A case of acute autoimmune hepatitis presenting after incomplete-type CREST syndrome and chronic thyroiditis.

A 55-year-old woman was admitted to our hospital with acute hepatitis of unknown origin. She had a history of incomplete-type CREST (calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, and telangiectasia) syndrome and chronic thyroiditis approximately 10 years earlier. Although she achieved spontaneous remission without treatment, she was re-admitted 18 months later due to recurrent liver dysfunction. Liver biopsy was performed as we strongly suspected autoimmune hepatitis despite her normal serum immunoglobulin G level. Liver biopsy findings were histologically compatible with autoimmune hepatitis, and administering prednisolone (30 mg/day) led to a prompt recovery of her liver dysfunction. No relapse occurred during the tapering of prednisolone to a maintenance dose of 5 mg/day. Here we report a rare case of autoimmune hepatitis in a patient with a history of incomplete-type CREST syndrome and chronic thyroiditis.

Clinical significance of autoantibodies to p53 protein in patients with autoimmune liver diseases.

BACKGROUND: Autoantibodies to p53 (anti-p53) are rarely present in the sera of patients with autoimmune diseases or the sera of patients with malignancies. OBJECTIVE: To examine the prevalence of anti-p53 in patients with autoimmune liver disease including autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), AIH/PBC overlap syndrome (AIH/PBC OS) and primary sclerosing cholangitis (PSC), and to determine the clinical significance of anti-p53 in autoimmune liver diseases. METHODS: Forty patients with AIH, 41 patients with PBC, eight patients with AIH/PBC OS and five patients with PSC were enrolled. Anti-p53 and antibodies to double-stranded DNA (anti-ds-DNA) were analyzed using commercially available ELISA kits. Demographic, laboratory and histological data were compared between the AIH groups seropositive and seronegative for anti-p53. RESULTS: Six of 40 (15.0%) patients with AIH and four of eight (50.0%) patients with AIH/PBC OS were positive for anti-p53. One of 41 (2.4%) patients with PBC was also positive for anti-p53, but all five patients with PSC were negative, indicating a significantly higher prevalence of anti-p53 in patients with AIH or AIH/PBC OS compared with patients with PBC. None of the AIH patients positive for anti-p53 progressed to hepatic failure or relapsed after immunosuppressive treatment. Titres of anti-ds-DNA in patients with AIH and AIH/PBC OS significantly correlated with titres of anti-p53 (r=0.511; P=0.0213). CONCLUSION: The emergence of anti-p53 is likely to be useful for discriminating AIH or AIH/PBC OS from PBC and helpful for predicting favourable prognoses in patients with AIH. DNA damage may trigger the production of anti-p53 in patients with AIH or AIH/PBC OS.

Clinical relevance of antibodies to cardiolipin in patients with chronic hepatitis C.

The significance of antibodies to cardiolipin (anti-CL) remains uncertain in patients with chronic hepatitis C (CH-C). The main purpose of this study was to elucidate the clinical characteristics of patients with CH-C seropositive for anti-CL. The prevalence of anti-CL and clinical parameters associated with anti-CL in those patients were examined. Six of the 45 (13%) patients with CH-C had anti-CL. However, none of these six CH-C patients fulfilled the criteria for antiphospholipid syndrome. Serum triglyceride and apolipoprotein B (ApoB) levels in CH-C patients with anti-CL were significantly higher than those in CH-C patients without anti-CL. Serum triglyceride levels positively correlated with serum ApoB levels. CH-C patients with anti-CL had significantly more progressive hepatic fibrosis than those without anti-CL. The degree of 8-hydroxy 2'-deoxyguanosine (8-OHdG) expression in the liver tissue was more severe in CH-C patients with anti-CL than in those without it. However, the emergence of anti-CL in CH-C patients was independent of insulin resistance, hepatic steatosis, and iron overload. These findings suggest that the emergence of anti-CL is associated with oxidative stress and that CH-C patients seropositive for anti-CL have clinical characteristics of hypertriglyceridemia, which derives from the facilitation of ApoB synthesis, and progressive hepatic fibrosis.

Severe hypoglycaemia under abemaciclib administration in a patient with breast cancer: A case report.

The current study reports the case of an 80-year-old woman who experienced severe hypoglycaemia after abemaciclib administration, with a recovery time of ~46 h. Abemaciclib is a cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitor that is used to treat metastatic breast cancer. A side effect of abemaciclib administration is an increase in creatinine levels. The half-life (t1 / 2) of 150 mg abemaciclib in patients with breast cancer was reported to be 17.5 h (nearly lower limit), and the time to reach Cmax was ~5 h (Tmax, 4-6 h). Therefore, the total time to reach half the maximum blood concentration after abemaciclib administration is ~24 h (Tmax + t1 / 2=5+17.5=22.5 h). As abemaciclib is administered twice daily, a considerable amount (Cmax = 123 ng/ml) may persist in the blood following the initial dose. Upon repeated administration, the blood abemaciclib concentration in patients with metastatic liver tumours might increase, although their liver function remains normal. The patient described in the current study had a creatinine level of 1.05 mg/dl at the start of abemaciclib administration. At the time of emergency hospitalisation (on day 5 of abemaciclib administration), the creatinine level was 1.40 mg/dl; however, dehydration was not observed. The patient had been administered the same dose of glimepiride for >1 year and had not experienced hypoglycaemia previously. It can be speculated that the increase in blood creatinine level had some effect on glimepiride metabolism. It is thought that administered abemaciclib enhances metabolic delay in the blood in the same way as in patients with impaired liver function, and as a result, the creatinine level increases in patients with liver metastases. This causes a decrease in renal function, which in turn results in an increase in blood concentration of glimepiride, consequently leading to severe hypoglycaemia. Therefore, clinicians must be careful when using abemaciclib in patients with liver metastases, diabetes and poor renal function.

Immunohistochemically detected expression of p27(Kip1) and Skp2 predicts survival in patients with intrahepatic cholangiocarcinomas.

In intrahepatic cholangiocarcinomas (ICCs), the prognostic significance of p27(Kip1), a cyclin-dependent kinase inhibitor, remains controversial, and there have been no studies of degradation pathway associated proteins, S-phase kinase-interacting protein (Skp2), and Jun activation domain-binding protein-1 (Jab1). In the present study of 74 patients with ICC-mass forming type (ICC-MF) undergoing radical surgery, we determined immunohistochemical expression of p27(Kip1), Skp2, and Jab1 and examined relationships with clinicopathologic findings and patient survival. On the basis of the average of labeling indices, we set cutoff values to define high and low expressors and divided the cases into two groups. A statistically significant correlation was found between low p27(Kip1) expression and lymph node metastasis (P = .009). Patient survival in the low p27(Kip1) expression group (n = 25) was also significantly worse than that in the high p27(Kip1) expression group (n = 49, P = .0007). A significant inverse correlation was found between p27(Kip1) and Skp2 expression (P = .016). High Skp2 expression (n = 36) was significantly associated with poor prognosis (P = .0046). High Jab1 expression was observed in 32 cases, but there was no statistically significant relationship with clinicopathologic findings or patient survival. The multivariate analysis revealed that low p27(Kip1) and high Skp2 expression are independent and significant factors of poor prognosis. The results suggest that low p27(Kip1) and high Skp2 expression are associated with aggressive tumor behavior, and these cell-cycle regulators are useful markers to predict outcome of patients with ICC-MF.

Intravascular large B-cell lymphoma with FDG accumulation in the lung lacking CT/(67)gallium scintigraphy abnormality.

Intravascular large B-cell lymphoma (IVLBCL) is a rare lymphoma characterized by the presence of large tumour cells within the blood vessels. It has been considered that IVLBCL is a highly malignant disease with poor prognosis. However, it has been shown that a therapeutic effect resembling that of conventional B-cell lymphomas may be obtained with the application of systemic chemotherapy at the early stage of this disease. Although involvement in the lung is often detected at autopsy, early diagnosis is quite difficult. In this report, we present a case of IVLBCL with pulmonary involvement where 18-fluoro-deoxyglucose positron emission tomography (FDG-PET) was useful in the early diagnosis. Neither computed tomography (CT) nor (67)gallium scintigraphy could reveal the presence of disease in the lung. Histological evidence of IVLBCL was obtained by TBLB after FDG uptake in the lung was confirmed by FDG-PET. The patient exhibited a good response to the subsequent combination chemotherapy. We propose that FDG-PET is a powerful tool for the early diagnosis of IVLBCL with pulmonary involvement, if the possibility of this disease presents in the patient with respiratory symptoms without abnormal findings by CT and (67)gallium scintigraphy.

Annexin A2 expression and phosphorylation are up-regulated in hepatocellular carcinoma.

Annexins (ANXs) constitute a family of Ca2+-dependent membrane-binding proteins; at least 20 of them have been described to date. Among these, Annexin A2 (ANXA2) has been revealed as a multi-functional protein in vitro. Its actual role in vivo, however, requires further investigation. We already reported that ANX-I (ANXA1) was up-regulated in hepatocellular carcinoma (HCC). The role of ANXA2 in various liver diseases including HCC remains obscure. In the present study, the protein and mRNA levels of ANXA2, as well as its localization, were determined for the normal human liver, chronic hepatitis liver, and non-tumorous and tumorous portions of HCC tissues. ANXA2 was rarely detected in either normal or chronic hepatitis liver tissues, whereas it was overexpressed at both the transcriptional and translational levels in tumorous and non-tumorous regions of HCC. In addition, in many cases, more ANXA2 was expressed in the tumorous portion than in the non-tumorous portion of HCC. The expression of ANXA2 was mainly localized in cancer cells, especially in poorly differentiated HCC. Furthermore, ANXA2 was tyrosine-phosphorylated in HCC. These data suggest that overexpression and tyrosine phosphorylation of ANXA2 play important roles in the malignant transformation process leading to HCC and are related to the histological grade of HCC.

A combination therapy of ethanol injection and radiofrequency ablation under general anesthesia for the treatment of hepatocellular carcinoma.

AIM: To summarize the effects of laparoscopic ethanol injection and radiofrequency ablation (L-EI-RFA), thoracoscopic (T-EI-RFA) and open-surgery assisted EI-RFA (O-EI-RFA) under general anesthesia for the treatment of hepatocellular carcinoma (HCC). METHODS: Time-lag performance of RFA after ethanol injection (Time-lag PEI-RFA) was performed in all cases. The volume of coagulated necrosis and the applied energy for total and per unit volume coagulated necrosis were examined in the groups treated under general (group G) or local anesthesia (group L). RESULTS: The results showed that the total applied energy and the applied energy per unit volume of whole and marginal, coagulated necrosis were significantly larger in group G than those in the group L, resulting in a larger volume of coagulated necrosis in the group G. The rate of local tumor recurrence within one year was extremely low in group G. CONCLUSION: These results suggest that EI-RFA, under general anesthesia, may be effective for the treatment of HCC because a larger quantity of ethanol and energy could be applied during treatment under painfree condition for the patients.

Identification of c-Yes expression in the nuclei of hepatocellular carcinoma cells: involvement in the early stages of hepatocarcinogenesis.

It is thought that the subcellular distribution of Src-family tyrosine kinases, including c-Yes binding to the cellular membrane, is membranous and/or cytoplasmic. c-Yes protein tyrosine kinase is known to be related to malignant transformation. However, the expression patterns of c-Yes in hepatocellular carcinoma (HCC) remains unknown. In the present study, we report that c-Yes is expressed not only in the membrane and cytoplasm, but also in the nuclei of cancer cells in some human HCC tissues and in a human HCC cell line. We examined the expression and localization of c-Yes in human HCC cell lines (HLE, HLF, PLC/PRF/5 and Hep 3B) by Western blotting and immunohistochemical analyses; we also examined the expression of c-Yes by immunohistochemistry and Western blotting in the tissues of various liver diseases, including 39 samples from HCC patients. We used an antibody array to detect proteins that bind to nuclear c-Yes in PLC/PRF/5 cell line. c-Yes was found to be expressed in the membranes and cytoplasm of HLE, HLF and Hep 3B HCC cells; it was also detected in the nuclei in addition to the membranes and cytoplasm of PLC/PRF/5 HCC cells. HCC with nuclear c-Yes was detected in 5 of 39 cases (13.0%), and nuclear c-Yes expression was not detected in normal, chronic hepatitis or cirrhotic livers. All HCCs with nuclear c-Yes expression were well-differentiated, small tumors at the early stages. In the PLC/PRF/5 cell line, the nuclear localization of c-Yes with cyclin-dependent kinase 1 was confirmed by a protein antibody array. In conclusion, nuclear c-Yes expression was found in cancer cells at the early stages of hepatocarcinogenesis, suggesting that nucleus-located c-Yes may be a useful marker to detect early-stage HCC.

Comparative study of the effects of percutaneous ethanol injection and radiofrequency ablation in cases treated with a straight or expandable electrode.

Radiofrequency ablation (RFA) has become mainstream among non-surgical treatment modalities in clinical settings for the treatment of hepatocellular carcinoma. We have previously described the novel combination therapy of percutaneous ethanol injection and RFA (PEI-RFA) and reported that this combination therapy was more effective than RFA alone in terms of the induced volume of coagulated necrosis and the energy requirement for the treatment. RFA instruments are mainly divided into two types according to the electrode used, either the straight or expandable type electrode. Although PEI-RFA can be performed by either of the electrodes, there may be some important differences in PEI-RFA according to the type of electrode used. In the present study, the effect of using the straight or expandable electrode in PEI-RFA was evaluated by analyzing the ablation time, volume of coagulated necrosis, the energy requirement for ablation and the amount of injected ethanol into HCC. The comparative study showed that ablation time, total energy requirement and per unit volume of energy requirement for whole and marginal coagulated necrosis were significantly smaller in the group treated with the expandable electrode (E group) than those in the group treated with the straight electrode (S group). The volume of coagulated necrosis was similar between these groups. In group E, the amount of injected ethanol showed a positive correlation with the volume of coagulated necrosis and the size of the tumors. These results suggest that prior injection of ethanol works mainly by shortening the time and energy requirement for ablation in the time-lag PEI-RFA using the expandable electrode. Thus, prior injection of ethanol before RFA may make RFA treatment less invasive in the time-lag PEI-RFA using the expandable electrode as previously shown HCC cases treated with straight electrode.

Sequential assessment of the intrahepatic expression of epidermal growth factor and transforming growth factor-beta1 in hepatofibrogenesis of a rat cirrhosis model.

Responses of the liver to chronic injury include inflammation, regeneration and fibrosis, which finally lead to cirrhosis. The cause of liver cirrhosis appears to be impaired proliferative capability of hepatocytes caused by continuous hepatic damage, and subsequent accumulation of extracellular matrix produced by hepatic stellate cells (HSCs). Epidermal growth factor (EGF) and transforming growth factor-beta1 (TGF-beta1) play a crucial role in hepatocyte proliferation and hepatofibrogenesis, respectively. However, sequential analyses of the intrahepatic expression of EGF and TGF-beta1 in the course of cirrhosis development have not been examined fully. In the present study, liver cirrhosis was produced in rats by intraperitoneal administration of dimethylnitrosamine (DMN), and intrahepatic mRNA expression levels of proliferating cell nuclear antigen (PCNA), EGF and TGF-beta1 were quantitatively estimated by a real-time reverse transcription-polymerase chain reaction method. Histological and semiquantitative densitometric examination of liver sections revealed that the accumulation of extracellular matrix components was increased according to the period of DMN treatment. Histological examination of liver sections of rats treated with DMN for 4 and 6 weeks revealed pre-cirrhosis and cirrhosis, respectively. Intrahepatic mRNA expression levels of PCNA and EGF correlated well. Expression levels of both molecules were increased significantly during the course of cirrhosis development, but decreased significantly at the time of complete cirrhosis manifestation. In contrast, intrahepatic TGF-beta1 expression was increased significantly according to the period of DMN treatment, and reached a peak at the time of cirrhosis manifestation. These results suggest that proliferative capability of hepatocytes was impaired by continuous liver damage due, in part, to the decrease of a hepatocyte mitogen EGF, and that increased intrahepatic TGF-beta1 activated HSCs to retrieve space lost by hepatocyte destruction, resulting in complete cirrhosis manifestation.

Successful treatment of hypovascular advanced hepatocellular carcinoma with lipiodol-targetting intervention radiology.

We report a case of hypovascular advanced hepa-tocellular carcinoma (HCC) successfully treated with a novel combination therapy of percutaneous ethanol-lipiodol injection (PELI) and intervention radiology (IVR), lipiodol-targetting IVR (Lipi-IVR). The present case had a hypovascular HCC (3 cm in diameter) located in the S6 region of the liver. Although the tumor was not detectable at all by both of early and late phase of helical dynamic computed tomography (CT), it could be detected by ultrasonography (US) as a low echoic space occupying lesion (SOL) beside the gallbladder and right kidney. Serum levels of alpha fetoprotein (AFP) and AFP-L3 were extremely high. Combination therapy of PELI, firstly reported in our department, and IVR (PELI and IVR, lipiodol-targetting IVR) was performed twice for the treatment. PELI could effectively visualize the location of the tumor for IVR treatment and show the presence of a thin blood vessel branching from the right hepatic artery flowing into the lipiodol deposit. After treatment, the serum levels of AFP and AFP-L3 were rapidly decreased to normal and maintained for more than eight months. Thus, this case expressing the tremendous effect might give us insight into the effectiveness of the novel combination therapy of PELI and IVR for the treatment of hypovascular HCC.

Thoracoscopic ethanol injection and radiofrequency ablation for the treatment of hepatocellular carcinoma located immediately under the diaphragm.

We previously reported that the combination therapy of percutaneous ethanol injection and radiofrequency ablation (PEI-RFA) was more effective than RFA alone in inducing wider coagulated necrosis for the treatment of hepatocellular carcinoma (HCC). In the present study, we thoracoscopically applied the combination therapy to the treatment of HCC located immediately under the diaphragm. RFA electrode and ethanol injection needle were inserted into the tumor through the right side of the diaphragm in 6 patients with HCC close to the diaphragm. In all cases, the tumor was completely ablated with enough safety margin around the tumor. No local tumor recurrence has been observed in a relatively short-time follow-up period. The volume of coagulated necrosis and the energy requirement for coagulation in thoracoscopic ethanol injection and RFA (T-EI-RFA) were comparable to those of PEI-RFA. Although HCC located immediately under the diaphragm is difficult to treat with a percutaneous approach due to the poor visualization by ultrasonography, T-EI-RFA is considered to be an effective treatment modality.

Time-lag performance of radiofrequency ablation after percutaneous ethanol injection for the treatment of hepatocellular carcinoma.

We have previously reported that the combination therapy of percutaneous ethanol injection and radiofrequency ablation (PEI-RFA) was more effective than RFA alone to induce wider coagulated necrosis for the treatment of hepatocellular carcinoma (HCC). In the present study, the effect of time-lag performance of RFA after PEI was evaluated under the same ablation condition as PEI-RFA by analyzing the volume of coagulated necrosis, the energy requirement for ablation and the amount of ethanol injected into HCC. The comparative study between time-lag PEI-RFA and no time-lag PEI-RFA showed that the total energy requirement and the energy requirement per unit volume for whole and marginal coagulated necrosis were significantly smaller in the time-lag group than in the no time-lag PEI-RFA group. In time-lag PEI-RFA, the volume of coagulated necrosis induced positively correlated with the amount of ethanol injected into HCC as previously observed in PEI-RFA treatment. These results suggest that time-lag PEI-RFA can induce comparable coagulated necrosis with a smaller energy requirement than no time-lag PEI-RFA, and that time-lag PEI-RFA is likely to be less invasive than no time-lag PEI-RFA for inducing comparable coagulated necrosis. Thus, time-lag performance of RFA after PEI may make RFA treatment more effective and less invasive for the treatment of patients with HCC.

Successful treatment of large-size advanced hepatocellular carcinoma by transarterial chemoembolization followed by the combination therapy of percutaneous ethanol-lipiodol injection and radiofrequency ablation.

We report a case of large-size hepatocellular carcinoma (HCC) successfully treated with transarterial chemoembolization (TACE) followed by the combination therapy of percutaneous ethanol-lipiodol injection and radiofrequency ablation (PELI-RFA) and percutaneous ethanol-lipiodol injection (PELI) therapy. In the present case, the patient had a large-size advanced HCC, 7 cm in diameter, located in the S8 region of the liver. In addition, the hepatic reserve of the patient was severely poor. In order not to impair the poor hepatic reserve, we chose PELI-RFA and PELI, originally developed in our department and reported as milder treatment modalities than others. After TACE , PELI-RFA and PELI were performed several times, the HCC was totally destroyed and early enhancement shown by helical dynamic computed tomography disappeared completely after treatment. The hepatic reserve of the patient was not impaired by the series of treatments. Serum levels of tumor markers, alpha-fetoprotein and Des-gamma-carboxy prothrombin, were rapidly decreased to almost normal levels. PELI-RFA and PELI may be effective for the treatment of large-size HCC of patients with poor hepatic reserve.

Usefulness of liver infiltrating CD86-positive mononuclear cells for diagnosis of autoimmune hepatitis.

AIM: Although the pathogenic mechanism underlying autoimmune hepatitis (AIH) remains unclear, the immune system is thought to be critical for the progression of the disease. Cellular immune responses may be linked to the hepatocellular damage in AIH. Recently, much attention has been focused on the critical functions of costimulatory molecules expressed on mononuclear cells in the generation of effective T cell-mediated immune responses. Analysis of costimulatory molecule expressed on mononuclear cells from the patients with AIH may give us insight into the pathogenic mechanism of hepatocellular damage in AIH. METHODS: Peripheral blood mononuclear cells (PBMC) were taken from the patients with AIH (34 cases) and healthy controls (25 cases). Liver infiltrating mononuclear cells (LIMCs) were taken from the patients with AIH (18 cases), the patient with chronic hepatitis C (CH-C) (13 cases) and the patients with fatty liver (2 cases). Using flow cytometry, the cells were analyzed for the expression of costimulatory molecules, such as CD80, CD86, and CD152 (CTLA-4). The results were compared with clinical data such as the level of gammaglobulin, histological grade, presence or absence of corticosteroids administration and the response to corticosteroids. RESULTS: The levels of CD80+, CD86+ and CD152+ PBMC were significantly reduced in the patients with AIH as compared with healthy controls. By contrast, those cells were significantly higher in LIMC than in PBMC of the patients with AIH. Especially, the level of CD86+ LIMC showed a marked increase irrespective of the degree of disease activity in the patients with AIH, although CD86+ cells were rarely present in PBMC. The levels of CD86+ cells were present in significantly higher frequency in patients with AIH than in the patients with CH-C. Furthermore, the patients with AIH with high levels of CD86+ LIMC showed good responses to corticosteroids, whereas 2 cases of AIH with low levels of CD86+ LIMC did not respond well. CONCLUSION: These results suggest that LIMC over-expressing costimulatory molecules such as CD80 and CD86 appears to play a role in the pathogenesis of AIH. Especially, CD86 molecule expressed on the LIMC may be useful for the diagnosis of AIH and for the prediction of the therapeutic effects of corticosteroids on AIH.

Antitumor effects of vitamins K1, K2 and K3 on hepatocellular carcinoma in vitro and in vivo.

A number of studies have shown that various K vitamins, specifically vitamins K2 and K3, possess antitumor activity on various types of rodent- and human-derived neoplastic cell lines. In the present study, we examined the antitumor effects of vitamins K1, K2 and K3 on PLC/PRF/5 human hepatocellular carcinoma (HCC) cells in vitro and in vivo. Furthermore, we examined the mechanisms of antitumor actions of these vitamins in vitro and in vivo. Although vitamin K1 did not inhibit proliferation of PLC/PRF/5 cells at a 90-microM concentration (the highest tested), vitamins K2 and K3 suppressed proliferation of the cells at concentrations of 90 and 9 microM, respectively. By flow cytometric analysis, it was shown that not only vitamin K1, but also vitamin K2 did not induce apoptosis or cell cycle arrest on PLC/PRF/5 cells. In contrast, vitamin K3 induced G1 arrest, but not apoptosis on PLC/PRF/5 cells. Subsequent in vivo study using subcutaneous HCC-bearing athymic nude mice demonstrated that both vitamins K2 and K3 markedly suppressed the growth of HCC tumors to similar extent. Protein expression of cyclin D1 and cyclin-dependent kinase 4 (Cdk4), but not p16INK4a Cdk inhibitor in the tumor was significantly reduced by vitamin K2 or K3 treatment, indicating that vitamins K2 and K3 may induce G1 arrest of cell cycle on PLC/PRF/5 cells in vivo. Taken collectively, vitamins K2 and K3 were able to induce potent antitumor effects on HCC in vitro and in vivo, at least in part, by inducing G1 arrest of the cell cycle. The results indicate that vitamins K2 and K3 may be useful agents for the treatment of patients with HCC.

In vitro and in vivo antitumor effects of vitamin K5 on hepatocellular carcinoma.

Although a number of studies have shown that vitamins K1, K2 and K3 exerted antitumor effects on various types of rodent- and human-derived neoplastic cell lines, it has not been examined whether or not vitamin K5 also possesses antitumor activity. In the present study, we examined the antitumor effects of vitamin K5 on PLC/PRF/5 human hepatocellular carcinoma (HCC) cells in vitro and in vivo. Furthermore, we examined the mechanisms of antitumor actions of vitamin K5 not only in vitro but also in vivo. Vitamin K5 was shown to suppress the proliferation of PLC/PRF/5 cells at a concentration of 30 microM. By a flow cytometric analysis, it was shown that although vitamin K5 did not induce apoptosis on PLC/PRF/5 cells, it did induce G1 arrest on PLC/PRF/5 cells. Subsequent in vivo study using subcutaneous HCC-bearing athymic nude mice demonstrated that vitamin K5 markedly suppressed the growth of HCC tumors. Although protein expression levels of cyclin D1 and p16INK4a cyclin-dependent kinase (Cdk) inhibitor in HCC tumors were not decreased by vitamin K5 treatment, those of Cdk4 were reduced significantly by the treatment. Taken collectively, vitamin K5 could induce potent antitumor effects on HCC not only in vitro but also in vivo, at least in part by inducing G1 arrest of cell cycle through downregulation of Cdk4 expression. The results demonstrated here indicate that vitamin K5 may be a useful agent for the treatment of patients with HCC.