Discovery of indazole inhibitors for heat shock protein 90 as anti-cancer agents.

A series of indazole analogs, derived from the B,C-ring-truncated scaffold of deguelin, were designed to function as C-terminal inhibitors of heat shock protein 90 (HSP90) and investigated as novel antitumor agents against HER2-positive breast cancer. Among the synthesized compounds, compound 12d exhibited substantial inhibitory effects in trastuzumab-sensitive (BT474) and trastuzumab-resistant (JIMT-1) breast cancer cells, with IC50 values of 6.86 and 4.42 µM, respectively. Notably, compound 12d exhibited no cytotoxicity in normal cells. Compound 12d markedly downregulated the expression of the major HSP90 client proteins in both cell types, attributing its cytotoxicity to the destabilization and inactivation of HSP90 client proteins. Molecular docking studies using the homology model of an HSP90 homodimer demonstrated that inhibitor 12d fit nicely into the C-terminal domain, boasting a higher electrostatic complementary score than ATP. In vivo pharmacokinetic study indicated the high oral bioavailability of compound 12 d at F = 66.9 %, while toxicological studies indicated its negligible impact on hERG channels and CYP isozymes. Genotoxicity tests further confirmed its safety profile. The findings collectively position compound 12d as a promising candidate for further development as an antitumor agent against HER2-positive breast cancer.

Design, synthesis and biological evaluation of novel quinazoline derivatives as immune checkpoint inhibitors.

In this work, we report 14 novel quinazoline derivatives as immune checkpoint inhibitors, IDO1 and PD-L1. The antitumor screening of synthesized compounds on ovarian cancer cells indicated that compound V-d and V-l showed the most activity with IC50 values of about 5 µM. Intriguingly, compound V-d emerges as a stand out, triggering cell death through caspase-dependent and caspase-independent manners. More importantly, V-d presents its ability to hinder tumor sphere formation and re-sensitized cisplatin-resistant A2780 cells to cisplatin treatment. These findings suggest that compound V-d emerges as a promising lead candidate for the future development of immuno anticancer agents.

The HSP90 inhibitor HVH-2930 exhibits potent efficacy against trastuzumab-resistant HER2-positive breast cancer.

Rationale: Resistance to targeted therapies like trastuzumab remains a critical challenge for HER2-positive breast cancer patients. Despite the progress of several N-terminal HSP90 inhibitors in clinical trials, none have achieved approval for clinical use, primarily due to issues such as induction of the heat shock response (HSR), off-target effects, and unfavorable toxicity profiles. We sought to examine the effects of HVH-2930, a novel C-terminal HSP90 inhibitor, in overcoming trastuzumab resistance. Methods: The effect of HVH-2930 on trastuzumab-sensitive and -resistant cell lines in vitro was evaluated in terms of cell viability, expression of HSP90 client proteins, and impact on cancer stem cells. An in vivo model with trastuzumab-resistant JIMT-1 cells was used to examine the efficacy and toxicity of HVH-2930. Results: HVH-2930 was rationally designed to fit into the ATP-binding pocket interface cavity of the hHSP90 homodimer in the C-terminal domain of HSP90, stabilizing its open conformation and hindering ATP binding. HVH-2930 induces apoptosis without inducing the HSR but by specifically suppressing the HER2 signaling pathway. This occurs with the downregulation of HER2/p95HER2 and disruption of HER2 family member heterodimerization. Attenuation of cancer stem cell (CSC)-like properties was associated with the downregulation of stemness factors such as ALDH1, CD44, Nanog and Oct4. Furthermore, HVH-2930 administration inhibited angiogenesis and tumor growth in trastuzumab-resistant xenograft mice. A synergistic effect was observed when combining HVH-2930 and paclitaxel in JIMT-1 xenografts. Conclusion: Our findings highlight the potent efficacy of HVH-2930 in overcoming trastuzumab resistance in HER2-positive breast cancer. Further investigation is warranted to fully establish its therapeutic potential.

Design, synthesis and evaluation the bioactivities of novel 1,3-dimethyl-6-amino-1H-indazole derivatives as anticancer agents.

Indoleamine 2,3-dioxygenase (IDO1) is a heme-containing enzyme mainly responsible for the metabolism of tryptophan to kynurenine. To date, the IDO1 inhibitors have been developed intensively for the re-activation of the anticancer immune response. In this report, we designed, and synthesized novel 1,3-dimethyl-6-amino indazole derivatives as IDO1 inhibitors based on the structure of IDO1 active site. We further examined their anticancer activity on hypopharyngeal carcinoma cells (FaDu), squamous cell carcinoma of the oral tongue (YD-15), breast cancer cells (MCF7), and human dental pulp stem cells (HDPSC). Of them, compound N-(4-bromobenzyl)-1,3-dimethyl-1H-indazol-6-amine (7) remarkably suppressed IDO1 expression in a concentration - dependent manner. In addition, 7 was the most potential anticancer compound with inducing apoptosis activity as well as selectively activated extracellular signal-regulated kinases (ERK) in mitogen-activated protein kinase (MAPK) pathways on FaDu cells. Finally, compound 7 suppressed cell mobility in wound healing assay with the reduced expression of matrix metalloproteinase MMP9. Taken together, we believe that 7 is the most promising compound, which may be applied to treatment of hypopharyngeal carcinoma.

Syntheses and antitumor activities of neorautenol and shinpterocarpin analogs.

The natural products neorautenol and shinpterocarpin and their structural analogs were investigated as novel anticancer agents. Twenty-four analogs, including analogs containing a polar chain and simplified analogs, were synthesized efficiently by a modified method from previous reports. The antitumor screening of synthesized compounds toward six cancer cell lines indicated that compounds 37, 42 and 43 with a dialkylaminoethyl-type side chain exhibited more promising activity than neorautenol and shinpterocarpin against lung and colon cancer lines with a range of 4-9 µM. They showed selective toxicity in normal cells.

Discovery of potent indazole-based human glutaminyl cyclase (QC) inhibitors as Anti-Alzheimer's disease agents.

The toxic pyroglutamate form of amyloid-ß (pE-Aß) is important for the pathogenesis of early Alzheimer's disease (AD); therefore, reducing pE-Aß by inhibiting glutaminyl cyclase (QC) provides a promising strategy for developing disease-modifying AD drugs. In this study, potent and selective QC inhibitors with desirable drug-like properties were discovered by replacing the 3,4-dimethoxyphenyl group in a QC inhibitor with a bioisosteric indazole surrogate. Among them, 3-methylindazole-6-yl and 3-methylindazole-5-yl derivatives with an N-cyclohexylurea were identified as highly potent inhibitors with IC50 values of 3.2 nM and 2.3 nM, respectively, both of which were approximately 10-fold more potent than varoglutamstat. In addition, the three inhibitors significantly reduced pE-Aß3-40 levels in an acute animal model after intracerebroventricular (icv) injection and were selective for hQC. Further in vitro pharmacokinetic and toxicity studies, including those investigating cytotoxicity, hERG inhibition, blood-brain barrier (BBB) permeability and metabolic stability, indicated that N-(3-methylindazole-6-yl)-N'-(cyclohexyl)urea derivative exhibited the most promising efficacy, selectivity and drug-like profile; thus, it was evaluated for its in vivo efficacy in an AD model.

Identifying Possible AChE Inhibitors from Drug-like Molecules via Machine Learning and Experimental Studies.

Acetylcholinesterase (AChE) is one of the most important drug targets for Alzheimer's disease (AD) treatment. In this work, a machine learning model was trained to rapidly and accurately screen large chemical databases for the potential inhibitors of AChE. The obtained results were then validated via in vitro enzyme assay. Moreover, atomistic simulations including molecular docking and molecular dynamics simulations were then used to understand molecular insights into the binding process of ligands to AChE. In particular, two compounds including benzyl trifluoromethyl ketone and trifluoromethylstyryl ketone were indicated as highly potent inhibitors of AChE because they established IC50 values of 0.51 and 0.33 µM, respectively. The obtained IC50 of two compounds is significantly lower than that of galantamine (2.10 µM). The predicted log(BB) suggests that the compounds may be able to traverse the blood-brain barrier. A good agreement between computational and experimental studies was observed, indicating that the hybrid approach can enhance AD therapy.

A novel HSP90 inhibitor SL-145 suppresses metastatic triple-negative breast cancer without triggering the heat shock response.

Despite recent advances, there remains a significant unmet need for the development of new targeted therapies for triple-negative breast cancer (TNBC). Although the heat shock protein HSP90 is a promising target, previous inhibitors have had issues during development including undesirable induction of the heat shock response (HSR) and off-target effects leading to toxicity. SL-145 is a novel, rationally-designed C-terminal HSP90 inhibitor that induces apoptosis in TNBC cells via the suppression of oncogenic AKT, MEK/ERK, and JAK2/STAT3 signaling and does not trigger the HSR, in contrast to other inhibitors. In an orthotopic allograft model incorporating breast cancer stem cell-enriched TNBC tumors, SL-145 potently suppressed tumor growth, angiogenesis, and metastases concomitant with dysregulation of the JAK2/STAT3 signaling pathway. Our findings highlight the potential of SL-145 in suppressing metastatic TNBC independent of the HSR.

Discovery of highly potent human glutaminyl cyclase (QC) inhibitors as anti-Alzheimer's agents by the combination of pharmacophore-based and structure-based design.

The inhibition of glutaminyl cyclase (QC) may provide a promising strategy for the treatment of early Alzheimer's disease (AD) by reducing the amount of the toxic pyroform of ß-amyloid (AßΝ3pE) in the brains of AD patients. In this work, we identified potent QC inhibitors with subnanomolar IC50 values that were up to 290-fold higher than that of PQ912, which is currently being tested in Phase II clinical trials. Among the tested compounds, the cyclopentylmethyl derivative (214) exhibited the most potent in vitro activity (IC50 = 0.1 nM), while benzimidazole (227) showed the most promising in vivo efficacy, selectivity and druggable profile. 227 significantly reduced the concentration of pyroform Aß and total Aß in the brain of an AD animal model and improved the alternation behavior of mice during Y-maze tests. The crystal structure of human QC (hQC) in complex with 214 indicated tight binding at the active site, supporting that the specific inhibition of QC results in potent in vitro and in vivo activity. Considering the recent clinical success of donanemab, which targets AßΝ3pE, small molecule-based QC inhibitors may also provide potential therapeutic options for early-stage AD treatment.

Design, synthesis and bioevaluation of novel 6-substituted aminoindazole derivatives as anticancer agents.

In the present study, a series of 6-substituted aminoindazole derivatives were designed, synthesized, and evaluated for bio-activities. The compounds were initially designed as indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors based on the structural feature of five IDO1 inhibitors, which are currently on clinical trials, and the important anticancer activity of the indazole scaffold. One of them, compound N-(4-fluorobenzyl)-1,3-dimethyl-1H-indazol-6-amine (36), exhibited a potent anti-proliferative activity with an IC50 value of 0.4 ± 0.3 µM in human colorectal cancer cells (HCT116). This compound also remarkably suppressed the IDO1 protein expression. In the cell-cycle studies, the suppressive activity of compound 36 in HCT116 cells was related to the G2/M cell cycle arrest. Altogether, the current findings demonstrate that compound 36 would be promising for further development as a potential anticancer agent.

Discovery of Conformationally Restricted Human Glutaminyl Cyclase Inhibitors as Potent Anti-Alzheimer's Agents by Structure-Based Design.

Alzheimer's disease (AD) is an incurable, progressive neurodegenerative disease whose pathogenesis cannot be defined by one single element but consists of various factors; thus, there is a call for alternative approaches to tackle the multifaceted aspects of AD. Among the potential alternative targets, we aim to focus on glutaminyl cyclase (QC), which reduces the toxic pyroform of ß-amyloid in the brains of AD patients. On the basis of a putative active conformation of the prototype inhibitor 1, a series of N-substituted thiourea, urea, and α-substituted amide derivatives were developed. The structure-activity relationship analyses indicated that conformationally restrained inhibitors demonstrated much improved QC inhibition in vitro compared to nonrestricted analogues, and several selected compounds demonstrated desirable therapeutic activity in an AD mouse model. The conformational analysis of a representative inhibitor indicated that the inhibitor appeared to maintain the Z-E conformation at the active site, as it is critical for its potent activity.

Investigation of B,C-ring truncated deguelin derivatives as heat shock protein 90 (HSP90) inhibitors for use as anti-breast cancer agents.

On the basis of deguelin, a series of the B,C-ring truncated surrogates with N-substituted amide linkers were investigated as HSP90 inhibitors. The structure activity relationship of the template was studied by incorporating various substitutions on the nitrogen of the amide linker and examining their HIF-1α inhibition. Among them, compound 57 showed potent HIF-1α inhibition and cytotoxicity in triple-negative breast cancer lines in a dose-dependent manner. Compound 57 downregulated expression and phosphorylation of major client proteins of HSP90 including AKT, ERK and STAT3, indicating that its antitumor activity was derived from the inhibition of HSP90 function. The molecular modeling of 57 demonstrated that 57 bound well to the C-terminal ATP-binding pocket in the open conformation of the hHSP90 homodimer with hydrogen bonding and pi-cation interactions. Overall, compound 57 is a potential antitumor agent for triple-negative breast cancer as a HSP90 C-terminal inhibitor.

C-terminal HSP90 inhibitor L80 elicits anti-metastatic effects in triple-negative breast cancer via STAT3 inhibition.

Triple-negative breast cancer (TNBC) is an aggressive heterogeneous disease with a divergent profile. It has an earlier tendency to form metastases and is associated with poor clinical outcomes due to the limited treatment options available. Heat-shock protein (HSP90) represents a potential treatment target as it promotes tumor progression and metastasis by modulating the maturation and stabilization of signal transduction proteins. We sought to investigate the efficacy of the C-terminal HSP90 inhibitor L80 on cell proliferation, breast cancer stem cell (BCSC)-like properties, tumor growth and metastasis. L80 suppressed cell viability and concomitantly inhibited AKT/MEK/ERK/JAK2/STAT3 signaling in TNBC cells but did not induce cytotoxicity in normal cells. L80 effectively targeted BCSC-like traits, together with significant reductions in the CD44high/CD24low-population, ALDH1 activity and mammosphere forming-ability. In support of the in vitro observations, L80 administration caused significant impairment in tumor growth, angiogenesis and distant metastases in an orthotopic allograft model with BCSC-enriched cells in vivo. These phenomena were associated with the suppression of BCSC-like characteristics and STAT3 dysfunction. Our findings highlight properties of the L80 compound that may be useful in suppressing metastatic TNBC.

HIV knowledge and risk behaviors among drug users in three Vietnamese mountainous provinces.

BACKGROUND: Globally, people who inject drugs are highly vulnerable to HIV transmission. Methadone maintenance treatment (MMT) programs are one of the most cost-effective mechanisms to substitute opioid use and improve the quality of life of patients. Since the coverage of MMT is still limited and even for those patients who are treated, improving their knowledge on HIV and maintaining healthy behaviors are key to maximizing the outcomes of HIV harm reduction programs. This study examined the knowledge on HIV, perceived risk and HIV testing among drug users accessing methadone maintenance services in three Vietnamese mountainous areas. METHODS: A cross-sectional study of 300 people enrolling for MMT services in three provinces in Vietnam was conducted. The factors associated with the knowledge, attitudes, and practices of respondents about HIV/AIDS were exploited using multivariable logistic model. RESULTS: Of the 300-people surveyed, 99% knew of HIV and 60.6% were identified as having good knowledge. While 75.2% identified that injecting drugs was a risk factor for HIV, 52.2% thought they were not at risk of HIV mainly as they did not share needles. 92.6% had undergone HIV testing with 17.4% being positive, a number which was significantly lower than Vietnam's national average for people who inject drugs. Age, ethnicity and education were associated with knowledge of HIV while ART treatment was linked to self-assessed HIV status. CONCLUSIONS: This study sheds new light on the knowledge attitudes and practices of people who inject drugs, particularly males in mountainous areas of Vietnam regarding HIV prevention. Overall, knowledge was good with most conducting safe practices towards transmission. Enhanced education and targeting of minority groups could help in increasing the numbers receiving MMT and HIV services.

In vitro and in silico determination of glutaminyl cyclase inhibitors.

Alzheimer's disease (AD) is the most common form of neurodegenerative disease currently. It is widely accepted that AD is characterized by the self-assembly of amyloid beta (Aß) peptides. The human glutaminyl cyclase (hQC) enzyme is characterized by association with Aß peptide generation. The development of hQC inhibitors could prevent the self-aggregation of Aß peptides, resulting in impeding AD. Utilizing structural knowledge of the hQC substrates and known hQC inhibitors, new heterocyclic and peptidomimetic derivatives were synthesized and were able to inhibit the hQC enzyme. The inhibiting abilities of these compounds were evaluated using a fluorometric assay. The binding mechanism at the atomic level was estimated using molecular docking, free energy perturbation, and quantum chemical calculation methods. The predicted log(BBB) and human intestinal absorption values indicated that these compounds are able to permeate the blood-brain barrier and be well-absorbed through the gastrointestinal tract. Overall, 5,6-dimethoxy-N-(3-(5-methyl-1H-imidazol-1-yl)propyl)-1H-benzo[d]imidazol-2-amine (1_2) was indicated as a potential drug for AD treatment.

Methadone Maintenance Treatment Reduces the Vulnerability of Drug Users on HIV/AIDS in Vietnamese Remote Settings: Assessing the Changes in HIV Knowledge, Perceived Risk, and Testing Uptake after a 12-Month Follow-Up.

Methadone Maintenance Treatment (MMT) program has been considered a medium through which human immunodeficiency virus (HIV) risks assessment and prevention on drug use/HIV-infected population can be effectively conducted. Studies concerning the implementation of such idea on patients in remote, under-developed areas, however, have been limited. Having the clinics established in three mountainous provinces of Vietnam, this study aimed to evaluate the changes in knowledge of HIV, perceived risk, and HIV testing uptake of the patients. A longitudinal study was conducted at six MMT clinics in three provinces with a pre- and post-assessments among 300 patients. Outcomes of interest were compared between baseline and after 12 months. The magnitude of changes was extrapolated. The proportion of participants reporting that their HIV knowledge was not good fell by 4.4% (61.3% at the baseline vs. 56.8% at 12 months). The significant improvement seen was in the knowledge that needle sharing was a mode of transmission (82.7% vs. 89.6%). Nevertheless, the majority of participants reportedly considered mosquitoes/insect and eating with the HIV-infected patient were the route of transmission at both time points (84.7% vs. 89.1%, 92.2% vs. 93.3%, respectively). This study found a limited improvement in HIV knowledge and testing uptake among MMT patients following a 12-month period. It also highlighted some shortcomings in the knowledge, attitudes and practices (KAP) of these patients, in particular, incorrect identification of HIV transmission routes, among patients both at program initiation and follow-up. The findings lent support to the argument for enhancing education and counseling efforts at MMT clinics regarding HIV, as well as for improving access to preventive and health care services through the integration of MMT/HIV services.

Structure-activity relationship investigation of Phe-Arg mimetic region of human glutaminyl cyclase inhibitors.

Glutamyl cyclase (QC) is a promising therapeutic target because of its involvement in the pathogenesis of Alzheimer's disease. In this study, we developed novel QC inhibitors that contain 3-aminoalkyloxy-4-methoxyphenyl and 4-aminoalkyloxyphenyl groups to replace the previously developed pharmacophore. Several potent inhibitors were identified, showing IC50 values in a low nanomolar range, and were further studied for in vitro toxicity and in vivo activity. Among these, inhibitors 51 and 53 displayed the most potent AßN3pE-40-lowering effects in in vivo acute model with reasonable BBB penetration, without showing cytotoxicity and hERG inhibition. The molecular modeling analysis of 53 indicated that the salt bridge interaction and the hydrogen bonding in the active site provided a high potency. Given the potent activity and favorable BBB penetration with low cytotoxicity, we believe that compound 53 may serve as a potential candidate for anti-Alzheimer's agents.

Potent human glutaminyl cyclase inhibitors as potential anti-Alzheimer's agents: Structure-activity relationship study of Arg-mimetic region.

Pyroglutamate-modified amyloid ß peptides (pGlu-Aß) are highly neurotoxic and promote the formation of amyloid plaques. The pGlu-Aß peptides are generated by glutaminyl cyclase (QC), and recent clinical studies indicate that QC represents an alternative therapeutic target to treat Alzheimer's disease (AD). We have previously developed a series of QC inhibitors with an extended pharmacophoric scaffold, termed the Arg-mimetic D-region. In the present study, we focused on the structure activity relationship (SAR) of analogues with modifications in the D-region and evaluated their biological activity. Most compounds in this series exhibited potent activity in vitro, and our SAR analysis and the molecular docking studies identified compound 202 as a potential candidate because it forms an additional hydrophobic interaction in the hQC active site. Overall, our study provides valuable insights into the Arg-mimetic pharmacophore that will guide the design of novel QC inhibitors as potential treatments for AD.

Discovery of Potent Human Glutaminyl Cyclase Inhibitors as Anti-Alzheimer's Agents Based on Rational Design.

Glutaminyl cyclase (QC) has been implicated in the formation of toxic amyloid plaques by generating the N-terminal pyroglutamate of ß-amyloid peptides (pGlu-Aß) and thus may participate in the pathogenesis of Alzheimer's disease (AD). We designed a library of glutamyl cyclase (QC) inhibitors based on the proposed binding mode of the preferred substrate, Aß3E-42. An in vitro structure-activity relationship study identified several excellent QC inhibitors demonstrating 5- to 40-fold increases in potency compared to a known QC inhibitor. When tested in mouse models of AD, compound 212 significantly reduced the brain concentrations of pyroform Aß and total Aß and restored cognitive functions. This potent Aß-lowering effect was achieved by incorporating an additional binding region into our previously established pharmacophoric model, resulting in strong interactions with the carboxylate group of Glu327 in the QC binding site. Our study offers useful insights in designing novel QC inhibitors as a potential treatment option for AD.

A Hybrid Neural Network Model for Sales Forecasting Based on ARIMA and Search Popularity of Article Titles.

Enhancing sales and operations planning through forecasting analysis and business intelligence is demanded in many industries and enterprises. Publishing industries usually pick attractive titles and headlines for their stories to increase sales, since popular article titles and headlines can attract readers to buy magazines. In this paper, information retrieval techniques are adopted to extract words from article titles. The popularity measures of article titles are then analyzed by using the search indexes obtained from Google search engine. Backpropagation Neural Networks (BPNNs) have successfully been used to develop prediction models for sales forecasting. In this study, we propose a novel hybrid neural network model for sales forecasting based on the prediction result of time series forecasting and the popularity of article titles. The proposed model uses the historical sales data, popularity of article titles, and the prediction result of a time series, Autoregressive Integrated Moving Average (ARIMA) forecasting method to learn a BPNN-based forecasting model. Our proposed forecasting model is experimentally evaluated by comparing with conventional sales prediction techniques. The experimental result shows that our proposed forecasting method outperforms conventional techniques which do not consider the popularity of title words.