Dutton Louise R, Hoare Owen P, McCorry Amy M B, Redmond Keara L, Adam Noor Eisa, Canamara Shannon, Bingham Victoria, Mullan Paul B, Lawler Mark, Dunne Philip D, Brazil Derek P
Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, Northern Ireland, UK.
These authors contributed equally to this work.
Oncotarget. 2019 Jul 23;10(45):4630-4639. doi: 10.18632/oncotarget.27050.
Gremlin1 (GREM1) is a secreted glycoprotein member of the differential screening-selected gene in aberrant neuroblastoma (DAN) family of bone morphogenetic protein (BMP) antagonists, which binds to BMPs preventing their receptor engagement. Previous studies have identified that stage II colorectal cancer (CRC) patients with high levels of gene expression in their tumour tissue have a poorer prognosis. Using a series of and methodologies, we demonstrate that gene expression is significantly higher ( < 0.0001) in CRC consensus molecular subtype 4 (CMS4), compared to the other CMS subtypes and correlates ( < 0.0001) with levels of cancer-associated fibroblasts (CAFs) within the CRC tumour microenvironment (TME). Our optimised immunohistochemistry protocol identified endogenous GREM1 protein expression in both the muscularis mucosa and adjacent colonic crypt bases in mouse intestine, in contrast to RNA expression which was shown to localise specifically to the muscularis mucosa, as determined by hybridisation. Importantly, we demonstrate that cells with high levels of GREM1 expression display low levels of phospho-Smad1/5, consistent with reduced BMP signalling. Taken together, these data highlight a novel paracrine signalling circuit, which involves uptake of mature GREM1 protein by colonic crypt cells following secretion from neighbouring fibroblasts in the TME.
Gremlin1（GREM1）是骨形态发生蛋白（BMP）拮抗剂异常神经母细胞瘤（DAN）家族中一种分泌型糖蛋白成员，它与BMP结合，阻止其与受体结合。先前的研究已经确定，肿瘤组织中基因表达水平高的II期结直肠癌（CRC）患者预后较差。使用一系列的……和……方法，我们证明，与其他共识分子亚型（CMS）相比，CRC共识分子亚型4（CMS4）中的基因表达显著更高（P<0.0001），并且与CRC肿瘤微环境（TME）中癌症相关成纤维细胞（CAF）的水平相关（P<0.0001）。我们优化的免疫组织化学方案确定了小鼠肠道肌层黏膜和相邻结肠隐窝底部内源性GREM1蛋白的表达，与之形成对比的是，通过……杂交确定，RNA表达特异性定位于肌层黏膜。重要的是，我们证明，GREM1表达水平高的细胞显示出低水平的磷酸化Smad1/5，这与BMP信号传导减少一致。综上所述，这些数据突出了一种新的旁分泌信号传导回路，该回路涉及TME中相邻成纤维细胞分泌后结肠隐窝细胞对成熟GREM1蛋白的摄取。
