Synthesis Of A New Quinoline Derivative And Its Anti-gastric Cancer Mechanism

Quinoline is a type of nitrogen-containing heterocyclic functional group with a variety of biological activities and is widely used in agriculture,medicine and other fields.With the continuous in-depth study of quinoline and its derivatives,it has been found that quinoline derivatives have strong anti-tumor activity.In recent years,in order to find more efficient quinoline drugs,drug design based on quinoline core has become a research hotspot.Therefore,this project has designed and synthesized a series of quinoline derivatives and screened their anti-tumor activity.The target compound805 with outstanding activity was screened out,and its target point and biological mechanism were studied in depth.The details are as follows:1.Synthesis and toxicology experiment of quinoline compounds.The quinoline series derivatives were designed and synthesized by the principle of molecular splicing,and the synthesized derivatives were tested by MTT method to detect the effects of MGC-803(human gastric cancer cells),PC-3(human prostate cancer cells)and HCT-116(human colon cancer).Cells)ability to inhibit proliferation.The results prove that these compounds are more sensitive to human gastric cancer cells,and the antiproliferative activity of compound 805 is the most prominent.To further prove the universality of compound 805 on gastric cancer cell lines,the inhibitory activity of compound 805 on three human gastric cancer cell lines(MGC-803,SGC-7901,HGC-27)was detected by MTT method.The results proved that compound 805 has strong anti-proliferative activity against all three gastric cancer cell lines,and it exhibits a concentration-dependence.Therefore,we selected compound 805 as the target compound to conduct in-depth research on the above three human gastric cancer cell lines.2.The inhibitory effect of compound 805 on tubulin.Some quinoline derivatives have the potential as new tubulin inhibitors.In order to explore whether compound 805 can be used as a new tubulin inhibitor,a tubulin polymerization experiment,an immunofluorescence experiment,an iodoacetamide experiment,and a molecular docking experiment were designed to verify the conjecture.The results show that compound 805 can act on the binding site of colchicine and can be used as a new tubulin inhibitor.3.Study on the anti-tumor mechanism of compound 805 in vitro.ERK/MAPK is one of the important signal pathways guiding cell proliferation,differentiation and survival,and it plays a role in many kinds of tumors.Therefore,we tested the ERK/MAPK pathway related proteins(Ras,p-c-Raf,p-MEK,p-ERK,etc.)under the action of compound 805 by Western Blotting experiment.The results showed that compound 805 inhibited the expression of related proteins in the Ras-Raf-MEK-ERK pathway,indicating that compound 805 can exert an anti-tumor effect by regulating the ERK/MAPK pathway.4.The inhibitory effect of compound 805 on tubulin and ERK/MAPK pathway will lead to cycle inhibition.Therefore,we conducted experiments to verify the inhibition of cell proliferation by compound 805.The clone formation experiment and growth curve experiment verified that compound 805 can inhibit cell proliferation and colony formation.Cycle detection and Western Blotting experiment proved that compound 805 blocked the cell cycle in G2/M phase.5.Compound 805 inhibits tubulin and ERK/MAPK signaling pathways leading to apoptosis.Use flow cytometry(FCM)to detect cell apoptosis.The results show that compound 805 induces apoptosis of human gastric cancer cells,and the apoptotic effect is directly proportional to the concentration of the drug.Apoptosis of cells will be accompanied by changes in cell morphology.Using DAPI fluorescent staining and living dead cell detection kit to observe the morphological changes of cells under the action of different drug concentrations,we found obvious morphological features representing cell apoptosis.Further verification was carried out by Western Blotting experiment.At the same time,statistical analysis showed that the anti-apoptotic proteins Bcl-2 and Mcl-1 showed a downward-regulation trend,the pro-apoptotic protein Noxa showed an upward-regulation trend,and the apoptosis executive protein cleaved-Caspase-7 protein was blocked.When activated,its substrate protein PARP is obviously cleaved.In addition,the apoptosis inhibitor proteins XIAP and c-IAP1 were confirmed to be down-regulated.These results all prove that compound 805 can induce apoptosis of gastric cancer cells,thereby reducing the survival rate of gastric cancer cells.The above results show that the derivative 805 with quinoline as the core has good inhibitory activity on human gastric cancer cells.It can not only be used as a new tubulin inhibitor,but also significantly inhibit the intracellular ERK/MAPK signaling pathway.In turn,it has a significant anti-proliferation ability,which blocks the cell cycle in G2/M phase and induces apoptosis of gastric cancer cells.These studies provide effective theoretical support and research basis for the further development of anti-gastric cancer drugs.