Stanniocalcin1 knockdown induces ferroptosis and suppresses glycolysis in prostate cancer via the Nrf2 pathway.

Stanniocalcin1 (STC1) is a secreted glycoprotein, which is highly expressed in prostate cancer cells. However, the biological functions of STC1 in modulating ferroptosis and glycolysis in prostate cancer are still not clear. The viability of PC-3 and DU145 cells was detected by CCK-8 assay. The relative Fe2+ level was detected by an Iron Assay Kit. MDA level was detected by Lipid Peroxidation MDA Assay Kit. Glucose uptake and lactate product were measured by Glycolysis Assay Kit and Lactate Assay Kit. In this study, STC1 was highly expressed in prostate cancer tissue specimens and cells. STC1 knockdown suppressed prostate cancer cell proliferation, and upregulated Fe2+ level, reduced glutathione (GSH) level, downregulated GPX4 and SLC7A11 protein expressions in PC-3 cells and DU145 cells. Besides, STC1 knockdown decreased glucose uptake, lactate product, and ATP level, as well as downregulated glycolysis-related protein HK2 and LDHA protein expressions. In addition, STC1 knockdown repressed the Nrf2/HO-1/NQO1 pathway. Nrf2 pathway activator, Oltipraz, upregulated Nrf2, total NQO1, and HO-1 expressions in PC-3 cells and DU145 cells. Moreover, Nrf2 pathway activator Oltipraz reversed the effect of STC1 knockdown on Fe2+ level and GPX4, SLC7A11, HK2, LDHA protein expressions in PC-3 cells and DU145 cells. Finally, STC1 knockdown restrained the tumor volume, tumor weight, and glycolysis in prostate cancer in vivo. Thus, STC1/Nrf2 pathway is a vital pathway to induce ferroptosis and suppress glycolysis in prostate cancer.

miR-155 facilitates calcium oxalate crystal-induced HK-2 cell injury via targeting PI3K associated autophagy.

Nephrolithiasis is one of the most common and highly recurrent diseases worldwide. Accumulating evidence revealed the elevated miR-155 levels both in serum and urine of nephrolithiasis patients. The aim of our research was to explore the role of miR-155 in CaOx-induced apoptosis in HK-2 cells. The expression levels of miR-155 in serum and renal tissues were quantified in 20 patients with nephrolithiasis using qRT-PCR assay. ELISA was performed to determine urinary levels of interleukin (IL)-1ß, IL-6 and tumor necrosis factor-alpha (TNF-α). Renal tubular cell model of CaOx nephrolithiasis was established to investigate the role and molelular mechanism of miR-155. Cell viability and apoptosis were assessed by MTT and flow cytometry, respectively. Immunofluoresent staining of LC3 autophagosome and western blotting were performed to evaluate the autophagic activity. Luciferase reporter assay was employed to verify the interaction between miR-155 and PI3KCA/Rheb. PI3K/Akt/mTOR signaling was further examined by western blotting. Serum and renal levels of miR-155 and inflammatory factors were significantly elevated in nephrolithiasis patients than in controls. CaOx treatment caused up-regulation of miR-155 and induced autophagy in renal tubular epithelial cells, while silencing miR-155 or inhibition of autophagy by 3-metheladenine (3-MA) ameliorated CaOx crystal-induced cell injury. PI3KCA and Rheb was identified as downstream targets of miR-155. Moreover, miR-155 activates autophagy and promotes cell injury through repressing PI3K/Akt/mTOR signaling pathway. Taken together, these findings demonstrated that miR-155 facilitates CaOx crystal-induced renal tubular epithelial cell injury via PI3K/Akt/mTOR-mediated autophagy, providing therapeutic targets for ameliorating cellular damage by CaOx crystals.

Inhibition of miR-155 Ameliorates Acute Kidney Injury by Apoptosis Involving the Regulation on TCF4/Wnt/ß-Catenin Pathway.

BACKGROUND: Acute kidney injury (AKI) is a complex clinical disorder with sudden decay in renal function. Ischemia-reperfusion injury (IRI) has been regarded as the main etiology for the occurrence of AKI. MicroRNAs have been consistently shown to be involved AKI. OBJECTIVES: We aimed to investigate the role of miR-155 in AKI and its underlying mechanism. METHODS: Ischemia-reperfusion (I/R)-induced AKI rat model and hypoxia-reoxygeneration (H/R)-induced NRK-52E cell model were established. The concentrations of serum creatinine and blood urea nitrogen were measured to evaluate renal function. Hematoxylin and eosin staining and TUNEL assay were performed to assess the severity of kidney injury. Additionally, quantitative real-time-PCR and western blot analysis were subjected to determine the expression of miR-155, TCF4, and apoptosis-related proteins, respectively. Moreover, cell proliferation and apoptosis were evaluated by Cell Counting Kit-8, bromodeoxyuridine, and flow cytometry analyses, respectively. Luciferase reporter assay was used to validate the direct targeting of TCF4 with miR-155. The protein levels of TCF4 and its downstream proteins in cells were measured by western blot. RESULTS: The expression level of miR-155 was upregulated in both I/R-induced AKI rat model and H/R-treated NRK-52E cells. Moreover, overexpression of miR-155 promoted H/R-induced NRK-52E cells apoptosis and suppressed cell proliferation, while inhibition of miR-155 expression exerted opposite effects. Additionally, TCF4 was identified as a target of miR-155, of which expression was downregulated both in vivo and in vitro. Furthermore, the activity of Wnt/ß-catenin signaling pathway was promoted following overexpression of TCF4 in NRK-52E cells, and this effect was attenuated by the increasing miR-155 expression. CONCLUSION: We demonstrated that miR-155 exacerbated AKI involving the targeting and regulation of TCF4/Wnt/ß-catenin signaling pathway, indicating a novel regulatory network and elucidating a potential target for IRI-induced AKI treatment.

Consolidation therapy is necessary following successful biofeedback treatment for pubertal chronic prostatitis patients: a 3-year follow-up study.

OBJECTIVE: To assess long-term effects of biofeedback training on pubertal chronic prostatitis (CP). METHODS: Pubertal CP patients received 12-week intensive biofeedback training and were divided into two groups: group 1 received further monthly training ≥ 24 (26-36) months; group 2 received further monthly training <24 (13-23) months. National Institutes of Health-CP Symptom Index (NIH-CPSI) scores, maximum urinary flow rate (Qmax) and postvoid residual urine volume (PVR) were recorded monthly. RESULTS: Total NIH-CPSI scores decreased significantly in group 1 (n = 10; mean age ± SD 16.5 ± 1.1 years) together with all subdomain scores (pain, urination, life impact). Total NIH-CPSI scores increased significantly in group 2 (n = 12; mean age ± SD 16.3 ± 1.2 years) at 30 and 36 months, and were significantly different from group 1 at these time points. Urination and life-impact scores increased significantly and Qmax decreased significantly in group 2 at 30 and 36 months. PVR was unchanged in either group. CONCLUSIONS: Twelve-week intensive biofeedback training requires lengthy consolidation sessions to achieve long-term success. Further investigation should assess longer intervals between consolidation sessions, for improving patient compliance and outcome.

Neuroendocrine differentiation is involved in chemoresistance induced by EGF in prostate cancer cells.

AIMS: Neuroendocrine (NE) cells were thought to be post-mitotic and non-proliferative. But it was recently reported that NE cells express, and induce surrounding cells to express potent antiapoptotic proteins. We hypothesize that neuroendocrine differentiation (NED), a common phenomenon in prostate cancer, is related to chemoresistance in prostate cancer. MAIN METHODS: Androgen-independent human prostate cancer DU145 and PC-3 cells were exposed to epidermal growth factor (EGF). MTT assays evaluated changes in chemoresistance after EGF treatment, and flow cytometry examined EGF-induced cell cycle changes in DU145 cells. Western blotting, real-time RT-PCR and transmission electron microscopy were utilized to confirm NED. KEY FINDINGS: After stimulation with EGF, DU145 and PC-3 cells exhibited stronger resistance to cisplatin. Flow cytometry showed that EGF stimulation substantially decreased the proportion of DU145 cells in G(1) phase. EGF treatment increased the expression of neuron-specific enolase, a marker of NED induction. SIGNIFICANCE: NED in prostate cancer is involved in the chemoresistance induced by EGF. EGF and/or the EGF receptor may be potential targets for medical intervention in chemo-resistant prostate cancer.