ABSTRACT
In the process of metastasis, cancer cells secrete several enzymes which degrade extracellular matrices (ECMs) and basement membranes (BMs) of blood vessels. One of them, heparanase, has been reported to be an important enzyme when metastatic cancer cells invade blood vessels. The enzyme cleaves heparan sulfate (HS), a main component of ECM and BM. In the present study, HS-degrading ability of several human oral cancer cell lines (HSC2, HSC3, HSC4, Ca9-22, NA, ACC3 and Ab-J) and tissues derived from human oral squamous cell carcinomas (both metastatic and non-metastatic) were investigated by measuring heparanase activities and levels of heparanase mRNA by a quantitative reverse transcriptase-polymerase chain reaction. The catalytic activities and the mRNA levels of heparanase showed a good agreement. Clinical demonstration of cancer metastasis generally correlated with high levels of heparanase activity and its mRNA. The results suggest that heparanase activity and its mRNA level are good diagnostic parameters for evaluating the metastatic properties of human oral cancer cells.
Subject(s)
Carcinoma, Squamous Cell/enzymology , Glucuronidase/metabolism , Mouth Neoplasms/enzymology , Neoplasm Proteins/metabolism , Adolescent , Adult , Aged , Aged, 80 and over , Basement Membrane/enzymology , Basement Membrane/metabolism , Carcinoma, Squamous Cell/secondary , Extracellular Matrix/enzymology , Extracellular Matrix/metabolism , Female , Glucuronidase/genetics , Humans , Male , Middle Aged , Mouth Neoplasms/pathology , Neoplasm Metastasis , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Tumor Cells, Cultured/enzymologyABSTRACT
Human carcinoma cells cultured in serum free medium produced an enzyme present as two different isoforms of 62 and 59 kDa which was found to degrade hyaluronan and chondroitin sulfate, with optimum activity at pH 4.0 and 0.03 M NaCl. The activity was suppressed by treatment with 250 mM apigenin and 1 mM DTT. The one-dimensional and two-dimensional gel patterns of tumor hyaluronidase differed from those of human serum hyaluronidase. Deglycosylation of tumor hyaluronidase caused nearly complete elimination of activity, suggesting the importance of sugar chains in enzymatic function. The results of treatment with neuraminidase, in addition to the findings for the enzyme mentioned above, suggest hyaluronidase from carcinoma cells and serum hyaluronidase to differ in sugar chains and/or the core protein. Tumor hyaluronidase was shown to be endo-beta-N-acetyl-D-hexosaminidase and tetrasaccharide was identified as the major product, thus indicating the tumor hyaluronidase to be a testis-type hyaluronidase.
