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Vossaert L, Wang Q, Salman R, Zhuo X, Qu C, Henke D, Seubert R, Chow J, U'ren L, Enright B, Stilwell J, Kaldjian E, Yang Y, Shaw C, Levy B, Wapner R, Breman A, Van den Veyver I, Beaudet A. Reliable detection of subchromosomal deletions and duplications using cell-based noninvasive prenatal testing. Prenat Diagn 2018; 38:1069-1078. [PMID: 30357877 PMCID: PMC6587831 DOI: 10.1002/pd.5377] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 09/04/2018] [Accepted: 10/13/2018] [Indexed: 12/19/2022]
Abstract
Objective To gather additional data on the ability to detect subchromosomal abnormalities of various sizes in single fetal cells isolated from maternal blood, using low‐coverage shotgun next‐generation sequencing for cell‐based noninvasive prenatal testing (NIPT). Method Fetal trophoblasts were recovered from approximately 30 mL of maternal blood using maternal white blood cell depletion, density‐based cell separation, immunofluorescence staining, and high‐resolution scanning. These trophoblastic cells were picked as single cells and underwent whole genome amplification for subsequent genome‐wide copy number analysis and genotyping to confirm the fetal origin of the cells. Results Applying our fetal cell isolation method to a series of 125 maternal blood samples, we detected on average 4.17 putative fetal cells/sample. The series included 15 cases with clinically diagnosed fetal aneuploidies and five cases with subchromosomal abnormalities. This method was capable of detecting findings that were 1 to 2 Mb in size, and all were concordant with the microarray or karyotype data obtained on a fetal sample. A minority of fetal cells showed evidence of genome degradation likely related to apoptosis. Conclusion We demonstrate that this cell‐based NIPT method has the capacity to reliably diagnose fetal chromosomal abnormalities down to 1 to 2 Mb in size. What is already known about this topic?
Fetal trophoblastic cells can be isolated from maternal blood and be used for the detection of fetal aneuploidies and copy number variants. The data on the detection of subchromosomal deletions and duplications is currently limited.
What does this study add?
Cell‐based NIPT can be used for the detection of copy number abnormalities of greater than or equal to 1 Mb in the fetus by low‐coverage next‐generation sequencing after single cell whole genome amplification. Data are provided here for five cases in which different subchromosomal deletions and duplications ranging from 1.2 to 18.9 Mb were detected in single cells.
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Affiliation(s)
- Liesbeth Vossaert
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Qun Wang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Roseen Salman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Xinming Zhuo
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Chunjing Qu
- Baylor Genetics Laboratory, Houston, TX, USA
| | - David Henke
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | | | | | | | | | - Jackie Stilwell
- RareCyte Inc., Seattle, WA, USA.,Immune Design, Seattle, WA, USA
| | | | - Yaping Yang
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Baylor Genetics Laboratory, Houston, TX, USA
| | - Chad Shaw
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Baylor Genetics Laboratory, Houston, TX, USA
| | - Brynn Levy
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Ronald Wapner
- Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, NY, USA
| | - Amy Breman
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Ignatia Van den Veyver
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Department of Obstetrics and Gynecology, Baylor College of Medicine, Houston, TX, USA
| | - Arthur Beaudet
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
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Buhrman JD, Jordan KR, U'ren L, Sprague J, Kemmler CB, Slansky JE. Augmenting antitumor T-cell responses to mimotope vaccination by boosting with native tumor antigens. Cancer Res 2012; 73:74-85. [PMID: 23161490 DOI: 10.1158/0008-5472.can-12-1005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Vaccination with antigens expressed by tumors is one strategy for stimulating enhanced T-cell responses against tumors. However, these peptide vaccines rarely result in efficient expansion of tumor-specific T cells or responses that protect against tumor growth. Mimotopes, or peptide mimics of tumor antigens, elicit increased numbers of T cells that crossreact with the native tumor antigen, resulting in potent antitumor responses. Unfortunately, mimotopes may also elicit cells that do not crossreact or have low affinity for tumor antigen. We previously showed that one such mimotope of the dominant MHC class I tumor antigen of a mouse colon carcinoma cell line stimulates a tumor-specific T-cell clone and elicits antigen-specific cells in vivo, yet protects poorly against tumor growth. We hypothesized that boosting the mimotope vaccine with the native tumor antigen would focus the T-cell response elicited by the mimotope toward high affinity, tumor-specific T cells. We show that priming T cells with the mimotope, followed by a native tumor-antigen boost, improves tumor immunity compared with T cells elicited by the same prime with a mimotope boost. Our data suggest that the improved tumor immunity results from the expansion of mimotope-elicited tumor-specific T cells that have increased avidity for the tumor antigen. The enhanced T cells are phenotypically distinct and enriched for T-cell receptors previously correlated with improved antitumor immunity. These results suggest that incorporation of native antigen into clinical mimotope vaccine regimens may improve the efficacy of antitumor T-cell responses.
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Affiliation(s)
- Jonathan D Buhrman
- Integrated Department of Immunology, University of Colorado School of Medicine, Denver, CO 80206, USA
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Lana S, U'ren L, Plaza S, Elmslie R, Gustafson D, Morley P, Dow S. Continuous low-dose oral chemotherapy for adjuvant therapy of splenic hemangiosarcoma in dogs. J Vet Intern Med 2007; 21:764-9. [PMID: 17708397 DOI: 10.1892/0891-6640(2007)21[764:clocfa]2.0.co;2] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Hemangiosarcoma (HSA) is a highly metastatic and often rapidly fatal tumor in dogs. At present, conventional adjuvant chemotherapy provides only a modest survival benefit for treated dogs. Continuous oral administration of low-dose chemotherapy (LDC) has been suggested as an alternative to conventional chemotherapy protocols. Therefore, we evaluated the safety and effectiveness of LDC using a combination of cyclophosphamide, etoposide, and piroxicam as adjuvant therapy for dogs with stage II HSA. HYPOTHESIS We hypothesized that oral adjuvant therapy with LDC could be safely administered to dogs with HSA and that survival times would be comparable to those attained with conventional doxorubicin (DOX) chemotherapy. ANIMALS Nine dogs with stage II splenic HSA were enrolled in the LDC study. Treatment outcomes were also evaluated retrospectively for 24 dogs with stage II splenic HSA treated with DOX chemotherapy. METHODS Nine dogs with stage II splenic HSA were treated with LDC over a 6-month period. Adverse effects and treatment outcomes were determined. The pharmacokinetics of orally administered etoposide were determined in 3 dogs. Overall survival times and disease-free intervals were compared between the 9 LDC-treated dogs and 24 DOX-treated dogs. RESULTS Dogs treated with LDC did not develop severe adverse effects, and long-term treatment over 6 months was well-tolerated. Oral administration of etoposide resulted in detectable plasma concentrations that peaked between 30 and 60 minutes after dosing. Both the median overall survival time and the median disease-free interval in dogs treated with LDC were 178 days. By comparison, the overall survival time and disease-free interval in dogs treated with DOX were 133 and 126 days, respectively. CONCLUSIONS Continuous orally administered LDC may be an effective alternative to conventional high-dose chemotherapy for adjuvant therapy of dogs with HSA.
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Affiliation(s)
- Susan Lana
- Animal Cancer Center, Department of Clinical Sciences , Colorado State University, Ft. Collins, 80523, USA
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