title: High energy shock waves and 5-aminolevulinic for sonodynamic therapy: effects in a syngeneic model of colon cancer.
abstract: The cytotoxic effect of the natural porphyrin precursor 5-aminolevulinic acid (ALA) exposed to high energy shock waves (HESW) was investigated in vitro on DHD/K12/TRb rat colon cancer cells and in vivo on a syngeneic colon cancer model. In vitro, viable cell growth was determined by trypan blue exclusion assay and cell death was investigated by flow cytometry. ALA (50 µg/ml) and HESW (E1, EFD = 0.22 mJ/mm², 1000 shots or E2, EFD = 0.88 mJ/mm², 500 shots) showed a significant reduction of cancer cell proliferation at day 3 compared to cells exposed to ALA (p < 0.01) or HESW (p < 0.001) alone. An enhancement of necrotic and apoptotic cells was observed after combined treatment at day 1 with ALA and HESW E1 (a 3.1 and 6.4 fold increase vs ALA alone) or E2 (a 3.4 and 5.3 fold increase vs ALA alone). In vivo, apoptosis detection was carried out by TUNEL assay, the pro-apoptotic gene Bad and Bcl-2 mRNA expression was evaluated by quantitative SYBR Green real time RT-PCR and cleavage of poly(ADP-ribose)-polymerase (PARP) was investigated by Western Blotting. An enhancement of apoptosis was observed in tumour tissues after the combined treatment at day 1 with ALA (375 mg/kg i.v.) and HESW (E2) compared to that of ALA exposure alone with improved apoptotic index (a 2.0 fold increase), Bad enhanced mRNA expression (p < 0.01), Bcl-2 decreased mRNA expression (p < 0.05) and increased PARP cleavage. The interaction between HESW and ALA is then effective in inducing apoptosis on a syngeneic colon cancer model.
authors.affiliation: Department of Anatomy, Pharmacology and Forensic Medicine University of Torino, Via P. Giuria 13, 10125 Torino, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Serpe
authors.forename: R
authors.initials: R
authors.lastname: Canaparo
authors.forename: L
authors.initials: L
authors.lastname: Berta
authors.forename: A
authors.initials: A
authors.lastname: Bargoni
authors.forename: G P
authors.initials: GP
authors.lastname: Zara
authors.forename: R
authors.initials: R
authors.lastname: Frairia
mesh_terms: D000622:Aminolevulinic Acid / Q000494:pharmacology* / Q000627:therapeutic use*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D015153:Blotting, Western; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000628:therapy*; D003131:Combined Modality Therapy; D005434:Flow Cytometry; D019254:Genes, bcl-2; D019220:High-Energy Shock Waves / Q000627:therapeutic use*; D020287:In Situ Nick-End Labeling; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014343:Trypan Blue; D051025:bcl-Associated Death Protein / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D051025:bcl-Associated Death Protein; D000622:Aminolevulinic Acid; D011065:Poly(ADP-ribose) Polymerases; D014343:Trypan Blue