CLINICAL-SIGNIFICANCE OF TISSUE INHIBITOR OF METALLOPROTEINASE EXPRESSION IN GASTRIC-CARCINOMA

Tissue inhibitor of metalloproteinase (TIMP) has been reported to inhi bit tumour invasion through an inactivation of matrix metalloproteinas e (MMP) both in vitro and in vivo. Among the TIMP family, TIMP-1 posse sses not only proteinase inhibitory activity but also a growth-promoti ng function. However, the significance of the expression of TIMP-1 in human gastric carcinoma tissue has yet to be clarified. In 50 examined cases of gastric carcinoma, 44 (88%) cases showed a higher expression of TIMP-1 mRNA in the biopsy samples from the tumour tissue (T) than in the biopsy samples from the corresponding normal tissue (N), as det ermined by semiquantitative reverse transcriptase-polymerase chain rea ction (RT-PCR). In a multivariate analysis, the T/N ratio of TIMP-1 mR NA was found to be an independent factor influencing the depth of tumo ur invasion and was the second most important factor in determining th e prognosis of patients. As RT-PCR assay can be performed on biopsy sp ecimens obtained before surgery, an evaluation of the TIMP-1 expressio n in biopsy specimens by RT-PCR may thus provide useful preoperative i nformation on tumour aggressiveness.