Pentamidine inhibit S100A4 - p53 interaction and decreases cell proliferation activity

Role of S100A1, S100A4, S100A8/A9 and S100B in myocardial infarction and heart failure

Myocardial infarction and heart failure represent major global health challenges, leading causes of hospitalization and mortality worldwide, especially among the elderly. Despite considerable advancements in treatment, there remains a substantial need to improve prognostic outcomes through further research into pathogenesis and therapeutic optimization. S100 proteins, as inflammatory factors within the heart, demonstrate binding capabilities to various target proteins. Notably, S100A1, S100A4, S100A8/A9, and S100B have emerged as key players in myocardial infarction and heart failure pathophysiology. This review comprehensively illustrates the underlying roles of these four S100 proteins in myocardial infarction and heart failure, highlights similarities and differences in their mechanisms. By synthesizing recent insights, this review offers valuable references and suggests future research directions to advance our understanding and treatment strategies for myocardial infarction and heart failure. Through continued investigation into S100 proteins, more effective therapeutic targets may be identified, ultimately improving patient care and outcomes in cardiovascular diseases.

Repurposing the anti-parasitic agent pentamidine for cancer therapy; a novel approach with promising anti-tumor properties

Pentamidine (PTM) is an aromatic diamidine administered for infectious diseases, e.g. sleeping sickness, malaria, and Pneumocystis jirovecii pneumonia. Due to similarities of cellular mechanisms between human cells and such infections, PTM has also been proposed for repurposing in non-infectious diseases such as cancer. Indeed, by modulating different signaling pathways such as PI3K/AKT, MAPK/ERK, p53, PD-1/PD-L1, etc., PTM has been shown to inhibit different properties of cancer, including proliferation, invasion, migration, hypoxia, and angiogenesis, while inducing anti-tumor immune responses and apoptosis. Given the promising implications of PTM for cancer treatment, however, the clinical translation of PTM in cancer is not without certain challenges. In fact, clinical trials have shown that systemic administration of PTM can be concurrent with serious adverse effects, e.g. hypoglycemia. Therefore, to reduce the administered doses of PTM, lower the risk of adverse effects, and prevent any potential drug resistance, while maintaining the anti-tumor efficacy, two main strategies have been suggested. One is combination therapy that employs PTM in conjunction with other anti-cancer modalities, such as chemotherapy and radiotherapy, and attacks tumor cells with significant additive or synergistic anti-tumor effects. The other is developing PTM-loaded nanocarrier drug delivery systems e.g. pegylated liposomes, chitosan-coated niosomes, squalene-based nanoparticles, hyaluronated lipid-polymer hybrid nanoparticles, etc., that offer enhanced pharmacokinetic characteristics, including increased bioavailability, sit-targeting, and controlled/sustained drug release. This review highlights the anti-tumor properties of PTM that favor its repurposing for cancer treatment, as well as, PTM-based combination therapies and nanocarrier delivery systems which can enhance therapeutic efficacy and simultaneously reduce toxicity.

S100A4 targets PPP1CA/IL-17 to inhibit the senescence of sheep endometrial epithelial cells

Background

Gonadotropin-releasing hormone (GnRH) is commonly used in animal reproduction and production, but it was previously reported that GnRH decreases the embryo implantation rate during artificial insemination or embryo transfer in sheep. In addition to the finding that GnRH can target S100A4 to inhibit endometrial epithelial cells proliferation, it was also found that endometrial cells were in poor condition and experienced cell death in S100A4 knockout mice, but the mechanism is unclear.

Methods

The protein PPP1CA, which interacts with S100A4, was detected by immunoprecipitation-mass spectrometry of overexpression and knockdown of S100A4 and PPP1CA. The effect of S100A4 and PPP1CA on cell senescence was detected by Galactosidase staining. To further reveal the mechanism effect of S100A4 and PPP1CA on cell senescence, transcriptome sequencing was conducted. Additionally, in vivo experiments were performed to assess PPP1CA protein expression in the endometrial tissue of S100A4 knockout mice.

Results

S100A4 inhibited cell senescence by activating PPP1CA, while PPP1CA overexpression suppressed the activation of the IL-17 signaling pathway. Inhibition of the IL-17 signaling pathway inhibited the senescence of endometrial cells.

Conclusion

S100A4 can target the PPP1CA/IL-17 signaling pathway and inhibit endometrial epithelial cell senescence.

Covalent Inhibitors of S100A4 Block the Formation of a Pro-Metastasis Non-Muscle Myosin 2A Complex

The S100 protein family functions as protein-protein interaction adaptors regulated by Ca2+ binding. Formation of various S100 complexes plays a central role in cell functions, from calcium homeostasis to cell signaling, and is implicated in cell growth, migration, and tumorigenesis. We established a suite of biochemical and cellular assays for small molecule screening based on known S100 protein-protein interactions. From 25 human S100 proteins, we focused our attention on S100A4 because of its well-established role in cancer progression and metastasizes by interacting with nonmuscle myosin II (NMII). We identified several potent and selective inhibitors of this interaction and established the covalent nature of binding, confirmed by mass spectrometry and crystal structures. 5b showed on-target activity in cells and inhibition of cancer cell migration. The identified S100A4 inhibitors can serve as a basis for the discovery of new cancer drugs operating via a novel mode of action.

Study on the mechanism of S100A4-mediated cancer oncogenesis in uveal melanoma cells through the integration of bioinformatics and in vitro experiments

BACKGROUND

The elevated metastasis rate of uveal melanoma (UM) is intricately correlated with patient prognosis, significantly affecting the quality of life. S100 calcium-binding protein A4 (S100A4) has tumorigenic properties; therefore, the present study investigated the impact of S100A4 on UM cell proliferation, apoptosis, migration, and invasion using bioinformatics and in vitro experiments.

METHODS

Bioinformatic analysis was used to screen S100A4 as a hub gene and predict its possible mechanism in UM cells, and the S100A4 silencing cell line was constructed. The impact of S100A4 silencing on the proliferative ability of UM cells was detected using the Cell Counting Kit-8 and colony formation assays. Annexin V-FITC/PI double fluorescence and Hoechst 33342 staining were used to observe the effects of apoptosis on UM cells. The effect of S100A4 silencing on the migratory and invasive capabilities of UM cells was assessed using wound healing and Transwell assays. Western blotting was used to detect the expression of related proteins.

RESULTS

The present study found that S100A4 is a biomarker of UM, and its high expression is related to poor prognosis. After constructing the S100A4 silencing cell line, cell viability, clone number, proliferating cell nuclear antigen, X-linked inhibitor of apoptosis protein, and survivin expression were decreased in UM cells. The cell apoptosis rate and relative fluorescence intensity increased, accompanied by increased levels of Bax and caspase-3 and decreased levels of Bcl-2. Additionally, a decrease in the cell migration index and relative invasion rate was observed with increased E-cadherin expression and decreased N-cadherin and vimentin protein expression.

CONCLUSION

S100A4 silencing can inhibit the proliferation, migration, and invasion and synchronously induces apoptosis in UM cells.

ANXA9 facilitates S100A4 and promotes breast cancer progression through modulating STAT3 pathway

Breast cancer has the highest global incidence and mortality rates among all cancer types. Abnormal expression of the Annexin family has been observed in different malignant tumors, including upregulated ANXA9 in breast cancer. We found highly expressed ANXA9 in metastatic breast cancer tissues, which is correlated with breast cancer progression. In vitro, the functional experiments indicated ANXA9 influenced breast cancer proliferation, motility, invasion, and apoptosis; in vivo, downregulation of ANXA9 suppressed breast cancer xenograft tumor growth and lung metastasis. Mechanically, on one side, we found that ANXA9 could mediate S100A4 and therefore regulate AKT/mTOR/STAT3 pathway to participate p53/Bcl-2 apoptosis; on the other side, we found ANXA9 transferred S100A4 from cells into the tumor microenvironment and mediated the excretion of cytokines IL-6, IL-8, CCL2, and CCL5 to participate angiogenesis via self- phosphorylation at site Ser2 and site Thr69. Our findings demonstrate significant involvement of ANXA9 in promoting breast cancer progression, thereby suggesting that therapeutic intervention via targeting ANXA9 may be effective in treating metastatic breast cancer.

Secreted S100A4 causes asthmatic airway epithelial barrier dysfunction induced by house dust mite extracts via activating VEGFA/VEGFR2 pathway

The airway epithelial barrier dysfunction plays a crucial role in pathogenesis of asthma and causes the amplification of downstream inflammatory signal pathway. S100 calcium binding protein A4 (S100A4), which promotes metastasis, have recently been discovered as an effective inflammatory factor and elevated in bronchoalveolar lavage fluid in asthmatic mice. Vascular endothelial growth factor-A (VEGFA), is considered as vital regulator in vascular physiological activities. Here, we explored the probably function of S100A4 and VEGFA in asthma model dealt with house dust mite (HDM) extracts. Our results showed that secreted S100A4 caused epithelial barrier dysfunction, airway inflammation and the release of T-helper 2 cytokines through the activation of VEGFA/VEGFR2 signaling pathway, which could be partial reversed by S100A4 polyclonal antibody, niclosamide and S100A4 knockdown, representing a potential therapeutic target for airway epithelial barrier dysfunction in asthma.

Regulation of p53 Function by Formation of Non-Nuclear Heterologous Protein Complexes

A transcription factor p53 is activated upon cellular exposure to endogenous and exogenous stresses, triggering either homeostatic correction or cell death. Depending on the stress level, often measurable as DNA damage, the dual outcome is supported by p53 binding to a number of regulatory and metabolic proteins. Apart from the nucleus, p53 localizes to mitochondria, endoplasmic reticulum and cytosol. We consider non-nuclear heterologous protein complexes of p53, their structural determinants, regulatory post-translational modifications and the role in intricate p53 functions. The p53 heterologous complexes regulate the folding, trafficking and/or action of interacting partners in cellular compartments. Some of them mainly sequester p53 (HSP proteins, G6PD, LONP1) or its partners (RRM2B, PRKN) in specific locations. Formation of other complexes (with ATP2A2, ATP5PO, BAX, BCL2L1, CHCHD4, PPIF, POLG, SOD2, SSBP1, TFAM) depends on p53 upregulation according to the stress level. The p53 complexes with SIRT2, MUL1, USP7, TXN, PIN1 and PPIF control regulation of p53 function through post-translational modifications, such as lysine acetylation or ubiquitination, cysteine/cystine redox transformation and peptidyl-prolyl cis-trans isomerization. Redox sensitivity of p53 functions is supported by (i) thioredoxin-dependent reduction of p53 disulfides, (ii) inhibition of the thioredoxin-dependent deoxyribonucleotide synthesis by p53 binding to RRM2B and (iii) changed intracellular distribution of p53 through its oxidation by CHCHD4 in the mitochondrial intermembrane space. Increasing knowledge on the structure, function and (patho)physiological significance of the p53 heterologous complexes will enable a fine tuning of the settings-dependent p53 programs, using small molecule regulators of specific protein–protein interactions of p53.

S100P Interacts with p53 while Pentamidine Inhibits This Interaction

S100P, a small calcium-binding protein, associates with the p53 protein with micromolar affinity. It has been hypothesized that the oncogenic function of S100P may involve binding-induced inactivation of p53. We used 1H-15N HSQC experiments and molecular modeling to study the molecular interactions between S100P and p53 in the presence and absence of pentamidine. Our experimental analysis indicates that the S100P-53 complex formation is successfully disrupted by pentamidine, since S100P shares the same binding site for p53 and pentamidine. In addition, we showed that pentamidine treatment of ZR-75-1 breast cancer cells resulted in reduced proliferation and increased p53 and p21 protein levels, indicating that pentamidine is an effective antagonist that interferes with the S100P-p53 interaction, leading to re-activation of the p53-21 pathway and inhibition of cancer cell proliferation. Collectively, our findings suggest that blocking the association between S100P and p53 by pentamidine will prevent cancer progression and, therefore, provide a new avenue for cancer therapy by targeting the S100P-p53 interaction.