Cyclin-dependent kinase 5（Cdk5） is a member of the serine-threonine kinase family of cyclin-dependent kinases. Cdk5 is critical to normal mammalian nervous system development and plays important regulatory roles in ...Cyclin-dependent kinase 5（Cdk5） is a member of the serine-threonine kinase family of cyclin-dependent kinases. Cdk5 is critical to normal mammalian nervous system development and plays important regulatory roles in multiple cellular functions. Recent evidence indicates that Cdk5 is inappropriately activated in several neurodegenerative conditions, including Parkinson＇s disease（PD）. PD is a chronic neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunction. During neurotoxicity, p35 is cleaved to form p25. Binding of p25 with Cdk5 leads deregulation of Cdk5 resulting in number of neurodegenerative pathologies. To date, strategies to specifically inhibit Cdk5 hyperactivity have not been successful without affecting normal Cdk5 activity. Here we show that inhibition of p25/Cdk5 hyperactivation through TFP5/TP5, truncated 24-aa peptide derived from the Cdk5 activator p35 rescues nigrostriatal dopaminergic neurodegeneration induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine（MPTP/MPP＋） in a mouse model of PD. TP5 peptide treatment also blocked dopamine depletion in the striatum and improved gait dysfunction after MPTP administration. The neuroprotective effect of TFP5/TP5 peptide is also associated with marked reduction in neuroinflammation and apoptosis. Here we show inhibition of Cdk5/p25-hyperactivation by TFP5/TP5 peptide, which identifies Cdk5/p25 as a potential therapeutic target to reduce neurodegeneration in PD.展开更多
TP-5 and Thy(1, synthesized by solid phase synthesis, have the effect to restrain the formation of superoxide anion in xanthine oxidase system in vitro. The formations of lipid peroxide in several organs (such as live...TP-5 and Thy(1, synthesized by solid phase synthesis, have the effect to restrain the formation of superoxide anion in xanthine oxidase system in vitro. The formations of lipid peroxide in several organs (such as liver, brain and thymus) of the mice treated with TP-5, TP-5(R, active fragment of Thy(1 and active fragment of Thy(1(R of 10 (g(kg(d-1 for 10 d were decreased. That means these peptides possess the capability of antioxidezation.展开更多
AIM To investigate the predictive value of PIK3 CA and TP53 mutation status in colorectal cancer(CRC) patients treated with 5-fluorouracil-based chemotherapy.METHODS In this study, a total of 315 patients with histolo...AIM To investigate the predictive value of PIK3 CA and TP53 mutation status in colorectal cancer(CRC) patients treated with 5-fluorouracil-based chemotherapy.METHODS In this study, a total of 315 patients with histologically proven CRC were enrolled from Yangpu Hospital affiliated to Shanghai Tongji University between 2007 and 2011. Of these patients, 241 with stage Ⅱ/Ⅲ CRC received 5-fluorouracil-based adjuvant chemotherapy. Formalin-fixed paraffin-embedded lesion samples of the patients with curatively resected CRC were collected.Next-generation sequencing was performed to identify somatic gene mutations. The correlation of PIK3 CA and TP53 mutation status with overall survival(OS) was analyzed using a Cox proportional hazard model and the Kaplan-Meier method.RESULTS Among the 241 patients with stage Ⅱ/Ⅲ in this cohort, the PIK3 CA and/or TP53 mutation was detected in 177 patients, among which 54 patients had PIK3 CA and TP53 double mutations. The PIK3 CA or TP53 mutation was not significantly correlated with OS in univariate and multivariate analyses. Compared with patients without PIK3 CA and TP53 mutations, those with double PIK3 CA-TP53 mutations showed a significantly worse survival(univariate HR = 2.21; 95%CI: 1.15-4.24; multivariate HR = 2.02; 95%CI: 1.04-3.91). The PIK3 CA mutation located in the kinase domain showed a trend toward a shorter OS compared with wild-type tumors(multivariate HR = 1.56; 95%CI: 1.00-2.44; P = 0.052). The Kaplan-Meier curve showed that patients harboring the PIK3 CA mutation located in the kinase domain had a worse clinical outcome than those with wild-type status(Log-rank P = 0.041)CONCLUSION Double mutation of PIK3 CA and TP53 is correlated with a shorter OS in stage Ⅱ/Ⅲ CRC patients treated with 5-fluorouracil-based therapy.展开更多
文摘Cyclin-dependent kinase 5（Cdk5） is a member of the serine-threonine kinase family of cyclin-dependent kinases. Cdk5 is critical to normal mammalian nervous system development and plays important regulatory roles in multiple cellular functions. Recent evidence indicates that Cdk5 is inappropriately activated in several neurodegenerative conditions, including Parkinson＇s disease（PD）. PD is a chronic neurodegenerative disorder characterized by the loss of dopamine neurons in the substantia nigra, decreased striatal dopamine levels, and consequent extrapyramidal motor dysfunction. During neurotoxicity, p35 is cleaved to form p25. Binding of p25 with Cdk5 leads deregulation of Cdk5 resulting in number of neurodegenerative pathologies. To date, strategies to specifically inhibit Cdk5 hyperactivity have not been successful without affecting normal Cdk5 activity. Here we show that inhibition of p25/Cdk5 hyperactivation through TFP5/TP5, truncated 24-aa peptide derived from the Cdk5 activator p35 rescues nigrostriatal dopaminergic neurodegeneration induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine（MPTP/MPP＋） in a mouse model of PD. TP5 peptide treatment also blocked dopamine depletion in the striatum and improved gait dysfunction after MPTP administration. The neuroprotective effect of TFP5/TP5 peptide is also associated with marked reduction in neuroinflammation and apoptosis. Here we show inhibition of Cdk5/p25-hyperactivation by TFP5/TP5 peptide, which identifies Cdk5/p25 as a potential therapeutic target to reduce neurodegeneration in PD.
文摘TP-5 and Thy(1, synthesized by solid phase synthesis, have the effect to restrain the formation of superoxide anion in xanthine oxidase system in vitro. The formations of lipid peroxide in several organs (such as liver, brain and thymus) of the mice treated with TP-5, TP-5(R, active fragment of Thy(1 and active fragment of Thy(1(R of 10 (g(kg(d-1 for 10 d were decreased. That means these peptides possess the capability of antioxidezation.
基金Supported by the National Natural Science Foundation of China,No.81272480Science and Technology Commi-ssion of Shanghai Municipality,No.15411969900 and No.16DZ2342200
文摘AIM To investigate the predictive value of PIK3 CA and TP53 mutation status in colorectal cancer(CRC) patients treated with 5-fluorouracil-based chemotherapy.METHODS In this study, a total of 315 patients with histologically proven CRC were enrolled from Yangpu Hospital affiliated to Shanghai Tongji University between 2007 and 2011. Of these patients, 241 with stage Ⅱ/Ⅲ CRC received 5-fluorouracil-based adjuvant chemotherapy. Formalin-fixed paraffin-embedded lesion samples of the patients with curatively resected CRC were collected.Next-generation sequencing was performed to identify somatic gene mutations. The correlation of PIK3 CA and TP53 mutation status with overall survival(OS) was analyzed using a Cox proportional hazard model and the Kaplan-Meier method.RESULTS Among the 241 patients with stage Ⅱ/Ⅲ in this cohort, the PIK3 CA and/or TP53 mutation was detected in 177 patients, among which 54 patients had PIK3 CA and TP53 double mutations. The PIK3 CA or TP53 mutation was not significantly correlated with OS in univariate and multivariate analyses. Compared with patients without PIK3 CA and TP53 mutations, those with double PIK3 CA-TP53 mutations showed a significantly worse survival(univariate HR = 2.21; 95%CI: 1.15-4.24; multivariate HR = 2.02; 95%CI: 1.04-3.91). The PIK3 CA mutation located in the kinase domain showed a trend toward a shorter OS compared with wild-type tumors(multivariate HR = 1.56; 95%CI: 1.00-2.44; P = 0.052). The Kaplan-Meier curve showed that patients harboring the PIK3 CA mutation located in the kinase domain had a worse clinical outcome than those with wild-type status(Log-rank P = 0.041)CONCLUSION Double mutation of PIK3 CA and TP53 is correlated with a shorter OS in stage Ⅱ/Ⅲ CRC patients treated with 5-fluorouracil-based therapy.
