Study On The Mechanism That Icaritin Inhibits Proliferation Of A549Cells

Lung cancer occurs in bronchial epithelium, and it can also be called bronchial lungcancer. At present, Lung cancer-induced death has ranked the first of the whole worldwide cancer death. Since1995, more than600000people worldwide die of lung cancer,and the annual death toll is on the rise. Therefore, the study of lung cancer treatments anddrugs is of great significance. Epimedium Genus has long been used in Chinese traditionalmedicine and recorded in medical books of past dynasties. It has many pharmacologicalactivities such as enhancement of osteoblastic and physical quality. Icaritin is a kind ofactive monomer extracted from the Chinese herb Epimedium and has important effect oncardiovascular protection, bone formation and the regulation of body’s immune systemand cancer inhibition. In addition, Icaritin However, the researching on tumor-suppressormechanism of Icaritin is still less, the anticancer mechanism has not been fully revealed. Ichoose Human A549cell line、HepG2cell line、SH-SY5Ycell line、PC-3cell line、A2780cell line as the test materials to detect the effect of Icaritin on those kinds of cancer celllines. We emphatically took MTT, RT–PCR and Western blotting research methods totest the influence of Icaritin on the proliferation of A549cell lines, the main researchresults include the following aspects:(1) Icaritin can inhibit the proliferation of several cancer cell lines including A549celleffectively depending on doses and time. Through MTT method, it shows the more dosesof drugs and the longer time, the stronger inhibition of the cell proliferation.(2) Icaritin induces S arrest of A549cell. After treating cells with drugs of differentconcentration for24h, we use the flow cytometry to test the cycle variation. The resultshows that with the increase of drug concentration, A549cell shows strong S period arrest.RT-PCR results show that CyclinA and its dependenct kinase CDK2are significantlyweakened in transcription level. And the result is the same to the flow cytometry test.They totally proved the S period arrest of A549cell inducing by Icaritin.(3) We took the Annexin V/PI binding and Hoechst33342staining method to detect theapoptosis of A549cells and find that it shows strong dose-dependent character. RT-PCR results show that the treatment of drugs can up-regulate the transcription level of p21andp53. It shows that Icaritin can induce the obvious apoptosis of A549cell line.(4) After treating cells with different concentration of Icaritin for24hours, We useRT-PCR method to detect the mRNA expression level of Bax and Bcl-2. The result showsthat drug treatment down-regulates the mRNA expression level of Bcl-2and up-regulatethe mRNA expression level of Bax. It is deduced that Icaritin can inhibit the proliferationof A549cells through Bax/Bcl-2signaling pathways.