Investigation of the potential effects of estrogen receptor modulators on immune checkpoint molecules.

Immune checkpoints regulate the immune system response. Recent studies suggest that flavonoids, known as phytoestrogens, may inhibit the PD-1/PD-L1 axis. We explored the potential of estrogens and 17 Selective Estrogen Receptor Modulators (SERMs) as inhibiting ligands for immune checkpoint proteins (CTLA-4, PD-L1, PD-1, and CD80). Our docking studies revealed strong binding energy values for quinestrol, quercetin, and bazedoxifene, indicating their potential to inhibit PD-1 and CTLA-4. Quercetin and bazedoxifene, known to modulate EGFR and IL-6R alongside estrogen receptors, can influence the immune checkpoint functionality. We discuss the impact of SERMs on PD-1 and CTLA-4, suggesting that these SERMs could have therapeutic effects through immune checkpoint inhibition. This study highlights the potential of SERMs as inhibitory ligands for immune checkpoint proteins, emphasizing the importance of considering PD-1 and CTLA-4 inhibition when evaluating SERMs as therapeutic agents. Our findings open new avenues for cancer immunotherapy by exploring the interaction between various SERMs and immune checkpoint pathways.

A Fast HPLC/UV Method for Determination of Ketoprofen in Cellular Media.

A simple, sensitive and quick HPLC method was developed for the determination of ketoprofen in cell culture media (EMEM, DMEM, RPMI). Separation was performed using a gradient on the C18 column with a mobile phase of acetonitrile and miliQ water acidified by 0.1 % (v/v) formic acid. The method was validated for parameters including linearity, accuracy, precision, limit of quantitation and limit of detection, as well as robustness. The response was found linear over the range of 3-100 µg/mL as demonstrated by the acquired value of correlation coefficient R2=0.9997. The described method is applicable for determination of various pharmacokinetic aspects of ketoprofen in vitro.

Combination of quinoxaline with pentamethinium system: Mitochondrial staining and targeting.

Pentamethinium indolium salts are promising fluorescence probes and anticancer agents with high mitochondrial selectivity. We synthesized two indolium pentamethinium salts: a cyclic form with quinoxaline directly incorporated in the pentamethinium chain (cPMS) and an open form with quinoxaline substitution in the γ-position (oPMS). To better understand their properties, we studied their interaction with mitochondrial phospholipids (cardiolipin and phosphatidylcholine) by spectroscopic methods (UV-Vis, fluorescence, and NMR spectroscopy). Both compounds displayed significant affinity for cardiolipin and phosphatidylcholine, which was associated with a strong change in their UV-Vis spectra. Nevertheless, we surprisingly observed that fluorescence properties of cPMS changed in complex with both cardiolipin and phosphatidylcholine, whereas those of oPMS only changed in complex with cardiolipin. Both salts, especially cPMS, display high usability in mitochondrial imaging and are cytotoxic for cancer cells. The above clearly indicates that conjugates of pentamethinium and quinoxaline group, especially cPMS, represent promising structural motifs for designing mitochondrial-specific agents.

TET protein inhibitors: Potential and limitations.

TET proteins (methylcytosine dioxygenases) play an important role in the regulation of gene expression. Dysregulation of their activity is associated with many serious pathogenic states such as oncological diseases. Regulation of their activity by specific inhibitors could represent a promising therapeutic strategy. Therefore, this review describes various types of TET protein inhibitors in terms of their inhibitory mechanism and possible applicability. The potential and possible limitations of this approach are thoroughly discussed in the context of TET protein functionality in living systems. Furthermore, possible therapeutic strategies based on the inhibition of TET proteins are presented and evaluated, especially in the field of oncological diseases.

Therapeutic potential and limitations of curcumin as antimetastatic agent.

Treatment of metastatic cancer is one of the biggest challenges in anticancer therapy. Curcumin is interesting nature polyphenolic compound with unique biological and medicinal effects, including repression of metastases. High impact studies imply that curcumin can modulate the immune system, independently target various metastatic signalling pathways, and repress migration and invasiveness of cancer cells. This review discusses the potential of curcumin as an antimetastatic agent and describes potential mechanisms of its antimetastatic activity. In addition, possible strategies (curcumin formulation, optimization of the method of administration and modification of its structure motif) to overcome its limitation such as low solubility and bioactivity are also presented. These strategies are discussed in the context of clinical trials and relevant biological studies.

Targeting of the Mitochondrial TET1 Protein by Pyrrolo[3,2-b]pyrrole Chelators.

Targeting of epigenetic mechanisms, such as the hydroxymethylation of DNA, has been intensively studied, with respect to the treatment of many serious pathologies, including oncological disorders. Recent studies demonstrated that promising therapeutic strategies could potentially be based on the inhibition of the TET1 protein (ten-eleven translocation methylcytosine dioxygenase 1) by specific iron chelators. Therefore, in the present work, we prepared a series of pyrrolopyrrole derivatives with hydrazide (1) or hydrazone (2-6) iron-binding groups. As a result, we determined that the basic pyrrolo[3,2-b]pyrrole derivative 1 was a strong inhibitor of the TET1 protein (IC50 = 1.33 µM), supported by microscale thermophoresis and molecular docking. Pyrrolo[3,2-b]pyrroles 2-6, bearing substituted 2-hydroxybenzylidene moieties, displayed no significant inhibitory activity. In addition, in vitro studies demonstrated that derivative 1 exhibits potent anticancer activity and an exclusive mitochondrial localization, confirmed by Pearson's correlation coefficient of 0.92.

Azulene hydrazide-hydrazones for selective targeting of pancreatic cancer cells.

Dysregulation of iron homeostasis is one of the important processes in the development of many oncological diseases, such as pancreatic cancer. Targeting it with specific agents, such as an iron chelator, are promising therapeutic methods. In this study, we tested the cytotoxicity of novel azulene hydrazide-hydrazone-based chelators against pancreatic cancer cell lines (MIA PaCa-2, PANC-1, AsPC-1). All prepared chelators (compounds 4-6) showed strong cytotoxicity against pancreatic cancer cell lines and high selectivity for cancer cell lines compared to the healthy line. Their cytotoxicity is lower than thiosemicarbazone-based chelators Dp44mT and DpC, but significantly higher than hydroxamic acid-based chelator DFO. The chelator tested showed mitochondrial and lysosomal co-localization and its mechanism of action was based on the induction of hypoxia-inducible factor-1-alpha (HIF-1α), N-myc downstream-regulated gene-1 (NDRG1) and transferrin receptor 1 (TfR1). This strongly implies that the cytotoxic effect of tested chelators could be associated with mitophagy induction. Lipinski's rule of five analyses was performed to determine whether the prepared compounds had properties ensuring their bioavailability. In addition, the drug-likeness and drug-score were calculated and discussed.

Pentamethinium salts suppress key metastatic processes by regulating mitochondrial function and inhibiting dihydroorotate dehydrogenase respiration.

Mitochondria generate energy and building blocks required for cellular growth and function. The notion that mitochondria are not involved in the cancer growth has been challenged in recent years together with the emerging idea of mitochondria as a promising therapeutic target for oncologic diseases. Pentamethinium salts, cyan dyes with positively charged nitrogen on the benzothiazole or indole part of the molecule, were originally designed as mitochondrial probes. In this study, we show that pentamethinium salts have a strong effect on mitochondria, suppressing cancer cell proliferation and migration. This is likely linked to the strong inhibitory effect of the salts on dihydroorotate dehydrogenase (DHODH)-dependent respiration that has a key role in the de novo pyrimidine synthesis pathway. We also show that pentamethinium salts cause oxidative stress, redistribution of mitochondria, and a decrease in mitochondria mass. In conclusion, pentamethinium salts present novel anti-cancer agents worthy of further studies.

New-Generation Heterocyclic Bis-Pentamethinium Salts as Potential Cytostatic Drugs with Dual IL-6R and Mitochondria-Targeting Activity.

IL-6 signaling is involved in the pathogenesis of a number of serious diseases, including chronic inflammation and cancer. Targeting of IL-6 receptor (IL-6R) by small molecules is therefore an intensively studied strategy in cancer treatment. We describe the design, synthesis, and characteristics of two new bis-pentamethinium salts 5 and 6 (meta and para) bearing indole moieties. Molecular docking studies showed that both compounds have the potential to bind IL-6R (free energy of binding -9.5 and -8.1 kcal/mol). The interaction with IL-6R was confirmed using microscale thermophoresis analyses, which revealed that both compounds had strong affinity for the IL-6R (experimentally determined dissociation constants 26.5 ± 2.5 nM and 304 ± 27.6 nM, respectively). In addition, both compounds were cytotoxic for a broad spectrum of cancer cell lines in micromolar concentrations, most likely due to their accumulation in mitochondria and inhibition of mitochondrial respiration. In summary, the structure motif of bis-pentamethinium salts represents a promising starting point for the design of novel multitargeting compounds with the potential to inhibit IL-6 signaling and simultaneously target mitochondrial metabolism in cancer cells.

Fractional Flow Reserve Versus Instantaneous Wave-Free Ratio in Assessment of Lesion Hemodynamic Significance and Explanation of their Discrepancies. International, Multicenter and Prospective Trial: The FiGARO Study.

Background The FiGARO (FFR versus iFR in Assessment of Hemodynamic Lesion Significance, and an Explanation of Their Discrepancies) trial is a prospective registry searching for predictors of fractional flow reserve/instantaneous wave-free ratio (FFR/iFR) discrepancy. Methods and Results FFR/iFR were analyzed using a Verrata wire, and coronary flow reserve was analyzed using a Combomap machine (both Philips-Volcano). The risk polymorphisms for endothelial nitric oxide synthase and for heme oxygenase-1 were analyzed. In total, 1884 FFR/iFR measurements from 1564 patients were included. The FFR/iFR discrepancy occurred in 393 measurements (20.9%): FFRp (positive)/iFRn (negative) type (264 lesions, 14.0%) and FFRn/iFRp (129 lesions, 6.8%) type. Coronary flow reserve was measured in 343 lesions, correlating better with iFR (R=0.56, P<0.0001) than FFR (R=0.36, P<0.0001). The coronary flow reserve value in FFRp/iFRn lesions (2.24±0.7) was significantly higher compared with both FFRp/iFRp (1.39±0.36), and FFRn/iFRn lesions (1.8±0.64, P<0.0001). Multivariable logistic regression analysis confirmed (1) sex, age, and lesion location in the right coronary artery as predictors for FFRp/iFRn discrepancy; and (2) hemoglobin level, smoking, and renal insufficiency as predictors for FFRn/iFRp discrepancy. The FFRn/iFRp type of discrepancy was significantly more frequent in patients with both risk types of polymorphisms (endothelial nitric oxide synthaser+heme oxygenase-1r): 8 patients (24.2%) compared with FFRp/iFRn type of discrepancy: 2 patients (5.9%), P=0.03. Conclusions Predictors for FFRp/iFRn discrepancy were sex, age, and location in the right coronary artery. Predictors for FFRn/iFRp were hemoglobin level, smoking, and renal insufficiency. The risk type of polymorphism in endothelial nitric oxide synthase and heme oxygenase-1 genes was more frequently found in patients with FFRn/iFRp type of discrepancy. Registration URL: https://clinicaltrials.gov; Unique identifier: NCT03033810.

Molecular characterization of a novel His333Arg variant of human protoporphyrinogen oxidase IX.

Variegate porphyria is caused by mutations in the protoporphyrinogen oxidase IX (PPOX, EC 1.3.3.4) gene, resulting in reduced overall enzymatic activity of PPOX in human tissues. Recently, we have identified the His333Arg mutation in the PPOX protein (PPOX(H333R)) as a putative founder mutation in the Moroccan Jewish population. Herein we report the molecular characterization of PPOX(H333R) in vitro and in cells. Purified recombinant PPOX(H333R) did not show any appreciable enzymatic activity in vitro, corroborating the clinical findings. Biophysical experiments and molecular modeling revealed that PPOX(H333R) is not folded properly and fails to adopt its native functional three-dimensional conformation due to steric clashes in the vicinity of the active site of the enzyme. On the other hand, PPOX(H333R) subcellular distribution, as evaluated by live-cell confocal microscopy, is unimpaired suggesting that the functional three-dimensional fold is not required for efficient transport of the polypeptide chain into mitochondria. Overall, the data presented here provide molecular underpinnings of the pathogenicity of PPOX(H333R) and might serve as a blueprint for deciphering whether a given PPOX variant represents a disease-causing mutation.

Circulating Tumour Cells (CTCs) in NSCLC: From Prognosis to Therapy Design.

Designing optimal (neo)adjuvant therapy is a crucial aspect of the treatment of non-small-cell lung carcinoma (NSCLC). Standard methods of chemotherapy, radiotherapy, and immunotherapy represent effective strategies for treatment. However, in some cases with high metastatic activity and high levels of circulating tumour cells (CTCs), the efficacy of standard treatment methods is insufficient and results in treatment failure and reduced patient survival. CTCs are seen not only as an isolated phenomenon but also a key inherent part of the formation of metastasis and a key factor in cancer death. This review discusses the impact of NSCLC therapy strategies based on a meta-analysis of clinical studies. In addition, possible therapeutic strategies for repression when standard methods fail, such as the administration of low-toxicity natural anticancer agents targeting these phenomena (curcumin and flavonoids), are also discussed. These strategies are presented in the context of key mechanisms of tumour biology with a strong influence on CTC spread and metastasis (mechanisms related to tumour-associated and -infiltrating cells, epithelial-mesenchymal transition, and migration of cancer cells).

Heterologous expression and purification of recombinant human protoporphyrinogen oxidase IX: A comparative study.

Human protoporphyrinogen oxidase IX (hPPO) is an oxygen-dependent enzyme catalyzing the penultimate step in the heme biosynthesis pathway. Mutations in the enzyme are linked to variegate porphyria, an autosomal dominant metabolic disease. Here we investigated eukaryotic cells as alternative systems for heterologous expression of hPPO, as the use of a traditional bacterial-based system failed to produce several clinically relevant hPPO variants. Using bacterially-produced hPPO, we first analyzed the impact of N-terminal tags and various detergent on hPPO yield, and specific activity. Next, the established protocol was used to compare hPPO constructs heterologously expressed in mammalian HEK293T17 and insect Hi5 cells with prokaryotic overexpression. By attaching various fusion partners at the N- and C-termini of hPPO we also evaluated the influence of the size and positioning of fusion partners on expression levels, specific activity, and intracellular targeting of hPPO fusions in mammalian cells. Overall, our results suggest that while enzymatically active hPPO can be heterologously produced in eukaryotic systems, the limited availability of the intracellular FAD co-factor likely negatively influences yields of a correctly folded protein making thus the E.coli a system of choice for recombinant hPPO overproduction. At the same time, PPO overexpression in eukaryotic cells might be preferrable in cases when the effects of post-translational modifications (absent in bacteria) on target protein functions are studied.

Iron Complexes of Flavonoids-Antioxidant Capacity and Beyond.

Flavonoids are common plant natural products able to suppress ROS-related damage and alleviate oxidative stress. One of key mechanisms, involved in this phenomenon is chelation of transition metal ions. From a physiological perspective, iron is the most significant transition metal, because of its abundance in living organisms and ubiquitous involvement in redox processes. The chemical, pharmaceutical, and biological properties of flavonoids can be significantly affected by their interaction with transition metal ions, mainly iron. In this review, we explain the interaction of various flavonoid structures with Fe(II) and Fe(III) ions and critically discuss the influence of chelated ions on the flavonoid biochemical properties. In addition, specific biological effects of their iron metallocomplexes, such as the inhibition of iron-containing enzymes, have been included in this review.

Spectroscopic study of in situ-formed metallocomplexes of proton pump inhibitors in water.

Proton pump inhibitors, such as omeprazole, pantoprazole and lansoprazole, are an important group of clinically used drugs. Generally, they are considered safe without direct toxicity. Nevertheless, their long-term use can be associated with a higher risk of some serious pathological states (e.g. amnesia and oncological and neurodegenerative states). It is well known that dysregulation of the metabolism of transition metals (especially iron ions) plays a significant role in these pathological states and that the above drugs can form complexes with metal ions. However, to the best of our knowledge, this phenomenon has not yet been described in water systems. Therefore, we studied the interaction between these drugs and transition metal ions in the surrounding water environment (water/DMSO, 99:1, v/v) by absorption spectroscopy. In the presence of Fe(III), a strong redshift was observed, and more importantly, the affinities of the drugs (represented as binding constants) were strong enough, especially in the case of omeprazole, so that the formation of a metallocomplex cannot be excluded during the explanation of their side effects.

Novel Mitochondria-targeted Drugs for Cancer Therapy.

The search for mitochondria-targeted drugs has dramatically risen over the last decade. Mitochondria are essential organelles serving not only as a powerhouse of the cell but also as a key player in cell proliferation and cell death. Their central role in the energetic metabolism, calcium homeostasis and apoptosis makes them an intriguing field of interest for cancer pharmacology. In cancer cells, many mitochondrial signaling and metabolic pathways are altered. These changes contribute to cancer development and progression. Due to changes in mitochondrial metabolism and changes in membrane potential, cancer cells are more susceptible to mitochondria-targeted therapy. The loss of functional mitochondria leads to the arrest of cancer progression and/or a cancer cell death. Identification of mitochondrial changes specific for tumor growth and progression, rational development of new mitochondria-targeted drugs and research on delivery agents led to the advance of this promising area. This review will highlight the current findings in mitochondrial biology, which are important for cancer initiation, progression and resistance, and discuss approaches of cancer pharmacology with a special focus on the anti-cancer drugs referred to as 'mitocans'.

Anticancer pentamethinium salt is a potent photosensitizer inducing mitochondrial disintegration and apoptosis upon red light illumination.

Despite progress in the development and application of novel therapeutic agents, cancer remains a major cause of death worldwide. Therefore, there is a need for new approaches to increase therapeutic options and efficiency. The metabolism of cancer cells differs from that of non-malignant cells and their mitochondria show altered activities that can be utilized as a target for drug development. Salt 1 is a low-molecular weight heterocyclic compound of the polymethine class that accumulates in the mitochondria of cancer cells and selectively disrupts their metabolism. Salt 1 leads to a non-apoptotic form of cell death in vitro that is associated with an autophagic cellular response and eventual metabolic collapse, and inhibits human tumor xenograft growth in vivo without apparent toxicity for normal cells. As a pentamethinium compound, salt 1 exhibits intrinsic fluorescence and is a candidate for photosensitization after excitation by appropriate wavelengths of light. Herein, we report that salt 1 is a potent photosensitizer, which generates a photodynamic effect and provides enhanced cytotoxicity compared to salt 1 without light exposure. Importantly, photosensitization is optimally induced by red light, which is used clinically for photosensitization and penetrates further into tissues than lower wavelengths. Cancer cells treated with non-cytotoxic doses of salt 1 and subsequently exposed to 630 nm light show severely damaged mitochondria, manifested by reduced mitochondrial membrane potential and disintegration of the mitochondrial tubular network. As a consequence, cancer cells lose their proliferative potential and die via apoptosis in the presence of light. These findings indicate that salt 1 is a promising photosensitizer with potential to be combined with 630 nm light to strengthen its efficacy in cancer therapy.

Role of mtDNA disturbances in the pathogenesis of Alzheimer's and Parkinson's disease.

Neurodegenerative diseases (e.g. Alzheimer's and Parkinson's disease) are becoming increasingly problematic to healthcare systems. Therefore, their underlying mechanisms are trending topics of study in medicinal research. Numerous studies have evidenced a strong association between mitochondrial DNA disturbances (e.g. oxidative damage, mutations, and methylation shifts) and the initiation and progression of neurodegenerative diseases. Therefore, this review discusses the risk and development of neurodegenerative diseases in terms of disturbances in mitochondrial DNA and as a part of a complex ecosystem that includes other important mechanisms (e.g. neuroinflammation and the misfolding and aggregation of amyloid-ß peptides, α-synuclein, and tau proteins). In addition, the influence of individual mitochondrial DNA haplogroups on the risk and development of neurodegenerative diseases is also described and discussed.

Formaldehyde Reacts with Amino Acids and Peptides with a Potential Role in Acute Methanol Intoxication.

Methanol, an aliphatic alcohol widely used in the industry, causes acute and chronic intoxications associated with severe long-term health damage, including permanent visual impairment, brain damage, mainly necrosis of the basal ganglia and high mortality due to cancer. However, the role of formaldehyde, an intermediate metabolite of methanol oxidation, in methanol toxicity remains unclear. Thus, we studied the reactivity of several amino acids and peptides in the presence of formaldehyde by identifying products by direct infusion electrospray high-resolution mass spectrometry (MS) and matrix-assisted laser desorption-ionization MS. Cysteine, homocysteine and two peptides, CG and CGAG, provided cyclic products with a +12 amu mass shift with respect to the original compounds. The proposed structures of the products were confirmed by high-resolution tandem MS. Moreover, the formation of the products with +12 amu mass shift was also shown for two biologically relevant peptides, fragments of ipilimumab, which is a human IgG1 monoclonal antibody against cytotoxic T-lymphocyte-associated protein 4. Overall, our experimental results indicate that formaldehyde reacts with some amino acids and peptides, yielding covalently modified structures. Such chemical modifications may induce undesirable changes in the properties and function of vital biomolecules (e.g., hormones, enzymes) and consequently pathogenesis.

Coumarin Tröger's base derivatives with cyanine substitution as selective and sensitive fluorescent lysosomal probes.

The fluorescent probes based on Tröger's base motive with both coumarin and cyanine substitution 11-13 have been synthesized by multi-step synthesis in high overall yields. Intracellular localization of prepared probes have been tested using four different cell lines (HF-P4, BLM, U-2 OS and A-2058). Prepared probes have intensive green and red fluorescence. Co-localization with commercial lysosome specific marker LysoTracker Blue DND 22 has been confirmed that all prepared fluorescent probes labeled lysosomal compartment with high selectivity and probes show excellent brightness at low concentration.