Yu Hao, Li Siyan, Li Xing, Liu Yanbiao, Wang Zhaobu, Cui Mengyao, Jin Feng, Yu Xinmiao
Department of Breast Surgery, The 1st Affiliated Hospital of China Medical University, Shenyang, Liaoning, China.
J Cancer. 2024 Jul 2;15(14):4623-4635. doi: 10.7150/jca.96903. eCollection 2024.
Breast cancer is the second most common cause of cancer-related mortality globally. Apolipoprotein L3 (APOL3), a member of the apolipoprotein family, has been implicated in the pathogenesis of cardiovascular diseases. Nevertheless, the functions and underlying mechanisms of APOL3 in breast cancer have yet to be elucidated. The patient data were sourced from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) database. Quantitative real-time PCR (qRT-PCR), western blotting, and immunohistochemistry (IHC) assays were used to assess expression of APOL3. Cell proliferation rates were determined by Cell Counting Kit-8 (CCK-8) and colony formation assays. Flow cytometry was used to examine cell cycle distribution. Western blotting was conducted to investigate the expression of cell cycle related proteins. A xenograft model was used to evaluate the effect of APOL3 . APOL3-binding proteins were identified through mass spectrometry, co-immunoprecipitation (CO-IP) assay and immunofluorescence assay. APOL3 expression was significantly downregulated in breast cancer, and its low expression was correlated with poor prognostic outcomes. Overexpression of APOL3 suppressed breast cancer cell proliferation, induced cell cycle disruption. Conversely, knockdown of APOL3 promoted cell proliferation. animal experiments demonstrated that APOL3 overexpression can inhibit tumor proliferation. Mass spectrometry, CO-IP and immunofluorescence assay confirmed the interaction between APOL3 and Y-box binding protein 1 (YBX1). Furthermore, YBX1 knockdown following APOL3 knockdown mitigated the enhanced proliferation. These results provide new ideas for clinically targeting APOL3 to inhibit proliferation in breast cancer. Our findings indicate that APOL3 inhibits breast cancer cell proliferation and cell cycle modulating P53 pathway through the interaction of YBX1.
乳腺癌是全球癌症相关死亡的第二大常见原因。载脂蛋白L3（APOL3）是载脂蛋白家族的一员，与心血管疾病的发病机制有关。然而，APOL3在乳腺癌中的功能和潜在机制尚未阐明。患者数据来自癌症基因组图谱（TCGA）和基因表达综合数据库（GEO）。采用定量实时聚合酶链反应（qRT-PCR）、蛋白质免疫印迹法和免疫组织化学（IHC）分析来评估APOL3的表达。通过细胞计数试剂盒-8（CCK-8）和集落形成试验测定细胞增殖率。采用流式细胞术检测细胞周期分布。进行蛋白质免疫印迹法以研究细胞周期相关蛋白的表达。使用异种移植模型评估APOL3的作用。通过质谱分析、免疫共沉淀（CO-IP）试验和免疫荧光试验鉴定APOL3结合蛋白。APOL3在乳腺癌中表达明显下调，其低表达与不良预后结果相关。APOL3的过表达抑制乳腺癌细胞增殖，诱导细胞周期紊乱。相反，敲低APOL3可促进细胞增殖。动物实验表明，APOL3过表达可抑制肿瘤增殖。质谱分析、CO-IP和免疫荧光试验证实了APOL3与Y盒结合蛋白1（YBX1）之间的相互作用。此外，在敲低APOL3后敲低YBX1可减轻增殖增强。这些结果为临床上靶向APOL3抑制乳腺癌增殖提供了新思路。我们的研究结果表明，APOL3通过与YBX1相互作用抑制乳腺癌细胞增殖并调节细胞周期的P53途径。
