Interference of lysine-specific demethylase 1 inhibits cellular invasion and proliferation in vivo in gastric cancer MKN-28 cells

BackgroundLysine-specific demethylase 1(LSD1), the first identified histone demethylase, plays an important role in the epigenetic regulation of gene activation and repression. Up-regulated LSD1expression has been reported in several malignant tumors.Our aim, therefore, was to better understand the mechanisms underlying the upregulation of LSD1 in gastric cancer.MethodsWe used lentiviral shRNA to knockdown LSD1 in the gastric cancer MKN-28 cell line. Cell proliferation was measured by MTT assay while cell apoptosis was assessed by Annexin V-FITC/PI double staining flow cytometry. The invasive potential of gastric cancer cells was determined by matrigel invasion assay. Protein expression was detected by Western blot. In vivo, the effect of knocking down LSD1 on tumor growth and protein expression in gastric cancer cells in nude mice was investigated.ResultsLSD1 knockdown in MKN-28 cell lines resulted in increasing the activity of cisplatin in vitro and the inhibition of cancer cell proliferation and invasion, and induced cell apoptosis. The expression of TGF-β1, VEGF, Bcl-2, β-catenin, p-ERK and p-Smad 2/3 proteins was inhibited in LSD1 knockdown cells. Moreover, in an in vivo model of gastric cancer, LSD1 knockdown suppressed tumor growth and protein expression.ConclusionLSD1 knockdown affected the fuction of gastric cancer MKN-28 cell line. LSD1 may be a latent target in the diagnosis and therapy of gastric cancer.     

四种人胃癌细胞体外增殖和侵袭能力比较

目的比较四种不同组织来源、不同分化程度的胃癌细胞MGC-803、HGC-27、BGC-823、SGC-7901的体外增殖和侵袭能力。方法分别培养四种细胞,用直接计数法绘制细胞生长曲线,计算其群体倍增时间;以细胞克隆形成率比较其增殖能力;体外划痕法和Transwells法比较四种细胞迁移、侵袭能力。结果与MGC-803和HGC-27相比,BGC-823和SGC-7901的生长速度依次减慢,群体倍增时间依次增加(P<0.05);平板克隆形成率从MGC-803、HGC-27、BGC-823到SGC-7901分别是42.7±2.2、38.6±1.6、28.9±1.7、21.3±1.9,差异有统计学意义(P<0.05)。体外划痕法和Transwells小室侵袭实验均表明MGC-803和HGC-27细胞的迁移侵袭能力较BGC-823和SGC-7901高,差异有统计学意义(P<0.05)。结论四株胃癌细胞株,从MGC-803、HGC-27、BGC-823到SGC-7901其增殖和侵袭能力逐渐下降。     

Tetramethylpyrazine inhibits proliferation of colon cancer cells in vitro

BACKGROUNDColon cancer is one of the most common malignancies worldwide, and chemotherapy is a widely used strategy in colon cancer clinical therapy. However, chemotherapy resistance is a major cause of disease recurrence and progression in colon cancer, and thus novel drugs for treatment are urgently needed. Tetramethylpyrazine (TMP), a component of the traditional Chinese medicine Chuanxiong Hort, has been proven to exhibit a beneficial effect in tumors. AIMTo investigate the potential anticancer activity of TMP in colon cancer and its underlying mechanisms.METHODSColon cancer cells were incubated with different concentrations of TMP. Cell viability was evaluated by crystal violet staining assay and cell counting kit-8 assay, and cell apoptosis and cell cycle were assessed by flow cytometry.RESULTSTMP significantly inhibited the proliferation of colon cancer cells in a dose- and time-dependent manner. In addition, flow cytometry revealed that TMP induced cell cycle arrest at the G0/G1 phase. TMP treatment caused early stage apoptosis in SW480 cells, whereas it caused late stage apoptosis in HCT116 cells.CONCLUSIONOur studies demonstrated that TMP inhibits the proliferation of colon cancer cells in a dose- and time-dependent manner by inducing apoptosis and arresting the cell cycle at the G0/G1 phase. Our findings suggest that TMP might serve as a potential novel therapeutic drug in the treatment of human colon cancer.     

Dexamethasone inhibits epidermal growth factor-stimulated gastric epithelial cell proliferation

Epidermal growth factor (EGF) is essential to heal gastric ulcers, whereas glucocorticoid delays rat gastric ulcer healing. We found that dexamethasone inhibited EGF-stimulated rat gastric epithelial cell (RGM-1) proliferation by cell count and DNA synthesis analysis of flow cytometry and attempted to elucidate the possible mechanistic pathway via Western blot analysis. EGF (10 ng/ml) treatment for 24 h significantly increased RGM-1 cell proliferation, and dexamethasone (10(-8) and 10(-6) M) markedly suppressed EGF-stimulated cell proliferation. Western blotting results demonstrated that the phosphorylated extracellular signal-regulated kinase (pERK) (pERK1/pERK2) significantly increased at 10 min after EGF treatment. This was followed by increase of cyclooxygenase (COX)-2 expression at 3 h after EGF treatment. The continued increase of COX-2 (up to 18 h) resulted in increased intracellular prostaglandin E(2) and cyclin D1 expression significantly after 8 and 12 h of EGF treatment. Dexamethasone substantially reduced EGF-stimulated COX-2 expression at 3 and 6 h and cyclin D1 expression at 8 and 12 h. Pretreatment of RGM-1 cells with dexamethasone or 2'-amino-3'-methoxyflavone (PD98059)-mitogen-activated protein kinase kinase inhibitor (5 x 10(-5) M) significantly reduced EGF-stimulated pERK1/pERK2 expression. Simultaneous treatment of RGM-1 cells with PD98059 and EGF also markedly decreased EGF-stimulated COX-2 expression at 6 h. These findings indicate that dexamethasone significantly suppresses EGF-stimulated gastric epithelial cell proliferation, and one of the pathways involved is via inhibiting activation of ERK1/ERK2, followed by inhibition of COX-2, cyclin D1 expression, and finally DNA synthesis.     

The Rho-kinase inhibitor inhibits proliferation and metastasis of small cell lung cancer

The purpose of this study was to investigate the effects of Rho-kinase inhibitor on the growth, proliferation, apoptosis, adhesion, invasion and migration of NCI-H446 small cell lung cancer cells and to explore the underlying molecular mechanisms involved in this process. After treatment to NCI-H446 small cell lung cancer cells with Fasudil, a Rho-kinase inhibitor, cell biological behaviors were observed. Matrix metalloproteinase activity and Western blot assay were used to evaluate underlying molecular mechanisms. The IC50 of Fasudil to NCI-H446 small cell lung cancer cells was approximately 0.86 mg/ml (95% confidence limits: 0.65–1.17 mg/ml). After treatment with 0.75 mg/ml Fasudil, the ability of NCI-H446 small cell lung cancer cells, including growth, proliferation, adhesion, migration, and invasion were decreased, while their apoptosis was increased significantly. On the molecular level, the total amounts of active MMP2 and MMP9 were decreased about 20.5% (P < 0.05) and 57.5% (P < 0.01) respectively. Myosin phosphatase targeting subunit 1 phosphorylation (P-MYPT1) was reduced by 27.9% (P < 0.05). The activation of caspase-3, and PARP cleavage in experimental group were significantly higher than those in normal control group (P < 0.01). Meanwhile, treatment with Fasudil led to a remarkable reduction of the phosphorylated STAT3 (P-STAT3) (P < 0.01). Taken together, our findings show that Fasudil prevents the growth, metastasis and induces apoptosis of NCI-H446 small cell lung cancer cells by inhibiting the Rho/Rho-kinase pathway. Changes in MMP2, MMP9, P-MYPT1, caspase-3, PARP cleavage and P-STAT3 may be one of its molecular mechanisms.     

Ultrasonographic findings in gastric cancer: in vitro and in vivo studies

Ultrasonography was performed in 45 cases of gastric cancer. Specimens from all 45 cases of gastric cancer were subjects to ultrasonographic study by the water immersion method for comparison with histology. In 32 of these 45 cases in vivo ultrasonographic evaluation was performed prospectively. The overall accuracy rates for the diagnosis of the depth of cancerous invasion were almost 80% in both in vitro and in vivo studies. In vivo ultrasonographic findings agreed well with those from the specimen studies. Ultrasonography was considered to be useful in the diagnosis of gastric malignancies.     

Terbinafine inhibits the mitogenic response to platelet-derived growth factor in vitro and neointimal proliferation in vivo

Terbinafine [(E)-N(6,6-dimethyl-2-hepten-4-ynyl)-N-methyl-1-naphthale nemethanamine], an antimycotic agent that inhibits fungal squalene epoxidase activity, was examined for its effects on platelet-derived growth factor (PDGF)-stimulated aortic smooth muscle cell DNA synthesis in vitro and neointimal proliferation in vivo. Exposure of bovine aortic smooth muscle cells to 0.25 to 25 microM terbinafine resulted in a concentration-dependent inhibition of PDGF-induced mitogenesis as determined by [3H]thymidine incorporation into DNA or cell number. The IC50 for inhibition of PDGF-stimulated smooth muscle cell DNA synthesis was approximately 5 microM. Micromolar concentrations of terbinafine also suppressed the mitogenic response to PDGF in fibroblasts. Neither the binding of [125I]PDGF to its plasma membrane receptors nor the uptake of [3H]thymidine or [3H]uridine was affected significantly by terbinafine. Oral administration of terbinafine (200 mg/kg/day) to rats for 2 days before and 14 days after balloon catheter injury to the carotid artery was associated with a 40% decrease in the area of the neointimal lesion. These observations indicate that terbinafine is both a potent in vitro antagonist of the smooth muscle cell mitogenic response to PDGF and an effective, well-tolerated p.o. active inhibitor of neointimal proliferation in vivo.     

ErbB3 inhibitory surrobodies inhibit tumor cell proliferation in vitro and in vivo

ErbB3 is an important regulator of tumorigenesis and is implicated in development of resistance to several currently used oncology drugs. We have identified ErbB3 inhibitors based on a novel biologic scaffold termed a surrobody. Two of these inhibitors appear to work by a previously unrecognized mechanism of action. As a consequence, they not only inhibited cell proliferation and intracellular signaling driven by stimulation with the ErbB3 ligand neuregulin (NRG), but also inhibited signaling and proliferation that was driven by overexpression of ErbB2 in the absence of ligand stimulation. In addition, the surrobodies inhibited tumor growth in vivo in both ErbB2-overexpressing and nonoverexpressing cells. In ErbB2-overexpressing cells, both of the anti-ErbB3 surrobodies significantly augmented the activities of trastuzumab, lapatinib, and GDC-0941, agents that inhibit cell proliferation by different mechanisms. Moreover, although NRG diminished the efficacy of these agents, when they were combined with anti-ErbB3 surrobodies the affect of NRG was abrogated. In this capacity, the anti-ErbB3 surrobodies were more effective than the ErbB2/ErbB3 dimerization inhibitory antibody pertuzumab. Despite the fact that these surrobodies appear to engage ErbB3 differently than previously described anti-ErbB3 antibodies, they retain all of the beneficial characteristics of this class of agents, including the ability to augment drugs that inhibit EGF receptor. These anti-ErbB3 agents, therefore, show substantial promise for development as single agents or in combination with other ErbB-directed antibodies or small molecules and may provide for a broader range of therapeutic indications than previously described anti-ErbB3 antibodies.     

MicroRNA-137 down-regulates KIT and inhibits small cell lung cancer cell proliferation

MiR-137 expression was examined in parental and drug-resistant cell lines, H446 and H446/CDDP, of small lung cancer (SCLC), and the results showed there was fewer miR-137 expressed in H446/CDDP cells followed by KIT expression emergence. In order to confirm physiological function of these abnormal expressions, H446 and H446/CDDP cells were transfected with miR-137 inhibitor and miR-137 mimics, respectively, after that, miR-137 and KIT expression in two cell lines and drug sensitivity of these cells were evaluated. Results indicated that sensitivity of H446 cells to cisplatin significantly decreased after transfected with miR-137 inhibitor, while miR-137 mimics transfection increased drug sensitivity of H446/CDDP cells and deregulated KIT expression. Our data provided combined evidence that miR-137 was closely related to MDR of SCLC, and interfering of miR-137 expression may attenuate drug resistant of H446/CDDP cells to cisplatin partially through KIT expression regulation. Besides, it has also been proved that KIT might be only one of the downstream molecules of miR-137 that related to SCLC MDR.     

小干扰RNA靶向血管内皮生长因子基因抑制胆囊癌细胞的增殖体内外实验

背景:已有研究发现RNA干扰可通过抑制血管内皮生长因子基因表达抑制肿瘤细胞增殖,但目前关于应用RNA干扰胆囊癌血管内皮生长表达的研究国内外尚无相关报道.目的:构建并筛选靶向血管内皮生长因子的shRNA,观察RNA干扰血管内皮生长因子的效果及对胆囊癌细胞增殖的影响.方法:设计VEGF-shRNA片段,连接到pCYU6/GFPINeo-shRNA质粒载体上.shRNA转染胆囊癌细胞.建立裸鼠胆囊癌模型,随机分成空白组、阴性对照组、实验组(干扰pShRNA-VEGF2),每组6只.瘤内注射shRNA.荧光显微镜观察细胞生长状态,半定量反转录-聚合酶链反应法与实时荧光定量聚合酶链反应检测RNA干扰效果,观察胆囊癌裸鼠模型肿瘤体积变化. 结果与结论:RNA干扰血管内皮生长因子后,胆囊癌细胞细胞变圆,皱缩,部分细胞死亡脱落.ShRNA片段血管内皮生长因子2、血管内皮生长因子1均可抑制VEGF mRNA表达,抑制率可达86%,82%.裸鼠肿瘤模型中实验组肿瘤与对照组、阴性组相比明显变小,且生长缓慢(P<0.05),而对照组和阴性组在肿瘤大小及生长趋势上没有明显的差别.实验构建的hVEGF-shRNA质粒表达载体通过抑制血管内皮生长因子的表达,抑制胆囊癌细胞增殖,从而达到间接治疗肿瘤的目的.     

microRNA-138通过靶向作用于CCND1抑制结肠癌细胞增殖

目的探讨人结肠癌细胞SW620中细胞周期蛋白1(CCND1)的表达情况及其异常表达对细胞增殖的影响,阐述microRNA-138(miR-138)在SW620增殖中的可能机制。方法采用实时荧光定量聚合酶链式反应(qRT-PCR)以及Western blot确定结肠癌组织和癌旁组织中CCND1的表达情况;随后采用qT-PCR检测结肠癌组织内miR-138的表达,并通过统计学分析miR-138与CCND1表达的相关性,培养SW620细胞并转染miR-138模拟物(mimics)后验证miR-138与CCND1的相关性,在SW620细胞内进一步转染miR-138模拟物后,Transwell和MTT检测不同处理组中细胞增殖和迁移能力的改变情况;继续转染CCND1 siRNA后,探索miR-138影响细胞生物学过程的可能机制。结果结肠癌组织中,与相应癌旁组织相比,CCND1表达显著升高,miR-138表达降低,差异有统计学意义(P<0.05);转染miR-138mimics后,与空白对照组(未转染组)相比,细胞迁徙能力下降,同时增殖降低,差异有统计学意义(P<0.05);转染CCND1 siRNA后,与未转染组相比,miR-138表达变化无显著差异(P>0.05),而细胞侵袭能力和增殖能力较未转染组相比显著改变,差异有统计学意义(P<0.05)。结论结肠癌组织中CCND1异常升高可能与miR-138的表达降低有关,且miR-138影响SW620细胞的迁移和增殖能力可能是通过影响CCND1的表达实现的。     

Interleukin 4 inhibits in vitro proliferation of leukemic and normal human B cell precursors.

In the present study, we have investigated the effects of IL-4 on the proliferation and differentiation of leukemic and normal human B cell precursors (BCP). We have demonstrated that IL-4 significantly inhibited spontaneous [3H]thymidine ([3H]-TdR) incorporation by leukemic blasts from some B lineage acute lymphoblastic leukemia (BCP-ALL) patients (8 of 14). Furthermore, IL-4 was found to suppress the spontaneous and factor-dependent (IL-7 and IL-3) proliferation of normal BCP (CD10+ surface [s] IgM- cells) isolated from fetal bone marrow. Maximum growth inhibition of either leukemic or normal BCP was reached at low IL-4 concentrations (10 U/ml), and the effect was specifically neutralized by anti-IL-4 antibody. IL-4 was further found to induce the expression of CD20 antigen on BCP-ALL cells from a number of the cases examined (5 of 8), but in contrast to leukemic cells, IL-4 failed to induce CD20 antigen on normal BCP. Finally, IL-4 was found to induce neither the expression of cytoplasmic mu chain, nor the appearance of sIgM+ cells in cultures of normal or leukemic BCP. Our data indicate that IL-4 has the potential to inhibit cell proliferation in leukemic and normal human B lymphopoiesis but is unable to drive the transition from BCP to mature B cells.     

A novel small-molecule YLT256 inhibits proliferation and induces apoptosis both in vitro and in vivo in solid tumors

Pancreatic carcinoma is a still unsolved health problem all over the world with poor prognosis and high mortality rate. YLT256, a novel synthesized chemical small inhibitor, displays potent antineoplastic activities via inducing apoptosis both in vitro and in vivo. In this study, we found that YLT256 showed growth inhibition against a broad spectrum of human cancer cell lines and pancreatic cancer cell line BxPc-3 was the most sensitive with an IC₅₀ of 0.42 μM. We also found YLT256 could induce apoptosis of BxPc-3 cells in a dose-dependent manner. Western blot analysis revealed that the occurrence of its apoptosis was associated with activation of caspases-3 and -9, up-regulation of pro-apoptotic Bak, and down-regulation of anti-apoptotic Bcl-2. Moreover, YLT256-treated resulted in changes of mitochondrial membrane potential (Δψm), and generation of reactive oxygen species (ROS). Furthermore, our data also revealed that YLT256 suppressed the growth of established tumor-bearing xenograft models without obvious side effects. Immunohistochemical analyses and TUNEL assay revealed an increase in cleaved caspase-3-positive cells and TUNEL-positive cells, a decrease in Ki67-positive cells upon YLT256. Together, all the results of present study provided evidence demonstrating that YLT256 could be a promising potential drug candidate for pancreatic cancer therapy.     

Inhibition of human endothelial cell proliferation in vitro and neovascularization in vivo by D-penicillamine.

To investigate the effects of D-penicillamine (D-Pen) on angiogenesis, we have studied the effects of this drug on in vitro proliferation of human endothelial cells (EC) and in vivo corneal neovascularization. D-Pen, in the presence of copper sulfate, suppressed tritiated thymidine ([3H]TdR) incorporation into EC in a dose-dependent manner. Significant inhibition was observed with D-Pen concentrations attainable in the serum and tissues of treated patients. Neither D-Pen nor copper ion alone significantly affected [3H]TdR incorporation into EC. The inhibition by D-Pen and copper was blocked by catalase (CAT) or horseradish peroxidase but not by boiled CAT or SOD. When rabbits were daily injected intravenously with D-Pen at the per kilogram dosage administered to rheumatoid patients, neovascularization as quantitated by the proliferation of corneal new blood vessels was significantly inhibited. These results suggest that hydrogen peroxide generated by D-Pen and copper exerts a pronounced antiangiogenic effect through inhibition of EC proliferation. It is, therefore, considered that D-Pen may suppress rheumatoid synovitis by reducing the number of small blood vessels available for the emigration of chronic inflammatory cells, and the proliferation of the synovial tissue.     

Dipyridamole inhibits in vitro renal fibroblast proliferation and collagen synthesis

Fibroblasts are universally recognized in situations of tubulointerstitial injury, where their presence has been shown to be a marker of disease progression. The objective of this study was to determine whether the functions of fibroblasts relevant to fibrogenesis can be modified in vitro with dipyridamole. Cells were obtained from obstructed rat renal tissue and characterized on the basis of immunohistochemical findings. Fibroblasts constituted all of the cells from passage 3. Functional parameters were measured in cells cultured with 1, 5, and 50 micromol/L dipyridamole and compared to basal parameters of cells grown in Dulbecco's modified Eagle's medium plus 10% fetal calf serum (control). Northern-blot analysis indicated that dipyridamole decreased procollagen alpha1(I) messenger ribonucleic acid expression (P <.05, 50 micromol/L vs control), results that were reflected in a reduction in total collagen secretion as measured on the basis of hydroxyproline incorporation (P <.001, 50 micromol/L vs control). Mitogenesis, as measured on the basis of incorporation of tritiated thymidine, was decreased in a dose-dependent fashion by dipyridamole. Likewise, 50 micromol/L dipyridamole reduced cell-population growth to 16.8% +/- 2.1% of basal growth over 3 days (P <.001 vs control). Effects of dipyridamole on population growth were prevented by coincubation with a protein kinase G inhibitor peptide (P <.001 vs 50 micromol/L dipyridamole; P = not significant vs control). No such effect was observed with inhibitors for protein kinase A (H-89) and protein kinase C (bisindolylmaleimide I). Consistent with a protein kinase G-dependent mechanism, immunofluorescence staining indicated that dipyridamole increased basal expression of the inducible form of nitric oxide synthase. In conclusion, the results of this study demonstrate that at clinically relevant concentrations, dipyridamole inhibits profibrotic activities of renal fibroblasts. Effects on mitogenesis are mediated through a cyclic guanosine monophosphate-protein kinase G effector pathway.