Department of Pathogen Biology and Immunology, Xi'an Medical College, Xi'an 710021, Shaanxi, P.R. China.
Int J Mol Med. 2012 Jul;30(1):100-6. doi: 10.3892/ijmm.2012.953. Epub 2012 Mar 26.
Certain components of apples have been shown to prevent cancer growth and impede cancer progression. We hypothesized that extracted apple polysaccharides (APs) might, therefore, have anticancer effects, through a mechanism involving the induction of apoptosis in cancer cells, partly via the NF-κB pathway. Two human colorectal cancer (CRC) cell lines, HT-29 and SW620, were exposed to different concentrations of APs (0.01, 0.1 or 1 mg/ml). Cell apoptosis was measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay by flow cytometry and incorporation of 5'-bromodeoxyuridine (BrdU) into DNA to identify the proliferating cell fraction, using fluorescence microscopy in vitro. The protein levels of NF-κB/p65, I-κBα, pI-κBα, Bax, Bcl-xl and Bcl-2 were evaluated by western blotting. The target sites of APs on CRC cells were assessed by flow cytometry. At concentrations of 0.1 and 1 mg/ml, APs showed apoptosis-inducing effects, increased expressions of Bax, nuclear p65 and cytoplasmic pI-κBα, and decreased expressions of Bcl-2, Bcl-xl and cytoplasmic I-κBα. APs induced apoptosis by slightly activating the NF-κB pathway; the AP target site could be the Toll-like receptor 4 on the cell membrane. These results demonstrate the potential of APs as agents for clinical prevention and treatment of CRC.
苹果的某些成分已被证明可以阻止癌症生长并阻碍癌症的发展。我们假设提取的苹果多糖（APs）可能具有抗癌作用，其机制涉及诱导癌细胞凋亡，部分通过 NF-κB 途径。两种人结肠直肠癌（CRC）细胞系 HT-29 和 SW620 分别暴露于不同浓度的 APs（0.01、0.1 或 1 mg/ml）。通过流式细胞术的溴化 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑测定法和 5'-溴脱氧尿苷（BrdU）掺入 DNA 来测量细胞凋亡，以识别体外荧光显微镜下的增殖细胞分数。NF-κB/p65、I-κBα、pI-κBα、Bax、Bcl-xl 和 Bcl-2 的蛋白水平通过 Western blot 进行评估。通过流式细胞术评估 APs 在 CRC 细胞上的靶位。在 0.1 和 1 mg/ml 浓度下，APs 表现出诱导细胞凋亡的作用，增加了 Bax、核 p65 和细胞质 pI-κBα的表达，并降低了 Bcl-2、Bcl-xl 和细胞质 I-κBα的表达。APs 通过轻微激活 NF-κB 途径诱导细胞凋亡；AP 的靶位可能是细胞膜上的 Toll 样受体 4。这些结果表明 APs 具有作为 CRC 临床预防和治疗剂的潜力。
