KH型剪接调节蛋白（KHSRP，也称为KSRP）是一种多功能的RNA结合蛋白，在多个层面上通过调节基因表达在各种生理和病理条件下起关键作用。然而，KSRP在结清型肾细胞癌（ccRCC）中的作用尚不明确。本研究利用ccRCC组织芯片阵列和计算机分析检测了KSRP的表达。通过细胞功能消失和增强、集落形成、离基现象、透过试验和原位生物荧光显像异种移植模型，确定了KSRP在ccRCC进展中的功能作用。应用microRNA和相应的DNA微阵列来确定KSRP的下游靶标。通过Western blotting、定量实时聚合酶链反应以及启动子和3-非翻译区（3'UTR）荧光素酶报告基因试验来验证KSRP促进ccRCC进展的潜在机制。研究结果显示，KSRP的失调高表达与ccRCC的临床进展期、肿瘤大小增大、复发和预后不良相关。神经前体细胞表达发育调节下降4类似物（NEDD4L）被确定为KSRP的新靶标，能够在体外和体内通过逆转KSRP的促肿瘤和促转移特性以及上皮间质转化（EMT）的促进来发挥作用。分子研究揭示，KSRP可以通过诱导mir-629-5p上调和直接靶向3'UTR的富含AU元件（ARE）来降低NEDD4L信息（mRNA）稳定性。此外，KSRP经通过诱导转录抑制子Wilm氏肿瘤 1（WT1）来抑制NEDD4L的转录。在临床上，ccRCC样本显示KSRP与间充质相关基因呈正相关，而高表达KSRP且低表达NEDD4L的患者预后最差。本研究结果揭示了KSRP通过转录抑制和转录后不稳定NEDD4L转录本的新机制，促进ccRCC的恶性进展。靶向KSRP及其途径可能是ccRCC的新药物干预方法。© 2023年，中华民国（台湾）国家科学委员会。

KH-type splicing regulatory protein (KHSRP, also called KSRP), a versatile RNA-binding protein, plays a critical role in various physiological and pathological conditions through modulating gene expressions at multiple levels. However, the role of KSRP in clear cell renal cell carcinoma (ccRCC) remains poorly understood.KSRP expression was detected by a ccRCC tissue microarray and evaluated by an in silico analysis. Cell loss-of-function and gain-of-function, colony-formation, anoikis, and transwell assays, and an orthotopic bioluminescent xenograft model were conducted to determine the functional role of KRSP in ccRCC progression. Micro (mi)RNA and complementary (c)DNA microarrays were used to identify downstream targets of KSRP. Western blotting, quantitative real-time polymerase chain reaction, and promoter- and 3-untranslated region (3'UTR)-luciferase reporter assays were employed to validate the underlying mechanisms of KSRP which aggravate progression of ccRCC.Our results showed that dysregulated high levels of KSRP were correlated with advanced clinical stages, larger tumor sizes, recurrence, and poor prognoses of ccRCC. Neural precursor cell-expressed developmentally downregulated 4 like (NEDD4L) was identified as a novel target of KSRP, which can reverse the protumorigenic and prometastatic characteristics as well as epithelial-mesenchymal transition (EMT) promotion by KSRP in vitro and in vivo. Molecular studies revealed that KSRP can decrease NEDD4L messenger (m)RNA stability via inducing mir-629-5p upregulation and directly targeting the AU-rich elements (AREs) of the 3'UTR. Moreover, KSRP was shown to transcriptionally suppress NEDD4L via inducing the transcriptional repressor, Wilm's tumor 1 (WT1). In the clinic, ccRCC samples revealed a positive correlation between KSRP and mesenchymal-related genes, and patients expressing high KSRP and low NEDD4L had the worst prognoses.The current findings unveil novel mechanisms of KSRP which promote malignant progression of ccRCC through transcriptional inhibition and post-transcriptional destabilization of NEDD4L transcripts. Targeting KSRP and its pathways may be a novel pharmaceutical intervention for ccRCC.© 2023. National Science Council of the Republic of China (Taiwan).