Study On The Relationship Between Piral Ct Features And The Expression Of Mmp-9 And Hpa In Gastrointestinal Stromal Tumor

GIST(Gastrointestinal stromal tumors) are mesenchymal tumor with high expression of CD117 of spindle,epithelioid or allomorphic cells in addition to gastrointestinal smooth muscle tumors,schwannoma and neurofibroma.We still can't get consistent understanding due to their complexity,which brings a lot of inconvenience to the diagnosis and treatment.Spiral CT can detect more malignancy signs of GIST,thus it put an important guiding values on its early diagnosis and treatment as well as prognosis.Since the majority of GIST express CD117 and CD34,some scholars think it originated in the gastrointestinal tract Cajal cell wall (inter stitial cells of cajal,ICC).CD117 protein(C-KIT protein) is a transmembrane receptor protein of tyrosine kinase,belonging to C-KIT proto-oncogene protein product,expressed in hematopoietic stem cell subsets,mast cells,melanoma cells and the gastrointestinal tract of the Cajal mesenchymal cells.Many scholars have been reported they had found CD117 expression in GIST and regard it as a sign of its immune phenotype.CD34 is glycosylation protein and a hematopoietic progenitor cell antigen which is earlier applied to study GIST.Initially it has been detected in stromal tumors,and a higher expression rate in GIST.MMP-9 are an important protease in degradation of typeⅣcollagen,and play an important roleln extracellular matrix degradation,invasion of surrounding organizations for the tumor cells.At the same time,it affects tumor vascular angiogenesis as the number of vascular starting system.Researches found that in different tumor tissues such as malignant melanoma, endometrial cancer,prostate cancer and primary brain tumors,MMP-9 activation and (or) expression has a good correlation with malignant degree and(or) metastasis. Heparan sulfate proteoglycan(HSPG) are a complex biological macromolecules widely exist in the vertebrate extracellular matrix(extracellular matrix,ECM) and cell surface,constituting the main component of basement membrane.Heparanase (heparanase,Hpa) is an endo glycosidase Cracking component of the HSPG.It plays an extremely important role in tumor invasion and metastasis.About Hpa applications in cancer research reports have much,but still less reported in GIST.This topic study 54 cases of GIST patients with spiral CT scan and three dynamic contrast-enhanced scan.first using immunohistochemical SP method to observe the expression of CD117,CD34,MMP-9 and Hpa in these GIST tumor tissue,and then contrast GIST CT features of the patients,to study the biological characteristics of GIST,explore the relationship between the features of Spiral CT and Molecular Biology characteristics of GIST,This study may be of benefit to further clarifiing the biological behavior of GIST,and may provide a theoretical foundation for diagnosis,treatment,an effective method,especially in the imaging diagnosis and the pathological diagnosis of GIST, may also develop medical imaging applications in GIST.Methods1.54 cases of GIST patients were examined with spiral CT scan and three dynamic contrast-enhanced scan.Contrast agent was Ultravist 100ml(300mgI/ml), injection rate was 3.0ml/s,collimation 5mm,and Pitch=1.All patients experienced tumor resection or laparotomy within one week.2.Using immunohistochemical SP method to detect the expression of CD117, CD34,MMP-9 and Hpa protein in the 54 cases of GIST tissue.3.Statistical analysis:All the dates were analyzed by SPSS 11.0 statistical package; the count information calculated the positive rate.The comparison of positive rates uses the Chi-square;the relation of two variables is analyzed by the spearman level correlation analysis.The level of significant difference is a=0.05. Results1.Immunohistochemistry results showed that the positive expression of CD34 and CD117 in 54 cases of GIST were 82.40%and 98.30%.There were no statistical significance with the patient's age(＜50 years old and≥50 years),tumor size (＜5cm and≥5cm),shape(round,oval and lobulated),tumor border(clear and unclear),the center whether or not necrosis,the degree of malignancy(benign and borderline,malignant),and whether or not metastasis(P＞0.05).2.Results showed that MMP-9 and Hpa expression in GIST had correlation with tumor size(＜5cm and≥5cm),tumor border(clear and unclear),whether or not necrosis in the center,and whether or not metastasis.There were Statistical significance(P＜0.05).3.Statistical analysis showed that MMP-9 protein expression correlated withHpa level in tumortissue(P＜0.05).4.Spiral CT detected all 52 cases of Cancer.the positioning accuracy of Spiral CT on GIST were as follows:stomach lesions was 84.30%,small intestine lesions 80.20%,rectal lesions 100%.In This group preoperative localization accuracy rate was 82.40%,preoperative qualitative accuracy was 78.50%.Conclusions1.The expression of CD117 was high in GIST,and had no relation to malignancy,metastasis of GIST,which indicated that c-kit mutation were unrelated to benign or malignant and might be an early event in GIST.The positive expression of CD34 was 82.4%,and showed a complementary expression of CD117,which indicated that to Detect both CD117 and CD34 can enhance the diagnostic accuracy of GIST.2.MMP-9 and Hpa expression in GIST had correlation with tumor size(＜5cm and≥5cm),tumor border(clear and unclear),whether or not necrosis in the center,and whether or not metastasis,which showed that MMP-9 and Hpa may be involved in the invasion and metastasis process of GIST.3.The expression of MMP-9 in GIST is positive correlation with the expression of Hpa,suggesting that both participated invasion and metastasis of GIST synergistically.4.Spiral CT and pathological examination has good consistency on diagnosis of morphology,characterization and distant metastasis of Cancer,which indicated the results of spiral CT was credible and accurate.Spiral CT features combining with molecular biology would be possible to improve accuracy of invasion,metastasis and prognosis assessment of GIST.