Department of Oncology, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China.
Department of Breast Surgery, The First Affiliated Hospital of Hainan Medical University, Haikou, Hainan, China.
Cancer Biol Ther. 2024 Dec 31;25(1):2420383. doi: 10.1080/15384047.2024.2420383. Epub 2024 Nov 2.
To elucidate the biological functionality and regulatory mechanisms of GdX in breast cancer (BC).
The examination of GdX expression in human BC tissues and cell lines was conducted through immunohistochemical (IHC) and Western blot. Cell proliferation capacity was assessed via the CCK-8 and colony formation assay, while cell migration was determined through the wound healing assay. The expression levels of BCL-XL, Cyclin D1, and C-myc gene were quantified using RT-qPCR and Western blot. In vivo tumor growth was evaluated in nude mice xenografted with MDA-MB-231 cells overexpressing GdX, and a mouse model with GdX-deficient BC was established to observe the impact of GdX on BC formation and metastasis. Dual-luciferase reporter assay and immunofluorescence were employed to confirm the interaction between GdX and STAT3. Western blot was employed to validate the influence of GdX overexpression on the phosphorylation process of STAT3.
GdX exhibited low expression in the cancer tissues of BC patients and cell lines. MDA-MB-231 and MCF-7 cells overexpressing GdX displayed a notable reduction in proliferation and diminished migratory capabilities, accompanied by downregulated mRNA and protein expression of BCL-XL, Cyclin D1, and C-myc. In the xenograft mouse model, heightened GdX expression correlated with a decelerated in vivo tumor growth. Furthermore, in mice deteleing GdX, both the quantity and weight of tumors increased, along with evident pulmonary metastasis. Mechanistically, STAT3 emerged as a downstream target gene of GdX.
GdX exerts its inhibitory effects on the initiation and progression of BC by negatively modulating the phosphorylation of STAT3.
阐明 GdX 在乳腺癌（BC）中的生物学功能和调控机制。
通过免疫组织化学（IHC）和 Western blot 检测 GdX 在人 BC 组织和细胞系中的表达。通过 CCK-8 和集落形成实验评估细胞增殖能力，通过划痕愈合实验评估细胞迁移能力。使用 RT-qPCR 和 Western blot 定量检测 BCL-XL、Cyclin D1 和 C-myc 基因的表达水平。通过在 MDA-MB-231 细胞过表达 GdX 的裸鼠异种移植模型中评估体内肿瘤生长，并建立 GdX 缺陷型 BC 小鼠模型观察 GdX 对 BC 形成和转移的影响。双荧光素酶报告基因实验和免疫荧光实验用于证实 GdX 与 STAT3 之间的相互作用。Western blot 用于验证 GdX 过表达对 STAT3 磷酸化过程的影响。
GdX 在 BC 患者的癌组织和细胞系中表达较低。过表达 GdX 的 MDA-MB-231 和 MCF-7 细胞增殖能力显著降低，迁移能力减弱，BCL-XL、Cyclin D1 和 C-myc 的 mRNA 和蛋白表达下调。在异种移植小鼠模型中，GdX 表达升高与体内肿瘤生长速度减慢相关。此外，在敲除 GdX 的小鼠中，肿瘤的数量和重量增加，同时出现明显的肺转移。机制上，STAT3 是 GdX 的下游靶基因。
GdX 通过负调控 STAT3 的磷酸化来抑制 BC 的发生和发展。
