Browsing by Author "Caston, Rachel A."

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    Combined inhibition of Ref‐1 and STAT3 leads to synergistic tumour inhibition in multiple cancers using 3D and in vivo tumour co‐culture models
    (Wiley, 2021-01) Caston, Rachel A.; Shah, Fenil; Starcher, Colton L.; Wireman, Randall; Babb, Olivia; Grimard, Michelle; McGeown, Jack; Armstrong, Lee; Tong, Yan; Pili, Roberto; Rupert, Joseph; Zimmers, Teresa A.; Elmi, Adily N.; Pollok, Karen E.; Motea, Edward A.; Kelley, Mark R.; Fishel, Melissa L.; Pediatrics, School of Medicine
    With a plethora of molecularly targeted agents under investigation in cancer, a clear need exists to understand which pathways can be targeted simultaneously with multiple agents to elicit a maximal killing effect on the tumour. Combination therapy provides the most promise in difficult to treat cancers such as pancreatic. Ref‐1 is a multifunctional protein with a role in redox signalling that activates transcription factors such as NF‐κB, AP‐1, HIF‐1α and STAT3. Formerly, we have demonstrated that dual targeting of Ref‐1 (redox factor‐1) and STAT3 is synergistic and decreases cell viability in pancreatic cancer cells. Data presented here extensively expands upon this work and provides further insights into the relationship of STAT3 and Ref‐1 in multiple cancer types. Using targeted small molecule inhibitors, Ref‐1 redox signalling was blocked along with STAT3 activation, and tumour growth evaluated in the presence and absence of the relevant tumour microenvironment. Our study utilized qPCR, cytotoxicity and in vivo analysis of tumour and cancer‐associated fibroblasts (CAF) response to determine the synergy of Ref‐1 and STAT3 inhibitors. Overall, pancreatic tumours grown in the presence of CAFs were sensitized to the combination of STAT3 and Ref‐1 inhibition in vivo. In vitro bladder and pancreatic cancer demonstrated the most synergistic responses. By disabling both of these important pathways, this combination therapy has the capacity to hinder crosstalk between the tumour and its microenvironment, leading to improved tumour response.
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    The multifunctional APE1 DNA repair-redox signaling protein as a drug target in human disease
    (Elsevier, 2021) Caston, Rachel A.; Gampala, Silpa; Lee, Armstrong; Messmann, Richard A.; Fishel, Melissa L.; Kelley, Mark R.; Pediatrics, School of Medicine
    Apurinic/apyrimidinic (AP) endonuclease-reduction/oxidation factor 1 (APE1/Ref-1, also called APE1) is a multifunctional enzyme with crucial roles in DNA repair and reduction/oxidation (redox) signaling. APE1 was originally described as an endonuclease in the Base Excision Repair (BER) pathway. Further study revealed it to be a redox signaling hub regulating critical transcription factors (TFs). Although a significant amount of focus has been on the role of APE1 in cancer, recent findings support APE1 as a target in other indications, including ocular diseases [diabetic retinopathy (DR), diabetic macular edema (DME), and age-related macular degeneration (AMD)], inflammatory bowel disease (IBD) and others, where APE1 regulation of crucial TFs impacts important pathways in these diseases. The central responsibilities of APE1 in DNA repair and redox signaling make it an attractive therapeutic target for cancer and other diseases.