The Expression And Mechanism Of Integrin ?v?6?JunB And SRF In The Malignant Transformation Of Oral Leukoplakia

Objective:Oral Leukoplakia(OLK)is a typical precancerous lesion that occurs in the oral mucosal epithelium.The increased malignant transformation of precancerous lesions is the main cause of the increase in the prevalence of oral cancer.The exact mechanism of OLK developing into oral cancer remains unknown.SRF,JunB and integrin ?v?6 play important roles in the development,invasion and metastasis of tumors.SRF and JunB are involved in the regulation of integrin ?6 expression as transcriptional factors.Study on the mechanism of SRF,JunB and integrin avP6 on malignant transformation of oral leukoplakia may provide a new direction for early diagnosis,treatment and prognosis of malignant tansformation of oral leukoplakia.Methods:The animal model of malignant transformation of oral mucosa was induced by 4NQO.HE staining was used to determine the pathological period.Immunohistochemical staining was used to determine the expression of SRF and JunB protein in various lesions.After overexpressing of SRF,JunB and integrin ?v?6 in DOK cells,the infection efficiencies were detected by QPCR and Western-blot;the effects of the SRF,JunB and integrin ?v?6detected by cell function assay;The interaction between SRF,JunB and integrin ?v?6 on DOK cell migration and invasion were in DOK cells was detected by QPCR and Western-blot.Gelatin zymography experiments were used to detect the expression of MMP9 and MMP2 after overexpression of integrin ?v?6 in DOK cells.Results:1.Mice weight in all groups initially increased in the early stage,and peaked at 12 weeks,whereas the mice weight of two exprerimental groups started to decreased after 12 weeks.There was significant difference in body weight between the control group and the experimental groups from 14 weeks(p<0.05),but no significant difference between the two experimental groups(p>0.05).2.Tongue mucosa of mice in the distilled water control group had normal appearance,while the tongue mucosa of the experimental group showed white spot-like changes,granular lesions,and tongue-back projections as the experiment progressed.There was no significant difference in the macroscopic lesions of the tongue and mucosa of mice between the experimental group A and B.3.The mice in the distilled water control group had normal epithelial tissue-like changes.The epithelial tissues of the experimental groups showed histopathological changes such as abnormal hyperplasia,carcinoma in situ and invasive carcinoma along with the experiment progression.4.SRF and JunB proteins were overexpressed during malignant transformation of oral mucosa,with the highest expression level in cancer tissues.5.Overexpression of SRF,JunB and integrin ?v?6 in DOK cells,caused no morphological change of DOK cells,but promoted the migration and invasion of DOK cells,along with the down-regulation of E-cadherin and up-regulation of N-cadherin.6.Overexpression of SRF and JunB in DOK cells up-regulated the expression of integrin ?v?6 at the protein level;overexpression of JunB in DOK cells up-regulated expression of integrin ?v?6 at the mRNA level;overexpression of integrin ?v?6 in DOK cells also up-regulated the expression of SRF and JunB at the protein level.7.Overexpression of integrin ?v?6 in DOK cells had no effect on cell proliferation,but increased DOK cell MMP-9 expression.Conclusions:1.The animal model of malignant transformation of oral leukoplakia in mice was established by 4NQO drinking water method.SRF and JunB were expressed in different stages of disease,and the expression levels were up-regulated along with the progression of the disease,suggesting that SRF and JunB are involved in the malignant transformation of mucosal leukoplakia.2.Experiments with overexpression of SRF,JunB and integrin ?v?6 in DOK cells showed that EMT marker E-cadherin was down-regulated and N-cadherin was up-regulated,suggesting that SRF,JunB and integrin av(36 may promote the migration and invasion of DOK cells via EMT.3.Integrin P6 may promote the migration and invasion of DOK cells by regulating the activity of MMP9.4.Experiments with overexpression of SRF,JunB and integrin ?v?6 in DOK cells suggested that SRF,JunB and integrin ?v?6 may interact to promote the invasion and metastasis of oral leukoplakia.