Objective:To investigate the interaction between heat shock protein 90 (Hsp90) and silent mating-type information regulation 2 homolog 1 (SIRT1) and evaluate its effect on epithelial-mesenchymal transition (EMT) of lung cancer A549 cells.Methods:EMT model was established by treating lung cancer A549 cells with 5 μg/L transforming growth factor-β1 (TGF-β1), which was used as TGF-β1 group, and the normal lung cancer A549 cells were used as control group. The interaction between Hsp90 and SIRT1 in lung cancer A549 cells was detected by immunocoprecipitation method. The expression of Hsp90 gene was silenced by RNA interference technique, and the cells were divided into TGF-β1 group, TGF-β1+ siRNA-Hsp90-neg group and TGF-β1+ siRNA-Hsp90 group. Transwell invasion assay was used to investigate the effect of the interaction of Hsp90 and SIRT1 on the invasion ability of lung cancer A549 cells. The expressions of Hsp90, SIRT1, E-cadherin and vimentin were detected by Western blotting. The effect of inhibiting Hsp90 expression on the stability of SIRT1 protein and EMT of lung cancer A549 cells was observed.Results:After 48 h induction with TGF-β1, EMT characteristics of lung cancer A549 cells were induced successfully. The relative expression levels of Hsp90 protein in the control group and TGF-β1 group were 0.45±0.05 and 1.31±0.06, respectively, the relative expression levels of SIRT1 protein were 0.29±0.04 and 0.95±0.08, respectively, and there were statistically signigicant differences ( t=10.98, P=0.018; t=7.39, P=0.028). The results of immunocoprecipitation showed that there was an interaction between Hsp90 and SIRT1 protein in lung cancer A549 cells. The relative expression levels of Hsp90 in the TGF-β1 group, TGF-β1+ siRNA-Hsp90-neg group and TGF-β1+ siRNA-Hsp90 group were 0.75±0.07, 0.63±0.06 and 0.23±0.05, respectively, and there was a statistically significant difference ( F=18.85, P=0.012). The relative expression levels of SIRT1 in the above three groups were 0.99±0.08, 0.97±0.12 and 0.35±0.05, respectively, and there was a statistically significant difference ( F=16.52, P=0.014). The expression levels of Hsp90 and SIRT1 in the TGF-β1+ siRNA-Hsp90 group were significantly lower than those in the TGF-β1 group ( P=0.019, P=0.016). The numbers of cells passing Matrigel in the above three groups were 378.13±27.70, 323.52±19.82 and 142.51±22.54, respectively, and there was a statistically significant difference ( F=27.35, P=0.022). The number of cells passing Matrigel in the TGF-β1+ siRNA-Hsp90 group was significantly less than that in the TGF-β1 group ( P=0.028). The relative expression levels of E-cadherin in the above three groups were 0.31±0.02, 0.34±0.04 and 0.63±0.05, respectively, and there was a statistically significant difference ( F=19.39, P=0.031). The relative expression levels of vimentin in the above three groups were 0.33±0.02, 0.27±0.05 and 0.09±0.03, respectively, and there was a statistically significant difference ( F=12.58, P=0.012). The expression level of E-cadherin in the TGF-β1+ siRNA-Hsp90 group was significantly higher than that in the TGF-β1 group ( P=0.017), while the expression level of vimentin was significantly lower than that in the TGF-β1 group ( P=0.023). Conclusion:Hsp90 interacts with SIRT1, and Hsp90 inhibition can lead to the decrease of SIRT1 protein level. Hsp90 may play a role of molecular chaperone to maintain the conformation stability of SIRT1, and the interaction between Hsp90 and SIRT1 may be one of the molecular mechanisms for the occurrence of EMT and the enhancement of invasion ability of lung cancer A549 cells.

Objective To investigate the effect of smoking on the semen quality in infertile men.Methods A total of 360 male infertility patients were enrolled and divided into the smoking group(n=190)and non-smoking group(n=170)based on whether they smoked or not.Furthermore,the smoking group was subdivided into group A(≤10 sticks/d,n=63),group B(11～20 sticks/d,n=80),and group C(>20 sticks/d group,n=47)according to the amount of smoking.Semen volume,liquefaction time,sperm concentration,motility,DNA fragmentation rate and normal morphological rate were observed and compared between and within the groups.Results There were significant differences in semen volume,liquefaction time,sperm motility,normal morphological rate and DNA fragmentation rate between the smoking group and the non-smoking group(P<0.05).The semen volume,sperm motility and normal morphological rate of the smoking group were lower than those in the non-smoking group,and the DNA fragmentation rate and semen liquefaction time were higher than those in the non-smoking group.And with the increase of smoking volume,sperm motility and normal morphological rate decreased,semen liquefaction time and DNA fragmentation rate increased,and there was no significant difference in the sperm concentration between the smoking group and non-smoking group(P>0.05).There was no significant difference in the semen volume between the three groups with different smoking amounts(P>0.05).Conclusion Smoking has a negative impact on the sperm quality parameters such as semen volume,sperm motility,normal morphological rate,sperm motility,liquefaction time and DNA fragmentation,and the effect of heavy smoking is particularly obvious.We should strengthen the comprehensive health education,promote the healthy lifestyles and reduce smoking.