Zhenxing Yang

MicroRNAs in biofluids are novel tools for bladder cancer screening

MicroRNAs (miRNAs) are short non-coding RNAs that play important roles in basic cellular processes, including differentiation, proliferation, apoptosis and autophagy. They are also involved in various stages of tumorigenesis and play key roles in bladder cancer initiation and progression. Notably, the altered expression of miRNAs in the tumors is reflected in body fluids, including blood and urine, which opens avenues for non-invasive diagnosis and prognosis. Many studies have demonstrated that epigenetic changes extensively alter tumoral microRNA expression. The high reproducibility, specificity and sensitivity of miRNA levels in body fluids suggest their potential use as biomarkers for cancer screening and diagnosis. For example, recent technological advances have made it possible to detect miRNAs in urine for bladder cancer screening. In this review, we focus mainly on the current knowledge and future challenges for incorporating miRNAs in body fluids, like urine and blood, for making clinical diagnoses and assessing prognoses in bladder cancer.

The reverse-mode NCX1 activity inhibitor KB-R7943 promotes prostate cancer cell death by activating the JNK pathway and blocking autophagic flux

We explored the effects of KB-R7943, an inhibitor of reverse-mode NCX1 activity, in prostate cancer (PCa). NCX1 was overexpressed in PCa tissues and cell lines, and higher NCX1 levels were associated higher PCa grades. At concentrations greater than 10 μM, KB-R7943 dose-dependently decreased PC3 and LNCaP cell viability. KB-R7943 also increased cell cycle G1/S phase arrest and induced apoptosis in PC3 cells. KB-R7943 increased autophagosome accumulation in PCa cells as indicated by increases in LC3-II levels and eGFP-LC3 puncta. Combined treatment with chloroquine (CQ) and KB-R7943 decreased P62 and increased LC3-II protein levels in PC3 cells, indicating that KB-R7943 blocked autophagic flux. KB-R7943 induced autophagosome accumulation mainly by downregulating the PI3K/AKT/m-TOR pathway and upregulating the JNK pathway. In xenograft experiments, KB-R7943 inhibited tumor growth. Combined treatment with KB-R7943 and an autophagy inhibitor inhibited growth and increased apoptosis. These results indicate that KB-R7943 promotes cell death in PCa by activating the JNK signaling pathway and blocking autophagic flux.

Beneficial effects of urine-derived stem cells on fibrosis and apoptosis of myocardial, glomerular and bladder cells.

Urine-derived stem cells (USCs) are isolated from voided urine and display high proliferative activity and multiple differentiation potentials. The applicability of USCs in the treatment of bladder dysfunction and in cell-based urological tissue engineering has been demonstrated. Whether they could serve as a potential stem cell source for the treatment of diabetes mellitus (DM) and its complications has not been investigated. Here, we report the repairing and protective effects of USCs on pancreatic islets, the myocardium, the renal glomerulus and the bladder detrusor in diabetic rat models. Type 2 diabetic rat models were induced by means of a high fat diet and intraperitoneal injection with streptozotocin. USCs isolated from voided urine were administered via tail veins. The functional changes of pancreatic islets, left ventricle, glomerulus and bladder micturition were assessed by means of insulin tolerance tests, echocardiography, urine biochemical indexes and cystometry. The histologic changes were evaluated by hematoxylin and eosin staining, Massons trichrome staining and TUNEL staining. Treatment with USCs significantly alleviated the histological destruction and functional decline. Although the USC treatment did not decrease fasting blood glucose to a significantly different level, the fibrosis and apoptosis of the myocardium, glomerulus and detrusor were significantly inhibited. This study indicates that administration of USCs may be useful for the treatment of the complications of DM.

Interleukin‐6/signal transducer and activator of transcription 3 promotes prostate cancer resistance to androgen deprivation therapy via regulating pituitary tumor transforming gene 1 expression

Prostate cancer can progress from androgen dependence to androgen deprivation resistance with some unknown mechanisms. The current study aims to explore the possible role of pituitary tumor transforming gene1 (PTTG1) in castration‐resistant prostate cancer (CRPC). Initially, we found that PTTG1 expression was significantly increased in androgen‐independent prostate cancer cell lines PC3, DU145 and CRPC specimens compared with that in androgen‐dependent prostate cancer cell line LNCaP and initial prostate cancer specimens. PTTG1 overexpression significantly enhanced the cell survival rate, clonality and tumorigenicity in LNCaP cells upon androgen‐deprivation therapy (ADT). While knockdown of PTTG1 expression significantly elevated the sensitivity of DU145 cells to ADT. The effects of PTTG1 overexpression on LNCaP cells may be ascribed to the induced EMT and increased CD44+CD24‐ cancer stem cell population. Furthermore, we detected that PTTG1 expression was regulated by interleukin‐6 via activated signal transducer and activator of transcription 3 (STAT3) directly binding to the region −500 to +1 of PTTG1 promoter in LNCaP cells. In conclusion, our results elucidate that interleukin‐6/STAT3 activation can increase PTTG1 expression and, consequently, promote the resistance to ADT in CRPC by inducing EMT and increasing the cancer stem cell population, suggesting that PTTG1 may be a novel therapeutic target for CRPC.

Long noncoding RNA PVT1 inhibits renal cancer cell apoptosis by up-regulating Mcl-1

Long non-coding RNA plasmacytoma variant translocation 1 (PVT1) is up-regulated in various human cancers, and our results indicated that PVT1 was up-regulated in clear cell renal cell carcinoma tissues. The Cancer Genome Atlas cohort analysis revealed that in clear cell renal cell carcinoma, higher PVT1 expression correlated with advanced TNM stage, histological grade, and poor survival. PVT1 knockdown promoted apoptosis, inhibited renal cancer cell proliferation, decreased Mcl-1, and increased cleaved caspase-3 and cleaved PARP. PVT1 increased Mcl-1 mRNA levels in renal cancer cells by promoting mRNA stability without influencing its transcription. in vitro, the enhanced apoptosis arising from PVT1 suppression was attenuated by overexpressing Mcl-1. In addition, in vivo experiments showed that PVT1 knockdown repressed xenograft tumor growth, while Mcl-1 overexpression partially rescued xenograft tumor growth. These results indicate the PVT1/Mcl-1 pathway inhibits renal cancer cell apoptosis in vitro and in vivo. PVT1 may thus serve as a novel biomarker, and the PVT1/Mcl-1 pathway may be a useful therapeutic target for clear cell renal cell carcinoma.

Cyclophosphamide-induced HCN1 channel upregulation in interstitial Cajal-like cells leads to bladder hyperactivity in mice

Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are confirmed to be expressed in bladder interstitial Cajal-like cells (ICC-LCs), but little is known about their possible role in cystitis-associated bladder dysfunction. The present study aimed to determine the functional role of HCN channels in regulating bladder function under inflammatory conditions. Sixty female wild-type C57BL/6J mice and sixty female HCN1-knockout mice were randomly assigned to experimental and control groups, respectively. Cyclophosphamide (CYP)-induced cystitis models were successfully established in these mice. CYP treatment significantly enhanced HCN channel protein expression and Ih density and significantly altered bladder HCN1 channel regulatory proteins. Carbachol (CCH) and forskolin (FSK) exerted significant effects on bladder ICC-LC [Ca2+]i in CYP-treated wild-type (WT) mice, and HCN1 channel ablation significantly decreased the effects of CCH and FSK on bladder ICC-LC [Ca2+]i in both naive and CYP-treated mice. CYP treatment significantly potentiated the spontaneous contractions and CCH (0.001–10 μM)-induced phasic contractions of detrusor strips, and HCN1 channel deletion significantly abated such effects. Finally, we demonstrated that the development of CYP-induced bladder overactivity was reversed in HCN1−/− mice. Taken together, our results suggest that CYP-induced enhancements of HCN1 channel expression and function in bladder ICC-LCs are essential for cystitis-associated bladder hyperactivity development, indicating that the HCN1 channel may be a novel therapeutic target for managing bladder hyperactivity.

Polymorphisms of the VDR gene in patients with nephrolithiasis in a Han Chinese population

An association study between VDR gene polymorphisms and nephrolithiasis was conducted in different populations, but it is not yet known whether the association exists in the Han Chinese population. Here, we genotyped three SNPs (rs731236, rs7975232 and rs10735810) in the promoter region of the VDR gene by iMLDR genotyping assays in a large case–control cohort. The results demonstrated that there was no association found between the three SNPs (rs731236, rs7975232 and rs10735810) in the VDR gene and nephrolithiasis, whether in allele or genotype distribution. However, SNP rs10735810 was correlated with the level of serum calcium in control groups, but not in patient groups. In conclusion, considering the large sample size, we believe that the SNP rs10735810 allele A in the VDR gene promoter region may influence the level of serum calcium, but not influence the formation of nephrolithiasis in a Han Chinese population.

Increased Piezo1 channel activity in interstitial Cajal-like cells induces bladder hyperactivity by functionally interacting with NCX1 in rats with cyclophosphamide-induced cystitis

The Piezo1 channel is a mechanotransduction mediator, and Piezo1 abnormalities have been linked to several clinical disorders. However, the role of the Piezo1 channel in cystitis-associated bladder dysfunction has not been documented. The current study aimed to discover the functional role of this channel in regulating bladder activity during cyclophosphamide (CYP)-induced cystitis. One hundred four female rats were randomly assigned to the control, CYP-4h, CYP-48h and CYP-8d groups. CYP successfully induced acute or chronic cystitis in these rats. CYP treatment for 48h or 8d significantly increased Piezo1 channel expression in bladder interstitial Cajal-like cells (ICC-LCs), and the increase in CYP-8d rats was more prominent. In addition, 2.5 μM Grammostola spatulata mechanotoxin 4 (GsMTx4) significantly attenuated bladder hyperactivity in CYP-8d rats by inhibiting the Piezo1 channel in bladder ICC-LCs. Furthermore, by using GsMTx4 and siRNA targeting the Piezo1 channel, we demonstrated that hypotonic stress-induced Piezo1 channel activation significantly triggered Ca2+ and Na+ influx into bladder ICC-LCs during CYP-induced chronic cystitis. In addition, the Piezo1 channel functionally interacted with the relatively activated reverse mode of Na+/Ca2+ exchanger 1 (NCX1) in bladder ICC-LCs from CYP-8d rats. In conclusion, we suggest that the functional role of the Piezo1 channel in CYP-induced chronic cystitis is based on its synergistic effects with NCX1, which can significantly enhance [Ca2+]i and result in Ca2+ overload in bladder ICC-LCs, indicating that the Piezo1 channel and NCX1 are potential novel therapeutic targets for chronic cystitis-associated bladder hyperactivity.Chronic cystitis: proteins may open a channel to treatmentA protein that controls the passage of ions through cell membranes is implicated in interstitial cystitis/painful bladder syndrome (IC/PBS). This condition causes chronic pelvic pain and increased urinary frequency and urgency. Current treatment options are unsatisfactory. Researchers led by Longkun Li at the Third Military Medical University in Chongqing, China, and Mingjia Tan at the University of Michigan, Ann Arbor, USA, studied the role of this membrane channel protein, called Piezo1. Increased activity of Piezo1 was linked to bladder hyperactivity in rats with drug-induced cystitis. The research also identified a synergistic interaction between Piezo1 and a second membrane channel protein. A drug that inhibits Piezo1 activity reduced bladder hyperactivity in the rats. Drugs targeting these two proteins might help to treat the chronic cystitis of patients with IC/PBS.

De Novo Mutations Contribute to the Development of Clear-Cell Renal-Cell Carcinoma in a 5-Year-Old Girl

Clear-cell renal-cell carcinoma (ccRCC) rarely occurs in children, especially in pediatrics reported worldwide. This case is the first worldwide report of ccRCC in a 5year-old girl. It is difficult to distinguish the diagnosis between Wilms tumor and renal-cell carcinoma by using enhanced computed tomography and ultrasound. The purpose of the present report was to discuss the clinical manifestation, pathologic features, and genetic basis for pediatric ccRCC. The present report will play an effective role in guiding clinical practice on the diagnosis of ccRCC.

Cyanidin Curtails Renal Cell Carcinoma Tumorigenesis.

Background/Aims: Cyanidin is an anthocyanin found in many foods. Although its variable antioxidant levels are well-documented, little is known about its effects on renal cell carcinoma (RCC) tumorigenesis. This study, therefore, investigated the effects of cyanidin on the proliferation, migration, and invasion of renal cell carcinoma lines and demonstrated, for the first time, significant inhibitory effects of cyanidin on RCC tumorigenesis. Methods: RCC cells were treated with different doses of cyanidin and the effects were tested by Cell Counting Kit-8 reagent, clone formation assay, transwell assay, and flow cytometry. Moreover, the cyanidin-mediated mechanism that curtailed tumorigenesis was analyzed by RNA sequencing (RNA-seq). Sequencing data from The Cancer Genome Atlas (TCGA) were used to compare the expression of both early growth response protein 1 (EGR1) and selenoprotein W (SEPW1) in RCC and tumor-free adjacent normal tissue samples. Real-time PCR (RT-PCR) and/or western blot were used to assess the expression of E-cadherin, cleaved-caspase3, Bcl2, p62, and ATG4. Results: We found significantly greater induction of cell-cycle arrest, apoptosis, and suppression of RCC cell invasion and migration at concentrations of 25 µM and 100 µM than at a concentration of 50 µM. It was also discovered, first through RNA-seq then confirmed by RT-PCR, that cyanidin (100 µM) inhibited RCC carcinogenesis through EGR1 and SEPW1. TCGA data indicated that the expression level of EGR1 was lower and that of SEPW1 was higher in RCC tumor tissue than in normal tissues. Moreover, western blot and/or RT-PCR indicated that cleaved-caspase3 was enhanced and E-cadherin was inhibited by cyanidin treatment. Furthermore, western blot and RT-PCR also showed regulation of p62 and ATG4, which are associated with autophagy. Cyanidin in vivo significantly inhibited the growth of xenografts in nude mice. Conclusions: The results of this study showed the therapeutic potential of cyanidin for the treatment of RCC and the prevention of recurrence and metastasis.