Transient TTP in childhood.

Thrombotic thrombocytopenic purpura (TTP) is a type of microangiopathic hemolytic anemia that is uncommon in childhood. Adults with TTP have a high mortality rate unless they are treated with plasma exchange. There are few reports of children with acquired idiopathic TTP, and most of those children received some form of treatment.

Gene expression signatures predictive of early response and outcome in high-risk childhood acute lymphoblastic leukemia: A Children's Oncology Group Study [corrected].

Purpose: To identify children with acute lymphoblastic leukemia (ALL) at initial diagnosis who are at risk for inferior response to therapy by using molecular signatures.

Patients And Methods: Gene expression profiles were generated from bone marrow blasts at initial diagnosis from a cohort of 99 children with National Cancer Institute-defined high-risk ALL who were treated uniformly on the Children's Oncology Group (COG) 1961 study. For prediction of early response, genes that correlated to marrow status on day 7 were identified on a training set and were validated on a test set.

Diverse pathways mediate chemotherapy-induced cell death in acute lymphoblastic leukemia cell lines.

Cancer cell resistance to chemotherapy may be mediated by defects in apoptotic pathways. A prior study showed that in vivo apoptosis of Acute Lymphoblastic Leukemia (ALL) blasts in response to chemotherapy could occur through diverse pathways including both p53-dependent and -independent mechanisms. In this study we investigated the apoptotic response in more detail by using a panel of ALL cell lines that differed in respect to p53 status.

Biologic pathways associated with relapse in childhood acute lymphoblastic leukemia: a Children's Oncology Group study.

Outcome for children with childhood acute lymphoblastic leukemia (ALL) who relapse is poor. To gain insight into the mechanisms of relapse, we analyzed gene-expression profiles in 35 matched diagnosis/relapse pairs as well as 60 uniformly treated children at relapse using the Affymetrix platform. Matched-pair analyses revealed significant differences in the expression of genes involved in cell-cycle regulation, DNA repair, and apoptosis between diagnostic and early-relapse samples.