AIM: To investigate the predictive value of Ki67 and p53 and their correlation with thymidylate synthase (TS) gene expression in a rectal cancer patient cohort treated according to a standardized recommended neoadjuva...AIM: To investigate the predictive value of Ki67 and p53 and their correlation with thymidylate synthase (TS) gene expression in a rectal cancer patient cohort treated according to a standardized recommended neoadjuvant treatment regimen.METHODS: Formalin fixed, paraffin embedded pre-therapeutical tumor biopsies (n = 22) and post-therapeutical resection specimens (n = 40) from patients with rectal adenocarcinoma (clinical UICC stage Ⅱ/Ⅲ) receiving standardized neoadjuvant 5-fluorouracil (5-FU) based chemoradiotherapy were studied for Ki67 and p53 expression by immunohistochemistry and correlated with TS mRNA expression by quantitative TaqMan real-time PCR after laser microdissection. The results were compared with histopathological tumor regression according to a standardized semiquantitative score grading system.RESULTS: Responders (patients with high tumor regression) showed a significantly lower Ki67 expression than non-responders in the pre-therapeutical tumor biopsies (81.2% vs 16.7%; P < 0.05) as well as in the post-therapeutical resection specimens (75.8% vs 14.3%; P < 0.01). High TS mRNA expression was significantly correlated with a high Ki67 index and low TS mRNA expression was significantly correlated with a low Ki67 index in the pre-therapeutical tumor biopsies (corr. coef. = 0.46; P < 0.01) as well as in the post-therapeutical resection specimens (corr. coef. = 0.40; P < 0.05). No significant association was found between p53 and TS mRNA expression or tumor regression.CONCLUSION: Ki67 has, like TS, predictive value in rectal cancer patients after neoadjuvant 5-FU based chemoradiotherapy. The close correlation between Ki67 and TS indicates that TS is involved in active cell cycle processes.展开更多
Our previous study demonstrated that a chloroplast co-chaperonin 20(CPN20),one of the interaction partners of the magnesium-protoporphyrin IX chelatase H subunit(CHLH/ABAR),negatively regulates ABA signaling at the sa...Our previous study demonstrated that a chloroplast co-chaperonin 20(CPN20),one of the interaction partners of the magnesium-protoporphyrin IX chelatase H subunit(CHLH/ABAR),negatively regulates ABA signaling at the same node with ABAR but upstream of WRKY40 transcription repressor in Arabidopsis thaliana.In the present experiment,we showed that ABA directly inhibits the ABAR-CPN20 interaction,and also represses expression of CPN20,which depends on ABAR.CPN20 inhibits ABAR-WRKY40 interaction by competitively binding to ABAR.ABAR downregulates,but CPN20 upregulates,WRKY40 expression.The cpn20-1 mutation induces downregulation of WRKY40,and suppresses the upregulated level of WRKY40 due to the cch mutation in the ABAR gene.ABA-induced repressive effect of the WRKY40 gene is strengthened by downregulation of CPN20 but reduced by upregulation of CPN20.Together with our previously reported genetic data,we provide evidence that CPN20 functions through antagonizing the ABAR-WRKY40 coupled pathway,and ABA relieves this pathway of repression by inhibiting the ABAR-CPN20 interaction to activate ABAR-WRKY40 interaction.展开更多
文摘AIM: To investigate the predictive value of Ki67 and p53 and their correlation with thymidylate synthase (TS) gene expression in a rectal cancer patient cohort treated according to a standardized recommended neoadjuvant treatment regimen.METHODS: Formalin fixed, paraffin embedded pre-therapeutical tumor biopsies (n = 22) and post-therapeutical resection specimens (n = 40) from patients with rectal adenocarcinoma (clinical UICC stage Ⅱ/Ⅲ) receiving standardized neoadjuvant 5-fluorouracil (5-FU) based chemoradiotherapy were studied for Ki67 and p53 expression by immunohistochemistry and correlated with TS mRNA expression by quantitative TaqMan real-time PCR after laser microdissection. The results were compared with histopathological tumor regression according to a standardized semiquantitative score grading system.RESULTS: Responders (patients with high tumor regression) showed a significantly lower Ki67 expression than non-responders in the pre-therapeutical tumor biopsies (81.2% vs 16.7%; P < 0.05) as well as in the post-therapeutical resection specimens (75.8% vs 14.3%; P < 0.01). High TS mRNA expression was significantly correlated with a high Ki67 index and low TS mRNA expression was significantly correlated with a low Ki67 index in the pre-therapeutical tumor biopsies (corr. coef. = 0.46; P < 0.01) as well as in the post-therapeutical resection specimens (corr. coef. = 0.40; P < 0.05). No significant association was found between p53 and TS mRNA expression or tumor regression.CONCLUSION: Ki67 has, like TS, predictive value in rectal cancer patients after neoadjuvant 5-FU based chemoradiotherapy. The close correlation between Ki67 and TS indicates that TS is involved in active cell cycle processes.
基金supported by the National Key Basic Research Program of China(2012CB114302)National Natural Science Foundation of China(90817104 and 31170268)Ministry of Agriculture of China(2013ZX08009-003)
文摘Our previous study demonstrated that a chloroplast co-chaperonin 20(CPN20),one of the interaction partners of the magnesium-protoporphyrin IX chelatase H subunit(CHLH/ABAR),negatively regulates ABA signaling at the same node with ABAR but upstream of WRKY40 transcription repressor in Arabidopsis thaliana.In the present experiment,we showed that ABA directly inhibits the ABAR-CPN20 interaction,and also represses expression of CPN20,which depends on ABAR.CPN20 inhibits ABAR-WRKY40 interaction by competitively binding to ABAR.ABAR downregulates,but CPN20 upregulates,WRKY40 expression.The cpn20-1 mutation induces downregulation of WRKY40,and suppresses the upregulated level of WRKY40 due to the cch mutation in the ABAR gene.ABA-induced repressive effect of the WRKY40 gene is strengthened by downregulation of CPN20 but reduced by upregulation of CPN20.Together with our previously reported genetic data,we provide evidence that CPN20 functions through antagonizing the ABAR-WRKY40 coupled pathway,and ABA relieves this pathway of repression by inhibiting the ABAR-CPN20 interaction to activate ABAR-WRKY40 interaction.
