Objective: To explore the effects of postmastectomy radiotherapy(PMRT) on the locoregional failure-free survival(LRFFS) and overall survival(OS) of breast cancer patients under different tumor stages and with one to t...Objective: To explore the effects of postmastectomy radiotherapy(PMRT) on the locoregional failure-free survival(LRFFS) and overall survival(OS) of breast cancer patients under different tumor stages and with one to three positive axillary lymph nodes(ALNs). Methods: We conducted a retrospective review of 527 patients with one to three positive lymph nodes who underwent modified radical or partial mastectomy and axillary dissection from January 2000 to December 2002. The patients were divided into the T1-T2 N1 and T3-T4 N1 groups. The effects of PMRT on the LRFFS and OS of these two patient groups were analyzed using SPSS 19.0, Pearson's χ2-test, Kaplan-Meier method, and Cox proportional hazard model. Results: For T1-T2 N1 patients, no statistical significance was observed in the effects of PMRT on LRFFS [hazard ratio(HR)=0.726; 95% confidence interval(CI): 0.233-2.265; P=0.582] and OS(HR=0.914; 95% CI: 0.478-1.745; P=0.784) of the general patients. Extracapsular extension(ECE) and high histological grade were the risk factors for LRFFS and OS with statistical significance in multivariate analysis. Stratification analysis showed that PMRT statistically improved the clinical outcomes in high-risk patients [ECE(+), LRFFS: P=0.026, OS: P=0.007; histological grade III, LRFFS: P<0.001, OS: P=0.007] but not in low-risk patients [ECE(–), LRFFS: P=0.987, OS: P=0.502; histological grade I-II, LRFFS: P=0.816, OS: P=0.296]. For T3-T4 N1 patients, PMRT effectively improved the local control(HR=0.089; 95% CI: 0.210-0.378; P=0.001) of the general patients, whereas no statistical effect was observed on OS(HR=1.251; 95% CI: 0.597-2.622; P=0.552). Absence of estrogen receptors and progesterone receptors(ER/PR)(–) was an independent risk factor. Further stratification analysis indicated a statistical difference in LRFFS and OS between the high-risk patients with ER/PR(–) receiving PMRT and not receiving PMRT [ER/PR(–), LRFFS: P=0.046, OS: P=0.039]. However, PMRT had a beneficial effect on the reduction of locoregional recurrence(LRR) but not in total mortality [ER/PR(+), LRFFS: P<0.001, OS: P= 0.695] in T3-T4 N1 patients with ER/PR(+) who received endocrine therapy. Conclusion: PMRT could reduce ECE(+), histological grade III-related LRR, and total mortality of T1-T2 N1 patients. T3-T4 N1 patients with ER/PR(–) could benefit from PMRT by improving LRFFS and OS. However, PMRT could only reduce LRR but failed to improve OS for T3-T4 N1 patients with ER/PR(+) who received endocrine therapy.展开更多
In quorum sensing （QS） process, bacteria regulate gene expression by utilizing small signaling molecules called autoinducers in response to a variety of environmental cues. Autoinducer 2 （AI-2）, a QS signaling mol...In quorum sensing （QS） process, bacteria regulate gene expression by utilizing small signaling molecules called autoinducers in response to a variety of environmental cues. Autoinducer 2 （AI-2）, a QS signaling molecule proposed to be involved in interspecies communication, is produced by many species of gram-negative and gram-positive bacteria. In Escherichia coil and Salmonella typhimurium, the extracellular AI-2 is imported into the cell by a transporter encoded by the lsr operon. Upstream of the lsr operon, there is a divergently transcribed gene encoding LsrR, which was reported previously to repress the transcription of the lsr operon and itself. Here, we have demonstrated for the first time that LsrR represses the transcription of the lsr operon and itself by directly binding to their promoters using gel shift and DNase I footprinting assays. The β-galactosidase reporter assays further suggest that two motifs in both the lsrR and lsrA promoter regions are crucial for the LsrR binding. Furthermore, in agreement with the conclusion that phosphorylated AI-2 can relieve the repression of LsrR in previous studies, our data show that phospho- AI-2 renders LsrR unable to bind to its own promoter in vitro.展开更多
基金supported by the Tianjin Natural Science Foundation of China (Grant No.11JCZDJC28000)
文摘Objective: To explore the effects of postmastectomy radiotherapy(PMRT) on the locoregional failure-free survival(LRFFS) and overall survival(OS) of breast cancer patients under different tumor stages and with one to three positive axillary lymph nodes(ALNs). Methods: We conducted a retrospective review of 527 patients with one to three positive lymph nodes who underwent modified radical or partial mastectomy and axillary dissection from January 2000 to December 2002. The patients were divided into the T1-T2 N1 and T3-T4 N1 groups. The effects of PMRT on the LRFFS and OS of these two patient groups were analyzed using SPSS 19.0, Pearson's χ2-test, Kaplan-Meier method, and Cox proportional hazard model. Results: For T1-T2 N1 patients, no statistical significance was observed in the effects of PMRT on LRFFS [hazard ratio(HR)=0.726; 95% confidence interval(CI): 0.233-2.265; P=0.582] and OS(HR=0.914; 95% CI: 0.478-1.745; P=0.784) of the general patients. Extracapsular extension(ECE) and high histological grade were the risk factors for LRFFS and OS with statistical significance in multivariate analysis. Stratification analysis showed that PMRT statistically improved the clinical outcomes in high-risk patients [ECE(+), LRFFS: P=0.026, OS: P=0.007; histological grade III, LRFFS: P<0.001, OS: P=0.007] but not in low-risk patients [ECE(–), LRFFS: P=0.987, OS: P=0.502; histological grade I-II, LRFFS: P=0.816, OS: P=0.296]. For T3-T4 N1 patients, PMRT effectively improved the local control(HR=0.089; 95% CI: 0.210-0.378; P=0.001) of the general patients, whereas no statistical effect was observed on OS(HR=1.251; 95% CI: 0.597-2.622; P=0.552). Absence of estrogen receptors and progesterone receptors(ER/PR)(–) was an independent risk factor. Further stratification analysis indicated a statistical difference in LRFFS and OS between the high-risk patients with ER/PR(–) receiving PMRT and not receiving PMRT [ER/PR(–), LRFFS: P=0.046, OS: P=0.039]. However, PMRT had a beneficial effect on the reduction of locoregional recurrence(LRR) but not in total mortality [ER/PR(+), LRFFS: P<0.001, OS: P= 0.695] in T3-T4 N1 patients with ER/PR(+) who received endocrine therapy. Conclusion: PMRT could reduce ECE(+), histological grade III-related LRR, and total mortality of T1-T2 N1 patients. T3-T4 N1 patients with ER/PR(–) could benefit from PMRT by improving LRFFS and OS. However, PMRT could only reduce LRR but failed to improve OS for T3-T4 N1 patients with ER/PR(+) who received endocrine therapy.
基金We thank our colleagues J Zang and X Liu for their technical assistance in protein purification. This work was supported by the One Hundred Talent Project of the Chinese Academy of Sciences and the National Natural Science Foundation of China （50738006）.
文摘In quorum sensing （QS） process, bacteria regulate gene expression by utilizing small signaling molecules called autoinducers in response to a variety of environmental cues. Autoinducer 2 （AI-2）, a QS signaling molecule proposed to be involved in interspecies communication, is produced by many species of gram-negative and gram-positive bacteria. In Escherichia coil and Salmonella typhimurium, the extracellular AI-2 is imported into the cell by a transporter encoded by the lsr operon. Upstream of the lsr operon, there is a divergently transcribed gene encoding LsrR, which was reported previously to repress the transcription of the lsr operon and itself. Here, we have demonstrated for the first time that LsrR represses the transcription of the lsr operon and itself by directly binding to their promoters using gel shift and DNase I footprinting assays. The β-galactosidase reporter assays further suggest that two motifs in both the lsrR and lsrA promoter regions are crucial for the LsrR binding. Furthermore, in agreement with the conclusion that phosphorylated AI-2 can relieve the repression of LsrR in previous studies, our data show that phospho- AI-2 renders LsrR unable to bind to its own promoter in vitro.
