Analysis of human papillomavirus DNA in oral squamous cell carcinomas

Evidence from several laboratories suggests that HPV plays a role in the etiology of squamous cell carcinomas of the oral cavity. A rnultifactorial risk factor profile for the development of oral cancer may include HPV in addition to well-established risk factors such as tobacco and alcohol use. The prevalence of oral carcinomas repotted to be associated with HPV has varied widely due to differences in the sensitivity of the assay used for HPV detection. The aims of this study were: (1) to ascertain the prevalence of HPV DNA in oral squamous cell carcinomas using the most sensitive technique available, the polymerase chain reaction; (2) to determine the type of HPV in the tumors; and 3) to correlate the virologic data with other risk factor data obtained from patients' records. Fourteen (78%) of 18 primary tumors, 6 (67%) of 9 normal epithelial tissues from the patients and 5 (100%) of 5 neck metastases were HPV DNA-positive. Of the 14 HPV DNA-positive primary tumors, specific typing revealed HPV 16 in 2, HPV 18 in 2, HPV 16 and IS in 5, HPV 6/11, 16 and 18 in 4, and HPV 6/11 in 1. HPV types in the normal or metaslatic tissue were usually the same as those in the respective primary tumor. There was no significant association between HPV presence and any of 12 factors or patient characteristics studied.     

HPV detection in primary intra‐oral squamous cell carcinomas – commensal,aetiological agent or contamination?

BACKGROUND: High-risk human papilloma viruses (HPV) are reported to be significant independent risk factors for oral squamous cell carcinoma (OSCC). The prevalence of HPV in OSCC in a South African population sample was evaluated comparing three different HPV detection methods. METHODS: Tumour and adjacent morphologically normal oral mucosa of 59 resections of primary OSCC were evaluated for the presence of HPV using real-time polymerase chain reaction (PCR), conventional in situ hybridization (ISH), and a signal amplification ISH technique (Dako GenPoint). RESULTS: HPV18 DNA was detected in seven cases using real-time PCR. No positivity was found with the other two ISH techniques. CONCLUSIONS: We support the view that HPV is probably unimportant in the pathogenesis of OSCC and hypothesize HPV detection techniques as the main reason for the positive results in many studies. Real-time PCR was confirmed as the most sensitive technique, but researchers are urged to incorporate strict internal controls when using this detection method.     

The prevalence and distribution of human papillomavirus genotypes in oral epithelial hyperplasia: proposal of a concept

Background:  Evidence is accumulating for the aetiological role of human papillomavirus (HPV) in the pathogenesis of potentially malignant oral mucosal lesions and squamous cell carcinomas.
Methods:  Paraffin tissue sections from 49 patients with 'white patches' of the oral mucosa were investigated histologically, by broad-spectrum PCR followed by genotyping and chromogenic in situ hybridisation (CISH).
Results:  Histologically, 33 flat hyperplasias and 16 papillary hyperplasias were diagnosed. Twenty-two of 28 samples studied (78.6%) were positive for HPV DNA by PCR and six were negative. The following HPV types were detected in decreasing order of prevalence: HPV 35, HPV 6, HPV16, HPV 53, HPV 18, HPV 51 and HPV 55. Seventeen samples (60.7%) contained high-risk HPV DNA. Using CISH, ≥ 1 HPV signals were detected at least in a few epithelial cells in 95% of cases studied. All but one case were positive with the high-risk HPV probe and all HPV infections contained low viral load. Concordant positive results both by PCR and CISH were detected in 14 of 19 cases (73.7%) analysed.
Conclusions:  The high prevalence of HPV infection in hyperplastic 'white patches' of the oral mucosa supports the putative role of HPV at an early stage of oral carcinogenesis. These results further indicate that the majority of white oral mucosal lesions – flat, exophytic, wart-like or papillary proliferations – could be considered as the clinical manifestations of oral HPV infection. This finding has clinical relevance regarding therapy and patient management and may help in elucidating the role of HPV infection in oral carcinogenesis.     

人乳头瘤病毒和人巨细胞病毒与口腔癌的关系

目的：检测口腔白斑和口腔鳞状细胞癌中的人乳头瘤病毒（HPV16）DNA和人巨细胞病毒（HCMV）DNA,探讨HPV16和HCMV与口腔癌之间的关系。方法：应用多聚酶链反应（PCR）技术扩增HPV16DNA和HCMVDNA,采用2%琼脂糖凝胶电泳分析,检测口腔白斑和口腔鳞状细胞癌中的HPV16DNA和HCMVDNA。结果：6例口腔白斑中,HPV16DNA的阳性率为16.7%,HCMVDNA为16.7%,16例口腔鳞癌组织HPV16DNA的阳性率为31.3%,HCMVDNA为25%,例正常组织均未检测出。结论：4HCMV与HPV16在口腔癌的发生中具有协同致癌作用。     

Risk of oral cancer associated with human papillomavirus infection, betel quid chewing, and cigarette smoking in Taiwan — an integrated molecular and epidemiological study of 58 cases

BACKGROUND: The association between oral squamous cell carcinoma (OSCC) and human papillomavirus (HPV) 6, 11, 16 and 18 is uncertain. Past reports varied in the methodology and results. We conducted this study using in situ PCR in situ hybridization (ISH) assay which was considered as the most sensitive method for detection of viral DNA. We undertook an epidemiologic survey about the history of betel quid chewing and cigarette smoking, since these habits are common in Taiwan. METHODS: In situ PCR ISH was performed on the tumor specimens from 29 patients with OSCC and the oral mucosal specimens from 29 patients without OSCC. Their betel quid chewing and cigarette smoking histories were also reviewed. RESULTS: HPV16, HPV18, betel quid chewing and cigarette smoking were statistically significant risk factors in univariate analysis. HPV6 and 11 were not. Multivariate analysis showed that HPV16 infection (adjusted Odds ratio = 11.20) and betel quid chewing (adjusted Odds ratio = 17.06) remained to be independent factors for OSCC. CONCLUSIONS: Our results showed that HPV16 and betel quid chewing were two major risk factors for OSCC in Taiwan, indicating that they act through different mechanisms in the pathogenesis of OSCC.     

Detection of HPV in mouth floor squamous cell carcinoma and its correlation with clinicopathologic variables,risk factors and survival

The human papillomavirus (HPV) has been historically associated with head and neck cancers, although its role in oral carcinogenesis remains poorly defined. The purpose of this study was to investigate the prevalence of HPV in mouth floor squamous cell carcinoma and correlate it with clinicopathologic variables, risk factors and survival. HPV presence was evaluated by nested polymerase chain reaction (nPCR) in 29 paraffin‐embedded specimens of mouth floor squamous cell carcinoma. HPV DNA was detected in 17.2% (5 of 29) of the specimens; the highest prevalence was observed in non‐smoking patients over the age of 60 years. All HPV DNA positive specimens were detected in men with clinical stage III and IV lesions, being most of which were moderately differentiated. Despite this correlation there were no statistically significant differences observed among the analyzed variables, including patients’ survival. The relatively low incidence of HPV DNA present in these tumors suggests that this virus does not, by itself, have a significant role in the development of mouth floor squamous cell carcinoma.     

Increase in placental glutathione S-transferase in human oral epithelial dysplastic lesions and squamous cell carcinomas

This study investigated the immunohistochemical expression of human placental glutathione S-transferase (GST-φ) in the epithelium of oral premalignant and malignant lesions. Epithelial lining of normal oral mucosa, hyperplastic lesions and oral epithelium exhibiting mild dysplasia showed weak to moderate GST-φ staining. Moderate epithelial dysplasia revealed an increased antibody content while severe dysplasia. carcinoma- in-situ (CIS) and squamous cell carcinoma (SCC) demonstrated markedly increased antibody binding. The GST-φ staining was evident mainly in the cytoplasm. Severe dysplasia. CIS and SCC were also characterized by areas of cells with intensive nuclear GST-φ staining. These findings support the hypothesis that GST-φ plays a role in human oral carcinogenesis and may be used as a tumor marker for human oral premalignant and malignant lesions.     

Biopsy vs. superficial scraping: detection of human papillomavirus 6, 11, 16, and 18 in potentially malignant and malignant oral lesions

BACKGROUND: Several epidemiologic studies have shown a broad variation in the prevalence of human papillomavirus (HPV) in oral precancerous tissues and oral carcinomas. METHODS: Biopsies and superficial scrapes of lesions, clinically suspected of HPV infection, were taken from patients with potentially malignant and malignant oral lesions, and subject to HPV DNA detection by PCR-Southern blot analysis. RESULTS: From 22 patients with potentially malignant and malignant lesions analyzed, 41% of the biopsies were HPV DNA positive, whereas 95-100% of the superficial scrapes were positive (McNemar, P < 0.0001). Clinical presumption of HPV infection detected 67% (P < 0.0001) of the HPV DNA positive cases compared with 48% (P < 0.0001) determined by cytology and histopathology. The prevalence of HPV 6, 11, 16 and 18 in the oral mucosa was studied in 59 individuals. While 9% of normal controls were HPV DNA positive, 100% of the patients with potentially malignant and malignant lesions were HPV DNA positive, and the prevailing genotype was HPV 16 followed by HPV 18. CONCLUSIONS: The higher HPV DNA detection rate in superficial oral scrapes than in biopsies suggests that accurate epidemiological information on oral HPV infection/oral carcinogenesis depends not only on the DNA detection technique, but also on the tissue/cell sampling procedure.     

Detection of human papilloma virus type 16 DNA in oral squames from normal young adults

We have employed the polymerase chain reaction (PCR) to detect Human Papillomavirus (HPV) type 16 in oral squames and mononuclear cells from 62 healthy young adult volunteers. Two groups were screened for the presence of this virus, but in not all cases was DNA obtained from the scrapes. In the first (n = 30), the results show that 43% of normal individuals harbour HPV 16 (a genital type) in their buccal mucosa, epithelium of dorsum of tongue and hard palate. In the second group (n = 18), 44% of individuals were positive for HPV 16 in their oral epithelial scrapes, while only 6% were positive for the same virus in mononuclear cells. Interestingly, in 2 cases, peripheral blood lymphocyte DNA gave a positive reaction with the HPV 16 primers. To investigate possible HPV infection of lymphocytes, a further 42 lymphocyte samples, taken from the same age group as the epithelial study group, were analysed. None of these lymphocytes were positive for the presence of HPV 16 DNA.     

GSTM1 enzyme concentration and enzyme activity in correlation to the genotype of detoxification enzymes in squamous cell carcinoma of the oral cavity

BACKGROUND: Differences in genotype and phenotype of detoxification genes could be one reason for conflicting results in studies dealing with gene polymorphisms as susceptibility factors for tobacco associated cancer. OBJECTIVES: The objective of this study was to investigate gene polymorphisms of detoxification enzymes and to determine whether the enzyme concentration and activity of glutathione S transferase microliter 1 correlates with the genotype in patients with cancer of the oral cavity. MATERIAL AND METHODS: In 73 cancer patients and 136 matched healthy controls, the polymorphisms of glutathione S-transferase mu1 and theta (GSTM/GSTT), cytochrome p450 1A1 and CYP2D6 were detected. Simultaneously, GSTM1 protein concentration and total GSTM1-activity were determined. RESULTS: Only the coincidence of GSTM1 and GSTT null genotype was associated with oral cavity cancer. GSTM1 protein concentration and enzyme activity in null-genotype patients was significantly lower than in GSTM1-allele-carrier. But the enzyme concentration did not correlate with the activity. CONCLUSION: We assume that detoxification enzymes are functionally redundant and that only the simultaneous deficiency of several detoxification enzymes increases the risk for oral cancer.     

口腔疣状癌与口腔鳞癌中PTTG1 mRNA表达的对比研究

目的：研究垂体肿瘤转化基因-1（Pituitary tumor transforming gene 1,PTTG1）在口腔疣状癌中的表达,并与口腔鳞癌（OSCC）作比较,探讨其在口腔疣状癌及OSCC中发生发展中的作用。方法采用逆转录多聚酶链反应（RT-PCR）技术分别检测口腔疣状癌和OSCC中PTTG1 mRNA相对含量,并取自身的癌旁黏膜和正常口腔黏膜作比较。结果：PTTG1在疣状癌和无淋巴结转移的高分化SCC的癌组织、正常黏膜和癌旁黏膜中均有不同程度的表达,但这种表达无显著差异（P〉0.05）;在有淋巴结转移的高分化SCC中,PTTG1的表达在癌组织和癌旁黏膜比正常黏膜有增高的趋势,中分化SCC中这种增高趋势更为明显,但统计学上均无显著意义（P〉0.05）。PTTG1在口腔疣状癌、无淋巴结转移的高分化SCC、有淋巴结转移的高分化SCC及中分化SCC四组癌组织中的表达呈现依次增加的趋势,其中口腔疣状癌的表达低于中分化SCC（P〈0.05）,而与高分化SCC无差别（P〉0.05）。结论：在口腔疣状癌,PTTG1的表达与高分化SCC一致,但低于中分化SCC,从总体上说明口腔疣状癌的生物学行为比中分化SCC好,而与高分化SCC一致;PTTG1与口腔疣状癌的发生可能无关,但可能参与了SCC的发生发展过程。     

细胞角蛋白19mRNA在口腔鳞状细胞癌中表达的研究

目的探讨口腔鳞状细胞癌（OSCC）患者癌组织中细胞角蛋白（CK）19 mRNA的变化和其发生的可能机制以及CK19 mRNA检测的临床应用价值。方法收集未接受过放疗和化疗的20例OSCC患者的手术标本（包括癌组织20块、癌旁组织20块和颈清扫的淋巴结43枚）,采用荧光定量聚合酶链式反应（FQ-PCR）法检测组织内CK19 mRNA的表达,比较CK19 mRNA在上述组织中的相对表达量。结果CK19 mRNA在OSCC癌组织内表达比其在正常口腔黏膜内表达高1.85倍,比其在癌旁组织内表达高1.66倍。9例患者颈清扫淋巴结内CK19 mRNA表达阳性,阳性率为45%（9/20）,而9例患者的22枚淋巴结中CK19 mRNA表达阳性率是81.8%（18/22）,占20例患者43枚淋巴结的41.9%（18/43）。淋巴结CK19 mRNA阳性患者的癌组织与癌旁组织和正常口腔黏膜的表达量比CK19 mRNA阴性患者低。结论CK19 mRNA在OSCC癌组织中的表达高于其在癌旁组织和正常口腔黏膜内的表达,可能是由于癌组织中CK19的合成明显增加所致。淋巴结中CK19 mRNA的表达可以作为检测OSCC淋巴结微转移的指标之一,运用FQPCR法检测淋巴结中CK19 mRNA的表达来检测OSCC的淋巴结微转移比普通病理法检测更灵敏。     

High risk human papillomavirus in oral squamous carcinoma: evidence of risk factors in a Venezuelan rural population. Preliminary report

In a search for the presence of human papillomavirus (HPV) and some etiologic cofactors in oral squamous cell carcinoma (OSCC), 50 women diagnosed as OSCC were analyzed by a multiplex polymerase chain reaction (PCR) assay specific for HPV types 6, 11, 16, and 18. This study revealed that 60% (30/50) of the OSCC patients were positive for HPV-DNA sequences. This group was analyzed according to smoking, alcohol consumption, number of pregnancies, poor oral health and low social economic status. The current results indicate an increased incidence of HPV malignant types in the oral cavity in women with OSCC. Also, they support a multifactorial model of oral cancer causation.