二吲哚吡啶基噻唑烷对肺癌A549细胞增殖的影响

目的:探讨二吲哚吡啶基噻唑烷(DIIT)对肺癌A549细胞增殖的影响。方法:通过CCK-8法测定DIIT对肺癌A549细胞活力的影响;EdU/DAPI双染法观察细胞增殖情况;Western blot法检测DIIT对Akt和mTOR磷酸化及细胞周期蛋白依赖性激酶4(CDK4)及细胞周期蛋白D1(cyclin D1)表达水平的影响。结果:与DMSO对照组相比,用浓度为12.5、25、50和100 mg/L的DIIT处理A549细胞后,细胞的增殖情况分别下降12%、27%(P0.01)、33%(P0.01)及52%(P0.01);EdU阳性细胞相对数比DMSO对照组分别降低10%、21%(P0.05)、26%(P0.05)及34%(P0.01)。与DMSO对照组相比,DIIT可以抑制Akt及mTOR的磷酸化水平,抑制细胞周期蛋白CDK4及cyclin D1的表达水平(P0.01)。结论:二吲哚吡啶基噻唑烷抑制A549细胞增殖,其作用机制可能与Akt及mTOR的磷酸化水平下降及细胞周期蛋白表达受到抑制有关。     

氯喹对人肺癌A549细胞周期阻滞及增殖抑制的机制

目的 探讨氯喹抑制人非小细胞肺癌A549细胞增殖、促进凋亡、阻滞细胞周期的作用及其分子机制。 方法 应用MTT法和流式细胞术分别检测氯喹对A549细胞增殖、细胞凋亡和细胞周期的影响;Western blotting检测氯喹对A549细胞周期蛋白(cyclin E1)和细胞周期蛋白依赖性激酶（CDK2）、肿瘤抑制蛋白PTEN以及细胞周期抑制蛋白P21、P27表达水平的影响。 结果 氯喹能够抑制A549细胞增殖,并且具有时间-剂量依赖性。氯喹可以诱导细胞凋亡,不同浓度的氯喹作用于A549细胞24h后,细胞凋亡率随着作用剂量的增加而升高。进一步的研究发现,氯喹还能够阻滞细胞周期于G₀/G₁期,降低cyclinE1和CDK2表达水平,明显提高PTEN、P21和P27的表达水平。 结论 氯喹具有抑制肺癌细胞增殖、促进其凋亡和阻滞细胞周期的作用,其机制可能与其抑制CyclinE1和CDK2表达,并且上调PTEN、P21和P27蛋白的表达有关。     

小分子化合物P-275抑制胃癌细胞增殖及机制研究

目的研究小分子化合物P-275对人胃癌细胞BGC823、SGC7901、MKN-45增殖的抑制作用及其机制。方法分别用不同浓度的化合物P-275处理人胃癌细胞BGC823、SGC7901和MKN-45,MTT法检测化合物对细胞增殖的影响,流式细胞术检测化合物对细胞周期的影响,Western Blot检测化合物对周期调控蛋白Cyclin D1、CDK4表达的影响。结果化合物P-275能够以剂量依赖的方式抑制人胃癌细胞BGC823、SGC7901及MKN-45的增殖,同时能够抑制上述细胞G1期向S期的转化。Western Blot结果显示P-275能够以剂量依赖的方式下调胃癌细胞SGC7901中周期调控蛋白Cyclin D1、CDK4的表达。结论化合物P-275能够通过下调胃癌细胞中周期调控蛋白Cyclin D1、CDK4的表达,从而抑制胃癌细胞G1期向S期的转化,进而抑制胃癌细胞的增殖。     

D类细胞周期素在细胞周期中的作用

细胞周期进程由周期性表达的细胞周期素和细胞周期素依赖性激酶推动完成。 Cyclin D在 G1 期中期开始表达 ,是最早合成的细胞周期素 ,它与 Cdk4或 Cdk6形成的活性复合物 ,不仅可促进 p Rb的磷酸化 ,也可隔离P2 7对 cyclin E- Cdk2活性的抑制 ,使细胞顺利越过 G1 期进入 S期。除此之外 ,cyclin D过度表达还可抑制细胞增殖 ,在细胞分化和衰老过程中发挥重要作用     

K-ras反义核酸抑制肺腺癌细胞A549的生长

目的: 探讨K-ras反义核酸抑制肺癌生长的机制。方法: 应用Western blotting检测K-ras基因在6例肺腺癌标本和A549细胞中的表达;构建K-ras基因的反义表达载体(命名为antisense-K-ras-pcDNA3.1),转染后,MTT法测细胞的生长曲线,Annexin V检测细胞凋亡;Western blotting检测cyclin A、cyclinD1、cyclinE、CDK2、CDK4、P53、Rb和caspase-3的表达。结果: 在A549细胞和6例肺腺癌标本中,A549细胞和4例标本中K-ras基因高表达;MTT结果显示从第4 d开始,转染K-ras反义核酸的细胞生长明显受到抑制,而且细胞凋亡现象较明显;Western blotting显示转染反义K-ras基因的细胞中cyclin A、cyclin D1、cyclin E、CDK2和CDK4的表达降低,而caspase-3、P53和Rb的表达升高。结论: K-ras基因反义核酸能够抑制细胞生长,可能与cyclin A、cyclin D1、cyclin E、CDK2和CDK4的表达降低和caspase-3、P53、Rb的表达升高有关。     

应用丙戊酸钠调节组蛋白乙酰化对肿瘤细胞周期相关蛋白的调控作用

目的 探讨应用组蛋白脱乙酰酶抑制剂丙戊酸钠(VPA)调节染色体组蛋白低乙酰化修饰水平对肿瘤细胞增殖周期相关蛋白Cyclin A、Cyclin DI、Cyclin E和P21waf/cipl的调控作用. 方法 应用0.75～4.00 mmol/ VPA干预肝癌细胞HepG2、胃癌细胞BGC-823、乳腺癌细胞MCF-7 48 h后,PI标记流式细胞术检测细胞周期;间接免疫荧光法分析Cyclin A、Cyclin D1、Cyclin E、P21waf/cip1蛋白表达;RT-PCR检测分析Cyclin A、Cyclin D1、Cyclin E、P21waf/cip1 mRNA表达. 结果 HepG2、BGC-823、MCF-7这3种细胞系培养48 h后,流式细胞术分析可见0.75～4.00 mmol/L、VPA实验组随药物浓度的增加而出现逐渐递增的细胞增殖周期G1期阻滞趋势.HepG2、BGC-823细胞Cyclin A蛋白及mRNA表达被明显下调;MCF-7细胞Cyclin A蛋白及mRNA表达在两个浓度组均未见明显变化;Cyclin D1蛋白及mRNA表达在3个细胞系均被明显下调;P21waf/cip1蛋白及mRNA表达在3个细胞均被明显上调;Cyclin E蛋白及mRNA表达则未见明显变化. 结论 应用VPA干预组蛋白乙酰化修饰可对HepG2、BGC-823、MCF-7细胞Cyc-lin D1、P21waf/cip1表达起明显的调控作用;对Cychn A的调控作用则随肿瘤细胞来源及表型的不同而有所差异,而对Cyclin E则无明显的调控作用.在VPA诱导肿瘤细胞增殖周期G1期阻滞过程中,下调CyclinD1和上调P21waf/cip1蛋白及mRNA表达可能是其共同作用途径.     

Aβ25-35对PC12细胞周期及P21、CDK4、E2F1、BAX基因表达的影响

目的 观察β-淀粉样肽25-35（Aβ25-35）对体外血清饥饿培养PC12细胞周期及 P21、CDK4、E2F1和BAX基因表达的影响。方法 用终浓度为25?mol/L Aβ25-35诱导PC12细胞,流式细胞仪分析细胞周期的改变与凋亡的关系;RT-PCR 和Western blot检测P21、CDK4、E2F1和BAX基因mRNA和蛋白表达。结果 PC12细胞血清饥饿培养24h约90%停滞于G0/G1期;25?mol/L Aβ25-35诱导PC12细胞8、16和24h与对照组比较,S期细胞百分率增加(P<0.01),16h后细胞凋亡率增加(P<0.01),可见亚二倍体凋亡峰(Ap峰);25?mol/L Aβ25-35诱导PC12细胞0~20h, P21 mRNA和P21 蛋白的表达下降;CDK4、E2F1、BAX mRNA和CDK4、BAX蛋白表达增高。结论 Aβ25-35可诱导同步化于G0/G1的PC12细胞重新进入细胞周期并随之出现凋亡,其机制可能与下调P21 mRNA和P21蛋白的表达,增加CDK4、E2F1、BAX mRNA和CDK4、BAX蛋白的表达有关。     

luminal A型乳腺癌组织中长链非编码RNA ENST00000460164的表达及对细胞周期的影响

目的明确lncRNA-ENST00000460164在人luminal A型乳腺癌组织中的表达及作用。方法用RT-q PCR检测ENST00000460164在17例配对的luminal A型乳腺癌及癌旁组织中的表达。将pll3.7-ENST00000460164-shRNA及pll3.7空载体转染MCF-7细胞,用流式细胞计量技术和Western blot检测转染后MCF-7细胞周期及其关键蛋白cyclin D1和P16INK4A的表达。结果长链非编码RNA ENST00000460164在luminal A型乳腺癌组织中呈高表达趋势;在MCF-7细胞中敲低ENST0000460164后,G1期明显延长,S期明显缩短(P0.05);G1期关键调控蛋白cyclin D1表达水平明显降低,P16INK4A表达明显上调(P0.05)。结论 ENST00000460164在luminal A型乳腺癌组织中呈高表达状态;ENST00000460164可能通过调控cyclin D1或者P16INK4A的表达改变细胞周期。     

沉默ClC-3氯通道基因对HeLa细胞周期分布的影响

目的:探讨沉默HeLa细胞的ClC-3氯通道基因后细胞周期分布的变化及其作用机制。方法:依照siRNA设计原则构建沉默ClC-3基因的ClC-3 siRNA并转染HeLa细胞;实验分为空白对照组(control组)、转染试剂对照组(Lipo组)、阴性对照组(negative siRNA组)和ClC-3 siRNA组。采用real-time PCR检测ClC-3 siRNA的沉默效率;流式细胞术检测细胞周期分布情况;Western blot检测ClC-3蛋白及相关细胞周期蛋白(cyclin)D1、细胞周期蛋白依赖激酶(cyclin-dependent kinase,CDK)4、CDK6、P21和P27等表达。结果:CIC-3 siRNA成功沉默HeLa细胞的ClC-3基因。和其它组相比,ClC-3 siRNA组的细胞周期被阻抑在G_0/G_1期。CIC-3 siRNA组的cyclin D1、CDK4和CDK6蛋白表达水平明显下降,P21和P27蛋白表达水平明显上升。结论:沉默HeLa细胞ClC-3氯通道基因可影响cyclin D1、CDK4、CDK6、P21和27蛋白的表达水平胆抑HeLa细胞周期停滞在G_0/G_1期。     

STAT3siRNA对肺腺癌A549细胞STAT3表达和细胞生物学行为的影响

目的:观察经RNA干扰沉默STAT3基因对人肺腺癌细胞A549生长和凋亡的影响。方法:设计并经化学合成了针对STAT3基因不同位点的3条小干扰RNA(small interfering RNA,siRNA)序列(STAT3siRNA1、STAT3siRNA2、STAT3siRNA3),在脂质体(LipofectamineTM2000)介导下转染人肺腺癌细胞株A549,采用RT-PCR法检测STAT3mRNA表达变化,筛选出抑制作用最强的STAT3-siRNA。免疫印迹法检测细胞STAT3、Cyclin D1、BAX、Bcl-2、Caspase-9蛋白表达。AM-BLUE法测定A549细胞体外增殖情况。流式细胞仪检测细胞凋亡。结果:经RNA干扰能有效降低A549细胞STAT3mRNA表达水平(P0.05),转染STAT3siRNA后,A549细胞STAT3、Cyclin D1、Bcl-2蛋白的表达水平均显著降低(P0.05),而BAX、Caspase-9蛋白的表达水平升高(P0.05)。STAT3蛋白表达分别与CyclinD1、Bcl-2蛋白表达呈正相关(r=0.854,0.910,P0.05);与BAX蛋白表达呈负相关性(r=-0.848,P0.05);与Caspase-9蛋白表达呈无相关性(r=-0.787,P0.05)。RNA干扰法沉默STAT3基因表达后,A549细胞增殖受到明显抑制,细胞凋亡率明显增加。结论:STAT3siRNA可有效抑制A549细胞STAT3表达,抑制A549细胞生长并促进其凋亡。     

Silencing KLF16 inhibits oral squamous cell carcinoma cell proliferation by arresting the cell cycle and inducing apoptosis

Krüppel-like factor 16 (KLF16), a member of the Krüppel-like factor (KLF) family, has been extensively investigated in multiple cancer types. However, the role of KLF16 in oral squamous cell carcinoma (OSCC) remains unknown. Thus, we conducted this study to investigate its related mechanism. KLF16 expression in OSCC cell lines was quantified by western blotting. Then, OECM1 and OC3 cells were divided into Blank, siCtrl, siKLF16#1 and siKLF16#2 groups. Subsequently, cell proliferation was detected using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assays, cell migration and invasion were detected with wound healing and Transwell assays, and cell cycle distribution and cell apoptosis were detected via flow cytometry. KLF16, p21, CDK4, Cyclin D1 and p-Rb expression was detected by western blotting. Finally, xenograft models were established in nude mice to observe the in vivo effects of KLF16 on OSCC. KLF16 protein expression was upregulated in OSCC cells. Compared to the cells in the Blank group, the OECM1 and OC3 cells in the siKLF16#1 group and siKLF16#2 group exhibited a sharp decrease in proliferation but a remarkable increase in apoptosis. Moreover, the proportion of cells in the G0/G1 phase notably increased and that in the S phase decreased, with evident decreases in cell invasion and migration. Moreover, KLF16, cyclin-dependent kinase 4 (CDK4), Cyclin D1 and p-Rb protein expression was upregulated, but p21 expression was downregulated. The mice in the siKLF16#1 and siKLF16#2 xenograft model groups exhibited slower tumour growth and smaller tumours with evident downregulation of Ki67 expression compared to the mice in the Blank group. KLF16 expression was upregulated in OSCC cells, and interfering with KLF16 led to cell cycle arrest, inhibited OSCC cell growth and promoted cell apoptosis.     

小分子化合物H-131抑制胃癌细胞增殖及机制

目的研究小分子化合物H-131对人胃癌细胞SGC7901、BGC823、MKN-45增殖的抑制作用及其相关机制。方法应用不同浓度的化合物H-131处理人胃癌细胞SGC7901、BGC823和MKN-45,采用MTT法检测该化合物对细胞增殖的影响,流式细胞术检测其对细胞周期的影响,Westernblot检测化合物对周期调控蛋白CyclinD1和CDK4表达的影响。结果化合物H-131能够以剂量依赖的方式抑制人胃癌细胞SGC7901、BGC823及MKN-45的增殖,并且能够抑制上述细胞G_1期向S期的转化。Westernblot结果显示H-131能够以剂量依赖的方式下调胃癌细胞SGC7901中CyclinD1和CDK4的蛋白表达水平。结论化合物H-131能够通过下调胃癌细胞中CyclinD1和CDK4的表达水平,抑制胃癌细胞G_1期向S期的转化,进而抑制胃癌细胞增殖。     

Co-expression of XIAP and cyclin D1 complex correlates with a poor prognosis in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world. Despite improved diagnosis and treatment, the prognosis for HCC patients remains poor. The goal of this study was to identify key regulatory proteins and signaling pathways important for cell apoptosis and proliferation as biomarkers for prognostication and targeted therapy. Protein Pathway Array was applied to screen 38 signaling proteins and phosphoproteins in 12 paired HCC tumors and surrounding benign tissues and found that 20 of them, including XIAP, CDK4, CDK6, and Cyclin D1, were overexpressed in HCC tissues. Immunostaining results of XIAP, CDK4, and Cyclin D1 in an additional 59 HCC tissues showed that the expression of XIAP correlated with the expression of CDK4/Cyclin D1, and that the increased expression of these proteins correlated with poor overall survival in these patients. Further studies using the HCC Huh7 cell line transfected with XIAP siRNA or expression vector demonstrated that XIAP regulated the expression of CDK4, CDK6, and Cyclin D1 via NF-êB and PTEN pathways. Finally, inhibition of XIAP using embelin, a XIAP-specific small molecule, leads to an increased apoptosis and decreased cell proliferation via arrest at G1 phase. Taken together, XIAP is a central modulator regulating cell apoptosis and cell cycle progression. Therefore, XIAP together with cell cycle regulatory proteins can be used as prognostic markers and therapeutic targets.     

H-Ras mutation modulates the expression of major cell cycle regulatory proteins and disease prognosis in oral carcinoma.

Activating mutations of the Ras is a moderately frequent event in oral carcinogenesis in Indian patients. Ras pathway has essential roles in regulation of various phases of the cell cycle, especially at G1 phase. Despite a large body of in vitro evidence, the multidimensional interaction between mutated Ras pathway and G1 cell cycle regulatory proteins in tumours in vivo is poorly determined. In the present study, DNA samples were screened for mutations in hot spot exons of B-Raf and hot spot codons 12, 13 and 61 of H-, K- and N-Ras by PCR-SSCP. Mutations were confirmed by direct sequencing. Expression of G1 cell cycle regulatory proteins-cyclin D1, CDK4, Rb, p53, p16 and p21 and proliferation marker PCNA was analysed immunohistochemically. The results revealed the absence of B-Raf mutations in oral carcinoma in spite of 12.5% of the samples showing H-Ras mutation. The H-Ras mutant cases showed significantly low cyclin D1 (P=0.027) and CDK4 (P=0.046) expression and overexpression of Rb (P=0.011) and p16 (P=0.026). H-Ras mutant carriers also had significantly high recurrence-free survival (P=0.033). In summary the present study demonstrated an epistatic interaction between H-Ras mutation and G1 cell cycle regulatory proteins in vivo. H-Ras mutation, thus, defines a molecular subtype of oral carcinoma with favourable outcome and unique biology.     

Millimeter wave treatment promotes chondrocyte proliferation via G1/S cell cycle transition

Millimeter waves, high-frequency electromagnetic waves, can effectively alleviate the clinical symptoms in osteoarthritis patients, as a non-pharmaceutical and non-invasive physical therapy regimen. However, the molecular mechanisms of the therapeutic effects of millimeter wave treatment are not well understood. In the present study, the effect of millimeter waves on the G1/S cell cycle progression in chondrocytes and the underlying mechanism was investigated. Chondrocytes isolated from the knee of SD rats were cultured and identified using toluidine blue staining. The second generation chondrocytes were collected and stimulated with or without millimeter waves for 48 h. Chondrocyte viability was analyzed using the MTT assay. The cell cycle distribution of chondrocytes was analyzed by flow cytometry. mRNA and protein expression levels of cyclin D1, cyclin-dependent kinases 4 and 6 (CDK4 and CDK6) and p21 were detected using real-time PCR and western blotting, respectively. Millimeter wave stimulation was found to significantly enhance chondrocyte viability. Moreover, the percentage of chondrocytes in the G0/G1 phase was significantly decreased, whereas that in the S phase was significantly increased. In addition, following millimeter wave treatment, cyclin D1, CDK4 and CDK6 expression was significantly upregulated, whereas p21 expression was significantly downregulated. The results indicate that millimeter wave treatment promotes chondrocyte proliferation via cell cycle progression.