Mouse xenograft modeling of human adult acute lymphoblastic leukemia provides mechanistic insights into adult LIC biology.

The distinct nature of acute lymphoblastic leukemia (ALL) in adults, evidenced by inferior treatment outcome and different genetic landscape, mandates specific studies of disease-initiating mechanisms. In this study, we used NOD/LtSz-scid IL2Rγ null(c) (NSG) mouse xenotransplantation approaches to elucidate leukemia-initiating cell (LIC) biology in primary adult precursor B (pre-B) ALL to optimize disease modeling. In contrast with xenografting studies of pediatric ALL, we found that modification of the NSG host environment using preconditioning total body irradiation (TBI) was indispensable for efficient engraftment of adult non-t(4;11) pre-B ALL, whereas t(4;11) pre-B ALL was successfully reconstituted without this adaptation.

Does BCR/ABL1 positive acute myeloid leukaemia exist?

The BCR/ABL1 fusion gene, usually carried by the Philadelphia chromosome (Ph) resulting from t(9;22)(q34;q11) or variants, is pathognomonic for chronic myeloid leukaemia (CML). It is also occasionally found in acute lymphoblastic leukaemia (ALL) mostly in adults and rarely in de novo acute myeloid leukaemia (AML). Array Comparative Genomic Hybridization (aCGH) was used to study six Ph(+)AML, three bi-lineage and four Ph(+)ALL searching for specific genomic profiles.

Attenuated, oncolytic, but not wild-type measles virus infection has pleiotropic effects on human neutrophil function.

We previously showed that neutrophils play a role in regression of human tumor xenografts in immunodeficient mice following oncolytic vaccine measles virus (MV-Vac) treatment. In this study, we sought, using normal human neutrophils, to identify potential neutrophil-mediated mechanisms for the attenuated MV-Vac induced effects seen in vivo, by comparison with those consequent on wild-type (WT-MV) infection. Both MV-Vac and WT-MV infected and replicated within neutrophils, despite lack of SLAM expression.

Differential cytopathology and kinetics of measles oncolysis in two primary B-cell malignancies provides mechanistic insights.

Clinical trials using vaccine measles virus (MV) as anticancer therapy are already underway. We compared the oncolytic potential of MV in two B-cell malignancies; adult acute lymphoblastic leukemia (ALL, an aggressive leukemia) and chronic lymphocytic leukemia (CLL, an indolent leukemia overexpressing Bcl-2) using patient-derived material. In vitro, distinct cytopathological effects were observed between MV-infected primary ALL and CLL cells, with large multinucleated syncytia forming in ALL cultures compared to minimal cell-to-cell fusion in infected CLL cells.

Antigen receptor gene rearrangements reflect on the heterogeneity of adult Acute Lymphoblastic Leukaemia (ALL) with implications of cell-origin of ALL subgroups - a UKALLXII study.

Cytogenetic and molecular investigations of Acute Lymphoblastic Leukaemia (ALL) have identified the existence of distinct clinical subgroups. Molecular monitoring of clonal Immunoglobulin and T cell receptor (IG/TR) gene rearrangements has become an important tool in stratification of therapy of ALL. In order to determine whether certain features of the patient-specific rearrangements could hold further prognostic clues or provide information on the cell of origin of ALL, a comprehensive analysis of structural and biological features (V gene usage, coding frame and mutational status and complementarity-determining region -III length) of 473 IG/TR rearrangements identified in 229 adults with ALL was carried out.

Minimal residual disease is a significant predictor of treatment failure in non T-lineage adult acute lymphoblastic leukaemia: final results of the international trial UKALL XII/ECOG2993.

The predictive value of molecular minimal residual disease (MRD) monitoring using polymerase chain reaction amplification of clone-specific immunoglobulin or T-cell Receptor rearrangements was analysed in 161 patients with non T-lineage Philadelphia-negative acute lymphoblastic leukaemia (ALL) participating in the UK arm of the international ALL trial UKALL XII/Eastern Cooperative Oncology Group (ECOG) 2993. MRD positivity (> or =10(-4)) in patients treated with chemotherapy alone was associated with significantly shorter relapse-free survival (RFS) at several time-points during the first year of therapy. MRD status best discriminated outcome after phase 2 induction, when the relative risk of relapse was 8.