The androgen receptor (AR) is a validated therapeutic target for prostate cancer and has been a focus for drug development for more than six decades. Currently approved therapies that inhibit AR signaling, such as enzalutamide, rely solely on targeting the AR ligand-binding domain and, therefore, have limited efficacy on prostate cancer cells that express truncated, constitutively active AR splice variants (AR-Vs). The LNCaP95 cell line is a human prostate cancer cell line that expresses both functional full-length AR and AR-V7. LNCaP95 is a heterogeneous cell population that is resistant to enzalutamide, with its proliferation dependent on transcriptionally active AR-V7. The purpose of this study was to identify a LNCaP95 clone that would be useful for evaluating therapies for their effectiveness against enzalutamide-resistant prostate cancer cells. Seven clones from the LNCaP95 cell line were isolated and characterized using morphology, in vitro growth rate, and response to ralaniten (AR N-terminal domain inhibitor) and enzalutamide (antiandrogen). In vivo growth of the clones as subcutaneous xenografts was evaluated in castrated immunodeficient mice. All of the clones maintained the expression of full-length AR and AR-V7. Cell proliferation of the clones was insensitive to androgen and enzalutamide but importantly was inhibited by ralaniten, which is consistent with AR-Vs driving the proliferation of parental LNCaP95 cells. In castrated immunodeficient animals, the growth of subcutaneous xenografts of the D3 clone was the most reproducible compared to the parental cell line and other clones. These data support that the enzalutamide-resistant LNCaP95-D3 subline may be suitable as a xenograft tumor model for preclinical drug development with improved reproducibility.

雄激素受体 (AR) 是经过验证的前列腺癌治疗靶点，六年来一直是药物开发的焦点。目前批准的抑制 AR 信号传导的疗法，如恩杂鲁胺，仅依赖于靶向 AR 配体结合域，因此，对表达截短的组成型活性 AR 剪接变体 (AR-Vs) 的前列腺癌细胞的功效有限。LNCaP95 细胞系是表达功能性全长 AR 和 AR-V7 的人前列腺癌细胞系。LNCaP95 是一种异质细胞群，对恩杂鲁胺具有抗性，其增殖依赖于转录活性 AR-V7。本研究的目的是鉴定 LNCaP95 克隆，该克隆可用于评估治疗对恩杂鲁胺耐药性前列腺癌细胞的有效性。从 LNCaP95 细胞系中分离出 7 个克隆，并使用形态学、体外生长速率和对 ralaniten（AR N 末端结构域抑制剂）和恩杂鲁胺（抗雄激素）的反应对其进行表征。在去势免疫缺陷小鼠中评估了作为皮下异种移植物的克隆的体内生长。所有克隆都保持全长AR和AR-V7的表达。克隆的细胞增殖对雄激素和恩杂鲁胺不敏感，但重要的是被 ralaniten 抑制，这与驱动亲代 LNCaP95 细胞增殖的 AR-Vs 一致。在去势免疫缺陷动物中，与亲本细胞系和其他克隆相比，D3 克隆的皮下异种移植物的生长是最可重复的。这些数据支持恩杂鲁胺耐药的 LNCaP95-D3 亚系可能适合作为异种移植肿瘤模型用于临床前药物开发，并具有更高的可重复性。