LNCaP Prostate Cancer Cells Research Articles

Lactoferrin conjugated radicicol nanoparticles enhanced drug delivery and cytotoxicity in prostate cancer cells.

Pyruvate dehydrogenase kinase-1 (PDK1) plays a crucial role in cancer cell metabolism by regulating the glycolytic pathway. Although, inhibitors targeting PDK1 have been effective in inhibiting glycolysis in multiple cancers, their lack of selectivity leading to off-target effects limit their therapeutic benefit. Herein, we investigated the inhibitory potential of six PDK1 inhibitors on cellular proliferation, migration, and invasion of androgen-sensitive LNCaP and androgen-negative PC-3 prostate cancer cells. Of the six PDK1 inhibitors, radicicol and dicumarol significantly inhibited cellular proliferation and exhibited lower metabolic activity in both LNCaP and PC-3 metastatic prostate cancer cells. Radicicol was highly effective at lower concentration. Moreover, radicicol significantly inhibited migration and invasion in PC-3 cells. We then developed a lactoferrin nanoparticle (LF-NP) encapsulated with Radicicol (Ra-LF-NP), using a rotary evaporation method. Spheroid assays confirmed the higher inhibitory potential of Ra-LF-NP with a reduction in spheroid area by 80%, and invasiveness compared to radicicol alone. Lactoferrin receptors are overexpressed on the surface of many cancer cells, including prostate cancer. Conjugating radicicol with lactoferrin nanoparticles, potentially enhanced the specific uptake of the drug by prostate cancer cells while minimizing the off-target effects on healthy cells. This targeted therapy approach could lead to improved treatment outcomes and reduced side effects. Our study demonstrated the potential of radicicol delivery by lactoferrin-conjugated nanoparticle as an efficient drug delivery strategy for prostate cancer treatment.

Bioactivity Evaluation and Phytochemical Characterization of Euonymus alatus (Thunb.) Siebold Leaf Extract.

Euonymus alatus (E. alatus) has traditionally been used for medicinal purposes, and its leaves are considered edible. While E. alatus is known for its diverse biological activities, the antioxidant, antidiabetic, and anticancer effects of its leaves extracted using different solvents have not been thoroughly investigated. This study examined the antioxidant, antidiabetic, anticancer, and life-prolonging effects of Euonymus alatus (E. alatus) leaf extract. The phytochemical analysis showed that the ethanol extract contained the highest levels of polyphenols (347.2 mg/mL) and flavonoids (317.7 mg/mL) compared to the water and methanol extracts. In addition, specific phenolics, such as rutin, ellagic acid, and quercetin, were found in the ethanol extract. Antioxidant assays showed that the ethanol extract exhibited superior DPPH, ABTS radical, and H2O2-scavenging activities, as well as reducing power. In addition, the ethanol extract displayed strong α-glucosidase inhibitory activity in a dose-dependent manner. In cancer cell studies, the ethanol extract selectively inhibited the proliferation of MDA-MB-231 (breast) and LNCaP (prostate) cancer cells without affecting normal cells. Apoptosis induction was confirmed by nuclear condensation and increased caspase-3 activity. Furthermore, treatment with 30 mg/kg/day of the extract extended the lifespan of the tumor-bearing mice to 50 days, with no fatalities, indicating a dose-dependent protective effect. E. alatus leaf ethanol extract has potential as an antioxidant, antidiabetic, anticancer, and life-prolonging agent.

BUD23 promote the cell proliferation ability by affecting the PPAR signaling pathways: evidence from the online dataset and cell experiment

IntroductionProstate cancer is a major public health challenge for men worldwide, being the second most common cancer diagnosis and the fifth leading cause of cancer-related deaths among men. The etiology of prostate cancer is multifactorial, with age, genetic predispositions, and lifestyle factors playing critical roles. The role of the peroxisome proliferator-activated receptors (PPARs) in prostate cancer remains complex and not fully elucidated.MethodsTranscriptomic data from The Cancer Genome Atlas (TCGA) were utilized for this study. The data were analyzed using single-sample Gene Set Enrichment Analysis (ssGSEA), Gene Ontology (GO) enrichment analysis, KEGG pathway analysis, and Gene Set Enrichment Analysis (GSEA). A prognosis-prediction model was constructed using Cox regression and LASSO analysis. Functional experiments, including Western blotting, quantitative PCR (qPCR), Cell Counting Kit-8 (CCK-8) assays, and EdU incorporation assays, were performed to validate the role of BUD23 in prostate cancer.ResultsSignificant differences were observed in the immune microenvironment and HLA gene expression profiles between high and low PPAR expression groups in prostate cancer. The high PPAR group exhibited a less active immune microenvironment with higher fractions of immunosuppressive T regulatory cells (Tregs). A robust prognostic model identified key genes, including BUD23, associated with patient survival. Elevated BUD23 expression was correlated with more aggressive clinical features such as advanced pathological stages, nodal metastasis, and higher Gleason scores. Knockdown of BUD23 in PC-3 and LNCaP prostate cancer cell lines significantly inhibited cell proliferation. Western blotting and qPCR confirmed effective BUD23 knockdown, and CCK-8 and EdU assays demonstrated reduced cell proliferation. BUD23 knockdown resulted in significant reductions in PPAR-α, PPAR-β, and PPAR-γ protein levels, suggesting a regulatory axis between BUD23 and PPARs in prostate cancer.ConclusionThe study highlights the distinct roles of PPARα, PPARβ/δ, and PPARγ in prostate cancer progression and their potential as therapeutic targets. Elevated BUD23 expression is associated with aggressive prostate cancer features and patient survival, making it a potential prognostic biomarker. The knockdown of BUD23 not only inhibited cell proliferation but also reduced the expression of PPAR-related proteins, indicating a potential regulatory axis between BUD23 and PPARs. These findings suggest that targeting BUD23 could modulate PPAR signaling and inhibit tumor growth in prostate cancer.

Impact of cell geometry, cellular uptake region, and tumour morphology on 225Ac and 177Lu dose distributions in prostate cancer

BackgroundRadiopharmaceutical therapy with 225Ac- and 177Lu-PSMA has shown promising results for the treatment of prostate cancer. However, the distinct physical properties of alpha and beta radiation elicit varying cellular responses, which could be influenced by factors such as tumour morphology. In this study, we use simulations to examine how cell geometry, region of pharmaceutical uptake within the cell to model different internalization fractions, and the presence of tumour hypoxia and necrosis impact nucleus absorbed doses and dose heterogeneity with 225Ac and 177Lu. We also develop nucleus absorbed dose kernels for application to autoradiography images.MethodsWe used the GATE Monte Carlo software to simulate three geometries of LNCaP prostate cancer cells (spherical, cubic, and ovoid) with activity of 225Ac or 177Lu internalized in the cytoplasm or bound to the extracellular membrane. Nucleus S-values were calculated for each geometry, source region, and isotope. The cell models were used to create nucleus absorbed dose kernels for each source region describing the dose to each nucleus in a cell layer, which were applied to simulated tumours composed of normoxic, hypoxic, or necrotic cancer cells to obtain dose rate maps. Absorbed doses within the tumours and dose heterogeneity were analyzed for each tumour morphology and isotope. Cell geometry made a minimal impact on S-values to the nucleus, however internalization resulted in higher nucleus doses. Applying the kernels to the simulated tumour maps showed that doses to each cell type varied between 225Ac and 177Lu depending on tumour morphology. Dose heterogeneity within tumours was slightly higher with 225Ac, however the tumour morphology made a larger impact on dose heterogeneity compared to the choice of isotope, with hypoxic and necrotic tumours having very heterogeneous dose distributions.ConclusionsCell geometry simplifications may still allow robust results in simulation studies. Furthermore, the morphology of the tumour itself may make a larger impact on treatment response compared to other variables such as ratio of internalization. Finally, nucleus absorbed dose kernels were created that could enable microdosimetric studies with autoradiography.

The impact of androgen-induced translation in modulating androgen receptor activity

IntroductionDysregulated androgen receptor (AR) activity is central to various diseases, particularly prostate cancer (PCa), in which it drives tumour initiation and progression. Consequently, antagonising AR activity via anti-androgens is an indispensable treatment option for metastatic PCa. However, despite initial tumour remission, drug resistance occurs. Therefore, the AR signalling pathway has been intensively investigated. However, the role of AR protein stability in AR signalling and therapy resistance has not yet been deciphered. Therefore, this study aimed to investigate the role of AR protein changes in transactivity and assess its mechanism as a possible target in PCa.MethodsLNCaP, C4-2, and 22Rv1 cells were treated with R1881, enzalutamide, cycloheximide, and Rocaglamide. Mass spectrometry analyses were performed on LNCaP cells to identify the pathways enriched by the treatments. Western blotting was performed to investigate AR protein levels and localisation changes. Changes in AR transactivity were determined by qPCR.ResultsMass spectrometry analyses were performed on LNCaP cells to decipher the molecular mechanisms underlying androgen- and antiandrogen-induced alterations in the AR protein. Pathway analysis revealed the enrichment of proteins involved in different pathways that regulate translation. Translational and proteasome inhibitor experiments revealed that these AR protein changes were attributable to modifications in translational activity. Interestingly, the effects on AR protein levels in castration-resistant PCa (CRPC) cells C4-2 or enzalutamide-resistant cells 22Rv1 were less prominent and non-existent. This outcome was similarly observed in the alteration of AR transactivation, which was suppressed in hormone-sensitive prostate cancer (HSPC) LNCaP cells by translational inhibition, akin to the effect of enzalutamide. In contrast, treatment-resistant cell lines showed only a slight change in AR transcription.ConclusionThis study suggests that in HSPC, AR activation triggers a signalling cascade that increases AR protein levels by enhancing its translation rate, thereby amplifying AR activity. However, this mechanism appears to be dysregulated in castration-resistant PCa cells.

Kerstinginone, a new flavanone derivative from Commiphora kerstingii Engl. (Burseraceae) with potent apoptosis-inducing activity and inhibition of AKT/mTOR signaling pathway in non-sensitive prostate cancer cells

Ethnopharmacological relevanceCommiphora kerstingii Engl is a tree which is 20–30 m in height and commonly called “ararrabi” in Hausa. It is found in the Sahelian region (Cameroon, Chad, and Nigeria) where it is utilized for the treatment of several ailments including cancer. Aim of the studyThis study was aimed at investigating the chemical constituents and cytotoxic effect of extracts and isolates from the stem barks and leaves of C. kerstingii. Materials and methodsUsing classical chromatography technique coupled with spectroscopic analysis and literature information, ten (10) compounds were isolated from C. kerstingii stem barks and leaves, out of which two [kerstingilactone (3) and kerstinginone (10)] were new. To evaluate their potential cytotoxic effect, the impact on cell viability, growth, and proliferation was assessed using MTT and CCK-8 assays. Cell death mechanisms were analyzed via flow cytometry, and Western blotting was utilized to examine the expression of specific regulatory proteins. Furthermore, anti-metastatic properties were investigated through assays on cell migration, adhesion, and chemotaxis. ResultsAmong the tested compounds, 2 (Masticadienonic Acid) and 10 (kerstinginone) exhibited significant dose-dependent inhibition of PC3 and LNCaP cell growth. Compound 2 displayed optimal inhibitory effects within a concentration range of 10–40 μg/mL, while compound 10 demonstrated potent growth inhibition at concentrations of 2.5–10 μg/mL. Both compounds suppressed cell proliferation and the formation of clones. Specifically, compound 2 induced apoptosis solely in the androgen-sensitive LNCaP prostate cancer cells, whereas compound 10 induced a stronger and concentration-dependent apoptotic response in both PC3 and LNCaP cells, resulting in approximately 50–70% apoptotic cells. It also induced potent cell migration/invasion arrest at concentrations ranging from 2.5 to 5 μg/mL and increased cell adhesion to the extracellular matrix. ConclusionKerstinginone exhibits potent cytotoxicity and apoptosis-inducing activity, making it a promising lead for discovering a new anticancer drug.

Loss of PI5P4Kα Slows the Progression of a Pten Mutant Basal Cell Model of Prostate Cancer.

Although early prostate cancer depends on the androgen receptor signaling pathway, which is predominant in luminal cells, there is much to be understood about the contribution of epithelial basal cells in cancer progression. Herein, we observe cell type-specific differences in the importance of the metabolic enzyme phosphatidylinositol 5-phosphate 4-kinase alpha (PI5P4Kα; gene name PIP4K2A) in the prostate epithelium. We report the development of a basal cell-specific genetically engineered mouse model targeting Pip4k2a alone or in combination with the tumor suppressor phosphatase and tensin homolog (Pten). PI5P4Kα is enriched in basal cells, and no major histopathologic changes were detectable following gene deletion. Notably, the combined loss of Pip4k2a slowed the development of Pten mutant mouse prostatic intraepithelial neoplasia. Through the inclusion of a lineage tracing reporter, we utilize single-cell RNA sequencing to evaluate changes resulting from in vivo downregulation of Pip4k2a and characterize cell populations influenced in the established Probasin-Cre- and cytokeratin 5-Cre-driven genetically engineered mouse model. Transcriptomic pathway analysis points toward the disruption of lipid metabolism as a mechanism for reduced tumor progression. This was functionally supported by shifts of carnitine lipids in LNCaP prostate cancer cells treated with siPIP4K2A. Overall, these data nominate PI5P4Kα as a target for PTEN mutant prostate cancer. Implications: PI5P4Kα is enriched in prostate basal cells, and its targeted loss slows the progression of a model of advanced prostate cancer.

Effective Use of Euphorbia milii DCM Root Extract Encapsulated by Thermosensitive Immunoliposomes for Targeted Drug Delivery in Prostate Cancer Cells.

The delivery of anticancer drugs using nanotechnology is a promising approach aimed at improving the therapeutic efficacy and reducing the toxicity of chemotherapeutic agents. Liposomes were prepared using HSPC: DSPE-PEG-2000: DSPE-PEG2000-maleimide in the ratio of 4:1:0.2 and conjugated with a PSA antibody. Euphorbia milii extract (EME), doxorubicin (Dox), and docetaxel (Doc) encapsulated in temperature-sensitive immunoliposomes were investigated for their activities against the prostate cancer LNCap and DU145 cell lines. Organic extracts of EME leaves, roots, and stems were screened against both cell lines, inhibiting more than 50% of cell culture at concentrations of 10 μg/mL. The immunoliposomes incorporating the EME and docetaxel were active against the LNCap cells when exposed to heat at 39-40 °C. The liposomes not exposed to heat were inactive against the LNCap cells. The developed heat-sensitive immunoliposomes used for the delivery of both the EME and chemotherapeutic agents was able to successfully release the entrapped contents upon heat exposure above the phase transition temperature of the liposome membrane. The heat-sensitive immunoliposomes conjugated with a PSA antibody encapsulated the extract successfully and showed better cell antiproliferation efficacy against the prostate cancer cell lines in the presence of heat.

In Silico Design of Novel RGS2-Galpha-q Interaction Inhibitors with Anticancer Activity.

Regulators of G-protein signaling (RGS) are a family of approximately 30 proteins that bind to and deactivate the alpha subunits of G-proteins (Gα) by accelerating their GTP hydrolysis rates, which terminates G-protein coupled receptor (GPCR) signaling. Thus, RGS proteins are essential in regulating GPCR signaling, and most members are implicated as critical nodes in human diseases such as hypertension, depression, and others. Regulator of G-protein signaling 2 (RGS2), a member of the R4 family of RGS proteins, is overexpressed in many solid breast cancers, and its levels in prostate cancer significantly correlate with the metastatic stage and poor prognosis. We sought to develop RGS2 inhibitors as potential chemotherapeutic agents utilizing structure-based drug design approaches. Available structures of the RGS2-Gα complex were used to extract a pharmacophore model for searching chemical databases. Docking of identified hits to RGS2 as well as other RGS structures was used to screen the hits for potent and selective RGS2 inhibitors. Whole cell assays showed the top 10 ranking compounds, AJ-1-AJ-10, to inhibit RGS2-Gαq interactions. Differential scanning fluorimetry showed AJ-3 to bind RGS2 but not Gαq. All 10 compounds inhibited the growth of several RGS2 expressing cancers in cell culture assays. In addition, AJ-3 inhibited the migration of LNCaP prostate cancer cells in wound healing assays. This is the first group of RGS2 inhibitors identified by structure-based approaches and that show anticancer activity. These results highlight the potential RGS2 inhibitors have to be a new class of chemotherapeutic agents.

Advanced electrochemical detection of pyrophosphatase activity in LNCaP cells utilizing in-situ redox of copper

The necessity for precise delineation and quantitation of pyrophosphatase (PPase) activities is underscored, especially in aggressive prostate cancer, driving the demand for more refined analytical techniques due to challenges associated with inadequate sensitivity and poor signal amplification. In response, a novel electrochemical method utilizing in-situ copper(II) (Cu(II))-based Fast Scan Cyclic Voltammetry (FSCV) is introduced for the advanced detection of PPase in LNCaP prostate cancer cells. This technique is characterized by the exploitation of competitive binding between Cu(II) and L-Phenylalanine (L-Phe) versus pyrophosphate (PPi), with FSCV technology enhanced by ohmic drop compensation to improve detection sensitivity and signal reliability. Through the application of the FSCV technique transitioned to Current(I)-Voltage(V) analysis, the signal generation is facilitated by an L-Phe-Cu(II) complex, driven by the redox reaction of in-situ Cu(II), specifically its rapid transition from the Cu(0) state back to the Cu(II) state. When this complex is anchored onto a gold substrate modified with cucurbit[7]uril (CB[7]) through supramolecular host–guest interactions, a significant FSCV signal is elicited. A detection limit of 0.05 mU/mL (S/N = 3) is subsequently achieved when the method is applied to the quantification of PPase concentration. Leveraging the FSCV method, we have effectively analyzed PPase activity in LNCaP cells, offering a fresh perspective on tumor marker analysis and fostering advancements in drug development.

Docosahexaenoic acid enhances the treatment efficacy for castration-resistant prostate cancer by inhibiting autophagy through Atg4B inhibition

Autophagy induction in cancer is involved in cancer progression and the acquisition of resistance to anticancer agents. Therefore, autophagy is considered a potential therapeutic target in cancer therapy. In this study, we found that long-chain fatty acids (LCFAs) have inhibitory effects on Atg4B, which is essential for autophagosome formation, through screening based on the pharmacophore of 21f, a recently developed Atg4B inhibitor. Among these fatty acids, docosahexaenoic acid (DHA), a polyunsaturated fatty acid, exhibited the most potent Atg4B inhibitory activity. DHA inhibited autophagy induced by androgen receptor signaling inhibitors (ARSI) in LNCaP and 22Rv1 prostate cancer cells and significantly increased apoptotic cell death. Furthermore, we investigated the effect of DHA on resistance to ARSI by establishing darolutamide-resistant prostate cancer 22Rv1 (22Rv1/Dar) cells, which had developed resistance to darolutamide, a novel ARSI. At baseline, 22Rv1/Dar cells showed a higher autophagy level than parental 22Rv1 cells. DHA significantly suppressed Dar-induced autophagy and sensitized 22Rv1/Dar cells by inducing apoptotic cell death through mitochondrial dysfunction. These results suggest that DHA supplementation may improve prostate cancer therapy with ARSI.

Liver X Receptors Enhance Epithelial to Mesenchymal Transition in Metastatic Prostate Cancer Cells.

Prostate cancer (PCa) is one of the most common cancers in men. Metastasis is the leading cause of death in prostate cancer patients. One of the crucial processes involved in metastatic spread is the "epithelial-mesenchymal transition" (EMT), which allows cells to acquire the ability to invade distant organs. Liver X Receptors (LXRs) are nuclear receptors that have been demonstrated to regulate EMT in various cancers, including hepatic cancer. Our study reveals that the LXR pathway can control pro-invasive cell capacities through EMT in prostate cancer, employing ex vivo and in vivo approaches. We characterized the EMT status of the commonly used LNCaP, DU145, and PC3 prostate cancer cell lines through molecular and immunohistochemistry experiments. The impact of LXR activation on EMT function was also assessed by analyzing the migration and invasion of these cell lines in the absence or presence of an LXR agonist. Using in vivo experiments involving NSG-immunodeficient mice xenografted with PC3-GFP cells, we were able to study metastatic spread and the effect of LXRs on this process. LXR activation led to an increase in the accumulation of Vimentin and Amphiregulin in PC3. Furthermore, the migration of PC3 cells significantly increased in the presence of the LXR agonist, correlating with an upregulation of EMT. Interestingly, LXR activation significantly increased metastatic spread in an NSG mouse model. Overall, this work identifies a promoting effect of LXRs on EMT in the PC3 model of advanced prostate cancer.

PSMA-targeted combination brusatol and docetaxel nanotherapeutics for the treatment of prostate cancer

Active targeting to cancer involves exploiting specific interactions between receptors on the surface of cancer cells and targeting moieties conjugated to the surface of vectors such that site-specific delivery is achieved. Prostate specific membrane antigen (PSMA) has proved to be an excellent target for active targeting to prostate cancer. We report the synthesis and use of a PSMA-specific ligand (Glu-NH-CO-NH-Lys) for the site-specific delivery of brusatol- and docetaxel-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles to prostate cancer. The PSMA targeting ligand covalently linked to PLGA-PEG3400 was blended with methoxyPEG-PLGA to prepare brusatol- and docetaxel-loaded nanoparticles with different surface densities of the targeting ligand. Flow cytometry was used to evaluate the impact of different surface densities of the PSMA targeting ligand in LNCaP prostate cancer cells at 15 min and 2 h. Cytotoxicity evaluations of the targeted nanoparticles reveal differences based on PSMA expression in PC-3 and LNCaP cells. In addition, levels of reactive oxygen species (ROS) were measured using the fluorescent indicator, H2DCFDA, by flow cytometry. PSMA-targeted nanoparticles loaded with docetaxel and brusatol showed increased ROS generation in LNCaP cells compared to PC-3 at different time points. Furthermore, the targeted nanoparticles were evaluated in male athymic BALB/c mice implanted with PSMA-producing LNCaP cell tumors. Evaluation of the percent relative tumor volume show that brusatol-containing nanoparticles show great promise in inhibiting tumor growth. Our data also suggest that the dual drug-loaded targeted nanoparticle platform improves the efficacy of docetaxel in male athymic BALB/c mice implanted with PSMA-producing LNCaP cell tumors.

AKT Inhibition Sensitizes to Polo-Like Kinase 1 Inhibitor Onvansertib in Prostate Cancer.

Polo-like kinase 1 (PLK1) inhibitors have had limited antitumor efficacy as single agents, and focus of current efforts is on combination therapies. We initially confirmed that the PLK1-specific inhibitor onvansertib (ONV) could enhance responses to a PARP inhibitor (olaparib) in prostate cancer xenografts. To identify more effective combinations, we screened a library of bioactive compounds for efficacy in combination with ONV in LNCaP prostate cancer cells, which identified a series of compounds including multiple AKT inhibitors. We confirmed in vitro synergy between ONV and the AKT inhibitor ipatasertib (IPA) and found that the combination increased apoptosis. Mechanistic studies showed that ONV increased expression of the antiapoptotic protein SURVIVIN and that this was mitigated by IPA. Studies in three PTEN-deficient prostate cancer xenograft models showed that cotreatment with IPA and ONV led to significant tumor growth inhibition compared with monotherapies. Together, these in vitro and in vivo studies demonstrate that the efficacy of PLK1 antagonists can be enhanced by PARP or AKT inhibition and support further development of these combination therapies.

Synthesis and anticancer properties of a hybrid molecule with the testosterone and estradiol head-groups

This is the first report on a unique hybrid molecule made of estradiol and testosterone (TS). This distinctive hybrid molecule (1) was designed to interact with both the estrogen receptor (ER) and the androgen receptor (AR) found in hormone-dependent female and male cancer cells, and was synthesized using ethynylestradiol (17EE) as the estrogenic component and 7α-(4-azido-but-2-enyl)-4-androsten-17β-ol-3-one as the androgenic counterpart in a seven-step reaction with ∼ 26 % overall yield. We reasoned that the dual receptor binding ability could allow 1 to act as an antihormone. This was tested on hormone-dependent and hormone-independent breast cancer (BCa) and prostate cancer (PCa) cells. The antiproliferative activity was also assessed on colon and skin cancer cells. We found that 1 was active against MCF7 (ER + ) BCa cells (IC50 of 4.9 μM), had lower inhibitory potency on LNCaP (AR + ) PCa cells (IC50 > 5 μM) and no effect on PC3 and DU145 (AR-) PCa cells. This suggests that the estrogenic component of 1 can interact with the ER on MCF7 cells more effectively than the androgenic component with the AR on LNCaP PCa cells, possibly due to a suboptimal spacer or linkage site(s). Nonetheless, the hybrid 1 was active against colon (HT-29) and melanoma (M21) cancer cells (IC50 of 3.5 μM and 2.3 μM, respectively), and had low cross-reactivity with the drug- and androgen-metabolizing cytochrome P450 3A4 (CYP3A4, IC50 ≫ 5 µM). These findings demonstrate the anticancer potential of 1 and warrant further explorations on this new type of hybrids.

Design, Synthesis, Characterization, and Cytotoxicity of New Pyrazolylmethylene-2-thioxoimidazolidin-4-one Derivatives towards Androgen-Sensitive LNCaP Prostate Cancer Cells.

A new class of pyrazolylmethylene-2-thioxoimidazolidin-4-one derivatives 3a-p were rationally designed and synthesized with the aim of exploring their potential as treatments for prostate cancer. The synthesized compounds 3a-p were biologically analyzed for their anticancer effects against AR+LNCaP, AR-PC-3, and Wi38 cell lines. The observed IC50 values against AR+LNCaP ranged between 10.27 ± 0.14 and 109.72 ± 2.06 µM after 24 h of incubation. Compounds 3i-k, 3m, and 3o-p recorded IC50 values of 05.22 ± 0.12 to 11.75 ± 0.07 µM after 48 h incubation in the presence of 1 nM DHT, with higher selectivity towards AR+LNCaP. Moreover, compounds 3i and 3k significantly induced Caspase 3 accumulation, reduced DNA content at the various stages of the cell cycle, and ultimately caused AR+LNCaP cell growth arrest, as confirmed by cell apoptosis assays. These findings suggest that these analogues of androgen receptor blockers have promising potential for further investigation as effective treatments for prostate 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.

Metformin-induced oxidative stress inhibits LNCaP prostate cancer cell survival.

Preclinical and clinical studies over the past several decades have indicated the potential value of metformin, a widely utilized treatment for Type 2 diabetes, in prostate cancer therapy. Notably, these studies demonstrated metformin's pleiotropic effects on several molecular and metabolic pathways, such as androgen signaling, cell cycle, and cellular bioenergetics. In this study we investigated the role of metformin in regulating intracellular redox status and cell survival in LNCaP prostate cancer cells. The cytotoxic effects of metformin with or without the presence of SBI0206965 (AMPK inhibitor) on LNCaP cells were determined using MTT and trypan blue exclusion assays. Seahorse XP extracellular analysis, Liquid Chromatography/ Mass Spectrophotometry (LC/MS), and 2,7- and Dichlorofluoresin diacetate (DCFDA) assay were used to assess the effects of metformin on cellular bioenergetics, redox status, and redox-related metabolites. mRNA expression and protein concentration of redox-related enzymes were measured using Real Time-qPCR and ELISA assay, respectively. Independently of AMP-activated protein kinase, metformin exhibited a dose- and time-dependent inhibition of LNCaP cell survival, a response mitigated by glutathione or N-acetylcysteine (ROS scavengers) treatment. Notably, these findings were concomitant with a decline in ATP levels and the inhibition of oxidative phosphorylation. The results further indicated metformin's induction of reactive oxygen species, which significantly decreased glutathione levels and the ratio of reduced to oxidized glutathione, as well as the transsulfuration metabolite, cystathionine. Consistent with an induction of oxidative stress condition, metformin increased mRNA levels of the master redox transcription factor Nrf-2 (nuclear factor erythroid-derived 2-like), as well as transsulfuration enzymes cystathionine beta-synthase and cystathionase and GSH synthesis enzymes γ-glutamylcysteine synthetase and glutathione synthetase. Our findings highlight multiple mechanisms by which metformin-induced formation of reactive oxygen species may contribute to its efficacy in prostate cancer treatment, including promotion of oxidative stress, Nrf2 activation, and modulation of redox-related pathways, leading to its anti-survival action.

MR Molecular Imaging of Extradomain-B Fibronectin for Assessing Progression and Therapy Resistance of Prostate Cancer.

Accurate assessment and characterization of the progression and therapy response of prostate cancer are essential for precision healthcare of patients diagnosed with the disease. MRI is a clinical imaging modality routinely used for diagnostic imaging and treatment planning of prostate cancer. Extradomain B fibronectin (EDB-FN) is an oncofetal subtype of fibronectin highly expressed in the extracellular matrix of aggressive cancers, including prostate cancer. It is a promising molecular target for the detection and risk-stratification of prostate cancer with high-resolution MR molecular imaging (MRMI). In this study, we investigated the effectiveness of MRMI with an EDB-FN specific contrast agent MT218 for assessing the progression and therapy resistance of prostate cancer. Low grade LNCaP prostate cancer cells became an invasive phenotype LNCaP-CXCR2 with elevated EDB-FN expression after acquisition of the C-X-C motif chemokine receptor 2 (CXCR2). MT218-MRMI showed brighter signal enhancement in LNCaP-CXCR2 tumor xenografts with a ∼2-fold contrast-to-noise (CNR) increase than in LNCaP tumors in mice. Enzalutamide-resistant C4-2-DR prostate cancer cells were more invasive, with higher EDB-FN expression than parental C4-2 cells. Brighter signal enhancement with a ∼2-fold CNR increase was observed in the C4-2-DR xenografts compared to that of C4-2 tumors in mice with MT218-MRMI. Interestingly, when invasive PC3 prostate cancer cells developed resistance to paclitaxel, the drug-resistant PC3-DR cells became less invasive with reduced EDB-FN expression than the parental PC3 cells. MT218-MRMI detected reduced brightness in the PC3-DR xenografts with more than 2-fold reduction of CNR compared to PC3 tumors in mice. The signal enhancement in all tumors was supported by the immunohistochemical staining of EDB-FN with the G4 monoclonal antibody. The results indicate that MRMI of EDB-FN with MT218 has promise for detection, risk stratification, and monitoring the progression and therapy response of invasive prostate cancer.

Transcriptional Up-Regulation of FBXW7 by KCa1.1 K+ Channel Inhibition through the Nrf2 Signaling Pathway in Human Prostate Cancer LNCaP Cell Spheroid Model.

The tumor suppressor gene F-box and WD repeat domain-containing (FBXW) 7 reduces cancer stemness properties by promoting the protein degradation of pluripotent stem cell markers. We recently demonstrated the transcriptional repression of FBXW7 by the three-dimensional (3D) spheroid formation of several cancer cells. In the present study, we found that the transcriptional activity of FBXW7 was promoted by the inhibition of the Ca2+-activated K+ channel, KCa1.1, in a 3D spheroid model of human prostate cancer LNCaP cells through the Akt-Nrf2 signaling pathway. The transcriptional activity of FBXW7 was reduced by the siRNA-mediated inhibition of the CCAAT-enhancer-binding protein C/EBP δ (CEBPD) after the transfection of miR223 mimics in the LNCaP spheroid model, suggesting the transcriptional regulation of FBXW7 through the Akt-Nrf2-CEBPD-miR223 transcriptional axis in the LNCaP spheroid model. Furthermore, the KCa1.1 inhibition-induced activation of FBXW7 reduced (1) KCa1.1 activity and protein levels in the plasma membrane and (2) the protein level of the cancer stem cell (CSC) markers, c-Myc, which is a molecule degraded by FBXW7, in the LNCaP spheroid model, indicating that KCa1.1 inhibition-induced FBXW7 activation suppressed CSC conversion in KCa1.1-positive cancer cells.