Lim Jonathan Chee Woei, Jeyaraj Ethel Jeyaseela, Sagineedu Sreenivasa Rao, Wong Wai Shiu Fred, Stanslas Johnson
Pharmacotherapeutics Unit, Department of Medicine, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia.
Pharmacology. 2015;95(1-2):70-7. doi: 10.1159/000370313. Epub 2015 Jan 23.
Andrographolide has been reported with anticancer and anti-inflammatory properties through the inhibition of the activity of signaling molecules such as v-Src, nuclear factor-κB (NF-κB), STAT3, and PI3K. NF-κB has been proven to promote cancer cell survival, and targeting this pathway will halt the growth of cancer cells. Efforts have been made to produce semisynthetic derivatives of andrographolide with improved anticancer potency and selectivity. Subsequently, the effect of a selected derivative, 3,14,19-tripropionylandrographolide (SRS06), was tested for its action against NF-κB.
Screening against 60 US National Cancer Institute (NCI) human cancer cell lines representing leukemia and non-small cell lung (NSCL), colon, CNS, melanoma, ovarian, renal, prostate, and breast cancers was performed to determine the tumor type selectivity and potency of SRS06. Microculture tetrazolium, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and sulforhodamine B assays were used to determine the in vitro anticancer activity, while Western blot studies were performed to ascertain the inhibitory effect of SRS06 on the NF-κB signaling cascade. The TransAM™ p65 assay kit was used to determine NF-κB p65 DNA binding activity in the NSCL cancer cell line A549.
From the NCI screening, SRS06 was found to exhibit potent growth-inhibitory effects on multiple cancer cell lines with 10-fold lower 50% growth inhibition (GI50) compared with andrographolide. It was also discerned that the compound preferentially targeted melanoma, CNS, renal, colon, ovarian, prostate, and NSCL cancer cell lines. The DNA fragmentation assay indicated that the main mode of cell death of SRS06-treated A549 cells was via apoptosis. At 5 µmol/l the compound decreased NF-κB protein expression and caused a significant reduction in the nuclear p65 DNA binding activity.
SRS06 displayed improved anticancer selectivity and potency when compared with andrographolide. We alluded its anticancer activity to its effect of inhibiting NF-κB nuclear binding.
穿心莲内酯已被报道具有抗癌和抗炎特性，可通过抑制v-Src、核因子-κB（NF-κB）、信号转导和转录激活因子3（STAT3）以及磷脂酰肌醇-3激酶（PI3K）等信号分子的活性来实现。已证实NF-κB可促进癌细胞存活，靶向此信号通路将阻止癌细胞生长。人们已致力于生产具有更高抗癌效力和选择性的穿心莲内酯半合成衍生物。随后，对一种选定的衍生物3,14,19-三丙酰基穿心莲内酯（SRS06）针对NF-κB的作用进行了测试。
针对代表白血病、非小细胞肺癌（NSCL）、结肠癌、中枢神经系统癌、黑色素瘤、卵巢癌、肾癌、前列腺癌和乳腺癌的60种美国国立癌症研究所（NCI）人类癌细胞系进行筛选，以确定SRS06的肿瘤类型选择性和效力。采用微量培养四氮唑蓝、3-(4,5-二甲基噻唑-2-基)-2,5-二苯基溴化四氮唑蓝和磺酰罗丹明B试验来测定体外抗癌活性，同时进行蛋白质免疫印迹研究以确定SRS06对NF-κB信号级联的抑制作用。使用TransAM™ p65检测试剂盒来测定NSCL癌细胞系A549中NF-κB p65的DNA结合活性。
从NCI筛选中发现，SRS06对多种癌细胞系表现出强大的生长抑制作用，其50%生长抑制（GI50）比穿心莲内酯低10倍。还发现该化合物优先靶向黑色素瘤、中枢神经系统癌、肾癌、结肠癌、卵巢癌、前列腺癌和NSCL癌细胞系。DNA片段化分析表明，经SRS06处理的A549细胞的主要细胞死亡方式是凋亡。在5 μmol/L时，该化合物降低了NF-κB蛋白表达，并导致核p65 DNA结合活性显著降低。
与穿心莲内酯相比，SRS06表现出更高的抗癌选择性和效力。我们将其抗癌活性归因于其抑制NF-κB核结合的作用。
