The low dose hyper-radiosensitivity （HRS） in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the pos...The low dose hyper-radiosensitivity （HRS） in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the possible mechanisms were discussed. A549 cells in logarithmic growth phase were irradiated with ^60Co y-rays at doses of 0-2 Gy. Together with flow cytometry for precise cell sorting, cell survival fraction was measured by means of conventional colony-formation assay. The expression of ATM1981 Ser-P protein was examined by Western blot 1 h after radiation. Apoptosis was detected by Hoechst 33258 fluorescent staining, and Annexin V-FITC/PI staining flow cytometry 24 h after radiation. Cell cycle distribution was observed by flow cytometry 6, 12 and 24 h after radiation. The results showed that the expression of ATM1981Ser-P protein was observed at 0.2 Gy, followed by an increase at 〉0.2 Gy, and reached the peak at 0.5 Gy, with little further increase as the dose exceeded 0.5 Gy. Twenty-four h after radiation, partial cells presented the characteristic morphological changes of apoptosis, and the cell apoptosis curve was coincident with the survival curve. As compared with control group, the cell cycle almost had no changes after exposure to 0.1 and 0.2 Gy radiation （P〉0.05）. After exposure to 0.3, 0.4 and 0.5 Gy radiation, G2/M phase arrest occurred 6 and 12 h after radiation （P〈0.05）, and the ratio of G2/M phase cells was decreased 24 h after radiation （P〈0.05）. It was concluded that A549 cells displayed the phenomenon of HRS/IRR. The mode of cell death was mainly apoptosis. The activity of ATM and cell cycle change may take an important role in HRS/IRR.展开更多
Objective: To research the inhibitory effect on SGC-7901 cells of α-pinene, and the related mechanism of α-pinene. Methods: Used the MTT method to detect inhibition rate and western blotting to detect the influence ...Objective: To research the inhibitory effect on SGC-7901 cells of α-pinene, and the related mechanism of α-pinene. Methods: Used the MTT method to detect inhibition rate and western blotting to detect the influence on expression of ATM, Phos-S1981ATM, H2AX, γH2AX, CHK2 and p-CHK2, p53 and phos-p53 cell cycle related protein in SGC-7901 cells. Results: The research found α-pinene could inhibit the proliferation of SGC-7901 cells observably in vitro, and the inhibition rate assumes the dependence on concentration;and western blotting results showed that, α-pinene could activate phospho-ATM, increase the amount of γH2AX (p p < 0.05);increase the expression of p-CHK2, p53 and phos-p53 (p p p < 0.05);But there is no significant effect on expression of CHK2 (p > 0.05). Conclusions: α-pinene could inhibit the proliferation of SGC-7901 cells, and by inducing ATM (Ataxia Telangiectasia-Mutated) kinase signal pathway in DNA damage response, activating cell cycle checkpoint, making the cell cycle arrest then exerts its anti-tumor effects.展开更多
目的观察ATM蛋白激酶-检测点激酶2(ATM-Chk2)通路在氟抑制大鼠曲细精管上皮支持细胞增殖中的作用。方法将18日龄SPF级雄性SD大鼠曲细精管上皮支持细胞分别暴露于含0(对照)、0.25、0.50、1.00、2.00、4.00 mmol/L氟化钠的血清培养基。分...目的观察ATM蛋白激酶-检测点激酶2(ATM-Chk2)通路在氟抑制大鼠曲细精管上皮支持细胞增殖中的作用。方法将18日龄SPF级雄性SD大鼠曲细精管上皮支持细胞分别暴露于含0(对照)、0.25、0.50、1.00、2.00、4.00 mmol/L氟化钠的血清培养基。分别于染毒24、48、72 h,采用MTT法测定支持细胞的增殖情况;于染毒24 h,采用实时荧光定量PCR技术检测支持细胞内ATM、Chk2 m RNA的表达水平。结果与对照组比较,染毒24、48、72 h时,4.00 mmol/L氟化钠染毒组大鼠曲细精管上皮支持细胞的抑制率均较高,差异有统计学意义(P<0.05);且随着氟化钠染毒剂量的升高和染毒时间的延长,氟对曲细精管上皮支持细胞的抑制率均呈上升趋势。与对照组比较,1、2 mmol/L氟化钠染毒组曲细精管上皮支持细胞ATM和Chk2 m RNA的表达水平均升高,而4 mmol/L氟化钠染毒组ATM和Chk2 m RNA的表达水平均降低,差异有统计学意义(P<0.05);且随着氟化钠染毒剂量的升高,曲细精管上皮支持细胞ATM、Chk2 m RNA的表达水平均呈下降趋势。结论不同剂量氟抑制生殖细胞增殖可能是通过干扰曲细精管上皮支持细胞中DNA损伤检验点ATM、Chk2的表达而实现的。展开更多
文摘The low dose hyper-radiosensitivity （HRS） in human lung cancer cell line A549 was investigated, the changes of ATM kinase, cell cycle and apoptosis of cells at different doses of radiation were observed, and the possible mechanisms were discussed. A549 cells in logarithmic growth phase were irradiated with ^60Co y-rays at doses of 0-2 Gy. Together with flow cytometry for precise cell sorting, cell survival fraction was measured by means of conventional colony-formation assay. The expression of ATM1981 Ser-P protein was examined by Western blot 1 h after radiation. Apoptosis was detected by Hoechst 33258 fluorescent staining, and Annexin V-FITC/PI staining flow cytometry 24 h after radiation. Cell cycle distribution was observed by flow cytometry 6, 12 and 24 h after radiation. The results showed that the expression of ATM1981Ser-P protein was observed at 0.2 Gy, followed by an increase at 〉0.2 Gy, and reached the peak at 0.5 Gy, with little further increase as the dose exceeded 0.5 Gy. Twenty-four h after radiation, partial cells presented the characteristic morphological changes of apoptosis, and the cell apoptosis curve was coincident with the survival curve. As compared with control group, the cell cycle almost had no changes after exposure to 0.1 and 0.2 Gy radiation （P〉0.05）. After exposure to 0.3, 0.4 and 0.5 Gy radiation, G2/M phase arrest occurred 6 and 12 h after radiation （P〈0.05）, and the ratio of G2/M phase cells was decreased 24 h after radiation （P〈0.05）. It was concluded that A549 cells displayed the phenomenon of HRS/IRR. The mode of cell death was mainly apoptosis. The activity of ATM and cell cycle change may take an important role in HRS/IRR.
文摘Objective: To research the inhibitory effect on SGC-7901 cells of α-pinene, and the related mechanism of α-pinene. Methods: Used the MTT method to detect inhibition rate and western blotting to detect the influence on expression of ATM, Phos-S1981ATM, H2AX, γH2AX, CHK2 and p-CHK2, p53 and phos-p53 cell cycle related protein in SGC-7901 cells. Results: The research found α-pinene could inhibit the proliferation of SGC-7901 cells observably in vitro, and the inhibition rate assumes the dependence on concentration;and western blotting results showed that, α-pinene could activate phospho-ATM, increase the amount of γH2AX (p p < 0.05);increase the expression of p-CHK2, p53 and phos-p53 (p p p < 0.05);But there is no significant effect on expression of CHK2 (p > 0.05). Conclusions: α-pinene could inhibit the proliferation of SGC-7901 cells, and by inducing ATM (Ataxia Telangiectasia-Mutated) kinase signal pathway in DNA damage response, activating cell cycle checkpoint, making the cell cycle arrest then exerts its anti-tumor effects.
文摘目的观察ATM蛋白激酶-检测点激酶2(ATM-Chk2)通路在氟抑制大鼠曲细精管上皮支持细胞增殖中的作用。方法将18日龄SPF级雄性SD大鼠曲细精管上皮支持细胞分别暴露于含0(对照)、0.25、0.50、1.00、2.00、4.00 mmol/L氟化钠的血清培养基。分别于染毒24、48、72 h,采用MTT法测定支持细胞的增殖情况;于染毒24 h,采用实时荧光定量PCR技术检测支持细胞内ATM、Chk2 m RNA的表达水平。结果与对照组比较,染毒24、48、72 h时,4.00 mmol/L氟化钠染毒组大鼠曲细精管上皮支持细胞的抑制率均较高,差异有统计学意义(P<0.05);且随着氟化钠染毒剂量的升高和染毒时间的延长,氟对曲细精管上皮支持细胞的抑制率均呈上升趋势。与对照组比较,1、2 mmol/L氟化钠染毒组曲细精管上皮支持细胞ATM和Chk2 m RNA的表达水平均升高,而4 mmol/L氟化钠染毒组ATM和Chk2 m RNA的表达水平均降低,差异有统计学意义(P<0.05);且随着氟化钠染毒剂量的升高,曲细精管上皮支持细胞ATM、Chk2 m RNA的表达水平均呈下降趋势。结论不同剂量氟抑制生殖细胞增殖可能是通过干扰曲细精管上皮支持细胞中DNA损伤检验点ATM、Chk2的表达而实现的。
