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  • American Association for Cancer Research (AACR)  (2)
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  • American Association for Cancer Research (AACR)  (2)
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  • 1
    Online Resource
    Online Resource
    American Association for Cancer Research (AACR) ; 2016
    In:  Cancer Research Vol. 76, No. 14_Supplement ( 2016-07-15), p. 609-609
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 76, No. 14_Supplement ( 2016-07-15), p. 609-609
    Abstract: Patient-derived xenograft (PDX) models closely mimic the pathological phenotypes of the original tumors, thus they are ideal surrogates for preclinical anticancer drugs efficacy testing. However, there is an increasing demand to rapidly and reliably screen out candidate drugs at earlier stages, and in vivo animal studies usually take months to produce efficacy data. Compared to traditional two-dimensional (2D) culture, three-dimensional (3D) culture systems more closely reflect in vivo responses. Therefore, we developed an ex vivo 3D culture platform using freshly isolated PDX-derived tumor cells, cultured on the natural methylcellulose polymer as an ex vivo drug screening system to meet the need for patient relevant, lower cost and high-throughput methods. Single-cell suspensions freshly isolated from PDX tumors are seeded in semisolid methylcellulose media and the drug efficacy is quantitatively evaluated by CellTiter-Glo® (CTG) luminescent assay. The main advantage of this method is the possibility of testing cytotoxicity within days (7 days on average), rather than months. Also, the process is carried out in mild condition and the scaffold material is inert to avoid unwanted cellular response. Moreover, cell spheroids can be easily retrieved for further analysis. Dissociated primary tumor cells derived from either fresh or frozen PDX tumors remain highly viable and form colonies when cultured in 3D. The success rate of generating ex vivo 3D culture from PDX tumors is higher than 90%, and over 60 PDX models were validated from cancer of various origins. We monitored tumor colony formation and generated a fitted drug concentration-response curve with small variations in CTG cell viability assays. Most importantly, the ex vivo 3D drug response profiling correlated well with the response obtained in vivo from PDX models (over 80% in average), for anticancer drugs with a variety of mechanisms of action including kinase inhibitor, antineoplastic agent and antibodies. Compared with a commercialized 3D drug testing plates, similar results were obtained in our system, with the advantage of a significant reduction in the cost. These data suggest that our 3D ex vivo cell culture platform from freshly isolated or frozen PDX-derived cells is a feasible and authentic method for testing drug efficacy in a short time period before transitioning to multiple PDX models. To sum up, our ex vivo 3D culture platform can save time and reduce costs, and is extremely useful for preclinical evaluation of anticancer drug, filling the gap between cell line-based and tumor bearing mice-based drug studies, allowing low cost, high throughput in vitro drug screening and the clinically relevant in vivo drug efficacy studies. Citation Format: Xiaoxi Xu, Wenna Zhang, Bingying Xie, Zheng Zheng Bao, Zhu Mei, Jean-Pierre Wery, Jinying Ning. An established ex vivo 3D culture platform using patient-derived xenograft (PDX) tumors replicate the anti-tumor efficacy observed in vivo. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 609.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2016
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
    Location Call Number Limitation Availability
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  • 2
    Online Resource
    Online Resource
    American Association for Cancer Research (AACR) ; 2021
    In:  Cancer Research Vol. 81, No. 13_Supplement ( 2021-07-01), p. 551-551
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 81, No. 13_Supplement ( 2021-07-01), p. 551-551
    Abstract: Loss of expression of the PTEN gene is associated with poorer prognosis in many solid tumors. While cfDNA-based liquid biopsy testing are gradually adopted as the routine testing method in the clinical setting, most of them are unable to reliably detect copy number loss and/or are limited reporting copy number amplification events only. Method: We have developed a capture-based CLIA-certified NGS assay, PredicineCARE, to robustly identify tumor-derived aberrations including SNVs, Indels, fusions, copy number amplifications and deletions from blood samples. Analytical validation of the assay was performed with commercial standard reference materials and contrived cell lines. Copy number loss of PTEN was also confirmed by Immunohistochemistry (IHC) assay in 15 clinical samples. Clinical utility of PTEN copy number loss was further established by its significant association with poor outcome in clinical patients with metastatic castration-resistant prostate cancer (mCRPC). Results: Analytical validation of the PredicineCARE assay demonstrated its super sensitivity and robustness of detecting homozygous copy number loss at approximately 10% tumor fraction. Both the sensitivity and Positive Prediction Value reached 100% when overall gene copy number is below 1.75 copies. When comparing to tissue IHC results reviewed by two independent pathologists, PredicineCARE liquid biopsy assay revealed 86.7% concordance with IHC in detecting PTEN loss (80% sensitivity, 100% specificity, and 100% PPV). The copy number loss was further confirmed by low-pass whole-genome sequencing of cfDNA samples. When the assay was applied to profile mCRPC patients, copy number loss of PTEN was detected at the prevalence rate of 19.2% (10/52) and 35.9% (23/64) respectively. Notably, patients harboring PTEN copy number loss showed significantly worse overall survival in the two cohorts independently (log-rank P = 0.0001 and 0.0004 respectively). Conclusion: We have developed PredicineCARE for clinical use, a highly sensitive cfDNA-based assay to detect gene copy number variants in addition to gene mutations and fusions. Its ability to detect gene copy number loss in low fraction of tumor contents as a valuable molecular biomarker holds great potential for clinical applications and patient selections in personalized precision oncology, particularly for investigational drugs targeting the AKT-PI3K-PTEN pathway. Citation Format: Xiaoxi Dong, Minghua Zhang, Tiantian Zheng, Lu Tan, Feng Xie, Amy Xiaohong Wang, Pan Du, Shidong Jia, Chris Lu, Jianjun Yu. Clinical utility of cell-free DNA based PTEN copy number loss in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 551.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2021
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
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