Cultured Prostate Cancer Cells Research Articles

Mechanical stress shapes the cancer cell response to neddylation inhibition

BackgroundThe inhibition of neddylation by the preclinical drug MLN4924 represents a new strategy to combat cancer. However, despite being effective against hematologic malignancies, its success in solid tumors, where cell–cell and cell-ECM interactions play essential roles, remains elusive.MethodsHere, we studied the effects of MLN4924 on cell growth, migration and invasion in cultured prostate cancer cells and in disease-relevant prostate tumoroids. Using focused protein profiling, drug and RNAi screening, we analyzed cellular pathways activated by neddylation inhibition.ResultsWe show that mechanical stress induced by MLN4924 in prostate cancer cells significantly affects the therapeutic outcome. The latter depends on the cell type and involves distinct Rho isoforms. In LNCaP and VCaP cells, the stimulation of RhoA and RhoB by MLN4924 markedly upregulates the level of tight junction proteins at cell–cell contacts, which augments the mechanical strain induced by Rho signaling. This “tight junction stress response” (TJSR) causes the collapse of cell monolayers and a characteristic rupture of cancer spheroids. Notably, TJSR is a major cause of drug-induced apoptosis in these cells. On the other hand, in PC3 cells that underwent partial epithelial-to-mesenchymal transition (EMT), the stimulation of RhoC induces an adverse effect by promoting amoeboid cell scattering and invasion. We identified complementary targets and drugs that allow for the induction of TJSR without stimulating RhoC.ConclusionsOur finding that MLN4924 acts as a mechanotherapeutic opens new ways to improve the efficacy of neddylation inhibition as an anticancer approach.Graphical

Application of Surface-Enhanced Raman Spectroscopy to Guide Therapy for Advanced Prostate Cancer Patients

A critical unmet need for advanced prostate cancer (PCa) patients is optimizing systemic treatments to maximize the benefit for individuals. The response of patients with metastatic castration-resistant prostate cancer (mCRPC) to androgen receptor (AR)-directed hormonal treatments (i.e., enzalutamide and abiraterone) is mediated by the expression of a molecular variant of the androgen receptor called androgen receptor variant 7 (AR-V7). Detection and measurement of AR-V7 in mCRPC patients will lead to more informed PCa treatment. Herein, we demonstrate a quantitative nanoparticle-enhanced sandwich antibody assay for the successful ex vivo measurement of AR-V7 protein in serum from mCRPC patients. The nanoparticles are constructed as extrinsic Raman spectroscopy labels (ERLs), and surface-enhanced Raman spectroscopy (SERS) is used for assay readout. Our approach does not require specialized specimen collection materials, circulating tumor cell enrichment, or pretreatment of serum. Calibration of our assay is accomplished by expressing AR-V7 in an appropriate cell line as AR-V7 is not commercially available. We demonstrate a linear calibration curve from cell lysate and correlate lysate protein with mRNA from cultured prostate cancer cells. Finally, we demonstrate a novel pilot-scale application for clinical use by quantitatively measuring AR-V7 in serum of seven advanced PCa patients. Distinct separation of PCa patients by AR-V7 status (positive or negative) was observed. Together, the presence and amount of AR-V7 in serum offer predictive and prognostic value to inform selection between two classes of systemic treatments (i.e., hormones or taxanes). Triaging patients that are AR-V7-positive to other systemic treatments (e.g., taxane-based chemotherapy) can improve progression-free survival and overall survival.

New Insights and Emerging Therapeutic Approaches in Prostate Cancer.

Prostate cancer is the second most frequently diagnosed cancer in men and several therapeutic approaches are currently available for patient’s care. Although the androgen receptor status represents a good predictor of response to androgen deprivation therapy, prostate cancer frequently becomes resistant to this approach and spreads. The molecular mechanisms that contribute to progression and drug-resistance of this cancer remain still debated. However, few therapeutic options are available for patient’s management, at this stage. Recent years have seen a great expansion of the studies concerning the role of stromal-epithelial interactions and tumor microenvironment in prostate cancer progression. The findings so far collected have provided new insights into diagnostic and clinical management of prostate cancer patients. Further, new fascinating aspects concerning the intersection of the androgen receptor with survival factors as well as calcium channels have been reported in cultured prostate cancer cells and mouse models. The results of these researches have opened the way for a better understanding of the basic mechanisms involved in prostate cancer invasion and drug-resistance. They have also significantly expanded the list of new biomarkers and druggable targets in prostate cancer. The primary aim of this manuscript is to provide an update of these issues, together with their translational aspects. Exploiting the power of novel promising therapeutics would increase the success rate in the diagnostic path and clinical management of patients with advanced disease.

A loofah-inspired scaffold with enhanced mimicking mechanics and tumor cells distribution for in vitro tumor cell culture platform

Tumor cells cultured in a physiologically related three-dimensional (3D) matrix can replicate many basic characteristics of tumor tissue. Tumor tissues are harder than normal, so when using hydrogels for 3D tumor cell culture, attempts have been made to prepare hydrogel scaffolds that mimic the hardness of tumor tissues without reducing the porosity. In this study, a new 3D loofah-inspired scaffold was developed for prostate cancer cell culture. Since the loofah sponge structure of the spacer fabric, the composite scaffolds had a compression modulus similar to that of natural prostate tumor tissue at a lower hydrogel concentration (0.25% W/V), and also, endowed the scaffold with high porosity (85 ± 2.52%) for mass transfer. The results of in vitro cell experiments showed that the composite scaffold can support tumor cells to form clusters in a short time (3 days). Preliminary chemosensitivity analysis showed that the drug resistance of the composite scaffold was significantly higher than that of two-dimensional (2D) culture and COL scaffold. Therefore, the 3D tumor cell culture scaffold with bionic structures has the potential to be used as a tumor drug screening model.

New Antagonists of the Membrane Androgen Receptor OXER1 from the ZINC Natural Product Database.

OXER1 (oxoeicosanoid receptor 1) was deorphanized in 1993 and found to be the specific receptor for the arachidonic acid metabolite 5-oxo-ETE. Recently, we have reported that androgen binds to this receptor also, being a membrane androgen receptor, triggering a number of its membrane-mediated actions (cell migration, apoptosis, cell proliferation, Ca2+ movements). In addition, our previous work suggested that a number of natural monomeric and oligomeric polyphenols interact with OXER1, acting similar to testosterone. Here, we interrogated the natural product chemical space and identified nine polyphenolic molecules with interesting in silico pharmacological activities as putative OXER1 antagonists. The molecule with the best pharmacokinetic–pharmacodynamic properties (ZINC15959779) was purchased and tested on OXER1, in prostate cancer cell cultures. It showed that it has actions similar to those of testosterone in inhibiting cAMP, while it had no action in intracellular Ca2+ mobilization or actin cytoskeleton rearrangement/migration. These results are discussed under the prism of structure–activity relationships and in silico models of the OXER1 binding groove. We suggest that these compounds, together with the previously reported (poly)phenolic compounds, can be lead structures for the exploration of the anti-inflammatory and antiproliferative effects of OXER1 antagonists.

Curcumin and Carnosic Acid Cooperate to Inhibit Proliferation and Alter Mitochondrial Function of Metastatic Prostate Cancer Cells.

Anticancer activities of plant polyphenols have been demonstrated in various models of neoplasia. However, evidence obtained in numerous in vitro studies indicates that proliferation arrest and/or killing of cancer cells require quite high micromolar concentrations of polyphenols that are difficult to reach in vivo and can also be (geno)toxic to at least some types of normal cells. The ability of certain polyphenols to synergize with one another at low concentrations can be used as a promising strategy to effectively treat human malignancies. We have recently reported that curcumin and carnosic acid applied at non-cytotoxic concentrations synergistically cooperate to induce massive apoptosis in acute myeloid leukemia cells, but not in normal hematopoietic and non-hematopoietic cells, via sustained cytosolic calcium overload. Here, we show that the two polyphenols can also synergistically suppress the growth of DU145 and PC-3 metastatic prostate cancer cell cultures. However, instead of cell killing, the combined treatment induced a marked inhibition of cell proliferation associated with G0/G1 cell cycle arrest. This was preceded by transient elevation of cytosolic calcium levels and prolonged dissipation of the mitochondrial membrane potential, without generating oxidative stress, and was associated with defective oxidative phosphorylation encompassing mitochondrial dysfunction. The above effects were concomitant with a significant downregulation of mRNA and protein expression of the oncogenic kinase SGK1, the mitochondria-hosted mTOR component. In addition, a moderate decrease in SGK1 phosphorylation at Ser422 was observed in polyphenol-treated cells. The mTOR inhibitor rapamycin produced a similar reduction in SGK1 mRNA and protein levels as well as phosphorylation. Collectively, our findings suggest that the combination of curcumin and carnosic acid at potentially bioavailable concentrations may effectively target different types of cancer cells by distinct modes of action. This and similar combinations merit further exploration as an anticancer modality.

SPOP mutation induces DNA methylation via stabilizing GLP/G9a

Mutations in SPOP E3 ligase gene are reportedly associated with genome-wide DNA hypermethylation in prostate cancer (PCa) although the underlying mechanisms remain elusive. Here, we demonstrate that SPOP binds and promotes polyubiquitination and degradation of histone methyltransferase and DNMT interactor GLP. SPOP mutation induces stabilization of GLP and its partner protein G9a and aberrant upregulation of global DNA hypermethylation in cultured PCa cells and primary PCa specimens. Genome-wide DNA methylome analysis shows that a subset of tumor suppressor genes (TSGs) including FOXO3, GATA5, and NDRG1, are hypermethylated and downregulated in SPOP-mutated PCa cells. DNA methylation inhibitor 5-azacytidine effectively reverses expression of the TSGs examined, inhibits SPOP-mutated PCa cell growth in vitro and in mice, and enhances docetaxel anti-cancer efficacy. Our findings reveal the GLP/G9a-DNMT module as a mediator of DNA hypermethylation in SPOP-mutated PCa. They suggest that SPOP mutation could be a biomarker for effective treatment of PCa with DNA methylation inhibitor alone or in combination with taxane chemotherapeutics.

Investigating the Effect of Yttrium Oxide Nanoparticle in U87MG Glioma and PC3 Prostate Cancer: Molecular Approaches

Yttrium oxide (Y2O3) nanoparticles have very wide application areas such as biological imaging, photodynamic therapy, the material sciences, in the chemical synthesis of inorganic compounds, additives in plastic, paint, steel, optics, and iron. Potential risks to human health and the environment should be evaluated in a multi-dimensional perspective when developing nanoparticles for those applications. Therefore, in this research, we aimed to investigate changes in gene expression profiles (genes involved in different biological pathways) influenced by commonly Yttrium oxide (Y2O3) nanoparticle in human U87MG glioma and PC3 prostate cancer cell lines in vitro. The study was planned to be carried out in two stages. In the first stage, cell viability and cytotoxicity parameters were studied using 3-(4,5-dimethyl-thiazol-2-yl) 2,5-diphenyltetrazolium bromide and lactate dehydrogenase release assays, respectively, with human U87MG glioma and human PC3 prostate cancer cell cultures. In the second stage, to obtain a clear insight into the molecular events after exposing, we examined the effects of selected Y2O3 nanoparticle on the expression of genes in U87MG and PC3 cell cultures using RT2 Profiler PCR Arrays. Y2O3 nanoparticles have IC20 of 0,18 mg/L and 2,903 mg/L in PC3 and U87MG cell lines, respectively. Y2O3 nanoparticle induced up-regulation of 24 and down-regulation of 22 genes in PC3 cells and up-regulation of 53 and down-regulation of 27 genes in U87MG cells. This study of gene expression profiles affected by nanotoxicity provides critical information for the clinical and environmental applications of Y2O3 nanoparticles.

Abstract 2012: In vitro validation of tumor-derived large extracellular vesicles isolation and characterization as suitable tool for liquid biopsy

Abstract Extracellular vesicles (EVs) are involved in intercellular communication mediated by nucleic acid and protein exchange. Their role in cancer has been widely demonstrated and EVs are under investigation as possible tools for liquid biopsy. Large (L)-EVs represent a heterogeneous class of EVs that are characterized by a diameter >200 nm. Those derived by cancer cells show peculiar cargos including oncogenic proteins, lipids and large DNA fragments. Aim of this study was to validate in vitro the isolation, characterization and mutational analysis of tumor-derived L-EVs. L-EVs were isolated from supernatants (50 ml) of either prostate cancer (PC3) and melanoma (SK-Mel28) cell cultures by centrifugation at 10,000x g, and then resuspended in 200 µl of PBS. Tunable resistive pulse sensing (qNANO) investigated both dimensions and concentration of L-EV preparations. Flow cytometry and Western blotting were used to analyze the expression of typical markers of EVs (CD63 and CD81 tetraspanins) and L-EVs (HSPA5 or CK18), as well as of ALIX (cytoplasmic protein) and APOA1 (contaminant) as internal controls. For genomic analysis, L-EVs were initially treated with DNAse I, Exonuclease III and RNAse to disrupt the external nucleic acid coating, then L-EV-DNA was extracted by DNeasy blood and tissue Kit (Qiagen). Quantitative and qualitative analyses of L-EV-DNA have been assessed with Bioanalyzer DNA High Sensitivity Chip Kit (Agilent) and 1% agarose gel electrophoresis, as compared to parental cell DNA. Finally, Sanger sequencing was used to identify TP53 (p.K139fs*31) or BRAF (p.V600E) mutations in L-EV-DNA, respectively form PC3 and SK-Mel28 cells. L-EVs were purified at a mean concentration of 16.4±5.1 x 103 vesicles/µl. Typical characteristics of L-EVs were confirmed, including a diameter ranging from 0.5 µm to 2 µm as well as the expression of CD63/CD81 tetraspanins and HSPA5 or CK18. Moreover, L-EV preparations resulted all negative for APOA1 but positive for ALIX expression, confirming sample purity and vesicle integrity. The DNA content from each sample of L-EVs ranged from 0.36 to 5.21 ng/µl. Qualitative analysis revealed long DNA fragments (range 3,000-10,000 bp) packaged in L-EVs in a fashion almost similar to the genomic DNA from parental cells. Finally, DNA sequencing revealed either the BRAF p.V600E or the TP53 p.K139fs*31 mutations - respectively from SK-Mel28 and PC3 cells - in both L-EV-DNA and genomic DNA. L-EVs are easily obtainable from culture supernatants and represent a biological surrogate of the cell producer. L-EVs contain large DNA fragments that are suitable for molecular testing, including the identification of pathogenic gene variants. These results make L-EVs ideal candidates as liquid biopsy in oncology, thus justifying further efforts to validate their isolation from body fluids and down-stream analysis. Citation Format: Gaetano Pezzicoli, Domenica Lovero, Marco Tucci, Camillo Porta, Francesco Mannavola. In vitro validation of tumor-derived large extracellular vesicles isolation and characterization as suitable tool for liquid biopsy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2012.

Genetic and epigenetic bases of prostate tumor cell radioresistance.

Radiation therapy plays aleading role in the treatment of prostate cancer, but the emergence of radioresistant forms of this disease dictates the need for apersonalized ap-proach based on the data from genetic and epigenetic markers. Such markers include the copy number variation as well as gene and microRNA expression. The aim of the study was to validate the list of potential predictors of radioresistance of prostate tumor cells in amodel experiment based on the determination of gene copy number variation, gene transcriptional activity and microRNA expression. The study used aPC-3prostate cancer cell culture. The determination of the relative copy number variation and expression of 32genes (BRCA1, BRCA2, PTEN, CASP3, CASP8, BAX, BCL2, CASP9, P53, MDM2, AKT1, ATM, BRIP1, CDK1, CDKN1B, CCND1, CCND3, FGFR2, KU70, RAD50, RAP80, Rif1, RNF168, TopBP1, HIST, H2AX, EXO1, XRCC4, RBBP8, EP300, LIG4, C-FLIP), as well as 15microRNAs (let-7, miR15a/ 16, miR-17, miR-18a, miR-21, miR-24, miR-26b, miR-99a, miR-100, miR-101, miR-106a, miR-663a, miR-143, miR-145) was performed using the real-time quantitative polymerase chain reaction method. It was found that daily irradiation of PC-3cells on aNovalis TX linear accelerator at doses of 6and 7Gy for 5days leads to asignificant decrease in the total number of cells and the number of viable cells. Nevertheless, after 5days of irradiation, about 15% of the initial number of prostate tumor cells retained their viability, which is due to their special genetic and epigenetic characteristics: increased copy number and expression of genes BRCA2, CDK1, CDKN1B, H2AX, RAD50, XRCC4, RBBP8and EP300and reduced copy number and expression of CCND3, TP53, and BCL2genes, as well as differential expression of sixmicroRNAs (hsa-miR-18a-5p, hsa-miR-24-5p, hsa-miR-99a-5p, hsa-miR-100-5p, hsa-miR-145-5p, hsa-let-7a-3p). This study enabled to identify genetic and epigenetic markers of prostate tumor cells resistance to radiation therapy.

Androgen Activity in the Primary and Metastatic Prostate Cancer Microenvironments Influences Disease Progression and Patient Outcomes

Abstract Background: Cancers do not exist in isolation, surrounding tumours are supportive cells, which create the microenvironment in which cancer cells reside. In the prostate cancer (PCa), androgen receptor (AR) signalling in the surrounding fibroblasts is strikingly distinct from that within PCa cells, and has specific functions to produce, maintain, and modulate the extracellular matrix (ECM) which surrounds and interacts with PCa cells. The supportive cells of metastatic sites differ from those in the primary site and produce different types of cellular microenvironments. Since the advent of second generation anti-androgen therapy there has been an increase in the presence of liver metastasis. This project investigates how AR and anti-androgen therapy affect the prostate liver microenvironment and the subsequent effects on cancer. Results: Analysis of microenvironment of primary and metastatic sites indicates transcriptional responses distinct from that seen in PCa cells. This is exemplified by proliferation responses to androgen and anti-androgens in microenvironment cells being the reverse to that seen in Pca cells. Dichotomising microdissected PCa patient material of matched cancer and stromal tissue, based on stromal AR level shows distinct transcriptional profiles in the matched cancer cells. From previous studies, we know AR status in cancer adjacent fibroblasts (CAFs) of the primary tumor inversely associates with patient outcomes. Analysis of single cell CAFs and microdissected stromal samples points to a potential sub population of CAFs with this AR status. Conditioned media from liver and prostate fibroblast cells suggests that inactivation of AR signalling produces proliferative paracrine signals that can affect cancer cell growth. AR in primary site fibroblast and liver stellate cells regulates secretome and ECM production in the primary and metastatic site. Prostates and livers from enzalutamide treated mice showed changes in collagen fibres compared to control mice, as visualised by picro-direct-red staining. We cultured PCa cells within 3D-ECM microenvironments created in vitro from prostate fibroblasts or liver cells. The different 3D-ECM were able to produce changes in PCa cells, including gene transcription, intracellular signalling pathways, and proliferation and apoptotic responses. These data suggest that the responses of primary and metastatic microenvironments to androgens and anti-androgens can influence phosphorylation of intracellular pathways leading to alterations in gene transcription. Furthermore, the transcriptional responses of cancer cells in vitro to changes in microenvironmental AR signalling can be used to predict patient outcomes. Conclusions: Our data suggests that anti-AR therapy produces organ microenvironment-specific signals that influence the response of prostate cancer to treatments and affects patient outcomes.

Pleiotropic effects of probenecid on three-dimensional cultures of prostate cancer cells

AimsChemoresistance remains a persistent challenge in advanced prostate cancer therapy. Probenecid reportedly inhibits multiple drug-efflux transporters; hence, it can be employed as a potential sensitizer for chemotherapy. In the present study, we evaluated the effects of probenecid on three-dimensional (3D)-cultures of prostate cancer cells. Main methodsProstate cancer cell lines, 22Rv1 and PC-3 were cultured as multicellular tumor spheroids. The effects of probenecid were evaluated using the MTT assay for viability, microscopy for spheroid size, and soft agar colony formation assay for anchorage-independent growth. Key findingsThe 3D-cultured 22Rv1 cells were less sensitive to cisplatin and doxorubicin than two-dimensional (2D) cell culture. Co-administration of probenecid at a low (100 or 300 μM), but not high (500 μM), concentration increased the sensitivity to cisplatin or doxorubicin in 22Rv1 spheroids. Probenecid increased the expression of ABCG2, a multidrug resistance transporter, in a dose-dependent manner. Furthermore, treatment with probenecid alone reduced the growth of 22Rv1 spheroids. Conversely, probenecid inhibited spheroid compaction rather than growth inhibition in 3D-cultured PC-3 cells. Moreover, probenecid inhibited colony formation of 22Rv1 and PC-3 cells in soft agar, as well as downregulated focal adhesion kinase (FAK), a crucial factor in anchorage-independent growth. SignificanceIn 3D-cultured prostate cancer cells, probenecid demonstrated pleiotropic effects such as chemosensitization, growth suppression, inhibition of spheroid compaction, and suppression of anchorage-independent growth. Elucidating the detailed mechanism underlying these probenecid actions could result in the identification of novel therapeutic targets toward the advanced prostate cancer.

Oncogenic extrachromosomal DNA functions as mobile enhancers to globally amplify chromosomal transcription

Extrachromosomal, circular DNA (ecDNA) is emerging as a prevalent yet less characterized oncogenic alteration in cancer genomes. We leverage ChIA-PET and ChIA-Drop chromatin interaction assays to characterize genome-wide ecDNA-mediated chromatin contacts that impact transcriptional programs in cancers. ecDNAs in glioblastoma patient-derived neurosphere and prostate cancer cell cultures are marked by widespread intra-ecDNA and genome-wide chromosomal interactions. ecDNA-chromatin contact foci are characterized by broad and high-level H3K27ac signals converging predominantly on chromosomal genes of increased expression levels. Prostate cancer cells harboring synthetic ecDNA circles composed of characterized enhancers result in the genome-wide activation of chromosomal gene transcription. Deciphering the chromosomal targets of ecDNAs at single-molecule resolution reveals an association with actively expressed oncogenes spatially clustered within ecDNA-directed interaction networks. Our results suggest that ecDNA can function as mobile transcriptional enhancers to promote tumor progression and manifest a potential synthetic aneuploidy mechanism of transcription control in cancer.

Mutated SPOP E3 Ligase Promotes 17βHSD4 Protein Degradation to Drive Androgenesis and Prostate Cancer Progression.

Molecular mechanisms underlying intratumoral androgenesis and aberrant androgen receptor (AR) activation in prostate cancer remain poorly understood. Here we demonstrate that ectopic expression of the E3 ubiquitin ligase adaptor speckle-type poxvirus and zinc finger domain protein (SPOP) stabilizes 17βHSD4. SPOP bound a functional substrate-binding consensus (SBC) motif 315RATST319 in 17βHSD4 and promoted nondegradable K27- and K29-linked polyubiquitination of 17βHSD4. The effect of SPOP was antagonized by serum- and glucocorticoid kinase-3 (SGK3)-mediated phosphorylation of serine 318 (S318) in the SBC and S318 phosphorylation-dependent binding of SKP2 E3 ligase and subsequent K48-linked polyubiquitination and proteasomal degradation of 17βHSD4. Prostate cancer-associated SPOP mutations impaired the SPOP-17βHSD4 interaction, caused 17βHSD4 protein destruction in prostate cancer cells in culture and patient specimens, and increased testosterone production and prostate cancer cell growth in vitro and in mouse models. Thus, we have identified SPOP and SKP2 as two essential E3 ubiquitin ligases that exert opposite effects on 17βHSD4 protein degradation and intratumoral androgenesis in prostate cancer cells. We further demonstrate that SPOP mutations or SKP2 overexpression contribute to prostate cancer progression by decreasing 17βHSD4 expression and increasing intratumoral androgen synthesis. SIGNIFICANCE: This study reveals a novel mechanism of aberrant AR activation in SPOP-mutated prostate cancer and uncovers putative biomarkers for effective treatment by AR-targeted therapies.

A phase II study to evaluate the effects of docetaxel plus lycopene in advanced castrate-resistant prostate cancer.

77 Background: Lycopene, the carotenoid responsible for the red colors seen in tomatoes, grapefruit, and other foods, has demonstrated synergism with docetaxel in prostate cancer cell culture and tumor xenograft models. This phase II study investigated the clinical activity and safety profile of docetaxel plus lycopene in advanced castrate resistant prostate cancer. Methods: Eligible patients had histologically confirmed adenocarcinoma of the prostate, two rising pre-study prostate specific antigen (PSA) values ≥ 1 ng/ml, and no prior treatment with any chemotherapy, biological therapy, or investigational drug. All patients initially received docetaxel 75mg/m2 every 21 days in combination with lycopene 30 mg orally once daily. The primary endpoint was PSA response rate, defined as the proportion of subjects achieving a ≥ 50% reduction in PSA at any point after starting therapy. Secondary endpoints included median time to PSA progression, duration of response (DOR), and overall survival (OS). Results: Fourteen patients were screened, and thirteen patients were initiated on protocol therapy. Median age was 77 years (range 55-90). Twelve patients (92%) had bone metastases. Four patients (30%) had bone and visceral metastases. The PSA response rate was 76.9% [95% confidence interval (CI), 46.2-94.9], comprising of ten PSA responses. Two patients had a best response of stable disease, yielding a disease control rate of 92% [95% CI, 57.2-98.2]. Median time to PSA progression was 8 months [95% CI, 3.5-8.7]. Median duration of response was 7.3 months [95% CI, 4.8-13.2]. On 5-year follow-up, median overall survival was 35.1 months [95% CI, 25.7-57.7]. The most frequently reported ( > 15%) non-hematologic adverse events included diarrhea, nausea, vomiting, peripheral neuropathy, weight loss, fatigue, onycholysis, and alopecia. One patient (7%) experienced febrile neutropenia. No patients experienced grade 3 or above anemia. Conclusions: The combination of docetaxel with lycopene led to improved PSA response rate and tolerability in patients with advanced castrate resistant prostate cancer. Docetaxel plus lycopene merits further research in this patient population. Clinical trial information: NCT01882985.

D-pantotenik asidin PC-3 prostat kanseri hücreleri üzerindeki apoptotik etkilerinin incelenmesi

Purpose: The anti-inflammatory and antioxidant properties of D-pantothenic acid have been demonstrated and the effects of dexpentanol on inflammatory pathways and apopototic pathways that trigger cell death are of interest. Apoptotic pathways are important in resistance to chemotherapeutics in cancer diseases and in cancer development. Therefore, we planned how treatment of PC-3 human prostate cancer cells with dexpanthenol will affect the levels and activities of apoptotic and inflammation mediators. For this purpose, human prostate cancer cell culture was performed.
 Materials and Methods: The human prostate cancer cells were treated with dexpentanaol then protein levels and activities of inflammatory and apoptotic pathway mediators such as gadd153, AIF, grp78, bax and bcl-2 in the cells were analyzed by ELISA.
 Results: The results of our study showed that, D-pantothenic acid did not statisticaly decreased the leves of bax, bcl-2 and grp78 protein expression in PC-3 prostate cancer cells. The effect of D-pantothenic acid on gadd153 and AIF proteins in PC-3 cells was increased but this increased level did not statisticaly significant.
 Conclusion: Recent studies have demonstrated the potential benefits of anti-inflammatory drugs. Our study showed that D-pantothenic acid had no significant effect on the growth of PC-3 cells and has no significant effect on intracellular apoptotic pathways.

The Effect of Lycopene on Cancer Cell Apoptosis by Caspase-9 Concentration Measurement in Indonesian Human Prostate Cancer Cell Culture

BACKGROUND: Lycopene is an antioxidant that mostly found in daily ingredients such as tomatoes. Several studies have shown the lycopene potential in preventing prostate cancer. Nevertheless, the clinical use of lycopene as adjunctive therapy for prostate cancer is still under debate.
 AIM: The objective of the study was to determine the effect of lycopene on human prostate cancer cell culture growth by measuring caspase-9 concentration as a marker of the intrinsic pathway of apoptosis in cells.
 METHODS: This study was conducted on Indonesian prostate cancer cell culture from a patient with Gleason score 6, divided into 5 subgroups: 2 control groups and 3 treatment groups that were given 1 μM, 2 μM, and 4 μM of lycopene. Measurement of caspase-9 level was performed using enhanced chemiluminescence at 24, 28, and 72 h after lycopene addition in treatment groups. A comparative analysis was performed by two-way ANOVA.
 RESULTS: The result showed that there was a significant difference of mean caspase-9 levels in the provision of various concentrations of lycopene and time of observation (p < 0.05). Increased of mean caspase-9 levels started at 2 μM dose of lycopene at 48 h and 4 μM at 24 h (p < 0.05) and continue to rise at 72 h, but caspase-9 was not detected at 1 μM dose in every observation.
 CONCLUSION: There was a significant difference of mean caspase-9 levels in the provision of various concentrations of lycopene and time of observation.

DNA Damage Promotes TMPRSS2-ERG Oncoprotein Destruction and Prostate Cancer Suppression via Signaling Converged by GSK3β and WEE1

TMPRSS2-ERG gene fusion occurs in approximately 50% of cases of prostate cancer (PCa), and the fusion product is a key driver of prostate oncogenesis. However, how to leverage cellular signaling to ablate TMPRSS2-ERG oncoprotein for PCa treatment remains elusive. Here, we demonstrate that DNA damage induces proteasomal degradation of wild-type ERG and TMPRSS2-ERG oncoprotein through ERG threonine-187 and tyrosine-190 phosphorylation mediated by GSK3β and WEE1, respectively. The dual phosphorylation triggers ERG recognition and degradation by the E3 ubiquitin ligase FBW7 in a manner independent of a canonical degron. DNA damage-induced TMPRSS2-ERG degradation was abolished by cancer-associated PTEN deletion or GSK3β inactivation. Blockade of DNA damage-induced TMPRSS2-ERG oncoprotein degradation causes chemotherapy-resistant growth of fusion-positive PCa cells in culture and in mice. Our findings uncover a previously unrecognized TMPRSS2-ERG protein destruction mechanism and demonstrate that intact PTEN and GSK3β signaling are essential for effective targeting of ERG protein by genotoxic therapeutics in fusion-positive PCa.

Abstract 2015: A transcriptionally enhanced biosensor to detect and monitor biopsy-dissociated primary prostate cancer single cell drug responses by bioluminescence microscopy

Abstract Background: In the past decade, the therapeutic landscape of metastatic castration resistant prostate cancer (mCRPC) has been transformed with the introduction of novel pharmaceutical agents including novel antiandrogens (nAA) such as darolutamide, enzalutamide or apalutamide. Currently, the management of mCRPC is mainly based on biomarkers obtained from the patient's blood or bulk tumor samples, which do not take into account for prostate cancer (PCa) cell heterogeneity. Objectives: To develop a bioluminescence imaging technology enabling: 1) the detection of PCa single cells from dissociated biopsies and 2) single cell nAA sensitivity assessment. Methods: The PCA3 promoter (PCa specific) and PSEBC promoter (androgen receptor-driven to monitor response to nAA therapy) have been incorporated in the non-replicating adenoviral multi-promoter integrated two-step transcriptional amplification system (MP-ITSTA) that allows imaging of complementary activities of two different promoters by a single output reporter gene. Thus, PCA3/PSEBC-ITSTA system was designed to monitor androgen receptor (AR) activity specifically within each single PCa cell by bioluminescence microscopy. Prostatic biopsies were dissociated in the presence of collagenase II and DNase for 18h. PCa cell lines or fresh biopsies-dissociated cancer cells were transduced for 72h and then covered with an extracellular matrix gel. Single cell bioluminescence microscopy images were done before and after exposure to DHT or DHT+AA to specifically monitoring therapy response. Changes in cell number and luminescence intensity after AA were normalized to the DHT group to exclude non-specific cell-death due to infection or time spent in culture. Results: PCA3/PSEBC-ITSTA was specific to PCa cell lines. By determining the ratio of AR active cells before and after DHT or DHT+AA treatment in culture, PCA3-Cre-PSEBC-ITSTA was able to determine the AA sensitivity of LNCaP (sensitive), LAPC4 (moderately resistant) and 22Rv1 (resistant) PCa cell lines. Also, our method could detect and monitor AA sensitivity of primary PCa cells harvested from eight radical prostatectomy specimens. PCA3/PSEBC-ITSTA could dynamically quantify AR transcriptional activity during enzalutamide or bicalutamide treatments, in a dose dependent manner, and could unveil tumor AA response heterogeneity. As expected, inhibition of AR activity was stronger with enzalutamide than with bicalutamide. Conclusions: Our bioluminescence microscopy-based biosensor could detect primary PCa cells in culture and it allows dynamic evaluation of AA sensitivity at a single-cell level in a heterogeneous cell population harvested from radical prostatectomy biopsies. We believe our approach opens to a novel field of treatment response predictive tools for cancer treatment decision-making. Citation Format: Audrey Champagne, Pallavi Jain, Bertrand Neveu, Frédéric Pouliot. A transcriptionally enhanced biosensor to detect and monitor biopsy-dissociated primary prostate cancer single cell drug responses by bioluminescence microscopy [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 2015.

Photodynamic therapy on prostate cancer cells involve mitochondria membrane proteins

Photodynamic therapy for prostate cancer has emerged, however the evaluation of its mechanism of action has not yet been clarified. This study aims to explore the mechanism and significance of photodynamic therapy on prostate cancer in vitro. Cultured prostate cancer cells were divided into two groups: untreated and photodynamic therapy treatment. The protein of each group was extracted and analyzed by MALDI-TOF/MSMS method. The significantly expressed proteins were identified in the NCBI human protein database. The change of mitochondrial membrane permeability after photodynamic treatment was examined by transmission electron microscopy. The total protein content and band distribution of photodynamic treatment group were similar to the control group. Two mitochondrial membrane proteins were down-regulated significantly. They are mitochondrial heat shock protein (HSP60) (Entrez Gene ID: 31542947, PI 5.7, MW: 61016.4, Protein Score: 354, Protein Score C.I.%:100), and voltage-dependent anion channel (VDAC) (Entrez Gene ID: 340201, PI 7.49, MW: 31574.6, Protein Score: 178, Protein Score C.I.%:100). Transmission electron microscopy showed the loss of integrity of mitochondrial membranes. Photodynamic therapy changes mitochondrial membrane permeability, leading to the eventual death of cancer cells. The regulation of proteins related to mitochondrial membrane permeability may become an indicator of the efficacy of photodynamic therapy.