scholarly journals Generation of focal mutations and large genomic deletions in the pancreas using inducible in vivo genome editing

2019 ◽  
Vol 41 (3) ◽  
pp. 334-344
Author(s):  
Amrendra Mishra ◽  
Fatemeh Emamgholi ◽  
Zulrahman Erlangga ◽  
Björn Hartleben ◽  
Kristian Unger ◽  
...  
Keyword(s):  
Embryonic Stem ◽  
Genetic Alterations ◽  
Model Systems ◽  
Ductal Adenocarcinoma ◽  
In Vivo Model ◽  
Precision Oncology ◽  
Kras Mutations ◽  
Genomic Deletions ◽  
The Impact

Abstract Beyond the nearly uniform presence of KRAS mutations, pancreatic cancer is increasingly recognized as a heterogeneous disease. Preclinical in vivo model systems exist, but with the advent of precision oncology, murine models with enhanced genetic flexibility are needed to functionally annotate genetic alterations found in the human malignancy. Here, we describe the generation of focal gene disruptions and large chromosomal deletions via inducible and pancreas-specific expression of Cas9 in adult mice. Experimental mice are derived on demand directly from genetically engineered embryonic stem cells, without the need for further intercrossing. To provide initial validation of our approach, we show that disruption of the E3 ubiquitin ligase Rnf43 accelerates KrasG12D-dependent tumourigenesis. Moreover, we demonstrate that this system can be used to rapidly interrogate the impact of complex cancer-associated alleles through the generation of a previously unstudied 1.2 megabase deletion surrounding the CDKN2A and CDKN2B tumour suppressors. Thus, our approach is capable of reproducibly generating biallelic and precise loss of large chromosomal fragments that, in conjunction with mutant Kras, leads to development of pancreatic ductal adenocarcinoma with full penetrance.

scholarly journals Unbiased in vivo preclinical evaluation of anticancer drugs identifies effective therapy for the treatment of pancreatic adenocarcinoma

2020 ◽  
Vol 117 (48) ◽  
pp. 30670-30678
Author(s):  
Olivera Grbovic-Huezo ◽  
Kenneth L. Pitter ◽  
Nicolas Lecomte ◽  
Joseph Saglimbeni ◽  
Gokce Askan ◽  
...  
Keyword(s):  
Large Scale ◽  
Single Agent ◽  
Model Systems ◽  
Ductal Adenocarcinoma ◽  
In Vivo Model ◽  
Cancer Therapies ◽  
Hsp90 Inhibition ◽  
Dismal Prognosis

Pancreatic ductal adenocarcinoma (PDAC) is typically diagnosed at an advanced stage, which limits surgical options and portends a dismal prognosis. Current oncologic PDAC therapies confer marginal benefit and, thus, a significant unmet clinical need exists for new therapeutic strategies. To identify effective PDAC therapies, we leveraged a syngeneic orthotopic PDAC transplant mouse model to perform a large-scale, in vivo screen of 16 single-agent and 41 two-drug targeted therapy combinations in mice. Among 57 drug conditions screened, combined inhibition of heat shock protein (Hsp)-90 and MEK was found to produce robust suppression of tumor growth, leading to an 80% increase in the survival of PDAC-bearing mice with no significant toxicity. Mechanistically, we observed that single-agent MEK inhibition led to compensatory activation of resistance pathways, including components of the PI3K/AKT/mTOR signaling axis, which was overcome with the addition of HSP90 inhibition. The combination of HSP90(i) + MEK(i) was also active in vitro in established human PDAC cell lines and in vivo in patient-derived organoid PDAC transplant models. These findings encourage the clinical development of HSP90(i) + MEK(i) combination therapy and highlight the power of clinically relevant in vivo model systems for identifying cancer therapies.

DNA sequencing of the small bowel adenocarcinomas to identify targetable ErbB2 mutations.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e15800-e15800
Author(s):  
Liana Adam ◽  
Jerry Fowler ◽  
Wenhui Wu ◽  
Yao Yu ◽  
Huamin Wang ◽  
...  
Keyword(s):  
Small Bowel ◽  
Cell Lines ◽  
Somatic Mutations ◽  
Genetic Alterations ◽  
Model Systems ◽  
Parp Cleavage ◽  
In Vivo Model ◽  
Small Bowel Adenocarcinoma

e15800 Background: Small bowel adenocarcinoma (SBA) is a rare malignancy of the digestive tract with limited knowledge about its genetic alterations. Methods: Eighteen tumor and normal matched samples were sequenced using the whole-exome-Illumina platform. Various agnostic analysis methods were used to identify relevant somatic mutations and the results were compared with the available TCGA datasets. To test potential targetable mutations we developed eight patient-derived xenografts (PDX) and three cell lines from freshly-collected primary or metastatic SBA tissues. Two kinase-activating ErbB2 mutations (V842I and Y803H) and one wild-type (wt) ErbB2 (n = 30) PDX models were used to measure the effect of Dacomitinib (Daco) on tumor growth. ErbB2-mutant tumor-derived cell lines were tested for Daco and Lapatinib (Lapa) response in-vitro. Reverse-phase-protein-arrays (RPPA) were used to identify molecular changes. Results: Several unexpected oncogenic mechanisms were suggested by the pattern of somatic mutations across the dataset, including mutations in the Notch and Hippo pathways. In addition, we found 6/18 APC truncating mutations exclusive to mutations in ZNRF3 or RNF43 genes, suggesting that non-APC wnt-activating mechanisms are important in SBA, while considered a minority in CRC. Importantly, 6/18 samples displayed ErbB2 mutations, of which 4 resided in the kinase domain, D769Y, V777L, Y803H and V842I. Nanomolar doses of both Lapa and Daco significantly inhibited ErbB2-mutants’ cell proliferation in-vitro. Target inhibition was confirmed by the RPPA results: EGFR-Y1068, ErbB2-Y1248 and PKCα-S657 dephosphorylation, PCNA reduction and PARP cleavage increase. In-vivo-administered Daco resulted in significant tumor reduction in ErbB2-V841I (39%, p = 0.03) and ErbB2-Y803H (59%, p = 0.03) tumors, and had no anti-tumor effect on wt-ErbB2 tumors. Conclusions: The generation of in-vitro and in-vivo model systems from rare cancers is possible and provides a valuable resource into understanding potentially relevant targetable mutations. Our findings suggest that SBA patients with ErbB2-activating mutations should be considered for clinical trials targeting this alteration.

scholarly journals BIOL-11. THE ROLE OF ABERRANT EXPRESSION OF PRDM6 IN THE DEVELOPING CEREBELLUM AND IN GROUP 4 MEDULLOBLASTOMA

2021 ◽  
Vol 23 (Supplement_1) ◽  
pp. i5-i5
Author(s):  
Christin Schmidt ◽  
Annika Carlson ◽  
William Weiss ◽  
Bjoern Schwer
Keyword(s):  
Stem Cells ◽  
Embryonic Stem ◽  
Genetic Alterations ◽  
Cerebellar Development ◽  
Aberrant Expression ◽  
Group 4 ◽  
Mycn Expression ◽  
The Impact

Abstract Group 4 medulloblastoma is the most common medulloblastoma subgroup with an intermediate prognosis and a high incidence of metastasis and late-onset relapse cases. Despite several comprehensive genomic studies in medulloblastoma, Group 4 medulloblastomas lack a unifying oncogenic driver and treatment targets. This subgroup is characterized by recurrent genetic alterations in chromatin modifiers, amplification of stemness genes, and enhancer hijacking events. 17% of Group 4 medulloblastoma cases are characterized by enhancer hijacking through tandem duplication of SNCAIP, resulting in high expression of PRDM6, a putative transcriptional repressor and histone methyltransferase. PRDM6 amplified medulloblastoma cases show additional mutations in other chromatin regulators, such as KDM6A, KMT2C and KMT2D, ZMYM3, and high MYCN expression. In this project, we investigate the impact and oncogenic potential of sustained PRDM6 expression in early neural stem cell populations and the developing mouse cerebellum. We drive expression of PRDM6 in human iPSC-derived neuroepithelial stem cells (NESCs) with and without high MYCN expression to study its implications in tumorigenesis. To test for tumor growth in vivo and changes in tumor progression as a function of PRDM6 activity, NESCs are injected into the cerebellum of adult mice. In order to elucidate impact of PRDM6 activity during embryonic cerebellar development, we also introduce PRDM6 expression into mouse embryonic stem cells (ESCs) for analysis via a new, in vivo cerebellar blastocyst complementation model. The latter approach is designed to ablate and repopulate early granule neural precursor cells in the embryonal cerebellum with progenitors derived from injected PRDM6-ESCs and thus to recapitulate pre- and postnatal cerebellar development in vivo. Together, our studies aim to understand the role of PRDM6 during normal cerebellar development and tumorigenesis and advance the understanding of the genetic drivers for Group 4 medulloblastoma.

scholarly journals Mouse Models for Studying Oral Cancer: Impact in the Era of Cancer Immunotherapy

2018 ◽  
Vol 97 (6) ◽  
pp. 683-690 ◽  
Author(s):  
J.J. Luo ◽  
C.D. Young ◽  
H.M. Zhou ◽  
X.J. Wang
Keyword(s):  
Oral Cancer ◽  
Cancer Immunotherapy ◽  
Cancer Genetics ◽  
Tumor Stroma ◽  
Model Systems ◽  
Therapeutic Interventions ◽  
In Vivo Model ◽  
Oral Cancer Patients ◽  
The Impact

Model systems for oral cancer research have progressed from tumor epithelial cell cultures to in vivo systems that mimic oral cancer genetics, pathological characteristics, and tumor-stroma interactions of oral cancer patients. In the era of cancer immunotherapy, it is imperative to use model systems to test oral cancer prevention and therapeutic interventions in the presence of an immune system and to discover mechanisms of stromal contributions to oral cancer carcinogenesis. Here, we review in vivo mouse model systems commonly used for studying oral cancer and discuss the impact these models are having in advancing basic mechanisms, chemoprevention, and therapeutic intervention of oral cancer while highlighting recent discoveries concerning the role of immune cells in oral cancer. Improvements to in vivo model systems that highly recapitulate human oral cancer hold the key to identifying features of oral cancer initiation, progression, and invasion as well as molecular and cellular targets for prevention, therapeutic response, and immunotherapy development.

In Vitro and In Vivo Model Systems for the Study of Allergic and Inflammatory Disorders in Man

CHEST Journal ◽  
1985 ◽  
Vol 87 (5) ◽  
pp. 162S-164S ◽  
Author(s):  
Stephen P. Peters ◽  
Robert M. Naclerio ◽  
Alkis Togias ◽  
Robert P. Schleimer ◽  
Donald W. MacGlashan ◽  
...  
Keyword(s):  
Model Systems ◽  
In Vivo Model ◽  
Inflammatory Disorders

scholarly journals Stromal protein βig-h3 reprogrammes tumour microenvironment in pancreatic cancer

Gut ◽  
2018 ◽  
Vol 68 (4) ◽  
pp. 693-707 ◽  
Author(s):  
Delphine Goehrig ◽  
Jérémy Nigri ◽  
Rémi Samain ◽  
Zhichong Wu ◽  
Paola Cappello ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Tumour Growth ◽  
Matrix Protein ◽  
Immune Escape ◽  
Interaction Mechanism ◽  
Tumour Microenvironment ◽  
Extracellular Matrix Protein ◽  
Ductal Adenocarcinoma ◽  
The Impact

ObjectivePancreatic cancer is associated with an abundant stromal reaction leading to immune escape and tumour growth. This massive stroma drives the immune escape in the tumour. We aimed to study the impact of βig-h3 stromal protein in the modulation of the antitumoural immune response in pancreatic cancer.DesignWe performed studies with p48-Cre;KrasG12D, pdx1-Cre;KrasG12D;Ink4a/Arffl/fl, pdx1-Cre;KrasG12D; p53R172H mice and tumour tissues from patients with pancreatic ductal adenocarcinoma (PDA). Some transgenic mice were given injections of anti-βig-h3, anti-CD8, anti-PD1 depleting antibodies. Tumour growth as well as modifications in the activation of local immune cells were analysed by flow cytometry, immunohistochemistry and immunofluorescence. Tissue stiffness was measured by atomic force microscopy.ResultsWe identified βig-h3 stromal-derived protein as a key actor of the immune paracrine interaction mechanism that drives pancreatic cancer. We found that βig-h3 is highly produced by cancer-associated fibroblasts in the stroma of human and mouse. This protein acts directly on tumour-specific CD8+ T cells and F4/80 macrophages. Depleting βig-h3 in vivo reduced tumour growth by enhancing the number of activated CD8+ T cell within the tumour and subsequent apoptotic tumour cells. Furthermore, we found that targeting βig-h3 in established lesions released the tissue tension and functionally reprogrammed F4/80 macrophages in the tumour microenvironment.ConclusionsOur data indicate that targeting stromal extracellular matrix protein βig-h3 improves the antitumoural response and consequently reduces tumour weight. Our findings present βig-h3 as a novel immunological target in pancreatic cancer.

scholarly journals Diet, Obesity, and Cancer Progression: Are Adipocytes the Link?

2013 ◽  
Vol 6 ◽  
pp. LPI.S10871 ◽  
Author(s):  
Paul Toren ◽  
Benjamin C. Mora ◽  
Vasundara Venkateswaran
Keyword(s):  
Tumor Microenvironment ◽  
Cancer Progression ◽  
Tumor Biology ◽  
Model Systems ◽  
In Vivo Model ◽  
Diet Induced Obesity ◽  
Breast And Prostate Cancer ◽  
Obesity And Cancer

Obesity has been linked to more aggressive characteristics of several cancers, including breast and prostate cancer. Adipose tissue appears to contribute to paracrine interactions in the tumor microenvironment. In particular, cancer-associated adipocytes interact reciprocally with cancer cells and influence cancer progression. Adipokines secreted from adipocytes likely form a key component of the paracrine signaling in the tumor microenvironment. In vitro coculture models allow for the assessment of specific adipokines in this interaction. Furthermore, micronutrients and macronutrients present in the diet may alter the secretion of adipokines from adipocytes. The effect of dietary fat and specific fatty acids on cancer progression in several in vivo model systems and cancer types is reviewed. The more common approaches of caloric restriction or diet-induced obesity in animal models establish that such dietary changes modulate tumor biology. This review seeks to explore available evidence regarding how diet may modulate tumor characteristics through changes in the role of adipocytes in the tumor microenvironment.

scholarly journals Ultrasound and Transcriptomics Identify a Differential Impact of Cisplatin and Histone Deacetylation on Tumor Structure and Microenvironment in a Patient-Derived In Vivo Model of Gastric Cancer

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1485
Author(s):  
Aina Venkatasamy ◽  
Eric Guerin ◽  
Anais Blanchet ◽  
Christophe Orvain ◽  
Véronique Devignot ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Tumor Microenvironment ◽  
Real Time ◽  
Histone Deacetylase Inhibitors ◽  
Structural Changes ◽  
Histone Deacetylation ◽  
In Vivo Model ◽  
Specific Cell ◽  
The Impact

The reasons behind the poor efficacy of transition metal-based chemotherapies (e.g., cisplatin) or targeted therapies (e.g., histone deacetylase inhibitors, HDACi) on gastric cancer (GC) remain elusive and recent studies suggested that the tumor microenvironment could contribute to the resistance. Hence, our objective was to gain information on the impact of cisplatin and the pan-HDACi SAHA (suberanilohydroxamic acid) on the tumor substructure and microenvironment of GC, by establishing patient-derived xenografts of GC and a combination of ultrasound, immunohistochemistry, and transcriptomics to analyze. The tumors responded partially to SAHA and cisplatin. An ultrasound gave more accurate tumor measures than a caliper. Importantly, an ultrasound allowed a noninvasive real-time access to the tumor substructure, showing differences between cisplatin and SAHA. These differences were confirmed by immunohistochemistry and transcriptomic analyses of the tumor microenvironment, identifying specific cell type signatures and transcription factor activation. For instance, cisplatin induced an “epithelial cell like” signature while SAHA favored a “mesenchymal cell like” one. Altogether, an ultrasound allowed a precise follow-up of the tumor progression while enabling a noninvasive real-time access to the tumor substructure. Combined with transcriptomics, our results underline the different intra-tumoral structural changes caused by both drugs that impact differently on the tumor microenvironment.

scholarly journals The TRH Gene Is Regulated by Thyroid Hormone at the Level of Transcription in Vivo

2010 ◽  
Vol 31 (1) ◽  
pp. 136-136
Author(s):  
Michelle L. Sugrue ◽  
Kristen R. Vella ◽  
Crystal Morales ◽  
Marisol E. Lopez ◽  
Anthony N. Hollenberg
Keyword(s):  
Thyroid Hormone ◽  
Genomic Region ◽  
Model System ◽  
Model Systems ◽  
In Vivo Model ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Normal Production

ABSTRACT The expression of the TRH gene in the paraventricular nucleus (PVH) of the hypothalamus is required for the normal production of thyroid hormone (TH) in rodents and humans. In addition, the regulation of TRH mRNA expression by TH, specifically in the PVH, ensures tight control of the set point of the hypothalamic-pituitary-thyroid axis. Although many studies have assumed that the regulation of TRH expression by TH is at the level of transcription, there is little data available to demonstrate this. We used two in vivo model systems to show this. In the first model system, we developed an in situ hybridization (ISH) assay directed against TRH heteronuclear RNA to measure TRH transcription directly in vivo. We show that in the euthyroid state, TRH transcription is present both in the PVH and anterior/lateral hypothalamus. In the hypothyroid state, transcription is activated in the PVH only and can be shut off within 5 h by TH. In the second model system, we employed transgenic mice that express the Cre recombinase under the control of the genomic region containing the TRH gene. Remarkably, TH regulates Cre expression in these mice in the PVH only. Taken together, these data affirm that TH regulates TRH at the level of transcription in the PVH only and that genomic elements surrounding the TRH gene mediate its regulation by T3. Thus, it should be possible to identify the elements within the TRH locus that mediate its regulation by T3 using in vivo approaches.

Sign in / Sign up

Export Citation Format

Share Document