Evgenii S. Mozhaitsev

Background: Hypoxia-inducible factor-1α (HIF-1α) is a well-known transcriptional regulator that mediates a broad spectrum of cellular responses to hypoxia, including angiogenesis, extracellular matrix remodeling, and metabolic reprogramming. These activities can be achieved by upregulation of numerous genes, such as vascular endothelial growth factors, fibroblast growth factors, and platelet-derived growth factors, which are involved in the growth regulation of normal tissues and solid tumors. Notably, HIF-1α-mediated regulation of the solid tumor’s microenvironment effectively modulates tumor sensitivity to anticancer therapies and thereby can contribute to disease progression. Methods: The study was performed on breast, lung and prostate cancer cell lines. Protein expression was examined by western blotting. Antitumor activity of 2-ANPC was measured by syngeneic 4T1 breast cancer mouse model. Results: We show here that a 2-aminopyrrole derivative (2-amino-1-benzamido-5-(2-(naphthalene-2-yl)-2-oxoethylidene)-4-oxo-4,5-dihydro-1-H-pyrrole-3-carboxamide—2-ANPC), previously shown as a potent microtubule-targeting agent, effectively downregulates HIF-1α expression in a broad spectrum of cancer cell lines, including breast, lung, and prostate cancer. The downregulation of HIF-1α expression in 2-ANPC-treated cancer cells was due to enhanced proteasome-mediated degradation, whereas the proteasome inhibitor MG-132 effectively reversed this downregulation. 2-ANPC’s potency in downregulating HIF-1α was also shown in vivo by using the 4T1 breast cancer syngraft model. Importantly, this 2-aminopyrrole derivative also downregulated the expression of vascular endothelial growth factor receptors 1 and 3 (VEGFR1 and 3) in 4T1 tumors, which correlated with decreased tumor weight and size. As expected, an increase in apoptotic (i.e., cleaved caspase-3-positive) cells was detected in 4T1 tumors treated with 2-aminopyrrole derivative. Lastly, using various computational tools, we identified four potential binding sites for 2-ANPC to interact with HIF-1α, HIF-1β, and the p300 complex. Conclusions: Collectively, we show here, for the first time, that HIF-1α is a novel molecular target for the 2-aminopyrrole derivative (2-ANPC), thereby illustrating it as a potential scaffold for the development of potent chemotherapeutic agents with anti-angiogenic activity.

Hypoxia-inducible factor-1α (HIF-1α) is a well-known transcriptional regulator that me-diates a broad spectrum of cellular responses to hypoxia, including angiogenesis, extra-cellular matrix remodeling, and metabolic reprogramming. These activities can be achieved by up-regulation of numerous genes, such as vascular endothelial growth fac-tors, fibroblast growth factors, and platelet-derived growth factors, which are involved in the growth regulation of normal tissues and solid tumors. Of note, HIF-1α-mediated regu-lation of the solid tumor’s microenvironment effectively modulates tumor sensitivity to anticancer therapies and thereby can contribute to disease progression. We show here that a 2-aminopyrrole derivative (2-amino-1-benzamido-5-(2-(naphthalene-2-yl)-2-oxoethylidene)-4-oxo-4,5-dihydro-1-H-pyrrole-3-carboxamide – 2-ANPC), previously shown as a potent microtubule-targeting agent, effectively down-regulates HIF-1α expression in a broad spectrum of cancer cell lines, including breast, lung, and prostate cancer. The downregulation of HIF-1α expression in 2-ANPC-treated cancer cells was due to en-hanced proteasome-mediated degradation, whereas the proteasome inhibitor MG-132 ef-fectively reversed this downregulation. 2-ANPC’s potency to down-regulate HIF-1α was also shown in vivo by using the 4T1 breast cancer syngraft model. Important, this 2-aminopyrrole derivative also down-regulated the expression of vascular endothelial growth factor receptors 1 and 3 (VEGFR1 and 3) in 4T1 tumors, which correlated with de-creased tumor weight and size. As expected, an increase of apoptotic (i.e., cleaved caspa-se-3-positive) cells was detected in 4T1 tumors treated with 2-aminopyrrole derivative. Lastly, using various computational tools, we identified four potential binding sites for 2-ANPC to interact with HIF-1α, HIF-1β, and the p300 complex. Collectively, we show here, for the first time, that HIF-1α is a novel molecular target for the 2-aminopyrrole de-rivative (2-ANPC), thereby illustrating it as a potential scaffold for the development of po-tent chemotherapeutic agents with anti-angiogenic activity.

The synthesis of urea and thiourea containing adamantane and campholene fragments was performed starting from adamant-1-yl isocyanate, adamant-1-yl isothiocyanate and campholenyl amine. The synthesised compounds were modified to their oxalyl derivatives, which may be of interest for biological activity screening.

A series of new (thio)semicarbazones containing adamantane and 3,7-dimethyloctyl fragments was synthesized. The configuration of imine bond was proposed based on the characteristic signals of ¹Н and ¹³С NMR spectra simulated by quantum-chemical calculations.

Multidrug resistance is the dominant obstacle to effective chemotherapy for malignant neoplasms. It is well known that neoplastic cells use a wide range of adaptive mechanisms to form and maintain resistance against antitumor agents, which makes it urgent to identify promising therapies to solve this problem. Hydroxamic acids are biologically active compounds and in recent years have been actively considered to be potentially promising drugs of various pharmacological applications. In this paper, we synthesized a number of hydroxamic acids containing a p-substituted cinnamic acid core and bearing bicyclic pinane fragments, including derivatives of (−)-myrtenol, (+)-myrtenol and (−)-nopol, as a Cap-group. Among the synthesized compounds, the most promising hydroxamic acid was identified, containing a fragment of (−)-nopol in the Cap group 18c. This compound synergizes with cisplatin to increase its anticancer effect and overcomes cisplatin resistance, which may be associated with the inhibition of histone deacetylase 1 and glycolytic function. Taken together, our results demonstrate that the use of hydroxamic acids with a bicyclic pinane backbone can be considered to be an effective approach to the eradication of tumor cells and overcoming drug resistance in the treatment of malignant neoplasms.

Tyrosyl-DNA phosphodiesterase 1 and 2 (Tdp1 and Tdp2) are DNA repair enzymes that repair DNA damage caused by various agents, including anticancer drugs. Thus, these enzymes resist anticancer therapy and could be the reason for resistance to such widely used drugs such as topotecan and etoposide. In the present work, we found compounds capable of inhibiting both enzymes among derivatives of (−)-usnic acid. Both (+)- and (−)-enantiomers of compounds act equally effectively against Tdp1 with IC₅₀ values in the range of 0.02–0.2 μM; only (−)-enantiomers inhibited Tdp2 with IC₅₀ values in the range of 6–9 μM. Surprisingly, the compounds protect HEK293FT wild type cells from the cytotoxic effect of etoposide (CC₅₀ 3.0–3.9 μM in the presence of compounds and 2.4 μM the presence of DMSO) but potentiate it against Tdp2 knockout cells (CC₅₀ 1.2–1.6 μM in the presence of compounds against 2.3 μM in the presence of DMSO). We assume that the sensitizing effect of the compounds in the absence of Tdp2 is associated with the effective inhibition of Tdp1, which could take over the functions of Tdp2.

Tdp1 and Tdp2 are DNA repair enzymes that repair DNA damages caused by various agents, including anticancer drugs. Thus, these enzymes resist anticancer therapy and could be the reasons of resistance to such widely used drugs as topotecan and etoposide. In the present work, we found compounds capable of inhibiting both enzymes among derivatives of (-)-usnic acid. Both (+)- and (-)-enantiomers of compounds act equally effectively against Tdp1, and only (-)-enantiomers inhibited Tdp2. Surprisingly, the compounds protect HEK293FT wild type cells from the cytotoxic effect of etoposide but potentiate it against Tdp2 knockout cells. We assume that the sensitizing effect of the compounds in the absence of Tdp2 is associated with effective inhibition of Tdp1, which could take over the functions of Tdp2.

Novel monoterpene-based hydroxamic acids of two structural types were synthesized for the first time. The first type consisted of compounds with a hydroxamate group directly bound to acyclic, monocyclic and bicyclic monoterpene scaffolds. The second type included hydroxamic acids connected with the monoterpene moiety through aliphatic (hexa/heptamethylene) or aromatic linkers. An in vitro analysis of biological activity demonstrated that some of these molecules had powerful HDAC6 inhibitory activity, with the presence of a linker area in the structure of compounds playing a key role. In particular, it was found that hydroxamic acids containing a hexa- and heptamethylene linker and (-)-perill fragment in the Cap group exhibit excellent inhibitory activity against HDAC6 with IC₅₀ in the submicromolar range from 0.56 ± 0.01 µM to 0.74 ± 0.02 µM. The results of the study of antiradical activity demonstrated the presence of moderate ability for some hydroxamic acids to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2ROO^• radicals. The correlation coefficient between the DPPH radical scavenging activity and oxygen radical absorbance capacity (ORAC) value was R² = 0.8400. In addition, compounds with an aromatic linker based on para-substituted cinnamic acids, having a monocyclic para-menthene skeleton as a Cap group, 35a, 38a, 35b and 38b, demonstrated a significant ability to suppress the aggregation of the pathological β-amyloid peptide 1-42. The 35a lead compound with a promising profile of biological activity, discovered in the in vitro experiments, demonstrated neuroprotective effects on in vivo models of Alzheimer’s disease using 5xFAD transgenic mice. Together, the results obtained demonstrate a potential strategy for the use of monoterpene-derived hydroxamic acids for treatment of various aspects of Alzheimer’s disease.

Chemoselective O‐alkylation of 1‐aryl‐3‐polyfluoroalkylpyrazol‐5‐oles under basic conditions resulted in a series of 5‐alkoxypyrazoles (26 derivatives). They showed an acceptable ADME profile (in silico) and can be considered as drug‐like. In experiments in vivo (CD‐1 mice), it was found that the obtained compounds do not have toxic properties at a dose of more than 150 mg/kg (for most compounds at a dose of >300 mg/kg, and for lead compounds – >600 mg/kg). 22 Compounds from this series demonstrated from moderate to high analgesic effects (28–104 % at 1 h and 37–109 % at 2 h after administration) in vivo in the hot plate test (SD rats, 15 mg/kg, intraperitoneal (ip)). The lead compound was 4‐([1‐phenyl‐3‐(trifluoromethyl)pyrazol‐5‐yl]oxy)butan‐1‐ol, which not only increased the latent period in the hot plate test by 103 % at both measurement points but also showed a pronounced analgesic effect under conditions of capsaicin‐induced nociception (CD‐1 mice, 15 mg/kg, ip). According to molecular modeling, all synthesized compounds can interact with the TRPV1 ion channel. This biological target was confirmed in in vitro experiments on Chinese hamster ovary cells expressing rTRPV1. 5‐Alkoxypyrazoles were partial agonists of the TRPV1 ion channel in various degree, and the most active was the same pyrazole as in in vivo tests.

Despite the fact that the variola virus is considered eradicated, the search for new small molecules with activity against orthopoxviruses remains an important task, especially in the context of recent outbreaks of monkeypox. As a result of this work, a number of amides of benzoic acids containing an adamantane fragment were obtained. Most of the compounds demonstrated activity against vaccinia virus, with a selectivity index SI = 18,214 for the leader compound 18a. The obtained derivatives also demonstrated activity against murine pox (250 ≤ SI ≤ 6071) and cowpox (125 ≤ SI ≤ 3036). A correlation was obtained between the IC₅₀ meanings and the binding energy to the assumed biological target, the p37 viral protein with R² = 0.60.