scholarly journals Mechanisms of targeted therapy resistance in a pediatric glioma driven by ETV6-NTRK3 fusion

2021 ◽  
pp. mcs.a006109
Author(s):  
Clare Keddy ◽  
Tanaya Neff ◽  
Jianya Huan ◽  
Joshua P Nickerson ◽  
Catherine Z Beach ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Genetic Analysis ◽  
Chromosomal Rearrangements ◽  
Resistance Mutation ◽  
Therapy Resistance ◽  
Model Systems ◽  
Pediatric Glioma ◽  
Functional Studies ◽  
Vitro Analysis

Chromosomal rearrangements of the NTRK genes generate kinase fusions that are targetable oncogenic drivers in diverse adult and pediatric malignancies. Despite robust clinical response to targeted NTRK inhibition, the emergence of therapeutic resistance poses a formidable clinical challenge. Here we report the characterization of an ETV6-NTRK3 fusion-driven pediatric glioma that progressed through NTRK-targeted treatments with entrectinib and selitrectinib. Genetic analysis of multifocal recurrent/resistant lesions identified a previously uncharacterized NTRK3 p.G623A and a known p.G623E resistance mutation, in addition to other alterations of potential pathogenic impact. Functional studies employing heterologous reconstitution model systems and patient-derived tumor cell lines establish that NTRK3G623A and NTRK3G623E mutated kinases exhibit reduced sensitivity to entrectinib and selitrectinib, as well as other NTRK inhibitors tested herein. In summary, this genetic analysis of multifocal recurrent/resistant glioma driven by ETV6-NTRK3 fusion captured a cross-section of resistance-associated alterations that, based on in vitro analysis, likely contributed to resistance to targeted therapy and disease progression.

In vitro analysis of chromatin structure in model systems

Methods ◽  
2004 ◽  
Vol 33 (1) ◽  
pp. 1-2 ◽  
Author(s):  
Jeffrey J. Hayes
Keyword(s):  
Chromatin Structure ◽  
Model Systems ◽  
Vitro Analysis ◽  
In Vitro Analysis

scholarly journals Packaging and transfer of mitochondrial DNA via exosomes regulate escape from dormancy in hormonal therapy-resistant breast cancer

2017 ◽  
Vol 114 (43) ◽  
pp. E9066-E9075 ◽  
Author(s):  
Pasquale Sansone ◽  
Claudia Savini ◽  
Ivana Kurelac ◽  
Qing Chang ◽  
Laura Benedetta Amato ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Hormonal Therapy ◽  
Horizontal Transfer ◽  
Metastatic Breast ◽  
Therapy Resistance ◽  
Peripheral Circulation ◽  
Functional Studies ◽  
Xenograft Models

The horizontal transfer of mtDNA and its role in mediating resistance to therapy and an exit from dormancy have never been investigated. Here we identified the full mitochondrial genome in circulating extracellular vesicles (EVs) from patients with hormonal therapy-resistant (HTR) metastatic breast cancer. We generated xenograft models of HTR metastatic disease characterized by EVs in the peripheral circulation containing mtDNA. Moreover, these human HTR cells had acquired host-derived (murine) mtDNA promoting estrogen receptor-independent oxidative phosphorylation (OXPHOS). Functional studies identified cancer-associated fibroblast (CAF)-derived EVs (from patients and xenograft models) laden with whole genomic mtDNA as a mediator of this phenotype. Specifically, the treatment of hormone therapy (HT)-naive cells or HT-treated metabolically dormant populations with CAF-derived mtDNAhi EVs promoted an escape from metabolic quiescence and HTR disease both in vitro and in vivo. Moreover, this phenotype was associated with the acquisition of EV mtDNA, especially in cancer stem-like cells, expression of EV mtRNA, and restoration of OXPHOS. In summary, we have demonstrated that the horizontal transfer of mtDNA from EVs acts as an oncogenic signal promoting an exit from dormancy of therapy-induced cancer stem-like cells and leading to endocrine therapy resistance in OXPHOS-dependent breast cancer.

scholarly journals Fusobacterium nucleatum facilitates cetuximab resistance in colorectal cancer via the PI3K/AKT and JAK/STAT3 pathways

2020 ◽  
Author(s):  
Hu Han ◽  
Yan Li ◽  
Wan Qin ◽  
Lu Wang ◽  
Han Yin ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Fusobacterium Nucleatum ◽  
Therapy Resistance ◽  
Tumor Burden ◽  
Wild Type ◽  
Poor Clinical Outcome ◽  
Functional Studies ◽  
Cetuximab Therapy

AbstractInfectious pathogens contribute to about 20% of the total tumor burden. Fusobacterium nucleatum (Fn) has been associated with the initiation, progression, and therapy resistance in colorectal cancer (CRC). The over-abundance of Fn has been observed in patients with right-sided CRC than in those with left-sided CRC. While the KRAS/NRAS/BRAF wild-type status of the CRC conferred better response to cetuximab in patients with left-sided CRC than with right-sided CRC. However, treatment failure remains the leading cause of tumor relapse and poor clinical outcome in patients with CRC. Here, we have studied the association of Fn to cetuximab resistance. Our functional studies indicate that Fn facilitates resistance of CRC to cetuximab in vitro and in vivo. Moreover, Fn was found to target the PI3K/AKT and JAK/STAT3 pathways, which altered the response to cetuximab therapy. Therefore, assessing the levels and targeting Fn and the associated signaling pathways may allow modulating the treatment regimen and improve prognoses of CRC patients.

scholarly journals Dissecting targeted therapy resistance: Integrating models to quantify environment mediated drug resistance

2017 ◽  
Author(s):  
Noemi Picco ◽  
Erik Sahai ◽  
Philip K. Maini ◽  
Alexander R. A. Anderson
Keyword(s):  
Drug Resistance ◽  
Targeted Therapy ◽  
Targeted Therapies ◽  
Carrying Capacity ◽  
Conflicts Of Interest ◽  
Treatment Strategies ◽  
Model Systems ◽  
Significant Heterogeneity

AbstractDrug resistance is the single most important driver of cancer treatment failure for modern targeted therapies. This resistance may be due to the presence of dormant or aggressive tumor cell phenotypes or to context-driven protection. Non-malignant cells and other factors, constituting the microenvironment in which the tumor grows (the stroma), are now thought to play a crucial role in both therapeutic response and resistance. Specifically, the dialogue between the tumor and stroma has been shown to modulate the response to molecularly targeted therapies, through proliferative and survival signaling. The goal of this work is to investigate interactions between a growing tumor and its surrounding stroma in facilitating the emergence of drug resistance. We use mathematical modeling as a theoretical framework to bridge between experimental models and scales, with the aim of separating the intrinsic and extrinsic components of resistance in BRAF mutated melanoma. The model describes tumor-stroma dynamics both with and without treatment. Calibration of our model, through the integration of experimental data, revealed significant variation across animal replicates in either the intensity of stromal promotion or intrinsic tissue carrying capacity. Furthermore our study highlights the need to account for this variation in the design of treatment strategies. Major Findings. Through the integration of a simple mathematical model with in vitro and in vivo experimental growth dynamics of melanoma cell lines (both with and without drug), we were able to dissect the relative contributions of intrinsic versus environmental resistance. Our study revealed significant heterogeneity in vivo, indicating that there is a diversity of either stromal promotion or tumor carrying capacity under targeted therapy. We believe this variation may be one possible explanation for the heterogeneity observed across patients and within individual patients with multiple metastases. Therefore, quantifying this variation both within in vivo model systems and in individual patients could have a significant impact on the design of future treatment strategies that target both the tumor and stroma. Further, we present guidelines for building more effective and longer lasting therapeutic strategies utilizing our experimentally calibrated model. These strategies explicitly consider the protective nature of the stroma and utilize inhibitors that modulate it.PrecisQuantification of the environmental contribution to drug resistance reveals heterogeneity that significantly alters treatment dynamics that can be exploited for therapeutic gain.Financial SupportPicco and Anderson: US National Cancer Institute grant U01CA151924.Picco: UK Engineering and Physical Sciences Research Council (EPSRC grant number EP/G037280/1).Conflict of Interest DisclosureThe authors declare no potential conflicts of interest.

scholarly journals Cancer Models to Defeat Therapy Resistance in Pancreatic Ductal Adenocarcinoma

2021 ◽  
pp. 43-62
Author(s):  
Britney He
Keyword(s):  
Cancer Research ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Therapy Resistance ◽  
Model Systems ◽  
Ductal Adenocarcinoma ◽  
Multi Drug Resistance ◽  
In Vivo Models ◽  
Incidence And Mortality

One of the largest hurdles to the efficacy of cancer therapeutics, and a main cause of relapse, is therapy resistance. In response, researchers have developed model systems to better understand therapy resistance. Cancer research employs several model systems that reflect the biology of actual human tumors: in vitro models (2D, 3D cell cultures), in vivo models (PDX, GEMMS, transgenic), proteomic models, and computational or mathematical models. One cancer that has been extensively modeled is pancreatic ductal adenocarcinoma (PDAC). PDAC is the third most common cause of annual cancer deaths in developed countries; as its incidence and mortality rates continue to increase, PDAC is projected to be the second leading cause of cancer deaths by 2030. Although chemotherapy is a pillar of clinical PDAC treatment, its outcome typically leads to multi-drug resistance, drastically restricting the curative effect of drugs for a variety of tumors. Elucidating the underlying mechanisms for resistance through different models is essential for the development of new strategies and therapies. This review provides insight into the range of in vitro and in vivo models of pancreatic cancer used in preclinical research. This paper provides an overview of platforms for cancer research with a focus on those devoted to resistance mechanisms in PDAC and to the primary therapeutic intervention for PDAC, gemcitabine (GEM).

Investigating the Biological and Molecular Mechanisms Underpinning the Engraftment/Selection Advantage Conferred to Hematopoietic Stem Cells by HOXB4.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2101-2101
Author(s):  
Michael D. Milsom ◽  
Laura Hollins ◽  
Dorothy Gagen ◽  
Lorna B. Woolford ◽  
Leslie J. Fairbairn
Keyword(s):  
Molecular Mechanisms ◽  
Current Knowledge ◽  
Cellular Transformation ◽  
Model Systems ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Increased Risk ◽  
Vitro Analysis

Abstract We have recently demonstrated that co-expression of HOXB4 enables the enhanced delivery of HSC harbouring a second therapeutic trans-gene. Nonetheless, it is of great importance to elaborate the current knowledge about the mechanism of HOXB4 action in order to both evaluate the safety implications of its use in a clinical strategy, and to gain greater insight into the regulation of HSC self-renewal/expansion. To these ends we have performed an extensive in vitro analysis of the consequences of HOXB4 overexpression in primary murine BMC and in a murine multipotent myeloid progenitor cell line (FDCP-mix). We demonstrate for the first time in murine cells, that ectopic HOXB4 reduces the responsiveness of murine hematopoietic cells to differentiation stimuli. Furthermore, by performing a detailed investigation into the kinetics of FDCP-mix differentiation, we reveal that HOXB4 overexpression results in a specific differentiation delay as opposed to an outright block. We propose that an analogous delay is in operation in repopulating cells in order that the shift to increased assymetrical self-renewal, a requirement for stem cell expansion, is achieved. Notwithstanding this, it is clear that any perturbation in differentiation constitutes an increased risk of cellular transformation if this technology were transferred to a clinical setting. In order to further define the repercussions of ectopic HOXB4 delivery, we have developed a retroviral vector which encodes an activatable version of HOXB4. We have shown that this vector is able to mediate an in vitro differentiation delay in primary murine BMC and FDCP-mix as well as enable enhanced engraftment of BMC in vivo, both dependent upon the addition of the estrogen analogue; tamoxifen. Using this system, we are currently examining the effect of ectopic HOXB4 on the transcriptome of FDCP-mix cells, in addition to performing an in depth study into the biological mechanisms affected by HOXB4 overexpression in BMC in vivo. We envisage that these model systems will be particularly amenable to the manipulation required for target gene identification/validation.

Patient samples of renal cell carcinoma show reduced expression of TRAF1 compared with normal kidney and functional studies in vitro indicate TRAF1 promotes apoptosis: potential for targeted therapy

Pathology ◽  
2012 ◽  
Vol 44 (5) ◽  
pp. 453-459 ◽  
Author(s):  
Retnagowri Rajandram ◽  
Nigel C. Bennett ◽  
Zhiqiang Wang ◽  
Joanna Perry-Keene ◽  
David A. Vesey ◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Targeted Therapy ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Normal Kidney ◽  
Functional Studies

scholarly journals Loss of desmoglein-2 promotes gallbladder carcinoma progression and resistance to EGFR-targeted therapy through Src kinase activation

2020 ◽  
Author(s):  
Sang-Hyun Lee ◽  
Jin-Man Kim ◽  
Dong Gwang Lee ◽  
Jangwook Lee ◽  
Jong-Gil Park ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Gallbladder Carcinoma ◽  
Therapy Resistance ◽  
Lymphatic Invasion ◽  
Patient Response ◽  
Kinase Activation ◽  
Tumor Growth And Metastasis ◽  
Signaling Activation

Abstract Gallbladder carcinoma (GBC) exhibits poor prognosis due to local recurrence, metastasis, and resistance to targeted therapies. Using clinicopathological analyses of GBC patients along with molecular in vitro and tumor in vivo analysis of GBC cells, we showed that reduction of Dsg2 expression was highly associated with higher T stage, more perineural, and lymphatic invasion. Dsg2-depleted GBC cells exhibited significantly enhanced proliferation, migration, and invasiveness in vitro and tumor growth and metastasis in vivo through Src-mediated signaling activation. Interestingly, Dsg2 binding inhibited Src activation, whereas its loss activated cSrc-mediated EGFR plasma membrane clearance and cytoplasmic localization, which was associated with acquired EGFR-targeted therapy resistance and decreased overall survival. Inhibition of Src activity by dasatinib enhanced therapeutic response to anti-EGFR therapy. Dsg2 status can help stratify predicted patient response to anti-EGFR therapy and Src inhibition could be a promising strategy to improve the clinical efficacy of EGFR-targeted therapy.

scholarly journals Familial and congenital polycythemia in three unrelated families

Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 3019-3030 ◽  
Author(s):  
PD Emanuel ◽  
CJ Eaves ◽  
VC Broudy ◽  
T Papayannopoulou ◽  
MR Moore ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Southern Blot Analysis ◽  
Chromosomal Rearrangements ◽  
Colony Growth ◽  
Erythroid Progenitors ◽  
Epo Receptor ◽  
Functional Studies ◽  
Standard Assay ◽  
Or Gene

Abstract Three families with polycythemia inherited through apparently different modes are described. Secondary causes of polycythemia were ruled out. Erythropoietin (EPO) levels were normal or low, even after phlebotomy. In vitro erythroid colony growth in standard assay cultures containing EPO was normal; however, in the absence of added EPO, a few progenitors from most of the affected individuals were able to generate recognizable colonies of mature erythroblasts, although these were smaller and proportionately less numerous than seen in polycythemia vera (PV). To search for EPO-receptor changes as a possible pathophysiologic mechanism, we examined, by Southern blot analysis, genomic DNA samples from affected and nonaffected family members, as well as three patients with PV. Two different probes, derived from the human EPO-receptor, were used. We found no evidence for chromosomal rearrangements or gene amplification in hereditary polycythemia or PV patients. Further, no nucleotide sequences were found that were homologous to the Friend spleen focus-forming virus glycoprotein gp55, which has been shown to bind to and activate the murine EPO-receptor. Functional studies examining number and binding affinity of the EPO- receptor on erythroid progenitors from three hereditary polycythemia patients demonstrated no abnormalities. We conclude that the mechanism(s) for the erythrocytosis in familial and congenital polycythemia and in PV may not involve the EPO-receptor and, therefore, may result from alterations of postreceptor responses.

scholarly journals Familial and congenital polycythemia in three unrelated families

Blood ◽  
1992 ◽  
Vol 79 (11) ◽  
pp. 3019-3030
Author(s):  
PD Emanuel ◽  
CJ Eaves ◽  
VC Broudy ◽  
T Papayannopoulou ◽  
MR Moore ◽  
...  
Keyword(s):  
Genomic Dna ◽  
Southern Blot Analysis ◽  
Chromosomal Rearrangements ◽  
Colony Growth ◽  
Erythroid Progenitors ◽  
Epo Receptor ◽  
Functional Studies ◽  
Standard Assay ◽  
Or Gene

Three families with polycythemia inherited through apparently different modes are described. Secondary causes of polycythemia were ruled out. Erythropoietin (EPO) levels were normal or low, even after phlebotomy. In vitro erythroid colony growth in standard assay cultures containing EPO was normal; however, in the absence of added EPO, a few progenitors from most of the affected individuals were able to generate recognizable colonies of mature erythroblasts, although these were smaller and proportionately less numerous than seen in polycythemia vera (PV). To search for EPO-receptor changes as a possible pathophysiologic mechanism, we examined, by Southern blot analysis, genomic DNA samples from affected and nonaffected family members, as well as three patients with PV. Two different probes, derived from the human EPO-receptor, were used. We found no evidence for chromosomal rearrangements or gene amplification in hereditary polycythemia or PV patients. Further, no nucleotide sequences were found that were homologous to the Friend spleen focus-forming virus glycoprotein gp55, which has been shown to bind to and activate the murine EPO-receptor. Functional studies examining number and binding affinity of the EPO- receptor on erythroid progenitors from three hereditary polycythemia patients demonstrated no abnormalities. We conclude that the mechanism(s) for the erythrocytosis in familial and congenital polycythemia and in PV may not involve the EPO-receptor and, therefore, may result from alterations of postreceptor responses.

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