Differential response of primary or secondary exon 13/14 and exon 17 c-kit mutant to nilotinib and sunitinib: Findings from a cell-based drug-screening platform

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e15636-e15636
Author(s):  
C. Chan ◽  
L. Chen ◽  
Y. Hsueh ◽  
W. Chuang ◽  
H. Lee ◽  
...  
Keyword(s):  
Double Mutant ◽  
Kinase Inhibitors ◽  
Acquired Resistance ◽  
Differential Response ◽  
Imatinib Treatment ◽  
Kit Mutation ◽  
Mutant Genotype ◽  
Exon 9 ◽  
Screening Platform ◽  
Exon 11

e15636 Background: Gastrointestinal stromal tumors (GIST) are frequently associated with mutation of c-kit oncogene that is accompanied with constitutional activation of c-kit protein. At present, imatinib is the drug of choice for unresectable or metastatic GIST, however, primary or acquired resistance to imatinib is frequently associated with the presence of an exon 13, 14 or 17 c-kit mutation. The current recommendations for GIST refractory to standard (400 mg/day) imatinib treatment include increasing dose of imatinib to 600–800 mg/day for tumors with primary exon 9 mutation or sunitinib. Several molecular targeted agents are also under investigation. With so many potential agents, personalized therapy based on c-kit mutant genotype for imatinib-resistant GIST deserves to explore. Methods: We prepared a series of c-kit cDNA constructs encoding mutant exon 9 (502AY insertion), 11 (V560D substitution and Δ555–576 deletion), 13 (V654A substitution), 14 (T670I substitution) and 17 (D820G and N822K substitutions) either alone or in combination to simulating the frequently occurred primary ± secondary c-kit mutants in GIST. We expressed these constructs in COS-1 cells to study the efficacy of different tyrosine kinase inhibitors (TKIs) on the autophosphorylation of various single or double mutant c- kit. Results: The efficacy of imatinib on single c-kit mutant was V560D > Δ555–576 > 502AY > D820G or N822K, and ineffective for single and double mutants containing V654A or T670I. Sunitinib is a more potent inhibitor for single 502AY, D820G and N822K mutant than imatinib and nilotinib; while single V654A and T670I c-kit mutant are more sensitive to nilotinib. Interestingly, double exon 11 (V560D or Δ555–576)/V654A or T670I mutant c-kit are more sensitive to sunitinib; while exon 11 (V560D or Δ555–576)/D820G or N822K double mutant c-kit are more sensitive to nilotinib. Conclusions: Our system provides a useful platform to select/screen effective TKIs for GIST with single or double mutant c-kit. The findings of differential response of c-kit mutant to nilotinib and sunitinib may help to select therapy for GIST with primary or secondary exon 13 / 14 and exon 17 mutations. [Table: see text]

Whole exome analysis of patients (pts) with metastatic GIST (mGIST) demonstrating exceptional survival with imatinib (IM) therapy compared to those with short term benefit.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 11513-11513
Author(s):  
Eytan Ben Ami ◽  
Sophia C. Kamran ◽  
Suzanne George ◽  
Jeffrey A. Morgan ◽  
Andrew J. Wagner ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Kinase Inhibitors ◽  
Response Modulation ◽  
Short Term ◽  
Kit Mutation ◽  
Whole Exome ◽  
Exon 9 ◽  
Exon 11 ◽  
Term Benefit

11513 Background: Most patients with mGIST initially benefit from IM therapy with durable disease control (DC), i.e. objective responses and stable disease, with median duration of approximately two years. We reported exceptional long-term benefit (LTB) with DC and overall survival (OS) >14 years in a subset of mGIST pts treated with IM. We aimed to characterize tumor and normal genomes of exceptional LTB pts treated with IM and compare with short-term benefit (STB) pts. Methods: Among 87 mGIST pts enrolled between July 2000 and June 2001 in the B2222 trial of IM and followed prospectively at the Dana Farber Cancer Institute, we identified 10 LTB (>14 years of DC) pts, and 6 STB (<2 years of DC) pts on IM. Targeted genotyping ( KIT/PDGFRA)was performed in all tumors (n=16). Whole exome sequencing (WES) was performed on archival FFPE tumor samples from LTB and STB pts prior to any IM treatment. We compared WES results from LTB with STB pts to identify unique features of long-term DC and OS with IM. Results: KIT mutation in LTB pts were as follows: exon 11(6 pts), exon 9 (3 pts), and SDH-deficient with KIT/PDGFRA wild type (1 pt). In STB pts, mutated KITwas found 4 pts (exon 11) and 2 pts (exon 9). WES was successful in six LTB (five exon 11, one exon 9) and three STB (two exon 11, one exon 9) pts. A total of 1211 somatic mutations were observed (546 missense, 37 nonsense, 256 silent, 285 indels, 36 splice mutations). The mean somatic mutational burden was 3.42 mutations/Mb (range 1.18-4.93) and 3.34 mutations/Mb (range 1.06-6.68) among LTB and STB, respectively. Genes mutated in LTB but not in STB were MUC7 (4 pts), H1F0 (3 pts), ZKSCAN1 (3 pts), SLC24A1 (3 pts) and USP4 (2 pts). Conclusions: KRAB domain containing zinc finger (KRAB-ZNF) gene expression signatures have been associated with prediction of response to IM, and a possible role in response modulation to tyrosine kinase inhibitors in GIST. We found variants in ZKSCAN1, a gene encoding a transcriptional regulator of the KRAB subfamily of zinc finger, to be present in LTB but not in STB. KRAB-ZNF family of genes may be linked to LTB and exceptional survival with IM in mGIST; functional analyses will be important to test such hypotheses.

scholarly journals Unraveling the spectrum of KIT mutations in gastrointestinal stromal tumors: An Indian Tertiary Cancer Center Experience

2017 ◽  
Vol 06 (03) ◽  
pp. 113-117 ◽  
Author(s):  
Trupti Pai ◽  
Munita Bal ◽  
Omshree Shetty ◽  
Mamta Gurav ◽  
Vikas Ostwal ◽  
...  
Keyword(s):  
Gastrointestinal Stromal Tumors ◽  
Complete Analysis ◽  
Cancer Center ◽  
Kit Mutation ◽  
Stromal Tumors ◽  
Molecular Alterations ◽  
Kit Gene ◽  
Exon 9 ◽  
Substitution Mutations ◽  
Exon 11

Abstract Background: Primary mutations in the KIT gene are the driving force for gastrointestinal stromal tumors (GIST) tumorigenesis. Predictive role of KIT mutation status aids oncologists in patient management. There is a paucity of comprehensive data on the frequency of mutations in the KIT gene in GIST affecting Indian patients. The aims of this study were to determine the frequency and spectrum of molecular alterations affecting the KIT gene and assess their association with clinicopathologic features in a cohort of patients of GIST. Materials and Methods: Morphological and immunohistochemically confirmed GIST cases (n = 114) accessioned from August 2014-June 2015 were analyzed for mutations in KIT exons 9, 11, 13, and 17 and subjected to Sanger sequencing onto the ABI 3500 Genetic Analyzer. The sequences were analyzed using sequence analysis software: SeqScape® and Chromas Lite. Results: KIT mutations were seen in 70% of cases and the majority of KIT mutations involved exon 11 (57%), followed by exon 9 (10%), exon 13 (3%), and exon 17 (1%). Most common exon 11 mutations were in-frame deletions (61.4%) followed by substitution mutations (19.3%). Exon 9 mutations showed identical duplication of Ala-Tyr at codons 502–503. Simultaneous mutations affecting exon 11 and 13 were discovered. Novel variations, namely, p.Q556E (c.1666C>G), p.Q556dup (c.1666_1668dupCAG), p.K558_V559delinsS (c.1672_1677delAAGGTTinsAGT), p.Y503_F504insTY (c.1509_1510insACCTAT), and p.K642R (c.1925A>G) involving exons 11, 9, and 13, respectively, were observed. Interpretation and Conclusions: First study with complete analysis of all 4 exons of KIT (exons 9, 11, 13, and 17) in Indian GIST patients. Along with well-described KIT mutations, several rare double mutations as well as novel alterations were reported in this series.

scholarly journals Cutaneous Hyperpigmentation and Familial Gastrointestinal Stromal Tumor Associated with Germline KIT Mutation Treated with Imatinib

2020 ◽  
Author(s):  
Wei Yuan ◽  
Wen Huang ◽  
Lei Ren ◽  
Chen Xu ◽  
Lijuan Luan ◽  
...  
Keyword(s):  
Abdominal Pain ◽  
Gastrointestinal Stromal Tumor ◽  
Mutational Analysis ◽  
Direct Sequencing ◽  
Correct Diagnosis ◽  
Saliva Sample ◽  
Stromal Tumor ◽  
Imatinib Treatment ◽  
Kit Mutation ◽  
Exon 11

Abstract Background: Familial gastrointestinal stromal tumor (GIST) has been identified with multiple GISTs containing the mutations in germline KIT and PDGFRA. There are only 35 kindreds with germline KIT and 6 with PDGFRA mutations have been reported so far. Familial GIST is often characterized by a series of manifestations, such as multiple lesions, hyperpigmentation, mastocytosis, and dysphagia. Only some kindreds have response to imatinib treatment.Materials and Methods: A 25-year-old Chinese woman went to hospital because of the abdominal pain, and through the computed tomography (CT) scan showed us the multiple tumors in the small intestine. Her father had a history of multifocal GISTs, and referred to the hospital with abdominal pain and tumor recurrences last year. Immuhistochemical analysis of CD117 and DOG-1 were performed on tumor samples from the two patients, while KIT mutational analysis was carried out by direct sequencing on DNA from paraffin-embedded specimens and saliva sample.Results: Multiple GISTs associated with diffuse interstitial cells of Cajal (ICC) hyperplasia were illustrated in these two patients. These tumors were positive for CD117 and DOG-1. The germline mutation at codon 560 of exon 11 (p.V560G) of the KIT gene were found. The treatment with imatinib resulted in favorable responses in both tumor and cutaneous hyperpigmentation.Conclusions: It is difficult to make a correct diagnosis of familial GIST at first time for its rarity. This case was finally diagnosed as familial GIST depending on the combination of diffuse ICC hyperplasia, germline KIT mutation, hyperpigmentation and its family history.

Predictive value of KIT immunohistochemical staining for KIT mutations in patients with gastrointestinal stromal tumors (GIST): A systematic review.

2012 ◽  
Vol 30 (4_suppl) ◽  
pp. 30-30
Author(s):  
Nay Min Tun ◽  
Gina M. Villani
Keyword(s):  
Systematic Review ◽  
Predictive Value ◽  
Immunohistochemical Staining ◽  
Mutational Analysis ◽  
Predictive Values ◽  
Kit Mutation ◽  
Medline Search ◽  
Mesh Terms ◽  
Exon 9 ◽  
Exon 11

30 Background: Immunohistochemical staining for KIT (CD117) is used as part of diagnostic tool for GIST. Approximately 95% of GIST are known to be positive for CD117. Studies have shown that not all CD117-positive GIST carry KIT mutations nor does CD117 negativity rule out KIT or PDGFRA mutations. We performed a systematic review to investigate the positive and negative predictive values of KIT immunostaining for KIT mutations in GIST. Methods: A Medline search of the MeSH terms “KIT mutation” and “GIST” and “prevalence” yielded 54 articles from year 1999 to 2011. English language studies on GIST with data available for KIT immunostaining as well as KIT gene mutations were included. Studies lacking data on either CD117 positivity or KIT mutations were excluded. Immunostaining was done using Dako polyclonal rabbit antibody or PKCh monoclonal mouse antibody in eligible studies. Denaturing high-pressure liquid chromatography (DHPLC) was used to screen mutations in majority of eligible studies, and ABI Prism Genetic Analyzer to sequence DNA. Results: 6 studies including 708 CD117-positive GIST patients were eligible for analysis of positive predictive value of KIT immunostaining for KIT mutations and 5 studies including 47 CD117-negative GIST patients for negative predictive value. Many studies were excluded due to insufficient data on CD117 positivity or KIT mutational analysis. 72.8% of CD117-positive GIST tumors carried KIT mutations (exon 11 62.2%, exon 9 10.2%, exon 13 1.8% and exon 17 1%), and 4.1% harbored PDGFRA mutations. In contrast, 74.5% of CD117-negative GIST tumors did not have KIT mutations. 25.5% of CD117-negative GIST harbored KIT exon 11 mutations (no mutations in exon 9, 13 or 17 were observed). In addition, 30% of CD117-negative GIST were found to have PDGFRA mutations. Conclusions: PDGFRA mutations were found to be 7 times more common in CD117-negative than in CD117-positive GIST (30% vs. 4.1%). Over half (55.5%) of CD117-negative GIST carried KIT exon 11 or PDGFRA mutations. We recommend mutational analysis in all tumors clinically suspected of GIST and that are CD117-negative for two reasons: 1. in order to make a diagnosis, and 2. to help tailor therapy.

scholarly journals KIT Mutation Incidence and Pattern of Melanoma in Central Europe

2019 ◽  
Vol 26 (1) ◽  
pp. 17-22 ◽  
Author(s):  
V. Doma ◽  
T. Barbai ◽  
M.-A. Beleaua ◽  
I. Kovalszky ◽  
E. Rásó ◽  
...  
Keyword(s):  
Mutation Rate ◽  
Cutaneous Melanoma ◽  
Mutation Frequency ◽  
Mucosal Melanoma ◽  
Wild Type ◽  
Mutation Site ◽  
Kit Mutation ◽  
Central European ◽  
Exon 9 ◽  
Exon 11

AbstractData on the KIT mutation rate in melanoma in the central European region is missing. Accordingly, in a cohort of 79 BRAF/NRAS double wild type cutaneous melanoma and 17 mucosal melanoma KIT mutation was assessed by Sanger sequencing of exons 9,11,13,17 and 18. In this cutaneous melanoma cohort KIT mutation frequency was found to be 34/79 (43.04%) with a significantly higher rate in acrolentiginous melanoma (ALM) as compared to UV-induced common variants (20/34, 58.8% versus 14/45, 31.1%, p = 0.014). In the double wild type mucosal melanoma cohort the KIT mutation frequency was found to be comparable (41.2%). The actual frequency of KIT mutation in the original 227 patient cutaneous melanoma cohort was 34/227, 14.9%. Exon 11 was the most frequent mutation site (44.7%) followed by exon 9 (21.1%) equally characterizing UV-induced common histotypes and ALM tumors. In mucosal melanoma exon 9 was the most frequently involved exon followed by exon 13 and 17. KIT mutation hotspots were identified in exon 9 (c482/491/492), in exon 11 (c559,c572, c570), in exon 13 (c642), in exon 17 (c822) and in exon 18 (c853). The relatively high KIT mutation rate in cutaneous melanoma in this central-European cohort justifies regular testing of this molecular target in this entity, not only in mucosal variants.

Clinical significance of mutational status in gastrointestinal stromal tumors (GIST).

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e20501-e20501
Author(s):  
Peter Arkhiri ◽  
Ivan S. Stilidi ◽  
I. Poddubnaya ◽  
Maxim P. Nikulin ◽  
Natalia Tsymzhitova ◽  
...  
Keyword(s):  
Survival Rate ◽  
Poor Prognosis ◽  
Kinase Inhibitors ◽  
Stromal Tumors ◽  
Mutational Status ◽  
Significant Difference ◽  
Localized Disease ◽  
Exon 9 ◽  
Small Intestinal ◽  
Exon 11

e20501 Background: Mutational status of GIST patients plays an important role in clinical practice. In most cases, mutations are localized in KIT exon 11. KIT exon 9 mutations are less common and are associated with poor prognosis. The study aims to analyze the prognostic role of mutational status and type of mutation in GIST patients. Methods: Analysis of the mutational status of 52 GIST patients with localized disease was conducted between January 1, 2001 and November 1, 2007. KIT/PDGFRA tyrosine kinase inhibitors were used in the treatment of GIST patients with diseases progression only. Results: 89.6% of KIT mutations were associated with spindle cell stromal tumors while 85.7% of PDGFRA - with gastric epithelioid GISTs. KIT mutations were discovered in 40 patients (76.9%), of which 34 cases (65.5%) exhibited 11 exon, 5 (9.6%) – 9 exon and 1(1.9%) case - 13 exon. PDGFRA mutations have been detected in 7 (13.5%) patients and all of them involved 18 exon. Deletions were detected in 17 cases: 10 in patients with gastric and 7 with small intestinal GISTs. Less frequent were substitutions, in 14 patients and duplications, in 3 patients. All 5 cases with KIT 9 exon mutations were duplications in small intestine stromal tumors. Duplications and substitutions in 11 exon KIT were associated with better clinical outcome (5-year survival rate of 100.0% and 75.0 ± 21.7%) when compared with deletions and duplications in 9 exon (5-year survival rate of 48.4 ± 14.1% and 25.0 ± 21.7%). Survival analyses with deletions KIT 11 exon showed no significant difference, with 5 year survival rate in patients with gastric stromal tumors of 47.6 ± 17.1%, compared with 53.3 ± 17.3% in intestinal tumors (g = 0.6496). Conclusions: The better prognosis was observed for patients with duplications and substitutions in 11 exon KIT and worse outcome—in patients with deletions in 11 and duplications in 9 exon KIT. No prognostic difference has been detected in patients with gastric and small intestinal stromal tumors with similar mutations (deletions in KIT exon 11). The poor prognosis in small intestinal stromal tumors patients is probably due to duplications in KIT exon 9.

Kinase Mutations and Imatinib Response in Patients With Metastatic Gastrointestinal Stromal Tumor

2003 ◽  
Vol 21 (23) ◽  
pp. 4342-4349 ◽  
Author(s):  
Michael C. Heinrich ◽  
Christopher L. Corless ◽  
George D. Demetri ◽  
Charles D. Blanke ◽  
Margaret von Mehren ◽  
...  
Keyword(s):  
Clinical Response ◽  
Growth Factor Receptor ◽  
Kit Mutation ◽  
Activating Mutations ◽  
Mutational Status ◽  
Factor Receptor Alpha ◽  
Phase Ii Clinical Study ◽  
Exon 9 ◽  
Exon 11

Purpose: Most gastrointestinal stromal tumors (GISTs) express constitutively activated mutant isoforms of KIT or kinase platelet-derived growth factor receptor alpha (PDGFRA) that are potential therapeutic targets for imatinib mesylate. The relationship between mutations in these kinases and clinical response to imatinib was examined in a group of patients with advanced GIST. Patients and Methods: GISTs from 127 patients enrolled onto a phase II clinical study of imatinib were examined for mutations of KIT or PDGFRA. Mutation types were correlated with clinical outcome. Results: Activating mutations of KIT or PDGFRA were found in 112 (88.2%) and six (4.7%) GISTs, respectively. Most KIT mutations involved exon 9 (n = 23) or exon 11 (n = 85). All KIT mutant isoforms, but only a subset of PDGFRA mutant isoforms, were sensitive to imatinib, in vitro. In patients with GISTs harboring exon 11 KIT mutations, the partial response rate (PR) was 83.5%, whereas patients with tumors containing an exon 9 KIT mutation or no detectable mutation of KIT or PDGFRA had PR rates of 47.8% (P = .0006) and 0.0% (P < .0001), respectively. Patients whose tumors contained exon 11 KIT mutations had a longer event-free and overall survival than those whose tumors expressed either exon 9 KIT mutations or had no detectable kinase mutation. Conclusion: Activating mutations of KIT or PDGFRA are found in the vast majority of GISTs, and the mutational status of these oncoproteins is predictive of clinical response to imatinib. PDGFRA mutations can explain response and sensitivity to imatinib in some GISTs lacking KIT mutations.

Mutationsanalysen zur Therapieoptimierung gefordert

2010 ◽  
Vol 01 (02) ◽  
pp. 96-96
Author(s):  
Petra Eiden
Keyword(s):  
Growth Factor ◽  
Platelet Derived Growth Factor ◽  
Gastrointestinale Stromatumoren ◽  
Exon 9 ◽  
Exon 11

Gastrointestinale Stromatumoren (GIST), an denen in Deutschland jährlich etwa 1250 Menschen neu erkranken, entstehen aus mesenchymalen, interstitiellen Stammzellen im Bereich des Auerbach-Plexus, weit überwiegend aufgrund spezifischer Mutationen im Gen des KIT-, seltener auch des PDGF-Rezeptors (Platelet Derived Growth Factor), die zur Selbstaktivierung der Rezeptoren führen. Die meisten KIT-Mutationen liegen im Exon 11 (ca. 65%) oder Exon 9 (ca. 15%). Da Chemo- und Strahlentherapie keine Wirksamkeit erzielen, stellte die Entwicklung der Tyrosinkinase-Inhibitoren (TKI) Imatinib und Sunitinib laut Prof. Jörg Thomas Hartmann, Tübingen, einen deutlichen Fort-schritt dar: Sie unterbrechen die Selbstaktivierung der Rezeptoren, indem sie diese in-trazellulär blockieren.

scholarly journals Computational evaluation of potent 2-(1H-imidazol-2-yl) pyridine derivatives as potential V600E-BRAF inhibitors

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Abdullahi Bello Umar ◽  
Adamu Uzairu ◽  
Gideon Adamu Shallangwa ◽  
Sani Uba
Keyword(s):  
Kinase Inhibitors ◽  
Kinase Inhibitor ◽  
Acquired Resistance ◽  
Docking Studies ◽  
Major Protein ◽  
Pharmacological Properties ◽  
Braf Inhibitors ◽  
Protein Target ◽  
Computational Evaluation ◽  
Better Than

Abstract Background V600E-BRAF is a major protein target involved in various types of human cancers. However, the acquired resistance of the V600E-BRAF kinase to the vemurafenib and the side effects of other identified drugs initiate the search for efficient inhibitors. In the current paper, virtual docking screening combined with drug likeness and ADMET properties predictions were jointly applied to evaluate potent 2-(1H-imidazol-2-yl) pyridines as V600E-BRAF kinase inhibitors. Results Most of the studied compounds showed better docking scores and favorable interactions with theiV600E-BRAF target. Among the screened compounds, the two most potent (14 and 30) with good rerank scores (−124.079 and − 122.290) emerged as the most effective, and potent V600E-BRAF kinase inhibitors which performed better than vemurafenib (−116.174), an approved V600E-BRAF kinase inhibitor. Thus, the docking studies exhibited that these compounds have shown competing inhibition of V600E-BRAF kinase with vemurafenib at the active site and revealed better pharmacological properties based on Lipinski’s and Veber’s drug-likeness rules for oral bioavailability and ADMET properties. Conclusion The docking result, drug-likeness rules, and ADMET parameters identified compounds (14 and 30) as the best hits against V600E-BRAF kinase with better pharmacological properties. This suggests that these compounds may be developed as potent V600E-BRAF inhibitors.

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