■据报道,含溴结构域的蛋白9(BRD9)在多种恶性肿瘤中上调,并促进癌症进展。然而,关于其在结直肠癌(CRC)中的表达和生物学作用的数据很少。因此,本研究探讨了BRD9在CRC中的预后作用及其相关机制.
■使用实时聚合酶链反应(PCR)和蛋白质印迹法检测BRD9在结肠切除术患者配对的新鲜CRC和肿瘤旁组织中的表达(n=31)。进行免疫组织化学(IHC)以评估524个石蜡包埋的存档CRC样品中的BRD9表达。临床变量包括年龄,性别,癌胚抗原(CEA),肿瘤的位置,T级,N级,和TNM分类。通过Kaplan-Meier和Cox回归分析探讨BRD9对CRC患者预后的影响。细胞计数试剂盒8(CCK-8),克隆形成测定,transwell分析,和流式细胞术用于确定CRC细胞增殖,迁移,入侵,和细胞凋亡,分别。在裸鼠中建立异种移植模型以研究BRD9在体内的作用。
■与正常结直肠上皮细胞相比,CRC细胞中BRD9mRNA和蛋白表达水平显著上调(P<0.001)。524个石蜡包埋存档的CRC组织的IHC分析显示,高BRD9表达与TNM分类显著相关,CEA,和淋巴浸润(P<0.01)。单因素和多因素分析表明BRD9[风险比(HR):3.04,95%置信区间(CI):1.78-5.20;P<0.01]表达和性别(HR:6.39,95%CI:3.94-10.37;P<0.01)是整个队列总生存的独立预后因素。过表达BRD9促进CRC细胞增殖,而沉默BRD9则抑制CRC细胞的增殖。此外,我们发现BRD9沉默通过雌激素途径显著抑制上皮-间质转化(EMT).最后,我们证明沉默BRD9能显著抑制SW480和HCT116细胞在裸鼠体内外的增殖和致瘤性(P<0.05)。
■这项研究表明BRD9高可能是CRC的独立预后危险因素。此外,BRD9/雌激素通路可能有助于CRC细胞增殖和EMT,提示BRD9可能是CRC治疗中的新分子靶点。
UNASSIGNED: Bromodomain-containing protein 9 (BRD9) has been reported to be upregulated in multiple malignancies and facilitate cancer progression. However, there is a paucity of data relating to its expression and biological role in colorectal cancer (CRC). Therefore, this current study examined the prognostic role of BRD9 in CRC and the underlying mechanisms involved.
UNASSIGNED: Real-time polymerase chain reaction (PCR) and Western blotting were used to examine the expression of BRD9 in paired fresh CRC and para-tumor tissues from colectomy patients (n=31). Immunohistochemistry (IHC) was performed to assess BRD9 expression in 524 paraffin-embedded archived CRC samples. The clinical variables are including age, sex, carcinoembryonic antigen (CEA), location of tumor, T stage, N stage, and TNM classification. The effect of BRD9 on the prognosis of CRC patients was explored by Kaplan-Meier and Cox regression analyses. Cell counting kit 8 (CCK-8), clone formation assay, transwell assay, and flow cytometry were used to determine CRC cell proliferation, migration, invasion, and apoptosis, respectively. Xenograft models in nude mice were established to investigate the role of the BRD9 in vivo.
UNASSIGNED: BRD9 mRNA and protein expression levels were significantly upregulated in CRC cells compared to normal colorectal epithelial cells (P<0.001). IHC analysis of 524 paraffin-embedded archived CRC tissues showed that high BRD9 expression was significantly associated with TNM classifications, CEA, and lymphatic invasion (P<0.01). Univariate and multivariate analyses indicated that BRD9 [hazard ratio (HR): 3.04, 95% confidence interval (CI): 1.78-5.20; P<0.01] expression and sex (HR: 6.39, 95% CI: 3.94-10.37; P<0.01) were independent prognostic factors for overall survival in the entire cohort. Overexpressing BRD9 promoted CRC cell proliferation, while silencing BRD9 inhibited the proliferation of CRC cells. Furthermore, we showed that BRD9 silencing significantly inhibited epithelial-mesenchymal transition (EMT) via the estrogen pathway. Finally, we demonstrated that silencing BRD9 significantly inhibited the proliferation and tumorigenicity of SW480 and HCT116 cells in vitro and in vivo in nude mice (P<0.05).
UNASSIGNED: This study demonstrated that BRD9 high could be an independent prognostic risk factor for CRC. Furthermore, the BRD9/estrogen pathway may contribute to the proliferation of CRC cells and EMT, suggesting that BRD9 may be a novel molecular target in the therapeutic treatment of CRC.