Immunohistochemical assessment of fibronectin and tenascin and their integrin receptors alpha5beta1 and alpha9beta1 in gastric and colorectal cancers with lymph node and liver metastases

The aim of the current study was to assess immunohistochemically and compare the level of expression of tenascin (TN) and fibronectin (FN) and their integrin receptors alpha9beta1 and alpha5beta1 in the primary colorectal and gastric tumors, and in corresponding lymph node and liver metastases from 53 patients. We detected similar high deposition of the studied ECM proteins and their receptors in the stroma of primary tumors and in liver metastases and a lower deposition in lymph node metastases. Cytoplasmic immune reaction for FN and TN was also seen in the tumor cells. A pronounced co-localization of immune deposits for FN and TN and their receptors was found in the stroma of the center and the invasion front (IF) (p<0.0001). A significant decrease of FN immune signal was observed in the IF in primary tumors and liver metastases (p<0.0001). The levels of immunolabeling of FN and TN correlated with the differentiation grade of primary tumors (p<0.0001). In conclusion, we may say that there is heterogeneous deposition of TN, FN and their integrin receptors in the different areas of primary colorectal and gastric tumors and of their metastases. These findings imply that the studied proteins may be involved in cell processes such as growth, adhesion, migration and apoptosis.