英文誌(2004-)
一般ポスター
基礎:デバイス・診断システムⅡ
(S636)
Ultrasound-induced killing of cancer cells enhanced by EDTA
FERIL, Jr. Loreto B.1, 立花 克郎1, 近藤 隆2, 小川 良平2, CUI Zheng-Guo3
Loreto B. FERIL, Jr.1, Katsuro TACHIBANA1, Takashi KONDO2, Ryohei OGAWA2, Zheng-Guo CUI3
1Department of Anatomy, Fukuoka University School of Medicine, 2Department of Radiological Sciences, University of Toyama, 3Department of Public Health, University of Toyama
キーワード :
This study aims to determine the effects of ultrasound in the presence of Ethylenediaminetetraacetic acid (EDTA) against human malignant melanoma (C-32) cells in comparison to its effect on normal melanocytes. In addition, other human cancer cell lines (leukemia U937, cervix carcinoma HeLa and oral squamous cell carcinoma HSC-2) will also be tested for the same effects. The cells were treated with various doses (0 to 500 μM) of EDTA prior to sonication (1.0 MHz; 0.54 W/cm2; duty factor of 25%; pulsed at 0.5 Hz for 20 s). Apoptosis was assayed 6 hr after the treatments using Annexin V-FITC kit to measure Phosphatidylserine externalization by flow-cytometry. Cell viabilities were assayed 6, 24 and 72 hr after the treatments using Trypan blue externalization and MTT assays. The results showed that EDTA alone is toxic to C-32 cells at doses ≥200 μM, and against melanocytes at doses ≥400 μM. Among the cancer cell lines, the order of sensitivity to the agent is as follows: U937>HSC-2>C-32>HeLa. HeLa is therefore the most resistant, while U937 and HSC-2 are the most sensitive types. Melanoma cells were more sensitive not only to EDTA alone but also to ultrasound alone as compared to melanocytes. Addition of 100 μM EDTA (non-toxic by itself alone) prior to sonication resulted in the killing of about 30% of melanoma cells that were supposed to survive the sonication alone. EDTA alone at 300 μM resulted in about 50% cell growth inhibition, and when combined with ultrasound, less than 20% of melanoma cells survived. Both cell lysis and apoptosis were enhanced in the combined treatments. The findings suggest potential clinical use of EDTA to augment the anticancer effect of therapeutic ultrasound.