USP1 Expression Driven by EWS::FLI1 Transcription Factor Stabilizes Survivin and Mitigates Replication Stress in Ewing Sarcoma.

In this study, we identify USP1 as a transcriptional target of EWS::FLI1 and demonstrate the requisite function of USP1 in Ewing sarcoma (EWS) cell survival in response to endogenous replication stress. EWS::FLI1 oncogenic transcription factor drives most EWS, a pediatric bone cancer. EWS cells display elevated levels of R-loops and replication stress. The mechanism by which EWS cells override activation of apoptosis or cellular senescence in response to increased replication stress is not known. We show that USP1 is overexpressed in EWS and EWS::FLI1 regulates USP1 transcript levels. USP1 knockdown or inhibition arrests EWS cell growth and induces cell death by apoptosis. Mechanistically, USP1 regulates Survivin (BIRC5/API4) protein stability and the activation of caspase-9 and caspase-3/7 in response to endogenous replication stress. Notably, USP1 inhibition sensitizes cells to doxorubicin and etoposide treatment. Together, our study demonstrates that USP1 is regulated by EWS::FLI1, the USP1-Survivin axis promotes EWS cell survival, and USP1 inhibition sensitizes cells to standard of care chemotherapy. IMPLICATIONS: High USP1 and replication stress levels driven by EWS::FLI1 transcription factor in EWS are vulnerabilities that can be exploited to improve existing treatment avenues and overcome drug resistance.

Azelaic acid and Melaleuca alternifolia essential oil co-loaded vesicular carrier for combinational therapy of acne.

Aim: Azelaic acid (AzA), a comedolytic, antibacterial, anti-inflammatory anti-melanogenic agent, prescribed against acne vulgaris is safe on skin. Its combination with another widely used anti-acne agent, tea tree oil (EO) whose delivery is limited by volatility, instability and lipophilicity constraints was attempted. Method: Solvent injection was used to prepare AzA-EO integrated ethosomes. Result: Ethosomes were transformed into carbopol hydrogel, which exhibited pseudo-plastic properties with appreciable firmness, work of shear, stickiness and work of adhesion. The hydrogel showed better permeation and retention characteristics vis-a-vis commercial formulation (AzidermTM), when evaluated in Wistar rat skin. Further, ethosome hydrogel composite was better tolerated with no side effects. Conclusion: The findings suggests that the aforementioned strategy could be a potential treatment used for acne management.

Hydrogel composite containing azelaic acid and tea tree essential oil as a therapeutic strategy for Propionibacterium and testosterone-induced acne.

Azelaic acid (AzA) is a USFDA bioactive prescribed against acne vulgaris. It possesses delivery challenges like poor aqueous solubility, low skin-penetrability, and dose-dependent side effects, which could be overcome by its synergistic combination with tea tree oil (TTO) as a microemulsion (ME)-based hydrogel composite. AzA-TTO ME was prepared to employ pseudo-ternary phase diagram construction. The best AzA-TTO ME was of uniform size (polydispersity index < 0.7), nano-range (~357.4 ± 2% nm), transmittance (> 90%), and negative zeta potential (-1.42 ± 0.25% mV) values. ME hydrogel composite with optimum rheological and textural attributes showed better permeation, retention, and skin-compliant characteristics, vis-a-vis marketed formulation (Aziderm™) when evaluated in Wistar rat skin. In vitro antibacterial efficacy in bacterial strains, i.e., Staphylococcus aureus, Propionibacterium acne, and Staphylococcus epidermidis, was evaluated employing agar well plate diffusion and broth dilution assay. ME hydrogel has shown an increase in zone of inhibition by two folds and a decrease in minimum inhibitory concentration (MIC) by eightfold against P. acnes vis-a-vis AzA. Finally, ME hydrogel composite exhibited a better reduction in the papule density (93.75 ± 1.64%) in comparison to Aziderm™ 72.69 ± 4.67%) on acne as developed in rats by inducing testosterone. Thus, the developed AzA-TTO ME hydrogel composite promises an efficacious and comparatively safer drug delivery system for the topical therapy of acne vulgaris.

Synergistic potential of Citrus aurantium L. essential oil with antibiotics against Candida albicans.

ETHNOPHARMACOLOGICAL RELEVANCE: Citrus aurantium L. is used in traditional medicine in India for treating stomach ache, vomiting, blood pressure, dysentery, diarrhea, cardiovascular analeptic, sedative, boils and urinary tract infections. Its essential oil from fruit peels has antioxidant, antimicrobial, antifungal, antiparasitic, and anti-inflammatory activities. AIM OF THE STUDY: The aim of the study was to characterize the antifungal activity and synergistic potential of essential oil extracted from leaves of Citrus aurantium L. of North-Western Himalayas against Candida albicans. MATERIALS AND METHODS: Citrus aurantium essential oil (CAEO) was extracted from leaves and characterized by GC-MS. The antifungal activity and synergistic potential of CAEO against C. albicans was studied by agar well diffusion, and broth microdilution assay. The anti-fungal potential of the phytoconstituents of CAEO was studied by in silico interaction with two fungal drug targets, N-myristoyl transferase (NMT) and Cytochrome P450 14 Alpha-sterol Demethylase (CYP51). RESULTS: CAEO exhibited strong antifungal activity against two strains of C. albicans, with fungicidal effect. The MIC of CAEO against C. albicans strains was 0.15 - 0.31% (v/v). CAEO exhibited synergistic potential with fluconazole and amphotericin B against C. albicans and enhanced the antifungal efficacy of the clinical drugs by 8.3 to 34.4 folds. The GC-MS analysis of CAEO identified at least ten compounds, with 2-ß pinene, δ-3 Carene and D-limonene as the major compounds. In silico molecular docking of the three major phytocompounds of CAEO with NMT and CYP51 revealed their potential to interact with both targets. δ-3 Carene showed best binding (Etotal of -131.13 kcal/mol) with NMT, while D-limonene exhibited highest binding energy (Etotal of -175.23 kcal/mol) with CYP51. ADME/T analysis showed that 2-ß pinene, δ-3 Carene and D-limonene exhibit drug likeliness and ideal toxicity profiles for their use as drug candidates. CONCLUSIONS: Thus, the essential oil from leaves of C. aurantium and its phytocomponents can be used as sustainable and natural therapeutic to treat candidiasis as well as a resource to enhance the potency of clinical antibiotics, which have lost efficacy due to emergence of drug resistance in C. albicans.