Antagomirs, also known as anti-miRs, are a class of chemically engineered oligonucleotides designed to silence endogenous microRNAs (also known as miRNAs or miRs).
Due to the promiscuity of microRNAs, each of which regulate multiple mRNAs, antagomirs can potentially affect the expression of many different mRNA molecules besides the desired target.
Because blockmirs bind individual mRNAs and not miRNAs, their activity is more predictable than antagomirs' and less likely to cause off-target effects.
[citation needed] MicroRNA-33a/b inhibition in mice leads to increased blood high-density lipoprotein (HDL) levels.
Therefore, in order to target the regulation of Abca1, a blockmir can be developed that specifically binds to Abca1 mRNA molecules, thus blocking its miRNA site and upregulating its expression.
[10] The drug has also been shown to enhance T cell infiltration in combination with immunotherapy in mouse models of pancreatic cancer.