FKA-A NPs enhances PTX-A NPs efficacy to suppress ovarian cancer via regulating Skp2/YAP pathway.

Recurrence and distant metastasis after paclitaxel (PTX)-based chemotherapy in ovarian cancer (OC) patients remains a clinical obstacle. Flavokawain A (FKA) is a novel chalcone from kava plant that can induce G2/M arrest and inhibit invasion and metastasis in different tumor cells. In this study, we examined the effects and the molecular mechanism of sodium aescinate (Aes)-stabilized nanoparticles FKA-A NPs in enhancing the efficacy of PTX-A NPs in vitro and in vivo. We showed that FKA-A NPs combined with PTX-A NPs notably inhibited the proliferation and migration and reduced the expression of EMT-related markers in OCs. YAP nuclear translocation and its downstream signaling pathway were remarkably activated after PTX-A NPs treatment in OCs. FKA-A NPs obviously inhibited YAP nuclear translocation and reduced the transcriptional activity of YAP target genes. Simultaneously, FKA-A NPs dose and time dependently inhibited Skp2 expression in A2780 and Skov3 cells. In contrast, overexpression of Skp2 significantly attenuated the inhibition of FKA-A NPs on YAP nuclear translocation. In OC homograft mice, treatment with FKA-A NPs and PTX-A NPs significantly suppressed the growth of homograft tumor compared with PTX-A NPs but did not decrease mice's body weight. In summary, we demonstrate that FKA-A NPs enhance the efficacy of PTX-A NPs against OCs in vitro and in vivo via reducing Skp2 expression, thus suppressing YAP nuclear translocation and activity of its target genes.

Discovery of 2,5-diphenyl-1,3,4-thiadiazole derivatives as HDAC inhibitors with DNA binding affinity.

Incorporating a DNA-binding fragment in HDAC inhibitors has been proved to be an effective strategy for the treatment of hematologic malignancies by our group. However, similar to other approved HDAC inhibitors, their effects on solid tumor were poor. For this issue, a series of 2,5-diphenyl-1,3,4-thiadiazole hydroxamate derivatives were designed and synthesized as the HDAC inhibitors with DNA binding affinity. Among the target compounds, 4j not only bound with DNA effectively but also exhibited the most potent inhibitory activity against HDAC1 with the IC50 of 15 nM. Compared to SAHA, compound 4j displayed stronger antiproliferative activity in tested tumor cell lines. Western blot analysis showed that 4j could enhance the acetylation of histone H3 and α-tubulin, as well as promote the activation of caspase 3 in HCT116 and MC38 cell lines. Furthermore, these responses resulted in significant suppression of tumor growth in the MC38 tumor model. This work validated that compound 4j was a promising lead compound for further structural optimization.

Amphiphilic small molecular mates match hydrophobic drugs to form nanoassemblies based on drug-mate strategy.

Nanomedicine has made great progress in the targeted therapy of cancer. Here, we established a novel drug-mate strategy by studying the formulation of nanodrugs at the molecular level. In the drug-mate combination, the drug is a hydrophobic drug that is poorly soluble in water, and the mate is an amphiphilic small molecule (SMA) that has both hydrophilic and lipophilic properties. We proposed that the hydrophobic drug could co-assemble with a suitable SMA on a nanoscale without additive agents. The proof-of-concept methodology and results were presented to support our hypothesis. We selected five hydrophobic drugs and more than ten amphiphilic small molecules to construct a library. Through molecular dynamic simulation and quantum chemistry computation, we speculated that the formation of nanoassemblies was related to the binding energy of the drug-mate, and the drug-mate interaction must overcome drug-drug interaction. Furthermore, the obtained SF/VECOONa nanoassemblieswas selected as a model, which had an ultra-high drug loading content (46%), improved pharmacokinetics, increased bioavailability, and enhanced therapeutic efficacy. In summary, the drug-mate strategy is an essential resource to design exact SMA for many hydrophobic drugs and provides a reference for the design of a carrier-free drug delivery system.

Inflammatory molecules facilitate the development of docetaxel-resistant prostate cancer cells in vitro and in vivo.

Numerous molecular mechanisms have been found to contribute to docetaxel-induced resistance in prostate cancer (PCa). In this study, the changes in gene expression profiles of multidrug resistant PCa cells that were established in response to docetaxel were determined using microarray analysis. In addition to alterations in the expression of multidrug resistance-associated genes, the expression levels of multiple inflammatory molecules, in particular IL-6, significantly increased in resistant cells in vitro and in vivo, which further increased with the development of drug resistance following microarray, qRT-PCR and ELISA analysis. Compared with parental cells, resistant cells also presented with stronger activation of multiple IL-6-associated signaling pathways STAT1/3, NF-κB, and PI3K/AKT. Inactivation of IL-6 using a neutralizing antibody resulted in a slight effect on the sensitivity of resistant cells to docetaxel, while blockade of of STAT1/3, NF-κB, or PI3K/AKT signaling significantly resensitized resistant cells to docetaxel. Of note, simultaneous inactivation of IL-6 and STAT1/3, PI3K/AKT or NF-κB further enhanced the sensitivity of the resistant cells to docetaxel. Thus, inflammatory molecules, in particular IL-6, and IL-6-associated signaling pathways NF-κB, STAT1/3, and PI3K/AKT, are crucial mediators of the development of docetaxel-resistance in PCa. Targeting inflammatory molecules and signaling pathways could be a potential therapeutic option for the intervention of drug resistance in PCa.

Synergistic Combination of Sodium Aescinate-Stabilized, Polymer-Free, Twin-Like Nanoparticles to Reverse Paclitaxel Resistance.

BACKGROUND: The development of paclitaxel (PTX) resistance seriously restricts its clinical efficacy. An attractive option for combating resistance is inhibiting the expression of P-glycoprotein (P-gp) in tumor cells. We have reported that flavokawain A (FKA) inhibited P-gp protein expression in PTX-resistant A549 (A549/T) cells, indicating that FKA combined with PTX may reverse PTX resistance. However, due to the variable pharmacokinetics of FKA and PTX, the conventional cocktail combination in clinics may cause uncertainty of treatment efficacy in vivo. MATERIALS AND METHODS: To synergistically elevate the anti-cancer activity of PTX and FKA in vivo, the national medical products administration (NMPA) approved sodium aescinate (Aes) was utilized to stabilize hydrophobic PTX and FKA to form polymer-free twin like PTX-A nanoparticles (NPs) and FKA-A NPs. RESULTS: The resulting nanoparticles prepared simply by nanoprecipitation possessed similar particle size, good stability and ultrahigh drug loadings of up to 50%. With the aid of Aes, these two drugs accumulated in tumor tissue by passive targeting and were efficiently taken up by A549/T cells; this resulted in significant suppression of tumor growth in A549/T homograft mice at a low PTX dose (2.5 mg·kg-1). Synergistic effects and reversed PTX resistance were achieved by the combination of PTX-A NPs and FKA-A NPs by inhibiting P-gp expression in tumor cells. CONCLUSION: Using NMPA-approved Aes to prepare twin-like nanoparticles without introducing any new materials provides an efficient platform for combination chemotherapy and clinical translation.

Preparation and evaluation of etoposide-loaded lipid-based nanosuspensions for high-dose treatment of lymphoma.

Aim: High-dose administration of etoposide (VP16) was limited by its poor aqueous solubility and severe systemic toxicity on lymphoma therapy. Herein, a novel VP16-loaded lipid-based nanosuspensions (VP16-LNS) was developed for improving drug solubility, enhancing antitumor effect and reducing systemic toxicity. Materials & methods: VP16-LNS with soya lecithin and D-α-tocopheryl PEG 1000 succinate (TPGS) as stabilizers were prepared by nanoprecipitation method. Results: VP16-LNS exhibited uniform spherical morphology, small particle size and favorable colloidal stability. The concentration of VP16 in VP16-LNS was high enough (1017.67 µg/ml) for high-dose therapy on lymphoma. Moreover, VP16-LNS displayed long blood circulation time, selective intratumoral accumulation, remarkable antitumor effect and upregulated safety. Conclusion: VP16-LNS would be an efficient nanoformulation for clinical intravenous application against lymphoma.

Unified D-α-Tocopherol 5-Fu/SAHA bioconjugates self-assemble as complex nanodrug for optimized combination therapy.

AIM: To optimize the synergistic efficacy of combination therapy with controlled molar ratio, complex small molecule-based nanodrug (Co-SMND) of 5-fluorouracil (5-Fu)/vorinostat (SAHA) was developed. MATERIALS & METHODS: Co-SMND with various ratios of 5-Fu-D-α-tocopherol (VE)/SAHA-VE were prepared and characterized including co-assembly mechanism, hydrolytic stability, cytotoxicity, synergistic effect and apoptosis inducing ability. The antitumor activity, systematic toxicity and biodistribution of optimized Co-SMND were evaluated in CT-26 bearing BALB/c mouse. RESULTS: Maximal synergistic effect of Co-SMND could be obtained via simply adjusting the feeding molar ratio. The optimized Co-SMND showed superior in vivo antitumor efficacy, upregulated security and selective intratumoral accumulation. CONCLUSION: Such Co-SMND is of great significance for future clinical translation, and would be an efficient platform for combination chemotherapy.

Ceramide-Fabricated Co-Loaded Liposomes for the Synergistic Treatment of Hepatocellular Carcinoma.

Combination therapy is one of the important methods to improve therapeutic effect on the treatment of hepatocellular carcinoma (HCC). Sorafenib (SF) is a canonical US Food and Drug Administration-approved multikinase molecule inhibitor against HCC. However, therapeutic benefit with Sorafenib alone was usually unsatisfactory. Ceramide (CE) is an endogenous bioactive sphingolipid, which has a strong potential to suppress various tumors. The combination of SF and CE was hoping to exert maximum synergistic antitumor effect through different tumor-suppressible mechanisms. In this respect, SF and CE co-loaded liposomes (SF/CE-liposomes) were developed to verify synergistic antitumor efficacy. The optimal molar ratio of SF and CE was determined through combination index. SF/CE-liposomes were prepared by thin-film hydration method, which exhibited spherical or ellipsoidal shape. Particle size of SF/CE-liposomes was 174 ± 4 nm with homogeneous distribution. Release profile of SF demonstrated that addition of CE imposed no significant impact on the release of SF. SF/CE-liposomes exhibited acceptable stability in different media and desirable storage stability over 30 days at 4°C. In vitro cellular uptake confirmed that SF/CE-liposomes could be efficiently internalized into HepG2 cells. In vitro cytotoxicity evaluation indicated that SF/CE-liposomes exhibited higher cytotoxicity on HepG2 cells. IC50 value of SF/CE-liposomes was 11.5 ± 0.44 µM, which was significantly lower than that of SF-liposomes (**p < 0.01). Evaluation of in vivo synergistic effect on H22-bearing mice verified that SF/CE-liposomes achieved robust antitumor activity in preventing tumor growth. All results suggested that SF/CE-liposomes might be served as an efficient co-delivery system for improving therapeutic efficacy of HCC.

Carboplatin-loaded SMNDs to reduce GSH-mediated platinum resistance for prostate cancer therapy.

Glutathione (GSH)-mediated drug resistance can strongly weaken the therapeutic efficiency of platinum(ii). Therapeutic platforms developed based on small-molecule-based nanodrugs (SMNDs) have gained great attention due to their unique properties. Herein, a novel SMND of carboplatin-lauric acid nanoparticles (CBP-LA NPs) was developed for the first time to reduce GSH-mediated platinum resistance and improve the antitumor efficiency of platinum(ii). A CBP-LA conjugate was synthesized and CBP-LA NPs were prepared. Intracellular glutathione determination and intracellular Pt-DNA adduct assay were performed. Then the cellular cytotoxicity, cellular uptake, targeted biodistribution and in vivo antitumor efficacy of CBP-LA NPs were investigated. The CBP-LA conjugate could self-assemble into nanoparticles with small, uniform size and high drug loading (48%). The CBP-LA NPs exhibited a low critical aggregation concentration of 1.4 µg mL-1 and outstanding plasma stability in vitro. Under reduced conditions, the CBP-LA NPs showed redox-responsive behavior. The intracellular glutathione determination and the Pt-DNA adduct assay revealed that CBP-LA NPs could reduce the intracellular GSH levels and improve the efficiency of platinum chelating with DNA, which would overcome GSH-mediated platinum(ii) resistance. The cellular uptake study revealed that CBP-LA NPs were internalized by tumor cells, which was very beneficial for improving the therapeutic efficiency. Furthermore, an in vivo study demonstrated that CBP-LA NPs significantly enhanced drug accumulation at tumor sites and improved antitumor efficiency (p < 0.05) compared to the CBP solution group. This study suggests that CBP-LA NPs are a potential formulation to enhance prostate cancer therapy.

Tumor microenvironment dual-responsive core-shell nanoparticles with hyaluronic acid-shield for efficient co-delivery of doxorubicin and plasmid DNA.

As the tumor microenvironment (TME) develops, it is critical to take the alterations of pH value, reduction and various enzymes of the TME into consideration when constructing the desirable co-delivery systems. Herein, TME pH and enzyme dual-responsive core-shell nanoparticles were prepared for the efficient co-delivery of chemotherapy drug and plasmid DNA (pDNA). A novel pH-responsive, positively charged drug loading material, doxorubicin (DOX)-4-hydrazinobenzoic acid (HBA)-polyethyleneimine (PEI) conjugate (DOX-HBA-PEI, DHP), was synthesized to fabricate positively charged polyion complex inner core DHP/DNA nanoparticles (DDN). Hyaluronic acid (HA) was an enzyme-responsive shell which could protect the core and enhance the co-delivery efficiency through CD44-mediated endocytosis. The HA-shielded pH and enzyme dual-responsive nanoparticles (HDDN) were spherical with narrow distribution. The particle size of HDDN was 148.3±3.88 nm and the zeta potential was changed to negative (-18.1±2.03 mV), which led to decreased cytotoxicity. The cumulative release of DOX from DHP at pH 5.0 (66.4%) was higher than that at pH 7.4 (30.1%), which indicated the pH sensitivity of DHP. The transfection efficiency of HDDN in 10% serum was equal to that in the absence of serum, while the transfection of DDN was significantly decreased in the presence of 10% serum. Furthermore, cellular uptake studies and co-localization assay showed that HDDN were internalized effectively through CD44-mediated endocytosis in the tumor cells. The efficient co-delivery of DOX and pEGFP was confirmed by fluorescent image taken by laser confocal microscope. It can be concluded that TME dual-responsive HA-shielded core-shell nanoparticles could be considered as a promising platform for the co-delivery of chemotherapy drug and pDNA.

A facile route to form self-carried redox-responsive vorinostat nanodrug for effective solid tumor therapy.

Small molecule-based nanodrugs with nanoparticles (NPs) that are mainly composed of small molecules, have been considered as a promising candidate for a next-generation nanodrug, owing to their unique properties. Vorinostat (SAHA) is a canonical US Food and Drug Administration-approved histone deacetylase (HDAC) inhibitor for the treatment of cutaneous T-cell lymphoma. However, the lack of efficacy against solid tumors hinders its progress in clinical use. Herein, a novel nanodrug of SAHA was developed based on disulfide-linked prodrug SAHA-S-S-VE. SAHA-S-S-VE could self-assemble into 148 nm NPs by disulfide-induced mechanisms, which were validated by molecular dynamics simulations. Under reduced conditions, the redox-responsive behavior of SAHA-S-S-VE was investigated, and the HDAC inhibition results verified the efficient release of free SAHA. With a biocompatible d-a-tocopheryl polyethylene glycol succinate (TPGS) functionalization, the SAHA-S-S-VE/TPGS NPs exhibited low critical aggregation concentration of 4.5 µM and outstanding stability in vitro with drug-loading capacity of 24%. In vitro biological assessment indicated that SAHA-S-S-VE/TPGS NPs had significant anticancer activity against HepG2. Further in vivo evaluation demonstrated that the resulting NPs could be accumulated in the tumor region and inhibit the tumor growth effectively. This approach, which turned SAHA into a self-assembled redox-responsive nanodrug, provided a new channel for the use of HDAC inhibitor in solid tumor therapy.

Design, synthesis and preliminary bioactivity studies of imidazolidine-2,4-dione derivatives as Bcl-2 inhibitors.

Anti-apoptotic B-cell lymphoma-2 (Bcl-2) proteins are promising targets for cancer therapy. In the present study, a series of imidazolidine-2,4-dione derivatives were designed and synthesized to test their inhibitory activities against anti-apoptotic Bcl-2 proteins. Among them, compound 8k had better growth inhibitory effects on K562 and PC-3 cell lines compared to lead compound WL-276.

Design, synthesis and biological evaluation of saccharin-based N-hydroxybenzamides as histone deacetylases (HDACs) inhibitors.

We report the development of a novel series of saccharin-based N-hydroxybenzamides as histone deacetylases inhibitors. Among them, 6 j exhibited potent HDACs inhibitory activity against Hela nuclear extract. Further biological evaluation found 6 i showed similar antiproliferative activities in vitro compared with the approved SAHA.

Design, synthesis and preliminary bioactivity studies of 1,2-dihydrobenzo[d]isothiazol-3-one-1,1-dioxide hydroxamic acid derivatives as novel histone deacetylase inhibitors.

Histone deacetylase (HDAC) is a clinically validated target for antitumor therapy. In order to increase HDAC inhibition and efficiency, we developed a novel series of saccharin hydroxamic acids as potent HDAC inhibitors. Among them, compounds 11e, 11m, 11p exhibited similar or better HDACs inhibitory activity compared with the approved drug SAHA. Further biological evaluation indicated that compound 11m had potent antiproliferative activities against MDA-MB-231 and PC-3.