Sudha V M, Hemavathy S
Department of Oral Pathology, Government Dental College, Bangalore, India.
Indian J Dent Res. 2011 Jul-Aug;22(4):520-5. doi: 10.4103/0970-9290.90286.
The product of bcl-2 gene, bcl-2 protein, an anti-apoptotic protein, is known to be over-expressed in potentially malignant disorders and squamous cell carcinoma (SCC) of the oral cavity. The aim of this study is to compare the topographical aspect and degree of bcl-2 over-expression in potentially malignant disorders including leukoplakia, oral submucous fibrosis (OSMF), and oral lichen planus (OLP), with that of the oral squamous cell carcinoma (OSCC), and to determine whether bcl-2 protein can be considered as a tumor marker.
A group of 60 histo-pathologically diagnosed, formalin-fixed, paraffin embedded tissue samples was included in the study. The study group was further subdivided into four groups: Group I, consisting of oral leukoplakia; Group II, OSMF; Group III, OLP and Group IV, OSCC. These samples were collected from Government Dental College, Bangalore, and then subjected to immunohistochemical (IHC) staining using indirect immunoenzyme labeled streptavidin biotin (LSAB) method.
Out of 30 cases of OSCC: 11 (36.7%) cases showed greater supra-basal keratinocyte staining; 15 (50%) cases showed greater number of positive cells in the basal cell layer, with relatively less number of supra-basal cells showing positive staining; and, rest of the 4 (13.3%) cases did not show convincing staining. Among the total 30 cases of potentially malignant disorders: 10 each of leukoplakia, OSMF and OLP, 2 (20%), 2 (20%), 4 (40%) of the cases showed greater supra-basal cell layer positive staining and 8 (80%), 6 (60%), 6 (60%) of them showed greater basal cell staining, respectively. Two cases of OSMF did not show convincing staining. In the cases that were bcl-2 positive: 2 (6.67%) of the OSCC, 3 (30%) of leukoplakia, 2 (20%) of OSMF and 1 (10%) of OLP, showed more than 50% of the cells positive. 25-50% cells were positive in 21 (70%) of OSCC, 6 (60%) of leukoplakia, 4 (40%) of OSMF and 6 (60%) of OLP cases. 10-25% of cells were positive in 4 (13.3%) of OSCC, 1(10%) of leukoplakia, 2 (20%) of OSMF and 3 (30%) of OLP cases. Less than 10% of cells were positive in 3 (10%) of OSCC and 2 (20%) of OSMF cases. CLINICAL SIGNIFICANCE AND CONCLUSION: As definite number of cases showed bcl-2 over expression in our study, the role of bcl-2 in the development and progression of oral neoplasia needs further investigation along with other oncogenes.
bcl-2基因的产物bcl-2蛋白是一种抗凋亡蛋白，已知其在潜在恶性疾病及口腔鳞状细胞癌（SCC）中过度表达。本研究旨在比较包括白斑、口腔黏膜下纤维化（OSMF）和口腔扁平苔藓（OLP）在内的潜在恶性疾病中bcl-2过度表达的形态学特征及程度与口腔鳞状细胞癌（OSCC）的差异，并确定bcl-2蛋白是否可被视为肿瘤标志物。
本研究纳入一组60例经组织病理学诊断、福尔马林固定、石蜡包埋的组织样本。研究组进一步分为四组：第一组为口腔白斑；第二组为OSMF；第三组为OLP；第四组为OSCC。这些样本取自班加罗尔政府牙科学院，然后采用间接免疫酶标记链霉亲和素生物素（LSAB）法进行免疫组织化学（IHC）染色。
在30例OSCC病例中：11例（36.7%）病例显示基底上层角质形成细胞染色更强；15例（50%）病例显示基底细胞层阳性细胞数量更多，基底上层显示阳性染色的细胞数量相对较少；其余4例（13.3%）病例未显示出有说服力的染色。在总共30例潜在恶性疾病病例中：白斑、OSMF和OLP各10例，其中2例（20%）、2例（20%）、4例（40%）病例显示基底上层细胞层阳性染色更强，8例（80%）、6例（60%）、6例（60%）病例分别显示基底细胞染色更强。2例OSMF病例未显示出有说服力的染色。在bcl-2阳性的病例中：OSCC中有2例（6.67%）、白斑中有3例（30%）、OSMF中有2例（20%）、OLP中有1例（10%）显示超过50%的细胞阳性。25%-50%的细胞阳性见于21例（70%）OSCC、6例（60%）白斑、4例（40%）OSMF和6例（60%）OLP病例。10%-25%的细胞阳性见于4例（13.3%）OSCC、1例（10%）白斑、2例（20%）OSMF和3例（30%）OLP病例。少于10%的细胞阳性见于3例（10%）OSCC和2例（20%）OSMF病例。临床意义与结论：由于在我们的研究中有一定数量的病例显示bcl-2过度表达，bcl-2在口腔肿瘤发生发展中的作用需要与其他癌基因一起进一步研究。
