Research our during coordination efficacy. Summary response to DNA damage, down-regulation of cell cycle genes contribute to cell cycle arrest. Recently, lab has uncovered a novel insight into cell cycle gene control t hat prevents mitotic events from occurring S phase. This insight into how DNA damage response and DNA replication-inhibitors can affect the between the G1/S and G2/M genes can help to improve our understanding of chemotherapy The MuvB core complex is a five-protein complex that In orchestrates cell cycle-dependent gene expression through the formation of at least three functionally distinct complexes. In component expression through expression G0/G1, MuvB is a of the DREAM complex ( D P, R B-like, E 2F, a nd M uvB), which maintains quiescence by repressing of G1/S and G2/M genes. In S phase, MuvB switches from epressing to activating complexes sequential recruitment of B-Myb and FoxM1. The B-Myb-MuvB (MMB) and complexes initiate of late cell cycle genes through recognition of the Myb, CHR, and Forkhead DNA binding elements. r The ATR-CHK1 pathway plays a central role in the cellular response to DNA damage during S/G2. Our lab performed a genome-wide CRISPR-Cas9 screen to identify genes that, when lost, confer resistance to CHK1 inhibition. We determined that loss of B-Myb, LIN54, or FoxM1 in two different non-small cell lung cancer (NSCLC) cell lines A549 and H460 led to a 200-fold resistance to CHK1 inhibition as well as a 5-fold resistance to ATR inhibition compared to control cells. These observations reveal an unexpected role for the MMB-FoxM1 complex as critical components of the S phase DNA damage response (manuscript in preparation). I explored the sensitivity of these knockout cells to DNA replication-inhibitors, specifically those used clinically for the treatment of solid tumors and hematologic malignancies. I observed that the LIN54 and FoxM1 knockout cells were highly sensitive to treatment with the DNA-damaging cytosine where agent competes with for incorporation into nascent DNA by the DNA polymerase and results in stalled replication forks, a potent ATR response and activation of p53. R gemcitabine. Gemcitabine ecent work from our lab has shown that p53-mediated cell cycle arrest is jointly enforced by DREAM and RB repressive complexes in response to doxorubicin, suggesting that disruption of DREAM-MuvB complexes could disrupt p53-mediated cell cycle arrest to DNA damage. Thus, altering DREAM/MuvB complex formation and activity could result in a potent p53 apoptotic response in S phase from an impaired cell cycle-controlled arrest and DNA repair. The research activators standard approaches inhibitors goal of this proposed is to determine the role of the DREAM B-Myb-MuvB complex in sensitivity to DNA replication and inhibitors. Completion of the proposed studies will broaden our mechanistic understanding of chemotherapy treatments. Long-term this work could lead to clinically relevant therapeutic for cancer treatment. Our hypothesis is that B-Myb-MuvB controls sensitivity to DNA replication- by control of G2/M genes.
of replication understanding response to DNA damage, down-regulation of cell cycle genes contribute to cell cycle arrest. The goal this proposed research is to determine the role of the DREAM B-Myb-MuvB complex in sensitivity t o DNA activators and inhibitors. Completion of the proposed studies will broaden our mechanistic of standard chemotherapy treatments. In
