Atsushi Miyamoto

Involvement of ribonucleotide reductase M1 subunit overexpression in gemcitabine resistance of human pancreatic cancer.

Pancreatic cancer is the most lethal of all solid tumors partially because of its chemoresistance. Although gemcitabine is widely used as a first selected agent for the treatment of this disease despite low response rate, molecular mechanisms of gemcitabine resistance in pancreatic cancer still remain obscure. The aim of this study is to elucidate the mechanisms of gemcitabine resistance. The 81‐fold gemcitabine resistant variant MiaPaCa2‐RG was selected from pancreatic cancer cell line MiaPaCa2. By microarray analysis between MiaPaCa2 and MiaPaCa2‐RG, 43 genes (0.04%) were altered expression of more than 2‐fold. The most upregulated gene in MiaPaCa2‐RG was ribonucleotide reductase M1 subunit (RRM1) with 4.5‐fold up‐regulation. Transfection with RRM1‐specific RNAi suppressed more than 90% of RRM1 mRNA and protein expression. After RRM1‐specific RNAi transfection, gemcitabine chemoresistance of MiaPaCa2‐RG was reduced to the same level of MiaPaCa2. The 18 recurrent pancreatic cancer patients treated by gemcitabine were divided into 2 groups by RRM1 levels. There was a significant association between gemcitabine response and RRM1 expression (p = 0.018). Patients with high RRM1 levels had poor survival after gemcitabine treatment than those with low RRM1 levels (p = 0.016). RRM1 should be a key molecule in gemcitabine resistance in human pancreatic cancer through both in vitro and clinical models. RRM1 may have the potential as predictor and modulator of gemcitabine treatment.

Expression pattern of angiogenic factors and prognosis after hepatic resection in hepatocellular carcinoma: importance of angiopoietin‐2 and hypoxia‐induced factor‐1a

Abstract: Background: Hepatocellular carcinoma (HCC) is a hypervascular tumor and angiogenesis plays an important role in its progression. Angiogenesis is regulated by a balance between pro and antiangiogenic molecules. The aim of this study was to investigate the expressions of angiogenic factors and elucidate their roles in angiogenesis in HCC.

Diagnosis of intrahepatic metastasis and multicentric carcinogenesis by microsatellite loss of heterozygosity in patients with multiple and recurrent hepatocellular carcinomas

BACKGROUND/AIMSnThe prognosis of hepatocellular carcinoma (HCC) is poor because of frequent intrahepatic metastasis (IM) or multicentric carcinogenesis (MC). We compared the effectiveness of loss of heterozygosity (LOH) analysis in the diagnosis of these two forms with that of histopathological diagnosis.nnnMETHODSnUsing LOH analysis of 15 specific DNA microsatellite loci, tumor clonality was assessed in 37 cases.nnnRESULTSnLOH was observed in 30% of seven solitary tumors. According to these results, the selected threshold to diagnose MC was a difference in the LOH status at more than 30% of the analyzed loci, when comparing two samples in the same liver. In nine multiple HCCs, identical genetic and histopathological diagnoses were found in four (IM: 2, MC: 2). Of 21 recurrent tumors, 19 showed LOH for at least one marker. IM and MC were genetically diagnosed in five and ten patients, respectively. Genetic and histopathological diagnoses were identical in ten of 19 patients (IM: 5. MC: 5). Five genetic MC were histopathologically diagnosed as IM (3) and undetermined (2).nnnCONCLUSIONSnGenetic diagnosis by LOH analysis may be more strict and specific than histopathological diagnosis in the differential diagnosis of IM and MC.

Interferon-α and 5-fluorouracil combination therapy after palliative hepatic resection in patients with advanced hepatocellular carcinoma, portal venous tumor thrombus in the major trunk, and multiple nodules

The authors reported previously the beneficial effects of interferon (IFN)‐α/5‐fluorouracil (5‐FU) combination therapy for patients with advanced hepatocellular carcinoma (HCC) who have tumor thrombi in the major portal branches. In this report, the authors describe the results from IFN/5‐FU chemotherapy for patients who underwent palliative hepatic resection for advanced HCC with tumor thrombus in the main trunk of the portal vein and multiple nodules in the whole liver. In addition, they evaluated the correlation between the response to such therapy and expression of IFN‐α type 2 receptor (IFNAR2).

Partial Contribution of Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)/TRAIL Receptor Pathway to Antitumor Effects of Interferon-α/5-Fluorouracil against Hepatocellular Carcinoma

Purpose: Our purpose was to explore the contribution of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)/TRAIL receptor pathway to antitumor effects of IFNα and 5-fluorouracil (5-FU) combination therapy for hepatocellular carcinoma (HCC). Experimental Design: Susceptibility of HCC cell lines to TRAIL and/or 5-FU was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The effects of 5-FU, IFNα, or both on the expression of TRAIL receptors (R1, R2, R3, and R4) on HCC cells or TRAIL in peripheral blood mononuclear cells (PBMC) were examined by flow cytometry. IFNα-induced cytotoxic effects of PBMC on HCC cell lines were examined by 51Cr release assay. TRAIL expression in peripheral blood mononuclear cells and liver tissue from patients was examined by real-time reverse transcription-PCR or immunohistochemistry. Results: HLE and HepG2 were sensitive to TRAIL, but HuH7, PLC/PRF/5, and HLF were resistant. 5-FU had synergistic effect on TRAIL in HLF and additive effect in four other HCC cell lines. TRAIL receptors on HCC cells were up-regulated by 5-FU, and IFNα induced TRAIL on CD4+ T cells, CD14+ monocytes, and CD56+ NK cells. Treatment of effector cells by IFNα and target HCC cells by 5-FU enhanced the cytotoxicity of CD14+ monocytes and CD56+ NK cells against HCC cells via a TRAIL-mediated pathway. TRAIL mRNA overexpression was noted in PBMC of HCC patients who clinically responded to IFNα/5-FU combination therapy, and TRAIL+ mononuclear cells were found in cancer tissue of a responder. Conclusion: Our results suggest that modulation of TRAIL/TRAIL receptor-mediated cytotoxic pathway might partially contribute to the anti-HCC effect of IFNα and 5-FU combination therapy.

Clinical and pathological features of Allen's type C classification of resected combined hepatocellular and cholangiocarcinoma: a comparative study with hepatocellular carcinoma and cholangiocellular carcinoma.

The clinical features of Allen’s type C of combined hepatocellular and cholangiocarcinoma (cHCC-CC) are not well known. In this study, we aim to define the clinicopathologic features of cHCC-CC and to evaluate the preoperative diagnosis and surgical treatment results in comparison with those of hepatocellular carcinoma (HCC) and cholangiocellular carcinoma (CCC). We retrospectively analyzed 13 patients with cHCC-CC, 509 patients with HCC, and 41 patients with CCC treated in our hospital within past two decades. Viral hepatitis B or C backgrounds were more prominent in HCC and cHCC-CC groups than in the CCC group. Elevated serum alpha-fetoprotein (AFP) levels were found in 60.3% of HCC patients and in 46.2% of cHCC-CC patients. Only one patient of cHCC-CC was correctly diagnosed before surgery. The postoperative survival rates between the cHCC-CC and HCC or the CCC group were not significantly different. Both intrahepatic and extrahepatic postoperative recurrences were frequent in cHCC-CC patients, and CCC component recurrences were more frequently seen. In conclusion, the preoperative diagnosis is difficult; liver masses similar to those of HCC, together with moderately elevated serum AFP and CA19-9 levels, are reliable indicators of cHCC-CC. Surgical resection of this tumor yields results intermediate between those of HCC and CCC in character. More cases are needed to further define the characteristics of this tumor.

Association Between Recurrence of Hepatocellular Carcinoma and α-Fetoprotein Messenger RNA Levels in Peripheral Blood

PurposeIntra- and extrahepatic recurrence is common, even after curative resection for hepatocellular carcinoma (HCC), suggesting preoperative or intraoperative tumor cell dissemination. Reverse transcription — polymerase chain reaction (RT-PCR) for α-fetoprotein (AFP) is used to detect circulating liver cancer cells. We previously developed a quantitative method that allows estimation of the AFP mRNA level by real-time PCR. In the present study, we used this method to measure the AFP mRNA level before and after resection of HCC, then correlated the findings with various clinicopathological characteristics and prognosis.MethodsWe prospectively examined peripheral blood samples from 38 patients with HCC, and bone marrow aspirate from 25 of these patients. As a control, we examined bone marrow from 20 patients with benign diseases. The follow-up period ranged from 32 to 66 months. Real-time RT-PCR was used to detect AFP mRNA levels in the samples.ResultsAFP was expressed in 9 (23.7%) of the 38 peripheral blood samples. The detection of AFP mRNA was significantly correlated with extrahepatic metastasis after primary surgery, and a shorter disease-free survival time (P = 0.0245 each). Bone marrow samples were defined as positive if they expressed AFP mRNA at levels higher than the maximum expressed level in the controls, because only 1 (5%) of the 20 control bone marrow samples had low AFP mRNA expression. Using this cutoff level, 12 (48%) of the 25 patients with HCC had positivity for AFP mRNA. The results of bone marrow RT-PCR did not correlate with the clinocopathological characteristics of prognosis.ConclusionsUsing real-time PCR to measure the AFP mRNA level in blood, but not bone marrow, could be useful for predicting postoperative tumor recurrence.

Sarcopenia is associated with severe postoperative complications in elderly gastric cancer patients undergoing gastrectomy

BackgroundMalignancy is a secondary cause of sarcopenia, which is associated with impaired cancer treatment outcomes. The aim of this study was to investigate the prevalence of preoperative sarcopenia among elderly gastric cancer patients undergoing gastrectomy and the differences in preoperative dietary intake and postoperative complications between sarcopenic and non-sarcopenic patients.MethodsNinety-nine patients over 65xa0years of age who underwent gastrectomy for gastric cancer were analyzed. All patients underwent gait and handgrip strength testing, and whole-body skeletal muscle mass was measured using a bioimpedance analysis technique based on the European Working Group on Sarcopenia in Older People (EWGSOP) algorithm for the evaluation of sarcopenia before surgery. Preoperative dietary intake was assessed using a food frequency questionnaire.ResultsOf these patients, 21 (21.2xa0%) were diagnosed with sarcopenia. Sarcopenic patients consumed fewer calories and less protein preoperatively (23.9 vs. 27.8xa0kcal/kg ideal weight/day and 0.86 vs. 1.04xa0g/kg ideal weight/day; Pxa0=xa00.001 and 0.0005, respectively). Although the overall incidence of postoperative complications was similar in the two groups (57.1xa0% vs. 35.9xa0%; Pxa0=xa00.08), the incidence of severe (Clavien–Dindo gradexa0≥xa0IIIa) complications was significantly higher in the sarcopenic group than in the non-sarcopenic group (28.6xa0% vs. 9.0xa0%; Pxa0=xa00.029). In the multivariate analysis, sarcopenia alone was identified as a risk factor for severe postoperative complications (odds ratio, 4.76; 95xa0% confidence interval, 1.03–24.30; Pxa0=xa00.046).ConclusionsPreoperative sarcopenia as defined by the EWGSOP algorithm is a risk factor for severe postoperative complications in elderly gastric cancer patients undergoing gastrectomy.

Pilot study of combination chemotherapy of S‐1, a novel oral DPD inhibitor, and interferon‐α for advanced hepatocellular carcinoma with extrahepatic metastasis

To the authors knowledge, there is no effective therapy for extrahepatic metastasis of hepatocellular carcinoma (HCC). In a pilot study, the results of combination therapy of S‐1, a novel oral dehydropyrimidine dehydrogenase (DPD) inhibitor, and interferon‐alpha (IFN‐α) are reported for HCC patients with extrahepatic metastasis.

Surgical Outcomes of Noninvasive and Minimally Invasive Intraductal Papillary-Mucinous Neoplasms of the Pancreas

BackgroundNoninvasive and minimally invasive intraductal papillary-mucinous neoplasms (IPMNs) have a favorable surgical outcome. However, cases of recurrent noninvasive or minimally invasive IPMN are sometimes encountered, and the patterns of the recurrence of those tumors have not yet been fully clarified. In this study, we evaluated the surgical outcome of noninvasive and minimally invasive IPMNs, concentrating particularly on the pattern of recurrences.MethodsTwenty patients with noninvasive and minimally invasive IPMNs were assessed. Resected specimens were evaluated histopathologically with regard to the malignant nature of the tumors, the status of the surgical margin, and peripancreatic lymph node involvement. Cumulative overall survival rates and recurrence after surgery were assessed.ResultsOf the 20 patients, 13 had benign IPMNs, including adenomas (n = 10) and borderlines (n = 3), and 7 had malignant IPMNs, including carcinomas in situ (n = 4) and minimally invasive IPMNs (n = 3). Histopathologic examination confirmed the absence of tumor involvement in the resected lymph nodes and at the surgical margins. During the follow-up period, one patient with minimally invasive IPMN and one patient with noninvasive IPMN died of tumor recurrence in the peritoneum that was presumably caused by intraoperative manipulation. All of the patients with benign IPMNs survived, whereas the 10-year survival rate of the patients with malignant IPMNs was 67%.ConclusionsSurgical resection can offer a favorable outcome for noninvasive and minimally invasive IPMNs. Tumor recurrence was observed only in the peritoneal cavity. More careful perioperative management concerned with peritoneal recurrence should be emphasized for noninvasive and minimally invasive IPMNs.