Tumor- and Fibroblast-Derived Cell-Free DNAs Differently Affect the Progression of B16 Melanoma In Vitro and In Vivo

It is widely postulated that the majority of pathologically elevated extracellular or cell-free DNA (cfDNA) in cancer originates from tumor cells; however, evidence has emerged regarding the significant contributions of other cells from the tumor microenvironment. Here, the effect of cfDNA originating from murine B16 melanoma cells and L929 fibroblasts on B16 cells was investigated. It was found that cfDNAL929 increased the viability and migration properties of B16 cells in vitro and their invasiveness in vivo. In contrast, cfDNAB16 exhibited a negative effect on B16 cells, reducing their viability and migration in vitro, which in vivo led to decreased tumor size and metastasis number. It was shown that cell treatment with both cfDNAs resulted in an increase in the expression of genes encoding DNases and the oncogenes Braf, Kras, and Myc. cfDNAL929-treated cells were shown to experience oxidative stress. Gene expression changes in the case of cfDNAB16 treatment are well correlated with the observed decrease in proliferation and migration of B16 cells. The obtained data may indicate the possible involvement of fibroblast DNA in the tumor microenvironment in tumor progression and, potentially, in the formation of new tumor foci due to the transformation of normal cells.

Cholesterol-Modified Anti-Il6 siRNA Reduces the Severity of Acute Lung Injury in Mice

Small interfering RNA (siRNA) holds significant therapeutic potential by silencing target genes through RNA interference. Current clinical applications of siRNA have been primarily limited to liver diseases, while achievements in delivery methods are expanding their applications to various organs, including the lungs. Cholesterol-conjugated siRNA emerges as a promising delivery approach due to its low toxicity and high efficiency. This study focuses on developing a cholesterol-conjugated anti-Il6 siRNA and the evaluation of its potency for the potential treatment of inflammatory diseases using the example of acute lung injury (ALI). The biological activities of different Il6-targeted siRNAs containing chemical modifications were evaluated in J774 cells in vitro. The lead cholesterol-conjugated anti-Il6 siRNA after intranasal instillation demonstrated dose-dependent therapeutic effects in a mouse model of ALI induced by lipopolysaccharide (LPS). The treatment significantly reduced Il6 mRNA levels, inflammatory cell infiltration, and the severity of lung inflammation. IL6 silencing by cholesterol-conjugated siRNA proves to be a promising strategy for treating inflammatory diseases, with potential applications beyond the lungs.

Cholesterol Conjugates of Small Interfering RNA: Linkers and Patterns of Modification

Cholesterol siRNA conjugates attract attention because they allow the delivery of siRNA into cells without the use of transfection agents. In this study, we compared the efficacy and duration of silencing induced by cholesterol conjugates of selectively and totally modified siRNAs and their heteroduplexes of the same sequence and explored the impact of linker length between the 3' end of the sense strand of siRNA and cholesterol on the silencing activity of "light" and "heavy" modified siRNAs. All 3'-cholesterol conjugates were equally active under transfection, but the conjugate with a C3 linker was less active than those with longer linkers (C8 and C15) in a carrier-free mode. At the same time, they were significantly inferior in activity to the 5'-cholesterol conjugate. Shortening the sense strand carrying cholesterol by two nucleotides from the 3'-end did not have a significant effect on the activity of the conjugate. Replacing the antisense strand or both strands with fully modified ones had a significant effect on silencing as well as improving the duration in transfection-mediated and carrier-free modes. A significant 78% suppression of MDR1 gene expression in KB-8-5 xenograft tumors developed in mice promises an advantage from the use of fully modified siRNA cholesterol conjugates in combination chemotherapy.

A Novel 3-meta-Pyridine-1,2,4-oxadiazole Derivative of Glycyrrhetinic Acid as a Safe and Promising Candidate for Overcoming P-Glycoprotein-Mediated Multidrug Resistance in Tumor Cells

Given the pharmacophore properties of the nitrogen-containing moiety in the molecular structure of P-glycoprotein (P-gp) inhibitors, we report the evaluation of the P-gp inhibitory and MDR reversal activities of 2g, a 3-meta-pyridin-1,2,4-oxadiazole derivative of 18βH-glycyrrhetinic acid. Through molecular docking, we have shown that 2g has the potential to directly interact with the transmembrane domain of P-gp with a low free binding energy (-10.2 kcal/mol). Using KB-8-5 human cervical carcinoma cells and RLS40 murine lymphosarcoma cells, both of which exhibit a multidrug-resistant (MDR) phenotype mediated by P-gp activation, we have shown that 2g, at nontoxic concentrations, effectively increased the intracellular accumulation of fluorescent P-gp substrates (rhodamine 123 or doxorubicin (DOX)), leading to a marked sensitization of the model cells to the cytotoxic effect of DOX. Considering the comparable activity of 2g with verapamil, a known P-gp inhibitor, 2g can be considered as a promising candidate for the development of agents capable of overcoming P-gp-mediated MDR in tumor cells.

The Nexus of Inflammation-Induced Epithelial-Mesenchymal Transition and Lung Cancer Progression: A Roadmap to Pentacyclic Triterpenoid-Based Therapies

Lung cancer is the leading cause of cancer-related death worldwide. Its high mortality is partly due to chronic inflammation that accompanies the disease and stimulates cancer progression. In this review, we analyzed recent studies and highlighted the role of the epithelial-mesenchymal transition (EMT) as a link between inflammation and lung cancer. In the inflammatory tumor microenvironment (iTME), fibroblasts, macrophages, granulocytes, and lymphocytes produce inflammatory mediators, some of which can induce EMT. This leads to increased invasiveness of tumor cells and self-renewal of cancer stem cells (CSCs), which are associated with metastasis and tumor recurrence, respectively. Based on published data, we propose that inflammation-induced EMT may be a potential therapeutic target for the treatment of lung cancer. This prospect is partially realized in the development of EMT inhibitors based on pentacyclic triterpenoids (PTs), described in the second part of our study. PTs reduce the metastatic potential and stemness of tumor cells, making PTs promising candidates for lung cancer therapy. We emphasize that the high diversity of molecular mechanisms underlying inflammation-induced EMT far exceeds those that have been implicated in drug development. Therefore, analysis of information on the relationship between the iTME and EMT is of great interest and may provide ideas for novel treatment approaches for lung cancer.

Cholesterol-Conjugated Supramolecular Multimeric siRNAs: Effect of siRNA Length on Accumulation and Silencing In Vitro and In Vivo

Conjugation of small interfering RNA (siRNA) with lipophilic molecules is one of the most promising approaches for delivering siRNA in vivo. The rate of molecular weight-dependent siRNA renal clearance is critical for the efficiency of this process. In this study, we prepared cholesterol-containing supramolecular complexes containing from three to eight antisense strands and examined their accumulation and silencing activity in vitro and in vivo. We have shown for the first time that such complexes with 2'F, 2'OMe, and LNA modifications exhibit interfering activity both in carrier-mediated and carrier-free modes. Silencing data from a xenograft tumor model show that 4 days after intravenous injection of cholesterol-containing monomers and supramolecular trimers, the levels of MDR1 mRNA in the tumor decreased by 85% and 68%, respectively. The in vivo accumulation data demonstrated that the formation of supramolecular structures with three or four antisense strands enhanced their accumulation in the liver. After addition of two PS modifications at the ends of antisense strands, 47% and 67% reductions of Ttr mRNA levels in the liver tissue were detected 7 days after administration of monomers and supramolecular trimers, respectively. Thus, we have obtained a new type of RNAi inducer that is convenient for synthesis and provides opportunities for modifications.

Bronchial Asthma, Airway Remodeling and Lung Fibrosis as Successive Steps of One Process

Bronchial asthma is a heterogeneous disease characterized by persistent respiratory system inflammation, airway hyperreactivity, and airflow obstruction. Airway remodeling, defined as changes in airway wall structure such as extensive epithelial damage, airway smooth muscle hypertrophy, collagen deposition, and subepithelial fibrosis, is a key feature of asthma. Lung fibrosis is a common occurrence in the pathogenesis of fatal and long-term asthma, and it is associated with disease severity and resistance to therapy. It can thus be regarded as an irreversible consequence of asthma-induced airway inflammation and remodeling. Asthma heterogeneity presents several diagnostic challenges, particularly in distinguishing between chronic asthma and other pulmonary diseases characterized by disruption of normal lung architecture and functions, such as chronic obstructive pulmonary disease. The search for instruments that can predict the development of irreversible structural changes in the lungs, such as chronic components of airway remodeling and fibrosis, is particularly difficult. To overcome these challenges, significant efforts are being directed toward the discovery and investigation of molecular characteristics and biomarkers capable of distinguishing between different types of asthma as well as between asthma and other pulmonary disorders with similar structural characteristics. The main features of bronchial asthma etiology, pathogenesis, and morphological characteristics as well as asthma-associated airway remodeling and lung fibrosis as successive stages of one process will be discussed in this review. The most common murine models and biomarkers of asthma progression and post-asthmatic fibrosis will also be covered. The molecular mechanisms and key cellular players of the asthmatic process described and systematized in this review are intended to help in the search for new molecular markers and promising therapeutic targets for asthma prediction and therapy.

Soloxolone Methyl Reduces the Stimulatory Effect of Leptin on the Aggressive Phenotype of Murine Neuro2a Neuroblastoma Cells via the MAPK/ERK1/2 Pathway

Despite the proven tumorigenic effect of leptin on epithelial-derived cancers, its impact on the aggressiveness of neural crest-derived cancers, notably neuroblastoma, remains largely unexplored. In our study, for the first time, transcriptome analysis of neuroblastoma tissue demonstrated that the level of leptin is elevated in neuroblastoma patients along with the severity of the disease and is inversely correlated with patient survival. The treatment of murine Neuro2a neuroblastoma cells with leptin significantly stimulated their proliferation and motility and reduced cell adhesion, thus rendering the phenotype of neuroblastoma cells more aggressive. Given the proven efficacy of cyanoenone-bearing semisynthetic triterpenoids in inhibiting the growth of neuroblastoma and preventing obesity in vivo, the effect of soloxolone methyl (SM) on leptin-stimulated Neuro2a cells was further investigated. We found that SM effectively abolished leptin-induced proliferation of Neuro2a cells by inducing G1/S cell cycle arrest and restored their adhesiveness to extracellular matrix (ECM) proteins to near control levels through the upregulation of vimentin, zonula occludens protein 1 (ZO-1), cell adhesion molecule L1 (L1cam), and neural cell adhesion molecule 1 (Ncam1). Moreover, SM significantly suppressed the leptin-associated phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) and ribosomal protein S6 kinase A1 (p90RSK), which are key kinases that ensure the survival and proliferation of cancer cells. Further molecular modeling studies demonstrated that the inhibitory effect of SM on the mitogen-activated protein kinase (MAPK)/ERK1/2 signaling pathway can be mediated by its direct interaction with ERK2 and its upstream regulators, son of sevenless homolog 1 (SOS) and mitogen-activated protein kinase kinase 1 (MEK1). Taken together, our findings in murine Neuro2a cells provide novel evidence of the stimulatory effect of leptin on the aggressiveness of neuroblastoma, which requires further detailed studies in human neuroblastoma cells and relevant animal models. The obtained results indicate that SM can be considered a promising drug candidate capable of reducing the impact of adipokines on tumor progression.

Influence of the Composition of Cationic Liposomes on the Performance of Cargo Immunostimulatory RNA

In this study, the impact of different delivery systems on the cytokine-inducing, antiproliferative, and antitumor activities of short immunostimulatory double-stranded RNA (isRNA) was investigated. The delivery systems, consisting of the polycationic amphiphile 1,26-bis(cholest-5-en-3-yloxycarbonylamino)-7,11,16,20 tetraazahexacosan tetrahydrochloride (2X3), and the lipid-helper dioleoylphosphatidylethanolamine (DOPE), were equipped with polyethylene glycol lipoconjugates differing in molecular weight and structure. The main findings of this work are as follows: (i) significant activation of MCP-1 and INF-α, β, and γ production in CBA mice occurs under the action of isRNA complexes with liposomes containing lipoconjugates with long PEG chains, while activation of MCP-1 and INF-γ, but not INF-α or β, was observed under the action of isRNA lipoplexes containing lipoconjugates with short PEG chains; (ii) a pronounced antiproliferative effect on B16 melanoma cells in vitro, as well as an antitumor and hepatoprotective effect in vivo, was induced by isRNA pre-complexes with non-pegylated liposomes, while complexes containing lipoconjugates with long-chain liposomes were inactive; (iii) the antitumor activity of isRNA correlated with the efficiency of its accumulation in the cells and did not explicitly depend on the activation of cytokine and interferon production. Thus, the structure of the delivery system plays a vital role in determining the response to isRNA and allows for the choice of a delivery system depending on the desired effect.

Effective Prognostic Model for Therapy Response Prediction in Acute Myeloid Leukemia Patients

Acute myeloid leukemia (AML) is a hematopoietic disorder characterized by the malignant transformation of bone marrow-derived myeloid progenitor cells with extremely short survival. To select the optimal treatment options and predict the response to therapy, the stratification of AML patients into risk groups based on genetic factors along with clinical characteristics is carried out. Despite this thorough approach, the therapy response and disease outcome for a particular patient with AML depends on several patient- and tumor-associated factors. Among these, tumor cell resistance to chemotherapeutic agents represents one of the main obstacles for improving survival outcomes in AML patients. In our study, a new prognostic scale for the risk stratification of AML patients based on the detection of the sensitivity or resistance of tumor cells to chemotherapeutic drugs in vitro as well as MDR1 mRNA/P-glycoprotein expression, tumor origin (primary or secondary), cytogenetic abnormalities, and aberrant immunophenotype was developed. This study included 53 patients diagnosed with AML. Patients who received intensive or non-intensive induction therapy were analyzed separately. Using correlation, ROC, and Cox regression analyses, we show that the risk stratification of AML patients in accordance with the developed prognostic scale correlates well with the response to therapy and represents an independent predictive factor for the overall survival of patients with newly diagnosed AML.

The Effect of Cell-Free DNA from Blood Serum of Mice with Metastatic Melanoma on Enhancement of Oncogenic Properties of Melanoma Cells

Currently, a significant increase in the levels of circulating cell-free DNA (cfDNA) in the blood of patients is considered as a generally recognized marker of the development of oncological diseases. Although the tumor-associated cfDNA has been well studied, its biological functions remain unclear. In this work, we investigated the effect of cfDNA isolated from the blood serum of the mice with B16-F10 metastatic melanoma on the properties of the B16-F10 melanoma cells in vitro. It was found that the profile of cfDNA isolated from the blood serum of mice with melanoma differs significantly from the cfDNA isolated from the blood serum of healthy mice, and is similar to the genomic DNA of B16 cells with regards to abundance of oncogenes and mobile genetic elements (MGE). It was shown that the cfDNA of mice with melanoma penetrated into B16 cells, resulting in the increase in abundance of oncogenes and MGE fragments, and caused 5-fold increase of the mRNA level of the secreted DNase Dnase1l3 and a slight increase of the mRNA level of the Jun, Fos, Ras, and Myc oncogenes. cfDNA of the healthy mice caused increase of the mRNA level of intracellular regulatory DNase EndoG and 4-fold increase of the mRNA level of Fos and Ras oncogenes, which are well-known triggers of a large number of signal cascades, from apoptosis inhibition to increased tumor cell proliferation. Thus, it is obvious that the circulating cfDNA of tumor origin is able to penetrate into the cells and, despite the fact that no changes were found in the level of viability and migration activity of the tumor cells, cfDNA, even with a single exposure, can cause changes at the cellular level that increase oncogenicity of the recipient cells.

Evaluation of the Antitumor Potential of Soloxolone Tryptamide against Glioblastoma Multiforme Using in silico, in vitro, and in vivo Approaches

Glioblastoma multiforme (GBM) is a highly aggressive brain tumor characterized by uncontrollable diffusive growth, resistance to chemo- and radiotherapy, and a high recurrence rate leading to a low survival rate of patients with GBM. Due to a large number of signaling pathways regulating GBM pathogenesis, one of the promising directions is development of novel anti-glioblastoma compounds based on natural metabolites capable of affecting multiple targets. Here, we investigated the antitumor potential of the semisynthetic triterpenoid soloxolone tryptamide (STA) against human glioblastoma U87 cells. STA efficiently blocked the growth of U87 cells in 2D and 3D cultures, enhanced adhesiveness of tumor cells, and displayed synergistic cytotoxicity with temozolomide. In silico analysis suggested that the anti-glioblastoma activity of STA can be explained by its direct interaction with EGFR, ERBB2, and AKT1 which play an important role in the regulation of GBM malignancy. Along with direct effect on U87 cells, STA normalized tumor microenvironment in murine heterotopic U87 xenograft model by suppressing the development of immature blood vessels and elastin production in the tumor tissue. Taken together, our results clearly demonstrate that STA can be a novel promising antitumor candidate for GMB treatment.

Protective effect of soloxolone derivatives in carrageenan- and LPS-driven acute inflammation: Pharmacological profiling and their effects on key inflammation-related processes

The anti-inflammatory potential of three cyanoenone-containing triterpenoids, including soloxolone methyl (SM), soloxolone (S) and its novel derivative bearing at the C-30 amidoxime moiety (SAO), was studied in murine models of acute inflammation. It was found that the compounds effectively suppressed the development of carrageenan-induced paw edema and peritonitis as well as lipopolysaccharide (LPS)-driven acute lung injury (ALI) with therapeutic outcomes comparable with that of the reference drugs indomethacin and dexamethasone. Non-immunogenic carrageenan-stimulated inflammation was more sensitive to the transformation of C-30 of SM compared with immunogenic LPS-induced inflammation: the anti-inflammatory properties of the studied compounds against carrageenan-induced paw edema and peritonitis decreased in the order of SAO > S > > SM, whereas the efficiency of these triterpenoids against LPS-driven ALI was similar (SAO ≈ S ≈ SM). Further studies demonstrated that soloxolone derivatives significantly inhibited a range of immune-related processes, including granulocyte influx and the expression of key pro-inflammatory cytokines and chemokines in the inflamed sites as well as the functional activity of macrophages. Moreover, SM was found to prevent inflammation-associated apoptosis of A549 pneumocytes and effectively inhibited the protease activity of thrombin (IC₅₀ = 10.3 µM) tightly associated with rodent inflammatome. Taken together, our findings demonstrate that soloxolone derivatives can be considered as novel promising anti-inflammatory drug candidates with multi-targeted mechanism of action.

siRNA-Mediated Timp1 Silencing Inhibited the Inflammatory Phenotype during Acute Lung Injury

Acute lung injury is a complex cascade process that develops in response to various damaging factors, which can lead to acute respiratory distress syndrome. Within this study, based on bioinformatics reanalysis of available full-transcriptome data of acute lung injury induced in mice and humans by various factors, we selected a set of genes that could serve as good targets for suppressing inflammation in the lung tissue, evaluated their expression in the cells of different origins during LPS-induced inflammation, and chose the tissue inhibitor of metalloproteinase Timp1 as a promising target for suppressing inflammation. We designed an effective chemically modified anti-TIMP1 siRNA and showed that Timp1 silencing correlates with a decrease in the pro-inflammatory cytokine IL6 secretion in cultured macrophage cells and reduces the severity of LPS-induced acute lung injury in a mouse model.

Symmetric lipophilic polyamines exhibiting antitumor activity

Unsymmetric lipophilic polyamine derivatives are considered as potential antitumor agents. Here, a series of novel symmetric lipophilic polyamines (LPAs) based on norspermine and triethylenetetramine (TETA) backbones bearing alkyl substituents with different lengths (from decyl to octadecyl) at C(1) atom of glycerol were synthesized. Performed screening of the cytotoxicity of novel compounds on the panel of tumor cell lines (MCF-7, KB-3-1, B16) and non-malignant fibroblasts hFF3 in vitro revealed a correlation between the length of the aliphatic moieties in LPAs and their toxic effects - LPAs with the shortest decyl substituent were found to exhibit the highest cytotoxicity. Furthermore, norspermine-based LPAs displayed somewhat more pronounced cytotoxicity compared with their TETA-based counterparts. Further mechanistic studies demonstrated that hit LPAs containing the norspermine backbone and tetradecyl or decyl substituents efficiently induced apoptosis in KB-3-1 cells. Moreover, decyl-bearing LPA inhibited motility and enhanced adhesiveness of murine B16 melanoma cells in vitro, showing promising antimetastatic potential. Thus, developed novel symmetric norspermine-based LPAs can be considered as promising anticancer chemotherapeutic candidates.

Dendritic Cell-Derived Artificial Microvesicles Inhibit RLS40 Lymphosarcoma Growth in Mice via Stimulation of Th1/Th17 Immune Response

Cell-free antitumor vaccines represent a promising approach to immunotherapy of cancer. Here, we compare the antitumor potential of cell-free vaccines based on microvesicles derived from dendritic cells (DCs) with DC- and cationic-liposome-based vaccines using a murine model of drug-resistant lymphosarcoma RLS40 in vivo. The vaccines were the following: microvesicle vaccines—cytochalasin B-induced membrane vesicles (CIMVs) obtained from DCs loaded with total tumor RNA using cholesterol/spermine-containing cationic liposomes L or mannosylated liposomes ML; DC vaccines—murine DCs loaded with total tumor-derived RNA using the same liposomes; and liposomal vaccines—lipoplexes of total tumor-derived RNA with liposomes L or ML. Being non-hepatotoxic, CIMV- and DC-based vaccines administered subcutaneously exhibited comparable potential to stimulate highly efficient antitumor CTLs in vivo, whereas liposomal vaccines were 25% weaker CTL inducers. Nevertheless, the antitumor efficiencies of the different types of the vaccines were similar: sizes of tumor nodes and the number of liver metastases were significantly decreased, regardless of the vaccine type. Notably, the booster vaccination did not improve the overall antitumor efficacy of the vaccines under the study. CIMV- and DC- based vaccines more efficiently than liposome-based ones decreased mitotic activity of tumor cells and induced their apoptosis, stimulated accumulation of neutrophil inflammatory infiltration in tumor tissue, and had a more pronounced immunomodulatory activity toward the spleen and thymus. Administration of CIMV-, DC-, and liposome-based vaccines resulted in activation of Th1/Th17 cells as well as the induction of positive immune checkpoint 4-1BBL and downregulation of suppressive immune checkpoints in a raw PD-1 >>> TIGIT > CTLA4 > TIM3. We demonstrated that cell-free CIMV-based vaccines exhibited superior antitumor and antimetastatic activity in a tumor model in vivo. The obtained results can be considered as the basis for developing novel strategies for oncoimmunotherapy.

Novel Soloxolone Amides as Potent Anti-Glioblastoma Candidates: Design, Synthesis, In Silico Analysis and Biological Activities In Vitro and In Vivo

The modification of natural or semisynthetic triterpenoids with amines can be explored as a promising strategy for improving their pharmacological properties. Here, we report the design and synthesis of 11 novel amide derivatives of soloxolone methyl (SM), a cyano enone-bearing derivative of 18βH-glycyrrhetinic acid. Analysis of their bioactivities in vitro and in silico revealed their high toxicity against a panel of tumor cells (average IC50(24 h) = 3.7 µM) and showed that the formation of amide moieties at the C-30 position of soloxolone did not enhance the cytotoxicity of derivatives toward tumor cells compared to SM, though it can impart an ability to pass across the blood–brain barrier. Further HPLC–MS/MS and mechanistic studies verified significant brain accumulation of hit compound 12 (soloxolone tryptamide) in a murine model and showed its high anti-glioblastoma potential. It was found that 12 induced ROS-dependent and autophagy-independent death of U87 and U118 glioblastoma cells via mitochondrial apoptosis and effectively blocked their clonogenicity, motility and capacity to form vessel-like structures. Further in vivo study demonstrated that intraperitoneal injection of 12 at a dosage of 20 mg/kg effectively inhibited the growth of U87 glioblastoma in a mouse xenograft model, reducing the proliferative potential of the tumor and leading to a depletion of collagen content and normalization of blood vessels in tumor tissue. The obtained results clearly demonstrate that 12 can be considered as a promising leading compound for drug development in glioblastoma treatment.

Asthma and Post-Asthmatic Fibrosis: A Search for New Promising Molecular Markers of Transition from Acute Inflammation to Pulmonary Fibrosis

Asthma is a heterogeneous pulmonary disorder, the progression and chronization of which leads to airway remodeling and fibrogenesis. To understand the molecular mechanisms of pulmonary fibrosis development, key genes forming the asthma-specific regulome and involved in lung fibrosis formation were revealed using a comprehensive bioinformatics analysis. The bioinformatics data were validated using a murine model of ovalbumin (OVA)-induced asthma and post-asthmatic fibrosis. The performed analysis revealed a range of well-known pro-fibrotic markers (Cat, Ccl2, Ccl4, Ccr2, Col1a1, Cxcl12, Igf1, Muc5ac/Muc5b, Spp1, Timp1) and a set of novel genes (C3, C3ar1, Col4a1, Col4a2, Cyp2e1, Fn1, Thbs1, Tyrobp) mediating fibrotic changes in lungs already at the stage of acute/subacute asthma-driven inflammation. The validation of genes related to non-allergic bleomycin-induced pulmonary fibrosis on asthmatic/fibrotic lungs allowed us to identify new universal genes (Col4a1 and Col4a2) associated with the development of lung fibrosis regardless of its etiology. The similarities revealed in the expression profiles of nodal fibrotic genes between asthma-driven fibrosis in mice and nascent idiopathic pulmonary fibrosis in humans suggest a tight association of identified genes with the early stages of airway remodeling and can be considered as promising predictors and early markers of pulmonary fibrosis.

Antisense oligonucleotide gapmers containing phosphoryl guanidine groups reverse MDR1-mediated multiple drug resistance of tumor cells

Antisense gapmer oligonucleotides containing phosphoryl guanidine (PG) groups, e.g., 1,3-dimethylimidazolidin-2-imine, at three to five internucleotidic positions adjacent to the 3' and 5' ends were prepared via the Staudinger chemistry, which is compatible with conditions of standard automated solid-phase phosphoramidite synthesis for phosphodiester and, notably, phosphorothioate linkages, and allows one to design a variety of gapmeric structures with alternating linkages, and deoxyribose or 2'-O-methylribose backbone. PG modifications increased nuclease resistance in serum-containing medium for more than 21 days. Replacing two internucleotidic phosphates by PG groups in phosphorothioate-modified oligonucleotides did not decrease their cellular uptake in the absence of lipid carriers. Increasing the number of PG groups from two to seven per oligonucleotide reduced their ability to enter the cells in the carrier-free mode. Cationic liposomes provided similar delivery efficiency of both partially PG-modified and unmodified oligonucleotides. PG-gapmers were designed containing three to four PG groups at both wings and a central "window" of seven deoxynucleotides with either phosphodiester or phosphorothioate linkages targeted to MDR1 mRNA providing multiple drug resistance of tumor cells. Gapmers efficiently silenced MDR1 mRNA and restored the sensitivity of tumor cells to chemotherapeutics. Thus, PG-gapmers can be considered as novel, promising types of antisense oligonucleotides for targeting biologically relevant RNAs.

"Bind, cleave and leave": multiple turnover catalysis of RNA cleavage by bulge-loop inducing supramolecular conjugates

Antisense sequence-specific knockdown of pathogenic RNA offers opportunities to find new solutions for therapeutic treatments. However, to gain a desired therapeutic effect, the multiple turnover catalysis is critical to inactivate many copies of emerging RNA sequences, which is difficult to achieve without sacrificing the sequence-specificity of cleavage. Here, engineering two or three catalytic peptides into the bulge-loop inducing molecular framework of antisense oligonucleotides achieved catalytic turnover of targeted RNA. Different supramolecular configurations revealed that cleavage of the RNA backbone upon sequence-specific hybridization with the catalyst accelerated with increase in the number of catalytic guanidinium groups, with almost complete demolition of target RNA in 24 h. Multiple sequence-specific cuts at different locations within and around the bulge-loop facilitated release of the catalyst for subsequent attacks of at least 10 further RNA substrate copies, such that delivery of only a few catalytic molecules could be sufficient to maintain knockdown of typical RNA copy numbers. We have developed fluorescent assay and kinetic simulation tools to characterise how the limited availability of different targets and catalysts had restrained catalytic reaction progress considerably, and to inform how to accelerate the catalytic destruction of shorter linear and larger RNAs even further.

Core genes involved in the regulation of acute lung injury and their association with COVID-19 and tumor progression: A bioinformatics and experimental study

Acute lung injury (ALI) is a specific form of lung damage caused by different infectious and non-infectious agents, including SARS-CoV-2, leading to severe respiratory and systemic inflammation. To gain deeper insight into the molecular mechanisms behind ALI and to identify core elements of the regulatory network associated with this pathology, key genes involved in the regulation of the acute lung inflammatory response (Il6, Ccl2, Cat, Serpine1, Eln, Timp1, Ptx3, Socs3) were revealed using comprehensive bioinformatics analysis of whole-genome microarray datasets, functional annotation of differentially expressed genes (DEGs), reconstruction of protein-protein interaction networks and text mining. The bioinformatics data were validated using a murine model of LPS-induced ALI; changes in the gene expression patterns were assessed during ALI progression and prevention by anti-inflammatory therapy with dexamethasone and the semisynthetic triterpenoid soloxolone methyl (SM), two agents with different mechanisms of action. Analysis showed that 7 of 8 revealed ALI-related genes were susceptible to LPS challenge (up-regulation: Il6, Ccl2, Cat, Serpine1, Eln, Timp1, Socs3; down-regulation: Cat) and their expression was reversed by the pre-treatment of mice with both anti-inflammatory agents. Furthermore, ALI-associated nodal genes were analysed with respect to SARS-CoV-2 infection and lung cancers. The overlap with DEGs identified in postmortem lung tissues from COVID-19 patients revealed genes (Saa1, Rsad2, Ifi44, Rtp4, Mmp8) that (a) showed a high degree centrality in the COVID-19-related regulatory network, (b) were up-regulated in murine lungs after LPS administration, and (c) were susceptible to anti-inflammatory therapy. Analysis of ALI-associated key genes using The Cancer Genome Atlas showed their correlation with poor survival in patients with lung neoplasias (Ptx3, Timp1, Serpine1, Plaur). Taken together, a number of key genes playing a core function in the regulation of lung inflammation were found, which can serve both as promising therapeutic targets and molecular markers to control lung ailments, including COVID-19-associated ALI.

Folate-Equipped Cationic Liposomes Deliver Anti-MDR1-siRNA to the Tumor and Increase the Efficiency of Chemotherapy

In this study, we examined the in vivo toxicity of the liposomes F consisting of 1,26-bis(cholest-5-en-3-yloxycarbonylamino)-7,11,16,20-tetraazahexacosan tetrahydrochloride, lipid-helper 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine and folate lipoconjugate (O-{2-[rac-2,3-di(tetradecyloxy)prop-1-yloxycarbonyl]aminoethyl}-O'-[2-(pteroyl-L-glutam-5-yl)aminoethyl]octadecaethyleneglycol) and investigated the antitumor effect of combined antitumor therapy consisting of MDR1-targeted siMDR/F complexes and conventional polychemotherapy using tumor xenograft initiated in immunodeficient mice. Detailed analysis of acute and chronic toxicity of this liposomal formulation in healthy C57BL/6J mice demonstrated that formulation F and parent formulation L (without folate lipoconjugate) have no acute and chronic toxicity in mice. The study of the biodistribution of siMDR/F lipoplexes in SCID mice with xenograft tumors formed by tumor cells differing in the expression level of folate receptors showed that the accumulation in various types of tumors strongly depends on the abandons of folate receptors in tumor cells and effective accumulation occurs only in tumors formed by cells with the highest FR levels. Investigating the effects of combined therapy including anti-MDR1 siRNA/F complexes and polychemotherapy on a multidrug-resistant KB-8-5 tumor xenograft in SCID mice demonstrated that siMDR/F increases the efficiency of polychemotherapy: the treatment leads to pronounced inhibition of tumor growth, reduced necrosis and inflammation, and stimulates apoptosis in KB-8-5 tumor tissue. At the same time, it does not induce liver toxicity in tumor-bearing mice. These data confirm that folate-containing liposome F mediated the extremely efficient delivery of siRNA in FR-expressing tumors in vivo and ensured the safety and effectiveness of its action.

Drug responsiveness of leukemic cells detected in vitro at diagnosis correlates with therapy response and survival in patients with acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is the most common acute leukemia in adults, and chemotherapy remains the most commonly used treatment approach for this group of hematological disorders. Drug resistance is one of the predictors of unfavorable prognosis for leukemia patients.

AIM

The purpose of this study was to perform a retrospective analysis of the survival rate in AML patients according to age, tumor status, and chemotherapy regimen received and to analyze the therapy response of AML patients depending on the treatment received, initial responsiveness of tumor cells to chemotherapeutic drugs measured in vitro at diagnosis and expression of immunological markers.

METHODS

The survival of AML patients (n = 127) was analyzed using the Kaplan-Meier method. Drug sensitivity of tumor cells of AML patients (n = 37) and the expression of immunological markers were evaluated by the WST test and flow cytometry, respectively. Correlation analysis was performed using Spearman's rank order correlation coefficient.

RESULTS

We found the treatment regimen to be the defining factor in the patient survival rate. In addition, the initial responsiveness of tumor cells to chemotherapeutic drugs measured in vitro at diagnosis correlated with the therapy response of AML: patients with high tumor cell sensitivity to particular cytotoxic drugs demonstrated a good response to treatment including these drugs, and patients with initial resistance of tumor cells to a particular chemotherapeutic agents and received it according to the clinical protocols demonstrated a poor response to antitumor therapy. Correlations of drug resistance in leukemic cells with the expression of immature and aberrant immunophenotype markers as established unfavorable prognostic factors confirm our assumption.

CONCLUSION

The evaluation of the responsiveness of tumor cells to chemotherapy in vitro at diagnosis can be a useful tool for predicting the response of leukemia patients to planned chemotherapy.

Strict conformational demands of RNA cleavage in bulge-loops created by peptidyl-oligonucleotide conjugates

Potent knockdown of pathogenic RNA in vivo is an urgent health need unmet by both small-molecule and biologic drugs. ‘Smart’ supramolecular assembly of catalysts offers precise recognition and potent destruction of targeted RNA, hitherto not found in nature. Peptidyl-oligonucleotide ribonucleases are here chemically engineered to create and attack bulge-loop regions upon hybridization to target RNA. Catalytic peptide was incorporated either via a centrally modified nucleotide (Type 1) or through an abasic sugar residue (Type 2) within the RNA-recognition motif to reveal striking differences in biological performance and strict structural demands of ribonuclease activity. None of the Type 1 conjugates were catalytically active, whereas all Type 2 conjugates cleaved RNA target in a sequence-specific manner, with up to 90% cleavage from 5-nt bulge-loops (BC5-α and BC5L-β anomers) through multiple cuts, including in folds nearby. Molecular dynamics simulations provided structural explanation of accessibility of the RNA cleavage sites to the peptide with adoption of an ‘in-line’ attack conformation for catalysis. Hybridization assays and enzymatic probing with RNases illuminated how RNA binding specificity and dissociation after cleavage can be balanced to permit turnover of the catalytic reaction. This is an essential requirement for inactivation of multiple copies of disease-associated RNA and therapeutic efficacy.

Immunostimulating RNA Delivered by P1500 PEGylated Cationic Liposomes Limits Influenza Infection in C57Bl/6 Mice

The emergence of highly pathogenic viruses and a high speed of infection spread put forward the problem of the development of novel antivirals and their delivery vehicles. In this study, we investigated the antiviral effect of the previously identified immunostimulatory 19-bp dsRNA (isRNA) with 3'-nucleotide overhangs, which stimulates interferon α synthesis when delivered using cationic liposomes consisting of 1,26-bis(cholest-5-en-3β-yloxycarbonylamino)-7,11,16,20-tetraazahexacosan tetrahydrochloride and lipid-helper dioleoylphosphatidylethanolamine and its PEGylated formulation P1500 in vitro and in vivo. In vitro data showed that isRNA/2X3-DOPE complexes protected L929 cells from encephalomyocarditis virus infection, while isRNA/P1500 complexes were not active, which correlates with their lower transfection activity in cell culture. Comparison of the interferon-inducing activity of isRNA in BALB/c, CBA and C57Bl/6 mice showed that PEGylated liposomes significantly enhance the interferon-inducing activity of isRNA in vivo. The antiviral efficacy of the isRNA in vivo was considerably affected by the delivery system. The cationic liposomes 2X3-DOPE did not enhance the antiviral properties of isRNA in vivo. Similar liposomes equipped with a PEGylated lipoconjugate provided a pronounced anti-influenza effect of the isRNA in vivo. Administration of isRNA to C57Bl/6 led to a decrease in virus titers in the lungs and a significant decrease in the severity of the infection. Administration of a similar formulation to BALB/c mice caused only a mild antiviral effect at the initial stages of the infection. The data show that isRNA in combination with the PEGylated delivery system can be considered an effective means of suppressing influenza A infection.

Trioxolone Methyl, a Novel Cyano Enone-Bearing 18βH-Glycyrrhetinic Acid Derivative, Ameliorates Dextran Sulphate Sodium-Induced Colitis in Mice

Semi-synthetic triterpenoids, bearing cyano enone functionality in ring A, are considered to be novel promising therapeutic agents with complex inhibitory effects on tissue damage, inflammation and tumor growth. Previously, we showed that the cyano enone-containing 18βH-glycyrrhetinic acid derivative soloxolone methyl (SM) effectively suppressed the inflammatory response of macrophages in vitro and the development of influenza A-induced pneumonia and phlogogen-stimulated paw edema in vivo. In this work, we reported the synthesis of a novel 18βH-glycyrrhetinic acid derivative trioxolone methyl (TM), bearing a 2-cyano-3-oxo-1(2)-en moiety in ring A and a 12,19-dioxo-9(11),13(18)-dien moiety in rings C, D, and E. TM exhibited a high inhibitory effect on nitric oxide (II) production by lipopolysaccharide-stimulated J774 macrophages in vitro and dextran sulfate sodium (DSS)-induced colitis in mice, displaying higher anti-inflammatory activity in comparison with SM. TM effectively suppressed the DSS-induced epithelial damage and inflammatory infiltration of colon tissue, the hyperproduction of colonic neutral mucin and TNFα and increased glutathione synthesis. Our in silico analysis showed that Akt1, STAT3 and dopamine receptor D2 can be considered as mediators of the anti-colitic activity of TM. Our findings provided valuable information for a better understanding of the anti-inflammatory activity of cyano enone-bearing triterpenoids and revealed TM as a promising anti-inflammatory candidate.

Novel 3'-Substituted-1',2',4'-Oxadiazole Derivatives of 18βH-Glycyrrhetinic Acid and Their O-Acylated Amidoximes: Synthesis and Evaluation of Antitumor and Anti-Inflammatory Potential In Vitro and In Vivo

A series of novel 18βH-glycyrrhetinic acid (GA) derivatives containing 3'-(alkyl/phenyl/pyridin(-2″, -3″, and -4″)-yl)-1',2',4'-oxadiazole moieties at the C-30 position were synthesized by condensation of triterpenoid's carboxyl group with corresponding amidoximes and further cyclization. Screening of the cytotoxicity of novel GA derivatives on a panel of tumor cell lines showed that the 3-acetoxy triterpenoid intermediates-O-acylated amidoxime 3a-h-display better solubility under bioassay conditions and more pronounced cytotoxicity compared to their 1',2',4'-oxadiazole analogs 4f-h (median IC50 = 7.0 and 49.7 µM, respectively). Subsequent replacement of the 3-acetoxy group by the hydroxyl group of pyridin(-2″, 3″, and -4″)-yl-1',2',4'-oxadiazole-bearing GA derivatives produced compounds 5f-h, showing the most pronounced selective toxicity toward tumor cells (median selectivity index (SI) > 12.1). Further detailed analysis of the antitumor activity of hit derivative 5f revealed its marked proapoptotic activity and inhibitory effects on clonogenicity and motility of HeLa cervical carcinoma cells in vitro, and the metastatic growth of B16 melanoma in vivo. Additionally, the comprehensive in silico study revealed intermediate 3d, bearing the tert-butyl moiety in O-acylated amidoxime, as a potent anti-inflammatory candidate, which was able to effectively inhibit inflammatory response induced by IFNγ in macrophages in vitro and carrageenan in murine models in vivo, probably by primary interactions with active sites of MMP9, neutrophil elastase, and thrombin. Taken together, our findings provide a basis for a better understanding of the structure-activity relationship of 1',2',4'-oxadiazole-containing triterpenoids and reveal two hit molecules with pronounced antitumor (5f) and anti-inflammatory (3d) activities.

[Tumor-Suppressing, Immunostimulating, and Hepatotoxic Effects of Immunostimulatory RNA in Combination with Dacarbazine in a Murine Melanoma Model]

Melanoma is one of the most aggressive tumors and is accompanied by the induction of local and systemic inflammatory responses. Combinations of chemotherapeutic agents with immunotherapy are therefore commonly used for melanoma treatment. A B16 melanoma model was used to study the tumor suppressive, immunostimulating, and hepatotoxic effects of a combination of a small double-stranded immunostimulatory RNA (isRNA) with 3'-trinucleotide overhangs and the cytotoxic drug dacarbazine compared with respective monotherapies. The drugs efficiently suppressed the tumor growth and acted synergistically. Histological and immunohistochemical examinations of tumor nodes showed that the combination of isRNA and dacarbazine significantly decreased mitotic activity and more efficiently increased apoptosis in tumor tissue as compared with either monotherapy. Regardless of the treatment regimen, signs of immune activation were observed in the spleen, including an increase in the number and diameter of lymphoid follicles and the volume density of the white pulp. Destructive changes were detected in the livers of nontreated animals with B16 melanoma. Administration of isRNA in combination with dacarbazine did not cause any additional damage to liver parenchyma, while stimulating regenerative processes in hepatic tissue of tumor-bearing animals.

RNA knockdown by synthetic peptidyl-oligonucleotide ribonucleases: behavior of recognition and cleavage elements under physiological conditions

Sequence-specific protein-based ribonucleases are not found in nature. Absolute sequence selectivity in RNA cleavage in vivo normally requires multi-component complexes that recruit a guide RNA or DNA for target recognition and a protein-RNA assembly for catalytic functioning (e.g. RNAi molecular machinery, RNase H). Recently discovered peptidyl-oligonucleotide synthetic ribonucleases selectively knock down pathogenic RNAs by irreversible cleavage to offer unprecedented opportunities for control of disease-relevant RNA. Understanding how to increase their potency, selectivity and catalytic turnover will open the translational pathway to successful therapeutics. Yet, very little is known about how these chemical ribonucleases bind, cleave and leave their target. Rational design awaits this understanding in order to control therapy, particularly how to overcome the trade-off between sequence specificity and potency through catalytic turnover. We illuminate this here by characterizing the interactions of these chemical RNases with both complementary and non-complementary RNAs using T_m profiles, fluorescence, UV-visible and NMR spectroscopies. Crucially, the level of counter cations, which are tightly-controlled within cellular compartments, also controlled these interactions. The oligonucleotide component dominated interaction between conjugates and complementary targets in the presence of physiological levels of counter cations (K⁺), sufficient to prevent repulsion between the complementary nucleic acid strands to allow Watson-Crick hydrogen bonding. In contrast, the positively-charged catalytic peptide interacted poorly with target RNA, when counter cations similarly screened the negatively-charged sugar-phosphate RNA backbones. The peptide only became the key player, when counter cations were insufficient for charge screening; moreover, only under such non-physiological conditions did conjugates form strong complexes with non-complementary RNAs.Communicated by Ramaswamy H. Sarma.

[Bacillus pumilus Ribonuclease Inhibits Migration of Human Duodenum Adenocarcinoma HuTu 80 Cells]

Migration of cancer cells from the primary tumor site to nearby tissues is the starting point of the metastatic process. The invasive properties of cells are especially important for carcinomas, since tumor cells need to overcome the basement membrane and go beyond its boundaries to the underlying tissues. Substances that reduce the invasive ability of malignant cells are promising as antimetastatic agents. In the present work, the possibility of inhibiting the ability of different cancer cell lines to migrate under the influence of the Bacillus pumilus ribonuclease (binase) was analyzed using the scratch-wound assay. It was established that binase at non-toxic concentrations (10 μg/mL) reliably suppressed the migratory ability of HuTu 80 human duodenum adenocarcinoma cells incubated with RNase for 48-72 h. The antimetastatic potential of binase is confirmed by molecular modeling data demonstrating the ability of binase to inhibit cellular metalloproteinases that determine the migration of tumor cells.

Targeting Circulating SINEs and LINEs with DNase I Provides Metastases Inhibition in Experimental Tumor Models

Tumor-associated cell-free DNAs (cfDNAs) are found to play some important roles at different stages of tumor progression; they are involved in the transformation of normal cells and contribute to tumor migration and invasion. DNase I is considered a promising cancer cure, due to its ability to degrade cfDNAs. Previous studies using murine tumor models have proved the high anti-metastatic potential of DNase I. Later circulating cfDNAs, especially tandem repeats associated with short-interspersed nuclear elements (SINEs) and long-interspersed nuclear elements (LINEs), have been found to be the enzyme's main molecular targets. Here, using Lewis lung carcinoma, melanoma B16, and lymphosarcoma RLS₄₀ murine tumor models, we reveal that tumor progression is accompanied by an increase in the level of SINE and LINEs in the pool of circulating cfDNAs. Treatment with DNase I decreased in the number and area of metastases by factor 3-10, and the size of the primary tumor node by factor 1.5-2, which correlated with 5- to 10-fold decreasing SINEs and LINEs. We demonstrated that SINEs and LINEs from cfDNA of tumor-bearing mice are able to penetrate human cells. The results show that SINEs and LINEs could be important players in metastasis, and this allows them to be considered as attractive new targets for anticancer therapy.

Molecular Mechanism of the Antiproliferative Activity of Short Immunostimulating dsRNA

Small double-stranded RNAs with certain sequence motifs are able to interact with pattern-recognition receptors and activate the innate immune system. Recently, we identified a set of short double-stranded 19-bp RNA molecules with 3-nucleotide 3′-overhangs that exhibited pronounced antiproliferative activity against cancer cells in vitro, and antitumor and antimetastatic activities in mouse models in vivo. The main objectives of this study were to identify the pattern recognition receptors that mediate the antiproliferative action of immunostimulating RNA (isRNA). Two cell lines, epidermoid carcinoma KB-3-1 cells and lung cancer A549 cells, were used in the study. These lines respond to the action of isRNA by a decrease in the growth rate, and in the case of A549 cells, also by a secretion of IL-6. Two sets of cell lines with selectively silenced genes encoding potential sensors and signal transducers of isRNA action were obtained on the basis of KB-3-1 and A549 cells. It was found that the selective silencing of PKR and RIG-I genes blocked the antiproliferative effect of isRNA, both in KB-3-1 and A549 cells, whereas the expression of MDA5 and IRF3 was not required for the antiproliferative action of isRNA. It was shown that, along with PKR and RIG-I genes, the expression of IRF3 also plays a role in isRNA mediated IL-6 synthesis in A549 cells. Thus, PKR and RIG-I sensors play a major role in the anti-proliferative signaling triggered by isRNA.

Deep insights into the response of human cervical carcinoma cells to a new cyano enone-bearing triterpenoid soloxolone methyl: a transcriptome analysis

Semisynthetic triterpenoids, bearing cyano enone functionality in ring A, are considered now as novel promising anti-tumor agents. However, despite the large-scale studies, their effects on cervical carcinoma cells and, moreover, mechanisms underlying cell death activation by such compounds in this cell type have not been fully elucidated. In this work, we attempted to reconstitute the key pathways and master regulators involved in the response of human cervical carcinoma KB-3-1 cells to the novel glycyrrhetinic acid derivative soloxolone methyl (SM) by a transcriptomic approach. Functional annotation of differentially expressed genes, analysis of their cis^- regulatory sequences and protein-protein interaction network clearly indicated that stress of endoplasmic reticulum (ER) is the central event triggered by SM in the cells. A range of key ER stress sensors and transcription factor AP-1 were identified as upstream transcriptional regulators, controlling the response of the cells to SM. Additionally, by using Gene Expression Omnibus data, we showed the ability of SM to modulate the expression of key genes involved in regulation of the high proliferative rate of cervical carcinoma cells. Further Connectivity Map analysis revealed similarity of SM's effects with known ER stress inducers thapsigargin and geldanamycin, targeting SERCA and Grp94, respectively. According to the molecular docking study, SM could snugly fit into the active sites of these proteins in the positions very close to that of both inhibitors. Taken together, our findings provide a basis for the better understanding of the intracellular processes in tumor cells switched on in response to cyano enone-bearing triterpenoids.

Catalytic Knockdown of miR-21 by Artificial Ribonuclease: Biological Performance in Tumor Model

Control of the expression of oncogenic small non-coding RNAs, notably microRNAs (miRNAs), is an attractive therapeutic approach. We report a design platform for catalytic knockdown of miRNA targets with artificial, sequence-specific ribonucleases. miRNases comprise a peptide [(LeuArg)₂Gly]₂ capable of RNA cleavage conjugated to the miRNA-targeted oligodeoxyribonucleotide, which becomes nuclease-resistant within the conjugate design, without resort to chemically modified nucleotides. Our data presented here showed for the first time a truly catalytic character of our miR-21-miRNase and its ability to cleave miR-21 in a multiple catalytic turnover mode. We demonstrate that miRNase targeted to miR-21 (miR-21-miRNase) knocked down malignant behavior of tumor cells, including induction of apoptosis, inhibition of cell invasiveness, and retardation of tumor growth, which persisted on transplantation into mice of tumor cells treated once with miR-21-miRNase. Crucially, we discover that the high biological activity of miR-21-miRNase can be directly related not only to its truly catalytic sequence-specific cleavage of miRNA but also to its ability to recruit the non-sequence specific RNase H found in most cells to elevate catalytic turnover further. miR-21-miRNase worked synergistically even with low levels of RNase H. Estimated degradation in the presence of RNase H exceeded 10³ miRNA target molecules per hour for each miR-21-miRNase molecule, which provides the potency to minimize delivery requirements to a few molecules per cell. In contrast to the comparatively high doses required for the simple steric block of antisense oligonucleotides, truly catalytic inactivation of miRNA offers more effective, irreversible, and persistent suppression of many copy target sequences. miRNase design can be readily adapted to target other pathogenic microRNAs overexpressed in many disease states.

[Systemic delivery of complexes of melanoma RNA with mannosylated liposomes activates highly efficient murine melanoma-specific cytotoxic T cells in vivo]

The efficiency of the antitumor immune response triggered by dendritic cell (DC)-based vaccines depends predominantly on the efficiency of delivering tumor antigen-coding nucleic acids into DCs. Mannosylated liposomes were used to deliver tumor total RNA into DCs both ex vivo and in vivo, and the cytotoxic T-lymphocyte (CTL) antitumor response was assayed. The liposomes contained the mannosylated lipid conjugate 3-[6-(α-D-mannopyranosyloxy)hexyl]amino-4-{6-[rac-2,3-di(tetradecyloxy)prop-1-yl oxycarbonylamino]hexyl}aminocyclobut-3-en-1,2-dione), the polycationic lipid 2X3 (1,26-bis(cholest-5-en-3β-yloxycarbonylamino)-7,11,16,20-tetraazahexacosane tetrahydrochloride), and the zwitterionic lipid DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine) at a molar ratio of 1: 3: 6 and were used as a transfection agent. Total RNA isolated from B16-F10 mouse melanoma cells served as a source of tumor antigens. Systemic administration of mannosylated liposomes-tumor RNA complexes into circulation of melanoma-bearing mice induced an efficient CTL response, which reduced the melanoma cell index in vitro with the same efficiency (by a factor of 2.8) as CTLs activated via an inoculation of DCs loaded with complexes of the same composition ex vivo. Complexes of tumor RNA with control liposomes, which lacked the mannosylated lipid conjugate, or DCs transfected with these complexes ex vivo were less efficient and reduced the melanoma cell count by a factor of only 1.6-1.8.

Fluorophore Labeling Affects the Cellular Accumulation and Gene Silencing Activity of Cholesterol-Modified siRNAs In Vitro

The objective of this study was to analyze the effects of fluorophores on the intracellular accumulation and biological activity of small interfering RNA (siRNA) and its cholesterol conjugates. In this study, we used stem-loop real-time PCR and calibration curves to quantitate cellular siRNA accumulation. Attachment of fluorophores significantly affected both the accumulation and biological activity of siRNA conjugates. The severity of this effect depended significantly on the structure of the conjugate; fluorophores (Cy5.5 or Alexa-488) attached to siRNA, facing the side of the duplex opposite to cholesterol, enhanced the unproductive intracellular accumulation of the conjugate when delivered in carrier-free mode. Enhanced cellular accumulation of siRNA conjugates did not result in enhanced biological activity of the conjugate. Moreover, the attachment of a hydrophobic fluorophore, such as Cy5.5, to conventional siRNA also enhanced its apparent intracellular accumulation, but not its biological activity. Thus, the use of fluorescent labels for the study of the intracellular accumulation of siRNA and its conjugates formed with different molecules is possible only for a limited range of structures, and requires verification using alternative methods.

[Novel Glycyrrhetinic Acid Derivative Soloxolone Methyl Inhibits the Inflammatory Response and Tumor Growth in vivo]

Due to wide spreading of inflammatory disease and imperfection of available anti-inflammatory drugs, mainly associated with their serious side effects, searching for new anti-inflammatory agents is a pressing problem. Natural triterpenoids and their synthetic analogs are a promising source of new drugs. In this study, we have investigated the anti-inflammatory and antitumor effects in vivo of the glycyrrhetinic acid derivative soloxolone methyl (SM), or methyl 2-cyano-3,12-dioxo-18βH-olean-9(ll),l(2)-dien-30-oate. SM was shown to efficiently suppress the development of edema in a mouse model of carrageenan- or histamine-induced acute inflammation. SM also inhibited the tumor growth and reduced the tumor cell count in the ascitic fluid in mice bearing Krebs-2 carcinoma, the development of which is accompanied by an inflammatory process in the surrounding tissues.

Autocrine-based selection of ligands for personalized CAR-T therapy of lymphoma

We report the development of a novel platform to enhance the efficacy and safety of follicular lymphoma (FL) treatment. Since lymphoma is a clonal malignancy of a diversity system, every tumor has a different antibody on its cell surface. Combinatorial autocrine-based selection is used to rapidly identify specific ligands for these B cell receptors on the surface of FL tumor cells. The selected ligands are used in a chimeric antigen receptor T cell (CAR-T) format for redirection of human cytotoxic T lymphocytes. Essentially, the format is the inverse of the usual CAR-T protocol. Instead of being a guide molecule, the antibody itself is the target. Thus, these studies raise the possibility of personalized treatment of lymphomas using a private antibody binding ligand that can be obtained in a few weeks.

[Downregulation of Human Adenovirus DNA Polymerase Gene by Modified siRNAs]

Human adenoviruses, in particular D8, D19, and D37, cause ocular infections. Currently, there is no available causally directed treatment, which efficiently counteracts adenoviral infectious diseases. In our previous work, we showed that gene silencing by means of RNA interference is an effective approach for downregulation of human species D adenoviruses replication. In this study, we compared the biological activity of siRNAs and their modified analogs targeting human species D adenoviruses DNA polymerase. We found that one of selectively 2'-O-methyl modified siRNAs mediates stable and long-lasting suppression of the target gene (12 days post transfection). We suppose that this siRNA can be used as a potential therapeutic agent against human species D adenoviruses.

Peptide-oligonucleotide conjugates exhibiting pyrimidine-X cleavage specificity efficiently silence miRNA target acting synergistically with RNase H

Taking into account the important role of miRNA in carcinogenesis, oncogenic miRNAs are attractive molecules for gene-targeted therapy. Here, we developed a novel series of peptide-oligonucleotide conjugates exhibiting ribonuclease activity targeted to highly oncogenic miRNAs miR-21 and miR-17. When designing the conjugates, we enhanced both nuclease resistance of the targeted oligodeoxyribonucleotide by introducing at its 3'-end mini-hairpin structure displaying high thermostability and robustness against nuclease digestion and the efficiency of its functioning by attachment of the catalytic construction (amide)NH2-Gly(ArgLeu)4-TCAA displaying ribonuclease activity to its 5'-end. Designed miRNases efficiently cleaved miRNA targets, exhibiting Pyr-X specificity, and cleavage specificity had strong dependence on the miRNA sequence in the site of peptide location. In vitro, designed miRNases do not prevent cleavage of miRNA bound with the conjugate by RNase H, and more than an 11-fold enhancement of miRNA cleavage by the conjugate is observed in the presence of RNase H. In murine melanoma cells, miRNase silences mmu-miR-17 with very high efficiency as a result of miR-17 cleavage by miRNase and by recruited RNase H. Thus, miRNases provide a system of double attack of the miRNA molecules, significantly increasing the efficiency of miRNA downregulation in the cells in comparison with antisense oligonucleotide.

[Inhibition of Invasive Properties of Murine Melanoma by Bovine Pancreatic DNase I In Vitro and In Vivo]

After a long pause, the accumulation of data on the involvement of tumor-specific DNA and extracellular DNA in metastasis has again placed enzymes with deoxyribonuclease activity in the focus of the search for antitumor and antimetastatic drugs. In this work, the ability of bovine pancreatic DNase I to reduce the invasive potential of B16 melanoma has been investigated in vitro and in vivo. It was found that DNase I had a cytotoxic effect on B16 melanoma cells (IC50 ≈ 10^(4) U/mL). At the same time, significantly lower doses of DNase I (10^(2)-10^(3) U/mL) inhibited the migratory activity of melanoma cells in vitro, causing a decrease in the distance of cell front migration and in the area of scratch healing 48 h after the enzyme addition, as well as reducing the rate of cell migration. In mice with B16 metastatic melanoma, intramuscular administration of DNase I in the dose range of 0.12-1.20 mg/kg resulted in a two- to threefold decrease in the number of surface lung metastases and caused nonspecific antigenic immune stimulation.

Nuclease-resistant 63-bp trimeric siRNAs simultaneously silence three different genes in tumor cells

We designed a multimeric nuclease-resistant 63-bp trimeric small-interfering RNA (tsiRNA) comprising in one duplex the sequence of siRNAs targeting mRNAs of MDR1, LMP2, and LMP7 genes. We show that such tsiRNA is able to suppress the expression of all the target genes independently and with high efficiency, acting via a Dicer-dependent mechanism. tsiRNA is diced into 42- and 21-bp duplexes inside the cell. tsiRNA-induced gene silencing is characterized by kinetics similar to that of canonical siRNA, while the silencing efficiency is significantly higher than that of canonical siRNA with the same sequence.

Targeted delivery of nucleic acids into xenograft tumors mediated by novel folate-equipped liposomes

Folate receptors (FR) are cellular markers highly expressed in various cancer cells. Here, we report on the synthesis of a novel folate-containing lipoconjugate (FC) built of 1,2-di-O-ditetradecyl-rac-glycerol and folic acid connected via a PEG spacer, and the evaluation of the FC as a targeting component of liposomal formulations for nucleic acid (NA) delivery into FR expressing tumor cells. FR-targeting liposomes, based on polycationic lipid 1,26-bis(cholest-5-en-3β-yloxycarbonylamino)-7,11,16,20-tetraazahexacosan tetrahydrochloride (2X3), lipid helper dioleoylphosphatidylethanolamine (DOPE) and novel FC, formed small compact particles in solution with diameters of 60 ± 22 nm, and were not toxic to cells. Complexes of NAs with the liposomes were prepared at various nitrogen to phosphate ratios (N/P) to optimize liposome/cell interactions. We showed that FR-mediated delivery of different nucleic acids mediated by 2X3-DOPE/FC liposomes occurs in vitro at low N/P (1/1 and 2/1); under these conditions FC-containing liposomes display 3-4-fold higher transfection efficiency in comparison with conventional formulation. Lipoplexes formed at N/P 1/1 by targeted liposomes and cargo (Cy7-labeled siRNA targeting MDR1 mRNA) in vivo efficiently accumulate in tumor (∼15-18% of total amount), and kidneys (71%), and were retained there for more than 24 h, causing efficient downregulation of p-glycoprotein expression (to 40% of control) in tumors. Thus, FC containing liposomes provide effective targeted delivery of nucleic acids into tumor cells in vitro and in xenograft tumors in vivo.

Synthesis and evaluation of antitumor, anti-inflammatory and analgesic activity of novel deoxycholic acid derivatives bearing aryl- or hetarylsulfanyl moieties at the C-3 position

Novel deoxycholic acid (DCA) derivatives were stereoselectively synthesised with -OH and -CH₂SR moieties at the C-3 position, where R was a substituted aryl [2-aminophenyl (8) or 4-chlorophenyl (9)] or hetaryl [1-methylimidazolyl (5), 1,2,4-triazolyl (6), 5-amino-1,3,4-thiadiazolyl (7), pyridinyl (10) or pyrimidinyl (11)]. These compounds were prepared in good yields from the C-3β-epoxy derivative 2 in the epoxide ring-opening reaction by S-nucleophiles. These derivatives were evaluated for their in vitro anti-proliferation activity in a panel of tumor cell lines. Data showed that: (i) heterocycle-containing derivatives displayed higher cytotoxicity profiles than the parent molecule; (ii) heterocyclic substituents were more preferable than aryl moieties for enhancing anti-proliferation activity; (iii) the sensitivity of tumor cell lines to analysed compounds decreased in the following order: HuTu-80 (duodenal carcinoma)>KB-3-1 (cervical carcinoma)>HepG2 (hepatocellular carcinoma)>MH-22a (hepatoma); (iv) compounds 5, 6 and 11 exhibited a high cytotoxic selectivity index (HuTu-80: SI>7.7, 38.5 and 12.0, respectively). Compounds 2 and 6-8 markedly inhibited NO synthesis by interferon γ-induced macrophages. Screening for anti-inflammatory activity of these derivatives in vivo showed their high potency on histamine- (5, 10) and formalin- (2, 10, 11) induced paw edema models.

Soloxolone methyl inhibits influenza virus replication and reduces virus-induced lung inflammation

Highly pathogenic influenza viruses pose a serious public health threat to humans. Although vaccines are available, new antivirals are needed to efficiently control disease progression and virus transmission due to the emergence of drug-resistant viral strains. In this study, we describe the anti-viral properties of Soloxolone methyl (SM) (methyl 2-cyano-3,12-dioxo-18βH-olean-9(11),1(2)-dien-30-oate, a chemical derivative of glycyrrhetinic acid) against the flu virus. Anti-flu efficacy studies revealed that SM exhibits antiviral activity against the H1N1 influenza A virus in a dose-dependent manner causing a more than 10-fold decrease in virus titer and a reduction in the expression of NP and M2 viral proteins. In a time-of-addition study, SM was found to act at an early stage of infection to exhibit an inhibitory effect on both the attachment step and virus uptake into cells. Also, in infected cells SM downregulates the expression of the inflammatory cytokines IL-6 and TNF-α. In infected mice, SM administered intranasally prior to and after infection significantly decreases virus titers in the lung and prevents post-challenge pneumonia. Together, these results suggest that Soloxolone methyl might serve as an effective therapeutic agent to manage influenza outbreaks and virus-associated complications, and further preclinical and clinical investigation may be warranted.

Modulation of Tumour-Related Signaling Pathways by Natural Pentacyclic Triterpenoids and their Semisynthetic Derivatives

Pentacyclic triterpenoids are a large class of natural isoprenoids that are widely biosynthesized in higher plants. These compounds are potent anticancer agents that exhibit antiproliferative, antiangiogenic, antiinflammatory and proapoptotic activities. Although their effects on multiple pathways have been reported, unifying mechanisms of action have not yet been established. To date, a huge number of semisynthetic derivatives have been synthesized in different laboratories on the basis of triterpenoid scaffolds, and many have been assayed for their biological activities. The present review focuses on natural triterpenoids of the oleanane-, ursane- and lupane-types and their semisynthetic derivatives. Here, we summarize the diverse cellular and molecular targets of these compounds and the signal pathways involved in the performance of their antitumour actions. Among the most relevant mechanisms involved are cell cycle arrest, apoptosis and autophagy triggered by the effect of triterpenoids on TGF-β and HER cell surface receptors and the downstream PI3KAkt- mTOR and IKK/NF-kB signaling axis, STAT3 pathway and MAPK cascades.

Novel derivatives of deoxycholic acid bearing aliphatic or cyclic diamine moieties at the C-3 position: Synthesis and evaluation of anti-proliferative activity

A new library of deoxycholic acid derivatives bearing nitrogen-containing moieties at the C-3 position was synthesised from epoxy derivative 1 via an epoxide ring-opening reaction promoted by aliphatic or cyclic diamines and fully characterised by NMR and mass-spectroscopy. The synthesised compounds were screened for cytotoxicity against four human tumour cell lines. The results showed that some of the novel diamine-bearing derivatives displayed improved anti-proliferative activities over the parent compound DCA. Among them, a 1-methylpiperazine containing compound (6) showed promising activity and the highest selectivity against tumour cells of enterohepatic origin (HepG2: IC₅₀=3.6µM, SI=9.0; HuTu-80: IC₅₀=4.6µM, SI=6.9) and was identified as a lead molecule.