| Oral leukoplakia (OLK) refers to the white lumps or white patches on the oralmucosa, not to any other disease by clinical and histopathological diagnosis. Thecanceration rate of OLK is high, and it could become oral squamous cell carcinoma(OSCC) which is seriously harm to human life. According to the survey, Nonhomogeneous leukoplakia canceration rate is about13%-17.5%, even in some areas therate can reach as high as50%-70%. OSCC is one of the top ten tumors of the world, andamong the malignant tumors to ranks sixth. Research results show that17%-35%ofOSCC patient are originated from oral leukoplakia malignant transformation. Therefore,researching molecular mechanism of canceration and screening molecular markers formalignancy has important scientific significance and clinical application values for earlydiagnosis tand and effective improvement of the prognosis on oral leukoplakiacanceration.Objective: The study through screened related protein of oral leukoplakiamalignant transformation, analyzed relevant information of differentially expressedproteins in malignant transformation of OLK, contributing to researching thecanceration mechanism of oral leukoplakia deeply, and exploring molecular markers and key therapeutic targets using proteomics approach.Methods: This experiment used oral leukoplakia malignant cells model weestablished, namely oral leukoplakia cell line DOK and its induced cell line-----oralsquamous carcinoma cell OSCC-B+D as the experimental object. Using relativequantitative proteomics method, high-throughput to screening the differentiallyexpressed proteome between DOK and OSCC-B+D cells. First, light-labelingformaldehyde（CH2O） and heavy-labeling formaldehyde （CD2O） were labeled intopeptide fragments of OLK cells and OSCC-B+D cells by stable isotope dimethyllabeling technique, respectively. Then, separating the samples by high performanceliquid chromatography after mixing the two cell samples. After that, samples were takeninto mass spectrometer Orbitrap Elite which is highly sensitive for peptide detection.Finally, MaxQuant software(v1.1.2.5) and IPI Human.(v3.87) database were applied forthe results to identify relevant information of differentially expressed proteins inmalignant transformation of OLK.Result: After HPLC-MS/MS analysis on cells of DOK OSCC-B+D samples,totally1459proteins were identified, and the common identification results of threerepeated experiments showed that931proteins were screened out. Through furtherfiltering the obtained results with the relative standard deviation of RSD <35%, finallywe got a total of621proteins. The analysis and comparison of the different expressionof DOK and OSCC-B+D cells, we screened out197different proteins before and afterthe malignant, among which125proteins were significantly up-regulated (averagedeuterium to hydrogen ratio>2) after malignant,72proteins were significantly down-regulated expression after malignant (average deuterium to hydrogen ratio <0.5).We used the uniprotKB database to classify and analyze the197proteins accordingto their cellular components, molecular functions and biological processes in order toobtain the related information of different protein. On the basis of cellular componentinformation, it indicated that most differential proteins were in the cytoplasm andnuclear, accounting for22%, the others were the mitochondria (12%), plasmamembrane (11%), endoplasmic reticulum (8%), integral to membrane (7%), respectively. On the basis of information of molecular function, DNA binding protein was at most,accounting for about9%, followed by RNA binding protein, accounting for about6%,the others were the transporter activity protein (5%), GTPase activity protein(3%),transcription regulator activity (2%) protein, respectively. According to the biologicalprocess information, the regulation of RNA/DNA/nucleotide/nucleosome metabolicprocess protein was up to about23%, followed by the protein metabolism proteinaccounting for about12%, the other were transport (11%) protein,cell growth (9%),apoptosis (7%), signal transduction (2%) and immune response (2%) associated protein.Conclusion: This study found197differentially expressed proteins by highthroughput screening between OLK and OSCC cells. According to the differentialprotein related information, we preliminary infer the mechanism of presumablymalignant occurrence on OLK. Proteins which participate in canceration of OLKmostly locate in the nucleus and cytoplasm, DNA/RNA binding protein and regulationof RNA/DNA/nucleotide/nucleosome metabolic process protein play an important role,while functional and metabolic abnormalities of DNA/RNA may be an importantmechanism in the malignant transformation of OLK process. This study providesimportant research foundation and scientific basis for further exploration of molecularmechanism and screening molecular markers of OLK malignant transformation. Objective: To understand the prevalence of dental caries among college studentsthrough oral examination of college students, provide scientific basis for making healthcare treatment for oral, and enrich the data of oral health epidemiological in Dalian area.Methods: We made oral examination table according to the basic method of WHOoral health survey and the third national oral health epidemiological investigation.Thesurvey of dental caries on570college students in Dalian University of Technologyabout caries prevalence rate, DMFT, DMFS were recorded in the table, through the wayof inspection combined probing.Results:Among570students, the caries rate was58.07%, DMFT was1013(766decayed teeth,10missing teeth,237filled teeth), X DMFT was1.78±2.335, thefilling rate of dental caries was23.40%. The caries prevalence rate of males and femaleswere54.3%and73.5%, respectively. The difference was statistically significant (P <0.05); boys and girls mean DMFT was1.54±2.130and2.73±2.845, the difference wasstatistically significant (P <0.05); The caries prevalence rate of students from city andthe ones from countryside were62.1%and53.2%, respectively. The difference wasstatistically significant (P <0.05); The X DMFT of students from city and the onesfrom countryside were1.95±2.322and1.56±2.389, respectively. The difference wasstatistically significant (P>0.05). The caries prevalence rate of different ages were58.5%(18-20years old),54.9%(21-23years old),64.3%(>24years). No statistically significant difference was found among the three groups (P>0.05); The X DMFT ofdifferent ages were1.72±2.108(18-20years old),1.63±2.325(21-23years old),2.36±2.968(>24years), with a significant difference among the three groups (P <0.05).The planned comparison of different age groups was no statistical difference between18-20years old and21-23years old. But there was a significant difference between thetwo and>24years old group, as the age increased, X DMFT increased.After furtheranalysis on the position decayed teeth, we found that caries prevalence rate of molarwas apparently higher than the rest of teeth.And the mandibular molar caries prevalencerate is higher than maxillary molar, with statistical difference (P <0.05).Conclusion: The results of this epidemiological investigation showed that thecaries prevalence rate was high, but the filling rate was low. The characteristics of theinvestigation on college students is the caries prevalence rate of female is higher thanmale, the rate of people in urban is higher than rural; X DMFT of female is higher thanmale, and>24years old group is higher than18-20years old group. Theepidemiological characteristics of the position of decayed tooth is that molars are higherthan the rest of teeth. And the mandibular molar caries prevalence rate is higher thanmaxillary molar. |
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