PC-3 Prostate Cancer Research Articles

Glucose Upregulates ChREBP via Phosphorylation of AKT and AMPK to Modulate MALT1 and WISP1 Expression.

Glucose can activate the carbohydrate response element binding protein (ChREBP) transcription factor to control gene expressions in the metabolic pathways. The way of ChREBP involvement in human prostate cancer development remains undetermined. This study examined the interactions between prostate fibroblasts and cancer cells under the influences of ChREBP. Results showed that high glucose (30 mM) increased the phosphorylation of AKT at S473 and AMP-activated protein kinase (AMPK) at S485 in human prostate fibroblast (HPrF) cells and prostate cancer PC-3 cells. High glucose enhanced the expression of ChREBP, which increased the expressions of fibronectin, alpha-smooth muscle actin (α-SMA), and WNT1 inducible signaling pathway protein 1 (WISP1), magnifying the cell growth and contraction in HPrF cells in vitro. The cell proliferation, invasion, and tumor growth in prostate cancer PC-3 cells were enhanced by inducing the expressions of ChREBP, mucosa-associated lymphoid tissue 1 (MALT1), and epithelial-mesenchymal transition markers with high glucose treatment. Moreover, ectopic ChREBP overexpression induced NF-κB signaling activities via upregulating MALT1 expression in PC-3 cells. Our findings illustrated that ChREBP is an oncogene in the human prostate. High glucose condition induces a glucose/ChREBP/MALT1/NF-κB axis which links the glucose metabolism to the NF-κB activation in prostate cancer cells, and a glucose/ChREBP/WISP1 axis mediating autocrine and paracrine signaling between fibroblasts and cancer cells to promote cell migration, contraction, growth, and invasion of the human prostate.

Talaketides A−G, linear polyketides with prostate cancer cytotoxic activity from the mangrove sediment-derived fungus Talaromyces sp. SCSIO 41027

Seven novel linear polyketides, talaketides A−G (1−7), were isolated from the rice media cultures of the mangrove sediment-derived fungus Talaromyces sp. SCSIO 41027. Among these, talaketides A−E (1−5) represented unprecedented unsaturated linear polyketides with an epoxy ring structure. The structures, including absolute configurations of these compounds, were elucidated through detailed analyses of nuclear magnetic resonance (NMR) and high-resolution mass spectrometry (HR-MS) data, as well as electronic custom distributors (ECD) calculations. In the cytotoxicity screening against prostate cancer cell lines, talaketide E (5) demonstrated a dose-dependent inhibitory effect on prostate cancer PC-3 cell lines, with an IC50 value of 14.44 μmol·L−1 . Moreover, compound 5 significantly inhibited the cloning formation of PC-3 cell lines and arrested the cell cycle in S-phase, ultimately inducing apoptosis. These findings indicate that compound 5 may serve as a promising lead compound for the development of a potential treatment for prostate cancer.

Discovery of the first selective and potent PROTAC degrader for the pseudokinase TRIB2

Pseudokinase TRIB2, a member of the CAMK Ser/Thr protein kinase family, regulates various cellular processes through phosphorylation-independent mechanisms. Dysregulation of TRIB2 has been implicated in promoting tumor growth, metastasis, and therapy resistance, making it a promising target for cancer treatment. In this study, we designed and synthesized a series of TRIB2 PROTAC degraders by conjugating a TRIB2 binder 1 with VHL or CRBN ligands via linkers of varying lengths and compositions. Among these compounds, 5k demonstrated potent TRIB2 degradation with a DC50 value of 16.84 nM (95 % CI: 13.66–20.64 nM) in prostate cancer PC3 cells. Mechanistic studies revealed that 5k directly interacted with TRIB2, selectively inducing its degradation through a CRBN-dependent ubiquitin-proteasomal pathway. Moreover, 5k outperformed the TRIB2 binder alone in inhibiting cell proliferation and inducing apoptosis, confirming that TRIB2 protein degradation could be a promising therapeutic strategy for TRIB2-associated cancers. Additionally, compound 5k also serves as an effective tool for probing TRIB2 biology.

Antagonist of Growth Hormone-Releasing Hormone Receptor MIA-690 Suppresses the Growth of Androgen-Independent Prostate Cancers

The development of resistance remains the primary challenge in treating castration-resistant prostate cancer (CRPC). GHRH receptors (GHRH-R), which are coupled to G-proteins (GPCRs), can mediate EGFR transactivation, offering an alternative pathway for tumour survival. This study aimed to evaluate the effects of the GHRH-R antagonist MIA-690, in combination with the EGFR inhibitor Gefitinib, on cell viability, adhesion, gelatinolytic activity, and the cell cycle in advanced prostate cancer PC-3 cells. The findings demonstrate a synergistic effect between MIA-690 and Gefitinib, leading to the inhibition of cell viability, adhesion, and metalloprotease activity. Cell cycle analysis suggests that both compounds induce cell cycle arrest, both individually and in combination. Furthermore, similar effects of the GHRH-R antagonist MIA-690 combined with Gefitinib were observed in PC-3 tumours developed by subcutaneous injection in athymic nude mice 36 days post-inoculation. These results indicate that combined therapy with a GHRH-R antagonist and an EGFR inhibitor exerts a stronger antitumor effect compared to monotherapy by preventing transactivation between EGFR and GHRH-R in CRPC.

The inhibition effect of psoralen on prostate cancer PC3 cells via down-regulation of long non-coding RNA ENST00000510619.

New medications are needed to improve outcomes of castration-resistant prostate cancer (CRPC). Psoralen has been reported to have anti-cancer properties for various tumors, but there are limited reports about psoralen treatment in prostate cancer (PCa). This study aimed to investigate the effect of psoralen on PC3 cells and to investigate potential underlying mechanisms of action. The effect of psoralen on the proliferation and cell cycle progression of PC3 cells was determined using Cell Counting Kit-8 (CCK-8) test and flow cytometry, respectively. The differential gene profiles in PC3 cells treated with psoralen were determined with microarray analyses. The effect of psoralen on long non-coding RNA (lncRNA) ENST00000510619 expression in PC3 cells was detected by real-time quantitative polymerase chain reaction (RT-qPCR). The effect of psoralen and transfection of small interfering lnc-RNA (si-lncRNA) ENST00000510619 on cell viability, invasion ability, and migratory activity of PC3 cells were evaluated using the CCK-8 test, transwell assay, and wound healing, respectively. Psoralen significantly inhibited PC3 cells in a concentration- and time-dependent manner and caused G1 phase and G2/M phase cycle arrests. When screened with a fold change (FC) of ≥2 and a P value of <0.05, 1,716 lncRNAs and 1,160 messenger RNAs (mRNAs) were significantly up-regulated, whereas 3,269 lncRNAs and 3,263 mRNAs were significantly down-regulated in PC3 cells after psoralen treatment. Among the differentially down-regulated lncRNAs in which the signal of the probe showed significant differences compared to the background, lncRNA ENST00000510619 had the highest FC. The expression of lncRNA ENST00000510619 was shown to be down-regulated by psoralen in a concentration-dependent manner. CCK-8 assay, wound healing, and transwell assay showed that both psoralen and si-lncRNA ENST00000510619 transfection significantly inhibited the activity, invasion, and migration of PC3 cells (P<0.01 for all). Psoralen was confirmed to inhibit proliferation and block the cell cycle in PC3 cells in this in vitro study. The molecular mechanism involves multiple differentially expressed lncRNAs and mRNAs and is related to the down-regulation of lncRNA ENST000000510619 expression. This study provides the experimental basis for the development of psoralen as a novel anti-CRPC drug and for the consideration of lncRNA ENST00000510619 as a potential clinical target for CRPC.

Design, Synthesis, and Biological Evaluation of Potent EZH2/LSD1 Dual Inhibitors for Prostate Cancer.

As histone modification enzymes, EZH2 mediates H3K27 trimethylation (H3K27me3), whereas LSD1 removes methyl groups from H3K4me1/2 and H3K9me1/2. Synergistic anticancer effects of combining inhibitors of these two enzymes are observed in leukemia and prostate cancer. Thus, a series of EZH2/LSD1 dual inhibitors are designed and synthesized to evaluate their anticancer activity. After the structure-activity study, one of the best compounds, ML234, displayed excellent antiproliferative capacity against prostate cancer cell lines LNCAP, PC3, and 22RV1. Enzymatic assays ascertained that the anticancer potency of ML234 was mediated through coinhibition of EZH2 and LSD1. Moreover, the accumulation of H3K4me2 and H3K9me2 and the decrease of H3K27me3 induced by ML234 were verified by Western blot analysis. More importantly, the compound remarkably suppressed the tumor growth and enhanced the therapeutic efficacy of clinical drug enzalutamide in the 22RV1 xenograft mouse model, indicating that it may have potential as an anticancer agent in prostate cancer.

Novel coumarin-6-sulfonamide-chalcone hybrids as glutathione transferase P1-1 inhibitors.

Multidrug resistance (MDR) mechanisms in cancer cells are greatly influenced by glutathione transferase P1-1 (hGSTP1-1). The use of synthetic or natural compounds as hGSTP1-1 inhibitors is considered an effective approach to overcome MDR. Nine compounds consisting of coumarin-6-sulfonamide linked to chalcone derivatives were synthesized and evaluated for their ability to inhibit hGSTP1-1. Among the synthetic derivatives, compounds 5g, 5f, and 5a displayed the most potent inhibitory effect, with IC50 values of 12.2 ± 0.5 μΜ, 12.7 ± 0.7 and 16.3 ± 0.6, respectively. Kinetic inhibition analysis of the most potent molecule, 5g, showed that it behaves as a mixed-type inhibitor of the target enzyme. An in vitro cytotoxicity assessment of 5a, 5f, and 5g against the human prostate cancer cell lines DU-145 and PC3, as well as the breast cancer cell line MCF-7, demonstrated that compound 5g exhibited the most pronounced cytotoxic effect on all tested cell lines. Molecular docking studies were performed to predict the structural and molecular determinants of 5g, 5f, and 5a binding to hGSTP1-1. In agreement with the experimental data, the results revealed that 5g exhibited the lowest docking score among the three studied inhibitors as a consequence of shape complementarity, governed by van der Waals, hydrogen bonds and a π-π stacking interaction. These findings suggest that coumarin-chalcone hybrids offer new perspectives for the development of safe and efficient natural product-based sensitizers that can target hGSTP1-1 for anticancer purposes.

Exploring a Novel Role of Glycerol Kinase 1 in Prostate Cancer PC-3 Cells.

Clinically, prostate cancer is infamous for its histological and molecular heterogeneity, which causes great challenges to pinpoint therapy and pharmaceutical development. To overcome these difficulties, researchers are focusing on modulating tumor microenvironment and immune responses in addition to genetic alteration and epigenetic regulation. Here, we aimed to identify potential biomarkers or modulators of prostate cancer by investigating genes specifically altered in prostate cancer cells treated with established anti-cancer agents. Glycerol kinase 1 (GK1) is phosphotransferase encoded on the X chromosome, is associated with the synthesis of triglycerides and glycerophospholipids, and has been mainly studied for X-linked metabolic disorder GK deficiency (GKD). Interestingly, our DNA microarray analysis showed that several anti-cancer agents highly induced the expression of GK1, especially GK1a and GK1b isoforms, in human prostate cancer PC-3 cells. To elucidate the relationship between GK1 and cancer cell death, a human GK1b-specific expression vector was constructed and transfected into the PC-3 cells. Surprisingly, GK1b overexpression dramatically reduced cell viability and significantly accelerated apoptotic cell death. These findings suggest that GK1b may serve as a promising modulator and biomarker of cell death in prostate cancer, offering potential avenues for therapeutic intervention.

Green synthesis of zinc oxide nanoparticles from Wodyetia bifurcata fruit peel extract: multifaceted potential in wound healing, antimicrobial, antioxidant, and anticancer applications.

This study focuses on the synthesis, characterization, and use of zinc oxide nanoparticles (ZnONPs) derived from W. bifurcata fruit peel extract. ZnONPs are frequently synthesized utilizing a green technique that is both cost-effective and ecologically friendly. ZnONPs were characterized utilizing analytical techniques. Ultra Violet visible (UV-Vis) spectra showed peaks at 364nm, confirming the production of ZnONPs. Scanning Electron Microscope analysis indicated that the nanoparticles generated were spherical/agglomerated, with diameters ranging from 11 to 25nm. FTIR spectroscopy was used to identify the particular functional groups responsible for the nanoparticles' reduction, stabilization, and capping. Phytochemical analysis of the extract revealed that flavonoids, saponins, steroids, triterpenoids, and resins were present. The antibacterial activity of W. bifurcata synthesised nanoparticles was evaluated against pathogenic bacteria. The ZnONPs antioxidant activity was assessed using DPPH assay. The in vitro cytotoxicity was assessed against prostate cancer PC3 cells. The wound healing potential was assessed by employing in vitro scratch assay and in vivo excision model in Wistar rats. Because of its environmentally benign production, low toxicity, and biocompatibility, ZnONPs exhibited potential antibacterial, antioxidant, anticancer, and wound healing activities, indicating that they could be used in cancer treatment and wound management. Further study is required to examine the fundamental mechanisms and evaluate the safety and effectiveness of the test sample in clinical situations.

Unveiling the potential of isatin-grafted phenyl-1,2,3-triazole derivatives as dual VEGFR-2/STAT-3 inhibitors: Design, synthesis and biological assessments

The use of VEGFR-2 inhibitors as a stand-alone treatment has proven to be ineffective in clinical trials due to the robustness of cellular response loops that lead to treatment resistance when only targeting VEGFR-2. The over-activation of the signal transducer/activator of transcription 3 (STAT-3) is expected to significantly impact treatment failure and resistance to VEGFR-2 inhibitors. In this study, we propose the concept of combined inhibition of VEGFR-2 and STAT-3 to combat induced STAT-3-mediated resistance to VEGFR-2 inhibition therapy. To explore this, we synthesized new isatin-grafted phenyl-1,2,3-triazole derivatives “6a-n” and “9a-f”. Screening on PANC1 and PC3 cancer cell lines revealed that compounds 6b, 6 k, 9c, and 9f exhibited sub-micromolar ranges. The most promising molecules, 6b, 6 k, 9c, and 9f, demonstrated the highest inhibition when tested as dual inhibitors on VEGFR-2 (with IC50 range 53–82 nM, respectively) and STAT-3 (with IC50 range 5.63–10.25 nM). In particular, triazole 9f showed the best results towards both targets. Inspired by these findings, we investigated whether 9f has the ability to trigger apoptosis in prostate cancer PC3 cells via the assessment of the expression levels of the apoptotic markers Caspase-8, Bcl-2, Bax, and Caspase-9. Treatment of the PC3 cells with compound 9f significantly inhibited the protein expression levels of VEGFR-2 and STAT-3 kinases compared to the control.

In vitro study on the anticancer effects of oxalipalladium against PC3 human prostate carcinoma cells

Prostate cancer is a common type of cancer in men with high incidence and mortality. Our aim was to investigate the effects of oxalipalladium (ox-Pd) on metastatic human prostate cancer PC3 cells and compare them with the effects of oxaliplatin (ox-Pt) (as an approved cancer drug). We synthesized ox-Pd through a new chemical method and used FT-IR, 1H NMR, 13C NMR, and MS analyzes to characterize it. The effects of ox-Pd on PC3 cells viability, apoptosis, cell cycle, migration, and gene expression were examined. Inhibition of topoisomerase IIα activity was investigated by pHOT1 plasmid relaxation and kDNA decatenation assays. Chemical tests showed ox-Pd with the correct composition and structure. For the first time, the exact fragmentation pathway of ox-Pd and its difference with ox-Pt was obtained by MS analysis. Ox-Pd significantly decreased PC3 cell viability with less/no toxicity effect on MHFB-1 normal skin fibroblasts. Wound scratch assay confirmed the strong anti-migratory activity of ox-Pd. According to flow cytometry analysis, this drug increased the number of PC3 cells in late apoptosis and decreased DNA replication and mitosis. Furthermore, pHOT1 plasmid relaxation and kDNA decatenation assays showed that ox-Pd strongly inhibited the catalytic activity of topoisomerase IIα. The expression of topoisomerase IIα, Bcl-2, P21, and survivin was decreased while the expression of Bax and p53 was increased under ox-Pd treatment. We provide the first evidence that ox-Pd exhibits more selective anticancer effects on PC3 cells compared to ox-Pt. Taken together, these data strongly suggest a therapeutic window for ox-Pd in cancer.

Quantitative analysis of radiosensitizing effect for magnetic hyperthermia-radiation combined therapy on prostate cancer cells.

Magnetic hyperthermia (MHT) has emerged as a promising therapeutic approach in the field of radiation oncology due to its superior precision in controlling temperature and managing the heating area compared to conventional hyperthermia. Recent studies have proposed solutions to address clinical safety concerns associated with MHT, which arise from the use of highly concentrated magnetic nanoparticles and the strong magnetic field needed to induce hyperthermic effects. Despite these efforts, challenges remain in quantifying therapeutic outcomes and developing treatment plan systems for combining MHTwith radiation therapy (RT). This study aims to quantitatively measure the therapeutic effect, including radiation dose enhancement (RDE) in the magnetic hyperthermia-radiation combined therapy (MHRT), using the equivalent radiation dose (EQD) estimation method. To conduct EQD estimation for MHRT, we compared the therapeutic effects between the conventional hyperthermia-radiation combined therapy (HTRT) and MHRT in human prostate cancer cell lines, PC3 and LNCaP. We adopted a clonogenic assay to validate RDE and the radiosensitizing effect induced by MHT. The data on survival fractions were analyzed using both the linear-quadradic model and Arrhenius model to estimate the biological parameters describing RDE and radiosensitizing effect of MHRT for both cell lines through maximum likelihood estimation. Based on these parameters, a new survival fraction model was suggested forEQD estimation of MHRT. The newly designed model describing the MHRT effect, effectively captures the variations in thermal and radiation dose for both cell lines (R2>0.95), and its suitability was confirmed through the normality test of residuals. This model appropriately describes the survival fractions up to 10Gy for PC3 cells and 8Gy for LNCaP cells under RT-only conditions. Furthermore, using the newly defined parameter r, the RDE effect was calculated as 29% in PC3 cells and 23% in LNCaP cells. EQDMHRT calculated through this model was 9.47Gy for PC3 and 4.71Gy for LNCaP when given 2Gy and MHT for 30 min. Compared to EQDHTRT, EQDMHRT showed a 26% increase for PC3 and a 20% increase for LNCaP. The proposed model effectively describes the changes of the survival fraction induced by MHRT in both cell lines and adequately represents actual data values through residual analysis. Newly suggested parameter r for RDE effect shows potential for quantitative comparisons between HTRT and MHRT, and optimizing therapeutic outcomes in MHRT for prostate cancer.

New piperazine derivatives helvamides B–C from the marine-derived fungus Penicillium velutinum ZK-14 uncovered by OSMAC (One Strain Many Compounds) strategy

Four extracts of the marine-derived fungus Penicillium velutinum J.F.H. Beyma were obtained via metal ions stress conditions based on the OSMAC (One Strain Many Compounds) strategy. Using a combination of modern approaches such as LC/UV, LC/MS and bioactivity data analysis, as well as in silico calculations, influence metal stress factors to change metabolite profiles Penicillium velutinum were analyzed. From the ethyl acetate extract of the P. velutinum were isolated two new piperazine derivatives helvamides B (1) and C (2) together with known saroclazin A (3) (4S,5R,7S)-4,11-dihydroxy-guaia-1(2),9(10)-dien (4). Their structures were established based on spectroscopic methods. The absolute configuration of helvamide B (1) as 2R,5R was determined by a combination of the X-ray analysis and by time-dependent density functional theory (TD-DFT) calculations of electronic circular dichroism (ECD) spectra. The cytotoxic activity of the isolated compounds against human prostate cancer PC-3 and human embryonic kidney HEK-293 cells and growth inhibition activity against yeast-like fungi Candida albicans were assayed.Graphical

Natural compound Alternol actives multiple endoplasmic reticulum stress-responding pathways contributing to cell death.

Background: Alternol is a small molecular compound isolated from the fermentation of a mutant fungus obtained from Taxus brevifolia bark. Our previous studies showed that Alternol treatment induced reactive oxygen species (ROS)-dependent immunogenic cell death. This study conducted a comprehensive investigation to explore the mechanisms involved in Alternol-induced immunogenic cell death. Methods: Prostate cancer PC-3, C4-2, and 22RV1 were used in this study. Alternol interaction with heat shock proteins (HSP) was determined using CETSA assay. Alternol-regulated ER stress proteins were assessed with Western blot assay. Extracellular adenosine triphosphate (ATP) was measured using ATPlite Luminescence Assay System. Results: Our results showed that Alternol interacted with multiple cellular chaperone proteins and increased their expression levels, including endoplasmic reticulum (ER) chaperone hypoxia up-regulated 1 (HYOU1) and heat shock protein 90 alpha family class B member 1 (HSP90AB1), as well as cytosolic chaperone heat shock protein family A member 8 (HSPA8). These data represented a potential cause of unfolded protein response (UPR) after Alternol treatment. Further investigation revealed that Alternol treatment triggered ROS-dependent (ER) stress responses via R-like ER kinase (PERK), inositol-requiring enzyme 1α (IRE1α). The double-stranded RNA-dependent protein kinase (PKR) but not activating transcription factor 6 (ATF6) cascades, leading to ATF-3/ATF-4 activation, C/EBP-homologous protein (CHOP) overexpression, and X-box binding protein XBP1 splicing induction. In addition, inhibition of these ER stress responses cascades blunted Alternol-induced extracellular adenosine triphosphate (ATP) release, one of the classical hallmarks of immunogenic cell death. Conclusion: Taken together, our data demonstrate that Alternol treatment triggered multiple ER stress cascades, leading to immunogenic cell death.

Synthesis and Evaluation of Novel 68Ga-Labeled [D-Phe6,Leu13ψThz14]bombesin(6-14) Analogs for Cancer Imaging with Positron Emission Tomography.

Gastrin-releasing peptide receptor (GRPR) is overexpressed in various cancers and is a promising target for cancer diagnosis and therapy. However, the high pancreas uptake and/or metabolic instability observed for most reported GRPR-targeted radioligands might limit their clinical applications. Our group recently reported a GRPR-targeted antagonist tracer, [68Ga]Ga-TacsBOMB2 ([68Ga]Ga-DOTA-Pip-D-Phe6-Gln7-Trp8-Ala9-Val10-Gly11-His12-Leu13ψThz14-NH2), which showed a minimal pancreas uptake in a preclinical mouse model. In this study, we synthesized four derivatives with unnatural amino acid substitutions (Tle10-derived Ga-LW01158, NMe-His12-derived Ga-LW01160, α-Me-Trp8- and Tle10-derived Ga-LW01186, and Tle10- and N-Me-Gly11-derived Ga-LW02002) and evaluated their potential for detecting GRPR-expressing tumors with positron emission tomography (PET). The binding affinities (Ki(GRPR)) of Ga-LW01158, Ga-LW01160, Ga-LW01186, and Ga-LW02002 were 5.11 ± 0.47, 187 ± 17.8, 6.94 ± 0.95, and 11.0 ± 0.39 nM, respectively. [68Ga]Ga-LW01158, [68Ga]Ga-LW01186, and [68Ga]Ga-LW02002 enabled clear visualization of subcutaneously implanted human prostate cancer PC-3 tumor xenografts in mice in PET images. Ex vivo biodistribution studies showed that [68Ga]Ga-LW01158 had the highest tumor uptake (11.2 ± 0.65 %ID/g) and good tumor-to-background uptake ratios at 1 h post-injection. Comparable in vivo stabilities were observed for [68Ga]Ga-LW01158, [68Ga]Ga-LW01186, and [68Ga]Ga-LW02002 (76.5-80.7% remaining intact in mouse plasma at 15 min post-injection). In summary, the Tle10 substitution, either alone or combined with α-Me-Trp8 or NMe-Gly11 substitution, in Ga-TacsBOMB2 generates derivatives that retained good GRPR binding affinity and in vivo stability. With good tumor uptake and tumor-to-background imaging contrast, [68Ga]Ga-LW01158 is promising for detecting GRPR-expressing lesions with PET.

Delivery of Chlorambucil to the Brain Using Surface Modified Solid Lipid Nanoparticles.

The delivery of drugs to the brain in the therapy of diseases of the central nervous system (CNS) remains a continuing challenge because of the lack of delivery systems that can cross the blood-brain barrier (BBB). Therefore, there is a need to develop an innovative delivery method for the treatment of CNS diseases. Thus, we have investigated the interaction of γ-aminobutyric acid (GABA) and S-(-)-γ-amino-α-hydroxybutyric acid (GAHBA) with the GABA receptor by performing a docking study. Both GABA and GAHBA show comparable binding affinities toward the receptor. In this study, we developed surface-modified solid lipid nanoparticles (SLNs) using GAHBA-derived lipids that can cross the BBB. CLB-loaded SLNs were characterized by a number of methods including differential scanning calorimetry, dynamic light scattering, UV-vis spectroscopy, and transmission electron microscopy. The blank and CLB-loaded SLN suspensions were found to exhibit good storage stability. Also, the SLNs showed a higher encapsulation efficiency for CLB drugs. In vitro release kinetics of CLB at physiological temperature was also investigated. The results of the in vitro cell cytotoxicity assay and flow cytometry studies in the human glioma U87MG cell line and human prostate cancer PC3 cell line suggested a higher efficacy of the GAHBA-modified CLB-loaded SLNs in U87MG cells. The transcription level of GABA receptor expression in the target organ and cell line was analyzed by a reverse transcription polymerase chain reaction study. The in vivo biodistribution and brain uptake in C57BL6 mice and SPECT/CT imaging in Wistar rats investigated using 99mTc-labeled SLN and autoradiography suggest that the SLNs have an increasing brain uptake. We have demonstrated the delivery of the anticancer drug chlorambucil (CLB) to glioma.

Sensitivity of magnetic resonance elastography to extracellular matrix and cell motility in human prostate cancer cell line-derived xenograft models

Prostate cancer (PCa) is a significant health problem in the male population of the Western world. Magnetic resonance elastography (MRE), an emerging medical imaging technique sensitive to mechanical properties of biological tissues, detects PCa based on abnormally high stiffness and viscosity values. Yet, the origin of these changes in tissue properties and how they correlate with histopathological markers and tumor aggressiveness are largely unknown, hindering the use of tumor biomechanical properties for establishing a noninvasive PCa staging system.To infer the contributions of extracellular matrix (ECM) components and cell motility, we investigated fresh tissue specimens from two PCa xenograft mouse models, PC3 and LNCaP, using magnetic resonance elastography (MRE), diffusion-weighted imaging (DWI), quantitative histology, and nuclear shape analysis. Increased tumor stiffness and impaired water diffusion were observed to be associated with collagen and elastin accumulation and decreased cell motility. Overall, LNCaP, while more representative of clinical PCa than PC3, accumulated fewer ECM components, induced less restriction of water diffusion, and exhibited increased cell motility, resulting in overall softer and less viscous properties. Taken together, our results suggest that prostate tumor stiffness increases with ECM accumulation and cell adhesion - characteristics that influence critical biological processes of cancer development.MRE paired with DWI provides a powerful set of imaging markers that can potentially predict prostate tumor development from benign masses to aggressive malignancies in patients. Statement of significanceXenograft models of human prostate tumor cell lines, allowing correlation of microstructure-sensitive biophysical imaging parameters with quantitative histological methods, can be investigated to identify hallmarks of cancer.

The LAT1 inhibitor JPH203 suppresses the growth of castration-resistant prostate cancer through a CD24-mediated mechanism.

L-type amino acid transporter 1 (LAT1) is specifically expressed in many malignancies, contributes to the transport of essential amino acids, such as leucine, and regulates the mammalian target of rapamycin (mTOR) signaling pathway. We investigated the expression profile and functional role of LAT1 in prostate cancer using JPH203, a specific inhibitor of LAT1. LAT1 was highly expressed in castration-resistant prostate cancer (CRPC) cells, including C4-2 and PC-3 cells, but its expression level was low in castration-sensitive LNCaP cells. JPH203 significantly inhibited [14C] leucine uptake in CRPC cells but had no effect in LNCaP cells. JPH203 inhibited the proliferation, migration, and invasion of CRPC cells but not of LNCaP cells. In C4-2 cells, Cluster of differentiation (CD) 24 was identified by RNA sequencing as a novel downstream target of JPH203. CD24 was downregulated in a JPH203 concentration-dependent manner and suppressed activation of the Wnt/β-catenin signaling pathway. Furthermore, an invivo study showed that JPH203 inhibited the proliferation of C4-2 cells in a castration environment. The results of this study indicate that JPH203 may exert its antitumor effect in CRPC cells via mTOR and CD24.

Abstract LB054: A novel chemical proteomics approach toward the identification of kinase targets to sensitize tumour cells to the standard of care drug paclitaxel

Abstract Introduction: Chemotherapy, through various signaling pathways changes the kinase activation profiles in tumour cells and it has been shown that blockade of specific kinases led to sensitization of tumour cells to chemotherapeutic drugs. We surmised that, following chemotherapeutic drug treatment, determination of the kinase binding profile of a specific inhibitor using its corresponding chemoprobe may lead to the identification of kinases to be targeted for potentiating the action of the chemotherapeutic drug. The approach we chose to study was to design a chemoprobe carrying a kinase inhibitor warhead to capture and read the kinase binding profiles before and after the chemotherapeutic drug treatment. Our proof-of-concept was made with AB19, a chemoprobe designed with the scaffold of crizotinib, a MET receptor tyrosine kinase inhibitor. The ability of AB19 to bind to MET was validated using KATO-II gastric cancer cells in which MET is amplified. Material and Methods: Gastric cancer cell line KATO-II, prostate cancer cells DU145, PC3 and 22RV1 and normal prostate cells RWPE-1 were used to determine IC50 values for the different drugs alone and in combination with paclitaxel. Cells were lysed 2 h and 24 h after drug treatment. The chemoprobes (control probe or AB19) were subsequently added and kinases captured using magnetic pull down. Proteomics analyses were performed by mass spectrometry. Results: The results showed that AB19 pulled down MET (its primary target) and many other kinases, including LCK, Src, EPHA2, and FAK1 that play an important role in cancer progression. Importantly, the kinase pull-down profiles by the chemoprobe were similar to that reported for free crizotinib, thereby validating the ability of the chemoprobe to simulate the binding of the free drug. In vitro studies with AB19 revealed the following: (a) the kinase pull-down profiles varied with cell lines, with the presence or absence of some important kinases and (b) under conditions where the cells were pretreated with paclitaxel, the kinase profiles between treated and non-treated cells were similar. However, disappearance and appearance of key targets were observed. Based upon the detection of an increase in aurora kinase A (AURKA) and mammalian target of rapamycin (mTOR) spectral counts, we designed 2-drug combinations of specific inhibitors of the latter targets with paclitaxel under equieffective and sequential administrations. Of all the combinations studied, Alisertib (AURKA inhibitor) + paclitaxel was the most synergistic. Conclusion: Taken together, the results suggest that AURKA is a unique target for sensitizing cells to paclitaxel and this novel chemical proteomics approach can be developed as a novel strategy to identify kinase inhibitors capable of significantly sensitizing cancer cells to standard of care drugs. Citation Format: Alaa Omar Baryyan, Ana Belen Fraga Timiraos, Kurt Dejgaard, Bertrand J. Jean-Claude. A novel chemical proteomics approach toward the identification of kinase targets to sensitize tumour cells to the standard of care drug paclitaxel [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB054.

7-O-tyrosyl Silybin Derivatives as a Novel Set of Anti-Prostate Cancer Compounds.

Silybin is a natural compound extensively studied for its hepatoprotective, neuroprotective and anticancer properties. Envisioning the enhancement of silybin potential by suitable modifications in its chemical structure, here, a series of new 7-O-alkyl silybins derivatives were synthesized by the Mitsunobu reaction starting from the silybins and tyrosol-based phenols, such as tyrosol (TYR, 3), 3-methoxytyrosol (MTYR, 4), and 3-hydroxytyrosol (HTYR, 5). This research sought to explore the antioxidant and anticancer properties of eighteen new derivatives and their mechanisms. In particular, the antioxidant properties of new derivatives outlined by the DPPH assay showed a very pronounced activity depending on the tyrosyl moiety (HTYR > MTYR >> TYR). A significant contribution of the HTYR moiety was observed for silybins and 2,3-dehydro-silybin-based derivatives. According to the very potent antioxidant activity, 2,3-dehydro-silybin derivatives 15ab, 15a, and 15b exerted the most potent anticancer activity in human prostate cancer PC-3 cells. Furthermore, flow cytometric analysis for cell cycle and apoptosis revealed that 15ab, 15a, and 15b induce strong G1 phase arrest and increase late apoptotic population in PC-3 cells. Additionally, Western blotting for apoptotic marker cleaved caspase-3 confirmed apoptosis induction by these silybin derivatives in PC-3 cells. These findings hold significant importance in the investigation of anticancer properties of silybin derivatives and strongly encourage swift investigation in pre-clinical models and clinical trials.