Defining the frequency of human papillomavirus and polyomavirus infection in urothelial bladder tumours

Human polyomaviruses JCPyV and MCPyV in urothelial cell carcinoma: a single institution experience

Objective

Urothelial cell carcinoma (UCC) is the most common type of urinary bladder. JCPyV and BKPyV have been detected in the urine and tissue of urothelial cell carcinomas (UCC) in immunocompetent patients. Here, we investigated the presence of several HPyVs in UCC samples using diverse molecular techniques to study the prevalence of HPyVs in UCC.

Methods

A large single-institution database of urine cytology specimens (UCS; n = 22.867 UCS) has previously been searched for decoy cells (n = 30), suggesting polyomavirus infection. The available urine sediments and formalin-fixed paraffin-embedded (FFPE) tissue samples of UCC patients were tested for the presence of JCPyV-LTAg expression by immunohistochemistry (IHC) labeled with SV40-LTAg antibody (clone: PAb416) and subsequent PCR followed by sequencing. In addition, the presence of the oncogenic Merkel cell polyomavirus (MCPyV) and the presence of human polyomavirus 6 (HPyV6) and 7 (HPyV7) DNA were tested with DNA PCR or IHC.

Results

Of the 30 patients harboring decoy cells, 14 were diagnosed with UCC of the urinary bladder (14/30; 46.6%) before presenting with decoy cells in the urine. The SV40-LTAg IHC was positive in all 14 UCC urine sediments and negative in the FFPE tissues. JCPyV-DNA was identified in all five available UCS and in three FFPE samples of UCC (three of 14; 21.4%). Two UCC cases were positive for MCPyV-DNA (two of 14; 14.3%), and one of them showed protein expression by IHC (one of 14; 7.1%). All specimens were HPyV6 and HPyV7 negative.

Conclusion

Our findings show the presence of JCPyV in the urine and UCC of immunocompetent patients. Moreover, MCPyV was detected in two UCC cases. In total, five UCC cases showed the presence of either JCPyV or MCPyV. The evidence here supports the hypothesis that these viruses might sporadically be associated with UCC. Further studies are needed to confirm the relevance of JCPyV or MCPyV as a possible risk factor for UCC development.

Analysis of Several Common APOBEC-type Mutations in Bladder Tumors Suggests Links to Viral Infection

FGFR3 and PIK3CA are among the most frequently mutated genes in bladder tumors. We hypothesized that recurrent mutations in these genes might be caused by common carcinogenic exposures such as smoking and other factors. We analyzed 2,816 bladder tumors with available data on FGFR3 and/or PIK3CA mutations, focusing on the most recurrent mutations detected in ≥10% of tumors. Compared to tumors with other FGFR3/PIK3CA mutations, FGFR3-Y375C was more common in tumors from smokers than never-smokers (P = 0.009), while several APOBEC-type driver mutations were enriched in never-smokers: FGFR3-S249C (P = 0.013) and PIK3CA-E542K/PIK3CA-E545K (P = 0.009). To explore possible causes of these APOBEC-type mutations, we analyzed RNA sequencing (RNA-seq) data from 798 bladder tumors and detected several viruses, with BK polyomavirus (BKPyV) being the most common. We then performed IHC staining for polyomavirus (PyV) Large T-antigen (LTAg) in an independent set of 211 bladder tumors. Overall, by RNA-seq or IHC-LTAg, we detected PyV in 26 out of 1,010 bladder tumors with significantly higher detection (P = 4.4 × 10-5), 25 of 554 (4.5%) in non-muscle-invasive bladder cancers (NMIBC) versus 1 of 456 (0.2%) of muscle-invasive bladder cancers (MIBC). In the NMIBC subset, the FGFR3/PIK3CA APOBEC-type driver mutations were detected in 94.7% (18/19) of PyV-positive versus 68.3% (259/379) of PyV-negative tumors (P = 0.011). BKPyV tumor positivity in the NMIBC subset with FGFR3- or PIK3CA-mutated tumors was also associated with a higher risk of progression to MIBC (P = 0.019). In conclusion, our results support smoking and BKPyV infection as risk factors contributing to bladder tumorigenesis in the general patient population through distinct molecular mechanisms.

PREVENTION RELEVANCE

Tobacco smoking likely causes one of the most common mutations in bladder tumors (FGFR3-Y375C), while viral infections might contribute to three others (FGFR3-S249C, PIK3CA-E542K, and PIK3CA-E545K). Understanding the causes of these mutations may lead to new prevention and treatment strategies, such as viral screening and vaccination.

Role of human papillomavirus and associated viruses in bladder cancer: An updated review

Bladder cancer (BC) is a complex disease affecting the urinary system and is regulated by several carcinogenic factors. Viral infection is one such factor that has attracted extensive attention in BC. Human papillomavirus (HPV) is the most common sexually transmitted infection, and although multiple researchers have explored the role of HPV in BC, a consensus has not yet been reached. In addition, HPV-associated viruses (e.g., human immunodeficiency virus, herpes simplex virus, BK virus, and JC virus) appear to be responsible for the occurrence and progression of BC. This study systematically reviews the relationship between HPV-associated viruses and BC to elucidate the role of these viruses in the onset and progression of BC. In addition, the study aims to provide a greater insight into the biology of HPV-associated viruses, and assess potential strategies for treating virus-induced BC. The study additionally focuses on the rapid development of oncolytic viruses that provide a potentially novel option for the treatment of BC.

Human polyomavirus BKPyV and JCPyV serostatus has no impact on women´s human papillomavirus infection outcome

Introduction

Polyomaviruses have both structural and functional similarities with papillomaviruses. Accordingly, their role in human papillomavirus (HPV) associated malignancies has been studied with conflicting results. Our goal was to disclose any association between BK (BKPyV) and/or JC (JCPyV) polyomavirus serology and HPV data derived from Finnish women (327) in a 6-year prospective follow-up.

Methods

Glutathione S-transferase fusion-protein-capture (ELISA) in combination with fluorescent bead technology was used to analyze antibodies to BKPyV and JCPyV. In the longitudinal setting, BKPyV or JCPyV serostatus was related to i) oral- and ii) genital low (LR)- and high risk (HR) HPV DNA detection, iii) HPV16 persistence at both these sites, iv) results of the Pap (Papanicolaou) smear taken at baseline, and v) development of incident CIN (cervical intraepithelial neoplasia) during the follow-up.

Results

Being BKPyV or JCPyV seropositive was not significantly associated with HPV seropositivity to either LR- or HR-genotypes, genital- or oral HPV DNA positivity, persistence of genital- or oral HPV16 infection, grade of Pap smear, or development of incident CIN.

Discussion

Thus, the present study could not provide any confirmation to the concept that co-infections by HPyV and HPV have interactions that impact on the clinical manifestations or outcomes of HPV infections either in the genital tract or in the oral mucosa.

Human papillomaviruses and bladder cancer risk: first report in south of Iran

Information regarding the possible carcinogenicity of human papillomaviruses (HPVs) in bladder tissue might pave the way for the prevention of bladder cancer through improving HPV vaccination of the at-risk population. To address this, this study was conducted to detect HPVs in bladder cancer tissues in the South of Iran. Bladder biopsy samples of 181 patients with bladder cancer were included in this study. The detection of HPVs was performed by nested PCR assay, targeting the L1 region of the genome, and sequencing. HPV was detected in 0.55% of the bladder cancer samples, while the non-cancerous bladder samples were negative for HPV. HPV genotype 6 was detected in this study. The HPV-positive patient was a 55-year-old man with papillary urothelial neoplasms of low malignant in stage Ta-T1. This patient was resident of Dayer city. Overall, HPV prevalence among patients with bladder cancer was not statistically associated with place of residency, gender, age, stage, and grade of the tumor (P value > 0.05). The presence of HPV is extremely rare in bladder cancer biopsy specimens in the south of Iran. Therefore, the results of our study rule out the possible role of HPVs in the etiology of bladder cancer. Due to the increasing air pollution in this region and high-risk jobs, and habits such as cigarette smoking and hookah smoking, the role of these factors alongside genetic factors seems more prominent than the role of HPVs in causing bladder cancer in the south of Iran.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-023-00819-w.

Evidence for virus-mediated oncogenesis in bladder cancers arising in solid organ transplant recipients

A small percentage of bladder cancers in the general population have been found to harbor DNA viruses. In contrast, up to 25% of tumors of solid organ transplant recipients, who are at an increased risk of developing bladder cancer and have an overall poorer outcomes, harbor BK polyomavirus (BKPyV). To better understand the biology of the tumors and the mechanisms of carcinogenesis from potential oncoviruses, we performed whole genome and transcriptome sequencing on bladder cancer specimens from 43 transplant patients. Nearly half of the tumors from this patient population contained viral sequences. The most common were from BKPyV (N=9, 21%), JC polyomavirus (N=7, 16%), carcinogenic human papillomaviruses (N=3, 7%), and torque teno viruses (N=5, 12%). Immunohistochemistry revealed variable Large T antigen expression in BKPyV-positive tumors ranging from 100% positive staining of tumor tissue to less than 1%. In most cases of BKPyV-positive tumors, the viral genome appeared to be clonally integrated into the host chromosome consistent with microhomology-mediated end joining and coincided with focal amplifications of the tumor genome similar to other virus-mediated cancers. Significant changes in host gene expression consistent with the functions of BKPyV Large T antigen were also observed in these tumors. Lastly, we identified four mutation signatures in our cases, with those attributable to APOBEC3 and SBS5 being the most abundant. Mutation signatures associated with an antiviral drug, ganciclovir, and aristolochic acid, a nephrotoxic compound found in some herbal medicines, were also observed. The results suggest multiple pathways to carcinogenesis in solid organ transplant recipients with a large fraction being virus-associated.

The association between human papillomavirus and bladder cancer: Evidence from meta-analysis and two-sample mendelian randomization

INTRODUCTION

Bladder cancer (BCa) is the 10th most common type of cancer worldwide, and human papillomavirus (HPV) is the most common sexually transmitted infection. However, the relationship between HPV infection and the risk of BCa is still controversial and inconclusive.

METHODS

This systematic review and meta-analysis were conducted following the PRISMA 2020 reporting guideline. This study searched four bibliographic databases with no language limitation. The databases included PubMed (Medline), EMBASE, Cochrane Library, and Web of Science. Studies evaluating the interaction between HPV infection and the risk of BCa from inception through May 21, 2022, were identified and used in this study. This study estimated the overall and type-specific HPV prevalence and 95% confidence intervals (95% CI) using Random Effects models and Fixed Effects models. In addition, this study also calculated the pooled odds ratio and pooled risk ratio with 95% CI to assess the effect of HPV infection on the risk and prognosis of bladder cancer. Two-sample mendelian randomization (MR) study using genetic variants associated with HPV E7 protein as instrumental variables were also conducted.

RESULTS

This study retrieved 80 articles from the four bibliographic databases. Of the total, 27 were case-control studies, and 53 were cross-sectional studies. The results showed that the prevalence of HPV was 16% (95% CI: 11%-21%) among the BCa patients, most of which were HPV-16 (5.99% [95% CI: 3.03%-9.69%]) and HPV-18 (3.68% [95% CI: 1.72%-6.16%]) subtypes. However, the study found that the prevalence varied by region, detection method, BCa histological type, and sample source. A significantly increased risk of BCa was shown for the positivity of overall HPV (odds ratio [OR], 3.35 [95% CI: 1.75-6.43]), which was also influenced by study region, detection method, histological type, and sample source. In addition, the study found that HPV infection was significantly associated with the progression of BCa (RR, 1.73 [95% CI: 1.39-2.15]). The two-sample MR analysis found that both HPV 16 and 18 E7 protein exposure increased the risk of BCa (HPV 16 E7 protein: IVW OR per unit increase in protein level = 1.0004 [95% CI: 1.0002-1.0006]; p = 0.0011; HPV 18 E7 protein: IVW OR per unit increase in protein level = 1.0003 [95% CI: 1.0001-1.0005]; p = 0.0089).

CONCLUSION

In conclusion, HPV may play a role in bladder carcinogenesis and contribute to a worse prognosis for patients with BCa. Therefore, it is necessary for people, especially men, to get vaccinated for HPV vaccination to prevent bladder cancer.

Prevalence and Impact of BK Polyomavirus in the Ureters of Kidney Donors: Research Letter

Background

More than 75% of the population is seropositive for BK polyomavirus (BKV), which remains quiescent in the urothelium in immunocompetent hosts. However, it can reactivate in kidney transplant recipients (KTRs), and up to 30% of them will develop BKV viremia in the 2 years following transplant, with a risk of developing BKV-associated nephropathy (BKVAN). Viral reactivation is associated with the level of immunosuppression, but there is currently no way to predict which patients are at high risk for reactivation.

Objective

As BKV originates from kidney donors, our primary objective was to determine the prevalence of detectable BKV in donor ureters. Our secondary objective was to see if there is a correlation between the presence of BKV in donor urothelium and the development of BKV viremia and BKVAN in KTR.

Design

Prospective cohort study.

Setting

Single-center academic kidney transplant program.

Patients

Prospective sequential KTRs that received a kidney transplant between March 2016 and March 2017.

Measurements

The presence of BKV in donor ureters was determined by TaqMan-based quantitative polymerase chain reaction (PCR; qPCR).

Methods

We performed a prospective study which was done on 35 out of the 100 donors initially foreseen to take part in the study. During surgery, the distal part of donor ureter was kept and analyzed by qPCR (to establish the presence of BKV in the urothelium). The primary outcome was the development of BKV viremia in KTR over a period of 2 years after transplant. Secondary outcome was the development of BKVAN.

Results

Out of 35 ureters analyzed, only one had a positive qPCR for BKV (2.86%, 95% confidence interval [CI]: [0.07-14.92]). Considering the primary objective would not be met, the study was interrupted after 35 specimens. After surgery, 9 recipients had a slow graft function and 4 had delayed graft function, one of which never recovered graft function. Over the 2-year follow-up, 13 patients developed BKV viremia, while 5 patients developed BKVAN. The patient who received a graft from a positive qPCR donor eventually developed BKV viremia and nephropathy.

Limitations

The specimen analyzed was a distal rather than a proximal portion of the ureter. However, BKV replication is known to concentrate in the corticomedullary junction.

Conclusion

BK polyomavirus prevalence in the distal part of donor ureters is lower than previously reported. It cannot be used as a predictor for the development of BKV reactivation and/or nephropathy.

BK and JC polyomaviruses and risk of urothelial bladder carcinoma: a preliminary study in the northern shores of Persian Gulf, Iran

Background

Bladder cancer is a challenging public health concern in South of Iran because of its high prevalence and the related medical expenses. Although the exact etiology of bladder cancer remains unknown, given the cell transforming ability and oncogenic potential of the members of Polyomaviridae families, this study was conducted to evaluate the magnitude of BK polyomavirus (BKPyV) and John Cunningham polyomavirus (JCPyV) among patients with bladder cancer residents in the northern shores of the Persian Gulf, South of Iran.

Methods

Totally 211 patients with bladder cancer were enrolled in this study. Bladder biopsy samples of these patients and patients with interstitial cystitis as well as autoptic samples of healthy bladder were tested for detection of BKPyV and JCPyV by semi-nested PCR–RFLP followed by sequencing.

Results

BKPyV and JCPyV were detected in 1.7% and 6.1% of bladder cancer samples, respectively. These samples were infected with JCPyV genotypes 2, 3 and 6 and BKPyV genotypes I and IV. BKPyV and JCPyV coinfection was detected in 2 samples. Moreover, one of the healthy bladder samples was positive for BKPyV, and one of the interstitial cystitis samples was positive for JCPyV. Although the majority of infected patients were in the age group 70–79 years, male, residents in Tangestan, stage Ta–T1, and low-grade and high-grade papillary urothelial carcinoma, the prevalence of BKPyV and JCPyV among patients with bladder cancer was not statistically associated with age, gender, place of residency, and stage and grade of the tumor.

Conclusion

Despite identifying BKPyV and JCPyV in a number of bladder cancer biopsy specimens and the high prevalence of bladder cancer among people resident in South of Iran, it is suggested that these viruses are unlikely to be effective causative factors in bladder carcinogenesis in this region. Therefore, environmental risk factors and genetic backgrounds may have a more prominent role than human polyomaviruses in the development of bladder cancer in South of Iran.

Prevalence of Human Papilloma Virus Infection in Bladder Cancer: A Systematic Review

The etiology of bladder cancer is known to be associated with behavioral and environmental factors. Moreover, several studies suggested a potential role of HPV infection in the pathogenesis with controversial results. A systematic review was conducted to assess the role of HPV. A total of 46 articles that reported the prevalence of HPV infection in squamous (SCC), urothelial (UC), and transitional cell carcinomas (TCC) were selected. A pooled prevalence of 19% was found, with a significant difference in SCC that was mainly driven by HPV-16. Moreover, infection prevalence in case-control studies showed a higher risk of bladder cancer in HPV-positive cases (OR: 7.84; p-value < 0.00001). The results may suggest an etiologic role of HPV in bladder cancer. HPV vaccine administration in both sexes could be key to prevent the infection caused by high-risk genotypes.

Prognostic Value of HPV E6 and APOBEC3B in Upper Urinary Tract Urothelial Carcinoma

Background

APOBEC mutation signature is common in upper urinary tract urothelial carcinoma (UTUC). When virus infection occurs, upregulated APOBEC plays an antiviral role by deoxycytidine deaminase activity. However, the carcinogenic roles of HPV E6 protein and APOBEC mutation signature in UTUC have not been investigated.

Aims

This study explored the relationship among HPV E6, APOBEC, and clinicopathological characteristics in patients with UTUC and impacts of their expression on the prognosis.

Methods

The expression of HPV E6 and APOBEC3B of 78 patients with UTUC was detected by immunohistochemistry. Correlation of HPV E6 and APOBEC3B expression levels with clinicopathological characteristics was statistically analyzed. Univariate and multivariate Cox regression analyses were used to evaluate the prognosis of HPV E6 and APOBEC3B for disease-free survival (DFS); survival analysis was performed using Kaplan-Meier methods.

Results

The expression of APOBEC3B was positively correlated with the expression of HPV E6 (r = 0.383, P = 0.001). HPV E6 was significantly increased in patients with stage I (χ² = 4.938, P = 0.026) and low-grade urothelial carcinoma (χ² = 3.939, P = 0.047), as well as in patients without LVI (χ² = 4.064, P = 0.044). Meanwhile, APOBEC3B was highly expressed in patients with stage I (χ² = 4.057, P = 0.044) and low-grade urothelial carcinoma (χ² = 7.153, P = 0.007). Multivariate Cox regression analysis revealed the APOBEC3B expression was the independent prognostic factor for DFS, Kaplan-Meier survival analysis showed that low expression of APOBEC3B and HPV E6 was significantly associated with the poor prognosis of UTUC patients.

Conclusion

HPV E6 expression is positively associated with APOBEC3B expression, and the high expression of HPV E6 and APOBEC3B is associated with favorable prognosis of patients with UTUC.

Induction of APOBEC3-mediated genomic damage in urothelium implicates BK polyomavirus (BKPyV) as a hit-and-run driver for bladder cancer

Limited understanding of bladder cancer aetiopathology hampers progress in reducing incidence. Mutational signatures show the anti-viral apolipoprotein B mRNA editing enzyme catalytic polypeptide (APOBEC) enzymes are responsible for the preponderance of mutations in bladder tumour genomes, but no causative viral agent has been identified. BK polyomavirus (BKPyV) is a common childhood infection that remains latent in the adult kidney, where reactivation leads to viruria. This study provides missing mechanistic evidence linking reactivated BKPyV-infection to bladder cancer risk. We used a mitotically-quiescent, functionally-differentiated model of normal human urothelium to examine BKPyV-infection. BKPyV-infection led to significantly elevated APOBEC3A and APOBEC3B protein, increased deaminase activity and greater numbers of apurinic/apyrimidinic sites in the host urothelial genome. BKPyV Large T antigen (LT-Ag) stimulated re-entry from G0 into the cell cycle through inhibition of retinoblastoma protein and activation of EZH2, E2F1 and FOXM1, with cells arresting in G2. The single-stranded DNA displacement loops formed in urothelial cells during BKPyV-infection interacted with LT-Ag to provide a substrate for APOBEC3-activity. Addition of interferon gamma (IFNγ) to infected urothelium suppressed expression of the viral genome. These results support reactivated BKPyV infections in adults as a risk factor for bladder cancer in immune-insufficient populations.

A Nomogram for Predicting BK Virus Activation in Kidney Transplantation Recipients Using Clinical Risk Factors

BK virus is a common opportunistic viral infection that could cause BK virus-associated nephropathy in renal transplant recipients. Thus, we retrospectively analyzed clinical and laboratory data associated with a higher risk of BK virus activation from 195 renal transplant recipients by the multivariate logistic regression analysis and performed the external validation. Results showed that patients with BK virus active infection were associated with a deceased donor, had lower direct bilirubin levels, a higher proportion of albumin in serum protein electrophoresis, and lower red blood cells and neutrophil counts. The multivariate logistic regression analyses revealed that the living donor, direct bilirubin, and neutrophil counts were significantly associated with BK virus activation. The logistic regression model displayed a modest discriminability with the area under the receiver operating characteristic curve of 0.689 (95% CI: 0.607–0.771; P < 0.01) and also demonstrated a good performance in the external validation dataset (the area under the receiver operating characteristic curve was 0.699, 95% CI: 0.5899–0.8081). The novel predictive nomogram achieved a good prediction of BK virus activation in kidney transplant recipients.

Bladder cancer and human papillomavirus association: a systematic review and meta-analysis

BACKGROUND

The possible association of human papillomavirus (HPV) and bladder cancer has been controversial. Older findings suggest a significant association between the virus and bladder cancer. The aim of this study was to evaluate the data from the last ten years to estimate the prevalence of the virus in bladder cancer patients and to assess the association between the virus and cancer.

METHOD

A search of major databases was conducted to retrieve published English language studies between January 2011 and March 2021. In the present study overall prevalence of the virus in bladder cancer patients was estimated along with the prevalence of subgroups. Also, the possible associations between the prevalence of the virus and bladder cancer and the possible impact of variables in the geographical area and the type of sample were measured by comprehensive meta-analysis software (V2.2, BIOSTAT).

RESULTS

Unlike previous studies, despite the relatively high prevalence of the virus [pooled prevalence: 14.3% (95% CI 8.9-22.2%)] no significant association was found between HPV and bladder cancer (OR 2.077, 95% CI 0.940-4.587). No significant association was found between geographical area (except Asia) and type of sample with bladder cancer.

CONCLUSIONS

Given the significant prevalence, despite the insignificance of the association between virus and cancer, it seems that more studies with case-control design are needed to elucidate this association.

Post-allogeneic hematopoietic stem cell transplantation viral reactivations and viremias: a focused review on human herpesvirus-6, BK virus and adenovirus

Human cytomegalovirus and Epstein-Barr virus have been recognized as potential drivers of morbidity and mortality of patients undergoing allogeneic stem cell transplantation for years. Specific protocols for monitoring, prophylaxis and pre-emptive therapy are in place in many transplant settings. In this review, we focus on the next three most frequent viruses, human herpesvirus-6, BK virus and adenovirus, causing reactivation and/or viremia after allogeneic transplant, which are increasingly detected in patients in the post-transplant period owing to emerging techniques of molecular biology, recipients' characteristics, treatment modalities used for conditioning and factors related donors or stem cell source. Given the less frequent detection of an illness related to these viruses, there are often no specific protocols in place for the management of affected patients. While some patients develop significant morbidity (generally older), others may not need therapy at all (generally younger or children). Furthermore, some of the antiviral therapies used are potentially toxic. With the addition of increased risk of secondary infections, risk of graft failure or increased risk of graft-versus-host disease as well as the relationship with other post-transplant complications, the outcomes of patients with these viremias remain unsatisfactory and even long-term survivors experience increased morbidity.

Human Papillomavirus Prevalence and Integration Status in Tissue Samples of Bladder Cancer in the Chinese Population

BACKGROUND

Human papillomavirus (HPV) infection is associated with multiple types of cancer, but the evidence has not yet been fully elucidated in bladder cancer.

METHODS

Frozen tissue samples collected from 146 patients aged 32 to 89 years with bladder cancer pathological diagnosis between 2015 and 2019 were analyzed. HPV genotyping and integration status determination were performed by capture-based next generation sequencing. Statistical analysis of HPV type distributions was performed according to stage, grade, sex, and age group of patients.

RESULTS

Mean (SD) age of the 146 patients was 66.64 ± 10.06 years and 83.56% were men. Overall HPV infection rate was 28.77% (37.50% in women and 27.05% in men), with 11.90% HPV integration events. Among them, 17.12% single and 11.65% coinfections were observed. HPV18 (24.66%) was the most prevalent genotype, followed by HPV33, 16, and 39. All HPV were European lineage (A). HPV16 was more prevalent in women (P = .04).

CONCLUSIONS

HPV infection may contribute to the etiology both in men and women with bladder cancer. HPV18, followed by HPV33, 16, and 39 genotypes, potentially represent the predominant oncogenic risk types for bladder carcinogenesis.

High-grade urothelial carcinoma in a kidney transplant recipient after JC virus nephropathy: The first evidence of JC virus as a potential oncovirus in bladder cancer

Kidney transplant (KT) recipients have an increased risk for urothelial carcinoma. A role for JC virus (JCV) in human cancers is not yet proved but there is an increasingly reported association between BK virus (BKV) nephropathy and renourinary neoplasms. We report a KT recipient who developed a high-grade urothelial carcinoma 5 years after a diagnosis of JCV nephropathy and 9 years after kidney transplantation. Neoplastic tissue was positive for JCV DNA by real-time polymerase chain reaction (PCR). Immunochemical staining showed strong positivity for cell cycle markers (p16, p53, and Ki67) and for early viral protein JCV large T antigen (JCV LTag; using a broad polyomavirus antibody); however, late viral protein (VP1) stained negative. In contrast, in non-neoplastic urothelium, JCV DNA and all immunochemical markers were negative. These facts suggest that malignancy was induced by JCV. To the best of our knowledge, this is the first report of urothelial high-grade carcinoma associated with JCV nephropathy in a KT recipient.

Pathogenicity of BK virus on the urinary system

Introduction

The polyomaviruses are omnipresent in nature. The major sites of BK virus appearance are the kidney tubular epithelial cells and urinary bladder surface transitional cells.

Material and methods

A literature search according to PRISMA guidelines within the Medline database was conducted in July 2019 for articles presenting data about BK virus in urologic aspect without setting time limits, using the terms ‘BK virus’ in conjunction with transplantation, nephropathy, stenosis, cancer, bladder, prostate, kidney.

Results

The BK virus usually stays latent, however, its replication may become active in various clinical situations of impaired immunocompetence such as solid organ transplantation, bone marrow transplantation, AIDS, pregnancy, multiple sclerosis, administration of chemotherapy or biologic therapy. BK virus is associated with two main complications after transplantation: polyomavirus-associated nephropathy in kidney transplant patients and polyomavirus-associated hemorrhagic cystitis in allogeneic hematopoietic stem cell transplant patients.

Conclusions

The aim of this article was to present available data on urologic aspects of BK virus infection, its detection methods and available treatment.

Effect of the Large and Small T-Antigens of Human Polyomaviruses on Signaling Pathways

Viruses are intracellular parasites that require a permissive host cell to express the viral genome and to produce new progeny virus particles. However, not all viral infections are productive and some viruses can induce carcinogenesis. Irrespective of the type of infection (productive or neoplastic), viruses hijack the host cell machinery to permit optimal viral replication or to transform the infected cell into a tumor cell. One mechanism viruses employ to reprogram the host cell is through interference with signaling pathways. Polyomaviruses are naked, double-stranded DNA viruses whose genome encodes the regulatory proteins large T-antigen and small t-antigen, and structural proteins that form the capsid. The large T-antigens and small t-antigens can interfere with several host signaling pathways. In this case, we review the interplay between the large T-antigens and small t-antigens with host signaling pathways and the biological consequences of these interactions.

BK virus: Current understanding of pathogenicity and clinical disease in transplantation

BK polyomavirus (BKV) is an important cause of graft loss in renal transplant recipients that continues to pose a significant challenge to clinicians due to its frequently unpredictable onset, persistence, and the lack of effective antiviral agents or prevention strategies. This review covers our current understanding of epidemiology, viral transmission and disease progression, and treatment and prevention strategies that have been used to manage this disease.

Anti-Cancer Vaccine for HPV-Associated Neoplasms: Focus on a Therapeutic HPV Vaccine Based on a Novel Tumor Antigen Delivery Method Using Endogenously Engineered Exosomes

Some human papillomavirus (HPV) genotypes are universally recognized as major etiological agents not only of ano-genital tumors but also of head and neck cancers, which show increasing incidence. The evaluation of current and future therapeutic approaches against HPV-induced tumors is a global health priority, despite an effective prophylactic vaccine against 7 of the 12 genotypes involved in the etiology of tumors being currently available. In this review, we present the main anti-HPV therapeutic approaches in clinical experimentation, with a focus on a novel tumor antigen delivery method using engineered exosomes, that we recently developed. Our system allows the induction of an efficient unrestricted cytotoxic T lymphocyte (CTL) immune response against the HPV16-E7 tumor-associated antigen, with the formation of endogenously engineered exosomes, i.e., nanovesicles spontaneously released by all cell types. Immunogenic exosomes are uploaded with HPV16-E7 due to the fusion with a unique exosome-anchoring protein referred to as Nefmut. Intramuscular injection of a DNA vector expressing the fusion protein generates exosomes sufficiently immunogenic to elicit a potent anti-16E7 CTL immune response. The approach is described here and the advantages over other existing methodologies are reported.