Correlation between mRNA and protein
We have been studying breast cancer cell lines and trying to determine how well the PIP (Prolactin Induced Protein) gene and its translated protein detects cancerous cells. mRNA levels for the PIP gene seem to be down regulated significantly (100 fold) within cancerous breast cells. However, the subsequent protein levels seem to not show the same trend. Protein levels of PIP seem to be similarly expressed within both cancerous and non-cancerous breast tissue. What would cause this dissociation between mRNA levels and its translated protein?
It appears that PIP is needed for these cancerous breast cells due to these consistent protein levels. Therefore, why would the mRNA levels be down regulated?
One hypothesis we have is that there may be a change in post transcriptional modification within cancerous cells. Alterations to mRNA made post transcriptionally might make the PIP gene not show up through use of PIP primers.