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Gao H, Williams JA. Predicting human clinical trial responses in mice. Mol Cell Oncol 2018; 5:e1162895. [PMID: 29487892 DOI: 10.1080/23723556.2016.1162895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 02/29/2016] [Accepted: 02/29/2016] [Indexed: 10/22/2022]
Abstract
Preclinical modeling of human Phase II oncology trials by traditional methods has failed to be highly predictive. Here, we comment on our data showing that much better prediction of clinical trial results can be achieved using a broad-based patient-derived xenograft (PDX) panel.
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Matossian MD, Burks HE, Elliott S, Hoang VT, Bowles AC, Sabol RA, Bunnell BA, Martin EC, Burow ME, Collins-Burow BM. Panobinostat suppresses the mesenchymal phenotype in a novel claudin-low triple negative patient-derived breast cancer model. Oncoscience 2018; 5:99-108. [PMID: 29854878 PMCID: PMC5978446 DOI: 10.18632/oncoscience.412] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/22/2018] [Indexed: 01/13/2023] Open
Abstract
Claudin-low triple negative breast cancer (CL-TNBC) is a clinically aggressive molecular TNBC subtype characterized by a propensity to metastasize, recur and acquire chemoresistance. CL-TNBC has a diverse intra- and extracellular composition and microenvironment, and currently there are no clinically approved targeted therapies. Histone deacetylase inhibitors (HDACi) have been investigated as therapeutic agents targeting invasive TNBC phenotypes. However, further studies are required to evaluate HDAC inhibition in CL-TNBC. Here, we utilize a novel CL- TNBC patient-derived xenograft model to study the various and diverse therapeutic potential targets within CL-TNBC tumors. To evaluate effects of the pan-HDACi panobinostat on metastasis and the mesenchymal phenotype of CL-TNBC, we utilize immunohistochemistry staining and qRT-PCR in in vitro, ex vivo and in vivo studies. Further, we evaluate pan-HDAC inhibition on stem-like subpopulations using 3D mammosphere culture techniques and quantification. Finally, we show that pan- HDACi suppresses collagen expression in CL-TNBC. In this study, we provide evidence that pan-HDAC inhibition has effects on various components of the CL-TNBC subtype, and we demonstrate the potential of our novel CL-TNBC PDX model in therapeutic discovery research.
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Wei L, Chintala S, Ciamporcero E, Ramakrishnan S, Elbanna M, Wang J, Hu Q, Glenn ST, Murakami M, Liu L, Gomez EC, Sun Y, Conroy J, Miles KM, Malathi K, Ramaiah S, Anbarasu A, Woloszynska-Read A, Johnson CS, Conroy J, Liu S, Morrison CD, Pili R. Genomic profiling is predictive of response to cisplatin treatment but not to PI3K inhibition in bladder cancer patient-derived xenografts. Oncotarget 2018; 7:76374-76389. [PMID: 27823983 PMCID: PMC5363516 DOI: 10.18632/oncotarget.13062] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 10/22/2016] [Indexed: 11/25/2022] Open
Abstract
Purpose Effective systemic therapeutic options are limited for bladder cancer. In this preclinical study we tested whether bladder cancer gene alterations may be predictive of treatment response. Experimental design We performed genomic profiling of two bladder cancer patient derived tumor xenografts (PDX). We optimized the exome sequence analysis method to overcome the mouse genome interference. Results We identified a number of somatic mutations, mostly shared by the primary tumors and PDX. In particular, BLCAb001, which is less responsive to cisplatin than BLCAb002, carried non-sense mutations in several genes associated with cisplatin resistance, including MLH1, BRCA2, and CASP8. Furthermore, RNA-Seq analysis revealed the overexpression of cisplatin resistance associated genes such as SLC7A11, TLE4, and IL1A in BLCAb001. Two different PIK3CA mutations, E542K and E545K, were identified in BLCAb001 and BLCAb002, respectively. Thus, we tested whether the genomic profiling was predictive of response to a dual PI3K/mTOR targeting agent, LY3023414. Despite harboring similar PIK3CA mutations, BLCAb001 and BLCAb002 exhibited differential response, both in vitro and in vivo. Sustained target modulation was observed in the sensitive model BLCAb002 but not in BLCAb001, as well as decreased autophagy. Interestingly, computational modelling of mutant structures and affinity binding to PI3K revealed that E542K mutation was associated with weaker drug binding than E545K. Conclusions Our results suggest that the presence of activating PIK3CA mutations may not necessarily predict in vivo treatment response to PI3K targeted therapies, while specific gene alterations may be predictive for cisplatin response in bladder cancer models and, potentially, in patients as well.
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Gonçalves A, Bertucci F, Guille A, Garnier S, Adelaide J, Carbuccia N, Cabaud O, Finetti P, Brunelle S, Piana G, Tomassin-Piana J, Paciencia M, Lambaudie E, Popovici C, Sabatier R, Tarpin C, Provansal M, Extra JM, Eisinger F, Sobol H, Viens P, Lopez M, Ginestier C, Charafe-Jauffret E, Chaffanet M, Birnbaum D. Targeted NGS, array-CGH, and patient-derived tumor xenografts for precision medicine in advanced breast cancer: a single-center prospective study. Oncotarget 2018; 7:79428-79441. [PMID: 27765906 PMCID: PMC5346725 DOI: 10.18632/oncotarget.12714] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 09/29/2016] [Indexed: 12/30/2022] Open
Abstract
Background Routine feasibility and clinical impact of genomics-based tumor profiling in advanced breast cancer (aBC) remains to be determined. We conducted a pilot study to evaluate whether precision medicine could be prospectively implemented for aBC patients in a single center and to examine whether patient-derived tumor xenografts (PDX) could be obtained in this population. Results Thirty-four aBC patients were included. Actionable targets were found in 28 patients (82%). A targeted therapy could be proposed to 22 patients (64%), either through a clinical trial (n=15) and/or using already registered drugs (n=21). Ten patients (29%) eventually received targeted treatment, 2 of them deriving clinical benefit. Of 22 patients subjected to mouse implantation, 10 had successful xenografting (45%), mostly in triple-negative aBC. Methods aBC patients accessible to tumor biopsy were prospectively enrolled at the Institut Paoli-Calmettes in the BC-BIO study (ClinicalTrials.gov, NCT01521676). Genomic profiling was established by whole-genome array comparative genomic hybridization (aCGH) and targeted next-generation sequencing (NGS) of 365 candidate cancer genes. For a subset of patients, a sample of fresh tumor was orthotopically implanted in humanized cleared fat pads of NSG mice for establishing PDX. Conclusions Precision medicine can be implemented in a single center in the context of clinical practice and may allow genomic-driven treatment in approximately 30% of aBC patients. PDX may be obtained in a significant fraction of cases.
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Mattar M, McCarthy CR, Kulick AR, Qeriqi B, Guzman S, de Stanchina E. Establishing and Maintaining an Extensive Library of Patient-Derived Xenograft Models. Front Oncol 2018. [PMID: 29515970 PMCID: PMC5825907 DOI: 10.3389/fonc.2018.00019] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Patient-derived xenograft (PDX) models have recently emerged as a highly desirable platform in oncology and are expected to substantially broaden the way in vivo studies are designed and executed and to reshape drug discovery programs. However, acquisition of patient-derived samples, and propagation, annotation and distribution of PDXs are complex processes that require a high degree of coordination among clinic, surgery and laboratory personnel, and are fraught with challenges that are administrative, procedural and technical. Here, we examine in detail the major aspects of this complex process and relate our experience in establishing a PDX Core Laboratory within a large academic institution.
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Deng M, Jiang Z, Li Y, Zhou Y, Li J, Wang X, Yao Y, Wang W, Li P, Xu B. Effective elimination of adult B-lineage acute lymphoblastic leukemia by disulfiram/copper complex in vitro and in vivo in patient-derived xenograft models. Oncotarget 2018; 7:82200-82212. [PMID: 27203215 PMCID: PMC5347685 DOI: 10.18632/oncotarget.9413] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 04/28/2016] [Indexed: 11/25/2022] Open
Abstract
Disulfiram (DS), a clinically used drug to control alcoholism, has displayed promising anti-cancer activity against a wide range of tumors. Here, we demonstrated that DS/copper (Cu) complex effectively eliminated adult B-ALL cells in vitro and in vivo in patient-derived xenograft (PDX) humanized mouse models, reflected by inhibition of cell proliferation, induction of apoptosis, suppression of colony formation, and reduction of PDX tumor growth, while sparing normal peripheral blood mononuclear cells. Mechanistically, these events were associated with disruption of mitochondrial membrane potential and down-regulation of the anti-apoptotic proteins Bcl-2 and Bcl-xL. Further analysis on B-ALL patients' clinical characteristics revealed that the ex vivo efficacy of DS/Cu in primary samples was significantly correlated to p16 gene deletion and peripheral blood WBC counts at diagnosis, while age, LDH level, extramedullary infiltration, status post intensive induction therapy, immune phenotype, risk category, and Ph chromosome had no effect. Together, these findings indicate that disulfiram, particularly when administrated in combination with copper, might represent a potential repurposing agent for treatment of adult B-ALL patients, including those clinically characterized by one or more adverse prognostic factors.
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Patient-derived xenograft models of colorectal cancer in pre-clinical research: a systematic review. Oncotarget 2018; 7:66212-66225. [PMID: 27517155 PMCID: PMC5323228 DOI: 10.18632/oncotarget.11184] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 07/18/2016] [Indexed: 12/17/2022] Open
Abstract
AIMS We sought to objectively assess the internal and external validity of patient-derived xenograft (PDX) models as a platform in pre-clinical research into colorectal cancer (CRC). Metastatic disease is the most common cause of death from CRC, and despite significant research, the results of current combination chemotherapy and targeted therapies have been underwhelming for most of this patient group. One of the key factors limiting the success of translational CRC research is the biologically inaccurate models in which new therapies are developed. METHODS We used the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) checklist and SYRCLE (Systematic Review Centre for Laboratory animal Experimentation) guidelines to search Ovid MEDLINE and Embase databases up to July 2015 to identify studies involving PDX models of CRC where the model had been validated across multiple parameters. Data was extracted including host mouse strain, engraftment rate, site of engraftment, donor tumour source and development of metastases in the model. RESULTS Thirteen articles satisfied the inclusion criteria. There was significant heterogeneity amongst the included studies, but overall the median engraftment rate was high (70%) and PDX models faithfully recapitulated the characteristics of their patient tumours on the microscopic, genetic and functional levels. CONCLUSIONS PDX models of CRC have a reasonable internal validity and a high external validity. Developments in xenografting technology are broadening the applications of the PDX platform. However, the included studies could be improved by standardising reporting standards and closed following the ARRIVE (Animals in Research: Reporting In Vivo Experiments) guidelines.
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Yu Y, Schleich K, Yue B, Ji S, Lohneis P, Kemper K, Silvis MR, Qutob N, van Rooijen E, Werner-Klein M, Li L, Dhawan D, Meierjohann S, Reimann M, Elkahloun A, Treitschke S, Dörken B, Speck C, Mallette FA, Zon LI, Holmen SL, Peeper DS, Samuels Y, Schmitt CA, Lee S. Targeting the Senescence-Overriding Cooperative Activity of Structurally Unrelated H3K9 Demethylases in Melanoma. Cancer Cell 2018; 33:322-336.e8. [PMID: 29438700 PMCID: PMC5977991 DOI: 10.1016/j.ccell.2018.01.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Revised: 10/16/2017] [Accepted: 01/04/2018] [Indexed: 12/23/2022]
Abstract
Oncogene-induced senescence, e.g., in melanocytic nevi, terminates the expansion of pre-malignant cells via transcriptional silencing of proliferation-related genes due to decoration of their promoters with repressive trimethylated histone H3 lysine 9 (H3K9) marks. We show here that structurally distinct H3K9-active demethylases-the lysine-specific demethylase-1 (LSD1) and several Jumonji C domain-containing moieties (such as JMJD2C)-disable senescence and permit Ras/Braf-evoked transformation. In mouse and zebrafish models, enforced LSD1 or JMJD2C expression promoted Braf-V600E-driven melanomagenesis. A large subset of established melanoma cell lines and primary human melanoma samples presented with a collective upregulation of related and unrelated H3K9 demethylase activities, whose targeted inhibition restored senescence, even in Braf inhibitor-resistant melanomas, evoked secondary immune effects and controlled tumor growth in vivo.
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Chang N, Lee HW, Lim JE, Jeong DE, Song HJ, Kim S, Nam DH, Sung HH, Jeong BC, Seo SI, Jeon SS, Lee HM, Choi HY, Jeon HG. Establishment and antitumor effects of dasatinib and PKI-587 in BD-138T, a patient-derived muscle invasive bladder cancer preclinical platform with concomitant EGFR amplification and PTEN deletion. Oncotarget 2018; 7:51626-51639. [PMID: 27438149 PMCID: PMC5239502 DOI: 10.18632/oncotarget.10539] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 06/29/2016] [Indexed: 11/25/2022] Open
Abstract
Muscle-invasive bladder cancer (MIBC) consists of a heterogeneous group of tumors with a high rate of metastasis and mortality. To facilitate the in-depth investigation and validation of tailored strategies for MIBC treatment, we have developed an integrated approach using advanced high-throughput drug screening and a clinically relevant patient-derived preclinical platform. We isolated patient-derived tumor cells (PDCs) from a rare MIBC case (BD-138T) that harbors concomitant epidermal growth factor receptor (EGFR) amplification and phosphatase and tensin homolog (PTEN) deletion. High-throughput in vitro drug screening demonstrated that dasatinib, a SRC inhibitor, and PKI-587, a dual PI3K/mTOR inhibitor, exhibited targeted anti-proliferative and pro-apoptotic effects against BD-138T PDCs. Using established patient-derived xenograft models that successfully retain the genomic and molecular characteristics of the parental tumor, we confirmed that these anti-tumor responses occurred through the inhibition of SRC and PI3K/AKT/mTOR signaling pathways. Taken together, these experimental results demonstrate that dasatinib and PKI-587 might serve as promising anticancer drug candidates for treating MIBC with combined EGFR gene amplification and PTEN deletion.
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Kim HR, Kang HN, Shim HS, Kim EY, Kim J, Kim DJ, Lee JG, Lee CY, Hong MH, Kim SM, Kim H, Pyo KH, Yun MR, Park HJ, Han JY, Youn HA, Ahn MJ, Paik S, Kim TM, Cho BC. Co-clinical trials demonstrate predictive biomarkers for dovitinib, an FGFR inhibitor, in lung squamous cell carcinoma. Ann Oncol 2018; 28:1250-1259. [PMID: 28460066 DOI: 10.1093/annonc/mdx098] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Background We conducted co-clinical trials in patient-derived xenograft (PDX) models to identify predictive biomarkers for the multikinase inhibitor dovitinib in lung squamous cell carcinoma (LSCC). Methods The PDX01-02 were established from LSCC patients enrolled in the phase II trial of dovitinib (NCT01861197) and PDX03-05 were established from LSCC patients receiving surgery. These five PDX tumors were subjected to in vivo test of dovitinib efficacy, whole exome sequencing and gene expression profiling. Results The PDX tumors recapitulate histopathological properties and maintain genomic characteristics of originating tumors. Concordant with clinical outcomes of the trial enrolled-LSCC patients, dovitinib produced substantial tumor regression in PDX-01 and PDX-05, whereas it resulted in tumor progression in PDX-02. PDX-03 and -04 also displayed poor antitumor efficacy to dovitinib. Mutational and genome-wide copy number profiles revealed no correlation between genomic alterations of FGFR1-3 and sensitivity to dovitinib. Of note, gene expression profiles revealed differentially expressed genes including FGF3 and FGF19 between PDX-01 and 05 and PDX-02-04. Pathway analysis identified two FGFR signaling-related gene sets, FGFR ligand binding/activation and SHC-mediated cascade pathway were substantially up-regulated in PDX-01 and 05, compared with PDX-02-04. The comparison of gene expression profiles between dovitinib-sensitive versus -resistant lung cancer cell lines in the Cancer Cell Line Encyclopedia database also found that transcriptional activation of 18 key signaling components in FGFR pathways can predict the sensitivity to dovitinib both in cell lines and PDX tumors. These results highlight FGFR pathway activation as a key molecular determinant for sensitivity to dovitinib. Conclusions FGFR gene expression signatures are predictors for the response to dovitinib in LSCC.
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Bradford JR, Wappett M, Beran G, Logie A, Delpuech O, Brown H, Boros J, Camp NJ, McEwen R, Mazzola AM, D'Cruz C, Barry ST. Whole transcriptome profiling of patient-derived xenograft models as a tool to identify both tumor and stromal specific biomarkers. Oncotarget 2018; 7:20773-87. [PMID: 26980748 PMCID: PMC4991491 DOI: 10.18632/oncotarget.8014] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 02/18/2016] [Indexed: 12/16/2022] Open
Abstract
The tumor microenvironment is emerging as a key regulator of cancer growth and progression, however the exact mechanisms of interaction with the tumor are poorly understood. Whilst the majority of genomic profiling efforts thus far have focused on the tumor, here we investigate RNA-Seq as a hypothesis-free tool to generate independent tumor and stromal biomarkers, and explore tumor-stroma interactions by exploiting the human-murine compartment specificity of patient-derived xenografts (PDX). Across a pan-cancer cohort of 79 PDX models, we determine that mouse stroma can be separated into distinct clusters, each corresponding to a specific stromal cell type. This implies heterogeneous recruitment of mouse stroma to the xenograft independent of tumor type. We then generate cross-species expression networks to recapitulate a known association between tumor epithelial cells and fibroblast activation, and propose a potentially novel relationship between two hypoxia-associated genes, human MIF and mouse Ddx6. Assessment of disease subtype also reveals MMP12 as a putative stromal marker of triple-negative breast cancer. Finally, we establish that our ability to dissect recruited stroma from trans-differentiated tumor cells is crucial to identifying stem-like poor-prognosis signatures in the tumor compartment. In conclusion, RNA-Seq is a powerful, cost-effective solution to global analysis of human tumor and mouse stroma simultaneously, providing new insights into mouse stromal heterogeneity and compartment-specific disease markers that are otherwise overlooked by alternative technologies. The study represents the first comprehensive analysis of its kind across multiple PDX models, and supports adoption of the approach in pre-clinical drug efficacy studies, and compartment-specific biomarker discovery.
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Dayot S, Speisky D, Couvelard A, Bourgoin P, Gratio V, Cros J, Rebours V, Sauvanet A, Bedossa P, Paradis V, Ruszniewski P, Couvineau A, Voisin T. In vitro, in vivo and ex vivo demonstration of the antitumoral role of hypocretin-1/orexin-A and almorexant in pancreatic ductal adenocarcinoma. Oncotarget 2018; 9:6952-6967. [PMID: 29467942 PMCID: PMC5805528 DOI: 10.18632/oncotarget.24084] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2017] [Accepted: 01/02/2018] [Indexed: 02/05/2023] Open
Abstract
Pancreatic ductal adenocarcinoma (PDAC) is still the poorest prognostic tumor of the digestive system. We investigated the antitumoral role of orexin-A and almorexant in PDAC. We analyzed the orexin receptor type 1 (OX1R) expression by immunohistochemistry in human normal pancreas, PDAC and its precursor dysplastic intraepithelial lesions. We used PDAC-derived cell lines and fresh tissue slices to study the apoptotic role of hypocretin-1/orexin-A and almorexant in vitro and ex vivo. We analyzed in vivo the hypocretin-1/orexin-A and almorexant effect on tumor growth in mice xenografted with PDAC cell lines expressing, or not, OX1R. Ninety-six percent of PDAC expressed OX1R, while adjacent normal exocrine pancreas did not. OX1R was expressed in pre-cancerous lesions. In vitro, under hypocretin-1/orexin-A and almorexant, the OX1R-positive AsPC-1 cells underwent apoptosis, abolished by the tyrosine phosphatase SHP2 inhibitor, NSC-87877, whereas the OX1R-negative HPAF-II cell line did not. These effects were mediated by phosphorylation of OX1R and recruitment of SHP2. Ex vivo, caspase-3 positive tumor cells were significantly higher in fresh tumour slices treated 48h with hypocretin-1/orexin-A, as compared to control, whereas cellular proliferation, assessed by Ki-67 index, was not modified. In vivo, when AsPC-1 cells or patient-derived cells were xenografted in nude mice, hypocretin-1/orexin-A or almorexant, administrated both starting the day of cell line inoculation or after tumoral development, strongly slowed tumor growth. Hypocretin-1/orexin-A and almorexant induce, through OX1R, the inhibition of PDAC cellular growth by apoptosis. Hypocretins/orexins and almorexant might be powerful candidates for the treatment of PDAC.
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Targeting hypoxic microenvironment of pancreatic xenografts with the hypoxia-activated prodrug TH-302. Oncotarget 2018; 7:33571-80. [PMID: 27248663 PMCID: PMC5085103 DOI: 10.18632/oncotarget.9654] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 05/16/2016] [Indexed: 11/25/2022] Open
Abstract
Previous reports have suggested that the hypoxic microenvironment provides a niche that supports tumor stem cells, and that this might explain clinical observations linking hypoxia to metastasis. To test this, we examined the effects of a hypoxia-activated prodrug, TH-302, on the tumor-initiating cell (TIC) frequency of patient-derived pancreatic xenografts (PDX). The frequencies of TIC, measured by limiting dilution assay, varied widely in 11 PDX models, and were correlated with rapid growth but not with the levels of hypoxia. Treatment with either TH-302 or ionizing radiation (IR), to target hypoxic and well-oxygenated regions, respectively, reduced TIC frequency, and the combination of TH-302 and IR was much more effective in all models tested. The combination was also more effective than TH-302 or IR alone controlling tumor growth, particularly treating the more rapidly-growing/hypoxic models. These findings support the clinical utility of hypoxia targeting in combination with radiotherapy to treat pancreatic cancers, but do not provide strong evidence for a hypoxic stem cell niche.
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Morishita T, Hayakawa F, Sugimoto K, Iwase M, Yamamoto H, Hirano D, Kojima Y, Imoto N, Naoe T, Kiyoi H. The photosensitizer verteporfin has light-independent anti-leukemic activity for Ph-positive acute lymphoblastic leukemia and synergistically works with dasatinib. Oncotarget 2018; 7:56241-56252. [PMID: 27494842 PMCID: PMC5302911 DOI: 10.18632/oncotarget.11025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 07/23/2016] [Indexed: 12/02/2022] Open
Abstract
Cell lines have been used for drug discovery as useful models of cancers; however, they do not recapitulate cancers faithfully, particularly from the viewpoints of microenvironmental independence. Patient-derived xenografts (PDX) are established by the transfer of primary tumor cells directly from patients into immunodeficient mice and can provide primary-like tumor cells of the amount needed at the desired time. We developed a high-throughput drug screening system using PDX cells and performed drug screening using the PDX cells of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL). We established four Ph+ ALL PDX mice and performed high-throughput screening of 3440 compounds using leukemia cells from the PDX mice (PDX-cell screening). The profiles of drugs selected by PDX-cell screening were markedly different from those by screening using the Ph+ ALL cell line. We found that verteporfin, an FDA-approved drug, exhibited strong PDX cell-specific cytotoxicity. In the validation assay, its GI50 was 228 nM, 395 nM, and 538 nM in three PDX cells and 3.93 μM, 2.11 μM, and 5.61 μM in three cell lines. Although verteporfin is a photosensitizer activated by photoirradiation, its cytotoxic effects were mediated by the light-independent production of reactive oxygen species; therefore, its anti-leukemic effects were also exerted in vivo without photoirradiation. Furthermore, it exhibited synergistic effects with dasatinib, an ABL kinase inhibitor. These results indicated the potential of verteporfin as a new anti-leukemic reagent.
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Cramer SL, Miller AL, Pressey JG, Gamblin TL, Beierle EA, Kulbersh BD, Garcia PL, Council LN, Radhakrishnan R, Hendrix SV, Kelly DR, Watts RG, Yoon KJ. Pediatric Anaplastic Embryonal Rhabdomyosarcoma: Targeted Therapy Guided by Genetic Analysis and a Patient-Derived Xenograft Study. Front Oncol 2018; 7:327. [PMID: 29376028 PMCID: PMC5768639 DOI: 10.3389/fonc.2017.00327] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 12/18/2017] [Indexed: 11/13/2022] Open
Abstract
Therapy for rhabdomyosarcoma (RMS) has generally been limited to combinations of conventional cytotoxic agents similar to regimens originally developed in the late 1960s. Recently, identification of molecular alterations through next-generation sequencing of individual tumor specimens has facilitated the use of more targeted therapeutic approaches for various malignancies. Such targeted therapies have revolutionized treatment for some cancer types. However, malignancies common in children, thus far, have been less amenable to such targeted therapies. This report describes the clinical course of an 8-year-old female with embryonal RMS having anaplastic features. This patient experienced multiple relapses after receiving various established and experimental therapies. Genomic testing of this RMS subtype revealed mutations in BCOR, ARID1A, and SETD2 genes, each of which contributes to epigenetic regulation and interacts with or modifies the activity of histone deacetylases (HDAC). Based on these findings, the patient was treated with the HDAC inhibitor vorinostat as a single agent. The tumor responded transiently followed by subsequent disease progression. We also examined the efficacy of vorinostat in a patient-derived xenograft (PDX) model developed using tumor tissue obtained from the patient’s most recent tumor resection. The antitumor activity of vorinostat observed with the PDX model reflected clinical observations in that obvious areas of tumor necrosis were evident following exposure to vorinostat. Histologic sections of tumors harvested from PDX tumor-bearing mice treated with vorinostat demonstrated induction of necrosis by this agent. We propose that the evaluation of clinical efficacy in this type of preclinical model merits further evaluation to determine if PDX models predict tumor sensitivity to specific agents and/or combination therapies.
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Fang T, Huang H, Li X, Liao J, Yang Z, Hoffman RM, Cheng XI, Liang L, Hu W, Yun S. Effects of siRNA Silencing of TUG1 and LCAL6 Long Non-coding RNAs on Patient-derived Xenograft of Non-small Cell Lung Cancer. Anticancer Res 2018; 38:179-186. [PMID: 29277771 DOI: 10.21873/anticanres.12206] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 10/31/2017] [Accepted: 11/01/2017] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM The aim of the present study was to establish a patient-derived xenograft (PDX) mouse model of non-small cell lung cancer (NSCLC) and investigate the anti-tumor efficacy of silencing of TUG1 and LCAL6 long non-coding RNA in the PDX model. MATERIALS AND METHODS PDXs were established by subcutaneously implanting NSCLC surgical tumor fragments into immunodeficient mice. PDX characterization was performed by histopathological, immunohistochemical and real-time polymerase chain reaction (RT-PCR) analyses for NSCLC subtype-specific markers and expression of LCAL6 and TUG1. Anti-tumor efficacy of siRNA silencing of TUG1 and LCAL6 was also investigated in the PDX model. The effect of TUG1 and LCAL6 silencing on protein expression of proliferation marker Ki67 and HOX-gene family HOXB7 in the tumors was assessed by immunohistochemical staining and Western blotting. RESULTS Establishment of NSCLC PDX models resulted in 9 of 26 cases (34.6%). Lung squamous cell carcinomas (SCC) had a higher engraftment rate (58.3%) than lung adenocarcinomas (ADC) (18.2%) (p<0.05). Comparative analysis indicated these established PDX models of NSCLC closely resembled the original tumors with regard to NSCLC subtype-specific markers TTF-1, napsin A, p63 and expression of LCAL6 and TUG1. The tumor volume and weight were significantly reduced in the TUG1-silenced group as compared to the control group (p<0.05). However, no significant tumor growth inhibition was found in the LCAL6-silenced group (p>0.05). Expression of both TUG1and LCAL6 was reduced by siRNA treatment. Expression of Ki67 and HOXB7 was significantly suppressed in both the TUG1- and LCAL6-silenced groups compared to the control group (p<0.01). The TUG1-silenced group showed more reduced Ki67 expression than the LCAL6-silenced group (p<0.05). CONCLUSION PDX NSCLC models were established with a high degree of similarity with the original tumor with regard to histological, immunohistochemical features and RNA expression of TUG1 and LCAL6. Silencing of TUG1 inhibited both tumor growth and expression of the proliferation marker Ki67 and HOX-gene family HOXB7 in the PDX model of NSCLC.
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Wang M, Yao LC, Cheng M, Cai D, Martinek J, Pan CX, Shi W, Ma AH, De Vere White RW, Airhart S, Liu ET, Banchereau J, Brehm MA, Greiner DL, Shultz LD, Palucka K, Keck JG. Humanized mice in studying efficacy and mechanisms of PD-1-targeted cancer immunotherapy. FASEB J 2018; 32:1537-1549. [PMID: 29146734 PMCID: PMC5892726 DOI: 10.1096/fj.201700740r] [Citation(s) in RCA: 227] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Establishment of an in vivo small animal model of human tumor and human immune system interaction would enable preclinical investigations into the mechanisms underlying cancer immunotherapy. To this end, nonobese diabetic (NOD).Cg-PrkdcscidIL2rgtm1Wjl/Sz (null; NSG) mice were transplanted with human (h)CD34+ hematopoietic progenitor and stem cells, which leads to the development of human hematopoietic and immune systems [humanized NSG (HuNSG)]. HuNSG mice received human leukocyte antigen partially matched tumor implants from patient-derived xenografts [PDX; non–small cell lung cancer (NSCLC), sarcoma, bladder cancer, and triple-negative breast cancer (TNBC)] or from a TNBC cell line-derived xenograft (CDX). Tumor growth curves were similar in HuNSG compared with nonhuman immune-engrafted NSG mice. Treatment with pembrolizumab, which targets programmed cell death protein 1, produced significant growth inhibition in both CDX and PDX tumors in HuNSG but not in NSG mice. Finally, inhibition of tumor growth was dependent on hCD8+ T cells, as demonstrated by antibody-mediated depletion. Thus, tumor-bearing HuNSG mice may represent an important, new model for preclinical immunotherapy research.—Wang, M., Yao, L.-C., Cheng, M., Cai, D., Martinek, J., Pan, C.-X., Shi, W., Ma, A.-H., De Vere White, R. W., Airhart, S., Liu, E. T., Banchereau, J., Brehm, M. A., Greiner, D. L., Shultz, L. D., Palucka, K., Keck, J. G. Humanized mice in studying efficacy and mechanisms of PD-1-targeted cancer immunotherapy.
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218
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Okada S, Vaeteewoottacharn K, Kariya R. Establishment of a Patient-Derived Tumor Xenograft Model and Application for Precision Cancer Medicine. Chem Pharm Bull (Tokyo) 2018; 66:225-230. [PMID: 29491256 DOI: 10.1248/cpb.c17-00789] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2024]
Abstract
Patient-derived xenograft (PDX) models can be created with the transplantation of cancerous cells or tissues from patients' primary tumors into immunodeficient mice. PDXs are now in the spotlight as more accurate human cancer models compared with mouse tumor and human cancer cell lines transplanted into mice. PDX technology leads to breakthroughs with the introduction of novel, highly immunodeficient mice such as NOG (NOD/Scid/IL2Rγnull), NSG (NOD/Scid/IL2Rγnull), and NOJ (NOD/Scid/Jak3null) mice. Xenograft efficiency differs by type of tumor, site of implantation, and tumor aggressiveness. Subcutaneous implantation is a standard method for PDX, and renal capsule or orthotropic implantation improves the efficiency. Despite positive test results in animal cancer models, significant numbers of novel drug candidates fail in clinical trials because conventional animal models such as murine tumor and human cancer cell line transplantation models do not always reflect the nature of human cancers. Since PDXs conserve the original tumor characteristics such as heterogeneous histology, clinical biomolecular signatures, malignant phenotypes and genotypes, tumor architecture, and tumor vasculature, they are currently believed to offer relevant predictive insights into clinical outcomes when evaluating the efficacy of novel cancer therapies. PDX banks with integrated genomic signatures are now established in many organizations including pharmaceutical companies. These PDX databases are becoming powerful tools for advancing precision cancer medicine.
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219
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Molecular crosstalk between tumour and brain parenchyma instructs histopathological features in glioblastoma. Oncotarget 2017; 7:31955-71. [PMID: 27049916 PMCID: PMC5077988 DOI: 10.18632/oncotarget.7454] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 01/29/2016] [Indexed: 12/11/2022] Open
Abstract
The histopathological and molecular heterogeneity of glioblastomas represents a major obstacle for effective therapies. Glioblastomas do not develop autonomously, but evolve in a unique environment that adapts to the growing tumour mass and contributes to the malignancy of these neoplasms. Here, we show that patient-derived glioblastoma xenografts generated in the mouse brain from organotypic spheroids reproducibly give rise to three different histological phenotypes: (i) a highly invasive phenotype with an apparent normal brain vasculature, (ii) a highly angiogenic phenotype displaying microvascular proliferation and necrosis and (iii) an intermediate phenotype combining features of invasion and vessel abnormalities. These phenotypic differences were visible during early phases of tumour development suggesting an early instructive role of tumour cells on the brain parenchyma. Conversely, we found that tumour-instructed stromal cells differentially influenced tumour cell proliferation and migration in vitro, indicating a reciprocal crosstalk between neoplastic and non-neoplastic cells. We did not detect any transdifferentiation of tumour cells into endothelial cells. Cell type-specific transcriptomic analysis of tumour and endothelial cells revealed a strong phenotype-specific molecular conversion between the two cell types, suggesting co-evolution of tumour and endothelial cells. Integrative bioinformatic analysis confirmed the reciprocal crosstalk between tumour and microenvironment and suggested a key role for TGFβ1 and extracellular matrix proteins as major interaction modules that shape glioblastoma progression. These data provide novel insight into tumour-host interactions and identify novel stroma-specific targets that may play a role in combinatorial treatment strategies against glioblastoma.
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220
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Allaway RJ, Fischer DA, de Abreu FB, Gardner TB, Gordon SR, Barth RJ, Colacchio TA, Wood M, Kacsoh BZ, Bouley SJ, Cui J, Hamilton J, Choi JA, Lange JT, Peterson JD, Padmanabhan V, Tomlinson CR, Tsongalis GJ, Suriawinata AA, Greene CS, Sanchez Y, Smith KD. Genomic characterization of patient-derived xenograft models established from fine needle aspirate biopsies of a primary pancreatic ductal adenocarcinoma and from patient-matched metastatic sites. Oncotarget 2017; 7:17087-102. [PMID: 26934555 PMCID: PMC4941373 DOI: 10.18632/oncotarget.7718] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 01/13/2016] [Indexed: 12/12/2022] Open
Abstract
N-of-1 trials target actionable mutations, yet such approaches do not test genomically-informed therapies in patient tumor models prior to patient treatment. To address this, we developed patient-derived xenograft (PDX) models from fine needle aspiration (FNA) biopsies (FNA-PDX) obtained from primary pancreatic ductal adenocarcinoma (PDAC) at the time of diagnosis. Here, we characterize PDX models established from one primary and two metastatic sites of one patient. We identified an activating KRAS G12R mutation among other mutations in these models. In explant cells derived from these PDX tumor models with a KRAS G12R mutation, treatment with inhibitors of CDKs (including CDK9) reduced phosphorylation of a marker of CDK9 activity (phospho-RNAPII CTD Ser2/5) and reduced viability/growth of explant cells derived from PDAC PDX models. Similarly, a CDK inhibitor reduced phospho-RNAPII CTD Ser2/5, increased apoptosis, and inhibited tumor growth in FNA-PDX and patient-matched metastatic-PDX models. In summary, PDX models can be constructed from FNA biopsies of PDAC which in turn can enable genomic characterization and identification of potential therapies.
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221
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Lin S, Huang G, Xiao Y, Sun W, Jiang Y, Deng Q, Peng M, Wei X, Ye W, Li B, Lin S, Wang S, Wu Q, Liang Q, Li Y, Zhang X, Wu Y, Liu P, Pei D, Yu F, Wen Z, Yao Y, Wu D, Li P. CD215+ Myeloid Cells Respond to Interleukin 15 Stimulation and Promote Tumor Progression. Front Immunol 2017; 8:1713. [PMID: 29255466 PMCID: PMC5722806 DOI: 10.3389/fimmu.2017.01713] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 11/20/2017] [Indexed: 12/16/2022] Open
Abstract
Interleukin 15 (IL-15) regulates the development, survival, and functions of multiple innate and adaptive immune cells and plays a dual role in promoting both tumor cell growth and antitumor immunity. Here, we demonstrated that the in vivo injection of recombinant human IL-15 (200 µg/kg) or murine IL-15 (3 µg/kg) to tumor-bearing NOD-SCID-IL2Rg−/− (NSI) mice resulted in increased tumor progression and CD45+ CD11b+ Gr-1+ CD215+ cell expansion in the tumors and spleen. In B16F10-bearing C57BL/6 mice model, we found that murine IL-15 has antitumoral effect since the activation and expansion of CD8+ T cells with murine IL-15 treatment. But no enhanced or reduced tumor growth was observed in mice when human IL-15 was used. However, both murine and human IL-15 promote CD45+ CD11b+ Gr-1+ CD215+ cells expansion. In xenograft tumor models, CD215+ myeloid cells, but not CD215− cells, responded to human IL-15 stimulation and promoted tumor growth. Furthermore, we found that human IL-15 mediated insulin-like growth factor-1 production in CD215+ myeloid cells and blocking IGF-1 reduced the tumor-promoting effect of IL-15. Finally, we observed that higher IGF-1 expression is an indicator of poor prognosis among lung adenocarcinoma patients. These findings provide evidence that IL-15 may promote tumor cell progression via CD215+ myeloid cells, and IGF-1 may be an important candidate that IL-15 facilitates tumor growth.
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Collins SD, Bialucha CU, Williams JA, Gao H. Utilizing panels of patient derived xenografts to aid the development of antibody drug conjugates. Mol Cell Oncol 2017; 5:e1394422. [PMID: 29404392 PMCID: PMC5791866 DOI: 10.1080/23723556.2017.1394422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 10/13/2017] [Accepted: 10/15/2017] [Indexed: 12/27/2022]
Abstract
Despite numerous endeavors in clinical trials there are few clinically approved Antibody Drug Conjugate (ADC) therapies. Here we comment on our recent publication demonstrating the power of using panels of patient-derived xenografts (PDX) prior to Phase 1, to assess the potential heterogeneity of response a clinical candidate may show across a population. Furthermore we discuss how the same approach has been used in an additional ADC program.
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Nicolle R, Blum Y, Marisa L, Loncle C, Gayet O, Moutardier V, Turrini O, Giovannini M, Bian B, Bigonnet M, Rubis M, Elarouci N, Armenoult L, Ayadi M, Duconseil P, Gasmi M, Ouaissi M, Maignan A, Lomberk G, Boher JM, Ewald J, Bories E, Garnier J, Goncalves A, Poizat F, Raoul JL, Secq V, Garcia S, Grandval P, Barraud-Blanc M, Norguet E, Gilabert M, Delpero JR, Roques J, Calvo E, Guillaumond F, Vasseur S, Urrutia R, de Reyniès A, Dusetti N, Iovanna J. Pancreatic Adenocarcinoma Therapeutic Targets Revealed by Tumor-Stroma Cross-Talk Analyses in Patient-Derived Xenografts. Cell Rep 2017; 21:2458-2470. [PMID: 29186684 PMCID: PMC6082139 DOI: 10.1016/j.celrep.2017.11.003] [Citation(s) in RCA: 134] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/12/2017] [Accepted: 10/31/2017] [Indexed: 01/06/2023] Open
Abstract
Preclinical models based on patient-derived xenografts have remarkable specificity in distinguishing transformed human tumor cells from non-transformed murine stromal cells computationally. We obtained 29 pancreatic ductal adenocarcinoma (PDAC) xenografts from either resectable or non-resectable patients (surgery and endoscopic ultrasound-guided fine-needle aspirate, respectively). Extensive multiomic profiling revealed two subtypes with distinct clinical outcomes. These subtypes uncovered specific alterations in DNA methylation and transcription as well as in signaling pathways involved in tumor-stromal cross-talk. The analysis of these pathways indicates therapeutic opportunities for targeting both compartments and their interactions. In particular, we show that inhibiting NPC1L1 with Ezetimibe, a clinically available drug, might be an efficient approach for treating pancreatic cancers. These findings uncover the complex and diverse interplay between PDAC tumors and the stroma and demonstrate the pivotal role of xenografts for drug discovery and relevance to PDAC.
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Gonzalez H, Robles I, Werb Z. Innate and acquired immune surveillance in the postdissemination phase of metastasis. FEBS J 2017; 285:654-664. [PMID: 29131550 DOI: 10.1111/febs.14325] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/20/2017] [Accepted: 11/08/2017] [Indexed: 12/14/2022]
Abstract
Metastasis is responsible for the majority of death in cancer patients. Of the different steps in the metastasis cascade, the postdissemination phase is perhaps one of the least understood. Many factors, both from the disseminated tumor cells and the microenvironment, impact the success of the metastatic outgrowth. In this article, we discuss the interactions between colonizing cancer cells and immune cells in the period between vascular arrest in a secondary organ and metastatic outgrowth. We address the ambiguity in the findings of current research regarding the role of immune cells in regulating the metastatic microenvironment, and their hand in determining cancer cell fate.
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225
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Contreras-Zárate MJ, Ormond DR, Gillen AE, Hanna C, Day NL, Serkova NJ, Jacobsen BM, Edgerton SM, Thor AD, Borges VF, Lillehei KO, Graner MW, Kabos P, Cittelly DM. Development of Novel Patient-Derived Xenografts from Breast Cancer Brain Metastases. Front Oncol 2017; 7:252. [PMID: 29164052 PMCID: PMC5673842 DOI: 10.3389/fonc.2017.00252] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/09/2017] [Indexed: 12/21/2022] Open
Abstract
Brain metastases are an increasing burden among breast cancer patients, particularly for those with HER2+ and triple negative (TN) subtypes. Mechanistic insight into the pathophysiology of brain metastases and preclinical validation of therapies has relied almost exclusively on intracardiac injection of brain-homing cells derived from highly aggressive TN MDA-MB-231 and HER2+ BT474 breast cancer cell lines. Yet, these well characterized models are far from representing the tumor heterogeneity observed clinically and, due to their fast progression in vivo, their suitability to validate therapies for established brain metastasis remains limited. The goal of this study was to develop and characterize novel human brain metastasis breast cancer patient-derived xenografts (BM-PDXs) to study the biology of brain metastasis and to serve as tools for testing novel therapeutic approaches. We obtained freshly resected brain metastases from consenting donors with breast cancer. Tissue was immediately implanted in the mammary fat pad of female immunocompromised mice and expanded as BM-PDXs. Brain metastases from 3/4 (75%) TN, 1/1 (100%) estrogen receptor positive (ER+), and 5/9 (55.5%) HER2+ clinical subtypes were established as transplantable BM-PDXs. To facilitate tracking of metastatic dissemination using BM-PDXs, we labeled PDX-dissociated cells with EGFP-luciferase followed by reimplantation in mice, and generated a BM-derived cell line (F2-7). Immunohistologic analyses demonstrated that parental and labeled BM-PDXs retained expression of critical clinical markers such as ER, progesterone receptor, epidermal growth factor receptor, HER2, and the basal cell marker cytokeratin 5. Similarly, RNA sequencing analysis showed clustering of parental, labeled BM-PDXs and their corresponding cell line derivative. Intracardiac injection of dissociated cells from BM-E22-1, resulted in magnetic resonance imaging-detectable macrometastases in 4/8 (50%) and micrometastases (8/8) (100%) mice, suggesting that BM-PDXs remain capable of colonizing the brain at high frequencies. Brain metastases developed 8-12 weeks after ic injection, located to the brain parenchyma, grew around blood vessels, and elicited astroglia activation characteristic of breast cancer brain metastasis. These novel BM-PDXs represent heterogeneous and clinically relevant models to study mechanisms of brain metastatic colonization, with the added benefit of a slower progression rate that makes them suitable for preclinical testing of drugs in therapeutic settings.
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