USP5 facilitates bladder cancer progression by stabilizing the c-Jun protein.

BACKGROUND: Bladder cancer is the second most common genitourinary malignancy worldwide. The death rate of bladder cancer has increased every year. However, the molecular mechanism of bladder cancer is not sufficiently studied. Deubiquitinating enzymes (DUBs) play an important role in carcinogenesis. Several studies have demonstrated that USP5 associated with malignancy and pathological progression in hepatocellular carcinoma, colorectal and non-small cell lung cancer. However, the role of USP5 in bladder cancer need to be explored. METHODS: The USP5 expression was analysed using the web server GEPIA. To explore USP5 function in bladder cancer, we constructed USP5-knockout cell lines in T24 cells. A FLAG-USP5 (WT USP5) plasmid and a plasmid FLAG-USP5 C335A (catalytic-inactive mutant) used to overexpress USP5 in EJ cells. CCK8, colony formation, transwell and scratch assays were used to assess cell viability, proliferation and migration. RNA sequencing (RNA-seq) and dual-luciferase reporter assays were performed to screen the pathway. Coimmunoprecipitation and immunofluorescence were used to explore the interaction between USP5 and c-Jun. Cycloheximide (CHX) chase assays were performed to establish the effect of USP5 on c-Jun stability. Xenograft mouse model was used to study the role of USP5 in bladder cancer. RESULTS: USP5 expression is increased in bladder cancer patients. Genetic ablation of USP5 markedly inhibited bladder cancer cell proliferation, viability, and migration both in vitro and in vivo. RNA-seq and luciferase pathway screening showed that USP5 activated JNK signalling, and we identified the interaction between USP5 and c-Jun. USP5 was found to activate c-Jun by inhibiting its ubiquitination. CONCLUSIONS: Our results show that high USP5 expression promotes bladder cancer progression by stabilizing c-Jun and that USP5 is a potential therapeutic target in bladder cancer.

Single-flavor color superconductivity in a magnetic field.

We investigate the single-flavor color superconductivity in a magnetic field. Because of the absence of the electromagnetic Meissner effect, forming a nonspherical CSC phase, polar, A, or planar, does not cost energy of excluding magnetic flux. We found that these nonspherical phases may be reached via a sequence of first order phase transitions under the typical quark density and magnetic field inside a neutron star.

Expression of CYP2E1 in human nasopharynx and its metabolic effect in vitro.

It was evident that nitrosamines can act directly on target tissue and result in carcinogenesis. As has been shown, the carcinogenic activity of nitrosamines relied on its bioactivation by Cytochrome P450 2E1 (CYP2E1). In this study, we investigated the expression of CYP2E1 in Nasopharyngeal carcinoma (NPC) cells, embryonic nasopharyngeal epithelial tissue (ENET) specimens, and NPC biopsies by RT-PCR analysis. CYP2E1 was expressed in all NPC cell lines (6/6, including 7429) and ENET (6/6), and 80% of NPC biopsie (8/10). The fact that Human nasopharynx expresses CYP2E1 suggests that CYP2E1 may play an important role in the course of NPC by indirect carcinogens nitrosamines. To further evaluate the function of CYP2E1, the CYP2E1 was stably expressed in the cell line NIH 3T3/rtTA under a tetracycline-controlled transactivator. The expression of CYP2E1 was tightly regulated in a dose-dependent manner by Doxycycline (Dox) When the catalytic activity of CYP2E1 was assayed, the result showed that the generation of 6-hydroxychlorzoxazone (6-OH-CZ) from chlorzoxazone (CZ) was dose- and time-dependent on Dox addition to the medium. In the presence of 1 microg/ml Dox, the CZ 6-hydroxylase activity of the cell line was found to be 0.986 +/- 0.034 nmol/10(6) cells/h. The metabolic activation of Tet/3T3/2E1-6 cells was also assayed by N,N'-dinitrosopiperazine (DNP) cytotoxicity, and the viability of Tet/3T3/2E1-6 cells treated with Dox was lower than that of untreated cells with a significant difference between them in 80 and 160 microg/ml DNP (P ( 0.05, t test. This cell line will be useful not only to assess the metabolic characteristics of CYP2E1, but also will be useful to investigate the role of CYP2E1 in metabolic activation of carcinogenic nitrosamines in vitro.

[Cloning and sequence analysis of human embryonic nasopharyngeal epithelial CYP2E1 cDNA].

OBJECTIVES: To investigate the role of CYP2E1 gene in chemical carcinogen-induced nasopharyngeal carcinogenesis and to provide new evidence about etiology and pathogenesis of nasopharyngeal carcinoma. METHODS: RT-PCR was used to clone the CYP2E1 gene in human embryonic nasopharyngeal epithelial (HENE) cell, the transformed nasopharyngeal epithelial cell line (7,429), and the nasopharyngeal carcinoma cell line (HNE1). The cloned segments were inserted into pGEM-T Easy vector to sequence by DNA recombination technique. RESULTS: In comparison with HENE-2E1 cDNA, there were two point mutations at positions 846 (A to T) and 901 (A to G) in 7,429-2E1 cDNA as well as only one point mutation at position 901 (A to G) in HNE1-2E1 cDNA. In comparison with human (adult, ethanol-inducible) liver CYP2E1 gene (GenBank NO. J02843), HENE-2E1 cDNA had one point mutation at position 901 (G to A). All these point mutations didn't affect the amino acid sequence. But no base change was found in HNE1-2E1 cDNA. CONCLUSION: There are a few of base substitutions among HENE-2E1 cDNA, 7,429-2E1 cDNA, and HNE1 cDNA sequences. All these point mutations are synonymous mutation. The study reconfirms that the human CYP2E1 gene is relatively well conserved.

[Transformation function of human bronchial epithelial cell by latent membrane protein1 encoded by Epstein-Barr virus gene].

BACKGROUND & OBJECTIVE: Although some results show that latent membrane protein 1 (LMP1) may play an important role in the development of epithelium-derived tumors. There are few studies on the relationship between LMP1 and normal epithelial cell. So this study was designed to evaluate the effect of EBV LMP1 on cell transformation in human bronchial epithelial (HBE) cell and its mechanism. METHODS: Retrovirus expression vectors (LMP1 and LMP1+hTERT) were transfected into HBE cells and selected with the appropriate drugs to get resistant cells. The biological characteristics were studied by cell growth curve, colony formation analysis, and the determination of telomerase activity and protein expression of Cyclin A, p21, and CDK4. RESULTS: wt-LMP1 together with hTERT gene transfected cells grew rapidly than HBE/wt-LMP1 cells. Soft agar plating rates of HBE/wt-LMP1-hTERT, HBE/wt-LMP1, and HBE/pLNSX+pBabe were 22.98%, 16.94%, and 8.85%, respectively. The activities of telomerase were 2.825, 2.441, and 1.876, respectively. In addition, there was no difference of protein expression of CDK4 among these groups. However, HBE/wt-LMP1-hTERT and HBE/wt-LMP1 cells had low-level p21 and high-level cyclin A protein expression than the vector groups. CONCLUSION: The results suggest that LMP1 is in tandem with hTERT in promoting cell proliferation and transformation through modulating expression level of cyclin A and p21 protein.