Trastuzumab联合丁酸钠对人乳腺癌细胞株SKBR3细胞增殖和p27~（Kip1）表达的影响

目的：观察组蛋白去乙酰化酶抑制剂（HDACIs）丁酸钠（NaB）及曲妥珠单抗Trastuzumab对人乳腺癌细胞株SKBR3细胞增殖、细胞周期及细胞凋亡的影响,探讨NaB及Trastuzumab调控乳腺癌细胞增殖的分子机制。方法：乳腺癌SKBR3细胞经NaB、Trastuzumab单独或联合作用后,MTT法检测细胞增殖情况,流式细胞仪分析细胞周期分布及细胞凋亡,Western Blot方法检测p27Kip1的表达。结果：NaB单独用药显著抑制SKBR3细胞增殖,促进细胞G0/G1期阻滞,增加细胞凋亡和p27Kip1蛋白的表达,P〈0.05;20μg/mL Trastuzumab单独用药,对细胞有增殖抑制和细胞周期阻滞作用（P〈0.05）,但对细胞凋亡及p27Kip1蛋白表达无明显影响,P〉0.05。Trastuzumab可协助NaB增加对SKBR3的抗肿瘤作用及p27Kip1蛋白表达,P〈0.05。结论：Trastuzumab联合NaB抑制乳腺癌细胞的增殖,促进细胞周期阻滞及细胞凋亡的发生,以上过程可能是通过增加p27Kip1的蛋白表达来实现。     

丁酸钠对人乳腺癌细胞株MCF-7细胞增殖及p27Kip1蛋白表达影响的研究

目的:通过观察组蛋白去乙酰化酶抑制剂(histon-deacetylase inhibitors,HDACIs)丁酸钠(sodium butyrate,NaB)对人乳腺癌细胞株MCF-7细胞的增殖影响以及p27Kip1蛋白表达改变,探讨NaB调控乳腺癌细胞增殖的分子机制.方法:乳腺癌MCF-7细胞经不同浓度NaB作用后,相差显微镜观察细胞形态变化和细胞增殖情况,流式细胞仪分析细胞周期分布,免疫组化检测p27Kip1蛋白表达.结果:NaB对MCF-7细胞有显著的增殖抑制作用,呈时间剂量依赖性,处理后的MCF-7细胞出现凋亡形态变化;细胞周期阻滞于G0/G1期,NaB 2 mmol/L组G0/G1期达(62.2±2.2)%,4 mmol/L组G0/G1期达(78.1±3.8)%,空白组G0/G1期达(53.1±2.4)%,P<0.05;p27蛋白表达水平上调.结论:NaB可抑制乳腺癌细胞的生长,该作用可能与p27蛋白表达增加有关.     

丁酸钠对人乳腺癌细胞株MCF-7细胞增殖及p27^kip1蛋白表达影响的研究

目的：通过观察组蛋白去乙酰化酶抑制剂（histon—deacetylase inhibitors，HDACIs）丁酸钠（sodium butyrate，NaB）对人乳腺癌细胞株MCF-7细胞的增殖影响以及p27^kip1蛋白表达改变，探讨NaB调控乳腺癌细胞增殖的分子机制。方法：乳腺癌MCF-7细胞经不同浓度NaB作用后，相差显微镜观察细胞形态变化和细胞增殖情况，流式细胞仪分析细胞周期分布，免疫组化检测p27^kip1蛋白表达。结果：NaB对MCF-7细胞有显著的增殖抑制作用，呈时间剂量依赖性，处理后的MCF-7细胞出现凋亡形态变化；细胞周期阻滞于（G0／G1期，NaB2 mmol／L组G0／G1，期达（62．2±2．2）％，4mmol／L组G0/G1，期达（78．1±3．8）％，空白组G0／C0期达（53．1±2．4）％，P〈0．05；p27蛋白表达水平上调。结论：NaB可抑制乳腺癌细胞的生长，该作用可能与p27蛋白表达增加有关。     

褪黑素对小鼠肝癌细胞增殖及p27Kip1、cyclin D1基因表达的影响

目的探讨褪黑素(melatonin MT)抑制H22小鼠肝癌细胞增殖的可能机制.方法通过体外细胞培养,分别采用不同剂量MT作用不同的时间,MTT显色技术检测细胞的增殖;RT-PCR检测MT作用4 d后,H22细胞中p27Kip1、cyclin D1mRNA的表达;免疫组化检测H22细胞中p27Kip1、cyclin D1蛋白的表达.结果MT具有抑制肝癌细胞的生长和增殖的作用,且具有时间依赖关系.MT诱导细胞凋亡的过程中,与对照组相比,MT药理剂量组H22细胞中的p27Kip1 mRNA及蛋白表达升高(P＜0.01);cyclin D1 mRNA及蛋白表达下降(P＜0.01).MT生理剂量组p27Kip1mRNA表达升高(P＜0.01),而p27Kip1蛋白表达水平与对照组相比差异无显著性(P＞0.05),cyclinD1 mRNA及蛋白表达均下降,差异元显著性(P＞0.05).结论MT抑制肝癌细胞的增殖可能与上调细胞周期抑制因子p27Kip1的表达,降低周期蛋白cyclin D1表达,进而延迟细胞周期的进程有关.     

乳腺癌组织p27Kip1的表达及其与细胞增殖的关系

目的:研究乳腺癌组织中细胞周期抑制剂p27Kip1的表达及其意义,并探讨其与细胞增殖的关系.方法:应用免疫组化SP法检测80例乳腺癌和20例癌旁正常组织中p27Kip1和增殖细胞核抗原(pro-liferative cell nuclear antigen,PCNA)的表达.结果:乳腺癌组织中p27Kip1高表达率为53.75%(43/80),明显低于癌旁正常组织(P<0.01).p27Kip1表达与组织学分级、TNM分期及淋巴结转移均相关,P<0.05.乳腺癌组织中p27Kip1的表达与PCNA LI呈负相关,r=-0.372,P<0.05.p27Kip1高表达的乳腺癌术后5年无病生存率(DFS)明显高于p27Kip1低表达者(P<0.05).结论:p27Kip1表达缺失可促进肿瘤细胞增殖,是判断乳腺癌发生、发展及预后的有效生物学指标.     

p27Kip1在As2O3诱导白血病细胞凋亡中的作用机制

目的:研究三氧化二砷(arsenic trioxide,As2O3)及转录生长因子(transforming growth factor-β1,TGF-β1)对人HL-60细胞增殖的影响,并探讨相关信号通路.方法:流式细胞术检测细胞周期及凋亡,RT-PCR检测p27Kip1、TGF-β1、Cyclin E和Bcl-2表达,免疫组织化学方法和Western blot方法检测p27Kip1、TGF-β1、Cyclin E和Bcl-2蛋白水平.结果:As2O3、TGF-β1单药或联合处理均可诱导细胞凋亡,以联合处理组凋亡最明显,并且As2O3单药组及联合处理组细胞周期阻滞于G1期.As2O3单药及联合处理组可见p27Kip1、内源性TGF-β1表达上调,Cyclin E和Bcl-2表达下调,外源性TGF-β1处理组可见p27Kip1 mRNA及蛋白表达上调,内源性TGF-β1 mRNA表达上调,内源性TGF-β1蛋白水平与对照组比较无明显变化,Cyclin E和Bcl-2表达下调,联合处理组p27Kip1及内源性TGF-β1表达上调及Cyclin E和Bcl-2表达下调程度强于单药处理组.结论:As2O3诱导细胞凋亡的机制可能是通过上调TGF-β1,从而上调p27Kip1,拮抗Cyclin E和Bcl-2的作用,抑制细胞增殖,使细胞周期阻滞于G1期,从而诱导细胞发生凋亡,外源性TGF-β1通过上调内源性TGF-β1,从而上调p27Kip1,增强As2O3诱导细胞凋亡的作用.     

丁酸钠对人子宫内膜癌细胞系HHUA细胞增殖影响的研究

目的 :探讨丁酸钠 (NaB)对人子宫内膜癌细胞系HHUA细胞体外增殖的影响及机制。方法 :不同浓度的NaB作用于体外培养的人子宫内膜癌细胞系HHUA ,通过绘制细胞生长曲线观察NaB对细胞生长的抑制作用 ;用流式细胞仪定量分析细胞周期分布 ;用WesternBlot分析p2 1、p5 3、pRb和E2F1蛋白表达。结果 :NaB能诱导HHUA细胞周期G1期阻滞 ,上调p2 1蛋白表达 ,促进pRb去磷酸化 ,下调E2F1和p5 3蛋白表达。结论 :NaB能抑制HHUA细胞体外生长 ,其诱导细胞周期G1期阻滞可能与p2 1等细胞周期调节蛋白的表达改变有关。     

Celecoxib下调NF-kB信号通路促进人乳腺癌MDA-MB-231细胞凋亡的体外研究

背景与目的:Celecoxib可以抑制多种肿瘤细胞增殖、诱导其凋亡,但具体的作用机制尚不明确.本研究探讨Celecoxib是否通过阻断NF-kB信号途径诱导人乳腺癌MDA-MB-231细胞的凋亡.方法:RT-PCR法检测MDA-MB-231细胞中COX-2 mRNA的表达.MTT法检测Celecoxib、PGE2与Celecoxib联合应用对MDA-MB-231细胞增殖的影响.流式细胞术检测细胞周期、凋亡的变化.Westernblot法检测0、40、80、120 μmol/L Celecoxib作用MDA-MB-231细胞24 h后细胞中Caspase-3、p65蛋白的表达变化.结果:RT-PCR检测显示MDA-MB-231细胞中COX-2 mRNA的表达随着Celecoxib浓度的增加而逐渐降低.Celecoxib能够显著地抑制MDA-MB-231细胞增殖(P<0.05),但Celecoxib联合PGE2与单独应用Celecoxib对细胞增殖的影响差异无统计学意义(P>0.05).流式细胞术结果显示Celecoxib可使MDA-MB-231细胞阻滞在G0/G1期,并可诱发细胞凋亡.Western blot检测发现Celecoxib作用MDA-MB-231细胞24 h,随着Celecoxib浓度的增加,Caspase-3蛋白表达增加,P65蛋白表达下调.结论:Celecoxib可以通过下调P65蛋白的表达从而阻断NF-kB信号途径,抑制人乳腺癌MDA-MB-231细胞增殖,促进其凋亡.     

miR-144-3p靶向zeb1调控卵巢癌细胞SKOV3的增殖和凋亡

目的:探讨miR-144-3p是否通过靶向E盒锌指结合蛋白1（zeb1）调控卵巢癌细胞SKOV3的增殖和凋亡。方法:qRT-PCR检测miR-144-3p在卵巢癌细胞和正常人卵巢上皮细胞中的表达差异。在卵巢癌细胞SKOV3中转染miR-144-3p mimics,MTT法测定细胞增殖,PI单染法检测细胞周期,Annexin V-FITC/PI双染法检测细胞凋亡,Western blot检测细胞中cyclinD1、p27、C-caspase-3蛋白表达。生物信息学软件预测miR-144-3p的靶基因可能为zeb1,荧光素酶报告系统鉴定其靶向关系。在卵巢癌细胞SKOV3中共转染miR-144-3p mimics、pcDNA3.1-zeb1,利用上述方法测定细胞增殖、周期和凋亡变化。结果:miR-144-3p在卵巢癌细胞中的表达水平低于正常人卵巢上皮细胞。转染miR-144-3p mimics后的卵巢癌细胞SKOV3增殖能力下降,细胞周期被阻滞在G1期,细胞凋亡增多,细胞中cyclinD1蛋白表达减少,p27、C-caspase-3蛋白表达增加。miR-144-3p靶向调控zeb1表达。pcDNA3.1-zeb1可以逆转miR-144-3p mimics对卵巢癌细胞增殖抑制、周期阻滞和凋亡促进作用。结论:miR-144-3p靶向zeb1抑制卵巢癌细胞SKOV3增殖并诱导细胞凋亡。     

丁酸钠对人子宫内膜癌细胞系HHUA细胞增殖影响的研究

目的：探讨丁酸钠(NaB)对人子宫内膜癌细胞系HHUA细胞体外增殖的影响及机制。方法：不同浓度的NaB作用于体外培养的人子宫内膜癌细胞系HHUA，通过绘制细胞生长曲线观察NaB对细胞生长的抑制作用；用流式细胞仪定量分析细胞周期分布；用Western Blot分析p21、p53、pRb和E2F1蛋白表达。结果：NaB能诱导HHUA细胞周期G1期阻滞，上调p21蛋白表达，促进pRb去磷酸化，下调E2F1和p53蛋白表达。结论：NaB能抑制HHUA细胞体外生长，其诱导细胞周期G1期阻滞可能与p21等细胞周期调节蛋白的表达改变有关。     

肿瘤细胞自噬的诱导及其细胞周期分析

背景与目的:自噬作为Ⅱ型程序性死亡——自噬性死亡过程中的主要现象,与细胞的自噬性死亡有着密切的关系。研究者们对凋亡与细胞周期的关系进行了深入而细致的研究,但对自噬性细胞死亡与细胞周期的关系却知之甚少。本研究的目的是探讨不同方法诱导的细胞自噬与细胞周期之间的关系。方法:用Hanks’液替代培养基的饥饿诱导和用长春新碱诱导两种方法分别处理对数生长期的HeLa细胞、SW480细胞以及经过和未经过植物血凝素(phytohemagglutinin,PHA)刺激的健康人外周血淋巴细胞;应用激光共聚焦显微镜和透射电镜检测细胞自噬的发生,兔抗人微管相关蛋白1轻链3Ⅱ(microtubule-associatedprotein1lightchain3,MAP1-LC3-Ⅱ)/DNA双参数流式细胞术分析自噬细胞的细胞周期。结果:HeLa细胞和SW480细胞用饥饿和长春新碱两种方法诱导的细胞自噬在G1、S、G2/M期均可以发生,且自噬发生率随诱导时间的延长逐渐增加。处于静止期(未经PHA刺激)的外周血淋巴细胞没有自噬的发生,48h时LC3-Ⅱ表达率<2.62%(HanksL液饥饿诱导)或<6.16%(长春新碱诱导);经PHA刺激48h进入细胞周期的外周血淋巴细胞,2h时已有明显的自噬发生。结论:MAP1-LC3-Ⅱ/DNA双参数流式细胞术是对细胞自噬与细胞周期进行同步分析的一种新的简便可靠的方法;细胞自噬只发生在细胞进入周期后,而静止期细胞对自噬诱导因素不敏感。     

Inhibition of S-adenosylhomocysteine hydrolase decreases cell mobility and cell proliferation through cell cycle arrest

S-adenosylhomocysteine hydrolase (AHCY) hydrolyzes S-adenosylhomocysteine to adenosine and l-homocysteine, and it is already known that inhibition of AHCY decreased cell proliferation by G2/M arrest in MCF7 cells. However, the previous study has not indicated what mechanism the cell cycle arrest is induced by. In this study, we aimed to investigate the different cell cycle mechanisms in both p53 wild-typed MCF7 and p53 mutant-typed MCF7-ADR by suppressing AHCY. We extensively proved that AHCY knockdown has an anti-proliferative effect by using the WST-1 assay, BrdU assay, and cell cytometry analysis and an anti-invasive, migration effect by wound-healing assay and trans-well analysis. Our study showed that down-regulation of AHCY effectively suppressed cell proliferation by regulating the MEK/ERK signaling pathway and through cell cycle arrests. The cell cycle arrest occurred at the G2/M checkpoint by inhibiting degradation of cyclinB1 and phosphorylation of CDC2 in MCF7 cells and at the G1 phase by inhibiting cyclinD1 and CDK6 in MCF7-ADR cells. Finally, we determined that AHCY regulates the expression of ATM kinase that phosphorylates p53 and affects to arrest of G2/M phase in MCF7 cells. The findings of this study significantly suggest that AHCY is an important regulator of cell proliferation through different mechanism in between MCF7 and MCF7-ADR cells as p53 status.     

RhoA and RhoC proteins promote both cell proliferation and cell invasion of human oesophageal squamous cell carcinoma cell lines in vitro and in vivo

There is growing evidence that Rho proteins are deregulated by overexpression in tumours; and according to some reports, this correlates with disease progression. Our previous clinical study had demonstrated a correlation between RhoA expression and tumour progression in oesophageal squamous cell carcinoma (ESCC). These findings prompted us to study, using nude mice, pathological roles of Rho proteins in human ESCC cells. Western blot analysis in ESCC cell lines, in addition to cell proliferation and in vitro migration assays, were performed to observe the malignant potential of RhoA and RhoC in untransfected and transfected cells. Constitutively active RhoA, RhoC and dominant negative RhoA (dnRhoA) proteins were transfected to ESCC (TE-1 and TE-2) cells. The stably transfected cells were injected into nude mice, and the growth and metastasis of these cells to the lungs were analysed. Tumour tissues were then examined using immunohistochemical methods for proteins Ki-67 (MIB-1), FAK, MMP-1, MMP-9 and TIMP-3. Protein levels of RhoA and RhoC in ESCC cell lines were visualised by Western blotting, and showed highest expression in TE-2 cells. Results from the migration assay illustrated that both RhoA and RhoC play a role in migration of ESCC cells. In TE-2 transfected cells, RhoC showed greater migration compared to RhoA. By using an experimental metastasis model in nude mice, RhoA was found to promote more tumour growth than RhoC, whereas RhoC induced lung metastasis in comparison to RhoA. Ki-67 labelling index was used to evaluate the proliferation potential of tumour tissue inoculated from nude mice. In TE-2 cells RhoA gave a proliferation capacity of 24.8+/-0.5, which was significantly higher than those of TE-2 RhoC 10+/-0.4 (P<0.01). Strong immunoreactivity for FAK, MMP-1 and MMP-9 proteins was present in all tumour cells. By contrast, loss of TIMP-3 expression was observed in all tumour cells. In conclusion, our results indicate that pro-oncogenic Rho proteins are involved in promoting tumour growth, cell migration and metastasis in human ESCC cells in nude mice. The results from this study suggest that active Rho proteins may induce a transforming effect that leads to a malignant phenotype.     

Selenium modulation of cell proliferation and cell cycle biomarkers in human prostate carcinoma cell lines

Prostate cancer (PCA) is the most common histological malignancy and the second leading cause of cancer deaths among North American men. There has been considerable interest in the chemopreventative properties of selenium. In this study, we assessed whether selenium inhibits cell growth and associated cell cycle regulatory proteins. Human PCA cells (LNCaP, PC3, PC3-AR2, and PC3-M) were incubated with and without selenium (Seleno-DL-methionine, 150 microM) for 24, 48, and 72 h. Cells were fixed and stained with propidium iodide for flow cytometry analysis. In parallel experiments, total protein was extracted, immunoprecipitated with cyclin E antibody, and analyzed by Western blot for the expression of cell cycle markers. Treatment with selenium caused G1 arrest and an 80% reduction in the S phase of LNCaP with no effect on PC3. However, PC3 cells transfected with the androgen receptor (PC3-AR2) exhibited a G2/M arrest and a marked reduction (57%) in the S phase during cell cycle progression. In the analysis of cell cycle regulatory molecules, selenium-treated cells demonstrated a significant induction of cyclin-dependent kinase inhibitors Cip1/p21 and Kip1/p27. These data suggest that selenium possesses strong antiproliferative properties in regard to human PCA. This effect appears to be dependent on the presence of a functioning androgen receptor. This provides a theoretical basis for Phase III studies of selenium in PCA prevention.     

Management of non-small cell and small cell lung cancer.

This review addresses means for the improvement of treatment results in small cell and non-small cell lung cancer. In small cell lung cancer prognostic factors such as the distinction between classic and variant type in vivo remain an important subject for further investigations. Data concerning the schedule dependency of etoposide will lead to the investigation of new treatment regimens. The effect of warfarin is intriguing and warrants further research. Investigations of the damaging effects of prophylactic brain irradiation versus the effect on survival should be awaited before the role of prophylactic brain irradiation can be defined. The role of radiotherapy in the improvement of survival of limited-disease patients remains controversial. In non-small cell lung cancer the role of both radiotherapy and chemotherapy is still a matter of a seemingly never-ending debate. A major problem is the selection of patients. Therefore only randomized phase III trials should be performed in carefully defined subgroups of patients, based upon stage, performance status, and presence or absence of symptoms.     

Effects of chartreusin on cell survival and cell cycle progression

Chartreusin was lethal to both L1210 and P388 cells in culture with 90% of the cells being killed after a 24-hr exposure to 1.1 and 2.6 microgram/ml, respectively. The lethality of the drug increased in direct proportion to dose and exposure time. Both L1210 and Chinese hamster ovary cells in S phase were more sensitive to the lethality of the drug than were their corresponding non-S-phase cells. L1210 cells were partially synchronized by exposing an asynchronous culture to [methyl-3H]thymidine (20 Ci/mmol) and Colcemid for 3 hr. Synchronous culture of Chinese hamster ovary cells was established by planting mitotic cells. The progression of cells through the cell cycle was studied with flow microfluorometry both in the presence of the drug and after the drug had been washed off. In the presence of chartreusin the progression of mitotic cells into G1 was not affected. The movement of G1 cells into S was slower, and the movement of G2 cells into mitosis was blocked. When the drug was removed, the G2 to M block persisted for at least 4 hr but the progression of G1 cells to S was no longer inhibited.     

Non-genomic cell growth inhibition by progesterone. cell cycle retardation and induction of cell death

BACKGROUND: Non-genomic mechanisms have been proposed to play a role in progesterone-dependent cell growth inhibition. MATERIALS AND METHODS: The human cell line C-4I, derived from a squamous carcinoma of the uterine cervix, was progesterone receptor-negative. The culture medium contained 10% (v/v) fetal calf serum and the cells, growing in monolayer, were exposed to various progesterone concentrations. Flow cytometry and morphometry were employed to assess the effects. RESULTS: Progesterone caused a concentration-dependent growth inhibition with an IC50 value of 2.06 +/- 0.46 microM (mean value +/- SEM, n = 4). At 320 microM no viable and attached cells were left. Two mechanisms appeared to be responsible for the effect. Firstly, the cells accumulated in the G1/G0-phase indicating a cell cycle-specific arrest. Secondly, progesterone induced cell death with apoptosis and necrosis. Morphometric analysis showed that progesterone caused a marked reduction in the nuclear size, compatible with apoptosis. CONCLUSION: The present results show that progesterone exerts non-genomic effect(s) by reducing the input of and accelerating the exit of cells from the C-4I cell population.