You are studying the expression of a proto-oncogene in a cancer cell and comparing it to expression in a non-cancer cell. You have done experiments to detect the presence of the proto-oncogene (DNA), the messenger RNA, and the protein in both cell types. Both cells have two copies of the gene. The non-cancer cells contain no RNA and no protein corresponding to the gene, but the cancer cells have abundant RNA and protein corresponding to the gene. How can these observations be explained?
A) by regulation of mRNA degradation only
B) by transcriptional and translation regulation
C) regulation by either transcription or mRNA degradation
D) by transcriptional regulation only