title: Cholesterol esters as growth regulators of lymphocytic leukaemia cells.
abstract: OBJECTIVE
  Alterations in plasma lipid profile and in intracellular cholesterol homoeostasis have been described in various malignancies; however, significance of these alterations, if any, in cancer biology is not clear. The aim of the present study was to investigate a possible correlation between alterations in cholesterol metabolism and expansion of leukaemia cell numbers.
  
  
  METHODS
  Lipid profiles in plasma and in primary leukaemia cells isolated from patients with acute or chronic lymphocytic leukaemia (ALL and CLL) were studied.
  
  
  CONCLUSIONS
  Decreased levels of HDL-C were observed in plasma of leukaemic patients, levels of total cholesterol, LDL-C, triglycerides and phospholipids were unchanged or only slightly increased. As compared to normal lymphocytes, freshly isolated leukaemic cells showed increased levels of cholesterol esters and reduction in free cholesterol. Growth stimulation of ALL and CLL cells with phytohemagglutinin led to further increase in levels of cholesterol esters. Conversely, treatment with an inhibitor of cell proliferation such as the mTOR inhibitor, RAD, caused decline in population growth rate of leukaemia cells, which was preceded by sharp reduction in rate of cholesterol esterification. On the other hand, exposure of leukaemic cells to two inhibitors of cholesterol esterification, progesterone and SaH 58-035, caused 60% reduction in their proliferation rate. In addition to demonstrating tight correlation between cell number expansion and cholesterol esterification in leukaemic cells, these results suggest that pathways that control cholesterol esterification might represent a promising targets for novel anticancer strategies.
authors.affiliation: Department of Internal Medicine, University of Cagliari, Italy.
authors.forename: M F
authors.initials: MF
authors.lastname: Mulas
authors.forename: C
authors.initials: C
authors.lastname: Abete
authors.forename: D
authors.initials: D
authors.lastname: Pulisci
authors.forename: A
authors.initials: A
authors.lastname: Pani
authors.forename: B
authors.initials: B
authors.lastname: Massidda
authors.forename: S
authors.initials: S
authors.lastname: Dessì
authors.forename: A
authors.initials: A
authors.lastname: Mandas
mesh_terms: D000328:Adult; D000368:Aged; D000577:Amides / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002788:Cholesterol Esters / Q000097:blood / Q000378:metabolism*; D008076:Cholesterol, HDL / Q000097:blood; D000068338:Everolimus; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000097:blood / Q000378:metabolism / Q000473:pathology*; D050356:Lipid Metabolism / Q000187:drug effects; D008055:Lipids / Q000097:blood; D008875:Middle Aged; D017646:Organosilicon Compounds / Q000494:pharmacology; D010835:Phytohemagglutinins / Q000494:pharmacology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000097:blood / Q000378:metabolism / Q000473:pathology*; D011374:Progesterone / Q000494:pharmacology; D020123:Sirolimus / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D000577:Amides; D000970:Antineoplastic Agents; D002788:Cholesterol Esters; D008076:Cholesterol, HDL; D008055:Lipids; D017646:Organosilicon Compounds; D010835:Phytohemagglutinins; D011374:Progesterone; C040256:SAN 58035; D000068338:Everolimus; D020123:Sirolimus