GSE185611
Human B-cell precursor acute lymphoblastic leukemia cells overexpressing ST6Gal1
Normal early human B-cells development from lymphoid progenitors in the bone marrow is dependent upon instructions from elements in that microenvironment which include stromal cells as well as extracellular matrix and factors secreted by these cells. Glycosylation is thought to play a key role in such interactions. The sialyltransferase ST6Gal1, with high expression in specific hematopoietic cell types, is the only enzyme thought to catalyze the terminal addition of sialic acids in an a2-6-linkage to galactose on N-glycans in such cells. Expression of ST6Gal1 increases as mouse B cells undergo normal B-lineage differentiation. B-cell precursor acute lymphoblastic leukemias (BCP-ALL) with differentiation arrest at various stages of early B-cell development have widely different expression levels of ST6GALl1 at diagnosis, with high ST6Gal1 in some relapses. We analyzed the consequences of increased ST6Gal1 expression in a diagnosis sample using lentiviral transduction of ST6Gal1 into US7 cells which have a relatively low level of ST6Gal1 expression. Controls were transduced with an empty vector. Gene expression analysis using RNA-seq showed a surprisingly large number of genes with significant differential expression, of which around 60% showed increased transcript levels, in the ST6Gal1 overexpressing BCP-ALL cells. Overall design: US7 BCP-ALL is stromal-dependent and was grown in co-culture with mitotically inactivated OP9 bone marrow stromal cells. Cells were transduced with empty pLV411G vector or with pLV411G-ST6GAL1. Inserts were introduced into the pLV411G vector by GateWay cloning (Invitrogen). The ST6GAL1 encodes human ST6Gal1 406 amino acid isoform A. Pure cell populations were obtained by flow sorting for EGFP. RNAs were isolated from the cells grown under steady-state conditions on OP9 stromal cells. BCP-ALL cells in the medium supernatant were harvested for RNA isolation. EV and OE conditions were each harvested as biological triplicates.