Oxidative stress in prostate hyperplasia and carcinogenesis

Epigallocatechin-3-gallate reduces the proliferation of benign prostatic hyperplasia cells via regulation of focal adhesions

AIMS

Benign prostatic hyperplasia (BPH) is the most common urological disease that is characterized by the excessive growth of prostatic epithelial and stromal cells. Pharmacological therapy for BPH has limited use due to the many side effects so there is a need for new agents including natural compounds such as epigallocatechin-3-gallate (EGCG). This study was undertaken to assess the role of EGCG, suppressing the formation of BPH by reducing inflammation and oxidative stress, in cytoskeleton organization and ECM interactions via focal adhesions.

MAIN METHODS

We performed MTT assay to investigate cell viability of BPH-1 cells, wound healing assay to examine cell migration, immunofluorescence assay for F-actin organization and paxillin distribution and finally immunoblotting to investigate focal adhesion protein levels in the presence and absence of EGCG.

KEY FINDINGS

We found that EGCG inhibits cell proliferation at the concentration of 89.12μM, 21.2μM and 2.39μM for 24, 48 and 72h, respectively as well as inhibitory effects of EGCG on BPH-1 cell migration were observed in a wound healing assay. Furthermore, it was determined by immunofluorescence labeling that EGCG disrupts F-actin organization and reduces paxillin distribution. Additionally, EGCG decreases the activation of FAK (Focal Adhesion Kinase) and the levels of paxillin, RhoA (Ras homolog gene family, member A), Cdc42 (cell division cycle 42) and PAK1 (p21 protein-activated kinase 1) in a dose-dependent manner.

SIGNIFICANCE

For the first time, by this study, we found evidence that BPH-1 cell proliferation could be inhibited with EGCG through the disruption of cytoskeleton organization and ECM interactions. Consequently, EGCG might be useful in the prevention and treatment of diseases characterized by excessive cell proliferation such as BPH.

Epithelial-to-mesenchymal transition in FHC-silenced cells: the role of CXCR4/CXCL12 axis

Background

Ferritin plays a central role in the intracellular iron metabolism; the molecule is a nanocage of 24 subunits of the heavy and light types. The heavy subunit (FHC) is provided of a ferroxidase activity and thus performs the key transformation of iron in a non-toxic form. Recently, it has been shown that FHC is also involved in additional not iron-related critical pathways including, among the others, p53 regulation, modulation of oncomiRNAs expression and chemokine signalling. Epithelial to mesenchymal transition (EMT) is a cellular mechanism by which the cell acquires a fibroblast-like phenotype along with a decreased adhesion and augmented motility. In this work we have focused our attention on the role of the FHC on EMT induction in the human cell lines MCF-7 and H460 to elucidate the underlying molecular mechanisms.

Methods

Targeted silencing of the FHC was performed by lentiviral-driven shRNA strategy. Reconstitution of the FHC gene product was obtained by full length FHC cDNA transfection with Lipofectamine 2000. MTT and cell count assays were used to evaluate cell viability and proliferation; cell migration capability was assayed by the wound-healing assay and transwell strategy. Quantification of the CXCR4 surface expression was performed by flow cytometry.

Results

Experimental data indicated that FHC-silenced MCF-7 and H460 cells (MCF-7^shFHC, H460^shFHC) acquire a mesenchymal phenotype, accompanied by a significant enhancement of their migratory and proliferative capacity. This shift is coupled to an increase in ROS production and by an activation of the CXCR4/CXCL12 signalling pathway. We present experimental data indicating that the cytosolic increase in ROS levels is responsible for the enhanced proliferation of FHC-silenced cells, while the higher migration rate is attributable to a dysregulation of the CXCR4/CXCL12 axis.

Conclusions

Our findings indicate that induction of EMT, increased migration and survival depend, in MCF-7 and H460 cells, on the release of FHC control on two pathways, namely the iron/ROS metabolism and CXCR4/CXCL12 axis. Besides constituting a further confirmation of the multifunctional nature of FHC, this data also suggest that the analysis of FHC amount/function might be an important additional tool to predict tumor aggressiveness.

Lipid associated antioxidants: arylesterase and paraoxonase-1 in benign prostatic hyperplasia treatment-naïve patients

Background

Oxidative stress and antioxidants have been implicated in many diseases including prostate cancer and benign prostatic hyperplasia (BPH). Lipid peroxidation contributes to oxidative stress. However, new and emerging antioxidants such as paraoxonase 1 (PON1) and arylesterase (ARE) associated with lipoprotein peroxidation have not been examined in BPH patients. PON1 and ARE, a high-density lipoprotein (HDL) cholesterol-bound enzyme system of antioxidants, protect low-density lipoprotein (LDL) cholesterol and HDL from oxidation by hydrolysis. The study primarily determined paraoxonase (PON1) and ARE activities in BPH treatment-naïve patients.

Materials and methods

Sixty newly diagnosed patients (treatment-naïve) alongside 30 apparently healthy controls were recruited. Blood examinations included lipid profile (total cholesterol, triglycerides, LDL, HDL), glutathione peroxidase, PON1, ARE, and prostate specific antigen (PSA).

Prostate volume and International Prostate Symptoms Score (IPSS) were determined.

Results

PSA was significantly different between patient and control groups (P < 0.0001). Total cholesterol, triglycerides, and LDL were significantly higher in the patient group (P = 0.002, P < 0.001, P = 0.003, respectively). Glutathione peroxidase was very low in the patient group compared to the control group (5.65 ± 2.30 ng/mL and 17.43 ± 10.98 ng/mL, respectively). Although PON1 was higher in the patient group (50.22 ± 19.68/61.30 ± 29.55 ng/mL; P > 0.05), ARE was significantly lower in the patient group (61.31 ± 21.76/49.30 ± 19.82 ng/mL; P = 0.0098). No correlation was established between antioxidants and the lipid profile except for the LDL and PON1 patient group (r = 0.1486, P = 0.0374). Similarly, a weak correlation was also established between PSA and LDL in the patient group (r = –0.275, P = 0.033). PON1/HDL ratio was not significantly different. However, the ARE/HDL ratio was significantly lower in the patient group (P < 0.0001).

Conclusion

These results signify the presence of a higher lipoprotein peroxidation activity and lower lipid-associated antioxidant activity in the patient group. The ARE/HDL ratio is a better indicator of the HDL associated antioxidant than the PON1/HDL ratio or the individual antioxidants (PON1 and ARE) as reported by others.

Stereological comparison of intraprostatic injection of alcohol and bleomycin with finasteride gavages in rats

INTRODUCTION

Resection of the prostate is one of the standard surgical treatments for symptomatic Benign Prostatic Hyperplasia (BPH). To evaluate minimally invasive treatments, intraprostatic injections of ethanol and bleomycin were compared with oral finasteride administration in rats with BPH.

MATERIAL AND METHODS

The rats were divided into six groups. The control rats received no BPH/no treatment. BPH was induced using injections of testosterone (2 mg/day/rat for 4 weeks) in groups II-VI. After 4 weeks, Group II received no treatment while Group III received oral finasteride (10 mg/kg/day). Moreover, Groups IV-VI received a single injection of ethanol (95%), bleomycin (5 mg/kg) and normal saline 25 mm³ in each ventral lobe of the prostate respectively. Two weeks after the injections, the ventral lobes underwent a quantitative stereological study.

RESULTS

The volume of the ventral lobes, glandular epithelium, fibromuscular tissue and microvessles increased by 1.7, 3.1, 2.4 and 1.6 times in BPH rats respectively (P <0.01). Alcohol or bleomycin injection in PBH rats induced drastic recession of the increased volume of the ventral lobe, glandular epithelium and fibromuscular tissue (P <0.01). Regarding the BPH+alcohol group, the glandular epithelium volume restored to the normal values of the control rats (P <0.01). BPH+finasteride also incited an atrophic change in the volume of the whole prostate and glandular epithelium, but not the fibromuscular tissue and microvessels (P <0.01).

CONCLUSIONS

Injection of alcohol and bleomycin (approximately 10% of the volume of ventral prostatic) as well as consuming finasteride can induce a reduction of 1/3, 1/4 and 1/5 in the hypertrophied gland respectively.

Management of Benign Prostatic Hyperplasia: Could Dietary Polyphenols Be an Alternative to Existing Therapies?

The incidence of benign prostatic hyperplasia (BPH) is gradually on the increase. While conventional drugs such as the α1-adrenergic receptor antagonists and 5α-reductase inhibitors have been found to be useful in the treatment of BPH, the adverse side effects associated with their usage, have led to increased search for alternative means of managing this disease. Furthermore, although surgery has also been suggested to be a sure method, the cost and risks associated with it excludes it as a routine treatment. Dietary polyphenols have gained public interest in recent times due to their roles in the prevention of various diseases that implicate free radicals/reactive oxygen species. However, their roles in the management of BPH have not been explored. Hence, this review on their prospects in the management of BPH and their mechanisms of action. Literature search was carried out in several electronic data bases such as PubMed, Google Scholar, Medline, Agora, and Hinari from1970 to 2017 to identify the current status of knowledge on this concept. The findings from these data bases suggest that while dietary polyphenols may not replace the need for the existing therapies in the management of BPH, they hold promise in BPH management which could be explored by researchers working in this field.

Potassium Homeostasis, Oxidative Stress, and Human Disease

Potassium is the most abundant cation in the intracellular fluid and it plays a vital role in the maintenance of normal cell functions. Thus, potassium homeostasis across the cell membrane, is very critical because a tilt in this balance can result in different diseases that could be life threatening. Both Oxidative stress (OS) and potassium imbalance can cause life threatening health conditions. OS and abnormalities in potassium channel have been reported in neurodegenerative diseases. This review highlights the major factors involved in potassium homeostasis (dietary, hormonal, genetic, and physiologic influences), and discusses the major diseases and abnormalities associated with potassium imbalance including hypokalemia, hyperkalemia, hypertension, chronic kidney disease, and Gordon's syndrome, Bartter syndrome, and Gitelman syndrome.

Sorbus rufopilosa Extract Exhibits Antioxidant and Anticancer Activities by Inducing Cell Cycle Arrest and Apoptosis in Human Colon Adenocarcinoma HT29 Cells

Background

Sorbus rufopilosa, a tsema rowan, is a species of the small ornamental trees in the genus Sorbus and the family Rosaceae found in East Asia. The bioactivities of S. rufopilosa have not yet been fully determined. The objective of this study is to evaluate the antioxidant and anticancer effects of ethanol extract of S. rufopilosa (EESR) and to determine the molecular mechanism of its anticancer activity in human colon carcinoma HT29 cells.

Methods

To examine the antioxidant activity of EESR, 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity assay was performed. Inhibitory effect of EESR on cancer cell growth and proliferation was determined by water-soluble tetrazolium salt assay. To investigate the mechanism of EESR-mediated cytotoxicity, HT29 cells were treated with various concentrations of EESR and the induction of cell cycle arrest and apoptosis was analyzed by flow cytometry, 4,6-diamidino-2-phenylindole staining, and Western blot analysis.

Results

EESR showed significant antioxidant activity and inhibitory effect on HT29 cell growth in a dose-dependent manner. EESR induced cell cycle arrest at G2/M phase in a dose-dependent manner by modulating cyclin B, cyclin-dependent kinase 1 (CDK1), and CDK inhibitor p21 expression. EESR-induced apoptosis was associated with the upregulation of p53, a death receptor Fas, and a pro-apoptotic protein Bax and the activation of caspase 3, 8, and 9, resulting in the degradation of PARP.

Conclusions

EESR possessing antioxidant activity efficiently inhibits proliferation of HT29 cells by inducing both cell cycle arrest and apoptosis. EESR may be a possible candidate for the anticancer drug development.