CA-125 as a Biomarker in Renal Medullary Carcinoma: Integrated Molecular Profiling, Functional Characterization, and Prospective Clinical Validation [RNA-Seq]. CA-125 as a Biomarker in Renal Medullary Carcinoma: Integrated Molecular Profiling, Functional Characterization, and Prospective Clinical Validation [RNA-Seq]

Purpose: Renal medullary carcinoma (RMC) is a highly aggressive malignancy defined by the loss of the SMARCB1 tumor suppressor. It mainly affects young individuals of African descent with sickle cell trait, and it is resistant to conventional therapies used for other renal cell carcinomas. This study aimed to identify potential biomarkers for early detection and disease monitoring of RMC. Experimental Design: Integrated profiling of primary untreated RMC tumor tissues and paired adjacent kidney controls was performed using RNA-sequencing (RNA-seq) and histone Chromatin Immunoprecipitation Sequencing (ChIP-seq). The expression of serum cancer antigen 125 (CA-125), was prospectively evaluated in 47 patients with RMC. Functional studies were conducted in RMC cell lines to assess the effects of SMARCB1 re-expression and MUC16 knockdown. Results: MUC16, encoding for CA-125, was identified as one of the top upregulated genes in RMC tissues, with concomitant enrichment of active histone marks H3K4me3 and H3K27ac at its promoter. Elevated serum CA-125 levels were found in 31 of 47 (66%) RMC patients and correlated significantly with metastatic tumor burden (p = 0.03). SMARCB1 re-expression significantly reduced MUC16 expression in RMC cell lines. Functional studies in RMC cell lines demonstrated that SMARCB1 re-expression significantly reduced MUC16 expression, and that MUC16 knockdown induced apoptosis and reduced cell proliferation. Conclusions: The correlation between serum CA-125 levels and metastatic burden suggests that CA-125 is a clinically relevant biomarker for RMC. These findings support further exploration of CA-125 for disease monitoring and targeted therapeutics in RMC. Overall design: Cell lines derived from Renal medullary carcinoma (RMC) were transfected with either empty vector or SNF5 (SMARCB1) constructs and treated with doxycycline to express SNF5 (SMARCB1).

研究目的：肾髓质癌（Renal medullary carcinoma, RMC）是一类以SMARCB1抑癌基因缺失为特征的高侵袭性恶性肿瘤，主要累及携带镰状细胞性状的非洲裔青年群体，且对其他肾细胞癌所采用的常规治疗方案耐药。本研究旨在发掘可用于肾髓质癌早期检测与疾病监测的潜在生物标志物。
实验设计：本研究对未经治疗的原发性肾髓质癌肿瘤组织及其配对的癌旁肾脏对照样本开展整合组学分析，采用RNA测序（RNA-sequencing, RNA-seq）与组蛋白染色质免疫沉淀测序（Chromatin Immunoprecipitation Sequencing, ChIP-seq）技术。同时，前瞻性评估了47例肾髓质癌患者血清中癌症抗原125（CA-125）的表达水平。此外，在肾髓质癌细胞系中开展功能实验，以探究SMARCB1重表达与MUC16基因敲降的生物学效应。
实验结果：本研究鉴定出编码CA-125的MUC16是肾髓质癌组织中上调最显著的基因之一，其启动子区域伴随活性组蛋白标记H3K4me3与H3K27ac的富集。在47例患者中，有31例（66%）血清CA-125水平升高，且该指标与肿瘤转移负荷呈显著正相关（p=0.03）。在肾髓质癌细胞系中，SMARCB1重表达可显著下调MUC16的表达；进一步功能实验显示，MUC16基因敲降可诱导细胞凋亡并抑制细胞增殖。
研究结论：血清CA-125水平与肿瘤转移负荷的相关性表明，CA-125可作为肾髓质癌的临床相关生物标志物。本研究结果支持进一步探索CA-125在肾髓质癌疾病监测与靶向治疗中的应用价值。
整体实验设计：将源自肾髓质癌的细胞系分别转染空载体或SNF5（SMARCB1）重组质粒，并用多西环素（doxycycline）诱导表达SNF5（SMARCB1）。