Epstein-Barr virus infection in urothelial transitional cell carcinoma tissues

Role of NRP1 in Bladder Cancer Pathogenesis and Progression

Bladder urothelial carcinoma (BC) is a fatal invasive malignancy and the most common malignancy of the urinary system. In the current study, we investigated the function and mechanisms of Neuropilin-1 (NRP1), the co-receptor for vascular endothelial growth factor, in BC pathogenesis and progression. The expression of NRP1 was evaluated using data extracted from GEO and HPA databases and examined in BC cell lines. The effect on proliferation, apoptosis, angiogenesis, migration, and invasion of BC cells were validated after NRP1 knockdown. After identifying differentially expressed genes (DEGs) induced by NRP1 silencing, GO/KEGG and IPA^® bioinformatics analyses were performed and specific predicted pathways and targets were confirmed in vitro. Additionally, the co-expressed genes and ceRNA network were predicted using data downloaded from CCLE and TCGA databases, respectively. High expression of NRP1 was observed in BC tissues and cells. NRP1 knockdown promoted apoptosis and suppressed proliferation, angiogenesis, migration, and invasion of BC cells. Additionally, after NRP1 silencing the activity of MAPK signaling and molecular mechanisms of cancer pathways were predicted by KEGG and IPA^® pathway analysis and validated using western blot in BC cells. NRP1 knockdown also affected various biological functions, including antiviral response, immune response, cell cycle, proliferation and migration of cells, and neovascularisation. Furthermore, the main upstream molecule of the DEGs induced by NRP1 knockdown may be NUPR1, and NRP1 was also the downstream target of NUPR1 and essential for regulation of FOXP3 expression to activate neovascularisation. DCBLD2 was positively regulated by NRP1, and PPAR signaling was significantly associated with low NRP1 expression. We also found that NRP1 was a predicted target of miR-204, miR-143, miR-145, and miR-195 in BC development. Our data provide evidence for the biological function and molecular aetiology of NRP1 in BC and for the first time demonstrated an association between NRP1 and NUPR1, FOXP3, and DCBLD2. Specifically, downregulation of NRP1 contributes to BC progression, which is associated with activation of MAPK signaling and molecular mechanisms involved in cancer pathways. Therefore, NRP1 may serve as a target for new therapeutic strategies to treat BC and other cancers.

[Lymphoepithelioma-like tumors: A review of literature and a clinical case of bladder carcinoma]

The paper presents historical information and literature data on lymphoepitheliomas and lymphoepithelioma-like tumors at various sites. It considers the specific features of their histological structure, a differential diagnostic series, and immunohistochemical markers and gives brief information on treatment and prognosis. The paper depicts a clinical case of lymphoepithelioma-like bladder carcinoma in an 80-year-old woman.

Epstein-Barr virus DNA load in tumour tissues correlates with poor differentiation status in non-muscle invasive urothelial carcinomas

OBJECTIVE

To detect the correlation between the clinical staging, grading and genomic Epstein-Barr virus (EBV) viral numbers in tumour tissues of urothelial carcinoma patients.

PATIENTS AND METHODS

From June 2004 to May 2008, 60 urothelial carcinoma patients (50 cases of bladder carcinoma and 10 of upper tract urothelial carcinoma (UTUC) were enrolled in the study. Eight patients who underwent transurethral resection of prostate for prostate hyperplasia and two patients receiving nephrectomy for non-function kidney were used as normal controls. The EBV viral copy numbers in genomic DNA were evaluated using a real-time PCR-based study. The BamHI W region of the Namalwa cell line was constructed to the plasmid clone and was used as standard curve for absolute quantitative PCR (Q-PCR).

RESULTS

Epstein-Barr virus DNA was detected in 56% (28/50) and 60% (6/10) of the bladder and UTUC patients, respectively. The EBV DNA could not be detected in the normal control group. By pooling the UTUC and bladder patients in stage Ta,T1, the high copy number in fixed genomic DNA amount (100 ng/20 µL) was correlated with the high grading in stage Ta,T1 urothelial carcinoma (P = 0.014). The overall grading was not statistically associated with EBV copy number (P = 0.25). Although the copy numbers between paired tumour and normal tissues were not statistically different (P= 0.169), there were more copies of EBV in the normal tissues adjacent to the tumours than in those free from urothelial carcinoma. There was no significant difference between recurrence of non-muscle invasive bladder cancer and the presence of EBV (P > 0.05).

CONCLUSIONS

Epstein-Barr virus DNA could be detected in the genome of the urothelial carcinoma specimens. The poor differentiation status was correlated with the high load of the EBV genome in non-muscle invasive urothelial carcinoma. However, recurrence-free survival was not greater in EBV-positive patients than in EBV-negative patients.

Infiltration of Epstein-Barr virus-harboring lymphocytes occurs in a large subset of bladder cancers

OBJECTIVE

Epstein-Barr virus (EBV) has been implicated in the genesis of a variety of human cancers. We aimed to confirm the presence and define the role of EBV in bladder cancer.

METHODS

A total of 39 bladder cancer specimens were analyzed. Ten urinary bladder tissues obtained at autopsy were used as a normal control. EBV-encoded RNA (EBER) was evaluated by in situ hybridization (ISH). Frozen material available from 18 EBER-positive cases was analyzed by using reverse transcription-polymerase chain reaction for BZLF1, an early lytic gene product. The expression of CD20, CD3, ZEBRA (BZLF1 product) and transforming growth factor beta1 (TGFbeta-1) was assessed using an immunohistochemical technique.

RESULTS

Infiltration of EBER-expressing lymphocytes was detected in 26 of 39 bladder cancer cases (66.7%). A small fraction of the tumor cells as well as the infiltrating lymphocytes were positive in two cases. All normal urinary bladder specimens showed negative results. The incidence of EBV-positive lymphocyte infiltration was significantly higher for advanced stage cancers than those in earlier stages (Ta-152% vs T2-4 93%, P = 0.013). The presence of BZLF1 mRNA was demonstrated in seven out of the 18 EBER-positive cases.

CONCLUSIONS

Infiltration of EBV-harboring lymphocytes occurs in a large subset of bladder cancers cases. It is more frequently associated with advanced stages. EBV infection in tumor cells is very limited. Our findings suggest that EBV-positive lymphocytes might play a role in bladder cancer progression.

Absence of Epstein-Barr virus infection in squamous cell carcinoma of upper urinary tract and urinary bladder

OBJECTIVES

To address whether Epstein-Barr virus (EBV) infection may be involved in the carcinogenesis of squamous cell carcinoma of the upper urinary tract and urinary bladder (SCC-UB). EBV has been implicated in the genesis of a variety of human cancers, including urothelial carcinoma of the urinary bladder.

METHODS

Whether EBV infection is related to SCC-UB carcinogenesis was investigated by in situ hybridization for EBV-encoded RNA and immunohistochemistry for latent membrane protein-1 in 26 cases of SCC-UB.

RESULTS

EBV-encoded RNA and latent membrane protein-1 were identified in the control case of nasopharyngeal carcinoma. None of the SCC-UB cases had a nuclear signal of EBV-encoded RNA, and the cancer cells, normal urothelial cells, and inflammatory cells were all negative for latent membrane protein-1, irrespective of the site of SCC-UB.

CONCLUSIONS

This study is the first to explore the role of EBV infection in SCC-UB. Our results suggest that EBV infection is not involved in the carcinogenesis of SCC of the renal pelvis, ureter, and urinary bladder.

Establishment and characterization of human urothelial cancer xenografts in severe combined immunodeficient mice

AIM

To establish and characterize a murine xenograft model of human urothelial cancer in severe combined immunodeficient (SCID) mice for therapeutic simulation.

METHODS

Pieces of 30 freshly resected urothelial tumors (24 obtained from bladder and 6 from ureter or pelvis) were implanted subcutaneously into SCID mice, and xenograft tumors were passed in tumorigenic cases. At each passage, histopathology, TP53 mutational status assessed by yeast p53 functional assay, and the Ki-67 labeling index (LI) were examined to evaluate the preservation of original features. A growth delay assay after single-dose irradiation was performed in four representative xenografts.

RESULTS

Tumor growth was observed in 18 mice (60%, 18/30). Histologically, 15 of the 18 were epithelial carcinomas similar to the original tumors, whereas the other 3 were Epstein-Barr virus-associated lymphoproliferative disease, resulting in a 50% (15/30) take rate. No correlation was found between the tumor take rate and the clinicopathologic features, TP53 mutational status, or Ki-67 LI of the patients' tumors. Of these 15 xenografts, 11 xenografts were passed from 3 to 10 generations. TP53 mutational status remained stable during the passages, and the Ki-67 LI of eight xenografts was within a range of 50% of the LI of the original tumors, although the other three xenografts increased by over 50%. Specific growth delay after irradiation, independent of the original tumor growth speed and Ki-67 LI, was observed in four xenografts.

CONCLUSIONS

SCID mice are useful recipients for investigations of human urothelial cancer with a wide biological range. This easy-to-handle xenograft system can help to develop a better in vivo preclinical evaluation system for therapeutic agents as well as the investigation of tumor pathophysiology.

Lymphoepithelioma-like carcinoma of the ureter

Lymphoepithelioma-like carcinoma is an undifferentiated epithelial tumor with a prominent lymphocytic infiltrate and is rarely seen in the upper urinary tract. Only 3 and 2 cases involving the ureter and renal pelvis, respectively, have been reported. We report the fourth documented case of lymphoepithelioma-like carcinoma of the ureter. Tumor cells were immunoreactive to cytokeratin and negative for Epstein-Barr virus. Our patient was disease free 30 months after nephroureterectomy. The prognosis is favorable for pure lymphoepithelioma-like carcinoma of the upper urinary tract.

Epstein-Barr virus infection in sarcomatoid renal cell carcinoma tissues

OBJECTIVE

To determine whether Epstein-Barr virus (EBV) infection is related to renal cell carcinoma (RCC) tissues.

MATERIALS AND METHODS

We investigated EBV infection and its genotypes in 73 cases of different types of RCC and 18 of non-neoplastic kidney. EBV infection and its genotypes were determined by EBV-encoded RNAs in situ hybridization (EBER-ISH) and polymerase chain reactions for EBV-encoded nuclear antigen 1 (EBNA-1) and EBNA-3C. The immunophenotype and EBV status of the EBV-infected cells were examined by double-labelling of EBER-ISH and/or immunohistochemistry for lymphoid cell markers, EBV proteins, and CD21.

RESULTS

EBER-ISH signals were detected in five of 73 RCC tissues (6.8%), but in none of 18 non-neoplastic kidneys. Interestingly, EBER-ISH was positive only in five of the 10 sarcomatoid RCCs, and of these, four also showed amplification of EBNA-1. EBV was located exclusively in the tumour-infiltrating B lymphocytes of sarcomatoid RCCs. The genotype of EBV was determined as type 1. A few EBV-infected B cells expressed BZLF1 (an EBV immediate-early gene product) while none expressed EBNA-2 or latent membrane protein 1. This indicates that the B cells are of EBV latency type I, often replicating EBV. EBV infection did not affect the survival rates of patients with sarcomatoid RCC (P = 0.635, Kaplan-Meier analysis, log-rank test).

CONCLUSION

EBV is present only in tumour-infiltrating B lymphocytes of sarcomatoid RCCs. The present study suggests that sarcomatoid RCC modulates a function of EBV-specific T cells controlling EBV replication, or stimulates differentiation of memory B cells into plasma cells.