Cell Survival in Rat Rhabdomyosarcoma Tumors Irradiated in Vivo with Extended-Peak Silicon Ions

Heavy-Ion Radiobiology: Cellular Studies

“…Preliminary results with a 670 MeV/u beam using the 10-cm spiral ridge filter indicate that it has an LET spectrum that (like argon) is superior in reducing the oxygeneffect {high OGF), but that also has RBE characteristics more like neon Tenforde et al, 1982a). Further silicon experiments are underway.…”

Cell cycle kinetic measurements in an irradiated rat rhabdomyosarcoma using a monoclonal antibody to bromodeoxyuridine

“…The R2C5 subline was derived by cloning from the R2D2 subline used in previous studies of cellular radiation response to accelerated beams of carbon, neon, argon, and silicon ions produced at the Berkeley Bevalac facility (7,22,24). This R2C5 tumor was chosen for in vivo cell survival studies because it produces totally nonnecrotic tumors in syngeneic WAG/Rij rats and has an in vivo to in vitro plating efficiency of more than 50%, as compared to 20% for R2D2 tumors (24).…”

“…No effect of irradiation on incorporation of BrdUrd in S-phase could be observed in the continuous labeling experiments in contrast to the pulse labeling with RrdUrd, where a small retardation of DNA synthesis was observed in the irradiated tumors during the first 15 h after irradiation. When dissociated cells of the tumor were plated in medium containing 20 pmol/L BrdUrd, only the tetraploid tumor cells were able to incorporate BrdUrd and to enter cycle.Key terms: Tumor cell cycle kinetics, flow cytometry, monoclonal antibody to BrdUrd, X-ray irradiation, continuous labeling with bromodeoxycytidineThe response of a rat rhabdomyosarcoma system to irradiation with heavy charged particles and X-rays has been extensively investigated previously with experiments conducted both in vivo and in vitro (5)(6)(7)(22)(23)(24). The radiobiological end-points studied included tumor volume response (22,231, cell survival after tumor irradiation in situ (24), and survival of oxic and hypoxic cells irradiated and assayed in vitro (7).…”

“…The response of a rat rhabdomyosarcoma system to irradiation with heavy charged particles and X-rays has been extensively investigated previously with experiments conducted both in vivo and in vitro (5)(6)(7)(22)(23)(24). The radiobiological end-points studied included tumor volume response (22,231, cell survival after tumor irradiation in situ (24), and survival of oxic and hypoxic cells irradiated and assayed in vitro (7).…”

“…The radiobiological end-points studied included tumor volume response (22,231, cell survival after tumor irradiation in situ (24), and survival of oxic and hypoxic cells irradiated and assayed in vitro (7). It is known that the redistribution of cells within the cell cycle after irradiation is a n important factor affecting the speed of tumor regrowth.…”