Epithelial growth fraction and expression of p53 tumour suppressor gene in oral submucous fibrosis

The incidence of squamous cell carcinoma in patients with oral submucous fibrosis (OSF) exceeds 7 per cent. The proliferative cell nuclear antigen (PCNA) is a convenient marker of epithelial cell proliferation and p53 tumour suppressor gene mutations or deletions are frequent in oral cancer. The present study estimated the basal epithelial cell growth fraction using a standard immunohistological method for the detection of nuclear PCNA from 20 Nepalese patients with OSF as 31.8 per cent compared with 7.6 per cent for oral mucosa from 43 normal subjects (p<0.001) and 39.4 per cent for 44 patients with oral cancer. The PCNA growth fraction correlated significantly with that derived by Ki-67 labelling. There was no correlation between the growth fraction and the severity of epithelial dysplasia found is OSF.
Abnormal expression of p53 protein identified by immunohistochemistry with a panel of antibodies was found in 70 per cent of the OSF specimens, and 21 per cent of mucosal specimens from subjects with clinically normal mouths. PCNA-positive cells and p53 expression were restricted to the basal epithelial layer in OSF. The unexpected finding of p53 protein in clinically healthy mucosa was confined to subjects aged over 40 years who smoked tobacco, a known risk factor for oral cancer. There was no association between p53 expression and epithelial atypia scores in OSF.
It is concluded that the proportion of actively cycling epithelial cells is increased in OSF and that p53 tumour suppressor gene mutations or deletions may be prevalent. Confirmation by molecular biology techniques of this genetic damage is now needed.     

Alterations in expression of retinoid receptor beta and p53 in oral submucous fibrosis

OBJECTIVE: Knowledge of the molecular pathogenesis of oral submucous fibrosis (OSF), a potentially malignant condition with high risk of transition to oral cancer, is meagre. Alterations in the expression of retinoic acid receptor beta (RARbeta) and tumor suppressor gene, p53 are early events in oral tumorigenesis. The aim of this study was to investigate the alterations in the expression of RARbeta and p53 in OSF lesions and determine their association with disease pathogenesis. METHODS: The expression of RARbeta and p53 proteins was analyzed by immunohistochemistry in 50 cases of OSF and 30 histologically normal oral tissues. RESULTS: No detectable RARbeta expression was observed in 35 of 50 (70%) OSF cases. p53 protein accumulation was observed in 24 of 50 (48%) OSF cases analyzed. Thirty-six percent OSF lesions showed loss of RARbeta and p53 overexpression. Interestingly, 41 of 50 (82%) of OSF lesions showed altered expression of at least one of these two proteins. CONCLUSION: Altered expression of either RARbeta or p53 in majority of OSF lesions suggests their association with disease pathogenesis and warrants follow-up to determine whether OSF lesions harboring concomitant alterations in RARbeta and p53 are at a high risk of transition to malignancy.     

p53 aberrations in oral submucous fibrosis and oral squamous cell carcinoma detected by immunocytochemistry and PCR-SSCP

Trivedy C, Warnakulasuriya KAAS, Tavassoli M, Steingrimsdottir H, Penhallow J, Maher R, Johnson NW: p53 aberrations in oral submucous fibrosis and oral squamous cell carcinoma detected by immunocytochemistry and PCR-SSCP. J Oral Pathol Med 1998; 27: 72–7. © Munksgaard, 1998.
An archival series of oral biopsies from Karachi, Pakistan, consisting of 21 cases of oral submucous fibrosis (OSF) and 27 cases of squamous cell carcinoma (SCC), of which 6 had arisen from OSF, were used to examine the aberrations in the structure and expression of the p53 tumour suppressor gene. The PCR-SSCP method was used for mutation analysis of exons 2–9, and (over)expression of p53 protein was detected by immunocytochemistry using monoclonal antibody DO 7. Positive immunostaining was observed in 15/20 (75%) of OSF specimens, 3/6 (50%) of SCC arising from OSF and 14/21 (67%) of SCC not arising from OSF. Mobility shifts in SSCP indicative of a mutation in p53 or loss of heterozygosity (deletion of a band) were seen in 13/21 cases of OSF and 15/27 cases of SCC. There was concordance between immunocytochemistry and SSCP results in a majority (33/48) of samples. Though the number of analysed SCC cases arising from OSF was limited, the results suggest that p53 mutation/protein stabilisation may play a part in the pathogenesis of OSF and its progression to SCC.     

口腔黏膜下纤维性变中MMP-2基因的表达及意义

目的：检测口腔黏膜下纤维性变中基质金属蛋白酶-2（MMP-2）的表达并探讨其病理意义.方法：抽提11例口腔黏膜下纤维化组织和10例正常口腔黏膜组织的总RNA,通过逆转录聚合酶链反应（PF-PCR）检测MMP-2mRNA在口腔黏膜下纤维性变患者颊黏膜中的表达并与正常口腔黏膜进行比较.结果：口腔黏膜下纤维性变患者颊黏膜组织中MMP-2 mRNA表达高于正常颊黏膜（p＜0.05）.结论：MMP-2基因的表达与口腔黏膜下纤维性变组织重塑过程密切相关.     

口腔黏膜下纤维性变组织中Smad7蛋白的表达研究

目的检测Smad7蛋白在口腔黏膜下纤维性变(OSF)组织中的表达及分布,探讨其在OSF发病机制中的作用。方法采用免疫组化抗生蛋白链菌素生物素复合体法(strept Avidin-Biotin complex,SABC),用Smad7兔抗人多克隆抗体检测20例OSF病变组织及10例正常口腔黏膜组织中的Smad7蛋白的表达及分布。结果Smad7在OSF病变组织中为弱阳性表达,在正常口腔黏膜组织中为阴性表达,差别具有显著意义(P<0.05)。结论Smad7蛋白在OSF病变组织中弱阳性表达,在OSF发病机制中有重要作用。     

c-fos、c-jun蛋白在口腔黏膜下纤维性变组织中的表达研究

目的 :检测c -fos、c -jun蛋白在口腔黏膜下纤维性变 (OSF)组织中的表达及分布 ,探讨其在OSF发病机制中的作用。方法 :采用免疫组化SABC法 ,用c -fos、c -jun兔抗人多克隆抗体检测 5 6例OSF病变组织、15例口腔黏膜扁平苔藓 (OLP)病变组织及 10例正常口腔黏膜组织中的c -fos、c -jun蛋白的表达及分布。 结果 :c -fos、c -jun蛋白在OSF病变组织有明显的阳性表达 ,正常口腔黏膜及OLP组织为阴性表达 (P <0 .0 5 )。其表达主要位于OSF病变上皮组织 (P <0 .0 5 ) ,且表达强度为正相关 (γs=0 .744 ,P <0 .0 1)。结论 :c -fos、c -jun蛋白在OSF病变组织中高表达 ,在OSF发病机制中有重要作用。     

口腔黏膜下纤维性变组织中Smad2/3蛋白的表达研究

目的：检测Smad2／3蛋白在13腔黏膜下纤维性变（OSF）组织中的表达及分布,探讨其在OSF发病机制中的作用。方法：采用免疫组化SABC法,用Smad2／3兔抗人多克隆抗体检测20例OSF病变组织及10例正常13腔黏膜组织中的Smad2／3蛋白的表达及分布。结果：Smad2／3在OSF病变组织中为中等强度表达,在正常口腔黏膜组织中为强阳性表达,具有显著性差异（P〈0．05）。结论：Smad2／3蛋白在OSF病变组织中中等强度表达,在OSF发病机制中有重要作用。     

舌癌P53蛋白的表达及p53基因的突变

目的:检测舌癌中P53蛋白表达和p53基因突变及其与临床病理的相关性。方法:应用免疫组织化学和聚合酶链反应—单链构象多态性分析(PCR-SSCP)检测10例舌白斑和32例舌癌,并结合临床资料进行分析。结果:PCR-SSCP检测舌白斑和舌癌p53基因突变率分别为20.0%(2/10)和59.4%(19/32)。突变的19例舌癌,12例出现第5外显子突变,7例出现第6外显子突变,2例出现第7外显子突变,15例出现第8外显子突变。其中单外显子突变10例,多外显子突变9例。免疫组化结果表明,舌白斑和舌癌P53蛋白阳性率分别为20.0%(2/10)和46.9%(15/32);P53的表达与临床分期及有无淋巴结转移密切相关。临床I、Ⅱ期病例P53蛋白表达水平低于Ⅲ、IV期病例(P<0.05)。无颈淋巴结转移病例的P53蛋白表达水平低于有转移的病例(P<0.05)。采用免疫组化和PCR-SSCP检测舌癌的符合率为75.0%(24/32)。结论:舌癌发生过程中p53基因有突变,最多发生在第8外显子,其次为第5、6外显子;P53蛋白阳性的舌癌患者多处于临床晚期,易发生淋巴结转移,且预后较差。     

TLR2在口腔黏膜下纤维性变组织中的表达及意义

目的：通过检测口腔黏膜下纤维性变（OSF）组织中TLR2的表达情况,初步探讨TLR2在OSF发病中的作用。方法：选取OSF患者30例（早、中、晚期各10例）为实验组,正常者5例为对照组,每例研究对象取其口腔颊黏膜,采用免疫组化SABC法检测各组织中TLR2的表达情况。结果：正常口腔颊黏膜组织中TLR2呈阳性表达,在OSF组织中TLR2表达明显增强（P〈0.05）,主要表达于黏膜下组织;OSF早、中、晚期组织中TLR2的表达无显著性差异（P〉0.05）。结论：与正常口腔黏膜相比,OSF组织中TLR2的表达增高,提示TLR2在OSF发病中起一定的促进作用。     

口腔黏膜下纤维化中VEGF和TSP表达及相关性的研究

目的:研究血管内皮生长因子(vascular endothelial growth factor,VEGF)和血小板反应蛋白(thrombo-spondin,TSP)在口腔黏膜下纤维化(oral submucous fibrosis,OSF)中的表达,探讨两者的相关性及在OSF发病中的作用.方法:选取30 例OSF患者,其中早、中、晚期各10 例, 5 例健康志愿者作为对照组.取每例研究对象口腔颊黏膜,采用免疫组化SP法检测VEGF和TSP的蛋白表达. 结果:VEGF在OSF早期较正常口腔黏膜中表达增高,中、晚期逐渐下降,其中早期组与正常组、中期组、晚期组比较均有显著性差异(P<0.05).TSP在OSF早、中期表达持续增高,晚期稍下降,各组间差异无显著性(P>0.05).病变组织黏膜下层中VEGF与TSP呈负相关(r=-0.620,P<0.05).结论:VEGF和TSP的异常表达可能是OSF微血管病变的重要发病机制之一.     

Aloe vera in the treatment for oral submucous fibrosis – a preliminary study

J Oral Pathol Med (2012) 41 : 755–761 Background and objectives: Oral submucous fibrosis (OSMF) is a potentially malignant disorder of the oral mucosa, mainly associated with the practice of chewing gutka and betel quid. The pathogenesis is obscure, and till date, no definitive therapy is available for the management of OSMF. Hence, this preliminary study was carried out to compare the efficacy of Aloe vera with antioxidants in the treatment for OSMF. Methods: Twenty study subjects with OSMF were included in the study. Patients were divided into two groups. There were 10 patients in each group; group A subjects received 5 mg of aloe vera gel to be applied topically three times daily for 3 months and group B subjects received antioxidant capsules twice daily for 3 months. The results were analyzed with paired ‘t’ test and unpaired ‘t’ test. Results: Aloe vera responded better in all the parameters assessed and responded in all the clinicohistopathological stages particularly in those with mild‐stage clinically and early‐stage histopathologically. Aloe vera showed a statistically significant reduction in burning sensation (P = 0.008), improvement in mouth opening (P = 0.02), and cheek flexibility (P = 0.01) on comparing with the antioxidant group. Interpretation and conclusion: Overall assessment of the parameters depicted that Aloe vera group showed a better treatment response compared to the antioxidants group. It reduces the burning sensation and improves mouth opening thereby enhanced the patients’ compliance. It proves to be a relatively safe, can be applied topically, easily available, economical, noninvasive, and efficacious in the treatment for OSMF.     

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.     

Mutated and wild-type p53 expression and HPV integration in proliferative verrucous leukoplakia and oral squamous cell carcinoma

The frequencies of overexpression and mutation in the p53 tumor suppressor gene were examined in proliferative verrucous leukoplakia and oral squamous cell carcinoma with immunohistochemistry and single-strand conformation polymorphism analysis of DNA fragments amplified by polymerase chain reaction. Ten samples each of normal oral mucosa, proliferative verrucous leukoplakia, and squamous cell carcinoma were immunostained with antibodies against p53 protein; 8 of 10 cases of proliferative verrucous leukoplakia cases and 7 of 10 cases of oral squamous cell carcinoma were positive for p53 protein. Minimal staining was observed in normal oral tissues. The quantified labeling indexes demonstrated a range that corresponded to lesion progression. Single-strand conformation polymorphism analysis revealed p53 gene mutations within exons 5 to 8 in 40% (4 of 10) of the squamous cell carcinoma samples. Two of the 4 mutated squamous cell carcinoma samples lacked p53 expression. No p53 mutations were detected in proliferative verrucous leukoplakia tissues. Human papillomavirus 16 was identified in 2 of 7 p53 positive oral squamous cell carcinoma samples. Human papillomavirus 16 and 18 were identified in two of eight p53 positive proliferative verrucous leukoplakia samples. One p53 negative squamous cell carcinoma sample was positive for human papillomavirus 16 and had a mutation in exon 6 of the p53 gene. Human papillomavirus infection along with p53 expression plays a yet to be defined role in the pathogenesis of a limited number of cases of proliferative verrucous leukoplakia and squamous cell carcinoma. p53 Immunohistochemistry, p53 gene mutations, and human papillomavirus infection prevalence do not provide a means to differentiate between leukoplakia and carcinoma and do not provide a predictive test for progression of leukoplakia to carcinoma.     

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.     

姜黄素治疗口腔黏膜下纤维性变有效性的Meta分析

目的系统性地评价姜黄素治疗口腔黏膜下纤维性变的有效性。方法检索Web of Science、PubMed、EBSCO、The Cochrane Library、中国知网、万方和维普7个数据库,检索时限为从建库到2019年6月30日,搜集姜黄素治疗口腔黏膜下纤维性变的随机对照试验,筛选文献,提取数据,用RevMan 5.3软件进行Meta分析。结果纳入6个随机对照试验,共350名患者。Meta分析结果显示,姜黄素改善口腔黏膜下纤维性变的最大张口度和烧灼感症状疗效优于安慰剂。改善张口度方面,治疗1个月后,姜黄素疗效不如番茄红素等控制组;但治疗2个月、3个月和6个月后姜黄素组和控制组疗效相似,差异无统计学意义。烧灼感改善方面,治疗3个月后,姜黄素的疗效比控制组更好,且差异有统计学意义;治疗1个月、2个月和6个月后,姜黄素组和控制组的疗效差异无统计学意义。结论当前证据显示,姜黄素可以有效地改善口腔黏膜下纤维性变患者的最大张口度和烧灼感等症状。由于纳入研究数量有限和质量不高,上述结论尚需更多高质量研究予以验证。