Publications by authors named "Charles R Dunlop"

Article Synopsis
  • Gemcitabine is a treatment for pancreatic cancer, but its effectiveness may be hindered by the tumor stroma, which obstructs the drug's distribution to cancer cells.
  • Researchers developed an advanced imaging technique combining various methods to study the distribution and metabolism of gemcitabine and its active metabolites in a mouse model of pancreatic cancer.
  • The study found that while gemcitabine's active metabolites reached viable tumor cells, they had a different distribution compared to the parent drug, and their presence correlated more with areas of high cell proliferation and DNA damage rather than the concentration of the parent drug.
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Background: Chemotherapy and targeted agent anti-cancer efficacy is largely dependent on the proliferative state of tumours, as exemplified by agents that target DNA synthesis/replication or mitosis. As a result, cell cycle specificities of a number of cancer drugs are well known. However, they are yet to be described in a quantifiable manner.

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Background: Personalised medicine strategies may improve outcomes in pancreatic ductal adenocarcinoma (PDAC), but validation of predictive biomarkers is required. Having developed a clinical trial to assess the ATR inhibitor, AZD6738, in combination with gemcitabine (ATRi/gem), we investigated ATM loss as a predictive biomarker of response to ATRi/gem in PDAC.

Methods: Through kinase inhibition, siRNA depletion and CRISPR knockout of ATM, we assessed how ATM targeting affected the sensitivity of PDAC cells to ATRi/gem.

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High rates of glycolysis in cancer cells are a well-established characteristic of many human tumors, providing rapidly proliferating cancer cells with metabolites that can be used as precursors for anabolic pathways. Maintenance of high glycolytic rates depends on the lactate dehydrogenase-catalyzed regeneration of NAD from GAPDH-generated NADH because an increased NADH:NAD ratio inhibits GAPDH. Here, using human breast cancer cell models, we identified a pathway in which changes in the extramitochondrial-free NADH:NAD ratio signaled through the CtBP family of NADH-sensitive transcriptional regulators to control the abundance and activity of p53.

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Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest cancers, and overall survival rates have barely improved over the past five decades. The antimetabolite gemcitabine remains part of the standard of care but shows very limited antitumor efficacy. Ataxia telangiectasia and Rad3-related protein (ATR), the apical kinase of the intra-S-phase DNA damage response, plays a central role in safeguarding cells from replication stress and can therefore limit the efficacy of antimetabolite drug therapies.

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Combination of cytotoxic therapy with emerging DNA damage response inhibitors (DDRi) has been limited by tolerability issues. However, the goal of most combination trials has been to administer DDRi with standard-of-care doses of chemotherapy. We hypothesized that mechanism-guided treatment scheduling could reduce the incidence of dose-limiting toxicities and enable tolerable multitherapeutic regimens.

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