Singh B B, Chandler F W, Whitaker S B, Forbes-Nelson A E
Department of Oral Pathology, School of Dentistry, Medical College of Georgia, Augusta 30912-1110, USA.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1998 Jun;85(6):692-8. doi: 10.1016/s1079-2104(98)90037-3.
The proto-oncogene bcl-2 is associated with follicular lymphoma involving translocation t(14;18)(q32;q21) and is also overexpressed in various neoplasms. We report deregulation of bcl-2 expression during progression from oral epithelial dysplasia to squamous cell carcinoma. Immunohistochemical analysis with monoclonal antibodies to bcl-2 oncoprotein in formalin-fixed paraffin-embedded tissue sections revealed that severe epithelial dysplasias had a higher percentage of immunoreactivity than did mild and moderate dysplasias and squamous cell carcinomas. Expression of this oncoprotein was directly proportional to the degree of epithelial dysplasia, and nondysplastic basal cells contiguous to neoplastic lesions also expressed bcl-2. These findings, along with down-regulation of bcl-2 in differentiating carcinomas, suggest a role for this oncoprotein in relatively early stages of oral tumor progression. Differentiating neoplastic cells with marginal or no bcl-2 reactivity showed heterogeneous cell labeling of varying intensity for differentiation-associated cytokeratin (CK13), indicating their inverse topographic relationship.
原癌基因bcl-2与涉及t(14;18)(q32;q21)易位的滤泡性淋巴瘤相关，并且在各种肿瘤中也过度表达。我们报告了在从口腔上皮发育异常进展为鳞状细胞癌的过程中bcl-2表达的失调。在福尔马林固定石蜡包埋的组织切片中，用针对bcl-2癌蛋白的单克隆抗体进行免疫组织化学分析显示，重度上皮发育异常的免疫反应性百分比高于轻度和中度发育异常及鳞状细胞癌。这种癌蛋白的表达与上皮发育异常的程度成正比，并且与肿瘤性病变相邻的非发育异常基底细胞也表达bcl-2。这些发现，连同分化型癌中bcl-2的下调，提示该癌蛋白在口腔肿瘤进展的相对早期阶段起作用。具有边缘性或无bcl-2反应性的分化型肿瘤细胞显示出与分化相关细胞角蛋白（CK13）强度不同的异质性细胞标记，表明它们的反向拓扑关系。
