Sakowicz-Burkiewicz Monika, Przybyla Tomasz, Wesserling Martyna, Bielarczyk Hanna, Maciejewska Izabela, Pawelczyk Tadeusz
Department of Molecular Medicine, Medical University of Gdansk, 80-211 Gdansk, Poland.
Departemnt of Laboratory Medicine, Medical University of Gdansk, 80-211 Gdansk, Poland.
Int J Biochem Cell Biol. 2016 Sep;78:268-278. doi: 10.1016/j.biocel.2016.07.024. Epub 2016 Jul 25.
The 5-fluorouracil (5FU)-based adjuvant chemotherapy improves the survival of patients with colorectal cancer, however the main obstacle affecting its effectiveness is a drug resistance. Our study aimed to investigate the impact of TWIST1 silencing on the sensitivity of cancer cells to 5FU. The suppression of TWIST1 expression in human colon cancer HT29 and HCT116 cell lines was achieved by transduction with lentiviral vector carrying the TWIST1 silencing sequence (pLL3.7-shTWIST1). The suppression of TWIST1 expression induced changes in the expression pattern of epithelial to mesenchymal transition markers, reduced the cells proliferation rate, increased their sensitivity to serum withdrawn, and increased the cytotoxic effect of 5FU. However, significantly higher 5FU cytotoxicity was observed in HT29 cell cultures. Cells with silenced TWIST1 displayed altered expression of enzymes metabolizing 5FU. The expression level of dihydropyrimidine dehydrogenase, and thymidylate synthase decreased significantly in HT29 shTWIST1 cells, but not in HCT116 shTWIST1 cells. On the other hand, significant increases in the expression levels of thymidine phosphorylase, and uridine phosphorylase 1 were seen in both cell lines with suppressed expression of TWIST1. The changes in enzymes expression were mirrored by enzymatic activities. In conclusion, our observations point to TWIST1 as a target protein to enhance the sensitivity of colorectal cancer cells to 5FU.
基于5-氟尿嘧啶（5FU）的辅助化疗可提高结直肠癌患者的生存率，然而影响其疗效的主要障碍是耐药性。我们的研究旨在探讨TWIST1沉默对癌细胞对5FU敏感性的影响。通过用携带TWIST1沉默序列的慢病毒载体（pLL3.7-shTWIST1）转导，实现了人结肠癌HT29和HCT116细胞系中TWIST1表达的抑制。TWIST1表达的抑制诱导了上皮-间质转化标志物表达模式的变化，降低了细胞增殖率，增加了它们对血清剥夺的敏感性，并增强了5FU的细胞毒性作用。然而，在HT29细胞培养物中观察到5FU细胞毒性明显更高。TWIST1沉默的细胞显示出代谢5FU的酶表达改变。二氢嘧啶脱氢酶和胸苷酸合成酶的表达水平在HT29 shTWIST1细胞中显著降低，但在HCT116 shTWIST1细胞中未降低。另一方面，在TWIST1表达受抑制的两种细胞系中，胸苷磷酸化酶和尿苷磷酸化酶1的表达水平均显著增加。酶活性反映了酶表达的变化。总之，我们的观察结果表明TWIST1是增强结直肠癌细胞对5FU敏感性的靶蛋白。
