Detection of human papillomavirus in esophageal squamous cell carcinoma

Effect of high-risk human papillomavirus in esophageal squamous cell carcinoma in Somalian and Turkish cases

This study aimed to investigate the role of high-risk human papillomavirus (Hr-HPV) in Somalian and Turkish patients with esophageal squamous cell carcinoma (ESCC). In the sections obtained from paraffin-embedded blocks, the results of invasive tumor, peripheral tumor dysplasia and normal mucosa were examined. Samples containing 45 and 47 ESCC, 46 and 42 dysplasia in Somalian (n = 52) and Turkish (n = 53) cases, respectively, were included in the study. We examined the presence of 14 types of Hr-HPV in ESCC collected from Somalia and Turkey by Aptima® Panther System. Hr-HPV types were not detected in Somalian cases. p16INK4a is positive in 5 (11.4%) tumors and 6 (13%) dysplasia. p53 is positive in 28 (62.2%) tumors and 35 (76.1%) dysplasia. HPV16-18/45 are positive only in one of the Turkish cases. p16INK4a is positive in 5 (10.6%) tumors and 4 (9.5%) dysplasia. p53 is positive in 31 (63.3%) tumors and 24 (57.1%) dysplasia. No reaction was detected in normal mucosa samples in both countries. This study is regional. Although the findings did not reflect the general population, the present study shows that the effect of HPV on carcinogenesis in Somalian and Turkish ESCC patients was not significant.

Prevalence of the integration status for human papillomavirus 16 in esophageal carcinoma samples

BACKGROUND/AIMS

To investigate the etiology of esophageal cancer (EC) related with human papillomavirus (HPV) infection.

MATERIALS AND METHODS

Fresh surgically resected tissue samples and clinical information were obtained from 189 patients. Genomic DNA was extracted, and HPV was detected using polymerase chain reaction (PCR) with HPV L1 gene primers of MY09/11; HPV16 was detected using HPV16 E6 type-specific primer sets. Copies of HPV16 E2, E6, and the human housekeeping gene β-actin were tested using quantitative PCR to analyze the relationship between HPV16 integration and esophageal squamous cell carcinoma and the relationship between the HPV16 integration status and clinical information of patients.

RESULTS

Of the 189 samples, 168 HPV-positive samples were detected, of which 76 were HPV16 positive. Among the HPV16 positive samples, 2 cases (E2/E6 ratio>1) were 2.6% (2/76) purely episomal, 65 (E2/E6 ratio between 0 and 1) were 85.6% (65/76) mixture of integrated and episomal, and 9 (E2/E6 ratio=0) were 11.8% (9/76) purely integrated. The results indicate that integration of HPV16 was more common in the host genome than in the episome genome. The prevalence rate of HPV16 integration is increasing with the pathological stage progression of esophageal carcinoma (EC).

CONCLUSION

A high prevalence of HPV16 suggested that HPV16 has an etiological effect on the progress of EC. Integration of HPV16 is more common than episome genome in the host cells, indicating that continuous HPV infection is the key to esophageal epithelial cell malignant conversion and canceration.

Esophageal Cancer: Associated Factors with Special Reference to the Kashmir Valley

Esophageal cancer is one of the most common cancers worldwide. It is a multifactorial disease, and no single agent has been identified so far as the sole cause of the cancer. Many factors like smoking, the consumption of alcohol, fungal-contaminated, spicy and various nitrosamine-containing food stuffs and hot beverages, nutritional deficiency of some vitamins like β-carotene, vitamin A, C and E and minerals like zinc, selenium and molybdenum, the use of opium, HPV infection and various genetic factors have been found associated with the occurrence of the disease worldwide. Wide geographic differences and substantial changes in the incidence of esophageal cancer occurring over time have been suggested. Among the risk factors in India, betel quid chewing carries a relatively high risk. High incidences in Kashmir have been associated with the consumption of hot salted tea, sun-dried, smoked foods, tobacco in the form of hukka and various genetic factors. The exact cause of esophageal squamous cell carcinoma is unknown. Much work has been carried out on the role of various environmental factors, gene mutations, and polymorphisms worldwide, including Kashmir. Although the Kashmir valley is present on the border of the ‘high risk esophageal cancer belt’ and esophageal squamous cell carcinoma represents the most commonly occurring malignancy in Kashmir, the amount of information available on various associated factors is still very little as there is a paucity of various epidemiological and molecular studies being carried out in this field.

HPV, KRAS mutations, alcohol consumption and tobacco smoking effects on esophageal squamous-cell carcinoma carcinogenesis

Esophageal squamous-cell carcinoma (ESCC) is an invasive neoplastic disease generally associated with poor survival rates. The incidence of ESCC is characterized by marked geographic variation, with highest rates noted in developing Southeastern African, Central and Eastern Asian countries. In the developed Western European and North American regions where there is a low disease incidence, heavy alcohol and cigarette consumption constitute major risk factors. The toxic effects of both these risk factors cause chronic irritation and inflammation of the esophageal mucosa, while at the cellular level they further confer mutagenic effects by the activation of oncogenes (e.g., RAS mutations), inhibition of tumor-suppressor genes, and profound DNA damage. Viral infections, particularly with human papillomavirus, may activate specific antiapoptotic, proliferative and malignant cellular responses that may be intensified in combination with the effects of alcohol and tobacco. In countries with a high ESCC incidence, low socioeconomic status and an inadequate diet of poorly preserved food are combined with basic nutritional deficiencies and inadequate medical treatment. These conditions are favorable to the above-mentioned risk factors implicated in ESCC development, which may be present and/or habitually used in certain populations. New perspectives in epidemiological studies of ESCC development and its risk factors allow genome-wide research involving specific environments and habits. Such research should consist of adequately large and representative samples, should use newly designed informative genetic markers, and apply genomic variation analysis of the functional transcripts involved in malignant cell cycle regulation and neoplastic transformation in the multi-step process of ESCC carcinogenesis.

Association between human papillomavirus (HPV) and oesophageal squamous cell carcinoma: a meta-analysis

SUMMARY

The oncogenic potential of human papillomaviruses (HPV) is well known in the context of cervical carcinoma; however, their role in the development of oesophageal squamous cell carcinoma (OSCC) is less clear. We aimed to determine the extent of the association between HPV infection and OSCC. A comprehensive literature search found 132 studies addressing HPV and OSCC in human cases, and a meta-analysis was performed using a random-effects model. There was evidence of an increased risk of OSCC in patients with HPV infection [odds ratio (OR) 2·69, 95% confidence interval (CI) 2·05-3·54]. The prevalence of HPV in OSCC was found to be 24·8%. There was an increased risk associated with HPV-16 infection (OR 2·35, 95% CI 1·73-3·19). Subgroup analyses showed geographical variance, with Asia (OR 2·94, 95% CI 2·16-4·00), and particularly China (OR 2·85, 95% CI 2·05-3·96) being high-risk areas. Our results confirm an increase in HPV infection in OSCC cases.

Role of Human papilloma virus infection and altered methylation of specific genes in esophageal cancer

BACKGROUND

Evaluation of Human papilloma virus (HPV) and its association with promoter methylation of candidate genes, p53 and Aurora A in esophageal cancer.

MATERIALS AND METHODS

One hundred forty-one esophageal tissue samples from different pathologies were evaluated for HPV infection by PCR, while the promoter methylation status of p53 and Aurora A was assessed by methylation-specific restriction based PCR assay. Statistical analyses were performed with MedCalc and MDR software.

RESULTS

Based on endoscopy and histopathology, samples were categorized: cancers (n=56), precancers (n=7), esophagitis (n=19) and normals (n=59). HPV infection was found to be less common in cancers (19.6%), whereas its prevalence was relatively high in precancers (71.4%), esophagitis (57.8%) and normals (45.7%). p53 promoter methylation did not show any significant difference between cancer and normal tissues, whereas Aurora A promoter methylation demonstrated significant association with disease (p=0.00016, OR:5.6452, 95%CI:2.18 to 14.6) when compared to normals. Aurora A methylation and HPV infection was found in a higher percentages of precancer (66.6%), esophagitis (54.5%) and normal (45.2%) when compared to cancers (14.2%).

CONCLUSIONS

Aurora A promoter methylation is significantly associated with esophageal cancer, but the effect of HPV infection on this epigenetic alteration is not significant. However MDR analysis showed that the hypostatic effect of HPV was nullified when the cases had Aurora methylation and tobacco exposure. Further HPV sub-typing may give an insight into its reduced prevalence in esophageal cancer verses normal tissue. However, with the present data it is difficult to assign any significant role to HPV in the etiopathology of esophageal cancer.

Prevalence of human papillomavirus among oesophageal squamous cell carcinoma cases: systematic review and meta-analysis

Background:

Oncogenic human papillomavirus (HPV) has been hypothesised as a risk factor for oesophageal squamous cell carcinoma (OSCC), but aetiological research has been limited by the varying methodology used for establishing HPV prevalence. The aims of this systematic review and meta-analysis were to estimate the prevalence of HPV DNA detected in OSCC tumours and the influence of study characteristics.

Methods:

Study-level estimates of overall and type-specific HPV prevalence were meta-analysed to obtain random-effects summary estimates.

Results:

This analysis included 124 studies with a total of 13 832 OSCC cases. The average HPV prevalence (95% confidence interval) among OSCC cases was 0.277 (0.234, 0.320) by polymerase chain reaction; 0.243 (0.159, 0.326) by in situ hybridisation; 0.304 (0.185, 0.423) by immunohistochemistry; 0.322 (0.154, 0.490) by L1 serology; and 0.176 (0.061, 0.292) by Southern/slot/dot blot. The highest HPV prevalence was found in Africa and Asia, notably among Chinese studies from provinces with high OSCC incidence rates.

Conclusions:

Future research should focus on quantifying HPV in OSCC cases using strict quality control measures, as well as determining the association between HPV and OSCC incidence by conducting large, population-based case–control studies. Such studies will provide a richer understanding of the role of HPV in OSCC aetiology.

Systematic review with meta-analysis: the association between human papillomavirus infection and oesophageal cancer

BACKGROUND

Human papillomavirus (HPV) infection might be one of the potential risk factors for oesophageal cancer. However, the previous epidemiological findings were heterogeneous.

AIM

To explore the association between HPV infection and oesophageal cancer risk by means of meta-analysis.

METHODS

Studies on HPV infection and oesophageal cancer were identified, the prevalence of HPV infection and its association with oesophageal cancer risk were quantitatively summarised by meta-analysis.

RESULTS

A total of 8990 oesophageal squamous cell carcinoma (SCC) patients and 174 oesophageal adenocarcinomas patients were evaluated from 76 included studies. Summarised HPV prevalence in oesophageal SCC was 22.2% [95% confidence interval (CI), 18.3-26.7%], HPV-16 was the most frequently observed subtype with a summarised prevalence of 11.4% (95% CI: 8.2-15.7%). With respect to oesophageal adenocarcinoma, HPV prevalence was 35.0% (95% CI, 13.2-65.7%) and HPV-16 prevalence was 11.4% (95% CI: 8.2-15.7%). Due to the limited number of included studies on oesophageal adenocarcinoma, association analyses were performed to oesophageal SCC only. Significant association was observed between HPV infection and oesophageal SCC with a summarised odds ratio of 3.32 (95% CI, 2.26-4.87). According to HPV-16, the strength of the association was found to be 3.52 (95% CI, 2.04-6.07).

CONCLUSIONS

Human papillomavirus infection was observed to be associated with an increased risk of oesophageal SCC in this meta-analysis. However, due to the evident heterogeneity observed between the included studies and the strength of the association not as strong as observed for cervical cancer and laryngeal cancer, further studies are needed to clarify the relation and its underlying mechanisms.

Human papillomavirus types 16 and 18 in esophagus squamous cell carcinoma: a meta-analysis

PURPOSE

A possible carcinogenic role of human papillomavirus (HPV) has been investigated in esophageal squamous cell carcinoma (ESCC) for nearly 30 years with mixed results. We performed a meta-analysis to assess the prevalence of "high-risk" HPV, HPV-16/18, in this disease. We also evaluated the association between infection with HPV-16/18 and ESCC risk by meta-analysis of case-control studies.

METHODS

Eligible studies published up to September 30, 2012 were retrieved via both computer searches of MEDLINE and EMBASE and manual review of references. A random-effects model was used to calculate summary prevalence and odds ratios (ORs) and corresponding 95% confidence intervals (CIs).

RESULTS

A total of 5755 cases of ESCC from 68 studies were included in this meta-analysis. Overall, 11.67% (95% CI, 7.74%-16.21%) of ESCC cases harbored HPV-16 and 1.82% (95% CI, 0.90%-2.95%) harbored HPV-18. In addition, meta-analysis of 10 case-control studies showed a significant increase in ESCC risk with HPV-16 infection (summary ORs = 3.55; 95% CIs, 2.05%-6.14%). However, this increased risk in ESCC was not made for HPV-18 infection (summary ORs = 1.25; 95% CIs, 0.46%-3.43%).

CONCLUSIONS

This meta-analysis indicated that HPV-16 and -18 can be detected in ESCC. HPV-16, but not HPV-18, is significantly associated with the risk of ESCC. However, it is early to conclude that both types of HPV are involved in esophageal carcinogenesis.

Amplification of the telomerase RNA component gene as a new genetic marker for disease progression and prognosis in esophageal squamous cell carcinoma

Amplification of the human telomerase RNA component (TERC) gene was found in esophageal squamous cell carcinoma (ESCC). However, its roles in the progression and prognosis of ESCC have not been well understood. The amplification of TERC in normal mucosa, low-grade and high-grade intraepithelial neoplasia, and invasive ESCC samples were evaluated using a fluorescence in situ hybridization assay. The amplification of TERC invariably occurred in high-grade intraepithelial neoplasia and invasive ESCC, partially occurred in low-grade intraepithelial neoplasia specimens, and seldom occurred in normal mucosa. The average signal ratio of TERC to chromosome 3 centromere-specific probe (TERC/CSP3) was 1.00 ± 0.01 (average ± standard deviation) in normal mucosas, 1.01 ± 0.08 in low-grade intraepithelial neoplasias, 1.39 ± 0.26 in high-grade intraepithelial neoplasias, and 1.56 ± 0.41 in invasive ESCC. High TERC/CSP3 ratio was positively associated with lymph node metastasis (P = 0.005) and advanced tumor stage (P = 0.045). Patients with high amplification of TERC had poor survival (P = 0.01). The amplification of TERC could be used as a new genomic marker for disease progression and prognosis of ESCC. The amplified TERC gene may be a potential therapeutic target for ESCC.

Role of human papillomaviruses in esophageal squamous cell carcinoma

Esophageal cancer (EC) is responsible for almost half a million deaths worldwide annually and has a multifactorial etiology, which may account for its geographical variation in incidence. In the last 30 years the potential of human papillomaviruses (HPV) as oncogenes or co-factors in the tumorigenic process of esophageal squamous cell carcinoma (ESCC) has been widely studied. While the etiology of HPV in cervical and certain other anogenital and aerodigestive cancers has been established, results regarding its role in EC have been largely inconclusive. A causal association can be evaluated only with a case-control study, where normal controls are compared to ESCC cases for the presence of HPV. We reviewed all studies investigating ESCC tissue for HPV DNA and identified 139 that met our inclusion criteria, of which only 22 were case-control studies. Our results support previous findings of higher levels of HPV detection in high-risk ESCC regions than in areas of low risk. In addition, we confirm that the role of HPV in ESCC remains unclear, despite an accumulation of studies on the subject. The variations in investigative technique, study design and sample types tested may account for the lack of consistency in results. There is a need for a meta-analysis of all case-control studies to date, and for large, well-designed case-control studies with adequate power to investigate the association. The potential benefits of prophylactic HPV vaccines could be evaluated if HPV is identified as an etiological factor in EC, highlighting the need for further research in this area.

Geographic origin is a significant determinant of human papillomavirus prevalence in oesophageal squamous cell carcinoma: systematic review and meta-analysis

BACKGROUND

Since the first reports in 1982 suggesting an aetiological role for human papillomavirus (HPV) in a subset of oesophageal squamous cell carcinomas (ESCC), the literature reporting HPV detection in ESCC has expanded rapidly. However no formal meta-analysis of this literature has been published yet. The objective of this study was to perform a systematic review and formal meta-analysis of the literature reporting HPV detection in ESCC.

METHODS

MEDLINE and Current Contents were searched through March 2012. The effect size was calculated as event rates and their 95% confidence interval (95% CI), with homogeneity testing using Cochran's Q and I² statistics. Meta-regression was used to test the impact of study-level covariates (HPV detection method, geographic origin of study) on effect size, and potential publication bias was estimated using funnel plot symmetry (Begg and Mazumdar rank correlation, Egger's regression, and Duval and Tweedie's trim and fill method).

RESULTS

Of the 1177 abstracts found, 152 studies were determined to be eligible for this meta-analysis. These 152 studies covered a total of 10,234 ESCC cases, analysed by different HPV detection methods in different geographic regions. Of these 10,234 cases, 3135 (30.6%) tested HPV-positive, translating to an effect size of 0.372 (95% CI 0.360-0.384; fixed effects model) and 0.290 (95% CI 0.251-0.31; random effects model). When stratified by HPV detection technique, there was a significant heterogeneity between the studies, but importantly, the between-strata summary comparison was not significant (random effects model; p = 0.440). In contrast, there was significant heterogeneity between the studies from the different geographic regions. In the maximum likelihood meta-regression, HPV detection method was not a significant study-level covariate, in contrast to the geographic origin of the study, which had a significant impact (p = 0.00005) on the summary effect size estimates. No evidence for significant publication bias was found in funnel plot symmetry testing. In the sensitivity analysis, all meta-analytic results appeared robust to all (n = 151) one-by-one study removals.

CONCLUSIONS

These meta-analysis results indicate that the reported wide variability in HPV detection rates in ESCC is not due to the HPV detection techniques, but is explained by the geographic origin of the study. These data substantiate the recently elaborated concept that ESCC might have a different aetiology in low-incidence and high-incidence geographic regions, HPV playing an important role only in the latter.

Integration of human papillomavirus 18 DNA in esophageal carcinoma 109 cells

AIM: To detect human papillomavirus (HPV) DNA in esophageal carcinoma (EC) 109 cells and investigate the relationship between HPV and EC.

METHODS: Genomic DNA and total RNA from EC109 cells were isolated. HPV DNA was detected by polymerase chain reaction (PCR) with the general primer sets of My09/11 and GP5 +/6 + for the HPV L1 gene and type-specific primer sets for HPV18 E6 and HPV18 E6-E7. Reverse transcription (RT) of mRNA isolated from EC109 cells was performed to produce a cDNA. And then a PCR-based protocol for the amplification of papillomavirus oncogene transcripts was used to analyze HPV18 DNA and integrated transcripts of HPV18 in the chromosomes of EC109 cells. The final nested PCR products were cloned into a pMD-18T vector and sequenced to analyze the chromosomal location of HPV integration.

RESULTS: HPV18 DNA was detected in EC109 cells by PCR using the general primer sets of My09/11 and GP5 +/6 + for HPV L1 and the type-specific primer sets for HPV18 E6 and E6-E7 to generate products of 450 bp, 150 bp, 335 bp and 944 bp, respectively. Approximately 600 bp of integrated HPV18-specific transcript was identified. The final nested PCR product of integrated HPV18 DNA was cloned into a pMD-18T vector and sequenced to analyze the chromosomal location of HPV integration. Sequence alignment showed that the HPV18 sequence from EC109 cells was identical to that of the encoded early protein E7-E1 of the standard HPV18 strain X05015, and another partial gene sequence was identical to a partial sequence of human chromosome 8.

CONCLUSION: Integration of the HPV genome into the host cell chromosome suggests that persistent HPV infection is vital for malignant cell transformation and carcinogenesis.

Assessment of immunohistochemistry for p16INK4 and high-risk HPV DNA by in situ hybridization in esophageal squamous cell carcinoma

The role of high-risk human papillomavirus (HPV) in the pathogenesis of esophageal squamous cell carcinoma (ESCC) remains unclear. p16(INK4) is used as a surrogate marker to detect HPV-related tumors but has had discrepant results in ESCC. In this study, 32 cases of ESCC were examined to determine the relationship between p16(INK4) expression and high-risk HPV. All the tumors were stained by immunohistochemistry for p16(INK4). Tumors having p16(INK4) nuclear and/or nuclear and cytoplasmic expression were considered positive. Tumors positive for p16(INK4) expression were tested for high-risk HPV by in situ hybridization (ISH). In all, 20 cases of ESCC (63%) showed only cytoplasmic staining for p16(INK4), and 11 cases (34%) showed both cytoplasmic and nuclear staining for p16(INK4); 4 cases (13%) showed no staining for p16(INK4). None of the p16(INK4) -positive cases were positive for high-risk HPV by ISH. These results indicate that p16(INK4) expression in ESCC does not correlate with the presence of high-risk HPV DNA by ISH. High-risk HPV does not seem to play a major role in the carcinogenesis of ESCC in low-risk areas.

Vaccination against human papilloma virus (HPV): epidemiological evidence of HPV in non-genital cancers

Recently, the vaccine against human papillomavirus (HPV) was introduced in the national vaccination programmes of several countries worldwide. The established association between HPV and the progression of cervical neoplasia provides evidence of the expected protection of the vaccine against cervical cancer. During the last two decades several studies have also examined the possible involvement of HPV in non-genital cancers and have proposed the presence of HPV in oesophageal, laryngeal, oropharyngeal, lung, urothelial, breast and colon cancers. The possible involvement of HPV in these types of cancer would necessitate the introduction of the vaccine in both boys and girls. However, the role of HPV in the pathogenesis of these types of cancer has yet to be proven. Moreover, the controversial evidence of the possible impact of the vaccination against HPV in the prevention of non-genital cancers needs to be further evaluated. In this review, we present an overview of the existing epidemiological evidence regarding the detection of HPV in non-genital cancers.

Papillomavirus and disease in humans and animals

Papillomavirus (PV) induces exophytic lesions (papillomas, warts) and flat lesions (flat warts, cervical intraepithelial neoplasia) in cutaneous and mucosal epithelia. The lesions are usually benign and generally regress without eliciting any serious clinical problems in a host but occasionally persist. Persistent lesions can be debilitating and can also provide a focus for malignant transformation to squamous cell carcinoma, particularly in the presence of environmental or genetic cofactors. This has been experimentally demonstrated in animals, particularly in cattle, where bovine PV (BPV)-induced papillomas progress to cancer of the upper gastrointestinal (GI) tract and the urinary bladder in animals exposed to bracken fern in the pasture, and in rabbits, where the progression of skin papillomas to squamous cell carcinoma depends on a particular variant of cottontail rabbit PV (CRPV) and on the major histocompatibility complex (MHC) class II haplotype of the animal. In this review, various aspects of the biology of BPV and CRPV are described and compared with those of human PV, including viral genome structure, regulation of transcription of the viral oncogenes, function of the viral oncoproteins, co-operation between virus and cofactors, virus latency, immunity and vaccination.

Basaloid squamous cell carcinoma of the esophagus: assessment for high-risk human papillomavirus and related molecular markers

Basaloid squamous cell carcinoma (BSCC) of the esophagus is rare, historically confused for adenoid cystic carcinoma, and recently shown to behave similar to conventional, keratinizing esophageal squamous cell carcinoma. At other sites (eg, oropharynx, anogenital tract) the basaloid phenotype is frequently associated with the presence of high-risk human papillomavirus (HPV). HPVs role in esophageal squamous cell carcinomas is less certain, and to our knowledge, a direct examination of esophageal BSCC for high-risk HPV has not been performed earlier. Nine cases of esophageal BSCC were retrieved from our surgical pathology files. Twenty-two cases of keratinizing esophageal squamous cell carcinoma served as controls. In situ hybridization (ISH) for high-risk HPV and immunohistochemistry for related molecular markers including p53, cyclin D1, and p16 (scored 0 to 4+ based on percentage of cells staining; p53 additionally scored for intensity) were performed. HPV ISH was nonreactive in all tested cases. Compared with controls, BSCC showed less immunoreactivity for p16 and p53 (P=0.003, 0.009). Esophageal BSCC is negative for high-risk HPV by ISH, distinguishing these lesions from other BSCCs. Differential p16 and p53 expression in BSCC suggests that these tumors are molecularly distinct from conventional esophageal squamous cell carcinomas.

Detection of human papillomavirus DNA in squamous cell carcinoma of the esophagus by auto-nested PCR

The aim of the present study was to investigate the presence of human papillomavirus (HPV) in surgical specimens of esophageal squamous cell carcinoma. One hundred and sixty-five paraffin-embedded specimens of esophageal carcinoma were analyzed through high-sensitivity auto-nested polymerase chain reaction (PCR) using the consensus GP5+/GP6+ primer. Twenty-six specimens of esophageal mucosa without malignant disease were also studied as a control group. Two different specific primer sets targeting the E6 region of the HPVs 16 and 18 were used for typing. Direct DNA sequence analysis was conducted to confirm positive PCR results. HPV DNA was detected in 26 esophageal carcinomas (15.75%), but in none of the benign esophageal specimens (P < 0.05). Out of the 26 positive cases, 24 were HPV-16 and one was HPV-18. One tumor contained both HPV-16 and -18 DNA. Positive PCR results were confirmed by the amplified viral sequences. Our findings suggest that the presence of either HPV-16 or -18 might be related to development of the malignant phenotype in the esophagus.

Evidence of human papilloma virus infection and its epidemiology in esophageal squamous cell carcinoma

AIM

To look for the evidence of human papilloma virus (HPV) infection in esophageal squamous cell carcinomas (ESCC) and to investigate the potential role and epidemiology of HPV infection in the pathogenesis of esophageal carcinomas in Henan emigrants.

METHODS

Papilloma virus(PV) and HPV were determined by Ultrasensive S-P immunohistochemistry (IHC) and in situ hybridization (ISH)in esophageal carcinoma tissues (82 cases) and the normal mucosa (40 cases).

RESULTS

IHC revealed that the positive rate of PV was 75.0%, 68.18% and 72.5% respectively while the HPV (16/18-E6) positive rate was 45.0%,36.36%, 37.5%, respectively in esophageal carcinoma tissue specimens from Henan emigrants,the local citizens and patients in Hubei Cancer Hospital. The PV and HPV (16/18-E6) were negative in all normal esophageal mucosa specimens. No correlation was found between HPV in esophageal squamous cell carcinoma tissues and in grade 1-3 esophageal squamous cell carcinoma cells. In situ hybridization showed that the HPV (16/18) DNA positive rate was 30.0%, 31.8%, 25.0%, respectively in the 3 groups of samples. No positive hybridization signal was found in 40 normal esophageal mucosa specimens. The positive rate of HPV (16/18) DNA in the esophageal carcinoma specimens was significantly higher than that in normal mucosa specimens (P<0.05). The positive rate was not different among the 3 groups of esophageal carcinoma tissue specimens (P>0.05).

CONCLUSION

HPV infection is high in esophageal carcinoma of Henan emigrants, local residents and patients in Hubei Cancer Hospital.HPV is closely related with esophageal squamous cell carcinoma. HPV infection may play an important role in esophageal squamous cell carcinoma.

Cancer risk among patients with condylomata acuminata

Condylomata acuminata have been shown to increase the risk of anogenital cancers. However, previous studies have been of limited sample size and/or short follow-up duration, which prevent precise estimates of long-term excess risk, especially for specific cancer sites. We estimated the risk of specific cancers in a large cohort of hospitalized patients with condylomata acuminata, as recorded in the Swedish Inpatient Register between 1965 and 1999. Altogether, 10,971 patients (1,685 men and 9,286 women) were followed through 1999 for a median of 13 years. The standardized incidence ratio (SIR)--the ratio of the observed number of cancers to the number expected on the basis of the incidence in the Swedish population at large--was used as a measure of relative risk. After excluding the first-year of follow-up, we observed 43 cases of anogenital cancer in women, and 7 cases in men. Risks were elevated for cancers of the vulva (N = 13, SIR = 10.2, 95% confidence interval (CI) = 5.4-17.4), vagina (N = 4, SIR = 12.0, 95% CI = 3.3-30.7) and penis (N = 5, SIR = 21.9, 95% CI = 7.1-51.2). There was a moderate excess risk of cervical cancer in situ (N = 259, SIR = 1.9, 95% CI = 1.7-2.1), but not invasive cervical cancer. Excess risks of esophageal, buccal cavity, nonmelanoma skin, lung and bladder cancers, and Hodgkin and non-Hodgkin lymphoma, were also observed in both men and women. In conclusion, condylomata acuminata are strongly associated with increased risk of cancers of the vulva, vagina, penis and anus, as well as some nonanogenital malignancies, but not invasive cervical cancer.

HPV-associated carcinoma of esophagus in the young: a case report and review of literature

Esophageal carcinoma (EC) is rare in the younger age group, with only 15 cases reported in world literature. It is even rarer for an etiological agent to be implicated.A case of a 15-yr-old boy with squamous cell carcinoma of the esophagus is reported. Human papillomavirus (HPV) 16 DNA sequences were detected in the neoplasm and the adjacent mucosa by polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP). The adjacent mucosa also showed virus-induced changes.

HPV-18 transformed cells fail to arrest in G1 in response to quercetin treatment

Previous work with primary human keratinocytes demonstrated that quercetin, a potent mutagen found in high levels in bracken fern (Pteridium aquilinum), arrested cells in G1 with concomitant elevation of the cyclin-dependent kinase inhibitor (cdki) p27Kip1. Expression of the human papillomavirus type 16 (HPV-16) E6 and E7 oncoproteins, under transcriptional control of a heterologous promoter, in transformed keratinocytes failed to abrogate this arrest [Beniston, R., Campo, M.S., 2003. Quercetin elevates p27Kip1 and arrests both primary and HPV-16 E6/E7 transformed human keratinocytes in G1. Oncogene 22, 5504-5514]. Given the link between papillomavirus infection, bracken fern in the diet and cancer of the oesophagus in humans, we wished to investigate further whether cells transformed by the whole genome of HPV-16 or HPV-18, with E6 and E7 under the transcriptional control of their respective homologous promoters, would be similarly arrested in G1 by quercetin. In agreement with earlier work, quercetin arrested HPV-16 transformed cells in G1 with an increase in the cyclin-dependent kinase inhibitor p27Kip1. However, HPV-18 transformed cells did not arrest after quercetin treatment. The failure of HPV-18 transformed cells to arrest in G1 was linked to the up-regulation of the HPV-18 long control region (LCR) by quercetin, maintaining high expression of the viral transforming proteins. Transcriptional up-regulation of the HPV-18 LCR was mediated by a "quercetin responsive element" homologous to the one identified previously in the bovine papillomavirus type 4 (BPV-4) LCR.

Quercetin elevates p27(Kip1) and arrests both primary and HPV16 E6/E7 transformed human keratinocytes in G1

Our previous work with primary bovine fibroblasts demonstrated that quercetin, a potent mutagen found in high levels in bracken fern (Pteridium aquilinum), arrested cells in G1 and G2/M, in correlation with p53 activation. The expression of bovine papillomavirus type 4 (BPV-4) E7 overcame this arrest and lead to the development of tumorigenic cells lines (Beniston et al., 2001). Given the possible link between papillomavirus infection, bracken fern in the diet and cancer of the upper gastrointestinal (GI) tract in humans, we investigated whether a similar situation would occur in human cells transformed by human papillomavirus type 16 (HPV-16) oncoproteins. Quercetin arrested primary human foreskin keratinocytes in G1. Arrest was linked to an elevation of the cyclin-dependent kinase inhibitor (cdki) p27(Kip1). Expression of the HPV16 E6 and E7 oncoproteins in transformed cells failed to abrogate cell cycle arrest. G1 arrest in the transformed cells was also linked to an increase of p27(Kip1) with a concomitant reduction of cyclin E-associated kinase activity. This elevation of p27(Kip1) was due not only to increased protein half-life, but also to increased mRNA transcription.

Epstein-Barr virus (EBV)-related oral squamous cell carcinoma in Okinawa, a subtropical island, in southern Japan--simultaneously infected with human papillomavirus (HPV)

Up to now, many authors have reported on the EBV infection and its carcinogenic importance in undifferentiated nasopharyngeal carcinoma (WHO classification, type III), but the infection of the virus in well differentiated oral squamous cell carcinoma has not been well described. We introduce the EBV-related well differentiated oral squamous cell carcinomas in Okinawa, a subtropical island in the southernmost part of Japan. This study aimed to clarify the pathogenesis of this malignancy in this area by carrying out analysis of the histology and the Epstein-Barr (EBV) and human papillomavirus (HPV) infection. In the Department of Oral Surgery, Ryukyu University Hospital Okinawa, 188 cases of oral malignant tumours were encountered from 1996 to 2000. The histopathological examination and the sequence analysis of LMP-1 carboxy terminal region and EBNA2 region of EBV were carried out, as were the analysis of virus subtypes, A and B, BamHI-F and f, and C and D. Additionally, HPV infection in the squamous cell carcinomas were demonstrated using E6 and E7 region primer sets by PCR method. In Okinawa, 94% (177/188) of the cases were squamous cell carcinomas. A surprisingly large number of EBV (72%) and HPV (78%) infections in the oral squamous cell carcinomas were demonstrated. EBV type B virus infection was found in 36% of EBV-related oral squamous cell carcinoma in Okinawa, but in only 2-5% of the mainland cases. In both regions the incidence of the BamHI- f variant infection was very low. The infected virus in 79 out of 80 (39 Okinawan and 41 mainland) cases was BamHI- F type. In Okinawa, the numbers of C and D variants were almost equal, whereas in the mainland the D variant was rare. Further, a 30 bp deletion in LMP-1 gene was frequently demonstrated in Okinawan and mainland cases of type A virus, but not in type B virus. Lastly, single nucleotide mutations in EBNA2 region of type A virus when compared with B95-8 strain were demonstrated in Okinawan cases. The prognosis for (mostly EBV/HPV infected) squamous cell carcinomas in Okinawa was better than that in the mainland where most cases were negative for EBV and/or HPV.

Detection of human papillomavirus DNA and p53 gene mutations in esophageal cancer samples and adjacent normal mucosa

BACKGROUND/AIM

There is evidence of a possible etiological role of human papillomaviruses (HPVs) in the development of esophageal tumors. Loss of function of the wild-type p53 tumor suppressor gene product by binding to E6 oncoproteins of high-risk HPVs is considered an important event in tumor development. The aim of this study was to verify the prevalence of HPV infection and p53 mutation in esophageal tumor tissue samples and in the adjacent normal mucosa in patients from a high-risk area in Italy.

METHODS

DNA from 33 biopsy specimens (17 tumor sample biopsies and 16 samples of adjacent normal mucosa) was screened for HPV DNA using two polymerase chain reaction based procedures. Restriction fragment length polymorphism analysis was used for typing. Screening of p53 mutations was performed with polymerase chain reaction-single strand conformation polymorphism analysis and DNA sequencing.

RESULTS

Overall, 8 of 17 patients presented HPV DNA; HPV 16 was detected in 4 of 8 samples. Samples from tumors and adjacent mucosa were positive for mucosal HPVs in 7 of 17 and 4 of 16 cases, respectively. In 1 case, HPV DNA was detected in the normal mucosa only. None of the samples contained HPVs of the epidermodysplasia verruciformis or cutaneous groups. Mutations of p53 were detected in two HPV DNA negative samples. In both cases, the mutation was present in the tumor only.

CONCLUSIONS

Our results are in favor of the involvement of both aberrant p53 expression and HPV infection in the development of esophageal tumors. The high HPV infection rate in patients from a high-risk region suggests that subjects harboring HPVs (in particular HPV 16) in the esophagus should be considered at risk of esophageal malignancies.

Animal models of papillomavirus pathogenesis

Tumorigenesis due to papillomavirus (PV) infection was first demonstrated in rabbits and cattle early last century. Despite the evidence obtained in animals, the role of viruses in human cancer was dismissed as irrelevant. It took a paradigm shift in the late 1970s for some viruses to be recognised as 'tumour viruses' in humans, and in 1995, more than 60 years after Rous's first demonstration of CRPV oncogenicity, WHO officially declared that 'HPV-16 and HPV-18 are carcinogenic to humans'. Experimental studies with animal PVs have been a determining factor in this decision. Animal PVs have been studied both as agents of disease in animals and as models of human PV infection. In addition to the study of PV infection in whole animals, in vitro studies with animal PV proteins have contributed greatly to the understanding of the mechanisms of cell transformation. Animal PVs cause distressing diseases in both farm and companion animals, such as teat papillomatosis in cattle, equine sarcoids and canine oral papillomatosis and there is an urgent need to understand the pathogenesis of these problematic infections. Persistent and florid teat papillomatosis in cows can lead to mastitis, prevent the suckling of calves and make milking impossible; heavily affected animals are culled and so occasionally are whole herds. Equine sarcoids are often recurrent and untreatable and lead to loss of valuable animals. Canine oral papillomatosis can be very extensive and persistent and lead to great distress. Thus the continuing research in the biology of animal PVs is amply justified. BPVs and CRPV have been for many years the model systems with which to study the biology of HPV. Induction of papillomas and their neoplastic progression has been experimentally demonstrated and reproduced in cattle and rabbits, and virus-cofactor interactions have been elucidated in these systems. With the advancements in molecular and cell culture techniques, the direct study of HPV has become less problematic and understandably research efforts have shifted in focus from animal to human PVs. However, there are still areas in which studies on animal PVs will continue to provide answers to questions pertaining to virus biology. One of these questions is the involvement of HPV in oesophageal and bladder cancer in humans as is the case for BPV in cattle. Another is the site of viral latency. Lymphocytes have been proposed as a site of latency for both BPV and HPV but only experiments performed in animals could clarify this point. Animal PVs have been instrumental in the development of vaccines as cattle, rabbit and more recently dog all provide the opportunity to study vaccination in the natural host. Several anti-HPV vaccines, both prophylactic and therapeutic, based on those developed in animals, are now in clinical trials with encouraging results. In vitro studies with two animal PV early proteins, the transcriptional regulator E2 and the oncoprotein E5, among others, have contributed to the elucidation of viral gene control and cell transformation. BPV E2 was the first viral product to be identified as a transcriptional regulator; more recently, its association with mitotic chromosomes has been suggested as a mechanism for the partition of viral genomes between daughter cells, and its L2-mediated localisation in the sub-nuclear compartments PODs is believed to favour viral DNA encapsidation. E5 is the major transforming protein of several BPVs. Many of the function of E5 proteins have been first established for BPV E5 and later validated for HPV E5. E5 interacts with 16k ductin/subunit c and this interaction is deemed responsible for the down-regulation of gap junction intercellular communication and the inhibition of acidification of endomembranes. E5 activates growth factor receptors and numerous kinases, including cdks, and down-regulates expression of MHC class I. Thus E5 would help the establishment of viral infection by promoting both cell proliferation and immune evasion. Despite the extensive studies on vaccination in animals, E5 has not been tried inE5 has not been tried in animal models as a possible anti-papillomavirus vaccine. A recent study has reported that vaccination of mice with HPV-16 E5 in a recombinant adenovirus reduced the growth of tumours induced by E5-expressing cells. Perhaps this is an instance in which work on animal PVs should follow HPV and the potential for E5 vaccination should be validated in naturally occurring animal models.

Detection of human papillomavirus in esophageal carcinoma

The aim of the study was to assess the prevalence of human papillomavirus (HPV) in the esophagus in the coastal region of Eastern Guangdong, Southern China, an area with a high incidence of esophageal carcinoma. Fresh surgical resection esophageal specimens were obtained from 176 esophageal carcinoma patients admitted to the Tumor Hospital of Shantou University Medical College. The samples were subjected to polymerase chain reaction (PCR) to detect HPV infection using consensus and type-specific primers for HPV type 6, 11, 16, and 18. The incidence rate was 65.5%, 69.1%, and 60% in tissues of cancerous, paracancerous and normal mucosa, respectively. Further analysis of the distribution of HPV types in the three sections of tissues showed that the high-risk HPV types 16 and 18 were found mainly in the cancer cells (43.2%), whereas the low-risk HPV types 6 and 11 were seen mainly in the normal mucosa (52.3%). The total infection rate of the high-risk HPV types 16 and HPV 18 was the highest in cancerous tissues (54.5%), followed by paracancerous tissues (19.5%), and the lowest in normal mucosa (11.7%). There was high incidence of HPV infection in the esophageal epithelium in Eastern Guangdong, Southern China, where esophageal carcinoma is prevalent. HPV was seen in the normal, paracancerous and cancerous tissues, with the high-risk HPV type 16 and 18 more common in cancerous tissues. The results indicate that the high incidence of esophageal carcinoma in this area is associated with HPV infection.

HPV infections and oesophageal cancer

The first reports suggesting an involvement of human papillomavirus (HPV) in the development of both benign and malignant squamous cell tumours of the oesophagus date back to 1982. Since then, a substantial amount of literature has accumulated on this subject, summarised in this review. To date, 239 oesophageal squamous cell papillomas have been analysed in 29 separate studies using different HPV detection methods, with HPV being detected in 51 (21.3%) cases. Many more squamous cell carcinomas have been analysed: of the 1485 squamous cell carcinomas analysed by in situ hybridisation, 22.9% were positive for HPV DNA, as were 15.2% of the 2020 cases tested by the polymerase chain reaction. In addition, evidence derived from large scale serological studies, animal experiments, and in vitro studies is discussed in the light of the highly variable geographical incidence rates of oesophageal carcinoma worldwide. It may be that the (multifactorial) aetiology of oesophageal cancer differs greatly between those geographical areas with a low risk and those with a high risk for this disease. Oncogenic HPV types seem to play an important causal role, particularly in high risk areas.

HPV infections and oesophageal cancer

The first reports suggesting an involvement of human papillomavirus (HPV) in the development of both benign and malignant squamous cell tumours of the oesophagus date back to 1982. Since then, a substantial amount of literature has accumulated on this subject, summarised in this review. To date, 239 oesophageal squamous cell papillomas have been analysed in 29 separate studies using different HPV detection methods, with HPV being detected in 51 (21.3%) cases. Many more squamous cell carcinomas have been analysed: of the 1485 squamous cell carcinomas analysed by in situ hybridisation, 22.9% were positive for HPV DNA, as were 15.2% of the 2020 cases tested by the polymerase chain reaction. In addition, evidence derived from large scale serological studies, animal experiments, and in vitro studies is discussed in the light of the highly variable geographical incidence rates of oesophageal carcinoma worldwide. It may be that the (multifactorial) aetiology of oesophageal cancer differs greatly between those geographical areas with a low risk and those with a high risk for this disease. Oncogenic HPV types seem to play an important causal role, particularly in high risk areas.

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.

Quercetin, E7 and p53 in papillomavirus oncogenic cell transformation

Bovine papillomavirus type 4 (BPV-4) infects the upper alimentary canal of cattle causing benign papillomas which can progress to squamous carcinomas in cattle grazing on bracken fern (BF). We have previously shown that quercetin, a well characterized and potent mutagen found in BF, causes cell cycle arrest of primary bovine cells (PalF), but that a single exposure to quercetin can cause full oncogenic transformation of PalF cells partially transformed by BPV-4. Here we show that cell cycle arrest correlates with an increase in p53 protein levels and transcriptional activity. However, in cells transformed but non-tumorigenic, p53 protein is elevated and transcriptionally activated in response to quercetin or other DNA damaging stimuli, but the cells bypass quercetin-induced G1 arrest likely due to E7 expression. In transformed tumorigenic cells, p53 is elevated in response to quercetin but its transcriptional activity is inhibited due to mutation, and the cells fail to stop in G1 in the presence of quercetin.

Excess incidence of squamous cell esophageal cancer among US Black men: role of social class and other risk factors

Data from a population-based case-control study were used to evaluate the relation between social class factors and squamous cell esophageal cancer and the extent to which alcohol, tobacco, diet, and low income contribute to the higher incidence among Black men than among White men in the United States. A total of 347 male cases (119 White, 228 Black) and 1,354 male controls (743 White, 611 Black) were selected from three US geographic areas (Atlanta, Georgia, Detroit, Michigan, and New Jersey). Cases were residents of the study areas aged 30-79 years who had been diagnosed with histologically confirmed esophageal cancer between 1986 and 1989. The adjusted odds ratios for subjects with annual incomes less than $10,000 versus incomes of $25,000 or more were 4.3 (95% confidence interval: 2.1, 8.7) for Whites and 8.0 (95% confidence interval: 4.3, 15.0) for Blacks. The combination of all four major risk factors-low income, moderate/heavy alcohol intake, tobacco use, and infrequent consumption of raw fruits and vegetables-accounted for almost all of the squamous cell esophageal cancers in Whites (98%) and Blacks (99%) and for 99% of the excess incidence among Black men. Thus, lifestyle modifications, especially a lowered intake of alcoholic beverages, would markedly decrease the incidence of squamous cell esophageal cancer in both racial groups and would narrow the racial disparity in risk. Further studies on the determinants of social class may help to identify a new set of exposures for this tumor that are amenable to intervention.

Recent striking changes in histological differentiation and rate of human papillomavirus infection in squamous cell carcinoma of the lung in Okinawa, a subtropical island in southern Japan

AIMS

The incidence of lung cancer in Okinawa has been the highest in Japan since 1975, and squamous cell carcinoma (SCC), especially the well differentiated form, is the most prevalent form in Okinawa, although well differentiated SCC is relatively rare in mainland Japan. Furthermore, a high proportion of SCC of the lung in Okinawa was positive for human papillomavirus (HPV). In this study, we report recent striking changes in histological features and in the incidence of HPV infection.

METHODS

In Okinawa between 1986 and 1998, 1109 surgically resected lung tumours were examined histopathologically. In addition, human papillomavirus infection was detected by the polymerase chain reaction and Southern blot analysis in SCC cases reported in 1993 and 1995-8. Non-isotopic in situ hybridisation of HPV DNA was also carried out.

RESULTS

Up until 1994 SCC, especially the well differentiated form, was the most prevalent type of tumour. However, since 1995 the number of such cases has diminished steadily, accompanied by a slight rise in the incidence of adenocarcinoma. Although most present and past patients are heavy smokers, the incidence of SCC, especially the well differentiated form, continues to decrease steadily. Furthermore, in 1993, HPV was detected in 79% of all cases, and was particularly prevalent in the well differentiated form, but the rate fell to 68% in 1995, 35% in 1996, 23% in 1997, and 24% in 1998. The age distribution of patients, the male to female ratio, and the number of tumours overexpressing p53 protein did not change significantly over the study period, and thus did not correlate with changes in the differentiation of SCC.

CONCLUSIONS

The decreasing incidence of viral infection correlates strongly with the falling numbers of SCC cases, especially well differentiated cases. These findings suggest that HPV might be involved in the development of SCC of the lung, affecting the histological differentiation of SCC in particular, at least in Okinawa, a subtropical island in southern Japan.

Detection of human papillomavirus DNA in bronchopulmonary carcinomas by hybrid capture II: a study of 185 tumors

BACKGROUND

Some human papillomaviruses (HPVs) are oncogenic in the cervix and are also associated with benign and malignant proliferations in other organs. Currently, the association of HPV with tumors of the lower respiratory tract is not so clearly defined because the studies are difficult to compare; series of cases reported from different geographic regions have used frozen or formalin fixed samples and a variety of techniques of HPV detection.

METHODS

The authors studied the prevalence of HPV in a large series of 185 frozen bronchopulmonary tumor samples with a new solution hybridization technique, Hybrid Capture II assay. This test is largely applied in cervical pathology. Its sensitivity is very close to the sensitivity of PCR. It allows the detection of 18 mucosal HPV types, divided into 1 oncogenic and 1 nononcogenic group.

RESULTS

Oncogenic HPV DNA was detected by the Hybrid Capture II assay in 5 cases (2.7%) of 185 (3 males and 2 females). In the rare positive cases detected, the authors could not find any consistent morphologic changes classically associated with HPV infection in anogenital lesions, such as koilocytosis.

CONCLUSIONS

Oncogenic HPV DNA is detected in a small proportion of cases of bronchopulmonary carcinoma, and thus HPV infection appears to play a limited role in the tumorigenesis of most lung carcinomas.

Molecular biology of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the predominant histologic subtype of esophageal cancer and characterized by high mortality rate and geographic differences in incidence. With the advances in the field of molecular biology, our understanding of the pathogenesis, epidemiology and behavior of ESCC continues to evolve. The recent development includes research in etiopathogenesis (viruses and cancer susceptibility genes), keratins, tumor related genes (oncogenes, tumor suppressor genes, genes involved in metastasis and apoptosis genes), proliferation-related factors (nuclear proteins, flow cytometry/morphometry, argyrophilic nucleolar organizer region) and factors related to metastases (cell adhesion molecules and enzymes related to degradation of extracellular matrix). There are ranges of molecular techniques potentially available to complement the traditional approaches in the management of ESCC. On the other hand, critics are needed in the interpretation and translation of these research findings from laboratories to clinics. Further investigations, education and collaborations between the various scientific and clinical disciplines are important to successful application of these molecular findings aiming at improving management of patients with ESCC.

Detection of Epstein-Barr virus in esophageal squamous cell carcinoma in Taiwan

OBJECTIVE

Recently, an association between viral infection and the development of esophageal carcinoma has been reported, particularly the human papilloma virus (HPV) and Esptein-Bar virus (EBV). However, geographic variation in carcinogenesis is realized. In this study, we investigate the viral carcinogenesis and the biologic effect of viral infection on esophageal squamous cell carcinoma (ESCC) in Taiwan.

METHODS

To determine the association of viral infection (EBV and HPV) with ESCC, we applied polymerase chain reaction (PCR), immunohistochemistry, and in situ hybridization (ISH) to examine 119 surgical specimens from different sites of esophagus in 31 ESCC patients. Additionally, an immunoperoxidase method was used to detect EBV latent membrane protein-1 (LMP-1), p53, CD45RO (UCHL-1), Fas ligand (Fas L), and RNA ISH with oligonucleotide sequences was used to detected interleukin-6 (IL-6) mRNA.

RESULTS

By PCR, EBV DNA was detected in 11 cases (35.5%). Expression of EBERs in ESCC was further confirmed with ISH. Nonetheless, no LMP-1 expression was detected. On the other hand, human papillomavirus (HPV) was identified in only one case (3.2%) of ESCC. Furthermore, HPV was located by ISH in the distant normal region rather than in tumor cells. In EBV-positive cases, accumulation of p53 protein was detected in 10 lesions (91%); CD45RO+ lymphocytes together with expressions of FasL and IL-6 were respectively identified in 100%, 63.6%, and 54.5% of 11 EBV-positive lesions. Interestingly, in the EBV-negative cases (n = 20), p53 protein was detected in 40% of lesions; CD45RO 30%; FasL 50%, and IL-6 10%.

CONCLUSIONS

In this study, no correlation was found between the presence of EBV in ESCC and the patients' age, sex, as well as survival. Although our results indicate that EBV could be associated with ESCC, the clinical role of EBV in ESCC remains to be determined.

Papillomavirus in esophageal papillomas and carcinomas

Human papillomavirus (HPV) has been implicated as a possible etiological factor in the development of squamous-cell carcinoma of the esophagus. Published data demonstrating HPV DNA in these lesions have been conflicting, varying between failure to detect HPV DNA to detection of up to 60% to 70% of the biopsies harboring HPV DNA, mainly HPV 16 and HPV 18. We have analyzed esophageal carcinoma samples from 2 high-risk areas, China and South Africa, using a degenerate PCR approach. All amplified products were cloned and sequenced. A broad spectrum of HPV types was demonstrated in 10/29 samples from China and 9/34 samples from South Africa. HPV types detected included mucosal types HPV 6, 18, 51, 52 and 57; cutaneous types HPV 9, 20, 24 and 25; and the putative new HPV types DL231, DL428 and DL436, with HPV 6/51, 6/57, 20/9 and 20/DL231 occurring as double infections. HPV 6 predominated (4 samples) in 11 esophageal papillomas originating from patients in Europe and tested for HPV DNA. Other HPV types present included HPV 20, DL284 and DL436. Another putative new HPV type, DL416, was identified in a dysplastic lesion of the esophagus.

The role of the human papilloma virus in esophageal cancer

Esophageal squamous cell carcinoma (ESCC) demonstrates wide regional variation in incidence and causal associations. Human papillomavirus (HPV) has been implicated in ESCC, particularly the sub-types 16 and 18. Transforming proteins E6 and E7 from these high risk sub-types, interact with p53 protein and Rb protein respectively, leading to loss of function of these tumor suppressor gene products. These interactions further lead to inactivation of the growth suppressive effects of the p53 and Rb proteins, resulting in abnormal proliferative states. p53 protein expression has been found in both HPV-positive and -negative tumors, indicating that HPV and p53 protein expression are not mutually exclusive and can occur together in the same tumor. It has been observed that HPV plays a more significant role in esophageal carcinogenesis in geographic areas with a high prevalence of the disease. A variation in the association between HPV and ESCC worldwide may be due to environmental and geographic factors, or to genetic susceptibility to esophageal HPV infections. Variations in the sensitivity of techniques used in the detection of the virus and in the methodology for processing the tumor tissues, may also be responsible for global differences. Esophageal carcinogenesis is a complex multistep process with a multifactorial etiology. Infection with oncogenic HPV types may be an integral part in a multistep process that leads to ESCC.

Human papillomavirus DNA in adenosquamous carcinoma of the lung

AIM

To investigate the presence of human papillomavirus (HPV) DNA in adenosquamous carcinoma of the lung--which is relatively common in Okinawa but not in mainland Japan--and examine its histological features.

METHODS

Of 207 cases where primary lung cancers were surgically removed between January 1995 and June 1997 in Okinawa, 23 were adenosquamous carcinoma. HPV was detected by non-isotopic in situ hybridisation (NISH) and polymerase chain reaction (PCR) amplification with primers specific for E6 and E7 regions of the HPV genome. PCR products were analysed by Southern blotting. Immunohistochemical determination of high molecular weight cytokeratin (HMC) and involucrin was also carried out.

RESULTS

18 cases were positive for HPV DNA by PCR and NISH. HPV types 6, 11, 16, and 18 were found. Seven cases were dual positive for different types of HPV. Using NISH, HPV was also found in the squamous cell components and in neighbouring enlarged adenocarcinoma cells. The HMC and involucrin were demonstrated immunohistochemically in the same areas.

CONCLUSIONS

HPV DNA was found in a high proportion (78.3%) of adenosquamous carcinomas in Okinawa, a region where HPV has previously been shown to be prevalent in squamous cell carcinoma of the lung. The adenocarcinoma cells adjacent to the squamous cell carcinoma component were enlarged and positive for HPV, HMC, and involucrin. This is thought to indicate the transition from adenocarcinoma to squamous cell carcinoma.

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 infection in esophageal carcinomas: a study of 121 lesions using multiple broad-spectrum polymerase chain reactions and literature review

To elucidate the putative role of human papillomavirus (HPV) infection in the etiology of esophageal cancer, 121 formalin-fixed, paraffin-embedded specimens originating from a non-high-incidence area for this carcinoma, from Slovenia, were screened for HPV infection using eight different polymerase chain reactions (PCR). Three different HPV consensus primer sets and four primer sets specific for HPV types 6, 16, and 18 failed to detect HPV DNA sequences in any of the tumor samples. Fragments of human beta-globin gene that served as internal controls were successfully amplified from 120 of 121 specimens. Our study confirms the opinion that most esophageal cancers originating from non-high-incidence geographic areas of this cancer are not associated with HPV infection. According to the studies reviewed, it is likely that HPV infection plays a much more significant role in esophageal carcinogenesis in those areas of the world with a high incidence of ESCC.

Carcinoma of the lung in Okinawa, Japan: with special reference to squamous cell carcinoma and squamous metaplasia

In Okinawa, a subtropical island in southern Japan, squamous cell carcinoma (SCC), especially the well-differentiated form, is prevalent, while this form is relatively rare in both the mainland and other countries (e.g. United States of America). More patients with SCC from Okinawa, moreover, were positive for human papillomavirus (HPV) DNA by polymerase chain reaction (PCR) (79%), and harbored HPV types 6, 16 and 18, in combination. On the other hand, less than 30% of the mainland patients were positive for HPV DNA by PCR. Those patients who were positive all harbored only one HPV type. Furthermore, in Okinawa, there were a significant number of cases with adenosquamous carcinoma, and they too were positive for HPV DNA. The SCC and the adenocarcinoma cells adjacent to the SCC component in these cases were also positive for HPV DNA, and such adenocarcinoma cells were enlarged in size with relatively wide cytoplasm. The authors postulate that HPV infects adenocarcinoma cells and changes them to enlarged cells, followed by squamous metaplasia. In this report, HPV DNA was transfected to adenocarcinoma cells (cultured cell lines) and this showed that HPV causes squamous metaplasia. In addition, aberrant expression of p53 was demonstrated in a large number of the SCC cases in Okinawa. The enlarged adenocarcinoma cells adjacent to the SCC components in adenosquamous carcinomas also showed aberrant expression of p53. The recent advances in the studies of anti-oncogenes, p53, etc. and oncogenes are outlined. It is to be noted that the molecular mechanisms of carcinogenesis in the lung have been studied in general, classifying lung tumors into two groups, namely, small cell carcinoma (SCLC) and non-small cell carcinoma (NSCLC). However, because human lung cancer is represented by a wide variety of histologic types, molecular genetic studies according to a more detailed histological subclassification is needed.

Prevalence of HPV infection in esophageal squamous cell carcinoma in Chinese patients and its relationship to the p53 gene mutation

Human papillomavirus (HPV), in particular types 16 and 18, is positively associated with anogenital cancers and may be an important etiologic factor in their pathogenesis. The goal of our study was to investigate the role of HPV infection in the pathogenesis of esophageal squamous cell carcinoma (ESCC) and its relationship with the p53 mutation. We have examined ESCC collected from Sichuan, China, for the presence of HPV infection and p53 mutation. The presence of HPV DNA was detected by PCR-Southern analysis while the p53 mutation was analyzed by PCR-SSCP. High-risk HPV (types 16 and 18) DNA was detected in 32 out of 152 cases of ESCC examined. In contrast, HPV DNA was not detected in normal esophageal tissues excised from the distant end (tumor free) of resected ESCC. Mutation of the p53 gene was detected in 22 out of 55 cases of ESCC. The distribution of the 22 p53 mutation was: 5 in exon 5, 1 in exon 6, 5 in exon 7, 10 in exon 8 and 1 in exon 10. The p53 mutation was detected at a significantly lower rate in ESCC with HPV infection. Our results support a role of HPV infection in the pathogenesis of ESCC from a high-incidence area.

Absence of human papillomavirus genomic sequences detected by the polymerase chain reaction in oesophageal and gastric carcinomas in Japan

AIMS

To estimate the occurrence of human papillomavirus (HPV) infection in oesophageal or gastric carcinomas in patients in Japan.

METHODS

103 oesophageal and 99 gastric carcinomas were investigated by polymerase chain reaction (PCR) assays using two consensus (targeting either the L1 or the E6-E7 regions) and two type specific (type 16 and 18) primer sets. A beta globin gene specific primer set was also applied to examine the quality of the extracted DNA.

RESULTS

Amplification of beta globin gene was clearly visible in 92 (89.3%) of the 103 oesophageal, and 89 (89.8%) of the 99 gastric carcinoma specimens. However, the entire series of tumour DNA was negative for HPV sequences by PCR assay using all four primer sets.

CONCLUSION

HPV is not likely to be involved in oesophageal or gastric tumorigenesis in Japanese patients.