DAB2IP stabilizes p27Kip1 via suppressing PI3K/AKT signaling in clear cell renal cell carcinoma.

Renal cell carcinoma (RCC) is the most lethal of the urologic malignancies. We previously discovered that DAB2IP, a novel Ras GTPase-activating protein, was frequently epigenetically silenced in RCC, and DAB2IP loss was correlated with the overall survival of RCC patients. In this study, we determined the biological functions of DAB2IP in clear cell RCC (ccRCC) and its potential mechanisms of action. Correlations between DAB2IP expression level and ccRCC tumor size and patient survival were analyzed, and the results showed that ccRCC patients with high DAB2IP mRNA level exhibited smaller tumor size and better survival than the patients with low DAB2IP. Compared to control, DAB2IP knockdown significantly increased cell proliferation, promoted cell cycle progression in G1/S phase, and decreased p27 expression. Mechanism studies demonstrated that loss of DAB2IP promoted p27 protein phosphorylation, cytosolic sequestration, and subsequently ubiquitination-mediated degradation in ccRCC cells. Further studies confirmed that the proline-rich domain in C terminal (CPR) of DAB2IP suppressed AKT phosphorylation and p27 phosphorylation on S10. Hence, DAB2IP is essential for p27 protein stabilization in ccRCC, which is at less partly mediated by PI3K/AKT signaling pathway.

The impact of genetic variants in the CYP2C8 gene on bladder cancer susceptibility.

Background: Bladder cancer is the most common leading cause of mortality around the world. Previous studies have indicated that genetic factors are significantly associated with bladder cancer progression-for instance, the CYP2C8 gene is involved in bladder cancer progression. However, little is known about the impact of CYP2C8 genetic polymorphisms on bladder cancer risk. We aimed to detect the association between CYP2C8 variations and bladder cancer susceptibility. Methods: This study included 550 healthy subjects and 217 bladder cancer patients. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to determine the correlation of CYP2C8 polymorphisms with bladder cancer risk. Multifactor dimensionality reduction (MDR) was carried out to investigate the influence of single-nucleotide polymorphism (SNP)-SNP interactions on bladder cancer. Results: Our study showed that two SNPs were significantly associated with an increased risk of bladder cancer (rs1934951: OR 1.96, 95% CI 1.37-2.82, p = 2.67E-04; rs17110453: OR 1.89, 95% CI 1.35-2.67, p = 2.53E-04). On the contrary, two SNPs identified in the study had protective effects on bladder cancer (rs1934953: OR 0.26, 95% CI 0.14-0.47, p = 1.20E-05; rs2275620: OR 0.40, 95% CI 0.21-0.76, p = 0.005). The MDR analysis suggested that the combination of rs1934953, rs1934951, rs2275620, and rs17110453 was the best model to predict bladder cancer (CVC 10/10, testing accuracy 0.6720, p < 0.0001). Conclusion: There was a significant association between CYP2C8 polymorphisms (rs1934953, rs1934951, rs2275620, and rs17110453) and susceptibility to bladder cancer.

NEK2 Serves as a Novel Biomarker and Enhances the Tumorigenicity of Clear-CellRenal-Cell Carcinoma by Activating WNT/ß-Catenin Pathway.

Objective: Currently, cumulative evidence has shown that loss of NEK2 function suppresses tumor growth. However, complete studies on the regulatory role of NEK2 in clear-cellrenal-cell carcinoma (ccRCC) are rarely reported. Methods: The GEPIA database was used for information mining to analyze the gene expression differences between ccRCC tumor and normal tissues. At the same time, we analyzed the protein expression of NEK2 in clinical ccRCC samples and ccRCC cell lines. We detected the effect of NEK2 on the biological behavior of ccRCC at the cell level and further verified the biological effect of NEK2 on ccRCC cells in vivo by nude mouse tumorigenesis experiment. The expression of WNT/ß-cateninpathway-related proteins and downstream proteins related to cell function were detected by Western blotting. Results: Using the GEPIA database, we observed that NEK2 expression level in ccRCC tissues was significantly higher than that in normal kidney tissues and was also related to tumor grade. The survival time of patients with ccRCC with high NEK2 expression was shorter than that of patients with low NEK2 expression. Compared with adjacent carcinoma and normal renal tubular epithelial cells, NEK2 levels were highly expressed in ccRCC tissues and ccRCC cell lines. NEK2 interference restrained ccRCC cell growth, migration, and invasion. NEK2 regulated the malignant behavior of ccRCC cells through the WNT/ß-catenin pathway. Nude mouse tumorigenesis assay results showed that the transplanted tumors from NEK2 silenced mice grew more slowly and were smaller in size than those from control mice. Conclusions: NEK2 elevation may be associated with poor prognosis in ccRCC, and NEK2 enhances ccRCC cell proliferation, migration, and invasion ability by activating the WNT/ß-catenin signaling pathway.

Ultrasound cavitation enhanced chemotherapy: In vivo research and clinical application.

IMPACT STATEMENT: The novelty of this research is that we used ultrasound cavitation to enhance the effects of chemotherapy in the subcutaneous and orthotopic hepatic carcinomas in nude mice. Case reports of the effects of the targeting ultrasound cavitation and chemotherapy on malignant tumors in clinical patients were also examined. We found that low-frequency ultrasound cavitation combined with chemotherapy is effective in the inhibition of tumor growth to some extent.

Transurethral endoscopic submucosal en bloc dissection for nonmuscle invasive bladder cancer: A comparison study of HybridKnife-assisted versus conventional dissection technique.

SUBJECTS: The aim of this study is to compare the efficacy and safety of en bloc bladder tumor-endoscopic submucosal dissection (BT-ESD) and conventional transurethral resection of BT (TURBT) in nonmuscle invasive bladder cancer (NMIBC) patients. METHODS: A retrospective cohort study was carried out in Shaanxi Provincial People's Hospital. A total of 193 eligible NMIBC (Ta/T1) patients were enrolled in this study (95 cases in BT-ESD group and 98 cases in TURBT group), between November 2013 and January 2017. The operation time, blood loss, postoperative bladder irrigation time, catheter indwelling time, hospital stay time, and complications were compared. Data were presented as median (range). Chi-squared or rank-sum test, two-way ANOVA, and Mantel-Cox (Log-Rank) test were performed using statistical software. A threshold of P < 0.05 was defined as statistically significant. RESULTS: The average operation time in the BT-ESD group was longer than that of in the TURBT group (40.0 [5.0, 100.0] min vs. 19.5 [3.0, 55.5] min); however, no significant longer operating time (P < 0.05) were observed in the smaller tumor (0 cm-3 cm). The postoperative bladder irrigation time, catheter indwelling time, and hospital stay in BT-ESD group were significantly shorter than that of in TURBT group (9.0 [5.0, 18.0] h, 2.5 [1.0, 4.0] d and 3.5 [2.0, 5.0] d for BT-ESD; 18.0 [12.0, 48.0] h, 3.5 [2.0, 7.0] d, and 4.5 [3.0, 8.0] d for TURBT). In addition, the BT-ESD group showed the decreased overall incidence of complications (2.1% vs. 9.2%). The univariate and multivariate analyses indicated an association between surgical option and tumor recurrence (hazard ratio = 5.624, odds ratio = 95% confidence interval = 1.582-19.991), Kaplan-Meir analysis showed significant difference in recurrence-free survival (RFS) (94.7% for ESD group vs. 78.4% for TURBT group) at 33 months. CONCLUSIONS: The application of the HybridKnife lead to a decrease in complications and RFS rate, which was a more safe and effective approach for NMIBC than conventional TURBT.

miR-489 Suppresses Proliferation and Invasion of Human Bladder Cancer Cells.

MicroRNAs (miRNAs) have been shown to be involved in bladder cancer progression. miR-489 (also known as miR-489-3p) was recently reported to be a tumor suppressor in several cancers. However, its exact role and mechanism in the progression of bladder cancer are largely unknown. In this study, we explore the role of miR-489 in the proliferation and invasion of human bladder cancer cells. The miR-489 expression levels were detected in bladder cancer and normal adjacent tissues, as well as in human normal bladder epithelial cells and bladder cancer cell lines. The results showed that miR-489 was sharply reduced in bladder cancer tissues and cell lines. Then the miR-489 mimic or oligo anta-miR-489 was transfected into T24 and UMUC3 bladder cancer cell lines. The results showed that the miR-489 mimic greatly increased the miR-489 level and significantly decreased the proliferation and invasion of T24 and UMUC3 cells. In contrast, the anta-miR-489 had a completely opposite effect on miR-489 expression, cell proliferation, and cell invasion. Moreover, bioinformatics and luciferase reporter gene assays confirmed that miR-489 targeted the mRNA 3'-untranslated region (3'-UTR) region of Jagged1 (JAG1), a Notch ligand. In conclusion, miR-489 suppressed proliferation and invasion of human bladder cancer cells.

The inhibitory effect of intravesical fisetin against bladder cancer by induction of p53 and down-regulation of NF-kappa B pathways in a rat bladder carcinogenesis model.

Intravesical chemotherapy after transurethral resection has been widely used as an adjuvant therapy to prevent recurrence and progression of superficial bladder cancer. Due to the insufficiency of the current chemotherapeutics, there is an urgent need to search for more novel, effective and safe intravesical agents. Previously, we have proved the in vitro apoptotic effects of fisetin, a dietary flavonoid, on bladder carcinoma cells. In the present study, we have further explored its intravesical efficacy and investigated the underlying mechanisms of its inhibitory effect of bladder cancer through an autochthonous rat model of bladder cancer induced by intravesical N-methyl-N-nitrosourea (MNU). We found that fisetin-induced apoptosis in bladder cancer is mediated via modulation of two related pathways: up-regulation of p53 and down-regulation of NF-κB pathway activity, causing changes in the ratio of pro- and antiapoptotic proteins. Meanwhile, administration of fisetin significantly reduced the incidence of MNU-induced bladder tumours by suppressing NF-κB activation and modulating the expression of NF-κB target genes that regulate cell proliferation and cell apoptosis. Our study suggests that the activation of p53 and inhibition of the NF-κB pathway may play important roles in the fisetin-induced apoptosis in bladder cancer. Furthermore, intravesical fisetin effectively inhibited, without any toxicity, the carcinogenesis of bladder cancer in MNU-initiated rats. These findings identify the in vivo chemopreventive efficacy of fisetin and suggest that fisetin could be used as a novel, effective and safe intravesical agent for bladder cancer.

QTAIM investigation of the electronic structure and large Raman scattering intensity of bicyclo-[1.1.1]-pentane.

Our previous studies of the variation of Raman scattering intensities in saturated hydrocarbons have identified a number of structural descriptors that correlate with calculated polarizability derivatives for particular bond displacements: ring strain, steric hindrance, and alignment and location of a C-H group within the molecular framework (e.g., endo-/exo-, axial/equatorial, in-plane/out-of-plane). The bridgehead C-H bond intensities in bicyclo-[1.1.1]-pentane appear to be extraordinarily large, given its size and structure. Molecular polarizability and derivatives are analyzed here for bicyclo-[1.1.1]-pentane and propane, with HF, MP2, CCSD, B3LYP, M06, and M062X levels of theory and the Dunning AVTZ basis set. Analyses of calculated electronic charge densities were performed with two implementations of QTAIM, including an origin-dependent method and an implementation with origin-independent atomic moments. Numerically accurate atomic partitioning of mean molecular polarizabilities is achievable with either; however, accurate partitioning of polarizability derivatives places stringent requirements on the numerical integration, more so for this highly strained bicyclic structure. QTAIM reveals that most of the polarizability (~90%) can be attributed to charge transfer between atomic basins. Calculated Raman intensities are in accord with our experimental data, notably in the prediction of large trace scattering intensities for stretching of the bridgehead CH in bicyclo-[1.1.1]-pentane and for the methyl in-plane C-H in propane. Density difference plots illustrate the effects of bond displacements on the electron densities and the resultant changes in polarizability. Stretching of the bridgehead C-H bond in bicyclo-[1.1.1]-pentane produces electron density changes that are similar to those encountered upon stretching the methyl in-plane C-H of propane.

Fisetin, a dietary flavonoid, induces cell cycle arrest and apoptosis through activation of p53 and inhibition of NF-kappa B pathways in bladder cancer cells.

There is an obvious urgent need to find effective and safe therapies to prevent both recurrence and progression of bladder cancer. In the present study, we report that fisetin-induced apoptosis in human bladder cancer is mediated via modulation of two related pathways: up-regulation of p53 and down-regulation of NF-kappa B activity, causing a change in the ratio of pro- and anti-apoptotic proteins. The results showed that fisetin inhibited the proliferation of T24 and EJ cells by inducing apoptosis and blocking cell cycle progression in the G0/G1 phase. Western blot assay showed that fisetin significantly increases the expression of p53 and p21 proteins, and decreases the levels of cyclin D1, cyclin A, CDK4 and CDK2, thereby contributing to cell cycle arrest. In addition, fisetin increased the expression of Bax and Bak but decreased the levels of Bcl-2 and Bcl-xL and subsequently triggered mitochondrial apoptotic pathway. Our study suggests that the activation of p53 and inhibition of the NF-kappa B system may play important roles in the fisetin-induced apoptosis in bladder cancer cells.

Ab initio calculations of nonlinear optical rotation by several small chiral molecules and by uridine stereoisomers.

Expressions for nonlinear optical rotation are presented based on the quantum theory of optical birefringence of Atkins and Barron [Proc. R. Soc. London, Ser. A 304, 303 (1968); 306, 119 (1968)]. As concrete examples, the ordinary and nonlinear optical rotations are calculated with density functional theory (DFT) methodology for some simple single-ring molecules, namely, oxaziridine, diaziridine, and their derivatives, and for two, somewhat more complicated, conformations of uridine. For the single-ring molecules, (1) the angles of the ordinary optical rotation are mostly positive and (2) the contributions of the nonlinear effect to the total optical rotation depend both on the nature of the substituted species and of the host atom located on the ring. For the two conformations of uridine, (1) the signs of nonlinear optical rotation differ even though their ordinary optical rotations have the same sign and (2) whether the molecular structures are geometrically optimized with Hartree-Fock or DFT methodologies has no significant effect on the calculated nonlinear optical rotation when gauge-including atomic orbitals were used, even though the basis sets are small. These studies are expected to be helpful for interpretation of experimental results on nonlinear optical rotation by molecules underway in our research group.