Effects Of Methionine Enkephalin Combined With Paclitaxel On Proliferation And Apoptosis Of Lung Cancer Cell Line A549

Objective: Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer-related deaths worldwide.About 85% of lung cancer patients have the histological characteristics of non-small cell lung cancer,which is characterized by a short proliferation cycle,strong metastatic activity,and high mortality.Clinically,only a small percentage of patients with non-small cell lung cancer can be diagnosed early.More than 60% of lung cancer patients have locally advanced or metastatic disease at the time of diagnosis.Surgical resection is no longer the best choice.The main treatments for patients with lung cancer are conventional chemotherapy and radiation therapy.Paclitaxel(PTX)is one of the most common anticancer drugs in clinical practice,and is often used as the first-line anticancer drug for clinical chemotherapy of non-small cell lung cancer.The anti-tumor mechanism of PTX is to bind to tubulin and stabilize non-functional microtubule bundles to block normal mitosis and spindle development,thereby achieving the effect of inhibiting tumor cell growth.However,the use of PTX often brings serious side effects and multidrug resistance,these disadvantages reduce its antitumor effect.Therefore,it is of great significance to explore new therapies for treating non-small cell lung cancer.Methionine enkephalin(MENK)is an endogenous opioid pentapeptide derived from the adrenergic hormone enkephalin.It is an important regulator between the immune system and the neuroendocrine system.After binding to the opioid receptor,it has direct antitumor activity.According to previous studies,MENK can inhibit the growth of gastric,pancreatic,ovarian,melanoma,hepatocellular carcinoma,and triple-negative breast cancer.In this study,human lung cancer A549 cells were used as the research object to explore the effects of MENK and PTX on the proliferation and apoptosis of lung cancer cells A549 when administered alone and in combination at different concentrations and at different times.Methods: 1.The CCK-8 method was used to detect the effects of MENK and PTX on theproliferation of lung cancer cells A549 when administered alone and in combinationat different concentrations and times.2.The effect of combined use of MENK and PTX was evaluated using theintermediate effect principle.3.Hoechst 33258 fluorescence staining experiment was used to observe themorphological changes of lung cancer A549 cells after MENK and PTX were usedalone and combined for 48 hours.4.Flow cytometry was used to detect the apoptosis rate of each experimental groupafter 48 hours of treatment with MENK and PTX alone and in combination.Results: 1.Compared with the control group,after 24 hours of MENK treatment,when theconcentrations were 6 mg / ml and 10 mg / ml,the inhibitory effect on cellproliferation was obvious,the difference was statistically significant.After 48 hoursof treatment,the inhibitory effects on cell proliferation were obvious atconcentrations of 2 mg / ml,6 mg / ml,and 10 mg / ml,and the differences werestatistically significant.The inhibitory effect was strongest in the MENK group at aconcentration of 10 mg / ml whether it was administered for 24 hours or 48 hours.2.Compared with the control group,after 24 hours and 48 hours of PTX treatment,theinhibitory effects on cell proliferation were obvious at concentrations of 6 ng / mland 10 ng / ml.Among them,the inhibitory effect was the strongest at aconcentration of 10 ng / ml.3.Compared with the control group,after 24 hours of treatment with MENK and PTX,the concentration of 6mg / ml + 6ng / ml,10 mg / ml + 10 ng / ml inhibited cellproliferation,and the difference was significant.After 48 hours of treatment,whenthe concentration was 2mg / ml + 2ng / ml,6mg / ml + 6ng / ml,10 mg / ml + 10 ng /ml,the cell proliferation was significantly inhibited,and the differences werestatistically significant.4.Compared with the drug-only group,the effect of inhibiting cell proliferation in thecombination group of MENK and PTX was slightly stronger after 24 hours,but itwas not statistically significant.After 48 hours of treatment,when the concentrationof the MENK and PTX combination group was 6mg / ml + 6ng / ml,10 mg / ml +10ng / ml,the effect of inhibiting cell proliferation was more obvious than that ofthe single group,and the difference was statistically significant.5.The inhibitory effect of the combination of MENK and PTX on human lung cancerA549 cells has a CI <1 in the entire effect range,indicating that the combinedapplication of the two drugs has a synergistic effect over the entire concentrationrange.6.Hoechst 33258 fluorescence staining experiments showed that the control group haduniformly stained nuclei and regular shapes,and basically no apoptosis wasobserved.Irregular nucleus shape,strong staining,and morphological changes ofapoptosis were observed in other experimental groups.Among them,thecombination of MENK and PTX had the highest number of apoptosis.7.Flow cytometry detected the apoptotic rates of the control group,MENK group,PTX group,and the combination of MENK and PTX groups were 1.53%,6.23%,6.04%,and 13.22%,respectively.Apoptosis rates of the combination group weresignificantly higher In the single medication group.Conclusion: 1.The MENK group,the PTX group,and the combination of the MENK and PTX groups have an inhibitory effect on the proliferation of lung cancer A549 cells,and the inhibitory effect is gradually strengthened with the increase of the concentration and the prolongation of the effect time.2.The combined use of MENK and PTX compared with the single-use group had a stronger inhibitory effect on A549 cell proliferation,and the combination of the two drugs had synergy.3.The MENK group,the PTX group,and the combination of MENK and PTX groups can induce lung cancer A549 cells to undergo apoptosis,and when MENK is combined with PTX,the ability to induce apoptosis is stronger.