A Novel Myricetin Derivative S4-10 Effectively Inhibits The Growth Of A549 Cells And The Underlying Mechanism

Background: Lung cancer is the main cause of global cancer-related death,among which the non-small cell lung cancer(NSCLC)accounts for about 80% of the total number of lung cancers,and the outcome of prognosis is always poor since the majority of cases were diagnosed at the middle and late stages.The strong ability of intrinsic evolution of lung cancer makes it easy to produce a novel drug-resistant variant.Clinically,there is an urgent need to update the therapeutic regime.The synthesis and screening of novel anti-tumor drugs provide more choice confronting the treatment of lung cancer and hence to complement and optimize the therapeutic regime of the cancer.Recently,a convergent of studies have discovered the broad anti-tumor activity of Myricetin and its derivatives,which is capable of inducing cell apoptosis and inhibiting the cell proliferation,cell migration,and cell invasiveness.While,natural compounds are seldom selected as direct countermeasures against tumors since the low activity and high toxicity.In this study,we synthesized several compounds based on the structure of Myricetin and evaluated their inhibitory activity on NSCLC cells.Objective: To screen novel Myricetin derivatives with inhibition activity on non-small cell lung cancer,and evaluate the suppression effects on cell growth of NSCLC cells and explore the potential underlying mechanism.Methods: 1.Based on the chemical formula of Myricetin,5 derivatives were synthesized and named as S2-1,S2-2,S2-3,S4-1,S4-10 with six steps.2.The synthesized compound was diluted with DMSO and A549 cells were selected as cell line of non-small lung cancer.MTT assay was employed to evaluated the inhibition activity of the five derivatives on cell proliferation of A549 cells and S4-10 was discovered as the one with strongest inhibition activity.3.The CCK-8 test was applied for measurement of 50% inhibiting concentration(IC50)when A549 cells were given the treatment of S4-10.4.The immunostaining of Ki-67 was adopted for measurement the impact of S4-10 on cell proliferation of A549 cells.5.Establish the xenograft tumor model of A549 cells,and evaluate the inhibition effects of S4-10 on tumor cells in vivo by HE staining and TUNEL staining.6.Examination the effects of S4-10 on cell apoptosis and cell cycle of A549 cells by Annexin V staining and PI staining.7.Wound healing and transwell assays were used to examine the effects of S4-10 on cell migration and cell invasiveness of A549 cells.8.Transcriptional sequencing,western blotting,and real-time PCR were applied to reveal the molecular mechanism underlying S4-10 inhibits the biofunction of A549 cells.Results: 1.The results of the MTT showed that the S4-10 had the most significant effect on cell inhibition of non-small cell lung cancer cells(A549)and the half inhibition concentration(IC50)was 6μM according to the data from CCK-8 staining.2.S4-10 can inhibit the activity of non-small cell lung cancer cells in vitro.The expression of cell proliferation relevant marker Ki-67 was significant downregulated compared with DMSO group(p<0.001).The wound healing and transwell experiments showed that the migration and invasion ability of A549 cells was mitigated after S4-10 intervention.Meanwhile,S4-10 stimuli can promote cell apoptosis(p<0.01)and arrest cell cycle at G2 stage(p<0.01).3.S4-10 can inhibit the activity of non-small cell lung cancer cells in vivo.Compared with the DMSO group,HE staining showed obvious tumor cell necrosis,and TUNEL staining showed that the number of apoptosis tumor cells were increased.4.Transcriptome sequencing data and other relevant results showed that S4-10 intervention can immediately induce the upregulation of genes associated with lipid metabolism pathway and endoplasmic reticulum stress pathway.Subsequently,the apoptotic protein Caspase3 was up-regulated(p < 0.05),the ratio of Bcl2 to Bax was down-regulated(p < 0.001),and the expression of P53 was down-regulated(p < 0.05),the changes induced cell death of A549 cells to further control the malignancy of the tumor.Conclusion: 1.S4-10 can inhibit the proliferation of A549 in vitro and in vivo.2.S4-10 can significantly suppress cell migration and cell invasiveness of A549 cells.3.S4-10 can induce cell apoptosis and cell cycle arrest of tumor cells.4.S4-10 induces cell death of A549 cells and control the tumor malignancy through changing the normal lipid metabolism and endoplasmic reticulum stress.