Browsing by Subject "CHK1"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Combating CHK1 resistance in triple negative breast cancer: EGFR inhibition as potential combinational therapy
    (OAE, 2022) Stefanski, Casey D.; Prosperi, Jenifer R.; Biochemistry and Molecular Biology, School of Medicine
    Triple negative breast cancer (TNBC) is marked by a lack of expression of the Estrogen Receptor, Progesterone Receptor, and human epidermal growth factor receptor 2. Therefore, targeted therapies are being investigated based on the expression profiles of tumors. Due to the potential for acquired and intrinsic resistance, there is a need for combination therapy to overcome resistance. In the article by Lee et al., the authors identify that, while prexasertib (a CHK1 inhibitor) lacks efficacy alone, combination with an EGFR inhibitor provides synergistic anti-tumor effects. Advances in targeted therapy for TNBC will benefit the clinical landscape for this disease, with this study initiating a new avenue of investigation.
  • Thumbnail Image
    Item
    Systems Biology Approach Identifies Prognostic Signatures of Poor Overall Survival and Guides the Prioritization of Novel BET-CHK1 Combination Therapy for Osteosarcoma
    (MDPI, 2020-08-26) Pandya, Pankita H.; Cheng, Lijun; Saadatzadeh, M. Reza; Bijangi-Vishehsaraei, Khadijeh; Tang, Shan; Sinn, Anthony L.; Trowbridge, Melissa A.; Coy, Kathryn L.; Bailey, Barbara J.; Young, Courtney N.; Ding, Jixin; Dobrota, Erika A.; Dyer, Savannah; Elmi, Adily; Thompson, Quinton; Barghi, Farinaz; Shultz, Jeremiah; Albright, Eric A.; Shannon, Harlan E.; Murray, Mary E.; Marshall, Mark S.; Ferguson, Michael J.; Bertrand, Todd E.; Wurtz, L. Daniel; Batra, Sandeep; Li, Lang; Renbarger, Jamie L.; Pollok, Karen E.; Pediatrics, School of Medicine
    Osteosarcoma (OS) patients exhibit poor overall survival, partly due to copy number variations (CNVs) resulting in dysregulated gene expression and therapeutic resistance. To identify actionable prognostic signatures of poor overall survival, we employed a systems biology approach using public databases to integrate CNVs, gene expression, and survival outcomes in pediatric, adolescent, and young adult OS patients. Chromosome 8 was a hotspot for poor prognostic signatures. The MYC-RAD21 copy number gain (8q24) correlated with increased gene expression and poor overall survival in 90% of the patients (n = 85). MYC and RAD21 play a role in replication-stress, which is a therapeutically actionable network. We prioritized replication-stress regulators, bromodomain and extra-terminal proteins (BETs), and CHK1, in order to test the hypothesis that the inhibition of BET + CHK1 in MYC-RAD21+ pediatric OS models would be efficacious and safe. We demonstrate that MYC-RAD21+ pediatric OS cell lines were sensitive to the inhibition of BET (BETi) and CHK1 (CHK1i) at clinically achievable concentrations. While the potentiation of CHK1i-mediated effects by BETi was BET-BRD4-dependent, MYC expression was BET-BRD4-independent. In MYC-RAD21+ pediatric OS xenografts, BETi + CHK1i significantly decreased tumor growth, increased survival, and was well tolerated. Therefore, targeting replication stress is a promising strategy to pursue as a therapeutic option for this devastating disease.