GNAS mutation as an alternative mechanism of activation of the Wnt/β-catenin signaling pathway in gastric adenocarcinoma of the fundic gland type
| Autor: | Ryosuke Nomura, Se-yong Lee, Takashi Yao, Tsuyoshi Saito, Hiroyuki Mitomi, Sumio Watanabe, Yasuhiro Hidaka |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Adult
Male musculoskeletal diseases MAPK/ERK pathway medicine.medical_specialty DNA Mutational Analysis Adenocarcinoma medicine.disease_cause Pathology and Forensic Medicine Exon Stomach Neoplasms Internal medicine Chromogranins GTP-Binding Protein alpha Subunits Gs medicine GNAS complex locus Humans Gastric Fundus Wnt Signaling Pathway beta Catenin Aged Aged 80 and over Mutation biology Wnt signaling pathway Middle Aged Immunohistochemistry Endocrinology Gastric Mucosa Cancer research biology.protein Female KRAS Signal transduction Carcinogenesis |
| Zdroj: | Human Pathology. 45:2488-2496 |
| ISSN: | 0046-8177 |
| DOI: | 10.1016/j.humpath.2014.08.016 |
| Popis: | Gastric adenocarcinoma of the fundic gland type (GAFG) is a rare variant of gastric tumor. We have recently reported the frequent accumulation of β-catenin in GAFGs and showed that approximately half of the cases studied harbored at least 1 mutation in CTNNB1/AXINs/APC, leading to the constitutive activation of the Wnt/β-catenin pathway. However, the mechanisms of Wnt signaling activation in the remaining cases are unknown. Accumulating evidence showed that the activating mutation in GNAS promotes tumorigenesis via the activation of the Wnt/β-catenin pathway or the ERK1/2 MAPK pathway. Therefore, we analyzed the mutations in GNAS (exons 8 and 9) and in KRAS (exon 2) in 26 GAFGs. Immunohistochemistry revealed nuclear β-catenin expression in 22 of 26 GAFGs, and 10 (38.5%) of 26 cases harbored at least 1 mutation in CTNNB1/AXINs/APC. Activating mutations in GNAS were found in 5 (19.2%) of 26 GAFGs, all of which harbored R201C mutations. Activating mutations in KRAS were found in 2 (7.7%) of 26 GAFGs, and both of these also contained GNAS activating mutations. Four of 5 cases with GNAS mutation showed nuclear β-catenin expression, and presence of GNAS mutation was associated with β-catenin nuclear expression (P = .01). Furthermore, 3 of these 4 cases did not harbor mutations in CTNNB1, APC, or AXINs, suggesting that mutations in the Wnt component genes and those in GNAS occur almost exclusively. These results suggest that GNAS mutation might occur in a small subset of GAFG as an alternative mechanism of activating the Wnt/β-catenin signaling pathway. |
| Databáze: | OpenAIRE |
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