The Study On Autophagy Protein 4EBP1 And Tumourgenesis

mTOR signal pathway is one of the most important signal transduction pathways in cells, which play a crucial role in cell growth and proliferation.4EBP1 and eIF4E, which are core elements in this pathway, have been found in a variety of tumor cells, and regarded as molecular markers as well as targets of tumor treatment.We firstly explored the expression of 4EBP1 and eIF4E in astrocytoma, meningeoma, oligdendrocytoma, cholesteatoma and normal brain tissues. Our results suggested that both eIF4E and 4EBP1 were found as mRNAs and proteins in all four cerebromas. Meanwhile, the LC-3 and LAMP-2A also increased significantly. Immunohistochemistry data suggested that levels of eIF4E and 4EBP1 proteins were higher in meningeoma, cholesteatoma, astrocytoma and oligdendrocytoma compared with normal tissue(**P<0.01). It is inferred that eIF4E and 4EBP1 can be regarded as molecular markers for cerebromas.RNAi techqique was employed to knock down 4EBP1in Hep-2 cell line to determine its effects on proliferation. The result showed that level of p-4EBP1 decreased synchronously with the rate of cell proliferationis arrested at S and G2-M phase. We hypothesized that the level of free eIF4E could increase when the level of p-4EBP1 decreased.To explore the synergism between knocking down of 4EBP1 and treatment of 5-FU(10μM), we analyze the proliferation of Hep-2 cell line whose expression of 4EBP1 is knocked down and treated with 5-FU (10μM). We found that knocked down of 4EBP1 together with 5-FU(10μM) treatment had stronger effect on the proliferation of Hep-2 cell line compared to each single treatment.Our work provided new ideas for the application of autophagy in cancer treatment in the future.