Differentially Expression Of Aurora A And Erk Pathway In Oral Lichen Planus And Its Malignant Tissue

Objective:Oral squamous cell carcinoma is one of the most common malignant tumors, which has a high incidence rate and a serious threat to human health. At present, the radical cure of oral squamous cell carcinoma mainly rely on surgical excision, however, postoperative survival rate is not high as early metastasis of oral squamous cell carcinoma, and the prognosis is poor in recent years. In recent years, with the development of tumor molecular biology, researchers get more chance to investigate the molecular mechanism of oral cancer. Therefore, Gene diagnosis and targeted therapy of tumor has gradually become a study focus of scientific researchers. A large number of studies show that the reason of occurrence and development of oral squamous cell carcinoma is the balance between cell proliferation and apoptosis has destroyed, which involves the activation of oncogene, the inactivation of tumor suppressor gene, abnormal cell cycle and apoptosis disorders. Futhermore, signal transduction pathways would elucidate the function of protein, the ossociations among proteins and between protein and genes. Signal transduction pathways would explain how the stimulation of signal going from outside to inside the cell, eventually leading to cellular biology effects.Ras/Raf/Mek/Erk signaling cascade is a small GTP binding of cytosolic protein kinase cascade activation. The pathway is one of "MAPK" pathways. The pathway has several steps. Firstly, under the extracellular stimulation, inactivated Ras turns into activated Ras, the phosphorylation of Ras activate Raf. Secondly, the activated Raf activates Mek, and activated Mek phosphorylates ERK. Thirdly, activativated Erk goes into nucleus, followed by activation of transcription factor, eventually leading to gene change and cell reaction.This cascade reaction regulates gene expression. Depending on different extracellular signal and cell types, Ras/Raf/Mek/Erk signal pathway can regulate cell cycle or apoptosis. It confirms that excessive activation of Ras/Raf/Mek/Erk signaling pathway is closely related to the occurrence and development of tumor. The protein phosphorylation and dephosphorylation is most closely to signal pathway activation. Inactive protein has no fuction in the signal pathway. Therefore the detection of phosphorylation protein expression could be more realistically significant.Most study of oral squamous cell carcinoma focused on different protein expression between oral squamous cell carcinoma and normal oral mucosa. In this study, we investigated the differences between oral lichen planus and oral squamous cell carcinoma from oral lichen planus; furthermore, we tried to research the different expression of phosphorylated proteins. We detected expression of Aurora A, pRaf-1(S259), ERK1/2 and pERK1/2(T202/Y204) in oral lichen planus and oral squamous cell carcinoma so as to further explore the malignant transformation mechanism of the occurrence and development in oral squamous cell carcinoma. We tried to provide a new idea for early diagnosis and a theoretical basis for cell targeted drug therapy.Materials and Methods:A series of 71 oral lichen planus, and 6 oral squamous cell carcinoma patients, who were treated in the first affiliated hospital of Dalian Medical University, were enrolled in this study. OSCC patients were all developed from OLP. In this study, using immunohistochemical S-P method, we detected Aurora A、 pRaf-1 (S259)、ERK1/2 and pERK1/2 (T202/Y204) protein expression and distribution characteristics in 71 oral lichen planus mucosa cases,6 patients with oral squamous cell carcinoma. Experimental data was based on two independent samples of 2×2 contingency analysis, using SPSS13.0 software for statistical analysis. Comparison of immunohistochemical positive rate used x2 test.Results:Aurora A 23 (32%) cases of OLP stained positive, however,48 (68%) cases of OLP stained negative. Six cases (100%) of OSCC stained positive. The staining rate of positive in OSCC group was higner than OLP group (P=0.005, P<0.05).pERK1/2(T202/Y204) the positive staining rate in OLP group was 15/71(21%) and the negative staining rate was 56/71(79%). The positive staining rate in OSCC group was 6/6(100%). pERK1/2(T202/Y204) expression in OSCC group was higher than OLP group. (P=0.003, P<0.05).pRaf-1(S259) protein positive expression rate was 46/71 (65%) in OLP sample and negative rate was 25/71 (35%). Positive expression rate in OSCC sample was 4/6(67%) and the negative rate was 2/6 (33%). There were no statistical differences between these two groups (P=0.325, P>0.05). ERK1/2 protein positive staining rate in the OLP sample was 47/71(66%) and negative rate was 24/71(34%). Positive staining rate in OSCC group was (4/6)67% and negative rate was 2/6(33%). There were no statistical differences between these two groups. (P=0.715, P>0.05).Conclusion:Aurora A and ERK singnal pathway maybe participate in oral lichen planus malignant occurrence; High expression of Aurora A and pERK1/2 more than 50% positive rate could be pre-warning of malignant transformation of OLP.