A Novel Approach for Monitoring TGF-ß Signaling in vivo in Colon Cancer

2020 ◽  
Author(s):  
Bin-hao Zhang ◽  
Chao Wang ◽  
Wei Dong ◽  
Xin Chen ◽  
Chao Leng ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Liver Metastasis ◽  
Luciferase Activity ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Reporter System ◽  
Antitumor Effects ◽  
Long Term Treatment

Abstract The TGF-β receptor kinase inhibitors (TRKI) have been reported to inhibit tumorigenicity in colon cancer. However, there is no direct evidence showing that these inhibitors function through inhibiting the TGF-β- mediated tumor-promoting effects in vivo. We established a TGF-β inducible reporter system by inserting a luciferase reporter gene to the vector downstream of TGF-β-inducible promoter elements, and transfected it into colon cancer cell lines. TRKIs SB431542 and LY2109761 were used to treat TGF-β inducible cells in vitro and in vivo. The luciferase activity was induced 5.24 folds by TGF-β in CT26 inducible cells, while it was marginally changed in MC38 inducible cells lacking Smad4 expression. Temporary treatment of mice with SB431542 inhibited the TGF-β pathway and TGF-β induced bioluminescence activity in vivo. Long-term treatment with LY2109761 inhibited tumorigenicity and liver metastasis in vivo in concomitant with reduced luciferase activity in the tumor. In this study, we established a model to monitor the TGF-β pathway in vivo and to compare the antitumor effects of TRKIs. Based on this novel experimental tool, we provided direct evidences that LY2109761 inhibits tumorigenicity and liver metastasis by blocking the pro-oncogenic functions of TGF-β in vivo.

scholarly journals Ectopic Methylation of a Single Persistently Unmethylated CpG in the Promoter of the Vitellogenin Gene Abolishes Its Inducibility by Estrogen through Attenuation of Upstream Stimulating Factor Binding

2019 ◽  
Vol 39 (23) ◽  
Author(s):  
Lia Kallenberger ◽  
Rachel Erb ◽  
Lucie Kralickova ◽  
Andrea Patrignani ◽  
Esther Stöckli ◽  
...  
Keyword(s):  
Dna Methyltransferase ◽  
Transcriptional Control ◽  
Dna Demethylation ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Reporter System ◽  
E Box ◽  
Stimulating Factor

ABSTRACT The enhancer/promoter of the vitellogenin II gene (VTG) has been extensively studied as a model system of vertebrate transcriptional control. While deletion mutagenesis and in vivo footprinting identified the transcription factor (TF) binding sites governing its tissue specificity, DNase hypersensitivity and DNA methylation studies revealed the epigenetic changes accompanying its hormone-dependent activation. Moreover, upon induction with estrogen (E2), the region flanking the estrogen-responsive element (ERE) was reported to undergo active DNA demethylation. We now show that although the VTG ERE is methylated in embryonic chicken liver and in LMH/2A hepatocytes, its induction by E2 was not accompanied by extensive demethylation. In contrast, E2 failed to activate a VTG enhancer/promoter-controlled luciferase reporter gene methylated by SssI. Surprisingly, this inducibility difference could be traced not to the ERE but rather to a single CpG in an E-box (CACGTG) sequence upstream of the VTG TATA box, which is unmethylated in vivo but methylated by SssI. We demonstrate that this E-box binds the upstream stimulating factor USF1/2. Selective methylation of the CpG within this binding site with an E-box-specific DNA methyltransferase, Eco72IM, was sufficient to attenuate USF1/2 binding in vitro and abolish the hormone-induced transcription of the VTG gene in the reporter system.

scholarly journals Ectopic methylation of a single persistently-unmethylated CpG in the promoter of the vitellogenin gene abolishes its inducibility by estrogen through attenuation of USF binding

2019 ◽  
Author(s):  
Lia Kallenberger ◽  
Rachel Erb ◽  
Lucie Kralickova ◽  
Andrea Patrignani ◽  
Esther Stöckli ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Dna Demethylation ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Reporter System ◽  
Active Dna Demethylation ◽  
E Box ◽  
Vitellogenin Gene

ABSTRACTThe enhancer/promoter of the vitellogenin II (VTG) gene has been extensively studied as a model system of vertebrate transcriptional control. While deletion mutagenesis and in vivo footprinting identified the transcription factor (TF) binding sites governing its tissue specificity, DNase hypersensitivity- and DNA methylation studies revealed the epigenetic changes accompanying its hormone-dependent activation. Moreover, upon induction with estrogen (E2), the region flanking the estrogen-responsive element (ERE) was reported to undergo active DNA demethylation. We now show that although the VTG ERE is methylated in embryonic chicken liver and in LMH/2A hepatocytes, its induction by E2 was not accompanied by extensive demethylation. In contrast, E2 failed to activate a VTG enhancer/promoter-controlled luciferase reporter gene methylated by SssI. Surprisingly, this inducibility difference could be traced not to the ERE, but rather to a single CpG in an E-box (CACGTG) sequence upstream of the VTG TATA box, which is unmethylated in vivo, but methylated by SssI. We demonstrate that this E-box binds the upstream stimulating factor USF1/2. Selective methylation of the CpG within this binding site with an E-box-specific DNA methyltranferase Eco72IM was sufficient to attenuate USF1/2 binding in vitro and abolish the hormone-induced transcription of the VTG gene in the reporter system.

scholarly journals Impact of RARα and miR-138 on retinoblastoma etoposide resistance

Tumor Biology ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 11-26
Author(s):  
Maike Busch ◽  
Natalia Miroschnikov ◽  
Jaroslaw Thomas Dankert ◽  
Marc Wiesehöfer ◽  
Klaus Metz ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cell Lines ◽  
Cancer Progression ◽  
Treated Patient ◽  
Luciferase Reporter ◽  
Luciferase Reporter Gene ◽  
Gene Assay ◽  
The Impact

BACKGROUND: Retinoblastoma (RB) is the most common childhood eye cancer. Chemotherapeutic drugs such as etoposide used in RB treatment often cause massive side effects and acquired drug resistances. Dysregulated genes and miRNAs have a large impact on cancer progression and development of chemotherapy resistances. OBJECTIVE: This study was designed to investigate the involvement of retinoic acid receptor alpha (RARα) in RB progression and chemoresistance as well as the impact of miR-138, a potential RARα regulating miRNA. METHODS: RARα and miR-138 expression in etoposide resistant RB cell lines and chemotherapy treated patient tumors compared to non-treated tumors was revealed by Real-Time PCR. Overexpression approaches were performed to analyze the effects of RARα on RB cell viability, apoptosis, proliferation and tumorigenesis. Besides, we addressed the effect of miR-138 overexpression on RB cell chemotherapy resistance. RESULTS: A binding between miR-138 and RARα was shown by dual luciferase reporter gene assay. The study presented revealed that RARα is downregulated in etoposide resistant RB cells, while miR-138 is endogenously upregulated. Opposing RARα and miR-138 expression levels were detectable in chemotherapy pre-treated compared to non-treated RB tumor specimen. Overexpression of RARα increases apoptosis levels and reduces tumor cell growth of aggressive etoposide resistant RB cells in vitro and in vivo. Overexpression of miR-138 in chemo-sensitive RB cell lines partly enhances cell viability after etoposide treatment. CONCLUSIONS: Our findings show that RARα acts as a tumor suppressor in retinoblastoma and is downregulated upon etoposide resistance in RB cells. Thus, RARα may contribute to the development and progression of RB chemo-resistance.

scholarly journals LINC00839 Knockdown Restrains The Metastatic Behaviors of Nasopharyngeal Carcinoma By Sponging miR-454-3p

2021 ◽  
Author(s):  
Feng Ying Zhang ◽  
Xia Li ◽  
Ting Ting Huang ◽  
Mei Ling Xiang ◽  
Lin Lin Sun ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Underlying Mechanism ◽  
Luciferase Reporter ◽  
Regulatory Function ◽  
Migration And Invasion ◽  
Luciferase Reporter Gene ◽  
Non Coding Rna ◽  
Invasive Capacity

Abstract Background Long intergenic non-coding RNA 00839 (LINC00839) has been verified as a cancer-promoting gene in malignancies. However, the significance of LINC00839 in nasopharyngeal carcinoma (NPC) has yet to be elaborated, as well as its underlying mechanism.Methods LINC00839 and miR-454-3p relative expression levels in NPC cells were examined by qRT-PCR. The growth of cells was examined by CCK-8 and colony formation assays. Cell migration and invasion were examined by wound healing and Transwell experiment, respectively. The binding sequence of LINC00839 and miR-454-3p was confirmed by the luciferase reporter gene experiment. The regulatory function of LINC00839 and miR-454-3p on c-Met was investigated by western blot.Results Here, we revealed that LINC00839 was elevated in NPC. Both LINC00839 knockdown and upregulation of miR-454-3p suppressed NPC cells proliferation, invasive capacity and EMT in vitro. Besides, LINC00839 was validated as a miR-454-3p “sponge”, and upregulation of LINC00839 could reverse miR-454-3p-mediated functions in NPC C666-1 and SUNE-1 cells. Furthermore, c-Met was determined to be targeted by miR-454-3p. Notably, c-Met was downregulated by LINC00839 knockdown through sponging miR-454-3p. In vivo, LINC00839 knockdown resulted in a slower tumor growth.Conclusions Altogether, knockdown of LINC00839 inhibits the aggressive properties of NPC cells via sponging miR-454-3p and regulating c-Met.

scholarly journals Circular RNA CDR1as Inhibits the Metastasis of Gastric Cancer through Targeting miR-876-5p/GNG7 Axis

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jiajia Jiang ◽  
Rong Li ◽  
Junyi Wang ◽  
Jie Hou ◽  
Hui Qian ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Epithelial Mesenchymal Transition ◽  
Circular Rna ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Luciferase Reporter Gene ◽  
Mesenchymal Transition ◽  
Underlying Mechanisms

Circular RNA CDR1as has been demonstrated to participate in various cancer progressions as miRNA sponges. The exact underlying mechanisms of CDR1as on gastric cancer (GC) metastasis remain unknown. Here, we found that CDR1as knockdown facilitated GC cell migration and invasion while its overexpression inhibited the migration and invasion abilities of GC cells in vitro and in vivo. Moreover, epithelial-mesenchymal transition- (EMT-) associated proteins and MMP2 and MMP9 were downregulated by CDR1as. Bioinformatics analysis combined with dual-luciferase reporter gene assays, western blot, RT-qPCR analysis, and functional rescue experiments demonstrated that CDR1as served as a miR-876-5p sponge and upregulated the target gene GNG7 expression to suppress GC metastasis. In summary, our findings indicate that CDR1as suppresses GC metastasis through the CDR1as/miR-876-5p/GNG7 axis.

CircRNA_0092516 regulates chondrocyte proliferation and apoptosis in osteoarthritis through the miR-337-3p/PTEN axis

2020 ◽  
Author(s):  
Zhihui Huang ◽  
Wenming Ma ◽  
Jinhuai Xiao ◽  
Xiaoyu Dai ◽  
Weiqi Ling
Keyword(s):  
Cell Apoptosis ◽  
Luciferase Reporter ◽  
Circular Rnas ◽  
Mechanism Analysis ◽  
Potential Mechanism ◽  
Luciferase Reporter Gene ◽  
Chondrocyte Proliferation ◽  
In Vivo Experiments

Abstract The dysregulation of circular RNAs (circRNAs) has been identified in various human diseases. Here, we probed into the potential mechanism of circRNA_0092516 in osteoarthritis (OA). The expression of circRNA_0092516 was tested by quantitative real-time PCR. MTT, flow cytometry and western blot were applied to confirm the functions of circRNA_0092516 in vitro. Besides, RNA pull-down and dual-luciferase reporter gene experiments were applied to probe into the mechanism. circRNA_0092516 was raised in the tissues of OA patients and chondrocytes stimulated by IL-1β. The potential mechanism analysis expounded that circRNA_0092516 bound to miR-337-3p, and the interference with circRNA_0092516 boosted chondrocyte proliferation and restrained cell apoptosis through the miR-337-3p/phosphatase and tensin homolog (PTEN) axis, thereby improving OA. In-vivo experiments expounded that circRNA_0092516 regulated cartilage production through miR-337-3p. Overall, our data expounded that the interference with circRNA_0092516 boosted chondrocyte proliferation and restrained cell apoptosis through the miR-337-3p/PTEN axis, eventually slowed down the progress of OA.

scholarly journals Synergistic tumor inhibition of colon cancer cells by nitazoxanide and obeticholic acid, a farnesoid X receptor ligand

2020 ◽  
Author(s):  
Junhui Yu ◽  
Kui Yang ◽  
Jianbao Zheng ◽  
Wei Zhao ◽  
Xuejun Sun
Keyword(s):  
Colon Cancer ◽  
Cancer Cells ◽  
Farnesoid X Receptor ◽  
Colon Cancer Cells ◽  
Antitumor Effects ◽  
Colorectal Tumorigenesis ◽  
Tumor Inhibition ◽  
Combination Study

Abstract The tumor-suppressive role of Farnesoid X receptor (FXR) in colorectal tumorigenesis supports restoring FXR expression as a novel therapeutic strategy. However, the complicated signaling network and tumor heterogeneity hinder the effectiveness of FXR agonists in the clinical setting. These difficulties highlight the importance of identifying drug combinations with potency and specificity to enhance the antitumor effects of FXR agonists. In this study, we found that the β-catenin level affected the antitumor effects of the FXR agonist OCA on colon cancer cells. Mechanistic studies identified a novel FXR/β-catenin complex in colon cancer cells. Furthermore, the depletion of β-catenin expedited FXR nuclear localization and enhanced its occupancy of the SHP promoter and thereby sensitized colon cancer cells to OCA. Furthermore, we utilized a drug combination study and identified that the antiparasitic drug nitazoxanide (NTZ) abrogated β-catenin expression and acted synergistically with OCA in colon cancer cells. The combination of OCA plus NTZ exerts synergistic tumor inhibition in CRC both in vitro and in vivo by cooperatively upregulating SHP expression. In conclusion, our study offers useful evidence for the clinical use of FXR agonists combined with β-catenin inhibitors in combating CRC.

scholarly journals Coxsackievirus B3 Responds to Polyamine Depletion via Enhancement of 2A and 3C Protease Activity

Viruses ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 403 ◽  
Author(s):  
Courtney N. Dial ◽  
Patrick M. Tate ◽  
Thomas M. Kicmal ◽  
Bryan C. Mounce
Keyword(s):  
Protease Activity ◽  
Rna Virus ◽  
Coxsackievirus B3 ◽  
Eukaryotic Cells ◽  
Luciferase Reporter ◽  
Reporter System ◽  
3C Protease ◽  
Picornavirus Infection

Polyamines are small positively-charged molecules abundant in eukaryotic cells that are crucial to RNA virus replication. In eukaryotic cells, polyamines facilitate processes such as transcription, translation, and DNA replication, and viruses similarly rely on polyamines to facilitate transcription and translation. Whether polyamines function at additional stages in viral replication remains poorly understood. Picornaviruses, including Coxsackievirus B3 (CVB3), are sensitive to polyamine depletion both in vitro and in vivo; however, precisely how polyamine function in picornavirus infection has not been described. Here, we describe CVB3 mutants that arise with passage in polyamine-depleted conditions. We observe mutations in the 2A and 3C proteases, and we find that these mutant proteases confer resistance to polyamine depletion. Using a split luciferase reporter system to measure protease activity, we determined that polyamines facilitate viral protease activity. We further observe that the 2A and 3C protease mutations enhance reporter protease activity in polyamine-depleted conditions. Finally, we find that these mutations promote cleavage of cellular eIF4G during infection of polyamine-depleted cells. In sum, our results suggest that polyamines are crucial to protease function during picornavirus infection. Further, these data highlight viral proteases as potential antiviral targets and highlight how CVB3 may overcome polyamine-depleting antiviral therapies.

scholarly journals Inhibitory Effects of Apigenin on Tumor Carcinogenesis by Altering the Gut Microbiota

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Shichang Bian ◽  
Hongjuan Wan ◽  
Xinyan Liao ◽  
Weisheng Wang
Keyword(s):  
Colon Cancer ◽  
Treatment Group ◽  
16S Rrna ◽  
Gut Microbiota ◽  
High Throughput Sequencing ◽  
Potential Mechanism ◽  
Inhibitory Effects ◽  
Antitumor Effects

The flavonoid apigenin is common to many plants. Although the responsible mechanisms have yet to be elucidated, apigenin demonstrates tumor suppression in vitro and in vivo. This study uses an azoxymethane (AOM)/dextran sodium sulfate- (DSS-) induced colon cancer mouse model to investigate apigenin’s potential mechanism of action exerted through its effects upon gut microbiota. The size and quantity of tumors were reduced significantly in the apigenin treatment group. Using 16S rRNA high-throughput sequencing of fecal samples, the composition of gut microbiota was significantly affected by apigenin. Further experiments in which gut microbiota were reduced and feces were transplanted provided further evidence of apigenin-modulated gut microbiota exerting antitumor effects. Apigenin was unable to reduce the number or size of tumors when gut microbiota were depleted. Moreover, tumor inhibition effects were initiated following the transplant of feces from mice treated with apigenin. Our findings suggest that the effect of apigenin on the composition of gut microbiota can suppress tumors.

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