Krishna A, Kaveri H, Naveen Kumar R K, Kumaraswamy K L, Shylaja S, Murthy Sarvani
Department of Oral and Maxillofacial Pathology, S.V.S Institute of Dental Sciences, Mahabubnagar, Andhra Pradesh, India.
J Cancer Res Ther. 2012 Apr-Jun;8(2):232-7. doi: 10.4103/0973-1482.98976.
Recent studies on odontogenic tumors have identified various molecular alterations responsible for their development, and determination of epithelial proliferation is a useful means of investigating the differences in biologic behavior of these tumors. One such specific marker to identify proliferative activity and tumor aggressiveness by immunohistochemistry (IHC) is MDM2, 90-95 kDa protein.
This immunohistochemical study using MDM2 expression was undertaken to understand better the diverse biological activity of two groups of odontogenic tumors namely ameloblastoma and adenomatoid odontogenic tumor (AOT) based on their cell proliferation activity.
A total of 50 cases, comprising of 36 ameloblastoma samples and 14 AOT samples, were subjected to heat-induced antigen retrieval method using citrate buffer in a pressure cooker. Consequently, the sections were stained with MDM2 monoclonal antibody and visualized using an LSAB+ kit.
In ameloblastomas, statistically significant association was seen between plexiform ameloblastomas, follicular ameloblastomas with granular cell changes, desmoplastic and unicystic variants. The predominant nuclear staining by MDM2 revealed overexpression in ameloblastomas as compared to AOT.
The MDM2 overexpression noticed in plexiform ameloblastoma, follicular ameloblastoma with granular cell changes and acanthomatous ameloblastoma when compared to simple unicystic and desmoplastic ameloblastoma suggest a relatively enhanced proliferative phenotype of these solid multicystic variants of ameloblastomas. On overall comparison, higher expression was noted in ameloblastomas when compared to AOT. This indicates differences in the aggressive nature between these two groups of odontogenic tumors favoring the perception of a greater aggressive nature of ameloblastomas.
近期关于牙源性肿瘤的研究已确定了多种导致其发生发展的分子改变，而确定上皮细胞增殖是研究这些肿瘤生物学行为差异的一种有用方法。一种通过免疫组织化学（IHC）鉴定增殖活性和肿瘤侵袭性的特异性标志物是MDM2，一种90 - 95 kDa的蛋白质。
本研究采用MDM2表达进行免疫组织化学分析，以更好地了解基于细胞增殖活性的两组牙源性肿瘤，即成釉细胞瘤和腺样牙源性肿瘤（AOT）的不同生物学活性。
总共50例病例，包括36例成釉细胞瘤样本和14例AOT样本，在高压锅中使用柠檬酸盐缓冲液进行热诱导抗原修复方法处理。随后，切片用MDM2单克隆抗体染色，并使用LSAB +试剂盒进行显色。
在成釉细胞瘤中，丛状成釉细胞瘤、伴有颗粒细胞改变的滤泡状成釉细胞瘤、促结缔组织增生性和单囊性变异型之间存在统计学上的显著关联。与AOT相比，MDM2主要的核染色显示成釉细胞瘤中存在过表达。
与单纯单囊性和促结缔组织增生性成釉细胞瘤相比，丛状成釉细胞瘤、伴有颗粒细胞改变的滤泡状成釉细胞瘤和棘皮瘤样成釉细胞瘤中MDM2的过表达表明这些实性多囊性成釉细胞瘤变异型的增殖表型相对增强。总体比较时，与AOT相比，成釉细胞瘤中的表达更高。这表明这两组牙源性肿瘤在侵袭性方面存在差异，提示成釉细胞瘤具有更强的侵袭性。
