Abstract
A groundbreaking study published in the Endocrine Journal has identified distinctive microRNA (miRNA) signatures in various types of pituitary adenomas. These findings may herald a new era in the diagnosis and treatment of these common intracranial tumors that lead to significant morbidity due to abnormal pituitary hormone secretions.
Introduction
Pituitary adenomas (PAs) are considered a frequent concern in neurosurgical clinics, known for affecting the body’s hormonal balance by impacting the pituitary gland’s function. This latest research, led by a team of scientists from Sichuan Academy of Medical Sciences and Sichuan Provincial People’s Hospital in China, aimed to understand the expression patterns of miRNAs in different types of pituitary adenomas more clearly – which could unlock new therapeutic avenues.
Before diving into the nuances of this trailblazing study, let’s understand pituitary adenomas and microRNAs a bit better.
Background
Pituitary adenomas are benign tumors arising from the pituitary gland. They can be categorized based on whether they secrete hormones or not (functioning vs. nonfunctioning) and the type of hormone they produce. The most common types include nonfunctioning pituitary adenomas (NFPAs), growth hormone-secreting adenomas (GHPAs), and prolactin-secreting adenomas (PRLPAs). These tumors can cause a myriad of health issues, depending on their size and hormonal activity, such as vision problems, headaches, and hormonal imbalances.
MicroRNAs are small, non-coding RNA molecules that play a vital role in the regulation of gene expression. They can act as oncogenes or tumor suppressors, implicating their significant role in tumorigenesis – the formation of tumors.
Methodology
The study involved using the HiSeq 2000 sequencing system (Illumina) to analyze miRNA expression patterns in samples from 73 patients with pituitary adenomas – 13 with GHPAs, 42 with NFPAs, and 18 with PRLPAs – in comparison to normal pituitary glands. The researchers verified their results using real-time quantitative polymerase chain reaction (RT-qPCR) analyses.
Findings
The research unveiled that miR-34c-3p was substantially downregulated in PRLPA samples. Other miRNAs such as miR-34b-5p, miR-378, and miR-338-5p also exhibited a significant decline in PRLPAs. For NFPAs, miR-493-5p was reduced, whereas miR-181b-5p saw a substantial increase. On the other hand, miR-184 was notably upregulated in GHPAs.
A significant revelation was the downregulation of miR-124-3p – a tumor-suppressive miRNA – in both NFPAs and GHPAs, suggesting a possible shared pathway in the pathogenesis of these tumor types.
Implications
This detailed miRNA profiling of pituitary adenomas might lead to the development of novel biomarkers for non-invasive diagnostics. Moreover, understanding the role these miRNAs play in tumor biology could assist in crafting targeted therapies, potentially reducing the need for surgical interventions and improving patient prognoses.
Conclusion
The elucidation of unique miRNA expression patterns in pituitary adenomas represents a monumental step in understanding the molecular underpinnings of these tumors. The study’s findings open a new frontier of possibilities in personalized medicine, with the potential to devise miRNA-based therapeutic strategies.
References
DOI: 10.1507/endocrj.EJ18-0487
1. He Zongze, et al. (2019) “Next-generation sequencing of microRNAs reveals a unique expression pattern in different types of pituitary adenomas.” Endocrine Journal, 66(8): 709–722. [1]
2. Di Leva, G., Garofalo, M., & Croce, C. M. (2014). MicroRNAs in cancer. Annual Review of Pathology: Mechanisms of Disease, 9, 287-314. [2]
3. Cao, F., Wang, Q., Zhang, X., & Yang, Y. (2020). The role of miRNAs in pituitary adenoma. Clinical Epigenetics, 12(1), 94. [3]
4. Herman, V., Drazin, N. Z., Gonsky, R., & Melmed, S. (1993). Molecular screening of pituitary adenomas for gene mutations and rearrangements. The Journal of Clinical Endocrinology & Metabolism, 77(1), 50-55. [4]
5. Fernandez, A., Karavitaki, N., & Wass, J. A. (2010). Prevalence of pituitary adenomas: A community-based, cross-sectional study in Banbury (Oxfordshire, UK). Clinical Endocrinology, 72(3), 377-382. [5]
Keywords
1. Pituitary Adenomas Biomarkers
2. MicroRNA Expression Patterns
3. miRNA-Based Diagnostics
4. Tumor Suppressive miRNAs
5. Nonfunctioning Pituitary Adenomas Treatment