EFFECT OF INTERLEUKIN-1β ON GROWTH HORMONE GENE EXPRESSION AND ITS POSSIBLE MOLECULAR MECHANISM IN RAT MtT/S SOMATOTROPH CELLS

Objective To elucidate the effect of interleukin-1β (IL-1β) on human growth hormone (hGH) gene expression in a rat somatotropic pituitary cell line MtT/S. Methods Stably transfected MtT/S cells were firstly established by transfecting 484-Luc1 plasmid which contained hGH gene promoter -484 to 30 bp and luciferase reporter gene. The effect of IL-1β on hGH gene expression was determined by assaying the luciferase activities. RT-PCR method was also used to determine whether IL-1 recepor mRNA was expressed in MtT/S cells. Results The 103 U/mL IL-1β stimulated secretion and synthesis of GH, and promoted the 5’-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.38 times above the control. Among inhibitors of signaling transduction pathways, mitogen-activated protein kinase kinase (MAPKK/MEK) inhibitor PD98059 (40 μmol/L) and p38 mitogen-activated protein kinase (MAPK) inhibitor SB203580 (5 μmol/L) completely blocked the stimulatory effect of IL-1β, and phosphatidylinositol-3-kinase (PI3-K) inhibitor LY294002 partly abolished the effect of IL-1β. Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells. Neither over-expression of Pit-1 nor inhibition of Pit-1 expression affected induction of hGH promoter activity by IL-1β. A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-1β, and results showed that the stimulatory effect of IL-1β was abolished following deletion of the -196 to -132 bp fragment. Conclusions IL-1β promotes GH secretion and synthesis in rat MtT/S somatotroph cells. The stimulatory effect of IL-1β on hGH gene promoter appears to require the activation of MEK, p38 MAPK, PI3-K, and a fragment of promoter sequence that spans the –196 to –132 bp of the gene, but it may be unlinked with Pit-1 protein.     

MEK AND p38 MAPK-DEPENDANT PATHWAYS ARE INVOLOVED IN THE POSITIVE EFFECT OF INTERLEUKIN-6 ON HUMAN GROWTH HORMONE GENE EXPRESSION IN RAT MtT/S SOMATOTROPH CELLS

Objective To investigate the effect of interleukin-6（IL-6） on the human growth hormone （hGH） gene expression in a rat somatotropic pituitary cell line MtT/S. Methods The plasmids containing various lengths of hGH gene 5＇-promoter fragments were constructed. Stably transfected MtT/S cells were created by cotransfecting the above plasmids and pcDNA3.1 （＋） with DMRIE-C transfection reagent. After the administration of these cells with IL-6 and/or various inhibitors of signaling transduction path-ways, the luciferase activities in MtT/S cells lysis were assayed to demonstrate the effects of IL-6 on hGH gene promoter activity and possibly involved mechanism. Results The 10^3U/mL IL-6 stimulated GH secretion and synthesis, and promoted the 5＇-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.69 times above the control. Among inhibitors of signaling transduction pathways, mitogen-activated protein kinase kinase （MAPKK/MEK） inhibitor PD98059 （40μmol/L） and p38 mitogen-activated protein kinase （MAPK） inhibitor SB203580 （5μmol/L） completely blocked the stimulatory effect of IL-6. Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells. Neither over-expression of Pit-1 nor inhibition of Pit-1 expression affected IL-6 induction of hGH promoter activity. A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-6. The results showed that the stimulatory effect of IL-6 was abolished following deletion of the - 196 to - 132 bp fragment. Conclusions IL-6 promotes GH secretion and synthesis by rat MtT/S somatotroph cells. The stimulatory effect of IL-6 on hGH gene promoter appears to require the activation of MEK and p38 MAPK, and a fragment of promoter se- quence that spans the - 196 to - 132 bp of the gene, but may be unlinked with Pit-1 protein.     

EFFECT OF INTERLEUKIN-1β ON GROWTH HORMONE GENE EXPRESSION AND ITS POSSIBLE MOLECULAR MECHANISM IN RAT MtT/S SOMATOTROPH CELLS

Objective To elucidate the effect of interleukin-1β （IL- 1β） on human growth hormone （hGH） gene expression in a rat somatotropic pituitary cell line MtT/S.
Methods Stably transfected MtT/S cells were firstly established by transfecting 484-Lucl plasmid which contained hGH gene promoter --484 to ＋30 bp and luciferase reporter gene. The effect of IL-1β on hGH gene expression was determined by assaying the luciferase activities. RT-PCR method was also used to determine whether IL-1 recepor mRNA was expressed in MtT/S cells.
Results The 10^3 U/mL IL-1β stimulated secretion and synthesis of GH, and promoted the 5＇-promoter activity of GH gene in stably transfected MtT/SGL cells with the action of 1.38 times above the control. Among inhibitors of signaling transduction pathways, mitogen-activated protein kinase kinase （MAPKK/MEK） inhibitor PD98059 （40 μmol/L） and p38 mitogen-activated protein kinase （MAPK） inhibitor SB203580 （5 μmol/L） completely blocked the stimulatory effect of IL-1μ, and phosphatidylinositol-3-kinase （PI3-K） inhibitor LY294002 partly abolished the effect of IL-1μ. Western blot analysis further confirmed the activation of phosphorylated MEK and p38 MAPK in MtT/SGL cells. Neither over-expression of Pit- 1 nor inhibition of Pit- 1 expression affected induction of hGH promoter activity by IL-1μ. A series of deletion constructs of hGH promoter were created to identify the DNA sequence that mediated the effect of IL-1β, and results showed that the stimulatory effect of IL-1β was abolished following deletion of the --196 to -- 132 bp fragment.
Conclusions IL-1β promotes GH secretion and synthesis in rat MtT/S somatotroph cells. The stimulatory effect of IL-1β on hGH gene promoter appears to require the activation of MEK, p38 MAPK, PI3-K, and a fragment of promoter sequence that spans the -196 to -132 bp of the gene, but it may be unlinked with Pit-1 protein.     

Effect of IFN-γ, IL-4 on proliferation and synthesis of hyaluronic acid and collagen in cultured human retroorbital fibroblasts in vitro

Objective To investigate the cellular immune mechanism of thyroid associated ophthalmopathy (TAO) and provide a basis for treating TAO with cytokine or anti-cytokine agents, we determined whether interferon (IFN)-γ and interleukin (IL)-4, representative cytokines of Th1 and Th2 cells, may have some effect on the development and progression of TAO.Method Retroorbital fibroblasts (RF) proliferation and the synthesis of hyaluronic acid (HA) and type Ⅳ collagen were measured with liquid scintillation and radioimmunoassay. Results IFN-γ stimulated RF proliferation and HA synthesis and had a significant inhibitory effect on type Ⅳ collagen synthesis. IL-4 stimulated proliferation and type Ⅳ collagen synthesis in RF and had inhibitory effect on HA synthesis. When IFN-γ (100U/ml) and IL-4 (1μg/L) were incubated together with RF, they antagonized their respective stimulatory or inhibitory effect on the proliferation and synthesis of HA and type Ⅳ collagen. Thyrotropin (TSH) stimulated RF proliferation and type Ⅳ collagen synthesis in a dose-dependent manner, while only at high dose (100U/L and 200U/L), stimulated RF to synthesize HA. Conclusions IFN-γ, a representative cytokine of Th1 cells, is responsible for the inflammatory process of TAO; whereas IL-4, a representative cytokine of Th2 cells, has some effect on the repair process. IL-4 could antagonize the inflammatory effect of IFN-γ on RF. TSH may have aggravating effect on the pathogenesis of TAO.     

Effect of vasoactive intestinal peptide on proliferation of hepatoma cells

It has been found that vasoactive intestinal peptide (VIP) stimulates the growth ofseveral kinds of tumor cells.There is no report so far about the effect of VIP on the growth ofhepatoma cells.Using the tetrazolium colorimetric assay (MTT assay) and cell countingmethod,it was investigated that the effect of VIP on the growth of a cultured rat hepatomaFSK-7902 cells.The results showed that VIP stimulated the proliferation of the rat hepatomacells obviously.The addition of 1μmol/L VIP caused a significant increase in the number of thecultured rat hepatoma cells on 3rd day and maximal increase occured on 4th day and 5th day ( P<0.01).The growth promoting effect was greater as the concentration of VIP increased.Thelowest effective concentration of VIP was 0.5μmol/L.Exposure to VIP for 12 h followed by re-moval of the peptide resulted in sustained growth for several days.     

Anticancer Activities of Trichostatin A on Maligant Lymphoid Cells

The anticancer activity of trichostain A (TSA) on human B cell non-Hodgkin's lymphoma and its mechanism were explored. The effect of TSA on the growth of Raji cells and normal peripheral blood mononuclear cells (NPBMNC) was studied by MTT assay. The effect of TSA on the apoptosis of Raji cells and NPBMNC was studied by flow cytometry and TDT-mediated dUTP nick end labeling (TUNEL). The effect of TSA on the cell cycle of Raji cells was studied by propidium iodide method. The results showed that TSA potently inhibited proliferation of Raji cells at microgram concentrations and induced apoptosis of Raji cells in a time- and concentration-dependent manner. Treatment with TSA induced accumulation of cells in G0/G1 or G2/M and a concomitant decrease of cell population in S phase. However, NPBMNC was less sensitive to the cytotoxic effect of TSA than Raji cells. It was concluded that TSA may inhibit the proliferation of Raji cells by regulating the cell cycle and inducing the cell apoptosis. Moreover, TSA demonstrates low toxicity in NPBMNC but selectively induces apoptosis of Raji cells.     

Phosphorylated extracellular signal-regulated kinase up-regulated p53 expression in shikonin-induced HeLa cell apoptosis

Background The role of extracellular signal-regulated kinase 1/2 (ERK1/2) in shikonin-induced HeLa cells apoptosis remains vague. This study was to investigate the activation of caspase pathways and the role of ERK1/2 in human cervical cancer cells, HeLa, by shikonin. Methods The inhibitory effect of shikonin on the growth of HeLa cells was measured by MTr assay. Fluorescent microscopic analysis of apoptotic cells stained with 4‘ , 6‘-oliiamiclino-2-phenylindole C (DAPI) and Hoechst 33258 was carried out. Caspase-3 and -8 activities were detected using caspase-3 substrate and caspase-8 substrate as substrates, respectively. The protein levels of ERK, p53 and p-ERK were determined by Western blot analysis. Results Shikonin inhibited cell growth in a time- and dose-dependent manner. Caspase-3 and caspase-8 were activated in the apoptotic process and caspase inhibitors effectively reversed shikonin-induced apoptosis. Phosphorylation of ERK resulted in up-regulation of p53 expression, which was blocked by mitogen-activated protein kinase (MEK) , inhibitor PD 98059. Conclusion Shikonin induces HeLa cell apoptosis through the ERK, p53 and caspase pathways.     

THE AUTOCRINE REGULATORY EFFECT OF VASOACTIVE INTESTINAL PEPTIDE ON THE GROWTH OF HUMAN PANCREATIC CARCINOMA CELLS

In the present study, the effets of VIP on the growth of two human pancreatic carcinoma cell lines PU-PAH-1 and PANC-1 were determined using tritiated thymidine incorporation, VIP receptors, intracellular cAMP and polyamings were investlsa.ted, The results indicated that VIP at a concentcation of 10^-8mol/L to 10^-7 mol/L can significantly Stimulate the growth of PU-PAN-1 cells but not PANC-1 cells, This effect is dose-dependent and abolished by VIP receptor antagonist, [4-CI-Phe^6 , Leu^7] VIP, suggesting VIP receptors in PU-PAN-1 cells maymediate this effect. VIP can markedly elevate the levels of intracellular cAMP and polyammes in PU-PAN-1 cells,indicating that the growth-promoting effect stimulated by VIP may be via a rapid increase in the biosynth~es of cAMP and polyamines. In addition, the VIP-antibody ir2Libited the growth of PU-PAN-1 cells in serum-free culture medium. The results above suggested that VIP has an autoctine regulatory effect on this pancreatic carcinoma cell line(PU-PAN-1).     

Growth Inhibition and Apoptosis Induced by Retinoic Acid Combined with Interferon Alpha-2a on Transitional Cell Carcinoma of Bladder

To identify new favorable agents and develop novel approaches for the chemoprevention and treatment of superficial bladder cancer and invesligate the effects of combination of relinoids and interferon α-2a on growth inhibition and apoptosis induction in bladder cancer cell lines. Methods: Four bladder cancer cell lines, grade 1 to 3,and two retinoids, all-trans-retinoic acid(ATRA) ,9.cis retinoic acid(9cRA) ,combined with inteferon α-2a(INF),were used in the study.We compared the competence of these agents to inhibit growth, induce apoptosis, affect the exptession of nuclear retinoid receptors, and modulate STAT1 protein. Resu/ts: Most of the bladder cancer cell lines were resistant to the effect of ATRA and 9cRA on growth inhibition and apoptosis induction, even at higher concentration (10^-5M).The effects of ATRA and 9c RA on cell growth and apoptosis were enhanced by INF α-2a.Combination of ATRA and IFNa-2a induced ~ and Slat 1 expression in three bladder cancer cell lines, ~: The results demonstrated that INFw2a synergize with the inhibitory effect of ATRA and 9c RA on the growth intn‘bition and apoptosis of bladder cancer cells in vitro, which suggested that it has a potenlJal intexest for the trealment of transitimml cell carcinmna of bladder.     

Chrysanthemum indicum linné extracts attenuate the mitogenic effect of epinephrine on human HCC cells

Objective

To investigate the stimulatory effect of epinephrine(Epi) and the antagonistic effect of Chrysanthemum indicum Linné extracts (CILE) on Epi-induced growth of human hepatocellular carcinoma(HCC) cells.

Methods

The stimulatory effect of Epi and inhibitory effect of CILE on the growth of HepG2 and MHCC97H cells were investigated using a proliferation assay in correlation with β adrenergic receptor(β2-AR) blockade, a MEK1/MEK2 inhibitor, and assessment of MAPK/ERK½ intracellular activity.

Results

Epi transiently activated MAPK/ERK½ in HepG2 and MHCC97H cells, resulting in a burst of growth. The effect of Epi was significantly attenuated by ICI 118551 and U0126. CILE exhibited a dose-dependent attenuation of the stimulatory effect of Epi on the growth of both cell lines and inhibited the Epi-induced activation of MAPK/ERK½.

Conclusion

Epi, mimicking a mitogen, stimulated the growth of HepG2 and MHCC97H cells, and CILE was effective in attenuating this effect of Epi on tumor cells by inhibiting the β2-AR-mediated activation of MAPK/ERK½.     

MEK1表达载体的构建及其对肝癌细胞ERK通路活性的影响

目的构建pcDNA3.1（＋）-MEK1真核表达载体,体外转染人肝癌MHCC97H细胞,观察MEK1在肝癌细胞中的表达及其对ERK通路活性的影响。方法应用RT-PCR扩增出MEK1基因插入pcDNA3.1（＋）中,形成重组载体pcDNA3.1（＋）-MEK1。经测序确认后,利用LipofectamineTM 2000将重组载体转染MHCC97H肝癌细胞,使用含G418的培养基进行筛选;将肝癌细胞分为不转染组、转染空载体组和转染重组载体组,运用Western-blot方法检测MEK1、p-MEK1、ERK1／2、p-ERK1／2在各组细胞中的表达并绘制各组细胞的生长曲线对比其增殖能力。结果重组载体pcDNA3.1（＋）-MEK1酶切鉴定电泳奈带大小正确,测序结果经Blast比对与人MEK1基因开放性读码框100％吻合;重组载体载体转染肝癌细胞后MEK1表达水平较不转染及转染空载体载体组细胞显著升高,且磷酸化的MEK1及ERK1／2水平也明显升高,转染重组载体载体的肝癌细胞增殖能力得到显著增强。结论成功构建了真核表达载体pcDNA3.1（＋）-MEK1,过表达MEK1蛋白可提高肝癌细胞MAPK／ERK通路活性。     

shRNA干扰基膜聚糖调控肝癌细胞侵袭和迁移能力的实验研究

目的 本研究旨在探索沉默基膜聚糖(lumican)对肝癌细胞侵袭和迁移的影响及其分子机制。方法 通过shRNA沉默肝癌细胞HepG2和MHCC97H中的lumican。通过实时定量PCR（qRT-PCR)检测细胞中lumican的mRNA水平,Transwell检测细胞侵袭,划痕实验分析细胞迁移。蛋白印记检测lumican、MMP-9、VEGF、ERK1、JNK、p-ERK1和p-JNK蛋白水平。结果 肝癌细胞HepG2和MHCC97H中lumican的mRNA水平和蛋白质水平高于正常肝细胞L02 (P<0.01)。HepG2和MHCC97H细胞中lumican shRNA组mRNA水平和蛋白质水平低于对照组(P<0.01)。与scramble组相比,HepG2和MHCC97H细胞中lumican shRNA组细胞侵袭和迁移显著降低(P<0.01)。HepG2和MHCC97H细胞中lumican shRNA组MMP-9和VEGF表达低于scramble组(P<0.01)。与scramble组相比,HepG2和MHCC97H细胞中lumican shRNA组p-ERK1和p-JNK蛋白水平下降(P<0.01)。结论 shRNA干扰lumican通过抑制ERK1/JNK通路激活减弱肝癌细胞侵袭和迁移。     

SATB1在不同侵袭潜能肝癌细胞株的表达

目的研究SATB1在不同侵袭潜能的人肝癌细胞株表达状况。方法分别用荧光定量PCR,RT-PCR,Western blotting及免疫荧光方法,检测人永生化肝细胞株HL-7702及肝癌细胞株HepG2、SMMC-7721、MHCC97L、MHCC97H、HCCLM3中SATB1的表达。结果相对于HL-7702,SATB1 mRNA在其余5种肝癌细胞株中都有较高程度的表达,其中高侵袭性HCCLM3、MHCC97H表达最高,MHCC97L次之,SMMC-7721、HepG2最低(P<0.001);Western blotting分析HepG2、SMMC-7721、MHCC97L、MHCC97H、HCCLM3肝癌细胞株的蛋白相对表达量分别为0.271±0.002;0.351±0.023;0.621±0.026;0.878±0.026;1.236±0.006,高侵袭性HCCLM3相当于HepG2的4.6倍(P<0.001);免疫荧光显示SATB1在5种肝癌细胞株的胞浆和胞核内均有分布,高侵袭性细胞株HCCLM3、MHCC97H表现强阳性染色。结论 SATB1在不同侵袭潜能肝癌细胞株中的表达有差异,与肝癌转移密切相关。     

雷帕霉素抑制肝癌细胞生长及转移的实验研究

目的探讨具有抗肿瘤特性的新型免疫抑制剂雷帕霉素(RPM)对肝癌细胞生长及转移的作用。方法应用流式细胞仪检测RPM(10 ng/m l)、环孢素(CsA)(100 ng/m l)、以及两者合用对人肝癌高转移细胞株MHCC97H细胞凋亡及细胞周期的影响;应用MTT法检测上述药物对细胞增殖的影响。用实时定量聚合酶链反应(PCR)法检测RPM处理后血管内皮细胞生长因子(VEGF)mRNA、碱性成纤维细胞生长因子(bFGF)mRNA、缺氧诱导因子-1α(H IF-1α)mRNA、转化生长因子b(TGFb)的表达。ELISA法检测MHCC97H培养液上清VEGF蛋白水平的变化。28只原位种植高转移性人肝癌模型LC I-D20裸鼠,随机分为CsA(25 mg/kg)组、RPM(2 mg/kg)组、CsA+RPM组及对照组(生理盐水),每组7只;探讨免疫抑制剂对肿瘤生长及自发肺转移的影响。结果体外实验中,RPM抑制了MHCC97H细胞的增殖,并使细胞停滞于G0/G1期,但未促进细胞凋亡。RPM下调了H IF-1α和VEGF的基因表达及MHCC97H培养液上清VEGF蛋白的表达(890.3 pg/m l±25.1 pg/m lvs 1583.7 pg/m l±17.3 pg/m l,P=0.000)。CsA对细胞周期及增殖无影响。体内实验中,RPM及CsA+RPM抑制了LC I-D20模型移植瘤的生长(0.76 g±0.38 g vs 2.09 g±0.75 g,P=0.001;0.40 g±0.22 g vs 2.09 g±0.75 g,P=0.000)及肺部转移的发生(均为2/7 vs 7/7,P=0.021)。CsA组肺部自发转移灶的数目多于对照组(6±2 vs 4±1,P=0.046)。结论RPM能明显抑制肝癌细胞的生长及转移,以RPM为基础的免疫抑制方案在肝癌肝移植中可能有临床应用前景。     

蛇毒半胱氨酸蛋白酶抑制剂重组腺病毒对人肝癌细胞MHCC97H侵袭转移的影响

目的 构建携带蛇毒半胱氨酸蛋白酶抑制剂（sv-cystatin）基因的重组腺病毒载体（Ad/sv-cystatin）,研究其对人肝癌细胞MHCC97H在体内、外侵袭转移的影响。 方法 构建携带sv-cystatin的重组腺病毒,体外感染MHCC97H细胞,采用CCK-8法检测细胞生长,Transwell小室检测细胞侵袭和迁移能力,通过裸鼠皮下肝癌细胞肺转移模型观察Ad/sv-cystatin瘤内注射对裸鼠的治疗作用。 结果 体外实验证实Ad/sv-cystatin能够感染MHCC97H细胞。与对照组及空载体组相比,Ad/sv-cystatin对MHCC97H细胞体外生长、侵袭和迁移均具有明显的抑制作用,瘤内注射Ad/sv-cystatin可以显著降低MHCC97H细胞的肺转移。 结论 重组腺病毒Ad/sv-cystatin具有抑制人肝癌细胞MHCC97H体内外侵袭转移的作用,在肝癌基因治疗方面具有开发应用潜能。     

慢病毒载体介导siRNA沉默Id-1通过ERK1/2信号通路抑制裸鼠人肝癌移植瘤生长

目的 构建慢病毒表达载体介导siRNA沉默Id-1,观察其对人肝癌HepG2细胞裸鼠皮下移植瘤生长的抑制作用及其对ERK1/2信号通路的影响。 方法 构建合成特异性针对Id-1基因的siRNA慢病毒载体,转染肝癌HepG2细胞系,经半定量RT-PCR鉴定筛选沉默效果最佳的细胞系,于倒置荧光显微镜(×400)下观察转染前后细胞的形态学变化。取细胞浓度为5×10⁶ mL^-1的干扰效率最佳的稳定转染细胞系、稳定转染空载体病毒细胞系及正常HepG2细胞系悬液各0.2 mL,分别注射到转染实验组、阴性对照组及空白对照组的裸鼠右腋皮下,每周测量肿瘤体积及裸鼠体质量,绘制肿瘤生长曲线,28 d后处死裸鼠,制作肿瘤组织标本,行常规病理检查,采用半定量RT-PCR及Western-blot方法检测肿瘤组织Id-1,ERK1/2的mRNA和蛋白的表达水平及p-ERK1/2的蛋白表达水平。 结果 倒置荧光显微镜显示,转染前后细胞形态学变化不明显。经半定量RT-PCR筛选出Id-1基因的siRNA慢病毒载体的最佳细胞系为sh31,与稳定转染空载体病毒细胞系相比,目的基因Id-1的表达降低了80%以上,与未干扰的HepG2细胞相比降低了60%; 转染细胞皮下接种后,转染组最终瘤体大小明显小于阴性对照组和空白对照组(P<0.05)。半定量RT-PCR显示,转染组肿瘤组织的Id-1及ERK1/2 mRNA分别为(0.389±0.058)及(0.475±0.079),均明显低于阴性对照组[(0.845±0.113),(0.977±0.082)]和空白对照组[(0.917±0.083),(0.978±0.056)](均为P<0.05)。Western-blot检测显示,转染组的Id-1及p-ERK1/2蛋白均明显低于阴性对照组和空白对照组(P<0.05)。 结论 Id-1基因特异性siRNA的慢病毒表达载体通过靶向抑制Id-1的表达,明显抑制人肝癌细胞HepG2裸鼠皮下移植瘤的生长,推测Id-1可能通过调节ERK1/2 MAPK信号通路参与肝癌的发生发展。     

体外RNA干扰下调ezrin表达对肝癌细胞生长和运动能力的影响

目的探讨膜-细胞骨架联接蛋白ezrin对肝癌生长和运动转移能力的影响。方法选取4株肝癌细胞系(SF/SMMC7721、MHCC97-H、MHCC-1和HepG2)作为研究材料,针对ezrin基因设计小干扰RNA(siRNA)并通过脂质体转染入细胞。分别通过荧光实时定量聚合酶链反应(PCR)和Western印迹验证siRNA对ezrin在基因和蛋白水平的下调及下调作用随转染时间的变化。根据Western印迹的结果选取ezrin蛋白表达最低的时间点检测干扰后肝癌细胞生物学行为的改变。运用四甲基偶氮唑蓝(MTT)法检测肝癌细胞增殖能力的变化;流式细胞仪检测细胞周期;电子显微镜观察细胞伪足的形态和数量改变;transwell实验检测肝癌细胞运动和转移能力的变化。结果荧光实时定量PCR和Western印迹显示ezrin siRNA对ezrin在基因和蛋白水平均有显著的下调作用。下调ezrin蛋白可显著减慢4株肝癌细胞的生长速度,处于分裂期的肝癌细胞比例明显下降(SF/SMMC7721:28·07%下降到21·53%;MHCC97-H:24·94%下降到13·92%;MHCC-1:19·30%下降到13·2%;HepG2:7·73%下降到4·24%)。肿瘤细胞的运动侵袭能力下降,细胞伪足变短,且伪足的形成数量显著减少(SF/SMMC7721:20·8个/细胞±3·0个/细胞与13·2个/细胞±2·4个/细胞,P<0·05;MHCC97-H:18·4个/细胞±2·7个/细胞与14·0个/细胞±2·9个/细胞,P<0·01;MHCC-1:22·6个/细胞±3·5个/细胞与13·3个/细胞±1·9个/细胞,P<0·01;HepG2:31·0个/细胞±2·9个/细胞与17·8个/细胞±2·3个/细胞,P<0·01;每株计数5个细胞)。穿过人工基底膜的细胞数量也明显减少(SF/SMMC7721:49·9个±7·7个与31·9±5·2个,P<0·05;MHCC97-H:58·5个±4·2个与33·0个±3·3个,P<0·01;MHCC-1:57·6个±6·1个与28·3个±3·4个,P<0·01;HepG2:37·3个±3·0个与25·3个±2·3个,P<0·01;每株8个视野)。结论ezrin在肝癌生长和侵袭转移过程中发挥重要的作用,有可能成为抑制肝癌复发转移的关键分子。     

趋化因子受体CXCR7在人肝癌细胞株中的表达及意义

目的探讨趋化因子受体(Chemokine receptor,CXCR7)在不同肝癌细胞株中的相对表达强度及意义。方法采用RT-PCR、Western blot法,检测8株不同转移潜能肝癌细胞中趋化因子受体CXCR7在mRNA及蛋白水平的表达情况。结果 CXCR7在8株肝癌细胞中的表达水平差异存在统计学意义,无论是mRNA水平还是蛋白水平,高转移潜能肝癌细胞株(MHCC97-L、MHCC97-H、HCCLM3)CXCR7的表达明显高于普通转移潜能肝癌细胞株(HepG2、PLC/PRF/5、SMMC-7721、BEL-7402、Hep3B),P<0.01。结论 CXCR7与肝癌的发生、发展及预后有一定的相关性。