biological complexities in radiation carcinogenesis and cancer radiotherapy impact of new biological paradigms生物复杂性辐射致癌作用和癌症放射治疗新的生物学范式的影响.pdf

Genes 2012, 3, 90-114; doi:10.3390/genes3010090 OPEN ACCESS genes ISSN 2073-4425 /journal/genes Review Biological Complexities in Radiation Carcinogenesis and Cancer Radiotherapy: Impact of New Biological Paradigms Hossein Mozdarani Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran P.O.Box 14115-111, Iran; E-Mail: mozdarah@modares.ac.ir Received: 30 December 2011; in revised form: 7 January 2012 / Accepted: 13 January 2012 / Published: 20 January 2012 Abstract: Although radiation carcinogenesis has been shown both experimentally and epidemiologically, the use of ionizing radiation is also one of the major modalities in cancer treatment. Various known cellular and molecular events are involved in carcinogenesis. Apart from the known phenomena, there could be implications for carcinogenesis and cancer prevention due to other biological processes such as the bystander effect, the abscopal effect, intrinsic radiosensitivity and radioadaptation. Bystander effects have consequences for mutation initiated cancer paradigms of radiation carcinogenesis, which provide the mechanistic justification for low-dose risk estimates. The abscopal effect is potentially important for tumor control and is mediated through cytokines and/or the immune system (mainly cell-mediated immunity). It results from loss of growth and stimulatory and/or immunosup