School of Pharmacy, Inner Mongolia Medical University, PR China; Jungar Banner Central Hospital, Erdos, Inner Mongolia Autonomous Region, PR China.
School of Pharmacy, Inner Mongolia Medical University, PR China.
Toxicol In Vitro. 2022 Sep;83:105372. doi: 10.1016/j.tiv.2022.105372. Epub 2022 Apr 27.
The effects of benzo (α) pyrene (BaP) on chaperone mediated autophagy (CMA) through heat shock protein 90 (HSP90) and hypoxia- inducible factor-1 (HIF-1) are studied by RNA interference and subcutaneous tumor formation technique in nude mice.
40 nude mice that were inoculated with the silenced HSP90ɑ A549 cells line under the armpits of the forelimbs were divided into 4 groups, and were intragastrically administered with 1.80 mg/kg/d BaP-corn oil solutionfor for 60d (except the Control group), and the growth curves of nude mice and transplanted tumors were recorded. The size and morphological changes of tumors were observed by small animal imaging technique. qPCR, Western blot and Immunohistochemistry were used to detect the expression of HSP90ɑ, HSC70 and Lamp-2A. A549 cells were treated with 0.1 μmol/L, 1 μmol/L and 10 μmol/L BaP for 24 h, EPO and HIF-1ɑ concentration and HIF-1ɑ protein expression were detected by Elisa and Western blot; A549 cells were treated with 10 μmol/L BaP and HIF-1ɑ inhibitor for 24 h, qPCR, Western blot and Immunofluorescence methods were used to detect the expression of HSP90ɑ, HSC70 and Lamp-2A.
The weight of nude mice and transplanted tumors silenced HSP90ɑ was reduced by BaP; the expression of HSP90ɑ, HSC70, Lamp-2A mRNA and proteins in transplanted tumor tissues silenced HSP90ɑ were reduced by BaP; the total number of bioluminescence photons of transplanted tumors silenced HSP90ɑ were reduced by BaP. The concentration of EPO and HIF-1ɑ and the expression of HIF-1ɑ protein in A549 cells was increased by 10 μmol/L BaP; with HIF-1ɑ inhibitors treated, HSP90ɑ, HSC70, Lamp-2A mRNA and proteins expression and the fluorescence intensity of HSP90ɑ were decreased of A549 cells.
The growth of transplanted tumor in nude mice is promoted by BaP, and is inhibited when HSP90ɑ was silenced. BaP promotes the occurrence of CMA by promoting the expression of HSP90ɑ and HIF-1ɑ, which are vital regulatory genes of BaP activation of CMA.
通过 RNA 干扰和裸鼠皮下肿瘤形成技术，研究苯并（α）芘（BaP）通过热休克蛋白 90（HSP90）和缺氧诱导因子-1（HIF-1）对伴侣介导的自噬（CMA）的影响。
将沉默 HSP90ɑ A549 细胞系接种于前肢腋窝下的 40 只裸鼠分为 4 组，每组每天灌胃给予 1.80mg/kg/d BaP-玉米油溶液，共 60d（对照组除外），记录裸鼠生长曲线和移植瘤。采用小动物成像技术观察肿瘤的大小和形态变化。qPCR、Western blot 和免疫组织化学法检测 HSP90ɑ、HSC70 和 Lamp-2A 的表达。用 0.1μmol/L、1μmol/L 和 10μmol/L BaP 处理 A549 细胞 24h，用 Elisa 和 Western blot 检测 EPO 和 HIF-1ɑ浓度和 HIF-1ɑ蛋白表达；用 10μmol/L BaP 和 HIF-1ɑ抑制剂处理 A549 细胞 24h，用 qPCR、Western blot 和免疫荧光法检测 HSP90ɑ、HSC70 和 Lamp-2A 的表达。
沉默 HSP90ɑ的裸鼠体重和移植瘤重量减轻；沉默 HSP90ɑ的移植瘤组织中 HSP90ɑ、HSC70、Lamp-2A mRNA 和蛋白表达降低；沉默 HSP90ɑ的移植瘤总生物发光光子数减少。10μmol/L BaP 增加 A549 细胞中 EPO 和 HIF-1ɑ的浓度和 HIF-1ɑ蛋白的表达；用 HIF-1ɑ抑制剂处理后，A549 细胞中 HSP90ɑ、HSC70、Lamp-2A mRNA 和蛋白表达及 HSP90ɑ荧光强度降低。
BaP 促进 HSP90ɑ和 HIF-1ɑ的表达，从而促进 CMA 的发生，促进裸鼠移植瘤的生长，当沉默 HSP90ɑ时，其生长受到抑制。BaP 是通过激活 CMA 的关键调节基因 HSP90ɑ和 HIF-1ɑ来促进 CMA 的发生。
