FEATURES OF THE RB1 GENE EXPRESSION IN BRAIN TUMORS

S. Kalman¹, Sushnyovа¹, L. Kovalevska¹, O. Malysheva², T. Malysheva², E. Kashuba¹

¹R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, NASU,

²The State Institution A.P. Romodanov Neurosurgery Institute of NAMSU, Kyiv, Ukraine

DOI: https://doi.org/10.15407/oncology.2024.03.180

Summary. Aim: to determine the features of the RB1 gene expression at mRNA and protein levels in malignant cells of brain neoplasms, as well as to reveal the relationship between the RB1 expression levels and the degree of tumor malignancy. Object and methods: Samples of surgical material of 27 patients with brain tumors G2–G4. RB1 gene expression levels were assessed by q-PCR, and the RB protein by immunohistochemistry. The RB1 gene expression pattern in brain tumors was also performed using bioinformatic analysis of the Oncomine and Protein Atlas databases. Statistical analysis was performed using the GraphPadPrism9 program. Results: we have found that the expression patterns of the RB1 gene at the mRNA and protein levels in brain tumors are mainly unidirectional. The RB1 expression pattern showed high heterogeneity in samples of astrocytoma NOS (Not Otherwise Specified): pilocytic G2, diffuse astrocytoma G2–G3, glioblastoma G4, and atypical meningioma (mixed variant) G2, where from 20 to 60% of tumors were positive, while in all embryonic tumors of CNS NOS — pineoblastoma G4 and medulloblastoma G4, RB1 gene expression was detected at the mRNA and protein levels. Conclusions: the molecular mechanisms underlying the inactivation of the RB-E2F pathway require further fundamental research to find the causes of brain tumors and markers for improved personalized diagnosis and prognosis of the course of disease.

Keywords: RB protein, brain tumors, astrocytoma, glioma, medulloblastoma, embryonic brain tumors.

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