■肝细胞腺瘤(HCA)很少见,良性,临床病理分类的肝肿瘤,遗传,和蛋白质组水平。β-连环蛋白激活(b-HCA)亚型在β-连环蛋白基因(CTNNB1)中具有几种突变类型,与恶性转化或出血的不同风险相关。谷氨酰胺合成酶是与恶性转化风险相关的β-连环蛋白途径激活的替代标记。最近,我们发现与其他肿瘤相比,外显子3S45突变的b-HCA和外显子7/8突变的b-HCA的边缘中谷氨酰胺合成酶的过表达。仅在肿瘤中心的弥散性CD34染色显示,在该边缘中发现了血管形成的差异。这里,我们旨在描述这种肿瘤异质性,以更好地了解其病理生理参与。
■使用质谱成像,遗传,和蛋白质组学分析结合激光捕获显微切割,我们比较了肿瘤中心与肿瘤边缘和邻近的非肿瘤组织。
■肿瘤边缘具有与肿瘤中心相同的突变,这意味着这两个部分属于同一个肿瘤。质谱成像显示边缘和肿瘤中心之间的不同光谱轮廓。蛋白质组学分析显示,与肿瘤中心相比,边缘有40种蛋白质的显着差异表达。这些蛋白质中的大多数与代谢有关,具有与正常静脉周围肝细胞表达谱相当的表达谱。
■外显子3S45突变的b-HCA和外显子7/8突变的b-HCA的肿瘤中心和肿瘤边缘之间的表型差异不取决于CTNNB1突变状态。在正弦动脉病理学的背景下,边缘的肿瘤异质性具有静脉周围特征,可能是由功能性外周静脉引流引起的。
■通过谷氨酰胺合酶在肿瘤边缘的差异表达,在β-连环蛋白突变的肝细胞腺瘤(b-HCA)中揭示了肿瘤异质性。几种空间方法的组合(质谱成像,遗传,和蛋白质组学分析)在激光捕获显微解剖后,可以鉴定出这种差异背后的外周静脉引流的潜在作用。通过这项研究,我们能够说明,超越突变的背景,许多因素可以下游调节基因表达,并导致不同的临床病理表型。我们相信,我们使用的空间分析的组合可能会鼓舞所有希望获得肝肿瘤异质性信息的研究人员。
UNASSIGNED: Hepatocellular adenomas (HCAs) are rare, benign, liver tumours classified at the clinicopathological, genetic, and proteomic levels. The β-catenin-activated (b-HCA) subtypes harbour several mutation types in the β-catenin gene (CTNNB1) associated with different risks of malignant transformation or bleeding. Glutamine synthetase is a surrogate marker of β-catenin pathway activation associated with the risk of malignant transformation. Recently, we revealed an overexpression of glutamine synthetase in the rims of exon 3 S45-mutated b-HCA and exon 7/8-mutated b-HCA compared with the rest of the tumour. A difference in vascularisation was found in this rim shown by diffuse CD34 staining only at the tumour centre. Here, we aimed to characterise this tumour heterogeneity to better understand its physiopathological involvement.
UNASSIGNED: Using mass spectrometry imaging, genetic, and proteomic analyses combined with laser capture microdissection, we compared the tumour centre with the tumour rim and with adjacent non-tumoural tissue.
UNASSIGNED: The tumour rim harboured the same mutation as the tumour centre, meaning both parts belong to the same tumour. Mass spectrometry imaging showed different spectral profiles between the rim and the tumour centre. Proteomic profiling revealed the significant differential expression of 40 proteins at the rim compared with the tumour centre. The majority of these proteins were associated with metabolism, with an expression profile comparable with a normal perivenous hepatocyte expression profile.
UNASSIGNED: The difference in phenotype between the tumour centres and tumour rims of exon 3 S45-mutated b-HCA and exon 7/8-mutated b-HCA does not depend on CTNNB1 mutational status. In a context of sinusoidal arterial pathology, tumour heterogeneity at the rim harbours perivenous characteristics and could be caused by a functional peripheral venous drainage.
UNASSIGNED: Tumour heterogeneity was revealed in β-catenin-mutated hepatocellular adenomas (b-HCAs) via the differential expression of glutamine synthase at tumour rims. The combination of several spatial approaches (mass spectrometry imaging, genetic, and proteomic analyses) after laser capture microdissection allowed identification of a potential role for peripheral venous drainage underlying this difference. Through this study, we were able to illustrate that beyond a mutational context, many factors can downstream regulate gene expression and contribute to different clinicopathological phenotypes. We believe that the combinations of spatial analyses that we used could be inspiring for all researchers wanting to access heterogeneity information of liver tumours.