title: Carcinostatic effects of platinum nanocolloid combined with gamma irradiation on human esophageal squamous cell carcinoma.
abstract: OBJECTIVE
  To explore the carcinostatic effects of platinum nanocolloid (Pt-nc) combined with gamma rays on human esophageal squamous cell carcinoma (ESCC).
  
  
  METHODS
  ESCC-derived KYSE-70 cells were treated with various concentrations of Pt-nc and/or gamma irradiation, and subsequently cultured in phenol red free DMEM with 10% FBS for 48 h. The proliferative status of the KYSE-70 cells was evaluated using trypan blue dye exclusion and WST-8 assays. Cellular and nucleic morphological aspects were evaluated using crystal violet and Hoechst 33342 stainings, respectively. Radiosensitivity was quantified by a cell viability assay, and the activated form of caspase-3, a characteristic apoptosis-related protein, was detected by Western blotting.
  
  
  RESULTS
  Although single treatment with either Pt-nc or gamma irradiation could slightly inhibit the growth of the KYSE-70 cells, their combination exerted remarkable carcinostatic effects in a manner dependent on either Pt-nc concentrations or gamma ray doses, compared with the effect of each treatment alone (p<0.05). By fluorescence micrographic observation, the KYSE-70 cells that were treated with Pt-nc and subsequently irradiated with gamma rays, were shown to undergo distinct apoptotic morphological changes. The carcinostatic effect of gamma rays at 7 Gy without Pt-nc was approximately equal to that when 3-Gy irradiation was combined with 100 ppm Pt-nc or that 5-Gy irradiation was combined with 50 ppm Pt-nc.
  
  
  CONCLUSIONS
  Pt-nc in combination with gamma rays may exert a cooperative effect through platinum- or gamma ray-induced apoptosis resulting in the inhibition of growth of cancer cells, while concurrently enabling the lowering of the radiative dose.
authors.affiliation: Department of Radiological Technology, Faculty of Health Sciences, Butsuryo College of Osaka, Otorikitamachi 3-33, Nishi-ku, Sakai, Osaka 593-8328, Japan.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.affiliation: Laboratory of Biology and Genetics, Faculty of Liberal Arts and Sciences, Osaka Prefecture University, Gakuen-cho 1-1, Nakaku, Sakai, Osaka 599-8531, Japan.
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Laboratory of Bioscience & Biotechnology for Cell Function Control, Faculty of Life and Environmental Sciences, Prefectural University of Hiroshima, Nanatsuka 562, Shobara, Hiroshima 727-0023, Japan.
authors.forename: Yasukazu
authors.initials: Y
authors.lastname: Saitoh
authors.affiliation: Department of Radiological Technology, Faculty of Health Sciences, Butsuryo College of Osaka, Otorikitamachi 3-33, Nishi-ku, Sakai, Osaka 593-8328, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Department of Radiological Technology, Faculty of Health Sciences, Butsuryo College of Osaka, Otorikitamachi 3-33, Nishi-ku, Sakai, Osaka 593-8328, Japan. Electronic address: miwa@butsuryo.ac.jp.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Miwa
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000532:radiotherapy*; D053148:Caspase 3 / Q000187:drug effects / Q000528:radiation effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D003102:Colloids; D004789:Enzyme Activation / Q000187:drug effects / Q000528:radiation effects; D004938:Esophageal Neoplasms / Q000188:drug therapy* / Q000532:radiotherapy*; D000077277:Esophageal Squamous Cell Carcinoma; D005720:Gamma Rays; D006801:Humans; D049329:Nanostructures; D017671:Platinum Compounds / Q000494:pharmacology*; D011205:Povidone / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D003102:Colloids; D017671:Platinum Compounds; C077842:polyvinylpolypyrrolidone; D053148:Caspase 3; D011205:Povidone
keywords: Carcinostatic effect; Gamma irradiation; Human esophageal squamous cell carcinoma (ESCC); KYSE-70 cells; Platinum-nanocolloid (Pt-nc)