Expressions And Clinical Significance Of HMGA2, SFRP2, GRP94 And CD9 In Pituitary Adenomas

Objective:To study the effects of HMGA2 and SFRP2 on the cycle course and proliferative activity of pituitary adenoma cells by testing HMGA2 and SFRP2 expression and analyzing the correlation between HMGA2 and SFRP2 expression in invasive and noninvasive pituitary adenomas.Methods:The pituitary adenoma specimen from 60 cases underwent hypophysectomy in the Department of Otorhinolaryngology and the Department of Neurosurgery in the Second Xiangya Hospital of Central South University were collected and divided into the invasive group (40 cases) and the noninvasive group (20 cases), and HMGA2, SFRP2 and SFRP2 methylation expressions of the invasive pituitary adenomas and the noninvasive pituitary adenomas were tested by RT-PCR. HMGA2 and SFRP2 protein expressions of the tumor cells were tested by En VisionTM staining, and the correlation between HMGA2 and SFRP2 protein expressions were analyzed.Results:The results of RT-PCR indcated that the HMGA2-mRNA expressive levels of the pituitary adenomas in the invasive group were significantly higher than that of the pituitary adenomas in the noninvasive group (t=8.051, P=0.000); and there was a significant difference of SFRP2-mRNA expressive levels of the pituitary adenomas between the invasive and that in the noninvasive group, and the SFRP2-mRNA expressive levels in the invasive group were obviously lower than that in the noninvasive group (t=-6.506, P=0.002); the expression of SFRP2 methylation of the pituitary adenomas in the invasive group was significantly higher than that in the noninvasive group (P<0.05) Immunohistochemical staining showed that the positive rate of HMGA2 protein expression of the pituitary adenomas in the invasive group was significantly higher than that in the noninvasive group (X2=6.25, P=0.000), while SFRP2 protein expression of the pituitary adenomas in the invasive group was significantly lower than that of the pituitary adenomas in the noninvasive group (3.11, P=0.02). Spearman rank correlation analysis suggested that there was a negative correlation between HMGA2 and SFRP2 protein expressions (r=-0.715, P<0.01).Conclusions:The HMGA2 gene expression in the invasive pituitary adenomas was significantly higher than that in the noninvasive pituitary adenomas, the enhancement of HMGA2 gene expression may be related to excessive proliferation of the pituitary adenoma cells and the invasiveness of the pituitary adenoma. That the SFRP2 gene expression in the invasive pituitary adenomas was significantly lower than that in the noninvasive pituitary adenomas suggested that SFRP2 may inhibit the proliferation activity of the pituitary adenoma cells. The negative correlation between HMGA2 and SFRP2 in the invasive and noninvasive pituitary adenomas and the enhancement of SFRP2 methylation indicated that HMGA2 inhibited the SFRP2 expression in the pituitary adenomas; the enhancement of HMGA2 gene expression and its inhibiting SFRP2 gene expression led to the excessive proliferation and invasiveness enhancement of the tumor cells, and to be prone to recurrence and unfavorable prognosis. Objective:To explore the relationship between GRP94 and CD9 expressions of pituitary adenomas and cell cycle control and the invasiveness of pituitary adenoma by means of testing GRP94 and CD9 expression levels in pituitary adenomas, comparing GRP94 with CD9 expression and analyzing the correlation between them.Methods:GRP94 and CD9 mRNA expressive levels of pituitary adenomas in 60 cases and that of brain tissue in 6 cases in the control group were tested by RT-PCR, and the average value of the ratio of GRP94 and CD9 of brain tissue without pathological changes was used as the reference value so as to determine the expression levels of GRP94 and CD9-mRNA in the pituitary adenomas. GRP94 and CD9 protein expressions were tested by En VisionTM staining, and the difference between GRP94 and CD9 protein expressions of the pituitary adenomas in the invasive group and that in the noninvasive group and the interrelationship between them were analyzed.Results:The tested incidence of the positive expression of GRP94-mRNA by RT-PCR in the specimens from 40 cases of the invasive pituitary adenomas was 100%, there was a significant difference between GRP94-mRNA expression in the invasive pituitary adenomas and that in the noninvasive pituitary adenomas (t=7.478, P=0.000); there was a significant difference between CD9-mRNA expression level in the invasive pituitary adenomas and that in the noninvasive pituitary adenomas (t=-5.524, P=0.000). GRP94 protein expressions of the pituitary adenomas in the invasive group tested by immunohistochemical staining significantly increased comparing with that in the noninvasive group (χ2=11.59, P=0.000), while CD9 protein expression in the invasive group tested by immunohistochemical staining significantly decreased comparing with that in the noninvasive group (χ2=8.16, P=0.000), there was a negative correlation between them.Conclusions:GRP94 gene expression in the invasive pituitary adenomas was significantly higher than that in the noninvasive pituitary adenomas, and the enhancement of GRP94 gene expression may reflect the abnormality of cytobiologic action, which conformed to the tumor's features of continuous proliferation and unlimited growth. That the CD9 gene expression in the invasive pituitary adenomas was significantly lower than that in the noninvasive pituitary adenomas suggested that CD9 gene may inhibit the movement, differentiation and proliferative activity of the pituitary adenoma cells, inhibiting the biological act of the pituitary adenoma cellular invasiveness. The negative correlation between GRP94 and CD9 in the invasive and noninvasive pituitary adenomas demonstrated that GRP94 inhibited the CD9 expression in the pituitary adenomas, which led to the acceleration of the cell cycle course and the development of the invasiveness of the pituitary adenomas, and it could be used as an indication to predict the invasiveness of pituitary adenomas. Objective:To explore the internal relations between HMGA2 and GRP94 and the relationship between their expression and the invasiveness of pituitary adenomas by testing HMGA2 and GRP94 mRNA expressions in cerebrospinal fluid of pituitary adenomas patients and the study on the correlation analysis between them.Methods:The CSF in 40 cases with invasive pituitary adenomas, the CSF in 20 cases with the noninvasive pituitary adenomas were collected respectively before hypophysectomy, and the CSF of 17 cases with recurrent pituitary adenomas was collected respectively after hypophysectomy, and the expressive levels of HMGA2 and GRP94 mRNA were tested by RP-PCR, the difference between the HMGA2 and GRP94 expressions in the invasive group and that in the noninvasive group and the interrelationship between them were analyzed.Results:The expression level of HMGA2-mRNA in the CSF of the patients with pituitary adenomas in the invasive group was significantly higher than that in the CSF of the patients with pituitary adenomas in the noninvasive group, and there was a significant difference between the two groups (t=8.993, P<0.01); and the expression level of GRP94-mRNA in the CSF of the patients with pituitary adenomas in the invasive group was significantly higher than that in the CSF of the patients with pituitary adenomas in the noninvasive group (t=9.281, P< 0.01). Pearson correlation analysis indicated that there was a positive correlation between HMGA2 and GRP94 expression (r=0.514, P<001), while for the cases with recurrent pituitary adenomas, there was no difference between the expression levels of HMGA2-mRNA and GRP94-mRNA protein in the CSF collected after. hypophysectomy and that in the CSF collected before hypophysectomy.Conclusions:1. The high level expression of HMGA2-mRNA and that of GRP94-mRNA in the CSF of the invasive pituitary adenomas patients often coexisted.2. The effect of HMGA2-mRNA and the effect of GRP94-mRNA in the pituitary adenomas were interactive, and the HMGA2-mRNA expression could enhance the increase of GRP94-mRNA expression level and cause the damage of the tumor extracellular base and the development of the invasiveness. The high level of GRP94-mRNA expression regulated HMGA2-mRNA expression through feedback control, promoting the growth of the pituitary adenomas, and as a result, strengthening the invasiveness of the pituitary adenomas.