磷脂酰肌醇3激酶在卵巢上皮性癌组织中的表达及其抑制剂对卵巢上皮性癌细胞生长抑制作用的研究

目的 探讨细胞信号转导信使磷脂酰肌醇3激酶(PI3K)在卵巢上皮性癌(卵巢癌)组织中的表达及其意义;并探讨PI3K抑制剂LY294002联合顺铂对卵巢癌细胞株的生长抑制作用.方法 应用蛋白印迹法和RT-PCR技术检测正常卵巢组织(正常组,20份)、卵巢良性上皮性肿瘤组织(良性组,6份)、卵巢交界性上皮性肿瘤组织(交界性组,6份)和卵巢癌组织(卵巢癌组,39份)中PI3K p85亚单位蛋白和mRNA的表达.将SKOV3细胞分为对照组(只加培养液)、LY294002组(加1、10、30、50、100 μmol/L LY294002)、顺铂组(加0.33、1.25、2.5、5、10 μmol/L顺铂)和联合组(加50 μmol/L LY294002+10 μmol/L顺铂),四甲基偶氮唑蓝还原法测定不同浓度的LY294002及顺铂对SKOV3细胞的生长抑制作用.结果 (1)PI3K p85亚单位蛋白的表达阳性率:正常组和良性组均为0,交界性组为2/6,卵巢癌组为85%(33/39),正常组、良性组、交界性组分别与卵巢癌组比较,差异均有统计学意义(P＜0.01).(2)PI3K p85亚单位mRNA的表达水平:正常组为0.178±0.102,良性组为0.643±0.112,交界性组为0.847±0.058,卵巢癌组为1.689±0.423,正常组、良性组、交界性组分别与卵巢癌组比较,差异均有统计学意义(P＜0.01).卵巢癌组织中,PI3K p85亚单位蛋白表达阳性率及mRNA的表达水平,不同年龄、病理类型间比较,差异均无统计学意义(P＞0.05);而不同病理分化程度、手术病理分期间比较,差异均有统计学意义(P＜0.05).(3)LY294002及顺铂呈剂量依赖性地抑制SKOV3细胞的生长.LY294002组(50 μmol/L)、顺铂组(10 μmol/L)、联合组SKOV3细胞的抑制率分别为(46.0±2.0)%、(44.4±3.2)%、(57.1±4.1)%,联合组SKOV3细胞的抑制率高于LY294002组及顺铂组(P＜0.01).结论 PI3K p85亚单位在卵巢癌组织中呈高表达,与病理分化程度、手术病理分期有关.LY294002与顺铂联合用药对卵巢癌细胞生长的抑制具有协同效应.

Expression of phosphatidylinositol-3 kinase in epithelial ovarian carcinoma

OBJECTIVE: To explore the expression and significance of phosphatidylinositol-3 kinase (PI3K) in ovarian cancer, and the effect of combined PI3K inhibitor (LY294002) therapy with cisplatin on epithelial ovarian carcinoma, and to explore if there is a synergistic effect between the two therapies. METHODS: The expression levels of PI3K p85 subunit proteins and mRNA were evaluated by western blot and RT-PCR in normal ovarian tissue (G1), ovarian benign tumor tissue (G2), ovarian borderline tumor tissue (G3) and ovarian cancer tissue (G4), and the relevant clinical pathological parameters were analyzed. SKOV3 cells were isolated and cultured by enzymolysis method. SKOV3 cells were treated with culture medium only, LY294002 (1, 10, 30, 50, 100 micromol/L), cisplatin (0.33, 1.25, 2.5, 5, 10 micromol/L), LY294002 (50 micromol/L) + cisplatin (10 micromol/L) for 2 days, respectively. The effect of LY294002 and cisplatin on the growth of SKOV3 cells was measured by methyl thiazolyl tetrazolium assay. RESULTS: There was no positive expression of PI3K p85 subunit proteins in G1 and G2, while the expression was 2/6 in G3, and 85% (33/39) in G4. PI3K p85 subunit mRNA expression levels were 0.178 +/- 0.102 in G1, 0.643 +/- 0.112 in G2, 0.847 +/- 0.058 in G3, 1.689 +/- 0.423 in G4; there was a significant difference between G1, G2, G3 and G4 (P<0.01). There was no significant correlation between protein expression and age at surgery or clinico-pathological staging (P>0.05). Significant differences were noted between protein expression levels in G4 (III, IV) and G4 (I, II; P<0.05). There was a significant difference between expression levels in tissues of different differentiation degrees (P<0.05). LY294002 and cisplatin inhibited the growth of SKOV3 cell in a concentration-dependent manner. The inhibitory activity of LY294002 at the concentration of 50 micromol/L was (46.0 +/- 2.0)% after treatment for two days. The inhibitory activity of cisplatin at the concentration of 10 micromol/L was (44.4 +/- 3.2)% after treatment for two days. After treatment for two days, the inhibitory activity of LY294002 50 micromol/L + cisplatin 10 micromol/L was (57.1 +/- 4.1)%. The inhibition effect on SKOV3 cell growth of the combined treatment group was better than the LY294002 or cisplatin treated group (P<0.01). CONCLUSIONS: PI3K p85 subunit is highly expressed and positively correlated with ovarian cancer. Different expression levels exist in tissues of late ovarian cancer, earlier ovarian cancer, borderline tumor, benign ovarian tumor and normal ovarian tissue. The changes in PI3K p85 subunit are correlated with tumor differentiation degree, but not pathologic typing. LY294002 combined with cisplatin can significantly enhance the killing efficiency in ovarian cancer cells.