The Effects Of Stromal Protein Periostin On The Apoptosis Of NPC Cells

objective: Periostin(POSTN) is a stromal protein which was found to be overexpressed in mesenchyma of the NPC(nasopharyngeal carcinoma). The statistics analysis of clinicopathologic features of patients indicated that the upregulated POSTN was closely correlated with the metastasis and prognosis of the NPC patients, and in vitro study of cells showed that Periostin can promotes the cell proliferation,invasion and metastasis. Based on the previous study, we aimed to explore the effects of POSTN played on the apoptosis of 6-10 B cells and possibly involved mechanisms. Methods: First, Western Blot was used to verify the transfection efficiency of POSTN in 6-10 B cells stored in our department. Sequently, the relative expression level of P53, P-AKT in Periostin transfected cells and control cells were measured with Western Blot. Then the Flow Cytometry was employed to detect the apoptosis rate of the cells after the transfection of POSTN. IHC was performed to detect the the expression level of P53 in normal nasopharyngeal mucosa and NPC tissues. At the same time we collect culture superlatant of series of6-10 B cells and series of 3T3 cells to culture the 6-10 B cells and then detect apoptosis related protein of 6-10 B cells. Lastly, shRNA againstP53 was implied to make a knockout of P53 gene in 6-10 B cells. And then Flow Cytometry was employed to evaluate the effects of P53 on the apoptosis of 6-10 B cells Results:(1)The results of Flow Cytometry indicated that transfected POSTN could contribute to the elevated apoptosis rate of 6-10 B cells, and transfected cells expressed higer level of pro-apoptosis protein and lower level of pro-survival protein.(2)compared with nomal nasopharyngeal mucosa, the higher expression level of P53 was observed in NPC tissues.(3)The supernatant of6-10B-POSTN can promote the apoptosis of 6-10 B cells, however, the expresson model of P53 is not the same with that of transfected cells, on the other hand, supernatant of series of 3T3 cells can promote the survival of 6-10 B cells.(4)We successfully constructed the shRNA that could get an efficient knockout of P53 gene in 6-10 B,and the knockout of P53 could not decrease the apoptosis rate of 6-10 B cells, and POSTN can increase the apoptosis rate of P53 knockout 6-10 B cells. Conclusions:(1)High expression level of POSTN can promote the apoptosis of 6-10 B cells;(2) POSTN facilitates the apoptosis of 6-10 B cells not through upregulating P53 expression(The involed mechanisms of promoting apoptosis of POSTN may be related to the disregulation of BAX and P-AKT).