61. Effects of high LET particles on Radio-resistant cells and the Molecular Biological Factors

Hideyuki lN4ajima, Chizuru Yamaguchi, Shizuko Kakinuma, Koichi Ando and Kazunobu Fujitaka

Keywords: radio-resistant cell, mitochondria DNA, HIMAC

Radiobiological effects of ¹²C ion-beams accelerated at HIMAC were examined. The biological effects following the irradiation were determined by colony formation methods to obtain survival curves as a function of dose. The cell line used in this study is 143B a human osteosarcoma cell line which is extremely resistant to low LET x-ray irradiation. The cells without mitochondria DNA from the 143B was established from the cells (Rho 0 cells) which were extremely sensitive to X-rays. The cells, in which normal mitochondria were brought to the Rho cells, (87wt), were in middle range in the sensitivity Effects of ¹²C ion-beams with different LET i. e. 13 and 77 keV/ m were examined in the three cell lines. The Rho O cell sensitivity to 13keV/ m beam was the highest and followed by 87wt and 143B. The sensitivity to 77 keV/ m of Rho O was also the highest, although the differences were not substantial in the sensitivity among the three cell lines, sug gesting mtDNA lacking Rho O cells might have a small capability in double-strand DNA repair.

Publications:
1)Yong Xu, Anuradha Krishnan, X. Steven Wan, Hideyuki Majima, Che-Chung Yeh, Gabriele Ludewig, Edward J. Kasarskis, and Daret K. St Clair: Oncogene, 18, 93-102, 1999.
2)Yong Xu, Kelley K. Kiningham, Madhav N Devalaraja, Che-Chung Yeh, Hideyuki Majima, Edward J. Kasarskis and Daret K. St. Clair: DNA and Cell Biology, 18, 709-722, 1999.