Step-by-step explanation:
A proto-oncogene is a normal gene that usually can stimulate growth and differentiation but if it mutates can become an oncogene and cause cancer. In order to test this gene, you can activate it by promoting its mutation with a DNA amplification (like the one you did in the question) or a chromosomal translocation, then you can observe it in a culture if there's cell transformation you can confirm your hypothesis.
I hope you find this information useful and interesting! Good luck!