MicroRNA Regulation of APOBEC3A and APOBEC3B

APOBEC3A (A3A) and APOBEC3B (A3B) are part of a family of enzymes that deaminate DNA cytosine to DNA uracil. Some APOBEC3 family members defend the body against viruses such as HIV, while A3B and A3A are upregulated in multiple cancers. One of the changes during oncogenesis is alteration of the expression profile of cellular miRNAs. This study focuses on the putative role of miRNAs in regulating A3A and A3B. I hypothesize that since A3A and A3B likely arose by a gene duplication event, some miRNAs will regulate both A3A and A3B, while other miRNAs will only regulate one. Previous work used prediction software to identify miRNAs that may interact with the 3\u27UTR of A3A and/or A3B. To confirm this interaction, the 3\u27UTRs of A3A and A3B were amplified from two cancer cell lines and cloned into the luciferase-containing psiCHECK-2 vector. Currently, we are cloning the predicted miRNAs into an expression plasmid so that we can co-express each miRNA with the 3\u27UTR of A3A or A3B using a Luciferase assay. Decreased luciferase activity compared to the control would indicate that the associated miRNA interacted with the 3\u27UTR to decrease protein levels. We expect to see that a subset of the miRNAs that interact with the A3B 3\u27UTR to decrease luciferase activity will also interact with the A3A 3\u27UTR to decrease luciferase activity. This study will provide information about the regulation of two proteins involved in cancer progression and may lead to the development of targeted cancer therapies