Human PC-3 Cells Research Articles

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

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

Meeting organometallic chemistry with drug discovery: C[sbnd]H activation enabled discovery of a new ring system of 12H-Indazolo[2,1-a]cinnolin-12-ones with anti-proliferation activity

A diverse library of new ring system 12H-indazolo[2,1-a]cinnolin-12-ones have been synthesized efficiently via Ru (II) and Rh (III) catalyzed tandem CH alkylation/[4 + 2] annulation with diazo compounds in high to excellent yields. For the first time, we evaluated the biological activity of these compounds with this new skeleton and found some compounds exhibited high cytotoxic activity against human PC-3 and PANC-1 tumor cell lines with nanomolar IC50. Among them, the most potent compound 36 showed broad-spectrum cytotoxic activities against a series of human tumor cell lines derived from different organs (IC50 ~ 41 to 197 nM). Moreover, preliminary mechanistic studies indicated that 36 could inhibit the colony formation, cause cell cycle arrest and induce apoptosis of PC-3 cancer cells in a dose-dependent manner. Further intracellular mechanisms investigation found that 36 treatments could dose-dependently decrease the levels of caspase-3 and PARP and up-regulate the level of cleaved PARP. These results suggested that 36 is a novel compound with good potential in the treatment of human cancers and worthy of further investigation.

Synthesis, characterization and biological evaluation of some novel sulfonylthiosemicarbazides

A series of thiosemicarbazides were synthesized and structurally characterized by spectroscopic techniques (NMR, FT-IR) besides elemental analysis. These compounds were evaluated for their cytotoxicity against human breast cancer cell line MCF7 and prostate cancer cell line PC3 and nonmalignant fibroblast L929 cell line by MTT assay. Among the compounds, N-[2-(4-chlorophenyl)ethyl]-2-[(4-methylphenyl)sulfonyl]hydrazinecarbothioamide (3d) and 2-[(4-methylphenyl)sulfonyl]-N-[4-(trifluoromethoxy)phenyl]hydrazinecarbothioamide (3f) were found to display significant cytotoxicity with IC50 of 13.87 μM (against PC3 cell line) and 1.47 μM (against MCF7 cell line), respectively. These compounds were non-cytotoxic to normal cell line with IC50>100 μM. Western blotting studies demonstrated that compound 3f induced apoptosis and caused cell death in the MCF7 and PC3 cell lines via an increase in Bax protein expression and a slight decrease in Bcl-2 protein expression. The gene expression ratio Bax/Bcl-2 showed the induction of mitochondrial apoptosis in cancer cell lines. All of synthesized compounds have also been tested for antioxidant activity and all compounds achieved strong inhibition of the DPPH radical. These findings showed that compound 3f, displays potential to be further explored in the development of new anticancer agents.

Synthesis and Evaluation of Novel Pyrazole Ethandiamide Compounds as Inhibitors of Human THP-1 Monocytic Cell Neurotoxicity.

Neuroinflammation and microglia-mediated neurotoxicity contribute to the pathogenesis of a broad range of neurodegenerative diseases; therefore, identifying novel compounds that can suppress adverse activation of glia is an important goal. We have previously identified a class of trisubstituted pyrazoles that possess neuroprotective and anti-inflammatory properties. Here, we describe a second generation of pyrazole analogs that were designed to improve their neuroprotective activity toward neurons under inflammatory conditions. Pyrazolyl oxalamide derivatives were designed to explore the effects of steric and electronic factors. Three in vitro assays were performed to evaluate the compounds’ anti-neurotoxic, neuroprotective, and cytotoxic activity using human THP-1, PC-3, and SH-SY5Y cells. Five compounds significantly reduced the neurotoxic secretions from immune-stimulated microglia-like human THP-1 monocytic cells. One of these compounds was also found to protect SH-SY5Y neuronal cells when they were exposed to cytotoxic THP-1 cell supernatants. While one of the analogs was discarded due to its interference with the cell viability assay, most compounds were innocuous to the cultured cells at the concentrations used (1–100 μM). The new compounds reported herein provide a design template for the future development of lead candidates as novel inhibitors of neuroinflammation and neuroprotective drugs.

Downregulation of CENPF Remodels Prostate Cancer Cells and Alters Cellular Metabolism.

Metabolic alterations in prostate cancer (PC) are associated with progression and aggressiveness. However, the underlying mechanisms behind PC metabolic functions are unknown. The authors' group recently reported on the important role of centromere protein F (CENPF), a protein associated with the centromere-kinetochore complex and chromosomal segregation during mitosis, in PC MRI visibility. This study focuses on discerning the role of CENPF in metabolic perturbation in human PC3 cells. A series of bioinformatics analyses shows that CENPF is one gene that is strongly associated with aggressive PC and that its expression is positively correlated with metastasis. By identifying and reconstructing the CENPF network, additional associations with lipid regulation are found. Further untargeted metabolomics analysis using gas chromatography-time-of-flight-mass spectrometry reveals that silencing of CENPF alters the global metabolic profiles of PC cells and inhibits cell proliferation, which suggests that CENPF may be a critical regulator of PC metabolism. These findings provide useful scientific insights that can be applied in future studies investigating potential targets for PC treatment.

Stereocontrolled Synthesis of Bispirooxindole-Based Hexahydroxanthones with Five Contiguous Stereocenters.

A bifunctional oxindole-chromone synthon 1 directed tandem reaction is developed, serving as a fruitful strategy for facile access to optically active hexahydroxanthones 3 bearing two spirooxindoles with five contiguous stereocenters. All of the bispirooxindole-based hexahydroxanthones 3 are smoothly obtained with up to 91% yield, >20:1 dr, and >99% ee. Biological evaluation of selected compounds 3 revealed that they exerted good cytotoxic effects on human K562, A549, and PC-3 cells.

The effect of tetrandrine on proliferation and apoptosis of human androgen-refractory prostate cancer PC-3 cell line

Objective To investigate the mechanism of proliferation and apoptosis of human androgen-refractory prostate cancer PC-3 cell line by tetrandrine. Methods The effects of TET(1 μg/mL, 2 μg/ml, 4 μg/mL, 8 μg/mL)on the growth of PC-3 cell line were measured by CCK assay. The apoptosis of cell line induced by TET(1 μg/mL, 2 μg/mL, 4 μg/mL, 8 μg/mL) was evaluated by Annexin-V and PI followed by flow cytometry (FCM). The effects of TET on the expression of IL-8 were measured by RT-PCR. Results TET inhibited the proliferation of PC-3 cell line in a dose dependent manner. After treated with TET(1 μg/mL, 2 μg/mL, 4 μg/mL, 8 μg/mL)for 48 h, the apoptotic rate increased with the increase of drug concentration(P<0.01). Similarly, the expression of IL-8 mRNA decreased gradually with the increase of drug concentration(P<0.01). Conclusions TET can inhibt the proliferation of PC-3 cell line, and induce apoptosis. This may be associated with the decreasing expression of IL-8 mRNA. Key words: Prostatic Neoplasms; TETRANDRINE; Cell Proliferation; Apoptosis

Inhibition of Autophagy Improves the Efficacy of Abiraterone for the Treatment of Prostate Cancer.

Although androgen deprivation therapy remains the standard treatment for the initial therapy of advanced prostate cancer (PC), castration does not eliminate persistent intratumoral androgens within the prostate tumor microenvironment, which is capable of activating androgen receptor. Abiraterone effectively target adrenal and tumor androgen production in castration-resistant PC (CRPC). However, abiraterone-resistant CRPC is now common challenge in clinic via multiple mechanisms. In this study, human CRPC cell line PC3 and androgen-sensitive cells LNCaP were used. The authors investigated the role of autophagy during the therapy of abiraterone in CRPC by analysis of transmission electron microscopy (TEM), Western blot and immunofluorescence assay. Cell cycle and apoptosis using flow cytometry analysis. The analysis of TEM showed more autophagic vesicles (AVs) in PC3 cell line than that in LNCaP cell line and indicated the high basic cellular autophagy in CRPC cell line PC3, which was confirmed by the upregulation of autophagy-related protein LC3, Atg5, and Beclin1. Interestingly, the treatment of abiraterone reduced the level of autophagic vesicles in two cell lines and inhibited the expressions of autophagic markers LC3, Atg5 and Beclin1 in parallel with decreased cell vitality and induced G2/M arrest in PC3 cell line and LNCaP cell line. Moreover, the addition of the autophagy inhibitor 3-methyladenine to the treatment of abiraterone inhibited the formation of AVs with downregulated autophagic markers, and inhibition of autophagy promoted the efficiency of cytotoxicity of abiraterone with further impaired cell vitality and G2/M arrest. These data suggested that inhibition of autophagy by its inhibitor benefits the treatment of abiraterone for CRPC patients.

Bromelain Inhibitory Effect on Colony Formation: An In vitro Study on Human AGS, PC3, and MCF7 Cancer Cells.

Bromelain is dotted with anticancer properties on various cancer cell lines. Anticancer pathways of bromelain, as well related intervening signalization are under investigation. Investigating the inhibitory potential of bromelain on AGS, PC3, and MCF7 cells proliferation and colony formation. The bromelain inhibitory potential on AGS, PC3, and MCF7 cells proliferation at various bromelain concentrations was assessed by MTT; thereby, bromelain potency on colony formation impediment was evaluated using clonogenic assays at determined 50% inhibitory concentrations (IC50) on four different cell densities (10, 50, 100, and 200 cells per well). Bromelain inhibits AGS, PC3, and MCF7 cells proliferation in such a dose-dependent manner. Determined IC50 to AGS, PC3, and MCF7 cells were 65, 60 and 65μg/ml respectively. At IC50, bromelain significantly suppressed the AGS, PC3, and MCF7 cells colony formation at four treated densities (10, 50, 100 and 200 cells per well). Plating efficiency percentage and cell surviving fraction were decreased after bromelain treatment to AGS, PC3, and MCF7 human cancer cells as a function of initial cell density. The 50, 50 or 100, and 10 or 50 cells per well were considered to be optimum number of initial cell density for AGS, PC3, and MCF7 cells. Cell proliferative and colony formation inhibition are two pathways to in vitro bromelain anticancer effects. The current study displayed a dose-dependent inhibitory effect of bromelain, as well impeding colony formation AGS, PC3, and MCF7 human cancer cells.

Centromere protein F (CENPF), a microtubule binding protein, modulates cancer metabolism by regulating pyruvate kinase M2 phosphorylation signaling

ABSTRACT Prostate cancer (PC) is the most commonly diagnosed cancer in men and is the second leading cause of male cancer-related death in North America. Metabolic adaptations in malignant PC cells play a key role in fueling the growth and progression of the disease. Unfortunately, little is known regarding these changes in cellular metabolism. Here, we demonstrate that centromere protein F (CENPF), a protein associated with the centromere-kinetochore complex and chromosomal segregation during mitosis, is mechanically linked to altered metabolism and progression in PC. Using the CRISPR-Cas9 system, we silenced the gene for CENPF in human PC3 cells. These cells were found to have reduced levels of epithelial-mesenchymal transition markers and inhibited cell proliferation, migration, and invasion. Silencing of CENPF also simultaneously improved sensitivity to anoikis-induced apoptosis. Mass spectrometry analysis of tyrosine phosphorylated proteins from CENPF knockout (CENPFKO) and control cells revealed that CENPF silencing increased inactive forms of pyruvate kinase M2, a rate limiting enzyme needed for an irreversible reaction in glycolysis. Furthermore, CENPFKO cells had reduced global bio-energetic capacity, acetyl-CoA production, histone acetylation, and lipid metabolism, suggesting that CENPF is a critical regulator of cancer metabolism, potentially through its effects on mitochondrial functioning. Additional quantitative immunohistochemistry and imaging analyzes on a series of PC tumor microarrays demonstrated that CENPF expression is significantly increased in higher-risk PC patients. Based on these findings, we suggest the CENPF may be an important regulator of PC metabolism through its role in the mitochondria.

Inhibition of miR-423-5p suppressed prostate cancer through targeting GRIM-19

ObjectiveTo determine the effect of miR-423-5p on the progression of prostate cancer (PC). MethodsmiR-423-5p and GRIM-19 expressions were detected by qRT-PCR and western blot. PC cell proliferation was measured by MTT assay. PC cell apoptosis was detected by flow cytometry. Dual luciferase reporter assay was used to confirm the interaction between miR-423-5p and GRIM-19. ResultsCompared with normal prostate tissues and prostate epithelial cell HPrEC, miR-423-5p was up-regulated in human PC tissues and PC3 cells, whereas GRIM-19 expression was decreased. Inhibition of miR-423-5p suppressed PC3 cell proliferation, promoted PC3 cell apoptosis, and decreased anti-apoptosis protein BCL-2 expression. GRIM-19 was a target of miR-423-5p, and GRIM-19 was negatively regulated by miR-423-5p in PC3 cells. In addition, miR-423-5p knockdown inhibited the proliferation and promoted the apoptosis of PC3 cells through GRIM-19. In vivo experiments showed that miR-423-5p inhibitor administration reduced tumor volume, down-regulated miR-423-5p and GRIM-19 expressions in PC tissues of nude mice. ConclusionInhibition of miR-423-5p suppressed PC through targeting GRIM-19.

Bioactive scalemic caged xanthones from the leaves of Garcinia bracteata

Four pairs of previously undescribed caged xanthones (1–4) and twelve known caged xanthones (5–16) were isolated from the leaf extract of Garcinia bracteata. Their structures were unambiguously elucidated on the basis of spectroscopic methods. The planar structure and relative configuration of 1 was confirmed by X-ray crystallographic analysis. The enantiomers of compounds 1, 2, 4 were further resolved by semi-preparative chiral HPLC, and the absolute configurations of enantiomers of compounds 1 and 4 were determined by measurement and calculation of electronic circular dichroism (ECD) spectra and specific rotations. The inhibitory activities of the isolated compounds against human HeLa, A549, PC-3, HT-29, and WPMY-1 cell lines were assayed, and garcibractatin A (4) showed the most potent inhibitory activities in vitro with IC50 values from 1.11 to 2.93 μM. A preliminary structure-activity relationship has been discussed, and some helpful conclusions have been drawn.

Preparation, characterization and in vitro activity of a docetaxel–albumin conjugate

Docetaxel is one of the most effective anticancer drugs. However, the current formulation of docetaxel contains Tween 80 and ethanol as the solvent, which can cause severe side effects. Consequently, the development of new type of formulation of docetaxel with high efficiency and low side effects is a very important issue. In this study, we explored the covalent linking of docetaxel and albumin via one organic linker. 6-Maleimidocaproic acid was applied to link the C2′ hydroxyl group of docetaxel with the cysteine-34 of albumin to obtain 1:1 docetaxel–albumin conjugate. The synthesized conjugate can control the release of docetaxel in the bovine serum. Furthermore, in vitro cell cytotoxicity experiments indicated that the docetaxel–albumin conjugate have high activities for human prostate cancer cell line PC3 and human breast cancer cell line MCF-7. The present study provides a valuable strategy for further development of a new type of docetaxel–albumin prodrug.

Cannabinoid WIN 55,212-2 induces cell cycle arrest and apoptosis, and inhibits proliferation, migration, invasion, and tumor growth in prostate cancer in a cannabinoid-receptor 2 dependent manner.

Cannabinoids have demonstrated anticarcinogenic properties in a variety of malignancies, including in prostate cancer. In the present study, we explored the anti-cancer effects of the synthetic cannabinoid WIN 55,212-2 (WIN) in prostate cancer. Established prostate cancer cells (PC3, DU145, LNCaP) were treated with varying concentrations of WIN. Cell proliferation was determined by the MTS assay. The anti-migration and anti-invasive potential of WIN was examined by the wound healing assay and the matrigel invasion assay. Cell cycle analysis was performed by flow cytometry, and mechanistic studies were performed by Western blot. Athymic mice (n = 10) were inoculated with human PC3 cells. Once tumors reached 100 mm3 , animals were randomized into two groups: saline control and WIN (5 mg/kg), delivered by intraperitoneal injection three times per week for 3 weeks. WIN significantly reduced prostate cancer cell proliferation, migration, invasion, induced apoptosis, and arrested cells in Go/G1 phase in a dose-dependent manner. Mechanistic studies revealed these effects were mediated through a pathway involving cell cycle regulators p27, Cdk4, and pRb. Pre-treatment with a CB2 antagonist, AM630, followed by treatment with WIN resulted in a reversal of the anti-proliferation and cell cycle arrest previously seen with WIN alone. In vivo, administration of WIN resulted in a reduction in the tumor growth rate compared to control (P < 0.05). The following study provides evidence supporting the use of WIN as a novel therapeutic for prostate cancer.

Expression of microRNA-30b-5p in prostate cancer and its effects on proliferation of prostate cancer cells

Objective To explore the expression of microRNA (miRNA, miR)-30b-5p in prostate cancer (PCa) and its impact on prostate cancer cells. Methods The expression of miR-30b-5p in 41 cases of PCa tissues and 41 cases of adjacent non-tumor tissues was detected by real-time quantitative reverse transcriptase-polymerase chain reaction (RT-qPCR). The relationship between the expression of miR-30b-5p and clinicopathological features was analyzed. Human prostate cancer PC-3 cells were divided into three groups: control group, negative control group and over-expression group. The expression of miR-30b-5p in PC-3 cells was detected by RT-qPCR. The cell proliferation was measured by cell counting kit-8 (CCK-8) assay and colony formation and anchorage-independent growth assay. The protein expression of proliferation cell nuclear antigen (Ki-67), β-catenin and Cyclin D1 was detected by Western blotting. Results The expression of miR-30b-5p in prostate cancer tissues (0.469±0.032) was significantly lower than that in adjacent tissues (0.997±0.016) (t=14.499, P=0.000). In addition, the rate of low miR-30b-5p expression in clinical state Ⅲ-Ⅳ [65.2% (15/23) vs. 33.3% (6/18), χ2=4.108, P=0.043], pathological grading G3-G4 [72.7% (16/22) vs. 26.3% (5/19), χ2=6.145, P=0.013] and Gleason scores ≥8 [72.0% (18/25) vs. 18.8% (3/16), χ2=11.072, P=0.001] groups were higher than those in clinical stage Ⅰ-Ⅱ, pathological grading G1-G2 and Gleason scores ≤7 groups. However, there were no difference in the rate of low miR-30b-5p expression in different age groups [54.5% (12/22) vs. 47.4% (9/19), χ2=0.210, P=0.647]. After transfection, the expression of miR-30b-5p in over-expression group (4.088±0.229) was higher than that in negative control group (1.028±0.054) (F=168.200, P=0.000). At 48 h and 72 h, the A450 in over-expression group measured by CCK-8 assay (0.308±0.040, 0.512±0.033) were lower than those in negative control group (0.494±0.035, 0.840±0.087) (F=6.514, P=0.001). The protein expressions of Ki-67, β-catenin and Cyclin D1 in negative control froup were 1.681±0.062, 1.067±0.188, 0.665±0.083. However, the protein expressions of them in over-expression group were remarkably decreased (Ki-67: 0.622±0.095, F=38.490, P=0.000; β-Catenin: 0.437±0.071, F=6.570, P=0.031; Cyclin D1: 0.237±0.049, F=13.510, P=0.006). Conclusion miR-30b-5p is low-expressed in prostate cancer cells, and over-expression of miR-30b-5p could inhibit the proliferation ability of prostate cancer cell, which may be related to the deactivation of Wnt/β-catenin signaling pathway. Key words: Prostate cancer; MicroRNA-30b-5p; Cell proliferation; Wnt/β-catenin signaling pathway

Abstract 53: Axl is sufficient but not necessary for disseminated prostate tumor cell dormancy

Abstract Prostate cancer (PCa) remains the second most common cancer among men in the U.S., and kills nearly 30,000 men each year. While the majority of patients with localized disease are cured by surgery and/or radiation, 10-15% of these patients will develop metastasis most commonly in the bone marrow. The time from primary tumor removal to recurrence can range from years to decades, and constitutes a period of minimal residual disease in which cancer cells remain in the body but are clinically undetectable. These disseminated tumor cells (DTCs) are seeds for lethal bone metastases and are thought to maintain a long-term state of dormancy in the bone marrow. Very little is known about the mechanism(s) by which dormancy is regulated, but further investigation may lead to therapeutic strategies aimed at preventing recurrent metastasis altogether. In this effort, we have previously found the secreted bone marrow factor Gas6 and the expression of its receptor Axl to be associated with dormant bone marrow DTCs in xenograft mouse models. We hypothesize that bone marrow Gas6 signals through Axl to induce dormancy in prostate DTCs, and explored the functional consequences of altering Axl expression in these models. To determine if Axl is sufficient to induce dormancy, we overexpressed it in the Axl-negative human PCa C42B cell line and monitored tumor growth by BLI after intracardiac injection in NSG mice. By the time half of the control overexpression injected mice developed tumors, less than 10% of mice injected with Axl overexpression cells developed tumor signal. This delay in tumorigenesis indicates a prolonged period of dormancy that is mediated by Axl expression. To determine if Axl is necessary for dormancy, we knocked out Axl in the Axl-positive human PCa PC3 cells using CRISPR and monitored growth after intracardiac injection in the same manner as the overexpression cells. Knockout of Axl did not increase the time to tumor signal compared to control cells. Loss of Axl also did not decrease the fraction of EdU negative, non-proliferative cells present in the bone marrow at one week post-injection. These data indicate that Axl is likely not necessary for DTC dormancy. Altogether this study suggests that Axl overexpression is sufficient to induce dormancy, but endogenous Axl is not required for dormancy. This is further supported by negative immunohistochemical staining of Axl on cancer cells within growing primary and metastatic tumors from a PCa tissue microarray. Axl also correlated with decreased incidence of biochemical recurrence (Decipher GRID) and increased overall survival (TCGA). Ongoing work includes assessing the expression of Axl on patient CTCs and DTCs, and correlating it with proliferation status. Citation Format: Haley D. Axelrod, Kenneth C. Valkenburg, Jessica L. Hicks, Angelo M. DeMarzo, Kenneth J. Pienta. Axl is sufficient but not necessary for disseminated prostate tumor cell dormancy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 53.

Abstract 272: Effect of inositol hexaphosphate on cancer stem cell pool of prostate tumors

Abstract Prostate cancer (PCa) is the most frequently diagnosed invasive malignancy and second leading cause of cancer-associated deaths in the males in the United States. Inositol hexaphosphate (IP6) a nutrient constituting 6.4% (w/w) or even higher levels in most cereals, legumes, nuts, oil seeds and soybean has been shown to protect against growth and progression of PCa in pre-clinical animal models. Our completed studies in a spontaneous transgenic mouse model of PCa (TRAMP) have shown that IP6 feeding suppresses growth and progression of PCa via its ability to alter tumor vascularity and the energy generating metabolic events in the tumor cells. We also employed quantitative high-resolution nuclear magnetic resonance spectroscopy (1H-, 13C- and 31P-NMR) to assess the metabolic profile and energy state of the IP6-treated human PCa PC3 cell line which validated these in vivo findings. Next, we assessed stage-specific efficacy of IP6 feeding on PCa initiation and growth, progression and angiogenesis, and elucidated the molecular events involved in IP6 effects during these stages. Different groups of male TRAMP mice starting at 4, 12, 20 and 30 weeks of age were fed with regular drinking water or 2% IP6 in regular drinking water for 8-10 weeks. Study end point assessments showed that IP6 treatment results in arrest of tumor grade at earlier stages and prevents its progression to more advanced forms of the disease. In more recent studies, to determine whether these protective effects are mediated via the effect of IP6 on expansion of cancer stem cells (CSCs) pool; we next assessed whether IP6 had the potential to affect the CSC pool in TRAMP prostate tumors. We observed that the anti-PCa effects of IP6 are associated with its potential to eradicate PCa CSC pool, which is recognized to be involved in the initiation, progression, relapse, and therapy-resistance of PCa. IP6 feeding also showed inhibitory effects on the CSC associated transcription factors and signaling pathways. Next, we performed in vitro sphere cluster assays to determine IP6 effect on the self-renewal capacity of the CSCs of PCa cell lines PC3 and HMVP-2. The % of floating spheroids (prostatospheres) generated in the presence of macrophage U-937 conditioned media (with and without IP6 pre-treatment) after 1-2 weeks were determined. The results indicated an inhibitory effect of IP6 on both number and size (volume) of prostatospheres. Since formation of spheroids under specific in vitro conditions is a measure of stemness, it is evident that IP6 has the potential to target the self-renewal of CSCs in PCa cell lines. Since these mechanistic events eventually result in arrest of tumor grade at neoplastic stages, this protective effect of IP6 against PCa might have clinical implications in controlling the malignancy at an early stage. Together, these findings suggest the practical and translational potential of IP6 treatment in suppressing growth and progression of PCa in humans. Citation Format: Komal Raina, Anil K. Jain, Dileep Kumar, Vijay Mohan, Paul Maroni, Rajesh Agarwal. Effect of inositol hexaphosphate on cancer stem cell pool of prostate tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 272.

Matched-pair, 86Y/90Y-labeled, bivalent RGD/bombesin antagonist, [RGD-Glu-[DO3A]-6-Ahx-RM2], as a potential theranostic agent for prostate cancer

IntroductionIn this study, we describe development of a true matched-pair theranostic agent that is able to target the αVβ3 integrin and the gastrin releasing peptide receptor (GRPR). We herein describe methods to metallate and characterize the new conjugate and to validate its biological efficacy by in vitro and in vivo methods. MethodsWe have previously described the development of [RGD-Glu-6Ahx-RM2] (where RGD: Arg-Gly-Asp; Glu: glutamic acid; 6-Ahx: 6-amino hexanoic acid; RM2: (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2)) that has been conjugated to a DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) bifunctional chelating agent (BFCA) to afford [RGD-Glu-[DO3A]-6-Ahx-RM2] peptide. In this study, we have radiolabeled [RGD-Glu-[DO3A]-6-Ahx-RM2] peptide with 86Y or 90Y. Natural-metallated (natY) conjugates were assessed for binding affinity for the αVβ3 integrin or GRPR in human glioblastoma U87-MG and prostate PC-3 cell lines, respectively. The effective stability of the new tracers was also evaluated prior to in vivo evaluation in normal CF-1 mice and SCID mice bearing xenografted tumors. ResultsCompetitive displacement binding assays in PC-3 cells showed high binding affinity for the GRPR (IC50, 5.65 ± 0.00 nM). On the other hand, competitive displacement binding assays in U87-MG cells revealed only moderate binding to the αVβ3 integrin (IC50, 346 ± 5.30 nM). Biodistribution studies in PC-3 tumor-bearing mice [RGD-Glu-[[90Y]Y-DO3A]-6-Ahx-RM2] showed high tumor uptake (8.70 ± 0.35%ID/g at 1 h post-intravenous injection) and retention of tracer (5.28 ± 0.12%ID/g) at 24 h post-intravenous injection. Micro-positron emission tomography (microPET) in PC-3 tumor-bearing mice using [RGD-Glu-[[86Y]Y-DO3A]-6-Ahx-RM2] correlated well with biodistribution investigations over the various time points that were studied. ConclusionsThe [RGD-Glu-[[86Y]Y-DO3A]-6-Ahx-RM2] and [RGD-Glu-[[90Y]Y-DO3A]-6-Ahx-RM2] matched-pair conjugates described herein exhibit favorable microPET and pharmacokinetic profiles and merit further investigations for molecular imaging and/or therapeutic evaluation in larger animal models and potentially humans. Advances in knowledge and implications for patient careThe theranostic, heterobivalent, agents described herein perform comparably with other mono- and multivalent conjugates we have reported and offer the potential of improved sensitivity for detecting prostate cancer cells that might exhibit differing profiles of receptor expression on tumor cells in human patients.

Effect of Lutein on Proliferation and Apoptosis of Human Prostate Cancer PC3 Cell Line and Related Mechanism

Effect of Lutein on Proliferation and Apoptosis of Human Prostate Cancer PC3 Cell Line and Related Mechanism

Ajmaline, Oxindole, and Cytotoxic Macroline-Akuammiline Bisindole Alkaloids from Alstonia penangiana.

Examination of the EtOH extract of the Malayan Alstonia penangiana resulted in the isolation of 10 new alkaloids, comprising two ajmaline (1, 2), four macroline oxindole (3-6), and four macroline-akuammiline bisindole alkaloids (7-10). The structures of these alkaloids were determined based on analysis of the spectroscopic data and, in the case of the oxindole 6 and the bisindole alkaloid 7, also confirmed by X-ray diffraction analysis. The bisindole alkaloids 7 and 8 showed pronounced in vitro growth inhibitory activity against an array of human cancer cell lines, including KB, vincristine-resistant KB, PC-3, LNCaP, MCF7, MDA-MB-231, HT-29, HCT 116, and A549 cells with IC50 values in the 0.3-8.3 μM range.