Expression of p53 in oral mucosal hyperplasia, dysplasia and squamous cell carcinoma

OBJECTIVE: To assess p53 expression in a range of oral mucosal lesions and to relate the results to the clinical outcome in patients with dysplastic oral mucosal lesions and oral squamous cell carcinomas (OSCC).
MATERIALS AND METHODS: Archival tissue was available for eight cases of normal oral mucosa, 50 cases of oral mucosal hyperplasia, 41 cases of oral mucosal dysplasia and 48 cases of OSCC. The monoclonal antibody DO-7, reactive to p53 protein, was applied to paraffin-embedded sections using microwave pretreatment and immu-nohistochemical techniques.
RESULTS: The results showed that normal oral mucosa did not express p53.Positive nuclear staining was found in 18/50 (36%) cases of hyperplasia, 35/41 (85%) cases of dysplasia and 45/48 (94%) cases of OSCC.None of the p53 negative dysplasias progressed, while 19% of p53 positive cases of dysplasia recurred following excision and 11% of the cases underwent neoplastic transformation. Five out of 10 (50%) cases of severe dysplasia which were p53 positive resolved.
CONCLUSION: The proportion of cases with positive p53 expression increased from hyperplasia to dysplasia to OSCC. These results may indicate an involvement of p53 in neoplastic transformation as well as in proliferative events although the presence or absence of p53 staining could not be used to predict the outcome of potentially malignant oral mucosal lesions.     

Evaluation of myofibroblasts in oral epithelial dysplasia and squamous cell carcinoma

Background:  Carcinogenesis is accompanied by a number of changes in the adjacent stroma including the appearance of myofibroblasts. The purpose of this study was to evaluate and compare the presence of myofibroblasts in normal mucosa, oral epithelial dysplasia, and different grades of oral squamous cell carcinoma.
Methods:  The study sample consisted of three groups, including 40 oral squamous cell carcinomas, 15 dysplasias, and 15 sections of normal oral epithelium. Vimentin, desmin, and alpha-smooth muscle actin were used to identify myofibroblasts.
Results:  The percentage and intensity of alpha-smooth muscle actin were examined, and positive immunostaining was observed in the myofibroblasts of all squamous cell carcinomas; however these cells did not stain in the dysplasias or normal epithelium specimens. The presence of myofibroblasts was significantly higher in oral squamous cell carcinomas compared to both, dysplasias and normal mucosa cases ( P  < 0.001). A significant difference was not observed between the different grades of oral squamous cell carcinoma ( P  = 0.2).
Conclusions:  These findings show the presence of myofibroblasts in the stroma of oral squamous cell carcinoma but not dysplasia and normal mucosa, suggesting further investigation to clarify the role of myofibroblasts in the carcinogenesis of this tumor.     

p53 expression in oral precancer and cancer

Expression of the p53 tumour suppressor gene is a frequent finding in human malignancies, including oral cancer, and it has been detected in some potentially malignant lesions. The results of the present project showed that 35 of the 41 (85 per cent) oral mucosal lesions with histological evidence of epithelial dysplasia expressed p53, but the presence or absence of p53 staining could not be used to predict the outcome of potentially malignant oral mucosal lesions.     

Shifts in cellular localization of moesin in normal oral epithelium, oral epithelial dysplasia, verrucous carcinoma and oral squamous cell carcinoma

BACKGROUND: Moesin, a member of ERM (ezrin/radixin/moesin) family, links actin filaments of cell surface structure to the cell membrane. The purpose of the study is to assess the shifts in cellular distribution of moesin in normal oral epithelium, oral epithelial dysplasia (OED), verrucous carcinoma (VC), and oral squamous cell carcinoma (OSCC). METHODS: The expression of moesin was evaluated immunohistochemically in paraffin-embedded tissues of 59 specimens of OSCC, 35 specimens of OED, 17 specimens of VC, and five specimens of normal oral epithelium. RESULTS: In the normal oral epithelia, all specimens showed a pattern of membranous expression against the anti-moesin antibody in the basal layer cells. In the OED specimens, moesin was dominantly expressed in the cell membrane except for the cornified layer. In VC and OSCC specimens, almost the whole of the carcinoma cells were stained with anti-moesin antibody. However, in OSCC samples, moesin was markedly expressed increasingly in the cytoplasm and decreasingly in the cell membrane, as compared with OED and VC. In addition, there was a significant correlation between the pattern of moesin expression and tumor differentiation in OSCC. CONCLUSIONS: Our results suggest that it is useful to detect the moesin expression as adjunct to screening mucosal lesions in the oral cavity.     

Expression of cadherins and catenins in oral epithelial dysplasia and squamous cell carcinoma

The immunocytochemical expression of cadherins and catenins was examined during the process of oral carcinogenesis by comparing their expression in normal and dysplastic epithelium with primary and metastatic carcinomas. While control epithelium showed normal distribution for P and E cadherin and the catenins, in severe dysplasia P-cadherin was upregulated. In other cases and in carcinoma- in-situ adjacent to infiltrating carcinomas, membranous expression of the cadherins and catenins was reduced or lost. The changes in expression of E-cadherin and the catenins suggest that disruption of the E-cadherin/catenin complex is a late event associated with invasion. In primary carcinomas reduced membranous and cytoplasmic staining were observed for both cadherins and catenins. Abnormal localisation of E-cadherin occurred in the more superficial parts of the better differentiated carcinomas, suggesting abnormality to the E-cadherin complex(es). In contrast, membranous expression of cadherins and catenins was reduced or lost in the deep invasive margin of primary carcinomas and in most poorly differentiated carcinomas. For E-cadherin at least, this reduction appears associated with differentiation, invasion and possibly prognosis. Possible mechanisms involved for changes in expression of the cadherins and associated catenins and areas for further study are discussed.     

Content and distribution of glycogen in oral epithelial dysplasia

Abstract— Forty-four oral lesions with epithelial dysplasia and 25 other benign and malignant lesionsof the oarl mucosa were examined after ataining with hematoxylin-eosin and diastase controlled PAS. The intensity of the PAS-Positivity for glycogen, The grade of dysplasia, the type of keratinization and the degreeof subepithelial inflmmation were recored. Histologically normal epithelium at the margins of the lesions were used as controls. The presence and amount of glycogen in normal epithlium varied with the Form of keratinization in that non-orparakeratinized epithelium was rich in glycogen where as there was a negative glycogen-reaction in orthokeratinized epithelium. The most striking feature was and abrupt limitation of the glycogen at the junction between nondysplastic and dysplastic epithlium. The difference in the amount of glycogen in normal and dysplastic epithlium as assessed semiquantitativbely, was statistically significant. The diastase controlled PAS-staining may therefore be a useful method of distinguishing dysplastic form nondysplastic epithlium in doubtjurl cases. Pseudoepitheliomatous hyperplastic epithelium covering granular cell myoblastoma did not contain any glycogen. Five of six squamous cell acrcinomas nand four verrucous carcinomas contained no demosstrable glycogen. Glycogen was present in the epithelium of the cases of lichen planus and "denture hyperplasia" investigated.     

Programmable bio‐nanochip‐based cytologic testing of oral potentially malignant disorders in Fanconi anemia

Fanconi anemia (FA) is caused by mutations of DNA repair genes. The risk of oral squamous cell carcinoma (OSCC) among FA patients is 800‐folds higher than in the general population. Early detection of OSCC, preferably at it precursor stage, is critical in FA patients to improve their survival. In an ongoing clinical trial, we are evaluating the effectiveness of the programmable bio‐nanochip (p‐BNC)‐based oral cytology test in diagnosing oral potentially malignant disorders (OPMD) in non‐FA patients. We used this test to compare cytomorphometric and molecular biomarkers in OSCC cell lines derived from FA and non‐FA patients to brush biopsy samples of a FA patient with OPMD and normal mucosa of healthy volunteers. Our data showed that expression patterns of molecular biomarkers were not notably different between sporadic and FA‐OSCC cell lines. The p‐BNC assay revealed significant differences in cytometric parameters and biomarker MCM2 expression between cytobrush samples of the FA patient and cytobrush samples of normal oral mucosa obtained from healthy volunteers. Microscopic examination of the FA patient's OPMD confirmed the presence of dysplasia. Our pilot data suggests that the p‐BNC brush biopsy test recognized dysplastic oral epithelial cells in a brush biopsy sample of a FA patient.     

Malignant transformation in a cohort of patients with oral epithelial dysplasia

Oral epithelial dysplasia (OED) is often diagnosed in oral potentially malignant disorders (OPMD) and carries an increased risk of malignant transformation. Currently, the reported risk of malignant transformation for OED varies. Here we present the risk in a cohort of 150 patients with OED at a specialist centre. In this cohort 2.6%, 4.1%, and 29.2% cases of mild, moderate, and severe OED, respectively, progressed to oral squamous cell carcinoma at the dysplastic site, while a small number developed a malignant lesion elsewhere. Moreover, 17 patients experienced an increase in grade of dysplasia and two showed histological resolution of their lesions.     

水通道蛋白3在口腔鳞癌中的表达及临床意义

目的: 探讨水通道蛋白3（AQP3）在口腔鳞癌中的表达及临床意义。方法: 收集2014年3月—2017年4月盘锦辽油宝石花医院保存的202例口腔黏膜组织石蜡标本。其中健康者41例（对照组）、口腔黏膜上皮异常增生45例（A组）、口腔鳞癌116例（B组）。利用免疫组织化学方法检测3组口腔黏膜组织中AQP3的表达情况,分析口腔鳞癌口腔黏膜组织中AQP3表达与临床病理因素及预后的关系。采用SPSS 18.0软件包对数据进行统计学分析。结果: B组口腔黏膜组织中AQP3阳性表达率显著高于A组和对照组（P<0.05）,A组口腔黏膜组织中AQP3阳性表达率显著高于对照组（P<0.05）。肿瘤侵袭深度>5 mm、临床T4分期、颈淋巴结转移、低分化患者,口腔黏膜组织中AQP3阳性表达率分别高于肿瘤侵袭深度≤5 mm、临床T2分期、无颈淋巴结转移、中高分化患者（P<0.05）。AQP3阳性表达的口腔鳞癌患者,术后3年生存率（65.85%）显著低于阴性表达患者（90.00%,P<0.05）。Cox回归分析显示,肿瘤临床分期、分化程度、颈淋巴结转移情况、AQP3阳性表达率是影响总生存率的独立预后因素（P<0.05）。结论: 口腔鳞癌患者口腔黏膜组织中AQP3阳性表达率显著高于口腔黏膜上皮异常增生者,AQP3表达与口腔鳞癌患者临床分期、颈淋巴结转移、分化程度、肿瘤侵袭深度及总生存率相关。     

Expression of p16 in oral cancer and premalignant lesions

Background:  Expression of p16 has been proposed as a marker for malignant transformation. This study aimed to evaluate p16 expression in oral squamous cell carcinoma (OSCC) and premalignant lesions including oral leukoplakia (OL) with and without dysplasia.
Methods:  Expression of p16 was investigated in 56 samples including OSCC, OL with and without dysplasia, and normal oral mucosa. Expression of p16 was identified by immunohistochemistry, using the CINtecTM p16INK4a Histology Kit. Both nuclear and/or cytoplasmic staining of the keratinocytes were considered to be positive and the percentage of positive cells was calculated.
Results:  Expression of p16 was detected in 3/16 (18.75%) cases of OSCC, in 4/15 (26.7%) cases of OL without dysplasia, and in none of OL with dysplasia and normal mucosa. No significant differences in p16 expression prevalence were found among OSCC, OL with and without dysplasia and normal mucosa. The percentages of positive cells in OSCC and OL without dysplasia were 0.89 and 0.17, respectively. No significant difference in the percentage of positive keratinocytes was found.
Conclusion:  As a marker, p16 is not reliable for oral mucosal dysplasia and malignant transformation.     

E‐cadherin downregulation and Twist overexpression since early stages of oral carcinogenesis

There is some evidence of Twist participation in oral carcinogenesis; however, little is known about its interaction with E‐cadherin in oral squamous cell carcinoma (OSCC) development. This experimental study included an immunohistochemical analysis of Twist and E‐cadherin proteins in paraffin‐embedded specimens of oral leukoplakia (OL), OSCC, and normal oral mucosa. In addition, it was also performed a Western blot and double‐immunofluorescence analysis of Twist and E‐cadherin expression in OSCC cell lines. Significant differences in Twist and E‐cadherin immunoexpression were observed between normal oral mucosa and OL, with an inverse relation since the earliest stages of oral dysplasia (r = ?0,512; P < 0.001). Western blot and double‐immunofluorescence analysis showed differences in Twist and E‐cadherin expression among human oral keratinocytes and OSCC cell lines suggesting that downregulation of E‐cadherin occurs in a dependent manner of Twist in OSCC. Our results showed a possible value of Twist and E‐cadherin in the prediction of risk of oral epithelium malignant transformation.