Hydrogen Peroxide Induces G2 Cell Cycle Arrest and Inhibits Cell Proliferation in Osteoblasts

Reactive oxygen species (ROSs) are involved in osteoporosis by inhibiting osteoblastic differentiation and stimulating osteoclastgenesis. Little is known about the role and how ROS controls proliferation of osteoblasts. Mammalian target of rapamycin, mTOR, is a central regulator of cell growth and proliferation. Here, we report for the first time that 5–200 μM hydrogen peroxide (H₂O₂) dose‐ and time‐dependently suppressed cell proliferation without affecting cell viability in mouse osteoblast cell line, MC3T3‐E1, and in human osteoblast‐like cell line, MG63. Further study revealed that protein level of cyclin B1 decreased markedly and the percentage of the cells in G₂/M phase increased about 2‐4 fold by 200 μM H₂O₂ treatment for 24–72 hr. A total of 0.5–5 mM of H₂O₂ but not lower concentrations (5–200 μM) of H₂O₂ inhibited mTOR signaling, as manifested by dephosphorylation of S6K (T389), 4E‐BP1 (T37/46), and S6(S235/236) in MC3T3‐E1 and MG63 cells. Rapamycin, which could inhibit mTOR signaling and cell proliferation, however, did not reduce the protein level of cyclin B1. In a summary, H₂O₂ prevents cell proliferation of osteoblasts by down‐regulating cyclin B1 and inducing G₂ cell cycle arrest. Inhibition of mTOR signaling by H₂O₂ may not be involved in this process. Anat Rec, 292:1107–1113, 2009. © 2009 Wiley‐Liss, Inc.     

Tolfenamic Acid Inhibits the Proliferation,Migration, and Invasion of Nasopharyngeal Carcinoma: Involvement of p38-Mediated Down-Regulation of Slug

PurposeTolfenamic acid (TA), a non-steroidal anti-inflammatory drug, is known to exhibit antitumor effects in various cancers apart from nasopharyngeal cancer (NPC). NPC exhibits high invasiveness, as well as metastatic potential, and patients continue to suffer from residual, recurrent, or metastatic disease even after chemoradiation therapy. Therefore, new treatment strategies are needed for NPC. In this study, we investigated the efficacy and molecular mechanisms of TA in NPC treatment.ResultsTreatment with TA suppressed the migration and invasion of HNE1 and HONE1 cells. Hepatocyte growth factor enhanced the proliferation, migration, and invasion abilities of NPC cells. This enhancement was successfully inhibited by TA treatment. Treatment with TA increased phosphorylation of p38, and the inhibition of p38 with SB203580 reversed the cytotoxic, anti-invasive, and anti-migratory effects of TA treatment in NPC cell lines. Moreover, inhibition of p38 also reversed the decrease in expression of Slug that was induced by TA treatment.ConclusionIn conclusion, the activation of p38 plays a role in mediating TA-induced cytotoxicity and inhibition of invasion and migration via down-regulation of Slug.     

miR-133b 靶向 PTBP1 对肾细胞癌增殖和侵袭的影响

目的 探讨 miR-133b 靶向多聚嘧啶区结合蛋白1 (polyrimidine tract binding protein 1, PTBP1) 对 肾细胞癌 (renal cell carcinoma, RCC) 增殖和侵袭的影响。 方法 检测 miR-133b 在 RCC 癌组织及细胞中 的表达水平; 验证 miR-133b 与 PTBP1 的靶向关系及 miR-133b 表达对肾癌细胞 PTBP1 表达及增殖、 迁移的 影响。 结果 与癌旁组织比较, miR-133b 在 RCC 组织中表达下降, 而 PTBP1 上升 (P< 0. 05)。 PTBP1 是 miR-133b 的靶基因; 与 miR-NC 组比较, miR-133b mimic 组的克隆形成率、 侵袭细胞数目及 PTBP1 表达明 显下降, 而 miR-133b inhibitor 组上升; 与 miR-133b mimic + pc-NC 组比较, miR-133b mimic + pc-PTBP1 组的 克隆形成率、 侵袭细胞数目及 PTBP1 表达水平上升 (P< 0. 05)。 结论 miR-133b 在 RCC 癌组织及细胞中 表达下调, 且其可能通过调控 PTBP1 的表达水平来影响细胞的增殖和侵袭能力。     

沉默lncRNA-H19对甲状腺癌细胞增殖、侵袭和细胞周期的影响

目的 探讨长链非编码RNA(lncRNA)-H19对甲状腺癌细胞增殖、 侵袭和细胞周期的影响.方法 检测lncRNA-H19在癌组织、 癌旁组织、 正常人甲状腺上皮细胞TEC及甲状腺癌细胞KAT18、FTC133、BCPAP、TPC-1中的表达;检测沉默lncRNA-H19对细胞增殖、 侵袭和细胞周期的影响.结果 ln...     

三种自噬调控蛋白在腮腺良、恶性多形性腺瘤中的表达及意义

目的:研究自噬调控中的主要蛋白雷帕霉素靶蛋白(mTO)R)、蛋白激酶B(AKT)、Beclin 1在良、恶性多形性腺瘤中的表达及意义。方法:用免疫组织化学显色检测p-AKT和p-mTOR在腮腺癌在多形性腺瘤、良性多形性腺瘤和正常腮腺组织中的表达。免疫印迹检测p-AKT、p-mTOR、Beclin 1在各组织中的表达。结果:p-AKT在正常腮腺组织、良性多形性腺瘤、癌在多形性腺瘤中的阳性表达分别为15%、40.5%、59.1%。p-mTOR在正常腮腺组织、良性多形性腺瘤、癌在多形性腺瘤中的阳性表达分别为20%、43.2%、65.7%。AKT、mTOR的表达在正常腮腺组织、良性多形性腺瘤、癌在多形性腺瘤中呈递增的趋势。Beclin 1在3种组织中呈递减趋势。结论:mTOR、AKT在大部分腮腺癌在多形性腺瘤组织中呈现过度表达而Beclin 1表达下降,这可能与腮腺癌在多形性腺瘤病因、病理机制相关。     

血红素加氧酶-1对肝癌细胞细胞周期调控因子的影响

目的 观察血红素加氧酶-1(heme oxygenase 1,HO-1)对人肝癌细胞HepG2细胞周期调控因子的影响.方法 构建含有野生型和突变型HO-1基因的重组载体pcDNA3.1(+)-wtHO-1和pcDNA3.1(+)-mHO-1G143H.利用脂质体介导的方法将构建好的重组载体转染肝癌细胞系HepG2,以空载体转染作为对照组.通过G418筛选建立稳定表达野生型和突变型HO-1的HepG2肝癌细胞系.经半定量RT-PCR、Western印迹检测转染细胞系中HO-1 mRNA和蛋白的表达水平.在HO-1表达改变的稳转细胞系中,利用Western 印迹检测转染细胞系中P21、P27蛋白表达水平.结果 成功实现了野生型和突变型HO-1在HepG2细胞中的过表达;野生型和突变型HO-1过表达均能诱导抑癌基因p21和p27的表达.结论 HO-1过表达诱导抑癌基因p21和p27的表达与血红素分解产物无关.HO-1可能通过其它机制调节p21和p27的表达.     

PLK1在细胞周期生物学的研究进展

PLK1(polo like kinase)是一类广泛存在于真核细胞中的丝/苏氨酸激酶,其结构及功能均十分保守。研究表明,plk1在启动、维持及完成有丝分裂中扮演重要角色,plk1磷酸化多种下游底物而实现其功能。已发现plk1基因在多种恶性肿瘤中存在过表达并与某些肿瘤的生物学行为及预后相关,有望成为恶性肿瘤的又一新的标记物,阻断plk1表达可导致体外肿瘤细胞分裂停滞及凋亡。     

PARP-1抑制剂对人肝癌细胞HepG2增殖和迁移的抑制作用

目的 研究证实聚腺苷二磷酸核糖聚合酶-1(poly ADP ribose polymerase,PARP-1)抑制剂对肿瘤细胞的增殖、凋亡和侵袭有影响,但对肝癌细胞生物学特性的影响尚不清楚,此研究的目的是观察3种不同的PARP-1抑制剂对人肝癌细胞株HepG2增殖、凋亡及迁移的影响及可能机制.方法 MTT检测体外不同浓度的PARP-1抑制剂AG014699,BSI-201,AZD-2281处理后HepG2细胞的增殖;随后选择抑制效果明显的抑制剂AG014699和BSI-201处理HepG2;Western印迹法检测HepG2细胞Casepase3、Casepase8、Bax、Bcl-2、PTEN、Timp3、MMP3蛋白的表达水平.Transwell实验检测AG014699和BSI-201对HepG2细胞迁移的影响.结果 AG014699,BSI-201,AZD-2281均具有抑制HepG2细胞增殖的作用,具有时间和浓度依赖性,作用HepG2细胞48 h后的Caspase3、Caspase8、Bax、PTEN、Timp3蛋白的表达水平随药物浓度的增加而增高,而Bcl-2和MMP3蛋白水平随药物浓度的增加而降低且与对照组相比有显著性差异(P<0.01).结论 在体外PARP-1抑制剂AG014699、BSI-201、AZD-2281明显抑制HepG2细胞的增殖,但AG014699和BSI-201展示较好的敏感性,同时二者诱导肝癌细胞凋亡和抑制肝癌细胞的迁移,这其中的机制可能与影响凋亡信号的通路以及迁移相关蛋白的表达有关.     

circ_ 0061140 靶向 miR-6838-5p 促进非小细胞肺癌细胞的增殖、 阻滞细胞周期、 诱导细胞凋亡

目的 通过实验研究确认环状 RNA (circRNA) circ_ 0061140 是否能靶向 miR-6838-5p 调控非小 细胞肺癌细胞的增殖、 细胞周期和凋亡。 方法 采用逆转录-定量聚合酶链反应 (RT-qPCR) 检测 circ_ 0061140 和 miR-6838-5p 在非小细胞肺癌细胞中的表达情况。 将非小细胞肺癌 NCI-H1299 细胞分为 si-circ_ 0061140 组 (转染 si-circ_ 0061140; 低表达 circ_ 0061140)、 si-NC 组 (转染 si-NC; 阴性对照)、 NC 组 (未 转染; 空白对照)、 miR-6838-5p 组 (转染 miR-6838-5p 模拟物; 高表达 miR-6838-5p)、 miR-NC 组 (转染 miR-NC; 高表达 miR-6838-5p 的阴性对照)、 si-circ_ 0061140 + anti-miR-NC 组 (共转染 si-circ_ 0061140 与 anti-miR-NC)、 si-circ_ 0061140 + anti-miR-6838-5p 组 (共转染 si-circ_ 0061140 与 anti-miR-6838-5p)。 采用 Western 印迹检测细胞周期蛋白 D1 ( cyclinD1)、 活化的含半胱氨酸的天冬氨酸蛋白水解酶-3 ( cleaved caspase-3) 蛋白表达, MTT 法检测细胞增殖能力, 流式细胞仪检测细胞周期和凋亡情况。 双荧光素酶活性 检测 circ_ 0061140 和 miR-6838-5p 的靶向结合。 结果 非小细胞肺癌组织、 细胞 NCI-H1299、 NCI-H2170、 NCI-H1975 中的 circ_ 0061140 表达量均比癌旁组织或正常肺上皮细胞 BEAS-2B 高, miR-6838-5p 表达量比 癌旁组织或 BEAS-2B 细胞低 (P均 < 0. 05)。 si-circ_ 0061140 组或 miR-6838-5p 组 NCI-H1299 细胞的 CyclinD1 蛋白表达量、 增殖能力、 S 期细胞比例比 NC 组减少, Cleaved-caspase-3 蛋白表达量、 G0 / G1期细胞比 例、 凋亡率比 si-NC 组或 miR-NC 组增加 (P均 < 0. 05)。 circ_ 0061140 靶向调控 miR-6838-5p 的表达。 共转 染 si-circ_ 0061140、 anti-miR-6838-5p 可减弱转染 si-circ_ 0061140 对细胞生物学行为的作用。 结论 低表达 circ_ 0061140 通过靶向非小细胞肺癌细胞的 miR-6838-5p, 抑制细胞增殖、 阻滞 G0 / G1期细胞周期, 并加速 凋亡。     

LncRNA-WTAPP1敲除抑制结肠癌细胞生长和运动能力以及裸鼠移植瘤的增生

目的 旨在研究LncRNA-WTAPP1敲除对结肠癌细胞生长和运动能力以及裸鼠移植瘤的增生的影响.方法 选择结肠癌SW480细胞进行研究.将shRNA1-WTAPP1,shRNA2-WTAPP1和shRNA3-WTAPP1用Lipofectamine 2000转染到SW480细胞.选择转染,shRNA2-WTAPP1的...     

miR-137对肾癌GRC-1细胞增殖与凋亡的影响

目的 研究miR-137对肾癌GRC-1细胞增殖与凋亡的影响.方法 采用miR-137模拟物转染至肾癌GRC-1细胞,实验分为未转染组(未进行miR-137模拟物转染)、miR-137对照组(转染随机序列)、miR-137转染组(进行miR-137模拟物转染).荧光定量PCR检测各组转染后48h细胞中miR-137表达水平,应用噻唑蓝细胞增殖试验(MTT)、流式细胞检测技术与免疫荧光评价miR-137对肾癌GRC-1细胞增殖和凋亡的影响.结果 转染miR-137模拟物48h后,荧光定量PCR检测发现未转染组、miR-137对照组及miR-137转染组GRC-1细胞中miR-137的相对表达量依次为(24.43±2.03)％、(26.57±2.55)％、和(73.30±3.29)％,差异有统计学意义(P＜0.05).MTT细胞增殖实验与流式细胞仪检测结果显示,与未转染组、miR-137对照组相比,miR-137转染组转染48h后肾癌GRC-1细胞的增殖率显著降低,凋亡率显著升高,差异有统计学意义(P＜0.05),而未转染组、miR-137对照组肾癌GRC-1细胞的增殖率、凋亡率比较差异无统计学意义(P＞0.02).结论 miR-137可明显抑制肾癌GRC-1细胞增殖和促进其凋亡,故有望成为肾癌基因治疗的新靶点.     

Ropivacaine Induces Cell Cycle Arrest in the G0/G1 Phase and Apoptosis of PC12 Cells via Inhibiting Mitochondrial STAT3 Translocation

Inflammation - STAT3 has neuroprotective effect via non-canonical activation and mitochondrial translocation, but its effect on ropivacaine-induced neurotoxicity remains unclear. Our previous study...     

Reduced MTA1 Expression by RNAi Inhibits in Vitro Invasion and Migration of Esophageal Squamous Cell Carcinoma Cell Line

To distinguish aggressive esophageal squamous cell carcinoma from indolent disease is the important clinical challenge. Studies have indicated that metastasis-associated gene 1(Mta1) played a role in the process of metastasis of carcinoma. The overexpression of Mta1 gene has been found in a variety of tumors. To identify the detailed roles of MTA1 protein in the carcinogenesis of esophageal squamous cell carcinoma, this study analyzed the pathological specimens on tissue microarray derived from 72 patients using immunohistochemistry. MTA1 expression increased in the nuclear with the development of esophageal squamous cell carcinoma from normal epithelial cell, dysplasia, to invasive cancer. In biological studies with human esophageal squamous cell carcinoma cell line, MTA1 plays its roles to promote cancer cell invasion, adhesion and movement. RNA interference (RNAi) against MTA1 decreased the malignant phenotypes. Gene microarray analysis revealed some metastasis-associated genes were altered by MTA1 RNAi. This study started an effective beginning to explore metastasis mechanisms and cancer gene therapy strategy targeting MTA1.     

Increased Expression of Macrophage Migration Inhibitory Factor and DJ-1 contribute to Cell Invasion and Metastasis of Nasopharyngeal Carcinoma

Background and aim: Both macrophage migration inhibitory factor (MIF) and DJ-1 protein have been shown to relate with cell invasion and metastasis in tumors. However, the role of DJ-1 in invasion and metastasis of nasopharyngeal carcinoma (NPC) and its relation to MIF expression in NPC are not fully understood. The aim of present study is to determine whether or not MIF and DJ-1 are correlated with tumor invasion and influence a worse outcome in NPC, as well as its related mechanism.Methods: 125 cases of NPC and 45 normal tissues of nasopharynx were collected. The expression of MIF and DJ-1 in tissue microarray was evaluated by immunohistochemical staining. Correlation between immunostainings and clinicopathological parameters, as well as the follow-up data of patients, was analyzed statistically. The association of MIF and DJ-1 with cell invasion and migration in NPC cell line were evaluated by small interfering RNA (siRNA) transfection, invasion assay and Western blotting.Results: MIF and DJ-1 staining was diffused and strong in tumor cells, whereas they were generally weaker and less common in normal lining epithelia of nasopharynx. High MIF expression in tumor cells (71.2%, 89/125 cases) were significantly associated with advanced clinical stage, lymph node metastasis, and worse prognosis of NPC patients. High expression of DJ-1 (75.2%, 94/125 cases) were closely correlated to lymph node metastasis and MIF high-expression. Only MIF high expression (P = 0.010) and lymph node metastasis (P = 0.004) emerged as strong independent prognostic factors for overall survival of NPC patients. In vitro, down-regulated expression of DJ-1 in NPC cell lines by siRNA was observed to reduce cell migration and invasion potential, however, exogenous MIF promoted cells invasion.Conclusions: The data provided evidence that increased expression of MIF and DJ-1 induced cell invasion and metastasis of NPC, supporting the idea that MIF and DJ-1 may play important roles as regulators in the progression of NPC.     

Therapeutic strategy targeting the mTOR–HIF-1α–VEGF pathway in ovarian clear cell adenocarcinoma

Malignant tumors usually involve a relatively hypoxic state, which induces overexpression of hypoxia-inducible factor-1α (HIF-1α) to satisfactorily enable the tumor to survive. Thus, inhibition of the mammalian target of rapamycin (mTOR) pathway including HIF-1α is expected to play a major role in suppression of tumor cell growth, having recently drawn much attention as an anti-cancer therapeutic strategy for various malignant tumors. In the present study, which compared clear cell adenocarcinoma (CLA) of the ovary with serous adenocarcinoma (SEA), the immunohistochemical expression of mTOR, phosphorylated-mTOR (p-mTOR), HIF-1α, and vascular endothelial growth factor (VEGF) was examined in surgically resected specimens of 29 SEA and 47 CLA. There were no significant differences in expression of mTOR, HIF-1α and VEGF between SEA and CLA, but it was noted that p-mTOR expression was more prominent in CLA than SEA. Then, using the cell lines of CLA (RMG-1 and W3uF), an experimental study was designed to clarify whether tumor suppression due to downregulation of mTOR activity could represent a promising therapeutic strategy for CLA. After treatment of an analogue of rapamycin (everolimus), expression of mTOR, p-mTOR, HIF-1α and VEGF was examined on western blot. As a result, although mTOR expression remained unchangeable, expression of p-mTOR, HIF-1α and VEGF was shown to be sharply depressed. The same expression alterations were demonstrated in the xenograft model treated with everolimus. In conclusion, mTOR-targeted therapy through usage of drugs such as everolimus may be more effective for CLA of the ovary because of its significant expression of p-mTOR.