Background: Ovarian cancer is the leading cause of mortality among malignant gynecological tumors. Surgical resection and chemotherapy with intravenous platinum/taxanes drugs are the treatments of choice, with little effectiveness in later stages and severe toxicological effects. Therefore, this study aimed to evaluate the antineoplastic activity of gallic acid (GA) and myricetin (Myr) administrated peritumorally in Nu/Nu mice xenotransplanted with SKOV-3 cells. Methods: Biological activity of GA and MYR was evaluated in SKOV-3 and OVCAR-3 cells (ovarian adenocarcinomas) by confocal/transmission electron microscopy, PI-flow cytometry, H 2-DCF-DA stain, MTT, and Annexin V/PI assays. Molecular targets of compounds were determined with ACD/I-Labs and SEA. Antineoplastic activity was performed in SKOV-3 cells subcutaneously xenotransplanted into female Nu/Nu mice treated peritumorally with 50 mg/kg of each compound (2 alternate days/week) for 28 days. Controls used were paclitaxel (5 mg/kg) and 20 μL of vehicle (0.5% DMSO in 1X PBS). Tumor lesions, organs and sera were evaluated with NMR, USG, histopathological, and paraclinical studies. Results: In vitro studies showed a decrease of cell viability with GA and Myr in SKOV-3 (50 and 166 μg/mL) and OVCAR-3 (43 and 94 μg/mL) cells respectively, as well as morphological changes, cell cycle arrest, and apoptosis induction due to ROS generation (p ≤ 0.05, ANOVA). In silico studies suggest that GA and MYR could interact with carbonic anhydrase IX and PI3K, respectively. In vivo studies revealed inhibitory effects on tumor lesions development with GA and MYR up to 50% (p ≤ 0.05, ANOVA), with decreased vascularity, necrotic/fibrotic areas, neoplastic stroma retraction and apoptosis. However, toxicological effects were observed with GA treatment, such as leukocyte infiltrate and hepatic parenchyma loss, hypertransaminasemia (ALT: 150.7 ± 25.60 U/L), and hypoazotemia (urea: 33.4 ± 7.4 mg/dL), due to the development of chronic hepatitis (p ≤ 0.05, ANOVA).

The axolotl (Ambystoma mexicanum) is a caudate amphibian, which has an extraordinary ability to restore a wide variety of damaged structures by a process denominated epimorphosis. While the origin and potentiality of progenitor cells that take part during epimorphic regeneration are known to some extent, the metabolic changes experienced and their associated implications, remain unexplored.However, a circuit with a potential role as a modulator of cellular metabolism along regeneration is that formed by Lin28/let-7. In this study, we report two Lin28 paralogs and eight mature let-7 microRNAs encoded in the axolotl genome. Particularly, in the proliferative blastema stage amxLin28B is more abundant in the nuclei of blastemal cells, while the microRNAs amx-let-7c and amx-let-7a are most downregulated. Functional inhibition of Lin28 factors increase the levels of most mature let-7 microRNAs, consistent with an increment of intermediary metabolites of the Krebs cycle, and phenotypic alterations in the outgrowth of the blastema. In summary, we describe the primary components of the Lin28/let-7 circuit and their function during axolotl regeneration, acting upstream of metabolic reprogramming events.The Axolotl Lin28/let-7 Circuit 3 Pioneer studies have related some components of the Lin28/let-7 circuit with regenerative processes, as those that report a high regenerative plasticity in juvenile stages of Caenorhabditis elegans, where immature neurons with low levels of mature let-7 retain a robust regeneration at the axon disruption site, nearby to neural body (Nix and Bastiani, 2013;Zou et al., 2013). Similarly, the transient overexpression of Lin28 in postnatal sensory neurons of mouse after injury, induce an axonal regeneration in vivo through changes in the balance of the AKT-mTOR pathway (Wang et al., 2018).Therefore, an adequate cell metabolic state is relevant for regeneration, since the AKT-mTOR pathway acts as an important mediator between anabolic and catabolic cell reactions (Altomare and Khaled, 2012;Saxton and Sabatini, 2017). In this sense, it has been shown that the inducible overexpression of Lin28A in mouse neonatal tissues, improves regeneration by a rewiring of the primary energetic metabolism, where the glycolysis is favored to increase intermediary metabolites of the Krebs cycle (Shyh-Chang et al., 2013). However, such metabolic reprogramming of the cell bioenergetics differs from other metabolic profiles also achieved with overexpression of Lin28A, but in the context of embryonic development, or during active proliferation of primed pluripotent stem cells and malignant neoplastic cells (Ma et al., 2014;Miyazawa et al., 2017;Zhang et al., 2016).Since the role of the Lin28/let-7 circuit has not been directly studied in the context of epimorphosis, using an amphibian model with a high and innate regenerative capacity, we decided to characterize its behavior and function during forelimb regeneration in axolotl (Ambystoma mexicanum). In this study, we describe the spatio-temporal expression dynamics of ...

The axolotl (Ambystoma mexicanum) is a caudate amphibian, which has an extraordinary ability to restore a wide variety of damaged structures by a process denominated epimorphosis. While the origin and potentiality of progenitor cells that take part during epimorphic regeneration are known to some extent, the metabolic changes experienced and their associated implications, remain unexplored. However, a circuit with a potential role as a modulator of cellular metabolism along regeneration is that formed by Lin28/let-7. In this study, we report two Lin28 paralogs and eight mature let-7 microRNAs encoded in the axolotl genome. Particularly, in the proliferative blastema stage amxLin28B is more abundant in the nuclei of blastemal cells, while the microRNAs amx-let-7c and amx-let-7a are most downregulated. Functional inhibition of Lin28 factors increase the levels of most mature let-7 microRNAs, consistent with an increment of intermediary metabolites of the Krebs cycle, and phenotypic alterations in the outgrowth of the blastema. In summary, we describe the primary components of the Lin28/let-7 circuit and their function during axolotl regeneration, acting upstream of metabolic reprogramming events.

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Some studies demonstrate that gallic acid (GA) and myricetin (MYR) isolated from Rhus trilobata provide the therapeutic activity of this plant against cancer. However, few reports demonstrate that both compounds could also have therapeutic potential in ovarian cancer. Therefore, evaluating the cytotoxic activity of GA and MYR against ovarian cancer cells and determining the possible action mechanism present are important. For this purpose, SKOV-3 cells (ovarian adenocarcinoma; HTB-77™, ATCC®) were cultivated according to the supplier’s instructions (37 °C and 5% CO2) to determine the biological activity of GA and MYR by confocal/transmission electron microscopy, PI-flow cytometry, H2DCF-DA, MTT, and Annexin-V assays. Possible molecular targets of the compounds were determined by the Similarity Ensemble approach. Results showed that GA and MYR treatments decreased the viability of SKOV-3 cells at 50 and 166 μg/mL, respectively (p ≤ 0.05, ANOVA vs. vehicle group). They also induced morphological changes (cytoplasmic reduction, nuclear chromatin condensation, cytoplasmic vesicles increment, polymerized actin, and stabilized tubulin), cell cycle arrest (GA: 8.3% G2/M and MYR: 78% G1), and apoptosis induction (GA: 18.9% and MYR: 8.1%), due to ROS generation (34 to 42%) for 24 h (p ≤ 0.05, ANOVA vs. vehicle group). In silico studies demonstrated that GA and MYR interact with carbonic anhydrase-IX and PI3K, respectively. In conclusion, GA and MYR show cytotoxic activity against SKOV-3 cells through ROS production, which modifies the cytoskeleton and induces apoptosis. Therefore, GA and MYR could be considered as base compounds for the development of new treatments in chemotherapy for ovarian cancer.

Linearolactone (LL) isolated from Salvia polystachya presents antiparasitic activity against E. histolytica and G. lamblia through ROS production, an apoptosis-like process, and alteration of the actin cytoskeleton. This effect limits the invasion and spread of parasites during host infection. However, the possible toxicological effects or the molecular mechanisms by which LL affects the E. histolytica mobility are still not understood. LL could act as an inhibitor of accessory cytoskeletal proteins, such as myosin, calreticulin, and calpain to achieve this end. The aim of this study was to determine the pharmacological and toxicological properties of LL via bioinformatic analyses to find therapeutic targets and to understand the action mechanism on the actin cytoskeleton against E. histolytica. The pharmacological activities, toxicological risks, and molecular targets of LL were determined using free software such as Molsoft© to define the bioactivity through comparison with standard drugs [1], Molinspiration© to calculate physicochemical properties [2], ToxiM© to determine possible intestinal permeability [3,4], SuperCYPsPred© to predict drug metabolism via the cytochrome-P450 system [5,6], and SEA© to find proteins with binding sites for the active compounds through an inverse protein–ligand approach [7,8]. Molecular docking with key proteins for the pathogenic activity of E. histolytica trophozoites, such as myosin-II and calreticulin, was performed with AutoDock-Vina and UCSF-Chimera. Results revealed that LL presents a drug-likeness of −0.55 and ToxiM of 0.958 due to medium toxicity associated with interactions in nuclear receptors (0.66), GPCR ligands (0.65), and enzymatic inhibitions (0.47) related to the cytochrome-P450 system (CYP3A4, low). Results indicate that LL is a hydrophobic molecule (LogP: 1.59) with intermediate intestinal absorption (TPSA: 65.75, CACO-2 permeability) and medium blood–brain barrier penetration (3.86). SEA analysis demonstrated that the potential target pharmacophores are OPRK1 (p-Value: 6.49 × 10−37, Max TC: 0.49) and NLRP3 (p-Value: 3.90 × 10−19, Max TC: 0.36) in humans. Molecular docking of LL with E. histolytica proteins showed high affinity to ATP-binding catalytic sites in the heavy-chain (GLU-187.A, THR-186.A, ASN-234.B) of myosin-II (−8.30 Kcal/mol), as well as in chain A and C (LYS-199.A, LYS-152.C) of calreticulin (−8.77 Kcal/mol). As for conclusions, LL is a compound with possible moderate toxicity, sedative effects on CNS, and anti-inflammatory properties. In addition, LL has antiparasitic activity involving the immobilization of E. histolytica trophozoites through interactions with accessory proteins from the actin cytoskeleton such as myosin-II and calreticulin. These proteins are present in the parasite and are fundamental to amoebic liver abscess formation during host infection. Therefore, LL could be a therapeutic alternative to the amoebiasis treatment and provide a leading compound for drug discovery against parasitic diseases, but in-depth studies are necessary to confirm these claims.