Yingchang Mi

Homoharringtonine-based induction regimens for patients with de-novo acute myeloid leukaemia: a multicentre, open-label, randomised, controlled phase 3 trial

BACKGROUND Homoharringtonine-based induction regimens have been widely used in China for patients with acute myeloid leukaemia. However, their efficacy has not been tested in a multicentre randomised controlled trial in a large population. We assessed the efficacy and safety of homoharringtonine-based induction treatment for management of newly diagnosed acute myeloid leukaemia. METHODS This open-label, randomised, controlled, phase 3 study was done in 17 institutions in China between September, 2007, and July, 2011. Untreated patients aged 14-59 years with acute myeloid leukaemia were randomly assigned (by a computer-generated allocation schedule without stratification) to receive one of three induction regimens in a 1:1:1 ratio: homoharringtonine 2 mg/m(2) per day on days 1-7, cytarabine 100 mg/m(2) per day on days 1-7, and aclarubicin 20 mg/day on days 1-7 (HAA); homoharringtonine 2 mg/m(2) per day on days 1-7, cytarabine 100 mg/m(2) per day on days 1-7, and daunorubicin 40 mg/m(2) per day on days 1-3 (HAD); or daunorubicin 40-45 mg/m(2) per day on days 1-3 and cytarabine 100 mg/m(2) per day on days 1-7 (DA). Patients in complete remission were offered two cycles of intermediate-dose cytarabine (2 g/m(2) every 12 h on days 1-3). The primary endpoints were the proportion of patients who achieved complete remission after two cycles of induction treatment and event-free survival in the intention-to-treat population. The trial is registered in the Chinese Clinical Trial Register, number ChiCTR-TRC-06000054. FINDINGS We enrolled 620 patients, of whom 609 were included in the intention-to-treat analysis. 150 of 206 patients (73%) in the HAA group achieved complete remission versus 125 of 205 (61%) in the DA group (p=0.0108); 3-year event-free survival was 35.4% (95% CI 28.6-42.2) versus 23.1% (95% CI 17.4-29.3; p=0.0023). 133 of 198 patients (67%) in the HAD group had complete remission (vs DA, p=0·20) and 3-year event-free survival was 32.7% (95% CI 26.1-39.5; vs DA, p=0.08). Adverse events were much the same in all groups, except that more patients in the HAA (12 of 206 [5.8%]) and HAD (13 of 198 [6.6%]) groups died within 30 days than in the DA group (two of 205 [1%]; p=0.0067 vs HAA; p=0.0030 vs HAD). INTERPRETATION A regimen of homoharringtonine, cytarabine, and aclarubicin is a treatment option for young, newly diagnosed patients with acute myeloid leukaemia. FUNDING Chinese National High Tech Programme, Key Special Research Foundation of the Ministry of Science and Technology of China, National Nature Science Foundation of China, National Clinical Key Specialty Construction Project.

TBLR1 fuses to retinoid acid receptor α in a variant t(3;17)(q26;q21) translocation of acute promyelocytic leukemia.

The majority of acute promyelocytic leukemia (APL) cases are characterized by the PML-RARα fusion gene. Although the PML-RARα fusion gene can be detected in >98% of APL cases, RARα is also found to be fused with other partner genes, which are also related to all-trans retinoic acid (ATRA)-dependent transcriptional activity and cell differentiation. In this study, we identified a novel RARα fusion gene, TBLR1-RARα (GenBank KF589333), in a rare case of APL with a t(3;17)(q26;q21),t(7;17)(q11.2;q21) complex chromosomal rearrangement. To our knowledge, TBLR1-RARα is the 10th RARα chimeric gene that has been reported up to now. TBLR1-RARα contained the B-F domains of RARα and exhibited a distinct subcellular localization. It could form homodimers and also heterodimers with retinoid X receptor α. As a result, TBLR1-RARα exhibited diminished transcriptional activity by recruitment of more transcriptional corepressors compared with RARα. In the presence of pharmacologic doses of ATRA, TBLR1-RARα could be degraded, and its homodimerization was abrogated. Moreover, when treated with ATRA, TBLR1-RARα could mediate the dissociation and degradation of transcriptional corepressors, consequent transactivation of RARα target genes, and cell differentiation induction in a dose- and time-dependent manner.

Polymorphisms in folate-related genes: impact on risk of adult acute lymphoblastic leukemia rather than pediatric in Han Chinese.

Folate metabolism plays an essential role in the processes of DNA synthesis and methylation. An aberrant folate metabolism caused by a genetic polymorphism may lead to genomic instability and affect the susceptibility to malignancies including acute lymphoblastic leukemia (ALL). This study was designed to explore the correlation between the polymorphisms in folate-related genes and the risk of ALL in Han Chinese. The DNA was isolated from 231 patients with pediatric ALL, 130 patients with adult ALL, and 367 healthy subjects (as controls). Polymorphisms were examined for RFC1 80G > A, DHFR 19 bp del/ins and 317A > G, SHMT1 1420C > T, MTHFR 677C > T and 1298A > C, MTR 2756A > G, MTRR 66A > G, TYMS 3R/2R, MTHFD1 1958G > A, and ABCG2 421G > T using real-time polymerase chain reaction (PCR) or PCR–restriction fragment length polymorphism (RFLP). The risk of adult ALL was increased by the RFC1 80AA variant (odds ratio [OR] = 2.09; 95% confidence interval [CI] 1.19–3.67) and MTRR 66GG variant (OR = 2.15; 95% CI 1.06–4.39) but reduced by the MTHFR 677TT variant (OR = 0.47; 95% CI 0.25–0.88), ABCG2 421GT variant (OR = 0.62; 95% CI 0.41–0.96), and ABCG2 421GT + TT variant (OR = 0.60; 95% CI 0.40–0.90). The increase in risk of adult ALL with the RFC1 80AA associated with the MTRR 66GG variant was even more significant (OR = 8.92; 95% CI 1.97–40.42). Furthermore, the MTHFR 677TT associated with the ABCG2 421GT + TT variant more significantly reduced the risk of adult ALL (OR = 0.32; 95% CI 0.12–0.85). However, all gene polymorphisms tested in this study failed to affect the pediatric ALL risk. Our study clearly demonstrates that polymorphisms in folate-related genes only modulate the susceptibility to adult ALL, but not to pediatric ALL, in Han Chinese.

Enrichment of N-Cadherin and Tie2-bearing CD34 + /CD38 /CD123 + leukemic stem cells by chemotherapy-resistance

Acute myeloid leukemia (AML) arises from genetic changes at the level of stem cell, various mutations have been elucidated, including AML1-ETO fusion gene has been shown as the representative target of cellular transformation for LSCs originating from hematopoietic stem cells (HSCs) compartment. LSCs resemble HSCs with respect to self-renewal capacity and chemotherapy-resistance. However, LSCs possess specific cell-surface markers, they are proposed to reside within the CD34(+)/CD38(-)/CD123(+) compartment. And the interaction mediated by adhesion molecules between LSCs and niche played a role in chemoresistance of LSCs. Therefore, study on the LSCs surface makers related to niche is helpful for the potential target therapy in the future. In this study, the proportions of CD34(+)/CD38(-)/CD123(+) LSCs compartment co-expressing the three adhesion molecules, N-Cadherin, Tie2 and CD44, respectively, from AML patients before and after chemotherapy were analyzed. We demonstrated N-Cadherin and Tie2 positive CD34(+)/CD38(-)/CD123(+) LSCs populations could be enriched by chemotherapy. Furthermore, AML1/ETO fusion signals and MDR1 expression were detected on the CD34(+)/CD38(-)/CD123(+) LSCs populations expressing N-Cadherin and Tie2. Therefore, N-Cadherin and Tie2 are probably the potential markers for identification of LSCs.

Some novel features of IDH1-mutated acute myeloid leukemia revealed in Chinese patients.

Mutations of isocitrate dehydrogenase 1 (IDH1) have recently been reported in acute myeloid leukemia (AML). However, the characteristics of IDH1-mutated AML are still not known clearly. We analyzed 416 Chinese AML patients and found 28 patients (6.7%) carried this mutation. One homozygous IDH1 mutant in AML was found. The IDH1 mutations were associated with NPM1 mutations (P=0.043) and could coexist with recurrent transcription factor aberrations including AML1-ETO (6/50), PML-RARα (3/77) and CBFβ-MYH11 (1/15). For AML with AML1-ETO fusion gene, IDH1(mut) patients may have worse disease-free survival (DFS) than IDH1(wild-type) patients.

Therapeutic experience of adult acute myeloid leukemia in a single institution of China and its relationship with chromosome karyotype

One hundred and ninety-six untreated de novo acute myeloid leukemia (AML) patients were treated with homoharringtonine + cytosine arabinoside (HA) based induction therapy composed of three chemotherapeutic drugs (HAD/M, D-daunorubicin-DNR, M-mitozantrone-MTZ) used in our hospital for the past 12 years. The patient population was relatively young (median age 37, oldest patient 67), and patients were excluded if they had prior MDS or prior chemotherapy or radiotherapy. Complete remission (CR) rate, disease free survival (DFS) and overall survival (OS) of the patients were calculated. One hundred and fifty-three patients who had karyotype results were divided into four groups according to Southwestern Oncology Group (SWOG) criteria. Differences of CR rate, DFS and OS of different groups were evaluated. The CR rate of all 196 cases was 153/196 (78.1%), and 95.3% of these were within 1 – 2 courses. Median DFS of the 153 CR patients was 23.8 (range from 1.0 to 153) months. DFS rates at 3 years and 5 years were 41.1% and 35.9%, respectively. The median OS of 196 patients was 19.3 (0.5 – 154) months. The probabilities of 3-year and 5-year OS were 31.5% and 29.2%, respectively. CR rate, DFS and OS of the different cytogenetic risk groups were also be analyzed. According to SWOG criteria, patients were classified into favorable, intermediate, adverse and unknown (a group where the meaning of chromosomes are unclear) groups. CR rate, median DFS and OS were 91.9%, 90.8 months and 94.4 months for the favorable group; 86.4%, 22.0 months and 22.8 months for the intermediate group; 59.4%, 9 months and 10.5 months for the adverse group; 76.0%, 22.0 months, 16.1 months for the unknown group, respectively. The differences among the four groups were statistically significant (P = 0.001, 0.0033, 0.0001). We conclude that triple-drugs induction regimens based on HA (HAD/M) are highly effective in adult AML in China. Cytogenetics is the important prognostic factor. SWOG karyotype subtyping criteria was appropriate for our patients, the prognosis of the unknown group was similar to that of the intermediate group.

RAD51 and XRCC3 polymorphisms: impact on the risk and treatment outcomes of de novo inv(16) or t(16;16)/CBFβ-MYH11(+) acute myeloid leukemia.

DNA double-strand break repair via homologous recombination (HR) is essential in maintaining genetic integrity, and may modulate susceptibility to the development of acute myeloid leukemia (AML) and influence outcomes of AML. This study was designed to evaluate the effects of polymorphisms in HR repair genes RAD51 and XRCC3 on the risk and treatment outcomes of inv(16)/t(16;16)/CBFβ-MYH11(+) AML. The distribution of polymorphisms in RAD51-G135C and XRCC3-Thr241Met were studied by PCR-RFLP analysis in 625 cases of de novo AML, including 105 cases with inv(16)/t(16;16)/CBFβ-MYH11, 806 family controls and 704 volunteer controls. It was found that the XRCC3-241Met variant significantly increased the risk of the development of the AML with inv(16)/t(16;16) as compared with both the volunteer control (OR=7.22; 95% CI, 4.37-11.91) and the family control (OR=7.99; 95% CI, 5.03-12.69). A retrospective study conducted in 103 inv(16)/t(16;16) AML patients. In multivariate analysis for the potential prognostic factors, the XRCC3-241Met variant significantly reduced disease-free survival (DFS) in complete remission (CR) achieved patients (HR=2.34, 95% CI, 1.32-4.16). These data indicate that the XRCC3-241Met variant may not be only a susceptibility factor to the AML with inv(16)/t(16;16), but also an independent poor-prognostic factor for this AML subtype.

N-Cadherin and Tie2 positive CD34 + CD38 − CD123 + leukemic stem cell populations can develop acute myeloid leukemia more effectively in NOD/SCID mice

Emerging studies suggest that the population of malignant cells found in human acute myelogenous leukemia (AML) arises from a rare population of leukemic stem cells (LSCs). A lot of investigators have reported the identification of cell surface markers, such as CD123. Here, we report the identification of N-cadherin and Tie2 as LSCs markers. Inoculation of CD34(+)CD38(-)CD123(+)N-cadherin(+) and CD34(+)CD38(-)CD123(+) Tie2(+) population can induce leukemia in NOD/SCID mice. The leukemic blast cells from the primary leukemic mice could also induce leukemia in the secondary transplantation. These findings suggested that N-cadherin and Tie2 were the important markers that can assist in leukemia development.

Oncogene iASPP enhances self-renewal of hematopoietic stem cells and facilitates their resistance to chemotherapy and irradiation

iASPP is a member of the apoptosis‐stimulating proteins of p53 (ASPP) family and negatively regulates the apoptotic function of p53. In a hematopoietic system, overexpression of iASPP results in blockage of apoptosis, which may play a role in regulating hematopoietic stem cell (HSC) numbers. To address this, we first analyzed the expression of iASPP in patients with acute leukemia (AL) and found it was highly expressed in patients with AL. We further established a transgenic mouse model in which human iASPP was specifically expressed in hematopoietic cells. Overexpression of iASPP led to an increase in the proportion of long‐term HSCs, short‐term HSCs, multipotent progenitors, and common myeloid progenitor. HSCs from iASPP transgenic mice had an advantage in long‐term reconstitution potential. In addition, the hematopoietic cells from iASPP transgenic mice exhibited a significantly lower level of p53 dependent apoptosis. After irradiation damage, hematopoietic cells of iASPP transgenic mice had a higher level of γ‐H2AX expression, which lasted for a longer time. These results provide the first evidence that the iASPP can increase HSC populations and reconstitution capacity. Interestingly, in response to cell damage stimuli, hematopoietic cells can be protected against apoptosis by iASPP; meanwhile these apoptosis‐resistant cells would have more mutation accumulation, which might be the potential risk for malignant transformation.—Jia, Y., Peng, L., Rao, Q., Xing, H., Huai, L., Yu, P., Chen, Y., Wang, C., Wang, M., Mi, Y., Wang, J. Oncogene iASPP enhances self‐renewal of hematopoietic stem cells and facilitates their resistance to chemotherapy and irradiation. FASEB J. 28, 2816–2827 (2014). www.fasebj.org

High-Dose Cytarabine in Acute Myeloid Leukemia Treatment: A Systematic Review and Meta-Analysis

The optimal dose, scheme, and clinical setting for Ara-C in acute myeloid leukemia (AML) treatment remain uncertain. In this study, we performed a meta-analysis to systematically assess the impact of high-dose cytarabine (HDAC) on AML therapy during the induction and consolidation stages. Twenty-two trials with a total of 5,945 de novo AML patients were included in the meta-analysis. Only patients less than 60 year-old were included in the study. Using HDAC in induction therapy was beneficial for RFS (HR = 0.57; 95% CI, 0.35–0.93; P = 0.02) but not so for CR rate (HR = 1.01; 95% CI, 0.93–1.09; P = 0.88) and OS (HR = 0.83; 95% CI, 0.66–1.03; P = 0.1). In consolidation therapy, HDAC showed significant RFS benefits (HR = 0.67; 95% CI, 0.49–0.9; P = 0.008) especially for the favorable-risk group (HR = 0.38; 95% CI, 0.21–0.69; P = 0.001) compared with SDAC (standard dose cytarabine), although no OS advantage was observed (HR = 0.84; 95% CI, 0.55–1.27; P = 0.41). HDAC treatment seemed less effective than auto-BMT/allo-BMT treatment (HR = 1.66, 95% CI, 1.3–2.14; P<0.0001) with similar OS. HDAC treatment led to lower relapse rate in induction and consolidation therapy than SDAC treatment, especially for the favorable-risk group. Auto-BMT/allo-BMT was more beneficial in prolonging RFS than HDAC.