目的：探讨口腔扁平苔癣（oral lichen planus，OLP）及口腔鳞状细胞癌（oral squamous cell carcinoma，OSCC）病变组织中p38丝裂原活化蛋白激酶（mitogen activated protein kinases，MAPK）、磷酸化p38MAPK及其下游核转录因子κB（nuclear factor kappa B，NF-κB）的表达情况，初步探讨p38MAPK通路在OLP及OSCC发病过程中的作用。方法：收集53例OLP、45例OSCC及18例正常对照口腔黏膜组织的石蜡切片，免疫组织化学染色分析法检测p38MAPK、磷酸化p38MAPK及NF-κB在3组中的表达及分布情况。同时收集11例OLP、5例OSCC及7例正常对照组织的新鲜冰冻组织，采用Western blotting法进一步比较p38MAPK、磷酸化p38MAPK在3组中的表达情况。结果：免疫组织化学染色分析显示：p38MAPK及NF-κB在细胞核及细胞质中均有表达，在OLP中主要在固有层淋巴细胞中呈高表达，而在上皮细胞表达阳性率低；磷酸化p38MAPK在OSCC中阳性表达率显著高于OLP及正常对照组。Western blotting结果显示：p38MAPK在OLP、OSCC及正常对照组中均有表达；磷酸化p38MAPK在8例（8/11）OLP、5例（5/5）OSCC和4例（4/7）正常对照组中有表达。结论：p38MAPK广泛存在于口腔黏膜的各种生理、病理过程中，它的磷酸化形式可能参与了OSCC的发生和发展，其在OLP发病和进展中的作用仍需进一步探索。

Objective：To assess the differences among the expressions of p38 mitogen activated protein kinases (MAPK), phospho-p38MAPK and nuclear factor kappa B (NF-κB) in oral lichen planus (OLP) and oral squamous cell carcinoma(OSCC).Methods:In the study, 53 cases of OLP, 45 of OSCC, and 18 controls were obtained and 4-μm-thick histological sections were prepared from formalin-fixed paraffin-embedded tissue blocks.The expressions of p38MAPK,phospho-p38MAPK and NF-κB were detected by immunohistochemistry staining. Furthermore, the expressions of p38MAPK and phospho-p38MAPK were detected using Western blotting analyses in the fresh tissues from 11 cases of OLP, 5 cases of OSCC, and 7 cases of the controls. Results:p38MAPK was over-expressed in the lamina propria, but lowly expressed in the epithelium in OLP group. Phosphop38MAPK was lower expressed in OLP group than in OSCC and control groups.NF-κB was found over-expressed in the lamina propria in OLP group.p38MAPK was found expressed in all the samples in the 3 groups. The expression of phospho-p38MAPK was observed in 8 (8/11) OLP samples, 5 (5/5) OSCC samples and 4 (4/7) controls by Western blotting, but no significant differences were found within the 3 groups. Conclusion:p38MAPK can be detected in normal oral mucosa, OLP and OSCC.phospho-p38MAPK may be related to the onset and progression of OSCC. The role of p38MAPK in OLP is yet to be revealed.