PO.ET01.02 · 实验与分子治疗
BEN结构域蛋白4（BEND4）在前列腺癌（PCa）中的作用及沉默BEND4对PCa细胞系的影响
Role of BEN domain protein 4 (BEND4) in prostate cancer (PCa) and the effect of silencing BEND4 in PCa cell lines
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
约13%的男性一生中会被诊断出前列腺癌（PCa），它是男性中第二常见的确诊癌症。现有的PCa治疗方法会引起许多严重的副作用，包括勃起功能障碍、脱发和贫血，同时由于治疗耐药性的产生，其疗效可能会降低。由于传统治疗存在这些弊端，分子肿瘤学领域正在开展靶向癌症治疗研究，以开发出针对PCa的高效、更安全的治疗方法。所探索的许多靶点都参与DNA损伤反应（DDR）。BEN结构域（BEND）蛋白便是其中一个潜在的癌症靶点，它是一种染色质边界标记物，可招募染色质修饰因子并调控转录。它在癌细胞中具有许多与DDR和细胞增殖相关的功能。近期研究表明，在胰腺导管腺癌（PDAC）中沉默BEND4表达可促进DNA损伤的累积，并使细胞对ATM/ATR抑制剂敏感，从而增加癌细胞凋亡。此外，已证明它是弥漫性大B细胞癌（DLBCL）和结直肠癌中的高甲基化靶点。因此，这些结果证明了靶向BEND4在PCa治疗和诊断中的潜力。然而，关于BEND4在PCa中的研究十分有限。根据Betastasis和PCA等在线预测工具，BEND4在PCa细胞系（雄激素依赖性和雄激素非依赖性）中的表达谱提示，雄激素受体依赖性（AR+）PCa细胞高水平表达BEND4，表明BEND4受AR依赖性调控。它们还提示，随着Gleason评分升高，BEND4表达降低。为了在体外验证这些发现，我们进行了蛋白质印迹（western blot）和RT-qPCR，结果显示BEND4在AR+ PCa细胞（如MDA-PCa-2b、LNCaP和VCaP）中表达较高，而在NCI-H660和LASCPC（AR阴性且侵袭性PCa细胞系）中表达较低。DepMap分析对VCaP和LNCaP等AR+细胞系赋予了负基因效应评分，提示BEND4沉默对PCa细胞的影响因其雄激素依赖性而异。对BEND4进行siRNA沉默的后续研究表明，在VCaP和MDA-PCa-2b等AR+细胞中，随着siRNA浓度增加，细胞增殖减少。综上所述，我们的结果提示BEND4可能在促进AR驱动的PCa中发挥作用，并可能作为AR依赖性PCa的潜在治疗靶点。
查看英文原文 English abstract
Prostate cancer (PCa) is diagnosed in approximately 13% of men in their lifetime and is the second most diagnosed cancer in men. The existing treatments for PCa cause many severe side effects, including erectile dysfunction, hair loss, and anemia, while their effects may be reduced due to the development of treatment resistance. Due to these drawbacks associated with traditional treatments, research on targeted cancer therapy is conducted in the field of molecular oncology to develop efficient and safer treatment approaches for PCa. Many of the targets explored are involved in DNA Damage Response (DDR). One such potential cancer target is the BEN domain (BEND) protein, which is a chromatin boundary marker that recruits chromatin-modifying factors and regulates transcription. It has many functions in cancer cells related to DDR and cell proliferation. Recent studies have suggested that silencing BEND4 expression in pancreatic ductal adenocarcinoma (PDAC) promotes the accumulation of DNA damage and sensitizes cells to ATM/ATR inhibitors, thereby increasing cancer cell apoptosis. Moreover, it has been shown to be hypermethylation target in diffuse large B-cell carcinoma (DLBCL) and colorectal cancer. Therefore, these results demonstrate the potential of targeting BEND4 in the treatment and diagnosis of PCa. However, limited research has been conducted on BEND4 in PCa. The expression profile of BEND4 in PCa cell lines (androgen-dependent and androgen-independent) suggests, according to online prediction tools such as Betastasis and PCA tools, that androgen receptor-dependent (AR+) PCa cells express high levels of BEND4, indicating AR-dependent regulation of BEND4. They also imply that as the Gleason score increases, BEND4 expression decreases. To validate these findings in vitro, western blot and RT-qPCR were conducted, revealing that BEND4 expression is high in AR+ PCa cells, such as MDA-PCa-2b, LNCaP, and VCaP , and is lower in NCI-H660 and LASCPC (AR-negative and aggressive PCa cell lines). DepMap analysis assigned negative gene effect scores to AR+ cell lines such as VCaP and LNCaP, suggesting that BEND4 silencing has differential effects on PCa cells based on their androgen dependency. Follow-up studies of siRNA silencing of BEND4 reduced proliferation with an increase in siRNA concentration in AR+ cells, such as VCaP and MDA-PCa-2b. Taken together, our results suggest that BEND4 may have a role in promoting AR-driven PCa and may serve as a potential therapeutic target for AR-dependent PCa.
利益披露 Disclosure
J. Harikrishnan, None..
G. Munirathinam, None.