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AIM:To investigate the role of ClC-3 chloride channel in the promotion of radio sensitization of na-sopharyngeal carcinoma CNE-2Z cells by dihydroartemisinin(DHA).METHODS:MTT was used to detect the inhibito-ry effect of DHA on the viability of CNE-2Z cells and normal nasopharyngeal epithelial NP69-SV40T cells,the radio sensi-tization effect of DHA on CNE-2Z cells was detected by cloning assay,the expression of ClC-3 protein was detected by Western blot,the expression of ClC-3 protein was down-regulated by siRNA technology,and the chlorine current of cells was recorded by whole cell patch-clamp technology.RESULTS:(1)Compared with NP69-SV40T cells,DHA selective-ly inhibited the proliferation of CNE-2Z cells,with IC10 values of(13.020±4.831)μmol/L and(5.244±1.050)μmol/L,respectively(P＜0.01).(2)The results of clonal formation experiments showed that DHA had a radio sensitizing effect on CNE-2Z cells,with a radio sensitization ratio of 1.9.(3)DHA could activate the chlorine channel of CNE-2Z cells and produce an outward chlorine current,but had no effect on the chlorine channel of NP69-SV40T cells.(4)DHA promoted the expression of ClC-3 chloric channel protein in CNE-2Z cells(P＜0.01).(5)Chlorine channel blocker NPPB could in-hibit the radio sensitizing effect of DHA on CNE-2Z cells by 1.84 times,and also inhibited the chlorine current activated by DHA.(6)the down-regulation of CNE-2Z ClC-3 protein could inhibit the radio sensitization effect of DHA on CNE-2Z cells by 4.19 times,and the activation of chlorine current by DHA on CNE-2Z cells was no longer produced.CONCLU-SION:DHA has a radio sensitizing effect on nasopharyngeal carcinoma CNE-2Z cells,which is likely to be related to the activation of ClC-3 chloride channel.
ABSTRACT
Lung cancer is the fastest-growing cancer type in terms of incidence and mortality worldwide， posing a huge threat to the health and life of the population. Radiation therapy is one of the main methods for treating lung cancer， and there is a clear dose-effect relationship between the radiation dose and local control rate of lung cancer. However， the lung is a radiation dose-limiting organ， and the radiation resistance of lung cancer tissues and the radiation damage to normal tissues limit the radiation efficacy for lung cancer. The pathogenesis of lung cancer in traditional Chinese medicine （TCM） is characterized by an initial deficiency in vital Qi， followed by the internal invasion and gradual accumulation of pathogenic Qi. After radiation therapy for lung cancer， the body's vital Qi becomes weaker， and syndromes of phlegm coagulation， Qi stagnation， and static blood blocking collaterals become more severe， leading to radiation resistance of lung cancer tissues. Therefore， the key issue to better clinical efficacy of radiation therapy for lung cancer patients is to use drugs to enhance the radiation sensitivity of lung cancer cells and improve the radiation tolerance of normal lung tissues. TCM can be used as a radiation sensitizer by regulating the cell cycle to increase the proportion of cells in the radiation-sensitive phase， promoting upregulation of pro-apoptotic genes and downregulation of anti-apoptotic genes to induce cell apoptosis， enhancing DNA damage caused by radiation and inhibiting damage repair， improving blood circulation and tissue oxygen supply， and so on， to enhance the sensitivity of tumor cells to radiation and amplify the toxicity of radiation to tumor tissues. TCM can also be used as a radiation protector by inhibiting cell damage， regulating cytokines and immune balance， reducing the release of inflammatory and fibrotic factors， and inhibiting the activation of related signaling pathways to prevent and treat radiation-induced lung injury. This article systematically reviewed the research results of TCM on radiation sensitization and radiation protection in lung cancer in recent years， aiming to elucidate the mechanism of TCM in regulating the effect of radiation therapy for lung cancer and provide more theoretical and practical basis for TCM to participate in improving the prognosis of lung cancer patients undergoing radiation therapy.
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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.
ABSTRACT
In order to effectively improve the radiation sensitivity of tumors and reduce the side effects during radiotherapy,people have been working on the development of radiation sensitizers.In recent years,many researches focused on the nanoparticles with high atomic number elements as radiosensitizers.Researchers have recently developed a kind of new gadolinium-based radiation-sensitizing nanoparticles,i.e.AGUIX,which have low toxicity,low quality,and radiation-activated drug activity.These nanoparticles are consisted by a polysiloxane core and a network of covalently attached gadolinium chelates.They have a hydrodynamic diameter of less than 5 nm,and can be administered intravenously due to the preferential accumulation in tumor sites and elimination by kidney.Studies have proved that AGUIX can be used as a safe and effective radiation sensitizer under various irradiation conditions.In addition,due to the presence of strontium,AGUIX itself can also be used as a MRI contrast agent to monitor the biodistribution of drugs and tumor evolution,and then guide the development of radiotherapy.In this paper,the research progress of AGUIX in recent years was reviewed.
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Objective To evaluate the radiosensitivity effects of apatinib on the esophageal cancer cell line ECA-109 and its cancer stem-like cells,and to investigate the underlying mechanism.Methods A serum-free medium (SFM) was used to culture esophageal cancer stem cell line ECA-109 and enrich the esophageal stem-like spheres.ECA-109 and its stem-like cells were divided into control group,drug treatment group,radiation group and drug plus radiation group.Cell proliferations of ECA-109 and its stem-like cells were detected with CCK-8 method.The concentration of vascular endothelial growth factor (VEGF) in the cell culture medium was determined by enzyme linked immunosorbent assay(ELISA).Cell cycle and apoptosis were detected by flow cytometry method.The expressions of CHK2 and P-STAT3 proteins were detected by Western blot assay.Results With the administration with apatinib for 24,48 and 72 h,the half of the inhibitory concentration (IC50) of ECA-109 stem-like cells was significantly higher than that of the parent cells (t =8.17,9.29,18.85,P ＜ 0.05) in a time dependent manner (parental cells:r2 =0.94-0.97,P ＜0.05;stem-like cells:r2 =0.94-0.98,P ＜0.05).After administration with different concentrations of apatinib (parental cells:10 and 20 μmol/L;stem-like cells:30 and 40 μmol/L) combined with different dose of X-rays (6 and 8 Gy),the proliferations of ECA-109 and its stem-like cells were significantly (t =5.20-39.68,P ＜ 0.05) inhibited compared with radiation alone group.VEGF secretion from both ECA-109 cells and its stem like cells were significantly decreased in different manner (t =7.45,P ＜ 0.05).Compared with control group,the cell apoptosis rate and the percentages of cells in G2/M phase were significantly increased in drug plus radiation group (t =8.83,11.59,P ＜ 0.05),and the expressions of CHK2 and P-STAT3 were decreased in drug group (t =3.36,4.10,P ＜ 0.05).Compared with radiation group,the expressions of CHK2 and P-STAT3 were decreased in drug plus radiation group (t =9.05,2.36,P ＜ 0.05).Conclusions Apatinib enhanced the radiosensitivity of ECA-109 cells and its stem-like cells,which was much more effective on ECA-109 cells and may be related to the radiation-induced inhibition of VEGF signal pathway that can further inhibit cell proliferation,promote cell apoptosis and induce cell cycle redistribution.The higher intrinsic level of VEGF protein may contribute to radioresistance of ECA-109 stem-like cells.