Occurrence and regression of BK polyomavirus associated carcinoma: a clinical and next-generation sequencing study

An Unusual Presentation of Metastatic BK Virus-Associated Urothelial Carcinoma Arising in the Allograft, Persisting After Transplant Nephrectomy

We report a 32-year-old male 14 years post-living-related kidney transplant presenting with new-onset hematuria and BK viremia. He was found to have BK virus-associated urothelial carcinoma originating in the renal allograft with locally advanced disease and metastases to multiple sites. He also developed acute T-cell-mediated rejection in the setting of immunosuppression reduction for BK viremia prior to undergoing transplant nephrectomy. Eight months following transplant nephrectomy and immunosuppression cessation, distant metastases persisted with partial response to chemotherapy and immunotherapy. Here, we discuss this unique presentation and compare it with other BK virus-associated allograft carcinomas reported in the literature, in addition to discussing evidence for the role of BK virus in oncogenesis.

Dynamic viral integration patterns actively participate in the progression of BK polyomavirus-associated diseases after renal transplantation

The classical lytic infection theory along with large T antigen-mediated oncogenesis cannot explain the BK polyomavirus (BKPyV)-associated tumor secondary to BKPyV-associated nephropathy (BKVAN), viremia/DNAemia, and viruria after renal transplantation. This study performed virome capture sequencing and pathological examination on regularly collected urine sediment and peripheral blood samples, and BKVAN and tumor biopsy tissues of 20 patients with BKPyV-associated diseases of different stages. In the early noncancerous stages, well-amplified integration sites were visualized by in situ polymerase chain reaction, simultaneously with BKPyV inclusion bodies and capsid protein expression. The integration intensity, the proportion of microhomology-mediated end-joining integration, and host PARP-1 and POLQ gene expression levels increased with disease progression. Furthermore, multiomics analysis was performed on BKPyV-associated urothelial carcinoma tissues, identifying tandem-like structures of BKPyV integration using long-read genome sequencing. The carcinogenicity of BKPyV integration was proven to disturb host gene expression and increase viral oncoprotein expression. Fallible DNA double-strand break repair pathways were significantly activated in the parenchyma of BKPyV-associated tumors. Olaparib showed an antitumor activity dose-response effect in the tumor organoids without BRCA1/2 genes mutation. In conclusion, the dynamic viral integration patterns actively participate in the progression of BKPyV-associated diseases and thus could be a potential target for disease monitoring and intervention.

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.

BK polyomavirus in Iranian patients with papillary thyroid cancer: Is it a major future challenge?

BK polyomavirus (BKPyV) is a well-known cause of nephropathy in renal transplant recipients. It has recently received much attention from researchers as a major predisposing factor for various cancers. This study aimed to investigate how BKPyV affected the advancement of papillary thyroid carcinoma (PTC). A total of 1057 samples were tested for BKPyV DNA and RNA, comprising 645 paraffin-embedded PTC biopsy samples (PEBS), 412 fresh biopsy samples (FBS), and 1057 adjacent noncancerous samples. The BKPyV DNA was found in 511 (48.3%) of the specimens, including 347 (84.2%) FBS and 164 (25.4%) PEBS. The mean BKPyV copy number was significantly lower in patients with PEBS (0.5 × 10^-4  ± 0.1 × 10^-4  copies/cell) than in FBS (1.3 × 10^-1  ± 0.2 × 10^-1  copies/cell) and non-PTC normal samples (0.3 × 10^-5  ± 0.04 × 10^-5  copies/cell). The PEBS had lower LT-Ag RNA expression than FBS, and no VP1 gene transcript expression was detected. In conclusion, although our findings indicated the presence of BKPyV in some Iranian PTC patients, more research is needed to corroborate these findings.

The Influence of Oncogenic Viruses in Renal Carcinogenesis: Pros and Cons

Viral infections are major contributors to the global cancer burden. Recent advances have revealed that known oncogenic viruses promote carcinogenesis through shared host cell targets and pathways. The aim of this review is to point out the connection between several oncogenic viruses from the Polyomaviridae, Herpesviridae and Flaviviridae families and renal carcinogenesis, highlighting their involvement in the carcinogenic mechanism. We performed a systematic search of the PubMed and EMBASE databases, which was carried out for all the published studies on RCC in the last 10 years, using the following search algorithm: renal cell carcinoma (RCC) and urothelial carcinoma, and oncogenic viruses (BKPyV, EBV, HCV, HPV and Kaposi Sarcoma Virus), RCC and biomarkers, immunohistochemistry (IHC). Our analysis included studies that were published in English from the 1st of January 2012 to the 1st of May 2022 and that described and analyzed the assays used for the detection of oncogenic viruses in RCC and urothelial carcinoma. The virus most frequently associated with RCC was BKPyV. This review of the literature will help to understand the pathogenic mechanism of the main type of renal malignancy and whether the viral etiology can be confirmed, at a minimum, as a co-factor. In consequence, these data can contribute to the development of new therapeutic strategies. A virus-induced tumor could be efficiently prevented by vaccination or treatment with oncolytic viral therapy and/or by targeted therapy.

Metastatic Urothelial Carcinoma from Transplanted Kidney with Complete Response to an Immune Checkpoint Inhibitor

Background

Donor-derived malignancy is a rare complication in patients who undergo organ transplant. Approaches to treatment have largely been individualized based on clinical circumstances given the lack of evidence-based guidelines, with therapeutic options ranging from discontinuation of immunosuppression and transplantectomy to the addition of chemotherapy or radiotherapy. Case Presentation. Herein, we describe a 60-year-old woman with metastatic donor-derived upper tract urothelial carcinoma (UTUC) discovered nine years postrenal transplant. Molecular diagnostic studies using polymerase chain reaction amplification of short tandem repeat alleles and HLA tissue typing proved that the urothelial carcinoma originated from donor tissue. She achieved sustained complete remission with transplant nephroureterectomy, retroperitoneal lymphadenectomy, immunosuppression withdrawal, and immunotherapy with pembrolizumab. Routine radiologic surveillance has demonstrated 15-month progression-free survival to date off pembrolizumab, and she is now under consideration for retransplantation.

Conclusions

Immunotherapy using checkpoint inhibitors can serve as a novel treatment option for patients in the clinical predicament of having a solid organ transplant and simultaneous metastatic malignancy. In this report, we also discuss the oncogenic potential of BK virus, the use of checkpoint inhibitors in urothelial carcinoma, and the feasibility of retransplant for this patient population.

Genome-wide profiling of BK polyomavirus integration in bladder cancer of kidney transplant recipients reveals mechanisms of the integration at the nucleotide level

Chronic BK polyomavirus (BKPyV) infection is recognized as a potential oncogenic factor of urothelial carcinoma (UC) in renal transplant recipients. Recent studies have reported a positive correlation among BKPyV integration, persistent overexpression of viral large T antigen (TAg), and malignancy, yet little is known about the specific integration mechanisms and the impacts of viral integration. Here, we performed whole-genome sequencing (WGS) and viral capture-based sequencing on high-grade immunohistochemically TAg-positive UCs in two renal transplant recipients. A total of 181 integration sites, including the three found by WGS, were identified by viral capture-based sequencing, indicating its enhanced sensitivity and ability in identifying low-read integration sites in subpopulations of the tumor cells. The microhomologies between human and BKPyV genomes were significantly enriched in the flanking regions of 84.5% the integration sites, with a median length of 7 bp. Notably, 75 human genes formed fusion sequences due to viral insertional integration. Among them, the expression of 15 genes were statistically associated with UC based on GEO2R expression analysis. Our results indicated a multisite and multifragment linear integration pattern and a potential microhomology or nonhomologous end joining integration mechanism at the single-nucleotide level. We put forward a potential selection mechanism driven by immunity and centered on viral integration in the carcinogenesis of BKPyV.

BK polyomavirus infection promotes growth and aggressiveness in bladder cancer

Background

Recent studies have confirmed the integration of the BK polyomavirus (BKPyV) gene into the cellular genome of urothelial carcinomas in transplant recipients, further confirming the correlation between BKPyV and urothelial carcinomas after transplantation. However, the role BKPyV infections play in the biological function of bladder cancer remains unclear.

Methods

We developed a BKPyV-infected bladder cancer cell model and a mice tumor model to discuss the role of BKPyV infections.

Results

Our research proves that BKPyV infections promote the proliferation, invasion and migration of bladder cancer cells, while the activation of β-catenin signaling pathway is one of its mediation mechanisms.

Conclusions

We first described BKPyV infection promotes the proliferation, invasion and migration of bladder cancer. We verified the role of β-catenin signaling pathway and Epithelial-Mesenchymal Transition effect in BKPyV-infected bladder cancer. These results provide meaningful information towards the diagnosis and treatment of clinical bladder cancer.

Viral integration in BK polyomavirus-associated urothelial carcinoma in renal transplant recipients: multistage carcinogenesis revealed by next-generation virome capture sequencing

BK polyomavirus (BKPyV)-associated cancer after transplantation has gained increasing attention. However, the role of BKPyV integration on oncogenesis is still unclear. In this study, next-generation virome capture sequencing of primary and metastatic tumors were performed in three patients with BKPyV-associated urothelial carcinoma after renal transplantation. As a result, a total of 332 viral integration sites were identified in the six tumors. Integration of BKPyV in both primary and metastatic tumors followed the mechanism of microhomology-mediated end joining mostly, since microhomologies between human and BKPyV genomes were significantly enriched in flanking regions of 84% of the integration sites. Viral DNA breakpoints were nonrandom and tended to assemble in large T gene, small T gene and viral protein 2 gene. There were three, one and one consensus integration sites between the primary and metastatic tumors, which affected LINC01924, eIF3c, and NEIL2 genes in the three cases respectively. Thus, we concluded that integration of BKPyV was a continuous process occurring in both primary and metastatic tumors, generating heterogenous tumor cell populations. Through this ongoing process, certain cell populations might have gained growth advantage or metastatic potential, as a result of viral integration either affecting the cellular genes where the viral DNA integrated to or altering the expression or function of the viral genes.

Variant morphology and random chromosomal integration of BK polyomavirus in posttransplant urothelial carcinomas

BK polyomavirus (BKPyV) causes major complications in solid organ transplant recipients but little is known about its role in the development of urothelial carcinoma (UC) during immunosuppression. Immunohistochemistry (IHC) screening for polyomavirus large T antigen (LTag) was performed in 94 micropapillary UC (MPUC), 480 unselected UC, 199 muscle invasive UC (including 83 UC with variant differentiation), 76 cases of plasmocytoid, nested and large nested UC and 15 posttransplant UC. LTag expressing UC were reevaluated regarding their histomorphological features and characterized by IHC for p53 and HER2, chromogenic in situ hybridization for HER2 and SNaPshot analysis of the TERT promoter and HRAS. Real-time PCR and next generation sequencing (NGS) were performed to search for BKPyV-DNA and for variants in the tumor and viral genomes. We detected five LTag expressing UC which were diagnosed between 2 and 18 years after kidney (n = 4) or heart (n = 1) transplantation. 89 MPUC without history of organ transplantation and overall 755 UC (including cases with variant histology) were LTag negative. Of the five LTag expressing UC, three were MPUC, one showed extensive divergent differentiation with Mullerian type clear cell carcinoma, and one displayed focal villoglandular differentiation. All five tumors had aberrant nuclear p53 expression, 2/5 were HER2-amplified, and 3/5 had TERT promoter mutations. Within the 50 most common cancer related genes altered in UC we detected very few alterations and no TP53 mutations. BKPyV-DNA was present in 5/5 UC, chromosomal integration of the BKPyV genome was detectable in 4/5 UC. Two UC with BKPyV integration showed small deletions in the BKPyV noncoding control region (NCCR). The only UC without detectable BKPyV integration had a high viral load of human herpesvirus 6 (HHV-6). Our results suggest that LTag expression of integrated BKPyV genomes and resulting p53 inactivation lead to aggressive high-grade UC with unusual, often micropapillary morphology.

Clinicopathologic Characterization of Post-Renal Transplantation BK Polyomavirus-Associated Urothelial CarcinomaSingle Institutional Experience

OBJECTIVES

To review rare cases of BK polyomavirus (BKPyV) associated urologic carcinomas in kidney transplant recipients at one institution and in the literature.

METHODS

We describe the clinicopathologic features of BKPyV-associated urologic carcinomas in a single-institution cohort.

RESULTS

Among 4,772 kidney recipients during 1994 to 2014, 26 (0.5%) and 26 (0.5%) developed posttransplantation urothelial carcinomas (UCs) and renal cell carcinomas (RCCs), respectively, as of 2017. Six (27%) UCs but none of the RCCs expressed large T antigen (TAg). TAg-expressing UCs were high grade with p16 and p53 overexpression (P < .05 compared to TAg-negative UCs). Tumor genome sequencing revealed BKPyV integration and a lack of pathogenic mutations in 50 cancer-relevant genes. Compared to TAg-negative UCs, TAg-expressing UCs more frequently presented at advanced stages (50% T3-T4) with lymph node involvement (50%) and higher UC-specific mortality (50%).

CONCLUSIONS

Post-renal transplantation BKPyV-associated UCs are aggressive and genetically distinct from most non-BKPyV-related UCs.

Urothelial carcinoma arising from the transplanted kidney: A single-center experience and literature review

Urothelial carcinoma (UC) is a malignancy predominantly arising in the bladder. Upper tract UC (UUC) is uncommon, accounting only for 5-10% of the cases. High incidence of neoplasms is associated with immunosuppressive therapy; thus, UCs of the transplanted grafts often lead to a more aggressive treatment, in order to withdraw completely the immunosuppression. It significantly affects the patient quality of life, meaning return to dialysis, along with the worse life expectancy. We present our single-institution experience of this rare malignancy in two mid-age kidney transplant recipients, with UCs successfully treated with radical nephroureterectomy: G3 pT3 N0 + G3 pT1 N0 in the first patient and G3 pT2 N0 in the second one. We also review the previous literature focusing on stage of presentation and treatment for the affected kidney transplant patients.