p53 polymorphism, human papillomavirus infection in the oral cavity, and oral cancer

OBJECTIVES: Human papillomavirus (HPV) infection has emerged as a risk factor in oral carcinogenesis. An arginine-coding polymorphism of the tumor suppressor protein p53 at codon 72 is more readily degraded by the HPV oncoprotein E6. Our objective was to evaluate the association between p53 polymorphism at codon 72 and HPV infection in the oral cavity, as well as its association with oral cancer.Study Design: Oral squamous cells from 202 patients with oral cancer and 333 age-sex frequency matched controls were evaluated by polymerase chain reaction for the presence and type of HPV and for alleles of codon 72 in p53. Fisher exact test and chi(2) tests were used to evaluate the data. RESULTS: The p53 codon 72 polymorphism is not associated with HPV infection, whether comparing HPV-negative controls with HPV-positive controls or comparing HPV-negative cases with HPV-positive cases. Additionally, we found no association with the codon 72 polymorphism and oral cancer, whether comparing HPV-negative controls with HPV-negative cases or comparing HPV-positive controls with HPV-positive cases. CONCLUSIONS: There is no association between p53 codon 72 polymorphism and HPV infection or between the p53 polymorphism and the risk of oral cancer.     

p53 mutations and human papillomavirus infection in oral squamous cell carcinomas: correlation with overall survival.

PURPOSE: The study investigated the pattern of p53 gene mutations and human papillomavirus (HPV) infection concerning their relation to overall survival in patients with oral squamous cell carcinomas of the tongue and floor of the mouth. PATIENTS AND METHODS: The presence of HPV infection in 50 patients, and p53 gene mutations (42 patients from the same group) in the tumour specimens were analysed by polymerase chain reaction and single-stranded conformational polymorphism method. The follow-up period ranged from 12 to 48 (median 29) months. RESULTS: p53 mutations were identified in 11/42 tumours. HPV infection was detected in 32/50 cases, mostly HPV16 (10/32), HPV18 and HPV31 (6/32). A significantly higher incidence of HPV infection was found among smokers (p<0.05) and among patients with poor oral hygiene (p<0.01). The highest incidence of p53 mutations was detected in tumours of histological grade I and nuclear grade III. Patients with p53 mutation or with HPV infection had significantly shorter overall survival when compared with those that were without p53 mutations (p<0.01) or HPV infection (p<0.05). HPV-infected patients with p53 mutation had the worst prognosis when compared with patients with HPV infection only (p<0.01) or with patients negative for both HPV and p53 (p<0.01). CONCLUSION: The results stress once more the importance of HPV for the prognosis of survival of patients with squamous cell carcinoma of lower parts of the oral cavity. The presence of p53 mutations in HPV-infected tumours was associated with an even poorer prognosis for the patients.     

p53, bcl-2 and bax abnormalities in non-Hodgkin''s lymphomas of the head and neck

In the present study, mutations or protein expression of p53, bcl-2 and bax are reported in 13 non-Hodgkin's B-cell lymphomas of the head and neck. Nine of 13 cases (69.2%) expressed p53 protein and 7 (53.8%) showed gene mutations. On comparing the results of immunostaining and SSCP analysis, there were two cases showing discrepancies between the p53 protein expression and gene mutations. Bcl-2 protein expression was observed in only two cases of follicular lymphoma. On the other hand, bax protein was detected in all 13 cases. One case with mutated bax gene showed a lower expression with a reduced frequency of bax-positive cells than the other 12. These results suggest that inactivation of p53 may be closely related to development and/or progression of these NHLs, and that bcl-2 and bax protein may not have a role.     

P53 and bcl-2 immunoexpression in patients with oral lichen planus and oral squamous cell carcinoma

Objective: The aim of this study was to determine by immunohistochemistry the presence and significance of p53 and bcl-2 proteins in oral lichen planus (OLP) and oral squamous cell carcinoma (OSCC). Study Design: We used 21 cases diagnosed as OLP 16 diagnosed as OSCC and four normal gingival biopsies taken from healthy patients were used as controls. Slides were processed for immunohistochemistry using anti-p53 and anti-bcl-2 monoclonal antibodies. Results: We found p53 immunoexpression in 71.4% OLP cases and 68.7% OSCC cases, with no immunoexpression in control cases. Bcl-2 was negative for all OLP and OSCC cases, and mild positivity was observed in normal tissue. We found significant correlation among p53 expression and OSCC malignancy. Conclusions: Our results suggest that TP53 system mainly promotes a hyperproliferative state by cell cycle arrest of the OLP epithelial cells for repairing damaged DNA nor apoptosis and that anti-apoptotic action of bcl-2 is not important in this disease.     

艾滋病感染者口腔疣状肿块人类乳头状瘤病毒感染与P53,Ki-67蛋白过度表达

目的 :了解艾滋病感染者口腔黏膜疣状肿块细胞生物学特性。方法 :应用免疫组织化学法、PCR对艾滋病感染者口腔黏膜疣状肿块、非艾滋病感染者口腔黏膜癌前病变和鳞癌组织中P5 3和Ki 67蛋白、人类乳头状瘤病毒 (HPV ) ,巨细胞病毒 (CMV)和EB病毒 (EBV )进行检测。结果 :( 1)艾滋病感染者口腔黏膜疣状肿块中P5 3蛋白阳性表达率为 2 3 % ,Ki 67蛋白阳性表达率为 76% ,二者均低于非艾滋病感染者口腔黏膜鳞癌(P <0 .0 5 ) ,但与非艾滋病感染者口腔黏膜癌前病变无明显差别 (P >0 .0 5 ) ;( 2 )艾滋病感染者口腔黏膜疣状肿块中 ,HPV感染率为 88.2 % ,明显高与非艾滋病感染者口腔黏膜癌前病变和口腔黏膜鳞癌 (P <0 .0 1)。没有检测到EBV、CMV病毒感染。结论 :艾滋病感染者口腔疣状肿块和HPV感染有关 ,存在抑癌基因突变和细胞过度增殖现象。     

Low prevalence of HPV infection and its natural history in normal oral mucosa among volunteers on Miyako Island, Japan

OBJECTIVE: To investigate the prevalence of human papillomavirus (HPV) infection in normal oral mucosa, and to observe the natural history in the oral cavity in oral swab samples collected from healthy volunteers on Miyako Island, Okinawa, Japan. STUDY DESIGN: The prevalence of HPV infection in oral buccal mucosa cell scrapes collected between 2000 and 2002 from a cohort of 668 healthy volunteers was determined. HPV DNA was detected by consensus polymerase chain reaction (PCR) using MY09/MY11 primers followed by direct cycle sequencing. Just over 2 years later the HPV-positive participants were reevaluated. RESULTS: Of the 668 subjects, 662 samples were analyzed for HPV. HPV DNA was detected in 4 (0.6%) specimens. HPV type 16 (HPV16), HPV53, and HPV71, mucosal types, and HPV12, a cutaneous type, were all identified by direct sequencing. In the follow-up survey, the HPV71- and HPV12-positive participants again tested positive, while HPV DNA was not detected in the HPV16- and HPV53-positive participants. CONCLUSION: The results of this study among healthy individuals from Miyako Island suggest that oral HPV infection is uncommon. In this cohort, HPV71 and HPV12 were persistent, while HPV16 and HPV53 were transient in normal oral mucosa.     

p53 gene mutations and HPV infection in primary head and neck squamous cell carcinomas do not correlate with overall survival: a long term follow-up study

We analyzed specimens of head and neck squamous cell carcinomas (HNSCC) from 110 patients for p53 gene mutations, and 92 of them for human papillomavirus (HPV) infection, in order to evaluate the prognostic significance of these factors by comparison with clinical follow-up data. Mutations within the exons 5 to 8 of the p53 gene were found in 48 tumors (44%). Sequencing revealed in most cases mis-sense mutations (16/21). Frequency of p53 gene mutations was not related to the tumor stage or the presence of lymph node metastases. Of the 46 tumors that were analyzed by immunohistochemistry. 26 stained positively (56%). The number of positively stained nuclei increased slightly with decreasing differentiation of the tumors, whereas no correlation was found between tumor stage and immunoreactivity. An infection with the high-risk HPV types 16 and 18 could be detected in 39/92 tumor specimens (42%.). Follow-up data were obtained from 99 patients within a range of 2 to 112 months. No dependence of overall survival on the presence of p53 gene mutations or HPV infection could be observed. The absence of statistically significant correlations between p53 gene mutation and progressive disease, however, does not deny its putative relevance in early phases of tumor development.     

口腔扁平苔藓患者细胞凋亡及凋亡相关基因p53,bcl—2,C—myc的表达

目的研究口腔扁平苔藓(OLP)患者病变组织中细胞凋亡的发生情况及凋亡相关基因p53、bcl-2、C-myc的表达,探讨其在 OLP病变发生中的意义.方法采用TUNEL法及免疫组织化学法,检测45例OLP(糜烂型23例,非糜烂型22例)中凋亡细胞情况,计算凋亡指数(AI)及p53、bcl-2、C-myc的表达情况. 结果 45例OLP均有凋亡细胞发生,AI为24.3%±12.0%(1.9%～50.5%);其中糜烂型AI为19.0%±10.4%(1.9%～ 50.5%),非糜烂型AI为29.4%±11.2%(10.4%～49.3%),两者间有显著差异(P＜0.05).OLP组织中p53、bcl-2、C-myc表达阳性率分别为31.1%、35.6和33.3%.其中糜烂型OLP中的p53、bcl -2、C-myc表达阳性率分别为39.1%、52.2%和43.5%,非糜烂型阳性率分别为22.7%、18 .2%和22.7%,两组间仅bcl-2的表达有显著差异(P＜0.05).结论细胞凋亡及凋亡相关基因p53、bcl-2、C-myc参与了OLP病变的发生发展,AI的变化与病变部位的慢性炎症有关,bcl-2在糜烂型OLP中的表达应引起高度重视.     

HPV and other risk factors of oral cavity/oropharyngeal cancer in the Czech Republic

OBJECTIVE: An association between high-risk human papillomavirus (HR HPV) infection and a risk of development of a subgroup of head and neck cancers has been proposed recently. The main risk factors of oral and oropharyngal cancer observed in our population are smoking and alcohol consumption. The incidence of oral/oropharyngeal tumours in the Czech Republic is relatively high and there are no data available about the prevalence of HPV DNA presence in these tumours. MATERIALS AND METHODS: Eighty patients with a primary oropharyngeal cancer were enrolled. The presence of HPV DNA has been evaluated by polymerase chain reaction in 68 cases from which the tumour tissue and demographical and clinical data were available. The typing of HPV was performed by nucleotide DNA sequencing. RESULTS: The HPV DNA was detected in 51.5% of samples tested. Among the HPV DNA positive tumours, 80% contained HPV16. In the analysed group there were 54 men and 14 women. The prevalence of HPV DNA was lower in oral (25%) than in oropharyngeal (57%) tumours, and higher in never smokers (100%) and never drinkers (68.8%). HPV DNA presence was not related to gender, age, number of lifetime sexual partners or practice of oral-genital sex, size of tumour or presence of regional metastases. CONCLUSIONS: The difference in the prevalence of HPV DNA positive tumours between cases of oral cavity and oropharyngeal carcinoma exposed and not exposed to tobacco or alcohol support the theory that HPV DNA positive tumours form an aetiologically distinct subgroup of head and neck tumours.     

P53 and bcl-2 immunoexpression in patients with oral lichen planus and oral squamous cell carcinoma

Objective: The aim of this study was to determine by immunohistochemistry the presence and significance of p53 and bcl-2 proteins in oral lichen planus (OLP) and oral squamous cell carcinoma (OSCC). Study Design: We used 21 cases diagnosed as OLP 16 diagnosed as OSCC and four normal gingival biopsies taken from healthy patients were used as controls. Slides were processed for immunohistochemistry using anti-p53 and anti-bcl-2 monoclonal antibodies. Results: We found p53 immunoexpression in 71.4% OLP cases and 68.7% OSCC cases, with no immunoexpression in control cases. Bcl-2 was negative for all OLP and OSCC cases, and mild positivity was observed in normal tissue. We found significant correlation among p53 expression and OSCC malignancy. Conclusions: Our results suggest that TP53 system mainly promotes a hyperproliferative state by cell cycle arrest of the OLP epithelial cells for repairing damaged DNA nor apoptosis and that anti-apoptotic action of bcl-2 is not important in this disease. Key words:Oral lichen planus, oral squamous cell carcinoma, p53, Bcl-2, carcinogenesis, malignant transformation.     

Human papillomavirus, p53 and cyclin D1 expression in oropharyngeal carcinoma

Forty-two specimens from oropharyngeal (tonsil and base of tongue) squamous cell carcinoma patients (SCC) were studied for presence of HPV 16 by in situ hybridization and by immunohistochemistry for p53 and Cyclin D1 protein overexpression. Thirty-one per cent of cases were HPV-16 positive, which correlates with the prevalence reported worldwide. 74% of cases showed p53 protein overexpression and 79% showed Cyclin D1 overexpression. There was no correlation between HPV status and either p53 or Cyclin D1 overexpression (P>0.05). These three variables also did not correlate with factors such as grade of the tumour, stage of the disease or lymph nodal metastasis at presentation.     

P53 immunohistochemical expression does not correlate with clinical features in 207 carcinomas of the oral cavity and in the head and neck region

Objectives

The present study aims to investigate the relevance of immunohistochemical p53 expression in carcinomas of the oral cavity and of the head and neck region. Long-term clinical and histopathological follow-up findings as well as HPV status are correlated with the results of this examination.

Materials and methods

Sections made from two tissue arrays composed of 222 oral squamous cell carcinomas and 427 squamous cell carcinomas of the head and neck region, respectively, were examined for p53 expression and Ki-67 index by means of immunohistochemistry. Correlation of long-term clinical findings of the patients and pathological features of tumours with laboratory results were examined statistically.

Results

No significant correlation was found between the p53 immunohistochemical expression in the 207 oral carcinomas and features of the tumours and patient outcomes. There was no significant association between the Ki-67 labelling index and the p53 expression.

Discussion

Our failure in detecting any association of the p53 immunohistochemical expression regardless of HPV status with clinical features of these tumours suggests it lacks a prognostic value for squamous cell carcinomas of the oral cavity.

Clinical relevance

The prognostic value of p53 immunostaining in oral squamous carcinoma is not clarified yet. In the present study, there is no impact on any prognostical item nor even a correlation with cell proliferation (Ki-67) regardless of HPV status.     

p53 protein expression in sequential biopsies of oral dysplasias and in situ carcinomas

Immunohistochemically detectable levels of p53 may be seen early in the malignant transformation of some neoplasms. To determine if p53 is immunocytochemically detectable, and therefore presumptively abnormal, in oral dysplasias and in situ carcinomas, and to explore the natural history of p53 protein expression in these lesions, sequential biopsies from patients with lesions occurring in the same anatomic site were examined. Formalin-fixed, paraffin-embedded sections from 19 patients were evaluated immunohistochemically for p53 protein using antibody clones Pab1801 and BP53-12. With two exceptions, comparable results were observed with these antibodies. p53 protein was detected immunocytochemically in 6 of 13 patients with dysplasias; 3 of these progressed to p53-positive invasive carcinoma, one advanced to a more severe grade of p53-positive dysplasia, one developed into a p53-negative verrucous carcinoma, and one represented a p53-positive dysplasia developing five years after treatment of a p53-positive carcinoma. The p53-positive dysplasias, which were found in all subtypes (mild, moderate, severe), preceded histologic malignant change by months to years. p53 detection was evident in 4 of 6 patients with in situ lesions. Sequential biopsies of three of these lesions showed no change in lesion histology or p53 staining, and one lesion advanced to a p53-positive carcinoma. It is concluded that p53 protein may be detected early in the development of a subset of p53-positive oral squamous cell carcinomas. This phenomenon may be seen in dysplasias and in situ lesions, and it may have prognostic implications.     

Immunohistochemical staining of Langerhans cells in HPV-positive and HPV-negative cases of oral squamous cells carcinoma

The Human Papillomavirus (HPV) has been strongly implicated in development of some cases of oral squamous cell carcinoma (OSCC). However, the immunological system somehow reacts against the presence of this virus. Among the cells involved in such mechanism of defense Langerhans cells (LC) stand out, which are responsible for processing and presenting antigens.

Objectives

The purposes of this study were to investigate the presence of HPV DNA and to evaluate the immunohistochemical reactivity for Langerhans cells between HPV-positive and HPV-negative OSCC. Twenty-seven cases of OSSC were evaluated.

Material and Methods

DNA was extracted from paraffin-embedded tissue samples and amplified by Polymerase Chain Reaction (PCR) for the detection of HPV DNA. Viral typing was performed by dot blot hybridization. Immunohistochemistry was performed by the Streptavidin-biotin technique.

Results

From the 27 cases, 9 (33.3%) were HPV-positive and 18 (66.0%) HPV-negative. HPV 18 was the most prevalent viral type (100% cases) and infection with HPV-16 (co-infection) was detected in only 1 case. In the OSCC specimens examined, immunoreactivity to S-100 antibody was detected in all cases, with a mean number of 49.48±30.89 Langerhans cells positive for immunostaining. The mean number of immunostained Langerhans cells was smaller in the HPV-positive cases (38 cells/case) than in the HPV-negative cases (42.5 cells/case), but this difference was not significant (p=0.38).

Conclusions

The low frequency of detection of HPV DNA in OSCC indicates a possible participation of the virus in the development and progression of only a subgroup of these tumors. There was no association between the immunohistochemical labeling for Langerhans cells (S-100+) and HPV infection of in OSSC. These findings suggest that the presence of HPV in such OSCC cases could not alter the immunological system, particularly the Langerhans cells.     

Expression and mutations of p53 in salivary gland tumours

A series of 219 salivary gland tumours (103 carcinomas and 116 benign tumours) were analysed for p53 protein expression using immunohistochemistry, and for mutations in p53 gene using non-radioactive single strand conformation polymorphism (SSCP). p53 expression was present in 36% (42/116) of the benign tumours and in 54% (56/103) of the carcinomas. The highest prevalence of p53 expression was found in adenoid cystic carcinomas (69%). followed by mucoepidermoid carcinomas (67%). Of the benign tumours, pleomorphic adenomas showed the highest prevalence of p53 positivity (41%). In malignant tumours, expression of p53 bore no correlation to local recurrence, metastatic disease or survival of the patients. Exons 5 through 9 were analysed and four mutations were found in 20 cases of p53-immunopositive tumours and two in 20 p53-negative tumours. Each of the exons 5.6 and 8/9 had two mutations, whereas no mutations were detected in exon 7.     

Human papillomavirus in the oral cavities of children and adolescents

OBJECTIVE: The purpose of this pilot study was to determine the frequency of human papillomavirus (HPV) in the oral cavities of children and adolescents and to identify potential risk factors for HPV infection. STUDY DESIGN: Sociodemographic information was obtained on 268 healthy infants, children, and adolescents who were < or = 20 years old. Oral squamous cells were collected from swabs with young children and from oral saline solution rinses with older children and adolescents. Extracted DNA was evaluated for HPV by polymerase chain reaction, dot blot hybridization, and DNA sequencing. Factors associated with the presence of HPV were tested by using chi(2), Fisher's exact test, and logistic regression tests. RESULTS: HPV was detected in 6.0% of the participants. HPV frequency among young children (<7 years old) was 8.7% (11/127), and among adolescents (13-20 years old) it was 5.2% (5/97). HPV was not detected in children aged 7 to 12 years old (0/44). Fifty-four percent (6/11) of HPV-positive children were 1 year of age or less; 3 of the HPV-positive children (<7 years old) were delivered by cesarean section. No statistically significant association was found between the detection of HPV in the oral cavity and method of delivery or gender; parent's race, education, HPV-related conditions, smoking history, or number of sex partners; or adolescent's smoking history or history of sexual activity. CONCLUSIONS: This study suggests that HPV is present in the oral cavity primarily in children 2 years old and younger and in adolescents 13 years and older. Cesarean delivery was not protective against oral HPV infection; in fact, half of the HPV-positive infants were born by cesarean delivery.     

涎腺肿瘤与癌基因c-myc抑癌基因p53和人类乳头状病毒感染的关系

本实验采用免疫组化、PCR技术和核酸电泳方法,对涎腺多形性腺瘤和其它类型良恶性肿瘤进行对比研究,结果显示:在涎腺多形性腺瘤中,c-myc和p53阳性率分别为50％(10/20)和25％(5/20,均远低于涎腺恶性肿瘤阳性率100％(3/3),提示c-myc表达与涎腺上皮细胞增殖速度加快有关,其表达率升高,与细胞癌变有密切联系。p53阳性表达率,虽在恶性肿瘤较高,但仅为判断细胞分化程度的一个参考指标。关于腮腺肿瘤与HPV关系,15例多形性腺瘤和3例腮腺癌中,HPV6.11均为阴性,HPV16.18阳性反应各为1例(1/5和1/3),远远低于HPV16.18在口腔肿瘤中的感染率,考虑到腮腺与口腔组织所处环境差异(后者易受烟草刺激),HPV16.18的致癌作用,主要表现为协同关系。     

口腔鳞癌中HPV感染及其对p5 3改变影响的研究

目的：探讨高危型人乳头状瘤病毒（ＨＰＶ）在口腔鳞癌中的感染情况及其对Ｐ５３蛋白表达和ｐ５３突变的影响。方法：采用免疫组化和ＰＣＲ－ＳＳＣＰ方法，分别检测４０例来癌中高危型ＨＰＶＥ６蛋白表达、Ｐ５３蛋白表达和ｐ５３基因突变的情况。结果：９例ＨＰＶＥ６蛋白染色阳性，阳性率２２．５％（９／４０），与正常粘膜对照组有显著差异（Ｐ＝０．０２１）。ＨＰＶ阳性组中Ｐ５３蛋白表达率１１．１％（１／９），ＨＰＶ阴性     

Immunohistochemical study of bcl-2 protein, Ki-67 antigen and p53 protein in epithelium of glandular odontogenic cysts and dentigerous cysts

The aim of the present study was the evaluation of the immunohistochemical expression of the apoptosis-inhibiting protein bcl-2, the cell-cycle-related antigen Ki-67 and the p53 protein, which is involved both in cell cycle and apoptosis regulation, in the lining epithelium of glandular odontogenic cysts of the jaws. Formalin-fixed and paraffin-embedded tissue sections of three glandular odontogenic cysts and six dentigerous cysts were immunostained with a standard avidin-biotin peroxidase procedure, after microwave antigen retrieval. The glandular odontogenic cysts showed immunoreactivity for bcl-2 protein in the basal and suprabasal layers, while staining in dentigerous cysts was basal or focal. Most mucous cells and superficial cuboidal cells were negative. The percentage of Ki-67- or p53-positive cells was lower in glandular odontogenic cysts compared with dentigerous cysts. The findings suggest that the biological behavior of glandular odontogenic cysts may be associated with deregulation of cell death in the lining epithelium, while cell proliferation and p53 status do not seem to play a significant role.     

The histologic differentiation of oral condyloma acuminatum from its mimics

OBJECTIVE: The purpose of this study was to determine which histologic features could enable one to distinguish oral condyloma, as defined by the detection of human papillomavirus (HPV) DNA through in situ hybridization, from its mimics. STUDY DESIGN: Thirty-two paraffin-embedded specimens from 28 patients that were clinically suggestive of oral condyloma were analyzed histologically and through in situ hybridization with a consensus HPV probe. RESULTS: HPV DNA was detected in 17/32 (53%) of the lesions; no additional positive cases were detected after polymerase chain reaction amplification. Only 5 of the 17 virus-positive cases were considered to be histopathologically unequivocal for condyloma. The histologic features significantly associated with HPV detection were nonuniform perinuclear halos, often in association with epithelial crevices (P =.02), and papillomatosis (P =.02). Each of the 17 patients who were HPV-positive had either HPV-6 or HPV-11, a finding that is similar to those for condyloma involving the penis and vulva/vagina. CONCLUSION: Differentiation between oral condyloma and its mimics is best accomplished by using a combination of histologic, clinical, and in situ viral studies.