Evofosfamide and Gemcitabine Act Synergistically in Pancreatic Cancer Xenografts by Dual Action on Tumor Vasculature and Inhibition of Homologous Recombination DNA Repair

Aims: Pancreatic ductal adenocarcinomas (PDACs) form hypovascular and hypoxic tumors, which are difficult to treat with current chemotherapy regimens. Gemcitabine (GEM) is often used as a first-line treatment for PDACs but has issues with chemoresistance and penetration in the interior of the tumor. Evofosfamide, a hypoxia-activated prodrug, has been shown to be effective in combination with GEM, although the mechanism of each drug on the other has not been established. We used mouse xenografts from two cell lines (MIA Paca-2 and SU.86.86) with different tumor microenvironmental characteristics to probe the action of each drug on the other. Results: GEM treatment enhanced survival times in mice with SU.86.86 leg xenografts (hazard ratio [HR] = 0.35, p = 0.03) but had no effect on MIA Paca-2 mice (HR = 0.91, 95% confidence interval = 0.37-2.25, p = 0.84). Conversely, evofosfamide did not improve survival times in SU.86.86 mice to a statistically significant degree (HR = 0.57, p = 0.22). Electron paramagnetic resonance imaging showed that oxygenation worsened in MIA Paca-2 tumors when treated with GEM, providing a direct mechanism for the activation of the hypoxia-activated prodrug evofosfamide by GEM. Sublethal amounts of either treatment enhanced the toxicity of other treatment in vitro in SU.86.86 but not in MIA Paca-2. By the biomarker γH2AX, combination treatment increased the number of double-stranded DNA lesions in vitro for SU.86.86 but not MIA Paca-2. Innovation and Conclusion: The synergy between GEM and evofosfamide appears to stem from the dual action of GEMs effect on tumor vasculature and inhibition by GEM of the homologous recombination DNA repair process. Antioxid. Redox Signal. 39, 432-444.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:39

Enthalten in:

Antioxidants & redox signaling - 39(2023), 7-9 vom: 28. Sept., Seite 432-444

Sprache:

Englisch

Beteiligte Personen:

Otowa, Yasunori [VerfasserIn]
Kishimoto, Shun [VerfasserIn]
Saida, Yu [VerfasserIn]
Yamashita, Kota [VerfasserIn]
Yamamoto, Kazutoshi [VerfasserIn]
Chandramouli, Gadisetti V R [VerfasserIn]
Devasahayam, Nallathamby [VerfasserIn]
Mitchell, James B [VerfasserIn]
Krishna, Murali C [VerfasserIn]
Brender, Jeffrey R [VerfasserIn]

Links:

Volltext

Themen:

0W860991D6
Blood volume
DCE MRI
Deoxycytidine
EPR
Evofosfamide
Gemcitabine
Journal Article
Prodrugs
Research Support, N.I.H., Intramural
TH 302
TH302

Anmerkungen:

Date Completed 18.09.2023

Date Revised 13.12.2023

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1089/ars.2022.0118

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM355560399