Abstract
Activating mutations in codon 12 and codon 13 of the KRAS (Kirsten rat sarcoma viral oncogene homolog) gene are implicated in the development of several human cancer types and influence their clinical evaluation, treatment and prognosis. Numerous different methods for KRAS genotyping are currently available displaying a wide range of sensitivities, time to answer and requirements for laboratory equipment and user skills. Here we present SensiScreen® KRAS exon 2 simplex and multiplex CE IVD assays, that use a novel real-time PCR-based method for KRAS mutation detection based on PentaBase's proprietary DNA analogue technology and designed to work on standard real-time PCR instruments. By means of the included BaseBlocker™ technology, we show that SensiScreen® specifically amplifies the mutated alleles of interest with no or highly subdued amplification of the wild type allele. Furthermore, serial dilutions of mutant DNA in a wild type background demonstrate that all SensiScreen® assays display a limit of detection that falls within the range of 0.25-1%. Finally, in three different colorectal cancer patient populations, SensiScreen® assays confirmed the KRAS genotype previously determined by commonly used methods for KRAS mutation testing, and notably, in two of the populations, SensiScreen® identified additional mutant positive cases not detected by common methods.
MeSH terms
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Biological Assay / methods*
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Cohort Studies
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Colorectal Neoplasms / diagnosis*
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Colorectal Neoplasms / genetics
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DNA, Neoplasm / genetics
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Exons*
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Genotype
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Humans
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Multiplex Polymerase Chain Reaction / methods*
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Mutation / genetics*
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Proto-Oncogene Proteins p21(ras) / genetics*
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Real-Time Polymerase Chain Reaction / methods*
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Tumor Cells, Cultured
Substances
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DNA, Neoplasm
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KRAS protein, human
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Proto-Oncogene Proteins p21(ras)
Grants and funding
Eurostars provided support in the form of salaries for authors MB, CA, UBC, MF, AR, MHK & JL, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. PentaBase ApS provided salaries for UBC, CA and MB and took part in the designing of the SensiScreen products, but not the testing and analysis of patient material nor in the conclusions of the performance of SensiScreen against competing technologies. The specific roles of these authors are articulated in the ‘author contributions’ section. The funders had no additional role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Support for this study was also provided by Danish Agency for Science Technology and Innovation [E!7034 ONSET diagnostics] and Fondazione Ticinese per la Ricerca contro il Cancro. The Institute of Pathology, Locarno, Switzerland, and Aarhus University Hospital, Aarhus, Denmark performed some analyses using their own funding.