Background: Abnormal transcriptional upregulation of telomerase reverse transcriptase (TERT) plays a dominant role in telomerase activation in various cancers. TERT promoter mutations (TPMs) have been identified as a key mechanism in TERT upregulation. However, the mechanism of TERT upregulation in cancers with low frequency of TPMs are not fully elucidated so far./nMethods: The expression of PUF60 and TERT was detected by real-time PCR, western blot and immunohistochemistry. TERT promoter binding proteins were identified by streptavidin-agarose pulldown assay and mass spectrum (MS) analysis. The role of PUF60/TERT in renal cancer was evaluated on cell growth in vitro and in vivo./nResults: In this study, we identify the regulation mechanism of TERT in renal cell carcinoma (RCC) cells which have rare TPMs but exert significant upregulation of TERT. We found that TERT was highly expressed in RCC tumor tissues, and elevated TERT expression was associated with poor prognosis for patients. We also detected the relatively rare TPM status in both RCC tumor tissues and RCC cell lines. Mechanistically, PUF60, a RNA binding protein, was identified as a novel TERT regulator which bound to the TERT and transcriptionally upregulated TERT expression in RCC cells. The in vitro and in vivo experiments also demonstrated that PUF60 could promote RCC cell growth through activation of TERT expression in a TPM status independent way. Furthermore, we showed that there was a strong correlation of the expression of PUF60 and TERT in RCC tumor tissues and RCC cell lines, and the patients with high expression of PUF60 and TERT had significantly shorter survival./nConclusions: Collectively, these results indicated that PUF60 transcriptionally upregulated TERT expression to promote RCC growth and progression in a TPM status independent way, suggesting that the PUF60/TERT signaling pathway may serve as potential prognostic biomarkers and therapeutic targets for RCC.

中文翻译：

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Poly(U) 结合剪接因子 60 通过转录上调端粒酶逆转录酶促进肾细胞癌生长

背景：端粒酶逆转录酶 (TERT) 的异常转录上调在各种癌症中的端粒酶激活中起主要作用。TERT 启动子突变 (TPM) 已被确定为 TERT 上调的关键机制。然而，目前还没有完全阐明 TERT 在 TPM 频率较低的癌症中上调的机制。/n方法：通过实时荧光定量 PCR、蛋白质印迹和免疫组织化学检测 PUF60 和 TERT 的表达。通过链霉亲和素-琼脂糖下拉测定和质谱（MS）分析鉴定叔启动子结合蛋白。PUF60/TERT 在肾癌中的作用通过体外和体内细胞生长进行评估。/n结果：在这项研究中，我们确定了 TERT 在肾细胞癌 (RCC) 细胞中的调节机制，这些细胞具有罕见的 TPM，但对 TERT 有显着上调。我们发现 TERT 在 RCC 肿瘤组织中高表达，升高的 TERT 表达与患者预后不良有关。我们还在 RCC 肿瘤组织和 RCC 细胞系中检测到相对罕见的 TPM 状态。从机制上讲，PUF60 是一种 RNA 结合蛋白，被鉴定为一种新的 TERT 调节剂，它与 TERT 结合并在 RCC 细胞中转录上调 TERT 表达。体外和体内_实验还表明，PUF60 可以通过以与 TPM 状态无关的方式激活 TERT 表达来促进 RCC 细胞生长。此外，我们发现 PUF60 和 TERT 在 RCC 肿瘤组织和 RCC 细胞系中的表达存在强相关性，PUF60 和 TERT 高表达的患者生存期显着缩短。/n结论：总的来说，这些结果表明PUF60 转录上调 TERT 表达以独立于 TPM 状态的方式促进 RCC 生长和进展，表明 PUF60/TERT 信号通路可能作为 RCC 的潜在预后生物标志物和治疗靶点。