scholarly journals Differential receptor tyrosine kinase phosphorylation in the uterus of rats following developmental exposure to tetrabromobisphenol A

2021 ◽  
Vol 5 ◽  
pp. 239784732110471
Author(s):  
Lysandra Castro ◽  
Jingli Liu ◽  
Linda Yu ◽  
Alanna D Burwell ◽  
Trey O Saddler ◽  
...  

Tetrabromobisphenol A (TBBPA) is a brominated flame retardant that induces endometrial adenocarcinoma and other uterine tumors in Wistar Han rats; however, early molecular events or biomarkers of TBBPA exposure remain unknown. We investigated the effects of TBBPA on growth factor receptor activation [phospho-receptor tyrosine kinases (RTKs)] in uteri of rats following early-life exposures. Pregnant Wistar Han rats were exposed to TBBPA (0, 0.1, 25, and 250 mg/kg bw/day) via oral gavage on gestation day 6 through weaning of pups on postnatal day (PND) 21. Pups were exposed in utero, through lactation, and by daily gavage from PND 22 to PND 90. Uterine horns were collected (at PND 21, PND 33, and PND 90) and formalin-fixed or frozen for histologic, immunohistochemical, phospho-RTK arrays, or western blot analysis. At PND 21, the phospho-RTKs, fibroblast growth factor receptor 2 and 3 (FGFR2 and FGFR3), neurotrophic tyrosine kinase receptor type 3 (TRKC), and EPH receptor A1 (EPHA1) were significantly increased at different treatment concentrations. Several phospho-RTKs were also significantly overexpressed at PND 33 which included epithelial growth factor receptor (EGFR), FGFR2, FGFR3, FGFR4, insulin-like growth factor receptor 1 (IGF1R), insulin receptor (INSR), AXL receptor tyrosine kinase (AXL), MER proto-oncogene, tyrosine kinase (MERTK), platelet derived growth factor receptor alpha and beta (PDGFRA and PDGFRB), ret proto-oncogene (RET), tyrosine kinase with immunoglobulin-like and EGF-like domains 1 and 2 (TIE1 and TIE2), TRKA, kinase insert domain receptor (KDR;VEGFR2), fms related receptor tyrosine kinase (FLT4; VEGFR3), and EPHA1 at different treatment concentrations. EGFR, a RTK overexpressed in endometrial cancer in women, remained significantly increased for all treatment groups at PND 90. Erb-B2 receptor tyrosine kinase 2 (ERBB2) and IGF1R were overexpressed at PND 33 and remained increased through PND 90, although ERBB2 was statistically significant at PND 90. The phospho-RTKs, FGFR3, AXL, TYRO3 protien tyrosine kinase (TYRO3; DTK), HGFR, TRKC, FLT1/VEGFR1, and EPHB2 and 4 were also statistically significant at PND 90 at different treatment doses. The downstream effector, phospho-MAPK44/42, was also increased in uteri of treated rats. Our findings show RTKs are dysregulated following early-life TBBPA exposures and their sustained activation may contribute to TBBPA-induced uterine tumors observed in rats later in life.

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Muhammad Tukur Ibrahim ◽  
Adamu Uzairu ◽  
Gideon Adamu Shallangwa ◽  
Sani Uba

Abstract Background The discovery of epidermal growth factor receptor (EGFR) inhibitors for the treatment of lung cancer, most especially non-small cell lung cancer (NSCLC), was one of the major challenges encountered by the medicinal chemist in the world. The treatment of EGFR tyrosine kinase to manage NSCLCs becomes an urgent therapeutic necessity. NSCLC was the foremost cause of cancer mortality worldwide. Therefore, there is a need to develop more EGFR inhibitors due to the development of drug resistance by the mutation. This research is aimed at designing new EGFR inhibitors using a structure-based design approach. Structure-based drug design comprises several steps such as protein structure retrieval and preparation, ligand library preparation, docking, and structural modification on the best hit compound to design new ones. Result Molecular docking virtual screening on fifty sets of quinazoline derivatives/epidermal growth factor receptor inhibitors against their target protein (EGFR tyrosine kinase receptor PDB entry: 3IKA) and pharmacokinetic profile predictions were performed to identify hit compounds with promising affinities toward their target and good pharmacokinetic profiles. The hit compounds identified were compound 6 with a binding affinity of − 9.3 kcal/mol, compounds 5 and 8, each with a binding affinity of − 9.1 kcal/mol, respectively. The three hit compounds bound to EGFR tyrosine kinase receptor via four different types of interactions which include conventional hydrogen bond, carbon-hydrogen bond, electrostatic, and hydrophobic interactions, respectively. The best hit (compound 6) among the 3 hit compounds was retained as a template and used to design sixteen new EGFR inhibitors. The sixteen newly designed compounds were also docked into the active site of EGFR tyrosine kinase receptor to study their mode of interactions with the receptor. The binding affinities of these newly designed compounds range from − 9.5 kcal/mol to − 10.2 kcal/mol. The pharmacokinetic profile predictions of these newly designed compounds were further examined and found to be orally bioavailable with good absorption, low toxicity level, and permeable properties. Conclusion The sixteen newly designed EGFR inhibitors were found to have better binding affinities than the template used in the designing process and afatinib the positive control (an FDA approved EGFR inhibitor). None of these designed compounds was found to violate more than the permissible limit set by RO5. More so, the newly designed compounds were found to have good synthetic accessibility which indicates that these newly designed compounds can be easily synthesized in the laboratory.


2021 ◽  
pp. 030089162110200
Author(s):  
Haci M. Turk ◽  
Mustafa Adli ◽  
Melih Simsek ◽  
Altay Aliyev ◽  
Mehmet Besiroglu

Background: Epidermal growth factor receptor tyrosine kinase inhibitors are effectively being used in the treatment of non-small cell lung cancer. Although most of their adverse effects are mild to moderate, they occasionally can cause life-threatening interstitial lung disease. We aimed to present a case of lung adenocarcinoma successfully re-treated with erlotinib after recovery with effective treatment of erlotinib-induced interstitial lung disease. Case description: A 54-year-old nonsmoking woman was diagnosed with metastatic adenocarcinoma of the lung. After progression with first-line chemotherapy, erlotinib 150 mg daily was initiated. On the 45th day of erlotinib treatment, interstitial lung disease occurred and erlotinib was discontinued. Clinical improvement was achieved with dexamethasone treatment and erlotinib was re-initiated. Ten weeks after re-initiation of erlotinib, 100 mg daily partial response was observed. Conclusions: Incidence of interstitial lung disease is higher in men, smokers, and patients with pulmonary fibrosis. Interstitial lung disease radiologically causes ground-glass opacity and consolidation. The physician should quickly evaluate new respiratory symptoms in patients treated with epidermal growth factor receptor tyrosine kinase inhibitors, discontinue the epidermal growth factor receptor tyrosine kinase inhibitor treatment, and initiate corticosteroids if clinical diagnosis is interstitial lung disease.


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