scholarly journals PNA Clamping in Nucleic Acid Amplification Protocols to Detect Single Nucleotide Mutations Related to Cancer

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 786 ◽  
Author(s):  
Munira F. Fouz ◽  
Daniel H. Appella

This review describes the application of peptide nucleic acids (PNAs) as clamps that prevent nucleic acid amplification of wild-type DNA so that DNA with mutations may be observed. These methods are useful to detect single-nucleotide polymorphisms (SNPs) in cases where there is a small amount of mutated DNA relative to the amount of normal (unmutated/wild-type) DNA. Detecting SNPs arising from mutated DNA can be useful to diagnose various genetic diseases, and is especially important in cancer diagnostics for early detection, proper diagnosis, and monitoring of disease progression. Most examples use PNA clamps to inhibit PCR amplification of wild-type DNA to identify the presence of mutated DNA associated with various types of cancer.

2015 ◽  
Vol 53 (11) ◽  
pp. 3606-3608 ◽  
Author(s):  
S. W. Peterson ◽  
I. Martin ◽  
W. Demczuk ◽  
A. Bharat ◽  
L. Hoang ◽  
...  

We developed a real-time PCR assay to detect single nucleotide polymorphisms associated with ciprofloxacin resistance in specimens submitted for nucleic acid amplification testing (NAAT). All three single nucleotide polymorphism (SNP) targets produced high sensitivity and specificity values. The presence of ≥2 SNPs was sufficient to predict ciprofloxacin resistance in an organism.


2021 ◽  
Vol 14 (3) ◽  
pp. 235
Author(s):  
Jen-Sheng Pei ◽  
Chao-Chun Chen ◽  
Wen-Shin Chang ◽  
Yun-Chi Wang ◽  
Jaw-Chyun Chen ◽  
...  

The purpose of our study was to investigate whether genetic variations in lncRNA H19 were associated with susceptibility to childhood leukemia. Two hundred and sixty-six childhood leukemia patients and 266 healthy controls were enrolled in Taiwan, and two single nucleotide polymorphisms (SNPs), rs2839698 and rs217727, in H19 were genotyped and analyzed. There was a significant difference in the genotypic distribution of rs2839698 between patients and healthy controls (p = 0.0277). Compared to the wild-type CC genotype, the heterozygous variant CT and homozygous variant TT genotypes were associated with significantly increased risks of childhood leukemia with an adjusted odd ratio (OR) of 1.46 (95% confidence interval (CI), 1.08–2.14, p = 0.0429) and 1.94 (95%CI, 1.15–3.31, p = 0.0169), respectively (pfor tread = 0.0277). The difference in allelic frequencies between childhood leukemia patients and controls was also significant (T versus C, adjusted OR = 1.53, 95%CI, 1.13–1.79, p = 0.0077). There were no significant differences in the genotypic and allelic distributions of rs217727 between cases and controls. Interestingly, the average level of H19 rs2839698 was statistically significantly higher for patients with CT and TT genotypes than from those with the CC genotype (p < 0.0001). Our results indicate that H19 SNP rs2839698, but not rs217727, may serve as a novel susceptibility marker for childhood leukemia.


Author(s):  
Oriana Kreutzfeld ◽  
Stephanie A. Rasmussen ◽  
Aarti A. Ramanathan ◽  
Patrick K. Tumwebaze ◽  
Oswald Byaruhanga ◽  
...  

Among novel compounds under recent investigation as potential new antimalarial drugs are three independently developed inhibitors of the Plasmodium falciparum P-type ATPase (PfATP4): KAE609 (cipargamin), PA92, and SJ733. We assessed ex vivo susceptibilities to these compounds of 374 fresh P. falciparum isolates collected in Tororo and Busia districts, Uganda from 2016-2019. Median IC 50 s were 65 nM for SJ733, 9.1 nM for PA92, and 0.5 nM for KAE609. Sequencing of pfatp4 for 218 of these isolates demonstrated many non-synonymous single nucleotide polymorphisms; the most frequent mutations were G1128R (69% of isolates mixed or mutant), Q1081K/R (68%), G223S (25%), N1045K (16%) and D1116G/N/Y (16%). The G223S mutation was associated with decreased susceptibility to SJ733, PA92 and KAE609. The D1116G/N/Y mutations were associated with decreased susceptibility to SJ733, and the presence of mutations at both codons 223 and 1116 was associated with decreased susceptibility to PA92 and SJ733. In all of these cases, absolute differences in susceptibilities of wild type (WT) and mutant parasites were modest. Analysis of clones separated from mixed field isolates consistently identified mutant clones as less susceptible than WT. Analysis of isolates from other sites demonstrated presence of the G223S and D1116G/N/Y mutations across Uganda. Our results indicate that malaria parasites circulating in Uganda have a number of polymorphisms in PfATP4 and that modestly decreased susceptibility to PfATP4 inhibitors is associated with some mutations now present in Ugandan parasites.


2013 ◽  
Vol 57 (11) ◽  
pp. 5658-5664 ◽  
Author(s):  
Soo-Jin Yang ◽  
Nagendra N. Mishra ◽  
Aileen Rubio ◽  
Arnold S. Bayer

ABSTRACTSingle nucleotide polymorphisms (SNPs) within themprFopen reading frame (ORF) have been commonly observed in daptomycin-resistant (DAPr)Staphylococcus aureusstrains. Such SNPs are usually associated with a gain-in-function phenotype, in terms of either increased synthesis or enhanced translocation (flipping) of lysyl-phosphatidylglycerol (L-PG). However, it is unclear if suchmprFSNPs are causal in DAPrstrains or are merely a biomarker for this phenotype. In this study, we used an isogenic set ofS. aureusstrains: (i) Newman, (ii) its isogenic ΔmprFmutant, and (iii) several intransplasmid complementation constructs, expressing either a wild-type or point-mutated form of themprFORF cloned from two isogenic DAP-susceptible (DAPs)-DAPrstrain pairs (616-701 and MRSA11/11-REF2145). Complementation of the ΔmprFstrain with singly point-mutatedmprFgenes (mprFS295LormprFT345A) revealed that (i) individual and distinct point mutations within themprFORF can recapitulate phenotypes observed in donor strains (i.e., changes in DAP MICs, positive surface charge, and cell membrane phospholipid profiles) and (ii) these gain-in-function SNPs (i.e., enhanced L-PG synthesis) likely promote reduced DAP binding toS. aureusby a charge repulsion mechanism. Thus, for these two DAPrstrains, the definedmprFSNPs appear to be causally related to this phenotype.


2009 ◽  
Vol 49 (8) ◽  
pp. 675 ◽  
Author(s):  
N. L. Feeley ◽  
K. A. Munyard

The aim of this study was to determine if any correlation exists between melanocortin-1 receptor (MC1R) polymorphisms and skin and fibre colour in alpacas. Primers capable of amplifying the entire alpaca MC1R gene were designed from a comparative alignment of Bos taurus and Mus musculus MC1R gene sequences. The complete MC1R gene of 41 alpacas exhibiting a range of fibre colours, and which were sourced from farms across Australia, was sequenced from PCR products. Twenty-one single nucleotide polymorphisms were identified within MC1R. Two of these polymorphisms (A82G and C901T) have the potential to reduce eumelanin production by disrupting the activity of MC1R. No agreement was observed between fibre colour alone and MC1R genotype in the 41 animals in this study. However, when the animals were assigned to groups based on the presence or absence of eumelanin in their fibre and skin, only animals that had at least one allele with the A82/C901 combination expressed eumelanin. We propose that A82/C901 is the wild-type dominant ‘E’ MC1R allele, while alpacas with either G82/T901 or G82/Y901 are homozygous for the recessive ‘e’ MC1R allele and are therefore unable to produce eumelanin.


The Analyst ◽  
2021 ◽  
Author(s):  
Sayantan Tripathy ◽  
Ashish Chalana ◽  
Arunansu Talukdar ◽  
P.V. Rajesh ◽  
Abhijit Saha ◽  
...  

Extraction and concentration of pure nucleic acid from complex biofluids is the prerequisite for nucleic acid amplification test (NAAT) applications in pathogen detection, biowarfare prevention, and genetic diseases. However, conventional...


2007 ◽  
Vol 25 (18_suppl) ◽  
pp. 2540-2540 ◽  
Author(s):  
J. J. Grau ◽  
M. Monzo ◽  
M. Vargas ◽  
S. Jansa ◽  
m. Campayo ◽  
...  

2540 Background: Gene SNPs correlate with survival in cancer patients (pts) treated with chemotherapy (CHM). CYP2C8 and GSTT1, GTSP1 genes are involved in phase 1 and 2 drug cellular metabolisms respectively; MDR1(A) and MDR1(B) are involved in drug membrane transport and ERCC1 in DNA repair Methods: We evaluated the presence of SNPs of these 6 genes and the survival of AHNCP treated with weekly paclitaxel, 80 mg/m2 iv for 6 weeks. Responding pts continue CHM till progression. All pts were cisplatin resistant and no other local therapies were available. We analysed paraffin-embedded biopsies from 47 consecutive AHNCP for SNPs of the mentioned genes. The status of the alleles wild type (wt) or at least 1 SNP was compared with response rate (RR), time to progression (TTP) and overall survival (OS) Results: Of 47 pts, 43 were male and 4 female. The median of age was 57 yr (46–80). RR was 45% (21/47) and the TTP in responders was 5 months of median. OS for all pts was 5.6 months. Wild type vs at least 1 SNPs frequencies according the genes were: CYP2C8 23/24; GSTT1 45/2; GSTP1 36/11; MDR1(A) 21/28; MDR1(B) 13/34; and ERCC1 27/20. OS was significantly better in pts with 2 or more SNPs accumulated (p=0.0455). No other significant differences were observed in RR, TTP or OS in SNPs vs wild type pts. Conclusions: SNPs of CYP2C8, MDR1(A) and MDR1(B) genes were more frequent than wt in our pts. OS was significantly better in pts with 2 or more SNPs accumulated. Paclitaxel provides high rate of responses of short duration in AHNC pts No significant financial relationships to disclose.


2004 ◽  
Vol 11 (4) ◽  
pp. 766-769 ◽  
Author(s):  
Michele Boniotto ◽  
Manzour Hernando Hazbón ◽  
William James Jordan ◽  
Greig Patrick Lennon ◽  
Joyce Eskdale ◽  
...  

ABSTRACT A powerful, cost-effective new method for studying single-nucleotide polymorphisms (SNPs) is described. This method is based on the use of hairpin-shaped primers (HP), which give a sensitive and specific PCR amplification of each specific allele, without the use of costly fluorophore-labeled probes and any post-PCR manipulation. The amplification is monitored in real-time using SYBR Green I dye and takes only 2 h to yield results. The HP assay has a simple design and utilizes a conventional real-time PCR apparatus. The −44 C→G transversion in the DEFB1 gene (which encodes human β-defensin 1) has been previously associated with Candida carriage in oral epithelia. In this study, we analyzed the association between early-onset periodontal disease (EOP) and the −44 SNP. We used an HP assay to study the distribution of the −44 SNP in 264 human DNAs obtained from two cohorts of EOP patients and healthy controls from different ethnic backgrounds. The results indicate that the −44 SNP has a similar distribution between EOP and healthy patients, suggesting that it is not associated with the disease.


2010 ◽  
Vol 2010 ◽  
pp. 1-12 ◽  
Author(s):  
Lynnette R. Ferguson ◽  
Dug Yeo Han ◽  
Alan G. Fraser ◽  
Claudia Huebner ◽  
Wen Jiun Lam ◽  
...  

DNA samples from 339 Crohn's disease (CD) and 407 randomly selected controls from the Auckland (New Zealand) IBD project, were genotyped for five common single nucleotide polymorphisms inIL-23R(rs11805303, rs7517847, rs1343151, rs11209026, and rs10889677) and two inIL-12B(rs1363670 and rs6887695). While theIL-12Bvariants did not show an overall association and otherIL23Rvariants led to minor changes in the risk of CD, rs1343151 and/or rs7517847 variants in theIL-23Rgene strongly reduced the risk of developing CD at both allelic and genotype levels. A significantly decreased risk of first diagnosis of childhood CD was observed in individuals carrying the A allele of rs1343151, or between 17–40 y in individuals carrying the G allele in rs7517847 ofIL-23R. A significantly decreased risk of ileocolonic or structuring disease was observed in individuals carrying the A allele in either rs11209026 or rs1343151, or the G allele in rs7517847 ofIL-23R, and when such individuals did develop the disease, they were unlikely to require a bowel resection. Certain haplotypes very strongly modified risk. There was evidence for interactions ofIL-23Rvariants with theNOD2wild-type (d/d) genotype. Down-regulating the function of theIL-23Rgene may decrease CD risk in the normal population.


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