PTK6 inhibits autophagy to promote uveal melanoma tumorigenesis by binding to SOCS3 and regulating mTOR phosphorylation

Sodium fluoride promotes myopia progression via the activation of the ferroptosis pathway by PIEZO1 and pharmacological targeting PIEZO1 represents an innovative approach for myopia treatment

Sodium fluoride-induced ocular damage constitutes a significant public health concern globally; however, the precise molecular mechanisms underlying this issue remain obscure. This study aims to investigate the effects of sodium fluoride on myopia and to offer novel theoretical foundations for future strategies in myopia prevention and control. The experimental data showed that sodium fluoride could promote myopia progression, and through bioinformatics analysis, we found that sodium fluoride could affect the ferroptosis pathway. Western blotting and redox kit assays further confirmed that sodium fluoride activates the ferroptosis pathway. We also demonstrated that PIEZO1 plays a crucial role in sodium fluoride-induced myopia, and that the PIEZO1 inhibitor (GsMTx4) can inhibit the ferroptosis pathway. Subsequently, we identified PIEZO1 as a potential target of baicalin, which inhibited PIEZO1 expression in vivo and in vitro, as confirmed by molecular docking modeling and CETSA assays. Finally, we found that baicalin inhibited sodium fluoride-induced myopia via PIEZO1. Taken together, our findings indicate that sodium fluoride can promote myopia progression by activating the ferroptosis pathway through PIEZO1, and that targeting PIEZO1 expression can delay myopia progression, which may provide a new drug target for myopia treatment in the future.

DCC-2036 inhibits osteosarcoma via targeting HCK and the PI3K/AKT-mTORC1 axis to promote autophagy

BACKGROUND

Osteosarcoma is a common bone tumor in adolescents and children, characterized by rapid progression, high malignancy, poor prognosis, and a tendency for pulmonary metastasis. Despite extensive research efforts, the specific driver gene associated with osteosarcoma remains unidentified, underscoring the urgent need for novel therapeutic targets and targeted treatment options.

METHODS

In vitro studies were conducted to assess the effects of DCC-2036 on the proliferation, migration, and invasion of osteosarcoma (OS) cell lines, employing cloning and Transwell experiments. Network pharmacological analysis, complemented by in vitro experimental validation, indicated the critical target responsible for the inhibitory effects of DCC-2036. RNA sequencing analysis demonstrated that DCC-2036 could induce autophagy in OS cells, with relative protein levels assessed using Western blotting following treatment with the autophagy inhibitor 3-MA and the mTOR agonist MHY1485. In vivo studies further confirmed the role of DCC-2036 in cell proliferation through subcutaneous tumorigenesis.

RESULTS

In this study, we demonstrated that the small molecule tyrosine kinase inhibitor DCC-2036 effectively inhibited osteosarcoma (OS) cells in both cellular and animal models. We found that DCC-2036 significantly suppressed the proliferation of osteosarcoma cells and induced apoptosis; additionally, it notably inhibited cell migration, invasion, and epithelial-to-mesenchymal transition (EMT). HCK was identified as the key target mediating the effects of DCC-2036 on osteosarcoma. Mechanistically, DCC-2036 was shown to inhibit the expression of phosphorylated AKT (p-AKT), phosphorylated S6 kinase (p-S6K), and phosphorylated 4E-binding protein 1 (p-4EBP1) within the downstream PI3K/AKT/mTORC1 signaling pathway. Furthermore, in vivo experiments utilizing subcutaneous tumor xenografts in mice demonstrated that DCC-2036 effectively inhibited the growth of xenografted 143B cells in BALB/C-nude mice.

CONCLUSIONS

Collectively, these findings indicate that DCC-2036 promotes autophagy in osteosarcoma (OS) cells by targeting the HCK/AKT/mTORC1 axis and exerts anti-tumor effects without significant toxicity. Consequently, DCC-2036 emerges as a promising therapeutic agent for the treatment of HCK-overexpressing osteosarcoma.

The BET inhibitor JQ1 suppresses tumor survival by ABCB5-mediated autophagy in uveal melanoma

Uveal melanoma (UM), the most common adult ocular tumor, is aggressive and resistant to treatment, posing threat to patients' lives. The novel, effective therapies and the exploration of chemosensitizer for UM are imperative. The anticancer efficacy was evaluated with and without JQ1 treatment or ABCB5 gene silencing or overexpression. RNA sequencing identified downstream effectors in JQ1-treated cells. Integrated analysis of The Cancer Genome Atlas data (TCGA) and immunohistochemistry (IHC) revealed the oncogenic role of ABCB5. Functional analyses of JQ1 and defective ABCB5 were conducted using flow cytometry, transmission electron microscopy (TEM), IHC and western blot. The effects of JQ1 were validated in a heterotopic tumor model derived from OCM-1 cells. JQ1 inhibited cell proliferation, migration and invasion, induced cell cycle arrest and promoted apoptosis. JQ1 also suppressed the survival of UM in heterotopic tumor model. RNA sequencing indicated that JQ1 down-regulated the expressions of ABCB5 and autophagy-related genes, which was confirmed in vitro and in vivo by western blot. ABCB5, a marker associated with cancer stem cells and chemo-resistance, exhibited heightened expression in UM tissues, linked to immune infiltration. Notably, disrupting ABCB5 expression impeded UM cell proliferation and interfered with autophagy. Moreover, the overexpression of ABCB5 promoted cell proliferation, migration and invasion, and rescued autophagy related gene expression. Of note, JQ1 enhanced the sensitivity of OCM-1 cells to chemotherapy. Thus JQ1 inhibits UM survival via ABCB5-mediated autophagy and enhances chemo-sensitivity, suggesting potential for BET-based approaches in UM clinical management.

STAT6/LINC01637 axis regulates tumor growth via autophagy and pharmacological targeting STAT6 as a novel strategy for uveal melanoma

Compelling evidence has revealed a novel function of the STAT pathway in the pathophysiology of uveal melanoma (UM); however, its regulatory mechanisms remain unclear. Here, we analyzed the clinical prognostic value of STAT family genes in UM patients using bioinformatics approaches and found that high STAT6 expression is associated with poor prognosis. Furthermore, cellular experiments and a nude mouse model demonstrated that STAT6 promotes UM progression through the autophagy pathway both in vivo and in vitro. Next, RIP-PCR revealed that STAT6 protein binds to LINC01637 mRNA, which in turn regulates STAT6 expression to promote UM growth. Finally, molecular docking indicated that STAT6 is a target of Zoledronic Acid, which can delay UM tumorigenicity by inhibiting STAT6 expression. Taken together, our results indicate that the STAT6/LINC01637 axis promotes UM progression via autophagy and may serve as a potential therapeutic target for UM.

PEGylated SOCS3 Mimetics Encapsulated into PLGA-NPs as Selective Inhibitors of JAK/STAT Pathway in TNBC Cells

Introduction

SOCS3 (suppressor of cytokine signaling 3) protein is a crucial regulator of cytokine-induced inflammation, and its administration has been shown to have therapeutic effects. Recently, we designed a chimeric proteomimetic of SOCS3, mimicking the interfacing regions of a ternary complex composed of SOCS3, JAK2 (Janus kinase 2) and gp130 (glycoprotein 130) proteins. The derived chimeric peptide, KIRCONG chim, demonstrated limited mimetic function owing to its poor water solubility.

Methods

We report investigations concerning a PEGylated variant of KIRCONG mimetic, named KIRCONG chim, bearing a PEG (Polyethylene glycol) moiety as a linker of noncontiguous SOCS3 regions. Its ability to bind to the catalytic domain of JAK2 was evaluated through MST (MicroScale Thermophoresis), as well as its stability in biological serum assays. The structural features of the cyclic compounds were investigated by CD (circular dichroism), nuclear magnetic resonance (NMR), and molecular dynamic (MD) studies. To evaluate the cellular effects, we employed a PLGA-nanoparticle as a delivery system after characterization using DLS and SEM techniques.

Results

KIRCONG chim PEG-revealed selective penetration into triple-negative breast cancer (TNBC) MDA-MB-231 cells with respect to the human breast epithelial cell line (MCF10A), acting as a potent inhibitor of STAT3 phosphorylation.

Discussion

Overall, the data indicated that miniaturization of the SOCS3 protein is a promising therapeutic approach for aberrant dysregulation of JAK/STAT during cancer progression.

The multiple roles of autophagy in uveal melanoma and the microenvironment

PURPOSE

Uveal melanoma (UM) is the most common primary malignant intraocular tumor in adults, and effective clinical treatment strategies are still lacking. Autophagy is a lysosome-dependent degradation system that can encapsulate abnormal proteins, damaged organelles. However, dysfunctional autophagy has multiple types and plays a complex role in tumorigenicity depending on many factors, such as tumor stage, microenvironment, signaling pathway activation, and application of autophagic drugs.

METHODS

A systematic review of the literature was conducted to analyze the role of autophagy in UM, as well as describing the development of autophagic drugs and the link between autophagy and the tumor microenvironment.

RESULTS

In this review, we summarize current research advances regarding the types of autophagy, the mechanisms of autophagy, the application of autophagy inhibitors or agonists, autophagy and the tumor microenvironment. Finally, we also discuss the relationship between autophagy and UM.

CONCLUSION

Understanding the molecular mechanisms of how autophagy differentially affects tumor progression may help to design better therapeutic regimens to prevent and treat UM.

The Role of Autophagy in Human Uveal Melanoma and the Development of Potential Disease Biomarkers and Novel Therapeutic Paradigms

Autophagy is a form of programmed cell degradation that enables the maintenance of homeostasis in response to extracellular stress stimuli. Autophagy is primarily activated by starvation and mediates the degradation, removal, or recycling of cell cytoplasm, organelles, and intracellular components in eukaryotic cells. Autophagy is also involved in the pathogenesis of human diseases, including several cancers. Human uveal melanoma (UM) is the primary intraocular malignancy in adults and has an extremely poor prognosis; at present there are no effective therapies. Several studies have suggested that autophagy is important in UM. By understanding the mechanisms of activation of autophagy in UM it may be possible to develop biomarkers to provide more definitive disease prognoses and to identify potential drug targets for the development of new therapeutic strategies. This article reviews the current information regarding autophagy in UM that could facilitate biomarker and drug development.

Multi-omics approaches identify novel prognostic biomarkers of autophagy in uveal melanoma

PURPOSE

Uveal melanoma (UVM) is a rare yet malignant ocular tumor that metastases in approximately half of all patients, with the majority of those developing metastasis typically succumbing to the disease within a year. Hitherto, no effective treatment for UVM has been identified. Autophagy is a cellular mechanism that has been suggested as an emerging regulatory process for cancer-targeted therapy. Thus, identifying novel prognostic biomarkers of autophagy may help improve future treatment.

METHODS

Consensus clustering and similarity network fusion approaches were performed for classifying UVM patient subgroups. Weighted correlation network analysis was performed for gene module screening and network construction. Gene set variation analysis was used to evaluate the autophagy activity of the UVM subgroups. Kaplan-Meier survival curves (Log-rank test) were performed to analyze patient prognosis. Gene set cancer analysis was used to estimate the level of immune cell infiltration.

RESULTS

In this study, we employed multi-omics approaches to classify UVM patient subgroups by molecular and clinical characteristics, ultimately identifying HTR2B, EEF1A2, FEZ1, GRID1, HAP1, and SPHK1 as potential prognostic biomarkers of autophagy in UVM. High expression levels of these markers were associated with poorer patient prognosis and led to reshaping the tumor microenvironment (TME) that promotes tumor progression.

CONCLUSION

We identified six novel potential prognostic biomarkers in UVM, all of which are associated with autophagy and TME. These findings will shed new light on UVM therapy with inhibitors targeting these biomarkers expected to regulate autophagy and reshape the TME, significantly improving UVM treatment outcomes.

Heterogeneity in the Metastatic Microenvironment: JunB-Expressing Microglia Cells as Potential Drivers of Melanoma Brain Metastasis Progression

Reciprocal signaling between melanoma brain metastatic (MBM) cells and microglia reprograms the phenotype of both interaction partners, including upregulation of the transcription factor JunB in microglia. Here, we aimed to elucidate the impact of microglial JunB upregulation on MBM progression. For molecular profiling, we employed RNA-seq and reverse-phase protein array (RPPA). To test microglial JunB functions, we generated microglia variants stably overexpressing JunB (JunBhi) or with downregulated levels of JunB (JunBlo). Melanoma-derived factors, namely leukemia inhibitory factor (LIF), controlled JunB upregulation through Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) signaling. The expression levels of JunB in melanoma-associated microglia were heterogeneous. Flow cytometry analysis revealed the existence of basal-level JunB-expressing microglia alongside microglia highly expressing JunB. Proteomic profiling revealed a differential protein expression in JunBhi and JunBlo cells, namely the expression of microglia activation markers Iba-1 and CD150, and the immunosuppressive molecules SOCS3 and PD-L1. Functionally, JunBhi microglia displayed decreased migratory capacity and phagocytic activity. JunBlo microglia reduced melanoma proliferation and migration, while JunBhi microglia preserved the ability of melanoma cells to proliferate in three-dimensional co-cultures, that was abrogated by targeting leukemia inhibitory factor receptor (LIFR) in control microglia-melanoma spheroids. Altogether, these data highlight a melanoma-mediated heterogenous effect on microglial JunB expression, dictating the nature of their functional involvement in MBM progression. Targeting microglia highly expressing JunB may potentially be utilized for MBM theranostics.

Therapeutic Potential of Protein Tyrosine Kinase 6 in Colorectal Cancer

PTK6, a non-receptor tyrosine kinase, modulates the pathogenesis of breast and prostate cancers and is recognized as a biomarker of breast cancer prognosis. There are over 30 known substrates of PTK6, including signal transducers, transcription factors, and RNA-binding proteins. Many of these substrates are known drivers of other cancer types, such as colorectal cancer. Colon and rectal tumors also express higher levels of PTK6 than the normal intestine suggesting a potential role in tumorigenesis. However, the importance of PTK6 in colorectal cancer remains unclear. PTK6 inhibitors such as XMU-MP-2 and Tilfrinib have demonstrated potency and selectivity in breast cancer cells when used in combination with chemotherapy, indicating the potential for PTK6 targeted therapy in cancer. However, most of these inhibitors are yet to be tested in other cancer types. Here, we discuss the current understanding of the function of PTK6 in normal intestinal cells compared with colorectal cancer cells. We review existing PTK6 targeting therapeutics and explore the possibility of PTK6 inhibitory therapy for colorectal cancer.