A branched small molecule-drug conjugate nanomedicine strategy for the targeted HCC chemotherapy.

Off-target toxicity is one of the main challenges faced by anticancer chemotherapeutics. For tumor targeted and precision chemotherapy, we take the advantages of the ligand directed tumor active targeting of small molecule drug conjugates (SMDCs) and the passive tumor targeting of nanoparticles via the enhanced penetration and retention (EPR) effects, put forward a branched small molecule drug conjugate (BSMDC) nanomedicine design concept. In a proof of concept, we used pentaerythritol as the branched moiety, galactosamine (GalN) as the hepatocellular carcinoma (HCC) directing ligands, PTX as a payload, and a stearoyl moiety as the amphiphilic property adjusting group, designed and synthesized BSMDC 1 and prepared its NPs. In cellular level, the BSMDC 1 NPs targeted asialoglycoprotein receptor (ASGPR)-overexpressing HepG2 cells, were effectively taken up in the cells and released in tumor microenvironments, inhibited the HepG2 cell proliferation, arrested HepG2 cell in G2/M phase and induced tumor cell apoptosis. In HepG2 xenograft nude mice, the BSMDC 1 NPs were high specific to target the tumor and demonstrated a higher antitumor efficiency than BSMDC 1, having no apparent influences on mice body weights and major organs, supporting our BSMDC nanomedicine design concept. Therefore, this new strategy may find applications for cancer targeted and precision chemotherapy.

Synthesis and biological evaluation of selective histone deacetylase 6 inhibitors as multifunctional agents against Alzheimer's disease.

Histone deacetylase 6 (HDAC6) is a potential target for Alzheimer's disease (AD). In this study, a series of novel phenothiazine-, memantine-, and 1,2,3,4-tetrahydro-γ-carboline-based HDAC6 inhibitors with a variety of linker moieties were designed and synthesized. As a hydrochloride salt, the phenothiazine-based hydroxamic acid W5 with a pyridyl-containing linker motif was identified as a high potent and selective HDAC6 inhibitor. It inhibited HDAC6 with an IC50 of 2.54 nM and was more than 290- to 3300-fold selective over other HDAC isoforms. In SH-SY5Y cells, W5 dose-dependently increased the acetylated α-tubulin levels and reduced the hyperphosphorylated tau proteins at Ser396. As an effective metal chelator, W5 inhibited Cu2+-induced Aß1-42 aggregation and disaggregated Cu2+-Aß1-42 oligomers, and showed protective effects on the SH-SY5Y cells against Aß1-42- as well as Cu2+-Aß1-42 induced cell damages, serving as a potential ligand to target AD metal dyshomeostasis. Moreover, W5 promoted the differentiated neuronal neurite outgrowth, increased the mRNA expression of the recognized neurogenesis markers, GAP43, N-myc, and MAP-2. Therefore, W5 might be a good lead for the development of novel HDAC6 inhibitors targeting multi-facets of AD.

SAR Investigation and Discovery of Water-Soluble 1-Methyl-1,4-dihydroindeno[1,2-c]pyrazoles as Potent Tubulin Polymerization Inhibitors.

Taking the previously discovered 1-methyl-1,4-dihydroindeno[1,2c]pyrazol derivative LL01 as a lead, systematic structural modifications were made at the phenolic 6- and 7-positions and the aniline at the 3-position of the indenopyrazole core to investigate the SARs and to improve water solubility. Among the designed indenopyrazoles ID01-ID33, a series of potent MTAs were identified. As the hydrochloride salt(s), ID09 and ID33 showed excellent aqueous solubility and favorable Log P value and displayed noteworthily low nanomolar potency against a variety of tumor cells, including those taxol-resistant ones. They inhibited tubulin polymerization, disrupted cellular microtubule networks by targeting the colchicine site, and promoted HepG2 cell cycle arrest and cell apoptosis. In the HepG2 xenograft mouse model, ID09 and ID33 effectively inhibited tumor growth at an oral dose of 25 mg/kg. At an intravenous (iv) injection dose of 10 mg/kg every other day, ID09 suppressed tumor growth by 68% without obvious toxicity.

Tubulin colchicine site binding agent LL01 displays potent antitumor efficiency both in vitro and in vivo with suitable drug-like properties.

Through rational drug design, we previously identified an indenoprazole derivative, 2-(6-ethoxy-3-(3-ethoxyphenylamino)-1-methyl-1,4-dihydroindeno[1,2-c]pyrazol-7-yloxy)acetamide (LL01), as a potent tubulin polymerization inhibitor targeting the tubulin colchicine binding site. In this study, we further demonstrated that LL01 was not a P-gp substrate. It potently inhibited the growth of a variety of tumor cells, including those with multidrug resistance, with GI50 values in the low nanomole ranges. In vitro liver microsome stability assay, LL01 was modest stable in the liver microsomes of human, mouse and rat, but was fast metabolized in dog. After single oral administration of LL01 at a dose of 10 mg/kg in SD male rats, LL01 showed acceptable PK properties with a mean bioavailability of 41%. In human HepG2 hepatoma xenograft, at the oral doses of 25 mg/kg/day and 12.5 mg/kg/day, LL01 inhibited the tumor growth by 61.27%, and 43.74%, respectively, which is much better than the positive drug sorafenib (29.45%; 30 mg/kg/day). Therefore, LL01 might be a potential drug candidate for further investigation for hepatocellular carcinoma therapy.

Synthesis and evaluation of novel GSK-3ß inhibitors as multifunctional agents against Alzheimer's disease.

To target the multi-facets of Alzheimer's disease (AD), a series of novel GSK-3ß inhibitors containing the 2,3-diaminopyridine moiety were designed and synthesized. The amide derivatives 5a-f showed moderate potency against GSK-3ß with weak Cu2+, Zn2+ and Al3+ chelating ability. The imine derivatives 9a, 9b and 9e were potent GSK-3ß inhibitors and selective Cu2+and Al3+ chelators. The 1,2-diamine derivatives 10a-e were strong metal-chelators, but decreased or lost their GSK-3ß inhibitory potency. In vitro, compounds 9a, 9b and 9e, especially 9b, exhibited good Cu2+-induced Aß aggregation inhibition, Cu2+-Aß complex disaggregation, ROS formation inhibition, and antioxidant activities. In cells, compounds 9a, 9b and 9e can inhibit tau protein phosphorylation and protect neuro cells against Cu2+-Aß1-42 and H2O2-induced cell damage. Furthermore, compound 9b was predicted to have the ability to pass the BBB with drug likeness properties. Therefore, compound 9b might be a good lead for the development of novel GSK-3ß inhibitors targeting multi-facets of AD.