scholarly journals Automated synthesis of 18F radiolabelled indole containing Oncrasin-like molecules; a comparison of iodonium salts and boronic ester chemistry.

2020 ◽  
Author(s):  
Alexander Franklin McDonald ◽  
Yit Wooi Goh ◽  
Jonathan M White ◽  
Andrew M Scott ◽  
Uwe Ackermann
Keyword(s):  
Boronic Acid ◽  
Radiochemical Purity ◽  
Mutant Cell ◽  
Salt Formation ◽  
Malignant Tumours ◽  
Iodonium Salts ◽  
Boronic Ester ◽  
Iodonium Salt ◽  
Kras Protein

Abstract Background: Oncrasin-1 is a small molecule which was identified from a screen of KRAS mutant cancer cells and has shown specificity for KRAS mutant cell killing. We aimed to develop a radiolabelled form of Oncrasin-1 to enable in-vivo imaging of mutant KRAS expression in malignant tumours. This work outlines the synthesis of 3 fluorinated derivatives and development of iodonium salt and boronic ester precursors for radiolabelling with the 18F isotope. Results: In our hands, synthesis of iodonium salts were not easily accessible due to the 3-carbaldehyde indole structure being preferentially oxidized by conditions required for iodonium salt formation, rather than benzyl iodide. Synthesis and radiolabelling of boronic acid pinacol ester precursors were successful, with the products being obtained in yields of 10.76% ± 0.96% (n=5), 14.7% ±8.58% (n=3) and 14.92% ±3.9% (n=3) for 18F KAM001, 18F KAM002 and 18F KAM003 respectively, with radiochemical purity of greater than 99%.Conclusions: The successful synthesis of these tracers has been undertaken utilizing boronic ester radio-fluorination methods and will allow for investigation of Oncrasin based molecules as potential diagnostics for cancers expressing mutant KRAS protein.

scholarly journals Automated synthesis of 18F radiolabelled indole containing Oncrasin-like molecules; a comparison of iodonium salts and boronic ester chemistry.

2020 ◽  
Author(s):  
Alexander Franklin McDonald ◽  
Yit Woo Goh ◽  
Jonathan M White ◽  
Andrew M Scott ◽  
Uwe Ackermann
Keyword(s):  
Boronic Acid ◽  
Radiochemical Purity ◽  
Mutant Cell ◽  
Salt Formation ◽  
Malignant Tumours ◽  
Iodonium Salts ◽  
Boronic Ester ◽  
Iodonium Salt ◽  
Kras Protein

Abstract Background: Oncrasin-1 is a small molecule which was identified from a screen of KRAS mutant cancer cells and has shown specificity for KRAS mutant cell killing. We aimed to develop a radiolabelled form of Oncrasin-1 to enable in-vivo imaging of mutant KRAS expression in malignant tumours. This work outlines the synthesis of 3 fluorinated derivatives and development of iodonium salt and boronic ester precursors for radiolabelling with the 18F isotope. Results: In our hands, synthesis of iodonium salts were not easily accessible due to the 3-carbaldehyde indole structure being preferentially oxidized by conditions required for iodonium salt formation, rather than benzyl iodide. Synthesis and radiolabelling of boronic acid pinacol ester precursors were successful, with the products being obtained in yields of 10.76% ± 0.96% (n=5), 14.7% ±8.58% (n=3) and 14.92% ±3.9% (n=3) for 18F KAM001, 18F KAM002 and 18F KAM003 respectively, with radiochemical purity of greater than 99%.Conclusions: The successful synthesis of these tracers has been undertaken utilizing boronic ester radio-fluorination methods and will allow for investigation of Oncrasin based molecules as potential diagnostics for cancers expressing mutant KRAS protein.

scholarly journals Automated synthesis of 18F radiolabelled indole containing Oncrasin-like molecules; a comparison of iodonium salts and boronic ester chemistry

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Alexander F. McDonald ◽  
Yit Wooi Goh ◽  
Jonathan M. White ◽  
Andrew M. Scott ◽  
Uwe Ackermann
Keyword(s):  
Boronic Acid ◽  
Radiochemical Purity ◽  
Mutant Cell ◽  
Salt Formation ◽  
Malignant Tumours ◽  
Iodonium Salts ◽  
Boronic Ester ◽  
Iodonium Salt ◽  
Kras Protein

Abstract Background Oncrasin-1 is a small molecule which was identified from a screen of KRAS mutant cancer cells and has shown specificity for KRAS mutant cell killing. We aimed to develop a radiolabelled form of Oncrasin-1 to enable in-vivo imaging of mutant KRAS expression in malignant tumours. This work outlines the synthesis of 3 fluorinated derivatives and development of iodonium salt and boronic ester precursors for radiolabelling with the 18F isotope. Results In our hands, synthesis of iodonium salts were not easily accessible due to the 3-carbaldehyde indole structure being preferentially oxidized by conditions required for iodonium salt formation, rather than benzyl iodide. Synthesis and radiolabelling of boronic acid pinacol ester precursors were successful, with the products being obtained in yields of 10.76% ± 0.96% (n = 5), 14.7% ±8.58% (n = 3) and 14.92% ±3.9% (n = 3) for 18F KAM001, 18F KAM002 and 18F KAM003 respectively, with radiochemical purity of greater than 99%. Conclusions The successful synthesis of these tracers has been undertaken utilizing boronic ester radio-fluorination methods and will allow for investigation of Oncrasin based molecules as potential diagnostics for cancers expressing mutant KRAS protein.

scholarly journals Automated synthesis of 18F radiolabelled indole containing Oncrasin-like molecules; a comparison of iodonium salts and boronic ester chemistry.

2020 ◽  
Author(s):  
Alexander Franklin McDonald ◽  
Yit Woo Goh ◽  
Jonathan M White ◽  
Andrew M Scott ◽  
Uwe Ackermann
Keyword(s):  
In Vivo Imaging ◽  
Boronic Acid ◽  
Mutant Cell ◽  
Salt Formation ◽  
Malignant Tumours ◽  
Iodonium Salts ◽  
Boronic Ester ◽  
Iodonium Salt ◽  
Kras Protein

Abstract Oncrasin-1 is a small molecule which was identified from a screen of KRAS mutant cancer cells and has shown specificity for KRAS mutant cell killing. We aimed to develop a radiolabelled form of Oncrasin-1 to enable in-vivo imaging of mutant KRAS expression in malignant tumours. This work outlines the synthesis of 3 fluorinated derivatives and development of iodonium salt and boronic ester precursors for radiolabelling with the 18F isotope. Attempted synthesis of iodonium salts showed that the indole structure is incompatible with oxidizing conditions required for iodonium salt formation. Synthesis and radiolabelling of boronic acid pinacol ester precursors were successful and resulted in RCY of 10–25% across the 3 different substitution patterns. The successful synthesis of these tracers will allow for investigation of Oncrasin based molecules as potential diagnostics for cancers expressing mutant KRAS protein.

In silico and in vivo study of radio-iodinated nefiracetam as a radiotracer for brain imaging in mice

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
M. H. Sanad ◽  
A. B. Farag ◽  
S. F. A. Rizvi
Keyword(s):  
Brain Imaging ◽  
Radiochemical Purity ◽  
High Yield ◽  
High Uptake ◽  
Oxidizing Agent ◽  
Receptor Ligand ◽  
Nootropic Agent ◽  
Biodistribution Studies

Abstract This study presents development and characterization of a radiotracer, [125I]iodonefiracetam ([125I]iodoNEF). Labeling with high yield and radiochemical purity was achieved through the formation of a [125I]iodoNEF radiotracer after investigating many factors like oxidizing agent content (chloramines-T (Ch-T)), substrate amount (Nefiracetam (NEF)), pH of reaction mixture, reaction time and temperature. Nefiracetam (NEF) is known as nootropic agent, acting as N-methyl-d-aspartic acid receptor ligand (NMDA). The radiolabeled compound was stable, and exhibited the logarithm of the partition coefficient (log p) value of [125I]iodonefiracetam as 1.85 (lipophilic). Biodistribution studies in normal mice confirmed the suitability of the [125I]iodoNEF radiotracer as a novel tracer for brain imaging. High uptake of 8.61 ± 0.14 percent injected dose/g organ was observed in mice

scholarly journals Akt kinase LANCL2 functions as a key driver in EGFR-mutant lung adenocarcinoma tumorigenesis

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Yuqing Lou ◽  
Jianlin Xu ◽  
Yanwei Zhang ◽  
Wei Zhang ◽  
Xueyan Zhang ◽  
...  
Keyword(s):  
Lung Adenocarcinoma ◽  
Cell Line ◽  
Quantitative Polymerase Chain Reaction ◽  
Mutant Cell ◽  
A549 Cells ◽  
The Cancer Genome Atlas ◽  
Akt Kinase ◽  
Egfr Expression

AbstractEpidermal growth factor receptor (EGFR) is a key oncogene in lung adenocarcinoma (LUAD). Resistance to EGFR tyrosine kinase inhibitors is a major obstacle for EGFR-mutant LUAD patients. Our gene chip array, quantitative polymerase chain reaction validation, and shRNA-based high-content screening identified the Akt kinase lanthionine synthetase C-like protein 2 (LANCL2) as a pro-proliferative gene in the EGFR-mutant LUAD cell line PC9. Therefore, we investigated whether LANCL2 plays a role in promoting cell proliferation and drug resistance in EGFR-mutant LUAD. In silico clinical correlation analysis using the Cancer Genome Atlas Lung Adenocarcinoma dataset revealed a positive correlation between LANCL2 and EGFR expression and an inverse relationship between LANCL2 gain-of-function and survival in LUAD patients. The EGFR-mutant LUAD cell lines PC9 and HCC827 displayed higher LANCL2 expression than the non-EGFR-mutant cell line A549. In addition, LANCL2 was downregulated following gefitinib+pemetrexed combination therapy in PC9 cells. LANCL2 knockdown reduced proliferation and enhanced apoptosis in PC9, HCC827, and A549 cells in vitro and suppressed murine PC9 xenograft tumor growth in vivo. Notably, LANCL2 overexpression rescued these effects and promoted gefitinib + pemetrexed resistance in PC9 and HCC827 cells. Pathway analysis and co-immunoprecipitation followed by mass spectrometry of differentially-expressed genes in LANCL2 knockdown cells revealed enrichment of several cancer signaling pathways. In addition, Filamin A and glutathione S-transferase Mu 3 were identified as two novel protein interactors of LANCL2. In conclusion, LANCL2 promotes tumorigenic proliferation, suppresses apoptosis, and promotes gefitinib+pemetrexed resistance in EGFR-mutant LUAD cells. Based on the positive association between LANCL2, EGFR, and downstream Akt signaling, LANCL2 may be a promising new therapeutic target for EGFR-mutant LUAD.

scholarly journals Focal adhesion kinase inhibitor TAE226 combined with Sorafenib slows down hepatocellular carcinoma by multiple epigenetics effects

2021 ◽  
Author(s):  
Ilaria Romito ◽  
Manuela Porru ◽  
Maria Rita Braghini ◽  
Luca Pompili ◽  
Nadia Panera ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Focal Adhesion Kinase ◽  
Focal Adhesion ◽  
Kinase Inhibitor ◽  
Malignant Tumours ◽  
Nurd Complex ◽  
Antitumor Effects ◽  
Combination Regimens

Abstract Background Hepatocellular carcinoma (HCC) is one of the most common and lethal malignant tumours worldwide. Sorafenib (SOR) is one of the most effective single-drug systemic therapy against advanced HCC, but the identification of novel combination regimens for a continued improvement in overall survival is a big challenge. Recent studies highlighted the crucial role of focal adhesion kinase (FAK) in HCC growth. The aim of this study was to investigate the antitumor effects of three different FAK inhibitors, alone or in combination with SOR, using in vitro and in vivo models of HCC. Methods The effect of PND1186, PF431396, TAE226 on cell viability was compared to SOR. Among them TAE226, emerging as the most effective FAKi, was then tested alone or in combination with SOR using 2D/3D human HCC cell line cultures and HCC xenograft murine models. The mechanisms of action were assessed by gene/protein expression and imaging approaches, combined with high-throughput methods. Results TAE226 emerged as the more effective FAKi to be combined with SOR against HCC. Combined TAE226 and SOR treatment reduced HCC growth both in vitro and in vivo by affecting tumour-promoting gene expression and inducing epigenetic changes via dysregulation of the nuclear interactome of FAK. We characterized a novel nuclear functional interaction between FAK and the NuRD complex. TAE226-mediated FAK depletion and SOR-promoted MAPK down-modulation causing an increase of histone H3 lysine 27 acetylation, counteracting its trimethylation by decreasing the nuclear amount of HDAC1/2. Conclusions Altogether, our findings provide the first evidence that TAE226 combined with SOR efficiently reduce HCC growth in vitro and in vivo. Our data also highlight that deep analysis of FAK nuclear interactome may lead to the identification of new promising therapeutic approaches for HCC.

scholarly journals Radiosynthesis of A Novel Antisense Imaging Probe Targeting LncRNA HOTAIR in Malignant Glioma.

2021 ◽  
Author(s):  
Jiongyu Ren ◽  
Xiyuan Zhang ◽  
Jiang Cao ◽  
Jiali Tian ◽  
Jin Luo ◽  
...  
Keyword(s):  
Malignant Glioma ◽  
Cellular Uptake ◽  
Gel Electrophoresis ◽  
Radiochemical Purity ◽  
Malignant Tumors ◽  
Biodistribution Study ◽  
Blocking Group ◽  
Uptake Test ◽  
Lncrna Hotair

Abstract Background: Long non-coding RNA (lncRNA) HOTAIR was manifested overexpressing and amplifying in many human carcinomas, which could serve as a useful target for cancer therapy. The 99mTc radiolabeled antisense oligonucleotides (ASON) could visualize the expression of HOTAIR and provide a diagnostic and therapeutic value for malignant tumors. The aim of this study was to radiosynthesis 99mTc with HOTAIR ASON and investigate the in vivo imaging in malignant glioma xenografts. Methods: The ASON targeting lncRNA HOTAIR as well as mismatched ASON probe (ASONM) were designed and modified. The radiolabeling of 99mTc with two probes was via the conjugation of bifunctional chelator HYNIC. Then the probes were purified by Sephadex G25 and tested for its radiolabeling efficiency and purity, as well as stability by iTLC and gel electrophoresis. Then the radiolabeled probes were transfected with lipofectamine 2000 for cellular uptake test and the next experimental use. Furthermore, biodistribution study and SPECT imaging was performed at different time after probes were intravenously injected in U87 tumor bearing nude mice models. All data were analyzed by statistical software. Results: The labeling efficiencies of 99mTc-HYNIC-ASON and 99mTc-HYNIC-ASONM measured by iTLC were (91 ±1.5) % and (90 ±0.6) %, respectively, and the radiochemical purity were more than 89%. The probes showed good stability within 12 hours for high radiochemical purity. Gel electrophoresis confirmed that the oligomers were successfully radiolabeled no significant degradation were found. Cellular uptake experiment showed that liposomes had ability to carry probes into cells. Biodistribution study demonstrated that liposome coated 99mTc-HYNIC-ASON had significantly higher uptake in the tumor and higher tumor to muscle ratio than mismatched group. Meanwhile tumor was clearly shown at 1 hours post probe injection of Liposome coated 99mTc-HYNIC-ASON on SPECT/CT imaging, compared with mismatched and blocking group. Conclusion: The Liposome encapsulated 99mTc-HYNIC-ASON probe can be radiosynthesized and used in the in vivo, real-time imaging of lncRNA HOTAIR expression in malignant glioma.

scholarly journals Development and Validation of an Analytical HPLC Method to Assess Chemical and Radiochemical Purity of [68Ga]Ga-NODAGA-Exendin-4 Produced by a Fully Automated Method

Molecules ◽  
2022 ◽  
Vol 27 (2) ◽  
pp. 543
Author(s):  
Silvia Migliari ◽  
Antonino Sammartano ◽  
Marti Boss ◽  
Martin Gotthardt ◽  
Maura Scarlattei ◽  
...  
Keyword(s):  
Radiochemical Purity ◽  
Cell Mass ◽  
Hplc Method ◽  
European Medicines Agency ◽  
Guidance Document ◽  
Limit Of Quantification ◽  
Technical Requirements ◽  
Automated Method ◽  
Pet Tracer

Background: Glucagon-like peptide 1 receptor (GLP-1R) is preferentially expressed in pancreatic islets, especially in β-cells, and highly expressed in human insulinomas and gastrinomas. In recent years several GLP-1R–avid radioligands have been developed to image insulin-secreting tumors or to provide a tentative quantitative in vivo biomarker of pancreatic β-cell mass. Exendin-4, a 39-amino acid peptide with high binding affinity to GLP-1R, has been labeled with Ga-68 for imaging with positron emission tomography (PET). Preparation conditions may influence the quality and in vivo behavior of tracers. Starting from a published synthesis and quality controls (QCs) procedure, we have developed and validated a new rapid and simple UV-Radio-HPLC method to test the chemical and radiochemical purity of [68Ga]Ga-NODAGA-exendin-4, to be used in the clinical routine. Methods: Ga-68 was obtained from a 68Ge/68Ga Generator (GalliaPharma®) and purified using a cationic-exchange cartridge on an automated synthesis module (Scintomics GRP®). NODAGA-exendin-4 contained in the reactor (10 µg) was reconstituted with HEPES and ascorbic acid. The reaction mixture was incubated at 100 °C. The product was purified through HLB cartridge, diluted, and sterilized. To validate the proposed UV-Radio-HPLC method, a stepwise approach was used, as defined in the guidance document released by the International Conference on Harmonization of Technical Requirements of Pharmaceuticals for Human Use (ICH), adopted by the European Medicines Agency (CMP/ICH/381/95 2014). The assessed parameters are specificity, linearity, precision (repeatability), accuracy, and limit of quantification. Therefore, a range of concentrations of Ga-NODAGA-exendin-4, NODAGA-exendin-4 (5, 4, 3.125, 1.25, 1, and 0.75 μg/mL) and [68Ga]Ga-NODAGA-exendin-4 were analyzed. To validate the entire production process, three consecutive batches of [68Ga]Ga-NODAGA-exendin-4 were tested. Results: Excellent linearity was found between 5–0.75 μg/mL for both the analytes (NODAGA-exendin-4 and 68Ga-NODAGA-exendin-4), with a correlation coefficient (R2) for calibration curves equal to 0.999, average coefficients of variation (CV%) <2% (0.45% and 0.39%) and average per cent deviation value of bias from 100%, of 0.06% and 0.04%, respectively. The calibration curve for the determination of [68Ga]Ga-NODAGA-exendin-4 was linear with a R2 of 0.993 and CV% <2% (1.97%), in accordance to acceptance criteria. The intra-day and inter-day precision of our method was statistically confirmed using 10 μg of peptide. The mean radiochemical yield was 45 ± 2.4% in all the three validation batches of [68Ga]Ga-NODAGA-exendin-4. The radiochemical purity of [68Ga]Ga-NODAGA-exendin-4 was >95% (97.05%, 95.75% and 96.15%) in all the three batches. Conclusions: The developed UV-Radio-HPLC method to assess the radiochemical and chemical purity of [68Ga]Ga-NODAGA-exendin-4 is rapid, accurate and reproducible like its fully automated production. It allows the routine use of this PET tracer as a diagnostic tool for PET imaging of GLP-1R expression in vivo, ensuring patient safety.

CBL mutations drive PI3K/AKT signaling via increased interaction with LYN and PIK3R1

Blood ◽  
2021 ◽  
Author(s):  
Roger Belizaire ◽  
Sebastian Hassan John Koochaki ◽  
Namrata D. Udeshi ◽  
Alexis Vedder ◽  
Lei Sun ◽  
...  
Keyword(s):  
Cell Lines ◽  
Ubiquitin Ligase ◽  
Therapeutic Potential ◽  
Mutant Cell ◽  
E3 Ubiquitin Ligase ◽  
Akt Signaling ◽  
Allelic Series ◽  
Genetic Ablation

CBL encodes an E3 ubiquitin ligase and signaling adaptor that regulates receptor and non-receptor tyrosine kinases. Recurrent CBL mutations occur in myeloid neoplasms, including 10-20% of chronic myelomonocytic leukemia (CMML) cases, and selectively disrupt the protein's E3 ubiquitin ligase activity. CBL mutations have been associated with poor prognosis, but the oncogenic mechanisms and therapeutic implications of CBL mutations remain incompletely understood. We combined functional assays and global mass spectrometry to define the phosphoproteome, CBL interactome, and mechanism of signaling activation in a panel of cell lines expressing an allelic series of CBL mutations. Our analyses revealed that increased LYN activation and interaction with mutant CBL are key drivers of enhanced CBL phosphorylation, PIK3R1 recruitment, and downstream PI3K/AKT signaling in CBL-mutant cells. Signaling adaptor domains of CBL, including the tyrosine-kinase binding domain, proline-rich region, and C-terminal phosphotyrosine sites, were all required for the oncogenic function of CBL mutants. Genetic ablation or dasatinib-mediated inhibition of LYN reduced CBL phosphorylation, CBL-PIK3R1 interaction, and PI3K/AKT signaling. Furthermore, we demonstrated in vitro and in vivo antiproliferative efficacy of dasatinib in CBL-mutant cell lines and primary CMML. Overall, these mechanistic insights into the molecular function of CBL mutations provide rationale to explore the therapeutic potential of LYN inhibition in CBL-mutant myeloid malignancies.

Oestrogens in breast tumours and fat

1989 ◽  
Vol 95 ◽  
pp. 161-168
Author(s):  
J. H. H. Thijssen ◽  
M. A. Blankenstein
Keyword(s):  
Biological Effects ◽  
Plasma Concentrations ◽  
Normal Breast ◽  
Malignant Tumours ◽  
Breast Tumours ◽  
Two Parameters ◽  
Breast Tissues

SynopsisThe levels of endogenous steroids in the target tissues are thought to be more closely related to the biological effects than their concentrations in plasma. Therefore studies on oestrogen levels in malignant and non-malignant breast tissues (expressed per g wet weight) were conducted and the following conclusions were drawn:(1) malignant tumours contained higher oestradiol levels than normal or benign breast tissues, whereas oestrone levels were more comparable;(2) in contrast to the large decrease in plasma concentrations after menopause, the levels of oestradiol in tumours and in normal breast tissue did not change with advancing age;(3) the oestradiol levels in breast tissues were lower than in uterine tissues, particularly in women before menopause; oestrone levels were very similar in all tissues studied;(4) the mean oestradiol level was higher in oestrogen-receptor-positive tumours, but no correlation between the two parameters was found;(5) preliminary results indicated lower oestradiol levels in tumours obtained from countries with a lower incidence of breast cancer;(6) as far as available, oestrone levels were comparable and those of oestradiol were lower in fat tissues than in breast tumours;(7) neither in vitro studies with breast tumours, nor in vivo results using myometrial tissues support a prominent role of the metabolism of oestrogens at the 16α-position in the development of tumours;(8) the role of local factors in the production, retention and metabolism of oestradiol in the breast remains to be elucidated.

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