Human Prostate Carcinoma Cells Research Articles

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

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

Splicing variants of versican in CD133+/CD44+ prostate cancer stem cells

A cancer mass is composed of a heterogeneous group of cells, a small part of which constitutes the cancer stem cells since they are less differentiated and have a high capacity to develop cancer. Versican is an extracellular matrix protein located in many human tissues. The mRNA of versican has been shown to have “splicing patterns” as detected by RT-PCR, northern blot analysis, and cDNA sequencing. Based on this knowledge this study aims to reveal the splice variants of versican molecules, which are thought to be involved in the pathogenesis of the DU-145 human prostatic carcinoma cell line and prostatic cancer stem cells isolated from this cell line. In this study, RWPE-1 normal prostatic and DU-145 human prostate cancer cell lines have been used. Prostatic cancer stem cells and the remaining group of non-prostatic-cancer stem cells (bulk population) were isolated according to their CD133+/CD44+. RNA was isolated in all groups, and sequence analysis was accomplished for splicing variants by Illumina NextSeq 500 sequencing system. The results were analyzed by bioinformatic evaluation. As five isoforms of the versican gene in the differential transcript expression are analyzed, it was observed that a significant change was only found in the isoforms Versican 0 and Versican 1. In this study, we explored the function of this molecule which we think to be effective in cancer progression, and suggested that more valuable results can be obtained after the accomplishment of in vivo experiments.

Abstract 2824: Establishing prostate cancer models for orthotopic and bone metastatic growth using the 22Rv1cell line

Abstract Prostate cancer is the second most common cancer in men with new cases diagnosed in 1.4 million men each year. Luckily the 5-year survival rates in developed countries are high reaching over 90%. However, approximately one third will develop a metastatic disease. In metastatic patients, prostate cancer almost always progresses despite the androgen deprivation therapy and is then referred to as “castration-resistant (mCRPC)”. Bone is involved in 80% of patients with metastasis, and the bone lesions are typically osteoblastic. The 22Rv1 human prostate carcinoma cell line is androgen sensitive and shown to express androgen receptor (AR). They also express low levels of prostate-specific membrane antigen (PSMA). The aim of this study was to establish orthotopic and intratibial preclinical in vivo prostate cancer models that can be used in drug development when targeting cancer cells and their local environment. Male athymic nude mice (5-6 weeks old) and NOG mice (over 20 weeks old) were used in the study. 2.5 × 105 22Rv1 cells (ATCC) were inoculated orthotopically into the prostate of NOG mice, and 5 × 105 cells were inoculated intratibially into the bone marrow cavity of athymic nude mice. Tumor growth was followed by PSA measurements every second week using Human PSA ELISA assay. In addition, in the intratibial model, tumor-induced bone changes were monitored by X-ray imaging of the hind limbs. Prostates and hind limbs were collected at sacrifice, fixed in 10% NBF, and processed to paraffin blocks for further histological analysis. Sections of prostate were stained with hematoxylin-eosin (HE) and AR. Tumor-bearing and contralateral (healthy) tibias were stained with HE - OrangeG, MGT, TRAP, and AR. The observed tumor take rate was 92% in the orthotopic and 100% in the intratibial models. Confirmed by IHC, tumors formed in both the orthotopic and intratibial models expressed AR. 22Rv1 cells formed osteoblastic - lytic mixed bone lesions in the intratibial model. Based on lesion areas, randomization of the tumor bearing mice in the intratibial model can be done after 2 weeks from cancer cell inoculation. Taken together, the 22Rv1 prostate cancer models are relatively fast growing, express AR and present good take rates. Furthermore, the intratibial model represents robust tumor-induced changes in bone with strong osteoblastic component. Thus, these models have several advantages in efficacy studies of novel drug candidates for prostate cancer. Citation Format: Justyna Zdrojewska, Katja Fagerlund, Jenni H. Mäki-Jouppila, Mari I. Suominen. Establishing prostate cancer models for orthotopic and bone metastatic growth using the 22Rv1cell line [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 2824.

Chemical profiling, bio-guided purification, and cytotoxic effect of two African spices: Hypodaphnis zenkeri Engl. Stapf (Lauraceae) and Staudtia kamerunensis warb (Myristicaceae) on human prostate cancer cell lines

Ethnopharmacological relevanceProstate cancer remains a significant burden in low- and middle-income countries and the second leading cause of death around the world. Spices used in daily cuisine contain interesting phytochemical components capable of helping prevent and cure cancer. AimThis study aims to give sufficient phytochemical information on two understudied species, Staudtia kamerunensis Warb. (Myristicaceae) and Hypodaphnis zenkeri Engl. Stapf. (Lauraceae), and to study their cytotoxicity against prostate cancer cells in its early form and when they have developed metastasis. Materials and methodsTo reach this goal, normal procedures for phytochemical analysis were followed; these include collection, drying, crushing and extraction of plant materials using organic solvents. GC-MS (Gas chromatography- Mass Spectrometry) was used to evaluate the volatile phytochemicals contained in the extracts, and open-column chromatography was used to isolate the pure compounds used in this study. A bio-guided exploration of Hypodaphnis zenkeri (Lauraceae) (leaves, seeds, stems) guided us in selecting the extract for further analysis. An established MTT assay was used to measure cell proliferation. Three prostate cancer cell lines were considered in this study, DU145 and PC3, human androgens-independent prostate carcinoma cells and LNCaP, which are cells derived from metastasis of a human prostate and respond to androgens, oestrogens and progestins. The eight compounds isolated were characterized using HREIMS, 1D and 2D NMR. ResultsAmong the three extracts from Hypodaphnis zenkeri, considered for biological testing, the leaf extract displayed better activities with a CC50 of 180 μg/mL against DU 145 cells, 184 μg/mL against PC3 cells and 194 μg/mL against LNCaP cells. These results were justified when GC-MS analysis of the different extracts was performed. Fifty compounds were identified from the leaves, representing 96.06% of the volatile components, with most displaying anticancer activities or activities against vectors favorizing cancer growth (inflammation, etc.). An attempt to isolate the active principle responsible for the cancer activity led to the isolation of five pure compounds, namely Eicosane [1], Nonacos-1-ene [2], Palmitic acid [3], Glucoside Stigmasterol [4] and Butane-1,2,3,4-tetraol [5]. Eicosane was identified as being responsible in part for the observed activity, even though it exhibited weak cytotoxicity with the lowest CC50 equal to 30 μg/mL against DU 145 cells. Staudtia kamerunensis sap was investigated in our previous studies with the isolation of Oleanan-12-ene-2α,3β –diol [6] and 2α, 3β -dihydroxylup-20-ene [7] among the major components, with significant antibacterial properties. Oleanan-12-ene-2α,3β –diol [7] in this study displayed a CC50 of 20 μg/mL against DU145 cells, 22 μg/mL against PC3 cells, 18 μg/mL against LNCaP cells, and 32 μg/mL in HMEC affording a selectivity index >2. Contrary to what was observed in our previous study, the activity of Oleanan-12-ene-2α,3β –diol was lost in the presence of 2α, 3β -dihydroxylup-20-ene. Conclusionthe cytotoxic effect of extract from Staudtia and Hypodaphnis genera and pure isolates are here reported for the first time, as well as the pure isolates. These studies exhibit the cytotoxic potential of two traditional African spices and, more specifically, Oleanan-12-ene-2α,3β –diol and eicosane, isolated from these plant species.

Structure based docking and biological evaluation towards exploring potential anti-cancerous and apoptotic activity of 6-Gingerol against human prostate carcinoma cells

Background6-Gingerol (6-G) is the primary active phytocomponent of ginger and has been shown to regulate multiple targets against cancer and its treatment. Androgen receptors (ARs) remain critical in the progression of prostate cancer (PCa). This study focuses on investigating 6-G as a promising anti-cancerous agent that inhibits AR activity significantly.MethodsIn this study, molecular docking simulation was done to investigate the binding affinity of 6-G and control drug Bicalutamide (BT) against oncogenic AR and tumor suppressor estrogen receptor β (ERβ). The crystal structure of AR and ERβ was retrieved from Protein Data Bank (PDB) and docked with 3D Pubchem structures of 6-G using iGEMDOCK and AutoDock. Further in vitro study was done to evaluate the antioxidant, anti-cancerous, apoptotic, and wound healing potential of 6-G.ResultsThe result displays that 6-G shows good binding affinity with AR and ERβ. Condensation of the nucleus, change in mitochondrial membrane potential (MMP) and the ability to induce reactive oxygen species (ROS) were done in human PCa PC-3 cells. Results from the MTT assay demonstrated that 6-G and control drug BT showed significant (p < 0.01) dose and time dependent inhibition of human PCa PC-3 cells. 6-G increased the ROS generation intracellularly and decreased the MMP, and cell migration in treated PCa PC-3 cells. 6-G treated cells showed fragmented, condensed chromatin and nuclear apoptotic bodies.ConclusionsThus, this study validates 6-G as a potential drug candidate against human PCa. However, further study of the anticancer potency of 6-G has to be done before its use for PCa treatment.

Decreased intracellular chloride enhances cell migration and invasion via activation of the ERK1/2 signaling pathway in DU145 human prostate carcinoma cells

Our previous study revealed that changes of the intracellular Cl− concentration ([Cl−]i) affected cell proliferation in cancer cells. However, the role of Cl− on cell migration and invasion in cancer cells remains unanalyzed. Therefore, the aim of the present study is to investigate whether changes of [Cl−]i affects cell migration and invasion of cancer cells. In human prostate cancer DU145 cells, cell migration and invasion were enhanced by culturing in the low Cl− medium (replacement of Cl− by NO3−). We also found that DU145 cells in the low Cl− condition caused significant transient ERK1/2 activation followed by an increase of MMP-1 mRNA levels. Inhibition of ERK1/2 activation in the low Cl− condition reduced enhancement of MMP-1 mRNA levels and decreased cell migration and invasion. These observations indicate that [Cl−]i plays important roles in metastatic function by regulating the ERK1/2 signaling pathway in human prostate cancer cells, and intracellular Cl− would be one of the key targets for anti-cancer therapy.

Study of the biological activity of photoactive bipyridyl-Ru(II) complexes containing 1,3,5-triaza-7-phosphaadamantane (PTA)

The water-soluble ruthenium complex cis-[Ru(dcbpyH)2(PTAH)2]Cl2·3H2O (1) (dcbpy = 4,4′-dicarboxy-2,2′-bipyridine; PTA = 1,3,5-triaza-7-phosphaadamantane) has been synthesized and characterised by NMR, IR spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The optical properties of 1 were studied, including photoactivation under visible light, as well as its biological properties, together with those of the previously published Ru complexes cis-[Ru(bpy)2(PTA)2]Cl2 (2), trans-[Ru(bpy)2(PTA)2](CF3SO3)2 (3) and cis-[Ru(bpy)2(H2O)(PTA)](CF3SO3)2 (4) (bpy = 2,2′-bipyridine). Anticancer activities of the complexes against human lung (A549), cervical (HeLa) and prostate (PC3) carcinoma cells were evaluated under dark conditions and upon photoactivation with visible light. None of the complexes exhibited cytotoxic activity in the absence of light irradiation (IC50 > 100 μM). However, after photoactivation, the cytotoxicity of complexes 1, 2 and 3 against the three cell lines markedly increased, resulting in IC50 values between 25.3 μM and 9.3 μM. Notably, these complexes did not show toxicity against red blood cells. These findings show the potential of complexes 1, 2 and, particularly, 3 for selective and controlled cancer photochemotherapy. The reactivity of the Ru complexes against DNA under UV–Vis irradiation was studied by analysing plasmid mobility. Experimental data shows that 4 unfolds supercoiled DNA (SC DNA) both in the dark and under visible irradiation, while 1 and 3 are only active under light, being 2 inactive in either case. The unfolding activities of complexes 3 and 4 were dependent on the air present in the reaction. The measured intracellular levels of reactive oxygen species (ROS) upon irradiation with complexes 1, 2 and 3 suggest that their mechanism of action is related to oxidative stress.

Abstract 2858: Radiotherapy and NK cell-based immunotherapy: An evolutionary double-bind

Abstract Evolution-informed therapies exploit the ecological and evolutionary consequences of drug resistance to inhibit the expansion of treatment resistant populations and prolong time to progression. One strategy, termed an evolutionary double-bind, uses an initial therapy to elicit a specific adaptive mechanism that is then selectively targeted by a follow-on therapy. Here we examine combining radiation therapy followed by immunotherapy as a double bind strategy. Radiotherapy (RT) induces lethal double-strand DNA breaks in tumor cells and radiosensitivity is governed by the cells’ DNA repair capabilities. Radioresistant cancer cells upregulate DNA damage response pathways. However, successful adaptations to RT and other DNA damaging agents can increase natural killer (NK) cell ligand expression on tumor cells increasing their vulnerability to the immune system. We conducted a multidisciplinary investigation of this potential evolutionary double bind using an isogenic cell line model of radiation resistance derived from an androgen-independent human prostate carcinoma cell line (22Rv1). We demonstrate that RT-resistant cells maintain higher expression of NK cell ligands and have a 2-fold increase in sensitivity to NK cell mediated killing. Furthermore, we show that preferential targeting of the RT-resistant population by NK cells is preserved in competition assays with varying initial population frequencies. Scope of treatment responses are dependent on population frequencies in our in vitro analysis. Mathematical modeling quantified three key elements of a double-bind: cost of resistance, inter-specific competition between RT-sensitive and RT-resistant lines, and preferential targeting of RT-resistant lines by NK cells. We conclude that RT followed by immunotherapy produces an evolutionary double bind that can be exploited in heterogenous tumors to limit RT resistance. Furthermore, model simulations predict that extinction of both populations is achievable by sequential RT and NK cell therapy. Citation Format: Kimberly Luddy, Jeffery West, Mark Robertson-Tessi, Bina Desai, Taylor M. Bursell, Sarah Barrett, Joel Brown, Jacintha O'Sullivan, Robert Gatenby, Laure Marignol, Alexander R. Anderson, Cliona O'Farrelly. Radiotherapy and NK cell-based immunotherapy: An evolutionary double-bind [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2858.

99mTc]Tc-HYNIC-RM2: A potential SPECT probe targeting GRPR expression in prostate cancers

IntroductionElevated density of gastrin releasing peptide receptors (GRPR) in prostate cancer has led to exploration of several radiolabeled peptides for imaging and staging of the disease. The GRPR antagonist peptide RM2 has been successfully conjugated with several chelators and radiolabeled with gallium-68. The goal of this study was to synthesize a 99mTc-labeled probe and investigate its potential for SPECT imaging of prostate cancer. Towards this HYNIC-RM2 peptide conjugate was synthesized, radiolabeled with 99mTc and evaluated in GRPR-positive PC3 tumor xenografts. MethodsHYNIC-RM2 was manually synthesized by standard Fmoc solid phase strategy and radiolabeled with 99mTc. In vitro cell studies were performed in GRPR-positive human prostate carcinoma (PC3) cells. Metabolic stability studies of [99mTc]Tc-HYNIC-RM2 were performed in normal mice in the presence as well as absence of neutral endopeptidase (NEP) inhibitor, phosphoramidon (PA). Biodistribution and imaging studies of [99mTc]Tc-HYNIC-RM2 were performed in SCID mice bearing PC3-xenograft. Results[99mTc]Tc-HYNIC-RM2 exhibited high binding affinity in low nanomolar range (Kd = 1.83 ± 0.31 nM). Metabolic stability studies in mice indicated that in the absence of PA, radiolabeled peptide was about 65 % intact in the blood at 15 min p.i., whereas proportion of intact radiolabeled peptide was enhanced to 90 % on co-administration of PA. Biodistribution studies in PC3 tumor bearing mice demonstrated high tumor uptake (8.02 ± 0.9%ID/g and 6.13 ± 0.44%ID/g at 1 h and 3 h p.i.). Co-administration of PA with the radiolabeled peptide resulted in further enhancement of tumor uptake (14.24 ± 0.76 % ID/g and 11.71 ± 0.59%ID/g at 1 h and 3 h p.i.). SPECT/CT images of [99mTc]Tc-HYNIC-RM2 could clearly visualize the tumor. Significant (p < 0.001) reduction in the tumor uptake with a co-injected blocking dose of unlabeled peptide ascertained the GRPR specificity of [99mTc]Tc-HYNIC-RM2. ConclusionEncouraging results obtained in biodistribution and imaging studies indicate the potential of [99mTc]Tc-HYNIC-RM2 for further exploration as GRPR targeting agent.

A Practical and Analytical Comparative Study of Gel-Based Top-Down and Gel-Free Bottom-Up Proteomics Including Unbiased Proteoform Detection.

Proteomics is an indispensable analytical technique to study the dynamic functioning of biological systems via different proteins and their proteoforms. In recent years, bottom-up shotgun has become more popular than gel-based top-down proteomics. The current study examined the qualitative and quantitative performance of these two fundamentally different methodologies by the parallel measurement of six technical and three biological replicates of the human prostate carcinoma cell line DU145 using its two most common standard techniques, label-free shotgun and two-dimensional differential gel electrophoresis (2D-DIGE). The analytical strengths and limitations were explored, finally focusing on the unbiased detection of proteoforms, exemplified by discovering a prostate cancer-related cleavage product of pyruvate kinase M2. Label-free shotgun proteomics quickly yields an annotated proteome but with reduced robustness, as determined by three times higher technical variation compared to 2D-DIGE. At a glance, only 2D-DIGE top-down analysis provided valuable, direct stoichiometric qualitative and quantitative information from proteins to their proteoforms, even with unexpected post-translational modifications, such as proteolytic cleavage and phosphorylation. However, the 2D-DIGE technology required almost 20 times as much time per protein/proteoform characterization with more manual work. Ultimately, this work should expose both techniques' orthogonality with their different contents of data output to elucidate biological questions.

Structures of Mammeasins P and Q, Coumarin-Related Polysubstituted Benzofurans, from the Thai Medicinal Plant Mammea siamensis (Miq.) T. Anders.: Anti-Proliferative Activity of Coumarin Constituents against Human Prostate Carcinoma Cell Line LNCaP.

A methanol extract of the flowers of Mammea siamensis (Miq.) T. Anders. (Calophyllaceae) showed anti-proliferative activity against human prostate carcinoma LNCaP cells (IC50 = 2.0 µg/mL). Two new coumarin-related polysubstituted benzofurans, mammeasins P (1) and Q (2), and a known polysubstituted coumarin mammea B/AC cyclo F (39) were isolated from the extract along with 44 previously reported polysubstituted coumarin constituents (3-38 and 40-47). The structures of two new compounds (1 and 2) were determined based on their spectroscopic properties derived from the physicochemical evidence including NMR and MS analyses and taking the plausible generative pathway into account. Among the coumarin constituents, mammeasins A (3, IC50 = 1.2 µM) and B (4, 0.63 µM), sugangin B (18, 1.5 µM), kayeassamins E (24, 3.0 µM) and G (26, 3.5 µM), and mammeas E/BA (40, 0.88 µM), E/BB (41, 0.52 µM), and E/BC (42, 0.12 µM) showed relatively potent anti-proliferative activity.

Multi-omics profiling of PC-3 cells reveals bufadienolides-induced lipid metabolic remodeling by regulating long-chain lipids synthesis and hydrolysis.

Lipid metabolism participates in various biological processes such as proliferation, apoptosis, migration, invasion, and maintenance of membrane homeostasis of prostate tumor cells. Bufadienolides, the active ingredients of Chansu, show a robust anti-proliferative effect against prostate cancer cells in vitro, but whether bufadienolides could regulate the lipid metabolism in prostate cancer has not been evaluated. Our study explored the regulatory effects of bufadienolides on lipid metabolism in human prostate carcinoma cells (PC-3). Untargeted lipidomics and transcriptomics were combined to study the effect of different bufadienolides interventions on lipid and gene changes of PC-3 cells. The key genes related to lipid metabolism and prostate cancer development were verified by qPCR and western blotting. Lipidomic analysis showed that the active bufadienolides significantly downregulated the content of long-chain lipids of PC-3 cells. Based on transcriptomic and qPCR analyses, many genes related to lipid metabolism were significantly regulated by active bufadienolides, such as ELOVL6, CYP2E1, GAL3ST1, CERS1, PLA2G10, PLD1, SPTLC3, and GPX2. Bioinformatics analysis of the Cancer Genome Atlas database and literature retrieval showed that elongation of very long-chain fatty acids protein 6 (ELOVL6) and phospholipase D1 (PLD1) might be important regulatory genes. Western blot analysis revealed that active bufadienolides could downregulate PLD1 protein levels which might promote anti-prostate cancer effect. All these findings support that bufadienolides might induce lipid metabolic remodeling by regulating long-chain lipids synthesis and phospholipid hydrolysis to achieve an anti-prostate cancer effect, and PLD1 would probably be the key protein.

Cytotoxic and antioxidant activities and phytochemical analysis of Smilax excelsa L. and Aegopodiumpodagraria L.

New curative and preventative approaches with high therapeutic efficacy and minimal side effects are needed for many forms of cancer. Therefore, the current study aimed to assess the cytotoxic and antioxidant capacity of Smilax excelsa and Aegopodium podagraria, which are consumed on a daily diet in the Black Sea region of Turkiye, as well as their phytochemical composition to pinpoint the compounds responsible for these activities. The effects of the treatments on human prostate (PC3), colorectal (HCT116), and lung (A549) carcinoma cell survival and free radical scavenging potentials were investigated. Total phenolic and flavonoid contents and significant phenolic compounds were detected and quantified by HPLC. The extracts reduced cell viability in all cancer cells in a dose-dependent manner, while the most potent cytotoxic effects were noted on PC3 cells. S. excelsa inhibited cell growth on PC3 cells at both lower and higher concentrations (50–1000 μg/mL) compared with the control (p < 0.05). S. excelsa methanol extract exhibited the strongest ABTS and DPPH free radical scavenging capacities, with the IC50 values of 17.16 and 45.81 μg/mL, respectively. The highest amounts of total phenolics and flavonoids, as well as chlorogenic acid and caffeic acid, were also observed in S. excelsa methanol extract. Our results suggest that S. excelsa and A. podagraria, along with the isolated compounds, may contribute to the treatment of prostate cancer. To the best of our knowledge, this is the first study analyzing the impacts of these plants on PC3, HCT116, and A549 cells.

Decursin inhibits EGFR-ERK1/2 signaling axis in advanced human prostate carcinoma cells.

We have shown that decursin, a coumarin compound, induces cell cycle arrest and apoptosis in human prostate cancer cells (PCa); however, its molecular mechanisms are largely unexplored. We studied the mechanisms associated with its anticancer activity in advanced human prostate carcinoma cells. We found that decursin inhibited epidermal growth factor receptor (EGFR) signaling by inhibiting its activating phosphorylation at tyrosine 1068 residue in DU145 and 22Rv1 cells. This inhibition of EGFR was associated with the downregulation of ERK1/2 phosphorylation. Both EGFR and ERK1/2 are known to be deregulated/activated in many human malignancies. Consistent with our earlier study, decursin (25-100 µM) treatment for 24-72 h inhibited DU145 cell proliferation by 49%-87% (p < 0.001) which was associated with strong G1 phase arrest and cell death. It also decreased (p < 0.001) the number of surviving colonies. Decursin moderately increased the expression of Rb-related proteins p107 and p130 but decreased the levels of E2F family transcription factors including E2F-3, E2F-4 and E2F-5. Further, decursin strongly inhibited the growth of androgen-dependent prostate carcinoma 22Rv1 cells from 61% to 79% (p < 0.001) and arrested these cells at G1 phase via induction of cyclin-dependent kinase inhibitor p27/Kip1 and downregulation of CDK2 and CDK4 protein expression. Additionally, EGFR inhibitor erlotinib- and EGF ligand-modulated EGFR activation validated EGFR signaling as a target of decursin-mediated cell growth inhibition and cytotoxicity. Decursin decreased EGF ligand-induced phosphorylation of EGFR (Y-1068) as well as activation of its downstream mediator, ERK1/2. Furthermore, inhibitory targeting of EGFR-ERK1/2 axis by combinatorial treatment of decursin and erlotinib further sensitized DU145 cells for the decursin-induced growth inhibition and cell death. Overall, these findings strongly suggest that anticancer efficacy of decursin against human PCa involves inhibitory targeting of EGFR-ERK1/2 signaling axis, a pathway constitutively active in advanced PCa.

Suppression of prostate cancer and amelioration of the immunosuppressive tumor microenvironment through selective immunoproteasome inhibition

ABSTRACT New treatment options to battle hormone-refractory prostate carcinoma (PC) are a pressing medical need. Chronic inflammation has been implicated in PC etiology. The pro-inflammatory cytokines IL-6, IL-23 and IL-17 are key mediators to promote growth of PC. Here, we evaluate the potential of immunoproteasome inhibition for anti-inflammatory and direct anti-tumorigenic therapy of PC. The anti-tumor effect of immunoproteasome inhibitor ONX 0914 was tested in mouse and human PC cells and the in vivo therapeutic efficacy of immunoproteasome inhibition was analyzed in transgenic adenocarcinoma of the mouse prostate (TRAMP) mice in preventive and therapeutic settings and in castration-resistant (CR)PC after castration. Inhibition of the immunoproteasome subunit LMP7 induced apoptotic cell death in PC cell lines. In TRAMP mice, ONX 0914-treatment resulted in significant inhibition of PC growth with a decreased frequency of malignant prostatic lesions and inhibition of metastasis formation. The number of immunosuppressive myeloid cells in PC was greatly reduced in response to ONX 0914. Thus, immunoproteasome inhibition shows remarkable efficacy against PC progression in vivo and impedes tumor recurrence in CRPC-TRAMP mice by blocking the immunosuppressive inflammatory response in the tumor microenvironment. In conclusion, we show that the immunoproteasome is a promising drug target for the treatment of PC.

Liposomal Binuclear Ir(III)-Cu(II) Coordination Compounds with Phosphino-Fluoroquinolone Conjugates for Human Prostate Carcinoma Treatment.

Novel heteronuclear IrIII-CuII coordination compounds ([Ir(η5-Cp*)Cl2Pcfx-Cu(phen)](NO3)·1.75(CH3OH)·0.75(H2O) (1), [Ir(η5-Cp*)Cl2Pnfx-Cu(phen)](NO3)·1.75(CH3OH)·0.75(H2O) (2), [Ir(η5-Cp*)Cl2Plfx-Cu(phen)](NO3)·1.3(H2O)·1.95(CH3OH) (3), [Ir(η5-Cp*)Cl2Psfx-Cu(phen)] (4)) bearing phosphines derived from fluoroquinolones, namely, sparfloxacin (Hsfx), ciprofloxacin (Hcfx), lomefloxacin (Hlfx), and norfloxacin (Hnfx), have been synthesized and studied as possible anticancer chemotherapeutics. All compounds have been characterized by electrospray ionization mass spectrometry (ESI-MS), a number of spectroscopic methods (i.e., IR, fluorescence, and electron paramagnetic resonance (EPR)), cyclic voltammetry, variable-temperature magnetic susceptibility measurements, and X-ray diffractometry. The coordination geometry of IrIII in all complexes adopts a characteristic piano-stool geometry with the η5-coordinated and three additional sites occupied by two chloride and phosphine ligands, while CuII ions in complexes 1 and 2 form a distorted square-pyramidal coordination geometry, and in complex 3, the coordination geometry around CuII ions is a distorted octahedron. Interestingly, the crystal structure of [Ir(η5-Cp*)Cl2Plfx-Cu(phen)] features the one-dimensional (1D) metal-organic polymer. Liposomes loaded with redox-active and fluorescent [Ir(η5-Cp*)Cl2Pcfx-Cu(phen)] (1L) have been prepared to increase water solubility and minimize serious systemic side effects. It has been proven, by confocal microscopy and an inductively coupled plasma mass spectrometry (ICP-MS) analysis, that the liposomal form of compound 1 can be effectively accumulated inside human lung adenocarcinoma and human prostate carcinoma cells with selective localization in nuclei. A cytometric analysis showed dominance of apoptosis over the other cell death types. Furthermore, the investigated nanoformulations induced changes in the cell cycle, leading to S phase arrest in a dose-dependent manner. Importantly, in vitro anticancer action on three-dimensional (3D) multicellular tumor spheroids has been demonstrated.

Evaluation of the toxicity, cytotoxicity and antibacterial activity of Tibouchina papyrus (Pohl) Toledo (Melastomataceae)

The objective of this research was to perform a preliminary phytochemical study and investigate the toxicity, cytotoxicity and antibacterial activity of the species Tibouchina papyrus (Melastomataceae). The toxicity test was performed with the extracts against Artemia salina. The cytotoxic study was also performed against the following cell lines: promyelocytic leukemia (HL60), human colon carcinoma (HCT-116), breast carcinoma (MCF-7), prostate carcinoma (PC3), astrocytoma (SNB-19) and non-tumor cells (L929). Last, antibacterial activity was assessed through against Staphylococcus epidermidis (25923), Staphylococcus aureus (12228), Escherichia coli (25312) and Pseudomonas aeruginosa (27853). The phytochemical investigation indicated the presence of these metabolite groups: flavonoids, triterpenes, steroids and tannins. The methanolic extracts showed moderate antibacterial activity against S. aureus, S. epidermidis and P. aeruginosa. T. papyrus extracts showed high cytotoxic activity against promyelocytic leukemia cell lines (80.43 to 93.31%). The other lines did not reveal good activity against the extracts tested.

Xenografts on nude mouse diaphragm of human DU145 prostate carcinoma cells: mesothelium removal by outgrowths and angiogenesis

ABSTRACT Human prostate carcinoma DU145 cells, androgen-independent malignant cells, implanted in the athymic nu/nu male mouse, developed numerous tumors on peritoneal and retro-peritoneal organs whose growth aspects and vascular supply have yet to be investigated with fine structure techniques. A series of necropsies from moribund implanted mice diaphragms were examined with light, scanning, and transmission electron microscopy. DU145 xenografts installations, far away from the implanted site, were described as the smallest installation to large diaphragm outgrowths in moribund mice. Carcinomas did not show extracellular matrix and, reaching more than 0.15 mm in thickness, they revealed new structures in these outgrowths. Voids to be gland-like structures with mediocre secretion and, unexpectedly, intercellular spaces connected with fascicles of elongated DU145 cells that merged with a vascular supply originated from either the tumor cells and/or some perimysium vessels. In the largest carcinomas, most important vascular invasions coincidently accompanied the mouse lethality, similarly to human cancers. This androgen-independent model would be useful to study tumor outgrowth’s changes related to testing anticancer strategy, including anti-angiogenic therapies involving toxicity, simultaneously with those of other vital organs with combined biomolecular and fine structure techniques.

Prostate Cancer Therapy Using Docetaxel and Formononetin Combination: Hyaluronic Acid and Epidermal Growth Factor Receptor Targeted Peptide Dual Ligands Modified Binary Nanoparticles to Facilitate the in vivo Anti-Tumor Activity.

ObjectiveTo evaluate the prostate cancer therapy efficiency of the synergistic combination docetaxel (DTX) and formononetin (FMN) in one nano-sized drug delivery system. Hyaluronic acid (HA) and epidermal growth factor receptor-targeted peptide (GE11) dual ligands were applied to modify the nano-systems.MethodsIn this study, GE11-modified nanoparticles (GE-NPs) were applied for the loading of DTX, and HA-decorated NPs (HA-NPs) were used to encapsulate FMN. HA and GE11 dual ligand-modified binary nanoparticles (HAGE-DTX/FMN-NPs) were constructed by the self-assembling of GE-NPs and HA-NPs. The anti-PCa ability of the system was evaluated in vitro on PC-3 human prostate carcinoma cells (PC3 cells) and in vivo on PC3 tumor-bearing mice in comparison with single NPs and free drugs formulations.ResultsHA/GE-DTX/FMN-NPs were nano-sized particles with smaller particles coating on the inner core and achieved a size of 189.5 nm. HA/GE-DTX/FMN-NPs showed a cellular uptake efficiency of 59.6%, and a more efficient inhibition effect on PC3 cells compared with single ligand-modified NPs and free drugs. HA/GE-DTX/FMN-NPs showed significantly higher tumor inhibition efficiency than their single drug-loaded counterparts and free drugs.ConclusionHA/GE-DTX/FMN-NPs have a synergistic anti-tumor effect and also could the reduce unexpected side effects during the cancer therapy. It could be used as a promising anti-PCa system.

Evaluation of antimicrobial, anticancer potential and Flippase induced leakage in model membrane of Centella asiatica fabricated MgONPs.

The use of chemically synthesized nanoparticles and crude plant extracts as antimicrobial -anticancer agents have many limitations. In this study, we have used Centella asiatica extract (CaE) having relatively less explored but tremendous medicinal properties, as reducing and stabilizing agents to green synthesize magnesium oxide nanoparticles (MgONPs) using magnesium nitrate. In comparison to the bulk material, capabilities of Ca-MgONPs as an improved antibacterial, antifungal, and anticancer agent in human prostatic carcinoma cells (PC3), as well as membranolytic capability in model cell membrane, were studied. The phyto-functionalized Ca-MgONPs were characterized using UV-Visible spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Spectroscopy (EDX), X-ray Diffraction (XRD), Fourier Transform Infra-Red Spectroscopy (FT-IR) and Atomic Force Microscopy (AFM). Observation of characteristic peaks by spectroscopic and microscopic analysis confirmed the synthesis of Ca-MgONPs. The Ca-MgONPs showed broad spectrum of bactericidal activity against both gram-positive and gram-negative bacteria and fungicidal activity against two species of the Candida fungus. The Ca-MgONPs also exhibited dose-dependent and selective inhibition of proliferating PC3 cells with IC50 of 123.65±4.82μg/mL at 24h, however, without having any cytotoxicity toward non-cancerous HEK293 cells. Further studies aimed at understanding the probable mechanism of toxicity of Ca-MgONPs in PC3 cells, the results indicated a significant reduction in cell migration capacities, increment in cytosolic ROS, loss of mitochondrial transmembrane potential, DNA damage and S-phase cell cycle arrest. Ca-MgONPs also induced pore formation in a synthetic large unilamellar vesicle. Thus, Ca-MgONPs might be useful in the effective management of several human pathogens of concern and some more cancer types.