Pi3Kinase-Akt-mTOR and somatostatin pathways study in intra-cranial tumors (pituitary adenomas, meningiomas, and chordomas)

1. Adénomes hypophysaires somatotropes : Elaboration d'un modèle in vitro et in vivo d'études du récepteur SST2 et des voies de signalisation somatostatinergiques.Afin de préciser l'étude du récepteur SST2, nous avons mis en place un modèle d'étude in vitro et in vivo, en établissant une lignée polyclonale exprimant le récepteur SST2 humain à de hauts niveaux. Ce modèle nous permettra de tester de nouveaux agonistes somatostatinergiques comme le pasiréotide et d'étudier de façon approfondie les voies de signalisation.2. Méningiomes : Mise en place d'un modèle de culture primaire de méningiome in vitro et étude de l'effet de l'octréotide, du pasiréotide et de l'everolimus sur la prolifération cellulaire et les voies de signalisation intracellulaire.Etant donné la forte expression du récepteur SST2, nous avons démontré in vitro un effet anti-prolifératif de l'octréotide sur les cellules de méningiomes via une inhibition de la voie Pi3kinase-Akt-mTOR. L'octréotide a significativement amélioré l'inhibition par l'everolimus de la prolifération cellulaire.Un effet additif des 2 drogues a été observé. Ces résultats ont permis la mise en place d'une étude clinique . Par ailleurs, on observe un meilleur effet du pasiréotide comparé à celui de l'octréotide.3. Chordomes : Mise au point d'un modèle de culture primaire de cellules de chordomes in vitro et études préliminaires.Les premiers résultats avec octréotide, pasiréotide et everolimus sont concluants, mettant en évidence une diminution de la prolifération cellulaire, et nous incitent à poursuivre les investigations.1.Somatotroph adenomas : Development of an in vitro and in vivo model to study SST2 receptor and somatostatin pathway.To precise SST2 role in tumorigenesis, we developed an in vitro and in vivo model, using a polyclonal cell line with high and stable SST2 expression level. This model will provide to test new somatostatin agonists as pasireotide and further studies on intracellular pathway in ''somatotroph'' context.2. Meningiomas : Development of a model of meningioma primary culture in vitro with study of octreotide, pasireoide and everolimus effects on cell proliferation and intracellular pathways. Given the strong SST2 expression, we demonstrated an in vitro antiproliferative effect of octreotide on meningioma cells via an inhibition of Pi3kinase-Akt-mTOR pathway.In vitro, we observed that octreotide significantly improved everolimus induced cell proliferation inhibition. An additive effect of the 2 drugs was observed in each tested tumor. These results supported the development of a clinical trial. Pasireotide provided a better effect than octreotide, alone or in combination with everolimus on cell proliferation and intracellular pathways.3. Chordomas : Development of an in vitro model of chordoma cell primary culture with preliminary studies.We developed a model of in vitro chordoma cell culture. This model is reliable and stable, providing study of different drugs. SST2 receptor expression was lower than in meningiomas but SST2 expression remained significant in the majority of the tumors. First results with octreotide, pasireotide and everolimus are relevant, with a decrease in cell proliferation leading to further studies

Chemotherapy and targeted therapies for meningiomas: what is the evidence?

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Treatment of aggressive recurrent meningiomas: spinning towards peptide receptor radionuclide therapy

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Preoperative Medical Treatment for Patients With Acromegaly: Yes or No

Transsphenoidal surgery is the first-line treatment for acromegaly. However, several factors can modify surgical remission rates, such as the initial hormone levels, the size and invasiveness of the tumor, and the degree of experience of the surgeon. Physicians treating patients with acromegaly should thus consider how to improve surgical remission rates. As stated in recent guidelines, the major point is to consider that any patient with acromegaly should be referred to an expert neurosurgeon to maximize the chances of surgical sure. The benefits of presurgical medical treatment, mainly using somatostatin receptor ligands (SRLs), given 3 to 6 months before surgery, remain controversial. By normalizing growth hormone and insulin-like growth factor 1 levels, SRLs may improve the overall condition of the patient, thus decreasing anesthetic and surgical complications. By decreasing the tumor size and modifying the consistency of the tumor, SRLs might also make surgical excision easier. This is however theoretical as published data are contradictory on both points, and only limited data support the use of a systematical presurgical medical treatment. The aim of this review is to analyze the potential benefits and pitfalls of using presurgical medical treatment in acromegaly in view of the contradictory literature data. We also attempt to determine the profile of patients who might most benefit from this presurgical medical treatment approach as an individualized therapeutic management of acromegaly

Parasellar Meningiomas

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Transfalcine approach for the resection of a bilateral falx meningioma: Technical nuances and review of literature

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Long-term outcome of macroprolactinomas

International audienceOBJECTIVE: Management of macroprolactinomas has dramatically changed in recent decades, from surgical to medical treatment as first-line therapy, with the development of dopamine agonists (DA). But few data exist on the long-term outcome of these patients.ăPATIENTS AND METHODS: Retrospective descriptive multicenter study of patients with macroprolactinoma followed for at least 5 years between 1973 and 2008 at the University Hospitals of Strasbourg and Marseille.ăRESULTS: Forty-eight patients were included with 27 men, hypopituitarism in 33.3% of all patients and mean serum prolactin (PRL) level at diagnosis 2218.2±4154.7μg/L. Among the patients, 58.3% received medical treatment, 25% had additional surgery and 12.5% surgery and radiotherapy. The mean follow-up duration was 196±100 months. At the end of follow-up, 10 patients (20.8%) were cured (i.e. normal PRL level and normal imaging, no symptoms and withdrawal of DA≥1 year), 33 (68.8%) were controlled (i.e. normal PRL level, normal or abnormal imaging, no symptoms, DA in progress) and 5 (10.4%) were uncontrolled. Uncontrolled patients had significant higher baseline PRL level (P=0.0412) and cabergoline cumulative dose (P=0.0065) compared to the controlled group. There was no increase in frequency of hypopituitarism. Clinically significant valvular heart disease was found in 2 patients but screening was not systematic.ăCONCLUSIONS: Macroprolactinoma is currently most often a chronic disease controlled with DA. However, uncertainty about the adverse effects associated with high cumulative doses and the lack of data on the prognosis at very long-term should incite to revisit current strategies, including the role of surgery combined to medical treatment

Surgical management of post-traumatic atlantoaxial rotatory fixation due to C2 facet fracture: 5 clinical cases

International audiencePURPOSE: Report the results of surgical treatment of post-traumatic atlantoaxial rotatory fixation (AARF) due to C2 articular facet fracture in adults.ăMATERIAL AND METHODS: The records of five patients treated since 2009 for AARF due to a C2 articular facet fracture were analyzed retrospectively. Three women and two men with an average age of 60 years (27-82) were included, one of whom initially had neurological deficits. In all cases, the surgical strategy consisted of posterior fixation: Harms-type in four cases and trans-articular with hooks in one case.ăRESULTS: Dislocations due to fracture of the C2 articular facet are rare in adults; various treatment strategies have been described. In our experience, posterior screw fixation leads to satisfactory clinical and radiological outcomes. Fusion is not necessary in these cases because the dislocation is related to an asymmetric fracture without ligament damage.ăCONCLUSION: Posterior fixation provides satisfactory reduction of these injuries and leads to satisfactory bone union. This surgical treatment can be performed early on after the trauma and is an interesting alternative to conservative treatment