Adiponectin and Its Effects on Acute Leukemia Cells: An Experimental and Bioinformatics Approach.

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. It is known that deregulation of adipokine pathways is probably implicated in the ontogenesis of ALL. The present work aims at investigating the role of adiponectin and its effects on an ALL cell line. The CCRF-CEM cells were used as a model. Cells have been treated with adiponectin, with different concentrations up to 72 h. Cytotoxicity and cell cycle distribution were investigated for all concentrations using flow cytometry. Selected concentrations were also used for additional microarray analysis, using a small gene set of cancer-related genes. Lower and higher adiponectin concentrations did not produce an inhibition of proliferation, as well as an increase in cell death. It was found that adiponectin regulated differentially genes, such as CD22, CDH1, IFNG, LCK, MSH2, SPINT2, and others. At the same time, it appeared that adiponectin-related gene expression was more active on chromosomes 18 and 1. Machine learning classification algorithms showed that several genes were grouped together indicating common regulatory mechanisms. The present study showed that adiponectin is able to induce gene differential expression in leukemic cells in vitro, suggesting a possible role in the progression of leukemia. It is also an indication that more studies are required in order to further understand the role of adiponectin and adipokines in general in the role of human neoplasms.

Early and Very Early GRIM19 and MCL1 Expression Are Correlated to Late Acquired Prednisolone Effects in a T-Cell Acute Leukemia Cell Line.

Glucocorticoids (GCs) are still first-line drugs for the treatment of childhood acute lymphoblastic leukemia (ALL). Prednisolone is a corticosteroid and one of the most important agents in the treatment of ALL. We report here a study of Prednisolone treatment using as a model a leukemia cell line with subsequent investigation of resistance-related gene expression. Gene silencing has been used in order to identify significant targets of resistance to GC-induced apoptosis in ALL cells. We analyzed effects of increasing doses of Prednisolone on ALL cell survival and growth, and we monitored immediate effects on gene expression through gene expression assays. We determined Prednisolone cytotoxicity and cell cycle distribution as well as DNA content. Upon treatment with escalating Prednisolone concentration, we observed a gradual decline in cell survival. MCL1 and GRIM19 were investigated as possible genes for the intrinsic capacity of this cell line to respond to corticosteroid and a snapshot of early changes was examined. Early MCL1 and GRIM19 expression correlated significantly to late GC-induced apoptosis. Prednisolone competitively induces MCL1 expression. Consistently with previous studies on primary leukemia blasts, cells are sensitive to proteasome inhibitor MG132; no interference of Prednisolone with MG132 effects on this cell line was noted. The inherent plasticity of clinically evolving cancer justifies approaches to characterize and prevent undesirable activation of early oncogenic pathways. Study of the pattern of intracellular signal pathway activation by anticancer drugs can lead to development of efficient treatment strategies by reducing detrimental secondary effects.