Focused ultrasound radiosensitizes human cancer cells by enhancement of DNA damage

Xinrui Zhang (Lead / Corresponding author), Mariana Bobeica, Michael Unger, Anastasia Bednarz, Bjoern Gerold, Ina Patties, Andreas Melzer (Lead / Corresponding author), Lisa Landgraf

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)
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Purpose: High-intensity focused ultrasound (HIFU/FUS) has expanded as a noninvasive quantifiable option for hyperthermia (HT). HT in a temperature range of 40-47 °C (thermal dose CEM43 ≥ 25) could work as a sensitizer to radiation therapy (RT). Here, we attempted to understand the tumor radiosensitization effect at the cellular level after a combination treatment of FUS+RT.

Methods: An in vitro FUS system was developed to induce HT at frequencies of 1.147 and 1.467 MHz. Human head and neck cancer (FaDU), glioblastoma (T98G), and prostate cancer (PC-3) cells were exposed to FUS in ultrasound-penetrable 96-well plates followed by single-dose X‑ray irradiation (10 Gy). Radiosensitizing effects of FUS were investigated by cell metabolic activity (WST‑1 assay), apoptosis (annexin V assay, sub-G1 assay), cell cycle phases (propidium iodide staining), and DNA double-strand breaks (γH2A.X assay).

Results: The FUS intensities of 213 (1.147 MHz) and 225 W/cm2 (1.467 MHz) induced HT for 30 min at mean temperatures of 45.20 ± 2.29 °C (CEM43 = 436 ± 88) and 45.59 ± 1.65 °C (CEM43 = 447 ± 79), respectively. FUS improves the effect of RT significantly by reducing metabolic activity in T98G cells 48 h (RT: 96.47 ± 8.29%; FUS+RT: 79.38 ± 14.93%; p = 0.012) and in PC-3 cells 72 h (54.20 ± 10.85%; 41.01 ± 11.17%; p = 0.016) after therapy, but not in FaDu cells. Mechanistically, FUS+RT leads to increased apoptosis and enhancement of DNA double-strand breaks compared to RT alone in T98G and PC-3 cells.

Conclusion: Our in vitro findings demonstrate that FUS has good potential to sensitize glioblastoma and prostate cancer cells to RT by mainly enhancing DNA damage.

Original languageEnglish
Pages (from-to)730-743
Number of pages14
JournalStrahlentherapie und Onkologie
Early online date22 Apr 2021
Publication statusPublished - Aug 2021


  • Apoptosis
  • DNA double-strand breaks
  • FUS
  • Hyperthermia
  • Radiation therapy

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Oncology


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