Nargis Nelofar, Lind Abigail, Sczepanski Adam, Herndon Randi, Smiley Olivia, Somji Seema, Sens Donald A, Mehus Aaron A
Department of Pathology, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58202, USA.
Cells. 2025 Jun 20;14(13):949. doi: 10.3390/cells14130949.
Urothelial carcinoma (UC) is a common genitourinary malignancy. Smoking, exposure to arsenic in drinking water, and age can increase the risk of developing UC. Neoadjuvant cisplatin-based chemotherapy prior to radical cystectomy is the standard treatment for the muscle invasive form of UC (MIUC). Tumors of the basal/squamous (Ba/Sq) subtype of MIUC are aggressive, express basal keratins (KRT5, 6, and 14), are associated with squamous differentiation (SD), and frequently develop chemotherapy resistance. The SOX2 transcription factor is a marker of UC stem cells, and its expression is associated with poor overall and disease-free survival. We hypothesized that the attenuation of SOX2 would reduce the expression of basal keratins and increase the chemotherapy response in human UC cells. For this study, we performed lentiviral knockdown (KD) of SOX2 expression in two separate arsenite (As)-transformed UROtsa (As_I, As_II), 5637, and RT4 cells. Cellular growth and colony-forming ability was inhibited in all UC cell lines after SOX2 KD. We demonstrate that SOX2 KD in the UC cells of the Ba/Sq subtype (As_I, As_II, 5637) decreased the expression of stem-associated proteins, oncoproteins, and basal keratins. Additionally, there was an induction of several luminal markers and enhanced cisplatin sensitivity following the repression of SOX2. Lastly, proteomics revealed reductions in lipid-, cholesterol-, and interferon-signaling pathways after SOX2 KD. This study provides a better understanding of the regulation of key genes responsible for defining the Ba/Sq subtype of UC and demonstrates that the inhibition of SOX2 improves chemotherapy response in UC.
尿路上皮癌（UC）是一种常见的泌尿生殖系统恶性肿瘤。吸烟、饮用含砷的水以及年龄增长会增加患UC的风险。根治性膀胱切除术前行以顺铂为基础的新辅助化疗是肌肉浸润性UC（MIUC）的标准治疗方法。MIUC的基底/鳞状（Ba/Sq）亚型肿瘤具有侵袭性，表达基底角蛋白（KRT5、6和14），与鳞状分化（SD）相关，且常出现化疗耐药。SOX2转录因子是UC干细胞的标志物，其表达与总体生存率和无病生存率较差相关。我们推测，SOX2的减弱会降低基底角蛋白的表达，并增加人UC细胞对化疗的反应。在本研究中，我们在两种不同的亚砷酸盐（As）转化的UROtsa（As_I、As_II）、5637和RT4细胞中进行了SOX2表达的慢病毒敲低（KD）。SOX2 KD后，所有UC细胞系的细胞生长和集落形成能力均受到抑制。我们证明，Ba/Sq亚型（As_I、As_II、5637）的UC细胞中SOX2 KD降低了干细胞相关蛋白、癌蛋白和基底角蛋白的表达。此外，SOX2受到抑制后，几种管腔标志物被诱导，顺铂敏感性增强。最后，蛋白质组学显示SOX2 KD后脂质、胆固醇和干扰素信号通路减少。本研究更好地理解了定义UC的Ba/Sq亚型的关键基因的调控，并证明抑制SOX2可改善UC的化疗反应。
