Protein-bound polysaccharide-K reduces colitic tumors and improves survival of inflammatory bowel disease in vivo.

Protein-bound polysaccharide-K (PSK) is a biological response modifier that possesses antitumor effects against various tumors. Although an inflammatory response has been considered to play an important role in the development of colorectal cancer, the anti-inflammatory effect of PSK has yet to be elucidated. An inflammatory bowel disease (IBD)-induced colorectal tumor model with 1.2-dimethyl hydrazine (DMH) and dextran sodium sulfate (DSS) was used to examine the effects of PSK on tumor suppression and survival. Although 90% of the mice that were not treated with PSK developed colitic tumors, oral administration of PSK suppressed tumor formation by less than 30%. Although deaths associated with DSS-induced melena were observed, PSK significantly reduced mortality. In conclusion, the present study showed that PSK not only suppressed colorectal tumor formation in the DMH+DSS-induced IBD model, but also improved the survival rate, indicating that anti-inflammatory activity is one of the mechanisms for the antitumor effects of PSK.

Antineoplastic effects of gamma linolenic Acid on hepatocellular carcinoma cell lines.

The aim of this study was to investigate the effect and the mechanism of gamma linolenic acid (GLA) treatment on human hepatocellular (HCC) cell lines. The human HCC cell line HuH7 was exposed to GLA. Cell proliferation and reactive oxygen species (ROS) generation including lipid peroxidation and apoptosis were compared. We then used a cDNA microarray analysis to investigate the molecular changes induced by GLA. GLA treatment significantly reduced cell proliferation, generated ROS, and induced apoptosis. After 24 h exposure of Huh7 cells to GLA, we identified several genes encoding the antioxidant proteins to be upregulated: heme oxygenase-1 (HO-1), aldo-keto reductase 1 family C1 (AKR1C1), C4 (AKR1C4), and thioredoxin (Trx). The HO-1 protein levels were overexpressed in Huh7 cells after GLA exposure using a Western blot analysis. Furthermore, chromium mesoporphyrin (CrMP), an inhibitor of HO activity, significantly potentiated GLA cytotoxicity. GLA treatment has induced cell growth inhibition, ROS generation including lipid peroxidation, and HO-1 production for antioxidant protection against oxidative stress caused by GLA in Huh7 cells. GLA treatment should be considered as a therapeutic modality in patients with advanced HCC.

Clinical significance of histone deacetylase 1 expression in patients with hepatocellular carcinoma.

OBJECTIVE: Histone deacetylases (HDACs) play an important role in chromatin remodeling, gene repression and regulating cell cycle progression and differentiation. This study was designed to clarify the role of HDAC1 expression in hepatocellular carcinoma (HCC). METHOD: The expression of HDAC1 in 47 patients with surgically resected HCC was immunohistochemically examined and analyzed in relation to their clinicopathological factors. The patients were divided into two groups according to the expression status of HDAC1: a high HDAC1 group (n = 25) with more than 20% of positively stained cells and a low HDAC1 group (n = 22) with 20% or fewer positively stained cells. RESULTS: A high HDAC1 expression indicated a higher incidence of cancer cell invasion into the portal vein, a poorer histological differentiation, and a more advanced TNM stage. The survival rates after a surgical resection in low and high HDAC1 patients at 1, 3, 5 and 10 years were 100, 95.5, 81.8 and 60.8% and 88.0, 60.0, 40.0 and 32.0%, respectively (p = 0.008). A multivariate analysis using the Cox regression analysis showed that a high HDAC1 expression was an independent prognostic factor of HCC in patients after hepatic resection (relative risk: 10.1, p = 0.0018). CONCLUSIONS: High HDAC1 expression might have an important role in the aggressiveness and cell dedifferentiation, and its expression status may be a useful biomarker for predicting the outcome of the patients with HCC.

Increase in both CEA and CA19-9 in sera is an independent prognostic indicator in colorectal carcinoma.

BACKGROUND AND OBJECTIVES: Carcinoembryonic antigen (CEA) and carbohydrate antigen (CA19-9) are well known to be the most common tumor markers of colorectal carcinomas. However, the significance of increase in these markers to predict the prognosis of the patients remains a problem for debate. METHODS: One hundred three patients with colorectal carcinoma, who had been treated by resection and reconstruction of digestive tracts were studied. Correlation of preoperative serum value of CEA and CA19-9 with clinicopathologic features including prognosis of the patients was investigated. RESULTS: Preoperative elevation of both of the two markers proved to be an independent prognostic indicator, however, an elevation of only one of the two markers did not obtain a prognostic significance. CONCLUSIONS: Combined data of preoperative increase in CEA and CA19-9 in sera can provide a powerful and useful information to predict prognosis of patients with colorectal carcinoma.

Role of tissue trace elements in liver cancers and non-cancerous liver parenchyma.

BACKGROUND/AIMS: The role of trace elements in liver fibrosis, carcinogenesis and progression of hepatocellular carcinoma (HCC) has not yet been clarified. The aim of this study is to analyze the characteristics of trace elements in liver cancers and non-cancerous liver and to discuss their role in hepatic fibrosis, hepatocarcinogenesis and progression of HCC. METHODOLOGY: The amount of zinc (Zn), iron (Fe), and copper (Cu) in 20 HCCs, 2 cholangiocellular carcinomas (CCC), 7 metastatic liver cancers (Meta) and their non-tumorous liver parenchyma were measured using an atomic absorption spectrophotometer. RESULTS: The amounts of Zn and Fe in non-tumorous liver parenchyma were reduced by liver fibrosis, and the amounts were lower in HCC tissue compared to non-tumorous liver parenchyma. The amounts of Zn and Cu were higher in HCC than the amounts found in CCC and Meta. The amount of Zn in HCC tissue decreased, but the amount of Fe increased in tumors more than 4cm in diameter. CONCLUSIONS: These results suggest that the decrease in the amount of Zn and Fe found in non-tumorous liver parenchyma correlates with liver fibrosis leading to cirrhosis and hepatocarcinogenesis. Also that decreases in Zn and increases of Fe in HCC tissue correlates with HCC tumor progression.

Effect of dietary conjugated linoleic acid on liver regeneration after a partial hepatectomy in rats.

We examined the effect of dietary conjugated linoleic acid (CLA) on liver regeneration after a partial hepatectomy (PH) in Sprague-Dawley rats. PH was performed on rats fed a 0 or 1 wt.% CLA diet for 3 wk. Average liver weight in the CLA fed rat population was heavier than the control rat population at the time of PH and 1-d after PH. Conversely. CLA fed rats' liver weight was significantly lower than control rats at 7-d after PH. This suggests that dietary CLA reduced liver weight gain after PH. Dietary CLA did not affect serum aspartate aminotransferase (AST) or alanine aminotransferase (ALT) activities. However. CLA significantly reduced serum albumin levels at 1-d but not at 7-d after PH. 5-Bromo- and 5-iododeoxyuridine incorporation into hepatocytes 1-d post PH was lower in the CLA group. In conclusion, the data suggests that dietary CLA inhibits DNA synthesis after PH, which results in hepatocyte proliferation inhibition.

Antioxidant and anti-inflammatory effects of a diet supplemented with sesamin on hepatic ischemia-reperfusion injury in rats.

BACKGROUND/AIMS: The antioxidant and anti-inflammatory properties of sesamin (a non-fat constituent of sesame oil) have been attributed to an increased accumulation of dihomo-y-linolenic acid, a precursor of 1-series prostaglandins, and the decreasing production of proinflammatory 2-series prostaglandins and 4-series leukotrienes by inhibiting the delta-5 desaturase activity. We investigated the effects of a diet containing sesamin on hepatic ischemia-reperfusion injury in rats. METHODOLOGY: After feeding rats either a basal diet (control group) or a diet supplemented with sesamin (sesamin group) for 14 days, the rats underwent 60 minutes of partial hepatic ischemia and 3 hours of reperfusion. The phospholipid fatty acid composition of both liver and lung tissue specimens were then analyzed. The plasma levels of leukotriene B4 and PCOOH (phosphatidylcholine hydroperoxide) were also determined. RESULTS: The consumption of the dietary sesamin resulted in a significant increase in the dihomo-y-linolenic acid content in the tissue phospholipids of the liver and lung specimens. The amounts of polyunsaturated fatty acids in the lungs subjected to the ischemia-reperfusion injury were well preserved in the animals from the sesamin group. Despite a lack of differences in the levels of arachidonic acid, the plasma levels of leukotriene B4 in the rats fed dietary sesamin (88 +/- 15 pg) tended to be lower (P = 0.07) than those fed the control diet (110 +/- 20 pg). Furthermore, the plasma concentrations of PCOOH in the sesamin group (130 +/- 62 pmol) were also significantly lower (P < 0.05) than those in the control group (223 +/- 33 pmol). CONCLUSIONS: These findings indicate that a diet containing sesamin may thus reduce hepatic ischemia-reperfusion injury by inducing both antioxidant and anti-inflammatory activities.

The role of MTA1 gene expression in human hepatocellular carcinoma.

The MTA1 gene has been identified as metastasis-associated gene and has been seen to correlate with the degree of invasion and lymphatic metastasis in gastric, colorectal, and esophageal carcinomas. We investigated the possible role of MTA1 gene expression in hepatocellular carcinoma (HCC). The mRNA expression level of the MTA1 gene was examined using reverse transcription polymerase chain reaction (RT-PCR) in HCC and paired non-tumor liver tissues which were obtained from 33 patients who underwent curative hepatectomy. The expression level of each case was calculated as tumor/non-tumor (T/N) ratios. To clarify the clinical significance of MTA1 gene expression in HCC, patient disease-free survival rate after hepatectomy were univariately analyzed using 25 clinicopathological variables, including MTA1 expression level. High expression (T/N > or =1) of the MTA1 gene in HCC as compared to the paired non-tumor tissues was recognized in 14 of 33 (42%) samples. With regard to the differentiation of HCC, the high expression of MTA1 gene in well or moderately differentiated HCC and poorly differentiated HCC were observed in 9 of 27 (33%) and 5 of 6 (83%) samples, respectively. There was no relation between expression levels of the MTA1 gene and cancer invasion to the portal vein or intrahepatic metastasis. However, the disease-free survival rate of the MTA1-high expression group (T/N > or =1) was significantly lower than that of the MTA1-low expression group (T/N <1) (p<0.05). High expression of the MTA1 gene is suggested to be a new prognostic indicator after curative hepatectomy for HCC.

Histone deacetylase inhibitor trichostatin A induces cell-cycle arrest/apoptosis and hepatocyte differentiation in human hepatoma cells.

Remodeling of the chromatin template by inhibition of HDAC activities represents a potential transcriptional therapy for neoplastic disease. A number of HDAC inhibitors that modulate in vitro cell growth and differentiation have been developed. We analyzed the effects of TSA, a specific and potent HDAC inhibitor, on the human hepatoma cell lines HepG2 and Huh-7. TSA increased levels of acetylated histones H3 and H4 in both HepG2 and Huh-7. It inhibited cell proliferation in vitro and induced G(0)/G(1) arrest in HepG2 and apoptosis in Huh-7. Gene expression of liver-specific functions and liver-enriched transcription factors was upregulated by TSA. TSA upregulated the ammonia removal rate and the albumin synthesis rate of HepG2 and Huh-7. Our results indicate that TSA can induce cell-cycle arrest/apoptosis and hepatocyte differentiation in human liver cancer cell lines.

Potent cytotoxic effect of the trans10, cis12 isomer of conjugated linoleic acid on rat hepatoma dRLh-84 cells.

We evaluated the cytotoxic effect of conjugated linoleic acid (CLA) on rat hepatoma dRLh-84 cells in vitro. When cells were cultured in the presence of CLA, strong cytotoxic effect on dRLh-84 cells was recognized at 1 microM level compared to the control vehicle group, and trans10, cis12-CLA but not cis9, trans11-CLA was shown to be an active isomer for inducing this effect. Increase of the sub-G1 population and activation of caspase-3 and 9 accompanied with a time-dependent cleavage of poly(ADP-ribose) polymerase were recognized in dRLh-84 cells treated with trans10, cis12-CLA. In addition, we could see nuclear fragmentation in dRLh-84 cells treated with trans10, cis12-CLA by laser scanning confocal microscopy observation. Cytotoxic effect of trans10, cis12-CLA on normal hepatocytes was weaker than on dRLh-84 cells. These data indicate trans10, cis12-CLA has a potent cytotoxic effect on dRLh-84 cells through at least in part by an apoptotic pathway.

The mechanisms of angiogenesis in hepatocellular carcinoma: angiogenic switch during tumor progression.

Solid tumors constantly require a vascular supply for their progression and metastasis. Hepatocellular carcinoma (HCC) is known to gain its hypervascularity during the process of dedifferentiation and progression. Various angiogenic growth factors and inhibitors regulate this angiogenic switch of HCC. The known endothelial cell-specific growth factors and their receptors can be classified into the vascular endothelial growth factor and angiopoietin families. Both vascular endothelial growth factors and angiopoietins have been found to work cooperatively, and both are essential for HCC angiogenesis. Because small and ill-vascularized HCCs slowly progress and only rarely metastasize, antiangiogenic therapy could therefore be a promising anticancer strategy for HCC.

Clinicopathologic risk factors for recurrence after a curative hepatic resection for hepatocellular carcinoma.

BACKGROUND: The long-term prognosis after resection for patients with hepatocellular carcinoma is still unsatisfactory because of the high recurrence rate. The survival of patients with multiple intrahepatic or extrahepatic recurrence is especially poor. METHODS: Among the patients who underwent hepatic resection for hepatocellular carcinoma between 1981 and 2000, 216 patients with 3 or less than 3 intrahepatic recurrences (group B); 156 patients with more than 3 intrahepatic recurrences, extrahepatic recurrences, or both (group C); and 51 patients who survived more than 5 years without recurrence (group A) were clinicopathologically studied. RESULTS: The period to recurrence of group C was significantly earlier than that of group B and also showed a significantly poor prognosis after recurrence. Tumor factors, including size, portal venous invasion, intrahepatic metastasis, histologic grade, or the number of tumors at resection in group C was significantly worse than in groups A and B. Although no differences are recognized in the tumor factors between groups A and B, except for the alpha-fetoprotein level, liver function in group B was significantly worse than that in group A. In addition, the frequency of hepatitis B surface antigen in group B and that of hepatitis C virus in group B was significantly less and higher than that in group A, respectively. CONCLUSION: Similar to extrahepatic metastasis, multinodular recurrences are also mainly caused by metastatic recurrence from the main tumor by means of the portal system, and recurrences with up to 3 intrahepatic nodules are mainly caused by metachronous multicentric hepatocarcinogenesis. Because the mechanisms of recurrence differed, determining the patterns of recurrence on the basis of the clinicopathologic findings is important for selecting the optimal postoperative therapy for each individual patient.

Minimally invasive hepatectomy: modulation of systemic reactions to operation or laparoscopic approach?

BACKGROUND: A new concept of surgical stress has been proposed that consists of both aggressiveness of operation and systemic reactions to an operation. METHODS AND RESULTS: We have investigated a possible modulation of such systemic reactions to operation and have demonstrated the following 3 points: (1) coagulation and fibrinolytic systems are independently activated during hepatectomy and such activation can be modulated by protease inhibitors such as nafamostat mesilate and antithrombin III; (2) elevated thromboxane A2 during hepatectomy is characterized in the prostanoid system, the elevation of thromboxane A2 is inhibited by thromboxane A2 synthetase inhibitor, and postoperative liver injury is reduced; (3) cytokine response induced by hepatectomy is modulated by preoperative administration of methylprednisolone, leading to possible prevention of bacterial translocation. Therefore, modulating systemic reactions to hepatectomy may be important for successful minimally invasive hepatectomy. Another important option for minimally invasive hepatectomy is the use of operative procedures such as laparoscope or thoracoscope. We have investigated the usefulness of a laparoscopic hepatectomy from the standpoints of early and long-term outcome after hepatectomy. Laparoscopic hepatectomy, which is a difficult and dangerous procedure, can be a feasible option and can result in better short-term outcome and a similar long-term outcome after hepatectomy when compared with conventional open hepatectomy. Therefore, the laparoscopic approach is also a viable option for minimally invasive hepatectomy. CONCLUSIONS: Modulation of systemic reactions to the operation itself and laparoscopic hepatectomy may be new strategies for performing minimally invasive hepatectomy.

Dose-dependent effect of dietary conjugated linoleic acid on the growth of rat hepatoma dRLh-84 cells in vivo.

In this study, the effect of varying doses of conjugated linoleic acid (CLA) on the growth of transplanted hepatoma dRLh-84 cells and the relationship between tumor growth and prostaglandin (PG) E2 production or cyclooxygenase (COX)-2 expression were examined. Donryu rats were fed an experimental diet containing 0, 0.1, 0.5, or 2 wt.% CLA for 3 wk, and then dRLh-84 cells were transplanted into the liver. Results show that dietary CLA (0.5 and 2 wt.%) significantly enhanced the growth of the transplanted hepatoma cells compared to the non-CLA diet group at 20 d after cell transplantation. Tumor weight at 10 d after transplantation was also significantly higher in the 2 wt.% CLA group than in non-CLA fed rats. Ten days after transplantation, the PGE2 level in the tumor tissue was shown to be depressed in a CLA dose-dependent manner. Cyclooxygenase-2 (COX-2) mRNA expression in the tumor also tended to be lower in the CLA group than in the non-CLA diet group 10 d after transplantation. Dietary CLA did not affect the tumor phospholipid arachidonic acid level, which is a substrate for PG synthesis. These results indicate that dietary CLA of at least 0.5 wt.% enhances the growth of transplanted dRLh-84 cells in vivo. It is believed that growth promotion of dRLh-84 cells in vivo by CLA cannot be clarified by the PG synthesis dependent mechanism.