Original Article

Phosphodiesterase specific for the hydrolysis of diphenylphosphate, one of aromatic phosphodiesters, was obtained from hog kidney by following procedure. To hog kidney homogenized in a Waring blendor with 3 volumes of distilled water was added solid sodium chloride to a final concentration of 1% and after adjusting of pH to 5 with ca. 5 N hydrochloric acid, it was shaken for 10 minutes with an equal volume of n-butanol, allowed to stand for one hour, and centrifuged. The aqueous extract present beneath the floating gel layer of protein and butanol mixture, was siphoned out and fractionated with ammonium sulfate. The precipitate obtained between 45 and 70 % saturation was dissolved in a small volume of distilled water, dialyzed for 48 hours against running tap water, and then, to inactivate the monoesterase, heated in water bath of 100° for 5 minutes, whereby the solution became faintly turbid. The enzyme solution, thus prepared, hydrolyzed diphenylphosphate, liberating phenol but no inorganic phosphate, while it was inactive to monophenylphosphate. Diphenylphosphate of a final concentration of 0.0005M could be hydrolyzed in one hour at the optimum pH 7 to the extent of 40%. At this pH, the enzyme activity was not influenced by addition of Mg^, Ca^, or CN^. Bis-dichloroisopropylphosphate, dibenzylphosphate, diethylphosphate, lysolecithin, RNA, and DNA were resistant to this enzyme. It is conceivable that these diesters are hydrolyzed by other enzymes different from the aromatic phosphodiesterase, presented in this paper

Primers used for Real-time quantitative PCR.

<p>Primers used for Real-time quantitative PCR.</p

E-cadherin expression at ITF vs MMP9 expression.

<p>E-cadherin expression at ITF vs MMP9 expression.</p

Top up-regulated genes in OTSCC compared to normal.

<p>Top up-regulated genes in OTSCC compared to normal.</p

Univariate Cox Regression Analysis for prognostic variables.

<p>Univariate Cox Regression Analysis for prognostic variables.</p

MMP 9 expression vs Pattern of Recurrence.

<p>MMP 9 expression vs Pattern of Recurrence.</p

Graphical representation of the number of DEG from the meta-analysis.

<p>Graphical representation of the number of DEG from the meta-analysis.</p

Protein-protein interaction network showing uPA and uPAR signaling pathway chiefly deregulated in OTSCC.

<p>Protein-protein interaction network showing uPA and uPAR signaling pathway chiefly deregulated in OTSCC.</p

Heat map showing DEG.

<p>The up regulated (red) and down regulated genes (green) shown after meta-analysis. The top bar shows the GEO dataset ID and the second bar shows the classification of tumor vs. normal. The gene list is shown in the right.</p

Kaplan-Meier survival curve for DFS based on E-cadherin expression at ITF.

<p>(A) First blue line indicates preserved membrane E-cadherin positivity at ITF, second green line indicates reduced membrane E-cadherin expression at ITF and third red line indicates absence of ITF in the sections. The short vertical lines denote the times at which patients were lost to censoring (Log Rank = 8.063; P value = 0.018).</p