Prostate Tumor Cell Lines Research Articles

Dynamic reciprocal interactions between activated T cells and tumor associated macrophages drive macrophage reprogramming and proinflammatory T cell migration within prostate tumor models

Tumor-associated macrophages (TAMs) have been implicated as a tumor microenvironment (TME) cell population, which may be playing a vital role in the inhibition of effective T cell responses in the prostate TME. In this manuscript, we leverage a novel microscale cell culture platform, known as Stacks, to investigate mono-, co-, and tri-culture TME models comprised of prostate tumor cell lines, primary macrophages, and autologous T cells from patients with prostate cancer. Through multiplexed analysis of these multi-cellular prostate tumor models, we capture a dynamic interaction between primary TAMs and activated T cells that resulted in reciprocal proinflammatory activation of both cell populations upon interaction. These findings suggest that activated T cells are capable of reprogramming immunosuppressive TAMs in the context of prostate tumor models and that TAM reprogramming may play a key supportive role in restoring proinflammatory T cell tumor responses in the prostate TME.

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.

Abstract 4102: Treatment with androgen receptor targeting vaccines provides an overall survival benefit in AR-V7 expressing tumor models

Abstract Background: Androgen receptor (AR) signaling inhibition is part of the mechanism behind many effective prostate cancer therapies, including androgen deprivation and next generation anti-androgens. However in castration resistant prostate cancer up to 50% of treatment resistance has been linked to AR amplification or expression of the constitutively active RNA splice variant, AR-V7. Although the use of immune checkpoint blockade has failed to demonstrate clinical success, immunotherapeutic interventions remain attractive as prostate cancer’s relatively slow progression provides time for anti-tumor immune responses to develop. Cancer specific vaccines have the potential to enable and enhance tumor specific immune responses by stimulating and directing T cell immunity to important oncologic targets. We hypothesized that a cancer vaccine designed to induce a T cell response against cells expressing high levels of AR would result in an anti-tumor effect and potentially prevent or delay the development of therapeutic resistance. Methods: Adenoviral vaccines against AR (Ad-AR) or AR splice variant 7 (Ad-AR-V7) were used to evaluate the potential of AR targeting vaccination in mouse models. We evaluated AR and AR variant specific adaptive responses produced by our vaccines with naïve and tumor-bearing mice by ex vivo peptide restimulation. We challenged vaccinated mice with multiple syngeneic subcutaneous tumor models that we engineered to express AR-V7, including a PTEN-/- p53-/- prostate tumor cell line. Finally we tested our vaccines in a therapeutic regimen, vaccinating mice after implanting our subcutaneous AR-V7 expressing models. Results: Across multiple strains of mice, AR or AR-V7 targeting adenoviral vaccination induced robust adaptive immune responses against the N-terminal domain of AR. Vaccination with either Ad-AR or Ad-AR-V7 resulted in significant anti-tumor responses, providing a significant overall survival benefit and complete tumor rejection by the majority of mice vaccinated against AR or AR-V7. Similarly tumor bearing mice treated with Ad-AR or Ad-AR-V7 vaccination displayed tumor growth inhibition or complete tumor regression resulting in an overall survival benefit. Additionally, we found that vaccine responses were unaffected by the use of the approved antiandrogen drug enzalutamide, suggesting that vaccinations could be deployed in tandem with standard-of-care therapies. Conclusions: Vaccination against AR and AR splice variants can induce AR specific adaptive immune responses capable of inhibiting the growth of AR-V7 expressing tumor models, illustrating the potential of AR and its splice variants as immunologic targets in prostate cancer. Citation Format: Robert D. Marek, Junping Wei, Tao Wang, Xiao-Yi Yang, Gangjun Lei, Zachary C. Hartman. Treatment with androgen receptor targeting vaccines provides an overall survival benefit in AR-V7 expressing tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4102.

Abstract 6816: Prevention of cancer cachexia by inhibition of soluble epoxide hydrolase

Abstract Background: Cancer cachexia is a devastating syndrome characterized by progressive muscle wasting and hyperinflammation. The underlying mechanisms remain poorly understood with no treatment options available. Cachexia is driven by systemic inflammation, pro-inflammatory cytokines, and apoptotic cell death (debris). The resolution of inflammation as an active biochemical process is regulated by novel pro-resolving lipid mediators. Arachidonic acid-derived epoxyeicosatrienoic acids (EETs) are lipid mediators stimulating inflammation resolution. EETs are rapidly metabolized by the enzyme soluble epoxide hydrolase (sEH). sEH is a critical cause of inflammation and a biomarker in several chronic inflammatory diseases. sEH inhibitors promote tissue regeneration and counter-regulate pro-inflammatory cytokines. We hypothesized that pharmacological inhibition of the sEH may prevent cachexia. Methods: We investigated murine cancer cachexia models using genetically engineered pancreatic (KPC) and prostate (TRAMP C1) tumor cell lines, and “TRAMP” mice (transgenic adenocarcinoma of the mouse prostate). We performed LC-MS/MS-based profiling of bioactive lipids in plasma from KPC and colon cancer (CT26)-induced cachectic mice. Results: KPC cells injected intraperitoneally induced 19.7% and 54.1% reduction in muscle weight in the tibialis anterior and soleus, respectively, in immunocompetent C57BL/6 mice compared to non-tumor bearing (NTB) mice. LC-MS/MS revealed KPC and CT26 cachexia induced a pro-inflammatory eicosanoid-driven cytokine storm. The human sEH inhibitor EC5026 delayed the onset of cachexia, leading to sustained survival over 250 days post-injection in the KPC model (n=15 mice/group). sEH expression was increased in the gastrocnemius of KPC mice by day 22 post-tumor cell injection vs. NTB. EC5026 counter-regulated sEH expression compared to vehicle-treated. In the TRAMP model, 5/5 of mice treated with EC5026 survived 230 days post-treatment compared to no survival of vehicle-treated mice (n=5). The transplanted KPC and TRAMP showed reduced CD4+ and CD8+ T lymphocytes and B lymphocytes in the tibialis anterior and gastrocnemius vs. NTB after flow cytometry analysis. EC5026 stimulated a general increase in CD3+ T lymphocytes and counter-regulated an eicosanoid-driven cytokine storm as shown by cytokine assays. EC5026 treatment increased tibialis anterior and gastrocnemius muscle weights and body weights compared to vehicle-treated KPC and TRAMP mice. Conclusions: sEH inhibition may be a novel therapeutic approach to cachexia by targeting the immune response via stimulation of resolution of inflammation without toxicity or immunosuppression. Since sEH inhibitors have proven safe and effective in clinical trials for controlling multiple inflammatory diseases, this study provides a basis for the rapid clinical translation of sEH inhibitors to prevent/reverse cachexia in cancer patients. Citation Format: Rachel L. Bayer, Sarina Virani, Michael Gillespie, Jacqueline Capuano, Keira Smith, Katherine Quinlivan, Kimberly Vasquez, Jun Yang, Haixia Yang, Nicholas Mitsiades, Bruce D. Hammock, Dipak Panigrahy. Prevention of cancer cachexia by inhibition of soluble epoxide hydrolase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6816.

Yellow scorpion (Buthus sinidicus) venom peptides induce mitochondrial-mediated apoptosis in cervical, prostate and brain tumor cell lines.

Scorpion venoms are known to contain over 100,000 biologically active constituents. However, only a few of them have been studied. The major constituents of venom are proteins and peptides, which exhibit various biological and pharmacological properties, including anticancer activities. In the current study, the venom of yellow scorpions (Buthus sindicus) found in Sindh, Pakistan, was extracted and evaluated for its anti-cancer and anti-inflammatory activities. The crude venom showed a dose dependent inhibition of phagocyte oxidative burst from human whole blood cells (28.3% inhibition at highest tested concentration of 300 μg/mL). In-vitro cytotoxicity of crude venom was evaluated against human prostrate (PC3), cervical (HeLa) and neuroblastoma (U87-MG) cell lines, along with cytotoxicity against normal human fibroblast (BJ) cells. Crude venom was cytotoxic to all cell lines, with prominent inhibitory effect on PC3 cells. Crude venom was fractionated through RP-UPLC, resulted in fifteen fractions, followed by evaluation of their anticancer potential. Among all, the fraction I significantly (P < 0.001) reduced the cell viability of all three cancer cell lines, and exhibited insignificant cytotoxicity against normal cell line. Furthermore, the apoptotic cell death pathway was evaluated for crude venom, and fraction I, in most sensitive cell line PC3, by using flow-cytometry analysis. Both crude venom and its fraction I caused a mitochondrial-mediated apoptosis in prostate cancer cells (PC3). To the best of our knowledge, this is the first report of the anticancer and anti-inflammatory activity of venom of Pakistani yellow scorpions. Results indicate their therapeutic potential, and a case for further purification and validation studies.

Radioactive gold nanoparticles coated with BSA: A promising approach for prostate cancer treatment.

Background: Nanotechnology has revolutionized medicine, especially in oncological treatments. Gold nanoparticles (AuNPs) stand out as an innovative alternative due to their biocompatibility, potential for surface modification, and effectiveness in radiotherapeutic techniques. Given that prostate cancer ranks as one of the leading malignancies among men, there's a pressing need to investigate new therapeutic approaches. Methods: AuNPs coated with bovine serum albumin (BSA) were synthesized and their cytotoxicity was assessed against prostate tumor cell lines (LNCaP and PC-3), healthy prostate cells (RWPE-1), and endothelial control cells (HUVEC) using the MTS/PMS assay. For in vivo studies, BALB/C Nude mice were employed to gauge the therapeutic efficacy, biodistribution, and hematological implications post-treatment with BSA-coated AuNPs. Results: The BSA-coated AuNPs exhibited cytotoxic potential against PC-3 and LNCaP lines, while interactions with RWPE-1 and HUVEC remain subjects for further scrutiny. Within animal models, a diverse therapeutic response was observed, with certain instances indicating complete tumor regression. Biodistribution data emphasized the nanoparticles' affinity towards particular organs, and the majority of hematological indicators aligned with normative standards. Conclusions: BSA-coated AuNPs manifest substantial promise as therapeutic tools in treating prostate cancer. The present research not only accentuates the nanoparticles' efficacy but also stresses the imperative of optimization to ascertain both selectivity and safety. Such findings illuminate a promising trajectory for avant-garde therapeutic modalities, holding substantial implications for public health advancements.

Discovery of a Dual Tubulin and Neuropilin-1 (NRP1) Inhibitor with Potent In Vivo Anti-Tumor Activity via Pharmacophore-based Docking Screening, Structure Optimization, and Biological Evaluation.

Dual inhibition of tubulin and neuropilin-1 (NRP1) may become an effective method for cancer treatment by simultaneously killing tumor cells and inhibiting tumor angiogenesis. Herein, we identified dual tubulin/NRP1-targeting inhibitor TN-2, which exhibited good inhibitory activity against both tubulin polymerization (IC50 = 0.71 ± 0.03 μM) and NRP1 (IC50 = 0.85 ± 0.04 μM). Importantly, it significantly inhibited the viability of several human prostate tumor cell lines. Further mechanism studies indicated that TN-2 could inhibit tubulin polymerization and cause G2/M arrest, thereby inducing cell apoptosis. It could also suppress cell tube formation, migration, and invasion. Moreover, TN-2 showed obvious antitumor effects on the PC-3 cell-derived xenograft model with negligible side effects and good pharmacokinetic profiles. These data demonstrate that TN-2 could be a promising dual-target chemotherapeutic agent for the treatment of prostate cancer.

Protein Kinase C Epsilon Overexpression in Prostate Adenocarcinoma is Associated with Oncogenesis

Background: PKCε, an isozyme of serine-threonine kinase, has been implicated in epithelial cancer metastasis and progression. This study investigates the impact of the oncogenic PKCε, overexpressed abnormally in human Prostate tumor samples and cell lines, to understand its efficacy. Methods: The microarray dataset, GSE86257, was processed for normalization. The identification of upregulated and downregulated genes was based on FDR &gt;1 and p &lt;0.05 values. Cytoscape analysis and functional enrichment of significant genes were done. The identified genes were validated on the TCGA dataset and survival analysis was performed by Kaplan-Meier analysis. Results: A total of 1524 DEGs were identified with 728 upregulated genes and 818 downregulated genes. The two significant modules with MCODE score:9.0 and Venn analysis provided cyclin-dependent kinase inhibitor protein (CDK1), Cyclin B1 (CCNB1), Phospholipase C Gamma 1 (PLCG1), Cyclin Dependent Kinase 9 (CDK9), Phosphoinositide-3-Kinase Regulatory Subunit 3 (PIK3R3), H4 Clustered Histone 6 (H4C6), Phospholipase C Gamma 2 (PLCG2) as most interacting genes. TCGA data analysis and Prognostic analysis revealed CCNBI, CDK9, and PLCG1 associated with poor prognosis. Conclusion: PKCε regulates genes that are responsible for cancer progression. Therefore, targeting PKCε in Prostate cancer may serve as an important regulatory effect and may improve the prognosis of the disease.

Impairment of SK-MEL-28 Development—A Human Melanoma Cell Line—By the Crataeva tapia Bark Lectin and Its Sequence-Derived Peptides

Melanoma is difficult to treat with chemotherapy, prompting the need for new treatments. Protease inhibitors have emerged as promising candidates as tumor cell proteases promote metastasis. Researchers have developed a chimeric form of the Bauhinia bauhinioides kallikrein inhibitor, rBbKIm, which has shown negative effects on prostate tumor cell lines DU145 and PC3. Crataeva tapia bark lectin, CrataBL, targets sulfated oligosaccharides in glycosylated proteins and has also demonstrated deleterious effects on prostate and glioblastoma tumor cells. However, neither rBbKIm nor its derived peptides affected the viability of SK-MEL-28, a melanoma cell line, while CrataBL decreased viability by over 60%. Two peptides, Pep. 26 (Ac-Q-N-S-S-L-K-V-V-P-L-NH2) and Pep. 27 (Ac-L-P-V-V-K-L-S-S-N-Q-NH2), were also tested. Pep. 27 suppressed cell migration and induced apoptosis when combined with vemurafenib, while Pep. 26 inhibited cell migration and reduced nitric oxide and the number of viable cells. Vemurafenib, a chemotherapy drug used to treat melanoma, was found to decrease the release of interleukin 8 and PDGF-AB/BB cytokines and potentiated the effects of proteins and peptides in reducing these cytokines. These findings suggest that protease inhibitors may be effective in blocking melanoma cells and highlight the potential of CrataBL and its derived peptides.

Antibacterial and Cytotoxic Silica-Polycaprolactone-Chlorogenic Acid Hybrids by Sol-Gel Route.

Organic-inorganic hybrid materials were synthesized by a sol-gel route, using silicon alkoxide together with low molecular weight polycaprolactone and caffetannic acid. The synthesized hybrids were characterized by scanning Fourier-transform infrared (FTIR) spectroscopy, and their surface morphology was acquired by scanning electron microscopy (SEM) analysis. The hybrids were investigated for their antiradical capacity using the DPPH and ABTS tests, while the Kirby-Bauer test was used to evaluate their effects on the growth of Escherichia coli and Enterococcus faecalis. Furthermore, a biologically active hydroxyapatite layer has been observed to form on the surface of intelligently synthesized materials. The MTT direct test showed that the hybrid materials are biocompatible with NIH-3T3 fibroblast cells, while they were cytotoxic towards colon, prostate, and brain tumor cell lines. These results shed new light on the suitability of the synthesized hybrids in the medical field, thus affording knowledge on the features of the bioactive silica-polycaprolactone-chlorogenic acid hybrids.

Antitumor Effect of Chalcone Derivatives against Human Prostate (LNCaP and PC-3), Cervix HPV-Positive (HeLa) and Lymphocyte (Jurkat) Cell Lines and Their Effect on Macrophage Functions

Chalcones are synthetic and naturally occurring compounds that have been widely investigated as anticancer agents. In this work, the effect of chalcones 1-18 against the metabolic viability of cervical (HeLa) and prostate (PC-3 and LNCaP) tumor cell lines was tested, to compare the activity against solid and liquid tumor cells. Their effect was also evaluated on the Jurkat cell line. Chalcone 16 showed the highest inhibitory effect on the metabolic viability of the tested tumor cells and was selected for further studies. Recent antitumor therapies include compounds with the ability to influence immune cells on the tumor microenvironment, with immunotherapy being one actual goal in cancer treatment. Therefore, the effect of chalcone 16 on the expression of mTOR, HIF-1α, IL-1β, TNF-α, IL-10, and TGF-β, after THP-1 macrophage stimulation (none, LPS or IL-4), was evaluated. Chalcone 16 significantly increased the expression of mTORC1, IL-1β, TNF-α, and IL-10 of IL-4 stimulated macrophages (that induces an M2 phenotype). HIF-1α and TGF-β were not significantly affected. Chalcone 16 also decreased nitric oxide production by the RAW 264.7 murine macrophage cell line, this effect probably being due to an inhibition of iNOS expression. These results suggest that chalcone 16 may influence macrophage polarization, inducing the pro-tumoral M2 macrophages (IL-4 stimulated) to adopt a profile closer to the antitumor M1 profile.

Synthesis, spectroscopic characterization, antibacterial activity and antiproliferative profile of a new silver(I) complex of 5-fluorocytosine

In this paper, we report the synthesis, structural characterization, and explore the potential antibacterial and antiproliferative activities of a new silver(I) complex of the nucleotide analogue 5-fluorocytosine, Ag-5FC. Elemental and thermogravimetric (TGA) analyses led to the minimal formula AgC4H4FN3O·H2O. Infrared (FT-IR) and solid-state 13C nuclear magnetic resonance (NMR) spectroscopic analyses indicate that the ligand coordinates to the metal ion by its nitrogen and oxygen atoms. High resolution mass spectrometric (HRMS) data confirmed the proposed composition of the complex as well as the presence of recombination species in solution. Molecular modeling reinforces the proposed N,O-coordination of 5FC to silver as indicated by IR data with a possible structure of the complex in a dimeric form, of coordination formula [Ag(C4H4FN3O)(OH2)]2. The complex showed a modest antimicrobial activity (MIC = 4.3 mmol⋅L−1) against Gram-negative (Pseudomonas aeruginosa and Escherichia coli) and Gram-positive (Staphylococcus aureus and Bacillus cereus) strains. Despite the low solubility, the Ag-5FC complex totally inhibited the proliferation of colon (HT-29), multidrug resistant ovarian (NCI/ADR-RES), prostate (PC-3), and renal (786–0) tumor cell lines in a concentration range of 6.2 to 9.3 µmol L−1. Further studies are necessary to confirm efficiency and safety for continuing the pre-clinical evaluation of the Ag-5FC complex.

SaKLK1-374 is more difficult to induce KLK1 expression in normal prostate cell lines than that in prostate cancer cell lines: Rethinking the universality of RNA activation

RNA activation, as a method of regulating gene expression at the transcriptional level, is far less widely used than RNA interference because of the insufficient understanding of the mechanism and the unstable success rate. It is necessary to analyze the failure cases of RNA activation to promote the application of RNA activation. When we validated the saRNAs designed to induce KLK1 expression, we found that saKLK1-374 can upregulate KLK1 expression in prostate tumor cell lines, but failed in normal prostate cell lines. To determine whether the RNA activation of normal cells is difficult only when the target gene is KLK1, we tested p21WAF1/CIP1 as the target gene in RNA activation experiments of normal and cancer prostate cells. Next, to determine whether the above phenomenon exists in other tissues, we used normal and cancerous bladder cells to perform RNA activation experiments with KLK1 and p21WAF1/CIP1 as targets. We have also extended the time from transfection to detection to evaluate whether a longer incubation time can make saRNA upregulate the target genes in normal cells. Fluorescently labeled dsRNA was transfected to evaluate the transfection efficiency, and the expression of Ago2 and IPO8 necessary for RNA activation was also detected. The p21WAF1/CIP1 could be significantly upregulated by saRNA in prostate cancer cells, but not in normal prostate cells. The expression of KLK1 in bladder-derived cell lines was extremely low and could not be induced by saRNA. The p21WAF1/CIP1 was upregulated by saRNA to a higher extent in bladder cancer cells but to a lower extent in normal bladder cells. Prolonging incubation time could not make saRNA induce the expression of target genes in normal cells. Compared with tumor cells used in this study, normal cells had lower transfection efficiency or lower expression of Ago2 and IPO8. Although it has been currently found that normal cell lines in the prostate and bladder might be more difficult to be successfully induced target gene expression by exogenous saRNA than tumor cells due to low transfection efficiency or Ago2 and IPO8 expression, it is not certain that this phenomenon occurs in other types of tissue. However, researchers still need to pay attention to the transfection efficiency and/or the expression levels of Ago2 and IPO8 when conducting RNA activation experiments in normal cells.

Preparation, Process Optimization and Cytotoxicity Evaluation of Lyophilized Etoposide Loaded Nanoparticles

The purpose of this study was to develop freeze dried Polylactide-co-glycolide (PLGA) nanoparticles loaded with etoposide intended to be administered intravenously with improved therapeutic efficacy of the drug and thereby reduced dose related toxicity associated with it. The etoposide loaded nanoparticles were prepared using modified spontaneous emulsification solvent diffusion method (SESD).The in Vitro release study of etoposide loaded Polylactide-co-glycolide (PLGA)–Nanoparticles NP was carried by dialysis bag diffusion technique.The incorporation efficiency was found to be higher in modified SESD technique than emulsification solvent evaporation method. The release behavior of etoposide exhibited a biphasic pattern characterized by an initial burst release followed by a slow and continuous release. The nanoparticles were characterized by particle size, zeta potential, polydispersity index, DSC and FTIR. The long term stability was achieved by lyophilisation technique. The cell line study using XTT assay on LNCaP prostate tumor cell lines revealed that etoposide loaded nanoparticles showed greater cancer cell inhibition compared to plain nanoparticles and marketed conventional formulations.&#x0D;

Abstract 2: Flavokawain A targets cancer stem cells for inhibiting the growth of prostate cancer

Abstract Prostate cancer stem cells (PCSC) are small tumor subpopulations capable of self-renewal and driving prostate cancer heterogeneity, which is critical for cancer initiation, recurrence, and development of therapeutic resistance. Thus, there’s an urgent need to explore and develop new CSC targeting agents. Flavokawain A (FKA), a novel chalcone from kava plant, can selectively inhibit the growth of pRb deficient cell lines and result in a proteasome-dependent and ubiquitination-mediated Skp2 (S-phase kinase-associated protein 2) degradation, while the potential of FKA to target PCSC is unknown. Therefore, we evaluated the effects of FKA on PCSC self-renewal both in vitro and in vivo. FKA treatment decreased both size and numbers of the tumor spheroids growing from CD44+/CD133+ tumor stem cells, which were sorted out from the prostate tumor cell line DU145 and 22RV1. Expression of the stem cell markers Nanog, Oct4, and Sox2 were all downregulated in the cancer spheroids treated with FKA. Growth of the 22RV1CD44+/CD133+ xenograft tumors was significantly inhibited in FKA diet-fed mice compared to the vehicle control diet-fed mice. Immunohistochemistry analysis revealed less positive Ki67, Nanog, and Oct4 cells in tumor tissues from the FKA dietary group than those from the control dietary group. These results demonstrated that FKA can inhibit prostate cancer stemness and suggested a potential role of FKA for preventing prostate cancer recurrence by targeting PCSC. Citation Format: Liankun Song, Merci Mino, Jana Yamak, Vyvyan Nguyen, Derron Lopez, Victor Pham, Ali Fazelpour, Vinh Le, Dongjun Fu, Matthew Tippin, Xiaolin Zi. Flavokawain A targets cancer stem cells for inhibiting the growth of prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2.

Niraparib Shows Superior Tissue Distribution and Efficacy in a Prostate Cancer Bone Metastasis Model Compared with Other PARP Inhibitors

Patients with prostate cancer whose tumors bear deleterious mutations in DNA-repair pathways often respond to PARP inhibitors. Studies were conducted to compare the activity of several PARP inhibitors in vitro and their tissue exposure and in vivo efficacy in mice bearing PC-3M-luc-C6 prostate tumors grown subcutaneously or in bone. Niraparib, olaparib, rucaparib, and talazoparib were compared in proliferation assays, using several prostate tumor cell lines and in a cell-free PARP-trapping assay. PC-3M-luc-C6 cells were approximately 12- to 20-fold more sensitive to PARP inhibition than other prostate tumor lines, suggesting that these cells bear a DNA damage repair defect. The tissue exposure and efficacy of these PARP inhibitors were evaluated in vivo in PC-3M-luc-C6 subcutaneous and bone metastasis tumor models. A steady-state pharmacokinetic study in PC-3M-luc-C6 tumor-bearing mice showed that all of the PARP inhibitors had favorable subcutaneous tumor exposure, but niraparib was differentiated by superior bone marrow exposure compared with the other drugs. In a PC-3M-luc-C6 subcutaneous tumor efficacy study, niraparib, olaparib, and talazoparib inhibited tumor growth and increased survival to a similar degree. In contrast, in the PC-3M-luc-C6 bone metastasis model, niraparib showed the most potent inhibition of bone tumor growth compared with the other therapies (67% vs. 40%-45% on day 17), and the best survival improvement over vehicle control [hazard ratio (HR), 0.28 vs. HR, 0.46-0.59] and over other therapies (HR, 1.68-2.16). These results show that niraparib has superior bone marrow exposure and greater inhibition of tumor growth in bone, compared with olaparib, rucaparib, and talazoparib.

Cytotoxic Action of Palladium-Based Compound on Prostate Stem Cells, Primary Prostate Epithelial Cells, Prostate Epithelial Cells, and Prostate Cell Lines.

Objective Prostate cancer is one of the most common types of cancer found to occur in males and is ranked as the second-highest cause of cancer-associated deaths among male patients. In this study, we have shown the influence of a new palladium-based anticancer agent in contrast to the six distinct prostate cancer lines and the primary cultures. Methods In this study, we have used six distinct prostate cell lines, that is, PNT2-C2, LNCaP, BPH-1, PC-3, PNT1A, and P4E6. The MTP and ATP assay were performed to evaluate the growth of the cell and the flow cytometry to investigate the status of the cell cycle. The antigrowth effect of the palladium complex was evaluated against different cell lines at three time zones 24 h, 48 h, and 72 h. [PdCl(terpy)] (capsule)-2H2O is synthesized by direct encapsulation of equimolar amounts of capsule ions into [Pd (terpy) Cl] Cl-2H2O. Results A comparative analysis was done on 25 mM etoposide and 12 mM cisplatin, cytotoxic agents. The lowest IC50 value at 72 hours was 0.128 mM for BPH-1 cell lines with 0.139 mM, whereas PNT2-C2 cells were found to be most resistant with IC50 values of 0.829 mM. The antigrowth effect of palladium complex on cell lines was measured using the MTS assay at 24, 48, and 72 hours. BPH-1, PNT2-C2, and PNT1A either possess normal tissues or have benign prostatic hyperplasia tissues whereas P4E6, PC-3, and LNCaP cell lines possess malignant origin. The Pd complex exhibited significant cytotoxic action in stem cells when compared against etoposide. An antigrowth effect was reported for Pd complex at lower concentration, but it was more cytotoxic than etoposide with significant cytotoxicity (P=0.001). Conclusion The palladium complex experienced a substantial antigrowth influence over most of the prostate tumor cell lines and the primary cultures, eventually, leading to the implementation of this Pd complex in the treating procedure of metastatic prostate cancer, which is tremendously resistant to the traditional treatment.

The Cationic Amphiphilic Drug Hexamethylene Amiloride Eradicates Bulk Breast Cancer Cells and Therapy-Resistant Subpopulations with Similar Efficiencies.

Simple SummaryA limitation to successful therapeutic outcomes for breast and other cancer patients is the ability of small subsets of tumor cells to resist the apoptotic cell death provoked by currently employed therapeutic agents. These therapy-resistant cancer stem cell populations can then seed recurrent tumors and metastatic lesions, compromising the efficacy of the treatment regimen. The aim of our study was to assess the hypothesis that cationic amphiphilic drugs (CADs), which induce tumor cell death via the unrelated programmed necrotic mechanism, exhibit efficacy toward cancer stem cell populations that are resistant to currently employed therapeutics. We found that the therapy-resistant stem-like subpopulation of cells from a variety of breast cancer models are as sensitive to CADs as the bulk population. Our observations imply that the incorporation of cationic amphiphilic anticancer agents into existing therapeutic regimens could ultimately improve breast cancer patient outcomes by minimizing tumor recurrence and metastatic outgrowth.The resistance of cancer cell subpopulations, including cancer stem cell (CSC) populations, to apoptosis-inducing chemotherapeutic agents is a key barrier to improved outcomes for cancer patients. The cationic amphiphilic drug hexamethylene amiloride (HMA) has been previously demonstrated to efficiently kill bulk breast cancer cells independent of tumor subtype or species but acts poorly toward non-transformed cells derived from multiple tissues. Here, we demonstrate that HMA is similarly cytotoxic toward breast CSC-related subpopulations that are resistant to conventional chemotherapeutic agents, but poorly cytotoxic toward normal mammary stem cells. HMA inhibits the sphere-forming capacity of FACS-sorted human and mouse mammary CSC-related cells in vitro, specifically kills tumor but not normal mammary organoids ex vivo, and inhibits metastatic outgrowth in vivo, consistent with CSC suppression. Moreover, HMA inhibits viability and sphere formation by lung, colon, pancreatic, brain, liver, prostate, and bladder tumor cell lines, suggesting that its effects may be applicable to multiple malignancies. Our observations expose a key vulnerability intrinsic to cancer stem cells and point to novel strategies for the exploitation of cationic amphiphilic drugs in cancer treatment.

Antiproliferative Activity of Two Unusual Dimeric Flavonoids, Brachydin E and Brachydin F, Isolated from Fridericia platyphylla (Cham.) L.G.Lohmann: In Vitro and Molecular Docking Evaluation.

Despite the breakthrough in the development of anticancer therapies, plant-derived chemotherapeutics continue to be the basis of treatment for most types of cancers. Fridericia platyphylla is a shrub found in Brazilian cerrado biome which has cytotoxic, anti-inflammatory, and analgesic properties. The aim of this study was to investigate the antiproliferative potential of the crude hydroethanolic extract, subfraction (containing 59.3% of unusual dimeric flavonoids Brachydin E and 40.7% Brachydin F), as well as Brachydin E and Brachydin F isolated from F. platyphylla roots. The cytotoxic activity was evaluated in glioblastoma, lung, prostate, and colorectal human tumor cell lines. The crude hydroethanolic extract did not present cytotoxic activity, but its subfraction presented lower IC50 values for glioblastoma (U-251) and prostate adenocarcinoma (PC-3) cell lines. Brachydins E and F significantly reduced cell viability, proliferation, and clonogenic potential of PC-3, inducing them to the process of regulated cell death. In silico studies have indicated nuclear receptors as targets for Brachydins E and F, and molecular docking has pointed out their binding into glucocorticoid receptor (GR) ligand pocket. Targeting GR pathway has been described as a therapeutic strategy, especially for prostate cancer. These results suggest that Brachydin E and Brachydin F are promising compounds to be further explored for their antitumor effects.

Comparison of characteristics and tumor targeting properties of extracellular vesicles derived from primary NK cells or NK-cell lines stimulated with IL-15 or IL-12/15/18

NK cell-based therapies have shown promise for hematological cancer forms, but their use against solid tumors is hampered by their poor ability to infiltrate the tumor. NK cells release extracellular vesicles (EVs) containing cytolytic proteins, indicating that NK-cell derived EVs may have therapeutic potential. In this study, we compared the tumor-targeting potential of EVs derived from either primary NK cells or the NK cell lines NK-92 and KHYG-1 cultured in IL-15 alone or in combination with IL-12 and IL-18. Primary NK cells were also stimulated through the activating receptor CD16. Tumor cell apoptosis was measured using a panel of human colon, melanoma, glioblastoma, prostate, breast, and ovarian tumor cell line spheroids. NK cells or NK-92 cells stimulated with IL-12, IL-15, and IL-18 generated EVs with higher efficiency than EVs from resting cells, although similar amounts of EVs were produced under both conditions. Proteomic analysis indicated similar distribution of cytolytic proteins in EVs from primary NK cells and NK-92, but lower levels in KHYG-1 EVs that translated into poor capacity for KHYG-1 EVs at targeting tumor cell lines. Further, we show that CD16-stimulated NK cells release low amounts of EVs devoid of cytolytic proteins. Importantly, EVs from cytokine-stimulated NK cells penetrate into the spheroid core, and tumor spheroid susceptibility to NK-cell derived EVs was linked to differential expression of the NKG2D ligands MICA/B, which was blocked with an anti-NKG2D antibody. We conclude that EVs from activated primary NK cells or NK-92 cells has the best potential to infiltrate and target solid tumors.