Establishment Of Animal Model And Cell Model For Oral Leukoplakia Malignant Transformation And Epidemiological Investigations Of College Students’ Recurrent Oral Ulcers

Objective:This study established the animal model and cell model of oral leukop-lakia malignant transformation, to provide a foundation for the study of the molecularmechanism of oral leukoplakia malignant transformation, and to achieve early warn-ing,diagnosis and to provide a foundation for the exploration of effective therapeutictargets.Methods:In this study,we painted the left cheek pouch of golden hamster(fiveweeks of age)with0.5%Benzo(a)pyrene(BaP) and7,12-dimethyl-benz[a]anthracene(DMBA) mixed solution every Monday, Wednesday and Friday at fixed time, then ex-ecuted at6weeks,9weeks,12weeks and15weeks respectively, took the left hamstercheek pouch mucosa or tumor tissue, fixed a part of the tissue with10%neutral forma-lin solution for histopathological diagnosis, stored the remaining tissue at-80℃aftercooled in the liquid nitrogen quickly. Painted the negative control group at the sametime on hamster left cheek pouch with solvent, blank control group received no treat-ment, executed after15weeks,took part of hamster cheek pouch samples for histopa-thological diagnosis, stored the remaining portion at-80℃after cooled in the liquidnitrogen quickly.The cell model in this study is to treat three experimental group with BaP,DMBA,BaP/DMBA mixed culture medium, medicate at regular interval to facilitatedysplastic oral keratinocyte(DOK)cell to malignant transformation. Observe the mor-phology variation of cell with inverted phase contrast microscope, take MTS assay, colony formation assay,nude mice experiments to compare the proliferation rate, colonyformation rate, tumorigenicity of cell before and after induced.Results:1.Buccal pouch mucosa sample of BaP/DMBA group was sorted by histopatho-logical examination, experienced a continuous process of inflammatory stage, mild andmoderate epithelial dysplasia (leukoplakia), severe epithelial dysplasia (carcinoma insitu), and invasive carcinoma. Negative control group and blank control group werenormal buccal mucosa histology appearance.2. After induced,the cell of BaP group, DMBA group,BaP/DMBA group showedirregular change and smaller than DOK cell; proliferation speed were much fast-er(P<0.05); the results of soft agar assay showed that BaP group, DMBA group,BaP/DMBA group could grow into colony in soft agar medium,while the DOK group couldnot; the results of nude mouse tumorigenicity assay showed that cells in BaP group,DMBA group, BaP/DMBA group could form tumor after30days hypodermic injec-tion, tumor growth was nodular, part of the tumor showed surface ulceration andbleeding, while the DOK group could not form tumor after cell injuction.Conclusions:1. The animal model of oral leukoplakia malignant transformation was successfullyestablished with BaP/DMBA on golden hamster cheek pouch.2. The animal model of oral leukoplakia malignant transformation was successfullyestablished with Bap,DMBA,BaP/DMBA on DOK cell. Objective: To provide scientific foundation for prevention and treatment of recur-rent oral ulcers, we investigate the prevalence status of recurrent oral ulcers of collegestudents of Dalian.Methods: We took570students in total in Dalian University of Technology,457of them were male, others were female. We took a record of age and native place inmethods of questionnaires, and asked about the condition of oral ulcers, such as the lo-cation and size of oral ulcers. Took gender, native place, age and location of ulcer asgrouping criteria for statistical analysis, to compare the constituent ratio of minor aphthaand severe aphtha.Results:1. The prevalence of recurrent oral ulcers was63.16%.2. Took gender as a grouping criteria, the prevalence of recurrent oral ulcers in maleand female had no statistically significance(P>0.05),the constituent ratio of minor aph-tha and severe aphtha in male and female had no statistically significance(P>0.05).3. Took native place as a grouping criteria, the prevalence of recurrent oral ulcers in ur-ban and rural areas had no statistically significance(P>0.05),the constituent ratio of minor aphtha and severe aphtha in urban and rural areas had no statistically significance(P>0.05).4. Took age as grouping criteria, the prevalence of recurrent oral ulcers in18-20agegroup,21-23age group and24years older group had no statistically significance(P>0.05),the constituent ratio of minor aphtha and severe aphtha in18-20age group,21-23age group and24years older group was statistically significant (P <0.05);compared theconstituent ratio of minor aphtha and severe aphtha in each two of the age groups, theconstituent ratio of minor aphtha and severe aphtha in24years older group were statis-tically significant to the other two age groups (P <0.05), the constituent ratio of minoraphtha and severe aphtha in18-20age group and21-23age group was not statisticallysignificant (P>0.05),5.Recurrent oral ulcers tended to occured in the lips, labial sulcus, buccal mucosa andtongue, the constituent ratio of minor aphtha and severe aphtha in different locationswere statistically significant (P <0.05).Conclusion:1. The prevalence of recurrent oral ulcers was63.16%.2. The prevalence of recurrent oral ulcers and constituent ratio of minor aphtha and se-vere aphtha had nothing on gender and native place.3. The prevalence of recurrent oral ulcers had nothing on age,the constituent ratio ofminor aphtha and severe aphtha was age-related, the percentage of severe aphtha in24years older group is higher than the other two age groups.4. Recurrent oral ulcers tended to occurred in the lips, labial sulcus, buccal mucosa andtongue, the constituent ratio of minor aphtha and severe aphtha was concerned with lo-cation.