title: Synthesized Pheophorbide a-mediated photodynamic therapy induced apoptosis and autophagy in human oral squamous carcinoma cells.
abstract: BACKGROUND
  Pheophorbide a (Pa) is a chlorine-based photosensitizer derived from an ethnopharmacological herb, and our group recently synthesized Pa by the removal of a magnesium ion and a phytyl group from chlorophyll-a. In this study, the effect of photodynamic therapy (PDT) with synthesized Pa was examined in a human oral squamous cell carcinoma (OSCC) cells.
  
  
  METHODS
  Cells were treated with PDT with Pa, and reactive oxygen species (ROS) and mitochondrial membrane potential [ΔΨ (m)] were examined. Apoptosis was measured using annexin V staining and immunoblot. Autophagy was characterized by the increase in LC3B-II and the formation of autophagosome and acidic vesicular organelles (AVOs).
  
  
  RESULTS
  Pa-PDT inhibited the proliferation of OSCC cells in a dose-dependent manner. Pa-PDT increased the number of apoptotic cells by inactivating ERK pathway. Pa-PDT also induced autophagy in OSCC cells evidenced by the increased levels of LC3 type II expression and the accumulation of AVOs. The inhibition of autophagy enhanced Pa-PDT-mediated cytotoxicity through an increase in necrosis.
  
  
  CONCLUSIONS
  These results suggest that synthesized Pa-PDT exerts anti-tumor effects by inducing apoptosis and autophagy and provide novel evidence that Pa-PDT induces autophagy, and autophagy inhibition enhances Pa-PDT-mediated necrosis in OSCC cells.
authors: Department of Pathology, Research Center for Oral disease Regulation of Aged, School of Dentistry, Chosun University, Gwangju, Korea.
authors: Mee Young
authors: MY
authors: Ahn
authors: Hyo-Eun
authors: HE
authors: Yoon
authors: Seong-Min
authors: SM
authors: Kwon
authors: Jun
authors: J
authors: Lee
authors: Seung-Ki
authors: SK
authors: Min
authors: Yong-Chul
authors: YC
authors: Kim
authors: Sang-Gun
authors: SG
authors: Ahn
authors: Jung-Hoon
authors: JH
authors: Yoon
mesh_terms: D017209:Apoptosis; D001343:Autophagy / Q000187:drug effects; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002734:Chlorophyll / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis; D009062:Mouth Neoplasms / Q000188:drug therapy*; D009336:Necrosis; D010588:Phagosomes; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000138:chemical synthesis / Q000494:pharmacology / Q000627:therapeutic use*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: C502070:MAP1LC3B protein, human; D008869:Microtubule-Associated Proteins; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; D002734:Chlorophyll; C032623:pheophorbide a