PC-3M Prostate Cancer Cell Line Research Articles

Tumor-suppressive microRNA-223 inhibits cancer cell migration and invasion by targeting ITGA3/ITGB1 signaling in prostate cancer.

Analysis of microRNA (miRNA) expression signatures in prostate cancer (PCa) and castration-resistant PCa has revealed that miRNA-223 is significantly downregulated in cancer tissues, suggesting that miR-223 acts as a tumor-suppressive miRNA by targeting oncogenes. The aim of this study was to investigate the functional roles of miR-223 and identify downstream oncogenic targets regulated by miR-223 in PCa cells. Functional studies of miR-223 were carried out to investigate cell proliferation, migration, and invasion using PC3 and PC3M PCa cell lines. Restoration of miR-223 significantly inhibited cancer cell migration and invasion in PCa cells. In silico database and genome-wide gene expression analyses revealed that ITGA3 and ITGB1 were direct targets of miR-223 regulation. Knockdown of ITGA3 and ITGB1 significantly inhibited cancer cell migration and invasion in PCa cells by regulating downstream signaling. Moreover, overexpression of ITGA3 and ITGB1 was observed in PCa clinical specimens. Thus, our data indicated that downregulation of miR-223 enhanced ITGA3/ITGB1 signaling and contributed to cancer cell migration and invasion in PCa cells. Elucidation of the molecular pathways modulated by tumor-suppressive miRNAs provides insights into the mechanisms of PCa progression and metastasis.

262 Improved cytotoxic activity of Nor-β-lapachone-loaded PLGA microcapsules in PC3M prostate cancer cell line

262 Improved cytotoxic activity of Nor-β-lapachone-loaded PLGA microcapsules in PC3M prostate cancer cell line

The aryl hydrocarbon receptor is constitutively active in advanced prostate cancer cells.

BackgroundDistant prostate cancers are commonly hormone refractory and exhibit increased growth no longer inhibited by androgen deprivation therapy. Understanding all molecular mechanisms contributing to uncontrolled growth is important to obtain effective treatment strategies for hormone refractory prostate cancers (HRPC). The aryl hydrocarbon receptor (AhR) affects a number of biological processes including cell growth and differentiation. Several studies have revealed that exogenous AhR ligands inhibit cellular proliferation but recent evidence suggests AhR may possess intrinsic functions that promote cellular proliferation in the absence of exogenous ligands.Methods/ResultsqRT-PCR and western blot analysis was used to determine AhR mRNA and protein expression in hormone sensitive LNCaP cells as well as hormone refractory DU145, PC3 and PC3M prostate cancer cell lines. LNCaP cells express AhR mRNA and protein at a much lower level than the hormone refractory cell models. Cellular fractionation and immunocytochemistry revealed nuclear localization of AhR in the established hormone refractory cell lines while LNCaP cells are devoid of nuclear AhR protein. qRT-PCR analysis used to assess basal CYP1B1 levels and a xenobiotic responsive element binding assay confirmed ligand independent transcriptional activity of AhR in DU145, PC3 and PC3M cells. Basal CYP1B1 levels were decreased by treatment with specific AhR inhibitor, CH223191. An in vitro growth assay revealed that CH223191 inhibited growth of DU145, PC3 and PC3M cells in an androgen depleted environment. Immunohistochemical staining of prostate cancer tissues revealed increased nuclear localization of AhR in grade 2 and grade 3 cancers compared to the well differentiated grade 1 cancers.ConclusionsTogether, these results show that AhR is constitutively active in advanced prostate cancer cell lines that model hormone refractory prostate cancer. Chemical ablation of AhR signaling can reduce the growth of advanced prostate cancer cells, an effect not achieved with androgen receptor inhibitors or growth in androgen depleted media.

Counteracting the activation of pAkt by inhibition of MEK/Erk inhibition reduces actin disruption-mediated apoptosis in PTEN-null PC3M prostate cancer cell lines

The actin cytoskeleton is important in the maintenance of cellular homeostasis and in signal transduction pathways leading to cell growth and apoptotic cell death in eukaryotic cells. Disruption of actin dynamics is associated with morphological changes in cancer cells. Deletion of phosphatase and tensin homolog (PTEN), a tumor suppressor gene involved in the regulation of the cell cycle and apoptosis, leads to cytoskeleton disruption and double-strand breaks (DSBs). To study the mechanism(s) of actin disruption-mediated apoptosis and its potential application for anticancer therapy, PTEN-null PC3M prostate cancer cells were treated with latrunculin B (LB). LB induced destabilization of the actin microfilament and apoptosis in a dose-dependent manner, as demonstrated by morphological changes and nuclear condensation in the PC3M cells. In addition, it resulted in an increase in the levels of γH2AX recruitment, implicating the induction of DNA damage, including DSBs. Induction of Bax, with little effect on Bcl-2 expression, indicated that actin disruption causes apoptosis through activation of Bax signaling in PC3M cells. Treatment with U20126, a mitogen-activated protein kinase kinase (MEK) inhibitor, resulted in attenuated induction of DSBs and apoptosis through activation of protein kinase B (Akt), suggesting that LB-mediated actin dysfunction induces DSBs via the MEK/extracellular signal-regulated kinase (Erk) pathway in cells. Therefore, counteracting activation of phosphorylated Akt stemming from the inhibition of MEK/Erk resulted in attenuation of actin disruption-induced apoptotic events in the PC3M cells. The results of this study provide information not only for use in delineation of the molecular association between actin disruption and tumorigenesis, but also for the development of a strategy for actin-based anticancer chemotherapy against highly metastatic prostate cancer.

Therapeutic effect and distribution of (32)P-chromic-poly (L-lactide) brachytherapy in nude mice bearing human prostate cancer

Objective To investigate the anti-tumor effects and distribution of 32P-chromic-phosphate poly(L-lactide)(CP-PLLA) in nude mice bearing the prostate cancer cell line PC-3M.Methods Tumor xenograft models were established with PC-3M prostate cancer cell line in male BALB/c nude mice.Based on the implanted dosage of 32P-CP-PLLA particles,the mice were randomly divided into four groups:control group (n =8,0 MBq),low-dose group (n =8,3.7 MBq),middle-dose group (n =8,7.4 MBq) and high-dose group (n =8,18.5 MBq).Three mice from each group were sacrificed 2 d after the 32P-CPPLLA particles were implanted into the tumor.Cell apoptosis was analyzed by a terminal oxynucleotidyl transferase mediated dUTP biotin nick and labeling (TUNEL) method,upon which the apoptotic rate was calculated.Tumor volume was measured every two days.The in vivo distribution of 32P-CP-PLLA was observed by SPECT.Mice in each group (n =5) were sacrificed on the 14th day.The weight and radioactivity of tumors were measured,so that the radioactive retention ratio and tumor growth inhibition rate could be calculated.The pathological changes of tumors and livers were observed,allowing the tumor necrotic rate to be calculated.The intratumoral microvessel density (MVD) was evaluated by an immunohistochemical method.Statistical analysis was performed by one-way analysis of variance and SNK-q analysis.Results 32P mainly accumulated in the tumor.Significant differences were noted in the tumor volumes among all groups on the 14th day (F =212.820,P ＜ 0.01).Massive tumor necrosis was observed by pathologic examination.After exposure to 0,3.7,7.4 and 18.5 MBq 32P-CP-PLLA,the apoptotic rates of tumors on the 2nd day were (1.66 ±0.56)％,(34.51 ±6.68)％,(42.45 ±6.09)％ and (57.01 ±3.13)％,respectively.On the 14th day,the tumor necrotic rates were (4.86 ±4.12)％,(65.43 ±8.06)％,(76.18 ±6.35)％ and (85.85 ±3.05)％,respectively and the tumor growth inhibition rates were (60.82 ± 3.81) ％,(73.17 ± 4.55) ％,(8 1.80 ± 4.74) ％,respectively.The apoptotic rate,tumor necrotic rate and tumor growth inhibition rate all showed a dose-effect relationship.When the dose was 3.7,7.4 and 18.5 MBq,the radioactive retention ratios in the tumors were (34.36 ±5.78)％,(41.16 ±5.26) ％ and (44.70 ± 3.83) ％,respectively (F =6.311,P ＜ 0.05).When the dose was 0,3.7,7.4 and 18.5 MBq,the MVD was 62.00 ±5.40,38.16 ±4.16,23.50 ±4.59 and 15.80 ±3.92,respectively (F=128.613,q=14.31,23.11,27.74,8.80,13.43,4.62,all P＜0.01).No pathological changes were observed in the liver or spleen.Conclusions The 32P-CP-PLLA particles released in the tumor and accumulated significantly at the implantation site.It shows apparent antitumor effects,including inducing apoptosis and inhibiting angiogenesis.In addition,a dose-effect relationship is noted between the antitumor effects and radioactive retention ratios of the tumors. Key words: Prostatic neoplasms; Neoplasm transplantation; Brachytherapy; Phosphorus radioisotopes; Chromic phosphate-poly (L-lactide); Mice, nude

Combinatorial cytotoxic effects of Curcuma longa and Zingiber officinale on the PC-3M prostate cancer cell line.

Many plant-derived products exhibit potent chemopreventive activity against animal tumor models as well as rodent and human cancer cell lines. They have low side effects and toxicity and presumably modulate the factors that are critical for cell proliferation, differentiation, senescence and apoptosis. The present study investigates the effects of some medicinal plant extracts from generally recognized as safe plants that may be useful in the prevention and treatment of cancer. Clonogenic assays using logarithmically-growing cells were performed to test the effect. The cytotoxic effects of Curcuma longa and Zingiber officinale were studied using sulforhodamine B assay, tetrazolium dye assay, colony morphology and microscopic analysis. Out of the 13 lyophilized plant-derived extracts evaluated for growth-inhibitory effects on the PC-3M prostate cancer cell line, two extracts derived from C. longa and Z. officinale showed significant inhibitory effects on colony-forming ability. The individual and augmentative effects of these two extracts were tested for their narrow range effective lower concentration on PC-3M in clonogenic assays. At relatively lower concentrations, C. longa showed significant inhibition of colony formation in clonogenic assays; whereas at same concentrations Z. officinale showed only moderate inhibitory effects. However, when both the agents were tested together at the same concentrations, the combined effects were much more significant than their individual ones. On normal prostate epithelial cells both C. longa and Z. officinale had similar effects but at a lower magnitude. These observations were confirmed by several cytotoxicity assays involving the morphological appearance of the colonies, microscopic observations, per cent inhibition in comparison to control by sulforhodamine B and tetrazolium dye assay. From these observations, it was concluded that the combined effects of C. longa and Z. officinale are much greater than their individual effects, suggesting the role of multiple components and their synergistic mode of actions to elicit stronger beneficial effects.

Chemopreventive Potential of an Ethyl Acetate Fraction from Curcuma Longa is Associated with Upregulation of p57kip2and Rad9 in the PC-3M Prostate Cancer Cell Line

Turmeric (Curcuma longa) has been shown to possess anti-inflammatory, antioxidant and antitumor properties. However, despite the progress in research with C. longa, there is still a big lacuna in the information on the active principles and their molecular targets. More particularly very little is known about the role of cell cycle genes p57(kip2) and Rad9 during chemoprevention by turmeric and its derivatives especially in prostate cancer cell lines. Accordingly, in this study, we have examined the antitumor effect of several extracts of C. longa rhizomes by successive fractionation in clonogenic assays using highly metastatic PC-3M prostate cancer cell line. A mixture of isopropyl alcohol: acetone: water: chloroform: and methanol extract of C. longa showed significant bioactivity. Further partition of this extract showed that bioactivity resides in the dichloromethane soluble fraction. Column chromatography of this fraction showed presence of biological activity only in ethyl acetate eluted fraction. HPLC, UV-Vis and Mass spectra studies showed presence three curcuminoids in this fraction besides few unidentified components. From these observations it was concluded that the ethyl acetate fraction showed not only inhibition of colony forming ability of PC-3M cells but also up-regulated cell cycle genes p57(kip2) and Rad9 and further reduced the migration and invasive ability of prostate cancer cells.

Ginsenoside Rg3 attenuates cell migration via inhibition of aquaporin 1 expression in PC-3M prostate cancer cells

Ginsenoside Rg3 (Rg3), one of the bioactive extracts found in ginseng root, was reported to have anti-cancer activity in various cancer models. The anti-proliferation effect of Rg3 on prostate cancer cells has been well reported. To test whether Rg3 has an anti-metastatic effect on prostate cancer, we treated a highly metastatic PC-3M prostate cancer cell line with Rg3. We found that Rg3 (10μM) led to remarkable inhibition of PC-3M cell migration. Simultaneously, exposure to Rg3 suppressed expression of the aquaporin 1 (AQP1) water channel protein, which has previously been reported to be involved in cell migration. Overexpression of AQP1 attenuated Rg3-induced inhibition of cell migration, and introduction of a shRNA targeting AQP1 abrogated the inhibitory effect of Rg3, although the basal level of cell migration was decreased by RNA interference. In mechanism study, estrogen receptor- and glucocorticoid receptor-dependent pathways are proved uninvolved in the AQP1 regulation by Rg3. However, Rg3 treatment triggered the activation of p38 MAPK; and SB202190, a specific inhibitor of p38 MAPK, antagonized the Rg3-induced regulation of AQP1 and cell migration, suggesting a crucial role for p38 in the regulation process. Deletion analysis of the promoter region of AQP1 was also conducted using dual-luciferase assay, which indicated that the −1000bp to −200bp promoter region was involved in the AQP1 regulation by Rg3. In all, we conclude that Rg3 effectively suppresses migration of PC-3M cells by down-regulating AQP1 expression through p38 MAPK pathway and some transcription factors acting on the AQP1 promoter.

Abstract C200: Second-generation PIM inhibitors exhibit improved activity in solid tumor models in vitro.

Abstract The proto-oncogene PIM kinase family (PIM-1, -2 and -3) comprises constitutively active serine/threonine kinases upregulated in multiple cancer indications, including lymphoma, leukemia, multiple myeloma, prostate, bladder, gastric and head & neck cancers. Overexpression of one or more PIM family members in patient tumors frequently correlates with poor prognosis. The PIM kinases function by inhibiting apoptosis in MYC-driven tumors, promoting tumor cell survival and proliferation. PIM-1 and PIM-2 overexpression models were obtained in the human prostate cancer cell lines PC-3M and 22RV-1 and the non-tumorigenic mouse NIH-3T3 background. Overexpression of PIM kinases led to enhanced cell growth and tumorigenicity in both NIH-3T3 and 22RV-1 cell lines. In the PC-3M cell line, enhanced phosphorylation of the PIM kinase substrate BAD (pBAD) was observed following PIM overexpression. Enhancement of pBAD was inhibited by SGI-1776, a well-described PIM inhibitor, as well as next generation PIM inhibitors exhibiting 4–10 fold improved potency against the PIM kinase family. The current PIM inhibitors display sub-μM activity in pharmacodynamic marker, proliferation and 2D colony formation assays using the PC-3M prostate cancer cell line, the UM-UC-3 bladder cancer cell line, and the HSC3 head & neck cancer cell line. The second generation PIM inhibitors possess favorable hERG and CYP inhibition profiles compared with SGI-1776, and demonstrate excellent oral bioavailability. In vivo xenograft studies using both PIM overexpression models and clinically relevant solid tumor models will facilitate identification of a clinical candidate. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr C200.

Proteomics Profiling and Cytotoxic Effect of Curcuma longa on Prostate Cancer

Turmeric (Curcuma longa) has been shown to possess anti-inflammatory, antioxidant and antitumor properties. Extraction, partition and column chromatography of the dry powder of C. longa rhizomes showed presence of biological activity only in ethyl acetate eluted fraction in clonogenic assays using highly metastatic PC-3M prostate cancer cell line. HPLC, UV-Vis and Mass spectra studies showed presence of three curcuminoids in this fraction. Accordingly, we have made an attempt to identify the proteins modulated by purified turmeric fraction in PC-3M human prostate cancer cell line using high-resolution two-dimensional gel electrophoresis (2-DE). Isoelectric focusing and 2-DE analysis showed a total of 29 proteins altered by treatment with ethyl acetate fraction (EAF) of C. longa. Out of 29 differentially expressed pro- teins, 15 were identified by peptide mass fingerprinting through LC/MS/MS sequencing. From these, a total of 7 were down-regulated and 8 were up-regulated spots. The down-regulated proteins identified by Peptide Mass Fingerprinting are Elongation Factor 2 (eEF2), Stress-induced phosphoprotein 1, Glutathione S-transferase (GST) Omega-1, Parvalbumin alpha, Succinyl-CoA: ketoacid, Lamin-A/C and Annexin A2. The up-regulated proteins identified by Peptide Mass Fin- gerprinting include 78 kDa Glucose-regulated protein precursor (GRP78), Protein disulfide isomerase (PDI) precursor, Actin cytoplasmic 2, protein SET, Calreticulin precursor, Nucleophosmin, Vimentin, and Aortic alpha-actin (ACTA2). The identified proteins have diverse cellular functions such as ER stress, Unfolded Protein Response (UPR), cytoskeletal, structural, regulatory, and apoptotic proteins that will require further in-depth studies to understand the biological signifi- cance.

Continuous and intermittent dosing of lonafarnib potentiates the therapeutic efficacy of docetaxel on preclinical human prostate cancer models

Lonafarnib is a potent, selective farnesyltransferase inhibitor (FTI) undergoing clinical studies for the treatment of solid tumors and hematological malignancies. Preclinically, a number of FTIs, including lonafarnib, interact with taxanes to inhibit cancer cell growth in an additive/synergistic manner. These observations provided rationale for investigating the effects of combining lonafarnib and docetaxel on preclinical prostate cancer models. To date, docetaxel is the only chemotherapeutic agent in clinical use for hormone-refractory prostate cancer. In vitro experiments with 22Rv1, LNCaP, DU-145, PC3 and PC3-M prostate cancer cell lines showed significantly enhanced inhibition of cell proliferation and apoptosis when lonafarnib was added to docetaxel. In human tumor xenograft models, continuous coadministration of lonafarnib with docetaxel caused marked tumor regressions (24-47%) in tumors from all of the cell types as well as parental CWR22 xenografts. Intermittent dosing of lonafarnib (5 days on then 5 days off) coadministered with docetaxel produced similar regressions in hormone-refractory 22Rv1 tumors. 22Rv1 tumors progressing on docetaxel treatment also responded to treatment with intermittent lonafarnib (5 days on then 5 days off). Moreover, animals did not exhibit any signs of toxicity during coadministration of lonafarnib and docetaxel. In conclusion, coadministration of continuous and intermittent lonafarnib enhanced the antitumor activity of docetaxel in a panel of prostate cancer models. An intermittent dosing schedule of lonafarnib coadministered with docetaxel may allow enhanced efficacy to that of continuous dosing by improving the tolerability of higher doses of lonafarnib.

Intracellular Cargo Delivery by an Octaarginine Transporter Adapted to Target Prostate Cancer Cells through Cell Surface Protease Activation

Delivery of therapeutics and imaging agents to target tissues requires localization and activation strategies with molecular specificity. Cell-associated proteases can be used for these purposes in a number of pathologic conditions, and their enzymatic activities can be exploited for activation strategies. Here, molecules based on the d-arginine octamer (r8) protein-transduction domain (PTD, also referred to as molecular transporters) have been adapted for selective uptake into cells only after proteolytic cleavage of a PTD-attenuating sequence by the prostate-specific antigen (PSA), an extracellular protease associated with the surface and microenvironment of certain prostate cancer cells. Convergent syntheses of these activatable PTDs (APTDs) are described, and the most effective r8 PTD-attenuating sequence is identified. The conjugates are shown to be stable in serum, cleaved by PSA, and taken up into Jurkat (human T cells) and PC3M prostate cancer cell lines only after cleavage by PSA. These APTD peptide-based molecules may facilitate targeted delivery of therapeutics or imaging agents to PSA-expressing prostate cancers.