Prevalence of JC polyomavirus genomic sequences from the large T-antigen and non-coding control regions among Bulgarian patients with primary brain tumours

Iliya Tsekov (1) , Dilyan Ferdinandov (2) , Ventzeslav Bussarsky (2) , Svetlana Hristova (3) , Zlatko Kalvatchev (1)

1 Virology
2 Clinic of Neurosurgery
3 Department of general and clinical pathology, Central cytopathology laboratory

A total of 111 fresh brain biopsies from patients with primary brain tumours were examined for JC polyomavirus (JCV) sequences from the Large T antigen encoding region (LT) and the viral non-coding control region (NCCR). SYBR Green and TaqMan real-time polymerase chain reaction assays were used. In the gliobastoma group of 39 patients 48.7% were positive for LT sequences. Among the astrocytoma group (19 patients) and the oligodendroglioma group (12 patients) 31.6% and 33.3% were also positive. The prevalence of LT genomic sequences among the other groups was as follows: in 2 out of 3 oligoastrocytomas; in 3 out 5 gangliogliomas; in 2 out of 5 meduloblastomas; in 1 out 3 pineocytomas; and in none of the tested 5 ependimomas. All positive samples had a late threshold cycle that varied from 36 to 49, indicative of very low starting viral number. Only 21 of all the 111 samples were positive for NCCR. Low copy number in range of 10 to 1000 was present. Notably, only 8 of all NCCR positive specimens were also LT positive. It might be suggested that the disproportion between the results for LT and NCCR is either due to clonally integrated LT fragments, with loss of genetic material, or changes in the NCCR. The latter would alter the productive course of the infection and may establish a premise for continuous interaction of viral regulatory proteins with cell molecules that are responsible for the control of the cell cycle. This may lead subsequently to malignant transformation.

Mots clés: Medicine

Iliya Tsekov, Dilyan Ferdinandov, Ventzeslav Bussarsky, Svetlana Hristova, Zlatko Kalvatchev. Prevalence of JC polyomavirus genomic sequences from the large T-antigen and non-coding control regions among Bulgarian patients with primary brain tumours. Journal of Medical Virology, 2011, 83 (9), pp.1608. ⟨10.1002/jmv.22130⟩. ⟨hal-00657574⟩