Dexamethasone suppresses DU145 cell proliferation and cell cycle through inhibition of the extracellular signal-regulated kinase 1 /2 pathway and cyclin D1 expression

Aim： To determine the mechanisms of glucocorticoids in inhibiting advanced prostate cancer growth. Methods： The cell proliferation and cell cycle of prostate cancer DU145 cells following dexamethasone treatment were determined by proliferation assay and fluorescence-activated cell sorter. Western blot analysis was carried out to evaluate the effects of dexamethasone on phosphorylation of extracellular signal-regulated kinase （ERK）1/2 and expression of cyclin D1 in DU145 cells with or without glucocorticoid receptor （GR） antagonist RU486. Reverse transcription- polymerase chain reaction verified the expression of GR mRNA in DU145 cells. Results： Dexamethasone significantly inhibited DU 145 cell proliferation at the G0/G1 phase. Westem blot analysis showed a dramatic reduction of ERK1/2 activity and cyclin D1 expression in dexamethasone-treated cells. The decreased phosphorylation of ERK1/2 in dexamethasone-treated cells was attenuated by GR blockade. Additionally, the effects of dexamethasone in inhibiting cyclin D1 expression were altered by GR blockade. Conclusion： Dexamethasone suppresses DU145 cell proliferation and cell cycle, and the underlying mechanisms are through the inhibition of phosphorylation of ERK1/2 and cyclin D1 expression. The inhibition of ERK1/2 phosphorylation and cyclin D1 expression is attenuated by GR blockade, suggesting that GR regulates ERK1/2 and cyclin D1 pathways. These observations suggest that dexamethasone has a potential clinical application in prostate cancer therapy.

Downregulation of Aquaporin 4 Expression through Extracellular Signal-regulated Kinases1/2 Activation in Cultured Astrocytes Following Scratch-injury

Objective To investigate the role of extracellular signal-regulated kinase1/2（ERK1/2） pathway in the regulation of aquaporin 4（AQP4） expression in cultured astrocytes after scratch-injury. Methods The scratch-injury model was produced in cultured astrocytes of rat by a 10-μL plastic pipette tip. The morphological changes of astrocytes and lactate dehydrogenase（LDH） leakages were observed to assess the degree of scratch-injury. AQP4 expression was detected by immunofluorescence staining and Western blot, and phosphorylated-ERK1/2（p-ERK1/2） expression was determined by Western blot. To explore the effect of ERK1/2 pathway on AQP4 expression in scratch-injured astrocytes, 10 μmol/L U0126（ERK1/2 inhibitor） was incubated in the medium at 30 min before the scratch-injury in some groups. Results Increases in LDH leakage were observed at 1, 12, and 24 h after scratch-injury, and AQP4 expression was reduced simultaneously. Decrease in AQP4 expression was associated with a significant increase in ERK1/2 activation. Furthermore, pretreatment with U0126 blocked both ERK1/2 activation and decrease in AQP4 expression induced by scratch-injury. Conclusion These results indicate that ERK1/2 pathway down-regulates AQP4 expression in scratch-injured astrocytes, and ERK1/2 pathway might be a novel therapeutic target in reversing the effects of astrocytes that contribute to traumatic brain edema.

Time-dependent effects of electroacupuncture at the Ren channel on extracellular signal-regulated kinases 1/2 expression in focal cerebral ischemia rats

BACKGROUND： The onset of focal cerebral ischemia activates extracellular signal-regulated kinases 1 and 2, regulates cell cycle, promotes cell proliferation and differentiation, and affects the normal stage and function of brain cells. OBJECTIVE： To observe the effects of electroacupuncture at the Ren channel on extracellular signal-regulated kinases 1/2 expression in the lateral cerebral ventricle wall of rats with focal cerebral ischemia. The effects were analyzed at different time points after intervention. DESIGN： Randomized controlled study. SETTING： Department of Anatomy, Sun Yat-Sen University. MATERIALS： A total of 60 healthy adult male Wistar rats weighing （250±10） g were provided by the Experimental Animal Center, Medical College of Sun Yat-Sen University. The animal experiment was conducted with confirmed consent by the local ethics committee. The GB6805-Ⅱ electric acupuncture apparatus was provided by Shanghai Medical Equipment High-techno Company. METHODS： The experiment was performed at the Laboratory of Anatomy, Sun Yat-Sen University, from February to July 2007. All experimental animals were randomly divided into the following groups： normal group （n = 6）, sham operation group （n = 18）, model group （n = 18）, and electroacupuncture group （n = 18）. Middle cerebral artery occlusion （MCAO） was performed in the model group and electroacupuncture group. Zea Longa＇s grading standard was used to assess neurological impairment after reperfusion; animals whose grades were between l and 4 were included in this study. The normal control group was not exposed to MCAO. In sham operation animals, the right common carotid artery （CCA） was isolated, and the external carotid artery （ECA） was damaged, but no embolism was induced. The electroacupuncture group was given acupuncture on the second day after surgery. The acupoint locations were chosen according to Experimental Acupuncture （People＇s Publishing House; 1997; First Edition）. The Chengjiang, Qihai, and Guanyuan acupoints were labeled and connected to a G6805 electroacupuncture apparatus with sparse-dense waves （sparse waves were 30 Hz, dense waves were 100 Hz）, with a frequency of 6-15 V. The duration was 20 minutes. Two days after surgery, the model and sham operation groups were placed with their backs on the operating table, but they received no acupuncture. However, the normal group received acupuncture. The experimental animals under anesthesia were sacrificed on days 7, 14, and 28 post-surgery. Western blot analysis was used to measure expression of extracellular signal-regulated kinases 1/2 in the inferior region of the lateral cerebral ventricle wall. Expression was measured in the normal group at time points corresponding to the sham operation group. MAIN OUTCOME MEASURES： Expression of extracellular signal-regulated kinases 1/2 in the inferior region of the lateral cerebral ventricle wall at different time points after intervention. RESULTS： All 60 rats were included in the final analysis, without any loss. Seven days after MCAO, there was no significant difference in extracellular signal-regulated kinases 1/2 expression in the electroacupuncture group compared to the model group （P 〉 0.05）. However, extracellular signal-regulated kinases 1/2 expression significantly increased in the model group at 14 and 28 days after treatment （P 〈 0.05）. CONCLUSION： Electroacupuncture at the Ren channel can enhance extracellular signal-regulated kinasesl/2 expression in the inferior region of the lateral cerebral ventricle wall of rats with focal cerebral ischemia. However, this effect is not apparent until 14 days after electroacupuncture intervention.

Activation of extracellular signal-related kinases 1 and 2 in Sertoli cells in experimentally cryptorchid rhesus monkeys

Aim： To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2 （ERK1/ 2）, c-Jun N-terminal kinases （JNK） and p38 mitogen-activated protein kinases （MAPK） in response to heat stress in the cryptorchid testis, and to investigate a possible relation to Sertoli cell dedifferentiation. Methods： Immunohistochemistry and western blot were used to examine the expression and activation of ERK1/2, p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism. Results： The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis. Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK. Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis. Changes in the spatiotemporal expression of cytokeratin 18 （CK18）, a marker of immature or undifferentiated Sertoli cells, were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2. Condusion： The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.

Activation of extracellular signal-related kinases 1 and 2 in Sertoli cells in experimentally cryptorchid rhesus monkeys

Aim:To assess the spatiotemporal changes in the expression of extracellular signal-regulated kinases 1 and 2(ERK1/ 2),c-Jun N-terminal kinases(JNK)and p38 mitogen-activated protein kinases(MAPK)in response to heat stress in the cryptorchid testis,and to investigate a possible relation to Sertoli cell dedifferentiation.Methods:Immunohis- tochemistry and western blot were used to examine the expression and activation of ERK1/2,p38 and JNK in the cryptorchid testis at various stages after experimental cryptorchidism.Results:The abdominal temperature did not obviously change the total ERK1/2 expression but significantly activated phospho-ERK1/2 in the Sertoli cells of the cryptorchid testis.Heat stress increased total JNK expression in the Sertoli cells of the cryptorchid testis but did not activate phospho-JNK.Neither total p38 nor phospho-p38 was induced by heat stress in the Sertoli cells of the cryptorchid testis.Changes in the spatiotemporal expression of cytokeratin 18(CK18),a marker of immature or undifferentiated Sertoli cells,were induced in the cryptorchid testis in a pattern similar to the activation of ERK1/2. Conclusion:The activation of ERK1/2 in the testis may be related to dedifferentiation of Sertoli cells under heat stress induced by experimental cryptorchidism.

人参皂苷Rg1对局灶性脑缺血再灌注损伤大鼠海马p-ERK1/2与p-JNK表达的影响

目的探讨人参皂苷Rg1抗脑缺血再灌注(ischemia reperfusion,I/R)损伤大鼠海马神经元凋亡的可能机制。方法成年健康雌性SD大鼠120只随机分为脑缺血再灌注模型组(模型组)、人参皂苷Rg1低(10mg/kg)、中(20mg/kg)、高剂量(40mg/kg)组及假手术组,每组18只。各组均腹腔注射给药,假手术组及模型组腹腔注射等量生理盐水,每天1次,连续7天,末次给药后30min,大鼠右侧大脑中动脉阻塞(middle cerebral artery occlusion,MCAO)2h再灌注24h制备I/R模型。以LongaEZ法评定神经功能,尼氏染色、TUNEL染色观察海马锥体神经细胞的损伤情况,并计算神经细胞凋亡率。采用Westernblot法检测细胞外信号调节蛋白激酶1/2(extracellular signal-regulated kinase1/2,ERK1/2)及磷酸化细胞外信号调节蛋白激酶1/2(phosphorylated extracellular signal-regulated kinase1/2,p-ERK1/2)、c-Jun氨基末端激酶(c-Jun N-terminal kinases,JNK)及磷酸化c-Jun氨基末端激酶(phosphorylated c-Jun N-terminal kinases,p-JNK)表达。结果与假手术组比较,模型组神经功能评分、细胞凋亡率、p-JNK、p-ERK1/2蛋白表达升高(P<0.05,P<0.01),锥体细胞存活数减少(P<0.01);与模型组比较,人参皂苷Rg1各剂量组神经功能评分、细胞凋亡率降低(P<0.05,P<0.01),人参皂苷Rg1中、高剂量组大鼠锥体细胞存活数增加,海马CA1区p-JNK蛋白表达降低,p-ERK1/2表达升高(P<0.05,P<0.01)。假手术组海马CA1区有3-4层锥体细胞,排列整齐、紧密,高倍镜下细胞核大而圆,有1～2个核仁。脑组织缺血损伤后,海马区神经细胞受损严重,CA1区失去正常结构,细胞排列散乱,细胞数量减少。部分神经元皱缩,核固缩、深染,呈三角形、长条形、梭形或不规则形,核染色聚集,核仁不清晰。与人参皂苷Rg1低剂量组比较,人参皂苷Rg1中、高剂量组神经功能评分、细胞凋亡率及p-JNK蛋白表达降低(P<0.05,P<0.01),锥体细胞存活数增加,p-ERK1/2表达升高(P<0.05,P<0.01)。人参皂苷Rg1中、高剂量能够改善缺血神经细胞形态,减少神经细胞的丢失,其中,高剂量组作用强于低剂量组。JNK蛋白条带分为两个亚带,JNK1是分子量为46kD的蛋白,JNK2分子量为54kD。ERK蛋白条带也分为两个亚带,ERK1是分子量为44kD的蛋白,ERK2分子量为42kD的蛋白。结论人参皂苷Rg1对I/R大鼠的保护作用与抑制海马神经元凋亡,调节p-JNK及p-ERK1/2表达水平有关。

TROP2、p-ERK1/2和Cyclin D1在胆囊癌组织中的表达及临床意义

目的探讨胆囊癌组织中人滋养层细胞表面抗原(TROP)2、磷酸化细胞外信号调节激酶(p-ERK)1/2和细胞周期蛋白D1(Cyclin D1)的表达及其与临床病理参数之间的关系,并分析其与胆囊癌患者预后的关系。方法搜集第二军医大学附属长征医院2005年6月-2010年6月确诊并获取病理标本的胆囊癌患者88例,采用免疫组化法检测88例胆囊癌组织及15例癌旁组织中TROP2、p-ERK1/2和Cyclin D1蛋白的表达。计数资料采用χ~2检验,Spearman检验法分析TROP2、p-ERK1/2和Cyclin D1间相关性;单因素和多因素Cox回归分析胆囊癌患者预后的影响因素;Kaplan-Meier法绘制患者的生存曲线。结果 TROP2、p-ERK1/2和Cyclin D1蛋白在胆囊癌组织中的阳性表达率分别为74.30%、58.40%和55.30%,明显高于癌旁组织中的表达(5.42%、35.67%和39.87%)(P值均<0.05)。TROP2、p-ERK1/2和Cyclin D1蛋白的表达与胆囊结石、肿瘤直径、分化程度、血管神经侵犯、淋巴结转移、手术方式及TNM分期相关(χ~2=4.300~53.315,P值均<0.05)。TROP2与p-ERK1/2、Cyclin D1的表达呈正相关(rs值分别为0.402、0.742,P值均<0.001),且p-ERK1/2与Cyclin D1的表达也呈正相关(rs=0.242,P=0.023)。多因素生存分析提示,TROP2的阳性表达是患者3年生存率的独立危险因素(相对危险度=2.412,95%可信区间:1.186~5.126,P=0.010)。结论 TROP2的高表达可能是胆囊癌恶性进展的重要原因,高表达的TROP2可能介导p-ERK1/2和Cyclin D1的高表达,导致胆囊癌恶性进展。TROP2是判断胆囊癌患者预后的独立危险因素,有可能是临床干预的有效靶点。

Involvement of MAPK/ERK kinase-ERK pathway in exogenous bFGF-induced Egr-1 binding activity enhancement in anoxia-reoxygenation injured astrocytes

Objective Intravenous administration of basic fibroblast growth factor （bFGF） is effective to reduce the volume of cerebral infract due to ischemia. This study was designed to investigate the molecular mechanism, especially the signal transduction pathways, involved in this protective role of bFGF. Methods Anoxia-reoxygenation treated atrocytes were used to study the role of mitogen-activated protein kinase/extracellular signal-regulated kinase kinase （MAPK/ERK kinase, MEK）-ERK signaling pathway after exogenous bFGF administration by Western blot. Electrophoretic mobile shift assay was used to detect the binding activity of early growth response factor-1 （Egr-1）, an important transcription factor for endogenous bFGF. Results bFGF could protect some signal transduction proteins from the oxygen-derived free radicals induced degradation. ERK1/2 was activated and involved in Egr-1 binding activity enhancement induced by exogenous bFGF. Conclusion MEK-ERK MAPK cascade may be an important signal transduction pathway contributed to bFGF induced enhancement of Egr-1 binding activity in anoxia-reoxygenation injured astrocytes.

p-ERK1/2在抗体介导的慢性排斥反应患者移植肾组织中的表达及意义

目的探讨移植肾组织中磷酸化细胞外信号调节激酶(p-ERK)1/2的表达,并分析其与肾间质纤维化及肾小管萎缩(interstitial fibrosis and tubular atrophy,IF/TA)的关系。方法检测解放军181医院全军器官移植与透析治疗中心收治的120例病理诊断符合抗体介导的慢性排斥反应(chronic antibody-mediated rejection,ABMR)患者移植肾组织中p-ERK1/2、TGF-β1和Ⅳ型胶原的表达情况,并进行半定量分析,分析p-ERK1/2表达与TGF-β1、Ⅳ型胶原表达的相关性,以及p-ERK1/2与IF/TA病理分级的相关性;以10例正常肾组织作为对照组。结果 ABMR患者移植肾组织中p-ERK1/2、TGF-β1和Ⅳ型胶原表达量均比正常肾组织明显增加(P<0.05),并随着IF/TA病理分级增加呈递增趋势(r=0.938、0.926、0.937,P<0.05)。移植肾组织中p-ERK1/2表达与TGF-β1、Ⅳ型胶原表达呈显著正相关(r=0.864、0.878,P<0.01)。结论 p-ERK1/2和TGF-β1可能促进了肾移植患者移植肾细胞外基质(ECM)异常沉积,而导致移植肾纤维化,p-ERK1/2在ABMR所致移植肾纤维化过程中起重要作用。

P-ERK1/2在2型糖尿病合并结直肠癌患者癌组织中的表达及意义

目的研究伴有2型糖尿病的结直肠癌(CRC)患者癌组织中磷酸化的细胞外信号调节激酶1/2蛋白P-ERK1/2的表达特点,并探讨其临床病理意义。方法选取行手术切除治疗的59例CRC患者,其中伴有2型糖尿病者29例(CRC/DM组),不伴2型糖尿病CRC患者30例(CRC组)。采用免疫组织化学的方法检测手术切除癌组织中P-ERK1/2的表达情况,比较2组间P-ERK1/2表达差异及其临床病理意义,并分析2组间生存时间和死亡率的差异。结果免疫组化染色结果表明,P-ERK1/2蛋白阳性免疫反应定位于肿瘤细胞浆及细胞核。P-ERK1/2蛋白在59例CRC组织阳性表达率为58.8%(17/59),其中CRC/DM组P-ERK1/2蛋白阳性表达率明显高于CRC组(P=0.036)。女性患者癌组织P-ERK1/2蛋白阳性率高于男性(P=0.03);无淋巴结转移组P-ERK1/2蛋白阳性率高于伴有淋巴结转移组(P=0.014);P-ERK1/2的表达与患者的年龄、分化程度、肿瘤长径、T分期均无相关关系(P>0.05),CRC/DM和CRC组差异无统计学意义(P>0.05)。随访结果表明,CRC组的中位生存时间是26个月,而CRC/DM组中位生存时间是19个月,差异有统计学意义(P=0.0304,P<0.05)。CRC/DM组死亡率明显高于CRC组(P=0.002)。P-ERK1/2蛋白阳性表达组的中位生存时间是22个月,而P-ERK1/2蛋白阴性表达组的中位生存时间是21个月,P-ERK1/2蛋白阳性表达组与阴性表达组死亡率比较差异无统计学意义(P>0.05)。结论伴有2型糖尿病的结直肠癌患者中位生存时间短,病死率高。CRC/DM组P-ERK1/2阳性表达率高于CRC组,但与患者病死率无关。

Overexpression of mitogen-activated protein kinase phosphatase-1 in endothelial cells reduces blood-brain barrier injury in a mouse model of ischemic stroke

Ischemic stroke can cause blood-brain barrier(BBB)injury,which worsens brain damage induced by stroke.Abnormal expression of tight junction proteins in endothelial cells(ECs)can increase intracellular space and BBB leakage.Selective inhibition of mitogen-activated protein kinase,the negative regulatory substrate of mitogen-activated protein kinase phosphatase(MKP)-1,improves tight junction protein function in ECs,and genetic deletion of MKP-1 aggravates ischemic brain injury.However,whether the latter affects BBB integrity,and the cell type-specific mechanism underlying this process,remain unclear.In this study,we established an adult male mouse model of ischemic stroke by occluding the middle cerebral artery for 60 minutes and overexpressed MKP-1 in ECs on the injured side via lentiviral transfection before stroke.We found that overexpression of MKP-1 in ECs reduced infarct volume,reduced the level of inflammatory factors interleukin-1β,interleukin-6,and chemokine C-C motif ligand-2,inhibited vascular injury,and promoted the recovery of sensorimotor and memory/cognitive function.Overexpression of MKP-1 in ECs also inhibited the activation of cerebral ischemia-induced extracellular signal-regulated kinase(ERK)1/2 and the downregulation of occludin expression.Finally,to investigate the mechanism by which MKP-1 exerted these functions in ECs,we established an ischemic stroke model in vitro by depriving the primary endothelial cell of oxygen and glucose,and pharmacologically inhibited the activity of MKP-1 and ERK1/2.Our findings suggest that MKP-1 inhibition aggravates oxygen and glucose deprivation-induced cell death,cell monolayer leakage,and downregulation of occludin expression,and that inhibiting ERK1/2 can reverse these effects.In addition,co-inhibition of MKP-1 and ERK1/2 exhibited similar effects to inhibition of ERK1/2.These findings suggest that overexpression of MKP-1 in ECs can prevent ischemia-induced occludin downregulation and cell death via deactivating ERK1/2,thereby protecting the integrity of BBB,alleviating brain injury,and improving post-stroke prognosis.

Glucocorticoid modulation of extracellular signal-regulated protein kinase 1/2 and p38 in human ovarian cancer HO-8910 cells

Objective To investigate the signaling pathway through testing the effects of dexamethasone (Dex) on the activation of the extracellular signal-regulated protein kinase 1/2 (ERK1/2) and p38 kinase (p38) in HO-8910 cells.Methods Activation of the ERK1/2 and p38 was detected by Western blotting using the antibodies against the total ERK1/2 and p38 mitogen-activated protein kinases (MAPKs) protein and the phosphorylated forms of them. Results Dex could suppress the activation of ERK1/2, while enhance the activation of p38 rapidly and strongly in a dose- and time- dependent manner. Neither effect could be blocked by RU486, the antagonist of glucocorticoid receptor (GR).Conclusion Dex has rapid effects on the activation of ERK1/2 and p38, and these effects are not mediated by GR.

Role of extracellular signal-regulated kinase 1/2 in cigarette smoke-induced mucus hypersecretion in a rat model

Background Airway mucus hypersecretion is an important pathophysiological feature of chronic obstructive pulmonary disease, which is closely associated with cigarette smoking. However, the signal transduction pathway from the cell surface to the nucleus through which cigarette smoke causes upregulation of mucin gene expression is not well known. This study was designed to investigate the role of extracellular signal-regulated Kinase 1/2 （ERK 1/2） in airway mucus hypersecretion induced by cigarette smoke in rats. Methods A rat model of airway mucus hypersecretion was induced by exposure to cigarette smoke for 4 weeks. Rats exposed to inhalation of cigarette smoke or normal saline were given an intraperitoneal injection of U0126, a specific MEK1 kinase inhibitor, at doses of 0.25 mg/kg, 0.5 mg/kg and 1 mg/kg for 14 days. Expression of MUC5AC mRNA and protein, ERK 1/2 and phosphorylated-ERK 1/2 （p-ERK 1/2） were detected by RT-PCR, immunohistochemistry and Western blotting. Results Cigarette smoke significantly increased airway goblet cells metaplasia, induced the overexpression of MUC5AC mRNA and protein in bronchial epithelia, and increased the ratio of p-ERK 1/2 and ERK 1/2. U0126 significantly attentuated the expression of MUC5AC mRNA and protein induced by cigarette smoke （P 〈0.05）. Moreover, there was a significant positive correlation between the ratio of p-ERK1/2 to ERK1/2 and the expression of MUC5AC mRNA and protein （P 〈0.05）. Conclusions Inhibition of ERK 1/2 by U0126 decreased the ratio of p-ERK 1/2 to ERK 1/2 and expression of MUC5AC mRNA and protein. ERK 1/2 may play an essential role in cigarette smoke-induced mucus hypersecretion in vivo.

7-二氟亚甲基-5,4’-二甲氧基染料木黄酮通过下调核因子κB和磷酸化细胞外信号调节激酶1/2的表达抑制血管内皮细胞与单核细胞的黏附

目的研究7-二氟亚甲基-5,4’-二甲氧基染料木黄酮对氧化诱导的血管内皮细胞与单核细胞黏附的影响,并初步探讨其作用机制。方法蛋白定量分析法测定内皮细胞与单核细胞的黏附率,酶联免疫吸附法检测E选择素、细胞间黏附分子1的释放,Western Blotting检测核因子κB、磷酸化细胞外信号调节激酶1/2的表达。结果1.0mmol/L H2O2孵育内皮细胞24h,内皮细胞与单核细胞的黏附增多,E选择素和细胞间黏附分子1的释放增加,核因子κB和磷酸化细胞外信号调节激酶1/2表达上调。用7-二氟亚甲基-5,4’-二甲氧基染料木黄酮预处理后可见内皮细胞与单核细胞的黏附率降低,E选择素和细胞间黏附分子1的释放减少,核因子κB和磷酸化细胞外信号调节激酶1/2的表达下调。结论7-二氟亚甲基-5,4’-二甲氧基染料木黄酮对氧化诱导的血管内皮细胞与单核细胞黏附及黏附分子E选择素、细胞间黏附分子1的释放有明显抑制作用,其作用机制可能与下调核因子κB和磷酸化细胞外信号调节激酶1/2的表达有关。

雌激素受体β与磷酸化细胞外信号调控蛋白激酶1、2在卵巢癌中的表达及其临床意义

目的:探讨上皮性卵巢癌组织中雌激素受体β(ERβ)与磷酸化细胞外信号调控蛋白激酶1、2(p-ERK1/2)的表达及其与临床病理参数的关系。方法:选取2010年10月至2011年12月青岛大学医学院附属医院经病理证实的上皮性卵巢癌组织标本70例,卵巢良性肿瘤24例,正常卵巢组织24例。采用RT-PCR和免疫组织化学SP法检测上述组织中ERβ和p-ERK1/2的表达。结果:(1)卵巢癌组织中ERβmRNA相对表达水平(0.3764±0.9826)显著低于卵巢良性肿瘤(0.4900±0.3742)及正常卵巢组织(0.4980±0.0434)(P<0.05)。卵巢癌组织中ERβ表达与组织学分型、细胞学分级及淋巴转移有关(P<0.05);ERβ蛋白阳性表达率及其与临床病理特征关系与ERβmRNA一致;(2)ERK1/2 mRNA相对表达水平(0.6007±0.1554、0.6951±1.3694)显著高于卵巢良性肿瘤(0.3575±0.0479、0.5125±0.0411)及正常卵巢组织(0.3027±0.1024、0.5431±0.0811)(P<0.05);ERK1/2表达与细胞学分级、临床分期及腹水有关(P<0.05);p-ERK1/2蛋白阳性表达率及其与临床病理特征与p-ERK1/2 mRNA一致。ERβ蛋白与p-ERK1/2蛋白表达呈负相关(r=-0.282,P<0.05)。结论:ERβ低表达和p-ERK1/2高表达于卵巢癌组织,可能在卵巢癌的发生、发展中有重要作用。

抗氧化剂硫辛酸对实验性偏头痛大鼠细胞外信号调节激酶1/2的作用

目的探讨α-硫辛酸(alpha-lipoid acid,α-LA)对硝酸甘油诱发的实验性偏头痛大鼠细胞外信号调节激酶1/2的作用。方法 48只SD大鼠随机分为正常对照组、模型组、α-LA组、溶剂组,采用皮下注射硝酸甘油(glyceryl trinitrate,GTN)法制作偏头痛大鼠模型。α-LA组在造模后30 min腹腔给予α-LA(60 mg·kg-1),观察大鼠行为学变化。采用Western blot印迹法和免疫组化法测定三叉神经节及三叉神经颈复合体、硬脑膜细胞外信号调节激酶1/2(ERK1/2)、磷酸化ERK1/2(p-ERK1/2)表达。结果模型组大鼠p-ERK1/2蛋白表达明显高于正常对照组;与模型组相比,α-LA组大鼠行为症状明显改善,p-ERK1/2蛋白表达下降,模型组与α-LA组组间比较有统计学意义(P<0.05)。结论α-LA可减弱偏头痛大鼠模型中p-ERK1/2的表达,α-LA可能有防治偏头痛的作用。

磷酸化ERK1/2与Cyclin D1、VEGF在非小细胞肺癌中表达的关系

目的:研究非小细胞肺癌(NSCLC)中磷酸化细胞外信号调节激酶(PERK1/2)及靶基因产物CyclinD1和血管内皮生长因子(VEGF)的表达关系,探讨PERK1/2在NSCLC发生、发展中的作用。方法:应用免疫组织化学技术检测10例正常肺组织和64例NSCLC组织中PERK1/2、CyclinD1和VEGF的表达情况,并与临床病理特征进行统计学分析。结果:NSCLC组织中PERK1/2、CyclinD1和VEGF的阳性表达率分别为57.8%、60.9%和71.9%,正常肺组织均为阴性表达;PERK1/2的核内表达和VEGF的表达率与TNM分期、淋巴结转移相关(P<0.05),CyclinD1的阳性表达率与肿瘤的分化程度及淋巴结转移相关(P<0.05);PERK1/2的核内表达与CyclinD1在NSCLC中的表达呈线性相关(P<0.05)。结论:PERK1/2介导的信号转导事件可能在NSCLC发生、发展过程中起重要促进作用。

Raf-1蛋白激酶、磷酸化丝裂原细胞外激酶1和磷酸化细胞外信号调节激酶1/2在肝癌中的表达与预后分析

目的探讨Raf-1蛋白激酶(Raf-1)、磷酸化丝裂原细胞外激酶1(pMEK1)和磷酸化细胞外信号调节激酶1/2(pERK1/2)在肝癌中的表达与肝癌预后的关系。方法应用免疫组织化学PV6000法检测原发性肝癌组织中Raf-1、pMEK1、pERK1/2蛋白的表达差异性与肝癌预后之间的关系。结果 Raf-1、pMEK1和pERK1/2在肝癌中的过表达率分别为38.3%、46.7%和38.3%,三者过表达率呈正相关(P<0.05)。Raf-1、pMEK1和pERK1/2过表达与性别、年龄、甲胎蛋白、乙肝表面抗原表达状态、肿瘤分化程度、TNM分期、是否存在癌栓、肿瘤大小等各临床病理因素无关(P>0.05)。单因素及多因素分析均显示Raf-1过表达与肝癌预后相关(P<0.05)。结论 Raf-1的过表达是肝癌预后不良的显著标记,可能为肝癌的靶向治疗提供理论依据。

磷酸化细胞外信号调节激酶1/2定位于成骨细胞的局部黏附时需要Src活性

目的探讨血小板源性生长因子(platelet-derived growth factor,PDGF)刺激成骨细胞,对磷酸化细胞外信号调节激酶1/2(phosphorylation extracellular signal-regulated kinase1/2,pERK1/2)位置的影响。方法出生3d清洁级健康小鼠10只,雌雄不拘,体重6～9g。取小鼠颅骨,分离培养原代成骨细胞。取第6代成骨细胞,1%血清培养液培养12h后,随机分成经10μmol/L PP2处理30min组(实验组)和未处理组(对照组),每组再随机分成2个亚组:其中一组用PDGF(20ng/ml)刺激10min,另一组不用PDGF刺激,采用免疫组织化学染色检测pERK1/2分布。另取第6代成骨细胞,当细胞生长至80%融合时,用细胞刮随机分成2组,一组用10μmol/L PP2预处理30min(实验组),另一组不用PP2作用(对照组),再用20ng/ml PDGF培养12h,采用划痕愈合法检测PP2对成骨细胞在PDGF刺激下迁移能力的影响。另取第6代成骨细胞,调整细胞浓度1×106/ml,随机分成2组,分别经DMSO(对照组)和10μmol/L PP2(实验组)预处理30min,每组再随机分成2个亚组:其中一组用PDGF(20ng/ml)刺激10min,另一组不用PDGF剌激,采用Western blot检测细胞骨架蛋白内pERK1/2活性。结果免疫荧光染色结果显示,PDGF促进pERK1/2定位于成骨细胞的局部黏附和细胞核内;而PP2显著抑制了由PDGF刺激引起的pERK1/2定位于成骨细胞的局部黏附,但并不影响pERK1/2定位于细胞核内。细胞划痕愈合实验显示,PP2明显抑制了由PDGF所诱导的成骨细胞迁移。Western blot检测结果显示,PP2明显抑制了由PDGF所诱导的成骨细胞局部黏附内ERK1/2的磷酸化。结论PDGF通过激活Src活性,促进pERK1/2定位于成骨细胞的局部黏附内;PP2通过抑制pERK1/2定位于成骨细胞的局部黏附,从而抑制由PDGF所诱导的成骨细胞迁移。

细胞外信号调节激酶1/2在肾癌中的表达及临床意义

目的:探讨细胞外信号调节激酶1/2(ERK1/2)及其磷酸化状态(p-ERK1/2)在肾癌中的表达及临床意义。方法:选取78例肾癌患者的肾癌组织及距离病灶超过3 cm的癌旁组织,免疫组织化学法检测ERK1/2及p-ERK1/2表达情况,比较性别、年龄、肿瘤直径、临床分期、淋巴结转移、远处转移、病理Fuhrman分级与癌组织ERK1/2及p-ERK1/2的关系,并通过Kaplan-Meier生存分析癌组织中ERK1/2、p-ERK1/2与肾癌患者生存情况的相关性。结果:肾癌组织中ERK1/2及p-ERK1/2阳性表达率均高于癌旁组织(P<0.05)。不同性别、年龄、肿瘤直径患者癌组织ERK1/2及p-ERK1/2阳性表达率之间比较,差异无统计学意义(P>0.05);临床分期为Ⅲ-Ⅳ期、有淋巴结转移、远处转移、病理Fuhrman分级为G2+G3者的癌组织中ERK1/2及p-ERK1/2阳性表达率分别高于临床分期Ⅰ-Ⅱ期、无淋巴结转移、远处转移、病理Fuhrman分级为G1者(P<0.05)。Kaplan-Meier生存分析结果显示,相较于ERK1/2、p-ERK1/2阴性表达者,肾癌组织中ERK1/2、p-ERK1/2阳性表达的患者生存情况较差(P<0.001)。结论:ERK1/2及p-ERK1/2在肾癌组织高表达,且与患者临床分期、淋巴结转移、远处转移、病理Fuhrman分级及生存期相关。