Effect of the phenylpyrrole fungicide fludioxonil on cell proliferation and cardiac differentiation in mouse embryonic stem cells

Exploring comprehensive toxic effects of fludioxonil on Caenorhabditis elegans

Fludioxonil is a phenylpyrrole fungicide widely used in agriculture. Despite its efficacy against target fungi, there have been concerns raised regarding the potential adverse effects on non-target organisms. This study assesses its toxicity effects on Caenorhabditis elegans (C. elegans) across physiological, cellular, neuronal, and behavioral dimensions. At the physiological level, fludioxonil significantly reduces the growth, lifespan, and reproductive capacity of C. elegans, indicating disruptive effects on overall organismal health. At the cellular level, fludioxonil elevates reactive oxygen species (ROS), which can result in oxidative stress. At the neuronal level, fludioxonil induces dopaminergic neurodegeneration and upregulates critical neurotransmission genes dat-1 and unc-47, which affects the nervous system. At the behavioral level, C. elegans exposed to fludioxonil exhibits increased locomotion and abnormal behaviors. These findings collectively demonstrate that fludioxonil exerts multifaceted toxic effects on non-target organisms, challenging the assumption of its safety and suggesting significant implications for ecosystem health and safety regulations.

A Fungicide, Fludioxonil, Formed the Polyploid Giant Cancer Cells and Induced Metastasis and Stemness in MDA-MB-231 Triple-Negative Breast Cancer Cells

Fludioxonil, an antifungal agent used as a pesticide, leaves a measurable residue in fruits and vegetables. It has been identified to cause endocrine disruption, interrupt normal development, and cause various diseases such as cancers. In this study, fludioxonil was examined for its effects on the development and metastasis of breast cancer cells. On fludioxonil exposure (10-5 M) for 72 h, mutant p53 (mutp53) MDA-MB-231 triple-negative breast cancer (TNBC) cells significantly inhibited cell viability and developed into polyploid giant cancer cells (PGCCs), with an increase in the number of nuclei and expansion in the cell body size. Fludioxonil exposure disrupted the normal cell cycle phase ratio, resulting in a new peak. In addition, PGCCs showed greater motility than the control and were resistant to anticancer drugs, i.e., doxorubicin, cisplatin, and 5-fluorouracil. Cyclin E1, nuclear factor kappa B (NF-κB), and p53 expressions were remarkably increased, and the expression of cell cycle-, epithelial-mesenchymal-transition (EMT)-, and cancer stemness-related proteins were increased in the PGCCs. The daughter cells obtained from PGCCs had the single nucleus but maintained their enlarged cell size and showed greater cell migration ability and resistance to the anticancer agents. Consequently, fludioxonil accumulated Cyclin E1 and promoted the inflammatory cytokine-enriched microenvironment through the up-regulation of TNF and NF-κB which led to the transformation to PGCCs via abnormal cell cycles such as mitotic delay and mitotic slippage in mutp53 TNBC MDA-MB-231 cells. PGCCs and their daughter cells exhibited significant migration ability, chemo-resistance, and cancer stemness. These results strongly suggest that fludioxonil, as an inducer of potential genotoxicity, may induce the formation of PGCCs, leading to the formation of metastatic and stem cell-like breast cancer cells.

Fludioxonil induces cardiotoxicity via mitochondrial dysfunction and oxidative stress in two cardiomyocyte models

Fludioxonil (Flu) is a phenylpyrrole fungicide and is currently used in over 900 agricultural products globally. Flu possesses endocrine-disrupting chemical-like properties and has been shown to mediate various physiological and pathological changes, such as apoptosis and differentiation, in diverse cell lines. However, the effects of Flu on cardiomyocytes have not been studied so far. The present study investigated the effects of Flu on mitochondria in AC16 human cardiomyocytes and H9c2 rat cardiomyoblasts. Flu decreased cell viability in a water-soluble tetrazolium assay and mediated morphological changes suggestive of apoptosis in AC16 and H9c2 cells. We confirmed that annexin V positive cells were increased by Flu through annexin V/propidium iodide staining. This suggests that the decrease in cell viability due to Flu may be associated with increased apoptotic changes. Flu consistently increased the expression of pro-apoptotic markers such as Bcl-2-associated X protein (Bax) and cleaved-caspase 3. Further, Flu reduced the oxygen consumption rate (OCR) in AC16 and H9c2 cells, which is associated with decreased mitochondrial membrane potential (MMP) as observed through JC-1 staining. In addition, Flu augmented the production of mitochondrial reactive oxygen species, which can trigger oxidative stress in cardiomyocytes. Taken together, these results indicate that Flu induces mitochondrial dysregulation in cardiomyocytes via the downregulation of the OCR and MMP and upregulation of the oxidative stress, consequently resulting in the apoptosis of cardiomyocytes. This study provides evidence of the risk of Flu toxicity on cardiomyocytes leading to the development of cardiovascular diseases and suggests that the use of Flu in agriculture should be done with caution and awareness of the probable health consequences of exposure to Flu.

Evaluation of the effect of boron derivatives on cardiac differentiation of mouse pluripotent stem cells

BACKGROUND

The heart is one of the first organs to form during embryonic development and has a very important place. So much that the formation of a functional heart is completed on the 55th day of human development and the 15th day of mouse development. Myocardial, endocardial and epicardial cells, which are derived from the mesoderm layer, are the cells that form the basis of the heart. Cardiac development, like other embryonic developments, is tightly controlled and regulated by various signaling pathways. The WNT signaling pathway is the most studied of these signaling pathways and the one with the clearest relationship with heart development. It is known that boron compounds and the Wnt/β-catenin pathway are highly correlated. Therefore, this study aimed to investigate the role of boron compounds in heart development as well as its effect on pluripotency of mouse embryonic stem cells for the first time in the literature.

METHODS

Toxicity of boron compounds was evaluated by using MTS analysis and obtained results were supported by morphological pictures, Trypan Blue staining and Annexin V staining. Additionally, the possible boron-related change in pluripotency of embryonic stem cells were analyzed with alkaline phosphatase activity and immunocytochemical staining of Oct4 protein as well as gene expression levels of pluripotency related OCT4, SOX2 and KLF4 genes. The alterations in the embryonic body formation capacity of mouse embryonic stem cells due to the application boron derivatives were also evaluated. Three linage differentiation was conducted to clarify the real impact of boron compounds on embryonic development. Lastly, cardiac differentiation of mESCs was investigated by using morphological pictures, cytosolic calcium measurement, gene expression and immunocytochemical analysis of cardiac differentiation related genes and in the presence of boron compounds.

RESULTS

Obtained results show that boron treatment maintains the pluripotency of embryonic stem cells at non-toxic concentrations. Additionally, endodermal, and mesodermal fate was found to be triggered after boron treatment. Also, initiation of cardiomyocyte differentiation by boron derivative treatments caused an increased gene expression levels of cardiac differentiation related TNNT2, Nkx2.5 and ISL-1 gene expression levels.

CONCLUSION

This study indicates that boron application, which is responsible for maintaining pluripotency of mESCs, can be used for increased cardiomyocyte differentiation of mESCs.

Combination of Tipifarnib and Sunitinib Overcomes Renal Cell Carcinoma Resistance to Tyrosine Kinase Inhibitors via Tumor-Derived Exosome and T Cell Modulation

Simple Summary

Metastatic renal cell carcinoma continues to have a poor prognosis. Chemotherapies and immuno-oncologic therapies have garnered increasing importance in cancer therapy, with improvements in patient care and survival. However, a large proportion of patients present with tumors resistant to these treatments. Exosomes are small extracellular vesicles secreted by all nucleated cells that have proven to be key actors in this resistance. Exosomes carry bioactive oncogenic cargos that reprogram target cells to promote tumor growth, migration, metastasis, immune evasion, and chemotherapy resistance. Tipifarnib, in combination with standard therapy, decreased tumor growth in the setting of chemotherapeutic resistance through an exosome-mediated mechanism. After using a qNANO IZON system to compare tumor-derived exosomes collected from untreated and tipifarnib-treated cells, all cancerous cell lines displayed a reduction of vesicle concentration. Tipifarnib also directly inhibited PD-L1 protein expression in chemo-sensitive cell lines and resistant cell lines.

Abstract

Background: Tyrosine kinase inhibitors (TKI) were initially demonstrated as an efficacious treatment for renal cell carcinoma (RCC). However, after a median treatment length of 14 months, a vast majority of patients develop resistance. This study analyzed a combination therapy of tipifarnib (Tipi) + sunitinib that targeted exosome-conferred drug resistance. Methods: 786-O, 786-O-SR (sunitinib resistant), A498, A498-SR, Caki-2, Caki-2-SR, and 293T cells were cultured. Exosomes were collected using differential ultracentrifugation. Cell proliferation, Jurkat T cell immune assay, and immunoblot analysis were used for downstream analysis. Results: SR exosomes treatment displayed a cytotoxic effect on immune cells. This cytotoxic effect was associated with increased expression of PD-L1 on SR exosomes when compared to sunitinib-sensitive (SS) exosomes. Additionally, Tipi treatment downregulated PD-L1 expression on exosomes derived from SR cell lines. Tipi’s ability to downregulate PD-L1 in exosomes has a significant application within patients. Exosomes collected from patients with RCC showed increased PD-L1 expression over subjects without RCC. Next, exosome concentrations were then compared after Tipi treatment, with all SS cell lines displaying an even greater reduction. On immunoblot assay, 293T cells showed a dose-dependent increase in Alix with no change in either nSMase or Rab27a. Conversely, all the SS and SR cell lines displayed a decrease in all three markers. After a cell proliferation employed a 48-h treatment on all SS and SR cell lines, the drug combination displayed synergistic ability to decrease tumor growth. Conclusions: Tipifarnib attenuates both the exosome endosomal sorting complex required for endosomal sorting complex required for transport (ESCRT)-dependent and ESCRT-independent pathways, thereby blocking exosome biogenesis and secretion as well as downregulating PD-L1 on SS and SR cells.