RESUMEN
Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors originating from interstitial cells of Cajal or related stem cell-like precursors present in the wall of the gastrointestinal tract. However, identical tumors originating from areas other than the gastrointestinal tract have been reported which are histologically identical to the usual GISTs. We are reporting a case of primary omental GIST in a 57-year-old female.
Asunto(s)
Tumores del Estroma Gastrointestinal , Epiplón/patología , Epiplón/cirugía , Neoplasias Peritoneales , Antineoplásicos/uso terapéutico , Benzamidas/uso terapéutico , Biomarcadores de Tumor , Femenino , Tumores del Estroma Gastrointestinal/diagnóstico , Tumores del Estroma Gastrointestinal/patología , Tumores del Estroma Gastrointestinal/cirugía , Tracto Gastrointestinal/patología , Humanos , Mesilato de Imatinib , Persona de Mediana Edad , Neoplasias Peritoneales/diagnóstico , Neoplasias Peritoneales/patología , Neoplasias Peritoneales/cirugía , Piperazinas/uso terapéutico , Inhibidores de Proteínas Quinasas/uso terapéutico , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Pirimidinas/uso terapéuticoRESUMEN
Latent membrane protein 1 (LMP1) of Epstein-Barr virus (EBV) can induce cell transformation and tumourigenesis, but the mechanism is not understood. Previous studies have suggested that LMP1 acts through up-regulation of cellular proliferation pathways including the Wnt/ß-catenin pathway, in which ß-catenin is the central effector. Increased levels of ß-catenin coupled with a decrease in E-cadherin lead to reduced cell adhesion. This pathway is antagonized by WTX (Wilms' tumour gene on the X chromosome), which can promote the ubiquitination and degradation of ß-catenin. In the present study, we established L2/LMP1B(95 - 8) /EGFP transgenic mice to investigate the in vivo role of LMP1. Down-regulation of WTX and E-cadherin was accompanied by increased expression of ß-catenin in these mice. Even though invasive tumours did not develop, dysplasia was seen in the nasopharynx and oropharynx epithelium of these transgenic mice. Analysis of LMP1(+) , WTX(+) , and LMP1 siRNA silenced HNE-1 cell lines demonstrated that WTX could exert a dominant role in LMP1-mediated WNT/ß-catenin pathway regulation. This study indicates that LMP1 antagonizes the WNT/ß-catenin pathway by inhibiting WTX, and this reduction in WTX is associated with epithelial dysplasia via regulation of the WNT/ß-catenin pathway molecules E-cadherin and ß-catenin. Further studies are required for a better understanding of the relationship between LMP1-mediated antagonization of the WNT/ß-catenin pathway and tumourigenesis.