A correlation study of BK Polyoma Virus infection and prostate Cancer among Sudanese patients - immunofluorescence and molecular based case-control study

Abstract Background Polyomavirus hominis1, also called BK virus (BKV) is a well-known etiological agent of renal transplant nephropathy and cystitis. Recently, it got great attention from the researcher as a principal predisposing factor for different kinds of cancers including prostate cancer (PCa). Thus, this study aims to determine the correlation between BKV infection and PCa through a descriptive case-control based study. Methods A total of 55 paraffin-embedded tissue blocks of patients with PCa and another 55 tissue blocks from BPH patients were obtained. In parallel, respective urine samples were collected from all the cases and controls. The existence of BKV large T antigen (LTAg) was analyzed by Direct Immunofluorescence assay. Only BKV LTAg positive specimens were further analyzed for the presence of viral DNA by using a conventional PCR then subjected to viral load quantitation by using Q-PCR. Result BKV LTAg was identified in 30% (17/55) of cases tissue specimens and only in 7% (4/55) of the controls tissue specimens with P-value 0.002 and Odd ratio 5.7. The conventional PCR detects the BKV DNA in 16 out of 17 cases specimens while only two out of four controls specimens were identified with a viral DNA. The mean of the BKV DNA load was higher significantly among cases 6733 ± 6745 copies/ml when compared to controls 509.0 ± 792.9 copies/m with a p-value of 0.002. Conclusion More BKV prevalence with high viral load was observed in PCa patients tissue compared to BPH specimens. PCa Gleason scores 9 and 7 were the most cancer grades identified with the presence of BKV DNA. Our findings are thus consistent with a significant link between the BKV infection and the PCa risk. Prostate or seminal fluids should be selected as principal specimens for future studies and can, therefore, be designated as screening samples to find early virus evidence in the prostate tissue. Detection of early virus evidence may help to reduce the risk of PCa cancer due to BKV.

Download Full-text

Restriction of Human Polyomavirus BK Virus DNA Replication in Murine Cells and Extracts

Journal of Virology ◽

10.1128/jvi.00300-09 ◽

2009 ◽

Vol 83 (11) ◽

pp. 5708-5717 ◽

Cited By ~ 11

Author(s):

Cathal Mahon ◽

Bo Liang ◽

Irina Tikhanovich ◽

Johanna R. Abend ◽

Michael J. Imperiale ◽

...

Keyword(s):

Dna Replication ◽

Topoisomerase I ◽

Simian Virus 40 ◽

T Antigen ◽

Bk Virus ◽

Human Polyomavirus ◽

Expression Vectors ◽

Viral Dna ◽

Viral Dna Replication ◽

Cell Extracts

ABSTRACT BK virus (BKV) causes persistent and asymptomatic infections in most humans and is the etiologic agent of polyomavirus-associated nephropathy (PVAN) and other pathologies. Unfortunately, there are no animal models with which to study activation of BKV replication in the human kidney and the accompanying PVAN. Here we report studies of the restriction of BKV replication in murine cells and extracts and the cause(s) of this restriction. Upon infection of murine cells, BKV expressed large T antigen (TAg), but viral DNA replication and progeny were not detected. Transfection of murine cells with BKV TAg expression vectors also caused TAg expression without accompanying DNA replication. Analysis of the replication of DNAs containing chimeric BKV and murine polyomavirus origins revealed the importance of BKV core origin sequences and TAg for DNA replication. A sensitive assay was developed with purified BKV TAg that supported TAg-dependent BKV DNA replication with human but not with murine cell extracts. Addition of human replication proteins, DNA polymerase α-primase, replication protein A, or topoisomerase I to the murine extracts with BKV TAg did not rescue viral DNA replication. Notably, addition of murine extracts to human extracts inhibited BKV TAg-dependent DNA replication at a step prior to or during unwinding of the viral origin. These findings and differences in replication specificity between BKV TAg and the TAgs of simian virus 40 (SV40) and JC virus (JCV) and their respective origins implicate features of the BKV TAg and origin distinct from SV40 and JCV in restriction of BKV replication in murine cells.

Download Full-text

Potential Transmission of Human Polyomaviruses through the Gastrointestinal Tract after Exposure to Virions or Viral DNA

Journal of Virology ◽

10.1128/jvi.75.21.10290-10299.2001 ◽

2001 ◽

Vol 75 (21) ◽

pp. 10290-10299 ◽

Cited By ~ 126

Author(s):

Sı́lvia Bofill-Mas ◽

Meritxell Formiga-Cruz ◽

Pilar Clemente-Casares ◽

Francesc Calafell ◽

Rosina Girones

Keyword(s):

Jc Virus ◽

Regulatory Region ◽

The United States ◽

T Antigen ◽

Bk Virus ◽

Virus Concentration ◽

Viral Dna ◽

Viral Particles ◽

The Stability ◽

Time Required

ABSTRACT The mechanism of human-to-human transmission of the polyomaviruses JC virus (JCV) and BK virus (BKV) has not been firmly established with regard to possible human exposure. JCV and BKV have been found in sewage samples from different geographical areas in Europe, Africa, and the United States, with average concentrations of 102 to 103 JCV particles/ml and 101 to 102BKV particles/ml. Selected polyomavirus-positive sewage samples were further characterized. The JCV and BKV present in these samples were identified by sequencing of the intergenic region (the region found between the T antigen and VP coding regions) of JCV and the VP1 region of BKV. The regulatory region of the JCV and BKV strains found in sewage samples presented archetypal or archetype-like genetic structures, as described for urine samples. The stability (the time required for a 90% reduction in the virus concentration) of the viral particles in sewage at 20°C was estimated to be 26.7 days for JCV and 53.6 days for BKV. The presence of JCV in 50% of the shellfish samples analyzed confirmed the stability of these viral particles in the environment. BKV and JCV particles were also found to be stable at pH 5; however, treatment at a pH lower than 3 resulted in the detection of free viral DNA. Since most humans are infected with JCV and BKV, these data indicate that the ingestion of contaminated water or food could represent a possible portal of entrance of these viruses or polyomavirus DNA into the human population.

Download Full-text

BK Virus as a Cofactor in the Etiology of Prostate Cancer in Its Early Stages

Journal of Virology ◽

10.1128/jvi.02461-07 ◽

2007 ◽

Vol 82 (6) ◽

pp. 2705-2714 ◽

Cited By ~ 56

Author(s):

Dweepanita Das ◽

Kirk Wojno ◽

Michael J. Imperiale

Keyword(s):

Prostate Cancer ◽

Tumor Suppressor ◽

Cancer Progression ◽

The United States ◽

T Antigen ◽

Bk Virus ◽

Wild Type ◽

Human Virus ◽

Early Stages ◽

Proliferative Inflammatory Atrophy

ABSTRACT Prostate cancer has been projected to cause almost 10% of all male cancer deaths in the United States in 2007. The incidence of mutations in the tumor suppressor genes Rb1 and p53, especially in the early stages of the disease, is low compared to those for other cancers. This has led to the hypothesis that a human virus such as BK virus (BKV), which establishes a persistent subclinical infection in the urinary tract and encodes oncoproteins that interfere with these tumor suppressor pathways, is involved. Previously, we detected BKV DNA in the epithelial cells of benign and proliferative inflammatory atrophy ducts of cancerous prostate specimens. In the present report, we demonstrate that BKV is present at a much lower frequency in noncancerous prostates. Additionally, in normal prostates, T-antigen (TAg) expression is observed only in specimens harboring proliferative inflammatory atrophy and prostatic intraepithelial neoplasia. We further demonstrate that the p53 gene from atrophic cells expressing TAg is wild type, whereas tumor cells expressing detectable nuclear p53 contain a mix of wild-type and mutant p53 genes, suggesting that TAg may inactivate p53 in the atrophic cells. Our results point toward a role for BKV in early prostate cancer progression.

Download Full-text

Tubulointerstitial Nephritis Due to a Mutant Polyomavirus BK Virus Strain, BKV(Cin), Causing End-Stage Renal Disease

Journal of Clinical Microbiology ◽

10.1128/jcm.36.6.1660-1665.1998 ◽

1998 ◽

Vol 36 (6) ◽

pp. 1660-1665 ◽

Cited By ~ 72

Author(s):

R. D. Smith ◽

J. H. Galla ◽

K. Skahan ◽

P. Anderson ◽

C. C. Linnemann ◽

...

Keyword(s):

Tubulointerstitial Nephritis ◽

Pcr Amplification ◽

Simian Virus 40 ◽

Simian Virus ◽

Buffy Coat ◽

T Antigen ◽

Bk Virus ◽

Coding Region ◽

Viral Dna ◽

Cycle Sequencing

A renal biopsy from a 36-year-old man with AIDS showed a severe tubulointerstitial nephritis with intranuclear inclusions in epithelial cells. Electron microscopy revealed the characteristic findings of a polyomavirus (PyV) infection, and immunofluorescence indicated the presence of BK virus (BKV) antigen. Inoculation of rhesus monkey kidney cell cultures both with urine and with buffy coat blood cells resulted in a cytopathic response which was subsequently confirmed to be due to BKV. Further characterization of the viral DNA from the kidney by PCR amplification and Southern blot analysis with PyV and strain-specific primers and probes indicated that the virus was closely related to the BK(Dun) strain but different in its apparent sequence arrangement. Subsequent cycle sequencing showed a dinucleotide mutation of TG→AA which substitutes hydrophilic Gln for hydrophobic Leu in a sequence homologous to an origin DNA-binding domain of simian virus 40 T antigen. It is suggested that the mutation and a coding region rearrangement of this strain of BKV designated BKV(Cin) has the potential to alter viral DNA replication and enhance pathogenicity.

Download Full-text

Molecular Characterization of BK Polyomavirus’ Large T Antigen Gene Sequences Detected in Prostate Cancer Tissues of Sudanese Patients

The Open Virology Journal ◽

10.2174/1874357901913010029 ◽

2019 ◽

Vol 13 (1) ◽

pp. 29-37

Author(s):

Babbiker M. T. Gorish ◽

Mohammed E. H. Ournasseir ◽

Iman M. Shammat

Keyword(s):

Prostate Cancer ◽

Adenine Nucleotide ◽

T Antigen ◽

Bk Virus ◽

Silent Mutation ◽

Protein Alignment ◽

Gene Sequences ◽

Bk Polyomavirus ◽

Cancer Tissues

Background: BK virus, which is associated with Prostate Cancer (PCa), have a global seroprevalence in humans. Based on the sequences of VP1 and the Large Antigen (LTAg) genes, there are four subtypes of BKV. Each subtype has its own subgroups. Objective: The aim of this study was to identify the BKV subtype that circulates among Sudanese patients with PCa. Materials and Methods: A total of 8 samples from our previous work on BKV were studied in this investigation. The LTAg gene was partially amplified (176nt) by a homemade PCR. All the amplicons were purified and subjected to sequencing. Bioedit version 7.0 and Mega X version 6.0 were used to analyze the sequence and compare the results with the BKV sequences and build a phylogenetic tree. Results: All the BKV LTAg gene sequences derived from Sudanese patients were classified with Subtype-1 BKV strains from Iran and Japan. Translated protein alignment showed that some isolates had identical amino acids with Iranian and Japanese strains, whereas others had a silent mutation. Interestingly, a point mutation was identified in the sequences of isolate 5 and 8 where adenine nucleotide (A) was replaced with Cytosine (C) at position 276, resulting in amino acid substitution. Conclusion: It was concluded that all the BKV isolates which circulated among Sudanese prostate tumor patients belonged to subtype 1. These findings only highlighted the need for the molecular detection and subtyping of BKV strains in Sudanese patients in order to better demonstrate the relationship between BKV infection and PCa.

Download Full-text

Prevalence of BK Virus and Human Papillomavirus in Human Prostate Cancer

The International Journal of Biological Markers ◽

10.1177/172460080702200402 ◽

2007 ◽

Vol 22 (4) ◽

pp. 245-251 ◽

Cited By ~ 14

Author(s):

V. Balis ◽

G. Sourvinos ◽

N. Soulitzis ◽

E. Giannikaki ◽

F. Sofras ◽

...

Keyword(s):

Prostate Cancer ◽

T Antigen ◽

Bk Virus ◽

Human Papillomaviruses ◽

Human Prostate ◽

Progeny Virus ◽

Sequencing Analysis ◽

Human Prostate Cancer ◽

Standard Polymerase Chain Reaction ◽

Two Samples

Polyomaviruses such as the BK virus (BKV), JC virus (JCV) and SV40, as well as the human papillomaviruses (HPV) are frequently detected throughout human populations, causing subclinical persistent infections and inducing oncogenesis in human and other cell lines. To test the involvement of these viruses in prostate tumorigenesis, we investigated the prevalence of BKV, JCV and HPV in a series of human prostatic malignancies. Forty-two samples of diagnosed prostatic malignancies were tested using standard polymerase chain reaction (PCR) protocols. Differentiation between BKV and JCV among the polyomavirus-positive samples was achieved after sequencing analysis of the PCR products. Reconstitution of BKV in vitro was performed and indirect immunofluorescence for the large T-antigen of the virus was applied to confirm the production of progeny virus. Detection and typing of HPV was carried out by PCR. The overall prevalence of polyomaviruses was 19% in the prostate cancer cases. Sequencing analysis of the polyomavirus-positive specimens revealed the presence of BKV in all samples. Reconstitution of the BKV from the BKV-positive prostate samples was successfully achieved in cell culture and progeny viral particles were obtained, confirming the presence of the virus in the human biopsies. HPV was detected in 4.8% of the samples, however, no HPV-11, HPV-16, HPV-18 or HPV-33 types were identified. BKV was frequently detected and could play a relevant role in the development and progression of human prostate cancer, whereas HPV does not seem to be implicated in this type of human neoplasia.

Download Full-text