The Effect Of PI3K Pathway On The Expression And Distribution In Cell Lines GES-1 And BGC-823

Objective:1.To investigate the differences of expression and distribution of P27, p-P27 (Thr187),p-P27 (Thr157) and p-P27 (Ser10) between cell lines GES-1 and BGC-823.2.To investigate the function of PI3K pathway in the process of expression and distribution of P27, p-P27 (Thr187), p-P27 (Thr157) and p-P27(Ser10) between cell lines GES-1 and BGC-823.Methods:Cultivate cell lines GES-1 and BGC-823.Cycles of the both cell lines were measured by flow-cytometry(FCM). The expressions of P27, p-P27 (Thr187),p-P27 (Thr157) and p-P27 (Ser10) in total cell, cytoplasm and nuclear were measured by Western blotting respectively. Then, inhibited PI3K pathway in the two cell lines by LY294002, and did the same measuring as before(FCM, Western blotting). All the information were put into software of SPSS 13.0 to analysis.Result:1. Comparative study of GES-1 and BGC-823 showed, in total cell, the expression of P27,p-P27 (Thr187),p-P27 (Thr157) and p-P27 (Ser10) were all different statistically (P=0.000; P=0.000; P=0.000; P=0.000); in cytoplasm, the expression of P27,p-P27 (Thr157) and p-P27 (Ser10) were different statistically (P=0.001; P=0.000; P=0.000), but p-P27 (Thr187) was not (P=0.052); in nuclear, the expression of P27, p-P27 (Thr187) and p-P27 (Ser10) showed statistical differences (P=0.001; P=0.000; P=0.000), but p-P27(Thr187)did not(P=0.288). Cell cycles of the two cell lines were different significantly (P=0.003)2. After inhibited by LY294002 in GES-1,in total cell, all the expression of P27, P-P27 (Thr187),p-P27 (Thr157) and p-P27 (Ser10) showed no statistical differences (P=0.651; P=0.482;P=0.357; P=0.070); in cytoplasm, the expression of p-P27 (Thr187) and p-P27 (Ser10) showed no statistical differences (P=0.053; P=0.056), but P27 and p-P27 (Thr187) were different statistically (P=0.013; P=0.002); in nuclear, all the expression of P27, p-P27 (Thr187),p-P27 (Thr157) and p-P27 (Ser10) showed no statistical differences (P=0.558; P=0.140; P=0.223; P=0.052). The change of the cell cycle before and after inhibiting by LY294002 showed no statistical difference (P=0.392). 3. After inhibited by LY294002 in BGC-823,in total cell, the expression of P27, p-P27(Thr157)and p-P27(Ser10)showed statistical difference(P=0.000; P=0.001; P=0.000), but p-P27 (Thr187) didn't (P=0.254); in cytoplasm, the expression of P27,p-P27 (Thr157) and p-P27 (Ser10) were different statistically(P=0.000; P=0.000; P=0.001), but p-P27 (Thr187) wasn't (P=0.070); in nuclear, the expression of P27 and p-P27 (Ser10) were different statistically (P=0.001; P=0.001), but p-P27(Thr187)and p-P27(Thr157)showed no difference(P=0.223; P=0.482). The cell cycles before and after inhibiting by LY294002 changed significantly (P=0.001)4. After inhibited by LY294002, comparative study of GES-1 and BGC-823 showed, in total cell, the expression of P27, p-P27 (Thr157) and p-P27 (Ser10) showed no difference (P=0.391; P=0.158; P=0.106), only p-P27 (Thr187) was different (P=0.000); in cytoplasm, the expression of P27, p-P27 (Thr157) and p-P27 (Ser10) showed no difference (P=0.279; P=0.062; P=0.196),only p-P27 (Thr187) showed difference (P=0.002); in nuclear, the expression of P27, p-P27 (Thr157) and p-P27 (Ser10) showed no difference (P=0.092; P=0.081; P=0.055), only p-P27 (Thr187) showed difference (P=0.000). Cell cycles of the two cell lines showed no statistical difference (P=0.003)Conclusion:1. The expression and distribution of P27 and p-P27 in GES-1 and BGC-823 are different statistically.2. Inhibiting of PI3K pathway has nearly no effect on the expression and distribution of P27 and p-P27 in GES-1, and it doesn't disturb the cell cycle.3. Inhibiting of PI3K pathway up-regulates the expression of P27 and down-regulates the expression of p-P27, and the cell cycle was changed by it.4. PI3K pathway can delocalize the distribution of P27, and make it localized in cytoplasm to inhibit it's function of anti-tumor. It seems that PI3K pathway has no effect on the degradation of P27.5. Inhibiting of PI3K pathway will be a probable new way to cure gastric cancer.