Section of Oral and Maxillofacial Oncology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
Int J Clin Oncol. 2013 Feb;18(1):154-63. doi: 10.1007/s10147-011-0358-4. Epub 2011 Dec 15.
Recent studies have demonstrated that the p75 neurotrophin receptor (p75NTR) is a useful marker of keratinocyte stem cells. Although the stem cell markers of original normal tissue have been used to identify cancer stem cells in a variety of cancers, the expression and function of p75NTR have been poorly understood in oral squamous cell carcinoma (OSCC). The objective of this study is, thus, to examine p75NTR expression immunohistochemically in oral leukoplakia (OL), the most frequent precancerous lesion, and OSCC, and to reveal the usefulness of p75NTR as a marker for undifferentiated cancer cells and a novel prognostic factor for OSCC patients.
In this study immunohistochemical expression of p75NTR, Ki-67, cytokeratin (CK) 5, and CK14 was examined in 112 cases of OL and 81 of OSCC. The labeling indices (LIs) of p75NTR and Ki-67 were calculated, and the association of these LIs with histopathologic characteristics was then evaluated.
In the normal oral epithelium and OL, p75NTR was expressed only in the basal layer, and its LI was invariant, irrespective of the extent of epithelial dysplasia. In OSCC, however, p75NTR-LI was significantly increased in association with upgrading of histologic grade and mode of tumor invasion. Furthermore, the prognosis of the high p75NTR-LI group (LI ≥ 53.1%) was poorer than that of the low p75NTR-LI group (LI < 53.1%).
These results suggest that p75NTR is expressed in undifferentiated cell populations in OL and OSCC. Furthermore, p75NTR is possibly involved in invasion and poor prognosis in OSCC.
最近的研究表明，p75 神经营养因子受体（p75NTR）是角质细胞干细胞的一个有用标志物。虽然原始正常组织的干细胞标志物已被用于鉴定各种癌症中的癌症干细胞，但 p75NTR 在口腔鳞状细胞癌（OSCC）中的表达和功能仍知之甚少。因此，本研究旨在通过免疫组织化学方法检测口腔白斑（OL）这一最常见的癌前病变和 OSCC 中 p75NTR 的表达，并揭示 p75NTR 作为未分化癌细胞标志物和 OSCC 患者新的预后因素的用途。
本研究检测了 112 例 OL 和 81 例 OSCC 中 p75NTR、Ki-67、细胞角蛋白（CK）5 和 CK14 的免疫组织化学表达。计算了 p75NTR 和 Ki-67 的标记指数（LI），并评估了这些 LI 与组织病理学特征的相关性。
在正常口腔上皮和 OL 中，p75NTR 仅在基底层表达，其 LI 不变，与上皮异型增生的程度无关。然而，在 OSCC 中，p75NTR-LI 与组织学分级和肿瘤侵袭模式的升级显著相关。此外，高 p75NTR-LI 组（LI≥53.1%）的预后比低 p75NTR-LI 组（LI<53.1%）差。
这些结果表明，p75NTR 在 OL 和 OSCC 中的未分化细胞群中表达。此外，p75NTR 可能参与 OSCC 的侵袭和不良预后。
