| Part I:The correlation between the expression of KIF3B and the prognosis of ovarian cancer patientsObjective:To investigate the correlation between the expression of KIF3B and the prognosis of ovarian cancer patientsMethods:Western blot was used to detect the expression of KIF3B in ovarian cancer tissues;immunohistochemistry was used to detect the expression of KIF3B in ovarian cancer tissues,and the relationship between the expression of KIF3B and Ki-67;the relationship between KIF3B and clinicopathological characteristics was analyzed;the relationship between KIF3B and the prognosis of ovarian cancer patients was assessed.Results:The expression of KIF3B in ovarian cancer tissues was significantly higher than that in normal ovarian tissues,and the expression of KIF3B was positively related to the grades of ovarian cancer;KIF3B,mainly localized in the cytoplasm,was highly expressed in ovarian cancer tissues,and the expression was consistent with Ki-67,which was the commonly used proliferating cell-related nuclear antigen;the expression of KIF3B was positively correlated with pathological grade;There were significant differences between histological grade,ascites,tumor cells,metastasis toother organs,the expression of Ki-67 and KIF3B respectively,wheras had no obvious significance between the expression of KIF3B and age,menstrual status,FIGO stage,lymph node stage;The survival rate of ovarian cancer patients was negatively related to FIGO stage;The survival rate of ovarian cancer patients was negatively correlated with histological grade;The survival rate of ovarian cancer patients was correlated with histological type;The survival rate of ovarian cancer patients was correlated with other organ metastases,and the survival rate of patients without metastasis was higher;The survival rate of ovarian cancer patients was correlated with the expression of Ki-67,and the survival rate of ovarian cancer patients with low expression of Ki-67 was higher;The survival rate of ovarian cancer patients was not related to age,lymph node stage,ascites;The survival rate of ovarian cancer patients was negatively related to the expression of KIF3B.Conclusion:KIF3B was highly expressed in ovarian cancer patients,which was positively related to histological grade and correlated with poor prognosis.Part II:KIF3B promoted cell cycle transition from G0/G1 phase to S phase,and accelerated the growth of ovarian cancer.Objective:To explore the relationship between KIF3B and the growth of ovarian cancer and its potential mechanismMethods:Western blot was used to detect the expression of KIF3B in different ovarian cancer cell lines;Lentivirus infection technical was used to establish cell lines that overexpressed or knocked down KIF3B;MTT was used to detect the effect of KIF3B on the growth of ovarian cancer cells;Subcutaneous xenograft nude mouse model was used to detect the effect of KIF3B on the growth of ovarian cancer cells;Flow cytometry was used to detect the effect of KIF3B expression on the cell cycle distribution of ovarian cancer cells;Western blot was used to detect the expression of cell cycle-related proteinsResults:The expression of KIF3B was highest in HO8910 cells and lowest in A2780 cells;Knockdown of KIF3B significantly inhibited the growth of ovarian cancer cell lines;Overexpressed KIF3B significantly promoted the growth of ovarian cancer cells;Knockdown of KIF3B significantly inhibited the growth of ovarian cancer in vivo;Overexpression of KIF3B significantly promoted the growth of ovarian cancer in vivo;Knockdown of KIF3B significantly increased the proportion of G0/G1 phase cells and decreased the proportion of S phase cells;Overexpression of KIF3B significantly increased the proportion of S phase cells and decreased the proportion of G0/G1 phase cells;Knockdown of KIF3B inhibited the expression of Cyclin A and CDK2 in HO8910 cell lines;Overexpression of KIF3B increased the expression of Cyclin A and CDK2 in A2780 cell lines.Conclusion:KIF3B promoted cell cycle transition from G0/G1 phase to S phase,and promoted the growth of ovarian cancer.Part III:KIF3B up-regulated expression of Cyclin A and CDK2 through PI3K/AKT pathwayObjective:To explore the mechanisms involved in the KIF3B mediated cell cycle transition from G0/G1 phase to S phaseMethods:Microarray was used to detect the effect of KIF3B on the gene expression profile of HO8910 cells;Gene ontology analysis was performed by using David software(https://david.ncifcrf.gov/);Pathway analysis was performed by using KEGG database(https://www.genome.jp/kegg/);Western blot was used to detect the expression level of PI3K regulatory subunit PIK3R2(p85)and phosphorylation of AKT.MTT was used to detect the growth of ovarian cancer cellsResults:Differentially expressed genes were defined as genes whose fold changes were more than 1.8 times.KIF3B knockdown decreased the expressions of 2293 genes and increased the expressions of 204 genes;Differentially expressed genes were enriched in tumor-related signaling pathways such as Ras and FoxO;Differentially expressed genes of KIF3B were enriched in PI3K/AKT,the key upstream pathway of FoxO;Knockdown of KIF3B inhibited the expression of p85 and the phosphorylation of AKT;Overexpression of KIF3B promoted the expression of p85 and the phosphorylation of AKT;Wortamannin could attenuate the activation of AKT by overexpression of KIF3B,suggesting that KIF3B activated AKT pathway in a PI3K dependent manner;Wortamannin could attenuate the up-regulation of Cyclin A and CDK2 by KIF3B;Wortamannin could attenuate the KIF3B-promoted growth of ovarian cancer cell lines.Conclusion:KIF3B could activate PI3K/AKT pathway,and then up-regulated the expressions of Cyclin A and CDK2,which promoted cell cycle transition from G0/G1 phase to S phase,leading to promoted the growth of ovarian cancer. |
