title: ALA-induced photodynamic effect on vitality, apoptosis, and secretion of vascular endothelial growth factor (VEGF) by colon cancer cells in normoxic environment in vitro.
abstract: BACKGROUND
  Cancer therapy is often based on combination of conventional methods of cancer treatment with immunotherapy. Photodynamic therapy (PDT) is one of the immunomodulating methods used in oncology. We examined how PDT influences the secretory activity of colon cancer cells in vitro, especially the secretion of vascular endothelial growth factor (VEGF) in aerobic conditions.
  
  
  METHODS
  We used two cancer cell lines with different malignancy potentials: a metastatic SW620 line and a non-metastatic SW480 line. In the first stage of the experiment, we exposed each cell line to three different concentrations of photosensitizer's precursor: 5-aminolevulinic acid (ALA) and varying levels of light radiation, after which we assessed cell viability and apoptosis induction in these lines, using the MTT and LDH assays. Then, we determined the secretion of VEGF by these cells in aerobic conditions and under the ALA-PDT parameters at which cells presented the highest viability.
  
  
  RESULTS
  Photodynamic treatment with ALA did not influence on VEGF secretion by the non-metastatic SW480 cells, but caused a decrease in VEGF secretion by the metastatic SW 620 cell line by 29% (p<0.05). SW 620 cell line secreted more actively VEGF than the SW480 cells, both before and after photo dynamic therapy (p<0.05).
  
  
  CONCLUSIONS
  The outcome of this in vitro study presented a beneficial effect of ALA-PDT, resulting in a decrease of VEGF secretion in the more malignant SW620 cell lines. Further studies should be considered to confirm the clinical relevance of this finding.
authors.affiliation: School of Medicine with the Division of Dentistry in Zabrze, Department and Clinic of Internal Diseases, Angiology and Physical Medicine, Center for Laser Diagnostics and Therapy, Medical University of Silesia, Batorego Street 15, 41-902 Bytom, Poland. Electronic address: akawczyk@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Kawczyk-Krupka
authors.affiliation: School of Health Sciences in Katowice, Department of Physical Medicine, Chair of Physiotherapy, Medical University of Silesia, Medykow Street 12, 40-752 Katowice, Poland.
authors.forename: K
authors.initials: K
authors.lastname: Sieroń-Stołtny
authors.affiliation: School of Medicine with the Division of Dentistry in Zabrze, Department and Clinic of Internal Diseases, Angiology and Physical Medicine, Center for Laser Diagnostics and Therapy, Medical University of Silesia, Batorego Street 15, 41-902 Bytom, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Latos
authors.affiliation: School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia in Katowice, Department of Microbiology and Immunology, 19 Jordana St., 41-808 Zabrze, Poland.
authors.forename: Z P
authors.initials: ZP
authors.lastname: Czuba
authors.affiliation: School of Medicine with the Division of Dentistry in Zabrze, Department and Clinic of Internal Diseases, Angiology and Physical Medicine, Center for Laser Diagnostics and Therapy, Medical University of Silesia, Batorego Street 15, 41-902 Bytom, Poland.
authors.forename: B
authors.initials: B
authors.lastname: Kwiatek
authors.affiliation: School of Medicine with the Division of Dentistry in Zabrze, Department and Clinic of Internal Diseases, Angiology and Physical Medicine, Center for Laser Diagnostics and Therapy, Medical University of Silesia, Batorego Street 15, 41-902 Bytom, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Potempa
authors.affiliation: School of Clinical Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Rd, Cambridge CB2 OSP, United Kingdom.
authors.forename: K
authors.initials: K
authors.lastname: Wasilewska
authors.affiliation: School of Medicine with the Division of Dentistry in Zabrze, Medical University of Silesia in Katowice, Department of Microbiology and Immunology, 19 Jordana St., 41-808 Zabrze, Poland.
authors.forename: W
authors.initials: W
authors.lastname: Król
authors.affiliation: School of Medicine with the Division of Dentistry in Zabrze, Department and Clinic of Internal Diseases, Angiology and Physical Medicine, Center for Laser Diagnostics and Therapy, Medical University of Silesia, Batorego Street 15, 41-902 Bytom, Poland.
authors.forename: A
authors.initials: A
authors.lastname: Stanek
mesh_terms: D000622:Aminolevulinic Acid / Q000008:administration & dosage*; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D016896:Treatment Outcome; D000072258:Tumor Hypoxia / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D017319:Photosensitizing Agents; D042461:Vascular Endothelial Growth Factor A; D000622:Aminolevulinic Acid
keywords: Colorectal cancer; Photodynamic therapy; SW480 cell line; SW620 cell line; Vascular endothelial growth factor