The Study On Expression Of HTRTmRNA And HTR In Retroperitoneal Liposarcoma

Liposarcoma is one of the most common soft tissue sarcomas of adult life. Among soft tissue sarcomas its incidence ranges from 9.8% to 16% . The retroperitoneal liposarcoma is remarkable because of its frequent large size and tending to recur . There are variable histological picture ranging from well-differentiated tumors to extremely cellullar pleomorphic neoplasms.Telomerase activity is detected in most human cancers. Little is known about telomerase in retroperitoneal liposarcoma. Analysis of the expression of the hTRTmRNA ( humen telomerase reverse transcriptase, hTRT ) and HTR (human telomerase RNA component,hTR) were carried out in this study.[ Objective ] To study on expression of hTRTmRNA and hTR in retro-peritoneal liposarcoma and their significance in the tumor clinicopatho-logic diagnosis and prognosis. The relationship on the expression of hTRTmRNA , hTR and P53,PCNAwere analyzed. [ Methods ] 57 cases of retroperitoneal liposarcoma from 43 patients had been investigated by analysing the histological type and grade in retroperitoneal liposarcoma . The expression of hTRTmRNA and hTR in 57 cases of retroperitoneal liposarcoma were observed and compared with the expression of 8 cases of lipoma by in situ hybridization technique. The expression of P53 and PCNA were detected by immuno-histochemistry SP method. 38 cases with follow-up were covered for this study.[Result] The positive rates of hTRTmRNA and hTR were detected in 84.2%(48/57) and 78.9%(45 / 57) cases of retroperitoneal liposarcoma respectively, while both hTRTmRNA and hTR were not detected in 8 cases of lipoma . The histopathological diagnosis and subclassification were based on the Enzinger and Weiss classification and the WHO histological typing of soft tissue tumor. 57 cases of retroperitoneal liposarcoma were divided into 6 pathological subtypes . These cases were divided into 3 grade according to FNCLCC Histological grading system . The positive rates for hTRTmRNA in well-differentiated, myxoid, round cell, pleo-morphic , dedifferentiated and mixed liposarcoma were 73%(11/15), 81%(13/16),88%(7/8), 100%(5/5), 100%(8/8) and 100%(5/5). The positive rates for hTR in well-differentiated , myxoid ,round cell, pleomorphic cell ,dedifferentiated type and mixed liposarcoma were 60%(9/15), 87%(14/16), 75%(6/8), 100%(5/5), 87%(7/8) and 80% (4/5). The positive rates for hTRTmRNA in grade I, grade II and grade III were 70%(14/20), 86.7%(13/15) and 95.5%(21/22); The positive rates for hTR in grade I, grade II and grade III were 65% (13/20) , 80% (12/15) and 90.9% (20/22) .There were remarkable difference in the positive rates and intensity among the three grade grapes(P < 0.05). The positive rates for P53 in well-differentiated liposarcoma, myxoid subtype, round cell subtype, pleomorphic cell subtype, de-differentiated subtype and mixed subtype were 20%(3/15), 17%(3/16),50%(4/8),100%(5/5), 88%(7/8) and 40%(2/5). The positive of PCNA of these cases was 94% (56/57). Regardless of sex,age and size of tumor, there were remarkable difference in the positive rates and intensity between the well and poorly differentiated cases( P < 0.05 ). The recurence interval were difference between the negative and positive expression group of hTRTmRNA ( high level expression group: 11.18?.88m ,low level and no expression group : 22.56?2.43m, P < 0.05 ). [Conclusion] There were remarkable difference in the positive rates and intensity among the three grade groups of retroperitoneal liposarcoma . The detection of hTRTmRNA and hTR are valuable in evaluating the malignant degree and prognosis of retroperitoneal liposarcoma. The expression of hTRTmRNA and hTR are both strongly correlated. The high expression levels appear to be associated with tumor progression of malignancy on retroperitoneal liposarcoma.