Association between hepatitis C virus genotype 4 and renal cell carcinoma: Molecular and virological studies.

Hepatitis C virus (HCV) is the most common infection worldwide. The correlation between HCV and renal cell carcinoma (RCC) is still mysterious. Therefore, the relationship between HCV and RCC was investigated. The study included 100 patients with RCC; 32 with HCV infection, and 68 without HCV infection. Expressions of viral proteins (NS3 and NS5A) were tested using an immune electron-microscope (IEM) and immunohistochemistry (IHC). IHC and quantitative real time-PCR investigated the presentation of human proteins TP53 and p21 genes. Transmission electron (TEM) detected viral-like particles in infected RCC tissues. The gene and protein expression of P53 was higher in HCV positive versus HCV negative patients and p21 was lower in HCV positive versus HCV negative in both tumor and normal tissue samples. Viral like particles were observed by TEM in the infected tumor and normal portion of the RCC tissues and the plasma samples. The IEM showed the depositions of NS3 and NS5A in infected renal tissues, while in noninfected samples, were not observed. The study hypothesizes that a correlation between HCV and RCC could exist through successfully detecting HCV-like particles, HCV proteins, and (p53 and p21) in RCC-infected patients.

Mapping of Human Polyomavirus in Renal Cell Carcinoma Tissues.

Worldwide, the incidence of renal cell carcinoma (RCC) is rising, accounting for approximately 2% of all cancer diagnoses and deaths. The etiology of RCC is still obscure. Here, we assessed the presence of HPyVs in paraffin-embedded tissue (FFPE) resected tissue from patients with RCC by using different molecular techniques. Fifty-five FFPE tissues from 11 RCC patients were included in this study. Consensus and HPyV-specific primers were used to screen for HPyVs. Both PCR approaches revealed that HPyV is frequently detected in the tissues of RCC kidney resections. A total of 78% (43/55) of the tissues tested were positive for at least one HPyV (i.e., MCPyV, HPyV6, HPyV7, BKPyV, JCPyV, or WUyV). Additionally, 25 tissues (45%) were positive for only one HPyV, 14 (25%) for two HPyVs, 3 (5%) for three HPyVs, and 1 one (1%) tissue specimen was positive for four HPyVs. Eleven (20%) RCC specimens were completely devoid of HPyV sequences. MCPyV was found in 24/55 RCC tissues, HPyV7 in 19, and HPyV6 in 8. The presence of MCPyV and HPyV6 was confirmed by specific FISH or RNA-ISH. In addition, we aimed to confirm HPyV gene expression by IHC. Our results strongly indicate that these HPyVs infect RCC and nontumor tissues, possibly indicating that kidney tissues serve as a reservoir for HPyV latency. Whether HPyVs possibly contribute to the etiopathogenesis of RCC remains to be elucidated.

Epstein-Barr virus infection is associated with the nuclear factor-kappa B p65 signaling pathway in renal cell carcinoma.

BACKGROUND: There have been few studies regarding viral involvement in the pathogenesis of renal cell carcinoma (RCC). The aim of this study was to examine the possible association of Epstein-Barr virus (EBV) infection with clinicopathological features and cellular biomarkers including p53, p16INK4a, Ki-67 and nuclear factor-kappa B (NF-κB) in RCC tumors. METHODS: In this prospective study, 122 histologically confirmed Formalin-fixed Paraffin-embedded RCC tissue specimens along with 96 specimens of their corresponding peritumoral tissues and 23 samples of blunt renal injuries were subjected to nested polymerase chain reaction (nPCR) in order to amplify EBV DNA sequences. The expression of p53, p16INK4a, Ki-67 and NF-κB was investigated by immunohistochemistry (IHC) assay. Statistical analysis was employed to demonstrate the possible associations. RESULTS: Infection with EBV was found to be significantly associated with RCC. Our results indicate that p65 NF-κB signaling pathway is probably involved in EBV-mediated RCC pathogenesis. Moreover, we found p53, Ki-67 and cytoplasmic NF-κB expression to be associated with tumor nuclear grade in RCC patients. The expression of p53 and Ki-67 was associated with primary tumor category as well. In addition, p53 overexpression was significantly more frequent among nonconventional RCC tumors than the conventional histologic type. CONCLUSIONS: Infection with EBV is likely to play an important role in the development of RCC through the constitutive and permanent activation of NF-κB p65 signaling pathway. However, more experiments and supporting data are required to reach a decisive conclusion.

Bluetongue Viruses Act as Novel Oncolytic Viruses to Effectively Inhibit Human Renal Cancer Cell Growth In Vitro and In Vivo.

BACKGROUND The bluetongue virus (BTV) is the prototype virus in the genus Orbivirus within the family Reoviridae. Recent studies indicate that BTVs are capable of infecting and selectively lysing human hepatic carcinoma cells (Hep-3B) and prostate carcinoma cells (pc-3). This study was designed to evaluate the oncolytic potential of BTV in experimental models of human renal cancer in vitro and in vivo. MATERIAL AND METHODS Five human renal cancer cell lines, ACHN, CAKI-1, OS-RC-2, 786-O, and A498, were used in this study to analyze BTV replication. These cells were lysed by oncolysis compared to normal control. Xenograft models were used to assess the efficacy and toxicity of BTVs in vivo. Data were analyzed by one-way ANOVA or two-sided unpaired t tests. RESULTS The results showed HPTEC cells to be relatively resistant to cytotoxic effects of BTVs and exhibited normal growth rate even at high dose of BTVs. Nonetheless, the renal cancer cells showed a remarkably higher sensitivity to BTVs. Moreover, the ultramicroscopic subcellular changes were also detected in the renal cells. The viral particles were observed in all the RCC cell lines, but not in HPTEC cells. Intratumoral injections of BTVs significantly decreased the tumor volume as compared to animals that received no virus treatment. Infection with BTVs significantly increased the percentage of apoptotic renal cancer cells but not the HPTEC cells. Moreover, BTV triggered apoptosis in renal cancer cells via a mitochondria-mediated pathway. CONCLUSIONS This study for the first time demonstrated the oncolytic potential of BTV in experimental models of human renal cancer. BTV exhibits the potential to inhibit human renal cancer cell growth in vitro and in vivo.

N6-methyladenosine modification and the YTHDF2 reader protein play cell type specific roles in lytic viral gene expression during Kaposi's sarcoma-associated herpesvirus infection.

Methylation at the N6 position of adenosine (m6A) is a highly prevalent and reversible modification within eukaryotic mRNAs that has been linked to many stages of RNA processing and fate. Recent studies suggest that m6A deposition and proteins involved in the m6A pathway play a diverse set of roles in either restricting or modulating the lifecycles of select viruses. Here, we report that m6A levels are significantly increased in cells infected with the oncogenic human DNA virus Kaposi's sarcoma-associated herpesvirus (KSHV). Transcriptome-wide m6A-sequencing of the KSHV-positive renal carcinoma cell line iSLK.219 during lytic reactivation revealed the presence of m6A across multiple kinetic classes of viral transcripts, and a concomitant decrease in m6A levels across much of the host transcriptome. However, we found that depletion of the m6A machinery had differential pro- and anti-viral impacts on viral gene expression depending on the cell-type analyzed. In iSLK.219 and iSLK.BAC16 cells the pathway functioned in a pro-viral manner, as depletion of the m6A writer METTL3 and the reader YTHDF2 significantly impaired virion production. In iSLK.219 cells the defect was linked to their roles in the post-transcriptional accumulation of the major viral lytic transactivator ORF50, which is m6A modified. In contrast, although the ORF50 mRNA was also m6A modified in KSHV infected B cells, ORF50 protein expression was instead increased upon depletion of METTL3, or, to a lesser extent, YTHDF2. These results highlight that the m6A pathway is centrally involved in regulating KSHV gene expression, and underscore how the outcome of this dynamically regulated modification can vary significantly between cell types.

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

Low-level BK polyomavirus (BKPyV) shedding is seen in at least 10% of seropositive immunocompetent adults. Moreover, BKPyV infection is highly prevalent amongst immunocompromised populations, yet little is known on its relationship with malignancy. We studied a female patient with BKPyV-associated and donor-derived de novo high-grade sarcomatoid urothelial carcinoma developed 8 years after kidney transplantation from a male donor. Through whole-genome sequencing, we discovered integration of genotype IV BKPyV genome into the non-coding RNA (ncRNA) intronic region of human chromosome 18. The two breakpoints in the virus genome were located at the non-coding control region (NCCR) and large T antigen (TAg) coding region, respectively. Nevertheless, the TAg was overexpressed. We, therefore, inferred that the BKPyV was clonally integrated into the human genome in the form of concatemers, facilitating the expression of the TAg. The patient presented with multiorgan metastases, which were reduced in size and number throughout the body after removal of the graft and cessation of immunosuppressants. The few remaining lesions located in the liver were identified, through biopsy to be necrotic tumor tissue with TAg detected; additionally, genomic sequencing of the liver mass found Y chromosome. In conclusion, we propose that integration of the BKPyV genome is closely related to oncogenesis in this patient; while oncogenesis occurred when host immunity was impaired, recovery of the patient's native immunity effectively curbed viral replication and eliminated the metastatic lesions.

Prevention of Hepatitis B Virus Reactivation With Lamivudine in a Patient With Advanced Renal Cell Carcinoma Treated With Everolimus.

Anticancer agents may trigger reactivation of hepatitis B virus infection ensuing in asymptomatic to severe liver damage. Preemptive administration of antiviral agents such as lamivudine to patients receiving cytotoxic chemotherapy has been shown to inhibit viral replication and prevent such events. No data are available so far concerning the coadministration of antiviral agents and everolimus, an oral mammalian target of rapamycin inhibitor recently approved for the treatment of advanced renal cell carcinoma. We present in this study the first case to our knowledge of a hepatitis B surface antigen-positive patient with metastatic renal cell carcinoma who has been successfully treated with prophylactic lamivudine and everolimus. Long-term depletion of viral replication was obtained along with stabilization of lung and bone metastases. Hepatitis B surface antigen positivity may be found in up to 10% of cancer patients but should not be considered a contraindication to treatment with everolimus.

Chronic hepatitis C infection as a risk factor for renal cell carcinoma.

BACKGROUND: Chronic hepatitis C virus (HCV) infection causes cirrhosis and hepatocellular carcinoma but is also etiologically linked to several extrahepatic medical conditions including renal disorders. HCV is also associated with extrahepatic malignancies and may be oncogenic. Whether HCV confers an increased risk of renal cell carcinoma (RCC) remains controversial. AIMS: Prospectively determine whether chronic HCV is associated with an increased risk of RCC. METHODS: At an integrated medical center in Detroit, Michigan, adult patients with suspected RCC or newly diagnosed colon cancer (controls) were screened for hepatitis C antibody (HCAB) and HCV RNA. Renal or colon cancers were confirmed histologically. The proportion of patients with HCAB and HCV RNA in each group was compared, and risk factors for renal cell carcinoma were determined by multivariable logistic regression analysis. RESULTS: RCC patients had a higher rate of HCAB positivity (11/140, 8 %) than colon cancer patients (1/100, 1 %) (p < 0.01). Of the HCAB-positive patients, 9/11 RCC and 0/1 controls had detectable HCV RNA. HCV RNA positivity was a significant risk factor for RCC (OR 24.20; 95 % CL 2.4, >999.9; p = 0.043). Additionally, viremic RCC patients were significantly younger than RCC patients who were HCV RNA negative (p = 0.013). CONCLUSIONS: Patients with chronic HCV are at heightened risk of RCC.

High-risk human papillomavirus infection in different histological subtypes of renal cell carcinoma.

Limited data exist regarding whether a high-risk human papillomavirus (HR-HPV) infection increases the risk of developing renal cell carcinoma. The aim of this study was to investigate whether HPV infection has a role in the pathogenesis or development of a certain histological subtype of renal cell carcinoma. Formalin-fixed paraffin-embedded (FFPE) specimens of 122 patients with histopathologically proven renal cell carcinoma and their respective peritumoral tissues were examined. The presence of HPV-DNA was determined by a combination of MY/GP+ consensus primers and HPV-16/18 type specific nested PCRs followed by direct sequencing. Catalyzed signal-amplified colorimetric in situ hybridization (CSAC-ISH) technique was applied to determine the physical status of viral genome. The expression of p16INK4a and HPV L1 capsid proteins was evaluated using immunohistochemistry. HPV genome was detected in 37 (30.3%) tumor specimens and their four (4.1%) corresponding peritumoral tissues. HPV-18 was the most common viral type identified followed by HPV-16 and 58. Immunoexpression of p16INK4a was detected in 24 (20.3%) cases. Data analysis showed a significant correlation between p16INK4a expression and the presence of HR-HPV DNA (P < 0.001). CSAC-ISH analysis confirmed HR-HPV infection in 45% of tumors, which were previously tested positive for HPV-DNA. Diffuse signal pattern was identified in 15 (83.3%) samples whereas a mixed pattern of diffuse and punctate signals was only detectable in three cases. The results indicate an association of HR-HPV types with renal cell carcinoma. It is proposed that HPV infection in high-grade tumors might precede disease progression in a number of tumors, particularly of the papillary subtype.

Potential relationship between BK virus and renal cell carcinoma.

The objective of the present study was to investigate the potential association between the presence of BK virus (BKV) DNA and mRNA and renal cell carcinoma and bladder transitional cell carcinoma. The formalin-fixed and paraffin-embedded tissue samples were obtained from 50 cancer patients with renal cell carcinoma, 40 cancer patients with bladder transitional cell carcinoma, 45 control patients with the benign renal pathology, and from another 25 control patients with benign bladder pathology. The samples were subjected to nested PCR for detection of BKV DNA and real-time reverse transcription PCR (real-time RT-PCR) for determining mRNA levels of BKV. The results of the nested PCR indicated that 23 (14.3%) of 160 samples were positive for BKV DNA. The relationship between the cancer and the presence of BKV DNA was significant (P < 0.05). The BKV DNA positivity was significantly associated with the histological diagnosis of renal cell carcinoma (P = 0.03), but not with that of bladder transitional cell carcinoma. The results of real-time RT-PCR showed that the mRNA of BKV VP1 was present in 69.5% of the BKV DNA positive samples. The levels of BKV mRNA were significantly higher in the renal cell cancer samples than in the control samples (P < 0.05). The results of the present study confirm the association between BKV and renal cell cancer. The findings also indicated that the presence of BKV DNA resulted in a fivefold increase in the risk of development of renal cell carcinoma.

Effects of G250 promoter controlled conditionally replicative adenovirus expressing Ki67-siRNA on renal cancer cell.

Replication-competent adenovirus (RCAd) has been used extensively in cancer gene therapy, and tumor-selection is critical for the use of replication-competent adenovirus. Here we investigated the anti-tumor characterization of oncolytic virus, whose E1A gene is under the control of a renal cell carcinoma specific promoter - the G250 promoter. The constructed oncolytic virus G250-Ki67 is armed with transgene of Ki67-siRNA, and G250-ZD55-Ki67 also with E1B-55 KD deleted. The tumor-specific expression of E1A and Ki67 was demonstrated by Western blot and immunohistochemistry staining, and the tumor-specific cytotoxicity was assessed by crystal violet staining and cell viability assays. The G250-Ki67 and G250-ZD55-Ki67 adenoviruses could express E1A protein in 786-O and OSRC cell lines but not in ACHN and HK-2 cell lines. The expression of Ki67 gene in 786-O and OSRC cell lines were suppressed by these adenoviruses. The cytotoxic effects induced by G250-ZD55-Ki67 and G250-Ki67 were more obvious on the 786-O cell lines than on the OSRC cell lines. Each group of adenoviruses could inhibit the proliferation of the 786-O cells and OSRC cells. However, the effects induced by G250-ZD55-Ki67 and G250-Ki67 on 786-O cells were stronger than on OSRC cells. Moreover, G250-ZD55-Ki67 had enhanced antitumor activities in these renal cancer cells compared with G250-Ki67. G250 promoter-derived CRAds carrying Ki67-siRNA could highly amplify and express Ki67-siRNA in renal cancer cells with expression of G250 antigen, inhibit renal cancer cells proliferation and induce apoptosis. These results demonstrated that the G250-specific oncolytic adenovirus expressing Ki67-siRNA is applicable for human renal clear cell cancer therapy.

A serotype 5/3 adenovirus expressing MDA-7/IL-24 infects renal carcinoma cells and promotes toxicity of agents that increase ROS and ceramide levels.

Agents that generate reactive oxygen species (ROS) are recognized to enhance MDA-7/IL-24 lethality. The present studies focused on clarifying how such agents enhanced MDA-7/IL-24 toxicity in renal cell carcinoma cells (RCCs). Infection of RCCs with a tropism-modified serotype 5/3 adenovirus expressing MDA-7/IL-24 (Ad.5/3-mda-7) caused plasma membrane clustering of CD95 and CD95 association with pro-caspase 8, effects that were enhanced by combined exposure to 17-N-allylamino-17-demethoxygeldanamycin (17AAG), As(2)O(3), or fenretinide and that correlated with enhanced cell killing. Knockdown of CD95 or expression of cellular FADD (Fas-associated protein with death domain)-like interleukin-1ß-converting enzyme inhibitory protein, short form (c-FLIP-s) blocked enhanced killing. Inhibition of ROS generation, elevated cytosolic Ca(2+), or de novo ceramide synthesis blocked Ad.5/3-mda-7 ± agent-induced CD95 activation and the enhancement of apoptosis. Ad.5/3-mda-7 increased ceramide levels in a PERK-dependent fashion that were responsible for elevated cytosolic Ca(2+) levels that promoted ROS generation; 17AAG did not further enhance cytokine-induced ceramide generation. In vivo, infection of RCC tumors with Ad.5/3-mda-7 suppressed the growth of infected tumors that was enhanced by exposure to 17AAG. Our data indicate that in RCCs, Ad.5/3-mda-7-induced ceramide generation plays a central role in tumor cell killing and inhibition of multiple signaling pathways may have utility in promoting MDA-7/IL-24 lethality in renal cancer.

Human endogenous retrovirus transcription profiles of the kidney and kidney-derived cell lines.

The human genome comprises approximately 8-9 % of human endogenous retroviruses (HERVs) that are transcribed with tissue specificity. However, relatively few organs have been examined in detail for individual differences in HERV transcription pattern, nor have tissue-to-cell culture comparisons been frequently performed. Using an HERV-specific DNA microarray, a core HERV transcription profile was established for the human kidney comparing 10 tissue samples. This core represents HERV groups expressed uniformly or nearly so in non-tumour kidney tissue. The profiles obtained from non-tumour tissues were compared to 10 renal tumour tissues (renal cell carcinoma, RCC) derived from the same individuals and additionally, to 22 RCC cell lines. No RCC cell line or tumour-specific differences were observed, suggesting that HERV transcription is not altered in RCC. However, when comparing tissue transcription to cell line transcription, there were consistent differences. The differences were irrespective of cancer state and included cell lines derived from non-tumour kidney tissue, suggesting that a specific alteration of HERV transcription occurs when establishing cell lines. In contrast to previous publications, all known HERV-derived tumour antigens, including those identified in RCC, were expressed both in multiple RCC cell lines and several non-tumour tissue-derived cell lines, a result that contrasts with findings from patient samples. The results establish the core kidney transcription pattern of HERVs and reveal differences between cell culture lines and tissue samples.

Sunitinib-associated hyperammonemic encephalopathy successfully managed with higher intensity conventional hemodialysis: A case report.

RATIONALE: Hyperammonemia encephalopathy is a rare but severe complication that has been reported in association with the use of sunitinib, a tyrosine kinase inhibitor. We report here a unique case of a patient with end stage renal disease that was initiated on sunitinib for metastatic renal cell carcinoma. PATIENT CONCERNS: A 65-year-old man with end stage renal disease on maintenance conventional hemodialysis and had concomitant stable Child-Pugh class B liver cirrhosis consequent of hepatitis C infection was started on sunitinib for metastatic renal cell carcinoma. He developed confusion few weeks after starting therapy with no other indication of worsening liver dysfunction otherwise. DIAGNOSIS: He was later diagnosed with hyperammonemia encephalopathy. INTERVENTIONS: His treatment was discontinued and reinitiated at a lower dose after recovery and titrated according to tolerance. As ammonia is a very low molecular weight molecule and is cleared well with diffusive clearance, we intensified his dialysis regimen by increasing intensity for each session and frequency per week. OUTCOMES: With this change in dialysis regimen, patient was able to continue treatment with sunitinib. LESSONS: Clinicians prescribing sunitinib should be vigilant to monitor for this complication in patients receiving sunitinib, apart from the more usual presentation of hepatotoxicity. We found that a more intensive hemodialysis regimen consisting of 4× a week conventional high-flux hemodialysis (HD) can permit the continuation of treatment with sunitinib in an end stage renal disease (ESRD) patient with Child-Pugh class B liver cirrhosis.

The association between hepatitis C virus infection and renal cell cancer, prostate cancer, and bladder cancer: a systematic review and meta-analysis.

To update the current evidence on whether hepatitis C virus (HCV) infection represents a possible risk factor for renal cell cancer (RCC), prostate cancer (PCa), and bladder cancer (BC). We searched the literature on Pubmed, Web of Science, and Embases before April 2021. A systematic review and meta-analysis were performed. Finally, we extracted 12 studies based on the eligible criteria. Across 11 studies for HCV and RCC, the incorporated RR was 1.28 (95% CI 1.05-1.55), which meant that participants with HCV infection were associated with higher RCC risk. The pooled RR in hazard ratio (HR) subgroup (HR 1.59, 95% CI 1.22-2.08), cohort studies subgroup (RR 1.47, 95% CI 1.18-1.82), and North America subgroup (RR 1.71, 95% CI 1.40-2.09) detected a stronger association between HCV and RCC risk. Although an inverse association was seen for PCa (RR 0.75, 95% CI 0.54-1.03) across seven studies, it was not statistically significant (P = 0.075). There was no significant association between HCV and BC with an incorporated RR of 0.92 (95% CI, 0.82-1.03) across five studies. Our study demonstrated that HCV infection was significantly associated with increased RCC risk. There appeared to be an inverse association for HCV in PCa risk but not statistically significant. No significant association was found between HCV and BC risk. Prospective, large-scale, and well-designed cohort studies are required to validate the association between HCV and RCC, and to investigate the role of HCV on PCa.

Immunologic Clearance of a BK Virus-associated Metastatic Renal Allograft Carcinoma.

BACKGROUND: Metastatic carcinoma of a renal allograft is a rare but life threatening event with a difficult clinical management. Recent reports suggested a potential role of BK polyomavirus (BKPyV) in the development of urologic tract malignancies in kidney transplant recipients. METHODS: We investigated a kidney-pancreas female recipient with an history of BKPyV nephritis who developed a rapidly progressive and widely metastatic donor-derived renal carcinoma 9 years after transplantation. RESULTS: Histology and fluorescence in situ hybridization analysis revealed a donor-derived (XY tumor cells) collecting (Bellini) duct carcinoma. The presence of BKPyV oncogenic large tumor antigen was identified in large amount within the kidney tumor and the bowel metastases. Whole genome sequencing of the tumor confirmed multiple genome BKPyV integrations. The transplanted kidney was removed, immunosuppression was withdrawn, and recombinant interleukin-2 (IL-2) was administered for 3 months, inducing a complete tumor clearance, with no evidence of disease at 6-year follow-up. The immunological profiling during IL-2 therapy revealed the presence of donor-specific T cells and expanded cytokine-producing bright natural killer cells but no donor-specific antibodies. Finally, we found persistently elevated anti-BK virus IgG titers and a specific anti-BKPyV T cell response. CONCLUSIONS: This investigation showed evidence for the potential oncogenic role of BKPyV in collecting duct carcinoma in renal allografts and demonstrated that immunosuppression withdrawal and IL-2 therapy can lead to an efficient antitumor cellular mediated rejection possibly via 3 distinct mechanisms including (1) host-versus-graft, (2) host-versus-tumor, and (3) anti-BKPyV responses.

Expression of Epstein-Barr virus in renal cell carcinoma.

There have been few studies regarding the etiology of renal cell carcinoma. To examine the possible involvement of Epstein-Barr virus (EBV) in this disease, 9 renal cell carcinoma (RCC), 2 nephroblastoma (Wilms' tumor) and 2 RCC cell lines were subjected to mRNA in situ hybridization and indirect immunofluorescence staining. Messenger RNA in situ hybridization using BamHIW, EBNA LP, EBNA 2 and EBER1 probes of EBV revealed signals in all the examined samples, although some samples showed weak signals using the EBNA LP probe. Indirect immunofluorescence staining using anti-EBNA LP, anti-EBNA2, anti-LMP1 and anti-BZLF1 antibodies showed definitive fluorescence. PCR also revealed EBV DNA in all 8 RCC specimens including 7 cases other than hybridization and fluorescence. EBV infected all the RCC and nephroblastoma irrespective of the histological or clinical stage. On the other hand, EBV expression was stronger in papillary and clear cell-type RCC than chromophobe cell-type, as well as being stronger in the higher grades of RCC. These results suggest that the expression of EBV may be involved in the pathogenesis of RCC and nephroblastoma.

Human Papillomavirus DNA and P16INK4A are not detected in renal tumors with immunohistochemistry and signal-amplified in situ hybridization in paraffin-embedded tissue.

The association between human papillomavirus (HPV) infection and carcinogenesis has long been established in literature, with the strongest evidence for its role in cervical carcinoma. The role of HPV in urological tumors has been investigated and sporadic reports have linked HPV infection to bladder, prostate, renal, penile, and testicular cancer. Although less rigorously studied, there are a few conflicting results about the role of HPV in the development of malignant renal tumors. Moreover, no data are available for association of HPV DNA and expression of P16 in benign renal tumors. Formalin-fixed, paraffin-embedded tissues from 62 renal tumors (40 clear cell, 9 papillary, and 3 chromophobe renal cell carcinomas, 1 collecting duct carcinoma, 2 urothelial carcinoma of renal pelvis and 7 oncocytomas) were immunostained with low-risk and high-risk HPV DNA (6, 11, 16, 18, 31, 33, 42, 51, 52, 56, 58). Tissue microarray sections of 62 tumors were stained with P16 by immunohistochemistry. Signal amplified colorimetric in situ hybridization was performed on microarray sections using biotinylated probes for HPV subtypes 6, 11, 16, 18. A nuclear dot-like signal was considered positive for low-risk and high-risk HPV by immunohistochemistry and in situ hybridization and nuclear or cytoplasmic staining is considered positive for P16. No staining for HPV DNA and P16 was found in any type of renal tumors. Our results support that HPV does not seem to play a role in the development of benign and malignant renal tumors.

Specific oncolytic effect of a new hypoxia-inducible factor-dependent replicative adenovirus on von Hippel-Lindau-defective renal cell carcinomas.

Mutations in the von Hippel-Lindau (VHL) tumor suppressor gene are responsible for a hereditary cancer syndrome characterized by high susceptibility to hemangioblastomas of the retina and central nervous system, pheochromocytomas, and renal cell carcinomas. In agreement with its role as a tumor suppressor, the vast majority of spontaneous clear cell carcinomas of the kidney present loss of heterozygosity at the VHL locus. Recently, it has been shown that VHL works as the substrate recognition component of an E3 ubiquitination complex that targets the hypoxia-inducible factor (HIF) for proteosomal degradation. Under normal oxygen tension, the half-life of HIF transcription factors is extremely short because of its high degradation rate by the proteasome, resulting in undetectable HIF activity in normal cells. However, in VHL-deficient tumor cells, the HIF transcriptional pathway is constitutively activated because of impaired ubiquitination of this transcription factor. To target VHL-deficient tumors, we have exploited this feature to develop a conditionally replicative adenovirus (Ad9xHRE1A), the replication of which is HIF dependent. In this new oncolytic adenovirus, the expression of the E1A gene is controlled by an optimized minimal promoter containing HIF recognition elements. Here, we show that the induction of the E1A gene, as well as the viral replication and cytolytic effect of Ad9xHRE1A, are dependent on HIF activity. As a consequence, this virus efficiently kills VHL-deficient cells both in vitro and in vivo, as well as cells growing under hypoxic conditions. These data suggest that Ad9xHRE1A could be used as a highly specific therapy for VHL-deficient cancers and probably many other tumors that show extensive hypoxic areas or increased HIF activity by genetic alterations other than VHL loss.