Radiotherapy Metastatic Prostate Cancer Cell Lines Treated with Gold Nanorods Modulate miRNA Signatures.

MicroRNA (miRNA) modulation has been identified as a promising strategy for improving the response of human prostate cancer (PCa) to radiotherapy (RT). Studies have shown that mimics or inhibitors of miRNAs could modulate the sensitivity of PCa cells to RT. In addition, pegylated gold nanoparticles have been studied as a therapeutic approach to treat PCa cells and/or vehicles for carrying miRNAs to the inside of cells. Therefore, we evaluated the capacity of hypofractionated RT and pegylated gold nanorods (AuNPr-PEG) to modulate the miRNA signature on PCa cells. Thus, RT-qPCR was used to analyze miRNA-95, miRNA-106-5p, miRNA-145-5p, and miRNA-541-3p on three human metastatic prostate cell lines (PC3, DU145, and LNCaP) and one human prostate epithelial cell line (HprEpiC, a non-tumor cell line) with and without treatment. Our results showed that miRNA expression levels depend on cell type and the treatment combination applied using RT and AuNPr-PEG. In addition, cells pre-treated with AuNPr-PEG and submitted to 2.5 Gy per day for 3 days decreased the expression levels of miRNA-95, miRNA-106, miRNA-145, and miRNA-541-3p. In conclusion, PCa patients submitted to hypofractionated RT could receive personalized treatment based on their metastatic cellular miRNA signature, and AuNPr-PEG could be used to increase metastatic cell radiosensitivity.

Expression, localisation and potential significance of aquaporins in benign and malignant human prostate tissue.

BACKGROUND: To study the expression pattern, localisation and potential clinical significance of aquaporin water channels (AQP) both in prostate cancer (PC) cell lines and in benign and malignant human prostate tissue. METHODS: The AQP transcript and protein expression of HPrEC, LNCaP, DU-145 and PC3 cell lines was investigated using reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence (IF) microscopy labelling. Immunohistochemistry (IHC) was performed to assess AQP protein expression in surgical specimens of benign prostatic hyperplasia as well as in PC. Tissue mRNA expression of AQPs was quantified by single-step reverse transcriptase quantitative polymerase chain reaction (qPCR). Relative gene expression was determined using the 40-ΔCT method and correlated to clinicopathological parameters. RESULTS: Transcripts of AQP 1, 3, 4, 7, 8, 10 and 11 were expressed in all four cell lines, while AQP 9 transcripts were not detected in malignant cell lines. IF microscopy confirmed AQP 3, 4, 5, 7 and 9 protein expression. IHC revealed highly heterogeneous AQP 3 protein expression in PC specimens, with a marked decrease in expression in tumours of increasing malignancy. Loss of AQP 9 was shown in PC specimens. mRNA expression of AQP3 was found to be negatively correlated to PSA levels (ρ = - 0.354; p = 0.013), D'Amico risk stratification (ρ = - 0.336; p = 0.012), ISUP grade (ρ = - 0.321; p = 0.017) and Gleason score (ρ = - 0.342; p = 0.011). CONCLUSIONS: This is the first study to systematically characterize human prostate cell lines, benign prostatic hyperplasia and PC in relation to all 13 members of the AQP family. Our results indicate the differential expression of several AQPs in benign and malignant prostate tissue. A significant correlation was observed between AQP 3 expression and tumour grade, with progressive loss in more malignant tumours. Taken together, AQPs may play a role in the progression of PC and AQP expression patterns may serve as a prognostic marker.

Biological Potential and Mechanism of Prodigiosin from Serratia marcescens Subsp. lawsoniana in Human Choriocarcinoma and Prostate Cancer Cell Lines.

Tripyrrole molecules have received renewed attention due to reports of numerous biological activities, including antifungal, antibacterial, antiprotozoal, antimalarial, immunosuppressive, and anticancer activities. In a screen of bacterial strains with known toxicities to termites, a red pigment-producing strain, HDZK-BYSB107, was isolated from Chamaecyparis lawsoniana, which grows in Oregon, USA. Strain HDZK-BYSB107 was identified as Serratia marcescens subsp. lawsoniana. The red pigment was identified as prodigiosin using ultraviolet absorption, LC-MS, and 1H-NMR spectroscopy. The bacterial prodigiosin had an inhibitory effect on both Gram-negative and Gram-positive bacteria. The main objective of this study was to explore the anticancer activities and mechanism of strain HDZK-BYSB107 prodigiosin by using human choriocarcinoma (JEG3) and prostate cancer cell lines (PC3) in vitro and JEG3 and PC3 tumor-bearing nude mice in vivo. In vitro anticancer activities showed that the bacterial prodigiosin induced apoptosis in JEG3 cells. In vivo anticancer activities indicated that the prodigiosin significantly inhibited the growth of JEG3 and PC3 cells, and the inhibitory activity was dose and time dependent. The anticancer efficacy of the bacterial prodigiosin on JEG3 and PC3 cells, JEG3 and PC3 tumor exhibited a correlation with the down regulation of the inhibitor of IAP family, including XIAP, cIAP-1 and cIAP-2, and the activation of caspase-9 and caspase-3 accompanied by proteolytic degradation of poly (ADP-ribose)-polymerase. The expressions of P53 and Bax/Bcl-2 in JEG3 and PC3 cells were significantly higher than in untreated groups. Our results indicated that the bacterial prodigiosin extracted from C. lawsoniana is a promising molecule due to its potential for therapeutic applications.

The Prostate Cancer Cells Resistant to Docetaxel as in vitro Model for Discovering MicroRNAs Predictive of the Onset of Docetaxel Resistance.

On the grounds that miRNAs present in the blood of prostate cancer (PCa) patients are released in the growth medium by PCa cells, it is conceivable that PCa cells resistant to docetaxel (DCT) (DCTR) will release miRNAs that may be found in PCa patients under DCT therapy if resistant PCa cells appear. We isolated DCTR clones respectively from 22Rv1 and DU-145 PCa cell lines and performed through next-generation sequencing (NGS) the miRNAs profiles of the released miRNAs. The analysis of the NGS data identified 105 and 1 miRNAs which were differentially released in the growth medium of the 22Rv1/DCTR and DU-145/DCTR clones, respectively. Using additional filters, we selected 12 and 1 miRNA more released by all 22Rv1/DCTR and DU-145/DCTR clones, respectively. Moreover, we showed that 6 of them were more represented in the growth medium of the DCTR cells than the ones of DCT-treated cells. We speculated that they have the pre-requisite to be tested as predictive biomarkers of the DCT resistance in PCa patients under DCT therapy. We propose the utilization of clones resistant to a given drug as in vitro model to identify the differentially released miRNAs, which in perspective could be tested as predictive biomarkers of drug resistance in tumor patients under therapy.

Delivery of tanshinone IIA and α-mangostin from gold/PEI/cyclodextrin nanoparticle platform designed for prostate cancer chemotherapy.

A new anti-cancer drug delivery system, based on gold nanoparticles, has been designed for hydrophobic active compounds. The system is a conjugate of gold/polyethyleneimine (AuNPs/PEI) nanoparticles and sulphated ß-cyclodextrin (CD). Anionic cyclodextrin was attached to the positively charged AuNPs/PEI nanoparticles by ionic bonds. Tanshinone IIA and α-mangostin were extracted, purified and encapsulated into the AuNPs/PEI/CD nanoparticles. In vitro preliminary cell viability assays against prostate cancer cell lines PC-3 and DU145 showed that encapsulation resulted in increased cytotoxicity.

γ-Oryzanol reduces caveolin-1 and PCGEM1 expression, markers of aggressiveness in prostate cancer cell lines.

BACKGROUND: Prostate cancer is a leading cause of death among men due to the limited number of treatment strategies available for advanced disease. γ-oryzanol is a component of rice bran, rich in phytosterols, known for its antioxidant, anti-carcinogenic and endocrinological effects. It is known that γ-oryzanol may affect prostate cancer cells through the down regulation of the antioxidant genes and that phytosterols have anti-proliferative and apoptotic effects. There are evidences showing that some of the components of γ-oryzanol can modulate genes involved in the development and progression of prostate cancer, as caveolin-1 (Cav-1) and prostate specific androgen-regulated gene (PCGEM1). METHODS: To determine the effects of γ-oryzanol on prostate cancer cell survival we evaluated the cell viability and biomass by MTT and sulforhodamine B assays, respectively. Cell death, cell cycle and pERK1/2 activity were assessed by flow cytometry. The changes in gene expression involved in the survival and progression of prostate cancer cav-1 and PCGEM1 genes were evaluated by quantitative real time reverse transcriptase polymerase chain reaction (RT-PCR) and cav-1 protein by immunofluorescence followed by confocal microscopy analysis. RESULTS: We found that γ-oryzanol decreases cell viability and culture biomass by apoptosis and/or necrosis death in androgen unresponsive (PC3 and DU145) and responsive (LNCaP) cell lines, and signals through pERK1/2 in LNCaP and DU145 cells. γ-oryzanol also appears to block cell cycle progression at the G2/M in PC3 and LNCaP cells and at G0/G1 in DU145 cells. These effects were accompanied by a down regulation in the expression of the cav-1 in both androgen unresponsive cell lines and PCGEM1 gene in DU145 and LNCaP cells. CONCLUSION: In summary, we used biochemical and genetics approaches to demonstrate that γ-oryzanol show a promising adjuvant role in the treatment of prostate cancer.

Prostate cell lines as models for biomarker discovery: performance of current markers and the search for new biomarkers.

BACKGROUND: Prostate cancer cell lines have been used in the search for biomarkers that are suitable for prostate cancer diagnosis. Unfortunately, many cell line studies have only involved single cell lines, partially characterized cell lines or were performed without controls, and this may have been detrimental to effective biomarker discovery. We have analyzed a panel of prostate cancer and nonmalignant control cell lines using current biomarkers and then investigated a set of prospective endosomal and lysosomal proteins to search for new biomarkers. METHODS: Western blotting was used to define the amount of protein and specific molecular forms in cell extracts and culture media from a panel of nonmalignant (RWPE-1, PNT1a, PNT2) and prostate cancer (22RV1, CaHPV10, DU-145, LNCaP) cell lines. Gene expression was determined by qRT-PCR. RESULTS: HPV-18 transfected cell lines displayed a different pattern of protein and gene expression when compared to the other cell lines examined, suggesting that these cell lines may not be the most optimal for prostate cancer biomarker discovery. There was an increased amount of prostatic acid phosphatase and kallikrein proteins in LNCaP cell extracts and culture media, but variable amounts of these proteins in other prostate cancer cell lines. There were minimal differences in the amounts of lysosomal proteins detected in prostate cancer cells and culture media, but two endosomal proteins, cathepsin B and acid ceramidase, had increased gene and protein expression, and certain molecular forms showed increased secretion from prostate cancer cells (P ≤ 0.05). LIMP-2 gene and protein expression was significantly increased in prostate cancer compared to nonmalignant cell lines (P ≤ 0.05). CONCLUSIONS: While the existing prostate cancer biomarkers and lysosomal proteins investigated here were not able to specifically differentiate between a panel of nonmalignant and prostate cancer cell lines, endosomal proteins showed some discriminatory capacity. LIMP-2 is a critical regulator of endosome biogenesis and the increased expression observed in prostate cancer cells indicated that other endosome related proteins may also be upregulated and could be investigated as novel biomarkers.

Optical genome mapping reveals balanced and unbalanced genetic changes associated with tumor-forming potential in an early-stage prostate cancer epithelial subline (M2205).

BACKGROUND: Identifying cytogenetic changes in tumors can aid in diagnosis/prognosis and disease management. Complete cytogenetic characterization has historically required a multimethod/time-consuming approach. Optical genome mapping (OGM) offers a potential solution to this challenge by detecting both balanced and unbalanced abnormalities in a single assay. METHODS: Genetic changes acquired with tumor-forming potential in a prostate xenograft subline [M2205] (derived from a Black male) that were detected using cytogenetic versus OGM analyses were compared to assess the utility of OGM for analyzing solid tumors. RESULTS: Cytogenetic/OGM concordance was noted for (a) copy number gains (16, 1p, 3q, 5q, 7p, 8q, 9q, 11p, 11q, 15q, 20q), (b) copy number losses (Y, 3p, 4p, 6p, 7p, 9p, 11q), and (c) structural changes, including multibreak rearrangements. Discordance was noted for two structural findings, both of which had breakpoints localized to repetitive sequences. The OGM studies identified new findings and confirmed/further characterized 8q24 structural abnormalities. It also detected genes gained/disrupted in the 8q24 region (e.g., MYC, DEPTOR, and EXT1); but recognizing a jumping translocation required cytogenetic analyses. CONCLUSION: These results support using OGM as a tool to analyze solid tumors in clinical/research settings. Moreover, this OGM analysis expanded the characterization of cytogenetic changes present in the M2205 subline, including alterations associated with tumors from Black males diagnosed with prostate cancer.

Mechanism of Antitumor Effects of Saffron in Human Prostate Cancer Cells.

Prostate cancer is the most common cancer and the second leading cause of cancer deaths among men in the USA. Several studies have demonstrated the antitumor properties of saffron in different types of cancers, including prostate cancer. The oral administration of saffron extract has been reported to have antitumor effects on aggressive prostate-cancer-cell-line-derived xenografts in nude male mice. The objective of this study was to carry out in vitro studies of saffron-treated prostate cancer cells to ascertain the effects of saffron on key intermediates in prostate carcinogenesis. Our studies demonstrated the significant inhibition of cell proliferation for androgen-sensitive prostate cancer cell lines via apoptotic pathways. We also demonstrate the statistically significant down-regulation of DNA methyltransferases (COMT, MGMT, EHMT2, and SIRT1 deacetylase) in saffron-treated prostate cancer cells. In addition, saffron-treated prostate cancer cells displayed a statistically significant dysregulation of DNA repair intermediates (WRN, p53, RECQ5, MST1R, and WDR70) in a time-dependent manner. Furthermore, Western blot analysis demonstrated that saffron treatment induced changes in the expression of other key genes (DNMT1, DNMT3b, MBD2, CD44, HDAC3, c-Myc, NF-kB, TNFα, AR, N-RAS, and PTEN) in prostate cancer cells. Collectively, our findings demonstrate the important mechanisms by which saffron mediates anti-tumor properties in prostate cancer. These findings suggest that the use of saffron supplements alongside standard treatment protocols may yield beneficial effects for individuals with prostate cancer.

The Leaf Essential Oil of Myrtus communis subsp. tarentina (L.) Nyman: From Phytochemical Characterization to Cytotoxic and Antimigratory Activity in Human Prostate Cancer Cells.

The aim of this study was to investigate the chemical profile and the cytotoxic activity in two castration-resistant prostate cancer (CRPC) cell lines of the leaf essential oil in Myrtus communis subsp. tarentina (L.) Nyman (EO MT), which was cultivated at the Ghirardi Botanical Garden (Toscolano Maderno, Brescia, Italy). The leaves were air-dried and extracted by hydrodistillation with a Clevenger-type apparatus, and the EO profile was characterized by GC/MS. For the cytotoxic activity investigation, we analyzed the cell viability by MTT assay, and the apoptosis induction by Annexin V/propidium iodide assay/Western blot analysis of cleaved caspase 3 and cleaved PARP proteins. Moreover, the cellular migration was analyzed by Boyden's chamber assay and the distribution of actin cytoskeleton filaments by immunofluorescence. We identified 29 total compounds; the main compound classes were oxygenated monoterpenes, monoterpene hydrocarbons, and sesquiterpenes. The main constituents were α-pinene, α-humulene, α-terpineol, durohydroquinon, linalool, geranyl acetate, and ß-caryophyllene. We found that EO MT was able to reduce cellular viability, activating an apoptotic process, and to decrease the migratory capacity of CRPC cells. These results suggest that it might be interesting to further investigate the effects of single compounds present in EO MT for their possible use in prostate cancer treatment.

Could Cisplatin Loading on Biosynthesized Silver Nanoparticles Improve Its Therapeutic Efficacy on Human Prostate Cancer Cell Line and Reduce Its In Vivo Nephrotoxic Effects?

Nanotechnology is a possible solution to the drawbacks of cancer therapy because it decreases the clinical side effects of chemotherapeutic drugs and increases their clinical activity. Thus, this work compared the in vitro cytotoxic activity and in vivo side effects of cisplatin (CP) with those of CP-loaded green silver nanoparticles (CP-AgNPs). The cytotoxic activity of CP, green AgNPs, and CP-AgNPs against PC-3, a human prostate cancer cell line, was assessed using MTT assay. CP-AgNPs had a superior cytotoxic effect on PC-3 cells with a 50% inhibition of viability (IC50) of 27.05 µg/mL, followed by CP with an IC50 of 57.64 µg/mL and AgNPs with an IC50 125.4 µg/mL. To evaluate in vivo side effects, 40 male adult Wistar rats were assigned into four groups and intraperitoneally injected with normal saline (control), CP (2.5 mg/kg body weight), green AgNPs (0.1 mL/kg body weight), and CP-AgNPs (2.5 mg/kg body weight). Intraperitoneal CP injection caused a substantial reduction in erythrocyte and leukocyte counts and hemoglobin concentration and a marked increase in urea and creatinine levels and disturbed the renal oxidant/antioxidant status. Furthermore, it caused noticeable structural alterations and significant upregulation of renal Bax and caspase-3 mRNA along with a significant downregulation of B-cell lymphoma 2 mRNA expressions. The loading of CP on green AgNPs significantly relieved the CP-induced pathological alterations and considerably enhanced its therapeutic effectiveness on PC-3 cells. These outcomes reflect the possible use of CP-AgNPs as a more efficient and safer anticancer agent than free CP.

New derivatives of 11-keto-ß-boswellic acid (KBA) induce apoptosis in breast and prostate cancers cells.

A series of new 11-keto-ß-boswellic acid were partially-synthesized by modifying the hydroxyl and carboxylic acid functional groups of ring A. The structures of the new analogs were confirmed by detailed spectral data analysis. Compounds 4, 5 and 9 exhibited potent anti-cancer results against two human tumor cancer cell lines having IC50 value of MCF-7 (breast) and LNCaP (prostate): 123.6, 9.6 and 88.94 µM and 9.6, 44.12 and 12.03 µM, respectively. Additionally, a maximum nuclear fragmentation was observed for 4 (78.44%) in AKBA treated cells after 24 hr followed by 5 and 9 with (74.25 and 66.9% respectively). This study suggests that the presence of hydrazone functionality (4 and 9) has effectively improved the potency of AKBA. Interestingly, compound 5 with a lost carboxylic acid group of ring A showed comparable potent activity. Highly selective AKBA requires further modification to improve its bioavailability and solubility inside the cancer cells.

Pheophorbide a-mediated sonodynamic, photodynamic and sonophotodynamic therapies against prostate cancer.

Anticancer efficiencies and mechanisms of Pheophorbide-a-mediated photodynamic, sonodynamic and sonophotodynamic therapies were investigated in vitro using androgen-sensitive (LNCaP) and androgen insensitive (PC3) prostate cancer cell lines. The cells were incubated in RPMI-1640 media at various concentrations of Pheophorbide-a. The media was treated with 0.5 W/cm2 ultrasound and/or 0.5 mJ/cm2 light irradiation. Cell proliferation in both cell lines was inhibited most effectively by sonophotodynamic therapy in comparison to that of both monotherapies. LNCaP cells were more sensitive to the applied treatments and the cell survival in LNCaP cell line was observed to be less than that of PC3 cell line. The results of histochemical analysis showed that there were more apoptotic cells in the treatment groups in comparison to control group. Additionally, the treatments induced apoptosis deduced by the overexpressed levels of caspase-3, caspase-8, PARP, and Bax proteins, while the expression levels of caspase-9 and Bcl-2 proteins were observed to be lower than those of control group. Treatments led to an increase in the oxidative stress markers, ROS and MDA, but a decrease in the activities of antioxidant enzymes, SOD, CAT and GSH. The results of this study revealed that Pheophorbide a-mediated sonophotodynamic therapy more efficiently activates the apoptotic mechanisms in prostate cancer cells and thus may provide a promising approach for treatment.

Investigation of the synergistic effects of paclitaxel and herbal substances and endemic plant extracts on cell cycle and apoptosis signal pathways in prostate cancer cell lines.

Paclitaxel, which isolated from Taxus brevifolia, is recently started to be used against prostate cancer treatment and it is a very effective compound against cancer. In this study, we aimed to test the synergistic effect of two plant active compounds (sulphoraphane (SFN) and silymarin (SILY)) and several endemic plant species from Turkey (such as Phlomis leucophracta, Rubia davisiana, Alkanna tinctoria), which are known to have anticarcinogenic effect on androgen-independent PC3 and DU145, and androgen-dependent VCaP prostate cancer cell lines, with paclitaxel on the expression of cell cycle signaling and apoptosis regulator genes. Herbal substances and endemic herbal extracts were combined with Paclitaxel drug. IC50 doses were identified as real-time online. The most effective synergistic doses were determined according to isobologram analysis. The apoptotic effects of effective combined doses were evaluated by TUNEL, Annexin V, and JC-1 methods. Apoptotic and/or cell cycle arrest effects of confirmed combined doses on the expression of genes in these pathways were assessed by real-time online. Endemic plant extracts (Alkanna tinctoria, Phlomis leucophracta and Rubia davisiana, IC50 < 220 µg/ml) and herbal substances (SILY, and SFN IC50 < 130 µM) indicated antiproliferative and apoptotic effects in prostate cancer cell lines. They testified to the synergistic effect of paclitaxel with endemic plant extracts (Combination Index CI, ED50 < 0.41). The combinations, which indicate the synergistic effect was increased to the Bax/Bcl­2 ratio by suppressing Bcl­2 gene expression into the prostate cancer cell lines. Besides, they increased the expression of TNFRSF10A, TNFRSF1A, CHEK1, CDKN1A, CDKN2B, CDK8, CDKN3 and CASP14 and decreased BAD, CDK5RAP1, CDC20, cyclin H, CDK5RAP1, CDC20. The effective doses of paclitaxel were reduced and G2/M arrest was induced by the endemic plant extracts and herbal substances that indicate a synergistic effect with paclitaxel. By using different combination of herbal extracts or active substances with paclitaxel, more economical and efficient treatment strategies can be developed.

Synthesis and Binding of a Novel PSMA-specific Conjugate.

BACKGROUND/AIM: Prostate-specific membrane antigen (PSMA) is emerging as a target for treatment of castration-resistant prostate cancer (CRPC) while its up-regulated in the majority of CRPC tumors. The most common approach is targeted radionuclide therapy. MATERIALS AND METHODS: The PSMA binding pharmacophore Glu-Urea-Lysine (GUL) and lysine were conjugated to oxidized dextran with reductive amination and subsequently labelled with fluorosceinisothiocyanate (FITC). Three prostate cancer cell lines were used for binding studies, 22Rv1 (PSMA positive), DU145 (PSMA negative) and PC3 (PSMA negative). Binding images were obtained by fluorescence microscopy. RESULTS: PDC binding was recorded on the 22Rv1 cell line while the negative cell lines showed no or slight background binding. PDC binding could be inhibited by pre-incubation with a molar excess of unlabelled PDC. CONCLUSION: This is a novel template for PSMA targeted CRPC therapy, either using cytostatics or radionuclides.

High-speed biosensing strategy for non-invasive profiling of multiple cancer fusion genes in urine.

Aberrant chromosal rearrangements, such as the multiple variants of TMPRSS2:ERG fusion gene mutations in prostate cancer (PCa), are promising diagnostic and prognostic biomarkers due to their specific expression in cancerous tissue only. Additionally, TMPRSS2:ERG variants are detectable in urine to provide non-invasive PCa diagnostic sampling as an attractive surrogate for needle biopsies. Therefore, rapid and simplistic assays for identifying multiple urinary TMPRSS2:ERG variants are potentially useful to aid in early cancer detection, immediate patient risk stratification, and prompt personalized treatment. However, current strategies for simultaneous detection of multiple gene fusions are limited by tedious and prolonged experimental protocols, thus limiting their use as rapid clinical screening tools. Herein, we report a simple and rapid gene fusion strategy which expliots the specificity of DNA ligase and the speed of isothermal amplification to simultaneously detect multiple fusion gene RNAs within a short sample-to-answer timeframe of 60min. The method has a low detection limit of 2 amol (1000 copies), and was successfully applied for non-invasive fusion gene profiling in patient urine samples with subsequent validation by a PCR-based gold standard approach.

Contextual effect of repression of bone morphogenetic protein activity in prostate cancer.

Several studies have focused on the effect of bone morphogenetic protein (BMP) on prostate cancer homing and growth at distant metastatic sites, but very little effect at the primary site. Here, we used two cell lines, one (E8) isolated from a primary tumor and the other (cE1) from a recurrent tumor arising at the primary site, both from the conditional Pten deletion mouse model of prostatic adenocarcinoma. Over-expression of the BMP antagonist noggin inhibited proliferation of cE1 cells in vitro while enhancing their ability to migrate. On the other hand, cE1/noggin grafts grown in vivo showed a greater mass and a higher proliferation index than the cE1/control grafts. For suppression of BMP activity in the context of cancer-associated fibroblasts (CAFs), we used noggin-transduced CAFs from the same mouse model to determine their effect on E8- or cE1-induced tumor growth. CAF/noggin led to increased tumor mass and greater de-differentiation of the E8 cell when compared with tumors formed in the presence of CAF/control cells. A trend of increase in the size of the tumor was also noted for cE1 cells when inoculated with CAF/noggin. Together, the results may point to a potential inhibitory role of BMP in the growth or re-growth of prostate tumor at the primary site. Additionally, results for cE1/noggin, and cE1 mixed with CAF/noggin, suggested that suppression of BMP activity in the cancer cells may have a stronger growth-enhancing effect on the tumor than its suppression in the fibroblastic compartment of the tumor microenvironment.

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.

Design and synthesis of novel quinazoline nitrogen mustard derivatives as potential therapeutic agents for cancer.

Thirteen novel quinazoline nitrogen mustard derivatives were designed, synthesized and evaluated for their anticancer activities in vitro and in vivo. Cytotoxicity assays were carried out in five cancer cell lines (HepG2, SH-SY5Y, DU145, MCF-7 and A549) and one normal human cell line (GES-1), in which compound 22b showed very low IC50 to HepG2 (the IC50 value is 3.06 µM), which was lower than Sorafenib. Compound 22b could inhibit cell cycle at S and G2/M phase and induce cell apoptosis. In the HepG2 xenograft model, 22b exhibited significant cancer growth inhibition with low host toxicity in vivo.

Mouse prostate cancer cell lines established from primary and postcastration recurrent tumors.

The clinical course of prostate cancer is grouped into two broad phases. The first phase, which is the growth of the androgen-dependent cancer (AD-Ca) responds well to androgen depletion treatment while the second phase, that could be termed as androgen depletion-independent cancer (ADI-Ca) does not. We used two separate prostate tumors, one AD-Ca and one ADI-Ca from the conditional Pten deletion mouse model to generate from each a pair of cell lines. The AD-Ca cell lines (E2 and E4) and the ADI-Ca cell lines (cE1 and cE2) display bi-allelic deletion at the Pten gene locus, an event which is specific for the prostate epithelium for this mouse model, and a fairly similar level of expression of the androgen receptor (AR). The ADI-Ca cell lines (cE series) grow well in the absence of androgen, display increased AR transcription under androgen-deprived environment, and retain the sensitivity to increased proliferation when androgen is supplemented. The AD-Ca cell lines (E series) grow slowly in the absence of androgen, and, unlike cE cells, do not show increased AR expression when maintained in the absence of androgen. The detection of epithelial cell markers, such as CK8, CK14, CK18 and E-cadherin in the cE series is conforming with the polygonal epithelial morphology of these cells in culture. The E cells also present mostly polygonal-shaped morphology with a small percent of cells with fibroblastoid morphology, and produce little or very low levels of cytokeratins, but increased levels of vimentin, Twist and Slug, the markers known to be associated with epithelial-mesenchymal transition. Each of the cell lines, when inoculated subcutaneously into male or female NOD.SCID mice induced tumors within eight weeks with 100% incidence. Histopathological examinations of the tumor sections, however, led to noticeable biological differences. The cE series engenders adenocarcinomas, particularly in male hosts, and the E series induces sarcomatoid carcinomas (positively stained for CK8 and AR as well as vimentin expression) in either male or female hosts. These new cell lines are promising models for the elucidation of the androgen metabolism and their role in prostate cancer.