Donor-derived T-cell leukemia after bone marrow transplantation.
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Adult↗
Biomedical subjects
Hiroya Tamaki
Publications and source records attributed to Hiroya Tamaki.
Different kinetics of WT1 and PML-RARalpha gene expression levels during remission induction therapy with all-trans retinoic acid alone in acute promyelocytic leukemia.
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Adult↗
[Clinical course of the disease and the level of WT1 mRNA in 191 patients with acute myeloid leukemia (AML): joint research by 23 institutions in Japan].
We evaluated the clinical course of acute myeloid leukemia (AML) and the levels of WT1 mRNA in 191 AML patients. Of 114 previously untreated patients with AML, 107 cases were positive for WT1 mRNA (93.9% : 107/114). WT1 mRNA expression-levels declined to below 50 copies/microg RNA ("negative") after remission was achieved in all 66 patients who achieved remission and 84.8% (47/54) cases were "negative" at the end of the follow-up periods. On the other hand, WT1 mRNA was expressed in 87.0% of non-remission cases (47/54), maintaining 50 copies/microg of RNA or higher ("positive"). In all 29 cases who relapsed during the follow-up observation period after achieving remission, WT1 mRNA levels declined transiently approximately around the time of achieving remission and then rose again when the disease relapsed. Moreover, we determined the time of elevation of WT1 mRNA in 29 relapsed cases. In 79.3% of relapsed cases (23/29), WT1 mRNA levels rose above 200 copies/microg RNA, 43 days (median) before the diagnosis of "relapse". Given the percent of the correct diagnosis, WT1 mRNA at 200 copies/microg RNA appeared to be a reasonable cut-off level for early detection of AML-relapse. The WT1 mRNA level reflected the clinical condition. Taken together, these findings indicate that WT1 mRNA levels allow us to detect the presence of so-called "minimal residual disease" (leukemic cells) that cannot be detected by morphological examination. Besides these promising data, this kit is suitable for routine monitoring of AML because this kit utilizes peripheral blood as a test specimen, reducing the patient's burden at the time of collection of clinical samples as compared with bone marrow aspirate.
Adult↗
WT1 gene transcript assay for relapse in acute leukemia after transplantation.
The WT1 gene is highly expressed in various types of leukemia, particularly in acute type leukemia. The extent of minimal residual disease (MRD) of leukemia can be evaluated by measuring the WT1 gene expression level using a quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) method. The WT1 transcript assay can be applied to almost all patients with leukemia regardless of the presence or absence of chimeric DNA markers. Furthermore, because of the fact that WT1 expression levels increase significantly at relapse compared with those at the time of diagnosis, and because of the decrease in background levels of WT1 expression in bone marrow following allogeneic SCT, the WT1 transcript assay possesses a high degree of sensitivity following allogeneic SCT. Frequent monitoring of the WT1 gene expression level predicts the risk of relapse following allogeneic SCT, and furthermore, the kinetics of WT1 transcripts predict the efficacy of immunomodulation therapy such as donor leukocyte infusion.
Acute Disease↗
Successful treatment of tacrolimus (FK506)-related leukoencephalopathy with cerebral hemorrhage in a patient who underwent nonmyeloablative stem cell transplantation.
A 46-year-old woman with Hodgkin's disease who underwent nonmyeloablative allogeneic stem cell transplantation developed cortical blindness, seizures, and left hemiparesis on day 100 while receiving tacrolimus (FK506) and prednisone for the treatment of graft-versus-host disease (GVHD). Magnetic resonance imaging revealed multiple changes, mainly in the bilateral occipital lobes, suggesting FK506-related leukoencephalopathy. These abnormalities improved after discontinuation of FK506. However, 3 days after the episode, cerebral hemorrhage in the left occipital lobe with perforation to the left subdural space occurred. Although FK506-induced leukoencephalopathy with cerebral hemorrhage is considered the more severe form of such leukoencephalopathy, the patient's neurological symptoms almost completely resolved and radiographic findings improved after discontinuation of FK506, tapering of methylprednisolone, and initiation of mycophenolate mofetil. FK506-related leukoencephalopathy is a rare complication after allogeneic stem cell transplantation. Although the symptoms usually subside after discontinuation of FK506, therapeutic intervention in many cases may result in severe complications, including GVHD and vascular disease. We consider it important to use immunosuppressive agents without vascular endothelial toxicity for preventing the development of fatal GVHD after discontinuation of FK506.
Cerebral Hemorrhage↗
[Molecular quantitation of minimal residual disease in leukemia].
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Biomarkers, Tumor↗
Monitoring minimal residual disease in leukemia using real-time quantitative polymerase chain reaction for Wilms tumor gene (WT1).
We previously showed that Wilms tumor gene (WT1) expression level, measured by quantitative reverse transcriptase polymerase chain reaction (RT-PCR), was useful as an indicator of minimal residual disease (MRD) in leukemia and myelodysplastic syndrome. However, in conventional quantitative RT-PCR (CQ-PCR), RT-PCR must be performed for various numbers of cycles depending on WT1 expression level. In the present study, we developed a new real-time quantitative RT-PCR (RQ-PCR) method for quantitating WT1 transcripts. Results of intraassay and interassay variability tests demonstrated that the real-time WT1 assay had high reproducibility. WT1 expression levels measured by the RQ- and the CQ-PCR methods were strongly correlated (r = 0.998). Furthermore, a strong correlation was observed among WT1 transcript values normalized with 3 different control genes (beta-actin, ABL, and glyceraldehyde-3-phosphate dehydrogenase) and between relative WT1 transcript values with WT1 expression in K562 cells as the reference and absolute WT1 transcript copy numbers per microgram RNA. When WT1 expression and minor bcr-abl expression were concurrently monitored in 2 patients with bcr-abl-positive acute lymphoblastic leukemia, both MRDs changed mostly in parallel, indicating the reliability and validity of our RQ-PCR method. In conclusion, this RQ-PCR method is convenient and reliable for monitoring MRD and enables routine clinical use of a WT1 assay.
Gene Dosage↗
The usefulness of monitoring WT1 gene transcripts for the prediction and management of relapse following allogeneic stem cell transplantation in acute type leukemia.
In acute-type leukemia, no method for the prediction of relapse following allogeneic stem cell transplantation based on minimal residual disease (MRD) levels is established yet. In the present study, MRD in 72 cases of allogeneic transplantation for acute myeloid leukemia, acute lymphoid leukemia, and chronic myeloid leukemia (accelerated phase or blast crisis) was monitored frequently by quantitating the transcript of WT1 gene, a "panleukemic MRD marker," using reverse transcriptase-polymerase chain reaction. Based on the negativity of expression of chimeric genes, the background level of WT1 transcripts in bone marrow following allogeneic transplantation was significantly decreased compared with the level in healthy volunteers. The probability of relapse occurring within 40 days significantly increased step-by-step according to the increase in WT1 expression level (100% for 1.0 x 10(-2)-5.0 x 10(-2), 44.4% for 4.0 x 10(-3)-1.0 x 10(-2), 10.2% for 4.0 x 10(-4)-4.0 x 10(-3), and 0.8% for < 4.0 x 10(-4)) when WT1 level in K562 was defined as 1.0). WT1 levels in patients having relapse increased exponentially with a constant doubling time. The doubling time of the WT1 level in patients for whom the discontinuation of immunosuppressive agents or donor leukocyte infusion was effective was significantly longer than that for patients in whom it was not (P <.05). No patients with a short doubling time of WT1 transcripts (< 13 days) responded to these immunomodulation therapies. These findings strongly suggest that the WT1 assay is very useful for the prediction and management of relapse following allogeneic stem cell transplantation regardless of the presence of chimeric gene markers.
Acute Disease↗
Combination of tacrolimus, methotrexate, and methylprednisolone prevents acute but not chronic graft-versus-host disease in unrelated bone marrow transplantation.
BACKGROUND: Graft-versus-host disease (GVHD) is still a major problem in allogeneic bone marrow transplantation (BMT). Prophylactic regimens used against GVHD in unrelated BMT, including cyclosporine (CsA)-plus-methotrexate (MTX), CsA-plus-MTX-plus-prednisone, and tacrolimus (FK506)-plus-MTX, are still unsatisfactory (34-70% occurrence of grades II-IV GVHD). To address this problem, we examined the efficacy of FK506-plus-MTX-plus-methylprednisolone (mPSL) in 20 patients who underwent BMT from unrelated donors. METHODS: All patients received FK506 beginning the day before transplantation at a dose of 0.03 mg/kg per day by continuous intravenous (IV) infusion. MTX was administered at a dose of 10 mg/m(2) IV on day 1, and 7 mg/m(2) on days 3, 6, and 11. Intravenous administration of mPSL was started at a dose of 2 mg/kg per day on day 1. In the absence of acute GVHD, mPSL was gradually tapered from day 29. RESULTS: Development of acute GVHD was almost completely suppressed (one patient with grade I, none with grades II-IV). However, the incidence and severity of chronic GVHD did not decrease. Eight of 12 patients with extensive chronic GVHD died of thrombotic microangiopathy or infection. A vigorous fluctuation (>100 U/mL per 10 days) of the soluble interleukin 2 receptor level in the serum after engraftment was highly related to the occurrence of chronic GVHD. CONCLUSIONS: An FK506-plus(+)-MTX-plus(+)-mPSL prophylactic regimen could almost completely suppress acute GVHD but not chronic GVHD in unrelated BMT. In this GVHD prophylactic system, the extent of the change of soluble interleukin 2 receptor level may be a good predictor of development of chronic GVHD.
Acute Disease↗
Overexpression of the Wilms' tumor gene WT1 in de novo lung cancers.
Expression of the Wilms' tumor gene WT1 in de novo lung cancer was examined using quantitative real-time RT-PCR and immunohistochemistry. Overexpression of the WT1 gene was detected by RT-PCR in 54/56 (96%) de novo non-small cell lung cancers examined and confirmed by detection of WT1 protein with an anti-WT1 antibody. Overexpression of the WT1 gene was also demonstrated in 5/6 (83%) de novo small cell lung cancers by immunohistochemistry. Furthermore, when the WT1 gene was examined for mutations by direct sequencing of genomic DNA in 7 lung cancers, no mutations were found. These results suggest that the nonmutated, wild-type WT1 gene plays an important role in tumorigenesis of de novo lung cancers and may provide us with the rationale for new therapeutic strategies for lung cancer targeting the WT1 gene and its products.
Aged↗
Humoral immune responses against Wilms tumor gene WT1 product in patients with hematopoietic malignancies.
Wilms tumor gene WT1 is expressed at high levels in hematopoietic malignancies, such as leukemias and myelodysplastic syndromes (MDS), and in various kinds of solid tumors, including lung cancer, and it exerts an oncogenic function in these malignancies. IgM and IgG WT1 antibodies were measured by means of dot blot assay in 73 patients with hematopoietic malignancies (16 acute myeloid leukemia [AML], 11 acute lymphoid leukemia [ALL], 13 chronic myeloid leukemia [CML], and 33 MDS) and 43 healthy volunteers. Immunoglobulin IgM, IgG, and IgM+IgG WT1 antibodies were detected in 40 (54.8%), 40 (54.8%), and 24 (32.8%), respectively, of the 73 patients with hematopoietic malignancies, whereas 7 (16.2%), 2 (4.7%), and none of the 43 healthy volunteers had IgM, IgG, or IgM+IgG WT1 antibodies, respectively. Furthermore, immunoglobulin isotype class switching of WT1 antibodies from IgM to IgG occurred in conjunction with disease progression from refractory anemia (RA) to RA with excess of blasts (RAEB), and further to RAEB in transformation (RAEB-t) in MDS patients. These results showed that humoral immune responses against the WT1 protein could be elicited in patients with WT1-expressing hematopoietic malignancies, and they suggested that the helper T-cell responses needed to induce humoral immune responses and immunoglobulin isotype class switching from IgM to IgG were also generated in these patients. Our findings may provide new insight into the rationale for elicitation of cytotoxic T-cell responses against the WT1 protein in cancer immunotherapy using the WT1 vaccine.
Adolescent↗
Very low frequencies of human normal CD34+ haematopoietic progenitor cells express the Wilms' tumour gene WT1 at levels similar to those in leukaemia cells.
The Wilms' tumour gene, WT1, is expressed at high levels in leukaemia cells and plays an important role in leukaemogenesis. WT1 is also expressed in human normal CD34+ bone marrow (BM) cells at about 100 times lower levels than in leukaemia cells. To identify and characterize WT1-expressing cells in CD34+ BM cells, they were sorted into single cells and analysed for WT1 expression using two kinds of single-cell reverse transcriptase polymerase chain reaction (RT-PCR) methods. Using the semiquantitative single-cell polyA-PCR + sequence-specific (SS)-PCR method, WT1 expression was detected in four (1.3%) out of 319 CD34+ BM single cells. To confirm the above results, a single-cell nested sequence-specific (NSS)-RT-PCR method that was less quantitative but more sensitive than the polyA-PCR + SS-PCR method was also performed, and WT1 expression was detected in 15 (1.1%) out of 1315 CD34+ BM single cells. In total, WT1 expression was found in 19 (1.2%) out of 1634 CD34+ BM single cells. No significant differences in the frequencies of WT1-expressing cells were found between CD34+CD38- and CD34+CD38+ BM single cells. Furthermore, WT1-expressing CD34+ BM single cells expressed WT1 at levels similar to those in K562 leukaemia single cells. Analysis of lineage-specific and cell cycle gene expression in WT1-expressing CD34+ BM single cells showed that the WT1 gene could be expressed in both uncommitted, dormant CD34+CD38- and lineage-committed, proliferating CD34+CD38+ BM cells. Our results could indicate that these WT1-expressing CD34+ BM cells were normal counterparts of leukaemia cells.
Antigens, CD34↗
High expression of Wilms' tumor suppressor gene predicts poor prognosis in breast cancer patients.
PURPOSE: The prognostic significance of the Wilms' tumor suppressor gene(WT1) mRNA expression was evaluated in patients with invasive breast cancer. EXPERIMENTAL DESIGN: WT1 mRNA expression in tumor tissues (n = 99) was examined by a quantitative, real-time PCR assay. RESULTS: No significant association was observed between WT1 mRNA levels and clinicopathological parameters such as menopausal status, tumor size, lymph node status, histological grade, and estrogen receptor status. Five-year disease-free survival rate of patients with high WT1 mRNA levels (62.6%) was significantly (P < 0.05) poorer than those with low WT1 mRNA levels (77.2%). Lymph node metastasis (P < 0.05), high histological grade (P < 0.01), and estrogen receptor negativity (P < 0.05) were also significantly associated with poor prognosis, respectively. Multivariate analysis revealed that WT1 mRNA levels were a significant prognostic factor, independent of the other conventional prognostic factors. CONCLUSIONS: These results suggest that measurement of WT1 mRNA levels in tumor tissues might be useful as a new prognostic factor in breast cancer patients.
Adult↗