In order to investigate a possible role of acid deoxyribonuclease (DNase) in tumorigenesis of osteosarcoma, activity of acid DNase in osteosarcoma tissue was determined and compared with that in the control tissue. The enzyme was partially purified by methods of centrifugation, concentration by ultrafiltration and DEAE-cellulose column chromatography to clarify the specificity against substrate and the mode of hydrolytic action of the enzyme.
1) Acid DNase activity was greatly increased in osteosarcoma tissue and the positive rate of the enzyme activity as a marker for the sarcoma was observed to be over 80%, suggesting that the acid DNase could be used as a biochemical marker for osteosarcoma.
2) The purified enzyme preferentially hydrolyzed double stranded(ds) DNA. The acid DNase was, however, fairly active against single stranded(ss) DNA, exhibiting 22% of activity against ds DNA.
3) The products of enzymatic hydrolysis of ds DNA by the acid DNase purified partially from osteosarcoma tissue were separated and observed mostly to be oligo-or poly-deoxyribonucleotides, indicating that the enzyme might be an endonuclease in nature.
4) PAGE patterns of proteins in osteosarcoma tissue revealed that at least two protein bands present in the normal control tissues disappeared in the tumor tissue.
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