title: [AG490 inhibits the proliferation of human medullary thyroid carcinoma TT cells and increases their radiosensitivity].
abstract: OBJECTIVE
  To investigate the effects of AG490 on the proliferation, apoptosis and radiosensitivity of human medullary thyroid carcinoma TT cells.
  
  
  METHODS
  Human medullary thyroid carcinoma TT cells were treated with different concentrations of AG490 (0, 25, 50, 100 μmol/L). Cell proliferation and apoptosis were detected by MTT and flow cytometry, respectively. Radiosensitivity was detected by clone formation assay. The expressions of Janus kinase 2 (JAK2), phosphated signal transducer and activator of transcription 3 (p-STAT3), Bcl-2 and Bax were evaluated by Western blotting.
  
  
  RESULTS
  Compared with the control group, the proliferation of thyroid TT cells in 25, 50, 100 μmol/L AG490 treated groups significantly decreased in a time- and concentration-dependent manner, and the apoptosis rate of TT cells gradually increased along with the increased of the concentrations of AG490. There was a significant decrease in cell survival fraction and radiobiological parameters (SF2, D0, Dq and N), while the sensitivity enhancement ratio (SER D0, SERDq) showed a significant increase in 50 μmol/L AG490 treated group compared with the control group. Western blotting showed that the expressions of JAK2, p-STAT3 and Bcl-2 were gradually reduced, while the expression of Bax was raised with the increasing concentration of AG490.
  
  
  CONCLUSIONS
  AG490 can inhibit the proliferation, increase the apoptosis rate and enhance the radiosensitivity of human medullary thyroid carcinoma TT cells in vitro.
authors.affiliation: Department of Radiation Medicine, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Radiation Medicine, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Shengmin
authors.initials: S
authors.lastname: Gan
authors.affiliation: Department of Radiation Medicine, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Luo
authors.affiliation: Department of Radiation Medicine, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Radiation Medicine, College of Basic Medical Sciences, Chongqing Medical University, Chongqing 400016, China.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Peng
mesh_terms: D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D018278:Carcinoma, Neuroendocrine; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D053614:Janus Kinase 2 / Q000378:metabolism; D011836:Radiation Tolerance / Q000187:drug effects*; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000528:radiation effects; D013964:Thyroid Neoplasms / Q000473:pathology*; D020032:Tyrphostins / Q000494:pharmacology*
chemical_list: D050796:STAT3 Transcription Factor; D020032:Tyrphostins; C095512:alpha-cyano-(3,4-dihydroxy)-N-benzylcinnamide; C507924:JAK2 protein, human; D053614:Janus Kinase 2