PO.TB03.01 · 肿瘤生物学
抑制STAT3和PARP1通过细胞骨架重塑减少TNBC侵袭
Inhibition of STAT3 and PARP1 reduces TNBC invasion through cytoskeletal remodeling
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
三阴性乳腺癌（TNBC）是一种侵袭性强、耐药的亚型，对非裔美国女性造成不成比例的影响，导致高死亡率。与受体阳性的Luminal亚型相比，TNBC的转移率显著更高。尽管研究仍在进行，但TNBC转移的生物学机制，特别是与细胞骨架组织相关的机制，仍不明确。理解TNBC细胞如何迁移，尤其是通过肌动蛋白细胞骨架重塑，至关重要。在此，我们证明联合抑制PARP1和STAT3可减少细胞骨架重塑，特别是肌动蛋白丝重塑，这是TNBC侵袭性的关键因素。我们使用TNBC细胞系BT-549（间充质表型）和MDA-MB-468（基底样1型/免疫调节型）来测试Olaparib（一种PARP1抑制剂）、Stattic（一种STAT3抑制剂）或两者联用。采用免疫共沉淀研究PARP1和STAT3之间的相互作用。我们通过蛋白质印迹、鬼笔环肽染色评估细胞骨架重塑，并使用划痕愈合和Boyden小室侵袭实验评估细胞运动性。结果显示，PARP1在TNBC中与STAT3相互作用，并使STAT3发生聚ADP核糖基化。我们观察到抑制剂降低了迁移，尤其是联合治疗时，并且抑制STAT3和PARP1会破坏肌动蛋白细胞骨架组织。联合抑制PARP1和STAT3导致外周肌动蛋白和应力纤维形成减少，这由Cofilin磷酸化驱动。此外，我们注意到Stattic和双抑制剂治疗使LIMK2（Cofilin激酶）和PDXP（Cofilin磷酸酶）下调。抑制剂治疗还在两种细胞系中下调了CCL2和其他细胞因子，可能通过MAP激酶通路影响细胞骨架组织。这些发现提示了联合治疗以及开发靶向治疗以改善预后（特别是通过减少转移）的潜在意义。我们的研究通过将PARP1和STAT3确定为肌动蛋白细胞骨架重塑的关键调控因子，加深了对TNBC转移的理解。
查看英文原文 English abstract
Triple Negative Breast Cancer (TNBC) is an aggressive, treatment-resistant subtype that disproportionately affects African American women, leading to high mortality. TNBCs have significantly higher metastasis rates compared to the receptor-positive Luminal subtype. Although research is ongoing, the biological mechanisms underlying metastasis in TNBC, particularly those related to cytoskeletal organization, remain unclear. Understanding how TNBC cells migrate, particularly through actin cytoskeleton remodeling, is crucial. Here, we demonstrate that combined inhibition of PAPR1 and STAT3 reduces cytoskeletal remodeling, particularly actin filament remodeling, a key factor in TNBC invasiveness. We used TNBC cell lines BT-549 (mesenchymal phenotype) and MDA-MB-468 (Basal-like 1/Immunomodulatory) to test Olaparib (a PARP1 inhibitor), Stattic (a STAT3 inhibitor), or both. Co-immunoprecipitation was used to study the interaction between PAPR1 and STAT3. We assessed cytoskeletal remodeling by western blotting, phalloidin staining, and cell motility using wound-healing and Boyden chamber invasion assays. The results show that PARP1 interacts with STAT3 in TNBC and poly-ADP-ribosylates STAT3. We observed reduced migration with inhibitors, especially with combined treatment, and disruption of actin cytoskeletal organization with the inhibition of STAT3 and PARP1. Combined PARP1 and STAT3 inhibition led to decreased peripheral actin and stress fiber formation, driven by Cofilin phosphorylation. Additionally, we noted downregulation of LIMK2 (Cofilin kinase) and PDXP (Cofilin phosphatase) with Stattic and dual-inhibitor treatment. The inhibitor treatment also downregulated CCL2 and other cytokines in both cell lines, potentially impacting cytoskeletal organization, possibly via the MAP kinase pathway. These findings suggest potential implications for combination therapies and the development of targeted treatments to improve outcomes, particularly by reducing metastasis. Our research enhances understanding of TNBC metastasis by identifying PARP1 and STAT3 as key regulators of actin cytoskeletal remodeling.
利益披露 Disclosure
A. McGlone, None..
A. Andalibi, None..
P. Dutta, None.