Abstract
New biomarkers with improved accuracy could be helpful for monitoring disease in patients with Non-Hodgkin's lymphomas (NHL). Towards this end, we have explored the feasibility of identifying the sequence of rearranged IgH genes using next-generation sequencing, then using PCR to detect specific rearranged DNA fragments in patients' plasma. By capturing and sequencing the IgH genomic regions (IgCap), we were able to detect and precisely determine the sequence of rearranged IgH loci in the tumors of three NHL patients. Moreover, circulating rearranged DNA fragments could be identified in the plasma of all three patients. Even in cases wherein tumor biopsies were unavailable, we were able to use the IgH capture approach to identify rearranged DNA loci in the plasma of 8 of 14 patients. IgCap may enable a more informed management of selected patients with NHL and other B-cell malignancies in the future.
Highlights
As cancer chemotherapeutics improve, the need for companion diagnostics to monitor the effects of such therapeutics becomes progressively more important. [1] The ideal marker would be one that can be assessed without the need for repeat biopsies or exposure to irradiation, is absolutely specific for the presence of the tumor, is sensitive for the presence of disease, and is cost-effective.[2]
Rearrangements can be accessed in the blood or bone marrow by virtue of the fact that any residual cancer cells will reside in these compartments.[8]
IgCap involves three steps: (i) the tumor DNA is first randomly sheared and ligated to adapters that allow their subsequent amplification by PCR; (ii) fragments containing IgH genes are captured on a solid support containing the sequences of interest [11]; and (iii) the captured DNA is amplified by conventional PCR, producing an IgCap library, and the ends of the captured DNA fragments are subjected to massively parallel sequencing
Summary
The need for companion diagnostics to monitor the effects of such therapeutics becomes progressively more important. [1] The ideal marker would be one that can be assessed without the need for repeat biopsies or exposure to irradiation, is absolutely specific for the presence of the tumor (to avoid false positives), is sensitive for the presence of disease, and is cost-effective.[2]. Circulating mutant DNA has been found in a variety of solid tumors and initial studies have shown them to provide sensitivity and specificity comparable or superior to conventional disease indicators.[6] In liquid tumors such as leukemias, consistently fused genes like BCRABL provide extraordinarily useful markers for following patients during their treatment.[7] In leukemia patients, rearrangements can be accessed in the blood or bone marrow by virtue of the fact that any residual cancer cells will reside in these compartments.[8] In tumors such as lymphomas, circulating cells are not consistently found in patients’ blood or marrow. Based on the above-cited results on solid tumors, we hypothesized that somatically rearranged DNA templates from lymphomas might be found in the cell-free fraction of blood, i.e., the plasma
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
