The role of long noncoding RNAs in acute myeloid leukemia

PROJECT SUMMARY/ABSTRACT Over the past 40-years, the standard therapy for acute myeloid leukemia (AML), a highly fatal blood cancer, remains a combination of chemo drugs such as cytarabine and an anthracycline. Drug resistance in AML inevi- tably occurs over time. While it is evident that drug resistance and AML burdens are often associated downreg-

ulation of tumor-suppressor transcription factors and the manifestation of oncogenic transcription factor fusions, therapeutic approaches directly focused on these pivotal biomolecules remains a technical challenge. Our long- term goals are to identify molecular regulators and partners of cancer-associated transcription factors and to

understand how they cross-regulate in cancer, thereby utilizing this understanding for preventative and thera- peutic purposes. The overall objective of this proposal is to understand the role and the mechanism underlying noncoding RNA deregulation in primary and relapsed AML. We recently discovered and characterized a PU.1

enhancer RNA that is capable of inducing myeloid cell differentiation while inhibiting cell growth. We also dis- covered that the noncoding RNA is inhibited by RUNX1-ETO, a transcription factor fusion that is derived from one of the most frequent chromosomal translocations associated with AML. We further revealed that it is inhibited

relapsed AML patients. Therefore, we propose that PU.1 regulatory RNAs acts as RNA modulators of the RUNX1-ETO/PU.1 axis and are important RNA regulators in both primary and relapsed AML. Toward that end, my lab has generated chemo-resistant AML cell models, and we plan to pursue the following specific aims: 1)

Determine the role of the RNA in primary and relapsed AML, and 2) Define the mechanism underlying its dereg- ulation in AML. These aims will be achieved by using a variety of approaches including RNA interactions and gene regulation via chromatin structure with the use of transcriptomic and genomic data from AML patients,

drug-resistant AML cell lines and AML mouse models. Completion of these aims will provide an important insight into the functions of enhancer RNAs in primary and relapsed AML and provide a scientific basis for modulating activities of tumor-suppressor transcription factors as well as oncogenic fusion protein. There is the promise that

regulatory RNAs could be utilized in AML treatment. Ultimately, this could be expected to result in the develop- ment of novel RNA-based drugs to circumvent the current challenge in targeting transcription factors and their oncogenic derivatives in cancer therapy.