scholarly journals Polyamine Biosynthetic Pathway as a Drug Target for Osteosarcoma Therapy

2018 ◽  
Vol 6 (3) ◽  
pp. 65 ◽  
Author(s):  
Rebecca Weicht ◽  
Chad Schultz ◽  
Dirk Geerts ◽  
Katie Uhl ◽  
André Bachmann

Osteosarcoma (OS) is the most common bone tumor in children. Polyamines (PAs) are ubiquitous cations involved in many cell processes including tumor development, invasion and metastasis. In other pediatric cancer models, inhibition of the PA biosynthesis pathway with ornithine decarboxylase (ODC) inhibitor alpha-difluoromethylornithine (DFMO) results in decreased cell proliferation and differentiation. In OS, the PA pathway has not been evaluated. DFMO is an attractive, orally administered drug, is well tolerated, can be given for prolonged periods, and is already used in pediatric patients. Three OS cell lines were used to study the cellular effects of PA inhibition with DFMO: MG-63, U-2 OS and Saos-2. Effects on proliferation were analyzed by cell count, flow cytometry-based cell cycle analysis and RealTime-Glo™ MT Cell Viability assays. Intracellular PA levels were measured with high-performance liquid chromatography (HPLC). Western blot analysis was used to evaluate cell differentiation. DFMO exposure resulted in significantly decreased cell proliferation in all cell lines. After treatment, intracellular spermidine levels were drastically decreased. Cell cycle arrest at G2/M was observed in U-2 OS and Saos-2. Cell differentiation was most prominent in MG-63 and U-2 OS as determined by increases in the terminal differentiation markers osteopontin and collagen 1a1. Cell proliferation continued to be suppressed for several days after removal of DFMO. Based on our findings, DFMO is a promising new adjunct to current osteosarcoma therapy in patients at high risk of relapse, such as those with poor necrosis at resection or those with metastatic or recurrent osteosarcoma. It is a well-tolerated oral drug that is currently in phase II clinical trials in pediatric neuroblastoma patients as a maintenance therapy. The same type of regimen may also improve outcomes in osteosarcoma patients in whom there have been essentially no medical advances in the last 30 years.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2372-2372
Author(s):  
Leon Bernal-Mizrachi ◽  
John Harding ◽  
Ratner Lee

Abstract The NFkB pathway has been implicated in tumorigenesis of several lymphoid malignancies. Most aggressive lymphomas have a constitutively active NFkB. Activation of NFkB results in processing of p105 and p100 to produce p50 and p52, respectively, and degradation of IkB. As a result, heterodimers of p65 and p50 or p52 and REL-B are formed and translocated to the nucleus where they induce transcription. Previously, it has been suggested that NFkB regulation of cyclin D and Myc expression is important for cell proliferation. However, these studies fail to explain all the NFkB regulatory effects, as well as the role of each individual pathway. To address these questions we tested the effect of NFkB on proliferation in two virally mediated murine lymphoma cell lines over-expressing Tax/HTLV-1 oncoprotein (SC and BLA) after knocking down (KD) p105 or p100, using a lentivirus expressing siRNAs. After synchronization, cells were released for 24 hrs and the rate of proliferation and cell cycle analysis were measured by thymidine incorporation and PI staining (4,8,16,24 hrs), respectively. As it is seen below, KD p100 or p105 cell lines had a reduced rate of thymidine incorporation compare to controls (Luciferase-siRNA). However, minimal changes were observed between cell lines in cell cycle analysis. To confirm these findings, xenograft experiments with siRNA expressing cell lines were developed. These experiments demonstrated that KD p100 or p105 in xenografts, prevented (in some) or delayed tumor formation, reduced tumor size and prolonged disease free survival. We then investigated NFkB regulation of cell proliferation by assessing gene expression in each cell line. Our results revealed a distinct proliferation-related gene profile between pathways: KD p105 dependent genes include: Cell cycle: Cyclin D2, B2 and G, CDK-8, P27, RB6, Transcription factor Dp2 and AKT-substrate-1, Growth factors: Platelet derived growth factor and RhoG, RNA synthesis: RNA Pol III. On the other hand KD p100 dependent genes include: Cell cycle: Cyclin D1,B2, retinoblastoma-like 1 (p107), p16, ring box-1 and histone deacetylase 2, Growth factors: HRAS and RhoG, RNA/DNA synthesis: RNA pol III and DNA pol (p17), histone 1 and 2, and thymidine kinases. Interestingly, both KD cell lines share many over-expressed genes such as TGFB, p21, p53, RB7 and BRCA1. In conclusion, our novel experimental model demonstrates: the main effect of both NFkB pathways involves DNA replication and early S phase. KD of either p100 or p105 reduces tumor development. The mechanism of cell proliferation regulated by each NFkB pathway is more complex than what was previously suspected; we suggest that RNA, DNA synthesis and regulation of p21, BRCA-1 and other cell cycle regulatory proteins also play an important role. Effect of Knocking Down p100 or p105 in Tumor Development Luciferase siRNA P100 siRNA P105 siRNA NR=Non reached. *Total 58 days f/u. Ten animals per cell line. H3 Thymidine SC 1 ± 0.09 0.38 ± 0.16 0.68 ± 0.37 H3 Thymidine BLA 1 ± 0.09 0.53 ± 0.07 0.69 ± 0.21 Tumor weight (mg) 617.18 ± 251 257.1± 285.1 258.6 ± 195.7 Tumor initiation (day) 32 ± 11 51 ± 11 43 ± 10 Tumor (+) animals (%) 100% 45% 78% Median DFS (day)* 30 NR 37


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 465
Author(s):  
Omer Anis ◽  
Ajjampura C. Vinayaka ◽  
Nurit Shalev ◽  
Dvora Namdar ◽  
Stalin Nadarajan ◽  
...  

Cannabis sativa contains more than 500 constituents, yet the anticancer properties of the vast majority of cannabis compounds remains unknown. We aimed to identify cannabis compounds and their combinations presenting cytotoxicity against bladder urothelial carcinoma (UC), the most common urinary system cancer. An XTT assay was used to determine cytotoxic activity of C. sativa extracts on T24 and HBT-9 cell lines. Extract chemical content was identified by high-performance liquid chromatography (HPLC). Fluorescence-activated cell sorting (FACS) was used to determine apoptosis and cell cycle, using stained F-actin and nuclei. Scratch and transwell assays were used to determine cell migration and invasion, respectively. Gene expression was determined by quantitative Polymerase chain reaction (PCR). The most active decarboxylated extract fraction (F7) of high-cannabidiol (CBD) C. sativa was found to contain cannabichromene (CBC) and Δ9-tetrahydrocannabinol (THC). Synergistic interaction was demonstrated between CBC + THC whereas cannabinoid receptor (CB) type 1 and type 2 inverse agonists reduced cytotoxic activity. Treatments with CBC + THC or CBD led to cell cycle arrest and cell apoptosis. CBC + THC or CBD treatments inhibited cell migration and affected F-actin integrity. Identification of active plant ingredients (API) from cannabis that induce apoptosis and affect cell migration in UC cell lines forms a basis for pre-clinical trials for UC treatment.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Michela Levi ◽  
Roberta Salaroli ◽  
Federico Parenti ◽  
Raffaella De Maria ◽  
Augusta Zannoni ◽  
...  

Abstract Background Doxorubicin (DOX) is widely used in both human and veterinary oncology although the onset of multidrug resistance (MDR) in neoplastic cells often leads to chemotherapy failure. Better understanding of the cellular mechanisms that circumvent chemotherapy efficacy is paramount. The aim of this study was to investigate the response of two canine mammary tumour cell lines, CIPp from a primary tumour and CIPm, from its lymph node metastasis, to exposure to EC50(20h) DOX at 12, 24 and 48 h of treatment. We assessed the uptake and subcellular distribution of DOX, the expression and function of P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP), two important MDR mediators. To better understand this phenomenon the effects of DOX on the cell cycle and Ki67 cell proliferation index and the expression of p53 and telomerase reverse transcriptase (TERT) were also evaluated by immunocytochemistry (ICC). Results Both cell lines were able to uptake DOX within the nucleus at 3 h treatment while at 48 h DOX was absent from the intracellular compartment (assessed by fluorescence microscope) in all the surviving cells. CIPm, originated from the metastatic tumour, were more efficient in extruding P-gp substrates. By ICC and qRT-PCR an overall increase in both P-gp and BCRP were observed at 48 h of EC50(20h) DOX treatment in both cell lines and were associated with a striking increase in the percentage of p53 and TERT expressing cells by ICC. The cell proliferation fraction was decreased at 48 h in both cell lines and cell cycle analysis showed a DOX-induced arrest in the S phase for CIPp, while CIPm had an increase in cellular death without arrest. Both cells lines were therefore composed by a fraction of cells sensible to DOX that underwent apoptosis/necrosis. Conclusions DOX administration results in interlinked modifications in the cellular population including a substantial effect on the cell cycle, in particular arrest in the S phase for CIPp and the selection of a subpopulation of neoplastic cells bearing MDR phenotype characterized by P-gp and BCRP expression, TERT activation, p53 accumulation and decrease in the proliferating fraction. Important information is given for understanding the dynamic and mechanisms of the onset of drug resistance in a neoplastic cell population.


2016 ◽  
Vol 11 (1) ◽  
pp. 206 ◽  
Author(s):  
Yong-Bin Song ◽  
Shao-Hui Zhou ◽  
Hong-Shang Cui ◽  
Hui-Ning Liu ◽  
Li-Jun Liu

<p class="Abstract">The present study demonstrates the effect of casticin on esophageal squamous cell carcinoma cell lines, TE-1 and TE-15. The cells were treated with various concentrations (10-50 μM) of casticin for different time periods. The results revealed that casticin treatment significantly inhibited the rate of cell proliferation in both TE-1 and TE-15 cell lines after 48 hours. Casticin treatment induced cell cycle arrest in S phase, enhanced the expression of proapoptotic gene, Bax and activation of caspase-3. Moreover, the morphological features of the cells were altered resulting in apoptosis. Casticin also inhibited the migration potential of TE-1 cells. Thus, casticin exhibits inhibitory effect on the esophageal squamous cell carcinoma cell lines by inhibiting cell proliferation, arresting cell cycle, inducing apoptosis and inhibiting migration. Therefore, casticin can be of therapeutic importance for the treatment of esophageal squamous cell carcinoma.</p><p> </p>


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Chao Hu ◽  
Xiaobin Zhu ◽  
Taogen Zhang ◽  
Zhouming Deng ◽  
Yuanlong Xie ◽  
...  

Introduction. Osteosarcoma is a malignant tumor associated with high mortality rates due to the toxic side effects of current therapeutic methods. Tanshinone IIA can inhibit cell proliferation and promote apoptosis in vitro, but the exact mechanism is still unknown. The aims of this study are to explore the antiosteosarcoma effect of tanshinone IIA via Src kinase and demonstrate the mechanism of this effect. Materials and Methods. Osteosarcoma MG-63 and U2-OS cell lines were stable transfections with Src-shRNA. Then, the antiosteosarcoma effect of tanshinone IIA was tested in vitro. The protein expression levels of Src, p-Src, p-ERK1/2, and p-AKt were detected by Western blot and RT-PCR. CCK-8 assay and BrdU immunofluorescence assay were used to detect cell proliferation. Transwell assay, cell scratch assay, and flow cytometry were used to detect cell invasion, migration, and cell cycle. Tumor-bearing nude mice with osteosarcoma were constructed. The effect of tanshinone IIA was detected by tumor HE staining, tumor inhibition rate, incidence of lung metastasis, and X-ray. Results. The oncogene role of Src kinase in osteosarcoma is reflected in promoting cell proliferation, invasion, and migration and in inhibiting apoptosis. However, Src has different effects on cell proliferation, apoptosis, and cell cycle regulation among cell lines. At a cellular level, the antiosteosarcoma effect of tanshinone IIA is mediated by Src downstream of the MAPK/ERK and PI3K/AKt signaling pathways. At the animal level, tanshinone IIA played a role in resisting osteosarcoma formation by Src downstream of the MAPK/ERK and PI3K/AKt signaling pathways. Conclusion. Tanshinone IIA plays an antiosteosarcoma role in vitro and in vivo and inhibits the progression of osteosarcoma mediated by Src downstream of the MAPK/ERK and PI3K/AKt signaling pathways.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 1-2
Author(s):  
Yao Yao ◽  
Woojun D Park ◽  
Eugenio Morelli ◽  
Mehmet Kemal Samur ◽  
Nicholas P Kwiatkowski ◽  
...  

Deregulated transcription and cell cycle control are hallmarks of cancer that are especially frequent in multiple myeloma (MM). Largely non-overlapping sets of cyclin-dependent kinases (CDKs) regulate cell division and RNA polymerase II (Pol II)-dependent transcription; and targeting of cell cycle CDKs has been long pursued as an attractive therapeutic strategy. Among CDKs, CDK7 presents a unique therapeutic opportunity as it functions as a CDK activating kinase (CAK), licensing the activity of cell cycle CDKs, and also serves as a core component of the general transcription factor TFIIH. Here we elucidated the biological role of CDK7 and its transcriptional regulatory landscape in MM, using genetic as well chemical approaches, including tools for CDK7 rapid protein degradation (dTAG) and the selective covalent inhibitor YKL-5-124 that targets a cysteine residue (C312) located outside of the kinase domain. We have observed that CDK7 inhibition via YKL-5-124 robustly inhibited the phosphorylation of the CDK1, 2 and 4 activation loops in a representative panel of MM cell lines at concentrations as low as 50 nM. This reduction was not observed in MM cells expressing a resistant mutation in the reactive cysteine (C312S). Consistent with decrease of CAK activity, we observed G1 arrest and S phase loss after CDK7 inhibition, which was also associated with a rapid and transient loss of Ser2 and Ser5 phosphorylation of the RNA Pol2 C-terminal domain. To understand the effect of CDK7 inhibition on MM cell growth and viability, we evaluated activity of YKL-5-124 across a large panel of 25 MM cell lines and observed a significant inhibition of MM cell proliferation, with a significantly lower IC50 compared to PHA-activated normal donor peripheral blood mononuclear cells (PBMCs), suggesting a specific sensitivity of MM cells to CDK7 inhibition. Longer exposure to YKL-5-124 caused apoptotic cell death in MM cells; however treatment with an inactive analog or in cells expressing the C312S mutation failed to inhibit MM cell proliferation, confirming that the antiproliferative potency of YKL-5-124 resides in its unique characteristic to covalently bind to C312 domain. Importantly, CDK7 inhibition impaired primary MM cells proliferation alone and when cultured in the presence of BM microenvironment. Selective pharmacological degradation of endogenously tagged CDK7 confirmed impact of CDK7 inhibition on MM cell proliferation via inhibition of CDK7 transcriptional and cell cycle activities. To complement the pharmacological studies, we have established MM cells to express inducible CRISPR/Cas9 constructs encoding 4 independent small guide RNAs targeting CDK7, resulting in the reduction of the abundance of CDK7 protein by 20-60% which was sufficient to inhibit MM cell viability over time, phenocopying pharmacologic inhibition of CDK7. These results support the view that CDK7 is a pharmacologically relevant target for MM. Gene expression analysis after CDK7 inhibition in MM1S and H929 cells revealed that transcripts for only a subset of genes were substantially affected by treatment with low dose of YKL-5-124, showing a strong leading-edge enrichment for downregulation of E2F expression program, cell cycle, DNA damage, and MYC targets. We have indeed confirmed a potent reduction in phosphorylation of RB protein, with consequent decrease of E2F activity in MM cells confirmed using E2F-driven luciferase reporter. These data suggest significant role for CDK7 in the CDK-pRB-E2F pathway in MM, which was strengthened by the observation of a positive correlation between expression of CDK7 and expression of E2F target genes in primary MM cells (n=409). Finally, we have evaluated the in vivo effect of CDK7 inhibition in several murine models of human MM. In the localized subcutaneous model, and the disseminated MM model where treatment with YKL-5-124 decreased tumor burden and improved survival. The effect of CDK7 inhibition explored in an aggressive, genetically engineered model of Myc-dependent MM, revealed evidence of response by decline in measurement of monotypic serum immunoglobulins. In conclusion, our study demonstrates that CDK7 contributes to the 'transcriptional addiction' and the cell cycle deregulation frequently observed in MM and represents an attractive molecular vulnerability to be exploited therapeutically. Disclosures Anderson: Millenium-Takeda: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees; Sanofi-Aventis: Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Membership on an entity's Board of Directors or advisory committees; Oncopep and C4 Therapeutics.: Other: Scientific Founder of Oncopep and C4 Therapeutics.; Celgene: Membership on an entity's Board of Directors or advisory committees. Munshi:Takeda: Consultancy; Karyopharm: Consultancy; AbbVie: Consultancy; Amgen: Consultancy; Legend: Consultancy; Adaptive: Consultancy; Janssen: Consultancy; C4: Current equity holder in private company; OncoPep: Consultancy, Current equity holder in private company, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; BMS: Consultancy. Fulciniti:NIH: Research Funding.


2017 ◽  
Vol 41 (4) ◽  
pp. 1519-1531 ◽  
Author(s):  
Beibei Bie ◽  
Jin Sun ◽  
Jun Li ◽  
Ying Guo ◽  
Wei Jiang ◽  
...  

Background/Aims: Baicalein has been shown to possess significant anti-hepatoma activity by inhibiting cell proliferation. Whether the anti-proliferative effect of baicalein is related to its modulation of miRNA expression in hepatocellular carcinoma (HCC) is still unknown. Methods: The anti-proliferative effects of baicalein on HCC cell line Bel-7402 was assessed by detecting the proliferation activity, cell cycle distribution, expression changes of p21/CDKN1A, P27/CDKN1B, total Akt and phosphoryted AKT. Microarray analysis was conducted to determine the miRNA expression profiles in baicalein-treated or untreated Bel-7402 cells and then validated by qRT-PCR in two HCC cell lines (Bel-7402 and Hep3B). The gain-of-function of miR-3127-5p was performed by detecting anti-proliferative effects after transfecting miRNA mimics in cells. Finally, the expression level of miR-3127-5p in different HCC cell lines was determined by qRT-PCR. Results: Baicalein was able to inhibit the proliferation of Bel-7402 cells by inducing cell cycle arrest at the S and G2/M phase via up-regulating the expression of p21/CDKN1A and P27/CDKN1B and suppressing the PI3K/Akt pathway. Baicalein could alter the miRNA expression profiles in Bel-7402 cells. Putative target genes for differentially expressed miRNAs could be enriched in terms of cell proliferation regulation, cell cycle arrest and were mainly involved in MAPK, PI3K-Akt, Wnt, Hippo and mTOR signaling pathways. MiR- 3127-5p, one of up-regulated miRNAs, exhibits low expression level in several HCC cell lines and its overexpression could inhibit cell growth of Bel-7402 and Hep3B cell lines by inducing S phase arrest by up-regulating the expression of p21and P27 and repressing the PI3K/Akt pathway. Conclusions: Modulation of miRNA expression may be an important mechanism underlying the anti-hepatoma effects of baicalein.


2022 ◽  
Author(s):  
Yunqiong Gu ◽  
Yu-Jun Zhong ◽  
Mei-Qi Hu ◽  
Huan-Qing Li ◽  
Kun Yang ◽  
...  

Four mononuclear terpyridine complexes [Cu(H-La)Cl2]·CH3OH (1), [Cu(H-La)Cl]ClO4 (2), [Cu(H-Lb)Cl2]·CH3OH (3), and [Cu(H-Lb)(CH3OH)(DMSO)](ClO4)2 (4) were prepared and fully characterized. Complexes 14 exhibited higher cytotoxic activity against several tested cancer cell lines...


1990 ◽  
Vol 10 (10) ◽  
pp. 5586-5590
Author(s):  
R W Wagner ◽  
C Yoo ◽  
L Wrabetz ◽  
J Kamholz ◽  
J Buchhalter ◽  
...  

A double-stranded RNA unwinding and modifying activity was found to be present in a wide range of tissues and cell types. The level of activity did not vary significantly with respect to the state of cell differentiation, cell cycle, or transformation. Thus, the unwinding and modifying activity, localized in the nucleus in somatic cells and capable of converting many adenosine residues to inosine, appears to be one of the housekeeping genes.


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