title: Comparison of photodynamic treatment produced cell damage between human breast cancer cell MCF-7 and its multidrug resistance cell.
abstract: BACKGROUND
  Multidrug resistance (MDR) of breast cancer is a major obstacle in chemotherapy of cancer treatments. Recently the anti-tumor effects of Chlorin e6 (Ce6) mediated photodynamic therapy (Ce6-PDT) were reported in skin cancer and hepatoma in vitro. However, its therapeutic potential in killing human breast cancer especially those with MDR and the differences between MCF-7 and MCF-7/ADR after PDT treatment has not been fully investigated.
  
  
  METHODS
  MTT assay was used to measure cell survival rate of MCF-7 cells and MCF-7/ADR cells. Intracellular reactive oxygen species (ROS) generation was measured by monitoring the fluorescence intensity of dichlorofluorescein (DCF) by flow cytometry. Nuclear morphology changes and DNA damage in both MCF-7 and MCF-7/ADR after Ce6-PDT were analyzed by hochest33342 staining and comet assay. Western blot and monodansylcadaverine (MDC) staining were used to monitor autophagic response in MCF-7/ADR.
  
  
  RESULTS
  Ce6-PDT induced cell viability decrease, intracellular ROS generation, and DNA damage in concentration-dependent and cell-specific manner, and MCF-7 was more sensitive to Ce6-PDT than MCF-7/ADR cells at the same PDT condition. PDT treatment could trigger cell death via apoptosis in MCF-7 cells but autophagic cell death in MCF-7/ADR cells.
  
  
  CONCLUSIONS
  These results suggested that MCF-7 was more sensitive to Ce6-PDT than MCF-7/ADR, and PDT treatment could trigger apoptotic response in MCF-7 cells, but stimulate autophagic response in MCF-7/ADR cells.
authors: Key Laboratory of Ministry of Education for Medicinal Plant Resources and Natural Pharmaceutical Chemistry, College of Life Sciences, Shaanxi Normal University, China.
authors: Haiping
authors: H
authors: Wang
authors: Key Laboratory of Ministry of Education for Medicinal Plant Resources and Natural Pharmaceutical Chemistry, College of Life Sciences, Shaanxi Normal University, China.
authors: Long
authors: L
authors: Li
authors: Key Laboratory of Ministry of Education for Medicinal Plant Resources and Natural Pharmaceutical Chemistry, College of Life Sciences, Shaanxi Normal University, China.
authors: Pan
authors: P
authors: Wang
authors: Key Laboratory of Ministry of Education for Medicinal Plant Resources and Natural Pharmaceutical Chemistry, College of Life Sciences, Shaanxi Normal University, China.
authors: Xiaobing
authors: X
authors: Wang
authors: Key Laboratory of Ministry of Education for Medicinal Plant Resources and Natural Pharmaceutical Chemistry, College of Life Sciences, Shaanxi Normal University, China. Electronic address: zkxian@snnu.edu.cn.
authors: Kun
authors: K
authors: Zhang
authors: Key Laboratory of Ministry of Education for Medicinal Plant Resources and Natural Pharmaceutical Chemistry, College of Life Sciences, Shaanxi Normal University, China. Electronic address: lshaof@snnu.edu.cn.
authors: Quanhong
authors: Q
authors: Liu
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy* / Q000503:physiopathology*; D002470:Cell Survival / Q000187:drug effects; D002735:Chlorophyllides; D004305:Dose-Response Relationship, Drug; D004307:Dose-Response Relationship, Radiation; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D006801:Humans; D061986:MCF-7 Cells; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D011166:Porphyrins / Q000008:administration & dosage*; D016896:Treatment Outcome
chemical_list: D002735:Chlorophyllides; D017319:Photosensitizing Agents; D011166:Porphyrins; C062985:phytochlorin
keywords: Adriamycin resistant cell; Apoptosis; Autophagy; Ce6-PDT; MCF-7