RESUMEN
Objective To investigate the radiosensitization effects and mechanisms of novel benzothiadiazole derivatives HL-095 to KRAS-mutant non-small cell lung cancer ( NSCLC ) H358 , A549 , and H460 cell lines . Methods The benzothiadiazole derivative HL-095 was designed and synthesized with AZD6244 as the lead compound. The ability of HL-095 to inhibit the activity of MEK kinase was detected by the mitogen-activated extracellular signal-regulated kinase 1 (MEK1). H358, A549 and H460 cells were inoculated and cultured at appropriate density, and divided into control group, HL-095 group, irradiation group and HL-095 combined irradiation group. One-time irradiation with 137Cs gamma rays was used with a dose rate of 1.02 Gy/min. The expression of phosphorylated extracellular regulatory protein kinase ( p-ERK ) in H358 , A549 and H460 cells was detected by Western Blot. The cell proliferation was detected by cloning assay. The degree of DNA damage was analyzed by Comet assay. The G2/M phase cells were detected by flow cytometry. The level of the checkpoint kinase 1 (CHK1) protein and its phosphorylation in A549 and H358 cells was detected by Western Blot. Results HL-095 can inhibit the activity of MEK1. Compared with the control group, the expression levels of p-ERK protein of H358, A549, and H460) cells in HL-095 group were decreased, the percentages of cells in the G2/M phase were also decreased, and the differences were statistically significant (all P<0.01). The expression and phosphorylation of CHK1, a key protein of DNA damage repair, was down-regulated in A549 and H358 cells. Compared with the irradiated group, the proliferation of the three kinds of cell in HL-095 combined irradiation group was inhibited, the DNA damage was more serious, the Olive tail moment, tail length, tail length and tail DNA percentage were significantly increased, and the differences were statistically significant (all P<0.05). Conclusion As a MEK inhibitor, the novel benzothiadiazole derivative HL-095 can enhance the radiosensitivity of KRAS mutant NSCLC cells by inhibiting DNA damage repair and reducing G2/M arrest.
RESUMEN
Objective To observe the protective effect of anthocyanin on irradiation induced bone marrow c-kit positive cell injury, and further explore its possible mechanism. Methods Mouse bone marrow c-kit positive cells were collected by cell sorting method. There were 2 groups: control group and anthocyanin group, which were sub-divided into three groups and received 0 Gy, 1 Gy and 4 Gy irradiation respectively. The control group was added 700μL cell suspension and an equal volume of serum-free hematopoietic stem/progenitor cell culture medium. The 2 × 10-5 mol/L anthocyanin was co-cultured with mouse bone marrow c-kit positive cells of anthocyanin group half an hour before irradiation exposure, then cells were cultured for 18 hours under the conventional culture conditions (37℃,5%CO2). Mouse c-kit positive cell viability was measured by bioluminescence, and which was reflected by relative light units (RLU). The ability of colony-forming units was reflected by CFU-GM. The reactive oxygen species (ROS) level and mean fluorescence intensity (MFI) ofγ-H2AX were detected by flow cytometry. Results Compared to un-irradiated control group, the cell viability and the number of CFU-GM were decreased significantly, while the ROS level and MFI ofγ-H2AX were increased in c-kit positive cells irradiated with 1 Gy and 4 Gy (P<0.05). Compared to 1 Gy and 4 Gy irradiation groups, c-kit positive cell viability and the number of CFU-GM were increased, the ROS level and MFI of γ-H2AX were decreased in anthocyanin group (P < 0.05). Conclusion Anthocyanin exhibits a promising protective effect on radiation-induced bone marrow c-kit positive cell injury, which may be related to the alleviating ROS and DNA damage in bone marrow cells.