SnoopyBentschi

Risks

If the modRNA does not enter the target cells but other cells, undesirable effects can occur. For example, if the encoded protein is supposed to stimulate cardiac muscle cells to proliferate, but is mistakenly produced in other cells, proliferation could result. However, such a negative effect is limited in time by the fact that the modRNA, despite its increased stability compared to normal mRNA, is ultimately degraded, as are the proteins it encodes.

It could be objected that changes in the genome of the cells, i.e. mutations, could be triggered with consequences that could even lead to the development of cancer. Now, the first thing to consider is that the genetic information is present in the cell nucleus as DNA (not as RNA), and modRNA does not enter the cell nucleus. Furthermore, physiologically there is no reverse transcriptase in the human body, i.e. no enzyme that can transcribe mRNA into DNA. Here again, it is objected that there are infections in humans with viruses that produce reverse transcriptases (for example, HIV), and that these same reverse transcriptases could lead to reverse transcription of modRNA. However, these viral reverse transcriptases are highly specific and only transcribe the virus's own RNA, so this problem can probably be neglected.