Computational Exploration of Fluorocyclopentenyl-purines and-pyrimidines Derivatives as Potential Inhibitors of Epidermal Growth Factor Receptor (EGFR) for the Treatment of Breast Cancer

The Epidermal Growth Factor Receptor (EGFR) is an important therapeutic target for the treatment of a variety of epithelial malignancies, including breast cancer, in which EGFR is aberrantly expressed.The fluorocyclopentenyl-purine-pyrimidines derivatives, which have previously been described as powerful compounds against breast cancer, were selected to investigate their potential against EGFR using computational tools in an effort to obtain potent inhibitors with fewer adverse effects. The molecule's chemical reactivity and stability were assessed by determining the HOMO-LUMO energy gap using density functional theory (DFT) calculations. Among all the selected compounds, PU4 displayed a HOMO-LUMO gap of 0.191 eV. Additionally, molecular docking analysis was performed to assess the binding affinities of PU4 within the active pocket of EGFR-TK. The compound PU4 showed potent interactions with EGFR exhibiting -32.3 kJ/mol binding energy which was found best as compared to gefitinib i. e., -27.4 kJ/mol which was further validated by molecular dynamics simulations and ADMET analysis. The results of these analyses indicate that the top hits obtained from the virtual screening possess the ability to act as effective EGFR inhibitor. Therefore, it is recommended to further investigate the inhibitory potential of these identified compounds using in vitro and in vivo approaches.

An extendable optical fibre probe survey meter for naturally occurring radioactive material (NORM) and other weak emitters

We have developed a radioluminescence-based survey meter for use in industries in which there is involvement in naturally occurring radioactive material (NORM), also in support of those needing to detect other weak emitters of radiation. The functionality of the system confronts particular shortcomings of the handheld survey meters that are currently being made use of. The device couples a LYSO:Ce scintillator with a photodetector via a polymer optical fibre waveguide, allowing for "intrinsically safe" inspection within pipework, separators, valves and other such component pieces. The small-diameter optical fibre probe is electrically passive, immune to electromagnetic interference, and chemically inert. The readout circuit is entirely incorporated within a handheld casing housing a silicon photomultiplier (SiPM) detection circuit and a microprocessor circuit connected to an LCD display. A 15 m long flexible PMMA optical fibre waveguide is butt coupled to an ABS plastic probe that retains the LYSO:Ce scintillator. Initial tests have included the use of lab-based mixed gamma-ray sources, measurements being made in concert with a reference conventional GM survey-meter. Characterization, via NORM sources at a decontamination facility, has shown useful sensitivity, covering the dose-rate range 0.10- to 28 µSv h^-1 (R-squared 0.966), extending to 80 µSv/h as demonstrated in use of a Cs-137 source. The system is shown to provide an effective tool for detection of radioactivity within hard to access locations, in particular for sources emitting at low radiation levels, down to values that approach background.

Induction of hemolysis and eryptosis by occupational pollutant nickel chloride is mediated through calcium influx and p38 MAP kinase signaling

OBJECTIVES

Nickel (Ni) is an abundant environmental hazard and an occupational pollutant. Exposure to Ni compounds is prevalent in electroplating workers and in the printing industry, among others. The toxicity of Ni manifests as dermatological, gastrointestinal, respiratory, allergic, and cardiovascular symptoms. In particular, hyperbilirubinemia and reticulocytosis have been detected in intoxicated subjects; an observation possibly implicating selective red blood cell (RBC) toxicity. Herein, the interaction of nickel chloride (NiCl2) with human RBCs and associated molecular mechanisms are described.

MATERIAL AND METHODS

Cells from healthy donors were incubated for 24 h at 37°C in the presence or absence of 0.5‒10 mM of NiCl2, and cytotoxicity was determined through hemoglobin leakage by colorimetry under different experimental conditions. Eryptotic markers were also identified by flow cytofluorometry using Annexin-V-FITC tagging for phosphatidylserine (PS) exposure, light scatter properties for cellular dimensions, Fluo4/AM labeling for intracellular calcium, and H2DCFDA staining for reactive oxygen species (ROS). Additionally, small molecule inhibitors were used to probe the signaling pathways involved.

RESULTS

It was found that NiCl2 at 10 mM caused profound intracellular calcium overload and significant calcium-dependent hemolysis. Also, NiCl2 reduced forward scatter and increased side scatter, Annexin- positive cells, and ROS levels. Importantly, NiCl2-induced hemolysis was significantly attenuated by the exclusion of extracellular calcium, and in the presence of p38 MAP kinase (MAPK) inhibitor SB203580.

CONCLUSIONS

It is concluded that NiCl2 induces p38 MAPK-dependent hemolysis, and stimulates the canonical features of premature eryptosis. This report presents the first description of the molecular mechanisms underlying the hemolytic and eryptotic potential of NiCl2 and, thus, may explain changes in hematological parameters observed in poisoning victims. Int J Occup Med Environ Health. 2022;35(1):1-11.