Transplanted 80 year old rose

hi, I dug up an 80 year old rose in an overgrown idle garden. There is actually a root of a tree grown around the root of the rose! I can't even see the roots of the rose but I didn't know about the tree root til I had the rose dug up. I know it blooms every year as I used to see it in the garden as I passed by in summer. The tree was cut down years ago and the stump was left just under the ground. Anyway, now the rose looks completely dead. I replanted it in good soil, watered it well & fed it with miracle grow. The rose is almost 6ft tall but leaves were only on the top of it. The bottom part is green and looks very alive. I'm wondering if I should give it a chance or prune it or what? Anyone have any ideas. This rose has sentimental value. any help would be really welcome. Thank you