Regulation of vitamin D receptor abundance and responsiveness during differentiation of HT-29 human colon cancer cells.
Regulation of vitamin D receptor abundance and responsiveness during differentiation of HT-29 human colon cancer cells.
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DOI：
10.1210/endo.132.4.8384998
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发表时间：
1993-04
期刊：
影响因子：
4.8
通讯作者：
Xi Zhao;David Feldman
中科院分区：
文献类型：
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作者：
Xi Zhao;David Feldman
我们研究了1,25-二羟基维生素D [1,25-(OH)2D3]对HT-29人结肠癌细胞系细胞分化的影响。我们的目的是评估1,25-二羟基维生素D受体（VDR）丰度和激素反应在快速增殖向分化细胞转变过程中的调节。通过三种方式诱导分化：细胞在不含葡萄糖的半乳糖补充培养基（GAL）中培养，在matrigel涂层表面（MTG）上生长，或用125 (OH)2D3处理。用[3H]胸腺嘧啶掺入来评估细胞增殖，用1,25(OH)2D3、GAL或MTG处理同样可以抑制细胞增殖。通过诱导增殖细胞中的低氨基寡聚肽酶活性来评估细胞分化。在用1,25(OH)2D3处理后，或者在GAL或MTG上生长，氨基寡聚肽酶活性增加了8- 9倍。与增殖细胞相比，通过[3H]1,25(OH)2D3结合测量的VDR丰度减少到一半，但亲和力没有显著变化。分化细胞的Northern blot分析显示VDR信使RNA （mRNA）的稳态水平降低，表明所有三种处理在mRNA水平上相似地降低了VDR的丰度，至少在一定程度上。暴露于1,25(OH)2D3时，增殖细胞表现出同源的VDR上调和24-羟化酶mRNA的诱导；分化的细胞没有表现出这两种生物学反应。我们的研究结果表明，1,25(OH)2D3、GAL和MTG处理均抑制HT-29细胞增殖并刺激分化。通过这三种方法实现的增殖后分化与VDR丰度降低、VDR同源上调缺失以及对1,25(OH)2D3的激素无反应相关。
We have studied the effects of 1,25-dihydroxyvitamin D [1,25-(OH)2D3] on cellular differentiation in the HT-29 human colon cancer cell line. Our aim was to evaluate the regulation of 1,25-dihydroxyvitamin D receptor (VDR) abundance and hormone responsiveness during the transition of rapidly proliferating to differentiated cells. Differentiation was induced by three means: cells were cultured in galactose-supplemented medium without glucose (GAL), grown on Matrigel-coated surfaces (MTG), or treated with 1,25(OH)2D3. Cell proliferation, assessed by [3H]thymidine incorporation, was equivalently inhibited by treatment with 1,25(OH)2D3, GAL or MTG. Differentiation was assessed by the induction of amino-oligo peptidase activity which was low in the proliferating cells. Following treatment with 1,25(OH)2D3, or growth in GAL or on MTG, amino-oligo peptidase activity increased 8- to 9-fold. The abundance of VDR measured by [3H]1,25(OH)2D3 binding, decreased to half without significant change in affinity, in cells differentiated by all three means compared to proliferating cells. Northern blot analyses of differentiated cells showed decreased steady-state levels of VDR messenger RNA (mRNA), indicating that all three treatments similarly decreased the abundance of VDR, at least in part, at the mRNA level. When exposed to 1,25(OH)2D3, the proliferating cells exhibited homologous up-regulation of VDR as well as the induction of 24-hydroxylase mRNA; the differentiated cells failed to exhibit both of these biological responses. Our findings demonstrate that 1,25(OH)2D3, GAL and MTG treatment all inhibit HT-29 cell proliferation and stimulate differentiation. Postproliferative differentiation achieved by the three approaches was associated with decreased VDR abundance, loss of VDR homologous up-regulation, and development of hormone unresponsiveness to 1,25(OH)2D3.