t(16;21)(p11.2;q22): a recurrent primary rearrangement in ANLL

Salvage therapy with azacitidine for pediatric acute myeloid leukemia with t(16;21)(p11;q22)/FUS-ERG and early relapse after allogeneic blood stem cell transplantation: A case report

Acute myeloid leukemia (AML) with FUS-ERG has a poor prognosis regardless of allo-hematopoietic stem cell transplantation (HSCT). Maintenance therapy such as azacitidine after allo-HSCT for AML with FUS-ERG may be clinically meaningful.

Acute basophilic leukemia associated with the t(16;21)(p11;q22)/FUS-ERG fusion gene

We herein report a rare case of acute basophilic leukemia with t(16;21)(p11;q22) generating the FUS‐ERG fusion gene. The basophilic nature of leukemia blasts was demonstrated by cytomorphology, toluidine blue metachromasia, mature basophil‐associated antigen expression, and characteristic granules under electron microscopy. The molecular link between t(16;21)/FUS‐ERG and basophilic differentiation remains unclear.

[Clinical characteristics of acute myeloid leukemia with t (16;21) (p11;q22):nine cases report and literature review]

目的

探讨t(16;21）（p11；q22）急性髓系白血病（AML）的生物学及临床特征、疗效及预后。

方法

回顾性分析2009年1月至2014年12月北京大学人民医院收治的9例初诊t(16;21）（p11；q22）AML患者临床资料，并汇总国外文献报道的42例患者，采用Kaplan-Meier法进行生存分析。

结果

9例t(16;21）（p11；q22) AML占同期AML患者的0.66%。9例患者中，男4例，女5例。FAB分型：M₁ 1例、M₂ 5例、M₄ 1例、M₅ 2例；其中3例在诊断时形态学可见空泡形成。免疫表型除表达髓系CD117、CD13、CD33及CD34外，均表达CD56。染色体G显带分析均可见t(16;21）（p11；q22），5例伴有复杂核型。所有患者均可检测到TLS/FUS-ERG融合基因。9例化疗后均获完全缓解（CR）。2例仅接受化疗的患者分别于诊断后5和16个月复发，并于10和27个月死亡。7例于缓解后接受异基因造血干细胞移植（allo-HSCT），中位生存21(11~46）个月。汇总文献报道的42例成人t(16;21）（p11;q22）AML患者，其中单纯化疗组27例，HSCT组15例，两组患者中位生存期分别为10(95% CI 1~17）个月及18(95% CI 2~76）个月，差异有统计学意义（P<0. 001）。

结论

t(16;21）（p11；q22) AML是一类少见的AML，其具有特殊的形态学及免疫表型特点，总体预后差，allo-HSCT治疗可改善其预后，推荐首次CR后行allo-HSCT治疗。

Novel translocation in acute megakaryoblastic leukemia (AML-M7)

The authors report a unique translocation in a patient with M7 acute myeloid leukemia and review the literature. A 22-month-old girl without Down syndrome was diagnosed with acute myeloid leukemia, subtype M7 (AML-M7), and died with relapsed disease following bone marrow transplantation. Tumor cells were evaluated using cytogenetics (including spectral karyotyping), immunohistochemistry, and flow cytometry. The patient was found to have a previously unreported complex translocation as follows: 50,XX,der(1)t(1;5)(p36?.1;p15?.1),del(5)(p15?.1), +6,+der(6;7)(?;?),der(7)t(6;7)(?;p22)[2],der(9)t(6;9) (?;p21)t(9;14)(q34;q11.2-q13),+10,t(12;16)(p13;q24),-14[2], del(14)(q13)[2],+der(19)t(1;19)(?;p13.3),+22[cp 4]. AML-M7 in non-Down syndrome patients is a rare disease that requires improved prognostic markers.

Detection of minimal residual disease in a patient having acute myelogenous leukemia with t(16;21)(p11;q22) treated by allogeneic bone marrow transplantation

A 29-year-old woman having acute myelogeneous leukemia-M1 subtype with the chromosomal abnormality t(16;21)(p11;q22) is presented. Complete blood count at onset showed a hemoglobin level of 7.2 g/dl, a platelet count of 48 x 10(9)/l, and a white blood cell count of 161.2 x 10(9)/l with 99% blasts and 1% lymphocytes. Bone marrow aspiration revealed massive proliferation of blasts that were positive for CD13, CD33, CD34, CD56 and myeloperoxidase, and negative for other T-cell, B-cell and monocytic markers. After achieving complete remission following conventional chemotherapy, she received an HLA-matched bone marrow transplantation (BMT) from her sibling after conditioning with busulfan, etoposide and cyclophosphamide. However, 9 months later, the leukemia relapsed as a painful extramedullary mass in her left femur. In spite of intensive re-induction chemotherapy, she died of progressive disease and sepsis. Although we could not detect the TLS/FUS-ERG fusion transcripts by reverse transcriptase-polymerase chain reaction in pre-BMT remission phase, they were clearly detectable in bone marrow cells obtained 6 months after transplantation with no translocation detected by conventional cytogenetics. We consider that even high-dose chemotherapy with BMT may not be effective in the eradication of this type of leukemia, and that the detection of minimal residual disease possibly contributes to the better planning of the therapeutic strategy.

Myeloid differentiation antigen and cytokine receptor expression on acute myelocytic leukaemia cells with t(16;21)(p11;q22): frequent expression of CD56 and interleukin-2 receptor alpha chain

We report the cellular characteristics of cells from three patients with de novo acute myelocytic leukaemia (AML) with t(16;21)(p11;q22), two M4 and one M5a according to the FAB classification, and two permanent cell lines with t(16;21)(p11;q22), TSU1621MT and YNH-1. The FUS/ERG fusion mRNA was demonstrated in all cases by reverse transcriptase-polymerase chain reaction (RT-PCR). The immunophenotypes of the AML cells, and YNH-1 and TSU1621MT cell lines with t(16;21) were characterized as CD34+CD33+CD13+CD11b+CD18+CD56+ HLA-DR-/+. Cells from all samples strongly expressed c-kit, granulocyte colony-stimulating factor receptor (G-CSFR), c-fms (macrophage colony-stimulating factor receptor), interleukin-3 receptor alpha chain (IL-3Ralpha), and granulocyte macrophage colony-stimulating factor receptor alpha chain (GM-CSFRalpha), and these data corresponded well to the growth responsiveness to the cytokines. IL-2Ralpha expression was also found in all t(16;21) samples, but IL-2 did not act on the proliferation of the leukaemic cells in in vitro cultures. G-CSF distinctly promoted the proliferation of leukaemic cells of t(16;21) AML, but did not enhance the expression of MPO and neutrophil differentiation of these cells. Our findings indicate that AML cells with t(16;21) preserve stem cell properties such as CD34 and c-kit expression, and suggest that they have the potential to differentiate into a monocytic lineage. The relationship between the unique cellular characteristics (especially CD56 and IL-2Ralpha expression) and FUS/ERG protein remains undetermined.

Translocation (3;16)(q27;p11) in a patient with diffuse large B-cell lymphoma associated with the BCL-6 gene rearrangement

A patient with B-cell lineage diffuse large-cell lymphoma carrying the t(3;16)(q27;p11) and BCL-6 rearrangement is described. Cytogenetic studies showed 46,XY,t(3;16)(q27;p11.2)[.11]/46,idem,add(18)(q21)[7]/46,XY[2]. The chromosomal translocation involving the 3q27 locus was associated with the BCL-6 gene rearrangement identified by Southern blot analysis. This case involved systemic lymph nodes, as large as 3 cm in diameter, bilaterally in neck, axilla, and inguinal regions. The patient obtained complete remission with chemotherapy.

Establishment and characterization of IRTA17 and IRTA21, two novel acute non-lymphocytic leukaemia cell lines with t(16;21) translocation

The t(16;21)(p11;q22) translocation is an infrequent chromosomal abnormality, but seems specific to acute non-lymphocytic leukaemia (ANLL). We established two cell lines with t(16;21)(p11;q22) from the bone marrow of a patient with ANL in relapse. Their morphological, karyotypic, immunohistochemical and genetic features are examined. Although both cell lines show monocytoid features morphologically, they express only CD13 (My7) and CD34, and neither expressed monocytoid or lymphoid markers. Reverse transcription-polymerase chain reaction showed that both cell lines expressed a similar TLS-ERG chimaeric mRNA as a result of the t(16;21)(p11;q22) translocation. As far as we know, there is no report of a leukaemia cell line with t(16;21). These cell lines represent a useful tool for leukaemia research.

Translocation (16;21)(p11;q22) in acute nonlymphocytic leukemia

A case of acute nonlymphocytic leukemia (ANLL) with a translocation (16;21)(p11;q22) is presented. Clinical features of ANLL with this chromosomal change are discussed.

An ets-related gene, ERG, is rearranged in human myeloid leukemia with t(16;21) chromosomal translocation

The t(16;21)(p11;q22) translocation is a nonrandom chromosomal abnormality found in several types of myeloid leukemia, which show variable cytomorphological features. We constructed rodent-human somatic cell hybrids containing the der(16) chromosome from leukemic cells of a patient with t(16;21). Using these hybrids, we mapped the translocation breakpoint on the Not I restriction map of chromosome 21 which we had previously constructed. The result showed the proximity of the breakpoint to the ERG gene, a member of the ets oncogene superfamily. Polymerase chain reaction and Southern blot analyses of genomic DNA from the hybrids and from peripheral blood cells and bone marrow cells of patients with t(16;21) showed that the breakpoints were clustered within a single intron in the coding region of the ERG gene. This finding and the results obtained by Northern blot analysis suggested the formation of a chimeric product(s) by fusion of the ERG gene and an unknown counterpart gene on chromosome 16.

Acute non-lymphocytic leukemia with t(16;21)

A patient with ANLL FAB subtype M1 was found to possess a t(16;21)(p11;q22) and trisomy 10. The 16;21 translocation has been reported in 12 other cases of ANLL, of various subtypes, and its relationship to the disease profile is discussed.