Min-Fei Pei

Use of all-trans retinoic acid in combination with arsenic trioxide for remission induction in patients with newly diagnosed acute promyelocytic leukemia and for consolidation/maintenance in CR patients.

In the present study, 90 patients with newly diagnosed acute promyelocytic leukemia (APL) were studied for all-trans retinoic acid (ATRA) and arsenic trioxide (As2O3) combination treatment in remission induction and postremission therapy. In addition, 20 APL patients who had achieved complete remission (CR) with an ATRA-based regimen received ATRA/As2O3 combination for consolidation and maintenance were also enrolled. The results showed that ATRA/As2O3 combination therapy yielded a high CR rate of 93.3% and a significantly shorter time to enter CR (median: 31 days; range: 18–59 days) compared to the ATRA-based regimen (n = 72; median: 39 days; range: 25–62 days). With the ATRA/As2O3 combination for CR maintaining, regardless of the way by which CR was attained, the relapse-free survival was significantly better than with an ATRA plus cytotoxic chemotherapy regimen (92.9 ± 3.2% vs. 72.4 ± 7.6%, for the 3-year Kaplan-Meier estimate of relapse-free survival). The drug toxicity profile showed that with the use of As2O3, the incidence of hepatotoxicity was obviously high during remission induction but decreased significantly during postremission treatment. We conclude that APL patients may benefit from the early use of the combination of ATRA and As2O3, in either remission induction or consolidation/maintenance.

Decreased 5-hydroxymethylcytosine levels are associated with TET2 mutation and unfavorable overall survival in myelodysplastic syndromes

Abstract The clinical significance and mechanisms of TET2 are not well defined in myeloid malignancies. We detected TET2 mutations and assayed its catalyzing conversion product 5-hydroxymethylcytosine (5-hmC) in 61 Chinese patients with MDS. Ten patients were identified to have TET2 mutations (16.4%). 5-hmC levels in patients with MDS with TET2 mutations were significantly lower than in those without mutations, and CD34+ cells of patients with MDS exhibited a lower 5-hmC content than that of controls. TET2 expression and 5-hmC in patients with MDS with P15 methylation were both significantly lower than in those without P15 methylation. We did not observe a correlation between TET2 mutations and overall survival (OS) in MDS. Interestingly, we found that patients with MDS with higher 5-hmC levels or in lower risk groups of the Revised International Prognostic Scoring System (IPSS-R) had a longer overall survival, suggesting that 5-hmC levels may be a new molecular marker for prognostic assessment of MDS and that revised IPSS criteria are also applicable to the risk categories of Chinese patients with MDS.

Deregulation of Mitochondrial ATPsyn-β in Acute Myeloid Leukemia Cells and with Increased Drug Resistance

The mechanisms underlying the development of multidrug resistance in acute myeloid leukemia are not fully understood. Here we analyzed the expressions of mitochondrial ATPsyn-β in adriamycin-resistant cell line HL-60/ADM and its parental cell line HL-60. Meanwhile we compared the differences of mitochondrial ATPsyn-β expression and ATP synthase activity in 110 acute myeloid leukemia (AML, non-M3) patients between relapsed/refractory and those in remission. Our results showed that down-regulation of ATPsyn-β expression by siRNA in HL-60 cells increased cell viability and apoptotic resistance to adriamycin, while up-regulation of mitochondrial ATPsyn-β in HL-60/ADM cells enhanced cell sensitivity to adriamycin and promoted apoptosis. Mitochondrial ATPsyn-β expression and ATP synthase activity in relapsed/refractory acute myeloid leukemia patients were downregulated. This downregulated ATPsyn-β expression exhibited a positive correlation with the response to adriamycin of primary cells. A lower expression of ATPsyn-β in newly diagnosed or relapsed/refractory patients was associated with a shorter first remission duration or overall survival. Our findings show mitochondrial ATPsyn-β plays an important role in the mechanism of multidrug resistance in AML thus may present both a new marker for prognosis assessment and a new target for reversing drug resistance.

An intron mutation in the ACVRL1 may be associated with a transcriptional regulation defect in a Chinese family with hereditary hemorrhagic telangiectasia.

Purpose To identify a novel pathogenic gene mutation present in a Chinese family with hereditary hemorrhagic telangiectasia (HHT) and to determine if an intron mutation may influence the transcriptional activity of the ACVRL1 gene. Methods HHT family members were ascertained following the presentation of proband and involved subjects. All family members (n = 5) and 113 healthy individuals were genotyped for the variant in intron 6 c.772+27G>C of ACVRL1 gene. The genomic structure of ACVRL1 in affected HHT patients and healthy individuals was determined by long range PCR and sequencing. The expression of ACVRL1 mRNA and protein in patients with HHT was evaluated using real-time polymerase chain reaction and immunoblot analysis. Luciferase activity assay and electrophoretic mobility shift assay (EMSA) were performed to uncover the mechanism of intron-related transcriptional regulation. Results Only one novel mutation in intron 6 (c.772+27G>C) of ACVRL1 gene, no other mutation, abnormal splice, gross genomic deletion or rearrangement was found in this HHT2 family. Compared with healthy individuals, ACVRL1 mRNA and protein were significantly decreased in affected HHT2 individuals. Luciferase activity assay demonstrated that the transcriptional activity of the mutated ACVRL1 was significantly lower than that of the wild-type of intron 6; EMSA results showed that intron 6 c.772+27G>C mutation was able to inhibit the binding of transcriptional factor Sp1. Conclusions A novel intron mutation in ACVRL1 gene is associated with familial HHT2. The mechanisms may be involved in the down-regulation of ACVRL1 gene transcription.

Thyroid diffuse large B cell lymphoma (DLBCL) following thyroid medullary cancer: long-term complete remission with R-CHOP therapy

Dear Editor, We present here a case of thyroid diffuse large B cell lymphoma (DLBCL) arising on the background of thyroid medullary cancer, which was treated with thyroid lobectomy 10 years ago, and highlight its excellent response to treatment with rituximab-based CHOP chemotherapy (RCHOP). To our knowledge, this is the first case of primary thyroid lymphoma following thyroid medullary cancer. A 63-year-old Chinese womanwas admitted to our hospital with the complaints of neck mass, slight cough and dyspnea for 2 weeks in Aug 2005. She had a previous history of thyroid mass in the right lobe and received lobectomy 10 years ago. At that time, histopathological examination of the biopsy specimen from the thyroid mass was reported as thyroid medullary cancer (Fig. 1a). Immunohistochemical and special stainings displayed Cal (+), CK (+), Syn (+), TG (−), EMA (−), Congo red (+) and NSE (+) (Fig. 1b), which were consistent with the diagnostic features of thyroid medullary cancer. She had not undergone any chemotherapy or radiotherapy, and kept in a good condition after the surgical operation. Regular examinations including thyroid function tests and ultrasonic scan for thyroid showed no abnormality. Two weeks before admission, she found a mass up to 6 cm in diameter in the thyroid, with slight cough and dyspnea. Physical examination showed III grade enlargement in thyroid with deviation of trachea. No lymphadenopathy and hepatosplenomegaly was found. Laboratory examinations revealed that, blood cell counts, urine routine, stool routine, serum electrolytes, liver function, and renal function were within normal limits; serum lactate dehydrogenase (LDH) was 360 u/L, serum β2-microglobulin (BMG), immunoglobulin, and calcitonin were normal. Thyroid functional profile included a T3 of 0.89 nmol/L (0.7–2.7), T4 of 73.6 nmol/L (58.1–164.8), FT3 of 1.80 pmol/L (2.1– 6.2), FrT4 of 13.7 pmol/L (9.0–23.9), TSH of 3.8 mIU/L (0.35–5.5). The anti-microsomal antibody (MCA) and thyroglobulin antibody (TGA) were detected as negative titers with a radio-immunity (RI) method. Bone marrow smear showed normal cellular morphology and cellular ratio. A computerized tomography (CT) scan of the neck showed a mass in thyroid with trachea compressed. Chest and abdomen CT showed no lymph node or organ involvement. With the dyspnea progressed, a tracheal intubation subsequently a surgical operation was performed. The surgery was palliative just for relieving the airway obstruction and mass biopsy. Histopathological examination from thyroid mass biopsy showed diffuse proliferation of lymphoma cells with large nuclei (Fig. 2a). Immunohistochemically staining indicated MUM1(−), CD45R0(−), EMA(−), LCK(−), CaL(−), TG(−), LCA(++), Bcl-6(+), CD10 (+), and CD20(++) (Fig. 2b). A diagnosis of diffuse large B cell lymphoma (DLBCL), stage IE, was made. The international prognostic index (IPI) portrayed a lowintermediate risk. The patient was treated with CHOP (cyclophosphamide, doxorubicin, vincristin, and prednisolone) combined with rituximab (MabThera). After six courses of R-CHOP regimen, the mass in thyroid completely disappeared and she is still in complete remission after a 34 month follow-up. Non-Hodgkin’s lymphoma (NHL) of the thyroid gland is uncommon, accounting for only 1–5% of all thyroid malignancies, and classified as non-epithelial thyroid tumors [1–3]. In this report, we present the case that developed a DLBCL in the thyroid site where a thyroid Ann Hematol (2009) 88:701–702 DOI 10.1007/s00277-008-0639-9

Acute promyelocytic leukemia with insertion of PML exon 7c: a novel variant transcript related to good prognosis that is not detected with real-time polymerase chain reaction

Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML) characterized by the specifi c chromosomal translocation t(15;17)(q22;q21), producing the PML – retinoic acid receptor α (RAR α ) fusion gene which contributes to APL pathogenesis and mediates the therapeutic response to all- trans retinoic acid (ATRA). Due to the diff erent PML breakpoints, three major PML – RAR α isoforms that cause diff erent clinical manifestations and therapeutic responses have been identifi ed: long or bcr1 (intron 6 PML), variant or bcr2 (exon 6 PML) and short or bcr3 (intron 3 PML) [1,2]. In addition to these isoforms, atypical PML – RAR α transcripts in patients with t(15;17) positive APL have been reported; these atypical transcripts may be undetected at diagnosis, and their clinical features and biological signifi cance remain unclear. Previous studies of atypical PML – RAR α variants have demonstrated that rare PML breakpoints downstream of intron 6 are potentially associated with an aggressive course of disease and adverse prognosis [3 – 5]. In this study, we report a novel PML – RAR α variant with insertion of PML exon 7c in a patient with APL with good clinical outcome.