@phdthesis{Sbiera2022,
  author    = {Sbiera, Iuliu},
  title     = {Possible role of epithelial to mesenchymal transition and its associated FGF/FGFR pathway in adrenocortical carcinoma},
  doi       = {10.25972/OPUS-27745},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-277454},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2022},
  abstract  = {Recent studies have hinted to an involvement of epithelial to mesenchymal transition, a mechanism often associated with metastasis in epithelial cancers, in adrenocortical carcinoma. In addition, the knowledge about the FGF/FGFR pathway in pathogenesis of the adrenal gland, a pathway often associated with the epithelial to mesenchymal transition, is sparse and fragmented. We assessed, in a large number of normal, benign and malignant adrenocortical tissues (a total of 181 different samples), the expression of canonical and novel epithelial and mesenchymal markers and compared it with their expression in typical epithelial and mesenchymal tissues. In addition, we also quantified the expression of most members of the FGF/FGFR pathway in adrenocortical tissues and compared it against well-studied epithelial and mesenchymal tissues as well as between malignant and not malignant adrenocortical tissues, in order to assess the possible connection to epithelial to mesenchymal transition and find possible drug targets. Surprisingly, both normal and neoplastic adrenocortical tissues lacked expression of epithelial markers (e.g. E-Cadhering or EpCAM) but strongly expressed mesenchymal markers (e.g. N-Cadherin or SLUG), suggesting a higher similarity of adrenocortical tissues to mesenchymal compared to epithelial tissues, reminiscent of the adrenocortical origin from the intermediate mesoderm. Despite their ubiquitous expression in all adrenocortical tissues, mesenchymal markers had a variable expression in adrenocortical carcinoma, associating either directly or inversely with different clinical markers of tumor aggressiveness. Lymph node infiltration was associated with high expression of SLUG (p = 0.04), and at the same time low expression of N-cadherin (p = 0.001), and the same pattern was observed for venous infiltration of tumoral tissue, Weiss score of tumor malignancy or Ki67 proliferation marker. In malignant compared to benign adrenal tumors, we found significant differences in the expression of 16 out of the 94 studied FGF receptor pathway related genes. Genes involved in tissue differentiation and metastatic spread through epithelial to mesenchymal transition were most strongly altered. The therapeutically targetable FGF receptors 1 and 4 were upregulated 4.6- and 6-fold, respectively, in malignant compared to benign adrenocortical tumors, which was confirmed by using two different quantification methods in both frozen and paraffin embedded tissue material. High expression of FGFR1 and 4 was significantly associated with worse patient prognosis (High FGFR1 expression was associated with a shorter overall patient survival of 84 vs 148 months (HR=1.8, 95\% CI: 1.01-3.25) as well as a shorter resection free survival of 25 vs 75 months ((HR=2.93, 95\% CI: 1.25-6.84), while high FGFR4 was associated with a much shorter overall survival of 50 vs 155 months (HR=2.44, 95\% CI: 1.41-4.22). In conclusion, epithelial to mesenchymal transition does not seem to play a role in adrenocortical carcinoma tumor progression, and the FGF/FGFR pathway, even if it is probably not related to EMT, is nonetheless associated with tumor aggressiveness. Furthermore, quantification of FGF receptors may enable a stratification of adrenocortical carcinoma for the use of FGFR inhibitors in future clinical trials.},
  subject      = {Nebennierenrindenkrebs},
  language  = {en}
}