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.     

诱导型一氧化氮合酶表达在口腔癌前病变口腔鳞癌发展过程中的作用研究

目的　探讨诱导型一氧化氮合酶 (iNOS)在口腔癌前病变、口腔鳞癌发展过程中的表达情况及其作用。方法　采用免疫组化SABC法检测 10例正常口腔黏膜、8例上皮单纯增生、2 0例上皮异常增生和 3 2例鳞状细胞癌组织中iNOS的表达。结果　正常口腔黏膜iNOS阴性表达 ;上皮异常增生组和鳞癌组中iNOS的表达较上皮单纯增生组均显著增加 (P <0 .0 5 ) ;随着上皮异常增生程度的加重 ,iNOS的标记指数逐级显著上升 (P <0 .0 5 ) ;上皮异常增生组与鳞癌组之间以及鳞癌的各病理分级之间iNOS的表达均无显著性差异 (P >0 .0 5 )。结论　iNOS的表达可能参与了口腔鳞癌的衍进过程     

Alteration in the expression of cdk4 and cdk6 proteins in oral cancer and premalignant lesions

J Oral Pathol Med (2010) 39 : 793–799 Background: Cdk4 and cdk6, key players in G1 phase, have been shown to play an important role in the development of oral squamous cell carcinoma (OSCC). This study investigated the expression of these two proteins in OSCC and premalignant lesions including oral leukoplakia (OL) with and without dysplasia and determined if alterations in the expression of these two proteins could be used as markers of malignant transformation. Methods: Expressions of cdk4 and cdk6 were evaluated in 61 samples including OSCC, OL with and without dysplasia and normal oral mucosa using immunohistochemistry method. Nuclear staining of the keratinocytes was considered positive and the percentage of positive cells was calculated. Results: Expression of cdk4 was found in 11/15 (73.33%) OSCC, 13/14 (92.85%) OL with dysplasia, 13/20 (65%) OL without dysplasia and 3/12 (25%) normal mucosa. Expression of cdk6 was detected in 9/15 (60%) OSCC, 3/14 (21.43%) OL with dysplasia, 5/20 (25%) OL without dysplasia and 1/12 (8.33%) normal mucosa. In cdk4 stained specimens, the frequency of positive cases and the percentage of positive cells in normal mucosa was significantly lower than OL with dysplasia and OSCC. For cdk6 staining, the prevalence of positive cases and the percentage of positive cells in normal mucosa were significantly lower than OSCC. Conclusions: Overexpressions of cdk4 and cdk6 were observed in OSCC, indicating that these two proteins play a crucial role in OSCC. The aberrant expression of cdk4 was found in OL with dysplasia, suggesting that cdk4 may be involved in the early event of carcinogenesis.     

口腔癌前病变、口腔鳞癌中诱导型一氧化氮合酶与p53蛋白表达及细胞增殖情况的相互关系的研究

目的探讨诱导型一氧化氮合酶(inducible netric oxide synthase,iNOS)在口腔鳞癌发展过程中的表达及与p53蛋白表达和细胞增殖的相互关系. 方法采用免疫组化SABC法检测10例正常口腔黏膜、8例上皮单纯增生、20例上皮异常增生和32例口腔鳞癌组织中iNOS、p53及Ki-67蛋白的表达. 结果口腔鳞癌发展过程中存在着iNOS、p53、Ki-67表达的上调;三种蛋白的表达与上皮异常增生的病理分级有关(P<0.05),与鳞癌的病理分级无关;各组中iNOS和p53表达之间均存在显著正相关(P<0.05);iNOS阳性表达的鳞癌组织中Ki-67标记指数较阴性者显著增高(P<0.05).结论iNOS与p53蛋白互为反馈影响,在口腔鳞癌发展过程中意义重大;鳞癌中iNOS的阳性表达可能提示该组织的快速增殖优势.     

口腔癌前病变、口腔鳞癌中诱导型一氧化氮合酶与p53蛋白表达及细胞增殖相互关系的研究

目的:探讨诱导型一氧化氮合酶(inducible netric oxide synthase,iNOS)在口腔鳞癌发展过程中的表达及与p53蛋白表达和细胞增殖的相互关系。方法:采用免疫组化SABC法检测10例正常口腔黏膜、8例上皮单纯增生、20例上皮异常增生和32例口腔鳞癌组织中iNOS、p53及Ki-67蛋白的表达。结果:口腔鳞癌发展过程中存在着iNOS、p53、Ki-67表达的上调;三种蛋白的表达与上皮异常增生的病理分级有关(P<0.05),与鳞癌的病理分级无关;各组中iNOS和p53表达之间均存在显著正相关(P<0.05);iNOS阳性表达的鳞癌组织中Ki-67标记指数较阴性者显著增高(P<0.05)。结论:iNOS与p53蛋白互为反馈影响,在口腔鳞癌发展过程中意义重大;鳞癌中iNOS的阳性表达可能提示该组织的快速增殖优势。     

Immunohistochemical expression of p53, p16 and hTERT in oral squamous cell carcinoma and potentially malignant disorders

Oral carcinogenesis is a multi-step process. One possible step is the development of potentially malignant disorders known as leukoplakia and erytroplakia. The objective of this study was to use immunohistochemistry to analyze the patterns of expression of the cell-cycle regulatory proteins p53 and p16(INK4a) in potentially malignant disorders (PMD) of the oral mucosa (with varying degrees of dysplasia) and in oral squamous cell carcinomas (OSCC) to correlate them with the expression of telomerase (hTERT). Fifteen PMD and 30 OSCC tissue samples were analyzed. Additionally, 5 cases of oral epithelial hyperplasia (OEH) were added to analyze clinically altered mucosa presenting as histological hyperplasia without dysplasia. p53 positivity was observed in 93.3% of PMD, in 63.3% of OSCC and in 80% of OEH. Although there was no correlation between p53 expression and the grade of dysplasia, all cases with severe dysplasia presented p53 suprabasal immunoexpression. p16(INK4a) expression was observed in 26.7% of PMD, in 43.3% of OSCC and in 2 cases of OEH. The p16(INK4a) expression in OEH, PMD and OSCC was unable to differentiate non-dysplastic from dysplastic oral epithelium. hTERT positivity was observed in all samples of OEH and PMD and in 90% of OSCC. The high hTERT immunoexpression in all three lesions indicates that telomerase is present in clinically altered oral mucosa but does not differentiate hyperplastic from dysplastic oral epithelium. In PMD of the oral mucosa, the p53 immunoexpression changes according to the degree of dysplasia by mechanisms independent of p16(INK4a) and hTERT.     

口腔鳞癌发展过程中抑癌基因PTEN的蛋白表达及意义

目的：探讨抑癌基因PTEN(phosphatase and tensin homologue deleted on chromosome ten)在口腔鳞癌(oral squamous cell cancer，OSCC)发展过程中的蛋白表达及临床病理意义。方法：应用免役组化S—P法检测10例正常口腔粘膜、10例上皮单纯增生、15例上皮异常增生及32例OSCC组织中抑癌基因PTEN的蛋白表达情况，同时结合患者的临床病理资料进行分析。结果：正常口腔粘膜和上皮单纯增生组织中VTEN蛋白全部阳性表达；上皮异常增生组织中PTEN蛋白阳性表达率为93．3％；OSCC组织中PTEN蛋白的阳性表达率为71．9％，其中高、中、低分化OSCC组织中PTEN蛋白的阳性表达率分别为85．7％、75％和33．3％。PTEN在OSCC组织中的蛋白表达与患者的性别、年龄无明显相关性，但与组织分化程度明显相关。结论：OSCC组织(尤其低分化)中PTEN蛋白的阴性表达率较高．说明PTEN基因突变或缺失在OSCC的发生、发展过程中起重要作用。     

Potentially malignant oral lesions in northern Ireland: a 20-year population-based perspective of malignant transformation

This retrospective laboratory-based study investigates the potential for malignant transformation of oral mucosal lesions in a population of 1.6 million. Over the 20-year period there were 745 patients diagnosed with primary intra-oral squamous cell carcinoma (OSCC), 165 patients with dysplasia and 1182 patients with 'non-dysplastic' lesions (epithelial hyperplasia, hyperkeratosis epithelial atrophy, lichen planus and lupus erythematosus). Malignant transformation occurred in 15% of dysplasias and in 1% of 'non-dysplastic' lesions at average intervals after diagnosis of 48 and 65 months respectively. Only 6% of patients with OSCC had a pre-invasive lesion biopsied. These data suggest that white lesions are only rarely the pre-invasive phase of OSCC. It is possible therefore that early changes are red, small or even microscopic with carcinoma developing without a clinically observable phase. More effective management strategies will require the development of tissue markers to enhance early detection.     

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.     

小分子锌指蛋白1在4-硝基喹啉-N-氧化物诱导SD大鼠颊黏膜癌变中的表达研究

目的 研究口腔黏膜癌变中小分子锌指蛋白1(LMO1)在基因转录和蛋白水平的表达变化。方法 取本课题组前期4-硝基喹啉-N-氧化物(4NQO)饮水法构建鳞癌动物模型的49例样本进行苏木精-伊红(HE)染色,依据上皮异常增生程度确定实验组病理分级并确定实验分组;免疫组织化学染色定性确定LMO1的表达部位;实时荧光定量聚合酶链式反应(RT-qPCR)和Western blot检测5组样本中LMO1 mRNA和蛋白的表达。结果 HE染色确定对照组7例,轻度组6例,中度组11例,重度组9例,OSCC组16例。免疫组织化学染色检测可见,LMO1主要表达于细胞质,对照组、轻度组、中度组、重度组和OSCC组的阳性表达率分别为14.3%、33.3%、81.8%、88.9%、93.8%。RT-qPCR检测可见,对照组LMO1 mRNA的表达量最低,OSCC组最高,对照组与轻度组间mRNA表达差异无统计学意义(P>0.05),其余各组组间两两比较,mRNA的表达差异均有统计学意义(P<0.05)。Western blot检测可见,随着上皮异常增生程度的加重,LMO1的蛋白表达量逐渐上...     

口腔鳞状细胞癌和癌前病变中细胞周期相关蛋白p27表达的研究

目的研究口腔黏膜癌前病变和口腔鳞状细胞癌（OSCC）中细胞周期相关蛋白p27的表达。方法采用免疫组织化学方法，研究p27、p53、MDM2（murine double minute）和p21蛋白在正常口腔黏膜、口腔白斑、红斑及OSCC共115例中的表达情况，探讨其表达水平的改变与Ki-67及相关临床病理指标的关系。结果p27蛋白在癌前病变和OSCC组中的阳性率分别为79．55％和81．25％。OSCC组p27蛋白表达强阳性率为70．83％（34／48），显著高于癌前病变组的31．82％（14／44）（P〈0．001）。p27蛋白高表达组其平均Ki-67阳性细胞百分率显著高于p27蛋白低表达组（P〈0．001）。OSCC组中，p27蛋白表达强度与p53和（或）MDM2的状态相关（P=0．034）。结论细胞周期调控分子p27、p53、MDM2和p21蛋白功能异常是口腔黏膜上皮发生癌变的重要因素之一。在口腔黏膜癌前病变和OSCC中普遍存在着上述一种或多种周期调控分子的异常，且不同调控分子之间也存在着互相调节、互相制约的关系。     

口腔白斑和鳞癌中p16基因甲基化的研究

目的　探讨p16基因甲基化在口腔黏膜白斑癌变中的作用。方法　采用甲基特异性PCR技术检测了 10例正常口腔黏膜、20例白斑上皮单纯增生、11例白斑上皮轻度异常增生、10例白斑上皮中度异常增生、9例白斑上皮重度异常增生、10例鳞癌Ⅰ级、12例鳞癌Ⅱ级、8例鳞癌Ⅲ级标本的p16基因甲基化情况。结果　上述各组的p16基因甲基化率分别为 0、5%、18%、10%、22%、50%、42%和 63%。p16基因甲基化率与口腔黏膜组织恶性度显著正相关,并与p16蛋白缺失表达率呈显著正相关关系(rp=0 777 , rs=0 960, P<0 001)。结论　p16基因甲基化状态可作为白斑癌变和口腔鳞癌诊断的分子生物学重要标志之一。     

p16,p53,Ki67在口腔癌前病变表达及4年临床随访

目的 :研究 p16,p5 3 ,Ki-67蛋白表达与口腔癌前病变的关系。 方法 :采用免疫组织化学LsAB法对43例上皮异常增生 ( 2 0例轻度上皮异常增生 ,2 3例重度上皮异常增生 )和 2 0例正常口腔黏膜 p16,P5 3和Ki -67蛋白的表达进行研究 ,并对上皮异常增生患者实际癌变率做了 4年追踪。结果 :正常黏膜组 ,p5 3不表达 ,Ki -67少量表达 ,p16的阳性表达为 10 0 %。轻度上皮异常增生 ,p5 3 ,Ki-67少数表达 ,p16表达率为 86.96%。重度上皮异常增生 ,p5 3和Ki-67过度表达 ,p16表达明显下降 ,与正常黏膜 ,轻度上皮异常增生相比差异显著 (P <0 .0 5 )。p5 3和Ki-67蛋白过度表达而 p16呈低表达与实际口腔癌前病变癌变率有一定相关性。 结论 :口腔黏膜癌变是一个由量变到质变的过程 ,它们的调控基因 p16,p5 3 ,Ki -6发生了显著的变化 ,可能起着重要的调控作用。     

Oral lichen planus has a high rate of TP53 mutations. A study of oral mucosa in icelanD

Oral squamous cell carcinoma (OSCC) is a world-wide health problem. In addition to external exposure (smoking and alcohol), certain oral lesions may increase the risk of oral cancer (e.g. leukoplakia, erythroplakia, and oral lichen planus). TP53 has been implicated in OSCC, but there are limited studies of mutations in premalignant oral lesions. In this study, 55 samples from OSCC, 47 from hyperkeratotic (HK) oral mucosa, clinically diagnosed as white patches, 48 samples from oral lichen planus (OLP), and 12 biopsies from normal oral mucosa were studied immunohistochemically for expression of TP53 protein. From all the carcinoma samples and selected non-malignant samples showing moderate or strong TP53 protein expression, malignant cells or TP53-positive nuclei were microdissected and screened for mutations in exons 5-8 by constant denaturation gel electrophoresis. Moderate to strong TP53 protein staining was seen in 56% of OSCC, 32% of OLP but only in 13% of HK. All OLP samples showed a characteristic pattern of positive nuclei confined to the basal layer, whereas TP53 staining was seen in suprabasal nuclei in HK. Mutation rate was 11 out of 52 for OSCC, three out of 20 tested for HK and, remarkably, nine out 27 tested for OLP. There was no correlation between TP53 protein staining and TP53 mutations. No associations were found with anatomical sites or disease progression. The unexpectedly high mutation rate of OLP might explain the premalignant potential of this lesion.     

P53蛋白在口腔鳞状细胞癌发生过程中的表达及意义

本研究采用微波处理暴露抗原,通过免疫组化ＬＳＡＢ方法对ＮＯＭ６例,ＯＰＬ２８例,ＯＳＣＣ３４例中Ｐ５３蛋白表达进行观察,其ＮＯＭ无表达;在ＯＰＬ中的表达率为８２％随着上皮异常增生的程度加重,表达率呈上升趋热（Ｐ〈０．０５）;而在ＯＳＣＣ中表达率为６５％,随着肿瘤的分极增加,表达率呈下降趋势（Ｐ〈０．０５）。结果表明,Ｐ５３蛋白在ＯＰＬ和ＯＳＣＣ中呈异常表达,并与ＯＰＬ程度和ＯＳＣＣ分级有关,Ｐ５３     

口腔黏膜癌变过程中Bmi-1及P16蛋白的表达及意义

目的:了解Bmi-1及P16蛋白在口腔黏膜癌变过程中的表达情况,探讨Bmi-1-P16通路在口腔鳞癌发生发展中的作用及意义。方法::正常口腔黏膜10例、上皮异常增生31例、口腔鳞癌61例的石蜡包埋组织,采用免疫组化SP法检测Bmi-1及P16表达情况,分析二者的相关性及其临床病理学意义。结果:Bmi-1在正常口腔黏膜、上皮异常增生及OSCC组织中的阳性率分别为0%、29%(9/31)和62.3%(38/61);P16在正常、上皮异常增生及OSCC组中的阳性率分别为100%(10/10)、77.4%(24/31)和47.5%(29/61)。OSCC中Bmi-1阳性率在P16阴性组高于P16阳性组,差异有统计学意义(P<0.05),Spearman相关分析显示两者间具负相关关系(r=-0.414,P<0.05)。Bmi-1阳性表达及Bmi-1高表达且P16失表达与OSCC临床分期及淋巴结转移密切相关(P<0.05)。结论:Bmi-1过表达是口腔黏膜癌变过程中的早期事件,口腔鳞癌中Bmi-1过表达可能与P16失表达有关并与临床分期及淋巴结转移密切相关,有可能作为临床评估口腔鳞癌浸润、转移和预后的参考指标之一。