@inproceedings{47726ad0af4145ec96c68289d422a8f3,
title = "Synergism between photochemical and ionizing radiation effects in MCF-7 cells in vitro",
abstract = "The complexes of platinum tetrachlorodianion with two molecules of rhodamine-123 (Rh-123) or Nile Blue (PtCl4 (Rh-123)2 or PtCl4(Nile Blue)2), have been reported to act as hypoxic cell radiosensitizers of malignant tumors in vitro and in vivo. Both PtCl4(Rh-123)2 and PtCl4(Nile Blue), interact positively in trimodality therapy including each drug, x-ray ana light (400-800 nm) in killing human mammary carcinoma cells (MCF-7) in vitro. The combination treatment results in more than additive killing as assessed by product of the surviving fractions and a significant reduction of the shoulder of the x-ray survival curve. Both of the drugs participate in photodynamic therapy (PDT) in drug and light dose dependent manner. With 15 /μM PtCl4 (Rh-123 )2 plus 24 J/cm2 the survival fraction was 0.03, and with 5 /iM PtCl4(Nile Blue)2 plus 24 J/cm2 the surviving fraction was 0.002 as compared with a surviving fraction of 0.9 ∼ 0.95 with light exposure alone. After treatment with 15 /xM PtCl4(Rh-123 )2 or 5 /xM PtCl4(Nile Blue)2 alone the surviving fractions were ∼ 0.4 or - 0.3 respectively. The primary subcellular targets for the neutral platinum complexes were indicated to be the nuclear DNA as opposed to the mitochondria for Rh-123 or the lysosomes for Nile Blue. Because the nuclear DNA is also the primary target for ionizing radiation, drug plus light plus x-ray might cause supraadditive killing. Both PtCl4(Rh-123)2 and PtCl4(Nile Blue)2 have been reported to be relatively non-toxic in vivo compared to the anionic or cationic compounds currently being used in photodynamic therapy. Based on these results PtCl4(Rh-123 )2 and PtCl4(Nile Blue) 2 have the potential for use in photodynamic therapy and in trimodality therapy.",
author = "Gulshan Ara and Herman, {Terence S.} and Archana Varshney and Timothy Korbut and Teicher, {Beverly A.}",
year = "1992",
month = aug,
day = "7",
doi = "10.1117/12.137459",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
pages = "195--206",
editor = "Jacques, {Steven L.}",
booktitle = "Laser-Tissue Interaction III",
note = "Laser-Tissue Interaction III 1992 ; Conference date: 19-01-1992 Through 24-01-1992",
}