title: Chlorophyll derivative mediated PDT versus methotrexate: an in vitro study using MCF-7 cells.
abstract: BACKGROUND
  Breast cancer is the most common cause of cancer deaths among women worldwide. Although chemotherapy is a standard method for the treatment of breast cancer, the photodynamic therapy (PDT) is a recent promising modality for cancer diagnosis and treatment. Its major advantages over chemotherapy are better selectivity of tumour tissue destruction and lack of severe local and systemic complications. This work is directed towards evaluation of the efficacy of Photodynamic therapy using chlorophyll derivative (CHL) as a photosensitizer in treatment of breast cancer. It also aims at investigation of the genetic safety of chlorophyll mediated PDT in comparison to the conventional chemotherapy.
  
  
  METHODS
  Both methotrexate (MTX) and light activated chlorophyll derivative were used to target MCF-7 breast cancer cell line. Standard karyotyping and alkaline single cell microgel electrophoresis assay (Comet assay) were applied on normal human peripheral blood lymphocytes (HPL) in order to investigate the respective possible mutagenic and genotoxic side effects that might result from application of each therapeutic modality.
  
  
  RESULTS
  Results obtained from this study showed that 50% of MCF-7 tumour cell death (LC(50)) was reached by using a concentration of chlorophyll derivative that is 138 times lower than MTX. Moreover, chlorophyll derivative exerted no genetic side effects as compared to MTX that resulted into several types of chromosomal breakages.
  
  
  CONCLUSIONS
  Compared to MTX, light activated chlorophyll derivative proved to be a better candidate for breast cancer cell toxicity, referring to its higher efficacy at tumour cells killing, safety to normal cells and simple method of extraction.
authors.affiliation: Faculty of Pharmacy and Biotechnology, German University in Cairo (GUC), Main Entrance of Al-Tagamoa Al-Khames, New Cairo City, Egypt.
authors.forename: Iman
authors.initials: I
authors.lastname: Gomaa
authors.forename: Sara E
authors.initials: SE
authors.lastname: Ali
authors.forename: Tarek A
authors.initials: TA
authors.lastname: El-Tayeb
authors.forename: Mahmoud H
authors.initials: MH
authors.lastname: Abdel-kader
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D002470:Cell Survival; D002735:Chlorophyllides / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007621:Karyotyping; D054023:Lasers, Semiconductor; D028022:Low-Level Light Therapy / Q000379:methods*; D061986:MCF-7 Cells; D008727:Methotrexate / Q000494:pharmacology*; D009152:Mutagenicity Tests; D017319:Photosensitizing Agents / Q000627:therapeutic use*
chemical_list: D000964:Antimetabolites, Antineoplastic; D002735:Chlorophyllides; D017319:Photosensitizing Agents; C007020:chlorophyllin; D008727:Methotrexate