Biomedical subjects

Junya Toguchida

Publications and source records attributed to Junya Toguchida.

30 records · Page 2Linked to original sources

PubMed2003

[Tissue engineering for bone and cartilage repair].

Huge bone defects that occur as a result of severe trauma or bone and oft tissue tumor are frequently difficult to achieve adequate union. Autogenous or allogeneic bone grafting and reconstruction using biomaterials are the traditional method used to repair bone defects, but it is not easy to reconstruct the structure and strength. Articular cartilage has very limited intrinsic healing capacity. Although numerous attempts to repair full-thickness articular cartilage defects have been conducted, no methods have successfully regenerated long-lasting hyaline cartilage. One of the most promising procedures for bone and cartilage repair is tissue engineering. New techniques of cell therapy for the treatment of bone and cartilage lesions are currently developed. This paper will summarize the current concepts of cell therapy for bone and cartilage repair and its future application.

Bone Marrow Cells↗

PubMed2003

mRNA expression levels of E2F transcription factors correlate with dihydrofolate reductase, reduced folate carrier, and thymidylate synthase mRNA expression in osteosarcoma.

Previous studies have shown that decreased expression of the reduced folate carrier (RFC) and increased expression of dihydrofolate reductase (DHFR) are associated with intrinsic and acquired methotrexate resistance, respectively, in osteosarcoma (OS). It has also been shown in colorectal cancer that E2F-1 expression correlates with thymidylate synthase (TS) and, to a lesser extent, DHFR expression. To begin to investigate the regulation of DHFR and RFC expression in OS samples, mRNA expression of E2F-1 and E2F-4 were measured in OS tumor samples and related to DHFR, RFC, and TS mRNA expression. Using fluorescent quantitative real-time PCR, 112 human OS patient samples were investigated for potential E2F-1/E2F-4:DHFR, E2F-1/E2F-4:RFC, and E2F-1/E2F-4:TS correlations. The expression ranges for each gene are as follows: DHFR, 0.02-33.13 (median = 0.20); RFC, 0.02-229.13 (median = 1.91); TS, 0.01-9.99 (median = 0.15); E2F-1, 0.05-69.07 (median = 0.52); and E2F-4, 0.24-52.35 (median = 1.45). Spearman correlation coefficients (r(s)) for E2F-1:DHFR, E2F-1:RFC, E2F-1:TS, E2F-4:DHFR, E2F-4:RFC, and E2F-4:TS were calculated to be 0.53, 0.63, 0.60, 0.41, 0.58, and 0.33, respectively (P < 0.001). On the basis of this data, moderate correlations exist between E2F-1/E2F-4 and DHFR, RFC, and TS. These results suggest E2F-1/E2F-4 may play a role in the regulation of RFC expression, which has not been reported previously. The E2F transcription factors are also related to DHFR and TS expression in OS samples, suggesting a possible involvement in methotrexate resistance. Although E2F mRNA levels correlate with DHFR, RFC, and TS mRNA expression, additional experiments are necessary to determine the direct effects of these transcription factors and identify other proteins that may influence this relationship.

Adolescent↗

PubMed2002

Mutation analyses of the NFAT1 gene in chondrosarcomas and enchondromas.

Mice lacking nuclear factor of activated T cell 1 (NFAT1) showed an abnormal proliferation of chondrocytes in articular cartilage and formed an extraosseous cartilaginous mass resembling a neoplastic lesion, suggesting that the NFAT1 gene is a tumor suppressor gene in cartilaginous neoplasms. Here we performed mutation analyses of the NFAT1 gene in human cartilaginous tumors including 30 chondrosarcomas and 15 enchondromas. Reverse transcription-polymerase chain reaction (PCR) analysis revealed the expression of the NFAT1 gene in 15/15 chondrosarcomas and 12/13 enchondromas. To find subtle alterations, the genomic structure of the NFAT1 gene was determined using human genome draft sequences, and a mutation analysis was performed using the exon-by-exon PCR-single-strand conformation polymorphism method. Two heterozygous missense mutations, A1557T (His446Leu) and C2859T (Pro880Leu), were found in eight tumor samples, but the same mutation was also present in the constitutional cells of corresponding patients. The incidence of the mutant alleles in the patient and control groups showed no significant difference, suggesting that these mutations are rare single nucleotide polymorphisms unrelated with tumorigenesis. These results suggest that the NFAT1 gene is not likely to be a tumor suppressor gene in human cartilaginous tumors.

Adolescent↗

PubMed2002

The Id2 gene is a novel target of transcriptional activation by EWS-ETS fusion proteins in Ewing family tumors.

We report here that the Id2 (inhibitor of DNA binding 2) gene is a novel target of transcriptional activation by EWS-FLI1 and EWS-ERG, two fusion proteins that characterize Ewing family tumors (EFTs). To identify downstream targets of these EWS-ETS fusion proteins, we introduced EWS-ETS fusion constructs into a human fibrosarcoma cell line by retroviral transduction. cDNA microarray analysis revealed that Id2 expression was up-regulated by introducing the EWS-ETS fusion gene but not by the normal full-length ETS gene. An Id2 promoter-luciferase reporter assay showed that transactivation by EWS-ETS involves the minimal Id2 promoter and may function in cooperation with c-Myc within the full-length regulatory region. A chromatin immunoprecipitation assay revealed direct interaction between the Id2 promoter and EWS-FLI1 fusion protein in vivo. Significantly higher expression of Id2 and c-Myc was observed in all of the six EFT cell lines examined compared to six other sarcoma cell lines. Moreover, high levels of Id2 expression were also observed in five of the six primary tumors examined. Id2 is generally thought to affect the balance between cell differentiation and proliferation in development and is highly expressed in several cancer types. Considering these previous studies, our data suggest that the oncogenic effect of EWS-ETS may be mediated in part by up-regulating Id2 expression. doi:10.1038/sj.onc.1206025

Base Sequence↗

PubMed2002

Genome-wide analysis of gene expression in synovial sarcomas using a cDNA microarray.

Among a histologically heterogeneous group of soft tissue sarcomas, synovial sarcoma (SS) is regarded as a "miscellaneous" entity of uncertain origin. Although recent molecular analysis has disclosed involvement of a specific chromosomal translocation in the pathogenesis of SS, its genetic features remain largely unclear. In the work reported here we examined genome-wide gene expression profiles of 13 SS cases and 34 other spindle-cell sarcoma cases by cDNA microarray consisting of 23,040 genes. A hierarchical clustering analysis grouped SS and malignant peripheral nerve sheath tumor into the same category, and these two types of tumor shared expression patterns of numerous genes relating to neural differentiation. Several genes were up-regulated in almost all SS cases, and the presumed functions of known genes among them were related to migration or differentiation of neural crest cells, suggesting the possibility of neuroectodermal origin of SS. Moreover, we identified a set of genes that divided SS cases into two putative subclasses, a feature that may shed light on novel biological aspects of SS in addition to those having to do with epithelial differentiation. These data have provided clues for understanding the origin and tumorigenesis of SS.

Cluster Analysis↗

PubMed2002

Morphological and biological heterogeneity of three tumorigenic cell lines derived from a single p53-/- osteoblast-like cell line, MMC2.

Osteosarcoma is a malignant tumor with heterogeneous features both in histological and biological aspects. We have established three tumorigenic cell lines, MMOS1, MMOS2, and MMOS3, from three independent tumors that developed in nude mice after the inoculation of MMC2, an osteoblast-like cell line derived from p53-/- mice. Expression patterns of the osteoblast-related genes showed a marked difference between MMOS2 and the other two cell lines, and were correlated well with the features of the original tumors, ranging from an osteoblastic osteosarcoma (MMOS2) to tumors with scarce or no osteoid formation (MMOS1 and MMOS3). The properties of malignant cells also varied in the three cell lines. MMOS1, which was the most serum-dependent in vitro, developed markedly larger tumors in vivo than the other two cell lines. MMOS3 showed the fastest growth in low-serum conditions and produced the largest number of colonies in soft agar, but did not develop lung metastases, whereas MMOS1 and MMOS2 developed lung metastases with a frequency of 30 and 50%. These data suggest that the biological activities in vivo do not necessarily reflect those in vitro. Because the three tumorigenic cell lines share MMC2 as a common precursor, our data showed an example that the heterogeneity of osteosarcoma was created by genetic alterations that took place during the transformation process of each tumor.

Alkaline Phosphatase↗

PubMed2002

Clonal heterogeneity in differentiation potential of immortalized human mesenchymal stem cells.

Mesenchymal stem cells (MSCs) are bone marrow stroma-derived cells, which can differentiate into several types of mesenchymal tissues. Although regarded as tissue-specific stem cells, human MSCs (hMSCs) have a low proliferative ability with a finite life span, which is a hurdle to further analysis of their biology. Here we attempted to establish immortalized hMSCs by retrovirus-mediated gene transfer. The gain in telomerase activity obtained on expression of human telomerase reverse transcriptase (hTERT) was found not to be enough to make the cell line immortal. A combination of hTERT with human papillomavirus E6 and E7 successfully immortalized hMSCs without affecting the potential for adipogenic, osteogenic, and chondrogenic differentiation. From the parental immortalized hMSC, 100 single-cell derived clones were established, of which the differentiation properties varied considerably, including tri-, bi-, and uni-directional clones, suggesting that hMSCs are constituted by a group of cells with different differentiation potential. These cell lines, being the first established immortalized clonal cell lines of hMSCs, could provide insights into the mechanisms regulating the early steps of differentiation from undifferentiated MSCs into a specific lineage.

Animals↗

PubMed2002

Intramuscular metastasis from gastric cancer.

Skeletal muscle is an uncommon site of hematogenous metastasis of gastric carcinoma. We report here a rare case of gastric carcinoma with multiple intramuscular metastases. Our patient had advanced gastric carcinoma and complained of left gluteal induration with tenderness. Because magnetic resonance imaging (MRI) revealed that the gluteal tumor showed iso-signal intensity on T1-weighted images and high signal intensity on T2-weighted images, with reticulated texture around the tumor, and the patient had advanced gastric carcinoma, we speculated that the tumor was an intramuscular metastatic tumor from primary gastric carcinoma. There were also multiple intramuscular metastatic lesions in both gluteal muscles on the MRI findings that were not detected by physical examination. Therefore, the patient underwent total gastrectomy with combined resection of spleen, with subsequent chemotherapy. Three months after the operation, we excised the gluteal tumor to alleviate the gluteal pain. Histological examinations confirmed that the gluteal tumor was a metastasis from primary gastric carcinoma.

Adenocarcinoma↗

PubMed2002

A novel type of EWS-CHOP fusion gene in two cases of myxoid liposarcoma.

Fusion genes consisting of TLS/FUS and CHOP or EWS and CHOP are characteristic markers for myxoid/round cell liposarcomas (MLS/RCLS). Several different structures of the fusion genes were reported in the case of the TLS/FUS-CHOP form, whereas only one type of structure has so far been found for the EWS-CHOP form, which consisted of exons 1 to 7 of the EWS and exons 2 to 4 of the CHOP gene. Here we describe a novel type of EWS-CHOP fusion gene in two cases of MLS/RCLS, which were found in a consecutive analysis of 21 cases. This fusion gene consisted of exons 1 to 10 of the EWS and exons 2 to 4 of the CHOP gene. The two cases with this fusion gene shared several clinical features, such as a large tumor mass, rapid and invasive growth, and local recurrence within 12 months after surgical resection. Histopathological findings also showed common features characterized by the diffuse proliferation of small spindle cells with a primitive mesenchymal appearance. The association of these clinical and histopathological features suggests a distinct biological property for this rare type of fusion product.

Adolescent↗

PubMed2002

TLS-CHOP target gene DOL54 expression in liposarcomas and malignant fibrous histiocytomas.

Downstream of the gene for the liposarcoma-associated fusion oncoprotein 54 (DOL54) is a target gene of the myxoid liposarcoma and round cell liposarcoma (M-LPS/RC-LPS) oncogene, TLS/FUS-CHOP. The DOL54 gene product is closely associated with adipogenic differentiation. DOL54 overexpression resulted in tumorigenicity when Chinese Hamster Ovary (CHO) cells were injected subcutaneously into nude mice. The biological significance of DOL54 expression for human malignant soft tissue tumors, however, has not yet been investigated. We examined TLS-CHOP and DOL54 expression in M-LPS/RC-LPS, well-differentiated liposarcoma and malignant fibrous histiocytoma (MFH), a tumor whose cellular origin has not been determined. We observed DOL54 expression in 50% of M-LPS/RC-LPS cases (in which TLS-CHOP was also expressed) and 33% of MFH cases, suggesting that a portion of MFH lesions may either derive from adipocytic precursor cells or have the potential to undergo adipogenic differentiation. In this manner, M-LPS/RC-LPS and MFH lesions may share tumorigenic characteristics, resulting from the unscheduled expression of DOL54.

Blotting, Northern↗

PubMedDate not supplied

Polymorphisms of B7 (CD80 and CD86) genes do not affect disease susceptibility to sarcoidosis.

BACKGROUND: B7 proteins (CD80, CD86) are costimulatory molecules expressed on antigen-presenting cells and are essential factors for T cell activation. OBJECTIVES: The aim of this study is to investigate the relationship of B7 gene polymorphisms either to disease susceptibility or to cell profile of bronchoalveolar lavage (BAL) fluid in Japanese sarcoidosis patients. METHODS: Gene polymorphisms located in CD80 promoter, CD80 exon 3 and exon 8 of CD86 were examined in 146 Japanese sarcoidosis patients and 157 healthy controls using single-strand conformation polymorphism and direct sequencing. The distribution of genotypes was compared between the two groups. BAL fluid cell profiles were compared for the various genotypes of the different polymorphisms for the 62 patients who underwent BAL. RESULTS: There were no significant differences in the distribution of genotypes or allele frequencies for all polymorphisms between sarcoidosis and controls. There were no significant differences in BAL fluid cell profiles among the different genotype groups of the various polymorphisms studied. CONCLUSIONS: There was no relationship between the B7 gene polymorphisms studied and disease susceptibility or BAL fluid cell profiles in Japanese sarcoidosis patients.

Antigens, CD↗

PubMedDate not supplied

Altered expression of the receptor and ligand in the TGF beta signaling pathway in diffusely infiltrating colon carcinoma.

A diffusely infiltrating colorectal carcinoma (DICC) is a distinct clinicopathological entity demonstrating invasive growth with extensive matrix production and associated with an extremely poor prognosis. The factors producing these peculiar features, however, remain to be determined. Here we investigated the receptor and ligand of the transforming growth factor (TGF) beta signaling pathway in 32 DICCs and 60 common type colorectal carcinomas (CCCs). Immunohistochemical analysis revealed that the expression of TGF beta 1 was markedly increased in DICC, especially of the schirrous type, compared to CCC, whereas the expression of the TGF beta type II receptor (RII) was significantly decreased in DICC compared to CCC. The molecular basis for the reduced expression of RII was further investigated in 15 cases of DICC with a diminished RII expression. Two somatic mutations were found: one was a missense mutation in the kinase domain (Cys533Tyr), and the other was a G to C transition at the putative Sp1 binding site in the core promoter region. The latter mutation reduced the promoter activity, which may be due to a reduced affinity of the mutant sequence to the putative transcriptional regulator, which was neither Sp1 nor Sp3. No methylated cytosine was found at any CpG sites in the promoter region. These results suggested the presence of unidentified mechanisms for the diminished expression of RII in DICC cases.

Colonic Neoplasms↗