Institute of Human Genetics, Department of Anatomy, Korea University College of Medicine, 126-1, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-705, Korea.
Anticancer Res. 2014 Jan;34(1):133-40.
Methylation-mediated inactivation of tumor-suppressor genes is a critical event during the pathogenesis of many malignancies. Vincristine is a conventional anticancer drug used to treat various types of cancers. However, few studies describe the epigenetic-based effects of vincristine. In this study, changes in the methylation of runt-related transcription factor-3 (RUNX3) were investigated in CCD18Co normal colon cells and DLD-1 colorectal adenocarcinoma cells.
CCD18Co and DLD-1 cells were treated with vincristine, and the methylation status was assessed using quantitative methylation-specific polymerase chain reaction (QMSP). Eleven normal colon tissues and 105 colorectal cancer tissues were investigated by methylation and mRNA expression of RUNX3 using QMSP and real-time reverse transcription polymerase chain reaction (real time-PCR).
RUNX3 was demethylated after vincristine treatment in DLD-1 cells. The expression of RUNX3 mRNA was down-regulated in DLD-1 cells because of DNA hypermethylation, but was restored after vincristine treatment. In addition, hypermethylation of RUNX3 was detected in 70 out of 105 colorectal carcinomas (66.7%). RUNX3 hypermethylation was greater in colon cancer tissues than in rectal cancer tissues. The expression of RUNX3 mRNA was reduced in 68 out of 105 colorectal cancer tissues (64.8%).
These results demonstrate that vincristine demethylates RUNX3 in colorectal adenocarcinoma cells, and restores its expression.
肿瘤抑制基因的甲基化失活是许多恶性肿瘤发病机制中的一个关键事件。长春新碱是一种用于治疗多种癌症的常规抗癌药物。然而，很少有研究描述长春新碱的表观遗传效应。在这项研究中，研究了长春新碱处理 CCD18Co 正常结肠细胞和 DLD-1 结直肠腺癌细胞中 runt 相关转录因子-3（RUNX3）的甲基化变化。
用长春新碱处理 CCD18Co 和 DLD-1 细胞，并用定量甲基化特异性聚合酶链反应（QMSP）评估甲基化状态。通过 QMSP 和实时逆转录聚合酶链反应（real time-PCR）检测 11 个正常结肠组织和 105 个结直肠癌组织中 RUNX3 的甲基化和 mRNA 表达。
长春新碱处理后 DLD-1 细胞中的 RUNX3 去甲基化。由于 DNA 高甲基化，DLD-1 细胞中 RUNX3 的 mRNA 表达下调，但长春新碱处理后恢复。此外，在 105 例结直肠癌中有 70 例（66.7%）检测到 RUNX3 高甲基化。结直肠癌组织中的 RUNX3 甲基化程度高于直肠组织。在 105 例结直肠癌组织中有 68 例（64.8%）RUNX3 mRNA 表达降低。
这些结果表明，长春新碱可使结直肠腺癌细胞中的 RUNX3 去甲基化，并恢复其表达。
