Expressions And Clinical Significance Of COX-2and Podoplanin In Thymoma Tissues

BACKGROUND: Thymoma from the thymic epithelial cells, is a commontumor in the anterior mediastinum, accounting for about15%in mediastinum.Thymomas, slow growth epithelial cells of the thymus stroma, clinical performance ofcomplex and without uniform histologic classification, prognostic factors. Thymomais thought to have multiple histological characteristics and variable biologic behaviors,its malignant potential can not be fully revealed using clinical histopathologicalexamination. So in recent years, people began using molecular biological indicator inthymoma pathology diagnosis. Many studies showed, COX-2in a number of humanbenign premalignant and malignant tumors is highly expressed, suggesting thatCOX-2may be involved in the occurrence and development of malignancy. D2-40first as lymphatic endothelial cell-specific markers used in tumor research. Withfurther study, it is found that D2-40in the surgical pathology also has some importantdiagnostic value. D2-40is relatively specific marker for lymphatic endothelial cells.The expression of D2-40is associated with tumor lymphangiogenesis and lymphaticvessel invasion. Through investigating the expression of D2-40in thymomas and itscorrelation, we analyse the relationship between the expression and clinicalpathological features of thymoma, and provide a theoretical basis for clinicaldiagnosis of malignant thymoma, predicting the aggressive and metastatic potential,choice of treatment and evaluation of prognosis.OBJECTIVE: To investigate the biological, clinincal significance andrelationship between COX-2and podoplanin expressions in thymoma.METHODS: We selected51cases of thymoma specimens, including male28,female23, age16~71years old, average48.31years old. Tumor HE staining tabletsby two pathologists for definitive diagnosis and pathological typing. According toWHO classification:5cases of type A,4cases of type AB;(B1~B3) in42cases,including15cases of type B1,15cases of type B2, type B3in12cases. According tothe Masaoka staging criteria: I in17cases, II–IV in34cases, including18cases ofstage II,7cases of stage III,9cases of stage IV. Take5cases of thymus diseasethoracotomy for resection of thymic tissue (rheumatic heart disease) as a controlgroup,3cases were male,2female, age45~57year old, average age is51years old.The expression of COX-2and podoplanin were detected and compared by usingimmunohistochemical technique among51thymomas.RESULTS: The expressions of COX-2and podoplanin significancly increased along with the advance of thymoma Masaoka stage (X2were28.00and23.64,P<0.05),and there is relevance with the thymoma histology(X2were11.79and25.27,P>0.05). The positive rate of COX-2of type A/AB thymomas was significantly lowerthan that of type B1-3.There was a significance relationship between the expressionsof COX-2and podoplanin (P<0.05). The expressions of COX-2and podoplanin had apositive correlation(r=0.569,P<0.01).The expression of COX-2of thymoma had noobvious correlation with MG(X2were0.370and0.004, P>0.05).CONCLUSIONS: COX-2and Podoplanin associated with thymoma occurrenceand development are closely related, especially in thymoma histological staging, itshigh protein expression is high, prompting COX-2and Podoplanin in thymomacarcinogenesis process plays an important role. COX-2and Podoplanin can serve asthymoma biological targets. COX-2and podoplanin expressions are positivecorrelation with advance of Masaoka stage. The increasing expressions of COX-2andpodoplanin can be important biological parameters to maligiancy and biologicalbehavior for thymoma, and can be provided the evidence for diagnosis andadjunctive therapy.