Also published as: A Williams, A. Williams, C Williams, Catrin F. Williams, D. Bradley G. Williams, E. Williams, Hugo D. Williams, J Williams, KA Williams, KJ Williams, L.D. Williams, LD Williams, LT Williams, Loren Dean Williams, M. Williams, M.A. Williams, M.C. Williams, Michael L. Williams, N.C. Williams, P. Williams, PR Williams, Patricia A. M. Williams, Patricia A.M Williams, Patricia AM Williams, RJ Williams, RJP Williams, RT Williams, S.C. Williams
Nucleic acid junctions are key to many biological functions from recombination and repair to viral nucleic acid insertion and are an attractive, functional biomolecular target. We describe a quadruple Show more
Nucleic acid junctions are key to many biological functions from recombination and repair to viral nucleic acid insertion and are an attractive, functional biomolecular target. We describe a quadruple-stranded diplatinum helicate that binds both three-way (3WJ) and four-way DNA junctions (4WJ). This allows us to probe the relative importance of size and shape in junction-binder design. Despite the helicate's tetragonal symmetry/shape being compatible with the 4WJ, microscale thermophoresis (MST), isothermal calorimetry (ITC), and gel electrophoresis competition experiments demonstrate that this metallo-supramolecule displays a stronger affinity for 3WJs (Kd = 12 nM) than for 4WJs (Kd > 4 μM) and other DNA structures. The experimental findings are supported by molecular dynamics simulations that reveal the critical role of size. While the open form of the 4WJ is promoted when the helicate is in the cavity, the helicate's small size means it is unable to maintain π contacts with all four junction base-pairs simultaneously. Although the helicate is slightly too large for the smaller 3WJ cavity, simulations and experiments show that it can open up the cavity (increasing the junction's hydrodynamic radius) by disrupting a base pair. The flexible helicate also responds to the cavity upon binding by favoring one enantiomer and allowing the helicate to adopt a stable final structure inside the 3WJ that is an induced fit of the two dynamic structures (supramolecule and DNA). This contrasts with previous lock-and-key examples of junction recognition and opens up new possibilities for how to design DNA and RNA junction-binding compounds. Show less
Carnitine O-acetyltransferase (CRAT) is a key mitochondrial enzyme involved in maintaining metabolic homeostasis by mediating the reversible transfer of acetyl groups between acetyl-CoA and carnitine. Show more
Carnitine O-acetyltransferase (CRAT) is a key mitochondrial enzyme involved in maintaining metabolic homeostasis by mediating the reversible transfer of acetyl groups between acetyl-CoA and carnitine. This enzymatic activity ensures the optimal functioning of mitochondrial carbon flux by preventing acetyl-CoA accumulation, buffering metabolic flexibility, and regulating the balance between fatty acid and glucose oxidation. CRAT’s interplay with the mitochondrial carnitine shuttle, involving carnitine palmitoyltransferases (CPT1 and CPT2) and the carnitine carrier (SLC25A20), underscores its critical role in energy metabolism. Emerging evidence highlights the structural and functional diversity of CRAT and structurally related acetyltransferases across cellular compartments, illustrating their coordinated role in lipid metabolism, amino acid catabolism, and mitochondrial bioenergetics. Moreover, the structural insights into CRAT have paved the way for understanding its regulation and identifying potential modulators with therapeutic applications for diseases such as diabetes, mitochondrial disorders, and cancer. This review examines CRAT’s structural and functional aspects, its relationships with carnitine shuttle members and other carnitine acyltransferases, and its broader role in metabolic health and disease. The potential for targeting CRAT and its associated pathways offers promising avenues for therapeutic interventions aimed at restoring metabolic equilibrium and addressing metabolic dysfunction in disease states. Show less
Non-small cell lung cancer (NSCLC) is one of the most prevalent and lethal types of cancers worldwide and its high incidence and mortality rates pose a significant public health challenge. Despite sig Show more
Non-small cell lung cancer (NSCLC) is one of the most prevalent and lethal types of cancers worldwide and its high incidence and mortality rates pose a significant public health challenge. Despite significant advances in targeted therapy and immunotherapy, the overall prognosis of patients with NSCLC remains poor. Hypoxia is a critical driving factor in tumor progression, influencing the biological behavior of tumor cells through complex molecular mechanisms. The present review systematically examined the role of the hypoxic microenvironment in NSCLC, demonstrating its crucial role in promoting tumor cell growth, invasion and metastasis. Additionally, it has been previously reported that the hypoxic microenvironment enhances tumor cell resistance by activating hypoxia-inducible factor and regulating exosome secretion. The hypoxic microenvironment also enables tumor cells to adapt to low oxygen and nutrient-deficient conditions by enhancing metabolic reprogramming, such as through upregulating glycolysis. Further studies have shown that the hypoxic microenvironment facilitates immune escape by modulating tumor-associated immune cells and suppressing the antitumor response of the immune system. Moreover, the hypoxic microenvironment increases tumor resistance to radiotherapy, chemotherapy and other types of targeted therapy through various pathways, significantly reducing the therapeutic efficacy of these treatments. Therefore, it could be suggested that early detection of cellular hypoxia and targeted therapy based on hypoxia may offer new therapeutic approaches for patients with NSCLC. The present review not only deepened the current understanding of the mechanisms of action and role of the hypoxic microenvironment in NSCLC but also provided a solid theoretical basis for the future development of precision treatments for patients with NSCLC. Show less
DNA structure has many potential places where endogenous compounds and xenobiotics can bind. Therefore, xenobiotics bind along the sites of the nucleic acid with the aim of changing its structure, its Show more
DNA structure has many potential places where endogenous compounds and xenobiotics can bind. Therefore, xenobiotics bind along the sites of the nucleic acid with the aim of changing its structure, its genetic message, and, implicitly, its functions. Currently, there are several mechanisms known to be involved in DNA binding. These mechanisms are covalent and non-covalent interactions. The covalent interaction or metal base coordination is an irreversible binding and it is represented by an intra-/interstrand cross-link. The non-covalent interaction is generally a reversible binding and it is represented by intercalation between DNA base pairs, insertion, major and/or minor groove binding, and electrostatic interactions with the sugar phosphate DNA backbone. In the present review, we focus on the types of DNA–metal complex interactions (including some representative examples) and on presenting the methods currently used to study them. Show less
Abstract Imaging contrast agents are widely investigated in preclinical and clinical studies, among which biogenic imaging contrast agents (BICAs) are developing rapidly and playing an increasingly i Show more
Abstract Imaging contrast agents are widely investigated in preclinical and clinical studies, among which biogenic imaging contrast agents (BICAs) are developing rapidly and playing an increasingly important role in biomedical research ranging from subcellular level to individual level. The unique properties of BICAs, including expression by cells as reporters and specific genetic modification, facilitate various in vitro and in vivo studies, such as quantification of gene expression, observation of protein interactions, visualization of cellular proliferation, monitoring of metabolism, and detection of dysfunctions. Furthermore, in human body, BICAs are remarkably helpful for disease diagnosis when the dysregulation of these agents occurs and can be detected through imaging techniques. There are various BICAs matched with a set of imaging techniques, including fluorescent proteins for fluorescence imaging, gas vesicles for ultrasound imaging, and ferritin for magnetic resonance imaging. In addition, bimodal and multimodal imaging can be realized through combining the functions of different BICAs, which helps overcome the limitations of monomodal imaging. In this review, the focus is on the properties, mechanisms, applications, and future directions of BICAs. Show less
This study is based on the premise that the application of chemical synthesis strategies to structurally modify commercial drugs by complexation with biometals is a valid procedure to improve their bi Show more
This study is based on the premise that the application of chemical synthesis strategies to structurally modify commercial drugs by complexation with biometals is a valid procedure to improve their biological effects. Our purpose is to synthesize a compound with greater efficacy than the original drug, able to enhance its antihypertensive and cardiac pharmacological activity. Herein, the structure of the coordination compound of Zn(II) and the antihypertensive drug olmesartan, [Zn(Olme)(H2O)2] (ZnOlme), is presented. After 8 weeks of treatment in SHR male rats, ZnOlme displayed a better blood pressure-lowering activity compared with olmesartan, with a noticeable effect even in the first weeks of treatment, while ZnCl2 showed similar results than the control. ZnOlme also reduced left ventricle (LV) weight and left ventricle/tibia length ratio (LV/TL), posterior wall thickness (PWT), and intraventricular septum in diastole (IVSd) suggesting its potential to prevent LV hypertrophy. Besides, ZnOlme reduced interstitial fibrosis (contents of collagen types I and III, responsible for giving rigidity and promoting vascular elasticity, respectively). The recovery of heart function was also evidenced by fractional shortening (diastolic left ventricular/systolic left ventricular) diameter determinations. Furthermore, ZnOlme increased the antioxidant capacity and prevented cardiac oxidative stress: it enhanced the reduction of reactive oxygen species generation, exerted a significant decrease in lipid peroxidation and enhanced glutathione contents in heart tissues compared to the control, Zn, and olmesartan treatments. Our results demonstrate that continuous oral administration of ZnOlme causes a better antihypertensive effect and grants enhancement of cardioprotection through antioxidant activity, in combination with hemodynamic improvement. Graphical Abstract Show less
Developing novel therapeutics often follows three steps: target identification, design of strategies to suppress target activity and drug development to implement the strategies. In this review, we re Show more
Developing novel therapeutics often follows three steps: target identification, design of strategies to suppress target activity and drug development to implement the strategies. In this review, we recount the evidence identifying the basic leucine zipper transcription factors ATF5, CEBPB, and CEBPD as targets for brain and other malignancies. We describe strategies that exploit the structures of the three factors to create inhibitory dominant-negative (DN) mutant forms that selectively suppress growth and survival of cancer cells. We then discuss and compare four peptides (CP-DN-ATF5, Dpep, Bpep and ST101) in which DN sequences are joined with cell-penetrating domains to create drugs that pass through tissue barriers and into cells. The peptide drugs show both efficacy and safety in suppressing growth and in the survival of brain and other cancers in vivo, and ST101 is currently in clinical trials for solid tumors, including GBM. We further consider known mechanisms by which the peptides act and how these have been exploited in rationally designed combination therapies. We additionally discuss lacunae in our knowledge about the peptides that merit further research. Finally, we suggest both short- and long-term directions for creating new generations of drugs targeting ATF5, CEBPB, CEBPD, and other transcription factors for treating brain and other malignancies. Show less
The elucidation of a compound's Mechanism of Action (MoA) is a challenging task in the drug discovery process, but it is important in order to rationalise phenotypic findings and to anticipate potenti Show more
The elucidation of a compound's Mechanism of Action (MoA) is a challenging task in the drug discovery process, but it is important in order to rationalise phenotypic findings and to anticipate potential side-effects. Bioinformatic approaches, advances in machine learning techniques and the increasing deposition of high-throughput data in public databases have significantly contributed to recent advances in the field, but it is not straightforward to decide which data and methods are most suitable to use in a given case. In this review, we focus on these methods and data and their applications in generating MoA hypotheses for subsequent experimental validation. We discuss compound-specific data such as -omics, cell morphology and bioactivity data, as well as commonly used supplementary prior knowledge such as network and pathway data, and provide information on databases where this data can be accessed. In terms of methodologies, we discuss both well-established methods (connectivity mapping, pathway enrichment) as well as more developing methods (neural networks and multi-omics integration). Finally, we review case studies where the MoA of a compound was successfully suggested from computational analysis by incorporating multiple data modalities and/or methodologies. Our aim for this review is to provide researchers with insights into the benefits and drawbacks of both the data and methods in terms of level of understanding, biases and interpretation – and to highlight future avenues of investigation which we foresee will improve the field of MoA elucidation, including greater public access to -omics data and methodologies which are capable of data integration. Show less
Abstract In eukaryotes, three RNA polymerases (RNAPs) play essential roles in the synthesis of various types of RNA: namely, RNAPI for rRNA; RNAPII for mRNA and most snRNAs; and RNAPIII for tRNA and Show more
Abstract In eukaryotes, three RNA polymerases (RNAPs) play essential roles in the synthesis of various types of RNA: namely, RNAPI for rRNA; RNAPII for mRNA and most snRNAs; and RNAPIII for tRNA and other small RNAs. All three RNAPs possess a short flexible tail derived from their common subunit RPB6. However, the function of this shared N-terminal tail (NTT) is not clear. Here we show that NTT interacts with the PH domain (PH-D) of the p62 subunit of the general transcription/repair factor TFIIH, and present the structures of RPB6 unbound and bound to PH-D by nuclear magnetic resonance (NMR). Using available cryo-EM structures, we modelled the activated elongation complex of RNAPII bound to TFIIH. We also provide evidence that the recruitment of TFIIH to transcription sites through the p62–RPB6 interaction is a common mechanism for transcription-coupled nucleotide excision repair (TC-NER) of RNAPI- and RNAPII-transcribed genes. Moreover, point mutations in the RPB6 NTT cause a significant reduction in transcription of RNAPI-, RNAPII- and RNAPIII-transcribed genes. These and other results show that the p62–RPB6 interaction plays multiple roles in transcription, TC-NER, and cell proliferation, suggesting that TFIIH is engaged in all RNAP systems. Show less
Background Chemotherapy, radiotherapy, targeted therapy and immunotherapy have demonstrated expected clinical efficacy, while drug resistance remains the predominant limiting factor to therapeutic fa Show more
Background Chemotherapy, radiotherapy, targeted therapy and immunotherapy have demonstrated expected clinical efficacy, while drug resistance remains the predominant limiting factor to therapeutic failure in patients with colorectal cancer (CRC). Although there have been numerous basic and clinical studies on CRC resistance in recent years, few publications utilized the bibliometric method to evaluate this field. The objective of current study was to provide a comprehensive analysis of the current state and changing trends of drug resistance in CRC over the past 20 years. Methods The Web of Science Core Collection (WOSCC) was utilized to extracted all studies regarding drug resistance in CRC during 2002-2021. CiteSpace and online platform of bibliometrics were used to evaluate the contributions of various countries/regions, institutions, authors and journals in this field. Moreover, the recent research hotspots and promising future trends were identified through keywords analysis by CiteSpace and VOSviewer. Results 1451 related publications from 2002 to 2021 in total were identified and collected. The number of global publications in this field has increased annually. China and the USA occupied the top two places with respect to the number of publications, contributing more than 60% of global publications. Sun Yat-sen University and Oncotarget were the institution and journal which published the most papers, respectively. Bardelli A from Italy was the most prolific writer and had the highest H-index. Keywords burst analysis identified that “Growth factor receptor”, “induced apoptosis” and “panitumumab” were the ones with higher burst strength in the early stage of this field. Analysis of keyword emergence time showed that “oxaliplatin resistance”, “MicroRNA” and “epithelial mesenchymal transition (EMT)” were the keywords with later average appearing year (AAY). Conclusions The number of publications and research interest on drug resistance in CRC have been increasing annually. The USA and China were the main driver and professor Bardelli A was the most outstanding researcher in this field. Previous studies have mainly concentrated on growth factor receptor and induced apoptosis. Oxaliplatin resistance, microRNA and EMT as recently appeared frontiers of research that should be closely tracked in the future. Show less
Platinum-based anticancer drugs represented by cisplatin play important roles in the treatment of various solid tumors. However, their applications are largely compromised by drug resistance and side Show more
Platinum-based anticancer drugs represented by cisplatin play important roles in the treatment of various solid tumors. However, their applications are largely compromised by drug resistance and side effects. Much effort has been made to circumvent the drug resistance and general toxicity of these drugs. Among multifarious designs, monofunctional platinum(II) complexes with a general formula of [Pt(3A)Cl] + (A: Ammonia or amine) stand out as a class of “non-traditional” anticancer agents hopeful to overcome the defects of current platinum drugs. This review aims to summarize the development of monofunctional platinum(II) complexes in recent years. They are classified into four categories: fluorescent complexes, photoactive complexes, targeted complexes, and miscellaneous complexes. The intention behind the designs is either to visualize the cellular distribution, or to reduce the side effects, or to improve the tumor selectivity, or inhibit the cancer cells through non-DNA targets. The information provided by this review may inspire researchers to conceive more innovative complexes with potent efficacy to shake off the drawbacks of platinum anticancer drugs. Show less
Background: Angiotensin II receptor blockers were designed as therapeutic agents to block the binding site of the angiotensin II receptor type 1 (AT1R). Methodology: The structure of tel Show more
Background: Angiotensin II receptor blockers were designed as therapeutic agents to block the binding site of the angiotensin II receptor type 1 (AT1R). Methodology: The structure of telmisartan was modified by coordination to the biometal Zn(II), resulting in the compound ZnTelm. Its antihypertensive activity and cellular mechanisms in comparison to telmisartan were studied. Results: Compared with telmisartan, ZnTelm displayed stronger binding to AT1R (binding studies on AT1R-transfected human embryonic kidney cells) and a greater reduction of reactive oxygen species and cytosolic calcium concentration induced by angiotensin II. The antihypertensive activity of the complex (assessed in an N(G)-Nitro-L-arginine methyl ester-induced hypertension model) was significantly higher. ZnTelm also reduced hypertrophy in aortic artery rings and tubular collagen deposition. Conclusion: ZnTelm enhances the AT1R blockade and consequently its antihypertensive effect. Show less
Cellular oxidative stress is considered an inducer of carcinogenesis but the association of reactive oxygen species (ROS) with cancer is sometimes contradictory. The antihypertensive drugs can Show more
Cellular oxidative stress is considered an inducer of carcinogenesis but the association of reactive oxygen species (ROS) with cancer is sometimes contradictory. The antihypertensive drugs candesartan and valsartan were reported to behave as antioxidant agents. In the present study, we prepared their Zn(II) coordination complexes, [ZnCand(H2O)2]·2H2O (ZnCand) and [ZnVals(H2O)2] (ZnVals), and determined that they also depleted ROS by the induction of a reductive state in response to glutathione (GSH) generation and decreased lung cancer cell viability (IC50 = 175 and 220 µM, respectively), while being non-cytotoxic for normal lung fibroblasts (MRC5). The Zn complexes affected the mitochondria membrane, increased the pro- and anti-apoptotic protein ratio, Bax/Bcl-XL, and caspase-9 activation, by late apoptosis. Their co-incubation with N-acetylcysteine (NAC) exacerbated ROS reduction and increased cell death, whereas the H2O2 co-treatment restored the ROS values and normal cell growth. These data suggest that the excess reducing equivalents and low levels of ROS are also critical for the functioning of A549 cells.
Show less
Simple Summary The gene-regulatory factors ATF5, CEBPB and CEBPD promote survival, growth, metastasis and treatment resistance of a range of cancer cell types. Presently, no drugs target all three at Show more
Simple Summary The gene-regulatory factors ATF5, CEBPB and CEBPD promote survival, growth, metastasis and treatment resistance of a range of cancer cell types. Presently, no drugs target all three at once. Here, with the aim of treating cancers, we designed novel cell-penetrating peptides that interact with and inactivate all three. The peptides Bpep and Dpep kill a range of cancer cell types in culture and in animals. In animals with tumors, they also significantly increase survival time. In contrast, they do not affect survival of non-cancer cells and have no apparent side effects in animals. The peptides work in combination with other anti-cancer treatments. Mechanism studies of how the peptides kill cancer cells indicate a decrease in survival proteins and increase in death proteins. These studies support the potential of Bpep and Dpep as novel, safe agents for the treatment of a variety of cancer types, both as mono- and combination therapies. Abstract Transcription factors are key players underlying cancer formation, growth, survival, metastasis and treatment resistance, yet few drugs exist to directly target them. Here, we characterized the in vitro and in vivo anti-cancer efficacy of novel synthetic cell-penetrating peptides (Bpep and Dpep) designed to interfere with the formation of active leucine-zipper-based dimers by CEBPB and CEBPD, transcription factors implicated in multiple malignancies. Both peptides similarly promoted apoptosis of multiple tumor lines of varying origins, without such effects on non-transformed cells. Combined with other treatments (radiation, Taxol, chloroquine, doxorubicin), the peptides acted additively to synergistically and were fully active on Taxol-resistant cells. The peptides suppressed expression of known direct CEBPB/CEBPD targets IL6 , IL8 and asparagine synthetase ( ASNS ), supporting their inhibition of transcriptional activation. Mechanisms by which the peptides trigger apoptosis included depletion of pro-survival survivin and a required elevation of pro-apoptotic BMF. Bpep and Dpep significantly slowed tumor growth in mouse models without evident side effects. Dpep significantly prolonged survival in xenograft models. These findings indicate the efficacy and potential of Bpep and Dpep as novel agents to treat a variety of cancers as mono- or combination therapies. Show less
The association of proteins with metals, metalation, is challenging because the tightest binding metals are rarely the correct ones. Inside cells, correct metalation is enabled by controlled bioavaila Show more
The association of proteins with metals, metalation, is challenging because the tightest binding metals are rarely the correct ones. Inside cells, correct metalation is enabled by controlled bioavailability plus extra mechanisms for tricky combinations such as iron and manganese. Show less
Abstract Significance: Mitochondria are the energetic, metabolic, redox, and information signaling centers of the cell. Substrate pressure, mitochondrial network dynamics, and cristae morphology Show more
Abstract Significance: Mitochondria are the energetic, metabolic, redox, and information signaling centers of the cell. Substrate pressure, mitochondrial network dynamics, and cristae morphology state are integrated by the protonmotive force Δ p or its potential component, Δ Ψ , which are attenuated by proton backflux into the matrix, termed uncoupling. The mitochondrial uncoupling proteins (UCP1–5) play an eminent role in the regulation of each of the mentioned aspects, being involved in numerous physiological events including redox signaling. Recent Advances: UCP2 structure, including purine nucleotide and fatty acid (FA) binding sites, strongly support the FA cycling mechanism: UCP2 expels FA anions, whereas uncoupling is achieved by the membrane backflux of protonated FA. Nascent FAs, cleaved by phospholipases, are preferential. The resulting Δ p dissipation decreases superoxide formation dependent on Δ p . UCP-mediated antioxidant protection and its impairment are expected to play a major role in cell physiology and pathology. Moreover, UCP2-mediated aspartate, oxaloacetate, and malate antiport with phosphate is expected to alter metabolism of cancer cells. Critical Issues: A wide range of UCP antioxidant effects and participations in redox signaling have been reported; however, mechanisms of UCP activation are still debated. Switching off/on the UCP2 protonophoretic function might serve as redox signaling either by employing/releasing the extra capacity of cell antioxidant systems or by directly increasing/decreasing mitochondrial superoxide sources. Rapid UCP2 degradation, FA levels, elevation of purine nucleotides, decreased Mg 2+ , or increased pyruvate accumulation may initiate UCP-mediated redox signaling. Future Directions: Issues such as UCP2 participation in glucose sensing, neuronal (synaptic) function, and immune cell activation should be elucidated. Antioxid. Redox Signal. 29, 667–714. Show less
Lipid droplet (LD) accumulation is a now well-recognised hallmark of cancer. However, the significance of LD accumulation in colorectal cancer (CRC) biology is incompletely understood under chemothera Show more
Lipid droplet (LD) accumulation is a now well-recognised hallmark of cancer. However, the significance of LD accumulation in colorectal cancer (CRC) biology is incompletely understood under chemotherapeutic conditions. Since drug resistance is a major obstacle to treatment success, we sought to determine the contribution of LD accumulation to chemotherapy resistance in CRC. Here we show that LD content of CRC cells positively correlates with the expression of lysophosphatidylcholine acyltransferase 2 (LPCAT2), an LD-localised enzyme supporting phosphatidylcholine synthesis. We also demonstrate that LD accumulation drives cell-death resistance to 5-fluorouracil and oxaliplatin treatments both in vitro and in vivo. Mechanistically, LD accumulation impairs caspase cascade activation and ER stress responses. Notably, droplet accumulation is associated with a reduction in immunogenic cell death and CD8 + T cell infiltration in mouse tumour grafts and metastatic tumours of CRC patients. Collectively our findings highlight LPCAT2-mediated LD accumulation as a druggable mechanism to restore CRC cell sensitivity. Show less
Highly ordered interactions between immune and metabolic responses are evolutionarily conserved and paramount for tissue and organismal health. Disruption of these interactions underlies the emergence Show more
Highly ordered interactions between immune and metabolic responses are evolutionarily conserved and paramount for tissue and organismal health. Disruption of these interactions underlies the emergence of many pathologies, particularly chronic non-communicable diseases such as obesity and diabetes. Here, we examine decades of research identifying the complex immunometabolic signaling networks and the cellular and molecular events that occur in the setting of altered nutrient and energy exposures and offer a historical perspective. Furthermore, we describe recent advances such as the discovery that a broad complement of immune cells play a role in immunometabolism and the emerging evidence that nutrients and metabolites modulate inflammatory pathways. Lastly, we discuss how this work may eventually lead to tangible therapeutic advancements to promote health. Show less
Mitochondrial Ca 2+ uptake plays a pivotal role both in cell energy balance and in cell fate determination. Studies on the role of mitochondrial Ca 2+ signaling in pathophysiology have been favored Show more
Mitochondrial Ca 2+ uptake plays a pivotal role both in cell energy balance and in cell fate determination. Studies on the role of mitochondrial Ca 2+ signaling in pathophysiology have been favored by the identification of the genes encoding the mitochondrial calcium uniporter (MCU) and its regulatory subunits. Thus, research carried on in the last years on one hand has determined the structure of the MCU complex and its regulation, on the other has uncovered the consequences of dysregulated mitochondrial Ca 2+ signaling in cell and tissue homeostasis. Whether mitochondrial Ca 2+ uptake can be exploited as a weapon to counteract cancer progression is debated. In this review, we summarize recent research on the molecular structure of the MCU, the regulatory mechanisms that control its activity and its relevance in pathophysiology, focusing in particular on its role in cancer progression. Show less
Abstract The coordination compound of the antihypertensive ligand irbesartan (irb) with copper(II) (CuIrb) was synthesized and characterized by FTIR, FT-Raman, UV–visible, reflectance and EPR spectros Show more
Abstract The coordination compound of the antihypertensive ligand irbesartan (irb) with copper(II) (CuIrb) was synthesized and characterized by FTIR, FT-Raman, UV–visible, reflectance and EPR spectroscopies. Experimental evidence allowed the implementation of structural and vibrational studies by theoretical calculations made in the light of the density functional theory (DFT). This compound was designed to induce structural modifications on the ligand. No antioxidant effects were displayed by both compounds, though CuIrb behaved as a weak 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) scavenger (IC50 = 425 μM). The measurements of the contractile capacity on human mesangial cell lines showed that CuIrb improved the antihypertensive effects of the parent medication. In vitro cell growth inhibition against prostate cancer cell lines (LNCaP and DU 145) was measured for CuIrb, irbesartan and copper(II). These cell lines have been selected since the angiotensin II type 1 (AT1) receptor (that was blocked by the angiotensin receptor blockers, ARB) has been identified in them. The complex exerted anticancer behavior (at 100 μM) improving the activity of the ligand. Flow cytometry determinations were used to determine late apoptotic mechanisms of cell death. Graphical Abstract Experimental and DFT characterization of an irbesartan copper(II) complex has been performed. The complex exhibits low scavenging activity against DPPH· and significant growth inhibition of LNCaP and DU 145 prostate cancer cell lines. Flow cytometry determinations were used to determine late apoptotic mechanisms of cell death. This compound improved the antihypertensive effect of irbesartan. This effect was observed earlier for the mononuclear Cu–candesartan complex, but not in structurally modified sartans forming dinuclear or octanuclear Cu–sartan compounds. Show less
Various commonly used organic solvents were dried with several different drying agents. A glovebox-bound coulometric Karl Fischer apparatus with a two-compartment measuring cell was used to determine Show more
Various commonly used organic solvents were dried with several different drying agents. A glovebox-bound coulometric Karl Fischer apparatus with a two-compartment measuring cell was used to determine the efficiency of the drying process. Recommendations are made relating to optimum drying agents/conditions that can be used to rapidly and reliably generate solvents with low residual water content by means of commonly available materials found in most synthesis laboratories. The practical method provides for safer handling and drying of solvents than methods calling for the use of reactive metals, metal hydrides, or solvent distillation. Show less
Dying tumour cells can elicit a potent anticancer immune response by exposing the calreticulin (CRT)/ERp57 complex on the cell surface before the cells manifest any signs of apoptosis. Here, we enumer Show more
Dying tumour cells can elicit a potent anticancer immune response by exposing the calreticulin (CRT)/ERp57 complex on the cell surface before the cells manifest any signs of apoptosis. Here, we enumerate elements of the pathway that mediates pre-apoptotic CRT/ERp57 exposure in response to several immunogenic anticancer agents. Early activation of the endoplasmic reticulum (ER)-sessile kinase PERK leads to phosphorylation of the translation initiation factor eIF2alpha, followed by partial activation of caspase-8 (but not caspase-3), caspase-8-mediated cleavage of the ER protein BAP31 and conformational activation of Bax and Bak. Finally, a pool of CRT that has transited the Golgi apparatus is secreted by SNARE-dependent exocytosis. Knock-in mutation of eIF2alpha (to make it non-phosphorylatable) or BAP31 (to render it uncleavable), depletion of PERK, caspase-8, BAP31, Bax, Bak or SNAREs abolished CRT/ERp57 exposure induced by anthracyclines, oxaliplatin and ultraviolet C light. Depletion of PERK, caspase-8 or SNAREs had no effect on cell death induced by anthracyclines, yet abolished the immunogenicity of cell death, which could be restored by absorbing recombinant CRT to the cell surface. Show less
We describe a 1.2 A X-ray structure of a double-stranded B-DNA dodecamer (the Dickerson Dodecamer, DDD, [d(CGCGAATTCGCG)]2) associated with a cytotoxic platinum(II) complex, [{trans-Pt(NH3)2(NH2(CH2)6 Show more
We describe a 1.2 A X-ray structure of a double-stranded B-DNA dodecamer (the Dickerson Dodecamer, DDD, [d(CGCGAATTCGCG)]2) associated with a cytotoxic platinum(II) complex, [{trans-Pt(NH3)2(NH2(CH2)6(NH3+)}2-mu-{trans-Pt(NH3)2(NH2(CH2)6NH2)2}] (TriplatinNC). TriplatinNC is a multifunctional DNA ligand, with three cationic Pt(II) centers, and directional hydrogen bonding functionalities, linked by flexible hydrophobic segments, but without the potential for covalent interaction. TriplatinNC does not intercalate nor does it bind in either groove. Instead, it binds to phosphate oxygen atoms and thus associates with the backbone. The three square-planar tetra-am(m)ine Pt(II) coordination units form bidentate N...O...N complexes with OP atoms, in a motif we call the Phosphate Clamp. The geometry is conserved among the 8 observed phosphate clamps in this structure. The interaction appears to prefer O2P over O1P atoms (frequency of interaction is O2P > O1P, base and sugar oxygens > N). The high repetition and geometric regularity of the motif suggests that this type of Pt(II) center can be developed as a modular nucleic acid binding device with general utility. TriplatinNC extends along the phosphate backbone, in a mode of binding we call "Backbone Tracking" and spans the minor groove in a mode of binding we call "Groove Spanning". Electrostatic forces appear to induce modest DNA bending into the major groove. This bending may be related to the direct coordination of a sodium cation by a DNA base, with unprecedented inner-shell (direct) coordination of penta-hydrated sodium at the O6 atom of a guanine. Show less