Department of Cellular and Molecular Biotechnology, Institute of Biotechnology, Urmia University, Urmia, Iran.
Department of Pathology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran.
Nutr Cancer. 2021;73(11-12):2654-2664. doi: 10.1080/01635581.2020.1856387. Epub 2020 Dec 7.
Efforts to develop effective drugs targeting PI3K and KRAS signaling pathways in -mutant colorectal cancer stem cells (CRCSCs) remain challenging. Finding safe compounds that can easily enter CRCSCs with the ability to target metastasis-driver gene and pluripotency network genes as key upstream and downstream effectors of both PI3K and KRAS signaling pathways may provide promising results. -mutant CRCSCs display high expression of glucose transporters (GLUTs) on their cell membrane and a glycolytic phenotype providing an opportunity to deliver antiglycolytic compounds into these cells via the GLUTs. CRC patients with low levels of vitamin C in their plasma show a shorter survival suggesting the ability of this vitamin at the physiologic levels for caspase-3 activation and apoptosis in CRCSCs. Vitamin C in an oxidized form (L-dehydroascorbic acid; L-DHA) with antiglycolytic activity can be taken up into CRC cells via the GLUTs. This may provide selective toxicity on CRCSCs and affect and stemness markers genes expression in these cells. To this end, we treated /-mutant LS174T cells with high glycolytic activity as an attractive model for CRCSCs with L-DHA equal to the pharmacological levels of vitamin C in human plasma, after which cell numbers, metabolic activity, proliferation-rate, and pluripotency network genes expression, caspase-3 activity with apoptosis were evaluated. 48 h post-treatment with 100- to 1000 µM L-DHA, cell numbers were decreased and measured to be 70-47% control. L-DHA with selective toxicity on LS174T cells diminished metabolic activity and cell proliferation-rate to 1.4-0.8 (Control OD = 1.5) and 92-54.5% respectively with no toxicity on PBMCs. L-DHA decreased , , -2 and expression to 45%, 85%, 45% and 48% control respectively followed by caspase-3 reactivation by 2.5 to 4.9-fold increases and induction of apoptosis ranging from 0.5% to 58.3% for 100- to 1000 µM L-DHA. According to our data, CRC stem-like cells were highly sensitive to L-DHA in . L-DHA selectively targeted LS174T cells and successfully reactivated caspase-3 and apoptosis in these cells. , stemness marker genes and metabolic activity appear to be promising targets of L-DHA. Our results may provide a new therapeutic approach to target selectively GLUT-overexpressing -mutant CRCSCs using L-DHA with no toxicity on normal cells.
在 - 突变结直肠肿瘤干细胞（CRCSCs）中开发针对 PI3K 和 KRAS 信号通路的有效药物仍然具有挑战性。寻找安全的化合物，这些化合物能够很容易地进入 CRCSCs，并以转移驱动基因和多能性网络基因为靶点，作为 PI3K 和 KRAS 信号通路的关键上游和下游效应物，可能会提供有希望的结果。- 突变的 CRCSCs在其细胞膜上表现出高葡萄糖转运蛋白（GLUTs）的表达和糖酵解表型，为通过 GLUTs 将抗糖酵解化合物递送到这些细胞中提供了机会。血浆中维生素 C 水平低的 CRC 患者的存活时间更短，这表明这种维生素在生理水平下能够激活 caspase-3 并诱导 CRCSCs 凋亡。具有抗糖酵解活性的氧化形式的维生素 C（L-脱氢抗坏血酸；L-DHA）可以通过 GLUTs 被摄取到 CRC 细胞中。这可能对 CRCSCs 具有选择性毒性，并影响这些细胞中的 和干性标记基因的表达。为此，我们用 L-DHA 处理具有高糖酵解活性的 /- 突变 LS174T 细胞，作为 CRCSCs 的有吸引力的模型，L-DHA 的浓度等于人血浆中维生素 C 的药理学水平，然后评估细胞数量、代谢活性、增殖率、 和多能性网络基因表达、caspase-3 活性和细胞凋亡。用 100-1000μM L-DHA 处理 48 小时后，细胞数量减少，测量值为对照的 70-47%。L-DHA 对 LS174T 细胞具有选择性毒性，将代谢活性和细胞增殖率分别降低至 1.4-0.8（对照 OD=1.5）和 92-54.5%，而对 PBMCs 无毒性。L-DHA 将 、 、 -2 和 表达降低至对照的 45%、85%、45%和 48%，随后 caspase-3 被重新激活 2.5 至 4.9 倍，凋亡诱导率为 0.5%至 58.3%，L-DHA 浓度为 100-1000μM。根据我们的数据，CRC 类干细胞对 L-DHA 高度敏感。L-DHA 选择性地靶向 LS174T 细胞，并成功地重新激活了这些细胞中的 caspase-3 和细胞凋亡。 、干性标记基因和代谢活性似乎是 L-DHA 的有前途的靶点。我们的结果可能为使用 L-DHA 靶向选择性 GLUT 过表达的 - 突变结直肠肿瘤干细胞提供一种新的治疗方法，对正常细胞没有毒性。
