Yoshiyasu Sumimoto

A mechanism of apoptosis induced by all-trans retinoic acid on adult T-cell leukemia cells: a possible involvement of the Tax/NF-κB signaling pathway

In this study, five single clones were randomly established by limiting dilution method from each of the HTLV-I positive T cell lines - HUT 102 and ATL-2, and examined for the all-trans retinoic acid (ATRA) sensitivity, respectively. For each clone, we found a significant correlation between the reduction in 3[H]-thymidine incorporation and the reduction in CD25 expression (r=0.701, P<0.05) following treatment with 10(-5) M ATRA for 48 h. Agarose gel electrophoresis revealed DNA fragmentation of the cell lines treated with ATRA, indicative of apoptosis. These results suggested that the tax gene in the HTLV-I genome might be a key molecule involved in cell proliferation and CD25 expression. Thereafter, we transfected the tax gene in the expression vector (pCMV-Tax-neo) into the HTLV-I(-) T cell line Jurkat and examined the effects of ATRA on cell growth. The results showed that ATRA sensitivity was acquired by the Jurkat cells transfected with the tax gene expression vector, but not in those transfected with the control vector. We also observed NF-kappaB transcriptional activity on Jurkat cells transfected with the tax gene by CAT assay in the presence or absence of ATRA. NF-kappaB transcriptional activity was decreased significantly on Jurkat cells transfected with the tax gene after ATRA treatment. Taken together, these results indicate that ATRA may affect or block the Tax/NF-kappaB signaling pathway in ATL cells.

Serum KL-6 Levels in Patients With Pulmonary Complications After Allogeneic Bone Marrow Transplantation

KL-6, a mucinous high—molecular weight glycoprotein expressed on type 2 pneumocytes, has been shown to be elevated in the serum and bronchoalveolar lavage fluid of patients with interstitial pneumonitis (IP). We measured the serum levels of KL-6 in patients after they had undergone allogeneic bone marrow transplantation (BMT) to determine whether KL-6 could be a clinically useful indicator for the development of IP. The serum concentrations of KL-6 were determined by a sandwichtype enzyme-linked immunosorbent assay using an anti—KL-6 monoclonal antibody. A total of 1028 samples were tested from 76 patients (78 transplantations) who received BMTs. The KL-6 values were markedly elevated in patients with pulmonary complications, but not in those with acute and chronic graft-versus-host disease, hemorrhagic cystitis, herpes encephalitis, sepsis, and veno-occlusive disease.The serum levels of KL-6 from patients with pulmonary complications were significantly higher than from those without pulmonary complications (P < .001) and those with other complications (P < .001). Of the 12 patients with pulmonary complications, 6 had idiopathic IP (IIP). The levels were not high at the onset of IIP. Four of 6 IIP patients showed marked elevations of KL-6 levels in parallel with the severity of IP and died of respiratory failure without response to treatment.Assessment of serum KL-6 levels might not be useful for the early diagnosis of IP, but may be a useful indicator for monitoring the severity of IP after BMT.

Possible involvement of soluble erythropoietin receptor in resistance to erythropoietin in patients with renal anemia.

Accessible online at: www.karger.com/journals/ajn Dear Sir, Recombinant human erythropoietin (rHuEpo) is effective in treating anemia associated with chronic renal failure (CRF). However, patients with CRF have sometimes developed a resistance to rEpo. This resistance can be due to iron or folate deficiency, aluminum toxicity, hyperparathyroidism, or autoantibodies for rHuEpo [1]. In this study, we focused on soluble erythropoietin receptor (sEpoR) [2], which can bind to rEpo. To prove the possibility that the sweeping of rEpo by sEpoR results in resistance to rHuEpo, we performed a bioassay using Epo-dependent cell line UT-7/Epo [3]. The growth of UT-7/Epo is not known to be inhibited by any cytokine except sEpoR. Recombinant sEpoR can reduce the proliferation of UT-7/Epo induced by rHu/Epo in a dose-dependent manner. Furthermore, the binding of 125I-labeled rEpo on UT-7/Epo has been seen to be significantly inhibited by recombinant sEpoR. We considered that this cell line could be a useful tool in a bioassay to detect the inhibitory factor(s) against Epo. We selected sera from the two groups of patients with renal anemia associated with CRF receiving hemodialysis 3 times a week, one is patient group with resistance to rHuEpo and the other patient group sensitive to rEpo. The definition of the rHuEpo resistance was described as hemoglobin rise of 1 g/dl/month despite a rHuEpo dose of 1200 U/ kg/week. Furthermore, concerning the clinical characteristics of the rHuPo-sensitive and -resistant groups regarding factors (infection, hyperparathyroid bone disease, aluminum accumulation, vitamin B12 and/ or folate deficiency, hemolysis, bone marrow dysfunction malnutrition and inadequate hemodialysis) known to create Epo resistance, no significant differences were observed between the two groups. Serum was collected the day before regular hemodialysis. Interestingly, the proliferation of UT-7/ Epo determined with [3H]thymidine incorporation was reduced significantly by the addition of sera from Epo-resistant patients, but not by the addition of sera from the Eposensitive group. These results indicate that sEpoR in serum plays an important role in the signal transduction via EpoR on erythroid progenitor in CRF patients. References

Establishment of a myelodysplastic syndrome (MDS)/secondary AML-derived T lymphoid cell line K2-MDS

We have established a T lymphoid cell line, K2-MDS, from the peripheral blood mononuclear cells (PBMC) of a patient with acute myeloblastic leukemia (AML) transformed myelodysplastic syndrome (MDS). K2-MDS cells are positive for the expression of CD4, CD5, CD13, CD25, CD71, CD95, HLA-DR and cytoplasmic CD3. Southern blotting analysis shows T cell receptor (TCR) beta chain genes rearrangements, whereas immunoglobulin heavy chain (IgH) genes are not rearranged. Further, the patient PBMC contains TCR beta chain genes rearrangements in the same manner as K2-MDS cells. The data indicate that K2-MDS is a T lymphoid cell line derived from a myelodysplastic clone in the patient PBMC. This new MDS-derived cell line K2-MDS may be a useful in vitro model for studies on the pathogenetic mechanisms leading to MDS.

Deleted mutation of GSTT-1 gene in patients with MDS.

Correspondence: Y Maeda, Third Dept of Internal Medicine, Kinki University School of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589, Japan

Establishment of a Myeloid Cell Line, YM711, Characterized by Retinoid Resistance

A myeloid cell line (YM711) was established by transfecting exogenous PML/RARα cDNA into peripheral blood stem cells. The cells were positive for CD33, CD34, CD38, CD13, CD14, and CD11b, Cytochemical examination revealed YM711 cells to be positive for peroxidase, α-naphtyl butyrate esterase, and acid phosphatase as well. Karyotypic analysis showed them to be nearly tetraploid (92 XXYY). Reverse-transcription polymerase chain reaction showed that, although PML/RARα mRNA was detected in YM711, these cells could not be differentiated by all-trans retinoic acid (ATRA). We therefore designated the YM711 cell line as being ATRA resistant. Because YM711 expressed multi drug resistance 1 (MDR-1) mRNA and p-glycoprotein cell surface protein, we assessed whether verapamil and ATRA would induce the differentiation of YM711 cells; they did not. An increased expression of cellular retinoic acid-binding protein (CRABP)-II was also detected on YM711 cells compared with that of HL-60. These results suggest that high level of expression of CRABP-II may contribute to be the mechanism of ATRA resistance. This cell line may be useful in evaluating the mechanism of resistance to retinoid.

Transient eosinophilia by HIV infection.

Abstract We describe a case of early human immunodeficiency virus infection characterized by transient eosinophilia without an elevated immunoglobulin E concentration, allergic symptoms, or atopic dermatitis. Possible mechanisms of the eosinophilia are discussed.

Soluble intercellular adhesion molecule-1 levels of patients with acute myeloid leukemia after allogeneic bone marrow transplantation☆☆☆★

Concentrations of serum-soluble intercellular adhesion molecule-1 (ICAM-1) were measured for 10 patients with or without chronic graft versus host disease after allogeneic bone marrow transplantation. Levels of soluble ICAM-1 were higher among patients with chronic graft versus host disease than among those without it, a statistically significant difference. The results indicated that measurement of serum-soluble ICAM-1 is useful for prediction of chronic graft versus host disease.

Exogenous PML/RARα Fusion Gene Responds to All-trans Retinoic Acid Results in Differentiation of the Human B Cell Line.

The interaction of an exogenous PML/RARα fusion gene, associated with acute promyelocytic leukemia, with all-trans retinoic acid (ATRA) was examined in B-lymphoid cell lines. RPMI8866 cells were transfected with PML/RARα cDNA in the expression vector pGD and two stable transformants (RPMI8866Y-4 and RPMI8866Y-17) were established by selection with G418. ATRA inhibited the growth of those stable transformants, as assessed by [3H]-thymidine incorporation, but had no effect on the growth of control cells stably transformed with neomycin resistant gene alone. ATRA also increased expression of CD38 and immunoglobulin production in RPMI8866Y-4 cells but not in control cells. When these results are taken together, it can be observed that the exogenous PML/RARα fusion gene responds to ATRA, which results in cell differentiation of the human B cell line.