Specifically, using a model based clustering of somatic mutations, one single founding clone arising in the HCA, which included catenin beta 1 (CTNNB1) and IL6ST driver mutations, was identified and displayed an increasing clonality rate in HCC, tumor thrombus and brain metastasis.
In summary, an impaired oxidative stress response in hepatocytes with gp130 gain-of-function mutations, as detected in dysplastic intrahepatic nodules and hepatocellular adenomas, is one of the central oncogenic mechanisms in chronic liver inflammation.
In a previous study, the frequent occurrence of somatic gain-of-function mutations was observed in the gp130-encoding IL6ST gene in exon 6 in 60% of inflammatory hepatocellular adenomas.
All 36 sequenced HCAs showed HNF1α mutations (72% missense, 28% synonymous), 2 hotspot polymorphisms of HNF1α (I27L: rs1169288 and S487N: rs2464196) were seen in 17 (47%) and 10 (27.8%) cases, respectively, and a novel single nucleotide polymorphism site (rs1169304) in intron 9 of HNF1α was detected in 32 (88%) cases, but no β-catenin or gp130 gene mutation was detected, and no nuclear β-catenin staining was detected by immunohistochemistry.
Finally, in a few MODY3 patients with HNF1A germline mutation leading to amino acid substitutions outside the POU-H domain, we identified a different subtype of HCA either with a gp130 and/or CTNNB1 activating mutation.
The recurrent gain-of-function gp130 mutations in these human hepatocellular adenomas fully explains activation of the acute inflammatory phase observed in tumourous hepatocytes, and suggests that similar alterations may occur in other inflammatory epithelial tumours with STAT3 activation.
The recurrent gain-of-function gp130 mutations in these human hepatocellular adenomas fully explains activation of the acute inflammatory phase observed in tumourous hepatocytes, and suggests that similar alterations may occur in other inflammatory epithelial tumours with STAT3 activation.