Research On Fibroblast Growth Factor10and Its Receptor’s Expression In Oral Lichen Planus

Objective: Oral lichen planus(OLP) is a kind of chronic inflammatorydisease which keratinizes abnormally and often happens on the oral mucosa; itis one of the common oral mucosal diseases. This disease is likely to occuramong middle-aged women, the prevalence is about0.51%. Its typicalhistopathological manifestations are: hyperkeratosis or parakeratosis of theepithelium mucosa, the stratum granulosum is obvious, acanthosis,liquefaction and deformation of the basal cells appears. A large number oflymphocyte under the basal cells is infiltrated in ribbon pattern. The basicclinical character is pearl-lustre gray stripes will appear on both sides on theoral mucosa symmetrically, the area around the stripes may appear hyperemia,anabrosis, atrophia, blister, etc. OLP can be divided into eight categoriesaccording to the lesion forms. The eight categories are: net shaped, annularshaped, stripe shaped, plaque shaped, papule shaped, blister shaped, erosionshaped and atrophy shaped. The etiology of OLP is varied, it is often related tothe factors like: spirit, internal secretion, immune, infection, microcirculationdisturbance, heredity, etc. However, the exact pathogenic mechanism is notvery clear yet; it is thought as a kind of T-cell immunoreaction for now. Itscourse of disease will procrastinate and repeat chronically, as a result, itstherapy has become a clinical problem.Fibroblast growth factor (FGF) is found in the tissue extracts of the brainand pituitary gland in the1930s; it has not been separated or purified until the1970s. FGF is an important mitosispromotingfactor,23types have beenidentified until now. Of which fibroblast growth factor10(FGF10) is able tostimulate the growth of the epithelial cell specially，it probably has importantregulating function in the dysplasia and prosoplasia of the Malpighian cells.FGF10is consisted of208amino acids, it has instability in acid and heat, it is a kind of basic protein, which comes from the embryonic epithelial cells,newly-born or grown-up mesenchyme fibroblast cells. Its manifestationsinclude the visceral organs like the grown-ups’ kidney, gastrointestinal tract,etc. It is composed and secreted by the mesenchymal cells, besides; itsreceptor is distributed on the cell surface of the ones which are originatedfrom the epithelial cells. For example, the skin cutin formed cells and theepithelial cells on the gastrointestinal mucosa. The research of FGF10in thepsoriasis lesion conducted by Professor Xi Yanping and Professor YuChunshui has manifested that: FGF10can induce the keratinocyte cell (KC) tokeep proliferating and migrating excessively, in order to further research thepathogenesis of the psoriasis. However, the FGF10’s expression in oral lichenplanus has not been researched yet.This experiment has tested the FGF10and its specific receptor FGFR2’sexpression level and distribution character in the oral lichen planus lesiontissue, further researched the oral lichen planus’s pathogenesis, and hasoffered new treatment thoughts for the clinical treatment of oral lichen planus.Methods: Collect22cases of oral lichen planus tissue paraffin block, allof them have been examined and verified by the pathology department ofHebei Medical University affiliated hospital. All the collected cases have notused any corticosteroid hormone or immunosuppressant drugs; have nogeneral disease three months before taking biopsies. Collect20cases normaloral mucosal tissue, all of them are from crown lengthening surgery or thesurgery of removing ambushed impacted wisdom tooth. The samples need tobe fixed by4%formaldehyde and embedded by the paraffin. Besides,5μmthick section should be prepared, too.Conduct immunohistochemical staining to FGF10and FGFR2respectively by using immunohistochemical SP method. Use phosphatebuffered saline to take the place of first PB as negative control. The alreadyknown FGF10and FGFR2positive samples will be positive control. FGF10and FGFR2immunohistochemical staining positive are cytoplasm or cellmembrane which exist yellow or claybank chromosome. The ones which have no claybank chromosome are negative expression. Image analysis system hasbeen adopted to conduct the image analysis. Record the grades of the twodifferent kinds of factors’ percents of positive cells and their staining intensity,the final result will be calculated by multiply the two marks. Divided the finalresults into the following four categories:0~1point will be negative (－),2~4points will be weak positive (＋),5~7will be medium positive (＋＋),≥8points will be strong positive (＋＋＋).Conduct statistical analysis by using the SPSS13.0statistical softwarepackage, Count material using nonparametric two sample rank and inspectionis Wilcoxon rank and inspection, the inspection level will be α=0.05,the oneswhose P<0.05are the results which own statistical significance.Results:1The immunohistochemical staining results of FGF10in OLP group andnormal groupThe FGF10positive expression in the immunohistochemical group is cellmembrane and cytoplasm present clay bank staining of different degrees,however, the clay bank staining has not been seen in the negative expression.In the normal oral mucosal tissue, FGF10’s positive expression in theepithelial layer mainly locates in the basal lamina, its expression is weakpositive. In the connective tissue, the cytoplasm of the vascular endothelialcell, fibroblast cell and lymphocyte cell present positive staining. In the orallichen planus tissue, FGF10’s epithelial layer expression mainly exists in thespinous layer and the basal lamina. Its expression in the epithelial layercytoplasm present strong positive expression, however, in the spinous layercytoplasm. In the connective tissue, the cytoplasm of the vascular endothelialcell, fibroblast cell and lymphocyte cell present positive staining. Thestatistical analysis result of Z is-4.248, P<0.05, it owns the statisticalmeaning.2The immunohistochemical staining results of FGFR210in OLP group andnormal groupThe FGFR2’s positive expression displayed by the immunohistochemical is cell membrane and cytoplasm present clay bank or sepia. However, claybank staining has not been found in the negative expression.In the normal oral mucosa tissue section, FGFR2’s positive expressionmainly lies in epithelium’s basal lamina. In the connective tissue under themucosa, clay bank staining can be seen in the cytoplasm and the cellmembrane of the lymphocyte cell, the vascular endothelial cell and thefibroblast cell. In the oral lichen planus tissue section, FGFR2present positiveexpression in the epithelium’s spinous layer and the basal lamina cell, whilethe spinous cells present strong positive expression, and the basal cells arepositive expression. In the connective tissue under the mucosa, clay bankstaining can be seen in the cytoplasm and cell membrane of the lymphocytecells, the vascular endothelial cells and the fibroblast cells. The calculated Z is-4.207by statistical analysis, P<0.05，it owns the statistical meaning.Conclusion:This experiment has tested the expression of FGF10and its receptorFGFR2’s expression in the normal oral mucosa tissue and the oral lichenplanus. The result shows that: FGF10and its receptor FGFR2are stronger inthe oral lichen planus than in the normal oral mucosa tissue. This indicatesthat it may have certain meaning in the happening process of the oral lichenplanus.