Discovery of the First-in-Class RORγ Covalent Inhibitors for Treatment of Castration-Resistant Prostate Cancer.

Nuclear receptor receptor-related orphan receptor γ (RORγ) is a ligand-dependent transcription factor and has been established as a key player in castration-resistant prostate cancers (CRPC) by driving androgen receptor (AR) overexpression, representing a potential therapeutical target for advanced prostate cancers. Here, we report the identification of the first-in-class RORγ covalent inhibitor 29 via the structure-based drug design approach following structure-activity relationship (SAR) exploration. Mass spectrometry assay validated its covalent inhibition mechanism. Compound 29 significantly inhibited RORγ transcriptional activity and remarkably suppressed the expression levels of AR and AR-targeted genes. Compound 29 also exhibited much superior activity in inhibiting the proliferation and colony formation and inducing apoptosis of the CRPC cell lines relative to the positive control 2 and noncovalent control 33. Importantly, it markedly suppressed the tumor growth in a 22Rv1 mouse tumor xenograft model with good safety. These results clearly demonstrate that 29 is a highly potent and selective RORγ covalent inhibitor.

Design, synthesis and evaluation of quinazoline derivatives as Gαq/11 proteins inhibitors against uveal melanoma.

Uveal melanoma (UM) represents the predominant ocular malignancy among adults, exhibiting high malignancy and proclivity for liver metastasis. GNAQ and GNA11 encoding Gαq and Gα11 proteins are key genes to drive UM, making the selective inhibition of Gαq/11 proteins to be a potential therapeutic approach for combating UM. In this study, forty-six quinazoline derivatives were designed, synthesized, and assessed for their ability to inhibit Gαq/11 proteins and UM cells. Compound F33 emerged as the most favorable candidate, and displayed moderate inhibitory activity against Gαq/11 proteins (IC50 = 9.4 µM) and two UM cell lines MP41 (IC50 = 6.7 µM) and 92.1 (IC50 = 3.7 µM). Being a small molecule inhibitor of Gαq/11 proteins, F33 could effectively suppress the activation of downstream signaling pathways in a dose-dependent manner, and significantly inhibits UM in vitro.F33 represents a promising lead compound for developing therapeutics for UM by targeting Gαq/11 proteins.

Discovery of novel indazole derivatives as SOS1 agonists that activate KRAS signaling.

KRAS serves as a vital regulator for cellular signaling and drives tumor pathogenesis after mutation. Despite extensive research efforts spanning several decades, targeting KRAS is still challenging due to the multiple KRAS mutations and the emergence of drug resistance. Interfering the interactions between KRAS and SOS1 is one of the promising approaches for modulating KRAS functions. Herein, we discovered small-molecule SOS1 agonists with novel indazole scaffold. Through structure-based optimization, compound 11 was identified with high SOS1 activation potency (p-ERK EC50 = 1.53 µM). In HeLa cells, compound 11 enhances cellular RAS-GTP levels and exhibits biphasic modulation of ERK1/2 phosphorylation through an on-target mechanism and presents the therapeutic potential to modulate RAS signaling by activating SOS1.

Identification of novel Pyrrolo[2,3-d]Pyrimidine-based KRAS G12C inhibitors with anticancer effects.

Oncogene KRAS plays predominant roles in human cancers by regulating cell proliferation, differentiation, and migration. Recent progress revealed that directly target KRAS G12C with allosteric inhibitors that covalently bind to the switch Ⅱ pocket is feasible. Herein, series of pyrrolo[2,3-d]pyrimidine derivatives were designed and synthesized through systematic structural optimization, leading to the discovery of compound 2-((S)-1-acryloyl-4-(2-(((2R,7aS)-2-fluorohexahydro-1H-pyrrolizin-7a(5H)-yl)methoxy)-7-methyl-6-(8-methylnaphthalen-1-yl)-7H-pyrrolo[2,3-d]pyrimidin-4-yl)piperazin-2-yl)acetonitrile (50) with high KRAS/SOS1 inhibitory potency (IC50 = 0.21 µM) and strong anti-proliferation activities on cancer cells harboring KRAS p.G12C. Compound 50 also exhibited satisfactory selectivity, moderate pharmacokinetic characters, and good anticancer effects in vivo. Meaningfully, the identification of these compounds highlights the necessity of an appropriate conformational constraint for acquiring the applicable binding pose in the cryptic pocket of KRAS, and the results support efforts toward design of KRAS inhibitors with novel skeleton and binding mechanism could be beneficial for targeting the acquired drug resistance.

Discovery of small molecule Gαq/11 protein inhibitors against uveal melanoma.

Constitutively activated G proteins caused by specific mutations mediate the development of multiple malignancies. The mutated Gαq/11 are perceived as oncogenic drivers in the vast majority of uveal melanoma (UM) cases, making directly targeting Gαq/11 to be a promising strategy for combating UM. Herein, we report the optimization of imidazopiperazine derivatives as Gαq/11 inhibitors, and identified GQ262 with improved Gαq/11 inhibitory activity and drug-like properties. GQ262 efficiently blocked UM cell proliferation and migration in vitro. Analysis of the apoptosis-related proteins, extracellular signal-regulated kinase (ERK), and yes-associated protein (YAP) demonstrated that GQ262 distinctly induced UM cells apoptosis and disrupted the downstream effectors by targeting Gαq/11 directly. Significantly, GQ262 showed outstanding antitumor efficacy in vivo with good safety at the testing dose. Collectively, our findings along with the favorable pharmacokinetics of GQ262 revealed that directly targeting Gαq/11 may be an efficient strategy against uveal melanoma.

Immunophenotype in acute exacerbation of chronic obstructive pulmonary disease: a cross-sectional study.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease, and the immune inflammatory response is thought to play an important role in pathogenesis. However, the immunophenotype of patients with COPD is unknown. Herein, we evaluated the immunophenotype of patients with acute exacerbation of COPD (AECOPD). METHODS: A cross-sectional study was conducted in West China Hospital from September 2018 to October 2019. The proportion of CD4 + T lymphocyte subtypes (Th1, Th2, Th17 and Treg) and levels of serum cytokines in the peripheral blood of patients with AECOPD, stable COPD (SCOPD), healthy smokers (HSs)and healthy controls (HCs) were evaluated. RESULTS: A total of 15 HCs, 19 HSs, 42 patients with SCOPD, and 55 patients with AECOPD were included. Compared to patients with SCOPD, Th1 cells, Th17 cells, Treg cell ratio, Th1/Th2 cell ratio, and the levels of C-reactive protein, interleukin (IL)-6, and IL-10 were significantly increased in patients with AECOPD (P < 0.001), while the proportion of Th2 cells was significantly reduced (P < 0.01). The proportion of Th17 cells was positively correlated with COPD Assessment Test score (r = 0.266, P = 0.009), modified Medical Research Council dyspnea score (r = 0.858, P < 0.0001), and Th1 cell ratio (r = 0.403, P < 0.0001) and negatively correlated with forced vital capacity (r = - 0.367, P = 0.009) and proportion of Th2 cells (r = - 0.655, P < 0.0001). CONCLUSIONS: The immunophenotype of patients with AECOPD shows abnormal activation of Th1, Th17, and Treg cells. There is a correlation between the proportion of Th17 cells and the severity of COPD; therefore, this may represent a novel index for the evaluation of COPD severity. TRIAL REGISTRATION: China Clinical Trials Registry, ChiCTR1800018452, registered 19 September 2018, https://www.chictr.org.cn/index.aspx .

Structure-based optimization of Toddacoumalone as highly potent and selective PDE4 inhibitors with anti-inflammatory effects.

Phosphodiesterase-4 (PDE4) is an important drug target for inflammatory diseases. Previously, we identified a series of novel PDE4 inhibitors derived from the natural Toddacoumalone, among which the hit compound 2 with a naphthyridine scaffold showed moderate potency with the IC50 value of 400 nM. Based on the co-crystal structure of PDE4D-2, further structural optimizations and structure-activity relationship studies led to a highly potent PDE4 inhibitor 23a with the IC50 value of 0.25 nM and excellent selectivity profiles over other PDEs (>4000-fold). The co-crystal structure of PDE4D-23a elucidated that 23a has strong interactions with the M and Q pocket of PDE4D. Importantly, compound 23a significantly inhibits the release of inflammatory cytokines TNF-α and IL-6 in lipopolysaccharide-stimulated RAW264.7 cells. Thus, compound 23a with a naphthyridine scaffold is a promising PDE4 inhibitor for the treatment of inflammatory diseases.

Synthesis and evaluation of imidazo[1,2-a]pyrazine derivatives as small molecule Gαq/11 inhibitors against uveal melanoma.

Uveal melanoma (UM) is an aggressive malignancy with high mortality in adults and lacks effective systemic therapies. Activating gene mutations related to the Gαq/11 signaling pathway are prevalent in UM, and Gαq/11 inhibitors have shown anti-UM activity in vitro and in vivo. In this study, we designed and synthesized a series of imidazo[1,2-a]pyrazine derivatives as Gαq/11 inhibitors, and discovered GQ352 with the selective antiproliferative activity against UM cells. Importantly, GQ352 directly binds to the Gαq and inhibits the dissociation of Gαßγ heterotrimers with the IC50 value of 8.9 µM. GQ352 inhibits UM tumorigenesis by suppressing Gαq/11 downstream ERK phosphorylation and YAP dephosphorylation, as shown in Western blot analysis. In addition, GQ352 displayed reasonable physiochemical properties and human liver microsome stability, indicating the potential application in UM treatment.

On-Resin Synthesis of Linear Aryl Thioether Containing Peptides and in-Solution Cyclization via Cysteine SNAr Reaction.

Cyclic peptides represent one of the most promising therapeutic agents in drug discovery due to their good affinity and selectivity. Herein, an on-resin synthesis of aryl thioether containing peptides and a concise cyclization strategy via chemoselective cysteine SNAr reaction was developed. The arylation group could be incorporated into a series of amino acids and used for standard SPPS and peptides cyclization. Constructed cyclic peptides showed increased cellular uptakes compared to their linear peptides.

The m6A demethylase FTO promotes the osteogenesis of mesenchymal stem cells by downregulating PPARG.

N6-methyladenosine (m6A) is the most abundant posttranscriptional methylation modification that occurs in mRNA and modulates the fine-tuning of various biological processes in mammalian development and human diseases. In this study we investigated the role of m6A modification in the osteogenesis of mesenchymal stem cells (MSCs), and the possible mechanisms by which m6A modification regulated the processes of osteoporosis and bone necrosis. We performed systematic analysis of the differential gene signatures in patients with osteoporosis and bone necrosis and conducted m6A-RNA immunoprecipitation (m6A-RIP) sequencing to identify the potential regulatory genes involved in osteogenesis. We showed that fat mass and obesity (FTO), a primary m6A demethylase, was significantly downregulated in patients with osteoporosis and osteonecrosis. During the differentiation of human MSCs into osteoblasts, FTO was markedly upregulated. Both depletion of FTO and application of the FTO inhibitor FB23 or FB23-2 impaired osteogenic differentiation of human MSCs. Knockout of FTO in mice resulted in decreased bone mineral density and impaired bone formation. PPARG, a biomarker for osteoporosis, was identified as a critical downstream target of FTO. We further revealed that FTO mediated m6A demethylation in the 3'UTR of PPARG mRNA, and reduced PPARG mRNA stability in an YTHDF1-dependent manner. Overexpression of PPARG alleviated FTO-mediated osteogenic differentiation of MSCs, whereas knockdown of PPARG promoted FTO-induced expression of the osteoblast biomarkers ALPL and OPN during osteogenic differentiation. Taken together, this study demonstrates the functional significance of the FTO-PPARG axis in promoting the osteogenesis of human MSCs and sheds light on the role of m6A modification in mediating osteoporosis and osteonecrosis.

Demethylative Alkylation of Methionine Residue by Employing the Sulfonium as the Key Intermediate.

Methionine (Met) offers a valuable handle to achieve peptide chemical modification owing to its unique thioether functional group. In contrast with cysteine, the site-selective functionalization of the hydrophobic and redox-sensitive thioether motif on peptides is still challenging, and strategies for diversification on the Met residue are rarely disclosed. Herein we report a transition-metal-free and redox-neutral approach for Met diversification with substrate diversity, which could be applied to synthesize cyclic peptides.

Targeting mutated GTPase KRAS in tumor therapies.

Kirsten rat sarcoma virus oncogene (KRAS) mutation accounts for approximately 85% of RAS-driven cancers, and participates in multiple signaling pathways and mediates cell proliferation, differentiation and metabolism. KRAS has been considered as an "undruggable" target due to the lack of effective direct inhibitors, although high frequency of KRAS mutations have been identified in multiple carcinomas in the past decades. Encouragingly, the KRASG12C inhibitor AMG510 (sotorasib), which has been approved for treating NSCLC and CRC recently, makes directly targeting KRAS the most promising strategy for cancer therapy. To better understand the current state of KRAS inhibitors, this review summarizes the biological functions of KRAS, the structure-activity relationship studies of the small-molecule inhibitors that directly target KRAS, and highlights the therapeutic agents with improved selectivity, bioavailability and physicochemical properties. Furthermore, the combined medication that can enhance efficacy and overcome drug resistance of KRAS covalent inhibitors is also reviewed.

Cleavable and tunable cysteine-specific arylation modification with aryl thioethers.

Cysteine represents an attractive target for peptide/protein modification due to the intrinsic high nucleophilicity of the thiol group and low natural abundance. Herein, a cleavable and tunable covalent modification approach for cysteine containing peptides/proteins with our newly designed aryl thioethers via a S N Ar approach was developed. Highly efficient and selective bioconjugation reactions can be carried out under mild and biocompatible conditions. A series of aryl groups bearing different bioconjugation handles, affinity or fluorescent tags are well tolerated. By adjusting the skeleton and steric hindrance of aryl thioethers slightly, the modified products showed a tunable profile for the regeneration of the native peptides.

Design, Synthesis, and Evaluation of Small Molecule Gαq/11 Protein Inhibitors for the Treatment of Uveal Melanoma.

Uveal melanoma is the ocular malignancy and mainly driven by oncogenic mutations of Gαq/11 proteins. Previous targeted therapy for melanoma treatment was limited to specific downstream signaling pathway, and inhibiting the "molecular switches" G proteins for melanoma treatment therapy was rarely described. We herein report the discovery of imidazopiperazine derivatives as Gαq/11 protein inhibitors. The most promising compound GQ127 showed good efficacy and safety in inositol monophosphate (IP1) assay by directly inhibiting Gαq/11 proteins. GQ127 induced uveal melanoma cells apoptosis and displayed potent antitumor activities in uveal melanoma cells viability, migration, and invasion. The effects of GQ127 on Gαq/11 signaling pathway were confirmed by analyzing the downstream effectors yes-associated protein (YAP) and extracellular signal-regulated kinase (ERK). More importantly, GQ127 significantly suppressed UM xenograft growth in mouse model without severe toxicity at the testing dose. These findings provide a lead compound that directly targets the Gαq/11 proteins for uveal melanoma treatment.

Tyrosine phosphatase SHP2 inhibitors in tumor-targeted therapies.

Src homology containing protein tyrosine phosphatase 2 (SHP2) represents a noteworthy target for various diseases, serving as a well-known oncogenic phosphatase in cancers. As a result of the low cell permeability and poor bioavailability, the traditional inhibitors targeting the protein tyrosine phosphate catalytic sites are generally suffered from unsatisfactory applied efficacy. Recently, a particularly large number of allosteric inhibitors with striking inhibitory potency on SHP2 have been identified. In particular, few clinical trials conducted have made significant progress on solid tumors by using SHP2 allosteric inhibitors. This review summarizes the development and structure-activity relationship studies of the small-molecule SHP2 inhibitors for tumor therapies, with the purpose of assisting the future development of SHP2 inhibitors with improved selectivity, higher oral bioavailability and better physicochemical properties.

Clinical features of asthma with comorbid bronchiectasis: A systematic review and meta-analysis.

BACKGROUND: This meta-analysis aimed to systematically estimate the prevalence of comorbid bronchiectasis in patients with asthma and to summarize its clinical impact. METHODS: Embase, PubMed, and Cochrane Library electronic databases were searched to identify relevant studies published from inception until March 2020. STUDY SELECTION: Studies were included if bronchiectasis was identified by high-resolution computed tomography. Outcomes included the prevalence of bronchiectasis and its association with demographic characteristics and indicators of asthma severity, including results of lung function tests and the number of exacerbations. RESULTS: Five observational studies with 839 patients were included. Overall, the mean prevalence of bronchiectasis in patients with asthma was 36.6% (307/839). Patients with comorbid bronchiectasis had lower forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) (MD: -2.71; 95% CI: -3.72 to -1.69) and more frequent exacerbations (MD: 0.68; 95% CI: 0.03 to 1.33) than those with asthma alone, and there was no significant difference of sex, duration of asthma and serum levels of immunoglobulin(Ig)Es between asthmatic patients with or without bronchiectasis. CONCLUSION: The presence of bronchiectasis in patients with asthma was associated with greater asthma severity. There are important therapeutic implications of identifying bronchiectasis in asthmatic patients.

Heterotrimeric G Proteins as Therapeutic Targets in Drug Discovery.

Heterotrimeric G proteins are molecular switches in GPCR signaling pathways and regulate a plethora of physiological and pathological processes. GPCRs are efficient drug targets, and more than 30% of the drugs in use target them. However, selectively targeting an individual GPCR may be undesirable in various multifactorial diseases in which multiple receptors are involved. In addition, abnormal activation or expression of G proteins is frequently associated with diseases. Furthermore, G proteins harboring mutations often result in malignant diseases. Thus, targeting G proteins instead of GPCRs might provide alternative approaches for combating these diseases. In this review, we discuss the biochemistry of heterotrimeric G proteins, describe the G protein-associated diseases, and summarize the currently known modulators that can regulate the activities of G proteins. The outlook for targeting G proteins to treat diverse diseases is also included in this manuscript.

RNA N6-methyladenosine demethylase FTO promotes breast tumor progression through inhibiting BNIP3.

BACKGROUND: N6-methyladenosine (m6A) modification is the most pervasive modification in mRNA, and has been considered as a new layer of epigenetic regulation on mRNA processing, stability and translation. Despite its functional significance in various physiological processes, the role of the m6A modification involved in breast cancer is yet fully understood. METHODS: We used the m6A-RNA immunoprecipitation sequencing to identify the potential targets in breast cancer. To determine the underlying mechanism for the axis of FTO-BNIP3, we performed a series of in vitro and in vivo assays in 3 breast cancer cell lines and 36 primary breast tumor tissues and 12 adjunct tissues. RESULTS: We showed that FTO, a key m6A demethylase, was up-regulated in human breast cancer. High level of FTO was significantly associated with lower survival rates in patients with breast cancer. FTO promoted breast cancer cell proliferation, colony formation and metastasis in vitro and in vivo. We identified BNIP3, a pro-apoptosis gene, as a downstream target of FTO-mediated m6A modification. Epigenetically, FTO mediated m6A demethylation in the 3'UTR of BNIP3 mRNA and induced its degradation via an YTHDF2 independent mechanism. BNIP3 acts as a tumor suppressor and is negatively correlated with FTO expression in clinical breast cancer patients. BNIP3 dramatically alleviated FTO-dependent tumor growth retardation and metastasis. CONCLUSIONS: Our findings demonstrate the functional significance of the m6A modification in breast cancer, and suggest that FTO may serve as a novel potential therapeutic target for breast cancer.

Long-term follow-up of self-expandable metallic stents in benign tracheobronchial stenosis: a retrospective study.

BACKGROUND: Self-expandable metallic stents (SEMSs) have enabled a approving management of malignant airway stenosis. However, the long-term efficacy and safety of this treatment in patients with benign airway stricture are unclear. We conducted this study to retrospectively determine the efficacy and long-term outcomes in patients who have undergone SEMS placement for benign tracheobronchial stenosis. METHODS: All patients treated with SEMSs from July 2003 to June 2016 were reviewed for symptomatic response, complications, and long-term outcomes. RESULTS: Total 131 stents were successfully deployed in 116 patients. Ninety-eight patients demonstrated clinical improvement after stent insertion (84.48%; 95% confidence interval [CI]: 77.89-91.07). Compared with uncovered stents, covered stents were associated with more sore throats complaints or chest pain (13.89% versus 28.81%, P = 0.036) and with higher incidences of major and minor granulation tissue formation and with recurrent stenosis (4.17% versus 15.25%, P = 0.029; 11.11% versus 37.29%, P < 0.0001 and 9.72% versus 28.81%, P = 0.005, respectively). Each covered and uncovered stent developing tissue hyperplasia required a median of 2 (range: 1-15) and 1(range: 1-7) fibrobronchoscope with electrocautery therapy, respectively. At follow-up (median: 1276 days; range: 2-4263), 68 patients had complete resolution, 15 remained under interventional treatment, 8 had bronchial occlusions, 7 underwent surgery, 14 were lost to follow-up, and 4 died of stent unrelated causes. CONCLUSION: SEMS placement achieved most clinical improvement among patients in our study, if adequate endotracheal measures were used to address stent-related complications. The use of permanent SEMSs for benign tracheobronchial stenosis was effective and safe for the majority of patients in a long-term follow-up. TRIAL REGISTRATION: The study has been retrospectively registered in the China Clinical Trial Registry on October 21, 2018 (Registry ID: ChiCTR1800019024 ).

Efficacy and Safety of CFTR Corrector and Potentiator Combination Therapy in Patients with Cystic Fibrosis for the F508del-CFTR Homozygous Mutation: A Systematic Review and Meta-analysis.

INTRODUCTION: Cystic fibrosis (CF) is a progressive, genetic disease that causes persistent lung infections and limits the ability to breathe over time. The combination of a cystic fibrosis transmembrane conductance regulator (CFTR) corrector and potentiator has provided a benefit by decreasing sweat chloride concentration in CF for the F508del-CFTR homozygous mutation, but it remains controversial in lung function, nutritional status, clinical score and safety. METHODS: The authors performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of combination therapy on lung function, nutritional status, clinical score and safety in CF for the F508del-CFTR homozygous mutation. Web of Science, Cochrane Central Register of Controlled Trials, Medline, and Embase were searched. The registered PROSPERO number was CRD42018085875. RESULTS: Five RCTs, including a total of 1637 participants with the F508del-CFTR homozygous mutation who accepted CFTR corrector and potentiator combination therapy along with basic treatment were enrolled in this analysis. Primary analysis revealed that combination therapy improved the percent of predicted FEV1 (ppFEV1) (MD 2.38, 1.62-3.15, P < 0.00001), Cystic Fibrosis Questionnaire-Revised (CFQ-R) respiratory domain score (MD 2.59, 0.96-4.22, P = 0.002) and body-mass index (BMI) (MD 0.21, 0.03-0.39, P = 0.02). In the secondary analysis, combination therapy had no impact on the number of participants reporting adverse events (OR 0.88, 0.58-1.33, P = 0.53), but increased the proportion of discontinued treatments due to adverse events (OR 2.71, 1.3-5.63, P = 0.008). CONCLUSIONS: CFTR corrector and potentiator combination therapy effectively improves lung function, nutritional status and clinical score in CF patients with the F508del-CFTR homozygous mutation, and has an acceptable safety profile.