Objective Study the function of p21-activated kinase 2 in Xenopus oocyte cytokinesis. Methods Xenopus oocyte was used as a model,and MPF activity and PAK2 phosphorylation status were observed during oocyte maturation.The specific inhibitor of PAK2 activity,PAK2-NT(PAK2-N-terminal) was used to microinject into Xenopus oocyte.Under fluorescent microscope germinal vesicle breakdown was observed during cytokinesis.To further observe the changes of F-actin and spindle,laser scanning confocal microscopy with time-lapse method was employed. Results Occurrences of germinal vesicle breakdown in control oocytes was similar to those oocytes injected with PAK2-NT mRNA,but no cytokinesis was observed in oocytes injected with PAK2-NT mRNA.Conclusion These results indicated that PAK2 might involved in Xenopus oocytes cytokinesis.

ObjectiveThe aim of this study is to evaluate diagnostic and prognostic value of matrix metalloproteinase-7 (MMP-7) in patients with bladder cancer.MethodsA total of 77 patients with bladder cancer and 65 healthy controls were recruited in this study.The levels of serum MMP-7 were measured by ELISA methods.ResultsThe level of serum MMP-7 in bladder cancer group was significantly higher than those in the healthy control [ [ 3.1 (0 - 32.1 ) ng/ml vs 1.0 ( 0.2 - 2.6) ng/ml,x2 =9.29,P ＜0.01 ].The level of serum MMP-7 was correlated to lymph node metastasis ( x2=10.49,P ＜ 0.01 ) and tumor grade ( x2=4.55,P =0.033 ).Receiver operating characteristic ( ROC ) curves of serum MMP-7level was 0.810.Serum MMP-7 was used to diagnose bladder cancer with the sensitivity of 83.6％ and specificity of 77.4％.The survival rate in patients with a high level of MMP-7 was lower than that with a low level of MMP-7 (x2=3.88,P =0.0488).ConclusionsMMP-7 may be closely associated with the progression of bladder cancer.Serum MMP-7 may be a useful index for diagnosis and prognosis for patients with bladder cancer.

p21-Activated kinases including p21-activated kinase 2 contributed to the regulation of actin cytoskeleton and cell dynamics. In order to investigate the function of PAK2 on the maturation of Xenopus oocyte, PAK2-NT(PAK2-N-terminal,PAK2-NT) and PAK2-NTm (PAK2-N-terminal mutation) mRNA were microinjected into Xenopus oocyte respectively. Under fluorescent microscopy germinal vesicle breakdown was observed during cytokinesis. To further observe the relationship of oocyte cytokinesis, polar body formation and Cdc42 activity, confocal microscopy with time-lapse was employed . As a result, occurrences of germinal vesicle breakdown in oocytes were similar to those oocytes injected with PAK2-NT mRNA or injected with PAK2-NTm mRNA,but no cytokinesis and polar body formation were observed in oocytes injected with PAK2-NT mRNA or PAK2-NTm mRNA. These results indicated that PAK2 involved in Xenopus oocytes cytokinesis and polar body formation independent of Cdc42 activity.