Objective Alkaline comet assay was used to evaluate DNA repair (nucleotide excision repair, NER) capacity of human fresh lymphocytes from 12 young healthy non-smokers (6 males and 6 females). Methods Lymphocytes were ...Objective Alkaline comet assay was used to evaluate DNA repair (nucleotide excision repair, NER) capacity of human fresh lymphocytes from 12 young healthy non-smokers (6 males and 6 females). Methods Lymphocytes were exposed to UV-C (254 nm) at the dose rate of 1.5 J/m2/sec. Novobiocin (NOV) and aphidicolin (APC), DNA repair inhibitors, were utilized to imitate the deficiency of DNA repair capacity at the incision and ligation steps of NER. Lymphocytes from each donor were divided into three grougs: UVC group, UVC plus NOV group, and UVC plus APC group. DNA single strand breaks were detected in UVC irradiated cells incubated for 0, 30, 60, 90, 120, 180, and 240 min after UVC irradiation. DNA repair rate (DRR) served as an indicator of DNA repair capacity. Results The results indicated that the maximum DNA damage (i.e. maximum tail length) in the UVC group mainly appeared at 90 min. The ranges of DRRs in the UVC group were 62.84%-98.71%. Average DRR value was 81.84%. The DRR difference between males and females was not significant (P<0.05). However, the average DRR value in the UVC plus NOV group and the UVC plus APC group was 52.98% and 39.57% respectively, which were significantly lower than that in the UVC group (P<0.01). Conclusion The comet assay is a rapid, simple and sensitive screening test to assess individual DNA repair (NER) capacity. It is suggested that the time to detect DNA single strand breaks in comet assay should include 0 (before UV irradiation), 90 and 240 min after exposure to 1.5 J·m-2 UVC at least. The DRR, as an indicator, can represent the individual DNA repair capacity in comet assay.展开更多
热休克蛋白90(heat shock protein 90,Hsp90)是生物进化过程中高度保守的一类蛋白质,参与很多生理过程,在信号转导中起重要作用。Hsp90抑制剂与Hsp90结合,抑制Hsp90活性,诱导Hsp90作用蛋白降解,从而阻断细胞的增殖生长,是一类具有开发...热休克蛋白90(heat shock protein 90,Hsp90)是生物进化过程中高度保守的一类蛋白质,参与很多生理过程,在信号转导中起重要作用。Hsp90抑制剂与Hsp90结合,抑制Hsp90活性,诱导Hsp90作用蛋白降解,从而阻断细胞的增殖生长,是一类具有开发前景的抗肿瘤、抗病毒药物。现对Hsp90的结构和作用机制以及4类Hsp90抑制剂——格尔德霉素及其衍生物、根赤壳菌素、新生霉素及以嘌呤结构为基础的抑制剂的研究现状进行综述。展开更多
文摘Objective Alkaline comet assay was used to evaluate DNA repair (nucleotide excision repair, NER) capacity of human fresh lymphocytes from 12 young healthy non-smokers (6 males and 6 females). Methods Lymphocytes were exposed to UV-C (254 nm) at the dose rate of 1.5 J/m2/sec. Novobiocin (NOV) and aphidicolin (APC), DNA repair inhibitors, were utilized to imitate the deficiency of DNA repair capacity at the incision and ligation steps of NER. Lymphocytes from each donor were divided into three grougs: UVC group, UVC plus NOV group, and UVC plus APC group. DNA single strand breaks were detected in UVC irradiated cells incubated for 0, 30, 60, 90, 120, 180, and 240 min after UVC irradiation. DNA repair rate (DRR) served as an indicator of DNA repair capacity. Results The results indicated that the maximum DNA damage (i.e. maximum tail length) in the UVC group mainly appeared at 90 min. The ranges of DRRs in the UVC group were 62.84%-98.71%. Average DRR value was 81.84%. The DRR difference between males and females was not significant (P<0.05). However, the average DRR value in the UVC plus NOV group and the UVC plus APC group was 52.98% and 39.57% respectively, which were significantly lower than that in the UVC group (P<0.01). Conclusion The comet assay is a rapid, simple and sensitive screening test to assess individual DNA repair (NER) capacity. It is suggested that the time to detect DNA single strand breaks in comet assay should include 0 (before UV irradiation), 90 and 240 min after exposure to 1.5 J·m-2 UVC at least. The DRR, as an indicator, can represent the individual DNA repair capacity in comet assay.
文摘热休克蛋白90(heat shock protein 90,Hsp90)是生物进化过程中高度保守的一类蛋白质,参与很多生理过程,在信号转导中起重要作用。Hsp90抑制剂与Hsp90结合,抑制Hsp90活性,诱导Hsp90作用蛋白降解,从而阻断细胞的增殖生长,是一类具有开发前景的抗肿瘤、抗病毒药物。现对Hsp90的结构和作用机制以及4类Hsp90抑制剂——格尔德霉素及其衍生物、根赤壳菌素、新生霉素及以嘌呤结构为基础的抑制剂的研究现状进行综述。
