Identification The OLK Malignant Transformation-related Proteins By Tissue Microarray

Objective: Oral leukoplakia(OLK)is white plaque or patch of oral mucosa,but can not be diagnosed as any other disease according to histopathological methods.Oral squamous cell carcinoma(OSCC)is the sixth most popular cancer,accounting for 90%of oral malignant tumor.500,000 people die of OSCC every year,because of bad prognosis of 50% 5-year-survival-rate.OSCC is mostly developed from precancerous lesion,especially tobacco stimulated OLK.Sadly,the definitive mechanism of canceration of OLK is still unkown.So,to find the molecular biomarkers of malignant OLK is of great importance to prevention and early diagnosis of OSCC.In this study,we builded a model cell line of OSCC-BD,and screened out the different expressed genes between OSCC-BD and OLK cell line by gene chips as well as verification of homologous RNA to find the molecular biomarkers and the malignantly transforming mechanism of OLK,providing new clues for the early treatment.Methods: OSCC-BD and OLK cell line are cultured simultaneously,then the totalprotein of these two cell lines are extracted to do Western Blotting tests to examine the expression of Protein X and Protein Y between them.Then,180 paraffin embedded OSCC tissue of Pathology Department of Cancer Institute & Hospital.Chinese Academy of Medical Sciences were selected to build clinical tissue chips of OSCC and corresponding normal adjacent mucosa.Immunohistochemistry(IHC)was conducted to determine the expressional difference of Protein X and Protein Y to analysise the relationship between expressional difference and clinical pathological characteristic.Result:According to the Western Blotting,Protein X overexpress in OSCC-BD and lose expression in OLK cell,but,Protein Y has a definitely opposite expression.IHC tests of clinical tissue chips show that Protein X positive expression rate is75%(135/180)in OSCC tissue and 39%(71/180)in normal adjacent mucosa,located in cytoplasm.And Protein X significantly overexpresses in OSCC tissue relative to corresponding normal adjacent mucosa(P<0.001);Protein Y positive expression rate is20%(35/180)in OSCC tissue and 33%(60/180)in normal adjacent mucosa,located in nucleus.And expression of Protein Y in two type of tissue has statistical significance(P=0.002,P<0.05).Conclusion:Protein X may take some parts in the transforming process of OLK to OSCC,Protein Y may inhibition the maligang process.This provides some research foundation and scientific basis of the potential molecular biomarkers and early treatment targets exploration of malignant OLK.