title: Leukemia cells display lower levels of intracellular cholesterol irrespective of the exogenous cholesterol availability.
abstract: BACKGROUND
  Different types of cancer cells are previously shown to accumulate intracellular cholesterol. However, the data on intracellular cholesterol levels in leukemia cells provide contradictory evidence. Various previous works indicate either increase, decrease or no difference in total cholesterol levels between leukemia cells and healthy peripheral blood mononuclear cells (PBMCs).
  
  
  METHODS
  We studied the intracellular cholesterol levels in acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL) cells and compared with that in PBMCs from the healthy subjects.
  
  
  RESULTS
  We observed that the PBMCs from AML (n=7) and ALL (n=7) patients displayed significantly lower intracellular levels of total cholesterol in comparison to PBMCs from the healthy subjects (n=26). Consistent with the patient data the ALL (CCRF-CEM and MOLT-3) and AML (KG-1 and THP-1) cell lines also displayed significantly lower intracellular levels of total cholesterol. We confirmed this observation using multiple methodological approaches. Both ALL and AML cell lines also displayed significantly lower levels of free cholesterol and cholesteryl ester contents in comparison to normal hematopoietic cells. We observed that >90% of the total cholesterol in leukemia cells as well as in normal PBMCs was present in the form of cholesteryl esters. It was also observed that the lower levels of cholesterol in leukemia cells are not affected by exogenous cholesterol availability.
  
  
  CONCLUSIONS
  Present study provides convincing evidence to prove that the cellular free cholesterol and cholesteryl ester content is significantly reduced in leukemia cells in comparison to normal hematopoietic cells in circulation. Moreover, it was shown that the lower levels of cholesterol in leukemia cells are not affected by exogenous cholesterol availability.
authors.affiliation: Microbiology and Molecular Genetics, University of the Punjab, Lahore-54590, Pakistan.
authors.forename: Hina
authors.initials: H
authors.lastname: Usman
authors.affiliation: Microbiology and Molecular Genetics, University of the Punjab, Lahore-54590, Pakistan.
authors.forename: Fatima
authors.initials: F
authors.lastname: Ameer
authors.affiliation: Microbiology and Molecular Genetics, University of the Punjab, Lahore-54590, Pakistan.
authors.forename: Rimsha
authors.initials: R
authors.lastname: Munir
authors.affiliation: Microbiology and Molecular Genetics, University of the Punjab, Lahore-54590, Pakistan.
authors.forename: Areeb
authors.initials: A
authors.lastname: Iqbal
authors.affiliation: Microbiology and Molecular Genetics, University of the Punjab, Lahore-54590, Pakistan.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Zaid
authors.affiliation: Microbiology and Molecular Genetics, University of the Punjab, Lahore-54590, Pakistan.
authors.forename: Shahida
authors.initials: S
authors.lastname: Hasnain
authors.affiliation: Department of Radiation Oncology, 1300 Morris Park Avenue, 10461, Bronx, NY, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Scandiuzzi
authors.affiliation: Microbiology and Molecular Genetics, University of the Punjab, Lahore-54590, Pakistan. Electronic address: nzzaidi@yahoo.com.
authors.forename: Nousheen
authors.initials: N
authors.lastname: Zaidi
mesh_terms: D016022:Case-Control Studies; D045744:Cell Line, Tumor; D002784:Cholesterol / Q000097:blood / Q000378:metabolism*; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000378:metabolism* / Q000473:pathology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000378:metabolism* / Q000473:pathology
chemical_list: D002784:Cholesterol
keywords: Cholesterol; HDL-C; LDL-C; Leukemia; Lipids; Metabolism