Evaluation of the effect of low and intermediate frequency electromagnetic waves on radiosensitivity
Year: 2016
Type: dissertation
Abstract: The incidence of epidemic Kaposi's sarcoma in HIV/AIDS patients is high due to their compromised immune system.HIV-positive individuals presenting with cancer tend to be more sensitive to ionising radiation and are at a higher risk of developing severe side effects during radiotherapy, and there is a need to develop non-invasive methods to preferentially sensitise cancer cells and reduce therapeutic doses.Here, the effects of 100 and 1000 Hz electromagnetic fields (EMF) broadcast via an argon plasma ray tube at 50 W on the radiosensitivity of apparently normal Chinese hamster lung fibroblasts (V79) and human malignant melanoma cells (MeWo) were evaluated using the colony forming assay.Pre-exposure of the fibroblasts to both fields had no effect on their radiosensitivity, if X-ray irradiation followed within 2 h or at 6 h.Significant radiosensitisation was observed when X-rays were administered 4 h after EMF exposure.For the MeWo cells, pre-exposure to 100 Hz resulted in a significant radioprotection when irradiation followed within 6 h.However, treatment of these cells with a 1000 Hz field significantly potentiated the effect of X-rays.When cells were irradiated prior to EMF exposure, the V79 cells were marginally protected by the 100 Hz field and sensitised by the 1000 Hz field.In contrast, the melanoma cells were slightly protected by the 1000 Hz field and sensitised by the 100 Hz field.The survival rate of the normal fibroblasts when treated with 2 Gy, in two fractions of 1 Gy 6 h apart, was similar to those obtained when cells received an acute dose of 2 Gy 6 h prior to or after exposure to both EMF frequencies.On the other hand, the melanoma cells were significantly sensitised when they were either treated with a Stellenbosch University https://scholar.sun.ac.za iv combination of X-rays and then 100 Hz EMF 6 h later or with a combination of either of the EMF frequencies and then X-rays 6 h later.These data suggest that use of electromagnetic fields may sensitise tumours to radiation therapy and reduce normal tissue toxicity.Informed and well-designed combinations of low-medium frequency electromagnetic fields and radiation therapy might be beneficial in the management of cancers, especially epidemic Kaposi's sarcoma.
Author: Angela Chinhengo
Language: English
Subfield: Biophysics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2598637942