Apoptosis In DU145 Cells Research Articles

A network pharmacology-based approach to explore the molecular mechanism of Aidi injection against prostate cancer

ObjectiveTo explore the molecular mechanism of Aidi injection in the treatment of prostate cancer (PCa). Materials and methodsCCK-8 and colony formation assays were used to detect the effects of Aidi on PC3 and DU145 cells; effects on the cell cycle and apoptosis of DU145 cells were detected by flow cytometry; effects on migration and invasion of PC3 and DU145 cells were detected by wound healing and transwell assay, respectively. The main active components of Aidi, their corresponding targets, and PCa associated pathways were predicted and analyzed by network pharmacology. Then predicted key targets and related signaling pathways were further verified by western blotting. The potential active components of Aidi were predicted by molecular docking technology. ResultsAidi significantly inhibited the proliferation, colony formation, migration, and invasion of PC3 and DU145 cells; Aidi induced apoptosis and cell cycle G2/M phase arrest of DU145 cells. Network pharmacology analysis yielded 36 potential core targets of Aidi against PCa, and the top 10 signaling pathways including MAPK, PI3K-Akt, and HIF-1α and so on were enriched. Western blotting confirmed that Aidi upregulated the expression levels of p-JNK, p-p38, p-ERK, and ERK in DU145 cells. Molecular docking study showed that kaempferol, (Z)-1-(2,4-dihydroxyphenyl)-3-(4-hydroxyphenyl)prop-2-en-1-one, 7-O-methylisomucronulatol, calycosin, and N-salicylidene-salicylamine can be well binding with JNK and p38. ConclusionAidi could inhibit PCa cell proliferation and metastasis through induction of apoptosis and cell cycle arrest, which may be related to activating JNK and p38 signaling pathway.

Design, Synthesis and Biological Evaluation of Glycosylated Derivatives of Silibinin as Potential Anti-Tumor Agents.

Silibinin, a natural product extracted from the seeds of the Silybum marianum, is versatile with variouspharmacologicaleffects. However, its clinical application was strongly hampered by its low bioavailability and poor water solubility. Herein, a series of glycosylated silibinin derivatives were identified as novel anti-tumor agents. The cell viability was evaluated by CCK8 assay. Furthermore, cell apoptosis and cell cycle progression were tested by flow cytometry. In addition, the pharmacokinetic assessment of compound 15 and silibinin through intravenous administration (i.v., 2 mg/kg) to ICR mice were performed. The synthesized compounds showed better water solubilities than silibinin. Among them, compound 15 exhibited inhibitory activity against DU145 cells with IC50 value of 1.37 ± 0.140 μM. Moreover, it arrested cell cycle at G2/M phase and induced apoptosis in DU145 cells. Additionally, compound 15 also displayed longer half-life (T1/2 = 128.3 min) in liver microsomes than that of silibinin (T1/2 = 82.5 min) and appropriate pharmacokinetic parameters in mice. Overall, glycosylation of silibinin would be a valid strategy for the development of silibinin derivatives as anti-tumor agents.

Anticancer Activity of Methyl Protodioscin against Prostate Cancer by Modulation of Cholesterol-Associated MAPK Signaling Pathway via FOXO1 Induction.

Methyl protodioscin (MPD), a furostanol saponin found in the rhizomes of Dioscoreaceae, has lipid-lowering and broad anticancer properties. However, the efficacy of MPD in treating prostate cancer remains unexplored. Therefore, the present study aimed to evaluate the anticancer activity and action mechanism of MPD in prostate cancer. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), wound healing, transwell, and flow cytometer assays revealed that MPD suppressed proliferation, migration, cell cycle, and invasion and induced apoptosis of DU145 cells. Mechanistically, MPD decreased cholesterol concentration in the cholesterol oxidase, peroxidase and 4-aminoantipyrine phenol (COD-PAP) assay, disrupting the lipid rafts as detected using immunofluorescence and immunoblot analyses after sucrose density gradient centrifugation. Further, it reduced the associated mitogen-activated protein kinase (MAPK) signaling pathway protein P-extracellular regulated protein kinase (ERK), detected using immunoblot analysis. Forkhead box O (FOXO)1, a tumor suppressor and critical factor controlling cholesterol metabolism, was predicted to be a direct target of MPD and induced by MPD. Notably, in vivo studies demonstrated that MPD significantly reduced tumor size, suppressed cholesterol concentration and the MAPK signaling pathway, and induced FOXO1 expression and apoptosis in tumor tissue in a subcutaneous mouse model. These results suggest that MPD displays anti-prostate cancer activity by inducing FOXO1 protein, reducing cholesterol concentration, and disrupting lipid rafts. Consequently, the reduced MAPK signaling pathway suppresses proliferation, migration, invasion, and cell cycle and induces apoptosis of prostate cancer cells.

Marsdenia tenacissima injection induces the apoptosis of prostate cancer by regulating the AKT/GSK3β/STAT3 signaling axis.

Marsdenia tenacissima injection, a standard Marsdenia tenacissima extract (MTE), has been approved as an adjuvant therapeutic agent for various cancers. Our previous study showed that MTE inhibited the proliferation and metastasis of prostate cancer (PCa) cells. However, the underlying mechanisms and active ingredients of MTE against PCa were not completely understood. This study revealed that MTE induced significant decreases in cell viability and clonal growth in PCa cells. In addition, MTE induced the apoptosis of DU145 cells by reducing the mitochondrial membrane potential and increasing the expression of Cleaved Caspase 3/7, Cyt c, and Bax. In vivo, DU145 xenografted NOD-SCID mice treated with MTE showed significantly decreased tumor size. TUNEL staining and Western blot confirmed the pro-apoptotic effects of MTE. Network pharmacology analysis collected 196 ingredients of MTE linked to 655 potential targets, and 709 PCa-associated targets were retrieved, from which 149 overlapped targets were screened out. Pathway enrichment analysis showed that the HIF-1, PI3K-AKT, and ErbB signaling pathways were closely related to tumor apoptosis. Western blot results confirmed that MTE increased the expression of p-AKTSer473 and p-GSK3βSer9, and decreased the expression of p-STAT3Tyr705in vitro and in vivo. A total of 13 compounds in MTE were identified by HPLC-CAD-QTOF-MS/MS and UPLC-QTOF-MS/MS. Molecular docking analysis indicated that six compounds may interact with AKT, GSK3β, and STAT3. In conclusion, MTE induces the endogenous mitochondrial apoptosis of PCa by regulating the AKT/GSK3β/STAT3 signaling axis, resulting in inhibition of PCa growth in vitro and in vivo.

Cirsilineol Inhibits the Proliferation of Human Prostate Cancer Cells by Inducing Reactive Oxygen Species (ROS)-Mediated Apoptosis

Cirsilineol has been reported to exhibit anticancer effects against several human cancer cell lines. The present study was designed to evaluate the anticancer effects of cirsilineol against the human DU-145 prostate cancer cells. The results showed that cirsilineol suppressed the proliferation of DU-145 cancer cells in a dose-dependent manner with minimal cytotoxic effects against the normal cells. The IC50 of cirsilineol was found to be 7 μM and 110 μM against prostate cancer DU-145 and normal HPrEC prostate cells, respectively. Acridine orange and ethidium bromide (AO/EB) staining showed that cirsilineol induced apoptosis in DU-145 prostate cancer cells. The Annexin V/PI staining further confirmed the induction of apoptosis in DU-145 cells. The western blot analysis showed that cirsilineol suppressed the expression of Bax and upregulated the expression of Bcl-2 in prostate cancer DU-145 cells. Moreover, cirsilineol caused a dose-dependent increase in reactive oxygen species (ROS) levels in prostate cancer. Wound healing and Transwell assays showed that cirsilineol inhibits migration and invasion of DU-145 prostate cancer cells. Summing up, the results suggest that cirsilineol suppresses the proliferation of prostate cancer cells and may prove to be a beneficial lead molecule for the development of chemotherapy for prostate cancer.

One-step synthesis of a radioiodinated anti-microRNA-21 oligonucleotide for theranostics in prostate tumor xenografts

Anti-miRNA oligonucleotide (AMO) has been used most widely to inhibit miRNA for loss-of-function studies and function as therapeutic agents. Iodine-131 (131I) radiolabeled AMO may have multiple functions for specific imaging, genetic inhibition, and radiotherapy. This study is to prepare a radioiodinated anti-miRNA-21 AMO by one-step synthesis for preliminary imaging in tumor xenografts and in vitro radiotherapy. A tyrosine was conjugated at the 3’ end of AMO via a C6 linker for labeling with 131I. After the molecular mass of AMO was confirmed by mass spectrometry, AMO was labeled with 131I by the chloramine-T method with high labeling yield (95.5% ± 3.1%). By gel electrophoresis, the radioactive distribution of 131I-AMO was located exactly where was AMO, verifying the successful radiolabeling. 131I-AMO presented high stability during 24 h of incubation in fresh human serum. The cellular uptake of 131I or FAM-labeled AMO in DU145 was significantly higher than that in PC-3 cells. After i.v. administration in mice, single-photon emission tomography (SPECT) imaging showed that increased 131I-AMO was found in DU145 tumor from 4 h to 24 h gradually. H&E staining of major organs validated the biocompatibility of 131I-AMO in vivo. Furthermore, the ability of 131I-AMO to inhibit cell growth is superior to that of 131I, along with stronger apoptosis in DU145 cells than in PC-3 cells. Therefore, AMO can be labeled with 131I via one-step synthesis after tyrosine conjugation in this study. Its high labeling yield, stability, inhibitory effect, and tumor distribution provide the potential value in the targeted theranostic role.

Fraxetin down-regulates polo-like kinase 4 (PLK4) to inhibit proliferation, migration and invasion of prostate cancer cells through the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway

ABSTRACT Fraxetin, a natural product isolated from herb Cortex Fraxini, has been demonstrated to exhibit anti-cancer effects on various cancers. The aim of this work is to investigate the anti-tumor effect of Fraxetin in prostate cancer and the potential mechanisms. In this study, the prostatic epithelial cell RWPE-1 and prostate cancer cell DU145 were exposed to Fraxetin (10, 20, 40, and 80 μM) to detect the changes in cell viability using cell counting kit-8 (CCK-8) assay. Fraxetin (10, 20, and 40 μM) was utilized to treat DU145 cell, then the changes in cell proliferation, apoptosis, migration, and invasion were assessed. Western blot assay was employed to detect the expression of proteins that participate in the above cellular processes as well as Polo-like kinase 4 (PLK4), phosphatidylinositol 3-kinase (PI3K). In addition to 40 μM Fraxetin treatment, DU145 cells were overexpressed with PLK4, and then the above experiments were repeated. Results revealed that Fraxetin markedly decreased DU145 cell viability, but didn’t affect the cell viability of RWPE-1. Fraxetin suppressed cell proliferation, migration, invasion, and induced apoptosis of DU145 cells in a concentration-dependent manner. Furthermore, the expression of PLK4 and phosphorylated PI3K and protein kinase B (Akt) were reduced upon Fraxetin treatment. Finally, PLK4 overexpression significantly reversed all the effects of Fraxetin on DU145 cells. Collectively, Fraxetin acted as a cancer suppressor in prostate cancer through inhibiting PLK4 expression thereby inactivating PI3K/Akt signaling.

Synthesis and antiproliferative activities of novel piscidinol a derivatives as potential anticancer agents

Piscidinol A (1), a major compound isolated from Aphanamixis polystachya, showed modest anticancer activity against cancer cell lines. Subsequently, a series of analogues were synthesised by modification of the key structural functionalities of this high yield natural product and assessed for their anticancer potential against various cancer cell lines. Among the tested derivatives, the compounds 6e and 6i are significantly reduced the cell viability at 5.38 and 5.02 µM against DU145 prostate cancer cells, respectively. Additionally, both the compounds arrested the cell cycle at S phase and induced the late apoptosis in DU145 cells. Together, the results demonstrated that the compounds 6e and 6i could be a promising lead for the development of anticancer agents against DU145 and well worth further investigation aiming to generate potential anticancer agents.

Preparation of Catechin Nanoemulsion from Oolong Tea Leaf Waste and Its Inhibition of Prostate Cancer Cells DU-145 and Tumors in Mice.

Anti-cancer activity of catechin nanoemulsions prepared from Oolong tea leaf waste was studied on prostate cancer cells DU-145 and DU-145-induced tumors in mice. Catechin nanoemulsions composed of lecithin, Tween-80 and water in an appropriate proportion was prepared with high stability, particle size of 11.3 nm, zeta potential of −67.2 mV and encapsulation efficiency of 83.4%. Catechin nanoemulsions were more effective than extracts in inhibiting DU-145 cell growth, with the IC50 being 13.52 and 214.6 μg/mL, respectively, after 48 h incubation. Furthermore, both catechin nanoemulsions and extracts could raise caspase-8, caspase-9 and caspase-3 activities for DU-145 cell apoptosis, arresting the cell cycle at S and G2/M phases. Compared to control, catechin nanoemulsion at 20 μg/mL and paclitaxel at 10 μg/mL were the most effective in reducing tumor volume by 41.3% and 52.5% and tumor weight by 77.5% and 90.6% in mice, respectively, through a decrease in EGF and VEGF levels in serum.

Peperomin E Induces Apoptosis and Cytoprotective Autophagy in Human Prostate Cancer DU145 Cells In Vitro and In Vivo.

Peperomin E was first isolated from Peperomia dindygulensis, an anticarcinogenic herb, and exhibited anticancer activity inmany cancer cell lines. To date, it is unknown whether peperomin E has an effect on human prostate cancer DU145 cells in vitro and in vivo. In this study, we used MTT to assess the proliferation inhibition activity of peperomin E in DU145 cells in vitro and observed the cell morphological changes by a phase contrast microscope. A DU145 cell xenograft tumor mouse model was used to evaluate the efficacy of peperomin E in vivo. Apoptosis rates were measured by flow cytometry, and protein expression levels were analyzed by western blot. The results showed that peperomin E significantly inhibited the proliferation of DU145 cells in vitro and reduced the weight and volume of tumors in vivo. Peperomin E also significantly induced the apoptosis and autophagic response of DU145 cells. The autophagic inhibitors LY294002 and chloroquine enhanced peperomin E-mediated inhibition of DU145 cell proliferation and induction of DU145 cell apoptosis. The results also showed that the Akt/mTOR pathway participated in peperomin E-induced autophagy in DU145 cells. In summary, our finding showed that peperomin E had an effect on DU145 cells in vitro and in a nude mouse DU145 cell xenograft model in vivo, demonstrated that peperomin E could significantly induce apoptosis and the autophagic response in DU145 cells and that autophagy played a cytoprotective role in peperomin E-treated DU145 cells. These results suggest that the combination of peperomin E treatment and autophagic inhibition has potential for the treatment of prostate cancer.

Long Noncoding RNA SNHG12 Promotes Prostate Tumor Occurrence and Progression via AKT Regulation.

The small nucleolar RNA host gene 12 (SNHG12) has been reported to play an important role in the tumorigenesis and progression of PCa, but the functional underlying mechanism has not been studied clearly. We detected the expression level of SNHG12 in PCa tissues and matched adjacent normal tissues that were collected from 85 patients. Then, colony formation assays, MTT experiments, and flow cytometry were used to examine the effect of SNHG12 on proliferation, cell cycle distribution, and apoptosis of DU145 cells. Further, Transwell invasion assay was utilized to assess whether SNHG12 participates in PCa cell invasion and affects the secretion of VEGF secretion in DU145 cells. Finally, we investigated the effect of SNHG12 on tumor growth in vivo. We found that SNHG12 promoted cell proliferation and suppressed apoptosis in PCa cells, which suggests that SNHG12 is probably a novel PCa biomarker and therapy target of PCa.

Abstract 4030: Synthetic cannabinoids AM-251 and AM-1241 induce cell death in prostate cancer cells

Abstract Background: Prostate cancer is a common malignancy and a leading cause of death. Despite advances in prostate cancer treatment, there is a need for novel therapeutic approaches. Cannabinoid compounds have attracted attention as potential anticancer drugs. Preclinical studies showed that cannabinoids have effects on cancer progression, inhibition of proliferation, invasion, chemoresistance, apoptosis, autophagy and the immune system. We investigated synthetic cannabinoids AM-251 and AM-1241 in cannabinoid receptor-expressing DU145 and PC3 prostate cancer cells. AM-251 is an inverse agonist of the CB1 receptor while AM-1241 is a selective agonist for CB2receptor. We examined the pro-apoptotic and anti-proliferative effect of AM-251 and AM-1241 in cancer cells. Materials and methods: MTT proliferation assay was used to assess the cytotoxicity in DU145 and PC3 cells. To assess apoptosis and effects on cell cycle, we applied Annexin V/Propidium iodide staining and FACS analysis. The ability to cause DNA fragmentation was measured with an ELISA assay. Mechanism of action was evaluated with Western Blot. Results: These show that AM-251 and AM-1241 inhibit the proliferation of DU-145 and PC3 prostate cancer cells with AM-251 been more potent than AM-1241 in reducing viable cell number in DU145 and PC3 cells.. Both AM-1241 and ΑΜ-251 increased DNA fragmentation in DU145 cells 18-fold compared to untreated control. In PC3 cells DNA fragmentation was not observed. DU145 treated cells stained positive for Annexin V indicating early apoptosis. A late apoptotic effect was observed at 72 h, staining double positive for AnV/PI following treatment with both agents.In PC3 cells, a late apoptotic effect was observed at 48h, staining double positive for AnV/PI following treatment with both agents. AM-251 induced cleavage of caspase 3, caspase 8 and PARP, supporting the induction of caspase-dependent apoptosis in DU145 cells. In PC3 cells, the levels of LC3B-II were increased suggesting autophagy induced after treatment with both drugs. Autophagy may be induced via the PI3K pathway / p-AKT / mTOR, as suggested by decrease in p-AKT levels in PC3 cells. Apoptosis i was also evident by an increase of the sub-G1 fraction in cells using flow cytometry. The pan-caspase inhibitor z.vad.fmk partially restored the viability of cells treated with ΑΜ251, while the viability was completely restored in cells treated with AM1241. This suggests that the mechanism of action involves the induction of caspase-dependent apoptosis. Consistently, DNA fragmentation was completely abolished in the presence of the pan-caspase inhibitor. The pan-caspase inhibitor z.vad.fmk did not restore the viability in PC3 cells, confirming that the cells are driven to cell death via a caspase-independent mechanism. Conclusions: Synthetic cannabinoids AM-251 and AM-1241 induce caspase-dependent apoptosis in DU145 cells while autophagy is likely involved in the mode of action of PC3 cells. Further studies will focus on further elucidating the effects and mechanism of action of these compounds in prostate cancer and normal cells. Citation Format: Sotiroula Louka, Christiana Neophytou, Andreas Constantinou. Synthetic cannabinoids AM-251 and AM-1241 induce cell death in prostate cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4030.

Silver Nanoparticles Synthesized Using Carica papaya Leaf Extract (AgNPs-PLE) Causes Cell Cycle Arrest and Apoptosis in Human Prostate (DU145) Cancer Cells.

Treatment of cancer has been limited by the poor efficacy and toxicity profiles of available drugs. There is a growing demand to develop alternative approaches to combat cancer such as use of nano-formulation-based drugs. Here, we report biosynthesis and characterization of silver nanoparticles (AgNPs) with papaya leaf extract (PLE) and its anti-cancer properties against different human cancer cells. Purified nanoparticles were characterized by standard techniques, such as TEM, STM, SEM, EDS, XRD, and FTIR. Furthermore, cytotoxic activity of AgNPs-PLE was carried out against different human cancer cells and non-tumorigenic human keratinocytes cells. AgNPs-PLE when compared with AgNPs-citric acid or PLE showed better efficacy against cancer cells and was also relatively less toxic to normal cells. Treatment of DU145 cells with AgNPs-PLE (0.5-5.0μg/ml) for 24-48h lowered total cell number by 24-36% (P < 0.05). Inhibition of cell growth was linked with arrest of cell cycle at G2/M phase at 24h, while G1 and G2/M phase arrests at 48h. ROS production was observed at earlier time points in presence of AgNPs-PLE, suggesting its role behind apoptosis in DU145 cells. Induction of apoptosis (57%) was revealed by AO/EB staining in DU145 cells along with induction of Bax, cleaved caspase-3, and cleaved PARP proteins. G1-S phase cell cycle check point marker, cyclin D1 was down-regulated along with an increase in cip1/p21 and kip1/p27 tumor suppressor proteins by AgNPs-PLE. These findings suggest the anti-cancer properties of AgNPs-PLE.

Long noncoding RNA SNHG14 promotes malignancy of prostate cancer by regulating with miR-5590-3p/YY1 axis.

Studies have demonstrated that long non-coding RNAs (lncRNAs) are important in the development and prognosis of prostate cancer. The aim of this study was to investigate the functions and mechanism of lnc-SNHG14 in prostate cancer. Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) or Western blot (WB) were performed to detect mRNA expressions of SNHG14 and miR-5590-3p, and the protein levels of Yin Yang-1 (YY1) in prostate cancer tissues, adjacent tissues, and cancer cell lines. The correlation analysis was used to analyze the correlations between SNHG14, miR-5590-3p, and YY1. Kaplan-Meier survival analysis was used to analyze the overall survival for prostate cancer patients. Cell Counting Kit-8 (CCK-8) assay was performed to measure cell proliferation ability and flow cytometry assay was used to detect cell apoptotic rate. Besides, transwell assay was used to measure cell invasion ability. In addition, WB was performed to measure protein expressions in prostate cancer cell lines. Finally, Luciferase reporter assay was performed to verify the binding sites between SNHG14 and miR-5590-3p, miR-5590-3p, and YY1. The results showed that SNHG14 was significantly increased in prostate cancer tissues and prostate cancer cell lines, which were related with advanced stage and poor diagnosis for prostate cancer patients. MiR-5590-3p was reduced in prostate cancer tissues and cell lines, which were negatively correlated with SNHG14. YY1 was found to be increased in prostate cancer tissues, which was negatively correlated with miR-5590-3p and positively correlated with SNHG14. Furthermore, SNHG14 knockdown inhibited cell proliferation, invasion, and promoted cell apoptosis in DU145 cells. In addition, protein expressions of Cyclin D1, Bcl-2, and N-cadherin were repressed, and the levels of Bax, Cleaved Caspase-3, and E-cadherin were increased. Besides, miR-5590-3p inhibition promoted cell proliferation and invasion, and inhibited apoptosis in DU145 cells. Importantly, Luciferase reporter assay proved that SNHG14 could directly sponge with miR-5590-3p, which could bind with YY1 and regulate the functions of cancer cell. Finally, we proved that SNHG14 regulated cell proliferation, cell apoptosis, and invasion via miR-5590-3p/ YY1 axis in prostate cancer. Above all, we found that SNHG14 was increased in prostate cancer patients, which was related with future diagnosis for prostate cancer patients. Of note, we discovered that SNHG14 could promote cell proliferation, invasion, and repress cell apoptosis via miR-5590-3p/YY1 axis in prostate cancer, which might provide a new target for treating prostate cancer.

The Antiproliferation Activity of Ganoderma formosanum Extracts on Prostate Cancer Cells

Androgen-independent prostate cancer accounts for mortality in the world. In this study, various extracts of a medical fungus dubbed Ganoderma formosanum were screened for inhibition of DU145 cells, an androgen-independent prostate cancer cell line. Results demonstrated that both hexane (GF-EH) and butanol (GF-EB) fraction of G. formosanum ethanol extract inhibited DU145 cell viability in a dose-dependent manner. GF-EH induced cell-cycle arrest in G1 phase of DU145 cells via downregulation of cyclin E2 protein expression. In addition, GF-EB triggered extrinsic apoptosis of DU145 cells by activating caspase 3 gene expression resulting in programed cell death. Above all, both GF-EH and GF-EB show lower toxicity to normal human fibroblast cell line compared to DU145 cell, implying that they possess specific drug action on cancer cells. This study provides a molecular basis of G. formosanum extract as a potential ingredient for treatment of androgen-independent prostate cancer.

Serum deprivation primes cancer cells to adapt and survive oxidative stress

Inadequate nutrient intake, a survival benchmark in cancer cells, leads to oxidative stress (OS) disrupting homeostasis, activating signaling, and altering metabolism. As reactive oxygen species (ROS) increase, oxidative stressors activate mechanisms allowing cancer cells to adapt and survive. Our data suggests that nutrient‐deprived cancer cells tolerate OS. Moreover, a quiescent phenotype along with nuclear factor‐kappaB (NF‐κB) signaling may synergistically protect tumor cells from OS induced by nutrient deprivation. In DU145 prostate cancer cell line, we observed that serum‐deprived cells maintained viability after exposure to H2O2 and transitioned to a quiescent phenotype via up‐regulated quiescent markers. Additionally, we transiently silenced NF‐κB (RelA/p65) via siRNA, and demonstrated the percentage of total apoptosis in DU145 cells significantly increased in serum‐deprived cells exposed to H2O2. Furthermore, we observed that inhibition of quiescence significantly reduced NF‐κB‐mediated cell survival in response to OS using two quiescence inhibitors targeting Mirk/Dyrk1b kinase (quiescence inducer), AZ191 and NCGC00185981‐05/ML195; concomitantly, a distinct NF‐κB nuclear localization was not observed. It is unclear how prostate cancer cells adapt and survive oxidative stress; however, we hypothesize nutrient deprivation primes cancer cells for OS cell survival, concurrent with a transition to a quiescent phenotype and NF‐κB signaling.Support or Funding InformationThese studies were supported by the NIH/NIGMS/RISE #5R25GM060414‐15 and NIH/NIHMD/RCMI #5G12MD007590.

Mechanistic investigations on substituted benzene sulphonamides as apoptosis inducing anticancer agents

In an approach to develop potent cytotoxic compounds with targeted action, a systematic methodology was employed to design and initially synthesize parent compounds A1, A8, A13 and A14 followed by synthesis of further analogs of A1 (A2-A7) and A8 (A9-A12) with characterization by IR, NMR, mass and elemental techniques. These compounds were evaluated for their in vitro anti-proliferative activities against DU-145, MCF-7, HCT-15, HT-29 cell lines and apoptosis inducing potential via various mechanistic studies. Compounds A2, A9, A10 exhibited significant cytotoxic activities compared to their parent compounds and standard drug 5-fluorouracil. Compound A2 displayed superior cytotoxicity with IC50 values less than 1 µM in most of the tested cell lines. Further, compound A2 also induced apoptosis in DU-145 cells as exemplified from DAPI staining, Annexin V-FITC assay, ROS generation and mitochondrial membrane alteration studies. The above studies depict the synthesized compound A2 as potent anticancer agent with the ability to induce apoptosis in prostate cancerous cells.

Antioxidation and Antiapoptosis Characteristics of Heme Oxygenase-1 Enhance Tumorigenesis of Human Prostate Carcinoma Cells

Heme oxygenase-1 (HO-1) has antiinflammatory and antioxidant properties and is deemed as a tissue protector. However, effects of HO-1 in prostate cancer remain in controversy. We evaluated the role of HO-1 in prostate carcinoma in vitro and in vivo.Overexpression of HO-1 did not affect prostate cell proliferation in the normal condition but enhanced cell proliferation under serum starvation. HO-1 overexpression enhanced cell invasion of PC-3 cells through epithelial–mesenchymal transition (EMT) induction, which was supported by increased Slug, N-cadherin, and vimentin expressions. In the xenograft animal study, HO-1 overexpression enhanced PC-3 cell tumor growth in vivo. HO-1 attenuated reactive oxygen species induced by H2O2 or pyocyanin treatment in PC-3 and DU145 cells. HO-1 further reduced PC-3 and DU145 cell apoptosis induced by H2O2 or serum starvation. Our results suggested that HO-1 was able to increase prostate carcinoma cell invasion in vitro and tumor growth in vivo. The EMT induction and antioxidant and antiapoptotic effects of HO-1 in the prostate carcinoma cells may be responsible for these findings.

P53 mutant-type in human prostate cancer cells determines the sensitivity to phenethyl isothiocyanate induced growth inhibition

BackgroundWe reported previously that phenethyl isothiocyanate (PEITC), a dietary compound, can reactivate p53R175H mutant in vitro and in SK-BR-3 (p53R175H) breast xenograft model resulting in tumor inhibition. Because of the diversity of human cancers with p53 mutations, these findings raise important questions whether this mechanism operates in different cancer types with same or different p53 mutations. In this study, we investigated whether PEITC recuses mutant p53 in prostate cancer cells harboring different types of p53 mutants, structural and contact, in vitro and in vivo.MethodsCell proliferation, cell apoptosis and cell cycle arrest assays were performed to examine the effects of PEITC on prostate cancer cell lines with p53 mutation(s), wild-type p53, p53 null or normal prostate cells in vitro. Western blot analysis was used to monitor the expression levels of p53 protein, activation of ATM and upregulation of canonical p53 targets. Immunoprecipitation, subcellular protein fraction and qRT-PCR was performed to determine change in conformation and restoration of transactivation functions/ inhibition of gain-of-function (GOF) activities to p53 mutant(s). Mice xenograft models were established to evaluate the antitumor efficacy of PEITC and PEITC-induced reactivation of p53 mutant(s) in vivo. Immunohistochemistry of xenograft tumor tissues was performed to determine effects of PEITC on expression of Ki67 and mutant p53 in vivo.ResultsWe demonstrated that PEITC inhibits the growth of prostate cancer cells with different “hotspot” p53 mutations (structural and contact), however, preferentially towards structural mutants. PEITC inhibits proliferation and induces apoptosis by rescuing mutant p53 in p53R248W contact (VCaP) and p53R175H structural (LAPC-4) mutant cells with differential potency. We further showed that PEITC inhibits the growth of DU145 cells that co-express p53P223L (structural) and p53V274F (contact) mutants by targeting p53P223L mutant selectively, but not p53V274F. The mutant p53 restored by PEITC induces apoptosis in DU145 cells by activating canonical p53 targets, delaying cells in G1 phase and phosphorylating ATM. Importantly, PEITC reactivated p53R175H and p53P223L/V274F mutants in LAPC-4 and DU145 prostate xenograft models, respectively, resulting in significant tumor inhibition.ConclusionOur studies provide the first evidence that PEITC’s anti-cancer activity is cancer cell type-independent, but p53 mutant-type dependent.

Buforin IIb induces androgen-independent prostate cancer cells apoptosis though p53 pathway in vitro

Prostate cancer (PCa) is one of the most common male cancer types, androgen-independent prostate cancer possesses poor prognosis. Buforin IIb, an attractive antibacterial peptide derived from histone H2A, showed selective cytotoxicity against most cancer cell lines. However, the molecular mechanism of buforin IIb on prostate cancer cell has still not been determined. In this study, we found buforin IIb significantly inhibited the prostate cancer cells proliferation, Furthermore, buforin IIb–induced cell apoptosis through downregulation of pro-caspase 3/8/9, poly (ADP-ribose) polymerase PARP and anti-apoptotic Bcl-2 and upregulation of pro-apoptotic Bax. In addition, buforin IIb increased the expression of tumor suppressor p53 and its target genes - p21, fas, noxa and puma. The cytotoxicity of buforin IIb on PC-3 and Du-145 cells is decreased by p53 knockdown. In conclusion, our results indicated that buforin IIb induced PC-3 and Du-145 cell apoptosis and could be considered as a potential drug for prostate cancer.