Xiaolu Duan

Prevalence of kidney stones in China: an ultrasonography based cross-sectional study

To investigate the prevalence and associated factors of kidney stones among adults in China.

β-Arrestin2 Contributes to Cell Viability and Proliferation via the Down-Regulation of FOXO1 in Castration-Resistant Prostate Cancer.

β‐Arrestin2 has been identified to act as a corepressor of androgen receptor (AR) signaling by binding to AR and serving as a scaffold to affect the activity and expression of AR in androgen‐dependent prostate cancer cells; however, little is known regarding its role in castration‐resistant prostate cancer (CRPC) progression. Here, our data demonstrated that β‐arrestin2 contributes to the cell viability and proliferation of CRPC via the downregulation of FOXO1 activity and expression. Mechanistically, in addition to its requirement for FOXO1 phosphorylation induced by IGF‐1, β‐arrestin2 could inhibit FOXO1 activity in an Akt‐independent manner and delay FOXO1 dephosphorylation through the inhibition of PP2A phosphatase activity and the attenuation of the interaction between FOXO1 and PP2A. Furthermore, β‐arrestin2 could downregulate FOXO1 expression via ubiquitylation and proteasomal degradation. Together, our results identified a novel role for β‐arrestin2 in the modulation of the CRPC progress through FOXO1. Thus, the characterization of β‐arrestin2 may represent an alternative therapeutic target for CRPC treatment. J. Cell. Physiol. 230: 2371–2381, 2015.

Inhibition of PARP1 by small interfering RNA enhances docetaxel activity against human prostate cancer PC3 cells

Though poly(ADP-ribose) polymerase 1 (PARP1) inhibitors have benefits in combination with radiotherapy in prostate cancers, few is known about the exactly role and underlying mechanism of PARP1 in combination with chemotherapy agents. Here our data revealed that inhibition of PARP1 by small interfering RNA (siRNA) could enhance docetaxels activity against PC3 cells, which is associated with an accelerate repression of EGF/Akt/FOXO1 signaling pathway. Our results provide a novel role of PARP1 in transcription regulation of EGFR/Akt/FOXO1 signaling pathway and indicate that PARP1 siRNA combined with docetaxel can be an innovative treatment strategy to potentially improve outcomes in CRPC patients.

β-arrestin1 promotes epithelial-mesenchymal transition via modulating GSK-3β/β-catenin pathway in prostate cancer cells.

Recently, β-arrestin1 was indicated as a tumor promoter in prostate cancer, but its exact role in cancer metastasis still have not been well clarified. Here, our data revealed that β-arrestin1 could promote the migration and invasion of prostate cancer cells via initiating epithelial-mesenchymal transition (EMT). Mechanically, β-arrestin1 could increase the transcriptional activity and expression of β-catenin, together with Akt activity, whereas decrease the activities of GSK-3β and PP2A. In addition, β-arrestin1 could function as a scaffold protein in modulating the interactions between PP2A, Akt, GSK-3β and β-catenin. These results reveal a novel mechanism of β-arrestin1 in modulating EMT and GSK-3β/β-catenin signaling in prostate cancer, thereby suggest that assessment of β-arrestin1 may provide a potential therapeutic target for prostate cancer.

Difference in 24-Hour Urine Composition between Diabetic and Non-Diabetic Adults without Nephrolithiasis.

Background Diabetic patients are more likely to develop kidney stones than the general population. The underlying mechanisms for this disparity remain to be elucidated. Little is known about the relationship between urine composition and diabetes mellitus in non-stone-forming individuals. We sought to examine the differences in the 24-hour (24-h) urine composition between diabetic and non-diabetic adults who were not stone formers. Methods A convenience sample of 538 individuals without a history of nephrolithiasis, gout, hyperparathyroidism, or gastroenteric diseases participated in this study. The 24-h urine profiles of 115 diabetic adults were compared with those of 423 non-diabetic adults. Diabetes was defined by self-reported physician diagnosis or medication use. All participants were non-stone formers confirmed by urinary tract ultrasonography. Participants provided a fasting blood sample and a single 24-h urine collection for stone risk analysis. Student’s t-test was used to compare mean urinary values. Linear regression models were adjusted for age, gender, body mass index, hypertension, fasting serum glucose, serum total cholesterol, estimated creatinine clearance rate and urinary factors. Results Univariable analysis showed that the diabetic participants had significantly higher 24-h urine volumes and lower urine calcium and magnesium excretions than non-diabetic participants (all P < 0.05). After multivariate adjustment, no significant differences in 24-h urine composition were observed between diabetic and non-diabetic participants except for a slightly increased 24-h urine volume in diabetic participants (all P > 0.05). The main limitation of this study is that the convenience samples and self-reported data may have been sources of bias. Conclusion Our data showed that there were no differences in 24-h urine composition between diabetic and non-diabetic adults who are not stone formers. The reason for it might be the improved glycemic control in diabetic individuals in our study. Therefore, a tighter glycemic control might reduce stone formation in diabetic adults.

Systematic Review and Cumulative Analysis of the Combination of Mitomycin C plus Bacillus Calmette-Guérin (BCG) for Non–Muscle-Invasive Bladder Cancer

This systematic review and cumulative analysis aimed to explore the efficacy and safety of the combination of intravesical mitomycin C (MMC) plus bacillus Calmette-Guerin (BCG) for non-muscle-invasive bladder cancer (NMIBC) patients. A comprehensive literature search using Pubmed, Embase, Medline, Cochrane Library, CBM, CNKI and VIP databases was performed to identify studies applying intravesical MMC plus BCG therapy on NMIBC patients up to June 2016. Summarized unadjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the efficacy and safety of the combination therapy. A total of 25 studies containing 2749 NMIBC patients were included in this systematic review. Compared with BCG monotherapy, the combination therapy could significantly reduce the tumor recurrence rate (OR = 0.64, 95% CI: 0.44–0.94, P = 0.02) and cancer-specific mortality (OR = 0.54, 95% CI: 0.34–0.87, P = 0.01), without more toxicities (OR = 0.58, 95% CI: 0.17–1.94, P = 0.37). The combination therapy could also lead to significant lower tumor recurrence rate than MMC monotherapy (OR = 0.41, 95% CI: 0.24–0.69, P = 0.0009). Our study indicates that the combination of MMC plus BCG instillation is an effective and safe adjuvant treatment for NMIBC patients.

Induction of TRPV5 expression by small activating RNA targeting gene promoter as a novel approach to regulate cellular calcium transportation.

AIM Promoter-targeted small activating RNAs (saRNAs) have been shown to be able to induce target gene expression, a mechanism known as RNA activation (RNAa). The present study tested whether saRNA can induce the overexpression of TRPV5 in human cells derived from the kidney and subsequently manipulate cell calcium uptake. MAIN METHODS Three saRNAs complementary to the TRPV5 promoter were synthesized and transfected into cells. TRPV5 expression at the RNA and protein levels was analyzed by quantitative real-time PCR and Western blotting respectively. For functional study, transcellular Ca(2+) transportation was tested by fura-2 analysis. Dihydrotestosterone (DHT), a suppressor of cellular calcium transportation, was administered to challenge the activating effect of selected saRNA. KEY FINDINGS One of these synthesized saRNAs, ds-2939, significantly induced the expression of TRPV5 at both mRNA and protein levels. Fura-2 analysis revealed that the intracellular Ca(2+) concentration was elevated by ds-2939. DHT treatment reduced transmembrane Ca(2+) transport, which was partially antagonized by ds-2939. SIGNIFICANCE Our results suggest that a saRNA targeting TRPV5 promoter can be utilized to manipulate the transmembrane Ca(2+) transport by upregulating the expression of TRPV5 and may serve as an alternative for the treatment of Ca(2+) balance-related diseases.

Autophagy inhibition attenuates hyperoxaluria-induced renal tubular oxidative injury and calcium oxalate crystal depositions in the rat kidney

Hyperoxaluria-induced oxidative injury of renal tubular epithelial cell is a casual and essential factor in kidney calcium oxalate (CaOx) stone formation. Autophagy has been shown to be critical for the regulation of oxidative stress-induced renal tubular injury; however, little is known about its role in kidney CaOx stone formation. In the present study, we found that the autophagy antagonist chloroquine could significantly attenuate oxalate-induced autophagy activation, oxidative injury and mitochondrial damage of renal tubular cells in vitro and in vivo, as well as hyperoxaluria-induced CaOx crystals depositions in rat kidney, whereas the autophagy agonist rapamycin exerted contrasting effects. In addition, oxalate-induced p38 phosphorylation was significantly attenuated by chloroquine pretreatment but was markedly enhanced by rapamycin pretreatment, whereas the protective effect of chloroquine on rat renal tubular cell oxidative injury was partly reversed by a p38 protein kinase activator anisomycin. Furthermore, the knockdown of Beclin1 represented similar effects to chloroquine on oxalate-induced cell oxidative injury and p38 phosphorylation in vitro. Taken together, our results revealed that autophagy inhibition could attenuate oxalate-induced oxidative injury of renal tubular cell and CaOx crystal depositions in the rat kidney via, at least in part, inhibiting the activation of p38 signaling pathway, thus representing a novel role of autophagy in the regulation of oxalate-induced renal oxidative injury and CaOx crystal depositions for the first time.

Crosstalk between VEGFR and other receptor tyrosine kinases for TKI therapy of metastatic renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma (RCC), and is frequently accompanied by the genetic features of von Hippel–Lindau (VHL) loss. VHL loss increases the expression of hypoxia-inducible factors (HIFs) and their targets, including epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and platelet-derived growth factor (PDGF). The primary treatment for metastatic RCC (mRCC) is molecular-targeted therapy, especially anti-angiogenic therapy. VEGF monoclonal antibodies and VEGF receptor (VEGFR) tyrosine kinase inhibitors (TKIs) are the main drugs used in anti-angiogenic therapy. However, crosstalk between VEGFR and other tyrosine kinase or downstream pathways produce resistance to TKI treatment, and the multi-target inhibitors, HIF inhibitors or combination strategies are promising strategies for mRCC. HIFs are upstream of the crosstalk between the growth factors, and these factors may regulate the expression of VEGR, EGF, PDGF and other growth factors. The frequent VHL loss in ccRCC increases HIF expression, and HIFs may be an ideal candidate to overcome the TKI resistance. The combination of HIF inhibitors and immune checkpoint inhibitors is also anticipated. Various clinical trials of programmed cell death protein 1 inhibitors are planned. The present study reviews the effects of current and potential TKIs on mRCC, with a focus on VEGF/VEGFR and other targets for mRCC therapy.

Antibiotic prophylaxis in ureteroscopic lithotripsy: a systematic review and meta‐analysis of comparative studies

To explore the efficacy of antibiotic prophylaxis and the different strategies used to prevent infection in ureteroscopic lithotripsy (URL) by conducting a systematic review and meta‐analysis.