Zinc-finger protein 331, a novel putative tumor suppressor, suppresses growth and invasiveness of gastric cancer.

Zinc-finger protein 331 (ZNF331), a Kruppel-associated box zinc-finger protein gene, was identified as a putative tumor suppressor in our previous study. However, the role of ZNF331 in tumorigenesis remains elusive. We aimed to clarify its epigenetic regulation and biological functions in gastric cancer. ZNF331 was silenced or downregulated in 71% (12/17) gastric cancer cell lines. A significant downregulation was also detected in paired gastric tumors compared with adjacent non-cancer tissues. In contrast, ZNF331 was readily expressed in various normal adult tissues. The downregulation of ZNF331 was closely linked to the promoter hypermethylation as evidenced by methylation-specific PCR, bisulfite genomic sequencing and reexpression by demethylation agent treatment. DNA sequencing showed no genetic mutation/deletion of ZNF331 in gastric cancer cell lines. Ectopic expression of ZNF331 in the silenced cancer cell lines MKN28 and HCT116 significantly reduced colony formation and cell viability, induced cell cycle arrests and repressed cell migration and invasive ability. Concordantly, knockdown of ZNF331 increased cell viability and colony formation ability of gastric cancer cell line MKN45. Two-dimensional gel electrophoresis and mass spectrometry-based comparative proteomic approach were applied to analyze the molecular basis of the biological functions of ZNF331. In all, 10 downstream targets of ZNF331 were identified to be associated with regulation of cell growth and metastasis. The tumor-suppressive effect of ZNF331 is mediated at least by downregulation of genes involved in cell growth promotion (DSTN, EIF5A, GARS, DDX5, STAM, UQCRFS1 and SET) and migration/invasion (DSTN and ACTR3), and upregulation of genome-stability gene (SSBP1) and cellular senescence gene (PNPT1). A novel target of ZNF331 (DSTN) was functionally validated. Overexpression of DSTN in BGC-823 cells increased colony formation and migration ability. In conclusion, our results suggest that ZNF331 possesses important functions for the suppression of gastric carcinogenesis as a novel functional tumor-suppressor gene.

Exogenous sodium hydrosulfide can attenuate naloxone-precipitated withdrawal syndromes and affect cAMP signaling pathway in heroin-dependent rat's nucleus accumbens.

BACKGROUND: H2S is a novel type of endogenous neural regulatory factor and gaseous mediator. Exogenous H2S can increase heroin-induced learning and memory damage in rat and alleviates heroin-induced rat hippocampus damage through antioxidant and anti-apoptosis effects. OBJECTIVE: Aim of this study was to identify whether hydrogen sulfide (H2S) protects heroin withdrawal rat is related with adenylate cyclase (AC)-cAMP-protein kinase A (PKA)-cAMP response element-binding protein (CREB) signaling pathway in heroin-dependent rat's nucleus accumbens or not. METHODS: Male Spragne-Dawley rats were randomly divided into Saline + Saline group, Saline + sodium hydrosulfide (NaHS) group, Saline + Heroin group, NaHS + Heroin group according to the principle of increasing heroin dosage day by day, with the establishment of heroin-naloxone-induced withdrawal symptoms determined at day 10. Then the levels of H2S and cAMP and AC and PKA activities were assayed, and the level of phosphorylated CREB (p-CREB), the levels of phosphorylated N-methyl-D-aspartate receptor 1 subunit (p-NR1), phosphorylated N-methyl-D-aspartate receptor 2a subunit (p-NR2A) and phosphorylated N-methyl-D-aspartate receptor 2b subunit (p-NR2B) were assayed in nucleus accumbens. RESULTS: Exogenous H2S can alleviate heroin withdrawal symptoms by increasing the level of H2S level in nucleus accumbens. Exogenous H2S can decrease the high activities of AC, PKA and the high levels of cAMP, p-CREB caused by heroin. Furthermore, exogenous H2S can decrease the high level of p-NR1 and can increase the low levels of p-NR2A and p-NR2B caused by heroin. It is surprising that exogenous H2S treatment alone was able to raise the activities of AC and PKA as well as the levels of cAMP, p-CREB, p-NR1, p-NR2A and p-NR2B. CONCLUSIONS: Exogenous H2S decreases naloxone-precipitated withdrawal signs, maybe through decreasing AC/cAMP/PKA/CREB/NMDR signaling pathway in heroin-dependent rats' nucleus accumbens.

Fracture of the patella treated by open reduction and external compressive skeletal fixation.

Open reduction combined with external compressive skeletal fixation was used to treat twenty-seven patients who had a separated fracture of the patella. Fixation was obtained by the use of two compressive clamps applied to stainless-steel pins that were inserted just proximal and distal to the proximal and distal poles of the patella. Range-of-motion exercises for the knee were begun at two weeks and the pins were removed at three to four weeks. All of the fractures healed. Twenty-four patients regained a range of motion that was equal to that of the opposite knee. There was no evidence of chronic osteomyelitis. Osteoarthritis was noted in one patient who refused excision of a portion of the patella.