Function of cell-cycle regulators in predicting silent pituitary adenoma progression following surgical resection

The kinome, cyclins and cyclin-dependent kinases of pituitary adenomas, a look into the gene expression profile among tumors from different lineages

Background

Pituitary adenomas (PA) are the second most common intracranial tumors and are classified according to hormone they produce, and the transcription factors they express. The majority of PA occur sporadically, and their molecular pathogenesis is incompletely understood.

Methods

Here we performed transcriptome and proteome analysis of tumors derived from POU1F1 (GH-, TSH-, and PRL-tumors, N = 16), NR5A1 (gonadotropes and null cells adenomas, n = 17) and TBX19 (ACTH-tumors, n = 6) lineages as well as from silent ACTH-tumors (n = 3) to determine expression of kinases, cyclins, CDKs and CDK inhibitors.

Results

The expression profiles of genes encoding kinases were distinctive for each of the three PA lineage: NR5A1-derived tumors showed upregulation of ETNK2 and PIK3C2G and alterations in MAPK, ErbB and RAS signaling, POU1F1-derived adenomas showed upregulation of PIP5K1B and NEK10 and alterations in phosphatidylinositol, insulin and phospholipase D signaling pathways and TBX19-derived adenomas showed upregulation of MERTK and STK17B and alterations in VEGFA-VEGFR, EGF-EGFR and Insulin signaling pathways. In contrast, the expression of the different genes encoding cyclins, CDK and CDK inhibitors among NR5A1-, POU1F1- and TBX19-adenomas showed only subtle differences. CDK9 and CDK18 were upregulated in NR5A1-adenomas, whereas CDK4 and CDK7 were upregulated in POUF1-adenomas.

Conclusions

The kinome of PA clusters these lesions into three distinct groups according to the transcription factor that drives their terminal differentiation. And these complexes could be harnessed as molecular therapy targets.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01206-y.

An Update on Silent Corticotroph Adenomas: Diagnosis, Mechanisms, Clinical Features, and Management

Simple Summary

The 2017 World Health Organization classification of endocrine tumors defines pituitary adenomas based on their cell lineages. T-PIT can serve as a complimentary tool for further identification of silent corticotroph adenomas (SCAs). Unlike functioning corticotroph adenomas in patients with Cushing’s disease, SCAs present no clinical and biochemical features of Cushing’s syndrome. SCAs have been shown to exhibit a more aggressive course characterized by a higher probability of recurrence and resistance to conventional treatment due to their intrinsic histological features. The aim of our review is to offer an update on the diagnosis, mechanisms, clinical features and management of SCAs. Studies of the molecular mechanisms of SCA pathogenesis will provide new directions for the diagnosis and management of SCAs.

Abstract

With the introduction of 2017 World Health Organization (WHO) classification of endocrine tumors, T-PIT can serve as a complementary tool for identification of silent corticotroph adenomas (SCAs) in some cases if the tumor is not classifiable by pituitary hormone expression in pathological tissue samples. An increase of the proportion of SCAs among the non-functioning pituitary adenomas (NFPAs) has been witnessed under the new rule with the detection of T-PIT-positive ACTH-negative SCAs. Studies of molecular mechanisms related to SCA pathogenesis will provide new directions for the diagnosis and management of SCAs. A precise pathological diagnosis can help clinicians better identify SCAs. Understanding clinical features in the context of the pathophysiology of SCAs is critical for optimal management. It could provide information on appropriate follow-up time and aid in early recognition and treatment of potentially aggressive forms. Management approaches include surgical, radiation, and/or medical therapies.

Comprehensive analysis of the immunological landscape of pituitary adenomas: implications of immunotherapy for pituitary adenomas

PURPOSES

Immunotherapies for solid tumor are gaining traction in the clinic, however, the immunological landscape of pituitary adenomas (PAs) is not well defined. In the present study, we used the RNA-seq data of PAs to investigate the impact of immunological landscape on clinical features of pituitary adenomas and aim to evaluate the potential immunotherapy for PAs.

METHODS

We analyzed tumor-infiltrating immune cells in 115 PA samples using RNA-seq. Main immune cell types (B cells, CD8⁺ T cells, CD4⁺ T cells, macrophages and NK cells) were detected from the expression of genes. The association between immune cells abundance and immune checkpoint, as well as inflammatory factors were analyzed. 10 additional patients were enrolled for validation.

RESULTS

In RNA sequencing data, landscape of PAs were identified. Our computationally inferred immune infiltrates significantly associate with patient clinical features. Growth hormone-secreting adenomas (GHomas) were found with higher B cells and CD8⁺ T cells infiltration. Moreover, GHomas showed relative different genetic background, significant invasive behavior and independently correlated with reduced progress-free time. Tumor progression was related to increased expression of PD-1/PD-L1 and was associated with higher immune infiltration. Analysis of cancer-testis antigen expression and CD8⁺ T-cell abundance suggested CTAG2 and TSPYL6 were potential immunotherapeutic targets in GHomas and non-functioning adenomas, respectively.

CONCLUSIONS

Tumor-infiltrating immune cells confer important clinical and biological implications. Our results of immune-infiltrate levels in PAs may inform effective cancer vaccine and checkpoint blockade therapies and make it possible to take immunotherapy into invasive PAs.

Pituitary tumors: epidemiology and clinical presentation spectrum

Pituitary tumors (PTs) are a heterogeneous group of lesions of the central nervous system that are usually benign. Most of them occur sporadically, but 5% can do so within family syndromes, usually at a young age. There are differences by sex, age, race, and genetic factors in the prevalence of different tumor cell types and clinical presentation. Functioning-PTs (FPTs) are usually diagnosed earlier than non-functioning PTs (NFPTs). However, this depends on the PT type. Headaches and visual disturbances are the most frequent mass-effect symptoms, but seizures or hydrocephalus may also occur. Pituitary apoplexy is another possible mode of presentation, and it requires special attention because of its potential severity. PTs in pregnancy, childhood, and old age present a series of clinical peculiarities that must be taken into account when evaluating these patients. Ectopic PTs (EPTs) are uncommon and share the same clinical-epidemiological data as eutopic PTs, but, depending on their location, other types of clinical manifestations may appear. Silent PTs are often detected as an incidentaloma or due to neurologic symptoms related to mass-effect. Aggressive PTs and pituitary carcinomas (PCs), which are very rare, are characterized by multiple local recurrences and metastases, respectively. This review addresses the epidemiology and clinical presentation of PTs, from the classical hormonal and mass-effect symptoms to the different rare presentations, such as pituitary apoplexy, hydrocephalus, or diabetes insipidus. Moreover, special situations of the presentation of PTs are discussed, namely, PTs in pregnancy, childhood, and the elderly, EPTs, silent and aggressive PTs, and PCs.