Anti-tumor Activity Of Phenanthroimidazole Derivatives And Its Mechanism Inducing Apoptosis Of Nasopharyngeal Carcinoma CNE-1 Cells

In the current world disease spectrum,malignant tumors are at the forefront of cause of death,becoming one of the important diseases that seriously endangering human life and health.Among the diversified treatment strategies,chemotherapeutic therapy still occupies the core position in tumor therapy.Although the anti-tumor drugs often used in clinic have a strong inhibitory effect on tumor cells,their toxic and side effects on normal tissues and the drug resistance generated after long-term application limit their clinical application.Therefore,it has become the focus and difficulty of current researchers to search for drugs with good anti-tumor effect,low toxicity and selectivity for tumor cells.It is reported that the imidazole ring is a nitrogenous heterocyclic ring containing rich electrons,which is conducive to the combination of its derivatives with a variety of therapeutic targets,and has good biological activities in anti-tumor,antibacterial and antiviral aspects.1,10-phenanthroline derivatives are most widely studied N-heterocyclic planar chelating agents.Its good rigid planar structure and large conjugated structure can influence the structure of DNA,and it is also widely used in anti-tumor and antibacterial activities.On the basis of this theory,a series of phenanthroimidazole derivatives were synthesized in this study,and compounds with good anti-tumor activity were screened out in vitro.The anti-tumor activity and its anti-tumor mechanism in vivo were explored through cell biology,molecular biology and experimental animal models.The specific research work of this paper is as follows:(1)A series of phenanthroimidazole derivatives containing different halogen elements were designed and synthesized by changing the substituent groups and the positions of substituent groups on the phenanthroimidazole derivatives,and the structures of the target compounds were characterized by electrospray nuclear magnetic resonance(NMR)and electrospray ionization mass spectrometry(ESIMS).(2)The antitumor activity of phenanthroimidazole derivatives(1-6)against multiple tumor cell lines was evaluated by MTT,and the results showed that phenanthroimidazole derivatives had good antitumor effect on different tumor cell lines.In particular,compound 4 had a strong growth inhibition effect on human nasopharyngeal carcinoma CNE-1 cells,and its toxicity against normal human cells was low.(3)In vivo anti-tumor activity of compound 4 was studied in zebrafish tumor xenotransplantation model.The results showed that compound 4(3 and 6 μM)could inhibit the proliferation and metastasis of human nasopharyngeal carcinoma CNE-1 cells in zebrafish,and compound 4 had no obvious toxic effect on zebrafish embryos when the concentration of compound 4 was ≤ 8 μM.(4)The anti-tumor mechanism of phenanthroimidazole derivatives 4 was studied by cell and molecular biology techniques.Flow cytometry and TUNEL-DAPI double staining showed that compound 4 induced CNE-1 cells apoptosis.Single cell gel electrophoresis and γH2AX immunofluorescence assay confirmed that compound 4 could induce DNA damage in CNE-1 cells.The results of mitochondrial membrane potential and intracellular reactive oxygen species(ROS)levels showed that compound 4 could lead to a decrease in mitochondrial membrane potential of CNE-1 cells and increase intracellular ROS levels.In summary,the phenanthroimidazole derivatives(1-6)was successfully synthesized in this paper,in which compound 4 can induce DNA damage in CNE-1 cells,and cause mitochondrial dysfunction by increasing intracellular ROS levels,and finally lead to CNE-1 cells apoptosis.Therefore,we believe that compound 4 has the potential to be an inducer of nasopharyngeal carcinoma cell apoptosis mediated by the mitochondrial.