Prognostic significance of karyotype analysis in children with acute lymphoblastic leukemia

The Basic Research of the Combinatorial Therapy of ABT-199 and Homoharringtonine on Acute Myeloid Leukemia

Background

Existing research shows that ABT-199, as a first-line drug, have been widely used in hematological malignancies, especially in leukemia, but the clinical efficacy of single drug therapy was limited part of the reason was that BCL-2 inhibitors failure to target other anti-apoptotic BCL-2 family proteins, such as MCL-1. In this case, combination therapy may be a promising way to overcome this obstacle. Here, we investigate the preclinical efficacy of a new strategy combining ABT-199 with homoharringtonine (HHT), a selective inhibitor of MCL-1 may be a promising approach for AML treatment as these two molecules are important in apoptosis.

Methods

A Cell Counting Kit-8 (CCK8) assay and flow cytometry were used to determine the half-maximal inhibitory concentration (IC50) value and cell apoptosis rate, respectively. The flow cytometry results showed that combined treatment with HHT and ABT-199 caused apoptosis in AML patient samples (n=5) but had no effect on normal healthy donor samples (n=11). Furthermore, we used a Western blot assay to explore the mechanism underlying the efficacy of HHT combined with ABT-199. Finally, antileukemic activity was further evaluated in vivo xenograft model.

Results

Our results indicated that ABT-199 combined with HHT significantly inhibited cell growth and promoted apoptosis in both AML cell lines and primary AML tumors in a dose- and time-dependent manner. Moreover, HHT combined with ABT-199 suppressed AML cell growth and progression in vivo xenograft model.

Conclusions

Our research found that HHT combined with ABT-199 exerted its anti-leukemia effect by inducing apoptosis through the treatment of AML in vitro and in vivo.

Organ Specific Tumor Markers: What's New?

Tumor markers are molecules produced in the body in response to cancer. An ideal tumor marker should have high sensitivity and specificity, should be cheap, and should be easily detected in body fluids. Identification of novel markers is important and it is expected that with the advent of newer technologies, more reliable markers will be discovered. This review discusses the currently available tumor markers for different malignancies.

Clinical implications of cytogenetic classification in adult acute lymphoblastic leukaemia patients

Cytogenetic analysis performed on pretreated unstimulated, bone marrow/peripheral blood samples of 46 adult patients with acute lymphoblastic leukaemia (ALL) showed sufficient metaphases in 39 patients and insufficient metaphases in 7 patients. G-banded karyotype analysis of these 39 patients revealed non-random clonal chromosome abnormalities in 31 patients and apparently normal karyotypes in 8 patients. Numerical abnormalities involving chromosome trisomies and structural abnormalities involving different types of chromosomal translocations and deletions were encountered in varying percentages. These patients were grouped into various cytogenetic subsets on the basis of their karyotype pattern and followed-up to evaluate their prognosis. Patients with apparently normal karyotypes showed good prognosis and those with 6q- showed intermediate prognosis. But all other patients with hyperdiploid, pseudodiploid and hypodiploid karyotypes were associated with poor prognosis. Cytogenetic classification of ALL patients is thus of clinical importance, as it helps the early identification of clinically important prognostic groups.

Duplication and loss of chromosome 21 in two children with Down syndrome and acute leukemia

Acute leukemia in Down syndrome (DS) is often associated with additional changes in the number or structure of chromosome 21. We present two DS patients whose leukemic karyotypes were associated with changes in chromosome 21 ploidy. Patient 1 developed acute lymphocytic leukemia (type L1); disomy for chromosome 21 was evident in all blast cells examined. Loss of the paternal chromosome in the leukemic clone produced maternal uniparental disomy with isodisomy over a 25-cM interval. The second patient had acute monoblastic leukemia (type M5) with tetrasomy 21 in all leukemic cells. DNA polymorphism analysis showed duplicate paternal chromosomes in the constitutional genotype. The maternal chromosome was subsequently duplicated in the leukemic clone. The distinct inheritance patterns of chromosome 21 in the blast cells of these patients would appear to indicate that leukemogenesis occurred by different genetic mechanisms in each individual.