Differential effects of cholesterol and phytosterols on cell proliferation, apoptosis and expression of a prostate specific gene in prostate cancer cell lines
Differential effects of cholesterol and phytosterols on cell proliferation, apoptosis and expression of a prostate specific gene in prostate cancer cell lines
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DOI：
10.1016/j.cdp.2008.12.002
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发表时间：
2009-01-01
影响因子：
--
通讯作者：
Ananaba, Godwin A.
中科院分区：
文献类型：
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作者：
Ifere, Godwin O.;Barr, Erika;Ananaba, Godwin A.
背景资料：我们研究的目的是显示与胆固醇作用不同的植物甾醇对前列腺癌细胞系的凋亡和抗增殖作用，以及它们对小窝蛋白-1和前列腺特异性基因PCGEM 1的差异表达。PC-3和DU 145细胞用甾醇处理（胆固醇和植物甾醇）处理48小时，然后分别进行细胞毒性的台盼蓝染料排除测量和MTT细胞增殖测定。细胞周期分析在显微镜下进行，并通过碘化丙啶摄取使用流式细胞术。通过RT-PCR评价甾醇对致癌基因表达的诱导作用。采用DNA片段化免疫细胞化学法和流式细胞术检测膜联蛋白V粘附来鉴定凋亡细胞。结果：生理剂量（16 μ M）的这些甾醇在这些细胞中没有细胞毒性。高胆固醇促进有丝分裂（在PC-3和DU 145中分别为54%和61%，通过显微镜检查，40.8%和34.08%，通过FACS分析）和细胞生长（P < 0.05），而植物甾醇抑制有丝分裂（在PC-3和DU 145中，显微镜下分别为29%和35%，流式细胞仪分析分别为27.71%和17.37%），并显著诱导肿瘤抑制（P < 0.05）和凋亡。我们首次证明，胆固醇上调PCGEM 1的表达，即使在雄激素不敏感的前列腺癌细胞系。植物甾醇逆转了这种效应，同时上调了小窝蛋白-1的表达，小窝蛋白-1是一种已知的雄激素依赖性原癌基因信号的介体，推测其控制生长和抗凋亡。结论：植物甾醇对PCGEM 1和细胞生长的抑制以及小窝蛋白-1的过表达表明，不良的疾病预后依赖于小窝蛋白-1调节下游癌基因和凋亡基因的能力。固醇摄入可能导致前列腺癌发病率的差异，阐明调节生长和凋亡信号传导的机制可能揭示癌症预防和/或化疗干预的潜在靶点。PCGEM 1表达的甾醇调节表明其作为生物标志物的潜力，用于预测对植物甾醇的化学预防有反应的肿瘤。爱思唯尔有限公司出版
Background: The purpose of our study was to show the apoptotic and anti-proliferative effects of phytosterols as distinct from cholesterol effects on prostate cancercell lines, and also their differential expression of caveolin-1, and a prostate specific gene, PCGEM1 Methods: PC-3 and DU145 cells were treated with sterols (cholesterol and phytosterols) for 48 h, followed by trypan blue dye exclusion measurement of cytotoxicity and MTT cell proliferation assays, respectively. Cell cycle analysis was carried out microscopically, and by propidium iodide uptake using flow cytometry. Sterol induction of oncogenic gene expression was evaluated by RT-PCR. Apoptotic cells were identified by immunocytochemistry using DNA fragmentation method, and by annexin V adhesion using flow cytometry. Results: Physiological doses (16 mu M) of these sterols were not cytotoxic in these cells. Cholesterol-enrichment promoted mitosis (54 and 61% by microscopy 40.8 and 34.08% by FACS analysis in PC-3 and DU145, respectively) and cell growth (P < 0.05), while phytosterols suppressed mitosis (29 and 35% by microscopy 27.71 and 17.37% by FACS analysis in PC-3 and DU145, respectively), and significantly induced tumor-suppression (P < 0.05) and apoptosis. We demonstrated for the first time that cholesterols upregulated the expression of PCGEM1 even in androgen insensitive prostate cancer cell lines. Phytosterols reversed this effect, while upregulating the expression of caveolin-1, a known mediator of androgen-dependent proto-oncogene signals that presumably control growth and anti-apoptosis. Conclusions: Phytosterol inhibition of PCGEM1 and cell growth and the overexpression of caveolin-1, suggests that poor disease prognosis anchors on the ability of caveolin-1 to regulate downstream oncogene(s) and apoptosis genes. Sterol intake may contribute to the disparity in incidence of prostate cancer, and elucidation of the mechanism for modulation of growth and apoptosis signaling may reveal potential targets for cancer prevention and/or chemotherapeutic intervention. Sterol regulation of PCGEM1 expression suggests its potential as biomarker for prediction of neoplasms that would be responsive to chemoprevention by phytosterols. Published by Elsevier Ltd.