Evaluation of Cellular miR-122 Expression in Association with the Presence of Varicella-Zoster Virus among Central Nervous System Tumors

Background: Brain tumors are all primary central nervous system (CNS) tumors with unclear etiologies and viral infections, especially human herpesviruses, which have emerged as a hot topic for comprehensive research. Objectives: The present study aimed at assessing the molecular epidemiology of varicella-zoster virus (VZV) and its association with microRNA 122 (miR-122) expression in CNS tumor samples. Methods: Fresh frozen tissue samples were collected from 60 CNS tumor patients and 45 healthy controls. A nested PCR assay was performed to detect the VZV-DNA. Subsequently, the expression level of miR-122 was evaluated in the CNS tumor tissue samples of patients and the brain tissue samples were obtained from healthy controls, using a real-time PCR assay. Results: Of 60 patients with CNS tumors, 29 were men and 31 were women. VZV-DNA was detected in 13.3% of the CNS tumor tissue specimens. There was no statistically significant association between the presence of VZV-DNA and different types of CNS tumors (P > 0.05). Furthermore, the expression level of miR-122 was significantly downregulated in the CNS tumor tissue samples obtained from the patients compared with those of the healthy controls (P < 0.05). Additionally, the expression level of miR-122 was significantly lower in the VZV-positive tumor samples as compared with those of the VZV-negative tumor samples and the healthy controls. Conclusions: Although VZV plays no direct role in the development of CNS tumors, the virus may affect the biology of CNS tumors by decreasing the expression levels of miR-122, which consequently leads to an increased risk of malignancy. However, the experimental data are not conclusive enough; so, further investigations are needed.