PM2.5对HK-2肾细胞部分癌基因和凋亡基因表达的影响

目的： 探讨PM_2.5对人肾上皮细胞（HK-2）部分癌基因和凋亡基因表达的影响。方法： 利用CCK-8试剂盒测定PM_2.5混悬液对HK-2细胞的半数抑制浓度（IC₅₀）；实验设阴性对照组、PM_2.5混悬液低剂量（10 μg/mL）、高剂量（50 μg/mL）染毒组和阳性对照组（Cr⁶⁺ 10 μmol/L），分别对HK-2细胞处理24 h后利用实时荧光定量PCR （qPCR）和Western blot检测癌基因（c-myc、c-fos、p53）和凋亡基因（Caspase-8、Caspase-9、Bcl-2） mRNA和蛋白的表达水平。结果： PM_2.5混悬液对HK-2细胞的IC₅₀为95.98 μg/mL；经PM_2.5混悬液染毒24 h，qPCR结果显示，与阴性对照组比较，PM_2.5混悬液高剂量组和阳性对照组c-myc、c-fos、Caspase-8、Caspase-9 mRNA表达均升高，差异均有统计学意义（P < 0.01）；p53和Bcl-2 mRNA表达降低，差异均有统计学意义（P < 0.01）。Western blot结果显示，与阴性对照组比较，PM_2.5混悬液高剂量组和阳性对照组c-myc、c-fos、Caspase-8、Caspase-9蛋白表达均升高，差异均有统计学意义（P < 0.01）；p53和Bcl-2蛋白表达均降低，差异均具有统计学意义（P < 0.05）。结论： PM_2.5可引起HK-2细胞中部分癌基因表达上升、抑癌基因表达下降、促凋亡基因表达上升和抑凋亡基因表达下降，提示PM_2.5对HK-2肾细胞部分癌基因和凋亡基因具有一定的促进与激活作用。

Effects of PM2.5 exposure on expression of oncogenes and apoptosis genes in human renal epithelial cells

OBJECTIVE: To investigate the effect of PM_2.5 exposure on expression of oncogenes and apoptosis genes in human renal epithelial cells (HK-2). METHODS: The CCK8 assay was used to obtain the half maximal inhibitory concentration (IC₅₀) of Taiyuan PM_2.5 on human renal epithelial (HK-2) cells. HK-2 cells were treated with PM_2.5 for 24 h. Four groups were set up:negative control group, low-dose PM_2.5 group (10 μg/mL PM_2.5), high-dose PM_2.5 group (50 μg/mL PM_2.5) and positive control group (Cr6+10 μmol/l). qPCR and Western blot were used to detect mRNA and proteins levels of apoptosis genes and oncogenes (c-myc, c-fos, p53, Caspase-8, Caspase-9 and Bcl-2). RESULTS: The IC₅₀ value of Taiyuan PM_2.5 on HK-2 cells was 95.98 μg/mL. After 24 hours of PM_2.5 exposure, qPCR results show that, compared with the control group, expressions of c-myc, c-fos, Caspase-8, Caspase-9 mRNAs were significantly increased in the high-dose and positive control groups (P < 0.01). However, expressions of p53 and Bcl-2 mRNAs were significantly decreased in these two groups (P < 0.01). Western blot data show that, compared with the control group, expressions of c-myc, c-fos, Caspase-8, Caspase-9 proteins were significantly increased in the high-dose and positive control groups (P < 0.01). However, expressions of p53 and Bcl-2 proteins were significantly decreased in these two groups (P < 0.05). CONCLUSION: PM_2.5 exposure to HK-2 cells increased the expression of oncogenes and apoptosis genes but decreased the expression of tumor suppressor and anti-apoptosis genes. Our results suggest that PM_2.5 exposure can promote oncogenesis.