YL064 directly inhibits STAT3 activity to induce apoptosis of multiple myeloma cells

An IL-1β-driven neutrophil-stromal cell axis fosters a BAFF-rich protumor microenvironment in individuals with multiple myeloma

Human bone marrow permanently harbors high numbers of neutrophils, and a tumor-supportive bias of these cells could significantly impact bone marrow-confined malignancies. In individuals with multiple myeloma, the bone marrow is characterized by inflammatory stromal cells with the potential to influence neutrophils. We investigated myeloma-associated alterations in human marrow neutrophils and the impact of stromal inflammation on neutrophil function. Mature neutrophils in myeloma marrow are activated and tumor supportive and transcribe increased levels of IL1B and myeloma cell survival factor TNFSF13B (BAFF). Interactions with inflammatory stromal cells induce neutrophil activation, including BAFF secretion, in a STAT3-dependent manner, and once activated, neutrophils gain the ability to reciprocally induce stromal activation. After first-line myeloid-depleting antimyeloma treatment, human bone marrow retains residual stromal inflammation, and newly formed neutrophils are reactivated. Combined, we identify a neutrophil-stromal cell feed-forward loop driving tumor-supportive inflammation that persists after treatment and warrants novel strategies to target both stromal and immune microenvironments in multiple myeloma.

Bioactivities and Mechanisms of Action of Sinomenine and Its Derivatives: A Comprehensive Review

Sinomenine, an isoquinoline alkaloid extracted from the roots and stems of Sinomenium acutum, has been extensively studied for its derivatives as bioactive agents. This review concentrates on the research advancements in the biological activities and action mechanisms of sinomenine-related compounds until November 2023. The findings indicate a broad spectrum of pharmacological effects, including antitumor, anti-inflammation, neuroprotection, and immunosuppressive properties. These compounds are notably effective against breast, lung, liver, and prostate cancers, exhibiting IC50 values of approximately 121.4 nM against PC-3 and DU-145 cells, primarily through the PI3K/Akt/mTOR, NF-κB, MAPK, and JAK/STAT signaling pathways. Additionally, they manifest anti-inflammatory and analgesic effects predominantly via the NF-κB, MAPK, and Nrf2 signaling pathways. Utilized in treating rheumatic arthritis, these alkaloids also play a significant role in cardiovascular and cerebrovascular protection, as well as organ protection through the NF-κB, Nrf2, MAPK, and PI3K/Akt/mTOR signaling pathways. This review concludes with perspectives and insights on this topic, highlighting the potential of sinomenine-related compounds in clinical applications and the development of medications derived from natural products.

Talin-1 inhibits Smurf1-mediated Stat3 degradation to modulate β-cell proliferation and mass in mice

Insufficient pancreatic β-cell mass and reduced insulin expression are key events in the pathogenesis of diabetes mellitus (DM). Here we demonstrate the high expression of Talin-1 in β-cells and that deficiency of Talin-1 reduces β-cell proliferation, which leads to reduced β-cell mass and insulin expression, thus causing glucose intolerance without affecting peripheral insulin sensitivity in mice. High-fat diet fed exerbates these phenotypes. Mechanistically, Talin-1 interacts with the E3 ligase smad ubiquitination regulatory factor 1 (Smurf1), which prohibits ubiquitination of the signal transducer and activator of transcription 3 (Stat3) mediated by Smurf1, and ablation of Talin-1 enhances Smurf1-mediated ubiquitination of Stat3, leading to decreased β-cell proliferation and mass. Furthermore, haploinsufficiency of Talin-1 and Stat3 genes, but not that of either gene, in β-cell in mice significantly impairs glucose tolerance and insulin expression, indicating that both factors indeed function in the same genetic pathway. Finally, inducible deletion Talin-1 in β-cell causes glucose intolerance in adult mice. Collectively, our findings reveal that Talin-1 functions as a crucial regulator of β-cell mass, and highlight its potential as a therapeutic target for DM patients.

The anti-tumor potential of sinomenine: a narrative review

Background and Objective

Currently, chemotherapy is the main treatment for most tumors. However, drug resistance and many adverse reactions associated with chemotherapy greatly limit its use. Therefore, an increasing number of researchers have shifted the research focus the anti-tumor activity of traditional Chinese medicine. The objective of this article is to review the anti-tumor mechanism of sinomenine and its derivatives to provide a reference for further study and clinical transformation.

Methods

In this study, we searched for relevant articles on the anti-tumor mechanism of Sinomenium using databases such as PubMed and Medline.

Key Content and Findings

Sinomenine is a monomer alkaloid component extracted from the rhizome of Sinomenium acuturn. A number of basic studies have proven that sinomenine and its derivatives show significant anti-tumor activity in breast cancer, lung cancer, liver cancer, stomach cancer, ovarian cancer, osteosarcoma and other tumors. They can induce apoptosis and autophagic death of tumor cells, inhibit proliferation, migration and invasion of tumor cells, increase the sensitivity of tumor cells to radiotherapy and chemotherapy, and reverse the drug resistance through various molecular mechanisms. In addition, sinomenine can effectively relieve osteolysis and bone pain in tumor patients. At present, anti-tumor research on sinomenine remains in the basic experimental stage.

Conclusions

Sinomenine and its derivatives are rich in substances with high anti-tumor potential. This analysis provides a review of the anti-tumor effects and mechanisms of sinomenine, with the hope of further exploring the medical value of sinomenine in anti-tumor treatments.

Chemistry and biology of ent-morphinan alkaloids

Morphinan alkaloids have attracted constant attention since the isolation of morphine by Sertürner in 1805. However, a group of 45 compounds possessing a complete ent-morphinan backbone can also be found in the literature. These compounds are related to the morphinandienone subgroup and display a substitution pattern which is different from the morphinans. In particular, these alkaloids could be substituted at position C-2 and C-8 either by a hydroxy function or a methoxy moiety. Four groups of ent-morphinan alkaloids can be proposed, the salutaridine, pallidine, cephasugine and erromangine series. Interestingly, the botanical distribution of the ent-morphinans is more widespread than for the morphinans and includes the Annonaceae, Berberidaceae, Euphorbiaceae, Fumariaceae, Hernandiaceae, Lauraceae, Menispermaceae, Monimiaceae, Papaveraceae, and Ranunculaceae families. To date, their exact mode of production remains elusive and their interplay with the biosynthetic pathway of other classes of benzyltetrahydroisoquinoline alkaloids, in particular aporphines, should be confirmed. Exploration of the biological and therapeutic potential of these compounds is limited to some areas, namely central nervous system (CNS), inflammation, cancer, malaria and viruses. Further studies should be conducted to identify the cellular/molecular targets in view of promoting these compounds as new scaffolds in medicinal chemistry.

A natural xanthone suppresses lung cancer growth and metastasis by targeting STAT3 and FAK signaling pathways

BACKGROUND

Nonsmall-cell lung cancer (NSCLC) is one of the most common malignant tumors, and the current drugs have not achieved ideal therapeutic effects. The abnormal activation of STAT3 and FAK signal transduction in tumor cells is highly correlated with their proliferation and migration ability. Therefore, bioactive compounds that can inhibit STAT3 and FAK activation have the potential to become agents to treat NSCLC.

PURPOSE

This study aims to discover new antitumor compounds from Garcinia xipshuanbannaensis and investigate the molecular mechanism by which they inhibit lung cancer proliferation and metastasis in vivo and in vitro, all of which may lead to obtainment of a potential antitumor agent.

METHODS

Xipsxanthone H was obtained by various chromatography methods (including silica gel, medium pressure liquid chromatography (MPLC), and preparative high-performance liquid chromatography (HPLC)). 1D and 2D nuclear magnetic resonance (NMR) spectra were used to analyze the structure. Cell viability and wound healing assays were employed to detect changes in the proliferation and migration of cancer cells. Cell cycle and apoptosis were analyzed by flow cytometry. The protein expression of STAT3 and FAK signaling pathways affected by xipsxanthone H was determined by Western blotting. The zebrafish model was used to evaluate the in vivo effects of xipshantone H on tumor proliferation and metastasis. Molecular docking was utilized to explore the interaction between xipsxanthone H and STAT3. Cellular thermal shift assays (CETSAs) were employed to explore the possible target of xipsxanthone H.

RESULTS

The novel compound xipsxanthone H was purified and characterized from G. xipshuanbannaensis. Xipsxanthone H exhibited strong anti-proliferation activity in a variety of tumor cell lines. In addition to inducing reactive oxygen species (ROS) production and arresting the cell cycle, mechanistic studies demonstrated that xipsxanthone H suppressed STAT3 and FAK phosphorylation and regulated the downstream protein expression of the STAT3 and FAK signaling pathways. The in vivo studies using the zebrafish model revealed that xipsxanthone H inhibited tumor proliferation, metastasis, and angiogenesis.

CONCLUSIONS

A new xanthone was obtained from G. xipshuanbannaensis, and this compound had the property of inhibiting tumor proliferation and metastasis by targeting STAT3 and FAK signaling pathways in NSCLC. These findings suggested that xipsxanthone H might be a potential candidate agent for NSCLC treatment.

Synthesis, Antitumor of Sinomenine Derivatives and Apoptotic Induction via IL-6/PI3K/Akt/NF-κB Signaling Pathway in MCF-7 Cells

Natural products have been widely considered as an important resource for new drugs or lead compounds. Sinomenine (SIN) and its derivatives exert antitumor activity via regulation of inflammatory mediators. For these reasons we synthesized three series of SIN derivatives (compounds 4a-i, 7a-c and 11a-c) as antitumor agents from this natural product. All compounds were prepared by the modification at the C1 and C4 positions of A ring, the C4 position of A ring and the C6 and C7 positions of C ring, respectively. All the derivatives were subjected to in vitro antitumor activity against HeLa, A549, HepG-2, MCF-7 and HT-29 cell lines. To observe the apoptotic induction of SIN derivatives and its mechanism, fluorescent staining and western bolt were carried out for active compound against MCF-7. Based on the screening results, most of SIN derivatives showed better antitumor activity than SIN. Some of them were found to possess broad spectrum antitumor activity. Most notably, 11c exhibited obvious antitumor activity in both cell lines with IC50 value less than 11 μM. Besides, 11c induced apoptosis of MCF-7 in a dose-dependent manner. Western blot assay demonstrated that 11c inhibited IL-6-mediated activation of PI3K/Akt pathway. A docking study revealed that 11c had stronger binding interaction with the residues of IL-6 than SIN. All these results indicate that 11c may be a potential anti-breast cancer agent by directly targeting IL-6.

Target identification and validation of natural products with label-free methodology: A critical review from 2005 to 2020

Natural products (NPs) have been an important source of therapeutic drugs in clinic use and contributed many chemical probes for research. The usefulness of NPs is however often marred by the incomplete understanding of their direct cellular targets. A number of experimental methods for drug target identification have been developed over the years. One class of methods, termed "label-free" methodology, exploits the energetic and biophysical features accompanying the association of macromolecules with drugs and other compounds in their native forms. Herein we review the working principles, assay implementations, and key applications of the most important approaches, and also give examples where they have been applied to NPs. We also assess the key advantages and limitations of each method. Furthermore, we address when and how the label-free methodology can be particularly useful considering some of the unique features of NP chemistry and bioactivation.

Validating Signal Transducer and Activator of Transcription (STAT) Protein-Inhibitor Interactions Using Biochemical and Cellular Thermal Shift Assays

Signal transducer and activator of transcription (STAT) proteins have important biological functions; however, deregulation of STAT signaling is a driving force behind the onset and progression of inflammatory diseases and cancer. While their biological roles suggest that STAT proteins would be valuable targets for developing therapeutic agents, STAT proteins are notoriously difficult to inhibit using small drug-like molecules, as they do not have a distinct inhibitor binding site. Despite this, a multitude of small-molecule STAT inhibitors have been proposed, primarily focusing on inhibiting STAT3 protein to generate novel cancer therapies. Demonstrating that inhibitors bind to their targets in cells has historically been a very challenging task. With the advent of modern target engagement techniques, such as the cellular thermal shift assay (CETSA), interactions between experimental compounds and their biological targets can be detected with relative ease. To investigate interactions between STAT proteins and inhibitors, we herein developed STAT CETSAs and evaluated known STAT3 inhibitors for their ability to engage STAT proteins in biological settings. While potent binding was detected between STAT proteins and peptidic STAT inhibitors, small-molecule inhibitors elicited variable responses, most of which failed to stabilize STAT3 proteins in cells and cell lysates. The described STAT thermal stability assays represent valuable tools for evaluating proposed STAT inhibitors.

Repurposing of drugs as STAT3 inhibitors for cancer therapy

Drug repurposing is a valuable approach in delivering new cancer therapeutics rapidly into the clinic. Existing safety and patient tolerability data for drugs already in clinical use represent an untapped resource in terms of identifying therapeutic agents for off-label protein targets. The multicellular effects of STAT3 mediated by a range of various upstream signaling pathways make it an attractive therapeutic target with utility in a range of diseases including cancer, and has led to the development of a variety of STAT3 inhibitors. Moreover, heightened STAT3 transcriptional activation in tumor cells and within the cells of the tumor microenvironment contribute to disease progression. Consequently, there are many STAT3 inhibitors in preclinical development or under evaluation in clinical trials for their therapeutic efficacy predominantly in inflammatory diseases and cancer. Despite these advances, many challenges remain in ultimately providing STAT3 inhibitors to patients as cancer treatments, highlighting the need not only for a better understanding of the mechanisms associated with STAT3 activation, but also how various pharmaceutical agents suppress STAT3 activity in various cancers. In this review we discuss the importance of STAT3-dependent functions in cancer, review the status of compounds designed as direct-acting STAT3 inhibitors, and describe some of the strategies for repurposing of drugs as STAT3 inhibitors for cancer therapy.

STAT3: A Promising Therapeutic Target in Multiple Myeloma

Multiple myeloma (MM) is an incurable plasma cell malignancy for which novel treatment options are required. Signal Transducer and Activator of Transcription 3 (STAT3) overexpression in MM appears to be mediated by a variety of factors including interleukin-6 signaling and downregulation of Src homology phosphatase-1 (SHP-1). STAT3 overexpression in MM is associated with an adverse prognosis and may play a role in microenvironment-dependent treatment resistance. In addition to its pro-proliferative role, STAT3 upregulates anti-apoptotic proteins and leads to microRNA dysregulation in MM. Phosphatase of regenerating liver 3 (PRL-3) is an oncogenic phosphatase which is upregulated by STAT3. PRL-3 itself promotes STAT-3 phosphorylation resulting in a positive feedback loop. PRL-3 is overexpressed in a subset of MM patients and may cooperate with STAT3 to promote survival of MM cells. Indirectly targeting STAT3 via JAK (janus associated kinase) inhibition has shown promise in early clinical trials. Specific inhibitors of STAT3 showed in vitro efficacy but have failed in clinical trials while several STAT3 inhibitors derived from herbs have been shown to induce apoptosis of MM cells in vitro. Optimising the pharmacokinetic profiles of novel STAT3 inhibitors and identifying how best to combine these agents with existing anti-myeloma therapy are key questions to be addressed in future clinical trials.