Klinik und Genetik der Neurofibromatose Typ 1

Sexual Self-Esteem and Psychological Burden of Adults With Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is one of the most common tumor predisposition syndromes which primarily affects the skin. NF1 is characterized by various degrees of skin tumors and pigmentation abnormalities such as café-au-lait macules. Other skin diseases, such as psoriasis or neurodermatitis, have a negative influence on sexuality and quality of life and represent a psychological burden for those affected. The present study investigated the extent to which skin tumors (disfigurement) are related to sexuality and psychosocial factors in NF1 individuals. An anonymous online survey was carried out on Facebook and the webpage of the German Neurofibromatosis Association and a total of 166 persons participated. Of these participants, 92 were affected by NF1.74 healthy persons took part in the survey as a comparative group. Results show a significant relation between sexuality, body image, quality of life and the presence of depressive symptoms of the NF1 affected persons. Individuals with NF1 show a more negative sexual self-esteem. These concerns should be taken into account in NF1- related health care approaches.

Combined Targeting of AKT and mTOR Inhibits Proliferation of Human NF1-Associated Malignant Peripheral Nerve Sheath Tumour Cells In Vitro but not in a Xenograft Mouse Model In Vivo

Persistent signalling via the PI3K/AKT/mTOR pathway is a major driver of malignancy in NF1-associated malignant peripheral nerve sheath tumours (MPNST). Nevertheless, single targeting of this pathway is not sufficient to inhibit MPNST growth. In this report, we demonstrate that combined treatment with the allosteric pan-AKT inhibitor MK-2206 and the mTORC1/mTORC2 inhibitor AZD8055 has synergistic effects on the viability of MPNST cell lines in comparison to the treatment with each compound alone. However, when treating animals bearing experimental MPNST with the combined AKT/mTOR regime, no influence on tumour growth was observed. Further analysis of the MPNST xenograft tumours resistant to AKT/mTOR treatment revealed a reactivation of both AKT and mTOR in several tumour samples. Additional targeting of the RAS/RAF/MEK/MAPK pathway with the allosteric MEK1/2 inhibitor AZD6244 showed synergistic effects on the viability of MPNST cell lines in vitro in comparison to the dual AKT/mTOR inhibition. In summary, these data indicate that combined treatment with AKT and mTOR inhibitors is effective on MPNST cells in vitro but tumour resistance can occur rapidly in vivo by restoration of AKT/mTOR signalling. Our data further suggest that a triple treatment with inhibitors against AKT, mTORC1/2 and MEK1/2 may be a promising treatment option that should be further analysed in an experimental MPNST mouse model in vivo.

RASopathien

Die RASopathien umfassen das Noonan-Syndrom, seltenere verwandte Syndrome (CFC-, Costello und LEOPARD-Syndrom) sowie die Neurofibromatose Typ 1 und ähnliche Erkrankungen (Legius-, NF1-Noonan-Syndrom). Die allen RASopathien zugrunde liegenden genetischen Veränderungen bedingen eine konstitutionelle Fehlregulation des RAS-MAPK-Signalwegs. Es resultiert ein typisches Muster an angeborenen Anomalien und Entwicklungsstörungen in variabler Ausprägung. Typische klinische Merkmale sind kardiale Anomalien, vermindertes Wachstum, kraniofaziale Dysmorphien und Entwicklungsverzögerung. Die Tumordisposition hängt von der jeweiligen Erkrankung und genetischen Veränderung ab. Die molekularen Erkenntnisse machen klinische Überschneidungen und Unterschiede zwischen den Entitäten verständlich. Die genetische Diagnostik ist breit verfügbar. Die Behandlung der Patienten ist bislang nur symptomatisch und erfordert ein interdisziplinäres Management und lebenslange Betreuung der Patienten.