Biomedical subjects

Yasuo Takimoto

Publications and source records attributed to Yasuo Takimoto.

7 recordsLinked to original sources

PubMed2005

The maturation of myeloma cells correlates with sensitivity to chemotherapeutic agents.

We analyzed both morphologic and phenotypic findings of myeloma cells before and after chemotherapy in 21 patients with multiple myeloma. The morphologic analysis was based on the Greipp classification, and phenotypic analysis was performed by 3-color flow cytometry using the CD38 plasma gating method (Marrow plasma 38). Results with flow cytometry using a combination of MPC1, CD49e, and CD45 supported the morphologic findings for the myeloma cells. Treatment with 3 or 4 cycles of VAD (vincristine, doxorubicin, and dexamethasone) therapy was effective in reducing the total numbers of myeloma cells, but the proportion of immature myeloma cells increased after this treatment. However, the immature myeloma cells were reduced by high-dose melphalan (HD-Mel) therapy followed by autologous stem cell transplantation (ASCT). High-dose cyclophosphamide treatment for stem cell harvesting did not show an effect on the residual immature myeloma cells after VAD treatment. In addition, thalidomide was not effective in reducing the numbers of immature myeloma cells. These results suggest that VAD (3 or 4 cycles) therapy plus HD-Mel followed by ASCT is a reasonable treatment for multiple myeloma and that Marrow plasma 38 analysis is a useful method for monitoring the response of multiple myeloma to chemotherapy.

ADP-ribosyl Cyclase↗

PubMed2004

Progressive myeloma after thalidomide therapy in a patient with immature phenotype of myeloma (plasma) cells.

In our experience with thalidomide treatment for refractory multiple myeloma (MM), most patients with progressive disease (PD) did not show an increase in M-protein despite the tumor burden of myeloma cells. This finding led us to suspect that proliferation of immature myeloma cells showing MPC-1(-)/CD49e(-) phenotype may be a sign of PD. We report the results of consecutive analysis of the phenotype of myeloma (plasma) cells in an MM patient with PD during treatment with thalidomide. The myeloma cells decreased by thalidomide therapy were mature (MPC-1(+)/CD49e(+)) and intermediate (MPC-1(+)/CD49e(-)) types. When the patient was in the PD state, extramedullary plasmacytoma was recognized without proliferation of myeloma cells in the bone marrow (BM). The phenotype of myeloma (plasma) cells in both of these locations was that of immature myeloma cells (MPC-1(-)/CD49e(-)), and they showed decreased intensity of CD38 expression. The level of immunoglobulin G (IgG) in serum was decreased, and myeloma (plasma) cells in BM did not increase in PD. Although these clinical features may not be specific to MM patients in PD undergoing treatment with thalidomide, we suggest that immature myeloma cells may be resistant to thalidomide.

Aged↗

PubMed2004

[Chronic myelogenous leukemia following therapy for pineal germinoma].

A 13-year-old male was diagnosed as having pineal germinoma in July 1998. Since then, he had been treated with tumor excision, radiation and chemotherapy. In June 2002, he was diagnosed as having the chronic phase of chronic myelogenous leukemia (CML), and following treatment with interferon-alpha, he achieved hematological complete remission. Although CML is rare in secondary leukemia, the present case seemed therapy-related CML because of its clinical course, as the CML occurred after the period with radiation and chemotherapy. This is the first case of secondary CML following therapy for intracranial tumors.

Adolescent↗

PubMed2004

Cyclin D1 overexpression is not a specific grouping marker, but may collaborate with CDC37 in myeloma cells.

Cyclin D1 is a positive-regulator of the cell cycle and is overexpressed in myeloma cells with t(11;14)(q13;q32). First, we analyzed whether there was a correlation between cyclin D1 overexpression and the presence of Ki67-positive myeloma cells in multiple myeloma (MM). Cyclin D1 overexpression was examined by competitive RT-PCR. Then we found these two markers were present independently in a given case. FISH analysis revealed that cyclin D1 over-expression was caused by t(11;14)(q13;q32) or extra copies of B-cell leukemia/lymphoma-1 (BCL-1/CCND1), and unknown mechanism without them. We compared the gene expression between myeloma cells with cyclin D1 overexpression and those without it using cDNA microarray analysis. Analysis of the expression profiles showed that the significantly up-regulated genes included cyclin D1, cell division cycle 37 (CDC37) and B-cell leukemia/lymphoma-2 (BCL-2), while the down-regulated genes included cyclin D2 and CD9 antigen (p24) in MM cases with cyclin D1 overexpression. However, hierarchical clustering analysis of the data showed that myeloma cells of MM cases with cyclin D1 overexpression could not be distinguished clearly from those without it. Real-time RT-PCR showed that the expression of CDC37 gene was significantly up-regulated in MM patients with cyclin D1 overexpression compared with those without it (p=0.0418). However, there was no significant difference in BCL-2 gene (p=0.5748). These results suggested that MM cases with cyclin D1 overexpression do not constitute a specific group, and cyclin D1 overexpression may not be caused only by abnormality of the BCL-1/CCND1 gene. The CDC37 may collaborate with cyclin D1 in progression of MM.

Biomarkers, Tumor↗

PubMed2003

A possible role for the loss of CD27-CD70 interaction in myelomagenesis.

CD27 is a marker of memory B cells and its interaction with its ligand, CD70, is very important for differentiation into plasma cells. Although CD27 is detected on normal plasma cells, its expression is significantly reduced with the progression of multiple myeloma (MM), including monoclonal gammopathy of undetermined significance (MGUS). CD27+ myeloma cells are thought to represent an early phase of myeloma, as CD27+ plasma cells from MM patients were found to be composed of normal plasma cells (CD19+/CD38++) and myeloma cells (CD19-/CD38++), and monoclonality was detected in the CD27+/CD38++ fraction. Given that the lack of CD27 on plasma cells is related to myelomagenesis and that the pro-apoptotic protein Siva is thought to bind to the cytoplasmic tail of CD27, we analysed alterations of cell growth and genes caused by co-culturing CD27-transfected myeloma cell lines (U266, KMS-5) with CD70-transfected NIH3T3 cells. CD27-CD70 interaction could not induce apoptosis in either type of myeloma transfectant, and binding between Siva and CD27 was not detected. cDNA microarray (human apoptosis CHIP) analysis showed a significant upregulation of expression of the ectodermal neural cortex 1 (ENC1) gene by CD27-CD70 interaction compared with CD27 transfection alone. These findings show that the relationship between the loss of CD27 and oncogenesis of plasma cells is not simple. It remains unclear whether the lack of CD27 leads to evasion of apoptosis.

3T3 Cells↗

PubMed2003

[Single-agent thalidomide for advanced and refractory multiple myeloma].

Thalidomide as a single agent (200-400 mg/day) was administered in fourteen cases of refractory myeloma, from March 2001 till February 2002. The median age was 71 years (range 58 to 85 years), and the efficacy of thalidomide was observed in cases receiving treatment for at least three consecutive months. Response was evaluated in February 2002, according to the criteria for assessment of response described by Kakimoto et al. At the time of evaluation, two cases were in the PR2 state, one in PR3, two were stable, and three were PD. Evaluation of the response was not possible in six cases in whom treatment had to be discontinued due to intolerable side effects. The response to thalidomide was variable, with some cases responding well even to a low dose (200 mg/day) while a few others showed an early relapse due to the refractory nature of the disease in its response to the drug. The efficacy of treatment seemed to be correlated with the maturation pattern of myeloma cells. Side effects included neurological complications like somnolence, physiological symptoms such as constipation and so on, etc but all were relieved with symptomatic treatment. The drug was well tolerated in geriatric patients. Neutropenia was a dose limiting factor with half of the cases (7/14) presenting with severe neutropenia (grade 3-4), but a response was observed in all of them on administration of G-CSF. Thromboembolism occurred in two cases, the cause of which is not clear. These results suggest that thalidomide is a well tolerated drug and can be considered as a mainstay in the therapy of refractory myeloma.

Aged↗

PubMed2002

High expression of MCL1 gene related to vascular endothelial growth factor is associated with poor outcome in non-Hodgkin's lymphoma.

We evaluated the level of MCL1 gene expression using quantitative reverse transcription polymerase chain reaction in lymph nodes of patients with non-Hodgkin lymphoma (NHL). MCL1 expression in patients in complete remission (CR) was significantly lower than in patients with progressive disease (PD, P = 0.0043). The disease-free survival rate was significantly higher in patients with MCL1 levels below the median level (P = 0.007). We also found that the level of expression of MCL1 mRNA was related to that of vascular endothelial growth factor mRNA in NHL lymph nodes. Our data suggest that the MCL1 expression level could be considered a prognostic factor in NHL.

Adolescent↗