TY - JOUR A1 - Wobser, Marion A1 - Roth, Sabine A1 - Appenzeller, Silke A1 - Houben, Roland A1 - Schrama, David A1 - Goebeler, Matthias A1 - Geissinger, Eva A1 - Rosenwald, Andreas A1 - Maurus, Katja T1 - Targeted deep sequencing of mycosis fungoides reveals intracellular signaling pathways associated with aggressiveness and large cell transformation JF - Cancers N2 - Introduction: Large-cell transformation (LCT) of mycosis fungoides (MF) has been associated with a higher risk of relapse and progression and, consequently, restricted prognosis. Its molecular pathogenesis has not been elucidated yet. Materials and Methods: In order to address molecular mechanisms of LCT, we performed hybrid capture panel-based sequencing of skin biopsies from 10 patients suffering from MF with LCT versus 17 patients without LCT including follow-up biopsies during clinical course, respectively (51 samples in total). The analyzed patients were attributed to three different groups based on the presence of LCT and clinical behavior. Results: While indolent MF cases without LCT did not show pathogenic driver mutations, a high rate of oncogenic alterations was detected in patients with LCT and aggressive clinical courses. Various genes of different oncogenic signaling pathways, including the MAPK and JAK-STAT signaling pathways, as well as epigenetic modifiers were affected. A high inter-individual and distinctive intra-individual mutation diversity was observed. Oncogenic RAS mutations were exclusively detected in patients with LCT. Conclusion: Our data demonstrate that LCT transition of MF is associated with increased frequency of somatic mutations in cancer-associated genes. In particular, the activation of RAS signaling — together with epigenetic dysregulation — may crucially contribute to the molecular pathogenesis of the LCT phenotype, thus conveying its adverse clinical behavior. KW - mycosis fungoides KW - cutaneous T-cell-lymphoma KW - panel sequencing KW - large cell transformation KW - CD30 Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-250094 SN - 2072-6694 VL - 13 IS - 21 ER -