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Missense mutations can alter the biochemical properties of proteins, including stability, structure, and function, potentially contributing to the development of multiple human diseases. Mutations in TBX5, a transcription factor necessary for heart development, are among the causes of congenital heart diseases. However, further research on biophysical and biochemical mechanisms is needed to understand how missense mutations in transcription factors alter their function in regulating gene expression. In this work, we applied in vitro and in silico approaches to understand how 5 missense mutations in the TBX5 T-box DNA-binding domain (I54T, M74V, I101F, R113K, and R237W) impact protein structure, thermal stability, and DNA-binding affinity to known TBX5 cognate binding sites. Differential scanning fluorimetry showed that mutants I54T and M74V had decreased thermal stability, mutants I101F and R113K had increased stability, and R237W had no significant effect on stability. Additionally, DNA-binding affinity decreased for all 5 missense mutants when evaluated in vitro for known TBX5 genomic binding sites within regulatory elements of Nppa and Camta1 genes. Structural modeling of the TBX5 predicted altered protein conformations and stability due to the loss or gain of amino acid residue interactions. Together, our findings provide biophysical and biochemical mechanisms that can be further explored to establish causality between TBX5 missense mutations and the development of congenital heart diseases. 

Deferasirox (Def), an orally administered iron‐chelating drug, has drawn significant interest in repurposing for anticancer application due to the elevated Fe demand by cancer cells. But there are also concerns about its severe off target health effects. Herein Cu(II) binding is studied as a potential off target interaction. The aqueous solution stability and speciation of the ternary complex Cu(Def)(pyridine) was studied by UV‐Vis and EPR spectroscopy, ESI‐mass spectrometry, and cyclic voltammetry under physiologically relevant conditions. The complex is observed to be a redox active, mononuclear Cu(II) complex in square planar geometry. UV‐Vis spectroscopy demonstrates that at pH 7.4 the complex is quite stable (ϵ337nm =10,820 M^−1cm^−1) with a log K=16.65±0.1. Cu scavenging from the Cu transporters ceruloplasmin and albumin was also studied. Def does not inhibit ceruloplasmin activity but forms a ternary Cu(II) complex at the bovine serum albumin ATCUN site. Cu(Def)(py) displays potent but nonselective cytotoxicity against A549 cancer and MRC‐5 noncancer lung cells but the potency of the ternary protein complex was more moderate. This work elucidates potential Def toxicity from Cu complexation in the body but also cytotoxic synergy between the metal and chelator that informs on new drug design directions. 

The discovery of regulated cell death (RCD) revolutionized chemotherapy. With caspase-dependent apoptosis initially being thought to be the only form of RCD, many drug development strategies aimed to synthesize compounds that turn on this kind of cell death. While yielding a variety of drugs, this approach is limited, given the acquired resistance of cancers to these drugs and the lack of specificity of the drugs for targeting cancer cells alone. The discovery of non-apoptotic forms of RCD is leading to new avenues for drug design. Evidence shows that ferroptosis, a relatively recently discovered iron-based cell death pathway, has therapeutic potential for anticancer application. Recent studies point to the interrelationship between iron and other essential metals, copper and zinc, and the disturbance of their respective homeostasis as critical to the onset of ferroptosis. Other studies reveal that several coordination complexes of non-iron metals have the capacity to induce ferroptosis. This collective knowledge will be assessed to determine how chelation approaches and coordination chemistry can be engineered to program ferroptosis in chemotherapy. 

Cardiovascular diseases (CVDs) are the leading cause of death worldwide and are heavily influenced by genetic factors. Genome-wide association studies have mapped >90% of CVD-associated variants within the noncoding genome, which can alter the function of regulatory proteins, such as transcription factors (TFs). However, due to the overwhelming number of single-nucleotide polymorphisms (SNPs) (>500,000) in genome-wide association studies, prioritizing variants for in vitro analysis remains challenging. In this work, we implemented a computational approach that considers support vector machine (SVM)-based TF binding site classification and cardiac expression quantitative trait loci (eQTL) analysis to identify and prioritize potential CVD-causing SNPs. We identified 1535 CVD-associated SNPs within TF footprints and putative cardiac enhancers plus 14,218 variants in linkage disequilibrium with genotype-dependent gene expression in cardiac tissues. Using ChIP-seq data from two cardiac TFs (NKX2-5 and TBX5) in human-induced pluripotent stem cell-derived cardiomyocytes, we trained a large-scale gapped k-mer SVM model to identify CVD-associated SNPs that altered NKX2-5 and TBX5 binding. The model was tested by scoring human heart TF genomic footprints within putative enhancers and measuring in vitro binding through electrophoretic mobility shift assay. Five variants predicted to alter NKX2-5 (rs59310144, rs6715570, and rs61872084) and TBX5 (rs7612445 and rs7790964) binding were prioritized for in vitro validation based on the magnitude of the predicted change in binding and are in cardiac tissue eQTLs. All five variants altered NKX2-5 and TBX5 DNA binding. We present a bioinformatic approach that considers tissue-specific eQTL analysis and SVM-based TF binding site classification to prioritize CVD-associated variants for in vitro analysis. 

Breast cancer is currently the most commonlydiagnosed cancer, with 287,850 new cases estimated for 2022 asreported by the American Cancer Society. Therefore, finding aneffective treatment for this disease is imperative. Chalcones are α,β-unsaturated systems found in nature. These compounds haveshown a wide array of biological activities, making them popularsynthetic targets. Chalcones consist of two aromatic substituentsconnected by an enone bridge; this arrangement allows for a largenumber of derivatives. Given the biological relevance of thesecompounds, novel ferrocene-heterocycle-containing chalcones weresynthesized and characterized based on a hybrid drug designapproach. These heterocycles included thiophene, pyrimidine,thiazolyl, and indole groups. Fourteen novel heterocyclic ferrocenyl chalcones were synthesized and characterized. Herein, we alsoreport their cytotoxicity against triple-negative breast cancer cell lines MDA-MB-231 and 4T1 and the noncancer lung cell lineMRC-5. System 3 ferrocenyl chalcones displayed superior anticancer properties compared to their system 1 analogues. System 3chalcones bearing five-membered heterocyclic substituents (thiophene, pyrazole, pyrrole, and pyrimidine) were the most activetoward the MDA-MB-231 cancer cell line with IC50 values from 6.59 to 12.51 μM. Cytotoxicity of the evaluated compounds in the4T1 cell line exhibited IC50 values from 13.23 to 213.7 μM. System 3 pyrazole chalcone had consistent toxicity toward both cell lines(IC50 ∼ 13 μM) as well as promising selectivity relative to the noncancer MRC-5 control. Antioxidant activity was also evaluated,where, contrary to anticancer capabilities, system 1 ferrocenyl chalcones were superior to their system 3 analogues. Antioxidantactivity comparable to that of ascorbic acid was observed for thiophene-bearing ferrocenyl chalcone with EC50 = 31 μM.