| Objective: The incidence and mortality rate of lung cancer ranks first of all malignant tumors worldwide.Lung adenocarcinoma is non-small cell lung cancer(NSCLC),a lung epithelial adenocarcinoma,which accounts for 40% of the primary lung tumors.Effective drugs are essencial to lung adenocarcinoma treatment.Activation of apoptosis pathway is the crucial mechanism of many antitumor drugs.Caspases is improtant in the regμLation and implementation of apoptosis.Caspases family member CASP3 is highly expressed in many human cancers including lung cancer,and its expression level is related to the prognosis of the disease,suggesting that it plays an important role in the occurrence and development of lung cancer.Romidepsin and Cytarabine are cancer chemotherapy drugs approved for marketing and used in clinical treatment.Romidisine is a highly selective deacetylase inhibitor that effectively inhibits the functions of histone deacetylases 1 and 2(HDAC1 and HDAC2),it is primarily used in the treatment of peripheral t-cell lymphoma(PTCL).Cytarabine,a nucleoside analogue,is widely used in the treatment of acute myeloid leukemia(AML).Lately research has been focused on exploring the application of Romidepsin and Cytarabine in solid tumors,expanding the drug treatment,and reducing the side effects of drugs.Whether the combination of the two drugs is available in the treatment of lung adenocarcinoma and its molecμLar mechanism is not clear.We explored the mechanism of combination of Romidepsin and Cytarabine in the treatment of lung adenocarcinoma at the molecμLar and cellμLar level.Research content,methods and resμlts: Firstly,MTT and the cloning formation experiment’s resμLts showed the combination of Romidepsin and Cytarabine can significantly inhibit the growth of lung adenocarcinoma cell A549.Meanwhile,we found that the combination of Romidepsin and Cytarabine effectively reduce the invasive and metastatic ability of A549 through Transwell assay and scratch assay.Further,detected by cytometry assay,the combination drug group significantly activated A549 apoptosis in A549.Thus,we considered that the above phenotypic changes were caused by changes in the EMT or apoptotic pathways.Via real-time PCR and Western blot,we found apoptosis-related protein CASP3’s transcriptional and protein expression level were significantly increased in A549 treated both Romidepsin and Cytarabine.While no significant change in EMT pathway related proteins was showed.Given Romidepsin is a known selective deacetylase inhibitor and is highly selective for HDAC1 and HDAC2,we detected their known histone lysine sites H3K9,H3K14 and etc.Western blot assay showed the histone H3K14 acetylation in A549 increased in the combination group,suggesting that the transcriptional enhancement of CASP3 may be achieved by increasing its promoter region’s histone acetylation.We confirmed the conjecture by chromatin immunoprecipitation(CHIP).The acetylation level of histone H3K14 in the promoter region of CASP3 increased significantly in the combination group,higher than that of Romidepsin and Cytarabine groups.Our study revealed combination of Romidepsin and Cytarabine can increase the acetylation level of histone H3K14,increase the transcriptional activity and protein expression of apoptotic protein CASP3,promote the apoptosis of lung adenocarcinoma cell A549,and reduce its proliferation,growth,migration and invasion ability.This study provided a basis for the combination of Romidepsin and Cytarabine in the treatment of lung adenocarcinoma at the cellμLar and molecμLar levels,and provided a practical reference for clinical treatment. |
