PubMed Health⌕ Search

Biomedical subjects

Michiie Sakamoto

Publications and source records attributed to Michiie Sakamoto.

At least 19 recordsLinked to original sources
PubMed2007

Angiotensin II type 1 receptor antagonist as an angiogenic inhibitor in prostate cancer.

BACKGROUND: Angiotensin II (AII) type 1 receptor (AT1R) antagonists are used widely as antihypertensive agents, and long-term AT1R blockade may have a protective effect against cancer. We previously demonstrated that specific AT1R blockade with candesartan, an AT1R antagonist, inhibited vascular endothelial growth factor (VEGF) production and dramatically decreased lung metastasis of renal cancer by inhibiting tumor angiogenesis. This study was then undertaken to investigate the effects of AT1R blockade using candesartan in prostate cancer (PCa). METHODS: We first determined whether hormone-independence is associated with tumor angiogenesis and AT1R expression. Accordingly, we postulated that AT1R blockade may affect angiogenesis in androgen-independent PCa rather than in androgen-dependent PCa, and investigated the effects of AII and candesartan on PCa cell lines and a tumor xenograft model. RESULTS: A human hormone-refractory PCa (HRPC) and C4-2 androgen-independent PCa cell line showed significantly higher expression of VEGF, MVD, and AT1R than did human androgen-dependent PCa and an LNCaP androgen-dependent PCa cell line. In vitro, AII and candesartan did not directly affect the proliferation of LNCaP and C4-2 cells, but candesartan significantly suppressed VEGF production in C4-2 cells. In vivo, candesartan significantly suppressed VEGF expression, serum PSA concentration and tumor growth (1.1 +/- 0.2, 45.0 +/- 17.6 ng/ml, 235.8 +/- 37.4 mm(3)) in C4-2 xenografts in castrated mice, compared with the controls (2.4 +/- 0.6, 376.7 +/- 74.2 ng/ml, 830.8 +/- 147.6 mm(3)). CONCLUSIONS: Candesartan exerted preventive effects on HRPC, rather than on androgen-sensitive PCa, through the inhibition of tumor angiogenesis.

Aged↗
PubMed2006

Overexpression of cyclase-associated protein 2 in multistage hepatocarcinogenesis.

PURPOSE: Hepatocellular carcinoma (HCC) associated with chronic liver disease is known to show an obvious multistage process of tumor progression. We previously identified heat shock protein 70 as a molecular marker of early HCC during investigation of expression profiling in multistage hepatocarcinogenesis. In this report, we examined cyclase-associated protein 2 (CAP2), which is also listed as an up-regulated gene in early HCC. EXPERIMENTAL DESIGN: We measured the level of CAP2 mRNA by real-time quantitative PCR. We raised a polyclonal antibody against CAP2 and we confirmed the expression of CAP2 by immunoblotting and immunohistochemistry in HCC cell lines and HCC tissues. RESULTS: According to real-time quantitative PCR, the level of CAP2 mRNA was up-regulated in early HCC when compared with noncancerous liver tissue, and it was further up-regulated in progressed HCC. We raised a polyclonal antibody against CAP2, which showed a single 53-kDa band of strong intensity in the human HCC cell lines and HCC tissues but only a weak band in the noncancerous liver tissues in Western blot analysis. Immunohistochemical examination of CAP2 revealed its significant overexpression in early HCC when compared with noncancerous and precancerous lesions and in progressed HCC when compared with early HCC. CONCLUSION: Our findings show that CAP2 is up-regulated in HCC when compared with noncancerous and precancerous lesions. This is the first report that proves that CAP2 is up-regulated in human cancers and that this is possibly related to multistage hepatocarcinogenesis.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Establishment of perineural invasion models and analysis of gene expression revealed an invariant chain (CD74) as a possible molecule involved in perineural invasion in pancreatic cancer.

PURPOSE: Perineural invasion causes frequent local recurrence even after resection and a poor prognosis for pancreatic cancer. We established perineural invasion models and analyzed the molecular mechanism of perineural invasion in pancreatic cancer. EXPERIMENTAL DESIGN: Seven pancreatic cancer cell lines with or without human peripheral nerves were s.c. implanted in nonobese diabetes/severe combined immunodeficient mice. We compared expression profiles among high and low perineural invasion cell lines by using an oligonucleotide microarray. We examined up-regulation of the invariant chain (CD74) in high perineural invasion cell lines in mRNA and protein levels and surgical cases immunohistochemically. RESULTS: Four of seven pancreatic cancer cell lines (CaPan1, CaPan2, CFPAC, and MPanc96) showed perineural invasion to s.c. transplanted human peripheral nerves. Moreover, CaPan1 and CaPan2 (high perineural invasion group) also resulted in a high frequency of perineural invasion to mouse s.c. peripheral nerves, whereas three pancreatic cancer cell lines HPAFII, AsPC1, and Panc1 (low perineural invasion group) did not show perineural invasion to either human or mouse nerves. We identified 37 up-regulated genes and 12 down-regulated genes in the high perineural invasion group compared with the low perineural invasion group. Among them, CD74 was up-regulated in the high perineural invasion group in mRNA and protein levels. Furthermore, immunohistochemical expression of CD74 in clinical cases revealed its significant overexpression in pancreatic cancer with perineural invasion (P < 0.008). CONCLUSIONS: This is the first report of perineural invasion models using human pancreatic cancer cell lines. In combination with gene expression profiling, it was indicated that CD74 could be a candidate molecule involved in perineural invasion. These models provide new approaches for study of perineural invasion in pancreatic cancer.

Aged↗
PubMed2006

Cryptogenic fulminant hepatic failure in infancy: report of 2 cases with unique vascular obstructive changes in native livers.

Although the causes of fulminant hepatic failure (FHF) remain cryptogenic in many cases, a few reports have reviewed the pathological findings of native livers to evaluate the etiology. We report 2 cases of infantile cryptogenic FHF with unique vascular obstructive changes in the native livers. Clinically, it was notable that these 2 patients developed FHF very early in life, at 2 months and 5 months of age, respectively. One patient died from chronic rejection associated with hepatic veno-occlusive disease 4 months after transplantation. Histologically, hepatocytes in the native livers were completely destroyed in both patients, and vascular findings revealed obstruction of central veins in 1 patient and obstruction of portal veins in the other patient. Although the pathogenesis of vascular obstructions is not yet understood, this study suggests that an obstructive vascular event may be a contributing etiologic factor of FHF in infancy.

Blood Vessels↗
PubMed2006

A solid pseudopapillary tumor arising from the greater omentum followed by multiple metastases with increasing malignant potential.

Solid pseudopapillary tumor is a rare, indolent neoplasm almost exclusively seen in the pancreas. We describe an unusual case of solid pseudopapillary tumor arising in the greater omentum of a 45-year-old man with subsequent multiple liver metastases and peritoneal dissemination. The patient underwent a total of ten laparotomies and died of unresectable disease 8 years after the initial presentation. Microscopically, the primary tumor and the relapsed tumors consistently exhibited identical growth patterns, which were characterized by solid sheets intermingling with pseudopapillary arrangements of uniformly small cells. Immunohistochemical staining was diffusely positive for vimentin and focally positive for alpha-1-antitrypsin. These features were compatible with those of conventional pancreatic solid pseudopapillary tumors. We also performed quantitative evaluation of Ki-67 immunoreactivity and mitotic figures, which indicated malignant transformation of this extremely rare tumor. This is the first detailed report of solid pseudopapillary tumor arising outside the pancreas complicated by repetitive liver metastases and peritoneal carcinomatosis, suggesting the existence of a more lethal subgroup of tumors.

Biomarkers, Tumor↗
PubMed2006

Sinolith in the ethmoid sinus.

We report a case of sinolith in the left ethmoid sinus of a 61-year-old man. The patient complained of nasal obstruction. Computed tomography revealed a small, calcified mass associated with a nasal polyp in the left ethmoid sinus. The antrolith and polyp were removed via endoscopic sinus surgery. Histopathological analysis of the antrolith revealed it to be bone-like in formation. The antrolith was about 1 cm in diameter. Infrared spectroscopy revealed that the antrolith contained protein (45 per cent), calcium phosphate (43 per cent) and calcium carbonate (12 per cent).

Calcinosis↗
PubMed2006

Unusual hemangioendothelioma of the liver with epithelioid morphology associated with marked eosinophilia: autopsy case.

Vascular neoplasms characterized by epithelioid endothelial cells consist of several different entities from benignity to high-grade malignancy. Because of histological overlap between them, there is substantial difficulty in classifying them correctly. The present patient, a 33-year-old man, presented with hepatomegaly, striking eosinophilia and elevated serum interleukin-5 level. Biopsy and autopsy revealed an unusual epithelioid vascular tumor in the liver, which is histologically distinct from epithelioid hemangioma, epithelioid hemangioendothelioma, or epithelioid angiosarcoma. The tumor cells had vasoformative and partly solid growth with no severe nuclear atypia and very low mitotic activity, and the histological features were similar to those of the entity recognized as hemangioendothelioma of bone. Organs other than the liver, for example the testes and bone, were also involved. This tumor should be considered in the differential diagnosis of severe eosinophilia.

Adult↗
PubMed2006

CT Evaluation of the progression of hypoattenuating nodular lesions in virus-related chronic liver disease.

OBJECTIVE: The purpose of this study was to clarify the natural outcomes of hypoattenuating nodular lesions in patients with virus-related chronic liver disease depicted on dynamic CT. MATERIALS AND METHODS: Sixty lesions (mean size, 1.3 cm) exhibiting hypoattenuation or isoattenuation in the arterial and delayed phases of dynamic CT were retrospectively evaluated with additional CT (mean, six examinations) for a mean period of 838 days. The primary end point was emergence of hyperattenuating areas within hypoattenuating lesions, a phenomenon called attenuation conversion. Cumulative attenuation conversion rates suggesting rates of malignant transformation were calculated with the Kaplan-Meier method, and factors affecting attenuation conversion rate were analyzed with the Cox proportional hazard model. RESULTS: Thirty-six (60%) of 60 hypoattenuating lesions developed to hyperattenuating lesions, 21 were unchanged, and three disappeared spontaneously. The 36 lesions that became hyperattenuating were divided into two subgroups according to lesion enhancement pattern: hyper-in-hypoattenuating (n = 25) and entirely hyperattenuating (n = 11). The cumulative attenuation conversion rates for the 60 hypoattenuating lesions were 15.8%, 44.3%, and 58.7% at 1, 2, and 3 years. The hyper-in-hypoattenuating lesions showed more rapid progression to entirely enhanced lesions. Positive results for hepatitis C viral antibody (p = 0.028) and initial lesion size (p = 0.007) showed a positive correlation with attenuation conversion rate. CONCLUSION: Hypoattenuating hepatic nodular lesions in chronic liver disease depicted on dynamic CT have high malignant potential and should be followed with special attention to conversion from hypoattenuation to hyperattenuation to determine the optimal timing of treatment.

Aged↗
PubMed2005

Fulminant Epstein-Barr virus (EBV)-associated T-cell lymphoproliferative disorder with hemophagocytosis following autologous peripheral blood stem cell transplantation for relapsed angioimmunoblastic T-cell lymphoma.

Post-transplant lymphoproliferative disorder (PTLD) is a complication that can develop after either solid-organ or hematopoietic stem cell transplantation (HSCT). T-cell PTLD is a rare disorder, especially following autologous HSCT. Here we report a case of T-cell PTLD which occurred after autologous peripheral blood stem cell transplantation (PBSCT) for relapsed angioimmunoblastic T-cell lymphoma (AILT). Three months after the transplant, the patient developed fever with elevated plasma Epstein-Barr virus (EBV)-PCR values. The patient subsequently developed pneumonitis, hepatomegaly and marked pancytopenia due to hemophagocytosis. The patient died of multi-organ failure, despite antiviral and steroid pulse therapy. Our post-mortem study confirmed the marked proliferation of EBV-infected T-cells that differed from the original AILT clone and macrophages/histiocytes were observed in the marrow, liver, lymph nodes and lungs. Phagocytosis was most evident in the bone marrow. The patient's AILT remained in complete remission. To the best of our knowledge, this is the first case of fulminant EBV-associated T-cell lymphoproliferative disorder (LPD) following autologous HSCT.

Antigens, CD↗
PubMed2005

Genetic profile of hepatocellular carcinoma revealed by array-based comparative genomic hybridization: identification of genetic indicators to predict patient outcome.

BACKGROUND/AIMS: We conducted an analysis of chromosomal numerical aberrations and their clinical significance in hepatocellular carcinoma. METHODS: We analyzed 87 hepatocellular carcinomas by array-based comparative genomic hybridization with an array containing 800 bacterial artificial chromosome clones. RESULTS: Frequent (>30%) chromosomal losses on 1p36.1, 4q21-25, 4q34-35.1, 8p23.3b-11.1, 13q14.1-14.3, 16p13.3, 16q22.1-24.3b, 17p13.3-13.1 and 17p13.3-11, and gains on 1q21-44f, 2q21.2, 2q34, 3q11.2, 5p14.2, 5q13.2-14, 7p22, 7p14.2, 7q21.1, 7q22.3, 7q34, 8q12-24.3 and 17q23, were observed. Recurrent (>5%) amplifications were detected on 1q25, 8q11 and 11q11, and we discovered a novel homozygous deletion at 14q32.11. The extent of chromosomal aberrations correlated significantly with various clinicopathological characteristics of the tumors, and increased in a stepwise manner with the progression of hepatocellular carcinoma. We also identified novel chromosomal alterations that were significantly associated with a range of malignant phenotypes. Multivariate analysis revealed that both chromosomal loss on 17p13.3 and gain on 8q11 are independent prognostic indicators. CONCLUSIONS: Our results contribute to a complete description of genomic structural aberrations in relation to hepatocarcinogenesis and provide a valuable basis from which we can begin to understand the characteristics of tumors, predict patient outcomes and discover novel therapeutic targets for hepatocellular carcinoma.

Adult↗
PubMed2005

Domain-specific function of ShcC docking protein in neuroblastoma cells.

ShcC is a family member of the Shc docking proteins that possess two different phosphotyrosine-binding motifs and conduct signals as Grb2-binding substrates of various receptor tyrosine kinases. We have recently shown that some neuroblastoma cell lines, such as NB-39-nu cells, express a protein complex of hyperphosphorylated ShcC and anaplastic lymphoma kinase (ALK), which is self-activated by gene amplification. Here, we demonstrate that the expression of a mutant ShcC lacking Grb2-binding sites, 3YF-ShcC, significantly impaired the survival, differentiation and motility of NB-39-nu cells by blocking the ERK and Akt pathways. On the other hand, cells overexpressing ShcC or 3YF-ShcC, but not a mutant ShcC that lacks SH2, showed decreased anchorage independency and in vivo tumorigenicity, suggesting a novel ShcC-specific suppressive effect through its SH2 domain on cell transformation. Notably, overexpression of ShcC suppressed the sustained phosphorylation of Src family kinase after cell detachment, which might be independent of phosphorylation of Grb2-binding site. It was indicated that the Src/Fyn-Cas pathway is modulated as a target of these suppressive effects by ShcC. Reciprocal change of ShcC expression and phosphorylation observed in malignant neuroblastoma cell lines might be explained by these phosphotyrosine-dependent and -independent functions of ShcC.

Agar↗
PubMed2005

Akt phosphorylation is a risk factor for early disease recurrence and poor prognosis in hepatocellular carcinoma.

BACKGROUND: Patients with hepatocellular carcinoma (HCC) who showed early massive disease recurrence due to hematogenous intrahepatic metastasis after curative resection had a poor prognosis. The authors previously reported that Akt phosphorylation was correlated with hematogenous intrahepatic metastasis, using HCC cell lines. METHODS: The authors analyzed clinicopathologic features and the status of selected biologic markers, including phosphorylated Akt, to identify risk factors for early disease recurrence and poor prognosis in HCC. In the current series, 49 postoperative patients developed intrahepatic disease recurrence within 6 months (Group 1) and 86 patients remained disease recurrence free > 3 years after resection (Group 2). Group 1 was further divided into 2 subgroups: 19 patients who died of disease recurrence within a year after resection (Group 1A) and 27 patients who survived > 1 year (Group 1B). RESULTS: Using univariate analysis, the risk factors for early disease recurrence were tumor size, macroscopic classification, tumor differentiation, microscopic capsule infiltration, microscopic portal vein (MPV) invasion, microscopic intrahepatic metastasis (MIM), and positive immunostaining for phosphorylated Akt, Ki-67, and p53 (P < 0.05). The risk factors for poor prognosis were the number of intrahepatic metastases, tumor differentiation, and positive immunostaining for phosphorylated Akt and Ki-67 (P < 0.05). Multivariate analysis revealed that the risk factors for early disease recurrence were MPV invasion, MIM, and positive immunostaining for phosphorylated Akt, and that the risk factors for poor prognosis were positive immunostaining for phosphorylated Akt and Ki-67 (P < 0.05). CONCLUSIONS: The current clinical study showed the critical involvement of Akt phosphorylation in the aggressiveness of HCC. The potential benefits of surgery should be assessed carefully in patients with any of these risk factors.

Aged↗
PubMed2005

Interobserver variation in the histopathological assessment of nonalcoholic steatohepatitis.

Pathological assessment is considered as the gold standard for the diagnosis of nonalcoholic steatohepatitis (NASH). However, there is no agreement of histological features required for the diagnosis of NASH. In the present study, eight experienced hepatopathologists read liver biopsy specimen slides of 21 cases of NASH and suspected NASH independently and were asked to assess histopathological features and render a diagnosis. Interobserver variation among pathologists was evaluated by kappa statistics. Significant, good agreement was present in evaluation of the extent of steatosis and grade of fibrosis. Agreement was moderate concerning the localization of steatosis, localization of fibrosis, and glycogen nuclei. Only slight or poor agreement was seen in evaluation of type of steatosis, ballooning, intralobular necroinflammatory change, portal inflammation, and degree of neutrophilic infiltration. Thus the agreement varied for histological variables. Significant, moderate agreement was seen in the diagnosis of NASH but agreement was poor in the diagnosis of suggestive NASH. The agreement for the diagnosis of NASH was not high as for the individual histological findings that were thought to be the basis of the diagnosis. In conclusion, some histological features in NASH might prove useful for the development of a standardized and reliable pathological diagnosis and scoring system.

Journal Article↗
PubMed2005

Multistep and multicentric development of hepatocellular carcinoma: histological analysis of 980 resected nodules.

BACKGROUND/AIMS: Histological observations support the concept of multistep and multicentric development of hepatocellular carcinoma (HCC) in cases of chronic liver disease. However, the relationship between the incidence of such a modality of development of HCC and the type of background liver disease has not been fully investigated. METHODS: A total of 980 HCC nodules resected from 664 patients were analyzed. Multistep HCC was defined as well differentiated HCC containing the portal tracts (early HCC), or the presence of early HCC-like areas in the periphery of the nodule. In cases with multiple nodules, if the smaller nodule showed the features of multistep HCC, or if each nodule showed a distinct histology, the case was defined to have multicentric HCC. RESULTS: Of the 980 nodules, 369 (37.7%) met the criteria of multistep HCC. Of the 664 patients, 177 (26.7%) had multiple nodules that met the criteria of multicentric HCC. Both the incidences of multistep and multicentric HCC were significantly higher in HCV-Ab-positive cases than in HBs-Ag-positive cases (46.0 vs. 19.1%, P<0.001 and 34.1 vs. 16.5%, P=0.005, respectively). CONCLUSIONS: Multistep and multicentric HCC develops most frequently in patients with HCV infection.

Carcinoma, Hepatocellular↗
PubMed2005

Clinical and pathologic significance of activation of signal transducer and activator of transcription 3 in prostate cancer.

OBJECTIVES: To evaluate the association of signal transducer and activator of transcription 3 (STAT3) with the invasiveness and aggressiveness of localized prostate cancer. METHODS: Paraffin-embedded specimens from 92 patients with clinically localized prostate cancer who underwent radical prostatectomy without neoadjuvant treatment were analyzed by immunohistochemistry using two antibodies: anti-phospho-specific STAT3 (p-STAT3) antibody, which recognized only activated STAT3, and anti-total STAT3 antibody, which recognized both activated and inactivated STAT3. The patients were separated into one of four groups according to the percentage of the cells with positive nuclear staining using a 0 to 3+ scoring system. The associations between the immunostaining and invasiveness and aggressiveness of clinically localized prostate cancer were analyzed. RESULTS: Pathologically, 66 patients (71.7%) had organ-confined disease. Of the 92 tumors examined, 8, 20, 23, and 41 showed staining patterns for p-STAT3 of 0, 1+, 2+, and 3+, respectively. In addition, 0, 3, 2, and 87 tumors showed staining patterns for STAT3 of 0, 1+, 2+, and 3+, respectively. The staining patterns for p-STAT3 correlated significantly with pathologic stage, Gleason score, and extracapsular extension. No significant correlation was found between p-STAT3 immunostaining and microvascular invasion, perineural invasion, or seminal vesicle invasion. Patients with 3+ immunostaining of p-STAT3 had a significantly greater biochemical prostate-specific antigen failure rate than those with 2+ or less immunostaining. CONCLUSIONS: Increased p-STAT3 immunoreactivity showed a highly invasive and aggressive potential in patients with localized prostate cancer treated with radical prostatectomy. This suggests that STAT3 signaling contributes to the invasiveness and aggressiveness of prostate cancer.

Aged↗
PubMed2005

Proposal of histological criteria for intraepithelial atypical/proliferative biliary epithelial lesions of the bile duct in hepatolithiasis with respect to cholangiocarcinoma: preliminary report based on interobserver agreement.

Biliary lining epithelia of the bile ducts in biliary diseases are known to have intraepithelial atypical/proliferative lesions related to the development of cholangiocarcinoma. The purpose of the present study was to determine the histological criteria for these lesions based on interobserver agreement. Digital images of 30 intraepithelial atypical/proliferative lesions in the stone-containing intrahepatic bile ducts of hepatolithiasis (30 cases) were sent to 10 pathologists. At first, 10 pathologists made a diagnosis (either of reactive/regenerative change, low-grade or high-grade biliary intraepithelial neoplasia (BilIN-1 and BilIN-2), or in situ carcinoma (BilIN-3)) based on their own criteria. The histological criteria for these four lesions were then determined, and the digital images of the same lesions with proposed criteria were re-distributed. Interobserver agreement on these four lesions was slightly improved (kappa = 0.44, first diagnosis; 0.49, second diagnosis) and intraobserver agreement was 'almost perfect' (kappa = 0.82 at both first and second diagnosis). Interobserver agreement between BilIN-1 and BilIN-2 and that between BilIN-2 and BilIN-3 were 'moderate', although the agreement between regenerative/reactive change and BilIN-1 was 'fair'. In this report, we propose histological criteria for reactive/regenerative change, BilIN-1, BilIN-2 and BilIN-3. Improvement of interobserver agreement suggests their applicability in diagnostic and research fields.

Bile Duct Neoplasms↗