Therapeutic targeting of extracellular FGFR2 activating deletions in intrahepatic cholangiocarcinoma.

2020 ◽  
Vol 38 (4_suppl) ◽  
pp. 567-567 ◽  
Author(s):  
James M. Cleary ◽  
Srivatsan Raghavan ◽  
Yvonne Y. Li ◽  
Liam Spurr ◽  
Qibiao Wu ◽  
...  
Keyword(s):  
Intrahepatic Cholangiocarcinoma ◽  
Acquired Resistance ◽  
Growth Factor Receptor ◽  
Extracellular Domain ◽  
Kinase Domain ◽  
Genomic Alteration ◽  
Resistance Mutations ◽  
Clinical Sensitivity

567 Background: Fibroblast growth factor receptor (FGFR) pathway alterations have been identified in approximately 20% of patients (pts) with intrahepatic cholangiocarcinoma (IHCC), most commonly by FGFR2 fusions. Early phase clinical trials have demonstrated encouraging efficacy of FGFR inhibitors in pts with FGFR2-translocated cholangiocarcinoma, but efficacy in pts with other FGFR2 activating alterations is less clear. Methods: Pts with cholangiocarcinoma underwent CLIA-certified next generation DNA sequencing (NGS) to identify actionable alterations. FGFR2 fusions and other FGFR2 genomic events were assessed, with genomic characterization performed before and after treatment with FGFR inhibitors in appropriate pts. Novel extracellular domain in-frame deletions (INDELs) of FGFR2 and apparent resistance mutations were investigated for oncogenic activity and inhibitor resistance in vitro and in vivo. Results: Cholangiocarcinomas from 284 pts (136 male, 148 female; median age, 64 [20-89], including 139 IHCCs, were sequenced. Among the IHCCs, 16 (11.5%) had FGFR2 fusions, with 9 different gene partners. Surprisingly, 5 (3.6%) IHCCs harbored extracellular domain FGFR2 INDELs. Two of these IHCCs harbored an exon 5 deletion FGFR2 p.H167_N173del. Expression of FGFR2 p.H167_N173del in 3T3 cells resulted in oncogenic transformation. In the clinic, two pts with FGFR2 p.H167_N173del were treated with Debio1347, an oral FGFR-1/2/3 inhibitor. Both patients achieved a durable partial response (PR) of 11 months, with one of the pts still on active treatment with Debio-1347. The patient who developed acquired resistance underwent repeat biopsy, and NGS identified a secondary mutation ( FGFR2 p. L617F) in the kinase domain. In vitro studies demonstrated that this mutation confers resistance to Debio1347. This patient was subsequently treated with another FGFR inhibitor and again experienced a PR lasting 17 months. A third biopsy after disease progression demonstrated a previously undetected L597Q BRAF mutation. Conclusions: Extracellular domain FGFR2 in-frame deletions are a novel genomic alteration in IHCC that are transforming and predict clinical sensitivity to FGFR inhibitors.

scholarly journals Normal cellular and transformation-associated abl proteins share common sites for protein kinase C phosphorylation.

1987 ◽  
Vol 7 (12) ◽  
pp. 4280-4289 ◽  
Author(s):  
A M Pendergast ◽  
J A Traugh ◽  
O N Witte
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Growth Factor Receptor ◽  
Kinase Domain ◽  
Kinase Assay ◽  
Amino Terminal ◽  
Kinase C ◽  
Carboxy Terminal

Viral transduction and chromosomal translocations of the c-abl gene result in the synthesis of abl proteins with structurally altered amino termini. These altered forms of the abl protein, but not the c-abl proteins, are detectably phosphorylated on tyrosine in vivo. In contrast, all forms of the abl protein are phosphorylated on serine following in vivo labeling with Pi. Treatment of NIH-3T3 cells with protein kinase C activators resulted in a four- to eightfold increase in the phosphorylation of murine c-abl due to modification of two serines on the c-abl protein. Purified protein kinase C phosphorylated all abl proteins at the same two sites. Both sites are precisely conserved in murine and human abl proteins. The sites on the abl proteins were found near the carboxy terminus. In contrast, for the epidermal growth factor receptor (T. Hunter, N. Ling, and J. A. Cooper, Nature [London] 311:480-483, 1984) and pp60src (K. L. Gould, J. R. Woodgett, J. A. Cooper, J. E. Buss, D. Shalloway, and T. Hunter, Cell 42:849-857, 1985), the sites of protein kinase C phosphorylation are amino-terminal to the kinase domain. The abl carboxy-terminal region is not necessary for the tyrosine kinase activity or transformation potential of the viral abl protein and may represent a regulatory domain. Using an in vitro immune complex kinase assay, we were not able to correlate reproducible changes in c-abl activity with phosphorylation by protein kinase C. However, the high degree of conservation of the phosphorylation sites for protein kinase C between human and mouse abl proteins suggests an important functional role.

scholarly journals Recapitulation in Saccharomyces cerevisiae of Cytochrome b Mutations Conferring Resistance to Atovaquone in Pneumocystis jiroveci

2003 ◽  
Vol 47 (9) ◽  
pp. 2725-2731 ◽  
Author(s):  
Philip Hill ◽  
Jacques Kessl ◽  
Nicholas Fisher ◽  
Steven Meshnick ◽  
Bernard L. Trumpower ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Drug Resistance ◽  
Efflux Pump ◽  
Pathogenic Fungus ◽  
Acquired Resistance ◽  
Resistance Mutations ◽  
Pneumocystis Jiroveci ◽  
Pump System

ABSTRACT Pneumocystis jiroveci (human-derived P. carinii) is an opportunistic pathogenic fungus which causes pneumonia and is life-threatening in immunocompromised individuals. Spontaneously acquired resistance to atovaquone, a hydroxynaphthoquinone that is used to treat P. jiroveci infections, was linked to mutations in the mitochondrially encoded cytochrome b gene. Because P. jiroveci cannot be easily cultivated, we have developed Saccharomyces cerevisiae as an alternative system to study atovaquone resistance mutations. In this work, we introduced seven mutations linked with atovaquone resistance in P. jiroveci into the S. cerevisiae cytochrome b gene. The effects of the mutations on the respiratory function and on the sensitivity to the inhibitor were then characterized. Six of the reported mutations lowered the sensitivity of the S. cerevisiae bc 1 complex to atovaquone, while one mutation had no effect on the drug resistance. These results were confirmed by monitoring the in vivo resistance of S. cerevisiae mutants which carried both the cytochrome b mutations and a deletion of the ABC transporter genes, allowing the drug to bypass the weakened efflux pump system. S. cerevisiae thus provides an easy-to-use system to characterize in vivo and in vitro cytochrome b mutations reported in pathogens and to assess their role in drug resistance.

scholarly journals PKCδ-mediated SGLT1 upregulation confers the acquired resistance of NSCLC to EGFR TKIs

Oncogene ◽  
2021 ◽  
Author(s):  
Chia-Hung Chen ◽  
Bo-Wei Wang ◽  
Yu-Chun Hsiao ◽  
Chun-Yi Wu ◽  
Fang-Ju Cheng ◽  
...  
Keyword(s):  
Glucose Uptake ◽  
Kinase Inhibitors ◽  
Acquired Resistance ◽  
Growth Factor Receptor ◽  
Tki Treatment ◽  
Nsclc Patients ◽  
Egfr Tki ◽  
Egfr Tkis

AbstractThe tyrosine kinase inhibitors (TKIs) targeting epidermal growth factor receptor (EGFR) have been widely used for non-small cell lung cancer (NSCLC) patients, but the development of acquired resistance remains a therapeutic hurdle. The reduction of glucose uptake has been implicated in the anti-tumor activity of EGFR TKIs. In this study, the upregulation of the active sodium/glucose co-transporter 1 (SGLT1) was found to confer the development of acquired EGFR TKI resistance and was correlated with the poorer clinical outcome of the NSCLC patients who received EGFR TKI treatment. Blockade of SGLT1 overcame this resistance in vitro and in vivo by reducing glucose uptake in NSCLC cells. Mechanistically, SGLT1 protein was stabilized through the interaction with PKCδ-phosphorylated (Thr678) EGFR in the TKI-resistant cells. Our findings revealed that PKCδ/EGFR axis-dependent SGLT1 upregulation was a critical mechanism underlying the acquired resistance to EGFR TKIs. We suggest co-targeting PKCδ/SGLT1 as a potential strategy to improve the therapeutic efficacy of EGFR TKIs in NSCLC patients.

Preclinical evaluation of SIM1803-1A, a small molecule Trk/ROS1 dual inhibitor for wild and mutate NTRK/ROS1 fusion solid malignancies.

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e21663-e21663
Author(s):  
Jianfei Wang ◽  
xiaohong yu ◽  
Shunwei Zhu ◽  
Qingying Chen ◽  
Jikui Sun ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Cell Lines ◽  
Acquired Resistance ◽  
Antitumor Efficacy ◽  
Resistance Mutations ◽  
Dual Inhibitor ◽  
Pediatric Tumor ◽  
Solid Malignancies

e21663 Background: Fusions and rearrangements of NTRK1/2/3 and ROS1 genes are oncogenic drivers in multiple solid malignancies. Drugs targeting tyrosine kinases TrkA/B/C and ROS1, such as larotrectinib and entrectinib, are proven highly efficacious in diverse adult and pediatric tumor types (ORR > 75%). However, the treatment-related drug resistance, including S.F. mutations, G.K. mutations and DFGx mutations, has been identified in clinical trials. The use of second generation of TKI, such as repotrectinib to against these acquired resistance mutations, has been explored in clinical trials and reported unsatisfied efficacy in patients under acceptable dosages, which might due to its broader inhibition of multiple kinases. Here we report a novel potent Trk/ROS1 dual inhibitor SIM1803-1A, targeting both the wild type and multiple clinical mutations of Trk and ROS1 with clean selectivity profile and expected in vitro and in vivo efficacy for wild and mutant NTRK/ROS1 fusion solid tumors. Methods: Kinase inhibiting potency was determined with Reaction Biology kinase assays. Kinase selectivity was screened on Eurofins Kinase Profiler panel. Cellular anti-proliferative potency was evaluated on relevant fusion cell lines. Antitumor efficacy was evaluated in the related CDX and PDX mice models shown in results. Results: SIM1803-1A displayed high kinase inhibiting potency with IC50 3.64/1.24 /4.45 nM on TrkA( WT/G595R/G667C) kinase, 0.07/5.03/5.68 nM on TrkC( WT/G623R/L686M), and 0.08/0.10 nM on ROS1( WT/G2032R) respectively. A clean selectivity profile was also identified in 112 enzymes from TK and TKL family at 0.5 µM. The proliferation inhibition IC50 of SIM1803-1A in following cell lines were: 0.3 nM on KM12 TPM3-NTRK1, 2.2/0.9/5.7/5.6 nM on Ba/F3 LMNA-NTRK1( WT/F589L/G595R/G667A), 2.9/6.2 nM on Ba/F3 ETV6-NTRK3( WT/G623R), and 7.3/15.0 nM on Ba/F3 SLC34A2-ROS1(WT/G2032R) respectively. SIM1803-1A showed high antitumor efficacy in the subcutaneous colon cancer KM12 TPM3-NTRK1 CDX model with 68% and 80% TGI at 1 and 3 mg/kg (bid) dosing, and similar high efficacy in the subcutaneous NSCLC LU-01-0414 SDC4-ROS1 PDX model with 60% and 74% TGI at 1 and 3 mg/kg (bid) dosing. Conclusions: Collectively, these studies have shown SIM1803-1A is a potent Trk/ROS1 dual inhibitor with better safety potentially from improved kinase selectivity. SIM1803-1A is currently at IND submission stage and represents a promising clinical candidate for the treatment-naïve and acquired-resistance NTRK/ROS1 fusion-positive malignancies.

Normal cellular and transformation-associated abl proteins share common sites for protein kinase C phosphorylation

1987 ◽  
Vol 7 (12) ◽  
pp. 4280-4289
Author(s):  
A M Pendergast ◽  
J A Traugh ◽  
O N Witte
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Growth Factor Receptor ◽  
Kinase Domain ◽  
Kinase Assay ◽  
Amino Terminal ◽  
Kinase C ◽  
Carboxy Terminal

Viral transduction and chromosomal translocations of the c-abl gene result in the synthesis of abl proteins with structurally altered amino termini. These altered forms of the abl protein, but not the c-abl proteins, are detectably phosphorylated on tyrosine in vivo. In contrast, all forms of the abl protein are phosphorylated on serine following in vivo labeling with Pi. Treatment of NIH-3T3 cells with protein kinase C activators resulted in a four- to eightfold increase in the phosphorylation of murine c-abl due to modification of two serines on the c-abl protein. Purified protein kinase C phosphorylated all abl proteins at the same two sites. Both sites are precisely conserved in murine and human abl proteins. The sites on the abl proteins were found near the carboxy terminus. In contrast, for the epidermal growth factor receptor (T. Hunter, N. Ling, and J. A. Cooper, Nature [London] 311:480-483, 1984) and pp60src (K. L. Gould, J. R. Woodgett, J. A. Cooper, J. E. Buss, D. Shalloway, and T. Hunter, Cell 42:849-857, 1985), the sites of protein kinase C phosphorylation are amino-terminal to the kinase domain. The abl carboxy-terminal region is not necessary for the tyrosine kinase activity or transformation potential of the viral abl protein and may represent a regulatory domain. Using an in vitro immune complex kinase assay, we were not able to correlate reproducible changes in c-abl activity with phosphorylation by protein kinase C. However, the high degree of conservation of the phosphorylation sites for protein kinase C between human and mouse abl proteins suggests an important functional role.

scholarly journals FGFR2 fusion protein-driven mouse models of intrahepatic cholangiocarcinoma unveil a necessary role for Erk signaling

2020 ◽  
Author(s):  
Giulia Cristinziano ◽  
Manuela Porru ◽  
Dante Lamberti ◽  
Simonetta Buglioni ◽  
Francesca Rollo ◽  
...  
Keyword(s):  
Intrahepatic Cholangiocarcinoma ◽  
Clinical Studies ◽  
Kinase Inhibitors ◽  
Single Agent ◽  
Growth Factor Receptor ◽  
Erk Signaling ◽  
Cellular Models ◽  
Liver Organoids

AbstractBackground and aimsAbout 15% of intrahepatic cholangiocarcinoma (iCCA) express fibroblast growth factor receptor 2 (FGFR2) fusion proteins (FFs), most often in concert with mutationally inactivated TP53, CDKN2A or BAP1. FFs span residues 1-768 of FGFR2 fused to sequences encoded by any of a long list (>60) of partner genes, a configuration sufficient to ignite oncogenic FF activation. In line, FGFR-specific tyrosine kinase inhibitors (F-TKI) were shown to provide clinical benefit in FF+ iCCA, although responses were partial and/or limited by resistance mechanisms, including the FF V565F gatekeeper mutation. Herein we present an FF-driven murine iCCA model and exploit its potential for pre-clinical studies on FF therapeutic targeting.MethodsFour iCCA FFs carrying different fusion sequences were expressed in Tp53-/- mouse liver organoids. Tumorigenic properties of genetically modified liver organoids were assessed by intrahepatic/subcutaneous transplantation in immuno-deficient mice. Cellular models derived from neoplastic lesions were exploited for pre-clinical studies.ResultsTumors diagnosed as CCA were obtained upon transplantation of FF-expressing liver organoids. The penetrance of this tumorigenic phenotype was influenced by FF identity. Tumor organoids and 2D cell lines derived from CCA lesions were addicted to FF signaling via Ras-Erk, regardless of FF identity or presence of V565F mutation. Double blockade of FF-Ras-Erk pathway by concomitant pharmacological inhibition of FFs and Mek1/2 provided greater therapeutic efficacy than single agent F-TKI in vitro and in vivo.ConclusionsFF-driven iCCA pathogenesis was successfully modelled in murine Tp53-/- background. This model revealed biological heterogeneity among structurally different FFs. Double blockade of FF-Erk signaling deserves consideration for improving precision-based approaches against human FF+ iCCA.

Toxicity and efficacy evaluation of multiple targeted polymalic acid conjugates for triple-negative breast cancer treatment

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Triple Negative ◽  
Growth Factor Receptor ◽  
Engineered Nanoparticles ◽  
Efficacy Evaluation ◽  
Dual Action ◽  
Epidermal Growth ◽  
Laminin 411 ◽  
Immunologic Analysis

Engineered nanoparticles are widely used for delivery of drugs but frequently lack proof of safetyfor cancer patient's treatment. All-in-one covalent nanodrugs of the third generation have beensynthesized based on a poly(β-L-malic acid) (PMLA) platform, targeting human triple-negativebreast cancer (TNBC). They significantly inhibited tumor growth in nude mice by blockingsynthesis of epidermal growth factor receptor, and α4 and β1 chains of laminin-411, the tumorvascular wall protein and angiogenesis marker. PMLA and nanodrug biocompatibility and toxicityat low and high dosages were evaluated in vitro and in vivo. The dual-action nanodrug and singleactionprecursor nanoconjugates were assessed under in vitro conditions and in vivo with multipletreatment regimens (6 and 12 treatments). The monitoring of TNBC treatment in vivo withdifferent drugs included blood hematologic and immunologic analysis after multiple intravenousadministrations. The present study demonstrates that the dual-action nanoconju-gate is highlyeffective in preclinical TNBC treatment without side effects, supported by hematologic andimmunologic assays data. PMLA-based nanodrugs of the Polycefin™ family passed multipletoxicity and efficacy tests in vitro and in vivo on preclinical level and may prove to be optimizedand efficacious for the treatment of cancer patients in the future.

scholarly journals The roles and prognostic significance of ABI1-TSV-11 expression in patients with left-sided colorectal cancer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yu Zhang ◽  
Zhaohui Zhong ◽  
Mei Li ◽  
Jingyi Chen ◽  
Tingru Lin ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Prognostic Significance ◽  
Growth Factor Receptor ◽  
The Cancer Genome Atlas ◽  
Actin Dynamics ◽  
Elevated Expression ◽  
Sw480 Cells ◽  
And Migration

AbstractAbnormally expressed and/or phosphorylated Abelson interactor 1 (ABI1) participates in the metastasis and progression of colorectal cancer (CRC). ABI1 presents as at least 12 transcript variants (TSVs) by mRNA alternative splicing, but it is unknown which of them is involved in CRC metastasis and prognosis. Here, we firstly identified ABI1-TSV-11 as a key TSV affecting the metastasis and prognosis of left-sided colorectal cancer (LsCC) and its elevated expression is related to lymph node metastasis and shorter overall survival (OS) in LsCC by analyzing data from The Cancer Genome Atlas and TSVdb. Secondly, ABI1-TSV-11 overexpression promoted LoVo and SW480 cells adhesion and migration in vitro, and accelerated LoVo and SW480 cells lung metastasis in vivo. Finally, mechanism investigations revealed that ABI1-isoform-11 interacted with epidermal growth factor receptor pathway substrate 8 (ESP8) and regulated actin dynamics to affect LoVo and SW480 cells biological behaviors. Taken together, our data demonstrated that ABI1-TSV-11 plays an oncogenic role in LsCC, it is an independent risk factor of prognosis and may be a potential molecular marker and therapeutic target in LsCC.

scholarly journals Techniques for the Assessment of In Vitro and In Vivo Antifungal Combinations

2021 ◽  
Vol 7 (2) ◽  
pp. 113
Author(s):  
Anne-Laure Bidaud ◽  
Patrick Schwarz ◽  
Guillaume Herbreteau ◽  
Eric Dannaoui
Keyword(s):  
Animal Models ◽  
Fungal Infections ◽  
Acquired Resistance ◽  
Adequate Treatment ◽  
Combination Treatments ◽  
Target Organs ◽  
Fungal Load ◽  
Time Kill

Systemic fungal infections are associated with high mortality rates despite adequate treatment. Moreover, acquired resistance to antifungals is increasing, which further complicates the therapeutic management. One strategy to overcome antifungal resistance is to use antifungal combinations. In vitro, several techniques are used to assess drug interactions, such as the broth microdilution checkerboard, agar-diffusion methods, and time-kill curves. Currently, the most widely used technique is the checkerboard method. The aim of all these techniques is to determine if the interaction between antifungal agents is synergistic, indifferent, or antagonistic. However, the interpretation of the results remains difficult. Several methods of analysis can be used, based on different theories. The most commonly used method is the calculation of the fractional inhibitory concentration index. Determination of the usefulness of combination treatments in patients needs well-conducted clinical trials, which are difficult. It is therefore important to study antifungal combinations in vivo, in experimental animal models of fungal infections. Although mammalian models have mostly been used, new alternative animal models in invertebrates look promising. To evaluate the antifungal efficacy, the most commonly used criteria are the mortality rate and the fungal load in the target organs.

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