DU145 Human Prostate Cancer Cells Research Articles

Comparison of the Gene Expression Profiles of Human Primary Prostate Epithelial Cells and DU145 Prostate Cancer Cells

Prostate cancer remains the second leading cause of cancerassociated deaths of men in the United States...

Role of class I histone deacetylases in the regulation of maspin expression in prostate cancer

Maspin repression is frequently observed in prostate cancer; however, the molecular mechanism(s) causing the loss is not completely understood. Here, we demonstrate that inhibition of class I histone deacetylases (HDACs) mediates re-expression of maspin which plays an essential role in suppressing proliferation and migration capability in prostate cancer cells. Human prostate cancer LNCaP and DU145 cells treated with HDAC inhibitors, sodium butyrate, and trichostatin A, resulted in maspin re-expression. Interestingly, an exploration into the molecular mechanisms demonstrates that maspin repression in prostate tumor and human prostate cancer cell lines occurs via epigenetic silencing through an increase in HDAC activity/expression, independent of promoter DNA hypermethylation. Furthermore, transcriptional activation of maspin was accompanied with the suppression of HDAC1 and HDAC8 with significant p53 enrichment at the maspin promoter associated with an increase in histone H3/H4 acetylation. Our results provide evidence of maspin induction as a critical epigenetic event altered by class I HDACs in the restoration of balance to delay proliferation and migration ability of prostate cancer cells.

Endosulfan triggers epithelial-mesenchymal transition via PTP4A3-mediated TGF-β signaling pathway in prostate cancer cells

Endosulfan is a persistent organochlorine pesticide that bioaccumulates in human body through the food chain and thus represents a potential risk to public health. Despite epidemiological studies, the molecular mechanisms underlying the carcinogenic effects of endosulfan in the prostate remain poorly understood. In this study, we investigated the effect of endosulfan on epithelial-mesenchymal transition (EMT) in human prostate cancer PC3 and DU145 cells. Endosulfan induced alterations of EMT biomarkers, reflecting repression of E-cadherin expression and induction of fibronectin, snail2, ZEB2, Twist1 and Vimentin. The expression of Protein-tyrosine Phosphatase 4A3 (PTP4A3) at mRNA and protein levels was upregulated by endosulfan. PTP4A3 inhibitor reversed the changes of EMT biomarkers, PTP4A3 and p-Smad2/Smad2, but did not affect the upregulation of Cleaved-Notch1 and Jagged1 in endosulfan-exposed cells. Endosulfan promoted cell migration and invasion, which were rescued by specific inhibitors for PTP4A3, TGF-β signaling and Notch signaling, respectively. These findings suggest that endosulfan promoted cell migration and invasion with the induction of EMT through PTP4A3-mediated TGF-β signaling pathway in prostate cancer cells.

Small molecule DTDQ exerts anti-metastatic effects in DU145 human castration-resistant prostate cancer cells via modulations of ERK, JNK, p38 and c-Myc signaling pathways

Small molecule is an organic compound with low molecular mass and can be used as a drug to treat cancer cells. 6,7-dimethyl-4-(3,4,5-trimethoxyphenyl)-3,4-dihydroquinolin-2(1H)-one (DTDQ) is a small molecule known to have potential anti-metastatic effects in human non-small cell lung cancer cells. Prostate cancer is one of the most common cancers in men and can progress to metastatic castration-resistant prostate cancer (CRPC) which possesses resistance to androgen deprivation therapy. In this study, we investigated the anti-metastatic effects of DTDQ in DU145 human CRPC cells. The results showed that DTDQ inhibited proliferation, migration and invasion of DU145 human CRPC cells. DTDQ suppressed activities of MMP-2 and MMP-9 of DU145 human CRPC cells via transcriptional regulation. DTDQ modulates the three major mitogen-activated protein kinases (MAPKs), ERK, JNK and p38 that are intimately associated with cancer cell metastasis. DTDQ also down-regulates c-Myc transcription factor of DU145 CRPC cells. Finally, we observed anti-metastatic effects of DTDQ in PC3 human CRPC cells, indicating that repressive effects of DTDQ are not limited to DU145 human CRPC cells. These results suggest that DTDQ may be a potential candidate of an anti-metastatic drug to treat human CRPC.

Evaluation of apoptotic effects of mPEG-b-PLGA coated iron oxide nanoparticles as a eupatorin carrier on DU-145 and LNCaP human prostate cancer cell lines

Many studies have so far confirmed the efficiency of phytochemicals in the treatment of prostate cancer. Eupatorin, a flavonoid with a wide range of phytomedical activities, suppresses proliferation of and induces apoptosis of multiple cancer cell lines. However, low solubility, poor bioavailability, and rapid degradation limit its efficacy. The aim of our study was to evaluate whether the use of mPEG-b-poly (lactic-co-glycolic) acid (PLGA) coated iron oxide nanoparticles as a carrier could enhance the therapeutic efficacy of eupatorin in DU-145 and LNcaP human prostate cancer cell lines. Nanoparticles were prepared by the co-precipitation method and were fully characterized for morphology, surface charge, particle size, drug loading, encapsulation efficiency and in vitro drug-release profile. The inhibitory effect of nanoparticles on cell viability was evaluated by MTT test. Apoptosis was then determined by Hoechest staining, cell cycle analysis, NO production, annexin/propidium iodide (PI) assay, and Western blotting. The results indicated that eupatorin was successfully entrapped in Fe3O4@mPEG-b-PLGA nanoparticles with an efficacy of (90.99 ± 2.1)%. The nanoparticle’s size was around (58.5 ± 4) nm with a negative surface charge [(−34.16 ± 1.3) mV]. In vitro release investigation showed a 30% initial burst release of eupatorin in 24 h, followed by sustained release over 200 h. The MTT assay indicated that eupatorin-loaded Fe3O4@mPEG-b-PLGA nanoparticles exhibited a significant decrease in the growth rate of DU-145 and LNcaP cells and their IC50 concentrations were 100 μM and 75 μM, respectively. Next, apoptosis was confirmed by nuclear condensation, enhancement of cell population in the sub-G1 phase and increased NO level. Annexin/PI analysis demonstrated that eupatorin-loaded Fe3O4@mPEG-b-PLGA nanoparticles could increase apoptosis and decrease necrosis frequency. Finally, Western blotting analysis confirmed these results and showed that Bax/Bcl-2 ratio and the cleaved caspase-3 level were up-regulated by the designing nanoparticles. Encapsulation of eupatorin in Fe3O4@mPEG-b-PLGA nanoparticles increased its anticancer effects in prostate cancer cell lines as compared to free eupatorin. Based on these results, this formulation can provide a sustained eupatorin-delivery system for cancer treatment with the drug remaining active at a significantly lower dose, making it a suitable candidate for pharmacological uses.

γ‐T3 and α‐TEA reduce the amount of docetaxel required to decrease cell viability in human prostate cancer cells and enhance the efficacy of docetaxel in the treatment of drug‐resistant cells

Prostate cancer is the second most commonly diagnosed cancer in men, and metastatic prostate cancer is currently incurable. Prostate cancer frequently becomes resistant to standard of care treatments. Moreover, the administration of conventional chemotherapeutic drugs, such as docetaxel (DOC), poses the risk of debilitating toxic side effects. Combination chemotherapy, in which several compounds targeting multiple cellular pathways are administered jointly, is one tool that can be used to combat therapeutic resistance and drug toxicity. Vitamin E (VE) compounds and analogs have been proposed as potential non‐toxic chemotherapeutics. We modeled combination therapy using mixture design response surface methodology (MDRSM), a statistical technique designed to optimize mixture compositions, to determine whether combinations of three chemotherapeutic agents (γ‐tocotrienol (γ‐T3), α‐tocopherol ether acetate (α‐TEA), and DOC) would prove more effective than DOC alone in the treatment of PC‐3 and DU145 human prostate cancer cells. A response surface was generated for cell viability, and the optimal treatment combination for reducing PC‐3 cell viability was calculated. We found that a combination of 30 μM α‐TEA, 20 μM γ‐T3, and 25 nm DOC was most effective in the treatment of PC‐3 cells. We also found that combining γ‐T3 and α‐TEA with DOC decreased the dose of DOC required to significantly reduce cell viability in PC‐3 and DU145 cells. Further, combination treatment consisting of α‐TEA, γ‐T3, and DOC induced apoptosis in PC‐3 cells as evidenced by upregulation of caspases 3 and 7. Finally, we found that combining γ‐T3 and α‐TEA with DOC enhanced treatment efficacy in DOC‐resistant PC‐3 cells.Support or Funding InformationBrigham Young University College Undergraduate Research AwardBryant Adams

Antiproliferative effect of Moringa oleifera methanolic leaf extract by down-regulation of Notch signaling in DU145 prostate cancer cells

ObjectiveRecent research suggested that Notch signaling pathway may be abnormally activated and thus leads to the development and progression of several carcinomas including prostate cancer. Various parts of Moringa oleifera and their phytochemicals are widely used in the treatment of various types of disorders including cancer. The present work designed to evaluate the anticancer effect of Moringa oleifera methanolic leaves extract mediated by inhibition of Notch signaling pathway in human prostate cancer DU145 cell line. MethodsThe human prostate cancer DU145 cell line was cultured and maintained in RPMI-1640 media. The cell viability was measured by MTT assay and phase-contrast microscopy after treatment with various concentrations of Moringa oleifera methanolic leaves extract. Nuclear morphology, the percentage of apoptotic cells were analyzed by DAPI staining and FITC-Annexin V/PI double staining methods respectively. Gene expression analysis of Bax, Bcl-2, and Notch signaling related genes were determined using real-time PCR. ResultsMoringa oleifera methanolic leaves extract significantly inhibits cell survival, marked morphological and nuclear alterations in a concentration-dependent manner. Apoptotic induction was associated with marked upregulation of Bax expression with concurrent downregulation of the Bcl-2 gene. Additionally, extract treatment results in suppression of abnormal Notch signaling pathway via downregulating Notch-1 and Hes-1 expression. ConclusionThese observations clearly revealed that the antiproliferative effect of Moringa oleifera methanolic leaves extract against prostate cancer DU145 is mediated through apoptotic induction and suppression of the aberrant Notch signaling pathway.

Inhibition of hypoxia-inducible factor 1α accumulation by glyceryl trinitrate and cyclic guanosine monophosphate.

A key mechanism mediating cellular adaptive responses to hypoxia involves the activity of hypoxia-inducible factor 1 (HIF-1), a transcription factor composed of HIF-1α, and HIF-1β subunits. The classical mechanism of regulation of HIF-1 activity involves destabilisation of HIF-1α via oxygen-dependent hydroxylation of proline residues and subsequent proteasomal degradation. Studies from our laboratory revealed that nitric oxide (NO)-mediated activation of cyclic guanosine monophosphate (cGMP) signalling inhibits the acquisition of hypoxia-induced malignant phenotypes in tumour cells. The present study aimed to elucidate a mechanism of HIF-1 regulation involving NO/cGMP signalling. Using human DU145 prostate cancer cells, we assessed the effect of the NO mimetic glyceryl trinitrate (GTN) and the cGMP analogue 8-Bromo-cGMP on hypoxic accumulation of HIF-1α. Concentrations of GTN known to primarily activate the NO/cGMP pathway (100 nM–1 µM) inhibited hypoxia-induced HIF-1α protein accumulation in a time-dependent manner. Incubation with 8-Bromo-cGMP (1 nM–10 µM) also attenuated HIF-1α accumulation, while levels of HIF-1α mRNA remained unaltered by exposure to GTN or 8-Bromo-cGMP. Furthermore, treatment of cells with the calpain (Ca2+-activated proteinase) inhibitor calpastatin attenuated the effects of GTN and 8-Bromo-cGMP on HIF-1α accumulation. However, since calpain activity was not affected by incubation of DU145 cells with various concentrations of GTN or 8-Bromo-cGMP (10 nM or 1 µM) under hypoxic or well-oxygenated conditions, it is unlikely that NO/cGMP signalling inhibits HIF-1α accumulation via regulation of calpain activity. These findings provide evidence for a role of NO/cGMP signalling in the regulation of HIF-1α, and hence HIF-1-mediated hypoxic responses, via a mechanism dependent on calpain.

Pimozide Inhibits the Human Prostate Cancer Cells Through the Generation of Reactive Oxygen Species.

The United States Food and Drug Administration-approved antipsychotic drug, pimozide, has anticancer activities. However, the role of reactive oxygen species (ROS) in its effect on prostate cancer is not well-known. We examined cell proliferation, colony formation, migration, ROS production, and the expression of antioxidant-related genes after treatment of human prostate cancer PC3 and DU145 cells with pimozide. In addition, histopathology, ROS production, and superoxide dismutase (SOD) activity were analyzed after administering pimozide to TRAMP, a transgenic mouse with prostate cancer. Pimozide increased the generation of ROS in both cell lines and inhibited cell proliferation, migration, and colony formation. Oxidative stress induced by pimozide caused changes in the expression of antioxidant enzymes (SOD1, peroxiredoxin 6, and glutathione peroxidase 2) and CISD2. Co-treatment with glutathione, an antioxidant, reduced pimozide-induced ROS levels, and counteracted the inhibition of cell proliferation. Administration of pimozide to TRAMP mice reduced the progression of prostate cancer with increased ROS generation and decreased SOD activity. These results suggest that the antipsychotic drug, pimozide, has beneficial effects in prostate cancer in vivo and in vitro. The mechanism of pimozide may be related to augmenting ROS generation. We recommend pimozide as a promising anticancer agent.

Role of Reactive Oxygen Species in the Cytotoxicity of Arsenic Trioxide and Pamidronate for Human Prostate Cancer Cells

To examine whether combining arsenic trioxide (ARS) and pamidronate (PAM), anticancer drugs that generate reactive oxygen species (ROS), enhanced targeting of redox sensitive growth signals, we studied cloning efficiency, protein tyrosine phosphatase (PTPase) activity, and epidermal growth factor receptor (EGFR) phosphorylation in DU-145 and PC-3 human prostate cancer cells in response to treatment with ARS and/or PAM for 24 h. IC50 concentrations in a clonogenic assay for ARS and PAM were 9 and 20 μM, respectively, in DU-145 cells; and 2 and 12 μM, in PC-3 cells. When combined, ARS and PAM demonstrated additive cytotoxicity in the DU-145 line (combination index [CI] of 1.10) and synergy for PC-3 cells (CI of 0.86). ARS (20 μM for 24 h) inhibited PTPase activity by 36 ± 7 %, p < 0.05 vs. untreated controls, in DU-145 cells; and by 58 ± 8%, p < 0.05, in the PC-3 line. PAM (20 μM for 24 h) decreased PTPase activity by 24 ± 9%, p = 0.06, and 8 ± 1%, p < 0.01, in DU-145 and PC-3 cells, respectively. Combining ARS and PAM significantly inhibited PTPase activity in both cell lines at lower concentrations of each drug. Pretreatment with N-acetyl-L-cysteine reversed ARS- and PAM-induced inhibition of PTPase activity. PTPase inhibition by ARS and/or PAM treatment in both DU-145 and PC-3 cells was associated with prolonged EGFR activation. These experiments demonstrate additive or synergistic cell killing by the ARS/PAM combination in DU-145 or PC-3 cells and suggest that enhanced antitumor activity may be related to alterations in receptor tyrosine kinase signaling that occur, in part, due to ROS-mediated PTPase inhibition.

Lipophilized Epigallocatechin Gallate Derivative Exerts Anti-Proliferation Efficacy through Induction of Cell Cycle Arrest and Apoptosis on DU145 Human Prostate Cancer Cells.

Epigallocatechin gallate (EGCG) is the predominant tea polyphenol and it exhibits a hydrophilic character. The lipophilized EGCG derivative (LEGCG) was synthesized by enzymatic esterification of EGCG with lauric acid to enhance its bioactivity. The tetralauroyl EGCG was confirmed by high-performance liquid chromatography-tandem mass spectrometry and further identified as 3′, 5′, 3″, 5″-4-O-lauroyl EGCG by 1H and 13C nuclear magnetic resonance. The anti-proliferation effect of LEGCG on DU145 human prostate carcinoma cells was evaluated by MTT assay. In addition, the underlying molecular mechanism by which LEGCG exerts anti-proliferation efficacy was elucidated by flow cytometry and immunoblot analysis. Results suggested that LEGCG exhibited a dose-dependent anti-proliferation effect on DU145 cells by G0/G1 phase arrest and induction of apoptosis. LEGCG induced cell cycle arrest via p53/p21 activation, which down-regulated the cyclin D1 and CDK4 expression. In addition, LEGCG induced apoptosis by increasing the Bax/Bcl-2 ratio, the cytochrome c release, and the caspases cleavage on DU145 cells. The results provide theoretical support to prevent prostate cancer with LEGCG.

Synthesis and antitumor activity of new silver(I)-N-heterocyclic carbene complexes

In this study, two novel benzimidazole-based N-heterocyclic carbene ligands (1a-b) and their silver(I) complexes (2a-b) were synthesized. All new compounds were characterized by FT-IR, LC-MS, 1H NMR, and 13C NMR spectroscopies. The in vitro antitumor activities of NHC ligands (1a-b) and their silver(I) complexes (2a-b) against DU-145 human prostate cancer cells, MDA-MB-231 and MCF-7 human breast cancer cells and L-929 (normal cells adipose from mouse) were also determined using MTT analysis for 24 h, 48 h, and 72 h. The results showed that while NHC ligands did not have in vitro antitumor activity on MCF-7, MDA-MB-231 and DU-145 cells, Ag(I)-NHC complexes have in vitro antitumor activities. The in vitro antitumor activity of 2a was found to be lower than that of 2b. Ag(I)-NHC complexes were observed to have higher IC50 values for non-cancerous cell lines than cancer cells.

Abstract B097: Development of a mouse-human chimeric antibody against human CXADR having a potent antitumor activity in animal models

Abstract Coxsackievirus and adenovirus receptor (CXADR) is a single-pass transmembrane protein that is expressed on some cancers including prostate, lung, and brain tumor tissues. We previously developed a mouse monoclonal antibody against human CXADR, mu6G10A, and found that mu6G10A significantly exerts an anti-tumor activity against various human cancer cell lines expressing CXADR through antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) activities. In this study, we have developed a mouse-human chimeric anti-CXADR antibody, ch6G10A, from mu6G10A, and evaluated its anti-tumor activity. As a result, in vitro experiments clearly showed that ch6G10A possesses binding, ADCC, and CDC activities against human prostate cancer DU-145 cells expressing CXADR like mu6G10A. In vivo xenograft models showed that ch6G10A exerts a significant anti-tumor activity against DU-145 cells when human NK cells were co-injected. These results indicate that a mouse-human chimeric anti-CXADR antibody, ch6G10A, has a therapeutic potential as a novel anti-tumor antibody drug. Citation Format: Manabu Kawada, Shuichi Sakamoto, Hiroyuki Inoue, Mika Kaneko, Satoshi Ogasawara, Masunori Kajikawa, Sakiko Urano, Shun-ichi Ohba, Yukinari Kato. Development of a mouse-human chimeric antibody against human CXADR having a potent antitumor activity in animal models [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr B097. doi:10.1158/1535-7163.TARG-19-B097

Integrated analysis of miRNA landscape and cellular networking pathways in stage-specific prostate cancer.

Dysregulation of miRNAs has been demonstrated in several human malignancies including prostate cancer. Due to tissue limitation and variable disease progression, stage-specific miRNAs changes in prostate cancer is unknown. Using chip-based microarray, we investigated global miRNA expression in human prostate cancer LNCaP, PC3, DU145 and 22Rv1 cells representing early-stage, advanced-stage and castration resistant prostate cancer in comparison with normal prostate epithelial cells. A total of 292 miRNAs were differentially expressed with 125 upregulated and 167 downregulated. These miRNAs were involved in pathways including drug resistance drug-efflux, adipogenesis, epithelial-to-mesenchymal transition, bone metamorphosis, and Th1/Th2 signaling. Regulation of miRNAs were interlinked with upstream regulators such as Argonaut 2 (AGO2), Double-Stranded RNA-Specific Endoribonuclease (DICER1), Sjogren syndrome antigen B (SSB), neurofibromatosis 2 (NF2), and peroxisome proliferator activated receptor alpha (PPARA), activated during stage-specific disease progression. Candidate target genes and pathways dysregulated in stage-specific prostate cancer were identified using CS-miRTar database and confirmed in clinical specimens. Integrative network analysis suggested some genes targeted by miRNAs include miR-17, let7g, miR-146, miR-204, miR-205, miR-221, miR-301 and miR-520 having a major effect on their dysregulation in prostate cancer. MiRNA-microarray analysis further identified miR-130a, miR-181, miR-328, miR146 and miR-200 as a panel of novel miRNAs associated with drug resistance drug-efflux and epithelial-to-mesenchymal transition in prostate cancer. Our findings provide evidence on miRNA dysregulation and its association with key functional components in stage-specific prostate cancer.

Cytotoxic effect of N-acetyl cysteine in DU145 human prostate cancer cells

Cytotoxic effect of N-acetyl cysteine in DU145 human prostate cancer cells

Effect of Sulfated Polysaccharide from Undaria pinnatifida (SPUP) on Proliferation, Migration, and Apoptosis of Human Prostatic Cancer

Objective. To observe the effect of sulfated polysaccharide from Undaria pinnatifida (SPUP) on proliferation, migration, and apoptosis of human prostatic cancer. Methods. DU145 human prostate cancer cells were cultured in vitro, and the proliferation activity both in the control group and the SPUP treatment groups (25, 50, 100, 200 μg/ml) was measured by CCK-8 assay. The wound healing assay was conducted to detect the cell migration. Cell apoptosis was measured by flow cytometry. The protein and mRNA expressions of matrix metalloproteinase-9 (MMP-9) and apoptosis-related factor Bax were detected by qRT-PCR and Western blot. The expressions of cleaved caspase-3 and cleaved caspase-9 were also determined by Western blot. Results. (1) CCK-8 results showed that the proliferative activity of DU145 cells was significantly decreased with the increase of SPUP treatment concentration (P&lt;0.05) in a dose-dependent manner and that the inhibitory effect of SPUP was most significant at 72 h (P&lt;0.05) as compared with the control group; (2) the migration rate of SPUP-treated cells was significantly decreased (P&lt;0.05) as compared with the control group. And the results of qRT-PCR and Western blot assays showed that SPUP inhibited the expression of MMP-9 in DU145 cells; (3) compared with the control group, the SPUP-treated groups had increased apoptosis of the cells. The expressions of apoptosis-related factors cleaved caspase-3, cleaved caspase-9, and Bax were upregulated (P&lt;0.05), and the mRNA expression of Bax was increased (P&lt;0.05). Conclusion. SPUP showed an antitumor activity in prostatic cancer, and the underlying mechanism may be pertaining to inhibition of migration, proliferation, and induction of apoptosis of cancer cells.

The effects of L-NAME on DU145 human prostate cancer cell line: A cytotoxicity-based study.

Of all cancer types, prostate cancer is the second most common one with an age-standardized incidence rate of 29.3 per 100,000 men worldwide. Nitric oxide (NO) is both a radical and versatile messenger molecule involved in many physiological activities. NO was documented to be highly secreted and utilized by cancer cells. Nω-nitro-L-arginine methyl ester (L-NAME) is utilized for inhibiting NO synthase. Its worst long-term side effect is reported to be hypertension, hence less cytotoxic than chemotherapeutic agents. Herein, we carried out a cytotoxicity study on how different doses of L-NAME affect DU145 human prostate cancer cells. First, toxic doses of L-NAME were determined. Then, while antioxidant capacity was determined by glutathione and total antioxidant status, oxidative stress was evaluated by quantifying malondialdehyde, NO, and total oxidant status levels. Inflammatory effects of L-NAME were investigated by measuring tumor necrosis factor-α and interleukin-6 (IL-6) levels. Apoptotic effects of L-NAME were evaluated by measuring cytochrome C somatic and caspase 3 levels and by staining Bax protein. Finally, morphological analysis was performed. IC50 of L-NAME against DU145 cells was 12.2 mM. In L-NAME-treated DU145 cells, a dose-dependent increase in oxidative stress, inflammatory, and apoptotic marker proteins and decrease in antioxidant capacity were observed. While at the moderate dose of L-NAME, apoptotic changes were commonly observed, at higher doses, vacuolated and swollen cells were also recorded. We believe that the present study will encourage future studies by providing insights about dose and effects of L-NAME.

1948P - Effect of docetaxel-resistance on the reactivity of prostate cancer cells to metformin

BackgroundMetronomic approach represent a promising strategy for the chemotherapy of drug-resistant tumors, because it can reduce the effective doses and adverse effects of chemotherapeutics. In particular, metabolic blockers reduce energy supply for multi-drug resistance systems, thus increasing tumor cells’ reactivity to chemotherapeutics. Metformin is an anti-diabetic drug that blocks mitochondrial respiration, interferes with ATP production and with proliferation of cancer cells. However, the effect of drug-resistance of prostate cancer cells on their reactivity to metformin has not yet been evaluated. MethodsHere, we analysed short- and long-term cytotoxic and pro-apoptotic effects of metformin on the phenotype of human prostate cancer PC-3 and DU145 cells and their docetaxel (DCX)-resistant lineages (PC-3-DCX20 and DU145_DCX20; obtained after long-term treatment with 20nM DCX). We concentrated on their DCX-resistance pattern and compared their epithelial-mesenchymal transition (EMT)-related phenotype, invasive potential and the activity of ATP-binding cassette (ABC) transporters in the presence of metformin and/or DCX. ResultsMetformin increased the sensitivity of drug-resistant PC-3 and DU145 cells to DCX; even though PC-3_DCX20 cells displayed reduced sensitivity to combined metformin/DCX treatment. When administered alone, metformin exerted less prominent cytostatic effects on PC_DCX20 cells than on their DU145_DCX20 counterparts. This effect was accompanied by EMT-related morphological changes, accompanied by the up-regulation of connexin (Cx)43. ConclusionsThese data indicate that reactivity of drug-resistant prostate cancer cells to metformin may depend on the efficiency of metabolic stress-induced EMT. EMT-related metabolic elasticity that apparently increases invasive potential of PC3 cells in the absence of DCX may limit the application of metformin in therapy of drug-resistant prostate tumors. Legal entity responsible for the studyJagiellonian University, Faculty of Biochemistry, Biophysics and Biotechnology. FundingHas not received any funding. DisclosureAll authors have declared no conflicts of interest.

Growth Inhibitory and Pro-Apoptotic Effects of Ornamental Pomegranate Extracts in Du145 Human Prostate Cancer Cells

Aims: Prostate cancer is the most common form of cancer in the male. Epidemiological studies have associated increased cancer incidence with reduced consumption of fruit and vegetables. This study was aimed to investigate the influence of dwarf pomegranate extracts (peel, juice, and seeds oil) on the proliferation and apoptosis of human prostate androgen-independent cell line DU145. Methods: The cell viability was determined by the MTT assay. Morphological changes are detected by light microscopy. The ELISA assay is used to evaluate the nuclear DNA fragmentation and western Blot to detect the expression of apoptosis-associated proteins including poly-ADP-ribose polymerase (PARP) and cyclooxygenase-2 (COX-2). Results: The three tested extracts exhibited a dose-response cytotoxic effect and antiproliferative action on DU145 cell line and induce morphological changes. The dose of each extract required to inhibit cell proliferation by 50% (IC50) was 0.12, 0.36, and 0.42 mg/mL, respectively, for seeds oil, juice, and peel. The three extracts could also induce prostate cancer cell apoptosis by an increase of DNA fragmentation, PARP cleavage, and inhibition of the COX-2 expression. The strongest pro-apoptotic effect was shown after peel treatment. Conclusion: Dwarf pomegranate extracts exhibited potent growth inhibitory activities in human prostate cancer cells (DU145), which appear to be mediated by a pro-apoptotic mechanism.

Concentration-Dependent Effects of Zinc Sulfate on DU-145 Human Prostate Cancer Cell Line: Oxidative, Apoptotic, Inflammatory, and Morphological Analyzes.

Zinc takes part in several of cellular signaling pathways, containing defense against free radicals, apoptosis, and inflammation. However, interaction between zinc and prostate cancer progression is poorly understood. Therefore, zinc treatment in DU-145 human prostate cancer cells was investigated. First, zinc sulfate (ZnSO4) concentrations with antiproliferative effect were determined using MTT assay. Then, ZnSO4-induced oxidative damage was evaluated by malondialdehyde (MDA) levels, glutathione (GSH) levels, total oxidant status (TOS) levels, and total antioxidant status (TAS) levels. Apoptotic effects of ZnSO4 were determined by measuring biochemical and immunohistochemical parameters including caspase 3 (CASP3), cytochrome C (CYC), Bcl-2-associated X protein (Bax), and B cell CLL/lymphoma 2 (Bcl-2) levels. Inflammatory effects of ZnSO4 were investigated by measuring interleukin-6 (IL-6) levels and tumor necrosis factor-alpha (TNF-α) levels. Finally, morphological analysis was performed using hematoxylin-eosin staining. We found that ZnSO4 caused a concentration-dependent increase in oxidative stress, apoptosis, and inflammation pathways. Moreover, there were a number of morphological alterations in treated cells depending on the ZnSO4 concentration. Consequently, our data showed that zinc acts as a regulator of increased oxidative damage and apoptosis through the upregulation of TNF-α and IL-6.