Department of Rehabilitation Science, Kobe University Graduate School of Health Science, Kobe, Japan.
John B. Little Center for Radiation Sciences, Harvard T.H. Chan School of Public Health, Boston, Massachusetts.
Prostate. 2020 Sep;80(12):986-992. doi: 10.1002/pros.24030. Epub 2020 Jun 18.
Focal therapies for prostate cancer (PC) can reduce adverse events and do not lead to androgen-independent progression. Ultrasound could be used for cancer treatments if the repetition frequency is fitted to the purpose. We investigated the possible therapeutic effect of ultrasound irradiation on PC cells.
We irradiated two PC cell lines, androgen-dependent LNCaP and -independent PC-3 with ultrasound (3.0 W/cm , 3 MHz, irradiation time rate: 20%) for 2 minutes for 1 day or 3 consecutive days at a repetition frequency of 1, 10, or 100 Hz in vitro. Cell proliferation and apoptosis were determined after irradiation.
Cell proliferation of PC-3 was significantly inhibited after 1 day (P < .0001) and 3 days (P < .0001) of 10 Hz ultrasound irradiation, and that of LNCaP after 1 day (P < .0001) and 3 days (P < .0001) of irradiation. LNCaP was more sensitive to ultrasound at both lower and higher cell density but PC-3 was only sensitive at a lower cell density (P < .01). Irradiation with 10 Hz ultrasound-induced significantly more PC-3 apoptotic cells than control (1 day, P = .0137; 3 days, P = .0386) rather than irradiation with 1 Hz. Apoptosis via caspase-3 was induced at 10 Hz in 1-day (P < .05) irradiation in both cell lines.
Ultrasound irradiation with even 1 day of 10 Hz significantly inhibited cell proliferation in both LNCaP and PC-3, especially by the remarkable induction of apoptosis in vitro. Our study indicated that ultrasound irradiation can be a therapeutic option for PC and further studies in vivo will be undertaken.
前列腺癌（PC）的局部治疗可以减少不良反应，并且不会导致雄激素非依赖性进展。如果重复频率适合于治疗目的，超声可以用于癌症治疗。我们研究了超声辐射对 PC 细胞的可能治疗效果。
我们用超声（3.0 W/cm 2 ，3 MHz，辐射时间率：20%）照射两种 PC 细胞系，雄激素依赖性 LNCaP 和雄激素非依赖性 PC-3，体外每天照射 1 分钟，连续 3 天，重复频率为 1、10 或 100 Hz。照射后测定细胞增殖和凋亡。
PC-3 细胞增殖在 10 Hz 超声照射 1 天（P <.0001）和 3 天（P <.0001）后明显受到抑制，LNCaP 细胞在照射 1 天（P <.0001）和 3 天（P <.0001）后也受到抑制。LNCaP 在较低和较高细胞密度下对超声更敏感，但 PC-3 仅在较低细胞密度下敏感（P <.01）。与对照相比，10 Hz 超声照射诱导的 PC-3 凋亡细胞明显更多（1 天，P =.0137；3 天，P =.0386），而不是 1 Hz 照射。两种细胞系在 1 天的 10 Hz 照射下均诱导 caspase-3 介导的凋亡（P <.05）。
即使每天 10 Hz 的超声照射也能显著抑制 LNCaP 和 PC-3 中的细胞增殖，尤其是体外显著诱导细胞凋亡。我们的研究表明，超声辐射可能是治疗前列腺癌的一种选择，将进一步进行体内研究。
