Radiopotentiation of Enzalutamide Over Human Prostate Cancer Cells as Assessed by Real-Time Cell Monitoring

Barrado, M.; Blanco‐Luquin, Idoia; Andrea-Navarrete, Paola; Visus, I.; Guerrero-Setas, David; Escors, David; Kochan, Grazyna; Arias, Fernando

doi:10.1101/324889

Cited by 3 publications

(3 citation statements)

References 14 publications

(17 reference statements)

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“…Trypan Blue extraction test was used to calculate the viability of PC-3 cells exposed to the 100 μM Enzalutamide drug. PC-3 cell is androgen-independent, and Enzalutamide at low concentrations cannot cause fast damage to the cell. , That is the reason we used a high drug concentration, so the changes can be observed in several hours. Figure S5 represents the percentile viability of PC-3 cells suspended in LCB and a 100 μM Enzalutamide drug mixture.…”

Section: Resultsmentioning

confidence: 99%

Quantification of Cell Death Using an Impedance-Based Microfluidic Device

2019

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Dielectric spectroscopy is a nondestructive method to characterize dielectric properties by measuring impedance data over a frequency spectrum. This method has been widely used for various applications such as counting, sizing, and monitoring biological cells and particles. Recently, utilization of this method has been suggested in various stages of the drug discovery process due to low sample consumption and fast analysis time. In this study, we used a previously developed microfluidic system to confine single PC-3 cells in microwells using dielectrophoretic forces and perform the impedance measurements. PC-3 cells are treated with 100 μM Enzalutamide drug, and their impedance response is recorded until the cells are totally dead as predicted with viability tests. Four different approaches are used to analyze the impedance spectrum. Equivalent circuit modeling is used to extract the cell electrical properties as a function of time. Principal component analysis (PCA) is used to quantify cellular response to drug as a function of time. Single frequency measurements are conducted to observe how the cells respond over time. Finally, opacity ratio is defined as an additional quantification method. This device is capable of quantitatively measuring drug effects on biological cells and detecting cell death. The results show that the proposed microfluidic system has the potential to be used in early stages of the drug discovery process.

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Section: Resultsmentioning

confidence: 99%

Quantification of Cell Death Using an Impedance-Based Microfluidic Device

2019

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“…Although DU145 cells are not dependent on androgen for growth-related effects, they do express AR at a low level with RNA editing [23,24]. The completely AR-negative PC-3 prostate cancer cell line does not exhibit changes in proliferation, apoptosis, or other endpoints at ENZ doses of 10 μM or up to 40 μM in combination with radiotherapy [25]. Altogether, this suggests that ENZ may radiosensitize DU145 cells through the AR-pathway, which presumably still influences the repair of DNA double strand breaks, likely mediated through direct AR targeting of DNA repair genes [4,6].…”

Section: Discussionmentioning

confidence: 99%

Radiosensitization by enzalutamide for human prostate cancer is mediated through the DNA damage repair pathway

et al. 2019

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Radiation therapy is often combined with androgen deprivation therapy in the treatment of aggressive localized prostate cancer. However, castration-resistant disease may not respond to testosterone deprivation approaches. Enzalutamide is a second-generation anti-androgen with high affinity and activity that is used for the treatment of metastatic disease. Although radiosensitization mechanisms are known to be mediated through androgen receptor activity, this project aims to uncover the detailed DNA damage repair factors influenced by enzalutamide using multiple models of androgen-sensitive (LNCaP) and castration-resistant human prostate cancer (22Rv1 and DU145). Enzalutamide is able to radiosensitize both androgen-dependent and androgen-independent human prostate cancer models in cell culture and xenografts in mice, as well as a treatment-resistant patient-derived xenograft. The enzalutamide-mediated mechanism of radiosensitization includes delay of DNA repair through temporal prolongation of the repair factor complexes and halting the cell cycle, which results in decreased colony survival. Altogether, these findings support the use of enzalutamide concurrently with radiotherapy to enhance the treatment efficacy for prostate cancer.

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“…6A). Of note, PC3 cells have been reported to be resistant to enzalutamide treatment due to the absence of AR expression 42,43 , however, PC3 TBX2DN cells wherein AR expression is strongly upregulated -responded to enzalutamide treatment at higher doses (Fig. 6A).…”

Section: Tbx2 Driven Switch From Ar To Gr Signaling Confers Enzalutam...mentioning

confidence: 99%

TBX2 driven switch from Androgen Receptor to Glucocorticoid Receptor signaling confers therapeutic resistance in Prostate Cancer

Dutta

Patel

Khedmatgozar

et al. 2023

Preprint

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Recent studies have highlighted that androgen receptor (AR) signaling can be bypassed via activation of the glucocorticoid receptor (GR), and that this bypass drives enzalutamide resistance in advanced prostate cancer (PCa). However, the molecular mechanism(s) that drive the switch from AR to GR signaling remain unknown. We have previously reported that TBX2, a developmental T-box transcription factor (TF), is over-expressed in castrate resistant prostate cancer (CRPC) and that TBX2 drives the CRPC phenotype via cell-intrinsic and exosome-mediated paracrine modes. Our current study demonstrates that TBX2, a TF with known repressor and activator functions, may be the molecular switch that represses AR on one hand while activating GR expression on the other to drive CRPC. Mechanistically, our studies revealed a two-tiered mechanism of AR repression by TBX2 wherein TBX2 directly binds to the promoters of AR and GATA2, an AR coregulator, thereby resulting in the repression of AR as well as GATA2. Conversely, our results demonstrate that TBX2 mediates increased expression of GR via directly binding to the GR promoter, and through TBX2-GR functional protein-protein interaction. Our results demonstrate that the TBX2 driven switch from AR to GR signaling results in enzalutamide resistance since GR inhibition in the context of TBX2 over-expression attenuates enzalutamide resistance. Further, we present evidence that SP2509 based allosteric inhibition of Lysine Specific Demethylase 1 (LSD1), a protein that interacts with TBX2 as part of the Co-repressor of RE1-Silencing Transcription Factor (COREST) complex, is able to disrupt TBX2-GR interaction. Taken together, our study has identified TBX2 as the molecular switch that drives AR to GR signaling and thereby confers enzalutamide resistance in CRPC. Furthermore, our study provides key insights into a potential therapeutic strategy of targeting the AR to GR switch wherein SP2509-based allosteric inhibition of TBX2-LSD1 could be harnessed to target the TBX2-GR interaction, thereby resulting in the inhibition of enzalutamide resistance in CRPC.

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Radiopotentiation of Enzalutamide Over Human Prostate Cancer Cells as Assessed by Real-Time Cell Monitoring

Cited by 3 publications

References 14 publications

Quantification of Cell Death Using an Impedance-Based Microfluidic Device

Quantification of Cell Death Using an Impedance-Based Microfluidic Device

Radiosensitization by enzalutamide for human prostate cancer is mediated through the DNA damage repair pathway

TBX2 driven switch from Androgen Receptor to Glucocorticoid Receptor signaling confers therapeutic resistance in Prostate Cancer

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