The neutral RNase isozyme with the highest activity isolated from bladder cancer tissue by an ion exchange column chromatography was shown to be specific to bladder cancer by means of analysis of high performance liquid chromatography (HPLC) and
polyacrylamide gel electrophoresis(PAGE) for the enzyme proteins. Also studied were substrate specificity and the product analysis of the RNase to investigate the role of the enzyme in pathogenesis of the bladder cancer.
Neutral RNase in the bladder cancer tissue was separated by a DEAE-cellulose column chromatography into 3 peaks and a single neutral RNase isozyme present in the control bladder tissue disappeared from the cancer tissue. The substracte
specificity
of
the peak V neutral RNase isozyme with the highest activity among the RNases isolated from the bladder cancer tissue appeared to be different from that from the control bladder tissue. HPLC and PAGE patterns of proteins complexed with the peak V
RNase
from the cancer tissue also appeared to be different from that from the control tissue. These resuslts suggested that the peak v neutral RNase was specific to the bladder cancer.
The peak V neutral RNase isozyme from the bladder cancer tissue was not active toward ds polyribonucleotide, but active toward ss polyribonucleotide. Principally catalyzing the hydrolysis of A-C, C-C, A-U and C-U linkages. The fact that majority
of
products of poly C digest by the RNase was oli goribonucleotide indicated that the enzyme was endoribonuclease in nature.
The present study indicated that 1) the peak V neutral RNase isozyme from the bladder cancer tissue was specific to the cancer, 2) the RNase isozyme was active toward ss polyribonucleotides (active toward A-C, C-C, A-U and C-U linkages) and 3)
the
enzyme was endoribonuclease in nature, suggesting that the enzyme was suppressive to the bladder cancer in action.
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