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

 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.

 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.

 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.

 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.

 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.