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Biomedical subjects

Fumiaki Sasaki

Publications and source records attributed to Fumiaki Sasaki.

At least 19 recordsLinked to original sources

Promoter hypermethylation of the RASSF1A gene predicts the poor outcome of patients with hepatoblastoma.

BACKGROUND: Despite the progress of therapy, about 25% of patients with hepatoblastoma succumb to the disease. Prognostic factors, as well as improved therapies, are needed for these patients. We investigated the incidence and clinical significance of genetic and epigenetic aberrations in hepatoblastoma. PROCEDURE: beta-catenin mutation was analyzed by sequencing and promoter hypermethylation of the RASSF1A and SFRP genes by methylation-specific PCR after bisulfate treatment of DNA samples from 39 hepatoblastomas. Association of the clinical and biological features, including sex, age of patients, stage of the disease, the histological type, and the beta-catenin and RASSF1A status with overall survival was evaluated using univariate and multivariate analysis. RESULTS: beta-catenin mutation and RASSF1A methylation were found in 22 (56.4%) and 15 (38.5%) of 39 hepatoblastomas, respectively, but SFRPs methylation was not found in any of them. RASSF1A and SFRPs were unmethylated in five adjacent normal liver tissues. Patients with a RASSF1A methylated tumor were older in age (>or=2 years, P=0.036), at more advanced stages (P=0.009), and had more frequent beta-catenin mutation (P<0.001) and poorer outcome (P<0.001) than those with a RASSF1A unmethylated tumor. While univariate analysis showed the prognostic significance of age, stage, the histological type, and the beta-catenin and RASSF1A status, multivariate analysis showed only the RASSF1A methylation status as an independent factor predicting outcome (relative risk, 10.51; 95% CI, 1.21 approximately 90.97; P=0.033). CONCLUSIONS: RASSF1A methylation may be a novel molecular-genetic marker for treatment outcome in hepatoblastoma if confirmed by studies examining a larger number of hepatoblastomas.

Adaptor Proteins, Signal Transducing↗

Reciprocal expression of CCAAT/enhancer binding proteins alpha and beta in hepatoblastomas and its prognostic significance.

Hepatoblastoma is one of the common pediatric solid tumors with frequent mutation of the beta-catenin gene which might be an early event of its carcinogenesis. However, the detailed molecular mechanism is still unknown. We studied the expression levels of CCAAT/enhancer binding protein alpha (C/EBPalpha) and C/EBPbeta, which regulate differentiation and growth of embryonic hepatocytes, to establish whether or not they were involved in affecting the clinical behavior of hepatoblastoma. The quantitative real-time reverse transcriptase-PCR revealed that expression of C/EBPalpha mRNA was significantly up-regulated in tumors 223% (p=0.013) as compared with that in adjacent normal livers, while expression of C/EBPbeta was down-regulated to 27% (p=0.002). Of interest, the immunohistochemical analysis showed that expression of C/EBPalpha was higher and that of C/EBPbeta lower in the poorly differentiated tumor cells than in the well-differentiated cells within the same tumor. Furthermore, high expression of C/EBPalpha (p=0.047) as well as low expression of C/EBPbeta (p=0.025) was significantly associated with poor prognosis of the patients. Cox hazard model suggested that expression of C/EBPalpha and that of C/EBPbeta were independent indicators to predict the prognosis from age but not from histology. Thus, expression of C/EBP proteins may play an important role in the genesis and clinical behavior of hepatoblastoma probably by inducing different stages of arrest of differentiation.

CCAAT-Enhancer-Binding Protein-alpha↗

Association of 11q loss, trisomy 12, and possible 16q loss with loss of imprinting of insulin-like growth factor-II in Wilms tumor.

We evaluated the WT1 and IGF2 status and performed chromosome and/or comparative genomic hybridization analysis in 43 tumor samples from patients with Wilms tumor. On this basis, we classified them into 4 groups: WT1 abnormality, loss of heterozygosity (LOH) of IGF2, loss of imprinting (LOI) of IGF2, and retention of imprinting (ROI) of IGF2, which were seen in 12%, 30%, 16%, and 42% of the tumors, respectively. Patients in the LOI group were older than those in other groups (P < 0.01), and tumors in the WT1 group had fewer cytogenetic changes than did those in the other groups (P < 0.01). It was found that 11q- and +12 were more frequent in the LOI group than in the WT1+LOH+ROI group (P < 0.01 and P < 0.01). There was no difference in the incidence of 16q- between the LOI group and the other groups; however, when we excluded 16 tumors with LOH on 11p15, 16q- tended to be more frequent in the LOI group than in the WT1+ROI group (P = 0.06). The association of 11q- or +12 with LOI of IGF2 found in the present study suggests that many tumors with no WT1 abnormalities need overexpression of IGF2 together with biallelic inactivation of the tumor-suppressor gene on 11q and/or overexpression of growth-promoting genes on chromosome 12. The 11q gene may code for one of the proteins that constitute a CTCF insulator complex, and its mutation, deletion, or haploinsufficiency may cause insulator abnormalities that might lead to LOI of IGF2.

Child↗

Multiple mesenteric teratomas: usefulness of spiral computed tomography with 3-dimensional reconstruction.

A very rare case of mesenteric teratoma is reported. Complete tumor resection is the main prognostic factor for survival in such cases. Therefore, an important factor for successful surgery is the exact preoperative visualization of the extent of the tumor, including visualization of the abdominal arteries. This report describes the use of spiral computed tomography with 3-dimensional reconstruction for visualization of the extent of multiple mesenteric teratomas.

Child↗

Macrophage migration inhibitory factor promotes tumor invasion and metastasis via the Rho-dependent pathway.

PURPOSE: Macrophage migration inhibitory factor (MIF) plays an important role not only in the immune system but also in tumorigenesis. In this study, we investigated the potential role of MIF in association with tumor invasion and metastasis. METHODS: To assess the function of MIF, we knocked down the MIF mRNA using small interfering RNA (siRNA). Twenty-one base siRNA specific for the mRNA sequence of mouse MIF was introduced to a murine colon cancer cell line, colon 26. Tumor cell invasion was evaluated using a transwell method (8-microm pores) coated with Matrigel on the upperside membrane and with fibronectin on the underside membrane. Moreover, we investigated the signal transduction of lysophosphatidic acid (LPA) relevant to the Rho-dependent pathway and further examined the effect of MIF siRNA on this signal transduction system. In vivo, the tumor cells were pretreated with MIF siRNA and injected into the portal vein, and the effects on metastasis to the liver were evaluated. RESULTS: We found that MIF siRNA markedly reduced the invasion of the cells from the upperside to lowerside membranes. We revealed that the Rho-dependent pathway activated by LPA was suppressed by MIF siRNA. Next, we found that the tyrosine-phosphorylation of focal adhesion kinase and LPA-induced expressions of integrin beta1 were significantly suppressed by MIF siRNA. In vivo, metastasis to the liver was significantly inhibited by pretreatment of the cells with MIF siRNA. CONCLUSION: Taken together, these results suggest that MIF promotes tumor invasion and metastasis via the Rho-dependent pathway.

Animals↗

Postoperative portal and splenic vein thrombosis in children: identification of risk factors.

Postoperative portal and splenic vein thrombosis (PSVT) is a rare but potentially fatal complication after abdominal surgery. We present 2 infants with PSVT after splenectomy and total colectomy, respectively, and also provide a review of the literature. We conclude that clinicians should consider that PSVT might occur after splenectomy for a huge splenomegaly or after a total colectomy for ulcerative colitis.

Adolescent↗

The impact of bilateral breast cancer on the prognosis of breast cancer: a comparative study with unilateral breast cancer.

BACKGROUND: The clinical significance of bilateral breast cancer is unclear and its influence on prognosis is controversial. We assessed the impact of synchronous and metachronous bilateral breast cancer on the prognosis compared with unilateral breast cancer. METHODS: Between January 1, 1960 and December 31, 2001, 1,214 women were treated for primary operable breast cancers. Thirteen (1.1%) had synchronous bilateral breast cancer; 33 (2.7%) had a metachronous contralateral breast cancer. We compared age at operation, menopausal status, clinical stage, tumor size and histology, lymph node status, hormone receptor status, and use of adjuvant chemotherapy or hormone therapy, and we analyzed the impact of these factors on recurrence and survival in the 46 patients with bilateral breast cancer and the 1,168 patients with unilateral breast cancer. RESULTS: The 5-and 10-year disease-free survival rates, respectively, were 65% and 65% in metachronous cases, 85.7% and 64.3% in synchronous cases, and 77.9% and 72.1% in unilateral cases. There was no significant difference in overall survival among the three groups. On multivariate analysis, metachronous bilaterality, tumor size, lymph node status and adjuvant hormone therapy were each independent risk factors for recurrence, whereas bilaterality of breast cancer did not influence overall survival. CONCLUSIONS: Our data suggest that metachronous bilateral breast cancer is associated with shorter disease-free survival than synchronous bilateral or unilateral breast cancer, although overall survival does not differ among the 3 groups. Patients with metachronous bilateral breast cancer should be followed particularly closely in order to detect recurrence early and maximize quality of life.

Adult↗

[Strategy for the treatment of hepatoblastoma in children].

Hepatoblastoma is the most common malignant live tumor in childhood. Multicenter trials have made it clear that pre- and/or postoperative chemotherapy are necessary to improve the outcome of the treatment of hepatoblastoma. The results of the Japanese Pediatric Liver Tumor (JPLT)-1 study since 1991 have been compatible with those of other group study trials in Europe and the USA. However, patients with unresectable primary tumors or with lung metastasis still have a poor prognosis. The JPLT has developed a new protocol that includes four courses of treatment based on the PRETEXT staging system. These treatments include intensive chemotherapy with stem cell transplantation for patients with unresectable primary tumors or with pulmonary metastases.

Adenomatous Polyposis Coli Protein↗

Expression profiling and differential screening between hepatoblastomas and the corresponding normal livers: identification of high expression of the PLK1 oncogene as a poor-prognostic indicator of hepatoblastomas.

Hepatoblastoma is one of the most common malignant liver tumors in young children. Recent evidences have suggested that the abnormalities in Wnt signaling pathway, as seen in frequent mutation of the beta-catenin gene, may play a role in the genesis of hepatoblastoma. However, the precise mechanism to cause the tumor has been elusive. To identify novel hepatoblastoma-related genes for unveiling the molecular mechanism of the tumorigenesis, a large-scale cloning of cDNAs and differential screening of their expression between hepatoblastomas and the corresponding normal livers were performed. We constructed four full-length-enriched cDNA libraries using an oligo-capping method from the primary tissues which included two hepatoblastomas with high levels of alpha-fetoprotein (AFP), a hepatoblastoma without production of AFP, and a normal liver tissue corresponded to the tumor. Among the 10,431 cDNAs randomly picked up and successfully sequenced, 847 (8.1%) were the genes with unknown function. Of interest, the expression profile among the two subsets of hepatoblastoma and a normal liver was extremely different. A semiquantitative RT-PCR analysis showed that 86 out of 1188 genes tested were differentially expressed between hepatoblastomas and the corresponding normal livers, but that only 11 of those were expressed at high levels in the tumors. Notably, PLK1 oncogene was expressed at very high levels in hepatoblastomas as compared to the normal infant's livers. Quantitative real-time RT-PCR analysis for the PLK1 mRNA levels in 74 primary hepatoblastomas and 29 corresponding nontumorous livers indicated that the patients with hepatoblastoma with high expression of PLK1 represented significantly poorer outcome than those with its low expression (5-year survival rate: 55.9 vs 87.0%, respectively, p=0.042), suggesting that the level of PLK1 expression is a novel marker to predict the prognosis of hepatoblastoma. Thus, the differentially expressed genes we have identified may become a useful tool to develop new diagnostic as well as therapeutic strategies of hepatoblastoma.

Cell Cycle Proteins↗

Nonfamilial juvenile polyposis coli in a child: report of a case.

Juvenile polyposis coli (JPC) is an uncommon condition, manifesting as hamartomatous gastrointestinal polyposis with potential malignancy. This report describes a 15-month-old girl who was diagnosed to have nonfamilial JPC accompanied by macrocephaly, clubbed fingers, and mental retardation. Radiography of the colon by a barium enema and total colonoscopy demonstrated numerous colonic polyps. A barium meal study did not show any abnormality in the stomach, duodenum, or small intestine. She died at 6 years of age from hemorrhagic shock due to massive lower gastrointestinal bleeding associated with a rectal prolapse. The related literature is reviewed, and the treatments and complications of JPC in children are also discussed. We emphasize that family members of patients diagnosed with juvenile polyposis should be questioned and undergo appropriate examinations of the entire intestine from the stomach to the rectum.

Adenomatous Polyps↗

Postnatal management for prenatally diagnosed choledochal cysts.

PURPOSE: The aim of this study was to determine an appropriate postnatal management plan for prenatally diagnosed congenital biliary dilatation (CBD). METHODS: Between 1962 and 2002, 5 (5.9 %) of 85 patients had CBD diagnosed prenatally and were examined clinically. Of these 5 patients, 2 (group A) underwent delayed primary definitive surgery after percutaneous transhepatic cholangiodrainage (PTCD), 1 (group B) underwent early definitive surgery in the neonatal period, and 2 (group C) underwent delayed primary definitive surgery without PTCD in early infancy (within 6 months after birth). The clinical data, operative findings, intra- and postoperative complications, and follow-up were evaluated in these 3 groups. RESULTS: There were no postoperative complications, such as catheter-related complications, in group A. However, there was adhesion around the choledochal cyst, and the operation was therefore difficult in group A. The diameter of the anastomosis in the hepaticojejunostomy was small, and the cyst wall was thin in group B. Consequently, anastomotic leakage of the hepaticojejunostomy occurred in group B. Neither operative nor postoperative complications such as anastomotic leakage or stenosis occurred in group C. Slight fibrosis of Glisson's sheath was seen in 2 patients of groups A and C. No liver cirrhosis was seen in any group. CONCLUSIONS: The authors propose that asymptomatic patients should undergo elective definitive surgery by 6 months of age. For symptomatic patients, especially when a differential diagnosis of type I cystic biliary atresia is doubtful, early definitive surgery is needed before 2 months of age. PTCD appears to be indicated only under certain circumstances, and delayed primary definitive surgery should be performed as early as possible thereafter.

Anastomosis, Surgical↗

Nuclear accumulation of beta-catenin without an additional somatic mutation in coding region of the APC gene in hepatoblastoma from a familial adenomatous polyposis patient.

The APC (adenomatous polyposis coli) gene status in a familial adenomatous polyposis (FAP) patient who developed hepatoblastoma was analyzed by the yeast color assay. Although a single base insertion at codon 462 resulting in truncation of its product was documented in hepatoblastoma cells, no additional somatic mutation was detectable in the whole coding sequence of the APC gene. The nuclear accumulation of beta-catenin without mutation in the exons 2-4 of the beta-catenin gene, however, was observed in the tumor cells by immunohistochemistry. The similar nuclear accumulation of beta-catenin without an additional somatic mutation in its gene, in the absence of somatic mutation in cluster region of the APC gene, has been previously reported in the single FAP case. Moreover, review in the hepatoblastoma cases in the FAP families showed a relatively later onset of the disease when compared with the sporadic cases. These observations suggest that accumulation of beta-catenin without an additional somatic mutation in the APC gene might be a possible mechanism for tumorigenesis of hepatoblastoma in the FAP families.

Adenomatous Polyposis Coli↗

Analysis of treatment outcome for children with recurrent or metastatic hepatoblastoma.

For better total survival rate of children with hepatoblastoma, the therapeutic strategy for recurrent or metastatic hepatoblastoma should be improved. From 1991 to 1999, 134 cases of hepatoblastoma were treated by surgery and combination chemotherapy of cisplatin (CDDP) and THP-Adriamycin (THP-ADR) based on the JPLT-1 protocol. In 114 non-metastatic cases, 90 primary liver tumors were resected completely by partial hepatectomy, but 12 recurrences were observed in the liver (4 cases) and the lungs (8 cases). Distant metastases on the diagnosis were observed in 20 cases. The treatment outcome of these 12 recurrent and 20 metastatic tumors was analyzed. In four recurrent liver tumors, surgical resection was performed in all four cases, and all the patients were alive and well. In eight recurrent lung tumors, surgical resection was performed completely in six cases with unilateral lung disease, and five of the six patients were alive and well. In stage IV tumors, the survival rate of the patients having primary tumors within two hepatic sections was significantly higher than that of the patients having primary tumors over three hepatic sections. Active surgical intervention to lung metastases and a more intensive chemotherapy to facilitate complete resection of primary hepatic tumor could improve survival rate of children with refractory hepatoblastoma.

Antineoplastic Combined Chemotherapy Protocols↗

No incidence of port-site recurrence after endosurgical procedure for pediatric malignancies.

Port-site recurrence (PSR) following laparoscopic procedures has been an unpredictable complication in adult cancer patients; however, no data exist about this phenomenon in the pediatric field. The aim of this study was to determine whether PSR, following endosurgical procedure for malignancies, is a typical complication or a rare event in the pediatric population. Eighty-one questionnaires were mailed to members of The Japanese Society of Pediatric Endosurgeons. They were asked to provide a list of their institutions that had experience with PSR after endosurgical procedures for pediatric malignancies. Among 29 institutions, a total of 129 endosurgical procedures for pediatric malignancies were reported; these included 85 laparoscopic and 44 thoracoscopic procedures, performed on 104 neuroblastomas, 8 hepatoblastomas, 7 nephroblastomas, and 10 other tumors. Of the 104 neuroblastomas, 83 were found by mass screening using high levels of urinary vanillylmandelic acid and homovanillic acid. Sixty-five of the 83 patients had their tumor excised, and 18 had their tumor biopsied by endosurgical procedures. Additionally, 47 of these patients did not require any postoperative chemotherapy. No incidence of PSR was reported in any of the patients that underwent endosurgical procedures. The PSR following endosurgical procedure is a rare phenomenon in the pediatric population. Both, laparoscopic and thoracoscopic procedures, are safe and recommended for treating pediatric malignancies, especially mass-screened neuroblastomas.

Child↗

Chromosomes that show partial loss or gain in near-diploid tumors coincide with chromosomes that show whole loss or gain in near-triploid tumors: evidence suggesting the involvement of the same genes in the tumorigenesis of high- and low-risk neuroblastomas.

We performed two-color fluorescence in situ hybridization analysis to detect the numbers of chromosomes 1 and 17, 1p deletion, and 17q gain in 177 neuroblastomas, including 101 tumors that were found by a mass-screening program for infants. Sixty-eight tumors with disomy 1 or tetrasomy 1 were classified as the Dis1 group, and 109 tumors with trisomy 1, pentasomy 1, or a mixed population of cells with trisomy 1 and cells with tetrasomy 1 were classified as the Tris1 group. 17q gain was the most frequent genetic event, followed by 1p deletion, and MYCN amplification in both Dis1 and Tris1 tumors. However, the incidence of all the genetic events was higher in Dis1 tumors than in Tris1 tumors. These findings suggest that Tris1 tumors are more resistant to acquiring the genetic events than are Dis1 tumors. In addition, there was an accumulation of genetic events in more advanced stages, with the exception of a high incidence of 17q gain in the stage IVS Tris1 tumors. Comparative genomic hybridization analysis, which was performed in 59 of the 177 tumors, showed that chromosomes partially lost or gained in Dis1 tumors coincided with chromosomes totally lost or gained in Tris1 tumors. Dis1 and Tris1 tumors were considered to have near-diploid/tetraploid and near-triploid/pentaploid chromosome numbers, respectively. These findings suggest that the same tumor-suppressor genes or oncogenes may be involved in the development and progression of both high- and low-risk neuroblastomas, and that the ploidy state of the tumor plays a fundamental role in the heterogeneous behavior.

Allelic Imbalance↗

[Weekly paclitaxel administration in the adjuvant therapy of primary breast cancer].

PURPOSE: To investigate feasibility and toxicity of weekly paclitaxel administration in the adjuvant therapy of primary breast cancer. PATIENTS AND METHODS: Thirty-one patients with primary breast cancer received sustained weekly infusion of paclitaxel at a dose of 90 mg/body for 6 weeks followed by a 2-week interval. This weekly schedule was repeated twice. Leukocytes were checked immediately before every infusion and the dose was reduced to 80 mg/body when grade 1 neutropenia occurred. All patients were assessable for feasibility and toxicity. RESULTS: A total 349 weekly paclitaxel infusions were administrated to 31 patients (median, 12 infusions/patient). The median delivered dose-intensity was 88.0 mg/body/week (range 80 to 90). Therapy was well tolerated and completed in 27 patients. Four patients refused to continue the therapy because of nausea, fatigue, dizziness and weight gain. Grade 2 neutropenia occurred in 10 patients (32.3%), but grade 3 neutropenia did not occur. Grade 1 peripheral neuropathy occurred in 3 patients (9.7%). Grade 1 nausea occurred in 3 patients (9.7%). CONCLUSION: Weekly paclitaxel administration is well tolerated with a favorable toxicity profile in patients with primary breast cancer in the adjuvant setting. Weekly paclitaxel therapy can be performed safely in the outpatient setting.

Adult↗