Laboratory of Basic Medicine, General Hospital of Northern Theater Command, Shenyang, China.
PLoS One. 2024 Jul 11;19(7):e0306969. doi: 10.1371/journal.pone.0306969. eCollection 2024.
Docetaxel (Doc) plays a crucial role in clinical antineoplastic practice. However, it is continuously documented that tumors frequently develop chemoresistance and relapse, which may be related to polyploid giant cancer cells (PGCCs). The aim of this study was investigate the formation mechanism and biological behavior of PGCCs induced by Doc. Ovarian cancer cells were treated with Doc, and then the effect of Doc on cellular viability was evaluated by MTT assay and microscopic imaging analysis. The biological properties of PGCCs were further evaluated by Hoechst 33342 staining, cell cycle and DNA content assay, DNA damage response (DDR) signaling detection, β-galactosidase staining, mitochondrial membrane potential detection, and reverse transcription-quantitative polymerase chain reaction. The results indicated that Doc reduced cellular viability; however, many cells were still alive, and were giant and polyploid. Doc increased the proportion of cells stayed in the G2/M phase and reduced the number of cells. In addition, the expression of γ-H2A.X was constantly increased after Doc treatment. PGCCs showed senescence-associated β-galactosidase activity and an increase in the monomeric form of JC-1. The mRNA level of octamer-binding transcription factor 4 (OCT4) and krüppel-like factor 4 (KLF4) was significantly increased in PGCCs. Taken together, our results suggest that Doc induces G2/M cell cycle arrest, inhibits the proliferation and activates persistent DDR signaling to promote the formation of PGCCs. Importantly, PGCCs exhibit a senescence phenotype and express stem cell markers.
多西紫杉醇（Doc）在临床抗肿瘤实践中起着至关重要的作用。然而，频繁有记录表明肿瘤常常产生化疗耐药性和复发，这可能与多倍体巨大癌细胞（PGCCs）有关。本研究旨在探讨 Doc 诱导 PGCCs 形成的机制和生物学行为。用 Doc 处理卵巢癌细胞，然后通过 MTT 检测和显微镜成像分析评估 Doc 对细胞活力的影响。通过 Hoechst 33342 染色、细胞周期和 DNA 含量检测、DNA 损伤反应（DDR）信号检测、β-半乳糖苷酶染色、线粒体膜电位检测和逆转录定量聚合酶链反应进一步评估 PGCCs 的生物学特性。结果表明，Doc 降低了细胞活力；然而，仍有许多细胞存活，且体积巨大，呈多倍体。Doc 增加了细胞停留在 G2/M 期的比例，并减少了细胞数量。此外，Doc 处理后γ-H2A.X 的表达持续增加。PGCCs 表现出衰老相关的β-半乳糖苷酶活性和 JC-1 的单体形式增加。PGCCs 中八聚体结合转录因子 4（OCT4）和 Kruppel 样因子 4（KLF4）的 mRNA 水平显著增加。总之，我们的结果表明，Doc 诱导 G2/M 细胞周期阻滞，抑制增殖并激活持续的 DDR 信号，从而促进 PGCCs 的形成。重要的是，PGCCs 表现出衰老表型并表达干细胞标志物。
