Detection of Merkel cell polyomavirus large T-antigen sequences in human central nervous system tumors

Quantitative analysis of Merkel cell polyomavirus (MCPyV) genome in non-melanoma skin cancer and normal tumor margins

Merkel cell polyomavirus (MCPyV) is the cause of approximately 80% of Merkel cell carcinomas (MCC). The common types of non-melanoma skin cancer (NMSC) including squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) are histologically similar to MCC. In the present study, 58 NMSC formalin-fixed paraffin-embedded tissue (FFPE) samples including 12 SCC, 46 BCC, and 58 FFPE samples of adjacent non-tumoral margins as the control were included. Determination of large tumor antigens (LTAg) copy number was performed by qReal-Time PCR as a viral copy number per cell to elucidate MCPyV carcinogenic role in non-melanoma skin cancer. Out of 58 samples, 36 (62%) cancerous and 22 (37.9%) normal tumor margins were positive for MCPyV LTAg. Median copy numbers of MCPyV LTAg among all NMSC samples and non-tumoral margins were 0.308×10-2 and 0.269×10-3 copies per cell respectively (P=0.001). In addition, although the viral load in the majority of samples was detected to be lower than one copy per cell, in 4 BCC samples, a viral load higher than one LTAg copy per cell was detected. The present study revealed that the detection of higher levels of MCPyV LTAg viral load in some BCC and SCC samples may be correlated with the role of MCPyV in some cases of BCC and SCC skin cancer.

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.

Association between human polyomavirus infection and brain cancer: A systematic review and meta-analysis

AIM

The aim of this study was to investigate the prevalence and potential association between the infection with some members of the polyomaviridae family of viruses and development of the brain tumors.

METHODS

A systematic literature search was performed by finding relevant cross-sectional and case-control studies from a large online database. Heterogeneity, OR, and corresponding 95% CI were applied to all studies by meta-analysis and forest plots. The analysis was performed using Stata Software v.14.

RESULTS

Twenty-three articles (33 datasets) were included in the meta-analysis, four (four datasets) of which were case/control studies and the rest were cross-sectional. The pooled prevalence of polyomaviruses among brain cancer patients was 13% (95% CI: 8-20%; I² = 96.91%). In subgroup analysis, the pooled prevalence of JCV, SV40, BKV and Merkel cell polyomavirus was 20%, 8%, 6%, and 16%, respectively. An association was found between polyomavirus infection and brain cancer [summary OR 7.22 (95% CI (2.36-22.05); I² = 0%)]. The subgroup analysis, based on the virus type, demonstrated a strong association between JCV infection and brain cancer development [summary OR 10.34 (95% CI 1.10-97.42; I² = 0%)].

CONCLUSION

The present study showed a significant association between polyomavirus infection and brain tumors. Moreover, these results suggest that polyomavirus infection may be a potential risk factor for the development of brain cancer.

Traces of JC polyomavirus in papillary thyroid cancer: a comprehensive study in Iran

Background

JC polyomavirus (JCPyV) is known to induce solid tumors such as astrocytomas, glioblastomas, and neuroblastomas in experimental animals, and recent studies have shown that the virus may be correlated with carcinogenesis. This study aimed to evaluate the impact of JCPyV on the progression of papillary thyroid cancer (PTC).

Methods

A total of 1057 samples, including 645 paraffin-embedded PTC biopsy samples (PEBS) and 412 fresh biopsy samples (FBS), and 1057 adjacent non-cancerous samples were evaluated for the presence of JCPyV DNA and RNA.

Results

We observed that 10.8% (114/1057) samples, including 17.5% (72/412) FBS and 6.5% (42/645) PEBS were positive for the JCPyV DNA. Among the JCPyV-positive samples, the mean JCPyV copy number was lower in patients with PEBS (0.3 × 10^–4 ± 0.1 × 10^–4 copies/cell) compared to FBS (1.8 × 10^–1 ± 0.4 × 10^–1 copies/cell) and non-PTC normal samples (0.2 × 10^–5 ± 0.01 × 10^–5 copies/cell), with a statistically significant difference (P < 0.001). The LT-Ag RNA expression was lower in PEBS than in FBS, while no VP1 gene transcript expression was found.

Conclusions

Although our results confirmed the presence of JCPyV in some Iranian patients with PTC, more research is needed to verify these results.

Prevalence of Merkel Cell Polyomavirus in Normal and Lesional Skin: A Systematic Review and Meta-Analysis

The prevalence of Merkel cell polyomavirus(MCPyV) in Merkel cell carcinoma(MCC) and non-MCC skin lesions and its possible role in the etiology of other skin diseases remain controversial. To systematically assess the association between MCPyV infection and MCC, non-MCC skin lesions, and normal skin. For this systematic review and meta-analysis, a comprehensive search for eligible studies was conducted using Medline Ovid, Pubmed, Web of Science, and the Cochrane CENTRAL databases until August 2021; references were searched to identify additional studies. Observational studies that investigated the association between MCPyV infection and MCC, non-MCC skin lesions, and normal skin using polymerase chain reaction(PCR) as a detection method and provided sufficient data to calculate the prevalence of MCPyV positivity. A total of 50 articles were included in the study after exclusion criteria were applied. Two reviewers independently reviewed and assessed the eligibility of the studies, and all disagreements were resolved by consensus. To determine the association between MCPyV and MCC, overall odds ratio (OR) were calculated with 95% CI using a random-effects model. Single-arm meta-analyses were performed to examine the prevalence rate of MCPyV+ in MCC, non-MCC skin lesions, and normal skin. The primary analysis was the prevalence rate of MCPyV+ in MCC. Secondary outcomes included the prevalence rate of MCPyV+ in non-MCC skin lesions and normal skin. A total of 50 studies involving 5428 patients were reviewed based on our inclusion and exclusion criteria. Compared with the control group, MCPyV infection was significantly associated with MCC (OR = 3.51, 95% CI = 2.96 - 4.05). The global prevalence of MCPyV+ in MCC, melanoma, squamous cell carcinoma, basal cell carcinoma, Bowen's disease, actinic keratosis, keratoacanthoma, seborrheic keratosis, and normal skin was 80%, 4%, 15%, 15%, 21%, 6%, 20%, 10%, and 11%, respectively. The current results suggest that MCPyV infection is significantly associated with an increased risk of MCC. However, the low prevalence rate of MCPyV+ in non-MCC skin lesions does not exclude a pathogenic association of this virus with the development of non-MCC skin lesions.

Evidencing the presence of merkel cell polyomavirus in papillary thyroid cancer

Merkel cell polyomavirus (MCPyV) infects most people asymptomatically, but recent reports indicate that the virus may be related to carcinogenesis. This study aimed to evaluate the impact of MCPyV on the development of papillary thyroid cancer (PTC). Totally, 1057 samples, including 412 fresh biopsy samples (FBS) and 645 paraffin-embedded PTC biopsy samples (PEBS), and 1057 adjacent non-cancerous samples were assessed for the presence of MCPyV DNA and RNA. MCPyV DNA was positive in 215 (20.3%) of samples, including 126 (30.6%) in FBS and 89 (13.8%) in PEBS. In MCPyV-positive samples, the mean MCPyV copy number was higher in the patients with FBS (2.3 × 10^-1 ± 0.5 × 10^-1 copies/cell) compared to PEBS (0.7 × 10^-4 ± 0.1 × 10^-4 copies/cell) and adjacent non-PTC normal samples (0.3 × 10^-5 ± 0.02 × 10^-5 copies/cell), indicating a statistically significant difference (P < 0.001). The LT-Ag RNA expression was higher in FBS compared to PEBS, while VP1 gene transcript was not detected in any samples. Although our findings showed the presence of MCPyV in a subset of PTC Iranian patients, further research is required to confirm these findings.

As Evidence-Based Tumorigenic Role of Epstein-Barr Virus miR-BART1-3p in Neurological Tumors

INTRODUCTION

Central nervous system tumors are a diverse group of tumors that account for 2% of all adult cancers and 17% of childhood malignancies. Several internal and external risk factors are involved in the development of this cancer such as viral infections. The aim of this study was to the determination of the EBV infection frequency and the expression level of miR-122 and miR-BART in CNS tumors samples.

METHODS

One hundred and thirty-eight  fresh tissue sample (106 case and 32 control) was collected from CNS specimens. The presence of Epstein-Barr virus (EBV) DNA was examined by PCR assay and the expression level of miR-122 and miR-BART were evaluated by using real-time PCR assay in CNS tissue samples.

RESULTS

EBV DNA was detected in 17% (18 of 106) of tumors tissue samples and 6.4% (2 of 32) of control samples. according to results, there was a significant relationship between the presence of EBV-DNA with CNS tumors. Additionally, the expression level of miR-122 was significantly downregulated in the EBV-positive sample compared to that of the EBV-negative sample. Also, the level of EBV-BART1-3p expression was significantly higher in EBV-positive tumors samples than EBV-positive normal samples.

CONCLUSION

The results of this study suggest that the EBV could change the condition of cancer cells by altering the expression of miR-122 and EBV-BART1-3p and maybe contribute to the development of cancer cells. However, the role of viral infections in CNS cancer requires further studies. <br />.

Possible Oncogenic Viruses Associated with Lung Cancer

Lung cancer is the most common cause of cancer death worldwide. Tobacco smoking is the most predominant etiology for lung cancer. However, only a small percentage of heavy smokers develop lung cancer, which suggests that other cofactors are required for lung carcinogenesis. Viruses have been central to modern cancer research and provide profound insights into cancer causes. Nevertheless, the role of virus in lung cancer is still unclear. In this article, we reviewed the possible oncogenic viruses associated with lung cancer.

Merkel cell polyomavirus and non-Merkel cell carcinomas: guilty or circumstantial evidence?

Merkel cell polyomavirus (MCPyV) is the major causative factor of the rare but aggressive cancer, Merkel cell carcinoma (MCC). Two characteristics of MCPyV-positive MCCs are integration of the viral genome and expression of a truncated version of one of its oncogenic proteins, namely large T antigen. The strong association of MCPyV with MCC development has incited researchers to further investigate a possible role of this virus in other cancers. However, many of the examples displaying the presence of the virus in the various non-MCC cancers are not able to clearly demonstrate a direct connection between cellular transformation and the presence of the virus. The prevalence of the virus is significantly lower in non-MCC cancers compared to MCCs, with a lower level of viral load and sparse viral protein expression. Moreover, the state of the viral genome, and whether a truncated large T antigen is expressed, has rarely been investigated. Nonetheless, considering the strong oncogenic potential of MCPyV proteins in MCC, the plausible contribution of MCPyV to transformation and cancer growth in non-MCC tumors cannot be ruled out. Furthermore, the absence of MCPyV in cancers does not exclude a hit-and-run mechanism, or the oncoproteins of MCPyV may potentiate the neoplastic process mediated by co-infecting oncoviruses such as high-risk human papillomaviruses and Epstein-Barr virus. The current review is focusing on the available data describing the presence of MCPyV in non-MCC tumors, with an aim to provide a comprehensive overview of the corresponding literature and to discuss the potential contribution of MCPyV to non-MCC cancer in light of this.

Human Polyomaviruses in the Cerebrospinal Fluid of Neurological Patients

BACKGROUND

Central nervous system (CNS) infections by human polyomaviruses (HPyVs), with the exception of JC (JCPyV), have been poorly studied.

METHODS

In total, 234 cerebrospinal fluid (CSF) samples were collected from patients affected with neurological disorders. DNA was isolated and subjected to quantitative real-time PCR (Q-PCR) for the detection of six HPyVs: JCPyV, BKPyV, Merkel cell PyV (MCPyV), HPyV6, HPyV7, and HPyV9. Where possible, the molecular characterization of the viral strains was carried out by nested PCR and automated sequencing.

RESULTS

JCPyV was detected in 3/234 (1.3%), BKPyV in 15/234 (6.4%), MCPyV in 22/234 (9.4%), and HPyV6 in 1/234 (0.4%) CSF samples. JCPyV was detected at the highest (p < 0.05) mean load (3.7 × 10⁷ copies/mL), followed by BKPyV (1.9 × 10⁶ copies/mL), MCPyV (1.9 × 10⁵ copies/mL), and HPyV6 (3.3 × 10⁴ copies/mL). The noncoding control regions (NCCRs) of the sequenced viral strains were rearranged.

CONCLUSIONS

HPyVs other than JCPyV were found in the CSF of patients affected with different neurological diseases, probably as bystanders, rather than etiological agents of the disease. However, the fact that they can be latent in the CNS should be considered, especially in immunosuppressed patients.

Droplet-digital PCR assay to detect Merkel cell polyomavirus sequences in chorionic villi from spontaneous abortion affected females

Droplet-digital polymerase chain reaction (ddPCR) technique was set up to detect/quantify Merkel cell polyomavirus (MCPyV) DNA in clinical specimens, including chorionic villi and peripheral blood mononuclear cells (PBMCs) from spontaneous abortion (SA)-affected females. This ddPCR assay showed high accuracy, sensitivity, and specificity in detecting MCPyV DNA cloned in a recombinant plasmid vector, the control. ddPCR was extended to MCPyV DNA to investigate/quantify its sequences in clinical samples. Overall, 400 samples were analyzed, that is, 100 chorionic villi and 100 PBMCs, from SA females (n = 100), the cases, and 100 chorionic villi and 100 PBMCs from females who underwent voluntary pregnancy interruption (VI, n = 100), the control. MCPyV DNA was detected in 4/100 (4%) and 5/100 (5%) of SA and VI chorionic villi, respectively. The mean viral DNA load was 1.99 ( ± 0.94 standard mean deviation [SD]) copy/10⁴ cells in SA and 3.02 ( ± 1.86 [SD]) copy/10⁴ cells in VI. In PBMCs, MCPyV DNA was revealed in 9/100 (9%) and 14/100 (14%) of SA and VI, with a mean of 2.09 ( ± 1.17 [SD]) copy/10⁴ cells and 4.09 ( ± 4.26 [SD]) copy/10⁴ cells in SA and VI, respectively. MCPyV gene expression analysis by quantitative PCR for the large T antigen (LT) and viral capsid protein 1 (VP1) showed their mRNAs in 2/4 (50%) SA- and 2/5 (40%) VI-MCPyV-positive samples. MCPyV DNA was detected/quantified using the ddPCR technique, in chorionic villi and PBMCs from SA and VI. In our experimental conditions, ddPCR provided a powerful tool to detect/quantify MCPyV DNA sequences in clinical samples.

Viral Sequences Detection by High-Throughput Sequencing in Cerebrospinal Fluid of Individuals with and without Central Nervous System Disease

Meningitis, encephalitis, and myelitis are various forms of acute central nervous system (CNS) inflammation, which can coexist and lead to serious sequelae. Known aetiologies include infections and immune-mediated processes. Despite advances in clinical microbiology over the past decades, the cause of acute CNS inflammation remains unknown in approximately 50% of cases. High-throughput sequencing was performed to search for viral sequences in cerebrospinal fluid (CSF) samples collected from 26 patients considered to have acute CNS inflammation of unknown origin, and 10 patients with defined causes of CNS diseases. In order to better grasp the clinical significance of viral sequence data obtained in CSF, 30 patients without CNS disease who had a lumbar puncture performed during elective spinal anaesthesia were also analysed. One case of human astrovirus (HAstV)-MLB2-related meningitis and disseminated infection was identified. No other viral sequences that can easily be linked to CNS inflammation were detected. Viral sequences obtained in all patient groups are discussed. While some of them reflect harmless viral infections, others result from reagent or sample contamination, as well as index hopping. Altogether, this study highlights the potential of high-throughput sequencing in identifying previously unknown viral neuropathogens, as well as the interpretation issues related to its application in clinical microbiology.

Association between human papillomavirus infection and prostate cancer: A global systematic review and meta-analysis

Although an increasing number of studies have been conducted to evaluate the association between human papillomavirus (HPV) infections and distribution of HPV types worldwide with the risk of prostate cancer (PC), the results remain inadequate. Hence, we investigated the association between HPV infection and PC risk using a meta-analysis. Relevant studies from January 1990 to December 2016 were searched in PubMed, Web of sciences, and Scopus databases. Pooled odds ratio (OR) and their corresponding 95% confidence interval (CI) were calculated to find the association between the prevalence of HPV and prostate cancer risk. To do so, data from 24 studies with 5546 prostate cancer cases were pooled in order to evaluate the heterogeneity of chief parameters including study region, specimen type, HPV DNA source, detection technique, publication calendar period, and Gleason score. All statistical analyses were performed using STATA 11 and MedCalc 13. A significant positive association was found between HPV infection and PC risk (OR = 1.281; P = 0.026). The genotype 16 was more frequently found in patients with PC which significantly increased the cancer risk (OR = 1.60; P < 0.001). Age 65 and older could significantly escalate PC risk (OR = 3.564; P < 0.001). Our results clearly favor the potential pathogenetic link between HPV infection and increased risk of PC affirming that HPV infections could play a part in the risk of PC.

Molecular survey on Merkel cell polyomavirus in patients with colorectal cancer

Background: Merkel cell polyomavirus (MCV) has been associated with Merkel cell carcinoma (MCC) in humans, and its role in other human cancers is under investigation. The aim of this study was to investigate MCV genome infection in patients with colorectal cancer (CRC).Methods: This retrospective, case-control study used archived formalin-fixed, paraffin-embedded (FFPE) tissue samples from colorectal cancer patients (cases) and matched healthy subjects (controls) diagnosed by an expert pathologist from hospitals affiliated with Iran University of Medical Sciences, Tehran, Iran from 2011 to 2016. After DNA extraction with a QIAamp® DNA FFPE Tissue Kit, real-time polymerase chain reaction (PCR) was used for diagnosis. A positive control was produced by cloning with the Generay Biotechnology system. SPSS v.22 was used for analysis of demographic variables.Results: There were 157 participants included in the study: 66 were cases and 91 were controls. Their mean ages (±SD) were 59.35±14.48 and 57.21±14.66, respectively. The proportion of males was 57.6% in the case group and 57.1% in the control group. None of the samples were positive for MCV expression by real-time PCR assay. Association was detected between males with CRC and tumor location in the rectum and between males with CRC and the mucinous tumor type.Conclusion: None of the tissues from the CRC or non-cancerous control groups were positive for MCV genome infection, although a low viral load, the sample type, or the method of use should not be neglected. Further studies are recommended to obtain more comprehensive results.

No Evidence for an Association between JC Polyomavirus Infection and Gastroduodenal Diseases

Background

Helicobacter pylori (HP) infection is one of the hypothesized infectious etiologies of gastric cancer (GC) and other gastroduodenal diseases. It was suggested that other infectious agents, including oncogenic viruses, may increase the risk of gastroduodenal diseases. A number of reports regarding JC polyomavirus (JCPyV) have shown that JCPyV could be implicated in colorectal cancer and gastrointestinal carcinogenesis.

Objective

The current investigation aimed to investigate whether JCPyV could have any association with the pathogenesis of gastroduodenal diseases either alone or together with HP.

Methods

A total of 237 fresh or formalin-fixed and paraffin-embedded gastroduodenal samples were examined by quantitative real-time polymerase chain reaction targeting the JCPyV large tumor antigen (LTag) oncogene, and viral load was determined as viral copy number/cell.

Results

In total, 2 out of 237 samples (0.8%) were positive for JCPyV LTag DNA. One positive sample derived from diffuse-type gastric adenocarcinoma (6.8 × 10^-3 copies/cell) and other JCPyV-positive sample obtained from a patient with gastritis (2.5 × 10^-3 copies/cell) were recorded. Both JCPyV-positive samples were negative for HP infection.

Conclusion

This study suggests no association between JCPyV infection and GC or other gastroduodenal diseases. The very low frequency of JCPyV LTag sequences in GC is an important aspect that weakens the hypothesis of the pathogenic role of JCPyV in gastric tumor induction.

Low viral load of Merkel cell polyomavirus in Iranian patients with head and neck squamous cell carcinoma: Is it clinically important?

Recent studies show that the human Merkel cell polyomavirus (MCPyV) may be involved in causing cancer. The objective of this study was to assess the impact of MCPyV on the development of head and neck squamous cell carcinoma (HNSCC). In total, 50 paraffin-embedded HNSCC biopsy samples and 50 adjacent non-cancerous samples were evaluated for the presence of MCPyV DNA and RNA. Among patients, the five most frequent histopathologic sites were the tongue (22.0%), lip (16.0%), submandibular (14.0%), cheek (14.0%), and throat (14.0%). MCPyV DNA was positive in eight (16.0%) samples. The median MCPyV LT-Ag copy number in the eight positive samples and in one non-cancerous sample was 4.8 × 10^-3 and 2.6 × 10^-5  copies/cell, respectively. Quantification of MCPyV LT-Ag revealed increased expression in stage III (5.6 × 10^-3  copies/cell) than in the other stages. The MCPyV DNA load in different stages of HNSCC was also statistically significant (P = 0.027). The viral load was low, suggesting that only a fraction of cancerous cells is infected. This result provides evidence confirming the presence of MCPyV in a subset of Iranian patients with HNSCCs, but further studies needed to confirm our findings.

Comprehensive analysis of Iranian reports of pediatric central nervous system tumors

PURPOSE

Iran lacks a national registry reporting the data of central nervous system (CNS) tumors in children. Consequently, treatment success and failure rates are unknown, and a centralized system for disease-management recommendations does not exist.

METHODS

To critically evaluate the current state of pediatric CNS tumor studies and reporting in Iran, we performed an extensive retrospective analysis of all known reports identified with multiple search engines.

RESULTS

Of 409 initially retrieved articles, we evaluated 123 matching our inclusion criteria. We further narrowed these reports to 74 by excluding studies pertaining to adult patients only, non-CNS tumors, or brain metastases. We also excluded studies that were performed outside of Iran or that did not contain relevant data from our analysis. We divided the remaining studies into those describing exclusively pediatric patients (3484 patients) and those describing mixed populations of adults and children (18,641 patients). In total, our analysis included 22,125 patients.

CONCLUSIONS

We identified many limitations in the reporting of studies describing the treatment or prevalence of CNS tumors in children in Iran. Our results may guide future efforts in Iran to improve the care for children with CNS tumors and may provide a valuable template for other comprehensive country- and disease-specific retrospective analyses.

Evaluation of Merkel cell polyomavirus in non-small cell lung cancer and adjacent normal cells

Several risk factors have been linked to lung cancer (LC). Nevertheless, a viral etiology has been mentioned for a subset of patients developing LC. The aim of this study was to evaluate the effect of Merkel cell polyomavirus (MCPyV) on developing non-small cell lung cancer (NSCLCs). In total, 96 paraffin-embedded NSCLC biopsies and 96 adjacent non-LC normal specimens were analyzed by quantitative real-time polymerase chain reaction (PCR) for the existence of the MCPyV DNA and the expressions of RNA transcripts. Among the 96 enrolled participants, 42 patients were adenocarcinomas (ADs) and 54 patients were squamous cell carcinoma (SCC). Of the 42 ADs, MCPyV DNA was determined in 15 (35.7%) samples and of the 54 SCC, MCPyV DNA was detected in 22 (40.7%) samples. Only one non-cancerous sample in SCC subjects was positive for MCPyV LT-Ag DNA load (0.216 × 10^-3). In MCPyV-positive subjects, the median MCPyV copy number was higher in the patients with ADs (0.016 × 10^-3 copies/cell) compared to SCCs (0.005 × 10^-3 copies/cell); but this difference was not statistically significant (P = 0.913). In the seven stages of LC, the MCPyV LT-Ag was quantified in stage IV (0.204 × 10^-3 copies/cell) more than in other stages. There was statistically significant difference between stages of cancer and MCPyV LT-Ag DNA load (P = 0.002). These results revealed for the first time the presence of MCPyV in a subset of patients with NSCLCs in Iran. Further studies should be carried out to clarify the role of MCPyV in lung carcinogenesis.

Detection of Merkel Cell Polyomavirus and Human Papillomavirus in Esophageal Squamous Cell Carcinomas and Non-Cancerous Esophageal Samples in Northern Iran

Human papillomavirus (HPV) infection is one of the hypothesized causes of esophageal squamous cell carcinoma (ESCC), but the etiological association remains uncertain. It was postulated that other infectious agents together with HPV may increase the risk of ESCC. The current investigation aimed to explore the presence of a new human tumor virus, Merkel cell polyomavirus (MCPyV), together with HPV in ESCC tumors and non-cancerous esophageal samples in northern Iran. In total, 96 esophageal samples (51 with ESCC, and 45 without esophageal malignancy) were examined. HPV DNA was detected in esophageal specimens of 16 out of the 51 ESCC cases (31.4 %) and 20 out of the 45 non-cancerous samples (44.4 %). Untypable HPV genotypes were recognized in high rates in cancerous (75.0 %) and non-cancerous (55.0 %) esophageal specimens. MCPyV DNA was detected in esophageal specimens of 23 out of the 51 ESCC cases (45.1 %) and 16 out of the 45 non-cancerous samples (35.6 %). The mean MCPyV DNA copy number was 1.0 × 10(-5) ± 2.4 × 10(-5) and 6.0 × 10(-6) ± 1.3 × 10(-5) per cell in ESCC cases and non-cancerous samples, respectively. There was no statistically significant difference between cancerous and non-cancerous samples regarding mean MCPyV DNA load (P = 0.353). A bayesian logistic regression model adjusted to the location of esophageal specimen and MCPyV infection, revealed a significant association between HPV and odds of ESCC (OR, 2.45; 95 % CI: 1.01-6.16). This study provides the evidence of the detection of the MCPyV DNA at a low viral copy number in cancerous and non- cancerous esophageal samples.

Human BK Polyomavirus-The Potential for Head and Neck Malignancy and Disease

Members of the human Polyomaviridae family are ubiquitous and pathogenic among immune-compromised individuals. While only Merkel cell polyomavirus (MCPyV) has conclusively been linked to human cancer, all members of the polyomavirus (PyV) family encode the oncoprotein T antigen and may be potentially carcinogenic. Studies focusing on PyV pathogenesis in humans have become more abundant as the number of PyV family members and the list of associated diseases has expanded. BK polyomavirus (BKPyV) in particular has emerged as a new opportunistic pathogen among HIV positive individuals, carrying harmful implications. Increasing evidence links BKPyV to HIV-associated salivary gland disease (HIVSGD). HIVSGD is associated with elevated risk of lymphoma formation and its prevalence has increased among HIV/AIDS patients. Determining the relationship between BKPyV, disease and tumorigenesis among immunosuppressed individuals is necessary and will allow for expanding effective anti-viral treatment and prevention options in the future.