Biological effects of types I and III collagens in human hepatocellular carcinoma tissue

AIM: To explore the biological effects of type I and III collagens in human hepatocellular carcinoma (HCC) and the relationship between the collagens and tumor behavior.METHODS: The distribution of types I and III collagens was determined by immunohistochemistry in 25 specimens of human HCC and surrounding liver tissue, as well as six normal liver specimens. In addition, the expression of types I and III collagens were studied by in situ hybridization in nine HCC and two normal liver specimens. Collagen content in the tissues was calculated according to the theory of sterology.RESULTS: The content of types I and III collagens was significantly lower in HCC than in the surrounding liver tissue. In addition, the collagen content was significantly lower in invasive/metastatic HCC tissue than in non-invasive/metastatic HCC tissue. However, collagen gene expression and protein synthesis were increased in HCC tissue.CONCLUSION: The decrease in collagen content in HCC tissue likely resulted from collagen degradation. Collagens may be inhibitors of tumor invasion and metastasis.