Microrna expression as a molecular marker for meningioma at a tertiary laboratory in north Pretoria, South Africa

ABSTRACT

¹Guada TT,

¹Department of Anatomical Pathology, Medicine, Sefako Makgatho Health Sciences University, Pretoria, South Africa

Background

Meningiomas are the most frequently reported primary intracranial tumors, comprising 20–30% of all primary brain tumors globally and in Africa. While diagnosis typically relies on histopathological evaluation, emerging molecular tools such as microRNAs (miRNAs) show potential as biomarkers for improved tumor classification and prognosis. This study investigated the expression patterns of specific miRNAs as molecular markers for meningiomas at a tertiary centre.

Method

This retrospective descriptive study was conducted using meningioma cases diagnosed between 2012 and 2022. Archived FFPE tissue samples were retrieved, and total RNA was extracted for cDNA synthesis. The miRCURY LNA Human Cancer Pathway miRNA PCR array was used to screen for differentially expressed miRNAs across WHO grade I, II, and III tumors. Relative quantification (2^–ΔCt method) was used to assess expression levels.

Result

The study included 72 cases where 8 cases (included representatives from grade I, II, III, and recurrent tumors) were analysed in the discovery phase, which identified Let-7b and Let-7e as the most differentially expressed miRNAs. In the 64 validation cases, Let-7b was downregulated in 28, normal in 19, and upregulated in 13 grade I tumors (n= 55). Let-7e showed more consistent downregulation, with 29 downregulated, 21 normal, and 6 upregulated in grade I. In grade II tumors (n = 6), Let-7e was consistently downregulated (n=2) or normal (n= 4), while Let-7b showed upregulation (n=2) and normal expressions (n=3). Grade III tumors (n = 3) showed downregulation (n=2), normal (n=1) in both microRNAs.

Conclusion

Let-7b and Let-7e are tumor-suppressing microRNAs, with their downregulation in meningiomas indicating a possible contribution to tumor progression through de-repression of oncogenes involved in proliferation and survival. These observations suggest that they could serve as molecular markers for classifying meningioma types and predicting patient outcomes. Further studies with larger cohorts and functional assays are recommended to validate their diagnostic and prognostic significance.

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PRESENTING AUTHOR

Ms. Theresia Guada, BSc in Life Sciences, BSc Hons (MS) in Anatomical Pathology

Part-time Junior lecture, Sefako Makgatho Health Sciences University (SMU)

Tshoyi Theresia Guada is a passionate and driven final year MSc candidate in Anatomical Pathology, currently based in Northern Pretoria, South Africa. Alongside her postgraduate studies, she serves as a part-time lecturer in the Department of Anatomical Pathology, where she combines her academic knowledge with practical mentorship and teaching.

Her research focuses on the expression of microRNAs as molecular markers for meningioma, with the goal of contributing to more precise diagnostic approaches in neuropathology. She is particularly interested in molecular diagnostics, research, histopathological innovations, and nurturing the next generation of scientists and medical professionals.

As a young scientist committed to excellence, collaboration, and transformation in healthcare, she continually seeks opportunities for growth, knowledge-sharing, and impactful research.

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