Functionally active telomerase is affected at various steps including transcriptional and post-transcriptional levels of major telomerase components (hTR and human telomerase reverse transcriptase (hTERT)). We therefore developed a rapid and sensitive method to quantify hTERT and its splicing variants as well as the hTR by a Taqman real-time reverse transcriptase -polymerase chain reaction to determine whether their altered expression may contribute to telomere attrition in vivo or not. Fresh leukaemia cells obtained from 38 consecutive patients were used in this study. The enzymatic level of telomerase activity measured by TRAP assay was generally associated with the copy numbers of full-length hTERT þ a þ b mRNA (P ¼ 0.0024), but did not correlate with hTR expression (P ¼ 0.6753). In spite of high copy numbers of full-length hTERT mRNA, telomerase activity was low in some cases correlating with low copy numbers of hTR, raising the possibility that alteration of the hTR : hTERT ratio may affect functionally active telomerase activity in vivo. The spliced nonactive hTERT mRNA tends to be lower in patients with high telomerase activity, suggesting that this epiphenomenon may play some role in telomerase regulation. An understanding of the complexities of telomerase gene regulation in biologically heterogeneous leukaemia cells may offer new therapeutic approaches to the treatment of acute leukaemia.
Summary. We encountered a patient with Philadelphianegative chronic myeloid leukaemia, with t(7;11)(p15;p15), in whom acute leukaemia phase (acute myeloid leukaemia-M2 morphology) developed within a short period. We detected a novel gene fusion between NUP98 and HOXA11 both in the chronic phase and in the acute leukaemia phase in this case. Although it is well known that a fusion of NUP98±HOXA9 in myeloid malignancies is created by the t(7;11)(p15;p15), this case suggests the possibility that HOXA11 might be another partner gene for NUP98 in t(7;11)(p15;p15) leukaemia.Keywords: CML, AML, NUP98, HOXA11, t(7;11).Translocation between chromosomal loci 7p15 and 11p15 was ®rst identi®ed in patients with Ph-negative chronic myeloid leukaemia (CML) (Kaneko et al, 1985), and this balanced translocation has recently been recognized to constitute a subset of acute myeloid leukaemia (AML) (Ohyashiki et al, 1987;Sato et al, 1987). Both Nakamura et al (1996) and Borrow et al (1996) demonstrated that the nucleoporin gene NUP98 is fused to HOXA9 by the t(7;11), and this fusion has thus been considered to be an essential genetic event for leukaemogenesis in patients with t(7;11), including AML (Borrow et al, 1996;Nakamura et al, 1996), Ph-positive CML (Yamamoto et al, 1999) and some patients with myelodysplastic syndromes (Hatano et al, 1999;Wong et al, 1999). We report here a patient with Ph-negative CML, but with t(7;11), who developed an acute leukaemia phase within a very short period. In this patient a novel fusion between NUP98 and HOXA11 was detected. CASE REPORTA 58-year-old Japanese woman was found to have leucocytosis and anaemia. Haematological ®ndings revealed the white blood cell (WBC) count to be 11á2´10 9 /l, including 0á5% metamyelocytes, 2á5% stab cells, 81á0% segmented cells, a haemoglobin (Hb) level of 10á0 g/dl, and a platelet count of 175´10 9 /l. Neither eosinophilia nor basophilia was present. A bone marrow aspirate revealed a hypercellular marrow (nucleated cell count of 1á386´10 12 /l) and myeloid hyperplasia (myeloid/erythroid ratio 26á1) with 7á2% myeloblasts, 10á4% promyelocytes, 26á8% myelocytes, 5á2% metamyelocytes, 28á0% stab cells and 15á6% segmented cells. Biochemical results were all within normal ranges, but serum vitamin B 12 was elevated (1800 ng/l) and there was a low level of neutrophil alkaline phosphatase (rate 27%, score 69). Chromosome study of the bone marrow cells revealed 46,XX,t(7;11)(p15;p15) in all 21 cells analysed. Based on the haematological data, the patient was diagnosed as Ph-negative CML with t(7;11). She was given hydroxyurea for about 1 month until admission owing to deterioration of haematological features.In October 2000, she was admitted to our hospital for re-evaluation of leukaemia. At this time, her WBC count was 40á3´10 9 /l, including 55% myeloblasts and 2% promyelocytes, a Hb level of 7á4 g/dl, and a platelet count of 68´10 9 /l. A bone marrow aspirate showed hypercelluar marrow with 84á5% myeloblasts and 5á6% promyelocytes. The blasts were positive for myelope...
To examine the properties of androphilic proteins in human benign prostatic hypertrophy, the binding capacity and affinity of the proteins were determined after acetone-treatment, ammonium sulfate precipitation and chromatographies of DEAE and Sephadex G-200. Androphilic proteins in the extract of acetone-dried cytosol from the hypertrophic human prostate was precipitated at 30-50% saturation of ammonium sulfate. The binding of this fraction to dihydrotestosterone and testosterone was high affinity, but the binidng to estradiol-17 beta was the one of non-specific. Androphilic proteins in the 30-50% fraction were eluted from DEAE-cellulose column by buffer containing 0.05 M KCL. On Sephadex G-200 chromatography of 30-50% fraction, the androphilic proteins were observed in three peaks; one was eluted in the void volume and other two were eluted at the sites of IgG and albumin. The amount and ratio of proteins eluted in the void volume and the site of IgG from Sephadex G-200 column were variable in individual tissue samples. The chromatographic behavior of the 30-50% fraction in Sephadex G-200 was not changed significantly by introducing 0.4 M KCl in the system. Polyacrylamide gel electrophoresis was applied for further separation of the proteins.
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