Name: characterization of functionally associated mirnas in glioblastoma and their engineering into artificial clusters for gene therapy
Uploaded: 2019-10-04T14:30:00
Description: Watch this Scientific Journal Video about Characterization of Functionally Associated miRNAs in Glioblastoma and their Engineering into Artificial Clusters for Gene Therapy at JoVE.com

The authors wish to thank the members of the Harvey Cushing Neuro Oncology Laboratory for support and constructive criticism. This work was supported by NINDS grants K12NS80223 and K08NS101091 to P. P.

1. Characterization of Functionally Associated miRNAs in Glioblastoma
<ol>
	<li>Analysis of broad differential miRNA expression in glioblastoma vs. brain
	<ol>
		<li>First, determine the most significantly deregulated miRNAs in the tumor. This can be achieved using at least three different methods:
		<ol>
			<li>Mine the Cancer Genome Atlas, found at https://www.cancer.gov/about-nci/organization/ccg/research/structural-genomics/tcga, for sequencing data11.</li>
			<li>Perform mi...

<ol>
	<li>Wu, Y. E., Parikshak, N. N., Belgard, T. G., Geschwind, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genome-wide,+integrative+analysis+implicates+miRNA+dysregulation+in+autism+spectrum+disorder.">Genome-wide, integrative analysis implicates miRNA dysregulation in autism spectrum disorder.</a> Nature Neuroscience. 19, 1463-1476 (2016).</li><li>Esteller, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-coding+RNAs+in+human+disease.">Non-coding RNAs in human disease.</a> Nature Reviews Genetics. 12, 861-874 (2011).</li><li>Moradifard, S., Hoseinbeyki, M., Ganji, S. M., Minuchehr, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+miRNA+and+Gene+Expression+Profiles+in+Alzheimer's+Disease:+A+Meta-Analysis+Approach.">Analysis of miRNA and Gene Expression Profiles in Alzheimer's Disease: A Meta-Analysis Approach.</a> Scientific Reports. 8, 4767 (2018).</li><li>Calin, G. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frequent+deletions+and+down-regulation+of+micro-+RNA+genes+miR15+and+miR16+at+13q14+in+chronic+lymphocytic+leukemia.">Frequent deletions and down-regulation of micro- RNA genes miR15 and miR16 at 13q14 in chronic lymphocytic leukemia.</a> Proceedings of the National Academy of Sciencesof the United States of America. 99, 15524-15529 (2002).</li><li>Croce, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Causes+and+consequences+of+miRNA+dysregulation+in+cancer.">Causes and consequences of miRNA dysregulation in cancer.</a> Nature Reviews Genetics. 10, 704-714 (2009).</li><li>Ambros, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=miRNAs:+tiny+regulators+with+great+potential.">miRNAs: tiny regulators with great potential.</a> Cell. 107, 823-826 (2001).</li><li>Treiber, T., Treiber, N., Meister, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+miRNA+biogenesis+and+its+crosstalk+with+other+cellular+pathways.">Regulation of miRNA biogenesis and its crosstalk with other cellular pathways.</a> Nature Reviews Molecular Cell Biology. 20, 5-20 (2019).</li><li>He, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+miRNA+polycistron+as+a+potential+human+oncogene.">A miRNA polycistron as a potential human oncogene.</a> Nature. 435, 828-833 (2005).</li><li>Santos, M. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=miR-124,+&#8722;128,+and+&#8722;137+orchestrate+neural+differentiation+by+acting+on+overlapping+gene+sets+containing+a+highly+connected+transcription+factor+network.">miR-124, &#8722;128, and &#8722;137 orchestrate neural differentiation by acting on overlapping gene sets containing a highly connected transcription factor network.</a> Stem Cells. 34, 220-232 (2016).</li><li>Bhaskaran, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+functional+synergism+of+miRNA+clustering+provides+therapeutically+relevant+epigenetic+interference+in+glioblastoma.">The functional synergism of miRNA clustering provides therapeutically relevant epigenetic interference in glioblastoma.</a> Nature Communications. 10 (1), 442 (2019).</li><li>Kim, T. 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S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DIANA-miRPath+v3.0:+deciphering+miRNA+function+with+experimental+support.">DIANA-miRPath v3.0: deciphering miRNA function with experimental support.</a> Nucleic Acids Research. 43 (W1), W460-W466 (2015).</li><li>Chen, J., Bardes, E. E., Aronow, B. J., Jegga, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ToppGene+Suite+for+gene+list+enrichment+analysis+and+candidate+gene+prioritization.">ToppGene Suite for gene list enrichment analysis and candidate gene prioritization.</a> Nucleic Acids Research. 305, W305-W311 (2009).</li><li>Aken, B. 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This protocol is based on the notion that rather than functioning in isolation, miRNAs are biologically relevant by working in groups, and these groups are transcriptionally determined by specific cellular contexts26. To justify this approach from a translational perspective, a follow-up protocol that allows recreation of this multi-miRNA pattern in cells/tissues is introduced. This is possible by taking advantage of the relatively simple biogenesis of miRNAs, whereby the recognition of the charac...

miRNAs offer an unmatched opportunity for the development of a broad gene therapy approach to many diseases1,2,3, including cancer4,5. This is based on several unique features of these biological molecules, including their small size6, simple biogenesis7, and natural tendency to function in association8. Many diseases are characterized by specific miRNA expression patterns, which often converge on the regulation of complex biological functions9. The purpose of this method is first to define a strategy to identify groups of miRNAs that are synergistically relevant for specific cellular functions. Consequently, it provides a strategy for the re-establishment of such miRNA combinations in downstream studies and applications.
This method allows for functional analysis of multiple miRNAs at once, leveraging on their simultaneous targeting of a large number of mRNAs, thus recapitulating the complex landscapes of diseases. This approach has been recently employed to define a group of three miRNAs that 1) are simultaneously downregulated in brain cancer and 2) show a strong co-expression pattern during neural differentiation as well as in response to genotoxic stress by radiation or a DNA alkylating agent. The combinatorial re-expression of this module of three miRNAs by the clustering method described below results in profound interference with the biology of cancer cells and can be easily used as a gene therapy strategy for preclinical studies10. This protocol may be of particular interest to those involved in miRNA research and its translational applications.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>0.4% low melting temperature agarose&#160;</td>
			<td>IBI Scientific</td>
			<td>IB70058</td>
			<td></td>
		</tr>
		<tr>
			<td>0.45 &#181;M sterile filter unit</td>
			<td>Merck Millipore</td>
			<td>SLH033RS</td>
			<td></td>
		</tr>
		<tr>
			<td>1.5-mL Microcentrifuge tube</td>
			<td>Eppendorf</td>
			<td>22431081</td>
			<td></td>
		</tr>
		<tr>
			<td>6-Well plates&#160;</td>
			<td>Greiner Bio-One</td>
			<td>657160</td>
			<td></td>
		</tr>
		<tr>
			<td>Athymic mice (FoxN1 nu/nu)</td>
			<td>Envigo</td>
			<td>069(nu)/070(nu/+)</td>
			<td></td>
		</tr>
		<tr>
			<td>B-27 Supplement&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>12587010</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell culture flask</td>
			<td>Greiner Bio-One</td>
			<td>660175</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell Scraper, 16cm</td>
			<td>Sarstedt</td>
			<td>83.1832</td>
			<td></td>
		</tr>
		<tr>
			<td>Cesium 137 irradiator&#160;</td>
			<td>JL Sheperd and Associates</td>
			<td>Core Facility (Harvard Medical School)</td>
			<td></td>
		</tr>
		<tr>
			<td>Chloroform</td>
			<td>Sigma-Aldrich</td>
			<td>439142-4L</td>
			<td></td>
		</tr>
		<tr>
			<td>DMEM, high glucose, pyruvate&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>11995040</td>
			<td></td>
		</tr>
		<tr>
			<td>Dulbecco&#8217;s phosphate-buffered saline&#160;</td>
			<td>Gibco</td>
			<td>14190144</td>
			<td></td>
		</tr>
		<tr>
			<td>Eosin Y solution&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>E4009</td>
			<td></td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>F9665</td>
			<td></td>
		</tr>
		<tr>
			<td>Formalin solution</td>
			<td>Sigma-Aldrich</td>
			<td>HT501128</td>
			<td></td>
		</tr>
		<tr>
			<td>GlutaMAX Supplement&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>35050061</td>
			<td></td>
		</tr>
		<tr>
			<td>HEK-293</td>
			<td>American Type Culture Collecti</td>
			<td>ATCC CRL-1573</td>
			<td></td>
		</tr>
		<tr>
			<td>Hematoxylin solution</td>
			<td>Sigma-Aldrich</td>
			<td>1051750500</td>
			<td></td>
		</tr>
		<tr>
			<td>Human primary glioma stem-like cells (GBM62)</td>
			<td></td>
			<td></td>
			<td>Provided by Dr. E. A. Chiocca (Brigham and Women&#8217;s Hospital, Boston, MA)</td>
		</tr>
		<tr>
			<td>Human primary glioma stem-like cells (MGG4)</td>
			<td></td>
			<td></td>
			<td>Provided by Dr. Hiroaki Wakimoto (Massachusetts General Hospital, Boston, MA)</td>
		</tr>
		<tr>
			<td>Lentiviral vector pCDH-CMV-MCS-EF1-copGFP</td>
			<td>System Biosciences</td>
			<td>CD511B-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Lipofectamine 2000&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>11668019</td>
			<td></td>
		</tr>
		<tr>
			<td>Microcentrifuge refrigerated</td>
			<td>Eppendorf</td>
			<td>model no. 5424 R, cat. no.5404000138</td>
			<td></td>
		</tr>
		<tr>
			<td>Mounting medium&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>4112APG</td>
			<td></td>
		</tr>
		<tr>
			<td>Nalgene High-Speed Polycarbonate Round Bottom Centrifuge Tubes&#160;</td>
			<td>Thermo Fisher Scientific&#160;</td>
			<td>3117-0380PK</td>
			<td></td>
		</tr>
		<tr>
			<td>NanoDrop</td>
			<td>Thermo Fisher Scientific</td>
			<td>2000c</td>
			<td></td>
		</tr>
		<tr>
			<td>Neural Progenitor cells (NPC)</td>
			<td></td>
			<td></td>
			<td>Provided by Dr. Jakub Godlewski (Brigham and Women&#8217;s Hospital, Boston, MA)</td>
		</tr>
		<tr>
			<td>Neurobasal Medium&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>21103049</td>
			<td></td>
		</tr>
		<tr>
			<td>Nikon eclipse Ti motorized fluorescent microscope system</td>
			<td>Nikon, Japan</td>
			<td>14314</td>
			<td></td>
		</tr>
		<tr>
			<td>Opti-MEM</td>
			<td>Thermo Fisher Scientific</td>
			<td>31985088</td>
			<td></td>
		</tr>
		<tr>
			<td>PCR tubes&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>CLS6571-960EA</td>
			<td></td>
		</tr>
		<tr>
			<td>Penicillin-Streptomycin&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>15140122</td>
			<td></td>
		</tr>
		<tr>
			<td>Petri-Dishes 94/16&#160;</td>
			<td>Greiner Bio-One</td>
			<td>632180</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly-D-Lysine&#160;</td>
			<td>Sigma- Aldrich</td>
			<td>P4707</td>
			<td></td>
		</tr>
		<tr>
			<td>Recombinant Human EGF&#160;</td>
			<td>PeproTech&#160;</td>
			<td>AF-100-15</td>
			<td></td>
		</tr>
		<tr>
			<td>Recombinant Human FGF-basic&#160;</td>
			<td>PeproTech&#160;</td>
			<td>AF-100-18B</td>
			<td></td>
		</tr>
		<tr>
			<td>Retinoic acid</td>
			<td>Gibco</td>
			<td>12587-010&#160;</td>
			<td></td>
		</tr>
		<tr>
			<td>RNA Miniprep Kit</td>
			<td>Direct-zol</td>
			<td>R2050</td>
			<td></td>
		</tr>
		<tr>
			<td>S1000 Thermal Cycler&#160;</td>
			<td>Bio-Rad</td>
			<td>1852196</td>
			<td></td>
		</tr>
		<tr>
			<td>Small Animal Image-Guided Micro Irradiator&#160;</td>
			<td>Xstrahal Life Sciences, UK</td>
			<td>Core facility (Dana-Farber Cancer Institute, Boston, MA)</td>
			<td></td>
		</tr>
		<tr>
			<td>Sorvall WX+ Ultracentrifuge&#160;</td>
			<td>Thermo Fisher Scientific&#160;</td>
			<td>75000100</td>
			<td></td>
		</tr>
		<tr>
			<td>StemPro Accutase&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>A1110501</td>
			<td></td>
		</tr>
		<tr>
			<td>StepOne Real-Time PCR System</td>
			<td>Applied Biosystems&#160;</td>
			<td>4376357</td>
			<td></td>
		</tr>
		<tr>
			<td>SterilGARD biosafety cabinet&#160;</td>
			<td>The Baker Company</td>
			<td>SG403A-HE</td>
			<td></td>
		</tr>
		<tr>
			<td>Sucrose</td>
			<td>Sigma-Aldrich</td>
			<td>S9378</td>
			<td></td>
		</tr>
		<tr>
			<td>T98-G</td>
			<td>American Type Culture Collecti</td>
			<td>ATCC CRL-1690</td>
			<td></td>
		</tr>
		<tr>
			<td>TaqMan MicroRNA Reverse Transcription Kit&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>4366596</td>
			<td></td>
		</tr>
		<tr>
			<td>TaqMan Universal PCR Master Mix</td>
			<td>Thermo Fisher Scientific</td>
			<td>4324018</td>
			<td></td>
		</tr>
		<tr>
			<td>Temozolomide</td>
			<td>Tocris Bioscience</td>
			<td>2706</td>
			<td></td>
		</tr>
		<tr>
			<td>Tissue-Tek optimum cutting temperature&#160;</td>
			<td>Fisher Scientific</td>
			<td>NC9636948</td>
			<td></td>
		</tr>
		<tr>
			<td>TRIzol Reagent&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>15596026</td>
			<td>Lysis reagent</td>
		</tr>
		<tr>
			<td>U251-MG</td>
			<td>American Type Culture Collecti</td>
			<td>ATCC HTB-17</td>
			<td></td>
		</tr>
		<tr>
			<td>U87-MG&#160;</td>
			<td>American Type Culture Collecti</td>
			<td>ATCC HTB-14</td>
			<td></td>
		</tr>
		<tr>
			<td>ViraPower Lentivector Expression system&#160;</td>
			<td>Thermo Fisher Scientific</td>
			<td>K4970-00</td>
			<td></td>
		</tr>
		<tr>
			<td>Water, HPLC grade</td>
			<td>Fisher</td>
			<td>W54</td>
			<td></td>
		</tr>
		<tr>
			<td>Xylene&#160;</td>
			<td>Sigma-Aldrich</td>
			<td>534056</td>
			<td></td>
		</tr>
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</table>

characterization of functionally associated mirnas in glioblastoma and their engineering into artificial clusters for gene therapy

The biological relevance of microRNAs (miRNAs) in health and disease significantly relies on specific combinations of many simultaneously deregulated miRNAs rather than the action of a single miRNA. The characterization of these specific miRNAs modules is a fundamental step in maximizing their use in therapy. This is extremely relevant because their combinatorial attributes can be practically exploited. Described here is a method to define a specific miRNA signature relevant to the control of oncogenic chromatin repressors in glioblastoma. The approach first defines a general group of miRNAs that are deregulated in tumors in comparison to normal tissue. The analysis is further refined by differential culture conditions, underscoring a subgroup of miRNAs that are co-expressed simultaneously during specific cellular states. Finally, the miRNAs that satisfy these filters are combined into an artificial polycistronic transgenes, which is based on a scaffold of naturally existing miRNA clusters genes, then used for overexpression of these miRNA modules into receiving cells.

This method allowed characterization of a module of three miRNAs that are consistently downregulated in brain tumors, which are co-expressed specifically during neuronal differentiation (Figure 1) and involved in the tumor survival response after therapy (Figure 2). This is accomplished by regulating a complex oncogenic chromatin repressive pathway. This co-expression pattern suggested a strong synergistic activity among these th...

Watch this Scientific Journal Video about Characterization of Functionally Associated miRNAs in Glioblastoma and their Engineering into Artificial Clusters for Gene Therapy at JoVE.com

Characterization of Functionally Associated miRNAs in Glioblastoma and their Engineering into Artificial Clusters for Gene Therapy

Described here is a protocol for characterizing modules of biologically synergistic miRNAs and their assembly into short transgenes, which allows simultaneous overexpression for gene therapy applications.

The biological relevance of microRNAs (miRNAs) in health and disease significantly relies on specific combinations of many simultaneously deregulated ...

This protocol allows the simultaneous modulation of many micro RNAs in eukaryotic cells and is based on a very simple and flexible method which minimizes molecular cloning steps. This technique has implications for the study of micro RNA functional interactions in vitro, but more importantly it provides a platform for a more effective use of micro RNAs in therapy. We have mainly developed and used it in the context of brain cancer, but it applies to any diseases where multiple alterations of gene expression are involved.We have tested our artificial trans genes in other models such as breast and thyroid cancer lines showing the reproducibility of this technique. Basic knowledge of bioinformatics and micro RNA biology is helpful for this protocol, but not indispensable. A bioinformatics approach is important to define relevant micro RNA combinations and the TRK-11, while familiarity with the micro RNA processing measurably is important to understand how these different micro RNAs can be assembled into artificial DNA clusters that can be successfully processed once stable to the specific cells.To coat dish, first dissolve poly-D-lysine in water at a concentration of 100 micrograms per milliliter. Pour the solution into the dish at the amount of one milliliter of solution per 25 square centimeters surface. Swirl the dish to make sure of coverage of the whole dish.After six hours aspirate the poly-D-lysine solution and rinse twice with PBS. Plate human neural stem cells in the amount of 100, 000 cells per five milliliter of the medium, either in stem cell medium, astrocytic differentiation medium or neuronal differentiation medium. After cell plating, place the dish in an incubator at 37 degrees Celsius and five percent carbon dioxide for one week and proceed to perform micro RNA expression analysis according to the manuscript.To culture GBM-34 glioblastoma stem-like cells, start with one times ten to the fifth cells and five milliliter of neurobasal medium in a 25 square centimeter low attachment flask. Place the flask into an incubator at 37 degrees Celsius and five percent carbon dioxide. 48 hours after plating, add doubling concentrations of DNA alkylating agent temozolomide every seven days.Start with addition of five micromolar TMZ supplemented in five milliliters medium for five days. After five days, remove the medium and replace with fresh medium without temozolomide to allow the surviving cells to recover. After 48 hours, add 10 micromolar temozolomide and incubate for another five days.Repeat the doubling temozolomide treatment until concentration of at least 100 micromolar is reached and cells become resistant to the drug. After the induction of resistance, lie cells using 1 milliliter of Lysis reagent. Extract total RNA and analyze the expression of the specific micro RNAs according to the manuscript.To obtain the predicted targetome of each micro RNA previously defined, use micro RNA targeting prediction tools. From the front page of TargetScan, select the micro RNA of interest from the pre-populated drop down menu. Click the submit button.Download the resulting list of targets as a spreadsheet using the download table link. To decrease the chances of false positive predictions, include only targets within the conserved sites column and downstream analysis. Additional micro RNA prediction programs obtain further stringency and only include targets that are common to all algorithms.Then, open ToppGene suite 20. To evaluate for the enrichment of pathways that are common to each micro RNA, paste the list of targets obtained in the training gene sets window. Click on HGNC Symbol as the entry type.Click submit and start. The program provides an output table showing the most significant GO categories for the entered list of genes. To finally establish the contribution of each micro RNA to the regulation of a common pathway or cellular process, open the venn-diagram function provided in the Bioinformatics and Evolutionary Genomics website.Check each obtained targetome against the full list of genes involved in the specific cellular process. If target messenger RNAs for each micro RNAs of interest are in the respective windows, upload of copy-paste the list. Name each list with a unique identifier.Click submit. The program provides a visual output of a venn-diagram with numbers of genes in each sector as well as a full list of messenger RNAs for each subset and intersection combinations. To group the selected micro RNAs into a functional trans gene, obtain a transgenic scaffold based on the miR-17-92 cluster locus.Obtain the nucleotide sequence from the ensembled genome browser. Select the approximately 800 base pair core sequence encompassing all six encoded micro RNA hairpins of the locus and at least 200 nucleotide flanking sequences both upstream and downstream of the core sequence. Paste the sequence into any word editing program.Define the sequence of each one of the six native hair pins by retrieving them in miR base. Mark each one of these sequences within the span of previously identified core sequence. Any sequences between each hairpin represent spacer sequences.Next, obtain the hairpin sequences of micro RNAs intended to be over expressed in the trans gene from miR base. Carefully note the specific nucleotides that are at the sites of micro processor cleavage. Delete the native hairpin sequences from the core sequence with the exception of three to five nucleotides at both the five and thee ends of each hairpin which will serve as an acceptor for the new hairpins.Paste the hairpin sequences of the desired micro RNAs to replace the previously deleted hairpins. Add desired restriction sequences at both flanking regions of the trans gene to facilitate sub-cloning into delivery vectors of choice. Verify that the chosen restriction sequences are not present within the sequence itself.To verify the two dimensional structure of the trans gene, copy the full transgenic sequence into the RNA structure prediction software program RNA Webfold. Select standard program settings and click proceed. Analyze the graphical output, particularly for the presence of well defined hairpins in presence of double stranded stem structures that are at least 11 nucleotides proximal to the micro processor cleavage site.Also, look for the absence of branching points within the hairpin sequences. At this point, the trans gene is ready to be produced by gene synthesis and cloned into the desired delivery vectors. This method allowed characterization of a module of three micro RNAs that are consistently down regulated in brain tumors, which are co-expressed specifically during neuronal differentiation.Co-expression patterns of micro RNA modules during genotoxic stress were confirmed and suggested a strong synergistic activity among these three micro RNAs. The designed trans gene could simultaneously recapitulate the expression of the three micro RNAs in glioblastoma cells, both in vitro and in vivo, with significant interference in tumor biology and promising translational applicability. Additionally, the transgenic cluster was also functional in a breast cancer model.The crucial requirements of this protocol are maintaining the original size of processor cleavage in the trans gene. And make sure that the stem loop structure of chimeric micro RNA hairpins is preserved. With this method, we can concentrate multiple biologically active micro RNA genes into very short DNA sequences which can literally be vitroly be fitted into any delivery vectors for gene therapy use.This method is ideal to study the functional interaction among different micro RNAs and to interfere with complex multifactorial cellular pathways which will otherwise require multiple drug combinations.

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Research

JoVE Journal

Genetics

In Vitro Transcription Assays and Their Application in Drug Discovery

In vitro transcription assays have been developed and widely used for many years to study the molecular mechanisms involved in transcription. This process requires multi-subunit DNA-dependent RNA polymerase (RNAP) and a series of transcription factors that act to modulate the activity of RNAP during gene expression. Sequencing gel electrophoresis of radiolabeled transcripts is used to provide detailed mechanistic information on how transcription proceeds and what parameters can affect it. In this paper we describe the protocol to study how the essential elongation factor NusA regulates transcriptional pausing, as well as a method to identify an antibacterial agent targeting transcription initiation through inhibition of RNAP holoenzyme formation. These methods can be used a as platform for the development of additional approaches to explore the mechanism of action of the transcription factors which still remain unclear, as well as new antibacterial agents targeting transcription which is an underutilized drug target in antibiotic research and development.

In Vitro Transcription Assays and Their Application in Drug Discovery

In this manuscript, we describe a protocol to functionally examine transcription and the inhibitory activity of antibacterial agents targeting bacterial transcription.

In vitro transcription assays have been developed and widely used for many years to study the molecular mechanisms involved in transcription. This process ...

Perturbations of Circulating miRNAs in Irritable Bowel Syndrome Detected Using a Multiplexed High-throughput Gene Expression Platform

The gene expression platform assay allows for robust and highly reproducible quantification of the expression of up to 800 transcripts (mRNA or miRNAs) in a single reaction. The miRNA assay counts transcripts by directly imaging and digitally counting miRNA molecules that are labeled with color-coded fluorescent barcoded probe sets (a reporter probe and a capture probe). Barcodes are hybridized directly to mature miRNAs that have been elongated by ligating a unique oligonucleotide tag (miRtag) to the 3&#39; end. Reverse transcription and amplification of the transcripts are not required. Reporter probes contain a sequence of six color positions populated using a combination of four fluorescent colors. The four colors over six positions are used to construct a gene-specific color barcode sequence. Post-hybridization processing is automated on a robotic prep station. After hybridization, the excess probes are washed away, and the tripartite structures (capture probe-miRNA-reporter probe) are fixed to a streptavidin-coated slide via the biotin-labeled capture probe. Imaging and barcode counting is done using a digital analyzer. The immobilized barcoded miRNAs are visualized and imaged using a microscope and camera, and the unique barcodes are decoded and counted. Data quality control (QC), normalization, and analysis are facilitated by a custom-designed data processing and analysis software that accompanies the assay software. The assay demonstrates high linearity over a broad range of expression, as well as high sensitivity. Sample and assay preparation does not involve enzymatic reactions, reverse transcription, or amplification; has few steps; and is largely automated, reducing investigator effects and resulting in high consistency and technical reproducibility. Here, we describe the application of this technology to identifying circulating miRNA perturbations in irritable bowel syndrome.

We describe the use of a multiplexed high-throughput gene expression platform that quantitates gene expression by barcoding and counting molecules in biological substrates without the need for amplification. We used the platform to quantitate microRNA (miRNA) expression in whole blood in subjects with and without irritable bowel syndrome.

The gene expression platform assay allows for robust and highly reproducible quantification of the expression of up to 800 transcripts (mRNA or miRNAs) in ...

Engineering Artificial Factors to Specifically Manipulate Alternative Splicing in Human Cells

The processing of most eukaryotic RNAs is mediated by RNA Binding Proteins (RBPs) with modular configurations, including an RNA recognition module, which specifically binds the pre-mRNA target and an effector domain. Previously, we have taken advantage of the unique RNA binding mode of the PUF domain in human Pumilio 1 to generate a programmable RNA binding scaffold, which was used to engineer various artificial RBPs to manipulate RNA metabolism. Here, a detailed protocol is described to construct Engineered Splicing Factors (ESFs) that are specifically designed to modulate the alternative splicing of target genes. The protocol includes how to design and construct a customized PUF scaffold for a specific RNA target, how to construct an ESF expression plasmid by fusing a designer PUF domain and an effector domain, and how to use ESFs to manipulate the splicing of target genes. In the representative results of this method, we have also described the common assays of ESF activities using splicing reporters, the application of ESF in cultured human cells, and the subsequent effect of splicing changes. By following the detailed protocols in this report, it is possible to design and generate ESFs for the regulation of different types of Alternative Splicing (AS), providing a new strategy to study splicing regulation and the function of different splicing isoforms. Moreover, by fusing different functional domains with a designed PUF domain, researchers can engineer artificial factors that target specific RNAs to manipulate various steps of RNA processing.

This report describes a bioengineering method to design and construct novel Artificial Splicing Factors (ASFs) that specifically modulate the splicing of target genes in mammalian cells. This method can be further expanded to engineer various artificial factors to manipulate other aspects of RNA metabolism.

The processing of most eukaryotic RNAs is mediated by RNA Binding Proteins (RBPs) with modular configurations, including an RNA recognition module, which ...

Chromatin Immunoprecipitation (ChIP) Protocol for Low-abundance Embryonic Samples

Chromatin immunoprecipitation (ChIP) is a widely-used technique for mapping the localization of post-translationally modified histones, histone variants, transcription factors, or chromatin-modifying enzymes at a given locus or on a genome-wide scale. The combination of ChIP assays with next-generation sequencing (i.e., ChIP-Seq) is a powerful approach to globally uncover gene regulatory networks and to improve the functional annotation of genomes, especially of non-coding regulatory sequences. ChIP protocols normally require large amounts of cellular material, thus precluding the applicability of this method to investigating rare cell types or small tissue biopsies. In order to make the ChIP assay compatible with the amount of biological material that can typically be obtained in vivo during early vertebrate embryogenesis, we describe here a simplified ChIP protocol in which the number of steps required to complete the assay were reduced to minimize sample loss. This ChIP protocol has been successfully used to investigate different histone modifications in various embryonic chicken and adult mouse tissues using low to medium cell numbers (5 x 104 - 5 x 105 cells). Importantly, this protocol is compatible with ChIP-seq technology using standard library preparation methods, thus providing global epigenomic maps in highly relevant embryonic tissues.

Chromatin Immunoprecipitation ChIP Protocol for Low-abundance Embryonic Samples

Here, we describe a chromatin immunoprecipitation (ChIP) and ChIP-seq library preparation protocol to generate global epigenomic profiles from low-abundance chicken embryonic samples.

Chromatin immunoprecipitation (ChIP) is a widely-used technique for mapping the localization of post-translationally modified histones, histone variants, ...

Microinjection of CRISPR/Cas9 Protein into Channel Catfish, Ictalurus punctatus, Embryos for Gene Editing

The complete genome of the channel catfish, Ictalurus punctatus, has been sequenced, leading to greater opportunities for studying channel catfish gene function. Gene knockout has been used to study these gene functions in vivo. The clustered regularly interspaced short palindromic repeats/CRISPR associated protein 9 (CRISPR/Cas9) system is a powerful tool used to edit genomic DNA sequences to alter gene function. While the traditional approach has been to introduce CRISPR/Cas9 mRNA into the single cell embryos through microinjection, this can be a slow and inefficient process in catfish. Here, a detailed protocol for microinjection of channel catfish embryos with CRISPR/Cas9 protein is described. Briefly, eggs and sperm were collected and then artificial fertilization performed. Fertilized eggs were transferred to a Petri dish containing Holtfreter's solution. Injection volume was calibrated and then guide RNAs/Cas9 targeting the toll/interleukin 1 receptor domain-containing adapter molecule (TICAM 1) gene and rhamnose binding lectin (RBL) gene were microinjected into the yolk of one-cell embryos. The gene knockout was successful as indels were confirmed by DNA sequencing. The predicted protein sequence alterations due to these mutations included frameshift and truncated protein due to premature stop codons.

Microinjection of CRISPR/Cas9 Protein into Channel Catfish, Ictalurus punctatus, Embryos for Gene Editing

A simple and efficient microinjection protocol for gene editing in channel catfish embryos using the CRISPR/Cas9 system is presented. In this protocol, guide RNAs and Cas9 protein were microinjected into the yolk of one-cell embryos. This protocol has been validated by knocking out two channel catfish immune-related genes.

The complete genome of the channel catfish, Ictalurus punctatus, has been sequenced, leading to greater opportunities for studying channel catfish gene ...

Production and Purification of Baculovirus for Gene Therapy Application

Baculovirus has traditionally been used for the production of recombinant protein and vaccine. However, more recently, baculovirus is emerging as a promising vector for gene therapy application. Here, baculovirus is produced by transient transfection of the baculovirus plasmid DNA (bacmid) in an adherent culture of Sf9 cells. Baculovirus is subsequently expanded in Sf9 cells in a serum-free suspension culture until the desired volume is obtained. It is then purified from the culture supernatant using heparin affinity chromatography. Virus supernatant is loaded onto the heparin column which binds baculovirus particles in the supernatant due to the affinity of heparin for baculovirus envelop glycoprotein. The column is washed with a buffer to remove contaminants and baculovirus is eluted from the column with a high-salt buffer. The eluate is diluted to an isotonic salt concentration and baculovirus particles are further concentrated using ultracentrifugation. Using this method, baculovirus can be concentrated up to 500-fold with a 25% recovery of infectious particles. Although the protocol described here demonstrates the production and purification of the baculovirus from cultures up to 1 L, the method can be scaled-up in a closed-system suspension culture to produce a clinical-grade vector for gene therapy application.

In this protocol, baculovirus is produced by transient transfection of baculovirus plasmid into Sf9 cells and amplified in a serum-free suspension culture. The supernatant is purified by heparin affinity chromatography and further concentrated by ultracentrifugation. This protocol is useful for the production and purification of baculovirus for gene therapy application.

Baculovirus has traditionally been used for the production of recombinant protein and vaccine. However, more recently, baculovirus is emerging as a ...

Highly Efficient Gene Disruption of Murine and Human Hematopoietic Progenitor Cells by CRISPR/Cas9

Advances in the hematopoietic stem cell (HSCs) field have been aided by methods to genetically engineer primary progenitor cells as well as animal models. Complete gene ablation in HSCs required the generation of knockout mice from which HSCs could be isolated, and gene ablation in primary human HSCs was not possible. Viral transduction could be used for knock-down approaches, but these suffered from variable efficacy. In general, genetic manipulation of human and mouse hematopoietic cells was hampered by low efficiencies and extensive time and cost commitments. Recently, CRISPR/Cas9 has dramatically expanded the ability to engineer the DNA of mammalian cells. However, the application of CRISPR/Cas9 to hematopoietic cells has been challenging, mainly due to their low transfection efficiencies, the toxicity of plasmid-based approaches and the slow turnaround time of virus-based protocols.
A rapid method to perform CRISPR/Cas9-mediated gene editing in murine and human hematopoietic stem and progenitor cells with knockout efficiencies of up to 90% is provided in this article. This approach utilizes a ribonucleoprotein (RNP) delivery strategy with a streamlined three-day workflow. The use of Cas9-sgRNA RNP allows for a hit-and-run approach, introducing no exogenous DNA sequences in the genome of edited cells and reducing off-target effects. The RNP-based method is fast and straightforward: it does not require cloning of sgRNAs, virus preparation or specific sgRNA chemical modification. With this protocol, scientists should be able to successfully generate knockouts of a gene of interest in primary hematopoietic cells within a week, including downtimes for oligonucleotide synthesis. This approach will allow a much broader group of users to adapt this protocol for their needs.

A protocol for fast CRISPR/Cas9-mediated gene disruption in mouse and human primary hematopoietic cells is described in this article. Cas9-sgRNA ribonucleoproteins are introduced via electroporation with sgRNAs generated through in vitro transcription and commercial Cas9. High editing efficiencies are achieved with limited time and financial cost.

Advances in the hematopoietic stem cell (HSCs) field have been aided by methods to genetically engineer primary progenitor cells as well as animal models. ...

Biotin-based Pulldown Assay to Validate mRNA Targets of Cellular miRNAs

MicroRNAs (miRNAs) are a class of small noncoding RNAs that post-transcriptionally regulate cellular gene expression. MiRNAs bind to the 3&#39; untranslated region (UTR) of target mRNA to inhibit protein translation or in some instances cause mRNA degradation. The binding of the miRNA to the 3&#39; UTR of the target mRNA is mediated by a 2&#8211;8 nucleotide seed sequence at the 5&#39; end of miRNA. While the role of miRNAs as cellular regulatory molecules is well established, identification of the target mRNAs with functional relevance remains a challenge. Bioinformatic tools have been employed to predict sequences within the 3&#39; UTR of mRNAs as potential targets for miRNA binding. These tools have also been utilized to determine the evolutionary conservation of such sequences among related species in an attempt to predict functional role. However, these computational methods often generate false positive results and are limited to predicting canonical interaction between miRNA and mRNA. Therefore, experimental procedures that measure direct binding of miRNA to its mRNA target are necessary to establish functional interaction. In this report, we describe a sensitive method for validating direct interaction between the cellular miRNA miR-125b and the 3&#39; UTR of PARP-1 mRNA. We elaborate a protocol in which synthetic biotinylated-miRNA mimics were transfected into mammalian cells and the miRNA-mRNA complex in the cellular lysate was pulled down with streptavidin-coated magnetic beads. Finally, the target mRNA in the pulled-down nucleic acid complex was quantified using a qPCR-based strategy.

This report describes a fast and reliable method for validating mRNA targets of cellular miRNAs. The method uses synthetic biotinylated Locked Nucleic Acid (LNA)-based miRNA mimics to capture target mRNA. Subsequently, streptavidin-coated magnetic beads are employed to pulldown the target mRNA for quantification by qPCR polymerase chain reaction.

MicroRNAs (miRNAs) are a class of small noncoding RNAs that post-transcriptionally regulate cellular gene expression. MiRNAs bind to the 3&#39; ...

Isolation, Characterization and MicroRNA-based Genetic Modification of Human Dental Follicle Stem Cells

To date, several stem cell types at different developmental stages are in the focus for the treatment of degenerative diseases. Yet, certain aspects, such as initial massive cell death and low therapeutic effects, impaired their broad clinical translation. Genetic engineering of stem cells prior to transplantation emerged as a promising method to optimize therapeutic stem cell effects. However, safe and efficient gene delivery systems are still lacking. Therefore, the development of suitable methods may provide an approach to resolve current challenges in stem cell-based therapies.
The present protocol describes the extraction and characterization of human dental follicle stem cells (hDFSCs) as well as their non-viral genetic modification. The postnatal dental follicle unveiled as a promising and easily accessible source for harvesting adult multipotent stem cells possessing high proliferation potential. The described isolation procedure presents a simple and reliable method to harvest hDFSCs from impacted wisdom teeth. Also this protocol comprises methods to define stem cell characteristics of isolated cells. For genetic engineering of hDFSCs, an optimized cationic lipid-based transfection strategy is presented enabling highly efficient microRNA introduction without causing cytotoxic effects. MicroRNAs are suitable candidates for transient cell manipulation, as these small translational regulators control the fate and behavior of stem cells without the hazard of stable genome integration. Thus, this protocol represents a safe and efficient procedure for engineering of hDFSCs that may become important for optimizing their therapeutic efficacy.

This protocol describes the transient genetic engineering of dental stem cells extracted from the human dental follicle. The applied non-viral modification strategy may become a basis for the improvement of therapeutic stem cell products.

To date, several stem cell types at different developmental stages are in the focus for the treatment of degenerative diseases. Yet, certain aspects, such ...

Preparation and Gene Modification of Nonhuman Primate Hematopoietic Stem and Progenitor Cells

Hematopoietic stem and progenitor cell (HSPC) transplantation has been a cornerstone therapy for leukemia and other cancers for nearly half a century, underlies the only known cure of human immunodeficiency virus (HIV-1) infection, and shows immense promise in the treatment of genetic diseases such as beta thalassemia. Our group has developed a protocol to model HSPC gene therapy in nonhuman primates (NHPs), allowing scientists to optimize many of the same reagents and techniques that are applied in the clinic. Here, we describe methods for purifying CD34+ HSPCs and long-term persisting hematopoietic stem cell (HSC) subsets from primed bone marrow (BM). Identical techniques can be employed for the purification of other HSPC sources (e.g., mobilized peripheral blood stem cells [PBSCs]). Outlined is a 2 day protocol in which cells are purified, cultured, modified with lentivirus (LV), and prepared for infusion back into the autologous host. Key readouts of success include the purity of the CD34+ HSPC population, the ability of purified HSPCs to form morphologically distinct colonies in semisolid media, and, most importantly, gene modification efficiency. The key advantage to HSPC gene therapy is the ability to provide a source of long-lived cells that give rise to all hematopoietic cell types. As such, these methods have been used to model therapies for cancer, genetic diseases, and infectious diseases. In each case, therapeutic efficacy is established by enhancing the function of distinct HSPC progeny, including red blood cells, T cells, B cells, and/or myeloid subsets. The methods to isolate, modify, and prepare HSPC products are directly applicable and translatable to multiple diseases in human patients.

The goal of this protocol is to isolate nonhuman primate CD34+ cells from primed bone marrow, to gene-modify these cells with lentiviral vectors, and to prepare a product for infusion into the autologous host. The total protocol length is approximately 48 h.

Hematopoietic stem and progenitor cell (HSPC) transplantation has been a cornerstone therapy for leukemia and other cancers for nearly half a century, ...