Department of Biotechnology, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, 502284, India.
Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, 500046, India.
Exp Cell Res. 2024 May 1;438(1):114026. doi: 10.1016/j.yexcr.2024.114026. Epub 2024 Apr 9.
The emergence of AR-V7, a truncated isoform of AR upon androgen deprivation therapy treatment, leads to the development of castration resistant prostate cancer (CRPC). Understanding mechanisms that regulate AR-V7 expression is critical for developing newer therapeutic strategies. In this study, we have investigated the regulation of AR-V7 during cell cycle and identified a distinct pattern of periodic fluctuation, peaking during G2/M phase. This fluctuation correlates with the expression of Cdc-2 like kinase 1 (CLK1) and phosphorylated serine/arginine-rich splicing factor 1 (p-SRSF1) during these phases, pointing towards their role in AR-V7 generation. Functional assays reveal that CLK1 knockdown prolongs the S phase, leading to altered cell cycle distribution and increased accumulation of AR-V7 and pSRSF1 in G1/S phase. Conversely, CLK1 overexpression rescues AR-V7 and p-SRSF1 levels in the G2/M phase, consistent with observed cell cycle alterations upon AR-V7 knockdown and overexpression in CRPC cells. Furthermore, overexpression of kinase-deficient CLK1 mutant leads to diminished AR-V7 levels during G2/M, underlining the essential contribution of CLK1's kinase activity in modulating AR-V7 expression. Collectively, our findings, for the first time, show periodic regulation of AR-V7 expression, its effect on cell cycle progression and the critical role of CLK1-pSRSF1 axis in modulating AR-V7 expression throughout the cell cycle.
雄激素剥夺治疗后出现的 AR-V7,是一种 AR 的截断异构体,导致去势抵抗性前列腺癌(CRPC)的发生。了解调节 AR-V7 表达的机制对于开发新的治疗策略至关重要。在这项研究中,我们研究了 AR-V7 在细胞周期中的调节,并确定了一种独特的周期性波动模式,在 G2/M 期达到峰值。这种波动与 Cdc-2 样激酶 1(CLK1)和磷酸化丝氨酸/精氨酸丰富的剪接因子 1(p-SRSF1)在这些阶段的表达相关,表明它们在 AR-V7 产生中的作用。功能分析显示,CLK1 敲低延长了 S 期,导致细胞周期分布发生改变,G1/S 期 AR-V7 和 p-SRSF1 积累增加。相反,CLK1 过表达在 G2/M 期挽救了 AR-V7 和 p-SRSF1 的水平,这与在 CRPC 细胞中敲低和过表达 AR-V7 观察到的细胞周期改变一致。此外,过表达激酶缺陷型 CLK1 突变体导致 G2/M 期 AR-V7 水平降低,强调了 CLK1 激酶活性在调节 AR-V7 表达中的重要作用。总之,我们的研究结果首次表明,AR-V7 表达存在周期性调节,其对细胞周期进程的影响以及 CLK1-pSRSF1 轴在整个细胞周期中调节 AR-V7 表达的关键作用。