The Expression And Significance Of S100A4,MMP-2 And TIMP-2 In Colorectal Carcinoma

Objective: Invasion and metastasis, as two important biological features of malignant tumor, involve an extremely complicated multi-factor, multi-step process. This process is affected by factors as cellular adhesion, degradation of extracellular matrix(ECM) and migration of the tumor cell. Protein S100A4 is a kind of Ca²⁺ binding protein, which plays an important role through Ca²⁺ signal transduction in intracellular gene expression, cell multiplication and differentiation, cell adhesion and motion, degradation and remodeling of ECM and apoptosis. MPP-2, which is a member of the matrix metalloproteinase (MMP) family, can affect tumor invasion and metastasis by disintegrating ECM and basal membrane and promoting the diffusion of tumor cell. TIMP-2, as one of the four known tissue inhibitors of metalloproteinase (TIMP), can combine with MMP-2 in noncovalent bond at the ratio of 1:1 and specifically inhibit the activity of MMP-2. The disproportion between MMP-2 and TIMP-2 can induce the degradation of ECM and basal membrane, which is one of the committed steps of tumor's invasion and metastasis.Colorectal carcinoma is a frequent malignant tumor clinically, and many researches have been carried out on the related factors that affect the invasion and metastasis of colorectal carcinoma. In this research, immunohistochemical StreptavidinPeroxidase(S-P) method is used to detect the expression of S100A4, MMP-2 and TIMP-2 at the protein level in colorectal carcinoma, and we analyze the relationship between their expressions and biological behavior of colorectal carcinoma, approach the possibility of using S100A4,MMP-2 and TIMP-2 as molecular tumor marker to appraisal the latent energy of invasion and metastasis of tumor, and thus provide pathological foundation for research and clinical therapy of colorectal carcinoma.Methods: In this research 68 paraffin-embedded cancer biopsy specimens of patients with colorectal carcinoma who had been proved to have colorectal carcinoma through pathological diagnosis and had operation for cure in the People's Hospital of Linyi from January 2004 to January 2005 are selected. And 20 normal mucous membranes of rectum are selected as control. Routine slice is done for 4 serialsections in 5 jj. m thickness, and 1 section is made for H.E staining and observed byconventional pathological diagnosis while the other three sections are detected for the expression level of S100A4, MMP-2 and TIMP-2, applying the approach of SP (Streptavidin- Peroxidase) immunohistochemical staining. We have analyzed the expression differences of S100A4, MMP-2 and TIMP-2 in mucous membrane of rectum between colorectal carcinoma and normal tissue. We also have investigated the relationship between the expression of S100A4, MMP-2 and TIMP-2 and the clinical biological characteristics, including age, sex, tumor location, histological type, differential degree, Dukes stage and lymph node metastasis. The data have been statistically analyzed with Chi square test, Kruskal-Walk's test and Spearman rank correlation using SPSS 13.0 for windows.Results: 1. Positive expression of Protein S100A4 is not observed in the 20 normal colorectal mucosal tissues. While, of the 68 cases of colorectal carcinoma, 61.8% (42/68) is positive, among which 26.5% (18/68) is weakly positive, 22.1% (15/68) is positive, 13.2% (9/68) is strongly positive. There is significant difference between case group and control group for Protein S100A4 positive expression (P=0.003). And there are no significant statistical differences in Protein S100A4 expressions among the age, sex, tumor location, growth style, histological type, differential degree of the patients (P>0.05). There are significant differences in Protein S100A4 expressions in different Dukes stages and lymph node metastasis(P<0.05), and higher Protein S100A4 expression occurs in the later of the stage and lymph node metastasis sufferers. 2. For MMP-2 expression ,20%(4/20) is positive in the control group, while, of the 68 cases of colorectal carcinoma, 85.3%(58/68) is positive, among which 29.4%(20/68) is weakly positive, 39.7% (27/68) positive, 16.2%(11/68) strongly positive. There is significant statistical difference between the case group and control group for MMP-2 positive expression(P=0.001).And there are no significant statistical differences in MMP-2 expressions among the age, sex, tumor location, growth style, histological type of the patients respectively(P>0.05). There are significant differences in MMP-2 expression in differential degree, Dukes stage and lymph node metastasis(P<0.05), and higher protein MMP-2 expression occurs in the worse of the differentiation ,the later of the stage and lymph node metastasis sufferers. 3. For TIMP-2 expression, 40%(8/20) is positive in the control group, while, of the 68 cases of colorectal carcinoma, 58.8%(40/68) is positive, among which 22.1% (15/68) is weakly positive, 27.9% (19/68) positive, 8.8% (6/68) strongly positive. There is no significant difference between the case group and control group in TIMP-2 expression (P=0.609). And there are no significant differences in TIMP-2 expression among the age, sex, tumor location, growth style, histological type, differential degree of the patients respectively(P>0.05). There are significant differences in TIMP-2 expressions in different Dukes stage and lymph node metastasis(P<0.05), and lower TIMP-2 expression occurs in the later of the stage and lymph node metastasis sufferers. 4. Statistical analysis shows that Protein S100A4 and MMP-2 expressions are positively related in colorectal carcinoma (r=0.532,P<0.01), while, MMP-2 and TMP-2 expressions are negatively related (r=-0.425,P<0.01), and Protein S100A4 and TIMP-2 expressions are not related (r=0.095,P>0.05).Conclusions: 1. There is no Protein S100A4 expression in normal colorectal tissues while there are different degrees of expressions in tissues of colorectal carcinoma sufferers. The expression of MMP-2 is obviously higher in the tissues of colorectal carcinoma than that in normal colorectal tissues. There are TIMP-2 expressions at different degrees in both of them, but the mid-high expressions are obviously higher in colorectal carcinoma than those in normal colorectal tissues. 2. For the expressions of Protein S100A4, MMP-2 and TIMP-2 there are significant differences among different Dukes stages and lymph node metastasis. Higher Protein S100A and MMP-2 expressions occur in the later of the stage and lymph node metastasis, while TIMP-2 expression has a falling trend. The higher expression of Protein S100A4 and MMP-2 and the lower expression of TIMP-2 may have a synergistic effect for invasion and metastasis of colorectal carcinoma. 3. For colorectal carcinoma there are positive correlation between Protein S100A4 and MMP-2 expressions, however, there are negative correlation between MMP-2 and TIMP-2 expressions. Protein S100A4 may participate in mediating the expression of MMP-2, and TIMP-2 may inhibit MMP-2 expression through feedback. 4. It can be used as molecular tumor markers to appraisal the latent energy of invasion and metastasis of tumor and thus provide pathological foundation for research and clinical therapy of colorectal carcinoma to detect the expressions of Protein S100A4, MMP-2 and TIMP-2 in the use of immunohistochemical StreptavidinPeroxidase(S-P).