%%=v(@subject)=%%

%%[VAR @subject
SET @subject = "Some content" ]%%

<script runat="server">
    Platform.Load("Core", "1")
    var response = HTTP.Get('http://www.example.com');
    var jsonObject = eval("(" + response.Content + ")");
</script>

<script runat="server">
     var subject = evaluatedJSON.navigate.through.object.to.find.subject;
     Platform.Variable.SetValue("@subject",subject);
</script>

%%[VAR @subject]%%
<script runat="server">
    Platform.Load("Core", "1")
    var response = HTTP.Get('http://www.mynews.com/fresh.json');
    var jsonObject = eval("(" + response.Content + ")");
    var subject = jsonObject.news[0].subject;
    Platform.Variable.SetValue("@subject",subject);
</script>