Transition In Prostate Cancer Cells Research Articles

Electrical Impedance Spectroscopy as a Tool to Detect the Epithelial to Mesenchymal Transition in Prostate Cancer Cells.

Prostate cancer (PCa) remains a significant health threat, with chemoresistance and recurrence posing major challenges despite advances in treatment. The epithelial to mesenchymal transition (EMT), a biochemical process where cells lose epithelial features and gain mesenchymal traits, is linked to chemoresistance and metastasis. Electrical impedance spectroscopy (EIS), a novel label-free electrokinetic technique, offers promise in detecting cell phenotype changes. In this study, we employed EIS to detect EMT in prostate cancer cells (PCCs). PC3, DU145, and LNCaP cells were treated with EMT induction media for five days. EIS characterization revealed unique impedance spectra correlating with metastatic potential, distinguishing DU145 EMT+ and EMT- cells, and LNCaP EMT+ and EMT- cells (in combination with dielectrophoresis), with comparisons made to epithelial and mesenchymal controls. These changes were supported by shifts in electrical signatures, morphologies, and protein expression, including the downregulation of E-cadherin and upregulation of vimentin. No phenotype change was observed in PC3 cells, which maintained a mesenchymal phenotype. EMT+ cells were also distinguishable from mixtures of EMT+ and EMT- cells. This study demonstrates key advancements: the application of EIS and dielectrophoresis for label-free EMT detection in PCCs, characterization of cell electrical signatures after EMT, and EIS sensitivity to EMT transitions. Detecting EMT in PCa is important to the development of more effective treatments and overcoming the challenges of chemoresistance.

α-lipoic acid modulates prostate cancer cell growth and bone cell differentiation

Prostate cancer (PCa) progression leads to bone modulation in approximately 70% of affected men. A nutraceutical, namely, α-lipoic acid (α-LA), is known for its potent anti-cancer properties towards various cancers and has been implicated in treating and promoting bone health. Our study aimed to explore the molecular mechanism behind the role of α-LA as therapeutics in preventing PCa and its associated bone modulation. Notably, α-LA treatment significantly reduced the cell viability, migration, and invasion of PCa cell lines in a dose-dependent manner. In addition, α-LA supplementation dramatically increased reactive oxygen species (ROS) levels and HIF-1α expression, which started the downstream molecular cascade and activated JNK/caspase-3 signaling pathway. Flow cytometry data revealed the arrest of the cell cycle in the S-phase, which has led to apoptosis of PCa cells. Furthermore, the results of ALP (Alkaline phosphatase) and TRAP (tartrate-resistant acid phosphatase) staining signifies that α-LA supplementation diminished the PCa-mediated differentiation of osteoblasts and osteoclasts, respectively, in the MC3T3-E1 and bone marrow macrophages (BMMs) cells. In summary, α-LA supplementation enhanced cellular apoptosis via increased ROS levels, HIF-1α expression, and JNK/caspase-3 signaling pathway in advanced human PCa cell lines. Also, the treatment of α-LA improved bone health by reducing PCa-mediated bone cell modulation.

FABP5 can substitute for androgen receptor in malignant progression of prostate cancer cells.

Fatty acid‑binding protein 5 (FABP5) and androgen receptor (AR) are critical promoters of prostate cancer. In the present study, the effects of knocking out the FABP5 or AR genes on malignant characteristics of prostate cancer cells were investigated, and changes in the expression of certain key proteins in the FABP5 (or AR)‑peroxisome proliferator activated receptor‑γ (PPARγ)‑vascular endothelial growth factor (VEGF) signaling pathway were monitored. The results obtained showed that FABP5‑ or AR‑knockout (KO) led to a marked suppression of the malignant characteristics of the cells, in part, through disrupting this signaling pathway. Moreover, FABP5 and AR are able to interact with each other to regulate this pathway, with FABP5 controlling the dominant AR splicing variant 7 (ARV7), and AR, in return, regulates the expression of FABP5. Comparisons of the RNA profiles revealed the existence of numerous differentially expressed genes (DEGs) comparing between the parental and the FABP5‑ or AR‑KO cells. The six most abundant changes in DEGs were found to be attributable to the transition from androgen‑responsive to androgen‑unresponsive, castration‑resistant prostate cancer (CRPC) cells. These findings have provided novel insights into the complex molecular pathogenesis of CRPC cells, and have demonstrated that interactions between FABP5 and AR contribute to the transition of prostate cancer cells to an androgen‑independent state. Moreover, gene enrichment analysis revealed that the most highly enriched biological processes associated with the DEGs included those responsive to fatty acids, cholesterol and sterol biosynthesis, as well as to lipid and fatty acid transportation. Since these pathways regulated by FABP5 or AR may be crucial in terms of transducing signals for cancer cell progression, targeting FABP5, AR and their associated pathways, rather than AR alone, may provide a new avenue for the development of therapeutic strategies geared towards suppressing the malignant progression to CRPC cells.

NKX3.1 Expression Contributes to Epithelial-Mesenchymal Transition of Prostate Cancer Cells.

Studies demonstrate that inflammation synergizes with high-grade aggressive prostate tumor development and ultimately metastatic spread, in which a lot of work has been done in recent years. However, the clear mechanism of inflammation inciting prostate cancer remains largely uncharacterized. Our previous study has shown that the conditioned media (CM)-mediated LNCaP cell migration is partially correlated with the loss of expression of the tumor suppressor NKX3.1. Here, we continue to investigate the inflammation-mediated migration of prostate cancer cells, and the role of NKX3.1 in this process to gain insights into cell migration-related changes comprehensively. Earlier, the model of inflammation in the tumor microenvironment have been optimized by our research group; here, we continue to investigate the time-dependent effect of CM exposure together with NKX3.1 changes, in which we observed that these changes play important roles in gaining heterogeneous epithelial-to-mesenchymal transition (EMT) phenotype. Hence, this is an important parameter of tumor progression; we depleted NKX3.1 expression using the CRISPR/Cas9 system and examined the migrating cell clusters after exposure to inflammatory cytokines. We found that the migrated cells clearly demonstrate reversible loss of E-cadherin expression, which is consistent with subsequent vimentin expression alterations in comparison to control cells. Moreover, the data suggest that the AR-mediated transcriptional program also contributes to mesenchymal-to-epithelial transition (MET) in prostate cancer progression. Furthermore, the quantitative proteomic analysis showed that migrated subpopulations from the same cell line presented different phenotypes in which the proteins overexpressed are involved in cell metabolism and RNA processing. According to KEGG pathway analysis, the ABC transporters were found to be the most significant. Thus, the dynamic process of cellular migration favors diverse genetic compositions under changing tumor microenvironments. The different levels of invasiveness are supported by shifting the cells in between these EMT and MET phenotypes.

Dynamic modulation of matrix adhesiveness induces epithelial-to-mesenchymal transition in prostate cancer cells in 3D

Synthetic matrices with dynamic presentation of cell guidance cues are needed for the development of physiologically relevant in vitro tumor models. Towards the goal of mimicking prostate cancer progression and metastasis, we engineered a tunable hyaluronic acid-based hydrogel platform with protease degradable and cell adhesive properties employing bioorthogonal tetrazine ligation with strained alkenes. The synthetic matrix was first fabricated via a slow tetrazine-norbornene reaction, then temporally modified via a diffusion-controlled method using trans-cyclooctene, a fierce dienophile that reacts with tetrazine with an unusually fast rate. The encapsulated DU145 prostate cancer single cells spontaneously formed multicellular tumoroids after 7 days of culture. In situ modification of the synthetic matrix via covalent tagging of cell adhesive RGD peptide induced tumoroid decompaction and the development of cellular protrusions. RGD tagging did not compromise the overall cell viability, nor did it induce cell apoptosis. In response to increased matrix adhesiveness, DU145 cells dynamically loosen cell-cell adhesion and strengthen cell-matrix interactions to promote an invasive phenotype. Characterization of the 3D cultures by immunocytochemistry and gene expression analyses demonstrated that cells invaded into the matrix via a mesenchymal like migration, with upregulation of major mesenchymal markers, and down regulation of epithelial markers. The tumoroids formed cortactin positive invadopodia like structures, indicating active matrix remodeling. Overall, the engineered tumor model can be utilized to identify potential molecular targets and test pharmacological inhibitors, thereby accelerating the design of innovative strategies for cancer therapeutics.

LQB-118 Suppresses Migration and Invasion of Prostate Cancer Cells by Modulating the Akt/GSK3β Pathway and MMP-9/Reck Gene Expression.

Prostate cancer (PCa) is one of the most common malignancies in adult men. LQB-118 is a pterocarpanquinone with antitumor activity toward prostate cancer cells. It inhibits cell proliferation by down-regulating cyclins D1 and B1 and up-regulating p21. However, the effects of LQB-118 on PCa cell migration are still unclear. Herein, the LQB-118 effects on PCa metastatic cell migration/invasion and its mechanism of action were evaluated. PC3 cells were treated with LQB-118 or Paclitaxel (PTX), and cell migration (wound healing and Boyden chamber assays) and invasion (matrigel assay) were determined. The LQB-118 mechanisms were evaluated by αVβIII protein expression (flow cytometry), protein phosphorylation (Western blot), and mRNA expression (qPCR). LQB-118 impaired PCa cell migration and invasion, down-regulated Akt phosphorylation, and also reduced GSK3β phosphorylation, through a FAK-independent pathway. Also, it was observed that LQB-118 controlled the invasiveness behavior by reducing matrix metalloproteinase-9 (MMP-9) and up-regulating reversion-inducing cysteine rich protein with Kazal motifs (Reck) mRNA levels. Interestingly, LQB-118 increased integrin αvβIII expression, but this effect was not related to its activation, since the cell adhesion ability was reduced after LQB-118 treatment. These data highlight novel LQB-118 mechanisms in prostate cancer cells. LQB-118 acts as a negative regulator of the Akt/GSK3 signaling pathway and can modulate PCa cell proliferation, death, and migration/invasion. The results also support the use of LQB-118 for the treatment of metastatic PCa, alone or combined with another chemotherapeutic agent, due to its demonstrated pleiotropic activities.

CXCR4 and CXCR7 signaling promotes tumor progression and obesity-associated epithelial-mesenchymal transition in prostate cancer cells.

Obesity is associated with increased prostate cancer (PCa) progression and higher mortality, however, the mechanism(s) remain still unclear. Here, we investigated signaling by the ASC-secreted chemokine CXCL12 in a mouse allograft model of PCa and in HiMyc mice in the context of diet-induced obesity. Treatment of mice with CXCR4 antagonist inhibited CXCL12-induced signaling pathways, tumor growth and EMT in HMVP2 allograft tumors. Similar results were obtained following prostate epithelium-specific deletion of CXCR4 in HiMyc mice. We also show that CXCR4 signaling regulates expression of JMJD2A histone demethylase and histone methylation which is modulated by AMD3100. Importantly, treatment with a CXCR7 antagonist also inhibited allograft tumor growth and EMT. The current results demonstrate that both CXCR4 and CXCR7 play an important role in cancer progression and establish CXCL12 signaling pathways, activated in obesity, as potential targets for PCa intervention. In addition, other factors secreted by ASCs, may also contribute to cancer aggressiveness in obesity.

Inhibition of the proliferation, invasion, migration, and epithelial-mesenchymal transition of prostate cancer cells through the action of ATP1A2 on the TGF-β/Smad pathway.

BackgroundProstate cancer (PC) is one of the major male malignancies worldwide. Because Na+-K+-ATPase is widely involved in various pathological processes, but the action of its α2 subtype (ATP1A2) in PC is unclear, we investigated the role of ATP1A2 in the invasion and migration of PC cells.MethodsWe measured the expression levels of ATP1A2 in human normal prostate epithelial cell line (RWPE-1) and PC cell lines (PC-3 and DU145) by quantitative real-time PCR (qRT-PCR) and western blot. Cell proliferation, apoptosis, migration, and invasion of PC-3 and DU145 cells were investigated through clone formation assay, EdU assay, flow cytometry and transwell assay, respectively. The effect of ATP1A2 on a tumor-inhibitory pathway [transforming growth factor-β (TGF-β)/Smad] was assessed using western blot. In addition, tumor formation was detected using in vivo xenograft model in male BALB/c nude mice.ResultsThe Cancer Genome Atlas (TCGA) analysis showed that ATP1A2 expression was reduced in PC patients (P<0.05), and patients with low ATP1A2 expression had a lower survival rate (P<0.05). ATP1A2 levels were significantly reduced in PC-3 and DU145 cells, compared with RWPE-1 cells (P<0.01). We also demonstrated that overexpression of ATP1A2 significantly inhibited the proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of PC-3 and DU145 cells (P<0.01) and promoted apoptosis (P<0.01). However, silencing ATP1A2 had the opposite effect (P<0.01). In addition, overexpression of ATP1A2 significantly inhibited the TGF-β/Smad pathway (P<0.01), whereas silencing ATP1A2 activated the TGF-β/Smad pathway (P<0.01). Meanwhile, the effect of ATP1A2 silencing on the proliferation, apoptosis, migration and invasion was reversed by TGF-β/Smad pathway inhibitor (LY364947). Furthermore, ATP1A2 inhibited tumor growth in vivo.ConclusionsATP1A2 inhibited proliferation, apoptosis, migration, invasion, and EMT in PC by inhibiting the TGF-β/Smad pathway.

Chronic cadmium exposure induces epithelial mesenchymal transition in prostate cancer cells through a TGF-β-independent, endoplasmic reticulum stress induced pathway

In this study, we aimed to elucidate the role of chronic cadmium (Cd) exposure in epithelial-mesenchymal transition (EMT) and thus malignant phenotypic changes of prostate cancer cells. Prostate cancer cells (PC-3 and DU145) were exposed to a non-toxic level (0.5 or 2 μM) of Cd for up to 3 months, which resulted in significantly promoted migration and invasion of the cells. These phenotypic changes were considered to be the consequence of enhanced EMT as evidenced by diminished expression of E-cadherin and increased vimentin expression. Regarding the mechanisms of Cd-induced EMT, we found Smad3 was activated but without upregulation of TGF-β. Alternatively, we found endoplasmic reticulum (ER) stress of prostate cancer cells was significantly evoked, which was parallel with the increased reactive oxygen species (ROS). Removal of ROS by N-acetylcysteine significantly reduced ER stress in prostate cancer cells, followed by the decrease of Smad3 phosphorylation and expression of nuclear Snail, resulting in the inhibition of EMT and malignant phenotypic changes of prostate cancer cells. These findings indicated a new TGF-β independent, ROS-mediated ER stress/Smad signaling pathway in chronic Cd exposure-induced EMT of prostate cancer cells, which could be a novel mechanism involved in cadmium-mediated cancer cells malignant transformation. Accordingly, ROS-induced ERs may become a novel preventive and therapeutic target for cancer.

A Novel Splice Variant of the Inhibitor of Growth 3 Lacks the Plant Homeodomain and Regulates Epithelial-Mesenchymal Transition in Prostate Cancer Cells.

Inhibitor of growth 3 (ING3) is one of five members of the ING tumour suppressor family, characterized by a highly conserved plant homeodomain (PHD) as a reader of the histone mark H3K4me3. ING3 was reported to act as a tumour suppressor in many different cancer types to regulate apoptosis. On the other hand, ING3 levels positively correlate with poor survival prognosis of prostate cancer (PCa) patients. In PCa cells, ING3 acts rather as an androgen receptor (AR) co-activator and harbours oncogenic properties in PCa. Here, we show the identification of a novel ING3 splice variant in both the human PCa cell line LNCaP and in human PCa patient specimen. The novel ING3 splice variant lacks exon 11, ING3∆ex11, which results in deletion of the PHD, providing a unique opportunity to analyse functionally the PHD of ING3 by a natural splice variant. Functionally, overexpression of ING3Δex11 induced morphological changes of LNCaP-derived 3D spheroids with generation of lumen and pore-like structures within spheroids. Since these structures are an indicator of epithelial–mesenchymal transition (EMT), key regulatory factors and markers for EMT were analysed. The data suggest that in contrast to ING3, ING3Δex11 specifically modulates the expression of key EMT-regulating upstream transcription factors and induces the expression of EMT markers, indicating that the PHD of ING3 inhibits EMT. In line with this, ING3 knockdown also induced the expression of EMT markers, confirming the impact of ING3 on EMT regulation. Further, ING3 knockdown induced cellular senescence via a pathway leading to cell cycle arrest, indicating an oncogenic role for ING3 in PCa. Thus, the data suggest that the ING3Δex11 splice variant lacking functional PHD exhibits oncogenic characteristics through triggering EMT in PCa cells.

PHLDA3 exerts an antitumor function in prostate cancer by down-regulating Wnt/β-catenin pathway via inhibition of Akt

Pleckstrin homology-like domain family A, member 3 (PHLDA3) is a novel tumor-related protein that mediates carcinogenesis of multiple cancers. However, the relevance of PHLDA3 in prostate cancer has not been explored. The purpose of this work was to illustrate the possible roles and mechanisms of PHLDA3 in prostate cancer. Our data showed strikingly lower abundance of PHLDA3 in prostate cancer, and that low levels of PHLDA3 in prostate cancer patients was associated with reduced survival. PHLDA3 was also weakly expressed in prostate cancer cells, and demethylation treatment dramatically up-regulated the expression level of PHLDA3. Up-regulation of PHLDA3 restrained proliferation, induced G1 cell cycle arrest, suppressed epithelial-mesenchymal transition of prostate cancer cells. In addition, up-regulation of PHLDA3 increased the sensitivity of prostate cancer cells to docetaxel In-depth research into the mechanism elucidated that PHLDA3 overexpression decreased the phosphorylation of Akt and suppressed the activation of Wnt/β-catenin signaling. Overexpression of constitutively active Akt strikingly abolished PHLDA3-mediated inactivation of Wnt/β-catenin pathway. A xenograft assay revealed that prostate cancer cells with PHLDA3 overexpression displayed reduced tumorigenicity in vivo. Collectively, these data document that PHLDA3 exerts an outstanding cancer-inhibiting role in prostate cancer by down-regulating Wnt/β-catenin pathway via the inhibition of Akt. This work highlights PHLDA3 as a novel anticancer target for prostate cancer.

Dextran-Curcumin Nanosystems Inhibit Cell Growth and Migration Regulating the Epithelial to Mesenchymal Transition in Prostate Cancer Cells.

Functional nanocarriers which are able to simultaneously vectorize drugs to the site of interest and exert their own cytotoxic activity represent a significant breakthrough in the search for effective anticancer strategies with fewer side effects than conventional chemotherapeutics. Here, we propose previously developed, self-assembling dextran-curcumin nanoparticles for the treatment of prostate cancer in combination therapy with Doxorubicin (DOXO). Biological effectiveness was investigated by evaluating the cell viability in either cancer and normal cells, reactive oxygen species (ROS) production, apoptotic effect, interference with the cell cycle, and the ability to inhibit cell migration and reverse the epithelial to mesenchymal transition (EMT). The results proved a significant enhancement of curcumin efficiency upon immobilization in nanoparticles: IC50 reduced by a half, induction of apoptotic effect, and improved ROS production (from 67 to 134%) at low concentrations. Nanoparticles guaranteed a pH-dependent DOXO release, with a more efficient release in acidic environments. Finally, a synergistic effect between nanoparticles and Doxorubicin was demonstrated, with the free curcumin showing additive activity. Although in vivo studies are required to support the findings of this study, these preliminary in vitro data can be considered a proof of principle for the design of an effective therapy for prostate cancer treatment.

Metformin Induced Oxidative Stress Alters Transsulfuration Pathway and Inhibits Prostate Cancer Cell Growth

Objective To determine the role of metformin in regulating intracellular redox status and cell growth in prostate cancer cells Background : Prostate cancer is the second leading cause of cancer-related death among males in the United States. Despite several advances in treatment options, there are several underlying challenges that affect prostate cancer therapy, including patient age, cancer resistance and undesirable side effects. Moreover, current treatment options focus on two or more cellular targets, such as, androgen synthesis, DNA repair enzymes and immune cells. Such cellular targets bypass the underlying supportive metabolic and molecular phenotypes that contribute to a cancer cell's ability to evade apoptosis, proliferate, and develop chemoresistance. Over the last decade, both preclinical and clinical studies have indicated the potential of metformin in prostate cancer therapy. Notably, these extensive studies demonstrated metformin's pleiotropic effects on several molecular and metabolic pathways such as androgen signaling, cell cycle and cellular bioenergetics, including its unique ability to activate the energy sensor 5 AMP activated kinase (AMPK). We previously demonstrated that metformin alters mitochondrial function in LNCaP prostate cancer cells resulting in elevated glycolysis. In light of this, we hypothesized that metformin induced oxidative stress, modulates prostate cancer cell survival, and is involved in its antiproliferative effects via the transsulfuration pathway. Methods : Using Seahorse XP extracellular analysis, we measured LNCaP prostate cancer cellular bioenergetics oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) in the presence of metformin and SBI0206965 (an AMPK inhibitor). RT-PCR, Liquid Chromatography/ Mass Spectrophotometry (LC/MS), Trypan Blue Exclusion and MTT assays were used to assess the effect of metformin on intracellular redox status and prostate cancer survival. Additionally, we also measured transsulfuration-related enzymatic activities using an ELISA Assay. Results Metformin altered prostate cancer cellular bioenergetics resulting in decreased OCR and increased ECAR, reflecting oxidative phosphorylation and glycolytic activity, respectively. LC/MS analysis of metformin-treated cells showed a significant reduction in GSH/GSSG ratio and metabolite levels associated with the transsulfuration pathway such as glutathione (GSH) and cystathionine (CYS). These low levels of GSH and CYS were consistent with an increase in the gene expression of transsulfuration related enzymes, cystathionine beta synthase (CBS) and cystathionine gamma-lyase (CSE). Additionally, metformin increased the gene expression of the glutathione synthesis-related enzyme γ-glutamyl cysteine ligase (GCL), with no observable change in glutathione synthetase (GSS) gene expression. Notably, MTT and trypan blue exclusion assays indicated that metformin significantly decreased cell viability and had an anti-proliferative effect on LNCaP prostate cancer cells. Conclusion :Metformin induced oxidative stress modulates transsulfuration and glutathione synthesis pathways and exerts antiproliferative effects in LNCaP prostate cancer cells.

Verbascoside inhibits the epithelial-mesenchymal transition of prostate cancer cells through high-mobility group box 1/receptor for advanced glycation end-products/TGF-β pathway.

Prostate cancer has significant mortality and metastasis rate in the male. Unfortunately, effective treatment for patients with advanced prostate cancer is still lacking. Verbascoside, a phenylethanoid glycoside, displays various pharmacological properties, such as the anti-cancer activities. The present study aimed to evaluate the effects of purified verbascoside on human prostate cancer and the associated molecular mechanisms. The human prostate cancer cell lines, Du-145 and PC-3, were treated with various concentrations of verbascoside (0.1, 1, 10 μM) for 24 h followed by the examination of cell viability using MTT and trypan blue exclusion assays. Cell migration and invasion capacities were assessed by wound healing assay and transwell system. Western blot and immunofluorescence staining were used to detect the expression of epithelial-mesenchymal transition (EMT)-associated factors, components of transforming growth factor (TGF-β)/Smad signaling, and high-mobility group box (HMGB)/receptor for advanced glycation end-products (RAGE) axis. Verbascoside treatment significantly inhibited cell proliferation, migration, and invasion abilities of Du-145 and PC-3 cells. We showed that verbascoside decreased the expression of EMT promotors, Snail and Slug, and increased the expression of E-cadherin. Moreover, the expression level of alpha-smooth muscle actin was downregulated by verbascoside as well. Besides, we found that the TGF-β pathway was suppressed, which was demonstrated by the diminished expression of type I and II TGF-β receptors and phosphorylated Smad2/3 along with the upregulated Smad7. Our data suggested that this downregulation of TGF-β signaling was mediated by repression of HMGB 1 (HMGB1)/RAGE axis. Verbascoside mitigated the cell proliferation and aggressiveness of prostate cancer via downregulation of TGF-β-associated EMT progression through HMGB1/RAGE suppression. Collectively, our findings revealed that verbascoside may be a beneficial dietary supplement for prostate cancer patients.

Exosomes Promote the Transition of Androgen-Dependent Prostate Cancer Cells into Androgen-Independent Manner Through Up-Regulating the Heme Oxygenase-1.

BackgroundCastration-resistant prostate cancer (CRPC) is still considered incurable, even though the mechanisms of CRPC had been extensively researched. Studies have demonstrated that exosomes in the tumor microenvironment contribute to prostate cancer development and progression. However, the role of exosomes in the process of CRPC progression has not yet been determined.MethodsCo-culturing and exosome treatment assays combined with in vitro and in vivo assays were performed to determine the function of exosomes in the transformation of androgen-dependent prostate cancer (ADPC) cells into androgen-independent cells. Then, the mRNA expression profiles of ADPC cells and ADPC cells co-cultured with androgen-independent prostate cancer (AIPC) cell-derived exosomes were studied using microarrays. After silencing the expression of heme oxygenase-1 (HMOX1), Western blotting, quantitative real-time PCR, immunohistochemistry (IHC) studies, and MTS assay were used to confirm the mechanisms of exosome participation in CRPC progression.ResultsThe results showed that ADPC cells acquired tolerance for androgen deprivation due to the exosome-mediated communication between cells. AIPC cell-derived exosomes promoted the transformation of ADPC cells into androgen-independent cells in vivo and in vitro. Microarray analysis revealed that HMOX1 in ADPC cells was up-regulated after treatment with AIPC cell-derived exosomes. Further results showed that HMOX1 is overexpressed in human AIPC specimens and protects ADPC cells from androgen deprivation.ConclusionsOur findings revealed that exosomes contribute to CRPC progression via promoting the transition of prostate cancer cells into an androgen-independent growth stage by activating HMOX1.

NNT-AS1 modulates prostate cancer cell proliferation, apoptosis and migration through miR-496/DDIT4 axis

BackgroundEmerging studies have disclosed long non-coding RNAs (lncRNAs) as pivotal modulators in the progression of prostate cancer (PCa). Current research planned to figure out the involvement of lncRNA nicotinamide nucleotide transhydrogenase antisense RNA 1 (NNT-AS1) in PCa.MethodsRNA expression was examined using RT-qPCR in PCa cells. Functional assays assessed the viability, proliferation, apoptosis and migration of PCa cells. RNA pull down and luciferase reporter experiments detected the interplay between miRNA and lncRNA or mRNA.ResultsNNT-AS1 was apparently upregulated in PCa cells. NNT-AS1 deficiency abrogated PCa cell viability, proliferation and migration but promoted apoptosis. Besides, miR-496 could be sequestered by NNT-AS1 to elevate the expression of DNA damage inducible transcript 4 (DDIT4) in PCa. Rescue assays indicated that overexpressed DDIT4 or restrained miR-496 could reverse the influence of NNT-AS1 depletion on malignant processes in PCa cells.ConclusionNNT-AS1 contributes to the malignant phenotypes of PCa cells through targeting miR-496 to boost DDIT4 expression.

The assessment of a possible link between HPV‐mediated inflammation, apoptosis, and angiogenesis in Prostate cancer

BackgroundThe aim of this study was to determine the presence of HPV in patients with Prostate cancer (PCa) and its possible association with cancer progression. MethodsIn this case-control study, fresh prostate tissues and blood samples were collected from 90 individuals, including 58 cases samples with PCa and 32 non‐malignant prostate tissue samples as a control group. The expression level of viral genes (E2, E6, and E7) and cellular factors including tumor suppressor proteins (Rb and p53), anti-apoptotic mediators (Bcl-2 and survivin), and some mediators involved in inflammation and angiogenesis was evaluated. ResultsThe presence of the HPV genome was identified in 19 out of the 58 cases (32.7%) and five out of the 32 controls (15.6%). However, there was not any statistically significant relationship between the presence of the HPV genome and PCa (OR = 2.63, 95% C.I = 0.89–7.91, P-value = 0.078). Moreover, the HPV high-risk genotypes 16 and 18 were detected in 47.4% and 31.6% of HPV-infected PCa tissues, respectively. The expression level of the tumor suppressor proteins (Rb and p53) significantly decreased in the HPV-infected samples compared to the HPV negative specimens (P-value = 0.01, P-value = 0.01, respectively). However, the expression level of the anti-apoptotic mediators and those involved in angiogenesis and inflammation significantly increased in the HPV-infected PCa group compared to the HPV-negative PCa and control groups (P-value < 0.05, respectively). ConclusionOur study suggests that although it is not definitely known whether HPV causes PCa, this virus probably modulates PCa cell behavior by affecting inflammation, angiogenesis, and apoptosis mechanisms, which, in turn, promotes tumorigenesis.

3D porous chitosan-chondroitin sulfate scaffolds promote epithelial to mesenchymal transition in prostate cancer cells

Prostate cancer (PCa) is a common cancer in men that is curable prior to metastasis, when its prognosis worsens. Chondroitin sulfate (CS) is found in the extracellular matrix of normal prostate tissue and PCa, with greater content in metastatic PCa. Biomaterial scaffolds containing CS have yet to be evaluated for tumor microenvironment applications. Three-dimensional porous chitosan-CS (C-CS) scaffolds were developed and evaluated for PCa culture. Three C-CS scaffold compositions were prepared with 4 w/v% chitosan and 0.1, 0.5, and 1.0 w/v% CS and named 4-0.1, 4-0.5, and 4-1, respectively. The C-CS scaffolds had 90–95% porosity, average pore sizes between 143 and 166 μm, and no significant difference in scaffold stiffness. PC-3 and 22Rv1 PCa cells were cultured on the C-CS scaffolds to study the effect of CS on PCa growth and epithelial to mesenchymal transition (EMT). All C-CS scaffold compositions supported PCa growth and the 4-1 scaffolds had the greatest cell numbers for both PC-3 and 22Rv1. The C-CS scaffolds promoted upregulated EMT marker expression compared to 2D cultures with the greatest EMT marker expression in 4-1 scaffolds. Increasing CS concentration promoted upregulated vimentin expression in PC-3 cultures and N-cadherin and MMP-2 expression in 22Rv1 cultures. C-CS scaffolds promoted docetaxel drug resistance in PC-3 and 22Rv1 cultures and the 4-1 scaffold cultures had the greatest drug resistance. These results indicate that C-CS scaffolds are a promising in vitro platform for PCa.

CircHIPK3 Facilitates the G2/M Transition in Prostate Cancer Cells by Sponging miR-338-3p.

BackgroundCircular RNAs (circRNAs) play a crucial role in gene expression regulation. CircHIPK3 is a circRNA derived from Exon 2 of HIPK3 gene and its role in prostate cancer (PCa) is still unclear.MethodsCCK8 assays, flow cytometry and colony formation assays were performed to assess the effects of circHIPK3 in PCa cells. Bioinformatics analysis, RNA pull-down assay, RNA immunoprecipitation assay (RIP), and luciferase activity assay were performed to dissect the mechanism underlying circHIPK3-mediated G2/M transition in PCa cells.ResultsCircHIPK3 expression was upregulated in PCa cells and prostate cancer tissues. Overexpression of circHIPK3 or circHIPK3 silencing altered PCa viability, proliferation and apoptosis in vitro. CircHIPK3 could sponge miR-338-3p and inhibit its activity, resulting in increased expression of Cdc25B and Cdc2 in vitro.ConclusionCircHIPK3 promotes G2/M transition and induces PCa cell proliferation by sponging miR-338-3p and increasing the expression of Cdc25B and Cdc2. CircHIPK3 may play an oncogenic role in PCa.

Lipogenic signalling modulates prostate cancer cell adhesion and migration via modification of Rho GTPases

Fatty acid synthase (FASN) is commonly overexpressed in prostate cancer and associated with tumour progression. FASN is responsible for de novo synthesis of the fatty acid palmitate; the building block for protein palmitoylation. Recent work has suggested that alongside its established role in promoting cell proliferation FASN may also promote invasion. We now find depletion of FASN expression increases prostate cancer cell adhesiveness, impairs HGF-mediated cell migration and reduces 3D invasion. These changes in motility suggest that FASN can mediate actin cytoskeletal remodelling; a process known to be downstream of Rho family GTPases. Here, we demonstrate that modulation of FASN expression specifically impacts on the palmitoylation of the atypical GTPase RhoU. Impaired RhoU activity in FASN depleted cells leads to reduced adhesion turnover downstream of paxillin serine phosphorylation, which is rescued by addition of exogenous palmitate. Moreover, canonical Cdc42 expression is dependent on the palmitoylation status of RhoU. Thus we uncover a novel relationship between FASN, RhoU and Cdc42 that directly influences cell migration potential. These results provide compelling evidence that FASN activity directly promotes cell migration and supports FASN as a potential therapeutic target in metastatic prostate cancer.