Dastanpour Somayeh, Momen Beitollahi Jalil, Saber Kazem
Department of Oral Medicine, Dental Faculty, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Dental Research Centre, Dental Faculty, Tehran University of Medical Sciences, Tehran, Iran.
J Lasers Med Sci. 2015 Spring;6(2):74-9.
Laser phototherapy is used for the treatment of chemotherapy-induced oral mucositis in patients with leukemia, although there are limited data supporting the safety of this method. This study aimed to evaluate the effect of different doses of low-level laser on proliferation of acute myeloid leukemia (AML) cell line (KG-1a) in vitro.
A plastic flask containing 5,000,000 KG-1a cultured cells was provided by Iran Pasteur Institute. KG-1a cell line has been produced from the bone marrow aspirate of a 59-year-old white male with acute myelogenous leukemia. Upon completion of the proliferation steps of KG-1a cell line, 7×10(4) cells were placed in 96-well tissue culture plates. All the surrounding wells were filled with Wright-Giemsa stain in order to prevent laser from scattering to the neighboring wells. In total, 28 plates were prepared using this method. After a forty-eight hours incubation period, irradiation was performed in continuous mode with an infrared laser of 810nm wavelength. After 24 hours, cells cultures were exposed to one, two, or three applications of laser irradiation. Irradiation exposures were performed at energy densities of 5, 10, and 20 J/cm(2) . Each experiment included 18 replicates for each application of laser and 6 replicates of negative/untreated controls. For experiments with two and three repeated exposures, the irradiation applications were separated by 48 hours. All the culture plates were incubated for seven days. Cell proliferation was evaluated using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay after seven days. Spectroscopy (620nm) was used to determine the optical density (OD) of both irradiated and control samples.
Significant increase in cell proliferation was seen only after two exposures at energy density of 20J/cm2 (P=0.021).
Although LLLT is commonly used to treat radiotherapy- or chemotherapy- induced mucositis, as long as further studies demonstrate that different wavelengths and doses of laser phototherapy are safe and effective in treatment of mucositis, clinicians should remain cautious regarding the use of this treatment modality to treat patients with malignancies.
激光光疗用于治疗白血病患者化疗引起的口腔黏膜炎，尽管支持该方法安全性的数据有限。本研究旨在评估不同剂量的低强度激光对急性髓系白血病（AML）细胞系（KG-1a）体外增殖的影响。
伊朗巴斯德研究所提供了一个装有500万个培养的KG-1a细胞的塑料培养瓶。KG-1a细胞系由一名59岁患有急性髓性白血病的白人男性的骨髓抽吸物产生。在完成KG-1a细胞系的增殖步骤后，将7×10⁴个细胞置于96孔组织培养板中。所有周边孔都填充有瑞氏-吉姆萨染色剂，以防止激光散射到相邻孔中。总共用这种方法制备了28个培养板。在48小时的孵育期后，用波长为810nm的红外激光以连续模式进行照射。24小时后，细胞培养物接受一、二或三次激光照射。照射暴露在能量密度为5、10和20J/cm²下进行。每次激光照射的每个实验包括18个重复样本和6个阴性/未处理对照的重复样本。对于两次和三次重复照射的实验，照射之间间隔48小时。所有培养板孵育7天。7天后使用MTT（3-[4,5-二甲基噻唑-2-基]-2,5-二苯基溴化四氮唑）法评估细胞增殖。使用光谱仪（620nm）测定照射样本和对照样本的光密度（OD）。
仅在能量密度为20J/cm²下进行两次照射后，细胞增殖显著增加（P = 0.021）。
尽管低强度激光疗法通常用于治疗放疗或化疗引起的黏膜炎，但只要进一步研究表明不同波长和剂量的激光光疗在治疗黏膜炎方面是安全有效的，临床医生在使用这种治疗方式治疗恶性肿瘤患者时仍应谨慎。
