Remodeling Tumor Immune Microenvironment by Using Polymer-Lipid-Manganese Dioxide Nanoparticles with Radiation Therapy to Boost Immune Response of Castration-Resistant Prostate Cancer.

Despite substantial progress in the treatment of castration-resistant prostate cancer (CRPC), including radiation therapy and immunotherapy alone or in combination, the response to treatment remains poor due to the hypoxic and immunosuppressive nature of the tumor microenvironment. Herein, we exploited the bioreactivity of novel polymer-lipid manganese dioxide nanoparticles (PLMDs) to remodel the tumor immune microenvironment (TIME) by increasing the local oxygen levels and extracellular pH and enhancing radiation-induced immunogenic cell death. This study demonstrated that PLMD treatment sensitized hypoxic human and murine CRPC cells to radiation, significantly increasing radiation-induced DNA double-strand breaks and ultimately cell death, which enhanced the secretion of damage-associated molecular patterns, attributable to the induction of autophagy and endoplasmic reticulum stress. Reoxygenation via PLMDs also polarized hypoxic murine RAW264.7 macrophages toward the M1 phenotype, enhancing tumor necrosis factor alpha release, and thus reducing the viability of murine CRPC TRAMP-C2 cells. In a syngeneic TRAMP-C2 tumor model, intravenous injection of PLMDs suppressed, while radiation alone enhanced recruitment of regulatory T cells and myeloid-derived suppressor cells. Pretreatment with PLMDs followed by radiation down-regulated programmed death-ligand 1 and promoted the infiltration of antitumor CD8+ T cells and M1 macrophages to tumor sites. Taken together, TIME modulation by PLMDs plus radiation profoundly delayed tumor growth and prolonged median survival compared with radiation alone. These results suggest that PLMDs plus radiation is a promising treatment modality for improving therapeutic efficacy in radioresistant and immunosuppressive solid tumors.

Ester Prodrugs of Ketoprofen: Synthesis, In Vitro Stability, In Vivo Biological Evaluation and In Silico Comparative Docking Studies Against COX-1 and COX-2.

Prompted by the ineptness of the currently used non-steroidal antiinflammatory drugs (NSAIDs) to control gastric mucosal and renal adverse reactions, several ester prodrugs of ketoprofen were synthesized and characterized by IR, 1H NMR and mass spectral data. Physicochemical properties such as aqueous solubility, octanol-water partition coefficient log P, chemical stability and enzymatic hydrolysis of the synthesized molecules have been studied to assess their potential as prodrugs. The obtained results confirmed that all ester prodrugs are chemically stable, possess increased lipophilicity compared to their parent compounds and converted to the active drugs in vivo. All of the tested ester prodrugs exhibited marked anti-inflammatory activity ranging from 91.8% to 113.3% in comparison with the parent drug, ketoprofen. A mutual prodrug obtained from two antiinflammatory molecules, ketoprofen and salicylic acid has been noted to potentiate the activity making it most active molecule of the series. The ulcerogenic index of the ester prodrugs was significantly lower than the parent drug, ketoprofen. Comparative docking studies against X-ray crystal structures of COX-1 and COX-2 further provided understanding of their interaction with the cyclooxygenases that will facilitate design of better inhibitors (or prodrugs) with sufficient specificity for COX-2 against COX-1. The study offers an innovative strategy for finding a molecule with safer therapeutic profile for longterm treatment of inflammatory diseases.

Structure-based design, synthesis, molecular docking, and biological activities of 2-(3-benzoylphenyl) propanoic acid derivatives as dual mechanism drugs.

PURPOSE: 2-(3-benzoyl phenyl)propanohydroxamic acid (2) and 2-{3-[(hydroxyimino)(phenyl)methyl]phenyl}propanoic acid (3) were synthesized from non-steroidal anti-inflammatory drug, ketoprofen as dual-mechanism drugs. MATERIALS AND METHODS: Structures of the synthesized compounds were established by IR, (1)H NMR, and mass spectroscopy. Both compounds were screened for their anti-inflammatory activity in rat paw edema model and in vitro antitumor activity against 60 human tumor cell lines. Flexible ligand docking studies were performed with different matrix metalloproteinases and cyclooxygenases to gain an insight into the structural preferences for their inhibition. RESULTS: Compound (2) proved out to be more potent than ketoprofen in rat paw edema model. Both compounds showed moderate anticancer activity ranging from 1% to 23% inhibition of growth in 38 cell lines of 8 tumor subpanels at 10 µM concentration in a single dose experiment. Hydroxamic acid analogue was found to be more potent than ketoximic analogue in terms of its antitumor activity. CONCLUSION: Analysis of docking results together with experimental findings provide a good explanation for the biological activities associated with synthesized compounds which may be fruitful in designing dual-target-directed drugs that may inhibit cyclooxygenases and MMPs for the treatment of cancer.