In vitro Cytotoxic Effects of Control and Selenium Conjugated Transferrins against Leukemia Cell Lines K562 and THP-1

In vitro Cytotoxic Effects of Control and Selenium Conjugated Transferrins against LeHuman leukemia is a malignancy of hematopoietic stem cells with impaired differentiation and uncontrolled proliferation. Many leukemia cell lines over-express the trans-membrane transferrin receptor (TfR) which endocytoses iron (Fe) bound Holo-transferrin (Holo-Tf). Over-expression of the TfR has permitted transferrin-mediated drug delivery targeting leukemia cells. Selenides (RSe-), can generate free radicals, i.e.; superoxide (O2.-) and other Reactive Oxygen Species (ROS) by redox cycling; oxidizing thiols (RSH) within cells following endocytosis. Superoxide generation by selenium (Se) is reported to cause cell apoptosis/necrosis due to increased endogenous oxidative stress. In the present study, Se as ROCH2CH2SeCN was covalently attached to Lysine residues of Apo-, Holo-Tf, and Human Serum Albumin (HuSA) using a Se-modified Bolton-Hunter reagent. The Se conjugated proteins were used to target the TfR and experimentally treat K562 and THP-1 leukemia cell lines. Cells were also treated with sodium selenite (10 μgSe/well) as a positive control known to cause cell death.ukemia Cell Lines K562 and THP-1.