Prostate Cancer Cells Research Articles

Development of tripeptide-cyclotriphosphazene derivatives: In vitro cytotoxicity, genotoxicity studies and molecular docking analysis within ovarian and prostate cancer cell line receptors

Peptide-phosphazene compounds are important compounds of growing interest in biomedical research and have potential therapeutic effects. The tripeptide-cyclotriphosphazenes conjugates were synthesized and analyzed for their molecular docking analysis, visualizing their binding profiles within various cancer cell line receptors and tested in vitro cytotoxic and genotoxic properties. Determining in vitro cytotoxic studies of obtained compounds displayed cytotoxic effect against two selected human cancer cell lines, including ovarian (A2780) and prostate (PC-3), cancer cells. The compound DTAP demonstrated significantly higher efficacy at 100 µM in the PC-3 cancer cell line compared to the reference drug docetaxel at 50 µM. Among the tripeptide-phosphazene conjugtates, DTGG demonstrates the most promising anticancer activity with a logIC50 of 1.23 µM, forming five hydrogen bonds and a favorable salt bridge interaction, along with several hydrophobic interactions, thereby stabilizing its binding within the human ovarian tumor domain based on molecular docking analysis. The derivative DTGP emerges as the most potent among the DTG derivatives, achieving a ΔG model value of −108 kcal/mol, primarily due to a π-cationic interaction with the LYS204 amino acid in chain C, which significantly enhances its binding affinity. Additionally, DNA damage studies on human ovarian and prostate cancer cell lines determined that cell death due to DNA damage was the basis of the decrease in cell viability. These results support the evaluation of the compounds as potential drug candidates.

Understanding the development of enzalutamide resistance based on a functional single-cell approach.

Single-cell RNA-Sequencing reveals heterogeneities of tumor cell populations. In most cases, however, the functional significance of the observed heterogeneity is not tested. In this study, we first identified a possible therapy-resistant prostate cancer cell subpopulation with scRNA-Seq, then confirmed the resistant phenotype with single cell and colony - based cloning and functional testing. In addition, we also identified a therapeutic vulnerability of the resistant cells.

Bee venom prompts the inhibition of gefitinib on proliferation, migration, and invasion of non-small cell lung cancer cells via EGFR-mediated autophagy

It has been confirmed that bee venom (BV) can inhibit tumor metastasis of lung cancer cells induced by epidermal growth factor, suggesting the inhibitory role of BV on the regulation of epidermal growth factor receptor (EGFR), and may synergistically promote the anti-lung cancer effect of EGFR tyrosine kinase inhibitor gefitinib. This paper aims to ascertain the therapeutic potentials of BV combined with gefitinib against non-small cell lung cancer (NSCLC) in vitro. As results, the content of the main component melittin in air-dried BV was determined by HPLC. Subsequently, it was found that BV significantly inhibited the proliferation of NSCLC PC-9 and NCI-H1299 cells, but not generated apparent toxicity to human normal lung epithelial BEAS-2B cells. Meanwhile, the combination of BV and gefitinib also significantly inhibited the proliferation of these two cells, and suppressed the migration and invasion of PC-9 cells. By bioinformatics analysis and molecular docking, it was predicted that the main component melittin in BV could act on the cell membrane and transmembrane protein EGFR. Ultimately, Western blot assays showed BV alone or combined with gefitinib significantly decreased the protein expression of phosphorylated EGFR (p-EGFR) and the protein expression ratio of p-EGFR to EGFR, and increased the protein expression ratio of LC3-II to LC3-I in PC-9 cells or epidermal growth factor-activated PC-9 cells. The results demonstrated that BV could prompt the inhibition of gefitinib on proliferation, migration, and invasion of NSCLC cells via EGFR-mediated autophagy, showing the synergistic anti-NSCLC potential when combined with gefitinib.

Expression and role of CNIH2 in prostate cancer.

Prostate cancer is one of the most common cancers in men and poses a significant threat to global male health. Traditional prostate cancer assessment methods have certain limitations, necessitating the identification of new prognostic factors and treatment targets. Our study revealed that low expression of the cornichon family AMPA receptor auxiliary protein 2 (CNIH2) gene was associated with a better progression-free survival rate in prostate cancer patients. The area under the receiver operating characteristic (ROC) curve (AUC) showed that the prognostic ability of the CNIH2 gene was high at 1, 3, and 5 years. The gene was an independent prognostic factor according to multivariate analysis. Functional verification experiments showed that knocking down the CNIH2 gene could inhibit the proliferation, migration and invasion of prostate cancer cells and could also inhibit tumor growth in nude mice. Our study is the first to reveal the important role of the CNIH2 gene in prostate cancer. This discovery provides a new research direction for individualized treatment and prognostic evaluation of prostate cancer.

Advancing Anticancer Drug Discovery: Leveraging Metabolomics and Machine Learning for Mode of Action Prediction by Pattern Recognition.

A bottleneck in the development of new anti-cancer drugs is the recognition of their mode of action (MoA). Metabolomics combined with machine learning allowed to predict MoAs of novel anti-proliferative drug candidates, focusing on human prostate cancer cells (PC-3). As proof of concept, 38 drugs are studied with known effects on 16 key processes of cancer metabolism, profiling low molecular weight intermediates of the central carbon and cellular energy metabolism (CCEM) by LC-MS/MS. These metabolic patterns unveiled distinct MoAs, enabling accurate MoA predictions for novel agents by machine learning. The transferability of MoA predictions based on PC-3 cell treatments is validated with two other cancer cell models, i.e., breast cancer and Ewing's sarcoma, and show that correct MoA predictions for alternative cancer cells are possible, but still at some expense of prediction quality. Furthermore, metabolic profiles of treated cells yield insights into intracellular processes, exemplified for drugs inducing different types of mitochondrial dysfunction. Specifically, it is predicted that pentacyclic triterpenes inhibit oxidative phosphorylation and affect phospholipid biosynthesis, as confirmed by respiration parameters, lipidomics, and molecular docking. Using biochemical insights from individual drug treatments, this approach offers new opportunities, including the optimization of combinatorial drug applications.

PNU-74654 Enhanced the Antiproliferative Activity of Gemcitabine by Targeting Wnt/β-Catenin Pathway in Pancreatic Cancer

Background: The Wnt/beta-catenin pathway is one of the pathways that is deregulated in pancreatic cancer and is reported to be associated with a poor prognosis. This indicates the need for the identification of novel agents to improve the efficacy of current therapy or have an improved efficacy. Therefore, in the present study, we explored the anticancer activity of PNU- 74654 alone or in combination with gemcitabine in 2 and 3-dimensional cell culture models of pancreatic cancer. Methods: The MTT assay was carried out to determine the viability of PC cancerous cells (PCCs), while the cytotoxicity of this agent was evaluated in a 3D cell culture model (spheroid). The effects of PNU-74654 were investigated in established cell migration/invasion assays. Results: The expression of candidate genes affecting the cell cycle, migration, and Wnt/bcatenin pathway was evaluated at mRNA and/or proteins by RT-PCR or Western blot. PNU- 74654 inhibited the cell growth at IC50 of 122 ± 0.4 umol/L and had a synergistic effect on the antiproliferative properties of gemcitabine by modulating the Wnt pathway. The PNU- 74654/gemcitabine combination reduced the migratory and invasiveness of PC cells, compared to control cells, through perturbation of E-cadherin. Conclusion: Our findings demonstrate the profound antitumor properties of PNU-74654 in in vitro models of pancreatic cancer, supporting further in vivo studies to evaluate the therapeutic impact of this novel therapy to target the Wnt pathway in the treatment of pancreatic cancer.

Protein kinase D1 mitigation against etoposide induced DNA damage in prostate cancer is associated with increased α-Catenin.

The E-cadherin, α- and β-Catenin interaction at the cell adherens junction plays a key role in cell adhesion; alteration in the expression and function of these genes are associated with disease progression in several solid tumors including prostate cancer. The membranous β-Catenin is dynamically linked to the cellular cytoskeleton through interaction with α-Catenin at amino acid positions threonine 120 (T120) to 151 of β-Catenin. Nuclear presence of α-Catenin modulates the sensitivity of cells to DNA damage. The objective of this study is to determine the role of α-Catenin and protein kinase D1 (PrKD1) in DNA damage response. Prostate cancer cells; LNCaP, LNCaP (Sh-PrKD1; silenced PrKD1), C4-2 and C4-2 PrKD1 were used for various sets of experiments to determine the role of DNA damage in PrKD1 overexpression and silencing cells. These cells were treated with compound-10 (100 nM) and Etoposide (30 µM), total cell lysates, cytosolic and nuclear fractions were prepared to observe various protein expressions. We performed single cell gel electrophoresis (COMET assay) to determine the etoposide induce DNA damage in C4-2 and C4-2 PrKD1 cells. The animal experiments were carried out to determine the tolerability of compound-10 by mice and generate preliminary data on efficacy of compound-10 in modulating the α-Catenin and PrKD1 expressions in inhibiting tumor progression. PrKD1, a novel serine threonine kinase, phosphorylates β-Catenin T120. In silico analysis, confirmed that T120 phosphorylation alters β- to α-Catenin binding. Forced expression of PrKD1 in prostate cancer cells increased β- and α-Catenin protein levels associated with reduced etoposide induced DNA damage. Downregulation of α-Catenin abrogates the PrKD1 mitigation of DNA damage. The in vitro results were corroborated in vivo using mouse prostate cancer patient derived xenograft model by inhibition of PrKD1 kinase activity with compound-10, a selective PrKD inhibitor, demonstrating decreased total β- and α-Catenin protein levels, and β-Catenin T120 phosphorylation. Alteration in DNA damage response pathways play major role in prostate cancer progression. The study identifies a novel mechanism of α-Catenin dependent DNA damage mitigation role for PrKD1 in prostate cancer.

In vitro analysis suggests that SARS-CoV-2 infection differentially modulates cancer-like phenotypes and cytokine expression in colorectal and prostate cancer cells

The coronavirus disease 2019 (COVID-19) reportedly exacerbates cancer outcomes. However, how COVID-19 influences cancer prognosis and development remains poorly understood. Here, we investigated the effect of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2), the etiological agent of COVID-19, on cellular cancer phenotypes the expression of cancer-related markers, and various proinflammatory cytokines. We infected prostate (22RV1) and colorectal (DLD-1) cancer cell lines, which express angiotensin-converting enzyme 2 (ACE2), with spike pseudovirus (sPV) and laboratory stocks of live SARS-CoV-2 viruses. After infection, we quantified changes in the cellular cancer phenotypes, the gene expression levels of some cancer markers, including Ki-67, BCL-2, VIM, MMP9, and VEGF, and proinflammatory cytokines. Phenotypic analysis was performed using MTT and wound healing assays, whereas gene expression analysis was carried out using real-time quantitative PCR (RT-qPCR). We show that SARS-CoV-2 infection impacts several key cellular pathways involved in cell growth, apoptosis, and migration, in prostate and colorectal cancer cells. Our results suggest that SARS-CoV-2 infection does influence various cancer cellular phenotypes and expression of molecular cancer markers and proinflammatory cytokines, albeit in a cell-type-specific manner. Our findings hint at the need for further studies and could have implications for evaluating the impact of other viruses on cancer progression.

Structure-activity relationship of amino acid analogs to probe the binding pocket of sodium-coupled neutral amino acid transporter SNAT2.

The sodium-coupled neutral amino acid transporter SNAT2 (SLC38A2) has been shown to have important physiological functions and is implicated in various diseases like cancer. However, few compounds targeting this transporter have been identified and little is known about the structural requirements for SNAT2 binding. In this study, the aim was to establish the basic structure-activity relationship for SNAT2 using amino acid analogs. These analogs were first studied for their ability to inhibit SNAT2-mediated 3H-glycine uptake in hyperosmotically treated PC-3 cells. Then to identify substrates a FLIPR membrane potential assay and o-phthalaldehyde derivatization of intracellular amino with subsequent quantification using HPLC-Fl was used. The results showed that ester derivatives of the C-terminus maintained SNAT2 affinity, suggesting that the negative charge was less important. On the other hand, the positive charge at the N-terminus of the substrate and the ability to donate at least two hydrogen bonds to the binding site appeared important for SNAT2 recognition of the amine. Side chain charged amino acids generally had no affinity for SNAT2, but their non-charged derivatives were able to inhibit SNAT2-mediated 3H-glycine uptake, while also showing that amino acids of a notable length still had affinity for SNAT2. Several amino acid analogs appeared to be novel substrates of SNAT2, while γ-benzyl L-glutamate seemed to be inefficiently translocated by SNAT2. Elaborating on this structure could lead to the discovery of non-translocated inhibitors of SNAT2. Thus, the present study provides valuable insights into the basic structural binding requirements for SNAT2 and can aid the future discovery of compounds that target SNAT2.

MicroRNA-130a-3p regulates osimertinib resistance by targeting runt-related transcription factor 3 in lung adenocarcinoma

Overcoming resistance to epidermal growth factor receptor tyrosine kinase inhibitors, including osimertinib, is urgent to improve lung cancer treatment outcomes. Extracellular vesicle (EV)-derived microRNAs (EV-miRNAs) play important roles in drug resistance and serve as promising biomarkers. In this study, we aimed to identify EV-miRNAs associated with osimertinib resistance and investigate their clinical relevance. The release of excess EVs was confirmed in the osimertinib-resistant lung adenocarcinoma cell line PC9OR. The exposure of PC9OR-derived EVs and EV-miRNAs to PC9 cells increased cell viability after osimertinib treatment. Microarray analysis revealed that miR-130a-3p was upregulated in EVs derived from PC9OR cells and another osimertinib-resistant cell line (H1975OR). Transfection with miR-130a-3p attenuated osimertinib-induced cytotoxicity and apoptosis in both PC9 and H1975 cells, whereas osimertinib resistance in PC9OR cells was reversed after miR-130a-3p inhibition. Bioinformatics analysis revealed that runt-related transcription factor 3 is a target gene of miR-130a-3p, and it induced osimertinib resistance in PC9 cells. Patients with lower baseline serum miR-130a-3p concentrations had longer progression-free survival. miR-130a-3p is a potential therapeutic target and a predictive biomarker of osimertinib resistance in adenocarcinomas.

Prostate cancer cell-derived exosomes ZNF667-AS1 reduces TGFBR1 mRNA stability to inhibit Treg expansion and DTX resistance by binding to U2AF1

BackgroundDocetaxel (DTX) resistance attenuates anti-tumor effects of DTX on prostate cancer (mCRPC) and drug resistance was related to Treg expansion in tumors. ZNF667-AS1 played a suppressing role in various tumors and tumor-derived exosomes carry lncRNAs to participate in tumor progression. Here, the effects of ZNF667-AS1 on malignant characteristics and DTX resistance in PC and the effect and its underlying molecular mechanism of tumor-derived exosomes carrying ZNF667-AS1 on Treg expansion were investigated.MethodsThe identification of exosomes were determined using TEM, NTA and western blot. The abundance of genes and proteins were evaluated using IHC, RT-qPCR, western blot and FISH. Malignant phenotypes of PC cells were evaluated by means of Edu, scratch test, transwell, CCK-8 and flow cytometry. The percentage of CD4+CD25+Foxp3+ Tregs was detected using flow cytometry. The location of ZNF667-AS1 was detected using nuclear-cytoplasmic fractionation. The co-location of ZNF667-AS1 and U2AF1 protein was detected using IF-FISH assay. The interactions among ZNF667-AS1, TGFBR1 and U2AF1 were verified using RNA pull-down, RIP and dual luciferase activity.ResultsZNF667-AS1 expression in PC samples was lowered, which was negatively relative to poor prognosis and DTX resistance. ZNF667-AS1 overexpression inhibited malignant phenotypes of PC cells, tumor growth and DTX resistance. Besides, DTX resistant cell-derived exosomes expressed lower ZNF667-AS1 expression. Exosomes carrying exogenously high ZNF667-AS1 expression derived PC cells or serum of mice suppressed Treg expansion. On the mechanism, ZNF667-AS1 interacted with U2AF1 to destabilize TGFBR1 mRNA and reduce TGFBR1 expression in CD4+T cells.ConclusionZNF667-AS1 suppressed cell growth of PC cells, tumor growth of mice and DTX resistance to PC cells and exogenously high ZNF667-AS1 expression in tumor-derived exosomes destabilized TGFBR1 mRNA and reduce TGFBR1 expression through interacting with U2AF1, thus resulting in attenuated Treg expansion, which was related to DTX resistance.

YAP1 modulation of primary cilia-mediated ciliogenesis in 2D and 3D prostate cancer models.

The primary cilium, a non-motile organelle present in most human cells, plays a crucial role in detecting microenvironmental changes and regulating intracellular signaling. Its dysfunction is linked to various diseases, including cancer. We explored the role of ciliated cells in prostate cancer by using Gefitinib and Jasplakinolide compounds to induce ciliated cells in both normal and tumor-like prostate cell lines. We assessed GLI1 and IFT20 expression and investigated YAP1 protein's role, which is implicated in primary cilium regulation. Finally, we examined these compounds in 3D cell models, aiming to simulate in vivo conditions. Our study highlights YAP1 as a potential target for novel genetic models to understand the primary cilium's role in mediating resistance to anticancer treatments.

The role of NOP58 in prostate cancer progression through SUMOylation regulation and drug response.

Prostate cancer is one of the leading causes of cancer-related deaths in men. Its molecular pathogenesis is closely linked to various genetic and epigenetic alterations, including posttranslational modifications like SUMOylation. Identifying biomarkers that predict outcomes and specific therapeutic targets depends on a comprehensive understanding of these processes. With growing interest in SUMOylation as a mechanism affecting prostate cancer-related genes, this study aimed to investigate the central role of SUMOylation in prostate cancer prognostics, focusing on the significance of NOP58. We conducted a comprehensive bioinformatics analysis, integrating differential expression analysis, survival analysis, gene set enrichment analysis (GSEA), and single-cell transcriptomic analyses using data from The Cancer Genome Atlas (TCGA). Key genes were identified through intersections of Venn diagrams, Boralta algorithm signatures, and machine learning models. These signaling mechanisms were validated through experimental studies, including immunohistochemical staining and gene ontology analyses. The dual-gene molecular subtype analysis with SUMO1, SUMO2, and XPO1 genes revealed significant differences in survival outcomes across molecular subtypes, further emphasizing the potential impact of NOP58 on SUMOylation, a key post-translational modification, in prostate cancer. NOP58 overexpression was strongly associated with shorter overall survival (OS), progression-free interval (PFI), and disease-specific death in prostate cancer patients. Immunohistochemical analysis confirmed that NOP58 was significantly overexpressed in prostate cancer tissues compared to normal tissues. ROC curve analysis demonstrated that NOP58 could distinguish prostate cancer from control samples with high diagnostic accuracy. Gene Ontology analysis, along with GSVA and GSEA, suggested that NOP58 may be involved in cell cycle regulation and DNA repair pathways. Moreover, NOP58 knockdown led to increased BCL2 expression and decreased Ki67 levels, promoting apoptosis and inhibiting cell proliferation. Colony formation assays further showed that NOP58 knockdown inhibited, while its overexpression promoted, colony formation, highlighting the critical role of NOP58 in prostate cancer cell growth and survival. Additionally, NOP58 was linked to drug responses, including Methotrexate, Rapamycin, Sorafenib, and Vorinostat. NOP58 is a key regulator of prostate cancer progression through its mediation of the SUMOylation pathway. Its expression level serves as a reliable prognostic biomarker and an actionable therapeutic target, advancing precision medicine for prostate cancer. Targeting NOP58 may enhance therapeutic efficacy and improve outcomes in oncology.

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.

Downregulation of hsa_circ_0006620 inhibits the malignant progression of prostate cancer by regulation of the miR-502-3p/HK2 axis mediated by aerobic glycolysis.

Circular RNAs (circRNA) are a class of covalently-closed, single-stranded RNAs that have been implicated in cancer progression due to their regulation of metabolism. However, the roles of circRNA in prostate cancer remain largely unknown. In this study, fluorescence in situ hybridization and RT-qPCR were used to investigate hsa_circ_0006620 expressions in both prostate cancer cells and tissues, after high-throughput sequencing. The luciferase reporter assay was used to identify hsa_circ_0006620 downstream targets. Transwell migration assays, 5-ethynyl-20-deoxyuridine assays, and Cell Counting Kit-8assays were used to investigate both proliferation and migration. In vivo tumorigenesis and metastasis assays were performed to investigate the role of hsa_circ_0006620 in prostate cancer. The results showed that hsa_circ_0006620 expression increased in prostate cancer cells and tissues. Hsa_circ_0006620 downregulation inhibited prostate cancer cell proliferation as well as in vivo and in vitro migrations. The luciferase results validated that miR-502-3p and hexokinase 2 (HK2) were hsa_circ_0006620 downstream targets. HK2 overexpression or miR-502-3p inhibition reversed prostate cancer cell migration after hsa_circ_0006620 silencing. The study also found that overexpression of HK2 or inhibition of prostate cancer reversed aerobic glycolysis after hsa_circ_0006620 silencing. In summary, the results showed thathsa_circ_0006620 downregulation inhibited prostate cancerby regulation of the miR-502-3p/HK2 axis mediated by aerobic glycolysis.

Circ_0001047 inhibits prostate cancer progression and enhances abiraterone sensitivity via miR-122-5p/FKBP5/PHLPP1/AKT axis in vitro

Prostate cancer (PCa), with high heterogeneity and poor prognosis, is one of the most common malignant tumors in men. Circular RNAs (circRNAs) have been identified in tumor progression and resistance to medication in numerous studies. However, the role of circ_0001047 in PCa is unclear. In this research, we found that circ_0001047 had low expression in PCa cells and tissues and was negatively correlated with testosterone secretion in vivo. Overexpression of circ_0001047 inhibited the proliferation, migration, invasion, and anti-apoptotic abilities of human PCa cells in vitro. Mechanistically, circ_0001047 promoted the expression of FKBP5 through sponge adsorption of miR-122-5p and then inhibited the proliferation, anti-apoptotic migration, and invasion abilities of PCa cells. In addition, overexpression of circ_0001047 enhanced the sensitivity of PCa cells to abiraterone by inhibiting AKT phosphorylation activation through upregulation of FKBP5/PHLPP1. This study revealed a novel mechanism by which circ_0001047 regulates PCa progression and treatment sensitivity via the miR-122-5p/FKBP5/PHLPP1/AKT axis. These findings deepen our comprehension of the molecular mechanisms in latent PCa progression and treatment resistance.Graphical

Phosphorylation by JNK switches BRD4 functions.

Bromodomain 4 (BRD4), a key regulator with pleiotropic functions, plays crucial roles in cancers and cellular stress responses. It exhibits dual functionality: chromatin-bound BRD4 regulates remodeling through its histone acetyltransferase (HAT) activity, while promoter-associated BRD4 regulates transcription through its kinase activity. Notably, chromatin-bound BRD4 lacks kinase activity, and RNA polymerase II (RNA Pol II)-bound BRD4 exhibits no HAT activity. This study unveils one mechanism underlying BRD4's functional switch. In response to diverse stimuli, c-Jun N-terminal kinase (JNK)-mediated phosphorylation of human BRD4 at Thr1186 and Thr1212 triggers its transient release from chromatin, disrupting its HAT activity and potentiating its kinase activity. Released BRD4 directly interacts with and phosphorylates RNA Pol II, PTEFb, and c-Myc, thereby promoting transcription of target genes involved in immune and inflammatory responses. JNK-mediated BRD4 functional switching induces CD8 expression in thymocytes and epithelial-to-mesenchymal transition (EMT) in prostate cancer cells. These findings elucidate the mechanism by which BRD4 transitions from a chromatin regulator to a transcriptional activator.

Molecular Networking, Docking, and Biological Evaluation of Licarin A from Myristica fragrans as a Potential Cancer Chemopreventive Agent.

Currently, clinically available cancer chemopreventive drug options are limited to mostly tamoxifen and its derivatives, such as raloxifene, and approved specifically for breast cancer. Thus, the availability of chemopreventive drug molecules for other types of malignant cancers would be desirable. In previous reports, the arils of Myristica fragrans (mace) have been found to exhibit cancer chemopreventive activity. Therefore, the purpose of the present study was to identify a natural product from this species with potential chemopreventive activity guided by chemoinformatic sample analysis via Global Natural Products Social (GNPS) molecular networking and molecular docking. The neolignan licarin A (1) was identified as a potential chemopreventive constituent, and subsequently submitted to several in vitro bioassays and a zebrafish toxicity evaluation. In this work, 1 afforded superior phosphoNF-κBp65 phosphorylation activity in DU-145 prostate cancer cells compared to isoliquiritigenin (2), which was used as a natural product chemopreventive control. Both 1 and 2 showed a longer-lasting reduction in cellular stress in a cell oxidative stress real-time dose-response assay than the positive control using Hepa1c1c7 mouse hepatoma cells. In addition, 1 displayed similar activities to 2, while also being less toxic to zebrafish (Danio rerio) than both this chalcone and the clinically used chemopreventive drug tamoxifen.

Combinatorial Anti-Cancer Effect of Polypurine Reverse Hoogsteen Hairpins against KRAS and MYC Targeting in Prostate and Pancreatic Cancer Cell Lines

Introduction: KRAS and MYC are proto-oncogenes that are strictly regulated in healthy cells that have key roles in several processes such as cell growth, proliferation, differentiation, or apoptosis. These genes are tightly interconnected, and their dysregulation can lead to cancer progression. We previously individually targeted these oncogenes using Polypurine Reverse Hoogsteen (PPRH) hairpins, mostly targeting the complementary strand of G-quadruplex-forming sequences. We validated them in vitro in different cancer cell lines with deregulated KRAS and/or MYC. In this work we focused on our understanding of the cooperative dynamics between these oncogenes, by investigating the combined impact of PPRHs targeting KRAS and MYC in pancreatic and prostate cancer cells. Results: The combinations had a modulatory impact on the expression of both oncogenes, with transcriptional and translational downregulation occurring five days post-treatment. Out of the four tested PPRHs, MYC-targeting PPRHs, especially HpMYC-G4-PR-C directed against the promoter, showed a greater cytotoxic and expression modulation effect. When both KRAS- and MYC-targeting PPRHs were applied in combination, a synergistic reduction in cell viability was observed. Conclusion: The simultaneous targeting of KRAS and MYC demonstrates efficacy in gene modulation, thus in decreasing cell proliferation and viability.

Loss of miR-200c-3p promotes resistance to radiation therapy via the DNA repair pathway in prostate cancer

Radiotherapy represents a major curative treatment for prostate cancer (PCa), but some patients will develop radioresistance (RR) and relapse. The underlying mechanisms remain poorly understood, and miRNAs might be key players in the acquisition and maintenance of RR. Through their encapsulation in small extracellular vesicles (EVs), they can also be relevant biomarkers of radiation response. Using next-generation sequencing, we found that miR-200c-3p was downregulated in PCa RR cells and in their small EVs due to a gain of methylation on its promoter during RR acquisition. We next showed that its exogenous overexpression restores the radiosensitivity of RR cells by delaying DNA repair through the targeting of HP1α. Interestingly, we also observed downregulation of miR-200c-3p expression by DNA methylation in radiation-resistant lung and breast cancer cell lines. In summary, our study demonstrates that the downregulation of miR-200c-3p expression in PCa cells and in their small EVs could help distinguish radioresistant from sensitive tumor cells. This miRNA targets HP1α to delay DNA repair and promote cell death.