Patients with gastric juvenile polyposis and SMAD4 mutations are at a high risk of developing gastric cancer; hence, early gastrectomy should be considered.
The frequency of genomic alterations seen in SBA demonstrated distinct differences in comparison with either colorectal cancer (APC: 26.8% [85 of 317] vs 75.9% [4823 of 6353], P < .001; and CDKN2A: 14.5% [46 of 317] vs 2.6% [165 of 6353], P < .001) or gastric carcinoma (KRAS: 53.6% [170 of 317] vs 14.2% [126 of 889], P < .001; APC: 26.8% [85 of 317] vs 7.8% [69 of 889], P < .001; and SMAD4: 17.4% [55 of 317] vs 5.2% [46 of 889], P < .001).
Collectively, these data demonstrate that miR‑196a‑5p has a key role in EMT and invasion by targeting Smad4 in GCSCs. miR‑196a‑5p may serve as a potential target for gastric cancer therapy.
Therefore, these findings demonstrate that miR-558 facilitates the progression of gastric cancer through directly targeting the HPSE promoter to attenuate Smad4-mediated repression of HPSE expression.
In conclusion, EBV-encoded BARF1 promotes cell proliferation in stomach cancer by upregulating NFκB and miR-146a and downregulating SMAD4, thereby contributing to EBV-induced stomach cancer progression.
SB mutagenesis has, thus, helped to catalog the cooperative molecular mechanisms driving SMAD4-induced GC growth and discover genes with potential clinical importance in human GC.
In conclusion, our functional screening uncovers multiple miRNAs that regulate the cellular responsiveness to TGF-β signalling and reveals important roles of miR-199a in gastric cancer by directly targeting Smad4.
Thus, this study provides a mechanism by which a balance between Smad4 and Smad7 in human gastric cancer is critical for differentiation, metastasis, and apoptosis of tumor cells.
SMAD4 mutation carriers had a significantly higher frequency of gastric polyposis (73%) than did patients with BMPR1A mutations (8%) (p<0.001); all seven cases of gastric cancer occurred in families with SMAD4 mutations.
To clarify the clinical significance of TSG expression in gastric carcinoma, the expression of various TSG candidates (p53, E-cadherin, FHIT, smad4, rb, VHL, PTEN, MGMT, p16, and KAI1), as well as other proteins (bcl-2, MUC1, MUC2, MUC5AC, MUC6, CEA, CD44, beta-catenin, C-erbB2, and cyclin B2), was evaluated immunohistochemically in 329 consecutive gastric carcinomas using the tissue array method.
Allelic loss was also noted on chromosome 18q at a marker near Smad4 in this mutated gastric cancer, apparently producing complete inactivation of Smad4 in this tumor.