6甲酰基吲哚并[3,2-b]咔唑通过下调角质细胞生长因子受体抑制结肠癌细胞增殖

6-formylindolo [3,2-b] carbazole inhibits proliferation in colon cancer cells by down-regulating keratinocyte growth factor receptor

目的研究芳香烃受体(aryl hydrocarbon receptor,AhR)及其配体6甲酰基吲哚并[3,2-b]咔唑(6-formylindolo[3,2-b]carbazole,FICZ)对结直肠癌上皮细胞表面角质细胞生长因子受体(keratinocyte growth factor receptor,KGFR)的调控和对细胞增殖的影响。方法选用免疫组化和荧光定量PCR技术分别检测KGFR在结直肠正常组织和相应癌组织中的表达和定位,免疫荧光观察AhR在两种结肠癌细胞株(Lo Vo,Caco-2细胞株)中的分布,使用蛋白免疫印迹和荧光定量PCR检测AhR、细胞色素P4501A1(CYP1A1)、KGFR在FICZ处理组和对照组中的表达差异,使用细胞计数板分别检测对照组,KGF处理组,KGF+FICZ处理组和FICZ处理组各组的细胞数。结果 12个结直肠癌临床样本中有11个患者样品中KGF高表达,8个患者样品中KGFR显著增高且KGFR主要高表达于上皮细胞。体外实验发现,FICZ处理后的Lo Vo细胞中KGFR的蛋白水平和mRNA水平分别降低了50%和58.8%。在Caco2细胞中分别降低了52.6%和62.5%。这种调节过程能被AhR抑制剂CH223191阻断。同时,在两种结肠癌细胞系中,FICZ能够降低KGF对癌细胞的增殖作用(Lo Vo:34%;Caco-2:37%)。结论 AhR通过下调KGFR的表达,抑制KGF对癌细胞的增殖效应。

Objective To determine the regulative effect of aryl hydrocarbon receptor （AhR） and its ligand, 6-formylindolo [ 3, 2-b ] earbazole （FICZ）, in the expression of keratinocyte growth factor receptor （KGFR） and proliferation in colorectal cancer epithelial cells. Methods The expression and location of KGFR were detected in the normal tissues and coloreetal cancer tissues by immunohistochemical staining and real-time PCR. assay was used to observed the location of AhR in LoVe and Caco-2 cell lines. The expression levels of AhR, CYP1A1 and KGFR were detected by Western blotting and real-time PCR in the FICZ treated cells and control cells.. Cell proliferation was measured by counting the cell number among the normal, KGF treated, KGF ＋ FICZ treated and FICZ treated cells, respectively. Results KGF was highly expressed in the 11 specimens from the 12 cancer cases, and KGFR was strongly expressed in the 8 specimens of 12 cases and was located mainly on the intestinal epithelial cells. In vitro study found that FICZ treatment resulted in 50% and 58.8% respectively decreases in the expression of KGFR at protein and mRNAlevels in LoVo cells, and 52. 6% and 62. 5% respectively in Caco-2 cells. However, AhR inhibitor CH223191 could block this down-regulated expression of KGFR. Furthermore, FICZ could decrease the KGF- induced cell proliferation in LoVo （34%） and Caco-2 cells （37%）. Gonclusion AhR inhibits the proliferation of colon cancer cells induced by KGF through down-regulating the expression of KGFR.