Malignant progression of laryngeal papilloma associated with human papilloma virus type 6 (HPV-6) DNA

Genomic diversity of HPV6 and HPV11 in recurrent respiratory papillomatosis: Association with malignant transformation in the lungs and clinical outcomes

Recurrent respiratory papillomatosis (RRP) is a rare, proliferative disease caused by human papillomavirus 6 (HPV6) and HPV11. RRP can occasionally spread and undergo malignant transformation. We analysed samples across time for five RRP patients with malignant transformation and four with highly recurrent, non-malignant RRP by applying high-throughput sequencing. Patients with malignant transformation were infected by HPV11_A1/A2, while most non-malignant cases were associated with HPV6. Transient multiple infections with HPV6 and HPV11 were found in two patients, and resolved later to single infections. Viral genome loads were homogeneous across groups (median = 78 viral genomes per human genome). Within-patient, we did not observe differences between the viral sequences in the papillomatous lesions and in the malignant tissue. Genetic analysis of the NLRP1 gene revealed no known mutations linked to idiopathic RRP, though some novel variants merit to be explored in larger cohorts. HPV11 infections appear associated with RRP malignant transformation in young patients. Multiple infections can occur in RRP, but within-patient viral diversity is minimal for a given genotype. Our results confirm the importance of viral genotype in disease prognosis and are consistent with growing evidence of HPV11 infections to be differentially associated with RRP malignant transformation in young patients.

E6 and E7 gene polymorphisms in human papillomavirus Type-6 identified in Southwest China

BACKGROUND

Human papillomavirus type-6 (HPV6) is the major etiological agent of anogenital warts both men and women. The present study aimed to characterize the genetic diversity among HPV6 in Southwest China, and to investigate the origin of, selective pressure experienced by, and impact of the resultantly identified genetic variants on the HPV6 secondary structure.

METHODS

Phylogenetic trees were constructed by Maximum-likelihood and the Kimura 2-parameters methods by Molecular Evolutionary Genetics Analysis version 6.0. The diversity of secondary structure was analyzed by PSIPred software. The selection pressures acting on the E6/E7 genes were estimated by Phylogenetic Analyses by Maximum Likelihood version 4.8 software.

RESULTS

HPV6 was the most prevalent low risk HPV type in southwest China. In total, 143 E6 and E7 gene sequences of HPV6 isolated from patients were sequenced and compared to GenBank HPV6 reference sequence X00203. The results of these analyses revealed that both the HPV6 E6 and E7 were highly conserved within the analyzed patient samples, and comprised only 3 types of variant sequence, respectively. Furthermore, the analysis of HPV6 E6 and E7 sequences revealed seven/five single-nucleotide mutations, two/four and five/one of which were non-synonymous and synonymous, respectively. The phylogenetic analyses of the E6 and E7 sequences indicated that they belonged to sub-lineage A1 and sub-lineage B1, whereas the selective pressure analyses showed that only the E7 mutation sites 4R, 34E, and 52F were positive selection.

CONCLUSIONS

HPV6 (detection rate = 13.10%) was very prevalent in southwest China, both the HPV6 E6 and E7 sequences were highly conserved within the analyzed patient samples in southwest China, indicating that the low risk HPV6 can adapt to the environment well without much evolution.

Squamous Cell Carcinoma Originating from Adult Laryngeal Papillomatosis: Case Report and Review of the Literature

Background

The malignant transformation of laryngeal papillomatosis (LP) into squamous cell carcinoma (SCC) can occur in up to 4% of LP cases. The low-risk HPV types 6 and 11 are those that are most commonly related to LP; however, high-risk HPV types may be present. The present study reviews the literature on cases of malignant transformation of LP in adults and reports a clinical case.

Case Report

A 47-year-old male patient exhibiting hoarseness for 4 months presented an exophytic lesion in the right palatine tonsil and a digitiform-like lesion in the right vocal fold. The biopsy revealed a well-differentiated SCC in the vocal cord, which showed a transition zone with a squamous papillomatous lesion. By using the chromogenic in situ hybridization (CISH) test, both lesions showed a positive result for high-risk HPV types 16 and 18 and negative for low-risk HPV types 6 and 11. The final diagnosis was SCC arising from LP. The patient underwent surgical treatment. After 36 months of follow-up, no signs of recurrence were observed.

Results

The literature review revealed 25 cases of malignant transformation into SCC of LP with adult onset. Of these, only 9 cases were assessed by CISH and/or PCR for HPV identification, of which 7 were positive. The current study focuses on the eighth case, suggesting the involvement of the high-risk HPV types in its pathogenesis.

Conclusions

LP is considered a benign lesion with the potential for malignant transformation, which reinforces the need for its early diagnosis and the constant monitoring of patients with LP.

HPV in Head and Neck Cancer-30 Years of History

The interesting history of papillomavirus (PV) research has been reviewed before. The history of human papillomavirus (HPV) in head and neck region starts in 1901 when the contagious transmission of warty lesions into the mouth via oral sex was described, although the confirmation of their viral etiology had to wait until 1907. Ullman was the first to associate the human wart virus with laryngeal warts. Parsons and Kidd described the natural history of oral PV infections in rabbits already in 1942, but these findings were corroborated in humans only recently. Koilocytotic atypia described by Koss and Durfee in 1956 was recognized as a sign of HPV infection in cervical precancer lesions only in 1976-1977 (Meisels and Fortin; Purola and Savia). This prompted systematic surveys of head and neck lesions for the detection of koilocytosis since the late 1970s, and the authors of this communication were the first to propose the HPV involvement in a subgroup of head and neck cancers. Brandsma and Abramson demonstrated HPV16 DNA in tonsillar SCCs in 1989. Since the early 2000s, HPV research of head and neck squamous cell carcinomas (HNSCC) has made impressive progress, confirming that the specific anatomic site plays a key role in determining the susceptibility to HPV infection. The most likely cancer sites associated with HPV are the base of the tongue and palatine tonsils, followed by oral cavity, larynx, and sinonasal mucosa. There is substantial geographic variation in HPV association with HNSCC. Patients with HPV-associated HNSCC are younger, and survival is better than in the absence of HPV.

Laryngeal Papillary Squamous Cell Carcinoma

Objective

Papillary squamous cell carcinoma has emerged as a distinct entity from the more common keratinizing squamous cell carcinoma. The basis behind this distinction relates not only to its histologic variation but also to its overall prognosis and survival. The objective of this study was to demonstrate the incidence, demographics, and long-term survival of laryngeal papillary squamous cell carcinoma (LPSCC) and how it relates to other laryngeal malignancies using a population-based database.

Study Design

Analysis of a population-based tumor registry.

Methods

The United States National Cancer Institute’s Surveillance, Epidemiology, and End Results registry was used to perform a retrospective analysis. Patients diagnosed with LPSCC from 1973 to 2011 were identified. Data endpoints extracted included patient demographics, incidence, and survival.

Results

Three-hundred seventy cases of LPSCC were identified, corresponding to 0.5% of all laryngeal tumors. There was a 3:1 male predilection, without a significant racial preference. Most tumors identified were localized (T1) and at stage 1. The 1-year, 5-year, and 10-year disease-specific survival (DSS) for LPSCC was 97.1%, 83.1%, and 73.9%, respectively, compared with 87.9%, 64.5%, and 50.5% for other laryngeal malignancies ( P values <.0001). Surgery was associated with a higher overall DSS in both LPSCC (87.4% vs 78.8%) and other laryngeal malignancies (70% vs 59.4%) when compared with other treatment modalities.

Conclusion

This analysis of the largest sample of LPSCC demonstrates a better prognosis for this pathology compared with other laryngeal malignancies.

HPV associated with recurrent respiratory papillomatosis

Papillomaviruses are members of the Papillomaviridae family. Over 150 HPV types have been identified. Recurrent respiratory papillomatosis (RRP) is a chronic condition caused by HPV characterized by recurrent papillomas of the respiratory tract, mainly the larynx. During the early stages, the condition presents with hoarseness, while more advanced disease presents with stridor and respiratory distress. There is no specific cure and treatment consists of repeated surgical procedures to remove the papillomas. Most patients eventually go into remission, but some suffer for many years with this condition, which may be fatal. HPV-6 and HPV-11 are the HPV types most commonly associated with RRP. Although most studies have found RRP due to HPV-11 to be more aggressive than disease due to HPV-6, the variability in disease aggressiveness is probably multifactorial. Information regarding the current epidemiology, molecular diversity and host immune responses is important for strategizing ways to reduce disease. Data on HPV genotypes associated with RRP would provide valuable information for vaccination programs to reduce the incidence of these genotypes in mothers and, in the long term, reduce the incidence of RRP in children. This review focuses on HPV-6 and HPV-11 as the HPV types that cause RRP, and discusses the viral genome and replication, clinical presentation of RRP, current techniques of diagnosis and genotyping, and the molecular diversity of HPV-6 and HPV-11.

Current concepts on human papillomavirus infections in children

Current evidence is strong enough to conclude that human papillomavirus (HPV) can be transmitted both sexually and non-sexually. The debate on HPV infections in children still continues but it is more focused on HPV prevalence than on transmission modes. HPV DNA detection in amniotic fluid, foetal membranes, cord blood and placental trophoblastic cells all suggest HPV infection in utero, i.e. prenatal transmission. Based on recent meta-analysis, vertical transmission occurs in approximately 20% of cases. Most of the mucosal HPV infections in infants are incident, persistent infections in oral and genital mucosa being found in less than 10% and 2% respectively. The mother seems to be the main transmitter of HPV to her newborn, but subsequent HPV infections are acquired horizontally via saliva or other contacts. Bimodal peak prevalence is seen for skin warts, oral papillomas and recurrent respiratory papillomatosis (RRP) in younger and older age groups, suggesting similar epidemiology. Of the clinical HPV diseases, juvenile-onset-RRP and genital condylomata are problematic; the former because of its life-threatening potential and the latter because of possible sexual abuse. HPV6 and 11 are the most common genotypes in both the lesions. Early in life, infections by the high-risk HPV genotypes may also remain persistent for a considerable period, and should be of considerable importance for HPV vaccination strategies.

The role of HPV type in Recurrent Respiratory Papillomatosis

OBJECTIVE

Human Papillomavirus (HPV) 6 and 11 are the aetiological agents responsible for Recurrent Respiratory Papillomatosis (RRP). There is general consensus that HPV11 results in more aggressive disease compared to HPV6.

METHOD

Pubmed was searched using the terms respiratory papillomatosis, HPV 6 and HPV11. Comparisons were made in the outcomes of HPV6 versus HPV11 positive RRP disease.

RESULTS

There are numerous sub-types or variants of both HPV6 and HPV11. These sub-types have different activities at least in-vitro. The numbers of different HPV types within RRP tissue may be more extensive than initially appeared. This depends specifically upon the HPV types tested for.

CONCLUSION

The clinical differences between HPV6 and HPV11 disease may not be accurately predictable as these viruses exist in numerous sub-types. Also, RRP tissue may contain more than one subtype or even be co-infected with other viruses that may influence outcome. In-vitro studies upon cell lines are a reasonable starting point for evaluation of these differences.

An adult case of multiple squamous papillomas of the trachea associated with human papilloma virus type 6

A 72-year-old woman with primary biliary cirrhosis complained of dry cough and wheezing. Chest computed tomography showed a tumor arising from the posterior wall of the trachea. Bronchoscopic examination revealed that the tumor was cauliflower-like, with two small polypoid tumors. They were diagnosed as multiple squamous papillomas. The main tumor was recurrent and removed by repeated microwave coagulation therapy (MCT) through bronchoscopy, whereas the two polypoid tumors were likely to disappear spontaneously. Human papilloma virus (HPV) type 6 DNA was detected in the tumor by polymerase chain reaction (PCR) amplification, suggesting that this virus was the cause of her papillomas.

Integration of human papillomavirus type 11 in recurrent respiratory papilloma-associated cancer

OBJECTIVES/HYPOTHESIS

The main objective was to demonstrate that human papillomavirus (HPV) type 11 is an aggressive virus that plays a significant role in the development of laryngeal cancer in patients with a history of recurrent respiratory papillomatosis (RRP). We have done so by preliminary investigation into the molecular mechanism underlying the malignant transformation of RRP to invasive squamous cell carcinoma.

STUDY DESIGN

An experimental, nonrandomized, retrospective study using tissue specimens from nine patients with a history of RRP that progressed to laryngeal or bronchogenic cancer was performed.

METHODS

DNA and RNA were extracted from 20 formalin-fixed, paraffin-embedded specimens from six patients with a history of early onset RRP and laryngeal cancer and from three patients with early onset RRP and bronchogenic cancer. Polymerase chain reaction (PCR) was performed on DNA to determine the HPV type in each specimen. Reverse-transcriptase PCR specific for virus transcripts was performed on RNA to determine whether the viral genome was integrated into the host genome.

RESULTS

HPV-11 but not HPV-6, 16, or 18 was found in all of the laryngeal and bronchogenic cancers in patients with a history of early onset RRP in this study. RNA, sufficiently intact for examination, was obtained from seven patients. Analysis of HPV 11 transcripts revealed integration of the viral genome in three of seven patients.

CONCLUSIONS

HPV type 6 and 11 are considered "low-risk" viruses and are not associated with genital cancers, as are HPV types 16 and 18. However, our data suggests that HPV type 11 is an aggressive virus in laryngeal papilloma that should be monitored in patients with RRP.

Human papillomavirus in head and neck cancer: Molecular biology and clinicopathological correlations

Human papillomaviruses are known to cause cancers of the cervix and other anogenital tract sites. Epidemiologic and molecular pathology studies have also suggested that HPV infection may be associated with cancers of the head and neck. Modes of transmission of HPV infection in the head and neck region have not been fully resolved; however, perinatal transmission and an association between sexual behavior and risk for HPV-positive cancers have been presented. Among the HPV types infecting the mucosa, high-risk, intermediate-risk and low-risk genotypes are defined, depending on their presence in carcinoma or precursor lesions. The phylogenic groups of HPVs also showed a definite correlation with the morphology of head and neck tumors. The groups A6, A7, and A9 include viruses that are frequently demonstrated in basaloid and verrucosus squamous cell carcinomas known to associate with HPV infection. Integration of HPV DNA into the host cell genome occurs early in cancer development and is an important event in malignant transformation. There is a trend for patients with HPV-positive tumors to be nondrinkers or light drinkers, the majority of these patients are females, and the median age is lower than in the case of HPV-negative tumors, but this latter difference was not always statistically significant. In the Kaplan-Meier survival model, the HPV-positive verrucous and basaloid squamous cell carcinomas showed better survival rates than the HPV-negative typical squamous cell carcinomas. An increased radiocurability of HPV-positive head and neck squamous cell carcinoma (HNSCC) has also been demonstrated.

Molecular transformation of recurrent respiratory papillomatosis: viral typing and p53 overexpression

Recurrent respiratory papillomatosis (RRP) is a histologically benign disease of the larynx, trachea, and bronchi. Here we report on the histologic and molecular characteristics of 7 cases of malignant transformation of RRP to squamous cell carcinoma (SCCA). The clinical histories of 7 patients with RRP who developed SCCA were carefully reviewed. Sequential biopsies were available from 5 of the 7 cases of spontaneous transformation of RRP to SCCA and were reviewed. In addition, p53 protein overexpression and human papillomavirus (HPV) typing for all cases was examined. The average age of patients with juvenile-onset RRP was 3 years, and that of patients with adult-onset RRP was 31 years. The average age of onset of transformation to SCCA was 28 years. All patients had laryngeal involvement with RRP, and 3 of the 7 patients had tracheal extension of disease. Five patients were tracheotomy-dependent. Four of the 7 patients developed SCCA of the lung, while 3 patients developed laryngeal SCCA. There was no consistent histologic progression from squamous papilloma to papilloma with dysplasia, and all but 1 of the SCCAs were well differentiated. The overexpression of p53 protein was variable in each of the 5 patients. We detected HPV types 6/11 in papillomas from 3 patients, and HPV types 6/11, 16/18, and 31/33/51 in a papilloma of a fourth patient. No HPV DNA was detected in papillomas of 2 patients. We found HPV 6/11 in 4 of the carcinomas. We conclude that the spontaneous transformation of RRP to SCCA is not characterized by a histologic progression through dysplasia over time. Transformation can result in the loss of HPV expression. It does not appear that p53 is a molecular marker for monitoring the transformation process. Thus, these cancers may be very difficult to diagnose histologically and clinically early in the course of the transformation of the disease.

Human papillomavirus associated with oesophageal cancer

AIM

To study the prevalence and the different types of human papillomavirus (HPV) in patients with oesophageal cancer from a high risk area of South Africa (Transkei).

METHODS

DNA samples from 50 paraffin wax embedded tissue sections were analysed by nested polymerase chain reaction (PCR) using the degenerate HPV L1 consensus primer pairs MY09/MY11 and GP5+/GP6+. Positive PCR samples were subjected to DNA sequence analysis.

RESULTS

HPV DNA was detected in 23 of the 50 samples. Sequence analysis revealed that most patients (11) harboured DNA to HPV type 11, whereas other types included DNA HPV type 39 (seven patients), type 16 (two patients), and type 52 (one patient). HPV type 39 has not previously been shown to be associated with oesophageal cancer. In contrast to earlier studies that have found HPV type 16 to be more frequently associated with oesophageal cancer, HPV type 11 was the predominant subtype in this study.

CONCLUSIONS

The high frequency of occurrence of HPV in oesophageal tumours (23 of 50 patients; 46%) implicates HPV as one of the possible aetiological factors in this disease. The finding that the low risk HPV subtypes predominate indicates that transformation may be effected via the E6 and E7 proteins.

Squamous cell carcinoma arising in recurrent respiratory papillomatosis with pulmonary involvement: emerging common pattern of clinical features and human papillomavirus serotype association

Squamous papillomas of the lung are an uncommon feature of recurrent respiratory papillomatosis, occurring in fewer than 1% of cases. We describe a 23-year-old patient with pulmonary papillomas who developed a fatal squamous cell carcinoma of the lung. PCR-based human papillomavirus (HPV) typing showed the presence of HPV 11 DNA in both benign papillomas and invasive carcinoma. A review of the literature reveals four reports of malignant transformation of juvenile-onset recurrent respiratory papillomatosis in which HPV typing was performed. Similar clinical features are noted in all of the reports; specifically, each case has arisen in a young adult man with a history of papillomatosis since childhood. In each of the cases, HPV 11 was identified in association with the squamous cell carcinoma. Although HPV 11 is uncommonly associated with the development of invasive carcinoma at other sites, these findings suggest that it is correlated with malignant transformation in the setting of juvenile-onset recurrent respiratory papillomatosis.

A novel method to culture laryngeal human papillomavirus-positive epithelial cells produces papilloma-type cytology on collagen rafts

A novel method to culture human papillomavirus (HPV) positive laryngeal epithelial cells is described. Biopsies of laryngeal papillomas and of HPV-positive laryngeal mucosa were first cultured as a monolayer in which irradiated laryngeal fibroblasts originally derived from a papilloma (PPLF-XR) patient served as feeder cells. When these fourth or fifth passage epithelial cells were transferred to allow growth on an organotypic growth base (collagen raft containing unirradiated PPLF), they grew as a multilayer. This layer showed features typical of HPV infection with koilocytosis, parakeratosis, and isolated dyskeratotic cells. Based on in situ hybridisation, the original tumour sections and epithelial cells from each monolayer passage, as well as the collagen raft sections, contained HPV DNA. Our results show that HPV-infected epithelial cells can be maintained during passages in monolayer culture and that PPLF can support the growth of these cells well. The monolayer cell culture and the collagen raft, the latter providing differentiation-promoting effects, appears to facilitate maintenance of the infected cells and of the viral genome.

Human papillomavirus DNA sequences and p53 over-expression in laryngeal squamous cell carcinomas in Northeast China

One-hundred-two patients with laryngeal squamous cell carcinomas in Northeast China were examined for human papillomavirus (HPV) DNA by the polymerase chain reaction (PCR) coupled with Southern blot hybridization, and for p53 over-expression by immunohistochemical staining. HPV DNAs were found in 60 cases (58.8%). HPV-16, -18, -6, -11, and -33 DNAs were detected in 30 cases, 22 cases, 25 cases, two cases, and one case, respectively. In addition, coinfection either with HPV-6 and -16 or with HPV-6 and -18 was detected in 20 cases (33.3% of HPV DNA-positive cases). p53 over-expression was observed in 60 patients (58.8%). p53 was over-expressed significantly in the poorly-differentiated SCC and in patients with metastasis to lymph nodes (P < 0.05, respectively). Both HPV DNA and p53-expression were positive in 35 patients, and negative in 17 patients. Either HPV DNA or p53-expression were positive in 50 patients (25 cases each). Although p53 was detected in 35 (58.3%) of HPV-positive patients, there was no significant correlation between HPV infection and p53 over-expression in laryngeal squamous cell carcinomas of Northeast China.

A possible role for human papillomaviruses in head and neck cancer

Human papillomaviruses (HPVs) cause benign tumors in the respiratory tract. Mounting evidence suggests that they also play a role in the etiology of a subset of head and neck cancers. Carcinomas in patients with a history of recurrent respiratory papillomatosis clearly are caused by persisting HPV interacting with one of more carcinogenic agents. Verrucous carcinomas of the oral cavity, tonsillar and tongue carcinomas are strongly linked with HPVs, based on molecular epidemiologic data. Tonsillar cancer have been shown to express HPV RNA, presumed necessary to induce and maintain a carcinoma, supporting a viral etiology. This paper reviews the molecular and cellular basis for considering HPVs as causative agents of cancer, and reviews the literature that considers the possible role of HPVs in head and neck cancer.

Laryngeal carcinoma ex-papilloma in a non-irradiated, non-smoking patient: a clinical record and review of the literature

Malignant transformation of respiratory papillomata is not uncommon in the presence of precipitating factors such as tobacco smoking and therapeutic irradiation. Respiratory papilloma changing to carcinoma in the absence of smoking and irradiation is seldom seen, with only about 20 documented cases presented in the literature. Here we report one such case in a 30-year-old male patient.

Oral and laryngeal papilloma: a pediatric manifestation of sexually transmitted disease?

Laryngeal and oral papilloma in pediatric patients are generally considered transmitted by maternal fetal transmission. In adults and immunocompromised patients, it is well documented that human papilloma virus (HPV) of the oropharynx is sexually transmitted. The possibility of sexual transmission of oral and laryngeal papilloma in children by oral genital contact is discussed.

Human papillomavirus not found in squamous and large cell lung carcinomas by polymerase chain reaction

BACKGROUND

Human papillomavirus (HPV) has been identified not only in anogenital carcinomas, but also in malignancies of other organs, including bronchogenic carcinomas. Previous studies reporting detection of these viruses in lung cancers used mainly in situ hybridization. The authors applied the polymerase chain reaction (PCR) for investigating the occurrence of HPV in bronchial neoplasms.

METHODS

Formalin fixed, paraffin embedded tissues of 40 squamous and 7 large cell lung cancers were examined. PCR was done with consensus primers, capable of detecting HPV 6, 11, 16, 18, 31, 33, 52b, and 58.

RESULTS

None of the 47 samples contained any of the examined HPV types.

CONCLUSIONS

Because the squamous and large cell cancer cases were found not to be associated with HPV infection, this study does not support the potential role of these viruses in the development of lung cancers.

Antibody response to a synthetic peptide derived from the human papillomavirus type 6/11 L2 protein in recurrent respiratory papillomatosis: correlation between Southern blot hybridization, polymerase chain reaction, and serology

Recurrent respiratory papillomatosis (RRP) is the most common benign tumour of the larynx, affecting both children and adults. We present a series of 25 patients, including 10 cases of juvenile multiple, 8 cases of adult solitary, and 7 cases of adult multiple RRP. Biopsy tissue from each patient was screened by Southern blot hybridization and polymerase chain reaction for the presence of human papillomavirus (HPV) DNA. Sera from patients and age- and sex-matched controls were tested for the presence of HPV-specific antibodies using a synthetic peptide derived from the minor capsid protein (L2) of HPV 6/11. By Southern blot hybridization and/or polymerase chain reaction, biopsies from all patients were positive for HPV 6/11 DNA. There was no difference in antibody response between cases and controls. Female cases and controls had significantly higher antibody titers than male subjects. A correlation was observed between the HPV-specific antibody level and the number of surgery-necessitating recurrences.

Expression of the different viral mRNAs of human papilloma virus 6 in a squamous-cell carcinoma of the bladder and the cervix

The prevalence of HPV6 and HPV11 in benign condylomata or mild dysplasias has led to the view of HPV6/11 as rather harmless viruses in relation to carcinogenesis. However, the detection of HPV6/11 DNA in a number of individual cases of squamous-cell carcinomas of the anogenital/urinary tract could also point to a possible contribution of these viruses in the development of certain malignancies. Recently we have shown that the transcription of the E6 and E7 genes of HPV6 in benign anogenital condylomata is strictly confined to the basal cell layers of the epithelium, which express c-fos mRNA. This report describes the in situ hybridization analysis of individual mRNA species of HPV6 in 2 malignant tumours. A consistent feature of both carcinomas was the lack of detectable amounts of E6 mRNA, while the E7 mRNA was the major transcript observed. In situ hybridization with a riboprobe for c-fos revealed an expression pattern similar to that detected with the E7 probe. Hybridization with a probe specific for mRNA with a coding potential for a full-length E2 protein yielded weak signals in both carcinomas. Using restriction-enzyme analysis, we compared the long control region of HPV6 amplified by polymerase chain reaction from both tumours with already known HPV6 subtypes. In contrast to previous reports suggesting a correlation between genetic alterations in the long control region of HPV6 and increased malignant behaviour, our data do not support this hypothesis.

Analysis of prevalence of human papillomavirus in laryngeal carcinomas. Study of 40 cases using polymerase chain reaction and consensus primers

In this study we determined the frequency of association of human papillomavirus (HPV) and laryngeal carcinomas and investigated the possibility that HPV may be associated with larger or more aggressive tumors. Laryngeal squamous cell carcinomas from 40 patients who did not have preexisting papillomas by clinical history were retrieved from formalin-fixed, paraffin-embedded blocks and analyzed for HPV. Twenty-two cases were tumors of the true vocal folds, and 18 were supraglottic. Clinical follow-up was available for 25 patients. We used the polymerase chain reaction (PCR) with the "hot start" modification and consensus primers that can detect over 30 distinct HPV types. Three of the 40 patients (8%) had detectable HPV DNA. These 3 patients did not have unusual age demographics and were smokers. All but 1 of the 22 HPV-negative patients who were questioned were also smokers. We compared the outcomes for large (4 cm or greater) HPV-positive and -negative tumors. Six of the 40 tumors were 4 cm or greater and involved contiguous structures. Two of these 6 were HPV-positive, and these patients died of disease after 3 and 16 months, respectively. Of the 4 HPV-negative patients with tumors greater than 4 cm, 3 are disease-free at 41, 42, and 3 months, respectively, and 1 was lost to follow-up. The third HPV-positive patient had a tumor less than 1 cm, and is disease-free after 38 months. While the number of HPV-positive cases is too small for definitive conclusions, it is possible that for large tumors the presence of HPV DNA may portend a worse prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship between the clinical course and HPV typing of recurrent laryngeal papillomatosis. The Red Cross War Memorial Children's Hospital experience 1982-1988

During the period 1982-1988, 20 new cases of laryngeal papillomatosis in children were seen at The Red Cross War Memorial Children's Hospital. HPV typing of biopsy specimens was performed. Their clinical course was reviewed and age at presentation ranged from 1 to 10 years. There was no correlation between age and either aggression or a prolonged clinical course. HPV DNA was identified in all 20 cases (100%). Fifteen (75%) were HPV Type 11 and 5 (25%) were HPV Type 6. There were no mixed infections. HPV Type 6 infection was more clinically aggressive than HPV Type 11 infection. The intensity of the virus signal in the biopsy specimens was not in general indicative of the clinical behavior of the disease, although two children with particularly strong intensity exhibited aggressive disease. It is suggested that identification of HPV type 6 infection has prognostic significance.

Human papillomavirus type 6 in squamous cell carcinoma of the bladder and cervix

Human papillomavirus (HPV) types 16 and 18 are the most frequent genotypes identified in genital malignancies, while HPV types 6 and 11 are found predominantly in condylomas and low-grade dysplasias. It is thought that HPV types 16 and 18 represent high-risk genotypes, while HPV types 6 and 11 rarely, if ever, participate in the development of malignant tumors. In a series of over 300 invasive tumors of the lower genital tract analyzed for the presence of HPV three have been found to contain HPV type 6 DNA: two invasive squamous cell carcinomas of the cervix and one squamous cell carcinoma of the bladder. Human papillomavirus type 6 was the only HPV type detected in these tumor DNAs by Southern blot hybridization and by the polymerase chain reaction using both consensus and type-specific primers. In situ hybridization using whole genomic RNA probes localized viral DNA to tumor cells. Although extensive virologic and epidemiologic studies conducted in the last decade indicate that HPV types 16 and 18 are more likely to be associated with high-grade dysplasias and invasive cancer, HPV type 6 may not be as innocuous as previously supposed.

Duplication of the upstream regulatory sequences increases the transformation potential of human papillomavirus type 11

Infections with certain types of papillomaviruses, e.g., human papillomavirus type 16 (HPV-16), often progress to cancer. Malignant lesions associated with the closely related HPV-11 are extremely rare. Additionally, HPV-11 DNA, unlike HPV-16, does not normally transform cells in vitro. We determined that HPV-11 DNA was able to transform baby rat kidney cells in a ras-dependent focus assay when the upstream regulatory region (URR) was present in two copies. Addition of a second HPV-11 URR or an HPV-16 URR was equally effective and was position and orientation independent. The transformation was enhanced by dexamethasone. On passage the HPV-11 genome was not retained at a detectable level. This analysis supports isolated observations in vivo that duplications of regulatory sequences in HPV-11 increase the transformation potential of this virus type.

Sinonasal papillomas and human papillomavirus: human papillomavirus 11 detected in fungiform Schneiderian papillomas by in situ hybridization and the polymerase chain reaction

A series of 19 paraffin-embedded sinonasal papillomas (four squamous papillomas, three fungiform papillomas, nine inverted papillomas, and three cylindrical cell papillomas) were investigated for evidence of human papillomavirus (HPV) infection using immunohistochemistry (polyclonal antibody to HPV capsid antigen), in situ hybridization (DNA probes for HPV 6/11, 16/18, and 31/33/35), and the polymerase chain reaction (primers and probes for HPV 6, 11, 16, 18, and 33). All three fungiform papillomas were positive by all three techniques: immunohistochemistry, in situ hybridization for HPV 6/11, and the polymerase chain reaction for HPV 11. None of the other lesions contained detectable HPV using the specific probes included in this study. These results support the continued classification of fungiform papilloma as a distinctive variant of schneiderian papilloma characterized by a predominantly exophytic growth pattern and an association with HPV 11.

Malignant tumours in patients with a history of multiple laryngeal papillomas: the significance of irradiation

For a period of more than 30 years irradiation was used in the treatment of multiple laryngeal papillomas, especially in children. The treatment was discontinued because a number of irradiated patients developed laryngeal carcinomas. There are however a number of reports of laryngeal and even bronchial carcinomas arising in patients with laryngeal papillomas who had not been irradiated. In addition, HPV type 11 has recently been found in laryngeal papillomas as well as in laryngeal and bronchial carcinomas, subsequently arising in the same patients, both irradiated and non-irradiated. The analysis of a series of 113 patients with laryngeal papillomas has shown that irradiated patients have a 16-fold increased risk of a subsequent carcinoma in the respiratory system.

The presence of human papillomavirus (HPV) in solitary adult laryngeal papillomas demonstrated by in-situ DNA hybridization with sulphonated probes

Human papilloma virus (HPV) types 6 and 11 have been repeatedly demonstrated in multiple laryngeal papillomas, and there is little doubt that these lesions are caused by HPV. It has been clearly demonstrated in recent reports that the clinical course of solitary adult onset laryngeal papillomas is entirely different from that of multiple papillomas of juvenile as well as of adult onset. We here report the presence of HPV types 6 and 11 in 19 out of 20 solitary papillomas from 16 patients, while HPV types 16 and 18 were totally absent. We conclude that the milder clinical course in such patients is most likely to be due to host factors, rather than to viral factors.

Immunohistochemical demonstration of human papilloma virus antigen in human colon neoplasms

The presence of human papilloma virus (HPV) has recently been demonstrated in colon tumors, but the incidence of HPV infection in normal colon mucosa or in benign or malignant neoplasms of the mucosa is unknown. We studied both neoplastic and normal human colon tissue for the presence of HPV antigen using immunohistochemical techniques. Ninety colon specimens were studied. Three consecutive series of normal colon mucosa (N = 30), single benign tubulovillous adenomas (N = 30), and invasive carcinomas (N = 30) were selected and confirmed histologically. Formalin-fixed paraffin-embedded samples of each tissue were prepared using immunohistochemical techniques and resultant slides were read blindly and graded simply as positive or negative for HPV antigen. The presence of HPV antigen varied dramatically between groups, with 97% of the invasive carcinomas, 60% of the benign tubulovillous adenomas, and 23% of the normal mucosa positive for HPV antigen. Groups were statistically significant using chi 2 analysis (P less than 0.001). We conclude that an association exists between the human colon neoplasia and the presence of HPV antigen. This may suggest an etiologic role of the virus in colon cancer.

Apoptosis. The role of the endonuclease

Cell death by apoptosis mediates several important physiologic and pathologic processes and appears to be intrinsically programmed. Its characteristic features are distinctive morphologic changes of nucleus and cytoplasm, along with cleavage of chromatin at regularly spaced sites. Here we study DNA organization and nuclear structure in apoptotic thymocytes to define the cleavage event and, by implication, the role of the responsible endonuclease. We show that in apoptosis, double-stranded cleavage of DNA generates two classes of chromatin fragments: 70% of DNA exists as long, H1-rich oligonucleosomes bound to the nucleus, and 30% comprises short oligonucleosomes and mononucleosomes, which are depleted in H1, enriched in HMG1 and 2, and not attached to the nucleus. This minority class probably derives from chromatin in a transcriptionally active configuration, which would allow better access to enzymes in the nucleoplasm, producing more complete digestion. The characteristic nucleolar morphology in apoptosis can also be explained in terms of cleavage of the transcriptionally active ribosomal genes, with conservation of the nucleolin-rich fibrillar center. The chromatin cleavage, nucleolar morphologic changes, and chromatin condensation were closely mimicked by micrococcal nuclease digestion of normal thymocyte nuclei in the presence of protease inhibitors. Thus, in apoptosis, selective activation of an endogenous endonuclease appears to be responsible not only for widespread chromatin cleavage but also for the major nuclear morphologic changes.

Human papillomavirus 6/11 and 16/18 in Schneiderian inverted papillomas. In situ hybridization with human papillomavirus RNA probes

Schneiderian inverted papillomas may be troublesome lesions for clinicians with propensity for recurrences. Dysplasia is not uncommonly seen, and some of these lesions do progress to develop squamous carcinoma. The authors hybridized in situ seven inverted papillomas with RNA probes to human papillomavirus (HPV) 6, 11, 16, and 18. Four of these contained dysplasia, two were without dysplasia, and one contained invasive squamous cell carcinoma. Five inverted papillomas showed evidence of HPV infection based on hybridization. One with mild to moderate and one with severe dysplasia, and one without dysplasia hybridized with mixed probe HPV 6/11. One with mild dysplasia and one associated with invasive squamous cell carcinoma hybridized with mixed probe HPV 16/18. One inverted papilloma without dysplasia and one with severe dysplasia did not definitively hybridize with either mixed probe. These findings raise interesting questions as to role of HPV 6/11 and 16/18 in the development of inverted papillomas, and probably on the progression to and carcinoma.

Human papillomaviruses: are we ready to type?

The issue of determining which human papillomavirus (HPV) is present in a clinical specimen (typing specimens for HPVs) is receiving attention because HPVs cause condyloma acuminata and are associated with the continuum of disease which ranges from dysplasia to invasive genital cancer. Morphological inspection of precancerous lesions is not sufficient to determine which lesions will progress and which will not. A number of research tools based primarily on deoxyribonucleic acid hybridization have been developed. These permit identification and typing of HPV in genital tract scrapings or biopsies. Some HPV types (e.g., HPV-16 and HPV-18) have been identified in high-grade dysplasias and carcinomas more commonly than other types (e.g., HPV-6) and have been designated "high risk" types for cervical cancer. Thus, the question arises whether HPV typing would improve patient management by providing increased sensitivity for detection of patients at risk or by providing a prognostic indicator. In this review, the available typing methods are reviewed from the standpoint of their sensitivity, specificity, and ease of application to large-scale screening programs. Data implicating HPVs in the genesis of genital tract cancers are reviewed, as is the association of specific HPV types with specific outcomes. We conclude that there is currently no simple, inexpensive assay for HPV types, although such assays may be developed in the future. Analysis of the typing data indicates that, while HPV types can be designated high risk and low risk, these designations are not absolute and thus the low-risk group should not be ignored. In addition, interpretation of the data is complicated by finding high-risk types in individuals with no indication of disease. Insufficient data exist to indicate whether knowledge of the presence of a given HPV type is a better prognostic indicator than cytological or histological results. Thus, more research is needed before it can be determined whether typing information will augment the method currently in use for deciding treatment regimen and whether it warrants widespread use.