The short isoform of PRLR suppresses the pentose phosphate pathway and nucleotide synthesis through the NEK9-Hippo axis in pancreatic cancer.
The short isoform of PRLR suppresses the pentose phosphate pathway and nucleotide synthesis through the NEK9-Hippo axis in pancreatic cancer.
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PRLR 的短亚型通过 NEK9-Hippo 轴抑制胰腺癌中的戊糖磷酸途径和核苷酸合成
DOI：
10.7150/thno.51712
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发表时间：
2021
期刊：
影响因子：
12.4
通讯作者：
Zhang ZG
中科院分区：
文献类型：
--
作者：
Nie H;Huang PQ;Jiang SH;Yang Q;Hu LP;Yang XM;Li J;Wang YH;Li Q;Zhang YF;Zhu L;Zhang YL;Yu Y;Xiao GG;Sun YW;Ji J;Zhang ZG
催乳素与催乳素受体的结合在脊椎动物中发挥多效性生物学效应。由于选择性剪接，催乳素受体 (PRLR) 具有多种亚型。长亚型（PRLR-LF）的生物学作用和相关信号传导已得到充分阐明。然而，人们对短亚型 (PRLR-SF) 知之甚少，特别是在癌症发展和代谢重编程（癌症的核心标志）方面。在这里，我们揭示了 PRLR-SF 在胰腺导管腺癌（PDAC）中的作用和潜在机制。方法：使用人 PDAC 组织芯片来研究 PDAC 中 PRLR 的临床相关性。在皮下异种移植模型和原位异种移植模型中检查了 PRLR-SF 在 PDAC 中的体内影响。对从患有自发性肿瘤的基因工程 KPC（KrasG12D/+；Trp53R172H/+；Pdx1-Cre）小鼠获得的肿瘤组织进行免疫组织化学分析。使用 13C 标记代谢物测量、LC-MS、EdU 掺入测定和海马分析来确定 PRLR-SF 对磷酸戊糖途径和糖酵解的影响。我们通过免疫荧光、免疫共沉淀、邻近连接试验、染色质免疫沉淀和启动子荧光素酶活性鉴定了分子机制。利用公共数据库（TCGA、GEO和GTEx）分析相关基因的表达和生存相关性。结果：我们证明 PRLR-SF 主要在基因工程 KPC 小鼠和人 PDAC 细胞系的自发形成的胰腺肿瘤中表达。 PRLR-SF 抑制 PDAC 细胞（AsPC-1 和 BxPC-3）的体外增殖和体内肿瘤生长。我们发现 PRLR-SF 通过激活 Hippo 信号传导来降低磷酸戊糖途径 (PPP) 和核苷酸生物合成中基因的表达。 TEAD1 是 Hippo 信号传导的下游转录因子，直接调节 PPP 限速酶 G6PD 和 TKT 的表达。此外，NEK9 直接与 PRLR-SF 相互作用，是 PRLR 和 Hippo 途径之间的中介。 PRLR表达水平与PDAC患者的总生存率和TNM分期呈负相关。此外，怀孕和哺乳会增加野生型小鼠胰腺和皮下 PDAC 异种移植肿瘤中 PRLR-SF:PRLR-LF 的比率。结论：我们对 PRLR-SF 信号传导、NEK9-Hippo 通路、PPP 和核苷酸合成之间关系的表征解释了 PRLR-SF 与 PDAC 进展中代谢重编程之间的相关性机制。可以开发改变该途径的策略来治疗或预防胰腺癌。
Prolactin binding to the prolactin receptor exerts pleiotropic biological effects in vertebrates. The prolactin receptor (PRLR) has multiple isoforms due to alternative splicing. The biological roles and related signaling of the long isoform (PRLR-LF) have been fully elucidated. However, little is known about the short isoform (PRLR-SF), particularly in cancer development and metabolic reprogramming, a core hallmark of cancer. Here, we reveal the role and underlying mechanism of PRLR-SF in pancreatic ductal adenocarcinoma (PDAC). Methods: A human PDAC tissue array was used to investigate the clinical relevance of PRLR in PDAC. The in vivo implications of PRLR-SF in PDAC were examined in a subcutaneous xenograft model and an orthotopic xenograft model. Immunohistochemistry was performed on tumor tissue obtained from genetically engineered KPC (KrasG12D/+; Trp53R172H/+; Pdx1-Cre) mice with spontaneous tumors. 13C-labeled metabolite measures, LC-MS, EdU incorporation assays and seahorse analyses were used to identify the effects of PRLR-SF on the pentose phosphate pathway and glycolysis. We identified the molecular mechanisms by immunofluorescence, coimmunoprecipitation, proximity ligation assays, chromatin immunoprecipitation and promoter luciferase activity. Public databases (TCGA, GEO and GTEx) were used to analyze the expression and survival correlations of the related genes. Results: We demonstrated that PRLR-SF is predominantly expressed in spontaneously forming pancreatic tumors of genetically engineered KPC mice and human PDAC cell lines. PRLR-SF inhibits the proliferation of PDAC cells (AsPC-1 and BxPC-3) in vitro and tumor growth in vivo. We showed that PRLR-SF reduces the expression of genes in the pentose phosphate pathway (PPP) and nucleotide biosynthesis by activating Hippo signaling. TEAD1, a downstream transcription factor of Hippo signaling, directly regulates the expression of G6PD and TKT, which are PPP rate-limiting enzymes. Moreover, NEK9 directly interacts with PRLR-SF and is the intermediator between PRLR and the Hippo pathway. The PRLR expression level is negatively correlated with overall survival and TNM stage in PDAC patients. Additionally, pregnancy and lactation increase the ratio of PRLR-SF:PRLR-LF in the pancreas of wild-type mice and subcutaneous PDAC xenograft tumors. Conclusion: Our characterization of the relationship between PRLR-SF signaling, the NEK9-Hippo pathway, PPP and nucleotide synthesis explains a mechanism for the correlation between PRLR-SF and metabolic reprogramming in PDAC progression. Strategies to alter this pathway might be developed for the treatment or prevention of pancreatic cancer.