Prostate Adenocarcinoma PC-3 Cells Research Articles

Diagnosis of Prostate Cancer with a Neurotensin–Bombesin Radioligand Combination—First Preclinical Results

Background: The concept of radiotheranostics relies on the overexpression of a biomolecular target on malignant cells to direct diagnostic/therapeutic radionuclide-carriers specifically to cancer lesions. The concomitant expression of more than one target in pathological lesions may be elegantly exploited to improve diagnostic sensitivity and therapeutic efficacy. Toward this goal, we explored a first example of a combined application of [99mTc]Tc-DT11 (DT11, N4-Lys(MPBA-PEG4)-Arg-Arg-Pro-Tyr-Ile-Leu-OH; NTS1R-specific) and [99mTc]Tc-DB7(DB7, N4-PEG2-DPhe-Gln-Trp-Ala-Val-Gly-His-Leu-NHEt; GRPR-specific) in prostate cancer models. Methods: Accordingly, the behavior of [99mTc]Tc-DT11 was compared with that of the [99mTc]Tc-DT11+[99mTc]Tc-DB7 mixture in prostate adenocarcinoma PC-3 cells and xenografts in mice. The impact of stabilizing both radiotracers by Entresto®, as a source of the potent neprilysin inhibitor sacubitrilat, was also investigated. Results: The PC-3 cell binding of the [99mTc]Tc-DT11+[99mTc]Tc-DB7 mixture surpassed that of [99mTc]Tc-DT11. Likewise, the PC-3 tumor uptake of the [99mTc]Tc-DT11+[99mTc]Tc-DB7 mixture at 4 h post-injection was superior (7.70 ± 0.89%IA/g) compared with [99mTc]Tc-DT11 (4.23 ± 0.58%IA/g; p < 0.0001). Treatment with Entresto® led to further enhancement of the tumor uptake (to 11.57 ± 1.92%IA/g; p < 0.0001). Conclusions: In conclusion, this first preclinical study on prostate cancer models revealed clear advantages of dual NTS1R/GRPR targeting, justifying further assessment of this promising concept in other cancer models.

Development of a novel prostate Cancer-Stroma Sphere (CSS) model for In Vitro tumor microenvironment studies

Tumor employs non-cancerous cells to gain beneficial features that promote growth and survival of cancer cells. Despite intensive research in the area of tumor microenvironment, there is still a lack of reliable and reproducible in vitro model for tumor and tumor-microenvironment cell interaction studies. Herein we report the successful development of a heterogeneous cancer-stroma sphere (CSS) model composed of prostate adenocarcinoma PC3 cells and immortalized mesenchymal stem cells (MSC). The CSS model demonstrated a structured spatial layout of the cells, with stromal cells concentrated at the center of the spheres and tumor cells located on the periphery. Significant increase in the levels of VEGFA, IL-10, and IL1a has been detected in the conditioned media of CSS as compared to PC3 spheres. Single cell RNA sequencing data revealed that VEGFA was secreted by MSC cells within heterogeneous spheroids. Enhanced expression of extracellular membrane (ECM) proteins was also shown for CSS-derived MSCs. Furthermore, we demonstrated that the multicellular architecture altered cancer cell response to chemotherapeutic agents: the inhibition of sphere formation by topotecan was 74.92 ± 4.56 % for PC3 spheres and 45.95 ± 7.84 % for CSS spheres (p < 0.01), docetaxel showed 37,51± 20,88 % and 15,67± 14,08 % inhibition, respectively (p < 0.05). Thus, CSS present an effective in vitro model for examining the extracellular matrix composition and cell-to-cell interactions within the tumor, as well as for evaluating the antitumor activity of drugs.

Preclinical evaluation of new GRPR-antagonists with improved metabolic stability for radiotheranostic use in oncology

BackgroundThe gastrin-releasing peptide receptor (GRPR) has been extensively studied as a biomolecular target for peptide-based radiotheranostics. However, the lack of metabolic stability and the rapid clearance of peptide radioligands, including radiolabeled GRPR-antagonists, often impede clinical application. Aiming at circumventing these drawbacks, we have designed three new GRPR-antagonist radioligands using [99mTc]Tc-DB15 ([99mTc]Tc-N4-AMA-DIG-DPhe-Gln-Trp-Ala-Val-Sar-His-Leu-NHEt; AMA: p-aminomethylaniline; DIG: diglycolate) as a motif, due to its high GRPR-affinity and stability to neprilysin (NEP). The new analogues carry the DOTAGA-chelator (1,4,7,10-tetraazacyclododecane-1-glutaric acid-4,7,10-triacetic acid) through different linkers at the N-terminus to allow for labeling with the theranostic radionuclide pair In-111/Lu-177. After labeling with In-111 the following radioligands were evaluated: (i) [111In]In-AU-SAR-M1 ([111In]In-DOTAGA-AMA-DIG-DPhe-Gln-Trp-Ala-Val-Sar-His-Leu-NHEt), (ii) [111In]In-AU-SAR-M2 ([111In]In-[DOTAGA-Arg]AU-SAR-M1) and (iii) [111In]In-AU-SAR-M3 ([111In]In-[DOTAGA-DArg]AU-SAR-M1).ResultsThese radioligands were compared in a series of in vitro assays using prostate adenocarcinoma PC-3 cells and in murine models. They all displayed high and GRPR-specific uptake in PC-3 cells. Analysis of mice blood collected 5 min post-injection (pi) revealed similar or even higher metabolic stability of the new radioligands compared with [99mTc]Tc-DB15. The stability could be further increased when the mice were treated with Entresto® to in situ induce NEP-inhibition. In PC-3 xenograft-bearing mice, [111In]In-AU-SAR-M1 displayed the most favourable biodistribution profile, combining a good tumor retention with the highest tumor-to-organ ratios, with the kidneys as the dose-limiting organ.ConclusionsThese findings strongly point at AU-SAR-M1 as a promising radiotherapeutic candidate when labeled with Lu-177, or other medically appealing therapeutic radiometals, especially when combined with in situ NEP-inhibition. To this goal further investigations are currently pursued.

Hedychium spicatum rhizome essential oil induces apoptosis in human prostate adenocarcinoma PC-3 cells via mitochondrial stress and caspase activation

Hedychium spicatum is an essential oil bearing plant extensively used in the traditional system of medicine in several countries. Previous research has revealed H. spicatum essential oil (HSEO) to exhibit anti-tumor activity, although the mechanism of action is still unknown. Therefore, the current study was designed to carry out a comprehensive characterization of HSEO and evaluate the chemotherapeutic potential of HSEO against cancerous cells. The volatile constituents of HSEO was determined by one-dimensional gas chromatography with time-of-flight mass spectrometry (GC-TOFMS) and two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-TOFMS). In total, 193 phytocompounds could be detected, out of which 140 were identified for the first time. The major phytoconstituents detected by GCxGC-TOFMS were β-pinene (10.94%), eucalyptol (6.45%), sabinene (5.48%) and trans-isolimonene (5.00%). GCxGC-TOFMS analysis showed two and half fold increase in the constituents over GC-TOFMS due to better chromatographic separation of constituents in the 2nd dimensional column. HSEO was tested for in vitro cytotoxic activity against cancerous (PC-3, HCT-116 and A-549) and normal (3T3-L1) cell, with HSEO being most selective for prostate cancer cell (PC-3) over non-tumorigenic fibroblast (3T3-L1) cell. HSEO treatment inhibited the colony formation ability of PC-3 cells. HSEO treatment caused apoptotic cell death and cell cycle arrest at G2/M and S phase in PC-3 cells. HSEO induced apoptosis via intracellular ROS accumulation, mitochondria depolarization and increased caspase-3, 8, and 9 levels in PC-3 cells. Additionally, HSEO treatment led to a decrease of Bcl-2 and Bcl-xL and increase of Bax and Bak protein levels. Overall, results from this study highlighted the anticancer potential of H. spicatum essential oil, which could be considered as a new agent for treating prostate cancer.

Abstract 6321: Anti-BTN1A1 exhibits synergistic anti-tumor immunotherapeutic efficacy in combination with radiation therapy

Abstract Chronic inflammation is a critical risk factor in the context of cancer development that promotes the expression of immune checkpoint proteins including PD-1, PD-L1, LAG-3, and TIM-3, which in turn suppress T-cell mediated cytotoxic tumor cell killing. Inflammation induced by treatments including chemotherapy and radiotherapy (RT) can also promote immune checkpoint upregulation and consequent tumor immune escape. However, whether the acute inflammation associated with standard chemotherapy and RT can engage distinct immune checkpoints to further support tumor persistence remains unknown. Using an in vivo screening platform in which tumors were irradiated with high-dose γ-radiation, we identified the B7-related immunoglobulin superfamily protein butyrophilin 1A1 (BTN1A1) as an acute stress-inducible immune checkpoint. Herein, we aimed to investigate how BTN1A1 contributes to post-irradiation intratumoral immunosuppression. To assess BTN1A1 induction in response to γ-radiation, human cell lines were exposed to a range of radiation doses, and cell death and BTN1A1 expression were examined by flow cytometry. Radiation promoted apoptosis and BTN1A1 expression in a dose-dependent manner, and PD-L1 was downregulated by increasing the dosage of γ-radiation. As radiation-induced cell death results in cytosolic DNA accumulation within tumors, which in turn activates the production of type I interferons (IFNs) via the cGAS/STING pathway, we examined the effect of BTN1A1 on cGAS and STING expression. BTN1A1 overexpression in human prostate adenocarcinoma PC3 cells suppressed cGAS and STING expression. IFNs can promote antigen presenting cell activation, thus priming T cell responses. We then examined the impact of BTN1A1 overexpression on type I IFN production as assessed via qRT-PCR, revealing that BTN1A1 overexpression enhanced IFN-β expression in the presence of the STING agonist cGAMP. BTN1A1 was also found to harbor a C-terminal B30.2 domain that was able to specifically interact with xanthine oxidoreductase (XOR), an oxidizing enzyme involved in purine metabolism. BTN1A1 expression induced high levels of intracellular reactive oxygen species (ROS), which have the potential to be more toxic in lymphocytes as compared to tumor cells, and BTN1A1 knockdown decreased these ROS levels. In light of these observations, we assessed the combination therapeutic efficacy of RT and anti-BTN1A1 antibodies in a syngeneic murine Lewis lung carcinoma (LLC) model system, revealing that these two treatments exhibited synergistic anti-tumor activity. FACS and IHC further confirmed that BTN1A1 was upregulated within tumors following irradiation. Together, these data offer new insights regarding the immunomodulatory role of radiation-induced BTN1A1 within tumors, providing a more robust foundation for the development of BTN1A1 as an immunologic target for cancer therapy. Citation Format: Ezra Chung, Young-Seung Kim, Andrew Park, Steven H. Lin, Hyunjin Jung, Stephen S. Yoo. Anti-BTN1A1 exhibits synergistic anti-tumor immunotherapeutic efficacy in combination with radiation therapy [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 6321.

Increased Expressions of Matrix Metalloproteinases (MMPs) in Prostate Cancer Tissues of Men with Type 2 Diabetes.

Type 2 diabetes (T2D) is associated with worse prognosis of prostate cancer (PCa). The molecular mechanisms behind this association are still not fully understood. The aim of this study was to identify key factors, which contribute to the more aggressive PCa phenotype in patients with concurrent T2D. Therefore, we investigated benign and PCa tissue of PCa patients with and without diabetes using real time qPCR. Compared to patients without diabetes, patients with T2D showed a decreased E-cadherin/N-cadherin (CDH1/CDH2) ratio in prostate tissue, indicating a switch of epithelial-mesenchymal transition (EMT), which is a pivotal process in carcinogenesis. In addition, the gene expression levels of matrix metalloproteinases (MMPs) and CC chemokine ligands (CCLs) were higher in prostate samples of T2D patients. Next, prostate adenocarcinoma PC3 cells were treated with increasing glucose concentrations to replicate hyperglycemia in vitro. In these cells, high glucose induced expressions of MMPs and CCLs, which showed significant positive associations with the proliferation marker proliferating cell nuclear antigen (PCNA). These results indicate that in prostate tissue of men with T2D, hyperglycemia may induce EMT, increase MMP and CCL gene expressions, which in turn activate invasion and inflammatory processes accelerating the progression of PCa.

The Cytotoxic Effect of Eurycoma longifolia Jack Root Extract on The Prostate Adenocarcinoma PC-3 Cells through Apoptosis Enhancement

BACKGROUND: Prostate cancer is the second most common malignancy in men and has become the sixth leading cause of death in males worldwide. Eurycoma longifolia Jack root has active compounds, namely, quassinoids, eurycomanone, and canthine, which have potential as detoxicants, free radical antioxidants, and anticancer.&#x0D; AIM: This study aimed to analyze the potential of the active compounds in E. longifolia Jack root in induce apoptosis in the prostate adenocarcinoma PC-3 cells.&#x0D; METHODS: E. longifolia root active compounds were obtained by extracting them using ethanol solvent. The culture of prostate cancer PC-3 cell line was obtained from androgen-independent prostate adenocarcinoma with bone metastasis use as subject. Examination of the potency of E. longifolia root extract was conducted by observing the cells undergoing apoptosis with TUNEL assay.&#x0D; RESULTS: One-way ANOVA test showed that the increase in apoptotic cells was associated proportionally with the concentration levels of E. longifolia root extract and showed a significant difference (α &lt; 0.05).&#x0D; CONCLUSION: The higher the dose of E. longifolia root extract, the higher will be the apoptotic level of adenocarcinoma cells PC3. E. longifolia extract is potentially used in the treatment of prostate cancer by inducing apoptotic mechanisms.

Ionotropic Gelation Synthesis of Chitosan-Alginate Nanodisks for Delivery System and In Vitro Assessment of Prostate Cancer Cytotoxicity

We report on the synthesis of chitosan-alginate nanodisks (Cs-Al NDs) using a simple approach consisting of the ionotropic gelation method. Sodium tripolyphosphate (STPP) was used as crosslinking agent to promote the electrostatic interaction between amine groups the chitosan and hydroxyl and carboxyl groups of alginate. Scanning electron microscopy (SEM) images provided direct evidence of the morphology of the nanodisks where agglomeration was observed due to the electrostatic interaction between the functional groups. Furthermore, dynamic light scattering (DLS) showed that the hydrodynamic size of the Cs-Al NDs was 227 nm and 152 nm in pH 1.2 and pH 7.4, respectively, which is in agreement with the information observed in the SEM images. The chemical structure is presented mainly the amine and carboxyl groups due to the presence of chitosan and alginate in the nanodisks, respectively, which allow the electrostatic interaction through N-H linkages. According to the X-ray diffraction, we found that the Cs-Al NDs exhibited the typical structure of chitosan and alginate, which lead the formation of polyelectrolyte complexes. We also evaluated the encapsulation of amoxicillin in the nanodisk, obtaining a loading efficiency of 74.98%, as well as a maximum in vitro release amount of 63.2 and 52.3% at pH 1.2 and 7.4, respectively. Finally, the cytotoxicity effect of the Cs-Al nanodisks was performed in human prostatic epithelial PWR-1E and Caucasian prostate adenocarcinoma PC-3 cell lines, in which the cell viability was above 80% indicating low inhibition and determining the Cs-Al NDs as a promising technology for controlled delivery systems.

Protein kinase C-related kinase 1 and 2 play an essential role in thromboxane-mediated neoplastic responses in prostate cancer.

The prostanoid thromboxane (TX) A2 is increasingly implicated in neoplastic progression, including prostate cancer (PCa). Mechanistically, we recently identified protein kinase C-related kinase (PRK) 1 as a functional interactant of both the TPα and TPβ isoforms of the human T prostanoid receptor (TP). The interaction with PRK1 was not only essential for TPα/TPβ-induced PCa cell migration but also enabled the TXA2-TP axis to induce phosphorylation of histone H3 at Thr11 (H3Thr11), an epigenetic marker both essential for and previously exclusively associated with androgen-induced chromatin remodelling and transcriptional activation. PRK1 is a member of a subfamily of three structurally related kinases comprising PRK1/PKNα, PRK2/PKNγ and PRK3/PKNβ that are widely yet differentially implicated in various cancers. Hence, focusing on the setting of prostate cancer, this study investigated whether TPα and/or TPβ might also complex with PRK2 and PRK3 to regulate their activity and neoplastic responses. While TPα and TPβ were found in immune complexes with PRK1, PRK2 and PRK3 to regulate their activation and signalling, they do so differentially and in a TP agonist-regulated manner dependent on the T-loop activation status of the PRKs but independent of their kinase activity. Furthermore, TXA2-mediated neoplastic responses in prostate adenocarcinoma PC-3 cells, including histone H3Thr11 phosphorylation, was found to occur through a PRK1- and PRK2-, but not PRK3-, dependent mechanism. Collectively, these data suggest that TXA2 acts as both a neoplastic and epigenetic regulator and provides a mechanistic explanation, at least in part, for the prophylactic benefits of Aspirin in reducing the risk of certain cancers.

An insight into the cytotoxic activity of phytol at in vitro conditions

The cytotoxicity of the diterpene alcohol, phytol, was evaluated by using the MTT assay in vitro against seven tumour cells and one normal cell of human origin. The compound tested induced concentration-dependent cytotoxic response in all cell lines, demonstrating to be most and least effective against the breast adenocarcinoma MCF-7 and the prostate adenocarcinoma PC-3 cells, respectively (IC50 8.79 ± 0.41 μM and 77.85 ± 1.93 μM). The IC50 values towards the other five tumours (HeLa, HT-29, A-549, Hs294T and MDA-MB-231) ranged from 15.51 to 69.67 μM. However, mild toxicity was detected against the foetal lung fibroblast MRC-5 cells at the concentrations used (IC50 124.84 ± 1.59 μM). According to the experimental data obtained, this cost-effective natural product widely present in the biosphere may inspire the development of new drug-like substances with improved cytotoxic activity on breast cancer.

Synchrotron FTIR shows evidence of DNA damage and lipid accumulation in prostate adenocarcinoma PC-3 cells following proton irradiation

Synchrotron Radiation Fourier Transform Infrared (SR-FTIR) spectra of single human prostate adenocarcinoma PC-3 cells, irradiated with a defined number of 2MeV protons generated by a proton microbeam along with non-irradiated control cells, were analysed using multivariate methods. A number of different Principal Component Analysis (PCA) models were tested and the spectral ranges associated with nucleic acids, proteins and lipids were analysed separately. The results show a dose dependent shift of the OPO asymmetric stretching mode from 1234cm−1 to 1237cm−1, consistent with local disorder in the B-DNA conformation along with a change in intensity of the OPO symmetric stretching band at 1083cm−1 indicative of chromatin fragmentation – the natural consequence of a high number of DNA Double Strand Breaks (DSBs). 2D mapping of characteristic functional groups at the diffraction limit shows evidence of lipid deposition and chromatin condensation in cells exposed to protons indicative of cell apoptosis following irradiation. These studies lay the foundation for understanding the macromolecular changes that occur to cells in response to radiation therapy, which has important implications in the treatment of tumours.

Fermentation Product of Soybean, Black Bean, and Green Bean Mixture Induces Apoptosis in a Wide Variety of Cancer Cells

Previous studies have shown that soybean fermentation products can act as cancer chemoprevention or therapeutic agents. In this study, the anticancer activities of a fermentation product of soybean, black bean, and green bean mixture (BN999) were investigated. We found that BN999 inhibited the growth of human breast cancer AU565 cells and prostate adenocarcinoma PC-3 cells but not that of normal human cells. BN999 induced apoptosis in various human cancer cells but not in normal human cells. BN999 treatment of AU565 cancer cells resulted in activation of calpain and caspase-8, -9, and -3, suggesting that BN999 induces apoptosis via receptor-, mitochondria-, and endoplasmic reticulum-mediated pathways. Finally, we showed that BN999 inhibited the growth of mouse CT-26 colon cancer xenografts in syngenic BALB/c mice without causing obvious side effects. Together, these data suggest that BN999 has potential to be used as a cancer chemoprevention or therapeutic agent.

Multifaceted preventive effects of single agent quercetin on a human prostate adenocarcinoma cell line (PC-3): implications for nutritional transcriptomics and multi-target therapy

The aim of the present study is to evaluate the effects of quercetin, a dietary flavonoid, on human prostate adenocarcinoma PC-3 cells. Lactate dehydrogenase (LDH) release, microculture tetrazolium test (MTT assay) and real-time PCR array were employed to evaluate the effects of quercetin on cell cytotoxicity, cell proliferation and expression of various genes in PC-3 cell line. Quercetin inhibited cell proliferation and modulated the expression of genes involved in DNA repair, matrix degradation and tumor invasion, angiogenesis, apoptosis, cell cycle, metabolism and glycolysis. No cytotoxicity of quercetin on PC-3 cells was observed. Taken together, as shown by the issues of the current study, the manifold inhibitory effects of quercetin on PC-3 cells may introduce quercetin as an efficacious anticancer agent in order to be used in the future nutritional transcriptomic investigations and multi-target therapy to overcome the therapeutic impediments against prostate cancer.

Structurally similar diazenes exhibit significantly different biological activity

We have previously synthesized various diazenecarboxamides (subsequently referred to as diazenes) that were cytotoxic to several tumor cell lines. To increase their biological activity, the structure has been modified appropriately. In the present study we examined the effects of N(1)-phenyl-N(2)-(2-pyridinylmethyl)diazenedicarboxamide (RL-337) obtained from the previously examined cytotoxic compound N(1)-phenyl-N(2)-(2-pyridinyl)diazenecarboxamide (JK-279), and compared them with those of diazene JK-279. Using a modified colorimetric MTT assay, the cytotoxicity of RL-337 was determined on human cervical carcinoma HeLa cells, glioblastoma A1235 cells, and prostate adenocarcinoma PC-3 cells. The possible synergistic effect of diazene RL-337 with cisplatin, doxorubicin, and vincristine, and its influence on intracellular GSH content was examined on HeLa cells. Diazene RL-337 was cytotoxic against all three human tumor cell lines, being more cytotoxic to HeLa cells than diazene JK-279. The higher efficacy of RL-337 than of JK-279 can be connected with higher basicity of the 2-picoline moiety present in the former diazene comparing with the pyridine fragment that is a part of the latter. The diazene RL-337 acted synergistically with cisplatin, doxorubicin, and vincristine (diazene JK-279 exhibited synergistic effect only with cisplatin). Glutathione (determined by Tietze's method) was not a target molecule of diazene RL-337 (but was for JK-279, as shown earlier). After just 1 h treatment with diazene RL-337, the cells started to lose membrane integrity. There was no cleavage of caspase-3 in RL-337-treated samples, and the majority of cells died 6 h after the treatment through necrosis (previously, apoptosis-like cell death was detected for diazene JK-279). Thus, although diazenes JK-279 and RL-337 are very similar in their structure, they exhibit widely different biological activity.

MAPK and JNK transduction pathways can phosphorylate Sp1 to activate the uPA minimal promoter element and endogenous gene transcription

AbstractTwo upstream regions of the human urokinase (uPA) gene regulate its transcription: the minimal promoter (MP) and the enhancer element. The activity of the minimal promoter is essential for basal uPA transcription in prostate adenocarcinoma PC3 cells. Binding of a phosphorylated Sp1 transcription factor is, in turn, essential for the activity of the MP. Here we report that the Jun kinase (JNK) pathway is required for the basal activity of the MP and for the expression of the endogenous uPA gene in PC3 cells and for activated transcription in LNCaP cells. On the other hand, the p42/p44 mitogen-activated protein kinase (MAPK) pathway activates uPA gene expression through Sp1 phosphorylation in HeLa, LNCaP, and CCL39-derivative cells that do not typically express uPA in basal conditions. In HeLa cells the dominant-negative form of JNK interferes with the p42/p44 MAPK activation of the uPA-MP. The results suggest that the stress-activated protein kinase (SAPK)/JNK pathway plays an important role in the phosphorylation of Sp1, which, in turn, leads to basal or activated transcription from the uPA-MP element.