背景:关于膳食生物活性化合物萝卜硫素(SFN)和维生素D如何调节结直肠癌的基因表达,目前还不清楚。我们假设SFN与维生素D的组合将证明对结直肠癌有益。采用组合化学预防策略来研究SFN对大肠癌染色质重塑的影响。为了了解响应SFN和维生素D的表观遗传学介导的基因表达变化,将Caco-2细胞单独或与SFN和曲古抑菌素A联合暴露于维生素D(100nmolL-1)24小时(20和1μmolL-1,分别)在70%汇合(增殖)和汇合后13天(完全分化)。对VDR的更改,使用基于实时PCR的测定对CYP24A1、CYP27B1和TRPV6基因表达进行定量。使用HDACI/II测定法评估组蛋白脱乙酰酶(HDAC)抑制剂活性,该测定法测量乙酰化状态的整体变化。
结果:在分化的Caco-2细胞中,与单独D组相比,所有基因均无明显变化。D+SFN(P=0.99)显示出与单独的D相反的作用并降低VDR表达。然而,在增殖的Caco-2细胞中,D+SFN(P<0.04)比单独D(P=0.38和0.07)增加VDR表达并降低CYP27B1(P<0.01)。尽管具有统计学意义,D+SFN(P=0.01)对HDAC抑制剂活性的影响小于曲古抑菌素A单独组(P<0.0004)或SFN单独组(P<0.0014)。
结论:数据表明,结肠癌细胞在不同条件下对饮食成分的反应不同。维生素D和SFN在体外大肠癌发生的复杂多步骤过程中具有选择性和基因特异性。©2020化学工业学会。
BACKGROUND: It is relatively unknown as to how dietary bioactive compound sulforaphane (SFN) and vitamin D regulate gene expression in colorectal cancer. We hypothesized that a combination of SFN with vitamin D would prove beneficial in colorectal cancer. A combinatorial chemo-preventive strategy was employed to investigate the impact of SFN on chromatin remodeling in colorectal carcinoma. To understand the epigenetics-mediated changes in gene expression in response to SFN and vitamin D, Caco-2 cells were exposed for 24 h to vitamin D (100 nmol L-1 ) either alone or in combination with SFN and trichostatin A (20 and 1 μmol L-1 , respectively) at 70% confluency (proliferating) and after 13 days post-confluency (fully differentiated). Changes to VDR, CYP24A1, CYP27B1 and TRPV6 gene expressions were quantified using real-time PCR-based assays. Histone deacetylase (HDAC) inhibitor activity was assessed using HDAC I/II assay that measured global changes in acetylation status.
RESULTS: In differentiated Caco-2 cells, none of the genes had significant changes from D alone group. D + SFN (P = 0.99) demonstrated an opposing effect from D alone and decreased VDR expression. However, in proliferating Caco-2 cells, D + SFN (P < 0.04) increased VDR expression and decreased CYP27B1 (P < 0.01) more than D alone (P = 0.38 and 0.07, respectively). Although statistically significant, D + SFN (P = 0.01) effect on HDAC inhibitor activity was less than trichostatin A alone group (P < 0.0004) or SFN alone group (P < 0.0014).
CONCLUSIONS: The data suggest that colon cancer cells respond to dietary components differently under different conditions. The effect of vitamin D and SFN is selective and gene-specific in the complex multistep process of colorectal carcinogenesis in vitro. © 2020 Society of Chemical Industry.