mRNA EXPRESSION OF PTEN AND VEGF GENES IN EPITHELIAL OVARIAN CANCER

Objective:To investigate the mRNA expression of PTEN and vascular endothelial growth factor (VEGF) genes in ovarian cancer. Methods:We examined mRNA expression of PTEN and VEGF165 in normal ovary (n=5), ovarian cyst (n=5), ovarian borderline tumor (n=9), epithelial ovarian cancer (n=60) and ovarian cancer cell line (CAOV-3) by RT-PCR. Their expressions were compared with clinicopathological features of ovarian cancer. The relationship between their expressions was concerned in all ovarian samples as well. Results:mRNA expression level of PTEN gene was significantly lower in ovarian borderline tumor or ovarian cancer than that in normal ovary or ovarian cyst(P<0.05). It was negatively correlated with clinicopathological staging(P<0.05),whereas positively with histological differentiation (P<0.05). mRNA expression level of PTEN gene was significantly lower in ovarian endometrioid cancer than ovarian serous or mucinous cancer(P<0.05). mRNA expression level of VEGF165 gene was significantly higher in ovarian cancer than that in normal ovary or ovarian cyst(P<0.05). It was positively correlated with clinicopathological staging(P<0.05), whereas negatively with histological differentiation (P<0.05). mRNA expression level of VEGF165 gene was significantly higher in ovarian serous cancer than in other ovarian epithelial cancers (P<0.05). mRNA expression of VEGF165 gene was inversely correlated with mRNA expression level of PTEN gene. Conclusion:Down-regulated expression of PTEN and up-regulated expression of VEGF were considered as two important events in tumorigenesis of ovarian cancer and could be used as molecular markers to indicate the pathobiological behaviors of ovarian cancer. Decreased PTEN expression and increased VEGF expression were closely associated with tumorigenesis and pathobiological behaviors of ovarian endometrioid and serous cancer respectively. Reduced expression of PTEN gene might be involved in carcinogenesis and progression of ovarian cancer by up-regulating the VEGF expression to enhance angiogenesis.

Reversal of Multidrug Resistance and Inhibition of Phosphorylation of AKT in Human Ovarian Cancer Cell Line by Wild-type PTEN Gene

The reversing effect of wild-type PTEN gene on resistance of C 13K cells to cisplatin and its inhibitory effect on the phosphorylation of protein kinase B （AKT） were studied. The expression of PTEN mRNA and protein in OV2008 cells and C13K cells were semi-quantitatively detected by using RT-PCR and Western blotting. Recombinant eukaryotic expression plasmid containing human wild-type PTEN gene was transfected into C13K cells by lipofectamine2000. The expression of PTEN mRNA was monitored by RT-PCR and the expression of PTEN, Akt, p-Akt protein were ana- lyzed by Western blotting in PTEN-transfected and non-transfected C13K cells. Proliferation and chemosensitivity of cells to DDP were measured by MTT, and cell apoptosis was detected by flow cytometry after treatment with cisplatin. The expression of PTEN mRNA and protein in OV2008 cells were significantly higher than those in C13K cells. After transfection with PTEN gene for 48 h, the expression of PTEN mRNA and protein in C 13K cells were 2.04 ± 0.10, 0.94± 0.04 respectively and the expression of p-Akt protein （ 0.94± 0.07） was lower than those in control groups （1.68 ±0.14, 1.66± 0.10） （P〈 0.05）. The IC50 of DDP to C 13 K cells transfected with PTEN （7.2± 0.3 la mol/L） was obviously lower than those of empty-vector transfected cells and non-transfected cells （12.7±0.4 lamol/1, 13.0±0.3 lamol/L） （P〈0.05）. The apopototis ratio of wild-type PTEN-transfected, empty vector transfected and non-transfected C13K cells were （41.65___0.87）%, （18.61 ±0.70）% and （15.28±0.80）% respectively, and the difference was statistically significant （P〈0.05）. PTEN gene plays an important role in ovarian cancer multidrug resistance. Transfection of PTEN could increase the expression of PTEN and restore drug sensitivity to cisplatin in human ovarian cancer cell line C 13K with multidrug-resistance by decreasing the expression of p-Akt.

Brain delivering RNA-based therapeutic strategies by targeting mTOR pathway for axon regeneration after central nervous system injury

Injuries to the central nervous system(CNS)such as stroke,brain,and spinal cord trauma often result in permanent disabilities because adult CNS neurons only exhibit limited axon regeneration.The brain has a surprising intrinsic capability of recovering itself after injury.However,the hostile extrinsic microenvironment significantly hinders axon regeneration.Recent advances have indicated that the inactivation of intrinsic regenerative pathways plays a pivotal role in the failure of most adult CNS neuronal regeneration.Particularly,substantial evidence has convincingly demonstrated that the mechanistic target of rapamycin(mTOR)signaling is one of the most crucial intrinsic regenerative pathways that drive axonal regeneration and sprouting in various CNS injuries.In this review,we will discuss the recent findings and highlight the critical roles of mTOR pathway in axon regeneration in different types of CNS injury.Importantly,we will demonstrate that the reactivation of this regenerative pathway can be achieved by blocking the key mTOR signaling components such as phosphatase and tensin homolog(PTEN).Given that multiple mTOR signaling components are endogenous inhibitory factors of this pathway,we will discuss the promising potential of RNA-based therapeutics which are particularly suitable for this purpose,and the fact that they have attracted substantial attention recently after the success of coronavirus disease 2019 vaccination.To specifically tackle the blood-brain barrier issue,we will review the current technology to deliver these RNA therapeutics into the brain with a focus on nanoparticle technology.We will propose the clinical application of these RNA-mediated therapies in combination with the brain-targeted drug delivery approach against mTOR signaling components as an effective and feasible therapeutic strategy aiming to enhance axonal regeneration for functional recovery after CNS injury.

加味芪黄饮改善糖尿病肾病的PTEN/PI3K/Akt/mTOR通路机制研究

目的:研究加味芪黄饮通过PTEN/磷脂酰肌醇3激酶(PI3K)/蛋白激酶B(Akt)/哺乳动物雷帕霉素靶标(mTOR)通路改善糖尿病肾病(DN)的作用机制。方法:Sprague-Dawle(SD)大鼠利用高脂饲料饲养联合腹腔注射链脲佐菌素(STZ)建立DN模型,采用完全随机法分为模型组、加味芪黄饮低剂量组、中剂量组、高剂量组及氯沙坦组。各10只。根据临床用量换算,设定加味芪黄饮低剂量组、中剂量组、高剂量组[生药含量:200、400、800 mg·kg^(-1)·d^(-1)],空白组及模型组予0.9%氯化钠注射液灌胃。8周后取材,检测DN大鼠24 h尿蛋白、血肌酐(SCr)、血尿素氮水平(BUN),苏木精-伊红(HE)染色观察肾脏病理变化,免疫组化检测肾组织中PTEN、PI3K、Akt和mTOR等蛋白表达。结果:与空白组相比,模型组大鼠24 h尿蛋白、SCr、BUN水平显著升高(P<0.0001);加味芪黄饮干预后肾功能指标相比于模型组有所降低(P<0.001),免疫组化结果提示:模型组PTEN表达降低,PI3K、Akt、mTOR表达升高(P<0.01);加味芪黄饮干预后,PTEN表达量上升,PI3K、Akt及mTOR表达量下降,相比模型组差异均具有统计学意义(P<0.05)。加味芪黄饮高剂量组与氯沙坦组疗效差异无统计学意义(P>0.05)。结论:加味芪黄饮可能通过PTEN/PI3K/Akt/mTOR通路延缓DN发展。

The establishment of stable transfection of human breast cancer cell line MDA-MD-468 with exogenous PTEN gene

To investigate exogenous PTEN gene transfected human breast cancer cell line MDA-MD-468.Methods Using the lipofectamine 2000 transfection technique,wild type PTEN gene was transducted into an in vitro cultured highly metastatic breast cancer cell line MDA-MD-468.After transfection,the cells were selected by G418.The resistant clones were chosen and expanded in DMEM culture medium.RT-PCR,immunohistochemical method and western blot were used to determine the expression of target genes.Results An anti-G418 cell clone was established and expanded in culture.The transfected PTEN gene MDA-MD-468 cells showed expression of PTEN mRNA and PTEN protein.Conclusion Human breast cancer cell line MDA-MB-468 established in this study expresses consistently exogenous PTEN genes.4 refs,6 figs.

CircRNA ATF6 promotes ovarian cancer cell progression by activating PTEN/mTOR signaling pathway

Ovarian cancer is a malignant cancer type and affects women’s lives in the world.Circular RNAs(circRNAs)have been involved with the progression of cancers.In our study,we are going to explore the functions of circATF6 in ovarian cancer.The qRT-PCR assay was used to detect expressions of genes.Actinomycin D and RNase R treatment were implemented to verify the circular RNA character of circATF6.Besides,Cell proliferation was assessed by colony formation assay and EdU assay.Silenced circATF6 could reduce the proliferation of ovarian cancer cells.In addition,inhibited circATF6 could promote the cell apoptosis and inhibit related proteins in PTEN/mTOR signaling pathway in ovarian cancer.In conclusion,CircRNA ATF6 promotes ovarian cancer cell progression by activating PTEN/mTOR signaling pathway.

The effects of antisense PTEN gene transfection on the growth and invasion of glioma cells

Objective:To study the effects of antisense PTEN gene on the growth and invasion of glioma cells. Methods:A pcDNA3. 1/Hygro (-) recombinant plasmid containing antisense PTEN gene fragment was constructed. Glioma cells of primary culture were transfected with antisense PTEN gene vector and stably transfected clones were selected. Then, the different growth and invasion abilities and the different MMP9 mRNA expressions of three kinds of cells were observed, including the transfected cells, untransfected cells and the cells transfected with empty vector. Results :The abilities of growth and invasion of the transfected cells and the expressions of MMP9 mRNA were obviously enhanced. Conclusion: Antisense PTEN gene could have a negative impact on the growth and invasion of primary culture glioma cells.

阿伐他汀通过PTEN/mTOR信号调节糖酵解代谢逆转白血病耐药的作用及机制

目的:探讨阿伐他汀对耐阿霉素人急性早幼粒白血病细胞系HL-60/ADM糖酵解代谢的影响及作用机制。方法:取对数生长期耐阿霉素白血病细胞HL-60/ADM,给予不同浓度阿伐他汀处理后,采用CCK-8法测定细胞增殖活性,流式细胞术检测细胞凋亡,葡萄糖消耗实验检测白血病细胞糖酵解活性,Western blot方法检测PTEN、p-m TOR、PKM2、HK2、P-gp、MRP1蛋白的表达;将PTEN-si RNA转染至HL-60/ADM细胞后,进一步采用上述方法检测PTEN低表达对阿伐他汀调节HL-60/ADM细胞凋亡及糖酵解代谢的影响。结果:CCK-8结果显示,阿伐他汀呈浓度依赖性和时间依赖性抑制HL-60/ADM细胞增殖(r=0.872,r=0.936),10μmol/L阿伐他汀干预24 h后HL-60/ADM细胞增殖活性下降最明显,增殖活性降至(32.3±2.18)%。流式细胞术结果显示,阿伐他汀诱导HL-60/ADM细胞凋亡,该作用呈浓度依赖性(r=0.796),10μmol/L阿伐他汀对HL-60/ADM细胞的诱导凋亡作用最强,细胞凋亡率达到(48.78±2.95)%。葡萄糖消耗实验结果表明阿伐他汀明显抑制HL-60/ADM细胞糖酵解活性,该作用呈浓度依赖性和时间依赖性(r=0.915,r=0.748),10μmol/L阿伐他汀干预24 h后对糖酵解活性的抑制作用最强,相对葡萄糖消耗量降至(46.53±1.71)%。Western blot结果显示,给予阿伐他汀干预24 h后,p-m TOR、PKM2、HK2、P-gp、MRP1蛋白表达呈浓度依赖性降低(r=0.737,r=0.695,r=0.829,r=0.781,r=0.632),而PTEN蛋白表达呈浓度依赖性升高(r=0.531)。进一步将PTEN-si RNA转染HL-60/ADM细胞,结果显示,低表达PTEN减弱了阿伐他汀对细胞凋亡的促进作用以及对糖酵解代谢和多药耐药的抑制作用。结论:阿伐他汀能抑制白血病耐药株HL-60/ADM细胞增殖,诱导细胞凋亡,抑制糖酵解代谢,推测机制可能是通过上调PTEN表达,抑制m TOR激活,下调PKM2和HK2糖酵解代谢基因表达,从而逆转耐药。

EFFECTS OF MUTATION AND EXPRESSION OF PTEN GENEmRNA ON TUMORIGENESIS AND PROGRESSION OFEPITHELIAL OVARIAN CANCER

Objective To investigate the mutation and expression of tumor suppressor gene-PTEN mRNA and explore their roles in tumorigenesis and progression of ovarian cancer. Methods Mutated exon 5 of PTEN gene was examined in normal ovary(n = 5), ovarian cyst (n =5), ovarian borderline tumor (n = 9), epithelial ovarian cancer(n = 60), and ovarian cancer cell line (n = 1)by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). mRNA expression of PTEN gene was evaluated in corresponding tissues and cell line by reverse transcription polymerase chain reaction(RT-PCR). The mutation and mRNA expression of PTEN gene were compared with clini-copathological features of ovarian cancer. Results Mutated exon 5 of PTEN gene was detected only in 5(7.1%)cases of epithelial ovarian cancer. mRNA expression level of PTEN gene in ovarian borderline tumor or ovarian cancer was lower than that in normal ovary or ovarian cyst(P < 0.05). The level of PTEN gene mRNA expression was negatively correlated with clinicopathological staging of ovarian cancer, whereas positively correlated with histological differentiation (P < 0.05). mRNA expression level of PTEN gene in ovarian endometrioid cancer was significantly lower than that in ovarian serous or mucinous cancer (P < 0.05=. Conclusions Mutation of PTEN gene occurs in ovarian cancer. Down-regulated expression of PTEN is probably an important molecular event in tumorigenesis of ovarian cancer. Abnormal expression of PTEN gene is involved in progression of ovarian cancer. Reduced expression of PTEN gene is closely associated with tumorigenesis and pathobiological behaviors of ovarian endometrioid cancer.

Loss of heterozygosity on 10q23.3 and mutation of tumor suppressor gene PTEN in gastric cancer and precancerous lesions

AIM: To investigate the loss of heterozygosity (LOH) and mutation of tumor suppressor gene PTEN in gastric cancer and precancerous lesions.METHODS: Thirty cases of normal gastric mucosa, advanced and early stage gastric cancer, intestinal metaplasia, atrophic gastritis, and atypical hyperplasia were analyzed for PTEN LOH and mutations within the entire coding region of PTEN gene by PCR-SSCP denaturing PAGE gel electrophoresis,and PTEN mutation was detected by PCR-SSCP sequencing followed by silver staining.RESULTS: LOH rate found in respectively atrophic gastritis was 10% (3/30), intestinal metaplasia 10% (3/30), atypical hyperpiasia 13.3% (4/30), early stage gastric cancer 20%(6/30), and advanced stage gastric cancer 33.3% (9/30),None of the precancerous lesions and early stage gastric cancer showed PTEN mutations, but 10% (3/30) of the advanced stage gastric cancers, which were all positive for LOH, showed PTEN mutation.CONCLUSION: LOH of PTEN gene appears in precancerous lesions, and PTEN mutations are restricted to advanced gastric cancer, LOH and mutation of PTEN gene are closely related to the infiltration and metastasis of gastric cancer.

PCR-SSCP-DNA sequencing method in detecting PTEN gene mutation and its signifi cance in human gastric cancer

AIM: To discuss the possible effect of PTEN gene mutations on occurrence and development of gastric cancer. METHODS: Fifty-three gastric cancer specimens were selected to probe PTEN gene mutations in genome of gastric cancer and paracancerous tissues using PCR-SSCP-DNA sequencing method based on microdissection and to observe the protein expression by immunohistochemistry technique. RESULTS: PCR-SSCP-DNA sequencing indicated that 4 kinds of mutation sites were found in 5 of 53 gastric cancer specimens. One kind of mutation was found in exons. AA-TCC mutation was located at 40bp upstream of 3’ lateral exon 7 (115946 AA-TCC). Such mutations led to terminator formation in the 297th codon of the PTEN gene. The other 3 kinds of mutation were found in introns,including a G-C point mutation at 91 bp upstream of 5’ lateral exon 5(90896 G-C),a T-G point mutation at 24 bp upstream of 5’ lateral exon 5 (90963 T-G),and a single base A mutation at 7 bp upstream of 5’ lateral exon 5 (90980 A del). The PTEN protein expression in gastric cancer and paracancerous tissues detected using immunohistochemistry technique indicated that the total positive rate of PTEN protein expression was 66% in gastric cancer tissue,which was significantly lower than that (100%) in paracancerous tissues (P < 0.005). CONCLUSION: PTEN gene mutation and expression may play an important role in the occurrence and development of gastric cancer.

DOWN-REGULATED EXPRESSION OF PTEN GENE AND LOH OF ITS EPIGENETIC MICROSATELLITES IN GASTRIC CARCINOMA

Objective.To investigate PTEN expression and loss of heterozygosity(LOH)of its epigenetic microsatel-lites in gastric carcinoma and explore their roles in tumorigenesis and progression of gastric carcinoma.Methods.LOH of epigenetic microsatellites of PTEN(D10S541,D10S583and D10S1687)was exam-ined in advanced gastric carcinomas(n=56)by PCR-SSCP.The mRNA and protein expressions of PTEN gene were evaluated in normal mucosa(n=56),early(n=11)and advanced carcinomas(n=56)of the stomach using RT?PCR and immunohistochemoistry respectively.PTEN mRNA and protein expressions were compared with clinicopathological staging and lymph node metastasis of tumors.The relationship be-tween PTEN mRNA expression and LOH of microsatellites was discussed,as well as relationship between PTEN mRNA and protein expression.Results.LOH of D10S541,D10S583and D10S1687was found in28.6%(16/56)of advanced gas-tric carcinomas.The positive rates of PTEN expression were80.4%(45/56),45.5%(5/11)and32.1%(18/56)in normal gastric mucosa,early and advanced gastric carcinomas at mRNA level,while78.6%(44/56),36.4%(4/11)and28.6%(16/56)at protein level.PTEN mRNA and protein were less fre-quently expressed in early and advanced gastric carcinomas than normal gastric mucosa(P<0.05).There was negative correlation between PTEN mRNA expression and LOH of microsatellites(P<0.05).PTEN protein expression paralleled to its mRNA expression(P<0.05).The PTEN mRNA and protein expres-sions were negatively correlated with lymph node metastasis of advanced gastric carcinomas(P<0.05).Conclusion.Down?regulated expression of PTEN and frequent LOH of its epigenetic microsatellites might play an important role in gastric carcinogenesis.Reduced PTEN mRNA expression was closely as-sociated with LOH of its epigenetic microsatellites.Altered expression of PTEN might contribute to lymph node metastasis of gastric carcinoma by decreasing cell adhesion and apoptosis,increasing angiogenesis and cell mobility.

PTEN knockdown with the Y444F mutant AAV2 vector promotes axonal regeneration in the adult optic nerve

The lack of axonal regeneration is the major cause of vision loss after optic nerve injury in adult mammals. Activating the PI3K/AKT/mTOR signaling pathway has been shown to enhance the intrinsic growth capacity of neurons and to facilitate axonal regeneration in the central nervous system after injury. The deletion of the mTOR negative regulator phosphatase and tensin homolog （PTEN） enhances regeneration of adult corticospinal neurons and ganglion cells. In the present study, we used a tyrosine-mutated （Y444F） AAV2 vector to efficiently express a short hairpin RNA （shRNA） for silencing PTEN expression in retinal ganglion cells. We evaluated cell survival and axonal regeneration in a rat model of optic nerve axotomy. The rats received an intravitreal injection of wildtype AAV2 or Y444F mutant AAV2 （both carrying shRNA to PTEN） 4 weeks before optic nerve axotomy. Compared with the wildtype AAV2 vector, the Y444F mutant AAV2 vector enhanced retinal ganglia cell survival and stimulated axonal regeneration to a greater extent 6 weeks after axotomy. Moreover,post-axotomy injection of the Y444F AAV2 vector expressing the shRNA to PTEN rescued ～19% of retinal ganglion cells and induced axons to regenerate near to the optic chiasm. Taken together, our results demonstrate that PTEN knockdown with the Y444F AAV2 vector promotes retinal ganglion cell survival and stimulates long-distance axonal regeneration after optic nerve axotomy. Therefore, the Y444F AAV2 vector might be a promising gene therapy tool for treating optic nerve injury.

黄芩苷通过miR-23a-3p/PTEN/PI3K/AKT/mTOR抑制痛风性关节炎成纤维样滑膜细胞炎症反应机制探究

目的:探究黄芩苷(baicalin)通过微RNA-23a-3p/磷酸酶与紧张素同源物/磷脂酰肌醇-3-激酶/蛋白激酶B/哺乳动物雷帕霉素靶蛋白(miR-23a-3p/PTEN/PI3K/AKT/mTOR)抑制痛风性关节炎(GA)成纤维样滑膜细胞(FLS)炎症反应的机制。方法:提取GA患者和正常人外周血辅助性T淋巴细胞(CD4^(+)T),购买正常人FLS,应用单钠尿酸盐结晶液刺激正常人FLS构建GA-FLS模型,细胞迁移(transwell)进行CD4^(+)T细胞与GA-FLS共培养,构建miR-23a-3p模拟物(miR-23a-3p mimics)转染至GA-FLS中;黄芩苷作用24 h、48 h和72 h后,细胞计数8(CCK8)检测细胞活力并选取最佳作用浓度和时间;实验分为正常组(GA-FLS)、对照组(CD4^(+)T+GA-FLS)、模型组(GA-CD4^(+)T+GA-FLS)、黄芩苷组(GA-CD4^(+)T+GA-FLS+100μg/ml Baicalin)、miR-23a-3p-NC组(GA-CD4^(+)T+GA-FLS+miR-23a-3p-NC)、miR-23a-3p mimics组(GA-CD4^(+)T+GA-FLS+miR-23a-3p mimics)、黄芩苷miR-23a-3p mimics组(GA-CD4^(+)T+GAFLS+miR-23a-3p mimics+100μg/ml Baicalin);实时定量聚合酶链式反应(RT-qPCR)和免疫印迹(WB)检测miR-23a3p、PTEN、PI3K、AKT、mTOR的表达,酶联免疫吸附(ELISA)测定检测肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、白细胞介素-10(IL-10)的表达。结果:CCK8检测结果显示黄芩苷最佳作用浓度和时间为100μg/ml、48 h。RT-qPCR和WB检测结果显示:模型组miR-23a-3p mRNA、PI3K mRNA、AKT mRNA、mTOR mRNA的表达较正常组、对照组明显升高,差异有统计学意义(P<0.01);而PTEN mRNA组表达明显下降,差异有统计学意义(P<0.01);与miRNA-23a-3p-NC组相比,miR-23a-3p mimics组miRNA-23a-3p mRNA、PI3K mRNA、AKT mRNA、mTOR mRNA的表达明显上升,PTEN mRNA的表达明显下降,差异有统计学意义(P<0.01);与miR-23a3p mimics组相比,黄芩苷miR-23a-3p mimics组miRNA-23a-3p mRNA、PI3K mRNA、AKT mRNA、mTOR mRNA的表达明显下调,PTEN mRNA的表达明显上调,差异有统计学意义(P<0.01)。ELISA检测结果显示:模型组TNF-α、IL1β、IL-6的表达较正常组、对照组明显升高,而IL-10表达明显降低,差异有统计学意义(P<0.01);与miRNA-23a3p-NC组相比,miRNA-23a-3p mimics组TNF-α、IL-1β、IL-6的表达明显上升,IL-10表达明显下降,差异有统计学意义(P<0.01);与miR-23a-3p mimics组相比,黄芩苷miR-23a-3p mimics组TNF-α、IL-1β、IL-6的表达明显下调,IL-10表达明显上调,差异有统计学意义(P<0.01)。结论:黄芩苷可通过下调miR-23a-3p,抑制PTEN/PI3K/AKT/mTOR信号通路的激活,降低痛风性关节炎成纤维样滑膜细胞炎症反应。

LncRNA TUG1靶向AKT/mTOR信号通路促进卵巢癌细胞增殖和转移的研究

目的探究长链非编码RNA牛磺酸上调基因1(lncRNA TUG1)通过介导蛋白激酶B/磷酸化哺乳动物雷帕霉素靶蛋白(AKT/mTOR)信号通路对卵巢癌细胞增殖和转移的影响及可能机制。方法收集112例行卵巢癌根治术患者的卵巢癌组织及癌旁组织,采用RT-PCR检测两组织、卵巢癌细胞(OC3,SKOV3,A2780,HO-8910)及人正常卵巢上皮细胞IOSE80中TUG1表达。选择SKOV3细胞并分为si-TUG1组(转染TUG1 shRNA)和NC组(转染空载体质粒),采用CCK8、流式细胞术、划痕实验检测2组细胞增殖水平、细胞周期及细胞转移能力,Western blot检测2组蛋白激酶B(AKT)、磷酸化哺乳动物雷帕霉素靶蛋白(mTOR)、p-AKT、p-mTOR、细胞周期相关蛋白(Cyclin D1,Cyclin B1,CDK6)、转移相关蛋白(MMP-2,Snail)的相对表达量。结果RT-PCR检测结果显示,卵巢癌组织中TUG1表达高于癌旁组织(P<0.05),卵巢癌细胞OC3,SKOV3,A2780,HO-8910中TUG1表达均高于IOSE80细胞,且SKOV3中TUG1表达最高(P<0.05)。si-TUG1组细胞增殖水平、G2/M期比例、细胞迁移距离均低于NC组,细胞G0/G1期比例高于NC组(P<0.05);si-TUG1组p-AKT/AKT、p-mTOR/mTOR、Cyclin D1、Cyclin B1、CDK6、MMP-2,Snail蛋白表达低于NC组(P<0.05)。结论下调lncRNA TUG1表达能降低卵巢癌细胞增殖、转移能力,这可能与其能抑制AKT/mTOR信号通路有关。

miR-181-5p靶向PTEN/AKT/mTOR通路对氧化应激诱导下人皮肤成纤维细胞自噬及老化的影响

目的探讨miR-181-5p靶向10号染色体上缺失的磷酸酶及张力蛋白同源基因(PTEN)/蛋白激酶B(AKT)/哺乳动物雷帕霉素靶蛋白(mTOR)通路对氧化应激诱导下人皮肤成纤维(HDF)细胞自噬及老化的影响。方法以HDF细胞为研究对象,利用不同浓度H_(2)O_(2)(0、100、200、500μmol/L)处理细胞,通过CCK-8法检测细胞存活率,确定构建细胞老化模型的适宜H_(2)O_(2)浓度,并将该浓度H_(2)O_(2)诱导的HDF细胞命名为H_(2)O_(2)模型细胞;双荧光素酶报告基因实验验证miR-181-5p与PTEN的靶向关系;利用Lipofectamine2000试剂盒对H_(2)O_(2)模型细胞进行转染,细胞分组为:空白组(细胞未转染)、miR-181-5p mimics组、miR-NC组、anti-miR-181-5p组、anti-miR-NC组;荧光定量聚合酶链反应(qRT-PCR)检测细胞中miR-181-5p表达水平;Western印迹检测细胞中PTEN/AKT/mTOR通路相关蛋白、自噬相关蛋白(Beclin)-1、微管相关蛋白轻链(LC)3Ⅱ/Ⅰ表达水平;β-半乳糖苷酶(SA-β-gal)试剂盒观察各组细胞形态及SA-β-gal染色阳性比例。结果随着H_(2)O_(2)浓度的升高,HDF细胞存活率逐渐降低,有统计学差异(P<0.05),H_(2)O_(2)浓度为200μmol/L时,细胞存活率为51.64%,所以选择200μmol/L H_(2)O_(2)作为适宜诱导浓度;与HDF细胞相比,H_(2)O_(2)模型细胞中miR-181-5p、磷酸化(p)-AKT、p-mTOR蛋白表达明显上调,PTEN蛋白表达明显下调(P<0.05);双荧光素酶报告基因实验证实PTEN和miR-181-5p存在靶向关系;与空白组和miR-NC组比较,miR-181-5p mimics组中miR-181-5p、p-AKT、p-mTOR蛋白表达明显上调,PTEN、Beclin-1、LC3Ⅱ/Ⅰ蛋白表达明显下调(P<0.05),细胞排列不规则、变大,轮廓不清楚,折光性差等老化状态更加明显,SA-β-gal染色阳性率显著升高(P<0.05);与空白组和anti-miR-NC组比较,anti-miR-181-5p组中miR-181-5p、p-AKT、p-mTOR蛋白表达明显下调,PTEN、Beclin-1、LC3Ⅱ/Ⅰ蛋白表达明显上调(P<0.05),大多数细胞呈长梭形,轮廓清晰,折光性好,且SA-β-gal染色阳性率显著降低(P<0.05)。结论抑制miR-181-5p可能通过靶向上调PTEN蛋白表达,抑制AKT/mTOR通路,促进细胞自噬,进而延缓氧化应激诱导下HDF细胞老化。

PTEN对K562细胞mTOR调控的研究

目的:探讨肿瘤抑制基因PTEN在人慢性粒细胞白血病细胞株K562中对哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)的调控作用,以及雷帕霉素(rapamycin,RAPA)对K562细胞增殖抑制的影响。方法:通过实时荧光定量PCR(real-time fluorescent quantification PCR,RFQ-PCR)法检测甲磺酸伊马替尼(imatinib mexylate)干预K562细胞后BCR/ABL、PTEN、mTOR mRNA的表达水平及相互关系;Western印迹法检测甲磺酸伊马替尼干预和以腺病毒为载体感染野生型PTEN(Ad-PTEN-GFP)后K562细胞PTEN、Akt和p-Akt的蛋白表达水平;用MTT和FCM方法检测RAPA对不同腺病毒感染组K562细胞增殖及凋亡的影响。结果:格列卫干预K562细胞后,BCR/ABL和mTOR mRNA表达下调,PTEN mRNA表达上调;与感染Ad-GFP组相比,感染Ad-PTEN-GFP组的mTOR mRNA表达下调;Ad-PTEN-GFP感染与10nmol/L RAPA联合作用于K562细胞能够发挥协同作用,对K562细胞的增殖抑制率明显高于单独作用组。结论:PTEN是mTOR的上游调控基因,能够抑制mTOR的表达。RAPA与野生型PTEN一起可以协同抑制K562细胞的增殖。

PTEN和mTOR信号转导通路在胆管癌发展中作用的研究

目的研究PI3K/PTEN/AKT/mTOR信号转导通路中mTOR和PTEN蛋白在胆管癌中的表达及其在胆管癌发生、发展中的作用。方法用免疫组织化学方法和RT-PCR法,检测胆管癌中mTOR和PTEN的表达。结果与正常组织相比,免疫组化法和RT-PCR两种方法结果均显示,胆管癌中的mTOR表达明显增加,而PTEN的表达明显下降;两者呈负相关(r=-0.8 6 2,P<0.0 1)。结论PI3K/PTEN/AKT/mTOR信号转导通路中重要的调节位点和节点PTEN在胆管癌中的表达明显降低,而mTOR的表达明显增高。提示该信号转导通路在介导胆管癌的发生、发展的过程中起重要作用。

mTOR和PTEN在非小细胞肺癌组织中的表达及临床意义

背景与目的mTOR是调节细胞生长和增殖的重要信号转导分子,也是一种蛋白激酶。它通过活化下游的相关的效应蛋白发挥作用。在信号转导通路中PTEN基因可通过对该信号途径的负调控而抑制mTOR的活化。本研究通过分析mTOR信号转导途径中mTOR和PTEN基因在非小细胞肺癌(non-small cell lung cancer,NSCLC)组织中的表达和临床意义。方法外科手术中获取65例NSCLC组织及30例癌旁组织,RT-PCR技术检测NSCLC组织及癌旁组织中mTOR和PTEN基因的表达水平。结果mTOR在NSCLC组织中表达量(0.23±0.16)显著高于癌旁组(0.12±0.09)(P<0.01),PTEN在NSCLC组织中表达量(0.19±0.28)显著低于癌旁组(0.53±0.28)(P<0.01)。mTOR和PTEN与病人的性别、年龄、病理类型、淋巴结转移情况无关,与病人的肿瘤大小有关。结论mTOR在NSCLC中被激活,PTEN在NSCLC组织表达缺失或减少,mTOR通路的激活和PTEN表达缺失在NSCLC发生发展中起到一定的作用。