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Hum NR, Martin KA, Malfatti MA, Haack K, Buchholz BA, Loots GG. Tracking Tumor Colonization in Xenograft Mouse Models Using Accelerator Mass Spectrometry. Sci Rep 2018; 8:15013. [PMID: 30302019 PMCID: PMC6178347 DOI: 10.1038/s41598-018-33368-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 09/24/2018] [Indexed: 12/12/2022] Open
Abstract
Here we introduce an Accelerator Mass Spectrometry (AMS)-based high precision method for quantifying the number of cancer cells that initiate metastatic tumors, in xenograft mice. Quantification of 14C per cell prior to injection into animals, and quantification of 14C in whole organs allows us to extrapolate the number of cancer cells available to initiate metastatic tumors. The 14C labeling was optimized such that 1 cancer cell was detected among 1 million normal cells. We show that ~1–5% of human cancer cells injected into immunodeficient mice form subcutaneous tumors, and even fewer cells initiate metastatic tumors. Comparisons of metastatic site colonization between a highly metastatic (PC3) and a non-metastatic (LnCap) cell line showed that PC3 cells colonize target tissues in greater quantities at 2 weeks post-delivery, and by 12 weeks post-delivery no 14C was detected in LnCap xenografts, suggesting that all metastatic cells were cleared. The 14C-signal correlated with the presence and the severity of metastatic tumors. AMS measurements of 14C-labeled cells provides a highly-sensitive, quantitative assay to experimentally evaluate metastasis and colonization of target tissues in xenograft mouse models. This approach can potentially be used to evaluate tumor aggressiveness and assist in making informed decisions regarding treatment.
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Affiliation(s)
- Nicholas R Hum
- Lawrence Livermore National Laboratory, Physical and Life Sciences Directorate, Livermore, CA, USA
| | - Kelly A Martin
- Lawrence Livermore National Laboratory, Physical and Life Sciences Directorate, Livermore, CA, USA.,Georgetown University, Department of Biochemistry & Molecular Biology, Washington, DC, USA
| | - Michael A Malfatti
- Lawrence Livermore National Laboratory, Physical and Life Sciences Directorate, Livermore, CA, USA
| | - Kurt Haack
- Lawrence Livermore National Laboratory, Physical and Life Sciences Directorate, Livermore, CA, USA
| | - Bruce A Buchholz
- Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Gabriela G Loots
- Lawrence Livermore National Laboratory, Physical and Life Sciences Directorate, Livermore, CA, USA. .,UC Merced, School of Natural Sciences, Merced, CA, USA.
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Chan W, Wong SK, Li W. Quantification of DNA and Protein Adducts of 1-Nitropyrene: Significantly Higher Levels of Protein than DNA Adducts in the Internal Organs of 1-Nitropyrene Exposed Rats. Chem Res Toxicol 2018; 31:680-687. [DOI: 10.1021/acs.chemrestox.8b00035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Recent technical and biological development in the analysis of biomarker N-deoxyguanosine-C8-4-aminobiphenyl. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1087-1088:49-60. [PMID: 29709872 DOI: 10.1016/j.jchromb.2018.04.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 04/05/2018] [Accepted: 04/23/2018] [Indexed: 12/12/2022]
Abstract
4-Aminobiphenyl (4-ABP) which is primarily formed during tobacco combustion and overheated meat is a major carcinogen responsible for various cancers. Its adducted form, N-deoxyguanosine-C8-4-aminobiphenyl (dG-C8-4-ABP), has long been employed as a biomarker for assessment of the risk for cancer. In this review, the metabolism and carcinogenisity of 4-ABP will be discussed, followed by a discussion of the current common approaches of analyzing dG-C8-4-ABP. The major part of this review will be on the history and recent development of key methods for detection and quantitation of dG-C8-4-ABP in complex biological samples and their biological applications, from the traditional 2P-postlabelling and immunoassay methods to modern liquid chromatography-mass spectrometry (LC-MS) with the latter as the focus. Many vital biological discoveries based on dG-C8-4-ABP have been published by using the nanoLC-MS with column switching platform in our laboratory, which has also been adopted and further improved by many other researchers. We hope this review can provide a perspective of the challenges that had to be addressed in reaching our present goals and possibly bring new ideas for those who are still working on the frontline of DNA adducts area.
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