title: The effect of elemene on lung adenocarcinoma A549 cell radiosensitivity and elucidation of its mechanism.
abstract: OBJECTIVE
  To investigate the effect of elemene on the radiosensitivity of A549 cells and its possible molecular mechanism.
  
  
  METHODS
  Apoptosis of A549 cells was detected by flow cytometry and fluorescence microscopy. The effect of double-strand break (DSB) damage repair in A549 cells was evaluated using the neutral comet assay. Protein expression levels were detected using western blotting, and the correlation between protein levels was analyzed.
  
  
  RESULTS
  Elemene exhibited a radiosensitizing effect on A549 cells. The level of apoptosis induced by elemene combined with radiation was significantly greater (p<0.01) than that elicited by either radiation or elemene alone. Following radiation and subsequent repair for 24 h, the tail intensity of A549 cells treated with a combination of elemene and radiation was greater than that of cells treated with either elemene or radiation alone (p<0.01). This result indicates that elemene inhibits cellular DSB repair. Both elemene combined with radiation and radiation alone decreased the protein expression of DNA-PKcs and Bcl-2 compared to elemene alone (p<0.01), while p53 protein expression was increased (p<0.01). A negative correlation was observed between DNA-PKcs and p53 expression (r=-0.569, p=0.040), while a positive correlation was found between DNA-PKcs and Bcl-2 expression (r=0.755, p=0.012).
  
  
  CONCLUSIONS
  Elemene exhibits a radiosensitizing effect on A549 cells, and its underlying molecular mechanism of action may be related to the downregulation of DNA-PKcs gene expression.
authors.affiliation: 2nd Affiliated Hospital, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Zou
authors.affiliation: 2nd Affiliated Hospital, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Caigang
authors.initials: C
authors.lastname: Liu
authors.affiliation: 2nd Affiliated Hospital, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: 2nd Affiliated Hospital, Dalian Medical University, Dalian, Liaoning, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Zou
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics / Q000532:radiotherapy*; D000077192:Adenocarcinoma of Lung; D000704:Analysis of Variance; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D020552:Comet Assay; D004260:DNA Repair / Q000187:drug effects / Q000528:radiation effects; D051747:DNA-Activated Protein Kinase / Q000378:metabolism; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000187:drug effects / Q000528:radiation effects; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000532:radiotherapy*; D008856:Microscopy, Fluorescence; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000187:drug effects / Q000528:radiation effects*; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*; D012717:Sesquiterpenes / Q000494:pharmacology*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D011838:Radiation-Sensitizing Agents; D012717:Sesquiterpenes; D016159:Tumor Suppressor Protein p53; C038905:elemene; D051747:DNA-Activated Protein Kinase