Yoshio Yamaoka

AXIN1 mutations in hepatocellular carcinomas, and growth suppression in cancer cells by virus-mediated transfer of AXIN1

The Wnt signalling pathway is essential for development and organogenesis. Wnt signalling stabilizes β-catenin, which accumulates in the cytoplasm, binds to T-cell factor (TCF; also known as lymphocyte enhancer-binding factor, LEF) and then upregulates downstream genes. Mutations in CTNNB1 (encoding β-catenin) or APC (adenomatous polyposis coli) have been reported in human neoplasms including colon cancers and hepatocellular carcinomas (HCCs). Because HCCs tend to show accumulation of β-catenin more often than mutations in CTNNB1 , we looked for mutations in AXIN1, encoding a key factor for Wnt signalling, in 6 HCC cell lines and 100 primary HCCs. Among the 4 cell lines and 87 HCCs in which we did not detect CTNNB1 mutations, we identified AXIN1 mutations in 3 cell lines and 6 mutations in 5 of the primary HCCs. In cell lines containing mutations in either gene, we observed increased DNA binding of TCF associated with β-catenin in nuclei. Adenovirus mediated gene transfer of wild-type AXIN1 induced apoptosis in hepatocellular and colorectal cancer cells that had accumulated β-catenin as a consequence of either APC, CTNNB1 or AXIN1 mutation, suggesting that axin may be an effective therapeutic molecule for suppressing growth of hepatocellular and colorectal cancers.

Surgical techniques and innovations in living related liver transplantation.

The authors successfully performed a series of 33 living related liver transplantations (LRLT) on children (15 males and 18 females, ranging from 7 months to 15 years of age) from June 1990 to May 1992, with the informed consent of their parents and the approval of the Ethics Committee of Kyoto University. Before operation, six of the children required intensive care, another 14 were hospitalized, and 13 were homebound. Donors (12 paternal and 21 maternal) were selected solely from the parents of the recipients on the basis of ABO blood group and graft/recipient size matching determined by computed tomography scanning. Procurement of graft was performed using ultrasonic aspirator and bipolar electrocautery without blood vessel clamping and without graft manipulation. All donors subsequently had normal liver function and returned to normal life. The left lateral segment (16 cases), left lobe (16 cases), or right lobe (one case) were used as grafts. The partial liver graft was transplanted into the recipient who underwent total hepatectomy with preservation of the inferior vena cava using a vascular side clamp. Twenty-seven of 33 recipients are alive and well with the original graft and have normal liver function. The patient survival rate was 89% (24/27) in elective cases and 50% (3/6) in emergent cases. The other six recipients had functioning grafts but died of extrahepatic complications. Complications of the graft were minimal in all cases. Hepatic vein stenosis, which occurred three times in two cases, was successfully treated by balloon dilatation. In cases with sclerotic portal vein, the authors anastomosed the portal vein of the graft to the confluence of the splenic vein and the superior mesenteric vein without a vascular graft, after experiencing a case of vascular graft thrombosis. After hepatic artery thrombosis occurred in one of the initial seven recipients whose arterial anastomosis was done with surgical loupe, microsurgery was introduced for hepatic artery reconstruction. There has been no occurrence of thrombosis since then. The current results with LRLT suggested that the meticulous management of surgical factors at each stage of the LRLT procedure is crucial for successful outcome. Living related liver transplantation is a promising option for resolving the graft shortage in pediatric liver transplantation and may be regarded as an independent modality to supplement cadaver donation.

Tumor size predicts vascular invasion and histologic grade : Implications for selection of surgical treatment for hepatocellular carcinoma

Vascular invasion and high histologic grade predict poor outcome after surgical resection or liver transplantation for hepatocellular carcinoma (HCC). Despite the known association between tumor size and vascular invasion, a proportion of patients with large tumors can be treated surgically with excellent outcomes. Clarification of the association between tumor size, histologic grade, and vascular invasion has implications for patient selection for resection and transplantation. The objective of this study was to examine the relationship between HCC tumor size and microscopic (occult) vascular invasion and histologic grade in a multicenter international database of 1,073 patients who underwent resection of HCC. The incidence of microscopic vascular invasion increased with tumor size (≤3 cm, 25%; 3.1‐5 cm, 40%; 5.1‐6.5 cm, 55%; >6.5 cm, 63%) (P < 0.005). Both size and number of tumors were important factors predicting vascular invasion. Among all patients with tumors 5.1 to 6.5 cm, microscopic vascular invasion was present in 55% compared with 31% for all patients with tumors 5 cm or smaller (P < 0.001). Among patients with solitary tumors only, microscopic vascular invasion was significantly more common in tumors measuring 5.1 to 6.5 cm (41%) compared with 27% of tumors 5 cm or smaller (P < 0.003). Tumor size also predicted histologic grade: 36% of tumors 5 cm or smaller were high grade, compared with 54% of lesions 5.1 to 6.5 cm (P = 0.01). High histologic grade, an alpha‐fetoprotein level of at least 1000 ng/mL, and multiple tumor nodules each predicted occult vascular invasion in tumors larger than 5 cm. The high incidence of occult vascular invasion and advanced histologic grade in HCC tumors larger than 5 cm, as well as biologic predictors of poor prognosis, should be considered before criteria for transplantation are expanded to include these patients. (Liver Transpl 2005;11:1086–1092.)

Reevaluation of prognostic factors for survival after liver resection in patients with hepatocellular carcinoma in a Japanese nationwide survey

Advances in the diagnosis and surgical treatment of hepatocellular carcinoma (HCC) have improved the prognosis for patients with HCC who undergo liver resection. The objective of this study was to evaluate prognostic predictors for patients with HCC who underwent liver resection in a Japanese nationwide data base.

Adult T cell leukemia-derived factor/human thioredoxin protects endothelial F-2 cell injury caused by activated neutrophils or hydrogen peroxide.

Adult T cell leukemia-derived factor (ADF), originally defined as an interleukin 2 receptor/alpha (alpha) chain inducer produced by human T-lymphotropic virus type-I transformed cells, is identical to human thioredoxin (TRX). In this study, the protective effect of ADF/TRX on the cytotoxicity of endothelial cells caused by phorbol myristate acetate (PMA)-activated neutrophils or hydrogen peroxide (H2O2) was examined. When murine endothelial F-2 cells established from an ultraviolet light-induced tumor on a nude mouse were incubated with PMA-activated neutrophils or with 1 mM H2O2 for 6 hours, the cytotoxicity of F-2 cells was respectively 51 +/- 4% or 40 +/- 8% by the 51Cr releasing assay. Recombinant ADF/TRX (rADF/TRX) inhibited this cytotoxicity in a dose-dependent manner, although mutant ADF/TRX (cysteine 31 to serine), 2-mercaptoethanol and dithiothreitol did not. On a molar basis, rADF/TRX was more effective than glutathione but less effective than catalase. Immunoblotting analysis showed that treatment with 0.1 mM H2O2 induced murine TRX on F-2 cells. These findings indicate that ADF/TRX is an oxidative stress-inducible endogenous protein and rADF/TRX plays a protective role against activated neutrophils- or H2O2-induced endothelial cytotoxicity.

Ischemic preconditioning of the liver in rats: Implications of heat shock protein induction to increase tolerance of ischemia-reperfusion injury

It has been reported that ischemic preconditioning of the heart or brain has a possible relevance to heat shock protein (HSP). It is still unknown, however, whether HSP induced by means of ischemic preconditioning of the liver is a direct factor in the acquisition of tolerance to succeeding ischemia-reperfusion injury. In the present study we used ischemic preconditioning of the liver to verify the effects of induced HSP72 in the liver on the subsequent longer warm ischemia and reperfusion. Rats preconditioned with short-term (15-minute) ischemia were compared with rats preconditioned by heat exposure or with control rats. After a 48-hour recovery from the sublethal stress for preconditioning, all rats were exposed to longer (30-minute) warm ischemia and reperfusion. Forty-eight hours after ischemic preconditioning, HSP72 was clearly induced in the liver, as well as in the liver preconditioned with heat shock, but not in the kidney or heart. This ischemic preconditioning also attenuated the liver damage in the subsequent ischemia-reperfusion injury, improving the restoration of hepatic function during reperfusion and resulting in higher postischemic rat survival. According to the proposed model of tolerance acquisition for ischemia-reperfusion injury by stress preconditioning, these observations support the speculation that the induced HSP72 plays some beneficial role in this protection mechanism.

Pivotal Role of CXCR3 in Melanoma Cell Metastasis to Lymph Nodes

Chemokines and their receptors play key roles in leukocyte trafficking and are also implicated in cancer metastasis to specific organs. Here we show that mouse B16F10 melanoma cells constitutively express chemokine receptor CXCR3, and that its ligands CXCL9/Mig, CXCL10/IP-10, and CXCL11/I-TAC induce cellular responses in vitro, such as actin polymerization, migration, invasion, and cell survival. To determine whether CXCR3 could play a role in metastasis to lymph nodes (LNs), we constructed B16F10 cells with reduced CXCR3 expression by antisense RNA and investigated their metastatic activities after s.c. inoculations to syngeneic hosts, C57BL/6 mice. The metastatic frequency of these cells to LNs was markedly reduced to ∼15% (P < 0.05) compared with the parental or empty vector-transduced cells. On the other hand, pretreatment of mice with complete Freund’s adjuvant increased the levels of CXCL9 and CXCL10 in the draining LNs, which caused 2.5–3.0-fold increase (P < 0.05) in the metastatic frequency of B16F10 cells to the nodes with much larger foci. Importantly, such a stimulation of metastasis was largely suppressed when CXCR3 expression in B16F10 cells was reduced by antisense RNA or when mice were treated with specific antibodies against CXCL9 and CXCL10. We also demonstrate that CXCR3 is expressed on several human melanoma cell lines as well as primary human melanoma tissues (5 of 9 samples tested). These results suggest that CXCR3 inhibitors may be promising therapeutic agents for treatment of LN metastasis, including that of melanoma.

Is Hepatic Resection for Large or Multinodular Hepatocellular Carcinoma Justified? Results From a Multi-Institutional Database

BackgroundThe role of surgical resection in patients with large or multinodular hepatocellular carcinoma (HCC) remains unclear. This study evaluated the long-term outcome of patients with hepatic resection for large (>5 cm in diameter) or multinodular (more than three nodules) HCC by using a multi-institutional database.MethodsThe perioperative and long-term outcomes of 404 patients with small HCC (<5 cm in diameter; group 1) were compared with those of 380 patients with large or multinodular HCC (group 2). The prognostic factors in the latter group were analyzed.ResultsThe postoperative complication rate (27% vs. 23%; P = .16) and hospital mortality rate (2.4% vs. 2.7%; P = .82) were similar between groups. The overall survival rates were significantly higher in group 1 than group 2 (1 year, 88% vs. 74%; 3 years, 76% vs. 50%; 5 years, 58% vs. 39%; P < .001). Among patients in group 2, five independent prognostic factors were identified to be associated with a worse overall survival: namely, symptomatic disease, presence of cirrhosis, multinodular tumor, microvascular tumor invasion, and positive histological margin.ConclusionsHepatic resection can be safely performed in patients with large or multinodular HCC, with an overall 5-year survival rate of 39%. Symptomatic disease, the presence of cirrhosis, a multinodular tumor, microvascular invasion, and a positive histological margin are independently associated with a less favorable survival outcome.

Underlying liver disease, not tumor factors, predicts long-term survival after resection of hepatocellular carcinoma

HYPOTHESIS A subset of patients can be identified who will survive without recurrence beyond 5 years after hepatic resection for hepatocellular carcinoma (HCC). DESIGN A retrospective review of a multi-institutional database of 591 patients who had undergone hepatic resection for HCC and on-site reviews of clinical records and pathology slides. SETTING All patients had been treated in academic referral centers within university-based hospitals. PATIENTS We identified 145 patients who had survived for 5 years or longer after hepatic resection for HCC. MAIN OUTCOME MEASURES Clinical and pathologic factors, as well as scoring of hepatitis and fibrosis in the surrounding liver parenchyma, were assessed for possible association with survival beyond 5 years and cause of death among the 145 five-year survivors. RESULTS Median additional survival duration longer than 5 years was 4.1 years. Women had significantly longer median additional survival durations than did men (81 months vs 38 months, respectively, after the 5-year mark) (P =.008). Surgical margins, type of resection, an elevated preoperative alpha-fetoprotein level, and the presence of multiple tumors or microscopic vascular invasion had no bearing on survival longer than 5 years. However, patients who survived for 5 years who also had normal underlying liver or minimal fibrosis (score, 0-2) at surgery had significantly longer additional survival than did patients with moderate fibrosis (score, 3-4) or severe fibrosis/cirrhosis (score, 5-6) (P<.001). CONCLUSIONS Death caused by HCC is rare beyond 5 years after resection of HCC in the absence of fibrosis or cirrhosis. The data suggest that chronic liver disease acts as a field of cancerization contributing to new HCC. These patients may benefit from therapies directed at the underlying liver disease.

Preoperative Predictors of Survival After Resection of Small Hepatocellular Carcinomas

ObjectiveTo determine preoperative predictors of survival that can guide the choice of treatment for patients with small hepatocellular cancers (HCCs). Summary Background DataThe treatment of patients with small (≤5 cm in diameter) HCCs is controversial. MethodsA cohort of 249 patients (69 women, 180 men; median age 62 years) who underwent resection with curative intent for small HCC was identified from a multiinstitutional database. For each patient, the clinical data and pathology slides were reviewed. Six clinical factors (age, gender, preoperative &agr;-fetoprotein level, hepatitis serology, number of tumors [single vs. multiple], and Child-Pugh score) and three pathologic factors (hepatitis activity score, fibrosis score, and Edmondson-Steiner tumor grade) that can be determined before surgery were correlated with survival. Log-rank tests and Cox proportional hazards modeling were used to determine factors influencing survival. ResultsThe median overall survival for the entire cohort was 4.2 years. The estimated overall 5- and 8-year survival rates were 41.1% and 19.8%, respectively. Multivariate Cox analysis indicated that fibrosis score, Edmondson-Steiner grade, and Child-Pugh score were simultaneously significant predictors of survival after resection. A prognostic scoring system based on these covariates was derived and applied to the entire cohort. Patients lacking all three risk factors were assigned a score of 1, patients with one risk factor were assigned a score of 2, and patients with two or three risk factors were assigned a score of 3. Pairwise log-rank tests indicated significant differences in survival between scores 1 and 2, scores 2 and 3, and scores 1 and 3. This scoring system retained its prognostic significance when a subset of 98 patients with positive hepatitis C serology was analyzed separately. ConclusionsPatients with small HCCs who will derive the least benefit from resection can be identified before surgery using a score based on tumor grade and the severity of underlying liver disease. In these patients, transplantation and/or ablation should be considered as possible alternative therapies.