Gold nanoparticles in combination with megavoltage radiation energy increased radiosensitization and apoptosis in colon cancer HT-29 cells.
Gold nanoparticles (GNP) act as a radiosensitizer in radiation therapy. However, recent studies have shown contradictory evidence in terms of radiosensitization in the presence of GNP combined with X-ray megavoltage energy (MV) on different cell types. In this study, the effect of GNP on radiosensitization enhancement of HT-29 human colorectal cancer cells at MV X-ray energy was evaluated.



The cytotoxicity and radiosensitization of GNP were evaluated in HT-29 human colorectal cancer cells by MTS-assay and multiple MTS-assay, respectively. Cellular uptake was assayed using graphite furnace atomic absorption spectrometry (GFAAS). Apoptosis and cell cycle progression were determined by an Annexin V-FITC/propidium iodide (PI) kit and PI/RNase solution with flow cytometry, respectively.



Results showed that the cell viability of the HT-29 cells was not influenced by exposure to different concentrations of GNP (10-100 μM). GNP alone did not affect the cell cycle progression and apoptosis. In contrast, GNP, in combination with radiation (9 MV), induced more apoptosis. The interaction of GNP with MV energy resulted in a significant radiosensitization enhancement compared with irradiation alone.



It was concluded that GNP may work as bio-inert material on HT-29 cancer cells and their enhancement of radiosensitization may be due to increase in the absorbed irradiation dose.
a Department of Medical Genetics, Faculty of Medicine , Ahvaz Jundishapur University of Medical Sciences , Ahvaz , Iran.
Alihossein
A
Saberi
b Department of Medical Physics , School of Medicine, Isfahan University of Medical Sciences , Isfahan , Iran.
Daryoush
D
Shahbazi-Gahrouei
c Department of Biotechnology , College of Agriculture, Isfahan University of Technology , Isfahan , Iran.|d Stem Cell Research Center , Golestan University of Medical Science , Gorgan , Iran.
Mahdi
M
Abbasian
e Department of Cell Sciences Research Center Medical Science , School of Medicine, Isfahan University of Medical Sciences , Isfahan , Iran.
Mehrafarin
M
Fesharaki
f Department of Biotechnology , College of Agriculture, Isfahan University of Technology , Isfahan , Iran.
Azam
A
Baharlouei
d Stem Cell Research Center , Golestan University of Medical Science , Gorgan , Iran.|g Department of Medical Physics , School of Medicine, Golestan University of Medical Sciences , Gorgan , Iran.
Zahra
Z
Arab-Bafrani
D017209:Apoptosis / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D006046:Gold / Q000008:administration & dosage*; D019073:HT29 Cells; D006801:Humans; D053768:Metal Nanoparticles / Q000008:administration & dosage*; D011836:Radiation Tolerance / Q000187:drug effects*; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage*; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000379:methods*
D011838:Radiation-Sensitizing Agents; D006046:Gold
Apoptosis; cell cycle; gold nanoparticles; mega-voltage; radiosensitizer