Inhibition of PC3 human prostate cancer cell proliferation, invasion and migration by eicosapentaenoic acid and docosahexaenoic acid

Development and characterisation of suitably bioengineered microfibrillar matrix-based 3D prostate cancer model forin vitrodrug testing

Bioengineered 3D models that can mimic patient-specific pathologiesin vitroare valuable tools for developing and validating anticancer therapeutics. In this study, microfibrillar matrices with unique structural and functional properties were fabricated as 3D spherical and disc-shaped scaffolds with highly interconnected pores and the potential of the newly developed scaffolds for developing prostate cancer model has been investigated. The newly developed scaffolds showed improved cell retention upon seeding with cancer cells compared to conventional electrospun scaffolds. They facilitated rapid growth and deposition of cancer-specific extracellular matrix through-the-thickness of the scaffold. Compared to the prostate cancer cells grown in 2D culture, the newly developed prostate cancer model showed increased resistance to the chemodrug Docetaxel regardless of the drug concentration or the treatment frequency. A significant reduction in the cell number was observed within one week after the drug treatment in the 2D culture for both PC3 and patient-derived cells. Interestingly, almost 20%-30% of the cancer cells in the newly developed 3D model survived the drug treatment, and the patient-derived cells were more resistant than the tested cell line PC3. The results from this study indicate the potential of the newly developed prostate cancer model forin vitrodrug testing.

DHA- and EPA-Enriched Phosphatidylcholine Suppress Human Lung Carcinoma 95D Cells Metastasis via Activating the Peroxisome Proliferator-Activated Receptor γ

The antineoplastic effects of docosahexaenoic acid-containing phosphatidylcholine (DHA-PC) and eicosapentaenoic acid-containing phosphatidylcholine (EPA-PC) were explored, and their underlying mechanisms in the human lung carcinoma 95D cells (95D cells) were investigated. After treatment of 95D cells with DHA-PC or EPA-PC, cell biological behaviors such as growth, adhesion, migration, and invasion were studied. Immunofluorescence and western blotting were carried out to assess underlying molecular mechanisms. Results showed that 95D cells proliferation and adherence in the DHA-PC or EPA-PC group were drastically inhibited than the control group. DHA-PC and EPA-PC suppressed the migration and invasion of 95D cells by disrupting intracellular F-actin, which drives cell movement. The protein expression of PPARγ was induced versus the control group. Furthermore, critical factors related to invasion, including matrix metallopeptidase 9 (MMP9), heparanase (Hpa), and vascular endothelial growth factor (VEGF), were drastically downregulated through the PPARγ/NF-κB signaling pathway. C-X-C chemokine receptor type 4 (CXCR4) and cofilin were significantly suppressed via DHA-PC and EPA-PC through the PPARγ/phosphatase and tensin homolog (PTEN)/serine-threonine protein kinase (AKT) signaling pathway. DHA-PC and EPA-PC reversed the PPARγ antagonist GW9662-induced reduction of 95D cells in migration and invasion capacity, suggesting that PPARγ was directly involved in the anti-metastasis efficacy of DHA-PC and EPA-PC. In conclusion, DHA-PC and EPA-PC have great potential for cancer therapy, and the antineoplastic effects involve the activation of PPARγ. EPA-PC showed more pronounced antineoplastic effects than DHA-PC, possibly due to the more robust activation of PPARγ by EPA-PC.

Differential Transcriptomic Profiles Following Stimulation with Lipopolysaccharide in Intestinal Organoids from Dogs with Inflammatory Bowel Disease and Intestinal Mast Cell Tumor

Lipopolysaccharide (LPS) is associated with chronic intestinal inflammation and promotes intestinal cancer progression in the gut. While the interplay between LPS and intestinal immune cells has been well-characterized, little is known about LPS and the intestinal epithelium interactions. In this study, we explored the differential effects of LPS on proliferation and the transcriptome in 3D enteroids/colonoids obtained from dogs with naturally occurring gastrointestinal (GI) diseases including inflammatory bowel disease (IBD) and intestinal mast cell tumor. The study objective was to analyze the LPS-induced modulation of signaling pathways involving the intestinal epithelia and contributing to colorectal cancer development in the context of an inflammatory (IBD) or a tumor microenvironment. While LPS incubation resulted in a pro-cancer gene expression pattern and stimulated proliferation of IBD enteroids and colonoids, downregulation of several cancer-associated genes such as Gpatch4, SLC7A1, ATP13A2, and TEX45 was also observed in tumor enteroids. Genes participating in porphyrin metabolism (CP), nucleocytoplasmic transport (EEF1A1), arachidonic acid, and glutathione metabolism (GPX1) exhibited a similar pattern of altered expression between IBD enteroids and IBD colonoids following LPS stimulation. In contrast, genes involved in anion transport, transcription and translation, apoptotic processes, and regulation of adaptive immune responses showed the opposite expression patterns between IBD enteroids and colonoids following LPS treatment. In brief, the crosstalk between LPS/TLR4 signal transduction pathway and several metabolic pathways such as primary bile acid biosynthesis and secretion, peroxisome, renin-angiotensin system, glutathione metabolism, and arachidonic acid pathways may be important in driving chronic intestinal inflammation and intestinal carcinogenesis.

The Effect of Fatty Acids on Ciprofloxacin Cytotoxic Activity in Prostate Cancer Cell Lines. Does Lipid Component Enhance Anticancer Ciprofloxacin Potential?

Simple Summary

Most prostate cancers are initially hormone-dependent but later gain a hormone-independent phenotype associated with changes in lipid metabolism, including enhanced absorption of extracellular fatty acids. The aim of our study was to assess the effect of ciprofloxacin conjugates with fatty acids on different type of prostate cancer (LNCaP and DU-145) and normal (RWPE-1) cells, as well as their influence on cell lipid metabolism by proteomic analysis. All tested conjugates exhibited cytotoxic potential, the most powerful for oleic, elaidic and docosahexaenoic acids. The hormone-independent DU145 line was more sensitive to derivatives than the hormone-dependent LNCaP line. These results are consistent with previously observed pronounced cytotoxic effect of conjugates on a hormone-insensitive PC3 line. Tested derivatives decreased intensity of proteins involved in prostate cancer lipid metabolism. Our findings confirm the involvement of lipid metabolism in prostate carcinogenesis indicating a target for fatty acids as drug carriers.

Abstract

Purpose: To assess cytotoxic effect of ciprofloxacin conjugates with fatty acids on prostate cancer cells (LNCaP and DU-145) with different hormone sensitivity, based on previous promising results from the PC3 cells. Methods: Cytotoxicity were estimated using MTT and LDH tests, whereas its mechanisms were estimated by apoptosis and IL-6 assays. The intensity of proteins involved in lipid metabolism was determined using ML-CS assay. Results: The hormone insensitive DU-145 cells were more vulnerable than the hormone sensitive LNCaP cells. The IC50 values for oleic (4), elaidic (5) and docosahexaenoic acid (8) conjugates were 20.2 µM, 17.8 µM and 16.5 µM, respectively, in DU-145 cells, whereas in LNCaP cells IC50 exceeded 20 µM. The strong conjugate cytotoxicity was confirmed in the LDH test, the highest (70.8%) for compound (5) and 64.2% for compound (8) in DU-145 cells. This effect was weaker for LNCaP cells (around 60%). The cytotoxic effect of unconjugated ciprofloxacin and fatty acids was weaker. The early apoptosis was predominant in LNCaP while in DU-145 cells both early and late apoptosis was induced. The tested conjugates decreased IL-6 release in both cancer cell lines by almost 50%. Proteomic analysis indicated influence of the ciprofloxacin conjugates on lipid metabolic proteins in prostatic cancer. Conclusion: Our findings suggested the cytotoxic potential of ciprofloxacin conjugates with reduction in proteins involved in prostate cancer progress.

Docosahexaenoic acid (DHA), an omega-3 fatty acid, inhibits tumor growth and metastatic potential of ovarian cancer

Omega-3 polyunsaturated fatty acids (PUFAs), such as those found in fish oil, are thought to have anti-tumorigenic effects and may help to treat and prevent cancer, including ovarian cancer. Thus, we aimed to evaluate the potential of docosahexaenoic acid (DHA), an omega-3 PUFA, as a therapeutic agent in ovarian cancer cell lines and a transgenic mouse model of ovarian cancer. DHA significantly inhibited cellular proliferation, induced cell cycle arrest and caused apoptosis in Hey and IGROV-1 cells. Pre-treatment with the anti-oxidant, N-acetylcysteine (NAC), reversed DHA-induced caspase 3 activity and prevented DHA-reduced cell proliferation. DHA also induced cellular reactive oxygen species (ROS) and inhibited adhesion and invasion in IGROV-1 and Hey cells. Furthermore, treatment with DHA demonstrated anti-tumorigenic and anti-invasive activity in a K18-gT121 +/-; p53fl/fl; Brca1fl/fl mouse model of ovarian cancer including downregulation of Ki67 and VEGF expression. The data provide a preclinical rationale for applying DHA for dietary intervention and therapeutic adjunct in patients with ovarian cancer.

Microenvironmental Hypoxia Induces Dynamic Changes in Lung Cancer Synthesis and Secretion of Extracellular Vesicles

Extracellular vesicles (EVs) mediate critical intercellular communication within healthy tissues, but are also exploited by tumour cells to promote angiogenesis, metastasis, and host immunosuppression under hypoxic stress. We hypothesize that hypoxic tumours synthesize hypoxia-sensitive proteins for packing into EVs to modulate their microenvironment for cancer progression. In the current report, we employed a heavy isotope pulse/trace quantitative proteomic approach to study hypoxia sensitive proteins in tumour-derived EVs protein. The results revealed that hypoxia stimulated cells to synthesize EVs proteins involved in enhancing tumour cell proliferation (NRSN2, WISP2, SPRX1, LCK), metastasis (GOLM1, STC1, MGAT5B), stemness (STC1, TMEM59), angiogenesis (ANGPTL4), and suppressing host immunity (CD70). In addition, functional clustering analyses revealed that tumour hypoxia was strongly associated with rapid synthesis and EV loading of lysosome-related hydrolases and membrane-trafficking proteins to enhance EVs secretion. Moreover, lung cancer-derived EVs were also enriched in signalling molecules capable of inducing epithelial-mesenchymal transition in recipient cancer cells to promote their migration and invasion. Together, these data indicate that lung-cancer-derived EVs can act as paracrine/autocrine mediators of tumorigenesis and metastasis in hypoxic microenvironments. Tumour EVs may, therefore, offer novel opportunities for useful biomarkers discovery and therapeutic targeting of different cancer types and at different stages according to microenvironmental conditions.

The Crosstalk between Prostate Cancer and Microbiota Inflammation: Nutraceutical Products Are Useful to Balance This Interplay?

The human microbiota shows pivotal roles in urologic health and disease. Emerging studies indicate that gut and urinary microbiomes can impact several urological diseases, both benignant and malignant, acting particularly on prostate inflammation and prostate cancer. Indeed, the microbiota exerts its influence on prostate cancer initiation and/or progression mechanisms through the regulation of chronic inflammation, apoptotic processes, cytokines, and hormonal production in response to different pathogenic noxae. Additionally, therapies' and drugs' responses are influenced in their efficacy and tolerability by microbiota composition. Due to this complex potential interconnection between prostate cancer and microbiota, exploration and understanding of the involved relationships is pivotal to evaluate a potential therapeutic application in clinical practice. Several natural compounds, moreover, seem to have relevant effects, directly or mediated by microbiota, on urologic health, posing the human microbiota at the crossroad between prostatic inflammation and prostate cancer development. Here, we aim to analyze the most recent evidence regarding the possible crosstalk between prostate, microbiome, and inflammation.

Docosahexaenoic acid inhibits vascular smooth muscle cell migration and proliferation by decreasing microRNA‑155 expression levels

Vascular smooth muscle cell (VSMC) hyperplasia is a common cause of carotid restenosis. In the present study, the potential protective effects of docosahexaenoic acid (DHA) in carotid restenosis and the underlying mechanism of its effects were examined. VSMCs were treated with DHA, a polyunsaturated ω-3 fatty acid. Cell migration and proliferation were assessed using wound healing and Cell Counting Kit-8 assays and by measuring Ki-67 protein levels. Additionally, the expression levels of microRNA-155 were determined by reverse transcription-quantitative PCR (RT-qPCR). The involvement of microRNA-155 in the regulation of migration and proliferation was evaluated by transfecting VSMCs with microRNA mimics and inhibitors. Moreover, the reversal of migration and proliferation after transfection of VSMCs with the microRNA mimics and subsequent treatment with DHA was investigated. A target gene of microRNA-155 was identified using RT-qPCR and luciferase assays. The migration and proliferation of VSMCs, as well as the expression of microRNA-155 was inhibited by DHA stimulation. MicroRNA-155 regulated the migration and proliferation of VSMCs. Finally, proliferation and migration of VSMCs were reduced following DHA treatment, which was mediated by an increase in the expression levels of microRNA-155. Suppressor of cytokine signalling 1 (Socs1) was the target gene of microRNA-155. In conclusion, DHA inhibited VSMC migration and proliferation by reducing microRNA-155 expression. This effect may be caused by the microRNA-155 target gene Socs1.

Roles of endogenous ether lipids and associated PUFAs in the regulation of ion channels and their relevance for disease

Ether lipids (ELs) are lipids characterized by the presence of either an ether linkage (alkyl lipids) or a vinyl ether linkage [i.e., plasmalogens (Pls)] at the sn1 position of the glycerol backbone, and they are enriched in PUFAs at the sn2 position. In this review, we highlight that ELs have various biological functions, act as a reservoir for second messengers (such as PUFAs) and have roles in many diseases. Some of the biological effects of ELs may be associated with their ability to regulate ion channels that control excitation-contraction/secretion/mobility coupling and therefore cell physiology. These channels are embedded in lipid membranes, and lipids can regulate their activities directly or indirectly as second messengers or by incorporating into membranes. Interestingly, ELs and EL-derived PUFAs have been reported to play a key role in several pathologies, including neurological disorders, cardiovascular diseases, and cancers. Investigations leading to a better understanding of their mechanisms of action in pathologies have opened a new field in cancer research. In summary, newly identified lipid regulators of ion channels, such as ELs and PUFAs, may represent valuable targets to improve disease diagnosis and advance the development of new therapeutic strategies for managing a range of diseases and conditions.

Physiological Role of Glutamate Dehydrogenase in Cancer Cells

NH 4 + increased growth rates and final densities of several human metastatic cancer cells. To assess whether glutamate dehydrogenase (GDH) in cancer cells may catalyze the reverse reaction of NH 4 + fixation, its covalent regulation and kinetic parameters were determined under near-physiological conditions. Increased total protein and phosphorylation were attained in NH 4 + -supplemented metastatic cells, but total cell GDH activity was unchanged. Higher V _max values for the GDH reverse reaction vs. forward reaction in both isolated hepatoma (HepM) and liver mitochondria [rat liver mitochondria (RLM)] favored an NH 4 + -fixing role. GDH sigmoidal kinetics with NH 4 + , ADP, and leucine fitted to Hill equation showed n _H values of 2 to 3. However, the K _0.5 values for NH 4 + were over 20 mM, questioning the physiological relevance of the GDH reverse reaction, because intracellular NH 4 + in tumors is 1 to 5 mM. In contrast, data fitting to the Monod-Wyman-Changeux (MWC) model revealed lower K _m values for NH 4 + , of 6 to 12 mM. In silico analysis made with MWC equation, and using physiological concentrations of substrates and modulators, predicted GDH N-fixing activity in cancer cells. Therefore, together with its thermodynamic feasibility, GDH may reach rates for its reverse, NH 4 + -fixing reaction that are compatible with an anabolic role for supporting growth of cancer cells.

Influence of Diet and Nutrition on Prostate Cancer

The incidence of prostate cancer (PCa) displays widespread regional differences, probably owing to differences in dietary habits. Nutrients, including fat, protein, carbohydrates, vitamins (vitamin A, D, and E), and polyphenols, potentially affect PCa pathogenesis and progression, as previously reported using animal models; however, clinical studies have reported controversial results for almost all nutrients. The effects of these nutrients may be manifested through various mechanisms including inflammation, antioxidant effects, and the action of sex hormones. Dietary patterns including the Western and Prudent patterns also influence the risk of PCa. Recent studies reported that the gut microbiota contribute to tumorigenesis in some organs. Diet composition and lifestyle have a direct and profound effect on the gut bacteria. Human studies reported an increase in the abundance of specific gut bacteria in PCa patients. Although there are few studies concerning their relationship, diet and nutrition could influence PCa, and this could be mediated by gut microbiota. An intervention of dietary patterns could contribute to the prevention of PCa. An intervention targeting dietary patterns may thus help prevent PCa.

Contribution of Pyk2 pathway and reactive oxygen species (ROS) to the anti-cancer effects of eicosapentaenoic acid (EPA) in PC3 prostate cancer cells

Background

n-3 polyunsaturated fatty acids (n-3 PUFAs), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are thought to exert protective effects in cardiovascular diseases. In addition, n-3 PUFAs have demonstrated anti-cancer effects in vitro and in vivo.

Objective

We investigated the anti-cancer effects and mechanism of action of EPA on PC3 prostate cancer cells in vitro.

Methods

PC3 cells were treated with various concentrations of EPA, and cell survival and the abilities of migration and invasion were evaluated. The time course of the growth inhibitory effect of EPA on PC3 cells was also assessed. The mechanism underlying the anti-cancer effects of EPA was investigated by human phosphokinase and human apoptosis antibody arrays, and confirmed by western blot analysis. We also examined the contribution of reactive oxygen species (ROS) to the effects of EPA using the ROS inhibitor N-acetyl cysteine.

Results

EPA decreased the survival of PC3 cells in a dose-dependent manner within 3 h of application, with an effective concentration of 500 μmol/L. EPA inhibited proline-rich tyrosine kinase (Pyk)2 and extracellular signal-regulated kinase 1/2 phosphorylation as determined by western blotting and the antibody arrays. The growth of PC3 cells was inhibited by EPA, which was dependent on ROS induction, while EPA inhibited Pyk2 phosphorylation independent of ROS production.

Conclusions

Inhibition of Pyk2 phosphorylation and ROS production contribute to the anticancer effects of EPA on PC3 cells.

SQSTM1/p62 is involved in docosahexaenoic acid-induced cellular autophagy in glioblastoma cell lines

Docosahexaenoic acid (DHA) is the most abundant n-3 polyunsaturated fatty acid in the human brain and works as an anticancer agent to induce cell cycle arrest and apoptosis in glioblastoma multiforme (GBM) cell lines. However, little is known about the connection between DHA and autophagy in GBM cells. We found that high-dose DHA caused cellular autophagy in cultured U251 and U118 GBM cell lines, but there was no effect with a low dose. Moreover, after treatment with a high dose of DHA at 12, 24, and 48 h, the protein expression of SQSTM1/p62 decreased in DHA-treated U251 cells at 12 and 24 h, but increased at 48 h, while in DHA-treated U118 cells, the protein expression increased at all time points. Interestingly, the level of SQSTM1/p62 mRNA was elevated in both DHA-treated U251 and U118 cells at all time points, indicating that DHA activated SQSTM1/p62 transcription in both cell lines. Furthermore, downregulation of SQSTM1/p62 by siRNA attenuated DHA-induced cellular autophagy in both cell lines. This report confirms that high-dose DHA induces cellular autophagy in GBM cells, and demonstrates that SQSTM1/p62 acts as a regulator and participates in DHA-induced autophagy.

Anti-Apoptotic Effects of Docosahexaenoic Acid in IL-1β-Induced Human Chondrosarcoma Cell Death through Involvement of the MAPK Signaling Pathway

Osteoarthritis (OA) is a degenerative disease characterized by progressive articular cartilage destruction and joint marginal osteophyte formation with different degrees of synovitis. Docosahexaenoic acid (DHA) is an unsaturated fatty acid with anti-inflammatory, antioxidant, and antiapoptotic functions. In this study, the human chondrosarcoma cell line SW1353 was cultured in vitro, and an OA cell model was constructed with inflammatory factor IL-1β stimulation. After cells were treated with DHA, cell apoptosis was measured. Western blot assay was used to detect protein expression of apoptosis-related factors (Bax, Bcl-2, and cleaved caspase-3) and mitogen-activated protein kinase (MAPK) signaling pathway family members, including extracellular signal-regulated kinase (ERK), c-JUN N-terminal kinase (JNK), and p38 MAPK. Our results show that IL-1β promotes the apoptosis of SW1353 cells, increases the expression of Bax and cleaved caspase-3, and activates the MAPK signaling pathway. In contrast, DHA inhibits the expression of IL-1β, inhibits IL-1β-induced cell apoptosis, and has a certain inhibitory effect on the activation of the MAPK signaling pathway. When the MAPK signaling pathway is inhibited by its inhibitors, the effects of DHA on SW1353 cells are weakened. Thus, DHA enhances the apoptosis of SW1353 cells through the MAPK signaling pathway.

Melatonin and Docosahexaenoic Acid Decrease Proliferation of PNT1A Prostate Benign Cells via Modulation of Mitochondrial Bioenergetics and ROS Production

Prostate cancer development has been associated with changes in mitochondrial activity and reactive oxygen species (ROS) production. Melatonin (MLT) and docosahexaenoic acid (DHA) have properties to modulate both, but their protective role, mainly at early stages of prostate cancer, remains unclear. In this study, the effects of MLT and DHA, combined or not, on PNT1A cells with regard to mitochondria bioenergetics, ROS production, and proliferation-related pathways were examined. Based on dose response and lipid accumulation assays, DHA at 100 μM and MLT at 1 μM for 48 h were chosen. DHA doubled and MLT reduced (40%) superoxide anion production, but coincubation (DM) did not normalize to control. Hydrogen peroxide production decreased after MLT incubation only (p < 0.01). These alterations affected the area and perimeter of mitochondria, since DHA increased whereas MLT decreased, but such hormone has no effect on coincubation. DHA isolated did not change the oxidative phosphorylation rate (OXPHOS), but decreased (p < 0.001) the mitochondrial bioenergetic reserve capacity (MBRC) which is closely related to cell responsiveness to stress conditions. MLT, regardless of DHA, ameliorated OXPHOS and recovered MBRC after coincubation. All incubations decreased AKT phosphorylation; however, only MLT alone inhibited p-mTOR. MLT increased p-ERK1/2 and, when combined to DHA, increased GSTP1 expression (p < 0.01). DHA did not change the testosterone levels in the medium, whereas MLT alone or coincubated decreased by about 20%; however, any incubation affected AR expression. Moreover, incubation with luzindole revealed that MLT effects were MTR1/2-independent. In conclusion, DHA increased ROS production and impaired mitochondrial function which was probably related to AKT inactivation; MLT improved OXPHOS and decreased ROS which was related to AKT/mTOR dephosphorylation, and when coincubated, the antiproliferative action was related to mitochondrial bioenergetic modulation associated to AKT and ERK1/2 regulation. Together, these findings point to the potential application of DHA and MLT towards the prevention of proliferative prostate diseases.