Monitoring the Expression Profiles of Integrins and Adhesion/Growth-regulatory Galectins in Adamantinomatous Craniopharyngiomas: Their Ability to Regulate Tumor Adhesiveness to Surrounding Tissue and Their Contribution to Prognosis

Predictive Factors for Pediatric Craniopharyngioma Recurrence: An Extensive Narrative Review

Despite being classified as benign tumors, craniopharyngiomas (CPs) are associated with significant morbidity and mortality due to their location, growth pattern, and tendency to recur. Two types can be identified depending on age distribution, morphology, and growth pattern, adamantinomatous and papillary. The adamantinomatous CP is one of the most frequently encountered central nervous system tumors in childhood. Our aim was to review the relevant literature to identify clinical, morphological, and immunohistochemical prognostic factors that have been implicated in childhood-onset CP recurrence. Lack of radical surgical removal of the primary tumor by an experienced neurosurgical team and radiotherapy after a subtotal excision has been proven to significantly increase the recurrence rate of CP. Other risk factors that have been consistently recognized in the literature include younger age at diagnosis (especially <5 years), larger tumor size at presentation, cystic appearance, difficult tumor location, and tight adherence to surrounding structures, as well as the histological presence of whorl-like arrays. In addition, several other risk factors have been studied, albeit with conflicting results, especially in the pediatric population. Identifying risk factors for CP recurrence is of utmost importance for the successful management of these patients in order to ultimately ensure the best prognosis.

Can tissue biomarkers reliably predict the biological behavior of craniopharyngiomas? A comprehensive overview

BACKGROUND

The growing interest in the molecular and genetic alterations of craniopharyngiomas (CPs) is embodied in recent studies revealing insights into the CP tumorigenesis and identifying novel molecular pathways amenable of targeted therapies. The actual impact of this new information, however, remains inconclusive.

METHODS

We present a comprehensive review of the accumulated knowledge on molecular biology of CPs and a critical analysis on the strengths and weaknesses of the studies focused on CP molecular/genetic alterations published to date.

RESULTS

A thorough analysis of the alterations of β-catenin/CTNNB1 and BRAF genes investigated in 1123 CP cases included in 27 studies, showed that, on average, CTNNB1 mutations were present in two-thirds of adamantinomatous CPs and BRAF mutations in 90% of papillary CPs. Their role as oncogenic drivers has not been well established. Although rare, coexistence of both mutations may occur. The involvement of pituitary stem cells in human CP tumorigenesis is still uncertain. Expression of stem markers in human CP samples predominantly occurred along the CP border in contact with brain tissue. Finally, none of the various molecular alterations which have been proposed as markers for CP recurrence can be used today as reliable predictors of the CP behavior.

CONCLUSIONS

The isolated evaluation of CPs' molecular or genetic profiles that do not take into consideration fundamental pathological and therapeutic factors, specifically the tumor topography and the degree of tumor removal, may actually generate confusion regarding the reliability of some biomarkers to predict the CP biological behavior.

Activation and regulation of endogenous retroviral genes in the human pituitary gland and related endocrine tumours

AIMS

Adenohypophysis (AH) hormone-producing cells represent the origin of diverse groups of pituitary adenomas (PA). Deregulation of hypothalamic hormone receptors, growth factors and cAMP signalling have been implicated in the aetiology of PA. Endogenous retroviruses (ERVs) are derived from past exogenous retroviral infections and represent more than 8% of the human genome. Some ERV genes encode open reading frames and produce functional proteins, for example, the ERVW-1 envelope gene Syncytin-1, essential for placentogenesis, but also deregulated in human tumours. Data concerning ERV expression in the AH and related endocrine tumours are missing.

METHODS

Syncytin-1 protein was analysed in normal AH (n = 15) and compared with five PA subtypes (n = 117) by immunohistochemistry. Absolute gene expression of 20 ERV functional envelope genes and ERVW-5 gag was measured. PA tissues were examined for Syncytin-1 and the cAMP signalling marker phospho-CREB-Ser133 using immunohistochemistry. Isolated primary human PA cells were treated with different hormones. Murine embryonic and adult pituitary gland ERV expressions were compared with human AH.

RESULTS

Syncytin-1 protein colocalized with corticotropic cells of AH. In contrast, all PA demonstrated significant Syncytin-1 protein overexpression, supporting deregulation. All other ERV genes showed significant up-regulations in different PA subtypes. Phospho-CREB-Ser133 and Syncytin-1 colocalized in PA cells. Cultivated primary PA cells with ACTH or CRH induced their respective receptors and ERV genes. Syncytin-A/-B, murine orthologues to human Syncytin-1/-2, localized to embryonic and adult pituitary glands demonstrating functional mammalian conservation.

CONCLUSIONS

Deregulated ERV genes may contribute to PA development via cAMP signalling.

Proliferation rate of stem cells derived from human dental pulp and identification of differentially expressed genes

Stem cells from human exfoliated deciduous teeth (SHED) and dental pulp stem cells (DPSCs) obtained from the dental pulp of human extracted tooth were cultured and characterized to confirm that these were mesenchymal stem cells. The proliferation rate was assessed using AlamarBlue® cell assay. The differentially expressed genes in SHED and DPSCs were identified using the GeneFishing™ technique. The proliferation rate of SHED (P < 0.05) was significantly higher than DPSCs while SHED had a lower multiplication rate and shorter population doubling time (0.01429, 60.57 h) than DPSCs (0.00286, 472.43 h). Two bands were highly expressed in SHED and three bands in DPSCs. Sequencing analysis showed these to be TIMP metallopeptidase inhibitor 1 (TIMP1), and ribosomal protein s8, (RPS8) in SHED and collagen, type I, alpha 1, (COL1A1), follistatin-like 1 (FSTL1), lectin, galactoside-binding, soluble, 1, (LGALS1) in DPSCs. TIMP1 is involved in degradation of the extracellular matrix, cell proliferation and anti-apoptotic function and RPS8 is involved as a rate-limiting factor in translational regulation; COL1A1 is involved in the resistance and elasticity of the tissues; FSTL1 is an autoantigen associated with rheumatoid arthritis; LGALS1 is involved in cell growth, differentiation, adhesion, RNA processing, apoptosis and malignant transformation. This, along with further protein expression analysis, holds promise in tissue engineering and regenerative medicine.

Predictive factors for craniopharyngioma recurrence: a systematic review and illustrative case report of a rapid recurrence

BACKGROUND

Recurrence of craniopharyngiomas (CPs) represents a frequent and unpredictable incident. Rapid tumor recurrence within a few months after surgery has been rarely reported. Nondefinitive predictive factors for rapid CP recurrence have been identified to date. We have systematically analyzed the tumor factors that presumably influence in CP recurrence.

METHODS

We present the histologic and immunohistochemical analysis of an infundibulo-tuberal CP that was operated twice within a 3-month interval due to rapid recurrence. We investigated the differential characteristics of the subgroup of CPs that recurred in large surgical series published in the literature, along with cases reporting rapid tumor recurrence after surgery.

RESULTS

Specimens of our patient showed an adamantinomatous CP with whorl-like arrays and thick peritumoral gliosis. Ki-67 labeling index in primary and recurrent samples was 20% and 15%, respectively. p53 labeling index was 18% and 15%, respectively. The thorough analysis of literature showed that presence of tumor remnants and missing radiotherapy treatment after subtotal removal are strong predictors of tumor recurrence. Third ventricle involvement, large tumor size, tight adherence to surrounding structures, and presence of whorl-like arrays might also foster recurrence. High Ki-67 levels, p53 expression, and an intense reactive gliosis might point to rapid tumor growth.

CONCLUSIONS

Reliable tumor markers that predict CP recurrence are still lacking. The CP features presumably related to a higher risk of its recurrence are thought to be a larger tumor size, a tight adherence to the hypothalamus, the presence of whorl-like arrays, and high Ki-67 and p53 levels.

Recurrence rates after neuroendoscopic fenestration and Gamma Knife surgery in comparison with subtotal resection and Gamma Knife surgery for the treatment of cystic craniopharyngiomas

OBJECT

The object of this study was to compare the recurrence rates of cystic craniopharyngiomas after neuroendoscopic cyst fenestration combined with Gamma Knife surgery (GKS) and after subtotal resection (STR) combined with GKS.

METHODS

The records of 27 patients (age range 3-66 years) with cystic craniopharyngiomas that were treated surgically or neuroendoscopically before GKS between January 2000 and December 2007 were reviewed to compare recurrence rates. The patients were divided into 2 groups: Group 1 (13 patients) received the neuroendoscopic procedure before GKS, and Group 2 (14 patients) received an STR followed by GKS. Tumor volumes, radiation doses, visual field defects, endocrine levels, and recurrences were compared between the 2 groups. Patients with solid tumors and those who underwent complete resection were excluded from the study.

RESULTS

The recurrence rate for Group 1 was higher than that of Group 2 (p = 0.046). The radiation dose near the optic chiasm was higher in Group 1 (p = 0.021) than in Group 2. However, endocrine function was better preserved in Group 1 than in Group 2.

CONCLUSIONS

This investigation confirms that STR followed by GKS results in a lower recurrence rate than neuroendoscopy and GKS. Neuroendoscopy and GKS, however, results in a better preservation of endocrine function. These results suggest that a generalized multimodal approach including endoscopic fenestration in addition to GKS is hindered by higher recurrence rates.