Project leader: Aybike Birerdinc

B-cell chronic lymphocyte leukemia (B-CLL) accounts for ~30% of all leukemias in the Western world and has so far been treated with variable success (Byrd et al., 2004). KCNRG (chromosome 13q14.3) is thought to be a tumor suppressor candidate gene involved in the development of B-cell chronic lymphocytic leukemia due to its significant homology and functional similarity to potassium channel regulating proteins (Ivanov et al., 2003). In addition it has been found that KCNRG has two isoforms, both of which incorporate the potassium channel like segment, and differ in the end regions. The aim of this study is to determine whether the loss of KCNRG does indeed cause tumorigecinity and to elucidate a putative role for this gene in B-CLL disease development and progression.

Since KCNRG has been shown to have a negative mutation status in B-CLL samples, a novel approach for study based on haploinsufficiency is suggested (Baranova 2004). Hence, the experimental design consists of a series of overexpression studies by using cell lines natively expressing KCNRG, cell lines that can be induced to express KCNRG and cell lines that do not natively express KCNRG to determine the role of KCNRG in apoptosis, differentiation, invasiveness, and effects of overexpression of KCNRG on gene expression profiles. The KCNRG gene has been cloned into pcDNA 3.1 myc/his vector, and the cell lines: RPMI-8668, HL60, and LNCaP have been transfected with this clone using Fugene 6 (Roche Sciences). The transfected cells are grown in 400ug/ml of Geneticin supplemented RPMI media to select for stable transfectants.

Preliminary studies with BrdU chemiluminescence tests show stable transfectant cells to have a significant decrease in growth rate.