title: Signal transducer and activators of transcription 3 regulates cryptotanshinone-induced apoptosis in human mucoepidermoid carcinoma cells.
abstract: BACKGROUND
  Cryptotanshinone (CT) is a biologically active compound from the root of Salvia miltiorrhiza that has been reported to induce apoptosis in various cancer cell lines; but, it has not yet been fully explored in human mucoepidermoid carcinoma (MEC).
  
  
  OBJECTIVE
  Here, we demonstrated the apoptotic effects and its related mechanism in MC-3 and YD-15 human MEC cell lines.
  
  
  METHODS
  The effects of CT on apoptotic activity were evaluated by cell proliferation assay, Western blotting, 4'-6-diamidino-2-phenylindole staining, reverse transcription-polymerase chain reaction, and luciferase assay.
  
  
  RESULTS
  Our data show that CT treatment of MC-3 cells results in anti-proliferative and apoptotic activities in MC-3 and it is accompanied by a decrease in phosphorylation and dimerization of signal transducer and activators of transcription 3 (STAT3). CT decreased the expression levels of myeloid cell leukemia-1 (Mcl-1) and surviving, whereas Bcl-xL expression was not changed. CT clearly regulates survivin protein at a transcriptional level and alters Mcl-1 through proteasome-dependent protein degradation. In addition, CT-induced apoptotic cell death in YD-15, another human MEC cell line, was associated with the inhibition of STAT3 phosphorylation.
  
  
  CONCLUSIONS
  These data suggest that CT could be a good apoptotic inducer through modification of STAT3 signaling in human MEC cell lines.
authors.affiliation: Department of Oral Pathology and Cancer Biology, School of Dentistry, and Institute of Oral Bioscience, Chonbuk National Univerisity, Jeonju, 561-756, South Korea.
authors.forename: Hyun-Ju
authors.initials: HJ
authors.lastname: Yu
authors.affiliation: Department of Veterinary Internal Medicine, College of Veterinary Medicine, Chonbuk National Univerisity, Jeonju, 561-756, South Korea.
authors.forename: Chul
authors.initials: C
authors.lastname: Park
authors.affiliation: Department of Dental Hygiene, Division of Health Sciences, Cheongju University, Cheongju, 360-764, South Korea.
authors.forename: Sun-Ju
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Department of Oral Pathology and Cancer Biology, School of Dentistry, and Institute of Oral Bioscience, Chonbuk National Univerisity, Jeonju, 561-756, South Korea.
authors.forename: Nam-Pyo
authors.initials: NP
authors.lastname: Cho
authors.affiliation: Department of Oral Pathology and Cancer Biology, School of Dentistry, and Institute of Oral Bioscience, Chonbuk National Univerisity, Jeonju, 561-756, South Korea.
authors.forename: Sung-Dae
authors.initials: SD
authors.lastname: Cho
keywords: Apoptosis; cryptotanshinone; mucoepidermoid carcinoma; myeloid cell leukemia-1; signal transducer and activator of transcription 3; survivin