An exploratory study on the effect of kynurenine metabolites on sEnd-2 endothelioma cells

DATA AVAILABILITY STATEMENT : The data that support the findings of this study are available from the corresponding author upon reasonable request.Cancer is the second leading cause of mortality worldwide. The development of anticancer therapy plays a crucial role in mitigating tumour progression and metastasis. Epithelioid hemangioendothelioma is a very rare cancer, however, with a high systemic involvement. Kynurenine metabolites which include l-kynurenine, 3-hydroxykynurenine, 3-hydroxyanthranilic acid and quinolinic acid have been shown to inhibit T-cell proliferation resulting in a decrease in cell growth of natural killer cells and T cells. Furthermore, metabolites such as l-kynurenine have been shown to inhibit proliferation of melanoma cells in vitro. Considering these metabolite properties, the present study aimed to explore the in vitro effects of l-kynurenine, quinolinic acid and kynurenic acid on endothelioma sEnd-2 cells and on endothelial (EA. hy926 cells) (control cell line). The in vitro effect at 24, 48, and 72 h exposure to a range of 1−4 mM of the respective kynurenine metabolites on the two cell lines in terms of cell morphology, cell cycle progression and induction of apoptosis was assessed. The half inhibitory concentration (IC50), as determined using nonlinear regression, for l-kynurenine, quinolinic acid and kynurenic acid was 9.17, 15.56, and 535.40 mM, respectively. Optical transmitted light differential interference contrast and hematoxylin and eosin staining revealed cells blocked in metaphase, formation of apoptotic bodies and compromised cell density in l-kynurenine-treated cells. A statistically significant increase in the number of cells present in the sub-G1 phase was observed in l-kynurenine-treated sample. To our knowledge, this was the first in vitro study conducted to investigate the mechanism of action of kynurenine metabolites on endothelioma sEnd-2 cells. It can be concluded that l-kynurenine exerts an antiproliferative effect on the endothelioma sEnd-2 cell line by decreasing cell growth and proliferation as well as a metaphase block. These hallmarks suggest cell death via apoptosis. Further research will be conducted on l-kynurenine to assess the effect on cell adhesion in vitro and in vivo as cell-cell adhesion has been shown to increase metastasis to distant organs therefore, the inhibition of adhesion may lead to a decrease in metastasis.The National Research Foundation (NRF) and the University Capacity Development Programme (UCDP).https://wileyonlinelibrary.com/journal/cbfhj2024AnatomyPhysiologySDG-03:Good heatlh and well-bein

The involvement of a chemokine receptor antagonist CTCE-9908 and kynurenine metabolites in cancer development

Cancer is the second leading cause of mortality worldwide. Skin cancer is the most common cancer in South Africa with nearly 20,000 reported cases every year and 700 deaths. If diagnosed early, the 5‐year survival rate is about 90%, however, when diagnosed late, the 5‐year survival rate decreases to about 20%. Melanoma is a type of skin cancer with an estimated 5‐year survival rate of approximately 90%. Neuroblastoma is a paediatric cancer with a low survival rate. Sixty percent of patients with metastatic disease do not survive 5 years after diagnosis. Despite recent advances in targeted therapies, there is a crucial need to identify reliable prognostic biomarkers which will be able to contribute to the development of more precision‐based chemotherapeutic strategies to prevent tumour migration and metastasis. The compound, CTCE‐9908 inhibits the binding of CXC chemokine ligand 12 (CXCL12) to the CXC chemokine receptor 4 (CXCR4) receptor leading to reduced metastasis. Kynurenine metabolites are derived tryptophan, which is an essential amino acid. Kynurenine metabolites inhibit T‐cell proliferation resulting in cell growth arrest. For this reason, chemokines receptors represent potential targets for the treatment of cancer growth and metastasis. In this review paper, the role of the CXCL12/CXCR4 signalling pathway in the development of cancer is highlighted together with the current available treatments involving the CTCE‐9908 compound in combination with microtubule inhibitors like paclitaxel and docetaxel.The National Research Foundation, Struwig‐ Germeshuysen Research Trust, the Medical Research Council of South Africa, the Cancer Association of South Africa, the School of Medicine Research Committee of the Faculty of Health Sciences , the Research Development Programme and the University Capacity Development Programme at the University of Pretoria.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-0844am2023AnatomyPhysiolog

In vitro changes in mitochondrial potential, aggresome formation and caspase activity by a novel 17-beta-estradiol analogue in breast adenocarcinoma cells

2-Methoxyestradiol, a natural metabolite of estradiol, exerts antiproliferative and antitumour properties in vitro and in vivo. Because of its low oral bioavailability, several promising analogues of 2-methoxyestradiol have been developed. In this study, the in vitro influence of the compound, 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (C19), a non-commercially available 17-b-estradiol analogue, was tested on the breast adenocarcinoma MCF-7 cell line. The in vitro influence of 24 h exposure to 0.18 mM of C19 on MCF-7 cells was evaluated on cell morphology, cell cycle progression and possible induction of apoptosis and autophagy. Polarization-optical transmitted light differential interference contrast and fluorescence microscopy revealed the presence of cells blocked in metaphase, occurrence of apoptotic bodies and compromised cell density in C19-treated cells. Hallmarks of autophagy, namely an increase in the number of acidic vacuoles and lysosomes, were also observed in C19-treated samples. An increase in the number of cells present in the sub-G1 fraction, as well as a reduction in mitochondrial membrane potential was observed. No significant alterations in caspase 8 activity were observed. A twofold increase in aggresome formation was observed in C19-treated cells. C19 induced both apoptosis and autophagy in MCF-7 cells.The Medical Research Council of South Africa (AK076; AL343), the Cancer Association of South Africa (AK246), RESCOM, School of Medicine (Faculty of Health Sciences, University of Pretoria), the National Research Foundation of South Africa (AL239) and the Struwig-Germeshuysen Cancer Research Trust of South Africa (AN074). The Bioinformatics and Computational Biology Unit (University of Pretoria) contributed to the in silico-design of the compound.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-0844hb2013ay201

A novel 2-methoxyestradiol analogue is responsible for vesicle disruption and lysosome aggregation in breast cancer cells

BACKGROUND : 2-Methoxyestradiol (2ME2) is an endogenous metabolite of 17-β-estradiol with anti-proliferative and anti-angiogenic properties. Due to 2ME2’s rapid metabolism and low oral bioavailability in in vivo settings, 2ME2 analogues have been designed to alleviate these issues. One of these compounds is 2-ethyl-3-O-sulphamoyl-estra-1,3,5(10)16-tetraene (ESE-16). A previous work alluded to the ability of ESE-16 to induce autophagic cell death. Therefore, we investigated the mode of action of ESE-16 by studying its effects on autophagy, vesicle formation, and lysosomal organisation. SUMMARY : Vesicle formation and autophagy induction were analysed by transmission electron microscopy (TEM), monodansylcadaverine (MDC) staining and Lysotracker staining, while autophagosome turnover was analysed using microtubule-associated protein 1A/1B-light chain 3 (LC3 lipidation) analysis. MDC staining of acidic vesicles revealed an increase both in the number and size of vesicles after ESE-16 exposure. This was confirmed by TEM. Lysotracker staining indicated an increase in the size of lysosomes, as well as changes in their distribution within the cell. However, autophagy was not induced, since LC3 lipidation did not increase after exposure to ESE-16. KEY MESSAGES : This study showed that ESE-16 exposure leads to the aggregation of acidic vesicles, identified as lysosomes, not accompanied by an induction of autophagy. Therefore, ESE-16 disrupts normal endocytic vesicle maturation likely through the inhibition of the microtubule function.Grants awarded to Prof AM Joubert from the Medical Research Council of South Africa (AOS536, AOW110, AK076; AL343), the Cancer Association of South Africa (AOW228, A0V741, AK246), RESCOM, School of Medicine (Faculty of Health Sciences, University of Pretoria), the National Research Foundation of South Africa (N00375, AL239) and the Struwig-Germeshuysen Cancer Research Trust of South Africa (AN074).https://www.karger.com/PHA2019-04-19hj2018Physiolog