Name: adapting 3' rapid amplification of cdna ends to map transcripts in cancer
Uploaded: 2018-03-28T15:00:00
Description: Watch this Scientific Journal Video about Adapting 3' Rapid Amplification of CDNA Ends to Map Transcripts in Cancer at JoVE.com

We would like to acknowledge Bettine Gibbs for her technical help.

Wear a lab coat, gloves, and safety glasses at all times while performing all procedures in this protocol. Ensure that containers/tubes containing the phenol and guanidine isothiocyanate reagent are only opened in a certified hood, and dispose of phenol waste in a designated container. Use DNAse/RNAse-free sterile tubes, tips, and reagents.
1. Cell Culture
<ol>
	<li>Grow the HeLa cell line and two suspension mantle cell lymphoma cell lines, Granta-519 and Jeko-1, in DMEM containing 10% FBS a...

<ol>
	<li>Mandel, C., Bai, Y., Tong, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+factors+in+pre-mRNA+3'-end+processing.">Protein factors in pre-mRNA 3'-end processing.</a> Cell Mol Life Sci. 65 (7-8), 1099-1122 (2008).</li><li>Danckwardt, S., Hentze, M., Kulozik, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3'+end+mRNA+processing:+Molecular+mechanisms+and+implications+for+health+and+disease.">3' end mRNA processing: Molecular mechanisms and implications for health and disease.</a> EMBO J. 27 (3), 482-498 (2008).</li><li>Derti, 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=A+quantitative+atlas+of+polyadenylation+in+five+mammals.">A quantitative atlas of polyadenylation in five mammals.</a> Genome Res. 22 (6), 1173-1183 (2012).</li><li>Sambrook, J., Russell, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+amplification+of+3&#8242;+cDNA+ends+(3&#8242;-RACE).">Rapid amplification of 3&#8242; cDNA ends (3&#8242;-RACE).</a> Cold Spring Harb Protoc. 2006 (1), (2006).</li><li>Masamha, C. P., 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=CFIm25+regulates+glutaminase+alternative+terminal+exon+definition+to+modulate+miR-23+function.">CFIm25 regulates glutaminase alternative terminal exon definition to modulate miR-23 function.</a> RNA. 22 (6), 830-838 (2016).</li><li>Rodu, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+Biology+in+Medicine:+The+polymerase+chain+reaction:+the+revolution+within.">Molecular Biology in Medicine: The polymerase chain reaction: the revolution within.</a> Am J Med Sci. 299 (3), 210-216 (1990).</li><li>Bertioli, D., White, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+amplification+of+cDNA+ends.">Rapid amplification of cDNA ends.</a> PCR Cloning Protocols: Methods in Molecular Biology. 67, 233-238 (1997).</li><li>Freeman, L. A., Freeman, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cloning+full-length+transcripts+and+transcript+variants+using+5'+and+3'+RACE.">Cloning full-length transcripts and transcript variants using 5' and 3' RACE.</a> Lipoproteins and Cardiovascular Disease: Methods in Molecular Biology (Methods and Protocols). 1027, 3-17 (2013).</li><li>Masamha, C. P., Albrecht, T. R., Wagner, E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Discovery+and+characterization+of+a+novel+CCND1/MRCK+gene+fusion+in+mantle+cell+lymphoma.">Discovery and characterization of a novel CCND1/MRCK gene fusion in mantle cell lymphoma.</a> J Hematol Oncol. 9 (1), 1-5 (2016).</li><li>Parker, B. 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=The+tumorigenic+FGFR3-TACC3+gene+fusion+escapes+miR-99a+regulation+in+glioblastoma.">The tumorigenic FGFR3-TACC3 gene fusion escapes miR-99a regulation in glioblastoma.</a> J Clin Investig. 123 (2), 855-865 (2013).</li><li>Prakash, T., 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=Expression+of+conjoined+genes:+Another+mechanism+for+gene+regulation+in+eukaryotes.">Expression of conjoined genes: Another mechanism for gene regulation in eukaryotes.</a> PLOS ONE. 5 (10), e13284 (2010).</li><li>Mertens, F., Johansson, B., Fioretos, T., Mitelman, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+emerging+complexity+of+gene+fusions+in+cancer.">The emerging complexity of gene fusions in cancer.</a> Nat Rev Cancer. 15 (6), 371-381 (2015).</li><li>Mayr, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+and+biological+roles+of+alternative+3'UTRs.">Evolution and biological roles of alternative 3'UTRs.</a> Trends Cell Biol. 26 (3), 227-237 (2016).</li><li>International Committee For Standardization In, H., 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=Protocol+for+evaluation+of+automated+blood+cell+counters.">Protocol for evaluation of automated blood cell counters.</a> Clin Lab Haematol. 6 (1), 69-84 (1984).</li><li>Desjardins, P., Conklin, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=NanoDrop+microvolume+quantitation+of+nucleic+acids.">NanoDrop microvolume quantitation of nucleic acids.</a> J Vis Exp. (45), e2565 (2010).</li><li>Lorenz, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymerase+chain+reaction:+Basic+protocol+plus+troubleshooting+and+optimization+strategies.">Polymerase chain reaction: Basic protocol plus troubleshooting and optimization strategies.</a> J Vis Exp. (63), e3998 (2012).</li><li>Lee, P. Y., Costumbrado, J., Hsu, C. -. Y., Kim, Y. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Agarose+gel+electrophoresis+for+the+separation+of+DNA+fragments.">Agarose gel electrophoresis for the separation of DNA fragments.</a> J Vis Exp. (62), e3923 (2012).</li><li>Curtis, P. C., Thomas, J. L., Phillips, N. R., Roby, R. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+primer+specific+filter+metrics+for+the+assessment+of+mitochondrial+DNA+sequence+data.">Optimization of primer specific filter metrics for the assessment of mitochondrial DNA sequence data.</a> Mitochondrial DNA. 21 (6), 191-197 (2010).</li><li>Letowski, J., Brousseau, R., Masson, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Designing+better+probes:+Effect+of+probe+size,+mismatch+position+and+number+on+hybridization+in+DNA+oligonucleotide+microarrays.">Designing better probes: Effect of probe size, mismatch position and number on hybridization in DNA oligonucleotide microarrays.</a> J Microbiol Methods. 57 (2), 269-278 (2004).</li><li>Lefever, S., Pattyn, F., Hellemans, J., Vandesompele, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-nucleotide+polymorphisms+and+other+mismatches+reduce+performance+of+quantitative+PCR+assays.">Single-nucleotide polymorphisms and other mismatches reduce performance of quantitative PCR assays.</a> Clin Chem. 59 (10), 1470-1480 (2013).</li><li>Singh, V. K., Govindarajan, R., Naik, S., Kumar, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+hairpin+structure+on+PCR+amplification+efficiency.">The effect of hairpin structure on PCR amplification efficiency.</a> Mol Biol Today. 1, 67-69 (2000).</li><li>Kalle, E., Kubista, M., Rensing, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi-template+polymerase+chain+reaction.">Multi-template polymerase chain reaction.</a> Biomol Detect Quant. 2, 11-29 (2014).</li><li>Stransky, N., Cerami, E., Schalm, S., Kim, J. L., Lengauer, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+landscape+of+kinase+fusions+in+cancer.">The landscape of kinase fusions in cancer.</a> Nat Commun. 5, 4846 (2014).</li></ol>

Despite the advent of massive parallel sequencing technologies, on a gene-by-gene basis, 3&#39; RACE still remains the easiest and most economical method to identify the PAS and nucleotides adjacent to the poly(A) tail. The adaptation described here expands using 3&#39; RACE to both amplify and map sequences that include a portion of the ORF, the stop codon, and the entire 3&#39; UTR of the ANKHD1 mRNA transcript. A major advantage of 3&#39; RACE is that with a few minor adaptations, products from 3&#39; RACE ca...

The formation of the 3&#39; end is a critical step in mRNA maturation that comprises the cleavage of the pre-mRNA downstream of a PAS followed by the addition of ~250 untemplated adenines, which make up the poly(A) tail1,2. The poly(A) binding protein (PABP) binds to the poly(A) tail, and this protects the mRNA transcript from degradation, and facilitates translation1.
Current estimates suggest that 70% of human genes have multiple PASs, and thus undergo alternative polyadenylation, resulting in multiple 3&#39; ends3. Thus, it is important to identify where the poly(A) tail attaches to the rest of the 3&#39; UTR, as well as identify the PAS used by any given transcript. The advent of next-generation sequencing has resulted in the simultaneous identification of the 3&#39; UTRs and the PASs of thousands of genes. This increase in sequencing capability has required the development of bioinformatic algorithms to analyze data involving alternative polyadenylation of the 3&#39; end. For the de novo detection or validation of the PAS and hence mapping of the 3&#39; end of individual genes from large scale sequencing data, 3&#39; RACE remains the method of choice4,5. The sequences included in cDNA products of 3&#39; RACE normally include only a portion of the 3&#39; UTR that contains the poly(A) tail, the cleavage site, the PAS, and the sequences upstream of the PAS. Unlike PCR, which requires the design and use of gene specific forward and reverse primers, 3&#39; RACE only requires two gene specific nested forward primers. Hence, PCR requires a more detailed knowledge of the nucleotide sequence of a large region of the gene being amplified4,6. Since 3&#39; RACE uses the same reverse primer that targets the poly(A) tail for all polyadenylated RNA transcripts, only the forward primers need to be gene specific, thus, only requiring knowledge of a significantly smaller region of the mRNA. This enables the amplification of regions whose sequences are not fully characterized4,7. This has allowed 3&#39; RACE to be used not only to determine the 3&#39; end of a gene, but to also determine and characterize large regions upstream of the PAS that form a significant portion of the 3&#39; UTR. By combining 5&#39; RACE with the modified 3&#39; RACE that includes larger portions of the 3&#39; UTR and flanking regions, it is possible to fully sequence or clone an entire mRNA transcript from the 5&#39; end to its 3&#39; end8.
An example of this application of modified 3&#39; RACE is the recent identification of a novel CCND1-MRCK fusion gene transcript from Mantle Cell Lymphoma cell lines and cancer patients. The 3&#39; UTR consisted of sequences from both the CCND1 and MRCK genes and was recalcitrant to miRNA regulation9. The two nested CCND1 specific forward primers were complementary to the region immediately adjacent and downstream of the CCND1 stop codon. Although whole transcriptome sequencing together with specific bioinformatic tools can be used to detect gene fusions within the 3&#39; UTR10, many labs may lack the financial resources or bioinformatic expertise to make use of this technology. Hence, 3&#39; RACE is an alternative for de novo identification and validation of novel fusion genes involving the 3&#39; UTR. Considering the drastic increase in the number of reported fusion genes as well as read through transcripts, 3&#39; RACE has become a powerful tool in characterizing gene sequences11,12. In addition, recent studies have shown that different sequences within the 3&#39; UTR as well as the length of the 3&#39; UTR can affect mRNA transcript stability, localization, translatability, and function13. Due in part to an increased interest in mapping the transcriptome, there has been an increase in the number of different DNA polymerases being developed for use in the lab. It is important to determine what types of modifications can be made to the 3&#39; RACE protocol in order to utilize the available repertoire of DNA polymerases.
This work reports adapting 3&#39; RACE to map the entire 3&#39; UTR, the PAS, and the 3&#39; end cleavage site of the ANKHD1 transcript by using nested primers within the ANKHD1 section of the transcript and&#160;two different DNA polymerases.

<table>
	<tbody>
		<tr>
			<td>HeLa cells</td>
			<td>ATCC</td>
			<td>CCL-2</td>
			<td>Cervical cancer cell line.</td>
		</tr>
		<tr>
			<td>Jeko-1 cells</td>
			<td>ATCC</td>
			<td>CRL-3006</td>
			<td>Mantle cell lymphoma cell line.</td>
		</tr>
		<tr>
			<td>Granta-519 cells</td>
			<td>DSMZ</td>
			<td>ACC-342</td>
			<td>Mantle cell lymphoma cell line.</td>
		</tr>
		<tr>
			<td>Fetal Bovine Serum</td>
			<td>Sigma Aldrich</td>
			<td>F6178</td>
			<td>Fetal bovine serum for cell culture.</td>
		</tr>
		<tr>
			<td>Penicillin/Streptomycin</td>
			<td>ThermoFisherScientific</td>
			<td>15140122</td>
			<td>Antibiotic and antimycotic.</td>
		</tr>
		<tr>
			<td>GlycoBlue</td>
			<td>Ambion</td>
			<td>AM9545</td>
			<td>Coprecipitant.</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>ThermoFisherScientific</td>
			<td>10569044</td>
			<td>Gibco brand cell culture media with GlutaMAX.</td>
		</tr>
		<tr>
			<td>Nuclease Free-Water</td>
			<td>ThermoFisherScientific</td>
			<td>AM9938</td>
			<td>Ambion DNase and RNAse free water(non DEPC treated).</td>
		</tr>
		<tr>
			<td>Dulbecco&#8217;s Phosphate-Buffered Solution</td>
			<td>Corning</td>
			<td>21-030</td>
			<td>1X PBS.</td>
		</tr>
		<tr>
			<td>Chloroform</td>
			<td>Sigma&#160; Aldrich</td>
			<td>C7559-5VL</td>
			<td></td>
		</tr>
		<tr>
			<td>2-propanol</td>
			<td>Sigma Aldrich</td>
			<td>I9516</td>
			<td></td>
		</tr>
		<tr>
			<td>Reagent Alcohol</td>
			<td>Sigma Aldrich</td>
			<td>793175</td>
			<td>Ethanol</td>
		</tr>
		<tr>
			<td>Ethidium Bromide solution</td>
			<td>Sigma Aldrich</td>
			<td>E1510</td>
			<td></td>
		</tr>
		<tr>
			<td>TRIzol Reagent</td>
			<td>ThermoFisherScientific</td>
			<td>15596026</td>
			<td>Monophasic phenol and guanidine isothiocyanate reagent.</td>
		</tr>
		<tr>
			<td>2X Extender PCR-to-Gel Master Mix</td>
			<td>Amresco</td>
			<td>N867</td>
			<td>2X PCR-to-Gel Master Mix&#160; containing loading dye used in routine quick PCR assays and primer search.</td>
		</tr>
		<tr>
			<td>10mM dNTP</td>
			<td>Amresco</td>
			<td>N557</td>
			<td></td>
		</tr>
		<tr>
			<td>RQ1 RNase-Free DNase</td>
			<td>Promega</td>
			<td>M6101</td>
			<td>Dnase treatment kit.</td>
		</tr>
		<tr>
			<td>Gel Loading Dye Orange (6X)</td>
			<td>New England BioLabs</td>
			<td>B7022S</td>
			<td></td>
		</tr>
		<tr>
			<td>2X Phusion High-Fidelity PCR Master Mix with HF buffer</td>
			<td>ThermoFisherScientific</td>
			<td>F531S</td>
			<td>2X PCR MasterMix containing a chimeric DNA polymerase consisting of a DNA binding domain fused to a Pyrococcus-like proofreading polymerase and other reagents.</td>
		</tr>
		<tr>
			<td>PfuUltra II Fusion HS DNA polymerase</td>
			<td>Agilent Technologies</td>
			<td>600670</td>
			<td>Modified DNA Polymerase from Pyrococcus furiosus (Pfu).</td>
		</tr>
		<tr>
			<td>RevertAid RT Reverse Transcription Kit</td>
			<td>Thermo Fischer</td>
			<td>K1691</td>
			<td>Used for&#160; reverse transcription of mRNA into&#160; cDNA synthesis. Kit includes&#160; Ribolock RNAse inhibitor, RevertAid M-MuLV reverse transcriptase and other reagents listed in manuscript.</td>
		</tr>
		<tr>
			<td>Pefect size 1Kb ladder</td>
			<td>5 Prime</td>
			<td>2500360</td>
			<td>Molecular weight DNA ladder.</td>
		</tr>
		<tr>
			<td>Alpha Innotech FluorChem Q MultiImage III</td>
			<td>Alpha Innotech</td>
			<td></td>
			<td>Used to visualise ethidium bromide stained agarose gel.</td>
		</tr>
		<tr>
			<td>Low Molecular Weight Ladder</td>
			<td>New England BioLabs</td>
			<td>N3233L</td>
			<td>Molecular weight DNA ladder.</td>
		</tr>
		<tr>
			<td>Vortex Mixer</td>
			<td>MidSci</td>
			<td>VM-3200</td>
			<td></td>
		</tr>
		<tr>
			<td>Mini Centrifuge</td>
			<td>MidSci</td>
			<td>C1008-R</td>
			<td></td>
		</tr>
		<tr>
			<td>Dry Bath</td>
			<td>MidSci</td>
			<td>DB-D1</td>
			<td></td>
		</tr>
		<tr>
			<td>NanoDrop 2000C</td>
			<td>ThermoFisherScientific</td>
			<td>ND-2000C</td>
			<td>Spectrophotometer.</td>
		</tr>
		<tr>
			<td>Wide Mini-Sub&#160;Cell GT Horizontal Electrophoresis System</td>
			<td>BioRad</td>
			<td>1704469</td>
			<td>Electrophoresis equipment-apparatus to set up gel</td>
		</tr>
		<tr>
			<td>PowerPac Basic Power Supply</td>
			<td>BioRad</td>
			<td>1645050</td>
			<td>Power supply for gel electrophoresis.</td>
		</tr>
		<tr>
			<td>Agarose</td>
			<td>Dot Scientific</td>
			<td>AGLE-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Mastercycler Gradient</td>
			<td>Eppendorf</td>
			<td>950000015</td>
			<td>PCR thermocycler.</td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Eppendorf</td>
			<td>5810 R</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Eppendorf</td>
			<td>5430R</td>
			<td></td>
		</tr>
		<tr>
			<td>Wizard SV Gel and PCR Fragment DNA Clean-Up System</td>
			<td>Promega</td>
			<td>A9281</td>
			<td></td>
		</tr>
		<tr>
			<td>Zero Blunt TOPO PCR Cloning Kit, with One Shot&#160; TOP10 Chemically Competent E. coli cells</td>
			<td>ThermoFisherScientific</td>
			<td>K280020</td>
			<td></td>
		</tr>
		<tr>
			<td>MyPCR Preparation Station Mystaire</td>
			<td>MidSci</td>
			<td>MY-PCR24</td>
			<td>Hood dedicated to PCR work.</td>
		</tr>
		<tr>
			<td>Hamilton SafeAire II fume hood</td>
			<td>ThermoFisherScientific</td>
			<td></td>
			<td>Fume hood.</td>
		</tr>
		<tr>
			<td>Beckman Coulter Z1&#160;Particle&#160;Counter</td>
			<td>Beckman Coulter</td>
			<td>6605698</td>
			<td>Particle counter. For counting cells before plating&#160; for RNA extraction.</td>
		</tr>
		<tr>
			<td>Applied Biosystems Sequence Scanner Software v2.0</td>
			<td>Applied Biosystems (through ThermoFisherScientific)</td>
			<td></td>
			<td>Software to analyze Sanger sequencing data.</td>
		</tr>
	</tbody>
</table>

adapting 3' rapid amplification of cdna ends to map transcripts in cancer

Maturation of eukaryotic mRNAs involves 3&#39; end formation, which involves the addition of a poly(A) tail. In order to map the 3&#39; end of a gene, the traditional method of choice is 3&#39; rapid amplification of cDNA ends (3&#39; RACE). Protocols for 3&#39; RACE require the careful design and selection of nested primers within the 3&#39; untranslated region (3&#39; UTR) of the target gene of interest. However, with a few modifications the protocol can be used to include the entire 3&#39; UTR and sequences within the open reading frame (ORF), providing a more comprehensive picture of the relationship between the ORF and the 3&#39; UTR. This is in addition to identification of the polyadenylation signal (PAS), as well as the cleavage and polyadenylation site provided by conventional 3&#39; RACE. Expanded 3&#39; RACE can detect unusual 3&#39; UTRs, including gene fusions within the 3&#39; UTR, and the sequence information can be used to predict potential miRNA binding sites as well as AU rich destabilizing elements that may affect the stability of the transcript.

Nested Forward Primer Search:
The agarose gel from Figure 1 shows two distinct PCR gel products (Lanes 1 and 2) which use the same forward primer but different reverse primers. Lane 3 has a distinct PCR product and has a distinct forward and reverse primer. The ideal primers to use for the PCR based reaction are those that give one distinct PCR product (Lane 3). The forward primer used...

Watch this Scientific Journal Video about Adapting 3' Rapid Amplification of CDNA Ends to Map Transcripts in Cancer at JoVE.com

Adapting 3' Rapid Amplification of CDNA Ends to Map Transcripts in Cancer

The two different 3&#39; rapid amplification of cDNA ends (3&#39; RACE) protocols described here make use of two different DNA polymerases to map sequences that include a segment of the open reading frame (ORF), the stop codon, and the entire 3&#39; UTR of a transcript using RNA obtained from different cancer cell lines.

Maturation of eukaryotic mRNAs involves 3&#39; end formation, which involves the addition of a poly(A) tail. In order to map the 3&#39; end of a gene, the ...

The overall goal of this procedure is to determine the sequences of mRNA transcripts from the three-prime end to regions within the protein coding region by using transcript-specific nested primers in two subsequent PCRs and sequencing the purified PCR products. This method can help answer key questions in the genetic field, such as determining the polyadenylation signal, the stop codon, and the sequence of the three-prime untranslated region of the transcript. The main advantage of this technique is that it can be applied to any transcript if the sequence of the small region of the open reading frame is The implication of this technique extend toward cancer diagnosis, because it can detect tumor specific fusion genes and splice variants.We first had the idea for this method when we identified novel transcripts with previously uncharacterized, three-primed untranslated regions. To begin the protocol, thaw the phenol and guanidine isothiocyanate cell mixture on ice. Once thawed, add 100 microliters of chloroform to the microcentrifuge tube in a PCR hood.Vortex the sample for 10 to 15 seconds until the mixture is pink and opaque. Next, incubate the sample on ice for 15 minutes. After incubation, centrifuge the sample for 15 minutes at 20, 800 g and four degrees Celsius.Carefully remove the upper colorless aqueous phase and transfer it to a new 1.5 milliliter microcentrifuge tube. Then, move on to precipitation and add an equal volume of isopropanol to the sample. Add one microliter of co-precipitant to the sample to act as a carrier for the RNA and to help visualize the RNA in subsequent steps.Incubate the samples at 80 degrees Celsius for at least four hours. After incubation, transfer the sample to a cooled centrifuge and spin for 35 minutes at 20, 800 g and four degrees Celsius. After the spin, the RNA will appear as a blue spec on the bottom of the tube.Carefully remove the isopropanol from the sample. Add 500 microliters of 80%ethanol and resuspend the pellet by briefly vortexing for three seconds. Centrifuge the sample again.Remove all the ethanol from the sample and let the sample air dry for about 10 minutes. Once the sample is dry, resuspend it in 35 microliters of RNase-free water. Then, place the sample on a heat block.Set at 65 degrees Celsius for five minutes to ensure that the RNA is fully in solution. After heating, immediately place the tube on ice. For a final reaction volume of 50 microliters, add four micrograms of total RNA with added water to a total volume of 22 microliters to a new tube.Add two microliters of the Oligo dT 25 primer from the 10 micromolar primer solution. From the reverse transcription kit, add two microliters of the RNase inhibitor, eight microliters of the 5x reaction buffer, four microliters of 10 millimolar dNTPs, and two microliters of the reverse transcriptase. Set up a reaction without reverse transcriptase to act as a negative control.Incubate the tube at 42 degrees Celsius for one hour. After incubation, transfer the tube directly to ice before transporting it to the heating block. Then, heat the tube at 75 degrees Celsius for five minutes.After heating it 75 degrees Celsius, place the tube on ice. Transfer two microliters of the cDNA to a fresh 0.5 milliliter PCR tube. Add one microliter of the forward primer and one microliter of the reverse primer from a 10 millimolar primer solution.Make up to 12.5 microliters by adding 8.5 microliters of nuclease-free water and add 12.5 microliters of the 2x PCR to gel master mix. Then, enter the PCR thermal cycling conditions listed on the screen and run the PCR. After the PCR, prepare a 1%agarose gel stained with ethidium bromide.Dissolve one gram of agarose in 100 milliliters of triacetate or TAE buffer in a 250 milliliter flask. Boil the contents in a microwave. Allow the gel to cool for one minute, and add 7.5 microliters of ethidium bromide solution in a fume hood.Mix well by swirling the flask. Pour the contents into a horizontal gel apparatus and allow the gel to solidify at room temperature in the fume hood for at least 30 minutes. Cover the gel with 1x TAE buffer and load 10 microliters of the PCR product onto the agarose gel together with three to five microliters of the DNA molecular weight ladder.Run the gel at 175 volts for 10 minutes. For the first PCR, transfer one microliter of cDNA to a PCR tube and add five microliters of 10x Pfu reaction buffer. Add one microliter of the first nested forward primer, one microliter of the T7 Oligo dT 25 primer, and one microliter of dNTPs from a 10 millimolar solution.Make up to 49 microliters of total volume by adding 40 microliters of water. Add one microliter of Pfu DNA polymerase and mix well. Then, run the PCR.Next, prepare the second PCR. Transfer two microliters of the products from the first PCR to a new PCR tube and mix it with five microliters of 10x Pfu ultra two reaction buffer. Add one microliter of the second nested PCR primer, one microliter of the T7 primer and one microliter of dNTPs.Make up to 49 microliters total reaction volume by adding 39 microliters of water and add one microliter of Pfu DNA polymerase. Run the PCR using the same PCR profile as the first PCR set up. Alternatively, instead of using Pfu DNA polymerase, a chimeric DNA polymerase can be used in the two different PCRs.Take five to ten microliters of the second PCR product and run it on an agarose gel. Finally, visualize the result on an imager. This agarose gel shows two distinct PCR products which use the same forward primer but different reverse primers and a distinct PCR product that has a distinct forward and reverse primer.The ideal primers to use for the PCR based reaction are those that give one distinct PCR product. Products from the second PCR reaction with Pfu DNA polymerase and chimeric DNA polymerase produced the same sized PCR products despite having different PCR cycling conditions for the three-prime RACE. The reverse transcriptase negative controls showed no genomic contamination of the RNA used in cDNA synthesis as well as in subsequent downstream reactions.Gel-purified PCR products were sent for sequencing. A representative Sanger sequence from a sequence chromatogram identified the location of the stop codon, putative polyadenylation signal and the site as well as the poly A tail in the three-prime RACE product. While attempting this procedure, it's important to remember to wear protective gear and gloves at all time.In addition, use sterile DNase and RNase for your reagents tubes and other disposables. Don't forget that working with phenol and chloroform can be extremely hazardous. And precautions such as using the reagents in a hood and disposing material in a designated waste container should always be taken while performing this procedure.

Research

JoVE Journal

Genetics

Merging Absolute and Relative Quantitative PCR Data to Quantify STAT3 Splice Variant Transcripts

Human signal transducer and activator of transcription 3 (STAT3) is one of many genes containing a tandem splicing site. Alternative donor splice sites 3 ...

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 ...

High Resolution Fluorescent In Situ Hybridization in Drosophila Embryos and Tissues Using Tyramide Signal Amplification

High Resolution Fluorescent In Situ Hybridization in Drosophila Embryos and Tissues Using Tyramide Signal Amplification

In our efforts to determine the patterns of expression and subcellular localization of Drosophila RNAs on a genome-wide basis, and in a variety of ...

CRISPR-Mediated Reorganization of Chromatin Loop Structure

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A Murine Cell Line Based Model of Chronic CDK9 Inhibition to Study Widespread Non-Genetic Transcriptional Elongation Defects (TEdeff) in Cancers

A Murine Cell Line Based Model of Chronic CDK9 Inhibition to Study Widespread Non-Genetic Transcriptional Elongation Defects TEdeff in Cancers

We have previously reported that a subset of cancers is defined by global transcriptional deregulations with widespread deficiencies in mRNA transcription ...

Discrimintion and Mapping of the Primary and Processed Transcripts in Maize Mitochondrion Using a Circular RT-PCR-based Strategy

In plant mitochondria, some steady-state transcripts have 5&#39; triphosphate derived from transcription initiation (primary transcripts), while the ...

Investigation of the Transcriptional Role of a RUNX1 Intronic Silencer by CRISPR/Cas9 Ribonucleoprotein in Acute Myeloid Leukemia Cells

Investigation of the Transcriptional Role of a RUNX1 Intronic Silencer by CRISPR/Cas9 Ribonucleoprotein in Acute Myeloid Leukemia Cells

The bulk of the human genome (~98%) is comprised of non-coding sequences. Cis-regulatory elements (CREs) are non-coding DNA sequences that contain binding ...

Detection of Human Immunodeficiency Virus Type 1 (HIV-1) Antisense Protein (ASP) RNA Transcripts in Patients by Strand-Specific RT-PCR

Detection of Human Immunodeficiency Virus Type 1 HIV-1 Antisense Protein ASP RNA Transcripts in Patients by Strand-Specific RT-PCR

In retroviruses, antisense transcription has been described in both human immunodeficiency virus type 1 (HIV-1) and human T-lymphotropic virus 1 (HTLV-1). ...

Efficient Transcriptionally Controlled Plasmid Expression System for Investigation of the Stability of mRNA Transcripts in Primary Alveolar Epithelial Cells

Studying posttranscriptional regulation is fundamental to understanding the modulation of a given messenger RNA (mRNA) and its impact on cell homeostasis ...

Screening Sperm for the Rapid Isolation of Germline Edits in Zebrafish

The advent of targeted CRISPR-Cas nuclease technologies has revolutionized the ability to perform precise genome editing in both established and emerging ...