The Regulatory Role of Nuclear Respiratory Factor 1 in Bladder Cancer Cells.

BACKGROUND/AIM: Nuclear respiratory factor 1 (NRF1) is a key mediator of genes involved in mitochondrial biogenesis and the respiratory chain; however, its role in bladder cancer remains unknown. Transitional cell carcinoma, also known as urothelial cell carcinoma, is the most common type of bladder cancer resistant to chemotherapy. An established high-grade and invasive transitional cell carcinoma line from patients with urinary bladder cancer, known as T24, has been extensively used in cancer research. In this study, we aimed to investigate the mechanisms through which NRF1 regulates proliferation and cell migration of bladder cancer cells using the T24 cell line. MATERIALS AND METHODS: Cells were transfected with plasmid cloning DNA for NRF1 to evaluate the effect of NRF1 overexpression on bladder cancer cells. Western blot was used to examine epithelial and mesenchymal markers (E-cadherin and α-smooth muscle actin), transcriptional regulators for epithelial-mesenchymal transition (snail family transcriptional repressors), components of transforming growth factor-ß1/SMADs signaling, high-mobility group box 1 (HMGB1), and receptor for advanced glycation end-products (RAGE). The in situ expression of E-cadherin, α-smooth muscle actin and SMAD7 was determined using immunofluorescence staining. Cell migration capacity was assessed by wound-healing assay. RESULTS: Transfection with NRF1 expression vector repressed the migration capacity of bladder cancer cells, diminishing HMGB1/RAGE expression and reducing transforming growth factor ß-associated epithelial-mesenchymal transition in T24 cells. CONCLUSION: Therapeutic avenues that increase NRF1 expression may serve as an adjunct to conventional treatments for bladder cancer.

Nuclear Respiratory Factor 1 Overexpression Inhibits Proliferation and Migration of PC3 Prostate Cancer Cells.

BACKGROUND/AIM: The role of nuclear respiratory factor 1 (NRF1) on the prostate cancer progression is controversial. We aimed to investigate the effect of NRF1 overexpression on the metastasis potential of PC3 prostate cancer cells and the associated molecular mechanisms. MATERIALS AND METHODS: Cell survival, migration capacity, mitochondrial biogenesis, the expression of TGF-ß signaling and EMT markers were examined after overexpression and silencing of NRF1 in PC3 cells. RESULTS: We found that NRF1-overexpressing cells exhibited a decreased cell viability and proliferation ability as well as a reduced migration capacity compared to control cells. Moreover, ectopic expression of NRF1 increased the mitochondrial biogenesis and inhibited the EMT characteristics, including a decrease in the mesenchymal marker, α-SMA and an increase in the epithelial cell marker, E-cadherin. We also demonstrated that overexpression of NRF1 suppressed the expression of TGF-ß signaling in PC3 cells. As expected, silencing of NRF1 reversed the abovementioned effects. CONCLUSION: This study demonstrated that upregulation of NRF1 holds the potential to inhibit the metastasis of prostate cancer, possibly through an elevation of mitochondrial biogenesis and the subsequent repression of TGF-ß-associated EMT. Therapeutic avenues that increase NRF1 expression may serve as an adjunct to conventional treatments of prostate cancer.

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

INTRODUCTION: 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. MATERIALS AND METHODS: 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-ß)/Smad signaling, and high-mobility group box (HMGB)/receptor for advanced glycation end-products (RAGE) axis. RESULTS: 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-ß pathway was suppressed, which was demonstrated by the diminished expression of type I and II TGF-ß receptors and phosphorylated Smad2/3 along with the upregulated Smad7. Our data suggested that this downregulation of TGF-ß signaling was mediated by repression of HMGB 1 (HMGB1)/RAGE axis. CONCLUSION: Verbascoside mitigated the cell proliferation and aggressiveness of prostate cancer via downregulation of TGF-ß-associated EMT progression through HMGB1/RAGE suppression. Collectively, our findings revealed that verbascoside may be a beneficial dietary supplement for prostate cancer patients.