miR-503 inhibits cell proliferation and induces apoptosis in colorectal cancer cells by targeting E2F3

Objective: Colorectal cancer (CRC) is one of the major healthcare problems worldwide. A lot of miRNAs are aberrantly expressed in CRC and involved in its development and progression. The purpose of this study was to investigate the expression and function of miR-503 in CRC. Methods: miR-503 expression was detected in CRC tissues and cell lines by Quantitative real-time PCR. Cell proliferation was assessed by MTT assay. Cell apoptosis and cell cycle distribution were measured by flow cytometry. Moreover, luciferase reporter assay and western blot were performed to determine the potential target of miR-503 in CRC cells. Results: miR-503 was significantly decreased in CRC tissues and cell lines in comparison with controls. Overexpression of miR-503 in CRC cells remarkably inhibited cell proliferation and induced apoptosis. Furthermore, E2F3 was identified as a direct target of miR-503 in CRC cells and down-regulation of E2F3 had a similar effect as miR-503 overexpression on CRC cells. In addition, the expression of E2F3 was negatively correlated with miR-503 level in CRC tissues. Conclusions: miR-503 inhibits cell proliferation and induces apoptosis by directly targeting E2F3 in CRC cells, indicating its potential application in CRC diagnosis and therapy.     

Regulatory effect of e2, IL-6 and IL-8 on the growth of epithelial ovarian cancer cells

To determine the regulatory effects of estrogen and cytokine IL-6 and IL-8 on the growth of epithelial ovarian cancer （OVCA）, we first examined the status of estrogen receptors （ERα and ERβ）, IL-6 receptor （IL-6Rα and gp130）, and IL-8 receptor （IL-8RA and IL-8RB） on five epithelial OVCA cell lines by semiquantitative RT-PCR and Western blot analysis. Results showed that the expressions of these receptors were variable on the five cells. Those OVCA ceUs expressing the receptors were selected to study related molecular mechanism. MTT assay was performed to observe the effects of 17β-estradiol （E2）, IL-6 and IL-8 on cell proliferation. We discovered that E2 markedly promoted the proliferation of CAOV-3 and OVCAR-3 cell in a time- and dose-dependent manner. Tamoxifen （Txf）, an ER inhibitor, completely blocked the proliferation of the E2-induced cells, and IL-6- or/and IL-8-neutralizing antibody only showed partially blocking activity. IL-6 and IL-8 were able to significantly stimulate CAOV-3 and OVCAR-3 cell proliferation in a time- and dose-dependent manner, which had a potential synergistic effect on CAOV-3 cells but not on OVCAR-3 cells. The cell proliferation induced by these two cytokines was abolished completely by their specific neutralizing antibodies, partially by Txf, but not by unrelated goat IgG. Taken together, our results suggested that estrogen, IL-6 and IL-8 could modulate OVCA growth by forming a reciprocal cascade with amplifying effect.     

肿瘤干细胞与卵巢癌

卵巢肿瘤干细胞（OCSCs)是存在于卵巢癌组织中的一类具有自我更新和多向分化潜能的细胞,表面共表达CD44和CD117分子标记。虽然其起源不是很确定,但目前倾向于认为卵巢表面上皮细胞来源于OCSCs。研究OCSCs自我更新机制和表观遗传学的改变,可为肿瘤发生的机制及新药的开发提供很好的基础     

NEK2基因沉默促进卵巢癌细胞SKOV3凋亡

目的研究siRNA干扰NEK2表达对卵巢癌细胞SKOV3增殖和凋亡的影响及其分子机制。方法设计合成3条对NEK2的siRNA,转染进SKOV3细胞,采用real-time PCR和Western blot技术筛选出抑制效率最高的NEK2-siRNA序列,进行后续实验;分别采用MTT和流式细胞学技术检测细胞增殖和凋亡,用Western blot检测BAD、BCL-2和caspase-3的表达。结果 1)RNA干扰序列2对SKOV3细胞NEK2的抑制效果最明显;2)与空白组和阴性对照组相比,NEK2-siRNA转染48 h后,SKOV3细胞增殖能力下降,发生凋亡的细胞增加(P<0.01);3)与空白组和阴性对照组相比,NEK2-siRNA转染48 h后,SKOV3细胞中BAD和caspase-3的蛋白表达上调,而BCL-2的蛋白表达下调(P<0.01)。结论 NEK2-siRNA可能通过沉默NEK2的表达,促进卵巢癌细胞SKVO3的凋亡。     

Protein expression profiles and prognostic value of E2F family members in clear cell renal cell carcinoma

The derangement of the cell cycle facilitates uncontrolled cell proliferation and acquisition of genetic alterations favorable for malignancy. However, the protein expression profiles of E2 F family cell cycle regulators in clear cell renal cell carcinoma (ccRCC) have not yet been thoroughly investigated. In this study, we aimed to examine the protein expression profiles and prognostic value of E2 F1, E2 F3, and E2 F4 in ccRCC cases. The immunohistochemical expression of E2 F1, E2 F3, and E2 F4 was quantitatively scored in 180 ccRCC tumor tissues and 79 normal kidney tissues. The prognostic implications of these E2 F members were determined. We found that ccRCC tumor cells showed higher nuclear expression of E2 F1, E2 F3 and E2 F4 than normal kidney samples. High E2 F1 and E2 F3 expression in tumor cells was associated with poor prognostic factors of ccRCC, whereas high E2 F4 correlated with beneficial prognostic factors. High expression of E2 F1 and E2 F3 in tumor cells was correlated with a poor overall and recurrence-free survival, while high E2 F4 expression did not. In conclusion, E2 F1, E2 F3 and E2 F4 may function as oncogenes during tumorigenesis of ccRCC, although they contribute to the progression of ccRCC in different ways. Additional studies are required to clarify the conflicting role of E2 F4 in the tumor evolution of ccRCC.     

上调分子伴侣mortalin经由MAPK-ERK信号转导通路促进卵巢癌细胞增殖

目的 通过获得稳定表达mortalin的卵巢癌细胞株（A2780、A2780/cis）,检测mortalin与卵巢癌细胞增殖的关系及可能机制。方法 CCK-8实验检测mortalin过表达组和对照组细胞增殖的变化;通过流式细胞术检测mortalin过表达对卵巢癌细胞周期的影响;Western blotting检测mortalin上调表达后,卵巢癌细胞中MAPK/ERK和JNK/SAPK信号通路蛋白的变化。 结果 Mortalin上调表达促进卵巢癌细胞A2780和A2780/cis的增殖。Mortalin通过加快卵巢癌细胞由G₁期快速过渡到G₂/M期,促进细胞增殖,且MAPK/ERK信号通路参与该过程。结论 Mortalin上调表达促进了卵巢癌细胞的增殖,与其对MAPK-ERK信号通路的激活有关。     

ATF4对皮肤癌细胞增殖的影响及相关机制

目的：探讨沉默/过表达ATF4对人皮肤癌细胞增殖的影响及其相关作用机制。方法：Western blot技术检测不同类型皮肤癌细胞中ATF4的蛋白表达水平。构建ATF4沉默/过表达的A431皮肤癌细胞株,采用CCK-8法、克隆形成实验和流式细胞术检测A431细胞增殖能力的变化及细胞周期分布;Western blot技术检测细胞周期调控因子cyclin D1、cyclin E、P21和p-Rb/Rb的蛋白表达水平。结果：ATF4在3种不同类型的皮肤癌细胞中均呈高表达。CCK-8法和克隆形成实验结果显示沉默ATF4的A431细胞存活率和增殖能力均显著降低(P<0.05),而过表达ATF4可促进A431细胞的增殖;流式细胞仪检测结果显示沉默ATF4可明显抑制A431细胞从G0/G1期向S期转换,过表达ATF4则促进其G1/S转换。同时Western blot实验结果显示沉默ATF4后,cyclin D1、cyclin E和p-Rb的蛋白水平均显著降低,而P21的蛋白表达显著增加(P<0.05),过表达ATF4后则cyclin D1、cyclin E和p-Rb的蛋白水平显著增加,而P21的蛋白表达显著降低(P<0.05)。结论：ATF4能够促进人皮肤鳞状细胞癌细胞株A431的增殖,其潜在作用机制可能与促进细胞周期G1/S转换及影响相关周期调控因子的表达有关,提示AT F 4可作为治疗皮肤癌的一个潜在作用靶点。     

E2F陷阱DNA对前列腺癌PC-3M细胞凋亡的诱导

目的：为观察转录因子E2F陷阱DNA 对雄激素非依赖性前列腺癌细胞PC-3M增殖和凋亡的影响。方法：采用脂质体lipofectamine将E2F decoy DNA、ARE decoy DNA和control decoy DNA分别转染PC-3M细胞，MTT检测其对细胞增生的影响，倒置相差显微镜观察细胞形态变化，流式细胞术检测细胞凋亡率，并进行染色体DNA断裂的测定；通过RT-PCR检测转染的PC-3M细胞中c-Myc mRNA、cyclin D1 mRNA表达水平的变化，通过Western blotting检测细胞中c-Myc蛋白、cyclin D1蛋白表达水平的变化。结果：E2F decoy DNA转染后的PC-3M细胞的生长受到明显抑制;转染后的细胞形态变化符合凋亡的典型改变，染色体断裂明显,细胞凋亡率为26.35%；c-Myc、cyclin D1的表达受到抑制。结论：E2F decoy DNA可诱导雄激素非依赖性前列腺癌PC-3M凋亡和抑制细胞增殖,其机制可能涉及到c-Myc mRNA、cyclin D1的表达变化。     

siRNA对卵巢癌细胞周期及EGFR表达的影响

目的体外构建编码人类表皮生长因子受体（EGFR）的小干扰RNA（siRNA）的质粒表达载体,观察其对卵巢癌Skov-3细胞EGFR的特异性抑制作用及对细胞凋亡和周期的影响。方法构建pSilencer-EGFR siRNA真核基因表达载体,采用脂质体介导的方法将其转染到卵巢癌细胞株Skov-3,实验分为以下3组：空白对照组（未经转染的人卵巢癌Skov一3细胞）、非特异性转染组（转染非特异性质粒载体）及特异性转染组。用RT-PCR的方法检测mRNA水平的变化,用免疫荧光法检测EGFR蛋白水平的变化,流式细胞仪检测其对卵巢癌细胞周期及凋亡的影响。结果成功构建pSilencer—EGFR siRNA真核基因表达载体。psiRNA—EGFR质粒明显下调Skov-3细胞中EGFR的表达,阻断细胞周期在G1期,促进细胞凋亡。结论重组质粒psiRNA—EGFR能有效地抑制Skov-3细胞内EGFR的表达、抑制细胞增殖,其抑制机制可能与引起细胞周期再分布、降低S期细胞比例和促进细胞凋亡有关。     

内皮抑素对人卵巢癌细胞系生长的抑制作用

目的探讨人内皮抑素对人卵巢癌SKOV3细胞生长的抑制作用及其作用机制。方法MTT法检测细胞生长;透射电镜观察细胞凋亡;免疫细胞化学、RT-PCR及Western blot法检测细胞中BCL-2和BAX蛋白及mRNA的表达。结果内皮抑素抑制SKOV3细胞增殖(P<0.01);能诱导SKOV3细胞凋亡;而对细胞中BCL-2和BAX蛋白及mRNA的表达无明显影响。结论人内皮抑素具有抑制卵巢癌细胞SKOV3生长的作用,其作用机制可能与诱发细胞凋亡相关。     

MiRNA-429 suppresses the growth of gastric cancer cells in vitro

Micro-RNAs(miRNAs) have been found to be implicated in a very wide range of physiological processes.This study was aimed to investigate the regulation of miRNA-429(miR-429) in gastric cancer cells on cell proliferation and apoptosis.Quantitative PCR was employed to detect the expressions of miR-429 after eukaryotic expression plasmid of miR-429 and its inhibitor were transiently transfected into poorly differentiated human gastric can-cer cell line BGC823.The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) reduction as-says were used to examine proliferation ability.Apoptosis was analyzed by flow cytometry after transfection.The results showed that 48 h after transfection,overexpression of miR-429 reached maximum efficiency.Compared with mock transfection,miR-429 inhibited tumor cell proliferation significantly(P < 0.05) at 48 h and 72 h.of Overexpression of miR-429 promoted tumor cell apoptosis when compared with mock transfected cells(P < 0.05).On the contrary,miR-429 inhibitor promoted tumor cell proliferation and inhibited apoptosis when compared with controls(P < 0.05).Our results suggested that miRNA-429 may serve as a tumor suppressor during tumorigenesis of gastric cancer and may be a potential gastric cancer therapeutic target.     

Osthole inhibits proliferation of human breast cancer cells by inducing cell cycle arrest and apoptosis

Recent studies have revealed that osthole,an active constituent isolated from the fruit of Cnidium monnieri(L.) Cusson,a traditional Chinese medicine,possesses anticancer activity.However,its effect on breast cancer cells so far has not been elucidated clearly.In the present study,we evaluated the effects of osthole on the proliferation,cell cycle and apoptosis of human breast cancer cells MDA-MB 435.We demonstrated that osthole is effective in inhibiting the proliferation of MDA-MB 435 cells,The mitochondrion-mediated apoptotic pathway was involved in apoptosis induced by osthole,as indicated by activation of caspase-9 and caspase-3 followed by PARP degradation.The mechanism underlying its effect on the induction of G1 phase arrest was due to the up-regulation of p53 and p21 and down-regulation of Cdk2 and cyclin D1 expression.Were observed taken together,these findings suggest that the anticancer efficacy of osthole is mediated via induction of cell cycle arrest and apoptosis in human breast cancer cells and osthole may be a potential chemotherapeutic agent against human breast cancer.     

siRNA干扰沉默S100A4基因表达对喉癌Hep2细胞周期和侵袭的影响

目的应用RNA干扰技术下调喉癌Hep2细胞中S100A4基因的表达,探讨其对Hep2细胞周期和细胞侵袭力的影响。方法脂质体法转染S100A4siRNA至Hep2细胞。Real-time PCR和Western blot验证S100A4基因mRNA和蛋白水平的表达,流式细胞术和transwell实验分别检测下调S100A4表达对Hep2细胞周期和侵袭能力的影响。结果 S100A4 mRNA和蛋白表达水平明显降低,细胞增殖指数显著降低,并且处于G1期细胞数明显增多,细胞侵袭能力显著降低。结论 S100A4siRNA转染喉癌Hep2细胞能有效下调S100A4基因的表达,从而影响Hep2的细胞周期和抑制细胞的侵袭能力。     

MicroRNA-25 regulates small cell lung cancer cell development and cell cycle through cyclin E2

Purpose: We intended to examine the underlying mechanism of microRNA-25 (miR-25) in regulating small cell lung cancer (SCLC). Methods: The miR-25 expression was measured by quantitative RT-PCR (qRT-PCR) in 5 SCLC cell lines and 9 human SCLC tissues. In SCLC cell line H510A cells, endogenous miR-25 was downregulated by stable transfection of antisense oligonucleotide of miR-25 (miR-25-as). Then the effects of miR-25 downregulation on SCLC growth, invasion and chemoresistance were assessed by MTT, migration and cisplatin assays, respectively. Furthermore, the effects of miR-25 downregulation on cancer cell cycle arrest, production of cell cycle proteins cyclin E2 and CDK2 were examined by cell cycle assay, western blot and luciferase assays, respectively. Finally, cyclin E2 was over-expressed in H510A cells to investigate its effect on miR-25 mediated SCLC regulation. Results: In both SCLC cells and human SCLC tumor tissues, miR-25 was overexpressed. Down-regulation of miR-25 in H510A cells significantly reduced cancer cell growth, invasive capability and resistance to cisplatin. Also, it induced G1 cell cycle arrest and downregulated cell cycle related proteins cyclin E2 and CDK2. Luciferase assay demonstrated cyclin E2 was directly targeted by miR-25. Overexpression of cyclin E2 in H510A cells reversed the cell cycle arrest and restored invasive capability impaired by miR-25 downregulation. Conclusions: Our study shows miR-25 is overexpressed in SCLC and acting as oncogenic regulator by regulating cyclin E2.