scholarly journals miRNA Clusters with Down-Regulated Expression in Human Colorectal Cancer and Their Regulation

2020 ◽  
Vol 21 (13) ◽  
pp. 4633 ◽  
Author(s):  
Paulína Pidíkova ◽  
Richard Reis ◽  
Iveta Herichova
Keyword(s):  
Colorectal Cancer ◽  
Transcriptional Control ◽  
In Vitro Models ◽  
Mirna Regulation ◽  
Regulated Expression ◽  
Mirna Clusters ◽  
Position Regulation ◽  
Non Coding Rnas

Regulation of microRNA (miRNA) expression has been extensively studied with respect to colorectal cancer (CRC), since CRC is one of the leading causes of cancer mortality worldwide. Transcriptional control of miRNAs creating clusters can be, to some extent, estimated from cluster position on a chromosome. Levels of miRNAs are also controlled by miRNAs “sponging” by long non-coding RNAs (ncRNAs). Both types of miRNA regulation strongly influence their function. We focused on clusters of miRNAs found to be down-regulated in CRC, containing miR-1, let-7, miR-15, miR-16, miR-99, miR-100, miR-125, miR-133, miR-143, miR-145, miR-192, miR-194, miR-195, miR-206, miR-215, miR-302, miR-367 and miR-497 and analysed their genome position, regulation and functions. Only evidence provided with the use of CRC in vivo and/or in vitro models was taken into consideration. Comprehensive research revealed that down-regulated miRNA clusters in CRC are mostly located in a gene intron and, in a majority of cases, miRNA clusters possess cluster-specific transcriptional regulation. For all selected clusters, regulation mediated by long ncRNA was experimentally demonstrated in CRC, at least in one cluster member. Oncostatic functions were predominantly linked with the reviewed miRNAs, and their high expression was usually associated with better survival. These findings implicate the potential of down-regulated clusters in CRC to become promising multi-targets for therapeutic manipulation.

scholarly journals O23: CHARACTERISING PATIENT-DERIVED COLORECTAL CANCER TISSUE-ORIGINATED ORGANOIDAL SPHEROIDS FOR HIGH-THROUGHPUT MICROFLUIDIC APPLICATIONS

2021 ◽  
Vol 108 (Supplement_1) ◽  
Author(s):  
MI Khot ◽  
M Levenstein ◽  
R Coppo ◽  
J Kondo ◽  
M Inoue ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fluid Flow ◽  
High Throughput ◽  
Microfluidic Devices ◽  
In Vitro Models ◽  
Fluorescent Imaging ◽  
Cancer Tissue ◽  
Cell Models

Abstract Introduction Three-dimensional (3D) cell models have gained reputation as better representations of in vivo cancers as compared to monolayered cultures. Recently, patient tumour tissue-derived organoids have advanced the scope of complex in vitro models, by allowing patient-specific tumour cultures to be generated for developing new medicines and patient-tailored treatments. Integrating 3D cell and organoid culturing into microfluidics, can streamline traditional protocols and allow complex and precise high-throughput experiments to be performed with ease. Method Patient-derived colorectal cancer tissue-originated organoidal spheroids (CTOS) cultures were acquired from Kyoto University, Japan. CTOS were cultured in Matrigel and stem-cell media. CTOS were treated with 5-fluorouracil and cytotoxicity evaluated via fluorescent imaging and ATP assay. CTOS were embedded, sectioned and subjected to H&E staining and immunofluorescence for ABCG2 and Ki67 proteins. HT29 colorectal cancer spheroids were produced on microfluidic devices using cell suspensions and subjected to 5-fluorouracil treatment via fluid flow. Cytotoxicity was evaluated through fluorescent imaging and LDH assay. Result 5-fluorouracil dose-dependent reduction in cell viability was observed in CTOS cultures (p<0.01). Colorectal CTOS cultures retained the histology, tissue architecture and protein expression of the colonic epithelial structure. Uniform 3D HT29 spheroids were generated in the microfluidic devices. 5-fluorouracil treatment of spheroids and cytotoxic analysis was achieved conveniently through fluid flow. Conclusion Patient-derived CTOS are better complex models of in vivo cancers than 3D cell models and can improve the clinical translation of novel treatments. Microfluidics can streamline high-throughput screening and reduce the practical difficulties of conventional organoid and 3D cell culturing. Take-home message Organoids are the most advanced in vitro models of clinical cancers. Microfluidics can streamline and improve traditional laboratory experiments.

scholarly journals N6-Isopentenyladenosine Inhibits Colorectal Cancer and Improves Sensitivity to 5-Fluorouracil Targeting FBXW7 Tumor Suppressor

Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1456 ◽  
Author(s):  
Donatella Fiore ◽  
Chiara Piscopo ◽  
Maria Proto ◽  
Michele Vasaturo ◽  
Fabrizio Dal Piaz ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Tumor Suppressor ◽  
In Vitro Models ◽  
Antitumor Action ◽  
Cancer Proliferation ◽  
Ubiquitinated Proteins ◽  
Mutational Status ◽  
Ubiquitin Ligase Complex

N6-isopentenyladenosine has been shown to exert potent in vitro antitumor activity on different human cancers, including colorectal cancer. Although some potential biochemical targets have been identified, its precise mechanism of action remains unclear. We found that N6-isopentenyladenosine affects colorectal cancer proliferation in in vitro models carrying different mutational status of FBXW7 and TP53 genes, and in HCT116 xenografts in SCID mice, by increasing the expression of the well-established tumor suppressor FBXW7, a component of the SCF-E3 ubiquitin ligase complex that promotes degradation of various oncoproteins and transcription factors, such as c-Myc, SREBP and Mcl1. Corroborating our previous studies, we identified for the first time the FBXW7/SREBP/FDPS axis as a target of the compound. Pull down of ubiquitinated proteins, immunoprecipitation and luciferase assays, reveal that through the increase of FBXW7/c-Myc binding, N6-isopentenyladenosine induces the ubiquitination of c-Myc, inhibiting its transcriptional activity. Moreover, in FBXW7- and TP53-wild type cells, N6-isopentenyladenosine strongly synergizes with 5-Fluorouracil to inhibit colon cancer growth in vitro. Our results provide novel insights into the molecular mechanism of N6-isopentenyladenosine, revealing its multi-targeting antitumor action, in vitro and in vivo. Restoring of FBXW7 tumor-suppressor represents a valid therapeutic tool, enabling N6-isopentenyladenosine as optimizable compound for patient-personalized therapies in colorectal cancer.

scholarly journals Regulation of the proneural gene achaete by helix-loop-helix proteins.

1993 ◽  
Vol 13 (6) ◽  
pp. 3514-3521 ◽  
Author(s):  
C Martínez ◽  
J Modolell ◽  
J Garrell
Keyword(s):  
Transcriptional Control ◽  
Protein A ◽  
Antagonistic Effect ◽  
Helix Loop Helix ◽  
Regulated Expression ◽  
E Boxes ◽  
Bhlh Proteins ◽  
Self Stimulation

The Achaete (Ac) protein, a transcriptional regulator of the basic-helix-loop-helix (bHLH) type, confers upon ectodermal cells the ability to become neural precursors. Its temporally and spatially regulated expression, together with that of the related Scute (Sc) protein, helps define the pattern of Drosophila melanogaster sensory organs. We have examined the transcriptional control of the ac gene and shown, using in vivo assays, that several E-boxes, putative interacting sites for bHLH proteins, present in the ac promoter are most important for ac regulation. They most likely mediate ac self-stimulation and sc trans-activation. We also demonstrate that ac transcription is negatively regulated in vivo by the gene extramacrochaetae (emc) in a manner dependent on Ac and Sc products. emc encodes an HLH protein that lacks the basic region and presumably antagonizes Ac and Sc function by sequestering these proteins in complexes unable to interact with DNA. Our results strongly support the model of negative regulation of emc on ac and sc transcription through titration of their products. As currently thought, this seems accomplished by heterodimerization via the HLH domain, because an amino acid substitution in this region abolishes the emc antagonistic effect both in vitro and in vivo.

scholarly journals LncRNA DQ786243 contributes to proliferation and metastasis of colorectal cancer both in vitro and in vivo

2016 ◽  
Vol 36 (3) ◽  
Author(s):  
Longci Sun ◽  
Hanbing Xue ◽  
Chunhui Jiang ◽  
Hong Zhou ◽  
Lei Gu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cancer Progression ◽  
Cell Cycle Progression ◽  
Migration And Invasion ◽  
Cycle Progression ◽  
Proliferation And Metastasis ◽  
Non Coding Rnas ◽  
Colorectal Cancer Progression

This article aims to find the key long non-coding RNAs (LncRNAs) associated with colorectal cancer (CRC) and to study its biological functions in colorectal cancer progression. Our study has shown that upregulated LncRNA DQ786243 can regulate cell proliferation, cell cycle progression, cell apoptosis, migration, and invasion in CRC cells. Xenograft experiments confirmed that the growth of xenograft tumors formed by CRC cells was suppressed after silencing LncRNA DQ786243 expression. In conclusion, our study suggests that LncRNA DQ786243 is an oncogene that promotes tumor progression and leads us to propose that LncRNAs may serve as key regulatory hubs in CRC progression.

scholarly journals Both Estrogen Receptor α and β Stimulate Pituitary GH Gene Expression

2014 ◽  
Vol 28 (1) ◽  
pp. 40-52 ◽  
Author(s):  
Dimiter Avtanski ◽  
Horacio J. Novaira ◽  
Sheng Wu ◽  
Christopher J. Romero ◽  
Rhonda Kineman ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Mrna Expression ◽  
Transcriptional Control ◽  
Estrogen Receptor Α ◽  
In Vitro Models ◽  
Mrna Levels ◽  
Ovariectomized Mice ◽  
Serum Gh

Abstract Although sex steroids have been implicated in the control of mammalian growth, their direct effect on GH synthesis is less clear. The aim of this study was to establish whether estradiol (E2) directly affects GH synthesis in somatotrophs. Somatotroph GH3 and MtT/S cells were used as in vitro models. At physiological doses of E2 stimulation, GH mRNA levels were increased and the ER antagonist ICI 182,780 completely abolished this effect. Estrogen receptor (ER) α– and ERβ-selective agonists, propylpyrazole triol (PPT), and 2,3-bis(4-hydroxyphenyl) propionitrile (DPN), respectively, augmented GH mRNA expression and secretion, whereas E2 and PPT, but not DPN increased prolactin (PRL) mRNA levels. E2, PPT, and DPN stimulated expression of the pituitary transcription factor Pou1f1 and increased its binding to the GH promoter. In vivo evidence of E2 effects on GH synthesis was obtained from the generation of the somatotroph-specific ERα knockout (sERα-KO) mouse model. Basal pituitary GH, PRL, POU1F1, and ERα mRNA expression levels were lower in sERα-KO mice compared with those in controls; whereas ERβ mRNA levels remained unchanged. E2 and DPN stimulated pituitary GH mRNA expression and serum GH levels in control and sERα-KO ovariectomized mice; however, serum GH levels were unchanged in PPT-treated ovariectomized sERα-KO mice. In these animal models, PRL mRNA levels increased after either E2 or PPT, but an increase was not seen after DPN treatment. Thus, we propose a mechanism by which estrogen directly regulates somatotroph GH synthesis at a pretranslational level. In contrast to the predominant effect of ERα in the lactotroph, these results support a role for both ERα and ERβ in the transcriptional control of Gh in the somatotroph and illustrate important differences in ER isoform specificity in the anterior pituitary gland.

scholarly journals miRNA Clusters with Up-Regulated Expression in Colorectal Cancer

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2979
Author(s):  
Paulína Pidíková ◽  
Iveta Herichová
Keyword(s):  
Colorectal Cancer ◽  
Target Genes ◽  
Expression Patterns ◽  
Clinicopathological Characteristics ◽  
Cancer Tissue ◽  
Poor Patient ◽  
Regulated Expression ◽  
Mirna Clusters ◽  
Non Coding Rnas ◽  
Poor Patient Survival

Colorectal cancer (CRC) is one of the most common malignancies in Europe and North America. Early diagnosis is a key feature of efficient CRC treatment. As miRNAs can be used as CRC biomarkers, the aim of the present study was to analyse experimentally validated data on frequently up-regulated miRNA clusters in CRC tissue and investigate their members with respect to clinicopathological characteristics of patients. Based on available data, 15 up-regulated clusters, miR-106a/363, miR-106b/93/25, miR-17/92a-1, miR-181a-1/181b-1, miR-181a-2/181b-2, miR-181c/181d, miR-183/96/182, miR-191/425, miR-200c/141, miR-203a/203b, miR-222/221, mir-23a/27a/24-2, mir-29b-1/29a, mir-301b/130b and mir-452/224, were selected. The positions of such clusters in the genome can be intronic or intergenic. Most clusters are regulated by several transcription factors, and miRNAs are also sponged by specific long non-coding RNAs. In some cases, co-expression of miRNA with other cluster members or host gene has been proven. miRNA expression patterns in cancer tissue, blood and faeces were compared. Based on experimental evidence, 181 target genes of selected clusters were identified. Panther analysis was used to reveal the functions of the target genes and their corresponding pathways. Clusters miR-17/92a-1, miR-106a/363, miR-106b/93/25 and miR-183/96/182 showed the strongest association with metastasis occurrence and poor patient survival, implicating them as the most promising targets of translational research.

scholarly journals Downregulating Long Non-coding RNAs CTBP1-AS2 Inhibits Colorectal Cancer Development by Modulating the miR-93-5p/TGF-β/SMAD2/3 Pathway

2021 ◽  
Vol 11 ◽  
Author(s):  
Qiankun Li ◽  
Wenjing Yue ◽  
Ming Li ◽  
Zhipeng Jiang ◽  
Zehui Hou ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Proliferation ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Luciferase Reporter ◽  
Reverse Transcription Pcr ◽  
Non Coding Rnas ◽  
And Function

Background: Colorectal cancer (CRC), the most commonly diagnosed cancer in the world, has a high mortality rate. In recent decades, long non-coding RNAs (lncRNAs) have been proven to exert an important effect on CRC growth. However, the CTBP1-AS2 expression and function in CRC are largely unknown.Materials and Methods: The CTBP1-AS2 and miR-93-5p expression in CRC and para-cancerous tissues was detected by reverse transcription-PCR. The expression of CTBP1-AS2, miR-93-5p and the transforming growth factor-beta (TGF-β)/small mothers against decapentaplegic 2/3 (SMAD2/3) pathway was selectively regulated to study the correlation between CTBP1-AS2 expression and prognosis of patients with CRC. CRC cell proliferation, apoptosis, and invasion were measured in vivo and in vitro. In addition, bioinformatics was applied to explore the targeting relationship between CTBP1-AS2 and miR-93-5p. The targeting binding sites between CTBP1-AS2 and miR-93-5p, as well as between miR-93-5p and TGF-β, were verified by the dual-luciferase reporter assay and the RNA immunoprecipitation experiment.Results: Compared with normal para-cancerous tissues, CTBP1-AS2 was considerably overexpressed in CRC tissues and was closely associated with worse survival of patients with CRC. Functionally, gain and loss in experiments illustrated that CTBP1-AS2 accelerated CRC cell proliferation and invasion and inhibited cell apoptosis. Mechanistically, CTBP1-AS2 regulated the malignant phenotype of tumor cells through the TGF-β/SMAD2/3 pathway. Moreover, miR-93-5p, as an endogenous competitive RNA of CTBP1-AS2, attenuated the oncogenic effects mediated by CTBP1-AS2.Conclusion: CTBP1-AS2 promotes the TGF-β/SMAD2/3 pathway activation by inhibiting miR-93-5p, thereby accelerating CRC development.

Regulation of the proneural gene achaete by helix-loop-helix proteins

1993 ◽  
Vol 13 (6) ◽  
pp. 3514-3521
Author(s):  
C Martínez ◽  
J Modolell ◽  
J Garrell
Keyword(s):  
Transcriptional Control ◽  
Protein A ◽  
Antagonistic Effect ◽  
Helix Loop Helix ◽  
Regulated Expression ◽  
E Boxes ◽  
Bhlh Proteins ◽  
Self Stimulation

The Achaete (Ac) protein, a transcriptional regulator of the basic-helix-loop-helix (bHLH) type, confers upon ectodermal cells the ability to become neural precursors. Its temporally and spatially regulated expression, together with that of the related Scute (Sc) protein, helps define the pattern of Drosophila melanogaster sensory organs. We have examined the transcriptional control of the ac gene and shown, using in vivo assays, that several E-boxes, putative interacting sites for bHLH proteins, present in the ac promoter are most important for ac regulation. They most likely mediate ac self-stimulation and sc trans-activation. We also demonstrate that ac transcription is negatively regulated in vivo by the gene extramacrochaetae (emc) in a manner dependent on Ac and Sc products. emc encodes an HLH protein that lacks the basic region and presumably antagonizes Ac and Sc function by sequestering these proteins in complexes unable to interact with DNA. Our results strongly support the model of negative regulation of emc on ac and sc transcription through titration of their products. As currently thought, this seems accomplished by heterodimerization via the HLH domain, because an amino acid substitution in this region abolishes the emc antagonistic effect both in vitro and in vivo.

scholarly journals The Mechanistic Roles of ncRNAs in Promoting and Supporting Chemoresistance of Colorectal Cancer

2021 ◽  
Vol 7 (2) ◽  
pp. 24
Author(s):  
Isaac Micallef ◽  
Byron Baron
Keyword(s):  
Colorectal Cancer ◽  
Epithelial Mesenchymal Transition ◽  
Circular Rnas ◽  
Gastrointestinal Malignancies ◽  
Mesenchymal Transition ◽  
Non Coding Rna ◽  
Non Coding Rnas ◽  
Made In

Colorectal Cancer (CRC) is one of the most common gastrointestinal malignancies which has quite a high mortality rate. Despite the advances made in CRC treatment, effective therapy is still quite challenging, particularly due to resistance arising throughout the treatment regimen. Several studies have been carried out to identify CRC chemoresistance mechanisms, with research showing different signalling pathways, certain ATP binding cassette (ABC) transporters and epithelial mesenchymal transition (EMT), among others to be responsible for the failure of CRC chemotherapies. In the last decade, it has become increasingly evident that certain non-coding RNA (ncRNA) families are involved in chemoresistance. Research investigations have demonstrated that dysregulation of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) contribute towards promoting resistance in CRC via different mechanisms. Considering the currently available data on this phenomenon, a better understanding of how these ncRNAs participate in chemoresistance can lead to suitable solutions to overcome this problem in CRC. This review will first focus on discussing the different mechanisms of CRC resistance identified so far. The focus will then shift onto the roles of miRNAs, lncRNAs and circRNAs in promoting 5-fluorouracil (5-FU), oxaliplatin (OXA), cisplatin and doxorubicin (DOX) resistance in CRC, specifically using ncRNAs which have been recently identified and validated under in vivo or in vitro conditions.

scholarly journals Knockdown of MiR-20a Enhances Sensitivity of Colorectal Cancer Cells to Cisplatin by Increasing ASK1 Expression

2018 ◽  
Vol 47 (4) ◽  
pp. 1432-1441 ◽  
Author(s):  
Luyao Zhang ◽  
Liang He ◽  
Hua Zhang ◽  
Yan Chen
Keyword(s):  
Colorectal Cancer ◽  
Cancer Cells ◽  
Cell Lines ◽  
Western Blotting ◽  
Luciferase Reporter ◽  
Mirna Regulation ◽  
Platinum Based Chemotherapy ◽  
Colorectal Cancer Cells

Background/Aims: Platinum-based chemotherapy is one of the most important strategies for treatment of colorectal cancer. To improve the therapeutic efficiency, adjuvant drugs were sought to sensitize colorectal cancer cells to platinum-based agents such as cisplatin. As previous research has shown that miRNAs are associated with chemosensitivity, we aimed to alter miRNA regulation in colorectal cancer cells to increase their chemosensitivity. Methods: MTT assays were performed to determine the viability of HT29, SW480, and LoVo cells. Quantitative real time polymerase chain reaction (qRT-PCR) was performed to examine the expression of miR-20a in these cell lines. Regulation of the miR-20a/ASK1 axis was confirmed by western blotting and luciferase reporter assays. After treatment with miR-20a inhibitor (anti-miR-20a) and cisplatin, production of reactive oxygen species (ROS), mitochondrial membrane potential, and apoptosis were measured by flow cytometry. Activation of ASK1, Bcl-xl, JNK, and caspase-9, -7, and -3 was detected by western blotting. Results: miR-20a was overexpressed in colorectal cancer cell lines. Furthermore, knockdown of miR-20a increased the sensitivity of colorectal cancer cells to cisplatin treatment in vitro and in vivo. We demonstrated that the ASK1 gene was the target of miR-20a, and knockdown of miR-20a increased the expression of ASK1 in colorectal cancer cells. As cisplatin treatment induced production of ROS, knockdown of miR-20a enhanced ROS signaling through promoting the phosphorylation of ASK1. Phosphorylation of JNK and the subsequent mitochondrial apoptosis were triggered by the combination of cisplatin and anti-miR-20a. Conclusions: Knockdown of miR-20a enhanced sensitivity of colorectal cancer cells to cisplatin through the ROS/ASK1/JNK pathway.

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