Study On The Relationship Between PI3K/Akt Signal Transduction Pathway And DDP Resistance Of Ovarian Carcinoma

ObjectiveTo study the expression and alteration of the messenger of cell signal transduction phosphatidylinositol 3- kinase(P13K)and protein kinase B(PKB) in SKOV3 and SKOV3/DDP cells in order to comprehend the relationship between ovarian cancer and PI3K/Akt signal transduction pathway.That will help us to interpret the relationship PI3K/Akt pathway and occurrence and development of ovarian cancer which could provide new threads to prophase diagnosis of neoplasms,develop new drugs to anti-tumor and search target point of gene treatment.In addition, SKOV3 and SKOV3/DDP cells were freely divided into three groups and treated them with single P13K inhibitor(LY294002),single cisplatin(CDDP) and combination of LY294002 and CDDP in order to observe the effection of anti-tumor of LY294002 and the synergism action of LY294002 to CDDP.That intend to provid the basis of examination to formulate more effectivetherapy program,to screen effective anti-tumor drug and to provid thebasis of theory for clinical therapy of late stage' s ovarian cancer.Methods1.MIT assay was used to analyze the curve of growth of SKOV3 and SKOV3/DDP cells,IC₅₀ value of CDDP,the effection of LY294002 to control ovarian tumor cells growth and the synergism of LY294002 to CDDP.2.The effection of LY294002 and CDDP to expression of PI3K and Akt were detected by Western Blot.Results1.SKOV3 and SKOV3/DDP cells growth adhsively.The multiplicate time of SKOV3 cell was 33.36 hours and SKOV3/DDP cell was 42.60 hours;2.LY294002 could inhibite the growth of SKOV3 and SKOV3/DDP cells.The cells were divided into four groups which were 5μM,10μM,20μM and 40μM group. The inhibitory activities of LY294002 to SKOV3 cells in four groups were 20.80±1.35%,31.56±0.86%,39.39±1.29%,51.47±0.87%for 24 hours;29.76±2.04%, 33.81±1.50%,42.99±1.29%,54.45±1.04%for 48 hours;35.17±0.68%,39.31±0.92%, 48.75±2.28%,62.42±2.12%for 72 hours.The inhibitory activities of LY294002 to SKOV3/DDP cells in four groups were 7.82±2.44%,12.25±0.39%,17.72±0.22%, 31.17±2.49%for 24 hours;22.94±2.65%,34.13±2.14%,37.64±2.57%,53.42±2.07% for 48 hours;29.33±1.64%,39.04±1.38%,48.45±2.11%,60.20±3.89%for 72 hours;3.LY294002 could enhence the synergism of SKOV3 and SKOV3/DDP cells to CDDP.In SKOV3 cells,there was significant difference between associated used of LY294002 10μM and CDDP and signal used CDDP.In SKOV3/DDP cells,there was significant difference between associated used LY294002 5μM and CDDP and signal used CDDP.The IC₅₀ of SKOV3 cells was 3.3094±0.1771μg/ml.After interferenced by LY294002 5μM,10μM,20μM,40μM,the IC₅₀ of SKOV3 cells were 2.6815±0.0473μg/ml,2.4416±0.0138μg/ml,1.5865±0.1024μg/ml,1.0802±0.0621μg/ml.The sensitivities of SKOV3 cells to CDDP increased 18.97%,26.22%,52.06% and 67.36%separately.The IC₅₀ of SKOV3/DDP cells was 13.6307±0.9342μg/ml. After interferenced by LY294002 5μM,10μM,20μM,40μM,the IC₅₀ of SKOV3/DDP cells were 8.4017±0.5105μg/ml,7.6872±0.1927μg/ml,5.2926±0.1005μg/ml, 3.1949±0.1941μg/ml.The sensitivities of SKOV3/DDP cells to CDDP increased 38.36%,43.60%,61.17%and 76.56%separately;4.The expression of PI3K and Akt in SKOV3 cells were activer than that in SKOV3/DDP cells,the correspondence density of PI3K and Akt in SKOV3 cells were lower than that in SKOV3/DDP cells.The cells were divided into six groups which were LY294002 5+DDP group,LY294002 10+DDP group,LY294002 20+DDP group,LY294002 40+DDP group,DDP group and control group.Comparing to SKOV3 cells,the expression of PI3K in SKOV3/DDP cells were increased 51.86%, 54.38%,56.53%,59.58%,53.57%and 45.61%separately;the expression of Akt in SKOV3/DDP cells were increased 38.34%,35.64%,41.62%,48.69%,47.90%and 40.94%separately.In SKOV3 cells,the expression of PI3K in six groups were different(F=190.215,P＜0.05),there were significant difference between six groups(P＜0.05).There was negative linear correlationship between the expression of PI3K and the density of LY294002(r=-0.972,P＜0.05);the expression of Akt in six groups were different(F=143.998,P＜0.05),there were significant difference between six groups(P＜0.05).There was negative linear correlationship between the expression of PI3K and the density of LY294002(r=—0.986,P＜0.05).In SKOV3/DDP cells,the expression of PI3K in six groups were different(F=190.215,P＜0.05),there were significant difference between six groups(P＜0.05).There was negative linear correlationship between the expression of PI3K and the density of LY294002(r=—0.987,P＜0.05);the expression of Akt in six groups were different(F=1085.682, P＜0.05),there were significant difference between six groups(P＜0.05).There was negative linear correlationship between the expression of PI3K and the density of LY294002(r=—0.986,P＜0.05).Conclusions1.PI3K' s special inhibitor LY294002 could effective inhibit the multiplication of SKOV3 and SKOV3/DDP cells in vitro.The augmentation of inhibition ratio of SKOV3 and SKOV3/DDP cells followed by dosage of LY294002 and time which show the inhibition ratio of SKOV3 and SKOV3/DDP cells depended by dosage of LY294002 and time.2.Followed by the enhencement of density of LY294002,the IC₅₀ value of SKOV3 and SKOV3/DDP cells decreased.LY294002 could enhence the synergism action of LY294002 to CDDP,enhance apoptosis of cells and increase the sensibility of SKOV3 and SKOV3/DDP cells to CDDP.3.The expression of PI3K and Akt were influenced by dosage of LY294002. LY294002 could inhibit the expression of PI3K and competive integrate the ATP site, and then inhibit the activation of Akt.