BYSL contributes to tumor growth by cooperating with the mTORC2 complex in gliomas

Objective:BYSL,which encodes the Bystin protein in humans,is upregulated in reactive astrocytes following brain damage and/or inflammation.We aimed to determine the role and mechanism of BYSL in glioma cell growth and survival.Methods:BYSL expression in glioma tissues was measured by quantitative real-time PCR,Western blot,and immunohistochemistry.In vitro assays were performed to assess the role of BYSL in cell proliferation and apoptosis.Protein interactions and co-localization were determined by co-immunoprecipitation and double immunofluorescence.The expression and activity of the AKT/m TOR signaling molecules were determined by Western blot analysis,and the role of BYSL in glioma growth was confirmed in an orthotopic xenograft model.Results:The BYSL m RNA and protein levels were elevated in glioma tissues.Silencing BYSL inhibited glioma cell proliferation,impeded cell cycle progression,and induced apoptosis,whereas overexpressing BYSL protein led to the opposite effects.We identified a complex consisting of BYSL,RIOK2,and m TOR,and observed co-localization and positive correlations between BYSL and RIOK2 in glioma cells and tissues.Overexpressing BYSL or RIOK2 increased the expression and activity of AKT/m TOR signaling molecules,whereas downregulation of BYSL or RIOK2 decreased the activity of AKT/m TOR signaling molecules.Silencing BYSL or RIOK2 decreased the growth of the tumors and prolonged the lifespan of the animals in an orthotopic xenograft model.Conclusions:High expression of BYSL in gliomas promoted tumor cell growth and survival both in vitro and in vivo.These effects could be attributed to the association of BYSL with RIOK2 and m TOR,and the subsequent activation of AKT signaling.

Developmental expression of CAPON and Dexras1 in spinal cord of rats

To study the expression of the carboxy-ter-minal PSD-95/DLG/ZO-1 ligand of nNOS(CAPON)and Dexras1 mRNA during development in the spinal cord of rats,real-time polymerase chain reaction(Real-time PCR),as a quantitative method,was used to study the developmental expression of CAPON and Dexras1 mRNA level in the spinal cord.The spatial expression of CAPON and Dexras1 mRNA was examined by a com-bination of in situ hybridization(ISH)and immunofluor-escence.During the development of the spinal cord,CAPON mRNA was expressed in low levels from embryo day 14 to day 18.At postnatal day 1,it reached the peak and was expressed in the part which will become the dor-sal horn when mature.It then decreased gradually until postnatal week 12,when it presented in the ventral horn.At embryo day 14,Dexras1 mRNA was expressed at low levels,increased during embryo day 16 to day 18 and peaked at postnatal day 1.Spatiotemporal expression of Dexras1 mRNA was similar to CAPON as confirmed by correlation analysis and colocalization.CAPON and neuronal nitric oxide synthase(nNOS)was expressed within the same cells of the dorsal horn at postnatal day 1 but had different subcellular localizations.Co-express-ion of CAPON and Dexras1 mRNA in myeloid tissue during development process of rat indicates that the adaptor protein,CAPON may play a probable role in differentiation of neurons,synaptic plasticity and synap-togenesis by regulating nNOS to activate Dexras1.