The unified approach of radiation action on biological matter: The induction of oncogenic transformation by heavy charged particles in C3H10T1/2 cells

Abstract

The induction of oncogenic transformation to C3H10T1/2 cells by different types of ionizing radiation has been widely studied in various radiological laboratories. Based on the information available in literature, a database is structured to include radiological parameters, that manifest oncogenic effects as well as cellular inactivation of C3H10T1/2 cells, resulted from exposure to different types of heavy charged ions including neutrons. We find that oncogenic transformation effective cross-section is best correlated with mean free path for linear primary ionization. A simple radiobiological model is proposed merely to quantize cross-sections against mean free path. The model reveals saturations of; cellular inactivation cross-section of about 75 mm2, and oncogenic transformation cross-section of about 3.98 x 10-2 mm2, both started at mean free path of 1.8 nm (inflection points) and lower values. Since the interspacing distance between the DNA strands is about 1.8 nm, the model explains the crucial roles of DNA lesions (caused by heavy charged particles) to play as the starting point leading to cell death or oncogenic transformation. The effective cross -sections in the sloping regions are primarily due to repairable DNA single strand breaks while saturation regions are essentially due to unrepaired or incorrectly repaired DNA double strand breaks.