JD-312 - A novel small molecule that facilitates cartilage repair and alleviates osteoarthritis progression.

Background: The chondrogenic differentiation of mesenchymal stem cells (MSCs) to enhance cartilage repair and regeneration is a promising strategy to alleviate osteoarthritis (OA) progression. Method: The potency of JD-312 in inducing chondrogenic differentiation of MSCs was assessed and verified. The efficacy of JD-312-treated MSCs was evaluated using a Sprague-Dawley rat DMM model. Additionally, the capacity of JD-312 to successfully recruit bone marrow-derived mesenchymal stem cells (BMSCs) for the treatment of OA in vitro was confirmed via intra-articular injection. The repair status of the articular cartilage was analyzed in vivo through histological examination. Result: In this study, we identify JD-312 as a novel non-toxic small molecule that can promote chondrogenic differentiation in human umbilical cord-derived MSCs (hUCMSCs) and human bone marrow MSCS (hBMSCs) in vitro. We also show that transient differentiation of MSCs with JD-312 prior to in vivo administration remarkably improves the regeneration of cartilage and promotes Col2a1 and Acan expression in rat models of DMM, in comparison to kartogenin (KGN) pre-treatment or MSCs alone. Furthermore, direct intra-articular injection of JD-312 in murine model of OA showed reduced loss of articular cartilage and improved pain parameters. Lastly, we identified that the effects of JD-312 are at least in part mediated via upregulation of genes associated with the focal adhesion, PI3K-Akt signaling and the ECM-receptor interaction pathways, and specifically cartilage oligomeric matrix protein (COMP) may play a vital role. Conclusion: Our study demonstrated that JD-312 showed encouraging repair effects for OA in vivo. The translational potential of this article: Together, our findings demonstrate that JD-312 is a promising new therapeutic molecule for cartilage regeneration with clinical potential.

Targeting key proteins involved in transcriptional regulation for cancer therapy: Current strategies and future prospective.

The key proteins involved in transcriptional regulation play convergent roles in cellular homeostasis, and their dysfunction mediates aberrant gene expressions that underline the hallmarks of tumorigenesis. As tumor progression is dependent on such abnormal regulation of transcription, it is important to discover novel chemical entities as antitumor drugs that target key tumor-associated proteins involved in transcriptional regulation. Despite most key proteins (especially transcription factors) involved in transcriptional regulation are historically recognized as undruggable targets, multiple targeting approaches at diverse levels of transcriptional regulation, such as epigenetic intervention, inhibition of DNA-binding of transcriptional factors, and inhibition of the protein-protein interactions (PPIs), have been established in preclinically or clinically studies. In addition, several new approaches have recently been described, such as targeting proteasomal degradation and eliciting synthetic lethality. This review will emphasize on accentuating these developing therapeutic approaches and provide a thorough conspectus of the drug development to target key proteins involved in transcriptional regulation and their impact on future oncotherapy.

Suppression of the SLC7A11/glutathione axis causes synthetic lethality in KRAS-mutant lung adenocarcinoma.

Oncogenic KRAS is a major driver in lung adenocarcinoma (LUAD) that has yet to be therapeutically conquered. Here we report that the SLC7A11/glutathione axis displays metabolic synthetic lethality with oncogenic KRAS. Through metabolomics approaches, we found that mutationally activated KRAS strikingly increased intracellular cystine levels and glutathione biosynthesis. SLC7A11, a cystine/glutamate antiporter conferring specificity for cystine uptake, was overexpressed in patients with KRAS-mutant LUAD and showed positive association with tumor progression. Furthermore, SLC7A11 inhibition by either genetic depletion or pharmacological inhibition with sulfasalazine resulted in selective killing across a panel of KRAS-mutant cancer cells in vitro and tumor growth inhibition in vivo, suggesting the functionality and specificity of SLC7A11 as a therapeutic target. Importantly, we further identified a potent SLC7A11 inhibitor, HG106, that markedly decreased cystine uptake and intracellular glutathione biosynthesis. Furthermore, HG106 exhibited selective cytotoxicity toward KRAS-mutant cells by increasing oxidative stress- and ER stress-mediated cell apoptosis. Of note, treatment of KRAS-mutant LUAD with HG106 in several preclinical lung cancer mouse models led to marked tumor suppression and prolonged survival. Overall, our findings reveal that KRAS-mutant LUAD cells are vulnerable to SLC7A11 inhibition, offering potential therapeutic approaches for this currently incurable disease.

Discovery of potent ureido tetrahydrocarbazole derivatives for cancer treatments through targeting tumor-associated macrophages.

Tumor-associated macrophages (TAMs) are one of the prominent components of the tumor microenvironment (TME). The polarization peculiarity of TAMs drives them to infiltrate and active with states between M1 (anti-tumor) and M2 (pro-tumor) phenotypes in cancers. Exploiting small molecular drugs through targeting TAMs to repolarize them into an antitumor phenotype is considered as a novel strategy for cancer treatments in recent years. For discovering novel compounds that target TAMs, a series of ureido tetrahydrocarbazole derivatives were designed, synthesized and evaluated both in vitro and in vivo. Among them, compound 23a was found to dose-dependently repolarize TAMs from M2 to M1 both in vitro and in vivo. And more importantly, the in vivo experiments also revealed that compound 23a was capable of remarkably inhibiting tumor growth of the LLC mouse model. Moreover, the synergy of compound 23a with anti-PD-1 antibody had more superior antineoplastic effects than the exclusive use of either in vivo.

Modification and Biological Evaluation of a Series of 1,5-Diaryl-1,2,4-triazole Compounds as Novel Agents against Pancreatic Cancer Metastasis through Targeting Myoferlin.

Pancreatic cancer is one of the most common cancers with an extremely low survival rate. Metastasis, as one of the key reasons of cancer-related death, is found in more than 50% pancreatic cancer patients at diagnosis. Novel therapeutic targets and drugs blocking cancer metastasis are urgently needed. Herein, we report a series of 1,5-diaryl-1,2,4-triazole derivatives as potent antimetastatic agents. Lead compound 6y displayed effective antimetastatic activities in pancreatic cancer in vitro and in vivo. Concomitant studies indicated that 6y probably binds with myoferlin (MYOF), a novel potential antitumor metastasis target, which regulates vesicle trafficking and metastasis-related proteins. Subsequent biophysical and biochemical methods verified that 6y bound to MYOF. Mechanism studies revealed that 6y inhibited pancreatic cancer metastasis through reversing the epithelial mesenchymal transition, inhibiting the secretions of matrix metalloproteinase and blocking the receptor tyrosine kinases. Our findings suggest that targeting MYOF with 6y may be a promising therapeutic strategy to prevent pancreatic cancer metastasis.

Small molecule PROTACs: an emerging technology for targeted therapy in drug discovery.

Curing malignant carcinomas is a grand ambition in the development of human health. Over the past decades, targeted therapies have become one of the most successful ways of achieving this. Of these approaches, small molecule inhibitors and monoclonal antibodies are two major methods, however several barriers to their development and clinical use still exist. The use of proteolysis-targeting chimeras (PROTACs) is a new technology through utilizing a intracellular ubiquitin-proteasome system to induce targeted protein degradation, is receiving much attention in the field of targeted therapies. Hetero-bifunctional PROTACs have the potential to eliminate the "undruggable" proteome that comprises about 85% of human proteins, which indicates their great prospects in therapeutic fields. However, there are some hurdles preventing current PROTACs moving from bench to clinic, such as delivery and bioavailability. This review provides an overview of the development of PROTAC technology and will briefly summarize the future possible directions of this approach.

Design, synthesis and evaluation of hybrid of tetrahydrocarbazole with 2,4-diaminopyrimidine scaffold as antibacterial agents.

Several 6-substituted tetrahydrocarbazole derivatives were designed, synthesized and evaluated for the antibacterial activities against Staphylococcus aureus Newman strain. Subsequently, 2,4-diaminopyrimidine scaffold was merged with the tetrahydrocarbazole unit to generate a series of novel hybrid derivatives and the antibacterial activities were also investigated. Among these novel hybrids, compound 12c showed the most potent activity with a MIC of 0.39-0.78 µg/mL against S. aureus Newman and Escherichia coli AB1157 strain. In addition, compound 12c exhibited low MIC values against a panel of multidrug-resistant strains of S. aureus.

Targeting Twist expression with small molecules.

Twist, as one of the important embryonic transcription factors, regulates epithelial-mesenchymal transition (EMT) and migration in embryo formation and cancer development. Both Twist-1 and Twist-2 are rarely detectable in healthy adult tissues, but are frequently overexpressed in multiple kinds of human cancer tissues, such as breast, prostate, uterus, liver, melanoma, etc. Twist is considered as a crucial EMT inductor and correlated with carcinoma aggression, invasion and metastasis. In the past decades, in-depth investigation has been reported in terms of the role of Twist in cancers; in addition, several kinds of small molecules have played important roles in studying the effect of Twist on cancer development, suggesting that Twist can be regarded as one of the important potential targets for cancer treatment. Hence we provide a brief overview of Twist and several small molecules targeting its expression, highlighting the biological features that make it a charming target for cancer therapy.

Discovery and Optimization of N-Substituted 2-(4-pyridinyl)thiazole carboxamides against Tumor Growth through Regulating Angiogenesis Signaling Pathways.

Inhibition of angiogenesis is considered as one of the desirable pathways for the treatment of tumor growth and metastasis. Herein we demonstrated that a series of pyridinyl-thiazolyl carboxamide derivatives were designed, synthesized and examined against angiogenesis through a colony formation and migration assays of human umbilical vein endothelial cells (HUVECs) in vitro. A structure-activity relationship (SAR) study was carried out and optimization toward this series of compounds resulted in the discovery of N-(3-methoxyphenyl)-4-methyl-2-(2-propyl-4-pyridinyl)thiazole-5-carboxamide (3k). The results indicated that compound 3k showed similar or better effects compared to Vandetanib in suppressing HUVECs colony formation and migration as well as VEGF-induced angiogenesis in the aortic ring spreading model and chick embryo chorioallantoic membrane (CAM) model. More importantly, compound 3k also strongly blocked tumor growth with the dosage of 30 mg/kg/day, and subsequent mechanism exploration suggested that this series of compounds took effect mainly through angiogenesis signaling pathways. Together, these results suggested compound 3k may serve as a lead for a novel class of angiogenesis inhibitors for cancer treatments.