eprintid: 26803 rev_number: 13 eprint_status: archive userid: 1589 dir: disk0/00/02/68/03 datestamp: 2019-08-13 10:20:13 lastmod: 2019-09-15 08:27:04 status_changed: 2019-08-13 10:20:13 type: article metadata_visibility: show creators_name: Hartfiel, Sarah creators_name: Häfner, Matthias creators_name: Lopez Perez, Ramon creators_name: Rühle, Alexander creators_name: Trinh, Thuy creators_name: Debus, Jürgen creators_name: Huber, Peter E. creators_name: Nicolay, Nils H. title: Differential response of esophageal cancer cells to particle irradiation subjects: 610 divisions: 850300 divisions: 950400 keywords: Esophageal cancer, Proton radiation, Carbon ion radiation, Heavy ion radiotherapy abstract: Background: Radiation therapy is a mainstay in the treatment of esophageal cancer (EC) patients, and photon radiotherapy has proved beneficial both in the neoadjuvant and the definitive setting. However, regarding the still poor prognosis of many EC patients, particle radiation employing a higher biological effectiveness may help to further improve patient outcomes. However, the influence of clinically available particle radiation on EC cells remains largely unknown. Methods: Patient-derived esophageal adenocarcinoma and squamous cell cancer lines were treated with photon and particle irradiation using clinically available proton (1H), carbon (12C) or oxygen (16O) beams at the Heidelberg Ion Therapy Center. Histology-dependent clonogenic survival was calculated for increasing physical radiation doses, and resulting relative biological effectiveness (RBE) was calculated for each radiation modality. Cell cycle effects caused by photon and particle radiation were assessed, and radiation-induced apoptosis was measured in adenocarcinoma and squamous cell EC samples by activated caspase-3 and sub-G1 populations. Repair kinetics of DNA double strand breaks induced by photon and particle radiation were investigated. Results: While both adenocarcinoma EC cell lines demonstrated increasing sensitivities for 1H, 12C and 16O radiation, the two squamous cell carcinoma lines exhibited a more heterogeneous response to photon and particle treatment; average RBE values were calculated as 1.15 for 1H, 2.3 for 12C and 2.5 for 16O irradiation. After particle irradiation, squamous cell EC samples reacted with an increased and prolonged block in G2 phase of the cell cycle compared to adenocarcinoma cells. Particle radiation resulted in an incomplete repair of radiation-induced DNA double strand breaks in both adenocarcinoma and squamous cell carcinoma samples, with the levels of initial strand break induction correlating well with the individual cellular survival after photon and particle radiation. Similarly, EC samples demonstrated heterogeneous levels of radiation-induced apoptosis that also corresponded to the observed cellular survival of individual cell lines. Conclusions: Esophageal cancer cells exhibit differential responses to irradiation with photons and 1H, 12C and 16O particles that were independent of tumor histology. Therefore, yet unknown molecular markers beyond histology may help to establish which esophageal cancer patients benefit from the biological effects of particle treatment. date: 2019 publisher: BioMed Central id_scheme: DOI ppn_swb: 167190317X own_urn: urn:nbn:de:bsz:16-heidok-268039 language: eng bibsort: HARTFIELSADIFFERENTI2019 full_text_status: public publication: Radiation Oncology volume: 14 number: 119 place_of_pub: London pagerange: 1-9 issn: 1748-717X citation: Hartfiel, Sarah ; Häfner, Matthias ; Lopez Perez, Ramon ; Rühle, Alexander ; Trinh, Thuy ; Debus, Jürgen ; Huber, Peter E. ; Nicolay, Nils H. (2019) Differential response of esophageal cancer cells to particle irradiation. Radiation Oncology, 14 (119). pp. 1-9. ISSN 1748-717X document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/26803/1/13014_2019_Article_1326.pdf