The purity of nuclear and cytoplasmic isolates prepared from lymphocytes by ultracentrifugation was checked by assaying optimal response of the organelle specific markers in respective fractions

The purity of nuclear and cytoplasmic isolates prepared from lymphocytes by ultracentrifugation was checked by assaying optimal response of the organelle specific markers in respective fractions. characterized by the assemblage of CD5+ B-lymphocytes in the peripheral blood, bone marrow and secondary lymphoid organs (lymph nodes and spleen) [1, 2]. Lymphocyte count in the peripheral blood is found to be > 5 109L1. CLL Risedronate sodium is the most common type of Rabbit polyclonal to C-EBP-beta.The protein encoded by this intronless gene is a bZIP transcription factor which can bind as a homodimer to certain DNA regulatory regions. leukemia in adults in the western countries representing about 2530 % of all types of Risedronate sodium known leukemia [3]. Cholesterol homeostasis is one of the major regulatory events of cells lipid metabolism. The key regulatory steps of intracellular cholesterol homeostasis exist through its intracellular biosynthesis, uptake of LDL (source of exogenous cholesterol) by LDL receptors (LDLR), storage of cholesterol esters and efflux of VLDL or HDL [4, 5]. The recent studies show that LDLR is highly expressed in the cancer cells [6]. The increased level of cellular cholesterol, due to more LDL uptake, supports rapid membrane formation by the developing cancer cells [7]. Peripheral-type benzodiazepine receptor (PBR) was Risedronate sodium identified in peripheral tissues because of its ability to bind the benzodiazepine diazepam (ValiumTM) [8]. The PBR appears to be a heteromeric complex of at least three different subunits, viz., an isoquinoline binding subunit, a VDACvoltage-dependent anion channel, and ANT-adenine nucleotide translocase [911]. Recent studies demonstrated that PBR is a high affinity cholesterol binding protein [12, 13]. There are studies showing abundance of PBR in tumor cells and also specifically on nuclear membrane of tumor cells [1418]. The subunits of PBR act as cholesterol receptor as well as cholesterol channel. PBR has been found to be aggressively expressed in human breast cancer cells [19]. Cholesterol is even found in the nucleus in association with chromatin lipids [20]. But till date no detailed study has been done in effect to find relation of cell proliferative proteins with the turnover of this nuclear cholesterol in leukemic cells of CLL subjects. Ribonucleotide reductase (RR) is a regulated rate-limiting enzyme in the conversion of ribonucleoside diphosphate to 2-deoxyribonucleoside diphosphate, which is essential for DNA synthesis [21]. In humans the enzyme is a dimer having one large subunit (hRRM1, Mr 170, 000 dimer) and one of the two small subunits (hRRM2 and p53R2) identified separately [22, 23]. Inhibition of RR activity has been tested as a potential treatment modality in anticancer settings [24]. p53R2 plays a key role in the resolution of cellular DNA damage by providing deoxyribonucleotide triphosphates (dNTPs) to allow DNA repair in cells by making cell cycle arrest in response to p53 activation [21, 24]. Overexpression of p53R2 is associated with clinical response in myelodysplatic syndrome/acute Risedronate sodium myelogenous leukemia [25]. It has been suggested that the opposite regulation of hRRM2 and p53R2 in the invasion potential may play a critical role in determining the invasion and metastasis phenotype in cancer cells [26]. The impact, if any, of the turnover of intracellular cholesterol with the expression of tumor suppressor agent e. g. p53 protein and its simultaneous effects on the profile of ribonucleotide reductase, a protein responsible for DNA synthesis, are the initial targets of this study to understand the mechanism of regulation of genes by cholesterol in the pathogenesis of chronic lymphocytic leukemia. == Materials and Methods == == Selection Criteria == == For Patients == Inclusion criteria: Blood samples of CLL patients collected from Cancer clinic, AIIMS, New Delhi with informed consent. Samples were obtained after diagnosis of CLL. Exclusion criteria: Patients were excluded from the study if suffering from any acute or chronic infections, patients receiving any medication known to affect lipid metabolism at the time of initial blood sampling, patients not willing to give consent. == For Controls ==.