Human papillomavirus and Epstein-Barr virus infection in benign thyroid lesions

INTRODUCTION

The objective was to investigate the correlation between Epstein-Barr virus (EBV) and human papillomavirus (HPV) infection in the development of benign thyroid lesions.

MATERIAL AND METHODS

29 cases of Hashimoto's thyroiditis (HT), 133 cases of thyroid adenoma, and 34 cases of HT with thyroid adenoma paraffin embedded tissue samples were used for EBV and HPV quantitative detection.

RESULTS

None of the tissue samples carried HPV DNA. In HT tissue samples, the positive rate of EBV was 55.2% (16/29). In thyroid adenoma tissue samples, the positive rate was 37.6% (50/133). In HT combined with thyroid adenoma tissue samples, the positive rate of EBV was 67.6% (23/34). There was no correlation between EBV infection and clinical features such as age and gender.

CONCLUSION

The occurrence and development of benign thyroid lesions are closely related to EBV infection. HT combined with thyroid adenoma may be more susceptible to EBV infection than simple HT and thyroid adenoma, which provides a new idea for the diagnosis and treatment of benign thyroid lesions.

Inflammatory infiltrates in parathyroid tumors

CONTEXT

Inflammatory infiltrates are sometimes present in solid tumors and may be coupled to clinical behavior or etiology. Infectious viruses contribute to tumorigenesis in a significant fraction of human neoplasias.

OBJECTIVE

Characterize inflammatory infiltrates and possible viral transcription in primary hyperparathyroidism.

DESIGN

From the period 2007 to 2016, a total of 55 parathyroid tumors (51 adenomas and 4 hyperplasias) with prominent inflammatory infiltrates were identified from more than 2000 parathyroid tumors in the pathology archives, and investigated by immunohistochemistry for CD4, CD8, CD20 and CD45 and scored as +0, +1 or +2. Clinicopathological data were compared to 142 parathyroid adenomas without histological evidence of inflammation. Transcriptome sequencing was performed for 13 parathyroid tumors (four inflammatory, 9 non-inflammatory) to identify potential viral transcripts.

RESULTS

Tumors had prominent germinal center-like nodular (+2) lymphocytic infiltrates consisting of T and B lymphocytes (31%) and/or diffuse (+1-2) infiltrates of predominantly CD8+ T lymphocytes (84%). In the majority of cases with adjacent normal parathyroid tissue, the normal rim was unaffected by the inflammatory infiltrates (96%). Presence of inflammatory infiltrates was associated with higher levels of serum-PTH (P = 0.007) and oxyphilic differentiation (P = 0.002). Co-existent autoimmune disease was observed in 27% of patients with inflammatory infiltrates, which in turn was associated with oxyphilic differentiation (P = 0.041). Additionally, prescription of anti-inflammatory drugs was associated with lower serum ionized calcium (P = 0.037).

CONCLUSIONS

No evidence of virus-like sequences in the parathyroid tumors could be found by transcriptome sequencing, suggesting that other factors may contribute to attract the immune system to the parathyroid tumor tissue.

Detection of human papillomavirus infection by molecular tests and its relation to colonic polyps and colorectal cancer

Objectives:

To prospectively examine the association between human papilloma virus (HPV) colonization of the colonic mucosa and the development of colorectal polyps (CRPs), and colorectal cancer (CRC) in Saudi Arabia.

Methods:

A case control study was performed between January 2013 and December 2014. All eligible patients underwent standard diagnostic colonoscopy. Patients with polyps or colorectal cancer were considered cases, while those with any other endoscopic findings were controls. Biopsy samples from polyps and tumors, and/or from normal colonic mucosa were acquired. Human papilloma virus colonization was detected using a hybrid capture technique of samples taken from both normal tissue, and CRPs and CRC. The association between HPV and CRPs/CRC was evaluated.

Results:

A total of 132 patients were recruited. The mean age was 53 (±15.9) years. Sixty patients had endoscopically detectable CRPs/CRC, and 72 had either inflammation or normal endoscopic evaluations. Only 4 (0.8%) of the 132 samples that were collected and analyzed were positive for the HPV gene. Statistical analysis did not identify any significant association between HPV colonization and the presence of CRPs/CRC. The only significant predictor of detecting CRPs/CRC on colonoscopy was symptomatic presentation (odds ratio=11.072, 95% confidence interval 4.7-26.2, p<0.001).

Conclusion:

Human papilloma virus colonic colonization is rare in Saudi Arabia. An association between HPV colonization and CRP/CRC development could not be identified in this cohort of patients.

Molecular evidence of high-risk human papillomavirus infection in colorectal tumours from Cuban patients

The association between colorectal cancer and human papillomavirus (HPV) infection is still unproven. The aim of this study was to investigate the presence of high-risk HPV (HR-HPV) DNA in colorectal tissues from Cuban patients. A total of 63 colorectal formalin-fixed paraffin-embedded tissues were studied (24 adenocarcinoma, 18 adenoma, and 21 colorectal tissues classified as benign colitis). DNA from colorectal samples was analysed by quantitative real-time polymerase chain reaction to detect the most clinically relevant high HR-HPV types (HPV-16, -18, -31, -33, -45, -52, and -58). Associations between histologic findings and other risk factors were also analysed. Overall, HPV DNA was detected in 23.8% (15/63) of the samples studied. Viral infections were detected in 41.7% of adenocarcinoma (10/24) and 27.7% of adenoma cases (5/18). HPV DNA was not found in any of the negative cases. An association between histological diagnosis of adenocarcinoma and HPV infection was observed (odd ratio = 4.85, 95% confidence interval = 1.40-16.80, p = 0.009). The only genotypes identified were HPV 16 and 33. Viral loads were higher in adenocarcinoma, and these cases were associated with HPV 16. This study provides molecular evidence of HR-HPV infection in colorectal adenocarcinoma tissues from Cuban patients.

Evidence for possible role of toll-like receptor 3 mediating virus-induced progression of pituitary adenomas

Tumor-related viruses are known to be involved in initiation and progression of certain tumors. However, the relationship between virus and pituitary adenomas (PAs) remains unknown. Here, we investigated infection status of three types of viruses (HPV16, HHV6B and HSV1) and expression level of toll-like receptor 3 (TLR3) in 60 human PA samples. We also determined the role of TLR3 signaling pathway on a PA cell line (GH3). We firstly found that positive rates of HPV16 and HHV6B infection were significantly higher in invasive PA samples than in noninvasive samples (P < 0.01). Similarly, TLR3 mRNA and protein expression also increased in invasive PA samples (P < 0.01). In vitro analysis indicated that GH3 cell proliferation and survival were enhanced by TLR3 activation, which was accompanied by NF-κB activation. Our data indicate that HPV16 and HHV6B viruses may be involved in promoting the progression of PA by activating the TLR3 signaling pathway.

Altered expression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) during gastric carcinogenesis and its clinical implications on gastric cancer

DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is a 465-kDa catalytic subunit of DNA-PK, a DNA repair apparatus. DNA-PKcs has been reported to be a tumor suppressor, but details of its expression in human cancer are controversial. To determine the protein expression and clinical implications of DNA-PKcs in gastric carcinogenesis and cancer progression, we evaluated its expression status by immunohistochemistry in 122 non-neoplastic gastric mucosa samples, and in 115 gastric adenomas and 564 consecutive gastric cancers. In addition, we evaluated the clinicopathologic characteristics of gastric cancers showing altered DNA-PKcs expression, and performed microsatellite instability (MSI) analysis at BAT-26 and frameshift mutation analysis of DNA-PKcs. DNA-PKcs expression was negative in foveolar epithelium of normal gastric mucosal tissues, but was positive in most Helicobacter pylori-associated gastritis, intestinal metaplasia and gastric adenoma tissues. In gastric cancers, negative expression of DNA-PKcs was found in 114 of the 564 (20.2%) cancers and was significantly associated with intratumoral neutrophils, MSI-high (H) phenotype, tumor progression, and poor patient survival (p<0.05). Frameshift mutations of (A)10 mononucleotide repeats in DNA-PKcs were found in 24.3% of MSI-H gastric cancers and these were associated with negative expression of DNA-PKcs. Although patients with MSI-H gastric cancers were found to have a lower risk of lymph node metastasis, gastric cancers harboring the (A)10 mutation of DNA-PKcs were found to have a higher risk of lymph node metastasis. In conclusion, the expression of DNA-PKcs was found to be altered during gastric carcinogenesis and negative DNA-PKcs expression was associated with gastric cancer progression. The (A)10 frameshift mutation of DNA-PKcs in gastric cancers was a target of defective mismatch repair, and was associated with lymph node metastasis.

Detection of JC virus DNA sequences in colorectal cancers in Japan

JC virus (JCV), a ubiquitous polyoma virus that commonly infects humans, was first identified as the etiologic agent for the fetal demyelinating disease, progressive multifocal leukoencephalopathy. Recently, a number of reports have documented detection of JCV in samples derived from several types of neural as well as non-neural human tumors. It has been suggested that oncogenicity of JCV depends on a T antigen having a strict structural homology to the T antigen of simian virus 40. To clarify whether JCV might have a potential role with regard to colorectal cancers, we investigated the presence of its genome in a series of cases along with colorectal adenomas and normal colonic mucosa, targeting T antigen, VP and agnoprotein by nested polymerase chain reaction and Southern blotting and T antigen by immunohistochemistry. While VP and agnoprotein were not found in any of the samples examined, T antigen was detected in 6 of 23 colorectal cancers (26.1%) and 1 of 21 adenomas (4.8%), but none of 20 samples of normal colonic mucosa. No clear and diffuse staining with anti-T-antigen antibodies (1:100) could be detected, and there was no correlation with CD20-positive cells, which might have indicated JCV latent infection of B lymphocytes. Presence of T antigen did not influence clinicopathological variables, including survival. In one colonic cancer case positive for T antigen together with lymph node metastasis, DNA extracted from cancer cells in the lymph node revealed no detection of T antigen. Our results are in the intermediate position between the high T antigen rate (81%) in one report and the lack of it (0%) in another focused on colon cancers. It was concluded that T antigen might be integrated in cancer cells in approximately one fourth of Japanese colon cancer cases without clear and diffuse expression of the protein, suggesting a possible role in oncogenesis which might involve a hit-and-run mechanism.

Assessment of JC polyoma virus in colon neoplasms

PURPOSE

Research data have recently emphasized an intriguing association of JC polyoma virus with colon carcinogenesis. Tumorigenicity of JC virus is attributed to the T-antigen of its Mad-1 variant. Controversy arose when another research group did not confirm this association. The purpose of this study was to detect JC virus in a series of colon neoplasms from Greek patients.

METHODS

A nested polymerase chain reaction assay was used to detect JC virus in 80 cancerous, 25 adenomatous specimens of large bowel, and 20 colonoscopic biopsy samples from normal patients without colorectal neoplasia. Quantitation of JC virus DNA was performed by real-time polymerase chain reaction.

RESULTS

JC polyoma virus nucleotide sequence was detected in 61 percent of colon adenocarcinomas and in 60 percent of adenomas, at a viral load of 9 x 10(3) to 20 x 10(3) copies/microg DNA. Adjacent normal mucosa in 35 positive colon adenocarcinoma specimens, and normal mucosa from six patients of the control group, had low viral loads (50-450 copies/microg DNA).

CONCLUSIONS

JC polyoma virus genome is present in colon neoplasms. JC virus detection in adenomas at comparable viral loads to malignant tumors suggests its implication at early steps of colonic carcinogenesis. Taking into consideration other published data, infection of colonic epithelium with JC virus might be a prime candidate for a role in chromosomal and genomic instability.

Lentiviral vectors efficiently transduce human gonadotroph and somatotroph adenomas in vitro. Targeted expression of transgene by pituitary hormone promoters

Despite important advances in human therapeutics, no specific treatment for both non-functioning gonadotroph and resistant somatotroph adenomas is available. Gene transfer by viral vectors can be considered as a promising way to achieve a specific and efficient treatment. Here we show the possibility of efficient gene transfer in human pituitary adenoma cells in vitro using a human immunodeficiency virus (HIV)-type 1-derived vector. Using enhanced green fluorescent protein (eGFP) gene as a marker placed under the phosphoglycerate kinase (PGK) promoter, gonadotroph and somatotroph adenomas were transduced even with moderate viral loads. The expression started at day 2, reached a peak at day 5, and it was still present at day 90. For targeting somatotroph and gonadotroph adenomas, human growth hormone (GH) promoter (GH -481, +54 bp) and two fragments of the human glycoprotein hormone alpha-subunit promoter (alpha-subunit 1 -520, +33 bp, and alpha-subunit 2 -907, +33 bp) were tested. In gonadotroph adenomas, the percentage of identified fluorescent cells and the fluorescence intensity analyzed by fluorescence-activated cell sorting indicated that the strength of the alpha-subunit 1 and alpha-subunit 2 promoters were comparable to that of the PGK promoter. Primary cultures of rat pituitary cells showed that alpha-subunit 1 is more selective to thyreotroph and gonadotroph phenotypes than alpha-subunit 2. GH promoter activity appeared weak in somatotroph adenomas. The human GH enhancer did not increase the GH promoter activity at all but the human prolactin promoter (-250 bp) allowed 4-fold more fluorescent cells to be obtained than the GH promoter. Several cell lines appeared too permissive to test cell-specificity of pituitary promoters. However, on human non-pituitary cell cultures, the tested pituitary promoters seemed clearly selective to target endocrine pituitary phenotypes. This study gives a starting point for a gene-therapy program using lentiviral vectors to transfer therapeutic genes in human pituitary adenomas.

Investigation of Epstein-barr virus in Chinese colorectal tumors

AIM: To elucidate the association of Epstein-Barr virus (EBV) with colorectal tumors and to demonstrate whether infection of EBV existed in different stages of colorectal tumors involves in the carcinogenesis.

METHODS: One hundred and thirty paraffin-embedded tissues of colorectal tumors were classified into 5 groups: 26 adenomas, 23 adenomas complicated with dysplasia, 22 adenomas complicated with carcinomatous, 36 colon carcinoma and 23 HNPCC, were examined by PCR, IHC and ISH, respectively.

RESULTS: EBV DNA was detected by PCR in 26 cases out of the 130 specimens, including 5 cases of adenomas, 5 adenomas complicated with dysplasia, 5 adenomas complicated with carcinomatous, 7 colorectal carcinoma and 4 HNPCC. IHC detection showed the expression of LMP1 in 7 cases, including 1 adenoma, 1 adenoma with dysplasia, 1 HNPPC, 2 adenomas complicated with carcinomatous, and 2 colorectal carcinomas. The expression of EBER1 detected by ISH was positive in 6 cases, including 1 adenoma with dysplasia, 2 adenomas complicated with carcinomatous and 3 colorectal carcinomas. There were no significant differences among the results of PCR, IHC and ISH in the 5 groups. In all cases of HNPCC, none of the tumor cells showed positive signals of EBER1, but some EBV-positive tumor infiltrating lymphocytes were found in 2 of 23 cases.

CONCLUSION: Our results showed that infection of EBV exists in human colorectal tumors, which indicates that EBV may be involved in the carcinogenesis of colorectal tumors but does not play an important role. The mechanisms need to be clarified further.

Characteristics of clear cells and Toker cells in the epidermis of underlying nipple duct adenoma

Clinically, it is difficult to differentiate between nipple duct adenomas (NDAs) and Paget's disease of the nipple. These lesions share similar morphological and histological characteristics. Clear cell types present in NDA, epidermal clear cells (ECC) and Toker cells (TC), share immunoreactive similarities to Paget cells which can lead to confusion in classification. The aim of this study was to obtain information on the characteristics and histogenesis of ECC and TC, to distinguish these cells from Paget cells. Ten nipple epidermal with NDA were compared to 25 histologically normal nipples. Samples were analyzed for cytokeratins (CKs) 7, 8 and 18, carcinoembryonic antigen (CEA), c-erbB-2/HER2 expression and human papillomavirus (HPV-) DNA. In 13 out of 25 normal nipples the staining sequence demonstrated that ECC and TC cell types are immunoreactive with CKs 7, 8 and 18 in the basal region of the epidermis. In contrast, aggregated CKs 7, 8 and 18-immunoreactive ECC and TC were identified in the epidermal of 8 of the 10 NDA cases. In 2 cases, TC were continuous with the underlying NDA, suggesting that TC might be of ductal origin and migrate through the galactophorous ostia. In NDAs and 25 histologically normal nipples, ECC and TC were negative for CEA, c-erbB-2/HER2 and HPV-DNA. ECC and TC, normally present in the nipple epidermis, may proliferate and form aggregates in the presence of an underlying NDA. These cells show immunoreactivity for CKs 7, 8 and 18 but are negative for c-erbB-2/HER2, CEA and HPV-DNA and should not lead to the mistaken diagnosis of Paget's disease.

Epstein-Barr virus, p53 protein, and microsatellite instability in the adenoma-carcinoma sequence of the stomach

To elucidate the adenoma-carcinoma sequence in the stomach, we investigated Epstein-Barr virus (EBV) incorporation, p53 overexpression, and microsatellite instability (MSI) in gastric adenomas and carcinomas. The study involved 66 cases of gastric carcinomas within or adjacent to adenomas (adenoma-carcinoma cases), 81 cases of simple adenomas (without carcinoma), and 306 de novo carcinomas (without adenoma focus). EBV incorporation was revealed in 1 (1.5%) of the adenoma-carcinomas, in none of the adenomas, and in 17 (5.6%) of the de novo carcinomas. p53 overexpression was observed in 24.2% (16 of 66) of the adenomas in the adenoma-carcinoma cases and in 36.5% (23 of 63) of corresponding carcinomas (kappa = 0.63, P = 0.00). MSI was positive in 12.3% (8 of 65) of the adenomas in the adenoma-carcinoma cases and in 18.8% (12 of 64) of the corresponding carcinomas (kappa = 0.77, P = 0.00). In conclusion, EBV incorporation is not possibly associated with the gastric adenoma-carcinoma sequence, whereas the gastric adenoma-carcinoma sequence seems to be supported in terms of p53 overexpression or MSI. The transcriptional activation of EBV may occur relatively late (after the adenoma stage) in the gastric adenoma-carcinoma sequence.

Conditional liver-specific expression of simian virus 40 T antigen leads to regulatable development of hepatic neoplasm in transgenic mice

Adaptive epigenetic changes and toxicity often accompany constitutive expression of a transgene or knockout of an endogenous gene in mice. These considerations potentially limit the usefulness of transgenic technology in studying the in vivo functions of a gene. Using conditional gene expression technology, it is possible to override such restrictions to achieve temporal and tissue-specific manipulation of gene expression in vivo. Based on the tetracycline regulatory system, we established a binary transgenic model in which the conditional expression of two transgenes, SV40 T antigen (TAg) and lacZ, can be tightly regulated in the liver by administration of tetracycline. The mouse albumin or mouse major urinary protein promoter was used to achieve liver-specific expression of the tetracycline-responsive transcriptional activator (tTA) in one set of transgenic mice. These mice were crossed with transgenic mice carrying either TAg or lacZ under the control of the tTA-regulated promoter. Analyses of mice transgenic for both tTA and TAg (or lacZ) revealed that the liver-specific expression of the transgenes could be suppressed to undetectable levels and regulated in a reversible fashion by tetracycline administration and withdrawal. Mice with tTA and TAg transgenes developed hepatocellular adenomas and hyperplasia that could be prevented by continuous tetracycline administration. Our report demonstrates the value of this binary transgenic model in studying the physiological functions of any potential genes of interest in a liver-specific manner.

Papilloma virus and c-erbB-2 expression in diseases of the mammary nipple

PURPOSE

The detection of low/intermediate/high risk genital groups of human papillomavirus (HPV) in correlation with a growth-factor receptor c-erbB-2 in benign tumors of the mammary nipple.

MATERIALS AND METHODS

Ten nipple duct adenomas (NDAs) and twenty papillomas, all embedded in paraffin and taken from the breast, were analyzed for HPV DNA of the low- and high/intermediate-risk groups. Polymerase chain reaction (PCR) with HPV consensus primers (types 6/11/16/18/33) and dot-blot hybridization with type-specific primers were used for the detection of these HPV-DNA sequences. Indirect in situ PCR (ISPCR) was also used in one case of an HPV-DNA-positive papilloma. In addition, we examined c-erbB-2 oncogene expression in NDAs and central carcinomas of the mamma from an immunohistochemical perspective.

RESULTS

Using PCR and dot-blot hybridization we could not detect the gene sequences that are specific for the low- and high/intermediate-risk groups in any of the ten NDAs. Regarding the 20 cases of papilloma, a positive result for HPV types 6/11 was detected by indirect ISPCR; in one case in combination with a condyloma of the skin around the mammary nipple. The oncogene expression of c-erbB-2 displayed a strong signal in the papilloma cells and in the NDAs of the breast.

CONCLUSION

Our results showed that the HPV-DNA types of the low- and high/intermediate-risk groups are without relevance for the pathogenesis of benign diseases of the nipple. It was, therefore, not possible to establish a correlation between the oncogene expression of c-erbB-2 and the HPV-DNA types.

Pituitary neoplasia induced by expression of human neurotropic polyomavirus, JCV, early genome in transgenic mice

In recent years, there has been mounting evidence pointing to the association of polyomaviruses with a wide range of human cancers. The human neurotropic polyomavirus, JCV, infecting greater than 75% of the human population produces a regulatory protein named T-antigen which is expressed at the early phase of viral lytic infection and plays a critical role in completion of the viral life cycle. Furthermore, this protein has the ability to transform neural cells in vitro and its expression has been detected in several human neural-origin tumors. To further investigate the oncogenic potential of the JCV early protein in vivo, transgenic mice expressing JCV T-antigen under the control of its own promoter were generated. Nearly 50% of the animals developed large, solid masses within the base of the skull by 1 year of age. Evaluation of the location as well as histological and immunohistochemical data suggest that the tumors arise from the pituitary gland. As T-antigen is known to interact with several cell cycle regulators, the neoplasms were analysed for the presence of the tumor suppressor protein, p53. Immunoprecipitation/Western blot analysis demonstrated overexpression of wild-type, but not mutant p53 within tumor tissue. In addition, co-immunoprecipitation established an interaction between p53 and T-antigen and overexpression of p53 downstream target protein, p21/WAF1. This report describes the analysis of inheritable pituitary adenomas induced by expression of the human polyomavirus, JCV T-antigen in transgenic mice where T-antigen disrupts the p53 pathway by binding to and sequestering wild-type p53. This animal model may serve as a useful tool to further evaluate mechanisms of tumorigenesis by JCV T-antigen.

Calculus-producing and cytomegalovirus-infected nephrogenic adenoma of the bladder in a prepubertal renal transplant recipient

A 14-year-old prepubertal boy, a renal transplant recipient, was treated for a nephrogenic adenoma. His case is unique in that he is the second youngest renal transplant recipient diagnosed with a nephrogenic adenoma. In addition, the lesion was calculus producing, which has not been previously described, and contained cytomegalovirus inclusions, which has been described only once previously in association with a nephrogenic adenoma in a transplant patient.

Absence of Epstein-Barr virus encoded RNA and latent membrane protein (LMP1) in salivary gland neoplasms

A series of 55 (42 benign and 13 malignant) salivary gland tumours were investigated by immunohistochemistry, to detect Epstein-Barr virus (EBV) latent membrane protein (LMP1) and by in situ hybridization for EBV-encoded RNA. Non-neoplastic gland from all the patients with tumours and 15 control glands were also examined. All cases, both neoplastic and non-neoplastic were negative for LMP1 and failed to show any positive signal by in situ hybridization for EBV RNA. One undifferentiated carcinoma from a European patient was included in the group. These results confirm previous reports of an ethnic association between EBV and undifferentiated carcinomas of the salivary gland. They do not support an aetiological role for EBV in other salivary gland tumours.

[Clinical study of bilateral parotid tumors]

We studied retrospectively 212 patients with parotid tumors who were treated in our hospital between October 1981 and March 1998. One hundred seventy-two of the tumors were benign, and 40 of them were malignant. The tumors were bilateral in 13 patients. Since 1992, we have treated at least 1 bilateral parotid tumor patient per year, and the number of patients with bilateral parotid tumors has tended to increase. Histologically, adenolymphomas occurred in 11 patients, and there was one occurrence of pleomorphic adenoma and one occurrence of basal cell adenoma. Eighty-five percent of all bilateral parotid tumors were adenolymphomas, and the bilateral parotid tumors comprised twenty percent (11 of 53 patients) of all adenolymphomas that we encountered. Among the 13 patients with bilateral parotid tumors, 1 patient experienced them heterochronously. In 7 of the 13 patients the tumor on the opposite side was found by diagnostic imaging. One patient showed recurrence in both parotid glands 4 years after initial surgery. Comparing bilareral adenolymphomas with unilateral adenolymphomas, there was no significant difference in the age or sex of the patients. Regarding bilateral adenolymphoma, 4 patients showed a solitary tumor on either side, 4 patients showed a solitary tumor on one side and multiple tumors on the other side, and 4 patients showed multiple bilateral tumors. Regarding unilateral adenolymphoma, 38 patients showed solitary tumors and 4 patients showed multiple tumors. Bilateral adenolymphomas were more multicentric than unilateral adenolymphomas. Epstein-Barr virus-encoded RNA (EBER) was detected in 11 of the 12 bilateral adenolymphomas and in 18 of 35 patients with unilateral adenolymphoma, by in situ hybridization. EBER was detected more frequently in the multiple unilateral adenolymphomas than in the solitary unilateral adenolymphomas. Based on our experience, the bilateral parotid tumor is not rare. Care should be taken to observe the other side of the parotid gland with parotid tumors that are suspected adenolymphomas. Imaging may be helpful for the detection of bilateral tumors. A relationship may exist between Epstein-Barr virus and adenolymphoma multicentricity.

Sialadenoma papilliferum of the palate: case report and literature review

Sialadenoma papilliferum (SP) is a rare tumor of salivary gland ducts which bears a strong histologic resemblance to the more common syringocystadenoma papilliferum (SCAP). We report a case occurring on the palate of a 50-year-old man, and review the clinical and histologic features of this tumor. Because of the histologic similarities between these two tumors and squamous papillomas, polymerase chain reaction (PCR) for human papilloma virus (HPV) DNA was performed on this tumor and on two cases of SCAP, with negative results. To our knowledge, this is the first case report of SP in the dermatopathology literature.

Detection of polyomaviral DNA sequences in normal and adenomatous human pituitary tissues using the polymerase chain reaction

BACKGROUND

Tumor viruses are known to have a role in the pathogenesis of many types of benign and malignant human tumors. The possible roles of these viruses in the development of human pituitary tumors have not been investigated.

METHODS

The polymerase chain reaction was used to screen human pituitary tumors for human papillomaviral (HPV) and Polyomaviral DNA sequences. Sets of consensus primers, which are capable of amplifying HPV Types 16, 18, and 33 and polyomavirus BK, JC, and SV40, were used in these experiments.

RESULTS

Amplification products were not detected using HPV consensus primers in 30 tumors. Twenty-six of 30 tumors demonstrated an amplification product with polyomaviral primers that hybridized to SV40 and BK internal probes and was confirmed to be SV40 in one tumor by direct sequencing. Ten normal postmortem pituitary samples then were examined similarly with Polyomaviral consensus primers; 8 of 10 normal samples demonstrated a similar amplification product that also hybridized with SV40 and BK internal probes by Southern blotting. Polyomaviral DNA sequences in normal and tumor samples were not present at levels detectable by genomic Southern blotting. Expressed viral protein (large T antigen) was not demonstrated in positive samples by Western blot analysis.

CONCLUSIONS

These findings, that polyomaviral DNA sequences are detectable at low levels in certain normal tissues, are in agreement with those of other groups and, to the authors' knowledge, serve as the first report of polyomaviral latency in human pituitary tissue. A role for polyomaviruses in pituitary tumorigenesis could not be established in this analysis.

Detection of human papillomavirus DNA in colorectal carcinomas by polymerase chain reaction

Human papillomaviruses (HPVs) are associated with a number of benign and malignant neoplasms. To substantiate the relationship between HPV DNA and colorectal carcinomas, 70 carcinomas and 37 adenomas were analysed in this study. Specific types of HPV DNA in colorectal tumours were detected by polymerase chain reaction (PCR) and Southern blot hybridisation. HPV DNA was detected in 11 of 37 (29.7%) adenomas and in 52.9% 37 of 70 (52.9%) of carcinomas. The expression of HPV DNA in adenomas and carcinomas, especially that of HPV 16 in HPV positive cases (4 of 11 v 26 of 37), was significantly different (p < 0.05). There was no correlation, however, between HPV and the location, differentiation, stage, or survival of malignant neoplasms. These data suggest that HPV DNA, especially type 16, is associated with colorectal carcinogenesis.

ras, p53 and HPV status in benign and malignant prostate tumors

To study the role of ras, p53 genes and HPV virus (16 and 18) in the development of prostate cancer, we analyzed tissue sections from 27 patients affected with carcinomas (stages A to D) and from 24 patients with adenomas. Mutations of H, K and N-ras and p53 (exons 2-9) were studied by SSCP and DNA sequencing. Accumulation of p53 protein was studied by immunohistochemistry on tissue sections. Tumors were also analyzed for the presence of HPV16 and -18 sequences by PCR and DNA hybridization with sequence-specific oligonucleotides. No mutation was found in the three ras genes studied, either in carcinomas or adenomas. By SSCP analysis we identified p53 mutations in only 2 of 19 carcinomas studied, both in exon 7. Immunohistochemical results strongly correlate with the SSCP results: p53 protein was positive in tumors with p53 mutation but not in others; 32% of studied adenomas had detectable HPV16 DNA, while 53% of carcinomas were HPV16+. Among these I presented a p53 mutation. No HPV18 E6 sequence could be detected. Our data show that in prostate tumors from France, mutations of p53 and ras are rare events but that these tumors display detectable HPV16 DNA at a high frequency. The low incidence of p53 mutation, associated to a significant proportion of tumors showing HPV16 DNA, could suggest that in prostate cancer HPV16 infection could participate in p53 inactivation by E6.

Detection of human papillomavirus DNA in colorectal adenomas

OBJECTIVE

To assess the presence of different types of human papillomavirus (HPV) DNA in colorectal adenomas.

DESIGN

The extracted DNA of 109 formalin-fixed, paraffin-embedded tissue sections of colorectal adenomas were analyzed by polymerase chain reaction and Southern blot hybridization. The correlations of HPV types 6, 11, 16, 18, and 33 DNA with the histological patterns of adenomas were also analyzed.

RESULTS

Human papillomavirus DNA was detected in 28% of the adenomas. There were eight (21%) of 38 in tubular adenomas, 13 (33%) of 40 in tubulovillous adenomas, and 10 (32%) of 31 in villous adenomas. All HPV-6/11-positive cases were tubular or tubulovillous adenomas. However, most HPV-16 infections (8/12) were seen in villous adenomas. Human papillomavirus-positive adenomas included three (8%) of 38 that showed mild dysplasia, 10 (25%) of 40 that showed moderate dysplasia, and 18 (58%) of 31 that showed severe dysplasia.

CONCLUSION

The association of the histological type with HPV-16 and the association of the grade of epithelial dysplasia with HPV DNA were highly significant. These associations support the adenoma-carcinoma hypothesis. In addition, the results suggest that HPV infection may be an important factor for the development of colorectal neoplasia.