[Expression of integrin alpha 5, beta 1 subunit and fibronectin mRNAs in human hepatocellular carcinoma].

OBJECTIVE

To study the biologic significance of the expression of integrin alpha 5, beta 1 subunit and fibronectin (FN) mRNAs in hepatocellular carcinoma (HCC).

METHODS

Integrin alpha 5, beta 1 subunit and FN mRNAs were detected by using Northern blot (alpha-32P-labeled cDNA probes) and in situ hybridization (Dig-labeled cDNA probes) in 15 cases of HCC, 5 cases of paracancerous cirrhotic liver and 3 cases of normal liver tissue.

RESULTS

In well-differentiated HCC, the level of integrin alpha 5, beta 1 or FN mRNA expression was similar to those in normal liver and paracancerous cirrhotic liver tissues, but was markedly decreased, even absent in the poorly- and moderately-differentiated HCC tissues (P < 0.01, respectively). The expression of integrin alpha 5 and FN mRNAs was mainly detected in the cytoplasm of HCC cells. In all the HCC cases tested, the expression of integrin alpha 5, beta 1 and FN mRNAs was lower in 8 cases of HCC with focal invasion and/or intrahepatic metastasis than that in the others without invasion or metastasis(P < 0.05). In addition, the heterogeneous expression of FN mRNA was found in 5 cases of HCC with intrahepatic metastasis.

CONCLUSIONS

Combined with the immunohistochemical observation before, it might be deduced that the changes of integrin alpha 5 beta 1 and FN protein expression in HCC tissues are because of changing of the mRNA levels related, which might deeply influence the cell differentiation, tumor invasion and metastasis of HCC. The appearance of the heterogeneous FN mRNA and its encoded FN protein might be associated with the development of HCC metastasis.