ABSTRACT
<p><b>OBJECTIVE</b>To investigate the changes of ataxia-telangiectasia mutated (ATM) phosphorylation in HepG(2) cells in relation to HepG(2) cell survival under continuous low dose-rate irradiation.</p><p><b>METHODS</b>HepG(2) cells were exposed to equivalent irradiation doses delivered at either a continuous low dose-rate (7.76 cGy/h) or a high dose-rate (4500 cGy/h), and the phosphorylated ATM proteins and surviving fraction of HepG(2) cells after the exposures were compared.</p><p><b>RESULTS</b>The phosphorylation of ATM protein was maximal at 0.5 Gy irradiation delivered at either a high doserate or a continuous low doserate. As the radiation dose increased, ATM protein phosphorylation decreased under continuous low dose-rate irradiation, but remained stable under high dose-rate irradiation. With comparable ATM protein phosphorylation induced by continuous low dose-rate irradiation and high dose-rate irradiation, there was no significant difference in the surviving fraction of HepG(2) cells (P>0.05), but at a significantly lower ATM protein phosphorylation level than that induced by high dose-rate irradiation, continuous low dose-rate irradiation resulted in increased cell killing (P<0.01).</p><p><b>CONCLUSION</b>Continuous low dose-rate irradiation increases HepG(2) cells radiosensitivity as compared with high dose-rate irradiation. Increased cell killing following continuous low dose-rate irradiation is associated with reduced phosphorylated ATM protein, and inhibition of ATM phosphorylation may increase the radiosensitivity of HepG(2) cells.</p>
Subject(s)
Animals , Humans , Mice , Ataxia Telangiectasia Mutated Proteins , Cell Cycle Proteins , Metabolism , Cell Line, Tumor , Cell Survival , Radiation Effects , DNA-Binding Proteins , Metabolism , Dose-Response Relationship, Radiation , Phosphorylation , Radiation Effects , Protein Serine-Threonine Kinases , Metabolism , Radiation Tolerance , Radiation Effects , Time Factors , Tumor Suppressor Proteins , MetabolismABSTRACT
Objective To study the mechanisms of extrarenal arterial blood supply of renal malignancy for its interventional therapy.Methods Routine abdominal aortography and selective questionable feeding arteriography were performed in 141 patients with renal malignancy.The characteristics and formation mechanisms of extrarenal arterial blood supply for renal malignancy were analyzed.Results Of the 141 patients,extrarenal arterial blood supply of renal malignancy were found in 51 patients and there were 87 branchs.The breakthrough of renal capsule with malignancy were found in those 51 patients.No extrarena]arterial blood supply of renal malignancy was found in 90 patients,including 50 patients with and 40 patients without the renal capsule breakthrough with malignancy.The emerge of extrarenal arterial blood supply of renal malignancy were significantly different(x~2 = 31.64,P