Mechanism Study Of Selene-β-Lactoglobulin On Apoptotic Effect In K562 Cells

The in vitro effects of seleno-β-lactoglobulin(se-β-lg) on the proliferation and apoptosis of human leukemia K562 cells were investigated. The changes of cell morphological, cell cycle, relevant cyclin protein and mRNA expression which were induced by se-β-1g were explored by MTT, HE staining, flow cytometry, immunofluorescence and real-time PCR etc.First of all, the proliferation inhibition and apoptosis of K562 with Se-β-1g were researched. The MTT assays showed that se-β-1g significantly suppressed the growth of K562 cells in a dose-dependent and time-dependent manner, while mouse C2C12 myoblasts were viable after the same treatment. The cell growth inhibitory rate of K562 could reach 90% after exposure with 100 μg/mL se-β-1g for 48h. HE and PI/Hoechst staining revealed that treatment of K562 cells with se-β-1g appeared typical apoptotic characteristics such as cell volume reduction and chromatin shrinkage. The results of Annexin V-FITC/PI dyeing indicated that the apoptosis rate of K562 cells was 18.75% after cultured with Se-P-lg for 48 h, then the rate increased to 40.76% when cultured for 72 h. FCM analysis demonstrated that treatment of K562 cells with Se-β-1g result in the accumulation of cells in the S and G2/M phase.Apart from that, the signaling pathways of treatment of K562 cells with se-β-1g was studied. Immunofluorescence and elisa analysis uniformly revealed that the expression level of cyclin B1 was significantly down-regulated but the expression of p21 was extremely up-regulated. Real-time PCR analysis showed that the mRNA expression of these proteins had the same trends and also showed that the mRNA expression of CDK4 was decreased significantly.To sum up, se-β-1g could effectively inhibit the proliferation of k562 cells and induce apoptosis in vitro. It was proved that se-β-1g would be a potential anticancer active material in future development.