title: Hyaluronic Acid Inhibitor 4-Methylumbelliferone Activates the Intrinsic Apoptosis Pathway in K562 Chronic Myelogenous Leukemia Cells.
abstract: BACKGROUND
  As an inhibitor of hyaluronic acid (HA) synthesis, 4-methylumbelliferone (4-MU) has been shown to induce apoptosis of various types of cancer cells. However, the potential impact of 4-MU-induced apoptosis on leukemia cells via modulation of HA is not well-known.
  
  
  METHODS
  We examined apoptosis of chronic myelogenous leukemia (CML) cells after treatment with 4-MU using annexin V/propidium iodide (V/PI) analysis and poly (ADP-ribose) polymerase (PARP) cleavage. We further examined the mechanisms of 4-MU-induced apoptosis by measuring mitochondrial membrane potential and reactive oxygen species generation. Using real-time PCR, and western blot analysis we examined signaling pathways involved in apoptosis.
  
  
  RESULTS
  The current study demonstrated that treatment of CML cells with 4-MU led to induction of apoptosis through PARP cleavage and loss of mitochondria membrane potential. Mechanistically, 4-MU led to increased p53 mRNA expression, elevated cytoplasmic protein levels of cytochrome c and B-cell lymphoma-2-associated X (BAX) and reduced levels of B-cell lymphoma-2 (BCL2) expression. Addition of exogenous soluble HA was able to protect 4-MU-exposed cells from apoptosis.
  
  
  CONCLUSIONS
  Our findings suggest that 4-MU induces apoptosis in CML cells by activating components associated with the intrinsic apoptosis pathway.
authors.affiliation: Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, GA, U.S.A.
authors.forename: Hao
authors.initials: H
authors.lastname: Ban
authors.affiliation: Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, GA, U.S.A.
authors.forename: Olga
authors.initials: O
authors.lastname: Uchakina
authors.affiliation: Division of Basic Medical Sciences, Mercer University School of Medicine, Macon, GA, U.S.A. mckallip_r@mercer.edu.
authors.forename: Robert James
authors.initials: RJ
authors.lastname: McKallip
mesh_terms: D017209:Apoptosis; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D006820:Hyaluronic Acid / Q000037:antagonists & inhibitors*; D006923:Hymecromone / Q000494:pharmacology*; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D017382:Reactive Oxygen Species; D006923:Hymecromone; D006820:Hyaluronic Acid; D011065:Poly(ADP-ribose) Polymerases
keywords: 4-Methylumbelliferone; Apoptosis; BCL2 family; K562 cells; ROS; mitochondria