Biomedical subjects

Takashi Shimoji

Publications and source records attributed to Takashi Shimoji.

4 recordsLinked to original sources

PubMed2006

[Gene expression profiling for prediction of response to chemotherapy].

Numerous genes whose expression is controlled by complex regulatory networks are involved in the development and progression of each cancer,and those genes will be the key factors for determining each characteristic of the tumor. The recent development of DNA microarray and related technologies provides an opportunity to perform more detailed characterization( profiling) of individual tumor cells. Indeed, the gene expression profile of a tumor provides a unique molecular portrait or signature that can be correlated with clinical behavior and drug responsiveness. The development of personalized( or customized) medicine and molecularly targeted drugs is enthusiastically awaited based on the results of research examining genomic diversity such as SNPs( single nucleotide polymorphisms), gene expression profiling with DNA microarrays, and analysis of protein expression and interactions.

Antineoplastic Agents↗

PubMed2004

Clinico-molecular study of dedifferentiation in well-differentiated liposarcoma.

Well-differentiated liposarcoma (WD) acquires fully malignant potential when the histological progression named dedifferentiation occurs. This progression is supposed to occur in a time-dependent manner but this is still a debated issue. Clinically, the prediction of dedifferentiation for WD is very important from the therapeutic point of view. To identify genes that are predictive of dedifferentiation and to understand the mechanism of dedifferentiation, we investigated clinical information of 50 cases and studied the gene expression profiles of 36 lipomatous tumors using cDNA microarray. The clinical study showed that the dedifferentiation did not always seem to occur in a time-dependent manner. Interestingly, from the gene expression study, unsupervised hierarchical clustering analysis of well-differentiated lesions obtained from dedifferentiated liposarcoma (DD) cases that were indistinguishable from WD pathologically showed a clearly distinct gene expression pattern from WD. Using the pattern-matching program, 1687 genes including 487 known genes were identified, which discriminated WD cases from well-differentiated lipomatous lesions obtained from DD cases. These results suggest that the dedifferentiation may arise from different types of WD that could be distinguished from gene expression profiling but could hardly be classified by the pathological studies.

Base Sequence↗

PubMed2004

[Surgical treatment for bone and soft tissue sarcoma].

There are many kinds of wide excision or wide resection, which are methods to remove the tumor with surrounding tissues. The curability of wide resection depends on the range and characteristics of the normal surrounding tissues. The fascia, periosteum and perivascular sheath act as barriers against invasion of tumors. Therefore, evaluation of the surgical margin is essential in surgery for malignancy. Some sarcomas characteristically show invasive growth patterns while others have a discrete border. Causes of the local recurrence are 1) insufficient surgical margin, 2) skip metastasis, 3) tumor thrombus, and 4) lymph node metastasis. The so-called "Safety surgical margin" is the margin that prevents local recurrence due to insufficient surgical treatment. Local recurrence due to other causes can not be treated by surgery alone as chemotherapy is also required. For example, the infiltrative type of malignant fibrous histiocytoma requires a curative procedure. On the other hand, non-infiltrative types of sarcoma or high-grade sarcoma, which are good responders to preoperative treatment, are locally controlled by an adequate wide margin procedure. When the tumor is close to the bone, main vessels and/or nerves, it is sometimes very difficult to preoperatively decide whether or not to sacrifice these important organs. A new surgical method, "In Situ Preparation (ISP)," is a useful method to solve such problems. ISP makes it possible to evaluate the surgical margin without contamination. And additional procedures including alcohol soaking or pasteurization can be achieved according to the surgical margin. Because ISP can prevent overtreatment, the number of our cases that require resection of the nerves or vessels have decreased. After a wide resection, there have been many possible complications, including infection, deep venous thrombosis, loosening of prosthesis, skin necrosis, and arterial occlusion. Once postoperative complications occur, patients must remain in the hospital for a long time. To prevent this, the preservation of normal tissue, meaning reduction of surgical margin, is important.

Blood Vessel Prosthesis Implantation↗

PubMed2003

Systematic expression profiling of the mouse transcriptome using RIKEN cDNA microarrays.

The number of known mRNA transcripts in the mouse has been greatly expanded by the RIKEN Mouse Gene Encyclopedia project. Validation of their reproducible expression in a tissue is an important contribution to the study of functional genomics. In this report, we determine the expression profile of 57,931 clones on 20 mouse tissues using cDNA microarrays. Of these 57,931 clones, 22,928 clones correspond to the FANTOM2 clone set. The set represents 20,234 transcriptional units (TUs) out of 33,409 TUs in the FANTOM2 set. We identified 7206 separate clones that satisfied stringent criteria for tissue-specific expression. Gene Ontology terms were assigned for these 7206 clones, and the proportion of 'molecular function' ontology for each tissue-specific clone was examined. These data will provide insights into the function of each tissue. Tissue-specific gene expression profiles obtained using our cDNA microarrays were also compared with the data extracted from the GNF Expression Atlas based on Affymetrix microarrays. One major outcome of the RIKEN transcriptome analysis is the identification of numerous nonprotein-coding mRNAs. The expression profile was also used to obtain evidence of expression for putative noncoding RNAs. In addition, 1926 clones (70%) of 2768 clones that were categorized as "unknown EST," and 1969 (58%) clones of 3388 clones that were categorized as "unclassifiable" were also shown to be reproducibly expressed.

Animals↗