IDR-targeting compounds suppress HPV genome replication via disruption of phospho-BRD4 association with DNA damage response factors.

Compounds binding to the bromodomains of bromodomain and extra-terminal (BET) family proteins, particularly BRD4, are promising anticancer agents. Nevertheless, side effects and drug resistance pose significant obstacles in BET-based therapeutics development. Using high-throughput screening of a 200,000-compound library, we identified small molecules targeting a phosphorylated intrinsically disordered region (IDR) of BRD4 that inhibit phospho-BRD4 (pBRD4)-dependent human papillomavirus (HPV) genome replication in HPV-containing keratinocytes. Proteomic profiling identified two DNA damage response factors-53BP1 and BARD1-crucial for differentiation-associated HPV genome amplification. pBRD4-mediated recruitment of 53BP1 and BARD1 to the HPV origin of replication occurs in a spatiotemporal and BRD4 long (BRD4-L) and short (BRD4-S) isoform-specific manner. This recruitment is disrupted by phospho-IDR-targeting compounds with little perturbation of the global transcriptome and BRD4 chromatin landscape. The discovery of these protein-protein interaction inhibitors (PPIi) not only demonstrates the feasibility of developing PPIi against phospho-IDRs but also uncovers antiviral agents targeting an epigenetic regulator essential for virus-host interaction and cancer development.

Discovery of benzimidazole derivatives as potent and selective aldehyde dehydrogenase 1A1 (ALDH1A1) inhibitors with glucose consumption improving activity.

Aldehyde dehydrogenase 1A1 (ALDH1A1) plays vital physiological and toxicological functions in many areas, such as CNS, inflammation, metabolic disorders, and cancers. Overexpression of ALDH1A1 has been disclosed to play an important role in obesity, diabetes and other diseases, indicating the potential need for the identification and development of small molecule ALDH1A1 inhibitors. Herein, a series of benzimidazole derivatives was designed, synthesized and evaluated. Among them, compounds 21, 27, 29, 61 and 65 exhibited excellent inhibitory activity against ALDH1A1 with IC50 values in the low micromolar range and high selectivity over ALDH1A2, ALDH1A3, ALDH2 and ALDH3A1. Moreover, an in vitro study demonstrated that all five compounds effectively improved glucose consumption in HepG2 cells, of which, 61 and 65 at 10 µM produced nearly equal glucose consumption with positive control Metformin (Met) at 1 mM. Furthermore, 61 and 65 showed desirable metabolic stability in human liver microsomes. All these results suggest that 61 and 65 are suitable for further studies.

Design, synthesis of 1,3-dimethylpyrimidine-2,4-diones as potent and selective aldehyde dehydrogenase 1A1 (ALDH1A1) inhibitors with glucose consumption improving activity.

LDH1A1, one of 19 NAD(P)+-dependent aldehyde dehydrogenases, participates in multiple metabolic pathways and has been indicated to play an important role in obesity and diabetes. In this study, a series of 1,3-dimethylpyrimidine-2,4-diones were designed, synthesized and evaluated as novel selective aldehyde dehydrogenase 1A1 inhibitors. Among them, compounds 46, 50, 53, 56 and 57 exhibited excellent inhibitory activity against ALDH1A1 with IC50 values in the low nanomolar range and high selectivity over ALDH1A2, ALDH1A3, ALDH2 and ALDH3A1. Furthermore, in vitro study demonstrated that compound 57 effectively improved glucose consumption in HepG2 cells compared to compound 1 (CM026).

Synthesis and Anti-Hepatitis B Virus Evaluation of 7-Methoxy-3-heterocyclic quinolin-6-ols.

A series of novel 7-methoxy-3-heterocyclic quinolin-6-ol derivatives were synthesized and evaluated for their anti-hepatitis B virus (HBV) activities and cytotoxicities in the HepG2.2.15 cell line. Five compounds, 14a, 15c, 15e, 16b, and 16f, displayed excellent potency and selectivity toward the HBV, with IC50 values of less than 5.0 µM and selectivity index values of 11.0-71.5. Structure-activity relationship studies indicated that the 1,3,4-thiadiazole and sulfinylmethyl derivatives showed the most potent activities against the HBV.

Bromodomain-containing protein 4 (BRD4): a key player in inflammatory bowel disease and potential to inspire epigenetic therapeutics.

INTRODUCTION: Inflammatory bowel diseases (IBDs) are debilitating chronic inflammatory disorders with increasing prevalence worldwide. Epigenetic regulator bromodomain-containing protein 4 (BRD4) is critical in controlling gene expression of IBD-associated inflammatory cytokine networks. BRD4 as a promising therapeutic target is also tightly associated with many other diseases, such as airway inflammation and fibrosis, cancers, infectious diseases and central nervous system disorders. AREAS COVERED: This review briefly summarized the critical role of BRD4 in the pathogenesis of IBDs and the current clinical landscape of developing bromodomain and extra terminal domain (BET) inhibitors. The challenges and opportunities as well as future directions of targeting BRD4 inhibition for potential IBD medications were also discussed. EXPERT OPINION: Targeting BRD4 with potent and specific inhibitors may offer novel effective therapeutics for IBD patients, particularly those who are refractory to anti-TNFα therapy and IBD-related profibrotic. Developing highly specific BRD4 inhibitors for IBD medications may help erase the drawbacks of most current pan-BET/BRD4 inhibitors, such as off-target effects, poor oral bioavailability, and low gut mucosal absorbance. Novel strategies such as combinatorial therapy, BRD4-based dual inhibitors and proteolysis targeting chimeras (PROTACs) may also have great potential to mitigate side effects and overcome drug resistance during IBD treatment.

RIPTACs: A groundbreaking approach to drug discovery.

Regulated induced proximity targeting chimeras (RIPTACs), a new class of heterobifunctional molecules, show promise in specifically targeting and eliminating cancer cells while leaving healthy cells unharmed. As a groundbreaking drug discovery approach, RIPTACs work by forming a stable complex with two proteins, one specifically found in cancer cells (target protein, TP) and the other pan-essential for cell survival (effector protein, EP), selectively disrupting the function of the EP in cancer cells and causing cell death. Interestingly, the TPs need not be linked to disease progression, broadening the spectrum of potential drug targets. This review summarizes the discovery and recent advances of the RIPTAC strategy. Additionally, it discusses the associated opportunities and challenges as well as future perspectives in this field.

Drug Discovery Targeting Nuclear Receptor Binding SET Domain Protein 2 (NSD2).

Nuclear receptor binding SET domain proteins (NSDs) catalyze the mono- or dimethylation of histone 3 lysine 36 (H3K36me1 and H3K36me2), using S-adenosyl-l-methionine (SAM) as a methyl donor. As a key member of the NSD family of proteins, NSD2 plays an important role in the pathogenesis and progression of various diseases such as cancers, inflammations, and infectious diseases, serving as a promising drug target. Developing potent and specific NSD2 inhibitors may provide potential novel therapeutics. Several NSD2 inhibitors and degraders have been discovered while remaining in the early stage of drug development. Excitingly, KTX-1001, a selective NSD2 inhibitor, has entered clinical trials. In this Perspective, the structures and functions of NSD2, its roles in various human diseases, and the recent advances in drug discovery strategies targeting NSD2 have been summarized. The challenges, opportunities, and future directions for developing NSD2 inhibitors and degraders are also discussed.

Questionnaire survey of risk factors for recurrence of ocular inflammation in patients with uveitis after SARS-CoV-2 infection.

Introduction: During the COVID-19 pandemic in China, the proportion of patients with uveitis who were infected with SARS-CoV-2 increased greatly. The impact of SARS-CoV-2 infection on patients with uveitis has not been fully described. Methods: A questionnaire on SARS-CoV-2 infection was sent to patients with uveitis to assess ocular and systemic conditions before and after infection. Chi-square analysis and multifactorial regression analysis were used to investigate the associations between each risk factor and the recurrence of uveitis after SARS-CoV-2 infection. Results: One hundred thirty-nine patients with noninfectious uveitis completed the questionnaire; 114 (82.0%) had COVID-19, and 27 (23.7%) had recurrent or exacerbated uveitis after COVID-19. There was a higher rate of recurrence or aggravation of ocular inflammation in patients who developed severe COVID-19 symptoms (severe group 8/20 vs. nonsevere group 19/94). There were significant differences in the rates of recurrence and aggravation between the two groups of patients who differed in terms of ocular inflammatory activity within 3 months prior to SARS-CoV-2 infection (χ2 = 10.701, P=0.001), as well as in the rates of recurrence and aggravation after cessation of systemic immunomodulatory therapy. After multifactorial regression analysis, patients with active ocular inflammation within 3 months prior to SARS-CoV-2 infection had a greater risk of recurrence or exacerbation of uveitis after COVID-19 (OR=4.298, P=0.002). Conclusion: The degree of ocular inflammatory activity within 3 months prior to SARS-CoV-2 infection may be a major factor influencing the recurrence or exacerbation of uveitis after infection. Interruption of medication should be minimized in patients with unstable inflammatory control.

Specific non-genetic IAP-based protein erasers (SNIPERs) as a potential therapeutic strategy.

As a newly emerged technology, PROTAC (proteolysis targeting chimera) is a promising therapeutic strategy for varieties of diseases. Unlike small molecule inhibitors, PROTACs catalytically induce target proteins degradation, including currently "undruggable" target proteins. In addition, PROTACs can be a potentially successful strategy to overcome drug resistance. IAPs can inhibit apoptosis by inhibiting caspase, and also exhibits the activity of E3 ubiquitin ligase. Specific and nongenetic IAP-based protein erasers (SNIPERs) are hybrid molecules that designed based on IAPs, and used to degrade the target proteins closely associated with diseases. Their structures consist of three parts, including target protein ligand, E3 ligase ligand and the linker between them. SNIPERs (PROTACs) degrade diseases-associated proteins through human inherent ubiquitin-proteasome system. So far, many SNIPERs have been developed to treat diseases that difficult to handle by traditional methods, such as radiotherapy, chemotherapy and small molecule inhibitors, and showed promising prospects in application. In this paper, the recent advances of SNIPERs were summarized, and the chances and challenges associated with this area were also highlighted.

Discovery and development of selective aldehyde dehydrogenase 1A1 (ALDH1A1) inhibitors.

ALDH1A1, one important member of 19 ALDHs, can metabolize reactive aldehydes to their corresponding carboxylic acid derivatives and play important physiological and toxicological roles in many areas, including CNS, metabolic disorders, and cancers. Overexpression of ALDH1A1 correlates with poor prognosis and tumor aggressiveness, is associated with drug resistance in traditional chemotherapy for cancer treatment and contributes to obesity, diabetes, and inflammation. So, inhibition of ALDH1A1 may offer new therapeutic options for patients with cancer, obesity, diabetes, and inflammation. Up to now, many ALDH1A1 inhibitors with different scaffolds have been identified and developed as useful chemical tools for better understanding of the functions of ALDH1A1 in physiologic and pathophysiologic conditions. In this review, the advances in the discovery and development of selective ALDH1A1 inhibitors are summarized, and opportunities and challenges associated with this field are also discussed.

Chemical constituents from plant endophytic fungus Alternaria alternata.

Five new natural compounds (1-5) along with four known ones, involving dibenzo-α-pyrone derivatives, a benzo-γ-pyrone derivative and an amide-type compound were obtained from Alternaria alternata, an endophyte isolated from Paeonia lactiflora. The structures of these isolates were elucidated by intensive analysis of spectroscopic data including NMR, HRMS (ESI and EI), UV and IR spectra. Compounds (1-4) were evaluated for their cytotoxicities against five selected human tumourtumour cell lines (A-549, MDA-MB-231, MCF-7, KB and KB-VIN), and compound 3 exhibited activities against MDA-MB-231and MCF-7 with IC50 values of 20.1 µM and 32.2 µM.

Novel strategies targeting bromodomain-containing protein 4 (BRD4) for cancer drug discovery.

As epigenetic readers of the histone code, BRD4 is the most extensively and thoroughly studied member of BET family, which plays a critical role in many human diseases including cancer, inflammation, HIV infections, CNS disorders, and cardiovascular diseases and has been proved to be a promising therapeutic target for these diseases. To date, many small-molecule BRD4 inhibitors have been discovered, and some of them are in clinical trials for the treatment of different diseases. Due to the lack of selectivity of these small molecules for BRD4 BD1, BRD4 BD2 and/or other BET proteins, they exert some toxic side effects, including dizziness, nausea, and vomit. Now, novel strategies are urgent needed to improve the selectivity and reduce the side effects of current BRD4 inhibitors. Herein, in this article, we made a summary of the recent development of novel strategies targeting BRD4. Opportunities for these strategies to achieve selective and efficacious BRD4 inhibitors for treating human diseases are also highlighted.

Development of Novel Anticancer Agents with a Scaffold of Tetrahydropyrido[4,3-d]pyrimidine-2,4-dione.

ONC201 is a small molecular anticancer agent currently in multiple Phase II clinical trials. Based on the pharmacophore of ONC201, a series of small molecular compounds with a core structure of tetrahydropyrido[4,3-d]pyrimidine-2,4-dione were designed and synthesized. Preliminary mechanism studies of these compounds indicated that they can inhibit the phosphorylation of AKT and ERK, induce the dephosphorylation of Foxo3a, and promote the expression of TRAIL and the enhancement of activating transcription factor 4 (ATF4) in PC-3 cells. Structure-activity relationship (SAR) studies indicated that modifications of the substituted groups on the core structure can significantly improve the cellular activities of these compounds. The most potent compounds are over 100 times more potent than ONC201 in inhibition of cell growth in a panel of different types of human cancer cell lines.

Lack of Association Found between Helicobacter pylori Infection and Diarrhea-Predominant Irritable Bowel Syndrome: A Multicenter Retrospective Study.

Aims. The association between Helicobacter pylori (H. pylori) infection and diarrhea-predominant irritable bowel syndrome (IBS-D) is still controversial. Here we performed a retrospective study to explore this issue. Methods. A total of 502 inpatients with Rome III confirmed IBS-D and known H. pylori status from 8 hospitals were enrolled. H. pylori-positive patients, hospitalized in the recent year, were followed up to evaluate the effects of H. pylori eradication on IBS-D clinical course. Results. Of the 502 IBS-D patients, 206 were H. pylori-positive, with an infection rate that has no significant difference with that of the general population in Guangdong province (p = 0.348). For patients followed up, no significant differences were noted as to overall symptoms (p = 0.562), abdominal pain/discomfort (p = 0.777), bloating (p = 0.736), stool frequency (p = 0.835), or stool characteristics (p = 0.928) between the H. pylori-eradicated group and the control group. The results were the same in long-term follow-up patients except the improvement of bloating, which showed that the bloating score in the H. pylori-eradicated group was significantly lower (p = 0.047). Conclusions. No significant correlation between H. pylori infection and IBS-D was noted. Overall, IBS-D patients may not benefit from H. pylori eradication.

Novel hydrazone moiety-bearing aminopyrimidines as selective inhibitors of epidermal growth factor receptor T790M mutant.

The epidermal growth factor receptor (EGFR) T790M mutant is found in approximately 50% of clinically acquired resistance to gefitinib among patients with non-small cell lung cancer (NSCLC). Here, a series of novel aminopyrimidines bearing a hydrazone moiety were identified as potent and selective EGFR inhibitors. Compounds 14a, 15g, and 15i potently inhibited all EGFR mutants including EGFR T790M/L858R, EGFR T790M/delE746_A750, and EGFR T790M while they showed weak effects on the wild type (WT) EGFR. In addition, these compounds effectively suppressed proliferation of gefitinib-resistant H1975 (EGFR T790M/L858R) cells but were less potent against A549 (WT EGFR and k-Ras mutation) and HT-29 (non-special gene type) cells, showing a high safety index. Therefore, 14a, 15g, and 15i might be promising candidates to overcome drug resistance mediated by the EGFR T790M mutant.

Microencapsulation of tamoxifen: application to cotton fabric.

Tamoxifen microcapsules and drug loaded medicated fabrics were investigated. The microcapsules were prepared using a complex coacervation procedure involving gelatin B and acacia gum. The morphology, particle size, drug loading capacity and in vitro release characteristics of the drug microcapsules were optimized for coating tamoxifen microcapsules onto the cotton fabrics. Infrared (IR) spectra and SEM were used to characterize the medicated fabrics and air permeability and laundering testing were undertaken to determine the efficiency and effectiveness of the system. Results showed that optimum condition for the microcapsules was at drug/polymer ratio 1:4, polymer concentration 3%, and rate of stirring 1000 rpm. In vitro release assays demonstrated that the tamoxifen was liberated over 10h after an initial bust rate period. SEM images illustrated that the tamoxifen microcapsules were spherical in shape and were also tightly fixed on to the cotton fabrics fast. These observations demonstrate that we have designed and fabricated a medicated system that potentially could be applied within a transdermal drug delivery system and so act in a system for the treatment of breast cancer.

Polyacrylonitrile fibers efficiently loaded with tamoxifen citrate using wet-spinning from co-dissolving solution.

Tamoxifen citrate (TAM)-loaded polyacrylonitrile (PAN) fibers were prepared using an improved wet-spinning technique. TAM was used as a model drug to evaluate the potential application of the loaded fiber system for drug delivery. PAN was first homogeneously dissolved in the N,N-dimethylacetamide (DMAc) solution containing TAM and then the co-dissolving solution was solidified to prepare the fibers using a wet-spinning method. Chemical, morphological and mechanical property characterizations were carried out, as well as the studies of the drug release properties. TAM was successfully encapsulated into a monofilament fiber, and this system was stable in terms of high loading capacity and effectiveness in release. The diameter of drug-loaded fiber was in the range of 40-60 microm. The best values of the tensile strength at 2.968 cN/dtex and breaking elongation at 14.9% of drug-loaded fibers were obtained when the drug loading content was 23.1 wt.%. These characteristics were suitable for the weaving process. The in vitro release experiment indicated that constant drug release from the fiber was observed for a long duration of time. Kinetic studies demonstrated that the system followed the Higuchi kinetics. These findings demonstrate that controlled release of drugs from PAN fibers could be potentially useful in drug delivery systems.