Impact of DNA repair and reactive oxygen species levels on radioresistance in pancreatic cancer

Nguyen L, Dobiasch S, Schneider G, Schmid RM, Azimzadeh O, Kanev K, Buschmann D, Pfaffl MW, Bartzsch S, Schmid TE, Schilling D, Combs SE (2021)

Publication Type: Journal article

Publication year: 2021

Journal

Radiotherapy and Oncology Elsevier

Book Volume: 159

Pages Range: 265-276

DOI: 10.1016/j.radonc.2021.03.038

Abstract

Purpose: Radioresistance in pancreatic cancer patients remains a critical obstacle to overcome. Understanding the molecular mechanisms underlying radioresistance may achieve better response to radiotherapy and thereby improving the poor treatment outcome. The aim of the present study was to elucidate the mechanisms leading to radioresistance by detailed characterization of isogenic radioresistant and radiosensitive cell lines. Methods: The human pancreatic cancer cell lines, Panc-1 and MIA PaCa-2 were repeatedly exposed to radiation to generate radioresistant (RR) isogenic cell lines. The surviving cells were expanded, and their radiosensitivity was measured using colony formation assay. Tumor growth delay after irradiation was determined in a mouse pancreatic cancer xenograft model. Gene and protein expression were analyzed using RNA sequencing and Western blot, respectively. Cell cycle distribution and apoptosis (Caspase 3/7) were measured by FACS analysis. Reactive oxygen species generation and DNA damage were analyzed by detection of CM-H2DCFDA and γH2AX staining, respectively. Transwell chamber assays were used to investigate cell migration and invasion. Results: The acquired radioresistance of RR cell lines was demonstrated in vitro and validated in vivo. Ingenuity pathway analysis of RNA sequencing data predicted activation of cell viability in both RR cell lines. RR cancer cell lines demonstrated greater DNA repair efficiency and lower basal and radiation-induced reactive oxygen species levels. Migration and invasion were differentially affected in RR cell lines. Conclusions: Our data indicate that repeated exposure to irradiation increases the expression of genes involved in cell viability and thereby leads to radioresistance. Mechanistically, increased DNA repair capacity and reduced oxidative stress might contribute to the radioresistant phenotype.

Involved external institutions

Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt (HMGU) / Helmholtz Munich DE Germany (DE) Technische Universität München (TUM) DE Germany (DE)

How to cite

APA:

Nguyen, L., Dobiasch, S., Schneider, G., Schmid, R.M., Azimzadeh, O., Kanev, K.,... Combs, S.E. (2021). Impact of DNA repair and reactive oxygen species levels on radioresistance in pancreatic cancer. Radiotherapy and Oncology, 159, 265-276. https://dx.doi.org/10.1016/j.radonc.2021.03.038

MLA:

Nguyen, Lily, et al. "Impact of DNA repair and reactive oxygen species levels on radioresistance in pancreatic cancer." Radiotherapy and Oncology 159 (2021): 265-276.

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