scholarly journals Hypoxic Proliferation of Osteosarcoma Cells Depends on Arginase II

2016 ◽  
Vol 39 (2) ◽  
pp. 802-813 ◽  
Author(s):  
Bhuvana A. Setty ◽  
Yi Jin ◽  
Peter J. Houghton ◽  
Nicholas D. Yeager ◽  
Thomas G. Gross ◽  
...  
Keyword(s):  
Cellular Proliferation ◽  
Osteosarcoma Cell ◽  
Dependent Manner ◽  
Small Interfering Rnas ◽  
Osteosarcoma Cells ◽  
Protein Levels ◽  
Hypoxic Conditions ◽  
Human Osteosarcoma Cell ◽  
Arginase Ii

Background/Aims: Despite significant advancements in the diagnosis and treatment of osteosarcoma, the overall survival has remained relatively unchanged for over two decades. Hypoxic conditions have been demonstrated in solid tumors and are associated with increased cell proliferation and angiogenesis. L-arginine metabolism by arginase produces L-ornithine, the precursor for polyamine and proline synthesis required for cellular proliferation. We hypothesized that hypoxia would increase cellular proliferation via arginase induction in human osteosarcoma cell lines. Methods: We utilized a variety of approaches to examine the role of arginase II in hypoxic (1% O2, 5% CO2) cellular proliferation. Results: Arginase II mRNA and protein levels were significantly increased in osteosarcoma cells exposed to hypoxia for 48 hours. There were twice as many viable cells following 48 hours of hypoxia than following 48 hours of normoxia (21% O2, 5% CO2). The addition of difluoromethylornithine (DFMO), a putative arginase inhibitor, prevented hypoxia-induced proliferation. Transfection of small interfering RNAs (siRNA) targeting arginase II resulted in knockdown of arginase II protein levels and prevented hypoxia-induced cellular proliferation. Conclusions: These data support our hypothesis that hypoxia increases proliferation of osteosarcoma cells in an arginase II-dependent manner. We speculate that arginase II may represent a therapeutic target in osteosarcoma.

scholarly journals HDAC6 Inhibitor WT161 Performs Antitumor Effect on Ostersarcoma and Synergistically Interacts with 5-FU

2020 ◽  
Author(s):  
Jun Sun ◽  
Xiaofeng Tang ◽  
Feifei Zhang ◽  
Cheng Ju ◽  
Renfeng Liu ◽  
...  
Keyword(s):  
Osteosarcoma Cell ◽  
Dependent Manner ◽  
Osteosarcoma Cells ◽  
Proliferative Effect ◽  
Xenograft Models ◽  
Hdac6 Inhibitor ◽  
Underlying Mechanisms ◽  
Induced Apoptosis

Abstract Background: WT161 as a new selective HDAC6 inhibitor has been shown to play anti-tumor effects on multiple myeloma and breast cancer. However, the role of WT161 in osteosarcoma remains unclear. The aim of this study is to explore the role of WT161 in osteosarcoma and its underlying mechanisms.Methods: The anti-proliferative effect of WT161 on osteosarcoma cells was examined using MTT assay and colony formation assay. Cell apoptosis was analyzed using flow cytometer. The synergistic effect was evaluated by isobologram analysis using CompuSyn software. The osteosarcoma xenograft models were esatablished to evaluate the anti-proliferative effect of WT161 in vivo.Results: WT161 suppressed the cell growth and induced apoptosis of osteosarcoma cells in a dose- and time-dependent manner. Mechanistically, we found that WT161 treatment obviously increased the protein expression level of PTEN and decreased the phosphorylation level of AKT. Notably, WT161 shows synergistically inhibitory effects on osteosarcoma cell combined with 5-FU. Animal experiment results show WT161 inhibits the growth of osteosarcoma tumor and further illustrates that WT161 and 5-FU have a synergistic efficiency in osteosarcoma.Conclusions: These results indicate that WT161 inhibiting the growth of osteosarcoma through PTEN and has a synergistic efficiency with 5-FU.

scholarly journals Antiproliferative Properties of Oleuropein in Human Osteosarcoma Cells

2016 ◽  
Vol 11 (4) ◽  
pp. 1934578X1601100 ◽  
Author(s):  
Jose M. Moran ◽  
Olga Leal-Hernandez ◽  
Maria L. Canal-Macías ◽  
Raul Roncero-Martin ◽  
Rafael Guerrero-Bonmatty ◽  
...  
Keyword(s):  
Cell Lines ◽  
Osteosarcoma Cell ◽  
Dependent Manner ◽  
Osteosarcoma Cells ◽  
Probit Regression ◽  
Cytotoxic Effects ◽  
Human Osteosarcoma ◽  
Human Osteosarcoma Cells ◽  
Mg63 Cells ◽  
Human Osteosarcoma Cell

In this study, we evaluated the antiproliferative activity on two human osteosarcoma cell lines (MG-63 and Saos2) of oleuropein, an olive oil compound traditionally found in the Mediterranean diet. Oleuropein exhibited obvious cytotoxic effects on human osteosarcoma cells in a concentration- and time-dependent manner. Statistical analysis of IC50 by the Probit regression method suggested that oleuropein had similar toxic effects on both cell lines tested (IC50 range from 247.4–475.0 μM for MG63 cells and from 798.7–359.9 μM for Saos2 cells).

scholarly journals Elevated expression of serine/threonine phosphatase type 5 correlates with malignant proliferation in human osteosarcoma.

1970 ◽  
Vol 64 (1) ◽  
Author(s):  
Kun Han ◽  
Zhihua Gan ◽  
Shuchen Lin ◽  
Haiyan Hu ◽  
Zan Shen ◽  
...  
Keyword(s):  
Cell Lines ◽  
Functional Role ◽  
Osteosarcoma Cell ◽  
Osteosarcoma Cells ◽  
Facs Analysis ◽  
Human Osteosarcoma ◽  
Human Osteosarcoma Cell ◽  
Elevated Expression ◽  
Common Primary Malignant Bone

Osteosarcoma is the most common primary malignant bone tumor in adolescents and young adults. However, the involvement of serine/threonine phosphatase type 5 (PP5) in osteosarcoma remains unclear. The aim of this study was to evaluate the functional role of PP5 in osteosarcoma cells. Firstly, we found that PP5 is widely expressed in several human osteosarcoma cell lines. Then we used lentivirus-delivered siRNA to silence PP5 expression in Saos-2 and U2OS cell lines. Knockdown of endogenous PP5 expression by shRNA-expressing lentivirus significantly decreased the viability and proliferation of the osteosarcoma cells. Moreover, FACS analysis showed that knockdown of PP5 expression induced a significant arrest in the G0/G1 phase of the cell cycle, which was associated with the inhibition of cell proliferation. Therefore, knockdown of PP5 is likely to provide a novel alternative to targeted therapy of osteosarcoma and deserves further investigation.

scholarly journals IL6 sensitizes prostate cancer to the antiproliferative effect of IFNα2 through IRF9

2013 ◽  
Vol 20 (5) ◽  
pp. 677-689 ◽  
Author(s):  
Holger H H Erb ◽  
Regina V Langlechner ◽  
Patrizia L Moser ◽  
Florian Handle ◽  
Tineke Casneuf ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cell Lines ◽  
Cellular Proliferation ◽  
Tissue Expression ◽  
Type I ◽  
Regulatory Factor ◽  
Quantitative Real Time Pcr ◽  
Antiproliferative Effects ◽  
Protein Levels

Development and progression of prostate cancer (PCa) are associated with chronic inflammation. The cytokine interleukin 6 (IL6) can influence progression, differentiation, survival, and angiogenesis of PCa. To identify novel pathways that are triggered by IL6, we performed a gene expression profiling of two PCa cell lines, LNCaP and MDA PCa 2b, treated with 5 ng/ml IL6. Interferon (IFN) regulatory factor 9 (IRF9) was identified as one of the most prevalent IL6-regulated genes in both cell lines. IRF9 is a mediator of type I IFN signaling and acts together with STAT1 and 2 to activate transcription of IFN-responsive genes. The IL6 regulation of IRF9 was confirmed at mRNA and protein levels by quantitative real-time PCR and western blot respectively in both cell lines and could be blocked by the anti-IL6 antibody Siltuximab. Three PCa cell lines, PC3, Du-145, and LNCaP-IL6+, with an autocrine IL6 loop displayed high expression of IRF9. A tissue microarray with 36 PCa tissues showed that IRF9 protein expression is moderately elevated in malignant areas and positively correlates with the tissue expression of IL6. Downregulation and overexpression of IRF9 provided evidence for an IFN-independent role of IRF9 in cellular proliferation of different PCa cell lines. Furthermore, expression of IRF9 was essential to mediate the antiproliferative effects of IFNα2. We concluded that IL6 is an inducer of IRF9 expression in PCa and a sensitizer for the antiproliferative effects of IFNα2.

A novel mechanism of Ha-ras oncogene action: regulation of fibronectin mRNA levels by a nuclear posttranscriptional event

1994 ◽  
Vol 14 (5) ◽  
pp. 3085-3093
Author(s):  
L A Chandler ◽  
C P Ehretsmann ◽  
S Bourgeois
Keyword(s):  
Posttranscriptional Regulation ◽  
Tail Length ◽  
Common Mechanism ◽  
Osteosarcoma Cell ◽  
Mrna Levels ◽  
Ras Oncogene ◽  
Down Regulation ◽  
Regulate Gene Expression ◽  
Protein Levels ◽  
Human Osteosarcoma Cell

Although loss of cell surface fibronectin (FN) is a hallmark of many oncogenically transformed cells, the mechanisms responsible for this phenomenon remain poorly understood. The present study utilized the nontumorigenic human osteosarcoma cell line TE-85 to investigate the effects of induced Ha-ras oncogene expression on FN biosynthesis. TE-85 cells were stably transfected with metallothionein-Ha-ras fusion genes, and the effects of metal-induced ras expression on FN biosynthesis were determined. Induction of the ras oncogene, but not proto-oncogene, was accompanied by a decrease in total FN mRNA and protein levels. Transfection experiments indicated that these oncogene effects were not due to reduced FN promoter activity, suggesting that a posttranscriptional mechanism was involved. The most common mechanism of posttranscriptional regulation affects cytoplasmic mRNA stability. However, in this study the down-regulation of FN was identified as a nuclear event. A component of the ras effect was due to a mechanism affecting accumulation of processed nuclear FN RNA. Mechanisms that would generate such an effect include altered RNA processing and altered stability of the processed message in the nucleus. There was no effect of ras on FN mRNA poly(A) tail length or site of polyadenylation. There was also no evidence for altered splicing at the ED-B domain of FN mRNA. This demonstration of nuclear posttranscriptional down-regulation of FN by the Ha-ras oncogene identifies a new level at which ras oncoproteins can regulate gene expression and thus contribute to development of the malignant phenotype.

IL-4 and IL-13 upregulate arginase I expression by cAMP and JAK/STAT6 pathways in vascular smooth muscle cells

2000 ◽  
Vol 279 (1) ◽  
pp. C248-C256 ◽  
Author(s):  
Liu Hua Wei ◽  
Aaron T. Jacobs ◽  
Sidney M. Morris ◽  
Louis J. Ignarro
Keyword(s):  
Cell Proliferation ◽  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Muscle Growth ◽  
Muscle Cells ◽  
Protein Levels ◽  
Ifn Γ ◽  
Arginase Ii ◽  
Arginase I

The objectives of this study were to determine whether rat aortic smooth muscle cells (RASMC) express arginase and to elucidate the possible mechanisms involved in the regulation of arginase expression. The results show that RASMC contain basal arginase I (AI) activity, which is significantly enhanced by stimulating the cells with either interleukin (IL)-4 or IL-13, but arginase II (AII) expression was not detected under any condition studied here. We further investigated the signal transduction pathways responsible for AI induction. AI mRNA and protein levels were enhanced by addition of forskolin (1 μM) and inhibited by H-89 (30 μM), suggesting positive regulation of AI by a protein kinase A pathway. Genistein (10 μg/ml) and sodium orthovanadate (Na3VO4; 10 μM) were used to investigate the role of tyrosine phosphorylation in the control of AI expression. Genistein inhibited, whereas Na3VO4enhanced the induction of AI by IL-4 or IL-13. Along with immunoprecipitation and immunoblot analyses, these data implicate the JAK/STAT6 pathway in AI regulation. Dexamethasone (Dex) and interferon (IFN)-γ were investigated for their effects on AI induction. Dex (1 μM) and IFN-γ (100 U/ml) alone had no effect on basal AI expression in RASMC, but both reduced AI induction by IL-4 and IL-13. In combination, Dex and IFN-γ abolished AI induction by IL-4 and IL-13. Finally, both IL-4 and IL-13 significantly increased RASMC DNA synthesis as monitored by [3H]thymidine incorporation, demonstrating that upregulation of AI is correlated with an increase in cell proliferation. Blockade of AI induction by IFN-γ, H-89, or genistein also blocked the increase in cell proliferation. These observations are consistent with the possibility that upregulation of AI might play an important role in the pathophysiology of vascular disorders characterized by excessive smooth muscle growth.

LncRNA GAS5 suppresses the proliferation and invasion of osteosarcoma cells via the miR-23a-3p/PTEN/PI3K/AKT pathway

2020 ◽  
Author(s):  
Jianmin Liu ◽  
Ming Chen ◽  
Longyang Ma ◽  
Xingbo Dang ◽  
Gongliang Du
Keyword(s):  
Tumor Suppressor ◽  
Tumor Growth ◽  
Akt Pathway ◽  
Osteosarcoma Cell ◽  
Osteosarcoma Cells ◽  
Cell Behaviors ◽  
Human Osteosarcoma ◽  
Proliferation And Invasion

Abstract Background: Accumulating evidence has shown that lncRNA growth arrest special 5 (GAS5) is a well‑known tumor suppressor in the pathogenesis of a variety of human cancers. However, the detailed role of GAS5 in osteosarcoma is largely unclear. Here, we explore the role of GAS5 in progression of osteosarcoma. Methods: The expression level of GAS5 was detected in human osteosarcoma tissues and matched adjacent tissues, as well as osteosarcoma cell lines and non-malignant osteoblast cells. Then, in vitro gain- and loss-of-function experiments, with the pcDNA-GAS5 expression vector and GAS5-siRNA, were performed in U2OS and HOS cells to determine the effect of GAS5 on osteosarcoma cell proliferation and invasion. Subsequently, we searched potential miRNA targets with bioinformatics analysis and confirmed their interaction by using luciferase reporter gene and RNA pull-down assays. The function and mechanism of miR-23a-3p in proliferation and invasion was also investigated in U2OS and HOS cells. Furthermore, rescue experiments were performed to verify the involvement of miR-23a-3p and its target gene in GAS5-mediated cell behaviors. Finally, a xenograft nude mouse model was established by subcutaneous injection with U2OS cells overexpressing GAS5 or not, and the effect of GAS5 on tumor growth in vivo was evaluated. Results: GAS5 was downregulated in human osteosarcoma tissues and cell lines. Overexpression of GAS5 could significantly suppress, and downregulation of GAS5 promoted, proliferation and invasion of osteosarcoma cells. GAS5 could directly bind with and downregulated miR-23a-3p that post-transcriptionally downregulated the tumor suppressor PTEN and positively regulated proliferation and invasion of osteosarcoma cells. Rescue experiments confirmed the involvement of miR-23a-3p and PTEN in GAS5-mediated cell behaviors by modifying the phosphatidylinositol-3-kinases/protein-serine-threonine kinase (PI3K/AKT) pathway. GAS5 could inhibit tumor growth in vivo . Conclusion: GAS5 functions as a competing endogenous RNA , sponging miR-23a-3p, to promote PTEN expression and suppress cell growth and invasion in osteosarcoma by regulating the PI3K/AKT pathway.

scholarly journals Transcriptional activation of CBFβ by CDK11p110 is necessary to promote osteosarcoma cell proliferation

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Yong Feng ◽  
Yunfei Liao ◽  
Jianming Zhang ◽  
Jacson Shen ◽  
Zengwu Shao ◽  
...  
Keyword(s):  
Chromatin Immunoprecipitation ◽  
Transcriptional Analysis ◽  
Luciferase Assay ◽  
Osteosarcoma Cell ◽  
Osteosarcoma Cells ◽  
Chromatin Immunoprecipitation Assay ◽  
Immunoprecipitation Assay ◽  
Gel Shift Assay ◽  
Gel Shift

Abstract Background Aberrant expression of cyclin-dependent protein kinases (CDK) is a hallmark of cancer. CDK11 plays a crucial role in cancer cell growth and proliferation. However, the molecular mechanisms of CDK11 and CDK11 transcriptionally regulated genes are largely unknown. Methods In this study, we performed a global transcriptional analysis using gene array technology to investigate the transcriptional role of CDK11 in osteosarcoma. The promoter luciferase assay, chromatin immunoprecipitation assay, and Gel Shift assay were used to identify direct transcriptional targets of CDK11. Clinical relevance and function of core-binding factor subunit beta (CBFβ) were further accessed in osteosarcoma. Results We identified a transcriptional role of protein-DNA interaction for CDK11p110, but not CDK11p58, in the regulation of CBFβ expression in osteosarcoma cells. The CBFβ promoter luciferase assay, chromatin immunoprecipitation assay, and Gel Shift assay confirmed that CBFβ is a direct transcriptional target of CDK11. High expression of CBFβ is associated with poor outcome in osteosarcoma patients. Expression of CBFβ contributes to the proliferation and metastatic behavior of osteosarcoma cells. Conclusions These data establish CBFβ as a mediator of CDK11p110 dependent oncogenesis and suggest that targeting the CDK11- CBFβ pathway may be a promising therapeutic strategy for osteosarcoma treatment. Graphical Abstract

scholarly journals SASH1 is a prognostic indicator and potential therapeutic target in non-small cell lung cancer

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Joshua T. Burgess ◽  
Emma Bolderson ◽  
Mark N. Adams ◽  
Pascal H. G. Duijf ◽  
Shu-Dong Zhang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Cellular Proliferation ◽  
Prognostic Indicator ◽  
Small Cell ◽  
Dependent Manner ◽  
Small Cell Lung ◽  
Lung Cancers ◽  
Protein Levels ◽  
Cellular Processes ◽  
Novel Approach

Abstract SASH1 (SAM and SH3 domain-containing protein 1) is a tumor suppressor protein that has roles in key cellular processes including apoptosis and cellular proliferation. As these cellular processes are frequently disrupted in human tumours and little is known about the role of SASH1 in the pathogenesis of the disease, we analysed the prognostic value of SASH1 in non-small cell lung cancers using publicly available datasets. Here, we show that low SASH1 mRNA expression is associated with poor survival in adenocarcinoma. Supporting this, modulation of SASH1 levels in a panel of lung cancer cell lines mediated changes in cellular proliferation and sensitivity to cisplatin. The treatment of lung cancer cells with chloropyramine, a compound that increases SASH1 protein concentrations, reduced cellular proliferation and increased sensitivity to cisplatin in a SASH1-dependent manner. In summary, compounds that increase SASH1 protein levels could represent a novel approach to treat NSCLC and warrant further study.

scholarly journals Lentivirus-Mediated siRNA Targeting ER-αInhibits Tumorigenesis and Induces Apoptosis in Hepatocarcinoma Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ping Jiang ◽  
Jun Cao ◽  
Wen-Hui Bai
Keyword(s):  
Cell Proliferation ◽  
Cell Cycle Progression ◽  
Dependent Manner ◽  
Gene Therapy Approach ◽  
Protein Levels ◽  
Human Liver Cancer ◽  
Hepatocarcinoma Cells ◽  
Interfering Rna ◽  
Hcc Cells

Background and Objectives. Estrogen receptor-α(ER-α) plays important roles in hepatocarcinogenesis. Recent studies have shown that ER-αcould lead to cell cycle progression or inhibition of apoptosis. To better understand the role of ER-α, RNA interference (RNAi) was used to inhibit ER-αexpression in the human hepatocellular carcinoma (HCC) cells.Methods. Lentivirus-mediated ER-αsmall interfering RNA (siRNA) was transfected into HCC cells Hep3B. ER-αexpression was monitored by real-time polymerase chain reaction (PCR) and western blot. Cell proliferation, apoptosis, and invasion were examined by methyl thiazol tetrazolium (MTT), flow cytometry (FCM), and invasion assay, respectively.Results. ER-αsiRNA efficiently downregulated the expression of ER-αin Hep3B cells at both mRNA and protein levels in a time-dependent manner. ER-αsiRNA also inhibited cell proliferation and reduced cell invasion (compared with other groups,P<0.05, resp.). Furthermore, knockdown of ER-αslowed down the cell population at S phase and increased the rate of apoptosis (P<0.05, resp.).Conclusion. ER-αknockdown suppressed the growth of HCC cells. Thus, ER-αmay play a very important role in carcinogenesis of HCC and its knockdown may offer a new potential gene therapy approach for human liver cancer in the future.

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