for hepatocellular carcinoma (HCC) in vitro and in vivo. In this study, we examined the clinical impact of vitamin K dosing for sorafenib treatment. Methods: Twenty-nine out of 65 patients treated with sorafenib for HCC were simultaneously dosed with vitamin K. We retrospectively investigated progression-free survival (PFS) and overall survival (OS) in the vitamin K-dosed group and sorafenib alone group. We also examined the changes in serum des-γ-carboxy prothrombin (DCP) levels, which vitamin K is involved with. Results: The median PFS was prolonged in the sorafenib + vitamin K group compared with the sorafenib alone group (6.0 months and 2.0 months, respectively; P<0.001, hazard ratio〔HR〕: 0.25). The median OS was also significantly extended (12.5 months vs. 10.0 months; P=0.009, HR: 0.47). Despite suppressed tumor growth, serum DCP levels had increased in cases of disease-controlled patients in the sorafenib alone group 8 weeks after the beginning of treatment, (2.28±0.91 to 2.64±1.03, P= 0.048). In contrast, the serum DCP levels of the sorafenib + vitamin K group had declined both in patients with controlled disease and in patients with progressive disease (1.97±0.57 to 1.29±0.28, P=0.002 and 2.90±1.32 to 1.78±0.53, P=0.034, respectively). Conclusions: To the best of our knowledge, this is the first clinical report showing enhanced antitumor action of sorafenib by vitamin K. Our clinical findings suggest that vitamin K may have the synergistic effect by suppressing production of DCP, a tumor growth and angiogenesis factor.

Vitamin K4 inhibits the proliferation and induces apoptosis of U2OS osteosarcoma cells via mitochondrial dysfunction

Vitamin K (VK) is a group of fat‑soluble vitamins, which serve important roles in blood coagulation and bone metabolism. A recent study reported that several VK subtypes possess antitumor properties, however the antitumor effects of VK in osteosarcoma are unknown. The present study aimed to identify the antitumor effects of VK in osteosarcoma and the possible underlying mechanism of action. The effect of VK4 on cell viability was determined using a 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide (MTT) assay. Cellular and nuclear morphological changes were observed by phase contrast microscopy. Cell cycle analysis, apoptotic rate, mitochondrial membrane potential and levels of reactive oxygen species (ROS) were detected by flow cytometry. In vitro cancer cell migration activities were evaluated using a Wound healing assay and Transwell microplates. The results demonstrated that VK4 arrested the cells in S phase and induced apoptosis. Additional mechanistic studies indicated that the induction of apoptosis by VK4 was associated with the increased production of reactive oxygen species, dissipation of the mitochondrial membrane potential, decreased Bcl‑2 family protein expression levels and activation of caspase‑3. In conclusion, the results suggest that the sensitivity of U2OS osteosarcoma cells to VK4 may be as a result of mitochondrial dysfunction. As it is readily available for human consumption, VK4 may therefore present a novel therapeutic candidate for the treatment of patients with osteosarcoma.

Metabolomics identifies the intersection of phosphoethanolamine with menaquinone-triggered apoptosis in an in vitro model of leukemia

Altered metabolism is increasingly acknowledged as an important aspect of cancer, and thus serves as a potentially fertile area for the identification of therapeutic targets or leads. Our recent work using transcriptional data to predict metabolite levels in cancer cells led to preliminary evidence of the antiproliferative role of menaquinone (vitamin K2) in the Jurkat cell line model of acute lymphoblastic leukemia. However, nothing is known about the direct metabolic impacts of menaquinone in cancer, which could provide insights into its mechanism of action. Here, we used metabolomics to investigate the process by which menaquinone exerts antiproliferative activity on Jurkat cells. We first validated the dose-dependent, semi-selective, pro-apoptotic activity of menaquinone treatment on Jurkat cells relative to non-cancerous lymphoblasts. We then used mass spectrometry-based metabolomics to identify systems-scale changes in metabolic dynamics that are distinct from changes induced in non-cancerous cells or by other chemotherapeutics. One of the most significantly affected metabolites was phosphoethanolamine, which exhibited a two-fold increase in menaquinone-treated Jurkat cells compared to vehicle-treated cells at 24 h, growing to a five-fold increase at 72 h. Phosphoethanolamine elevation was observed prior to the induction of apoptosis, and was not observed in menaquinone-treated lymphoblasts or chemotherapeutic-treated Jurkat cells. We also validated the link between menaquinone and phosphoethanolamine in an ovarian cancer cell line, suggesting potentially broad applicability of their relationship. This metabolomics-based work is the first detailed characterization of the metabolic impacts of menaquinone treatment and the first identified link between phosphoethanolamine and menaquinone-induced apoptosis.

Vitamin K and hepatocellular carcinoma: The basic and clinic

Vitamin K (VK), which was originally identified as a cofactor involved in the production of functional coagulation factors in the liver, has been shown to be involved in various aspects of physiological and pathological events, including bone metabolism, cardiovascular diseases and tumor biology. The mechanisms and roles of VK are gradually becoming clear. Several novel enzymes involved in the VK cycle were identified and have been shown to be linked to tumorigenesis. The VKs have been shown to suppress liver cancer cell growth through multiple signaling pathways via the transcription factors and protein kinases. A VK2 analog was applied to the chemoprevention of hepatocellular carcinoma (HCC) recurrence after curative therapy and was shown to have beneficial effects, both in the suppression of HCC recurrence and in patient survival. Although a large scale randomized control study failed to demonstrate the suppression of HCC recurrence, a meta-analysis suggested a beneficial effect on the long-term survival of HCC patients. However, the beneficial effects of VK administration alone were not sufficient to prevent or treat HCC in clinical settings. Thus its combination with other anti-cancer reagents and the development of more potent novel VK derivatives are the focus of ongoing research which seeks to achieve satisfactory therapeutic effects against HCC.

Real-time cell analysis of the inhibitory effect of vitamin K2 on adhesion and proliferation of breast cancer cells

Breast cancer is the most prevalent cancer type worldwide. Continued efforts to improve treatment strategies for patients with breast cancer will be instrumental in reducing the death rates associated with this disease. In particular, the triple-negative breast cancer subtype of breast cancer has no targeted therapy available so it is essential to continue to work on any potential therapies. Vitamin K (VK) is known for its essential role in the clotting cascade. The antitumor properties of VK derivatives have been reported in both hepatocellular carcinoma and glioblastoma. Our hypothesis was that menaquinone-4, the most common form of vitamin K2 (VK2), is an effective anticancer agent against breast cancer cell types. In this study, we used a novel impedance-based live cell monitoring platform (xCELLigence) to determine the effects of VK derivatives on the triple-negative breast cancer cell line, MDA-MB-231, and the HER2+ breast cancer cell line, MDA-MB-453. Cells were treated with varying concentrations of menaquinone-4 (VK2) previously reported to have an antiproliferative effect on human glioblastoma cells. After initial testing, these concentrations were adjusted to 100, 125, and 150 μmol/L. A significant dose-dependent, growth inhibitory effect was found when cells were treated at these concentrations. These effects were seen in both adhesion and proliferation phases and show a dramatic reduction in cell growth. Additional analysis of MDA-MB-231 cells treated with VK2 (100 μmol/L) in combination with a low-glucose nutrient media showed a further decrease in adhesion and viability. This is the first study of its kind showing the real-time effects of VK derivatives on breast cancer cells and suggests that dietary factors may be an important consideration for patients.

Postoperative use of the chemopreventive vitamin K2 analog in patients with hepatocellular carcinoma

AIM

To evaluate the chemopreventive efficacy of vitamin K2 (VK2) analog in patients with hepatocellular carcinoma (HCC) after curative hepatic resection or local ablation, since a recent randomized control trial (RCT) and systematic review have given contradictory results.

METHODS

MEDLINE, EMBASE and Cochrane library databases were systematically searched through the end of May 2012. Meta-analysis of RCTs and cohort studies was performed to estimate the effects of the VK2 analog on tumor recurrence rate and overall survival (OS). Risk ratios (RRs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Six RCTs and one cohort study involving a total of 930 patients were included. VK2 analog therapy did not reduce the 1-year recurrence rate, with a pooled RR of 0.67 (95% CI 0.39-1.13, p = 0.13). However, VK2 analog therapy was associated with a significant reduction in the 2- and 3-year tumor recurrence rates, with respective pooled RRs of 0.65 (95% CI 0.51-0.83, p<0.001) and 0.70 (95% CI = 0.58-0.85, p<0.001). The therapy was also associated with a significant improvement in 1-, 2-, and 3-year OS, with respective pooled RRs of 1.03 (95% CI 1.01-1.05, p = 0.02), 1.11 (95% CI 1.03-1.19, p = 0.005) and 1.14 (95% CI 1.02-1.28, p = 0.02). None of the studies reported adverse effects attributable to VK2 analog therapy.

CONCLUSION

The VK2 analog may reduce recurrence rate after 1 year and improve OS in HCC patients as early as 1 year. However, these findings should be considered preliminary since the majority of patients came from an RCT with survival data out to only 1 year. More extensive studies with larger sample sizes and longer follow-up are needed.

Oral vitamin K2 analogs for hepatocellular carcinoma after surgery: A meta-analysis

AIM: To evaluate the efficacy and safety of oral vitamin K2 (VK2) analogs for patients with hepatocellular carcinoma (HCC) after surgery.

METHODS: Sources such as Chinese National Knowledge Infrastructure, Medline, Embase and Cochrane library were systematically searched. All clinical trials comparing curative treatments alone with curative treatments plus VK2 analogs for HCC patients were identified. Meta-analysis was performed to estimate the effects of VK2 analogs on tumor recurrence and overall survival (OS). Risk ratios (RR) and 95% confidence intervals (95% CI) were calculated.

RESULTS: Six randomized clinical trials and one cohort study involving 930 patients were included. VK2 analogs did not statistically reduced the 1-year tumor recurrence rate, with a pooled RR of 0.67 (95% CI: 0.39-1.13, P = 0.13). However, hepatic resection plus VK2 analogs were associated with significantly lower 2- and 3-year tumor recurrence rates, with pooled RRs of 0.65 (95% CI: 0.51-0.83, P < 0.001) and 0.70 (95% CI: 0.58-0.85, P < 0.001). Moreover, for the 1-, 2-, and 3-year OS, VK2 analogs also demonstrated statistically significant results (RR = 1.03, 95% CI: 1.01-1.05, P = 0.02; RR = 1.11, 95% CI: 1.03-1.19, P = 0.005; RR = 1.14, 95% CI: 1.02-1.28, P = 0.02). Oral VK2 analogs were safe and were not associated with adverse events.

CONCLUSION: Current evidence suggests that postoperative VK2 analogs have appreciable efficacy in patients with HCC after curative treatment.

Enhanced therapeutic efficacy of vitamin K2 by silencing BCL-2 expression in SMMC-7721 hepatocellular carcinoma cells

Vitamin K2 (VK2) exerts cell growth inhibitory effects in various human cancer cells such as SMMC-7721 hepatocellular carcinoma (HCC) cells. BCL-2 is an antiapoptotic protein that is frequently overexpressed in numerous tumors. Modulation of multiple antiapoptotic signaling pathways involving BCL-2, which are related to growth factor-stimulated signal transduction in cell survival, is essential for enhancement of the cytotoxic effect of anticancer drugs. In this study, we tested a new strategy of gene therapy by combining BCL-2 siRNA with VK2. In SMMC-7721 HCC cells, the combined treatment significantly enhanced cytotoxicity compared with treatment with either VK2 or siBCL-2 alone. We found that combined treatment induced a significantly different level of G2 stage inhibition. Furthermore, the p53 protein was overexpressed 24 h subsequent to combination treatment, and p21 was clearly increased at 36 h as a consequence of the increased p53 activity. In conclusion, these data suggest that the antitumor effect of VK2 may be improved by silencing BCL-2 expression in SMMC-7721 HCC cells and provides support for the combined use of VK2 and siBCL-2 as a promising approach in cancer gene therapy.