Abiraterone and Ionizing Radiation Alter the Sphingolipid Homeostasis in Prostate Cancer Cells

Late Effects of Ionizing Radiation on the Ultrastructure of Hepatocytes and Activity of Lysosomal Enzymes in Mouse Liver Irradiated In Vivo

The study aimed to investigate late radiation-induced changes in the histology, ultrastructure, and activity of lysosomal enzymes in mouse liver exposed to ionizing radiation. The experiment was conducted on C57BL/6J male mice whose distal part of the liver was exposed occasionally to single doses of radiation (6 MV photons) during targeted heart irradiation; estimated doses delivered to analyzed tissue were 0.025 Gy, 0.25 Gy, 1 Gy, and 2 Gy. Tissues were collected 40 weeks after irradiation. We have observed that late effects of radiation have an adaptive nature and their intensity was dose-dependent. Morphological changes in hepatocytes included an increased number of primary lysosomes and autophagic vacuoles, which were visible in tissues irradiated with 0.25 Gy and higher doses. On the other hand, a significant increase in the activity of lysosomal hydrolases was observed only in tissues exposed to 2 Gy. The etiology of these changes may be multifactorial and result, among others, from unintentional irradiation of the distal part of the liver and/or functional interaction of the liver with an irradiated heart. In conclusion, we confirmed the presence of late dose-dependent ultrastructural and biochemical changes in mouse hepatocytes after liver irradiation in vivo.

A Brief Review of FT-IR Spectroscopy Studies of Sphingolipids in Human Cells

In recent years, sphingolipids have attracted significant attention due to their pivotal role in cellular functions and physiological diseases. A valuable tool for investigating the characteristics of sphingolipids can be represented via FT-IR spectroscopy, generally recognized as a very powerful technique that provides detailed biochemical information on the examined sample with the unique properties of sensitivity and accuracy. In the present paper, some fundamental aspects of sphingolipid components of human cells are summarized, and the most relevant articles devoted to the FT-IR spectroscopic studies of sphingolipids are revised. A short description of different FT-IR experimental approaches adopted for investigating sphingolipids is also given, with details about the most commonly used data analysis procedures. The present overview of FT-IR investigations, although not exhaustive, attests to the relevant role this vibrational technique has played in giving significant insight into many aspects of this fascinating class of lipids.

Plasma Metabolomics for Discovery of Early Metabolic Markers of Prostate Cancer Based on Ultra-High-Performance Liquid Chromatography-High Resolution Mass Spectrometry

BACKGROUND

The prevention and early screening of PCa is highly dependent on the identification of new biomarkers. In this study, we investigated whether plasma metabolic profiles from healthy males provide novel early biomarkers associated with future risk of PCa.

METHODS

Using the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort, we identified plasma samples collected from 146 PCa cases up to 13 years prior to diagnosis and 272 matched controls. Plasma metabolic profiles were characterized using ultra-high-performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS).

RESULTS

Orthogonal partial least squares discriminant analysis (OPLS-DA) discriminated PCa cases from controls, with a median area under the receiver operating characteristic curve (AU-ROC) of 0.92 using a 1000-time repeated random sub-sampling validation. Sparse Partial Least Squares Discriminant Analysis (sPLS-DA) identified the top 10 most important metabolites (p < 0.001) discriminating PCa cases from controls. Among them, phosphate, ethyl oleate, eicosadienoic acid were higher in individuals that developed PCa than in the controls during the follow-up. In contrast, 2-hydroxyadenine, sphinganine, L-glutamic acid, serotonin, 7-keto cholesterol, tiglyl carnitine, and sphingosine were lower.

CONCLUSION

Our results support the dysregulation of amino acids and sphingolipid metabolism during the development of PCa. After validation in an independent cohort, these signatures may promote the development of new prevention and screening strategies to identify males at future risk of PCa.

Abiraterone suppresses irradiated lung cancer cells-induced angiogenic capacities of endothelial cells

Non-small cell lung cancer (NSCLC) threatens human life globally with high morbidity and mortality and radiotherapy is one of the most effective methods for the treatment of NSCLC. However, it is currently reported that the angiogenesis of tumors can be induced by a low dosage of irradiation. Abiraterone is an oral anti-tumor agent for the treatment of castration-resistant prostate cancer (CRPC). In the present study, the anti-angiogenesis effect of Abiraterone against HUVECs incubated with irradiated lung cancer cell medium will be investigated. The HUVECs were incubated with a cultural medium of the NSCLC cell line-A549, Abiraterone-treated A549 cells, irradiation-treated A549 cells, and Abiraterone and irradiation co-treated A549 cells. The tolerable concentration of Abiraterone against HUVECs was determined using MTT assay. The migration and angiogenesis abilities of HUVECs were evaluated using transwell and tube formation assays, respectively. The expression levels of VEGF, MMP-2, and MMP-9 in the treated HUVECs were detected using qRT-PCR and ELISA. Western blot was used to determine the expressions of p-PI3K and p-AKT. The tolerable concentration of Abiraterone used in the present study was 50 nM. First, the migration rate and numbers of formed tubes were significantly decreased by the A549 medium treated with Abiraterone and elevated by the A549 medium treated with irradiation but greatly suppressed by the co-treatment with Abiraterone. Subsequently, VEGF, MMP-2, and MMP-9 were significantly downregulated by the A549 medium treated with Abiraterone and upregulated by the A549 medium treated with irradiation but greatly inhibited by the co-treatment with Abiraterone. Lastly, the activated PI3K/AKT signaling pathway induced by the A549 medium treated with irradiation was significantly suppressed by the A549 medium treated with both irradiation and Abiraterone. Abiraterone suppressed irradiated lung cancer cells-induced angiogenic capacities of endothelial cells.

Antiandrogen abiraterone and docetaxel treatments affect Notch1, Jagged1 and Hes1 expressions in metastatic prostate cancer cells

BACKGROUND

Prostate cancer is the most common cancer in men. A Notch signaling pathway is an important pathway in cell proliferation, differentiation, and fate. However, currently, the effects of abiraterone based-anti-androgene therapy and docetaxel, the most commonly used standard chemotherapy in prostate cancer treatment, on Notch signaling pathway are unknown. This study aimed to investigate the effects of abiraterone acetate and docetaxel on the expression of Notch1, Jagged1 and Hes1 in prostate cancer cell lines.

METHODS

In vitro effects of abiraterone acetate and docetaxel were examined on Notch1, Jagged1, and Hes1 expression in LNCaP and PC3 PCa cell lines by immunofluorescence, Western blot, and qRT-PCR. MTT proliferation assay was used to evaluate cell proliferation and survival.

RESULTS

We found that in the treatment of PC3 cells with abiraterone acetate, docetaxel, and their combination, only mRNA expressions of Notch1, Jagged1 and Hes1 were affected compared to control, but these expression differences were not observed in protein expression. In LNCaP cells, abiraterone acetate and the combination groups reduced Notch1 protein expression. All treatment groups did not alter Jagged1 expression compared to control, but significantly increased the Hes1 gene and protein expression.

CONCLUSION

Our findings suggest that abiraterone and docetaxel treatments affects the expression of Notch signal pathway proteins. But these drugs especially cause significant upregulation in Hes1 expression in PCa cells. Therefore, co-application of Notch signaling inhibitors together with docetaxel and abiraterone chemotherapy, it was thought that decreased Hes1 expression could be stopped the deterioration of the prognosis of the patient.

Role of SPTSSB-Regulated de Novo Sphingolipid Synthesis in Prostate Cancer Depends on Androgen Receptor Signaling

Anti-androgens are a common therapy in prostate cancer (PCa) targeting androgen receptor (AR) signaling. However, these therapies fail due to selection of highly aggressive AR-negative cancer cells that have no therapeutic options available. We demonstrate that elevating endogenous ceramide levels with administration of exogenous ceramide nanoliposomes (CNLs) was efficacious in AR-negative cell lines with limited efficacy in AR-positive cells. This effect is mediated through reduced de novo sphingolipid synthesis in AR-positive cells. We show that anti-androgens elevate de novo generation of sphingolipids via SPTSSB, a rate-limiting mediator of sphingolipid generation. Moreover, pharmacological inhibition of AR increases the efficacy of CNL in AR-positive cells through de novo synthesis, while SPTSSB knockdown limited CNL's efficacy in AR-negative cells. Alluding to clinical relevance, SPTSSB is upregulated in patients with advanced PCa after anti-androgens treatment. These findings emphasize the relevance of AR regulation upon sphingolipid metabolism and the potential of CNL as a PCa therapeutic.

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AR-negative PCa cells are more susceptible to CNL than AR-positive cells

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Combination of anti-androgens and CNL results in enhanced efficacy for AR-positive PCa

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AR negatively regulates the de novo synthesis of sphingolipids through SPTSSB

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SPTSSB is crucial for CNL effect in AR-negative PCa and is upregulated in neuroendocrine tumors