PKC-a、K-Ras蛋白在结直肠癌中的表达及意义

目的探讨蛋白激酶C(PKC)-a、K-Ras蛋白在结直肠癌中的表达及意义。方法选取该院病理科收集的结直肠腺癌组织70例(腺癌组),结直肠腺瘤组织12例(腺瘤组),正常结直肠黏膜8例(正常组),采用免疫组化法检测PKC-a、K-Ras蛋白的表达,分析PKC-a、K-Ras蛋白表达在结直肠癌中的意义。结果 PKC-a蛋白免疫阳性物质多聚集于细胞质与部分细胞膜位置,主要表现为棕黄色颗粒沉着。腺癌组PKC-a蛋白阳性表达率明显低于腺瘤组与正常组(P<0.05)。K-Ras蛋白免疫阳性物质多聚集于细胞质。腺癌组及腺瘤组K-Ras蛋白阳性表达率明显高于正常组(P<0.05)。PKC-a蛋白阳性率与组织病理学分级、合并淋巴结转移存在相关性(P<0.05);K-Ras蛋白阳性率与组织病理学分级存在相关性(P<0.05)。K-Ras蛋白表达与PKC-a蛋白表达呈负相关性(r=-0.734,P=0.00)。结论在结直肠癌的发生、发展过程中,PKC-a、K-Ras蛋白发挥着重要的作用,两者的平衡紊乱会导致细胞癌变。

一氧化氮对体外培养大鼠软骨细胞Caspase-3及PKC-α表达的影响

目的:研究NO对大鼠软骨细胞Caspase-3及蛋白激酶C(PKC)-α(PKC-α)表达的影响,探讨NO诱导软骨凋亡的机制。方法:软骨细胞用不同浓度的NO处理24h后,用TUNEL、MTT法和流式细胞术检测细胞凋亡和细胞活力。Western blot检测Caspase-3及PKC-α的表达。结果:NO处理后软骨细胞TUNEL阳性率明显增高,细胞核片段损害明显,Caspase-3的表达升高,同时抑制PKC-α的表达。结论:NO诱导的软骨细胞凋亡可能通过促进Caspase-3表达,作用机制与抑制PKC-α有关。

Effect of Combination Regimen of Low-dose Gossypol Acetic Acid with Steroid Hormones on Expression of Protein Kinase C alpha (PKC-α) and Cyclin D1 in Rat Testes

Objective To investigate the contraceptive mechanism of combination regimen of low- dose gossypol acetic acid （GA） with steroid hormones [desogestre/ethinylestradiol/ testosterone undeeanote（DSG/EE/TU）]. Methods Adult male rats were randomly divided into four groups. Group GH： rats were fed orally with gossypol acetic acid （GA, 12.5 mg/kg） and desogestrel （DSG, 0.125 mg/kg）/ ethinylestradiol （EE, 0.025 mg/kg）/testosterone undecanoate （TU, 100 mg/kg per day, qd X4 weeks or 10 weeks）; group G： a single dose of GA （12.5 mg/kg per day, qd X 4 weeks or I0 weeks）; group H： the same dosage of DSG/EE/TUas in group GH; group C： rats were treated with vehicle （1% methyl cellulose） as the control. Expression of protein kinase C alpha （PKC-a） and cyclin D1 in rat testes were tested mainly by immunohistochemistry （IHC） and Western blotting. Results IHC results showed that protein PKC- a was expressed mainly in interstitial tissue of testis among seminiferous tubule. The expression of PKC-oc in groups H and GH at week 10 was decreased greatly compared with that in group C. The protein cyclin D1 was expressed mainly in residual body of seminiferous tubule eavosurface and interstitial tissue among seminiferous tubule of testis. Western blotting results showed that the expression of PKC-a in groups H and GH at week 10 was decreased significantly compared with that in group C （P〈0.05）. The expression of cyclin D1 in groups G, H or GH at week 10 rose significantly compared with that in group C （P 〈0.05）.Conclusion The administration of low-dose gossypol acetic acid with steroid hormones for 10 weeks can decrease the expression of PKC-a greatly.