Department of Nuclear Medicine, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal (576104), India.
Department of Nuclear Medicine, All India Institute of Medical Sciences, Jodhpur, Rajasthan (342005), India.
Biomed Phys Eng Express. 2020 Oct 7;6(6). doi: 10.1088/2057-1976/abbbd5.
Electrical impedance spectroscopy is a technique which evaluates differences in dielectric properties of tissues for cancer identification.Murine hepatic cancer model was developed by intraperitoneal administration of N-nitrosodiethylamine to male BALB/c mice. Tumors obtained were evaluated for their conductivity in frequency range of (4 Hz-5 MHz). All tumors were subjected to histopathological grading and parameters such as free spacing, necrosis, and cell density were estimated on histological slides. The status of gap junctions and gap junction intercellular communication (GJIC) were studied using enzyme-linked immunosorbent assay, immunohistochemistry, dye transfer assay, and electron microscopy.Histopathological investigation revealed the presence of moderately to poorly-differentiated hepatocellular carcinoma (HCC) in mice. All types of tumors showed higher electrical conductivity than normal liver tissue in frequency range (4 Hz-1 kHz). However, in frequency range (10 kHz-5 MHz) only poorly-differentiated tumors showed higher conductivity compared to normal tissue. The most prominent findings in moderately-differentiated and poorly-differentiated HCC were increased visible free spaces and necrosis respectively. The status of cell gap junctions were significantly deteriorated in tumors and a corresponding significant reduction in GJIC was also observed. These biological indicators were correlated with electrical conductivity of hepatic tumors.Variations in electrical conductivity spectra of hepatic tumors reflect progression of HCC.Future studies can be planned to perform hierarchical clustering of dielectric parameters with more number of tumor samples to establish dielectric spectroscopy-based classification or staging of hepatic tumors.
电阻抗频谱分析是一种评估组织介电特性差异以用于癌症识别的技术。通过向雄性 BALB/c 小鼠腹腔内给予 N-亚硝基二乙胺来建立鼠类肝癌模型。评估所获得的肿瘤在（4 Hz-5 MHz）频率范围内的电导率。所有肿瘤均进行组织病理学分级，并在组织学切片上评估自由间距、坏死和细胞密度等参数。使用酶联免疫吸附测定法、免疫组织化学、染料转移测定法和电子显微镜研究间隙连接和细胞间通讯（GJIC）的状态。组织病理学研究表明，在小鼠中存在中至低分化肝细胞癌（HCC）。所有类型的肿瘤在频率范围（4 Hz-1 kHz）中均显示出比正常肝组织更高的电导率。然而，在频率范围（10 kHz-5 MHz）中，仅低分化肿瘤与正常组织相比表现出更高的电导率。在中分化和低分化 HCC 中最显著的发现分别是可见的自由空间增加和坏死。肿瘤中细胞间隙连接的状态明显恶化，细胞间通讯也相应显著减少。这些生物学指标与肝肿瘤的电导率相关。肝肿瘤电阻抗谱的变化反映了 HCC 的进展。未来的研究可以计划用更多的肿瘤样本进行介电参数的层次聚类，以建立基于介电光谱的肝肿瘤分类或分期。
