Study On The Correlation Between SCT, MRI Features And Expression Of MMP-9, CD34 In Astrocytoma

Background and purpose: Astrocytoma is the most frequent primary brain malignancy. Invasiveness is an important characteristic of astrocytoma, contributing substantially to the failure of curative treatments. Therefore investigating the outside exhibition and the molecular basis of neoplasm invasiveness is always a significant problem in the fields of imageology, pathology and carcinomal molecular biology. SCT, MRI and contrast enhancement heighten the discovery and rate of qualitative diagnosis of astrocytomas. All imaging features are determined by molecular biology factors, which influence biological behavior of tumors. MMP-9 is a kind of metalloproteinases mat can degrade the components of the extracellular matrix and play an important role in facilitating neoplastic cell invasion of the normal brain. CD34 is a useful marker for quantification of angiogenesis that is necessary for tumor growth and infiltration and always calculated by microvessel density (MVD). The purpose of this study is to investigate the correlation between SCT, MRI features and expression of MMP-9, CD34 to evaluate the growth, invasion of astrocytoma.Materials and methods: 40 cases of astrocytoma were confirmed by operationand pathology. The histological grades are based on Kernohan's standards, gradeI ~II(n=18), grade III -IV (n=22). Expression of MMP-9 in 40 cases ofastrocytoma was examined with SP immunohistochemical technique and MVD isimmunostained for CD34. ,All of the cases were examined by postcontrast SCT and MRI within one week before surgery. Spiral CT examination was performed with a GE Hispeed advantage RP22 helical scanner. Scanning was performed at 140KVp, 240mAs, 10mm collimation. MRI examination was performed with LOT MRI system and special-purpose head coil. Conventional SE sequence was choosed.Statistical analysts was executed by SPSS 10,0 software. The data of both groups were compared using t-test. Three groups were compared using one-way ANOVA. Linear correlation, chi-square test were also used. The P values less than 0.05 were considered significantly different.Results: 1. MVD is immunostained for CD34. In 40 cases of astrocytoma, microvessel densities ranged from 15.33 to 88.2 with a mean of 47.88(standard deviation, 21.16). MVD in astrocytoma of grade HI ~ IV (63.96?8.29) was significantly higher man that in grade I ~II(34.73?2.56)( t=5. 975,p=0.000). MVD of the age more man forty (55.50?0.69), was higher than that the age less than forty (38.57?8.21X t=2.716, P=0.01). MVD was not related with the patient's sex and the site of tumor (P>0.05).2. In 40 cases of astrocytoma, expression of MMP-9 in I ~ II grade astrocytoma(48.13%?.74%) was significantly lower than that in III-IV grade astrocytoma(65.34%?.76%)( t=0. 077, P=0.000). The expression of MMP-9 was not related with the patient's age, sex, and the site of tumor (P>0.05).3. Expression of MMP-9 was correlated positively with MVD( r=0.635, P<0.05).4. The density/intensity heterogeneity, the extent of peritumor edema, and the extent of contrast enhancement showed by SCT, MRI correlated well with the grade of astrocytoma (P<0 05).5. The density/intensity heterogeneity, the extent of peritumor edema, and the extent of contrast enhancement showed by SCT, MRI correlated well with MVD, expression of MMP-9. The difference was statistically significant (P<0.05).Conclusion: 1. SCT, MRI imaging are reliable techniques in astrocytoma.2. Expression of MMP-9 CD34 are positively correlated with the grade of astrocytoma. It was suggested that the expression of MMP-9 and angiogenesis might play an important role in astrocytoma invasion.3. MMP-9 can influence neoplastic development through not only degrading the components of the extracellular matrix, but also promoting neoplastic angiogenesis.4. These findings indicate a relationship between SCT, MRI features and tumor angiogenesis, expression of MMP-9 and suggest MRI, SCT could in...