Association of aberrant p53 and p21WAF1 immunoreactivity with the outcome of oral verrucous leukoplakia in Taiwan

The expression of p53 and p21WAF1 in 53 oral verrucous leukoplakias (OVLs), mostly non-dysplastic lesions, was investigated to ascertain the role of such events in malignant conversion. Immunohistochemical analysis revealed aberrant p53 and p21WAF1 immunoreactivity in 51% (27 cases) and 75% (40 cases), respectively. After an average follow-up period of three and a half years, histopathological examination revealed that 22 (42%) cases had developed oral squamous cell carcinoma (OSCC), 14 (26%) cases had undergone recurrence, and 17 (32%) cases were free of disease. The oncogenic potential of this subset of premalignant lesions warrants attention. A significant difference in the frequency of OSCC progression/recurrence was noted in lesions bearing aberrant immunoreactivity of either p53 (93% vs 42%; P=0.00008) or p21WAF1 (80% vs 32%; P=0.002) in comparison with lesions without immunoreactivity. This study suggested that the aberrant immunoreactivity of p53 and p21WAF1 may represent important alterations of OVL and could affect the outcome of this lesion.     

Immunohistochemical study of syndecan-1 down-regulation and the expression of p53 protein or Ki-67 antigen in oral leukoplakia with or without epithelial dysplasia

BACKGROUND: Leukoplakia is an oral pre-cancerous lesion that sometimes develops into squamous cell carcinoma. Therefore, leukoplakia with epithelial dysplasia is useful for studying carcinogenesis at the cellular level. The purpose of this study was to evaluate a potential association between the loss of syndecan-1 expression and the expression of p53 protein and Ki-67 antigen, and to identify reliable markers for predicting malignant changes in oral leukoplakia with epithelial dysplasia. METHODS: Changes in the expression of syndecan-1, p53, and Ki-67 were examined immunohistochemically in 43 cases of oral leukoplakia with or without epithelial dysplasia. The subjects were categorized as: none, 13 cases; mild dysplasia, 5 cases; moderate dysplasia, 17 cases; and severe dysplasia, 8 cases. The expression of these molecules in normal oral epithelia (22 cases) was also investigated. RESULTS: Strong syndecan-1 expression was observed on the surface of keratinocytes in normal epithelium. Immunopositivity was lost gradually as the extent of epithelial dysplasia increased. In normal epithelium, p53 and Ki-67 appeared mainly in the basal cell layer, while they were more widely distributed in leukoplakia. Specifically, significant changes were observed in the labeling index of p53 and Ki-67 in leukoplakia as epithelial dysplasia progressed from mild to moderate or severe. CONCLUSION: Our results reveal that overexpression of p53 protein and Ki-67 antigen, and down-regulation of syndecan-1 expression in the lower part of the epithelium, are associated with dysplastic changes. Therefore, the down-regulation of syndecan-1 expression may be the most important reliable marker for dysplastic changes.     

Clinicopathological features and immunohistochemical expression of p53, Ki‐67, Mcm‐2 and Mcm‐5 in proliferative verrucous leukoplakia

J Oral Pathol Med (2010) 39 : 447–452 Background: Proliferative verrucous leukoplakia (PVL) is a distinct and aggressive type of oral leukoplakia which affects elderly women without risk behavior and presents high rates of malignant transformation. The objective of the present study was to evaluate the clinicopathological characteristics and the distribution of cell proliferation markers, aiming to elucidate the distinct biological behavior of the PVL. Methods: Clinical and microscopical features of 12 patients with PVL were reviewed. Immunohistochemical analysis for p53, Ki‐67, Mcm‐2 and Mcm‐5 were performed and the data were correlated. Results: All patients were women, above 50 years of age, 91.7% were non‐smoker and 100% were non‐habitual drinker. Alveolar ridge (66.6%), tongue (50%) and buccal mucosa (41.6%) were the most affected sites. Four patients developed squamous cell carcinoma (SCC). The immunohistochemical findings showed higher positivity for p53, Ki‐67, Mcm‐2 and Mcm‐5 in SCCs. However, some patients with mild or moderate dysplasia, specially the patients who developed SCC, presented high expression of Mcm‐2 and Mcm‐5. Conclusions: High immunoexpression of Mcm‐2 and Mcm‐5 in mild and moderate dysplasia could be helpful to predict the malignant transformation of PVL.     

Podoplanin expression as a predictive marker of dysplasia in oral leukoplakia

Purpose

Recent studies have emphasized the role of podoplanin in oral lesions at risk of malignant transformation. We investigated a group of oral leukoplakias (OLs) to determine a possible relation between altered podoplanin expression and dysplasia, and to compare the results with those obtained by other, widely used biomarkers.

新辅助化疗前后PCNA和p53在口腔鳞癌中的表达及其对化疗敏感性的预测研究

目的:探讨新辅助化疗前后增殖细胞核抗原(PCNA)和抑癌基因p53在口腔鳞癌组织中的表达水平及其与化疗疗效的关系.方法:采用SP免疫组化法,对106例口腔鳞癌患者新辅助化疗前后的PCNA和p53表达水平进行检测,分析其表达水平与化疗疗效的关系.结果:①化疗前口腔鳞癌组织中PCNA高表达率为50.94%,显著高于化疗后23.58%(P<0.05);化疗前PCNA高表达患者化疗有效率为62.96%,显著高于PCNA低表达患者的有效率30.77%(P<0.05);②化疗前p53在口腔鳞癌中的阳性表达率为44.34%,显著高于化疗后21.60%(P<0.05);化疗前口腔鳞癌p53表达阴性患者的有效率为55.93%,显著高于p53表达阳性患者的有效率36.17%(P<0.05).结论:新辅助化疗可明显降低PCNA和p53在口腔鳞癌组织中的表达水平,PCNA和p53的表达水平与新辅助化疗疗效具有显著的相关性,认为PCNA和p53的表达水平有可能成为口腔鳞癌化疗疗效的预测指标.     

p16和p53蛋白在口腔白斑和鳞状细胞癌中表达的比较研究

目的比较p16和p53在口腔白斑和口腔鳞状细胞癌中异常表达的情况。方法对17例健康者的口腔粘膜、60例白斑患者和40例口腔鳞状细胞癌患者的病损组织进行了p16和p53蛋白的免疫组化染色。结果正常口腔粘膜、白斑单纯增生、白斑异常增生和口腔鳞状细胞癌的p16阳性率分别为100％、90％、60％和35％，p53蛋白的阳性率分别为12％、27％、50％和73％，p16阳性率和细胞染色强度指数（stainning intensity index，SII）分别与口腔粘膜组织恶性度的增高显著负相关；p53阳性率和S11分别与口腔粘膜组织恶性度的增高显著正相关。p16和p53在不同组织中的阳性率显著负相关；p16和p53在白斑异常增生的协同失活率达23％，在口腔鳞状细胞癌中达到42．5％。p16阳性率、p16SII、p53SII及两种基因均异常的比率在口腔鳞状细胞癌无淋巴结转移和口腔鳞状细胞癌有淋巴结转移患者之间均有显著差异。结论p16可作为早期监视口腔白斑恶变、监测口腔鳞状细胞癌发展进程和判断口腔鳞状细胞癌预后的分子生物学指标。p16和p53失活在白斑癌变和口腔鳞状细胞癌的发展过程中可能有叠加效应。     

Prognostic value of cyclin D1, p27, and p63 in oral leukoplakia

BACKGROUND: Studies on the expression of genes regulating cell proliferation and apoptosis are essential to help better understand the severity and possible malignant transformation of oral leukoplakia. METHODS: The characteristics of cyclin D1, p27, and p63 were investigated in this microscopic study, complementing our previous results with Ki67, p53, and the apoptosis index. Clinical and histologic as well as immunohistochemical studies were carried out on oral leukoplakia of 18 patients. Homogenous, or non-homogenous (nodular or speckled) and erythroleukoplakia were determined clinically. Pathologic classification was performed according to the degree of dysplasia. Immunoperoxidase reaction for cyclin D1, p27, and p63 was carried out on the biopsy specimens and the positivity of the reactions was calculated for 1000 epithelial cells. RESULTS: The expression of cyclin D1 increased in parallel with the severity of leukoplakia. The p27 index was 14-16% in homogenous and nodular leukoplakias but it was substantially lower to 1-2% in erythroleukoplakia. The p63 index was 10% in homogenous, 5% in nodular or speckled, but nearly 20% in erythroleukoplakia, on the average. CONCLUSION: These results suggest that the characteristic expression of cyclin D1, p27, and p63 in various forms of leukoplakia may be of prognostic value.     

Altered growth response of oral mucosal keratinocytes in p53-deficient mice

P53 has important regulatory functions in cell growth, differentiation and apoptosis. Here we analyzed the effects of p53 on the growth response of oral mucosal keratinocytes (OMKCs) using p53-deficient (p53-/-) mice. No morphological difference was found between p53-/- and wild-type (p53+/+) oral mucosa. In a long-term culture, p53-/- OMKCs continued to proliferate past the point at which p53+/+ became senescent. The percentage of p53-/- OMKCs in the G0/G1 phase was lower than that of p53+/+ OMKCs. Proliferation of cultured OMKCs induced by epidermal growth factor (EGF) and interleukin-(IL)-1alpha was more strongly enhanced in p53-/- than in p53+/+ mice. Such an enhanced response was not due to increased mRNA expression of growth factor receptors. These data suggest that p53 acts as a modulator of G1 arrest in OMKCs and is also involved in the regulation of responses to EGF and IL-1alpha without affecting the expression of their receptors.     

PTEN、p27在口腔粘膜白斑和口腔癌组织中的表达及意义

目的　探讨抑癌基因PTEN、p2 7在口腔粘膜白斑 (oralleukoplakia ,OLK)和口腔癌 (oralsquamouscellcancer,OSCC)组织中的蛋白表达及意义。方法　应用免疫组化S -P法检测 10例正常口腔粘膜、2 5例口腔粘膜白斑 (其中白斑伴上皮异常增生 15例 ,白斑不伴上皮异常增生 10例 )及 32例口腔癌组织中抑癌基因PTEN和p2 7的蛋白表达情况。结果　正常口腔粘膜和白斑不伴上皮异常增生组织中PTEN和 p2 7蛋白全部阳性表达 ;白斑伴上皮异常增生组织中PTEN和 p2 7蛋白阳性表达率分别为93.3%、73.3%。OSCC组织中PTEN蛋白阳性表达率为71.9% ,其中高、中、低分化OSCC组织中PTEN蛋白阳性表达率分别为 85 .7%、75 %和 33.3% ,统计学分析表明PTEN在OSCC组织中的蛋白表达与组织分化程度明显相关 (P <0 .0 5 )。OSCC组织中 p2 7蛋白的阳性表达率为4 0 .6 % ,其中高、中、低分化OSCC组织中p2 7蛋白的阳性表达率分别为 4 2 .9%、4 1.7%和 33.3% ,统计学分析表明p2 7在OSCC组织中的蛋白表达与组织分化程度无明显相关 (P >0 .0 5 )。结论　OSCC组织中PTEN和 p2 7蛋白的阴性表达率较高 ,说明PTEN和 p2 7基因突变或缺失在OSCC的发生发展过程中起重要作用。     

口腔白斑和鳞癌中P_(53)基因突变的PCR─SSCP分析

本实验应用聚合酶链反应－单链构象多态性（PCR—SSCP）分析技术对5例正常口腔粘膜、22例白斑和30例鳞癌中P53基因突变情况进行检测。结果表明，轻、中、重度异常增生白斑，无和有淋巴结转移鳞癌P53突变率为12．5％，37．5％，50．0％，64．3％和75．0％，正常粘膜无一例阳性，白斑和鳞癌间P53变化有显著性差异（P＜0．05）。P53突变与鳞癌有否淋巴结转移无关。     

Immunohistological evaluation of Ki-67, p63, CK19 and p53 expression in oral epithelial dysplasias

BACKGROUND: Oral squamous cell carcinoma develops through a multistep of genetic mutations, and the process can be morphologically recognized as oral epithelial dysplasia. To evaluate the hypothesis that distributional alterations of proliferating and stem cells may be a useful index to estimate the grading and development of epithelial dysplasia, we examined the distribution patterns according to stratified cell layers. METHODS: Sixty-two oral dysplasia cases according to the histological grades were immunohistologically examined and the nuclear expression of Ki-67 and p63 antigens was counted according to epithelial layers as labeling index. RESULTS: The Ki-67 labeling index in the basal and suprabasal layers and that of p63 in the basal layer showed a significant difference between low- and high-grade groups of epithelial dysplasia. CONCLUSION: The architectural alteration of proliferating cell and stem cell distribution in the layers of epithelial dysplasias may provide useful information to evaluate the grading of oral epithelial dysplasias.     

Serum p53 antibodies as a prognostic indicator in oral squamous cell carcinoma

The purpose of the present study was to investigate the clinical usefulness of the detection of serum p53 antibodies (p53 Abs) in patients with oral squamous cell carcinoma (SCC). Preoperative values of p53 Abs were measured by enzyme-linked immunosorbent assay in 113 patients with primary oral SCC and seropositive patients were reevaluated postoperatively. The positivity rate of p53 Abs was 16%, and the 5-year survival rate of patients positive for p53 Abs was significantly lower than that of patients negative for p53 Abs (56.2% vs. 80.7%; P = 0.018). The preoperative presence of p53 Abs was found to be an independent prognostic factor in a multivariate analysis (P = 0.028, hazards ratio = 3.34), and its positivity was significantly related to secondary cervical lymph node metastases (P = 0.029). Six of nine patients who remained seropositive for p53 Abs through the disease course and the one with seropositive reversion from temporary negative status developed treatment failure. Therefore, the detection of p53 Abs in the serum of patients with SCC may be a useful prognostic marker.     

Aberrant expression of p53, p16INK4a and Ki‐67 as basic biomarker for malignant progression of oral leukoplakias

J Oral Pathol Med (2011) 40 : 629–635 Background: The risk of malignant progression of oral leukoplakia with and without dysplasia is unpredictable. Materials and methods: Leukoplakias without dysplasia of 35 patients, leukoplakias with dysplasia of 4 patients, and similar lesions obtained from tumor patients were retrospectively examined by immunohistochemistry for the expression of the proteins pRb, p53, p16^INK4a, Cyclin D1 and Ki‐67. The predictive power of combined aberrant expression patterns for the progression of leukoplakias without dysplasia was examined. Results: Increased expression of p53, Ki‐67 and Cyclin D1, and loss of p16^INK4a occurred in 45.9%, 38.9%, 29.4% and 32.4% of the leukoplakias without dysplasia, respectively. All alterations increased with progression but had poor positive predictive value. However, the combined p53/p16^INK4a/Ki‐67 aberration occurred in only three (9%) cases, of which two patients (66.7%) experienced progression to dysplasia and carcinoma in situ. The combined p53/p16^INK4a/Ki‐67 alteration had a negative predictive value (NPV) and sensitivity of 100%, specificity of 97% and positive predictive value (PPV) of 67%. By contrast, the combined p53/p16^INK4a/Cyclin D1 alteration had 97% NPV and sensitivity of 50%, specificity of 90% and only 25% PPV. Loss of pRb and concomitant overexpression of p16^INK4a were not observed arguing against an involvement of HPV in oral leukoplakia. Conclusions: We propose the combined p53/p16^INK4a/Ki‐67 alteration as a basic marker to define high risk leukoplakia patients. Lesions not showing this alteration appear to be harmless. Future studies should validate these findings and search for proteins which can further improve the PPV of the proposed basic marker.     

Expression of p53, Ki-67 and cytokeratin-4 (CK4) in oral papillomas

P53 is overexpressed in more than 50% of all human cancers. A previous study suggested that p53 was also overexpressed in oral papillomas. This study was carried out to investigate whether p53 expression was correlated with expression of the cellular proliferation marker Ki-67 and the epithelial differentiation marker cytokeratin-4 (CK4) in oral papillomas. Formalin-fixed paraffin-embedded sections of 30 oral papilloma specimens and 30 unmatched normal oral mucosal specimens were processed for immunohistochemistry, using an avidin-biotin- peroxidase procedure and monoclonal antibodies. A semiquantification analysis on p53 and Ki-67 labeling indices was performed. Twenty-eight of 30 (93%) papilloma specimens were positive for p53. The percentage of p53–positive cells in the basal layer was 60.4± 14.8 (mean±SD. n =28). and that of Ki-67–positive cells was 26.7± 14.4. There was no correlation between expression of p53 and that of Ki-67. Expression of CK4 was inversely correlated with the expression of Ki-67 but not correlated with the expression of p53.     

Bromodeoxyuridine incorporation and Ki 67 expression in oral hairy leukoplakia

OBJECTIVES: Oral hairy leukoplakia (HL) is an acan-thotic, hyperparakeratotic lesion characterised by the presence of a replicative Epstein-Barr virus (EBV) infection in the superficial and adjoining layers of the epithelium. EBV or its gene products are capable of modifying epithelial differentiation. The aim of this study was to establish whether the presence of EBV was associated with an alteration in cell turnover by assessing bromodeoxyuridine (BrdU) incorporation and Ki 67 expression in lesional tissue and control mucosa.
METHODS: Biopsies of HL together with age, site and sex matched controls ( n = 7 and 8 respectively) were incubated in 200 μM BrdU in vitro , fixed in methacarn and processed to paraffin wax. Following acid hydrolysis, incorporated BrdU and Ki 67 were identified in serial 5 fim sections using a three-stage immunoperoxidase technique and cell density expressed as the number of positive cells per mm basement membrane length.
RESULTS: Overall, there was no difference in the number of BrdU positive cells per mm basement membrane length between control and HL tissue. However, within HL alone, the presence'of focal EBV replication was associated with a significant reduction in the number of basal cells incorporating BrdU compared to adjacent EBV free areas (P < 0.05). There was no significant difference between Ki 67 positive cells in control and HL tissue and no evidence of a reduction of Ki 67 positive cells in areas associated with EBV replication.
CONCLUSIONS: These results suggest that there is no evidence of a generalised alteration of the proliferative capacity of basal cells in HL, although the focal reduction in BrdU incorporation may reflect subtle changes on cell turnover by EBV infection.     

Evaluation of p53 protein as a prognostic factor for oral cancer surgery

We have analysed concentrations of the p53 protein in advanced oral carcinomas immunohistochemically and genetically to detect the percentage of overexpression of this antioncogene that indicates a high probability of mutation. This would point to it being a useful prognostic factor, if we consider the importance of the relation between genetic alterations of p53 and poor overall survival. Seventy-five non-consecutive patients with oral squamous cell carcinoma and metastatic nodes were enrolled if there was homogeneity in histopathological grading (G2) of their tumours, and they were treated according to a multidisciplinary treatment plan. Monoclonal antibodies, extraction of DNA, and amplification of the polymerase chain reaction (PCR) were used for the immunohistochemical and genetic analyses. There was a significant inverse correlation between p53 overexpression and response to chemotherapy and a stronger association between high P53 overexpression (%) and a genetic mutation of p53 (p = 0.0001). More than 50% overexpression indicated a strong probability of genetic mutation. There was no association between response to chemotherapy and age-groups or TNM classification (p = 0.2), but there was a significant one between sex and site of tumour (p < 0.001). Three prognostic factors were significantly related to prognosis: site of tumour (p = 0.01), response to chemotherapy (p = 0.002), and immuno p53 (p = 0.0001). A tumour that is characterised by p53 overexpression of more than 50% indicates a poor prognosis.     

口腔白斑及鳞癌中Rb、P53蛋白的表达

目的 :探讨抑癌基因p5 3 、Rb蛋白产物在口腔白斑及鳞癌中的表达。方法 :用免疫组化法检测 2 0例口腔白斑 (OLK)、3 3例鳞癌 (OSCC)组织中P5 3 及Rb蛋白的表达。结果 :Rb蛋白在OLK、OSCC中的表达较正常口腔黏膜组增强 ,但无显著性差异 ;突变型P5 3 蛋白的表达在OLK即已出现 ,且随着细胞异常增生程度的增高而增强 ,在OSCC中其阳性表达率高达 80 %。结论 :p5 3 基因突变、P5 3 蛋白过度表达与OSCC的发生发展密切相关 ;OSCC的发生可能涉及Rb、p5 3 细胞周期生长抑制反馈调节通路的异常     

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.     

Immunohistochemical analysis of cell cycle-associated proteins p16, pRb, p53, p27 and Ki-67 in oral cancer and precancer with special reference to verrucous carcinomas

Alterations in cell proliferative activity are a common phenomenon in oral carcinogenesis. In this study, the expression of the cell cycle-associated proteins p16, pRb, p53, p27 and Ki-67 were examined by immunohistochemistry in precancerous and cancerous oral lesions, including verrucous carcinomas (VCs). Generally, expression of pRb, p53 and Ki-67 increased according to the cell proliferative activity or tumor progression, but p27 expression showed an inverse relationship. Comparing squamous cell carcinomas (SCCs) with VCs, there was a great difference in expression levels of p27, Ki-67 and p53, which seemed to reflect the different cell proliferative activities of these two tumors. Expression of p16 was low in both dysplasia and SCCs, whereas p16 expression was high in VCs. The high immunohistochemical expression for both p16 and pRb in VC is quite different compared with SCC, which may indicate a possible relationship between VC and human papillomavirus (HPV) infection.